WO2025005201A1 - Adhesive tape, adhesive composition, and adhesive - Google Patents
Adhesive tape, adhesive composition, and adhesive Download PDFInfo
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- WO2025005201A1 WO2025005201A1 PCT/JP2024/023429 JP2024023429W WO2025005201A1 WO 2025005201 A1 WO2025005201 A1 WO 2025005201A1 JP 2024023429 W JP2024023429 W JP 2024023429W WO 2025005201 A1 WO2025005201 A1 WO 2025005201A1
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- acrylate
- pressure
- sensitive adhesive
- structural unit
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08F220/00—Copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical or a salt, anhydride ester, amide, imide or nitrile thereof
- C08F220/02—Monocarboxylic acids having less than ten carbon atoms; Derivatives thereof
- C08F220/10—Esters
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08F283/00—Macromolecular compounds obtained by polymerising monomers on to polymers provided for in subclass C08G
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G18/00—Polymeric products of isocyanates or isothiocyanates
- C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
- C08G18/28—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the compounds used containing active hydrogen
- C08G18/40—High-molecular-weight compounds
- C08G18/42—Polycondensates having carboxylic or carbonic ester groups in the main chain
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G18/00—Polymeric products of isocyanates or isothiocyanates
- C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
- C08G18/28—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the compounds used containing active hydrogen
- C08G18/40—High-molecular-weight compounds
- C08G18/42—Polycondensates having carboxylic or carbonic ester groups in the main chain
- C08G18/44—Polycarbonates
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G18/00—Polymeric products of isocyanates or isothiocyanates
- C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
- C08G18/28—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the compounds used containing active hydrogen
- C08G18/40—High-molecular-weight compounds
- C08G18/48—Polyethers
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- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
- C09J133/00—Adhesives based on homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by only one carboxyl radical, or of salts, anhydrides, esters, amides, imides, or nitriles thereof; Adhesives based on derivatives of such polymers
- C09J133/04—Homopolymers or copolymers of esters
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
- C09J133/00—Adhesives based on homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by only one carboxyl radical, or of salts, anhydrides, esters, amides, imides, or nitriles thereof; Adhesives based on derivatives of such polymers
- C09J133/04—Homopolymers or copolymers of esters
- C09J133/14—Homopolymers or copolymers of esters of esters containing halogen, nitrogen, sulfur or oxygen atoms in addition to the carboxy oxygen
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- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
- C09J175/00—Adhesives based on polyureas or polyurethanes; Adhesives based on derivatives of such polymers
- C09J175/04—Polyurethanes
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
- C09J7/00—Adhesives in the form of films or foils
- C09J7/30—Adhesives in the form of films or foils characterised by the adhesive composition
- C09J7/38—Pressure-sensitive adhesives [PSA]
Definitions
- the present invention relates to an adhesive tape.
- the present invention also relates to an adhesive composition.
- the present invention further relates to an adhesive obtained from the adhesive composition.
- Adhesive tapes having an adhesive layer containing an adhesive composition have been widely used to fasten components in electronic components, vehicles, housing, and building materials (e.g., Patent Documents 1 to 3). Specifically, for example, adhesive tapes are used to adhere a cover panel for protecting the surface of a portable electronic device to a touch panel module or a display panel module, or to adhere a touch panel module to a display panel module.
- Adhesive tapes used in the electronics field require high adhesive strength to ensure long-term reliability, but also reworkability, which allows them to be peeled off after application without leaving any residue on the adherend.
- Normally, to improve adhesive strength it is necessary to soften the adhesive contained in the adhesive layer to improve adhesion, while to improve reworkability, it is necessary to harden the adhesive contained in the adhesive layer so that the adhesive layer does not break when peeled off. Therefore, to improve both adhesive strength and reworkability, it is necessary to achieve both the contradictory properties of softness and hardness of the adhesive.
- the present disclosure 1 is an adhesive tape having an adhesive layer containing an adhesive and satisfying at least one configuration selected from the group consisting of the following first configuration and second configuration.
- First configuration the pressure-sensitive adhesive contains a crosslinked product having a vinyl monomer polymer structure and a urethane polymer structure, and in the crosslinked product, the vinyl monomer polymer and the urethane polymer are crosslinked with a crosslinking agent, and the vinyl monomer polymer has a structural unit derived from a compound (C1) selected from the following (a), (b), or (c): (a) an aromatic group-containing (meth)acrylate and a nitrogen atom-containing (meth)acrylate; (b) a polymer having a structural unit derived from an aromatic group-containing (meth)acrylate and a structural unit derived from a nitrogen atom-containing (meth)acrylate; (c) a polymer having a structural unit derived from an aromatic group-containing (meth)acrylate and a nitrogen atom-containing (meth
- the pressure-sensitive adhesive layer has a thickness of 50 ⁇ m or more, a tensile stress at break of the pressure-sensitive adhesive layer at 23° C. of 0.50 MPa or more, and a 180° peel strength of the pressure-sensitive adhesive tape from SUS at 23° C. and a peel speed of 300 mm/min of 5.0 N/inch or more and 30.0 N/inch or less.
- Disclosure 2 is a pressure-sensitive adhesive tape according to Disclosure 1, in which the pressure-sensitive adhesive layer has one peak of loss tangent (tan ⁇ ) in a temperature range of -10° C. or more and 30° C. or less when measured at a frequency of 1 Hz, and the half-width of the loss tangent peak is 40° C.
- Disclosure 3 is the pressure-sensitive adhesive tape of Disclosure 1 or 2, wherein, in the first configuration, the thickness of the pressure-sensitive adhesive layer is 50 ⁇ m or more, the tensile stress at break of the pressure-sensitive adhesive layer at 23° C. is 0.50 MPa or more, and the 180° peel force of the pressure-sensitive adhesive tape from SUS at a peel speed of 300 mm/min at 23° C. is 5.0 N/inch or more and 30.0 N/inch or less.
- the present disclosure 7 is a pressure-sensitive adhesive tape according to the present disclosure 1, 2, 3, 4, 5, or 6, in which the content of the structural units derived from the aromatic group-containing (meth)acrylate is 5 parts by mass or more and 95 parts by mass or less per 100 parts by mass of the total of the structural units derived from the aromatic group-containing (meth)acrylate and the structural units derived from the nitrogen atom-containing (meth)acrylate.
- the present disclosure 8 is the pressure-sensitive adhesive tape of the present disclosure 1, 2, 3, 4, 5, 6, or 7, wherein the vinyl monomer polymer further has a structural unit derived from a hydroxyl group-containing (meth)acrylate.
- Disclosure 20 is the pressure-sensitive adhesive tape of Disclosure 19, wherein the substrate comprises a foam substrate.
- the present disclosure 21 is the adhesive tape of the present disclosure 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, or 18, which does not have a substrate.
- the present disclosure 22 is a pressure-sensitive adhesive composition containing a vinyl monomer polymer and a urethane polymer, wherein the vinyl monomer polymer has a structural unit derived from a compound (C1) selected from the following (a), (b), or (c): (a) an aromatic group-containing (meth)acrylate and a nitrogen atom-containing (meth)acrylate; (b) a polymer having a structural unit derived from an aromatic group-containing (meth)acrylate and a structural unit derived from a nitrogen atom-containing (meth)acrylate; (c) a polymer having a structural unit derived from an aromatic group-containing (meth)acrylate and a structural unit derived from a nitrogen atom-containing (meth
- the thickness of the pressure-sensitive adhesive layer is 50 ⁇ m or more
- the tensile stress at break of the pressure-sensitive adhesive layer is 0.50 MPa or more at 23° C.
- the 180° peel strength of the pressure-sensitive adhesive tape from SUS at a peel speed of 300 mm/min at 23° C. is 5.0 N/inch or more and 30.0 N/inch or less.
- the pressure-sensitive adhesive contains a crosslinked product having a vinyl monomer polymer structure and a urethane polymer structure.
- the pressure-sensitive adhesive contains the crosslinked product, and the urethane polymer structure of the crosslinked product makes the pressure-sensitive adhesive tape of the present invention excellent in reworkability, while the vinyl monomer polymer structure of the crosslinked product makes the pressure-sensitive adhesive tape of the present invention have high adhesive strength.
- the crosslinked product has a structure in which the vinyl monomer polymer structure and the urethane polymer structure are crosslinked, the pressure-sensitive adhesive becomes hard, and the reworkability of the pressure-sensitive adhesive tape of the present invention is improved.
- the pressure-sensitive adhesive contains the crosslinked product, and the pressure-sensitive adhesive tape of the present invention can achieve both high adhesive strength and excellent reworkability.
- the adhesive preferably contains a crosslinked product having a vinyl monomer polymer structure and a urethane polymer structure.
- the adhesive contains the crosslinked product, and the crosslinked product has a urethane polymer structure, which makes the adhesive tape of the present invention more excellent in reworkability, while the crosslinked product has a vinyl monomer polymer structure, which makes the adhesive tape of the present invention have a higher adhesive strength.
- the adhesive becomes harder, and the reworkability of the adhesive tape of the present invention is further improved. That is, in the second configuration, the adhesive contains the crosslinked product, and the adhesive tape of the present invention can achieve both higher adhesive strength and better reworkability.
- the vinyl monomer polymer has a structural unit derived from a compound (C1) selected from the following (a), (b), or (c): (a) aromatic group-containing (meth)acrylate and nitrogen atom-containing (meth)acrylate (b) polymer having a structural unit derived from aromatic group-containing (meth)acrylate and a structural unit derived from nitrogen atom-containing (meth)acrylate (c) polymer having a structural unit derived from aromatic group-containing (meth)acrylate and a structural unit derived from nitrogen atom-containing (meth)acrylate
- the compound (C1) has excellent compatibility with urethane polymers, so that in the first configuration, the vinyl monomer polymer has a structural unit derived from the compound (C1) selected from (a), (b), or (c), and thus the vinyl monomer polymer has excellent compatibility with the urethane polymer described below.
- the crosslinking between the vinyl monomer polymer having the structural unit derived from the compound (C1) and the compound (C1) and the urethane polymer described below proceeds uniformly.
- the crosslinked product has a vinyl monomer polymer structure and a urethane polymer structure, and the pressure-sensitive adhesive tape of the present invention can achieve both high adhesion and excellent reworkability.
- the compatibility between the compound (C1) and the urethane polymer is excellent, the pressure-sensitive adhesive layer can suppress interface formation due to microphase separation, making the pressure-sensitive adhesive layer less likely to break when pulled, and as a result, the pressure-sensitive adhesive tape of the present invention has excellent reworkability.
- the vinyl monomer polymer preferably has a structural unit derived from a compound (C1) selected from the following (a), (b), or (c): (a) aromatic group-containing (meth)acrylate and nitrogen atom-containing (meth)acrylate (b) polymer having a structural unit derived from aromatic group-containing (meth)acrylate and a structural unit derived from nitrogen atom-containing (meth)acrylate (c) polymer having a structural unit derived from aromatic group-containing (meth)acrylate and a structural unit derived from nitrogen atom-containing (meth)acrylate
- the compound (C1) has excellent compatibility with urethane polymers, so that in the second configuration, the vinyl monomer polymer has a structural unit derived from the compound (C1) selected from the above (a), (b), or (c), and thus the vinyl monomer polymer has better compatibility with the urethane polymer described below.
- the crosslinking between the vinyl monomer polymer having the structural unit derived from the compound (C1) and the compound (C1) and the urethane polymer described below proceeds more uniformly.
- the crosslinked product has a vinyl monomer polymer structure and a urethane polymer structure, and the pressure-sensitive adhesive tape of the present invention can achieve both higher adhesion and better reworkability.
- the pressure-sensitive adhesive layer can further suppress interface formation due to microphase separation, making the pressure-sensitive adhesive layer less likely to break when pulled, and as a result, the pressure-sensitive adhesive tape of the present invention has excellent reworkability.
- the term "(meth)acrylate" means acrylate or methacrylate.
- aromatic group-containing (meth)acrylate examples include benzyl acrylate, phenoxyethyl (meth)acrylate, phenoxydiethylene glycol acrylate, methylphenoxyethyl acrylate, 2-hydroxy-3-phenoxypropyl acrylate, 2-([1,1'-biphenyl]-2-yloxy)ethyl (meth)acrylate, etc.
- phenoxyethyl (meth)acrylate and phenoxydiethylene glycol acrylate are preferred.
- the more preferred lower limit of the content of the constituent units derived from the aromatic group-containing (meth)acrylate is 10% by mass
- the more preferred upper limit is 90% by mass
- the even more preferred lower limit is 15% by mass
- the even more preferred upper limit is 85% by mass.
- urethane bond-containing (meth)acrylate examples include 1,2-ethanediol 1-acrylate 2-(N-butylcarbamate).
- the imide bond-containing (meth)acrylate may, for example, be N-[2-(acryloyloxy)ethyl]phthalimide.
- hydroxyl group-containing (meth)acrylate examples include 2-hydroxyethyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, and tetrahydroxyfurfuryl (meth)acrylate.
- the weight average molecular weight (Mw) of the polymer having a structural unit derived from the aromatic group-containing (meth)acrylate is preferably 200,000 in lower limit and 2,000,000 in upper limit.
- the weight average molecular weight of the polymer having a structural unit derived from the aromatic group-containing (meth)acrylate is 200,000 or more, the reworkability of the adhesive tape of the present invention is further improved.
- the weight average molecular weight of the polymer having a structural unit derived from the aromatic group-containing (meth)acrylate is 2,000,000 or less, the adhesive strength of the adhesive tape of the present invention is further improved.
- azo compounds may be used alone or in combination of two or more.
- organic peroxides include 1,1-bis(t-hexylperoxy)-3,3,5-trimethylcyclohexane, t-hexylperoxypivalate, t-butylperoxypivalate, 2,5-dimethyl-2,5-bis(2-ethylhexanoylperoxy)hexane, t-hexylperoxy-2-ethylhexanoate, t-butylperoxy-2-ethylhexanoate, t-butylperoxyisobutyrate, t-butylperoxy-3,5,5-trimethylhexanoate, t-butylperoxylaurate, etc.
- an organic solvent that does not have an active hydrogen with which the isocyanate group can react e.g., ethyl acetate, methyl ethyl ketone, chloroform, etc.
- a catalyst e.g., organometallic catalysts such as tin chloride and organotin compounds, organic bases such as tertiary amine compounds, organic acids such as acetic acid and acrylic acid, etc.
- polyol compound examples include polyester polyols (polycondensates of dihydric alcohols and divalent basic acids such as adipic acid, azelaic acid, and sepatic acid), polyether polyols (those obtained by addition polymerization of ethylene oxide, tetrahydrofuran, and the like), polyacrylate polyols, polycarbonate polyols, polyolefin polyols, polybutadiene polyols or hydrogenated products thereof, polyisoprene polyols or hydrogenated products thereof, phenolic polyols, epoxy polyols, caprolactone polyols, polysulfone polyols, etc.
- polyester polyols polycondensates of dihydric alcohols and divalent basic acids such as adipic acid, azelaic acid, and sepatic acid
- polyether polyols examples obtained by addition polymerization of ethylene oxide, tetrahydrofuran, and the like
- urethane polymer having structural units derived from the above polyether diol is AG8451 (manufactured by Lubrizol Corporation).
- the above polyol compound may contain an alcohol compound having three or more hydroxyl groups.
- polyisocyanate compound examples include diphenylmethane diisocyanate, tolylene diisocyanate, naphthalene-1,5-diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, lysine diisocyanate, norbornane diisocyanate, transcyclohexane-1,4-diisocyanate, isophorone diisocyanate, hydrogenated xylylene diisocyanate, hydrogenated diphenylmethane diisocyanate, cyclohexane diisocyanate, bis(isocyanatemethyl)cyclohexane, dicyclohexylmethane diisocyanate, etc.
- polyisocyanate compounds containing aromatic groups are preferred from the viewpoint of excellent compatibility with the above compound (C1) and vinyl monomer polymers having structural units derived from the above compound (C1), exhibiting higher reworkability, and exhibiting higher adhesive strength, and among them, modified diphenylmethane diisocyanate such as diphenylmethane diisocyanate and liquid modified diphenylmethane diisocyanate are more preferred.
- modified diphenylmethane diisocyanate such as diphenylmethane diisocyanate and liquid modified diphenylmethane diisocyanate are more preferred.
- These polyisocyanate compounds may be used alone or in combination of two or more.
- the polyisocyanate compound preferably contains an isocyanate compound having three or more isocyanate groups.
- the preferred lower limit of the content ratio of the structural unit derived from the isocyanate compound having 3 or more isocyanate groups in the urethane polymer is 0.1% by mass, and the preferred upper limit is 20% by mass.
- the pressure-sensitive adhesive tape of the present invention can achieve both higher adhesive strength and better reworkability.
- the more preferred lower limit is 0.5% by mass, and the more preferred upper limit is 10% by mass.
- the preferred lower limit of the amount of the urethane polymer per 100 parts by mass of the combined total of the vinyl monomer polymer and the urethane polymer is 5 parts by mass, and the preferred upper limit is 90 parts by mass.
- the lower limit of the content of the urethane polymer is more preferably 10 parts by mass
- the upper limit is more preferably 70 parts by mass
- the further lower limit is 15 parts by mass
- the further upper limit is more preferably 60 parts by mass.
- isocyanate-based crosslinking agent examples include Coronate HX and Millionate MR200 (both manufactured by Tosoh Corporation).
- the preferred lower limit of the content of the crosslinking agent in the total of the pressure-sensitive adhesive composition and the crosslinking agent is 0.1% by mass, and the preferred upper limit is 20% by mass.
- the content of the crosslinking agent is 0.1% by mass or more, the pressure-sensitive adhesive can be cured more, and the reworkability of the pressure-sensitive adhesive tape of the present invention is further improved.
- the content of the crosslinking agent is 20% by mass or less, the pressure-sensitive adhesive does not become too hard, and the pressure-sensitive adhesive tape of the present invention can exert a higher adhesive strength.
- the adhesive may further contain a tackifier resin.
- a tackifier resin By containing a tackifier resin in the adhesive, the adhesive strength of the adhesive tape of the present invention is further improved.
- the rosin ester resin is a resin obtained by esterifying, with an alcohol, a rosin resin mainly composed of abietic acid, a disproportionated rosin resin, a hydrogenated rosin resin, a dimer of a resin acid such as abietic acid (polymerized rosin resin), etc.
- a part of the hydroxyl group of the alcohol used for esterification is not used for esterification and is contained in the resin, so that the hydroxyl value is adjusted to the above-mentioned range.
- the alcohol include polyhydric alcohols such as ethylene glycol, glycerin, and pentaerythritol.
- a resin obtained by esterifying a rosin resin is a rosin ester resin
- a resin obtained by esterifying a disproportionated rosin resin is a disproportionated rosin ester resin
- a resin obtained by esterifying a hydrogenated rosin resin is a hydrogenated rosin ester resin
- a resin obtained by esterifying a polymerized rosin resin is a polymerized rosin ester resin.
- the above terpene phenol resin is a resin obtained by polymerizing terpene in the presence of phenol.
- the preferred lower limit of the content of the tackifier resin in the adhesive is 1% by mass, and the preferred upper limit is 60% by mass.
- the adhesive tape of the present invention can exhibit higher adhesive strength.
- the adhesive strength of the adhesive tape of the present invention does not become too high, and reworkability is further improved.
- a more preferred lower limit of the content of the tackifier resin is 3% by mass, a more preferred upper limit is 50% by mass, an even more preferred lower limit is 5% by mass, and an even more preferred upper limit is 40% by mass.
- the method for producing the pressure-sensitive adhesive is not particularly limited, and the pressure-sensitive adhesive can be produced by a conventionally known method, etc.
- the pressure-sensitive adhesive can be produced by adding a urethane polymer, a vinyl monomer polymer, or the compound (C1), a crosslinking agent, etc. to a solvent and then thoroughly stirring the mixture.
- the compound (C1) is the compound (a)
- the above-mentioned monomer mixture, the above-mentioned photopolymerization initiator, and the above-mentioned urethane polymer are mixed, and the mixture is applied onto a release PET film or a substrate using an applicator.
- the upper surface of the coated layer is sealed with a release PET film or placed under a nitrogen atmosphere to prevent the coated surface from coming into contact with air, and then polymerized by UV irradiation to obtain a pressure-sensitive adhesive.
- the preferred upper limit of the thickness of the adhesive layer is 300 ⁇ m. By setting the thickness of the adhesive layer to 300 ⁇ m or less, the adhesive strength of the adhesive tape of the present invention is increased. The more preferred upper limit of the thickness of the adhesive layer is 250 ⁇ m, and the even more preferred upper limit is 200 ⁇ m.
- the preferred lower limit of the tensile stress at break of the pressure-sensitive adhesive layer at 23° C. is 0.50 MPa.
- the pressure-sensitive adhesive layer has a tensile stress at break of 0.50 MPa or more at 23° C., so that the pressure-sensitive adhesive tape of the present invention has better reworkability.
- the more preferred lower limit of the tensile stress at break of the pressure-sensitive adhesive layer at 23° C. is 0.60 MPa, and the even more preferred lower limit is 0.70 MPa.
- the lower limit of the tensile stress at break of the pressure-sensitive adhesive layer at 23° C. is 0.50 MPa.
- the lower limit of the breaking elongation percentage of the pressure-sensitive adhesive layer at 23° C. is preferably 300%. When the breaking elongation percentage of the pressure-sensitive adhesive layer at 23° C. is 300% or more, the pressure-sensitive adhesive tape of the present invention has better reworkability.
- the lower limit of the breaking elongation percentage of the pressure-sensitive adhesive layer at 23° C. is more preferably 350%, and even more preferably 400%.
- the upper limit of the breaking elongation of the pressure-sensitive adhesive layer is preferably 3000%. When the breaking elongation of the pressure-sensitive adhesive tape of the present invention is 3000% or less, the pressure-sensitive adhesive tape of the present invention has higher adhesive strength.
- the upper limit of the breaking elongation of the pressure-sensitive adhesive tape of the present invention is more preferably 2500%, and even more preferably 2000%.
- the tensile stress at break and the elongation at break are measured, for example, in accordance with JIS K7161, by performing a tensile test in which the adhesive layer is pulled in the long side direction using a tensile tester (such as "TBS-1225S” manufactured by A&D Co., Ltd.) under conditions of 23°C, 50% RH, and a tensile speed of 200 mm/min.
- the stress at break when the adhesive layer breaks can be obtained as the tensile stress at break, and the ratio of the length of the long side of the adhesive layer when it breaks to the length of the long side of the adhesive layer before the tensile test can be obtained as the elongation at break.
- the length of the long side of the adhesive layer refers to the distance between the chucks of the tensile tester that grip the adhesive layer in the tensile test.
- Examples of methods for adjusting the tensile stress at break within the above-mentioned range include a method of changing the composition of the vinyl monomer polymer or the urethane polymer, a method of changing the type or content of the crosslinking agent, a method of changing the type or content of an additive such as a tackifier resin, and the like.
- the composition of the vinyl monomer or the urethane polymer may be changed to increase the glass transition temperature of the vinyl monomer or the urethane polymer.
- Examples of methods for adjusting the breaking elongation rate within the above-mentioned range include a method of changing the composition of the vinyl monomer or the urethane polymer, a method of changing the type or content of the crosslinking agent, a method of changing the type or content of an additive such as a tackifier resin, and the like. Specifically, for example, the content of the urethane polymer in the crosslinked product may be increased.
- the pressure-sensitive adhesive layer preferably has one peak in loss tangent (tan ⁇ ) in the temperature range of -10° C. or more and 30° C. or less when measured at a frequency of 1 Hz.
- the pressure-sensitive adhesive layer is more uniform, and therefore the compatibility between the components in the pressure-sensitive adhesive layer is more excellent, so that the pressure-sensitive adhesive tape of the present invention can achieve both higher adhesive strength and better reworkability.
- "one peak” means that there is one maximum value of loss tangent (tan ⁇ ) in the temperature range from -10°C to 30°C on a spectrum chart of loss tangent (tan ⁇ ) obtained by dynamic viscoelasticity measurement.
- glass transition temperature when made into a homopolymer refers to the glass transition temperature measured by differential scanning calorimetry of a homopolymer when the (meth)acrylate has a weight average molecular weight of 100,000 to 2,000,000.
- the glass transition temperature when made into the homopolymer may be measured, for example, in a nitrogen atmosphere (nitrogen flow, flow rate 50 mL/min) using a differential scanning calorimeter (manufactured by Seiko Instruments Inc., "220C” or the like) in accordance with JIS K6240:2011 at a measurement temperature of -100°C to 200°C and a heating rate of 10°C/min.
- Methods for adjusting the half-width of the peak of the loss tangent (tan ⁇ ) when measured at a frequency of 1 Hz of the pressure-sensitive adhesive layer to the above-mentioned range include, for example, changing the composition of the vinyl monomer polymer or the urethane polymer, or changing the type or content of the crosslinking agent.
- the preferred lower limit of the gel fraction of the pressure-sensitive adhesive layer is 30% by mass, and the preferred upper limit is 99% by mass.
- the pressure-sensitive adhesive layer becomes hard, and the reworkability of the pressure-sensitive adhesive tape of the present invention is further improved.
- the pressure-sensitive adhesive tape of the present invention can exhibit higher adhesive strength.
- the more preferred lower limit of the gel fraction of the pressure-sensitive adhesive layer is 32% by mass, the more preferred upper limit is 90% by mass, the even more preferred lower limit is 35% by mass, and the even more preferred upper limit is 80% by mass.
- the gel fraction of the pressure-sensitive adhesive layer is measured by the following method.
- Methods for adjusting the Young's modulus at 23°C of the pressure-sensitive adhesive layer to fall within the above-mentioned range include, for example, changing the composition of the vinyl monomer polymer or the urethane polymer, changing the type or amount of the crosslinking agent, and changing the type or amount of additives such as tackifier resin.
- the adhesive tape of the present invention may be a non-support type adhesive tape that does not have a substrate, or a supported type adhesive tape in which an adhesive layer is formed on a substrate.
- the adhesive tape of the present invention only needs to have the adhesive layer on at least one side of the substrate, that is, it may be a single-sided adhesive tape having the adhesive layer on one side of the substrate, or a double-sided adhesive tape having the adhesive layers on both sides of the substrate.
- the thickness of the substrate is preferably 5 ⁇ m at the lower limit and 1000 ⁇ m at the upper limit. If the thickness of the substrate is within this range, the adhesive tape will have appropriate stiffness and excellent handling properties.
- a more preferred lower limit of the thickness of the substrate is 10 ⁇ m, a more preferred upper limit is 500 ⁇ m, an even more preferred upper limit is 200 ⁇ m, and an even more preferred upper limit is 150 ⁇ m.
- a release film other than the above release film is prepared, and a solution of adhesive b prepared in the same manner as above is applied to the release-treated surface of this release film, and the solvent in the solution is completely dried and removed to produce a laminated film in which adhesive layer b is formed on the surface of the release film.
- the obtained laminated film is superimposed on the other surface of a substrate on one side of which adhesive layer a is formed, with adhesive layer b facing each other, to produce a laminate.
- a double-sided adhesive tape can be obtained that has adhesive layers on both sides of the substrate and the surface of the adhesive layer is covered with a release film.
- two sets of laminate films may be prepared in a similar manner, and these laminate films may be superimposed on both sides of a substrate with the adhesive layer of the laminate film facing the substrate to produce a laminate.
- a double-sided adhesive tape having adhesive layers on both sides of the substrate and the surface of the adhesive layer covered with a release film may be obtained.
- the pressure-sensitive adhesive tape of the present invention is a non-support type pressure-sensitive adhesive tape having no substrate, or when the pressure-sensitive adhesive tape of the present invention is a double-sided pressure-sensitive adhesive tape having a substrate, a test piece is prepared in which the surface of the pressure-sensitive adhesive tape on which the 180° peel strength is not measured is backed with a PET film or the like, and the peel test is performed using the prepared test piece.
- the preferred lower limit of the content ratio of the constituent units derived from the aromatic group-containing (meth)acrylate in the entire vinyl monomer polymer is 5% by mass, and the preferred upper limit is 95% by mass.
- the content ratio of the constituent units derived from the aromatic group-containing (meth)acrylate is 5% by mass or more, the adhesive obtained from the pressure-sensitive adhesive composition of the present invention becomes harder, and the reworkability is further improved.
- the content ratio of the constituent units derived from the aromatic group-containing (meth)acrylate is 95% by mass or less, the adhesive obtained from the pressure-sensitive adhesive composition of the present invention does not become too hard, and can exhibit higher adhesive strength.
- a more preferred lower limit of the content ratio of the constituent units derived from the aromatic group-containing (meth)acrylate is 10% by mass, a more preferred upper limit is 90% by mass, an even more preferred lower limit is 15% by mass, and an even more preferred upper limit is 85% by mass.
- urethane bond-containing (meth)acrylate examples include 1,2-ethanediol 1-acrylate 2-(N-butylcarbamate).
- the imide bond-containing (meth)acrylate may, for example, be N-[2-(acryloyloxy)ethyl]phthalimide.
- the preferred lower limit of the content ratio of the constituent units derived from the nitrogen atom-containing (meth)acrylate in the entire vinyl monomer polymer is 5% by mass, and the preferred upper limit is 95% by mass.
- the content ratio of the constituent units derived from the nitrogen atom-containing (meth)acrylate is 5% by mass or more, the adhesive obtained from the adhesive composition of the present invention becomes harder, and the reworkability is further improved.
- the content ratio of the constituent units derived from the nitrogen atom-containing (meth)acrylate is 95% by mass or less, the adhesive obtained from the adhesive composition of the present invention does not become too hard, and can exhibit higher adhesive strength.
- the more preferred lower limit of the content ratio of the constituent units derived from the nitrogen atom-containing (meth)acrylate is 10% by mass
- the more preferred upper limit is 90% by mass
- the even more preferred lower limit is 15% by mass
- the even more preferred upper limit is 85% by mass.
- the preferred lower limit of the content of the structural unit derived from the aromatic group-containing (meth)acrylate in the total of 100 parts by mass of the structural unit derived from the aromatic group-containing (meth)acrylate and the structural unit derived from the nitrogen atom-containing (meth)acrylate is 5 parts by mass, and the preferred upper limit is 95 parts by mass.
- the compound (C1) and the vinyl monomer polymer having the structural unit derived from the compound (C1) have better compatibility with the urethane polymer described below, so that the pressure-sensitive adhesive obtained from the pressure-sensitive adhesive composition of the present invention can achieve both higher adhesive strength and better reworkability.
- the more preferred lower limit of the content of the structural unit derived from the aromatic group-containing (meth)acrylate is 10 parts by mass
- the more preferred upper limit is 90 parts by mass
- the even more preferred lower limit is 15 parts by mass
- the even more preferred upper limit is 85 parts by mass.
- the vinyl monomer polymer preferably further has a structural unit derived from a hydroxyl group-containing (meth)acrylate.
- the vinyl monomer polymer has a structural unit derived from a hydroxyl group-containing (meth)acrylate, which facilitates crosslinking between the compound (C1) and the urethane polymer by a crosslinking agent described below.
- the adhesive composition of the present invention is cured more, so that the breaking strength is improved and the reworkability of the adhesive obtained from the adhesive composition of the present invention is improved.
- a structural unit derived from a (meth)acrylate containing an aromatic group and a hydroxyl group is referred to as a structural unit derived from an aromatic group-containing (meth)acrylate.
- a structural unit derived from a (meth)acrylate containing a nitrogen atom and a hydroxyl group is referred to as a structural unit derived from a nitrogen-atom-containing (meth)acrylate.
- the preferred lower limit of the content ratio of the structural unit derived from the hydroxyl group-containing (meth)acrylate in the entire vinyl monomer polymer is 0.01% by mass, and the preferred upper limit is 20% by mass.
- the content ratio of the structural unit derived from the hydroxyl group-containing (meth)acrylate is 0.01% by mass or more, the reworkability of the adhesive obtained from the adhesive composition of the present invention is further improved.
- the content ratio of the structural unit derived from the hydroxyl group-containing (meth)acrylate is 20% by mass or less, the adhesive obtained from the adhesive composition of the present invention is not too hard, and the adhesive can exhibit higher adhesive strength.
- a more preferred lower limit of the content ratio of the structural unit derived from the hydroxyl group-containing (meth)acrylate is 0.1% by mass, a more preferred upper limit is 10% by mass, an even more preferred lower limit is 0.5% by mass, and an even more preferred upper limit is 5.0% by mass.
- the vinyl monomer polymer in the pressure-sensitive adhesive composition of the present invention may further have a structural unit derived from an alkyl (meth)acrylate.
- alkyl (meth)acrylate in the adhesive composition of the present invention examples include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, n-heptyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, 2-octyl (meth)acrylate, isooctyl (meth)acrylate, n-nonyl (meth)acrylate, isononyl (meth)acrylate, lauryl (meth)acrylate, myristyl (meth)acrylate, cetyl (meth)acrylate, isostearyl acrylate, and arachidyl (meth)acrylate.
- alkyl (meth)acrylates with short alkyl chain lengths are preferred, specifically n-butyl (meth)acrylate and 2-ethylhexyl (meth)acrylate.
- the vinyl monomer polymer in the pressure-sensitive adhesive composition of the present invention may further have a structural unit derived from the aromatic group-containing (meth)acrylate, a structural unit derived from the nitrogen atom-containing (meth)acrylate, a structural unit derived from the hydroxyl group-containing (meth)acrylate, and a structural unit derived from a monomer other than the structural unit derived from the alkyl (meth)acrylate.
- the weight-average molecular weight (Mw) of the polymer having a structural unit derived from the aromatic group-containing (meth)acrylate and a structural unit derived from the nitrogen atom-containing (meth)acrylate is preferably 200,000 in lower limit and 2,000,000 in upper limit.
- the weight-average molecular weight of the polymer having a structural unit derived from the aromatic group-containing (meth)acrylate and a structural unit derived from the nitrogen atom-containing (meth)acrylate is 200,000 or more, the reworkability of the pressure-sensitive adhesive obtained from the pressure-sensitive adhesive composition of the present invention is further improved.
- the adhesive strength of the pressure-sensitive adhesive obtained from the pressure-sensitive adhesive composition of the present invention is further improved.
- the weight average molecular weight of the polymer having a structural unit derived from the aromatic group-containing (meth)acrylate and a structural unit derived from the nitrogen atom-containing (meth)acrylate is more preferably 400,000 in lower limit, 1,500,000 in upper limit, 600,000 in even more preferred lower limit, and 1,000,000 in even more preferred upper limit.
- the weight-average molecular weight (Mw) of the polymer having a structural unit derived from the aromatic group-containing (meth)acrylate is preferably 200,000 in lower limit and 2,000,000 in upper limit.
- the weight-average molecular weight of the polymer having a structural unit derived from the aromatic group-containing (meth)acrylate is 200,000 or more, the reworkability of the pressure-sensitive adhesive obtained from the pressure-sensitive adhesive composition of the present invention is further improved.
- the adhesive strength of the pressure-sensitive adhesive obtained from the pressure-sensitive adhesive composition of the present invention is further improved.
- the weight-average molecular weight of the polymer having a structural unit derived from the aromatic group-containing (meth)acrylate is more preferably 400,000 in lower limit and 1,500,000 in upper limit, even more preferably 600,000 in lower limit and even more preferably 1,000,000 in upper limit.
- the weight-average molecular weight (Mw) of the polymer having a structural unit derived from the nitrogen-containing (meth)acrylate is preferably 200,000 in lower limit and 2,000,000 in upper limit.
- the weight-average molecular weight of the polymer having a structural unit derived from the nitrogen-containing (meth)acrylate is 200,000 or more, the reworkability of the pressure-sensitive adhesive obtained from the pressure-sensitive adhesive composition of the present invention is further improved.
- the adhesive strength of the pressure-sensitive adhesive obtained from the pressure-sensitive adhesive composition of the present invention is further improved.
- the weight-average molecular weight of the polymer having a structural unit derived from the nitrogen-containing (meth)acrylate is more preferably 400,000 in lower limit and 1,500,000 in upper limit, even more preferably 600,000 in lower limit and even more preferably 1,000,000 in upper limit.
- the vinyl monomer polymer can be produced, for example, by polymerizing a monomer mixture serving as raw materials such as the aromatic group-containing (meth)acrylate and the nitrogen atom-containing (meth)acrylate, and if necessary the hydroxyl group-containing (meth)acrylate, the alkyl (meth)acrylate, and the other monomers by radical reaction in the presence of a polymerization initiator.
- the method for polymerizing the monomer mixture may be a conventionally known method, such as solution polymerization (boiling point polymerization or constant temperature polymerization), UV polymerization, emulsion polymerization, suspension polymerization, bulk polymerization, etc.
- solution polymerization and UV polymerization are preferred because they result in higher adhesive strength of the adhesive obtained from the adhesive composition of the present invention.
- the reaction solvent include ethyl acetate, toluene, methyl ethyl ketone, dimethyl sulfoxide, ethanol, acetone, diethyl ether, etc. These reaction solvents may be used alone or in combination of two or more kinds.
- polymerization initiator examples include, in the case of solution polymerization, azo compounds and organic peroxides, and in the case of UV polymerization, photopolymerization initiators such as benzophenone compounds, acetophenone compounds, alkylphenone compounds, acylphosphine oxide compounds, titanocene compounds, oxime ester compounds, benzoin ether compounds, and thioxanthone can be used.
- photopolymerization initiators such as benzophenone compounds, acetophenone compounds, alkylphenone compounds, acylphosphine oxide compounds, titanocene compounds, oxime ester compounds, benzoin ether compounds, and thioxanthone can be used.
- azo compound examples include 2,2'-azobis(isobutyronitrile), 2,2'-azobis(2-methylbutyronitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), 1,1-azobis(cyclohexane-1-carbonitrile), 1-((1-cyano-1-methylethyl)azo)formamide, 4,4'-azobis(4-cyanovaleric acid), dimethyl-2,2'-azobis(2-methylpropionate), dimethyl-1,1'-azobis(1-cyclohexanecarboxylate), 2,2'-azobis(2-methyl-N-(1,1'-bis(hydroxymethyl)-2-hydroxyethyl)propionamide), 2,2'-azobis(2-methyl-N-(2-hydroxyethyl)propionamide), 2,2 '-Azobis(N-(2-propenyl)-2-methylpropion
- azo compounds may be used alone or in combination of two or more.
- organic peroxides include 1,1-bis(t-hexylperoxy)-3,3,5-trimethylcyclohexane, t-hexylperoxypivalate, t-butylperoxypivalate, 2,5-dimethyl-2,5-bis(2-ethylhexanoylperoxy)hexane, t-hexylperoxy-2-ethylhexanoate, t-butylperoxy-2-ethylhexanoate, t-butylperoxyisobutyrate, t-butylperoxy-3,5,5-trimethylhexanoate, t-butylperoxylaurate, etc.
- organic peroxides may be used alone or in combination of two or more.
- the photopolymerization initiator include Omnirad 184, Omnirad 369, Omnirad 379, Omnirad 379EG, Omnirad 651, Omnirad 784, Omnirad 819, Omnirad 907, Omnirad 2959, Omnirad TPO (all manufactured by IGM Resins), Omnirad OXE01 (manufactured by BASF), benzoin methyl ether, benzoin ethyl ether, and benzoin isopropyl ether (all manufactured by Tokyo Chemical Industry Co., Ltd.). These photopolymerization initiators may be used alone or in combination of two or more.
- the urethane polymer in the pressure-sensitive adhesive composition of the present invention is a compound obtained by reacting a polyol compound with a polyisocyanate compound.
- the polyol compound is a polyol diol having a small number of carbon atoms
- a hard segment having high polarity is obtained as a constituent unit of the urethane polymer.
- the cohesive strength of the obtained urethane polymer is improved by physical crosslinking via hydrogen bonds, and the reworkability of the pressure-sensitive adhesive obtained from the pressure-sensitive adhesive composition of the present invention is improved.
- the polyol compound is a polyol having a large number of carbon atoms
- a soft segment having low polarity is obtained as a constituent unit of the urethane polymer.
- the degree of freedom of deformation of the obtained urethane polymer is further improved, and as a result, the adhesive strength of the adhesive obtained from the adhesive composition of the present invention is further improved.
- the urethane polymer contains the hard segment.
- the method for producing the urethane polymer in the pressure-sensitive adhesive composition of the present invention is not particularly limited, but may be, for example, obtained by mixing and stirring a polyol compound and a polyisocyanate compound.
- the reaction between the polyol compound and the polyisocyanate compound may be carried out by any suitable method employed in the production of urethane polymers.
- an organic solvent that does not have active hydrogen with which the isocyanate group can react e.g., ethyl acetate, methyl ethyl ketone, chloroform, etc.
- a catalyst e.g., organometallic catalysts such as tin chloride and organotin compounds, organic bases such as tertiary amine compounds, organic acids such as acetic acid and acrylic acid, etc.
- organometallic catalysts such as tin chloride and organotin compounds
- organic bases such as tertiary amine compounds
- organic acids such as acetic acid and acrylic acid, etc.
- polyester polyols polycondensates of dihydric alcohols and divalent basic acids such as adipic acid, azelaic acid, sepatic acid, etc.
- polyether polyols titanium oxide, titanium oxide, etc.
- polyacrylate polyols polycarbonate polyols, polyolefin polyols, polybutadiene polyols or hydrogenated products thereof, polyisoprene polyols or hydrogenated products thereof, phenolic polyols, epoxy polyols, caprolactone polyols, polysulfone polyols, etc.
- polyol compounds are copolymer polyols such as polyester-polyether polyols.
- copolymer polyols such as polyester-polyether polyols.
- the urethane polymer has at least one selected from the group consisting of structural units derived from polyether diol, structural units derived from polyester diol, and structural units derived from polycarbonate diol.
- the urethane polymer has at least one selected from the group consisting of structural units derived from polyester diol and structural units derived from polycarbonate diol, and it is even more preferable that the urethane polymer has structural units derived from polycarbonate diol.
- These polyol compounds may be used alone or in combination of two or more.
- the diol compound used in the synthesis of the polycarbonate diol may be, for example, one of the polyol compounds described above in which the hydroxyl group has a valence of 2. These diol compounds may be used alone or in combination of two or more.
- the preferred lower limit of the content of the structural unit derived from the polycarbonate diol in the urethane polymer is 3% by mass, and the preferred upper limit is 70% by mass.
- the content of the structural unit derived from the polycarbonate diol is 3% by mass or more, the cohesive strength of the obtained urethane polymer is further improved, and the reworkability of the adhesive obtained from the pressure-sensitive adhesive composition of the present invention is further improved.
- the content of the structural unit derived from the polycarbonate diol is 70% by mass or less, the degree of freedom of deformation of the obtained urethane polymer is further improved, and as a result, the adhesive strength of the adhesive obtained from the pressure-sensitive adhesive composition of the present invention is further improved.
- a more preferred lower limit of the content of the structural unit derived from the polycarbonate diol is 5% by mass, a more preferred upper limit is 60% by mass, an even more preferred lower limit is 7% by mass, and an even more preferred upper limit is 50% by mass.
- the preferred lower limit of the content of the constituent units derived from the polyester diol in the urethane polymer is 3% by mass, and the preferred upper limit is 70% by mass.
- the content of the constituent units derived from the polyester diol is 3% by mass or more, the cohesive strength of the resulting urethane polymer is improved, and the reworkability of the adhesive obtained from the adhesive composition of the present invention is improved.
- the content of the constituent units derived from the polyester diol is 70% by mass or less, the degree of freedom of deformation of the resulting urethane polymer is improved, and as a result, the adhesive strength of the adhesive obtained from the adhesive composition of the present invention is improved.
- the more preferred lower limit of the content of the constituent units derived from the polyester diol is 5% by mass, the more preferred upper limit is 60% by mass, the even more preferred lower limit is 7% by mass, and the even more preferred upper limit is 50% by mass.
- the preferred lower limit of the content of the structural unit derived from the polyether diol in the urethane polymer is 3% by mass, and the preferred upper limit is 70% by mass.
- the content of the structural unit derived from the polyether diol is 3% by mass or more, the cohesive strength of the obtained urethane polymer is further improved, and the reworkability of the adhesive obtained from the pressure-sensitive adhesive composition of the present invention is further improved.
- the content of the structural unit derived from the polyether diol is 70% by mass or less, the degree of freedom of deformation of the obtained urethane polymer is further improved, and as a result, the adhesive strength of the adhesive obtained from the pressure-sensitive adhesive composition of the present invention is further improved.
- a more preferred lower limit of the content of the structural unit derived from the polyether diol is 5% by mass, a more preferred upper limit is 60% by mass, an even more preferred lower limit is 7% by mass, and an even more preferred upper limit is 50% by mass.
- examples of the urethane polymer having structural units derived from the above polyether diol include AG8451 (manufactured by Lubrizol Corporation).
- the above polyol compound may contain an alcohol compound having three or more hydroxyl groups.
- polyisocyanate compound in the adhesive composition of the present invention examples include diphenylmethane diisocyanate, tolylene diisocyanate, naphthalene-1,5-diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, lysine diisocyanate, norbornane diisocyanate, transcyclohexane-1,4-diisocyanate, isophorone diisocyanate, hydrogenated xylylene diisocyanate, hydrogenated diphenylmethane diisocyanate, cyclohexane diisocyanate, bis(isocyanatemethyl)cyclohexane, dicyclohexylmethane diisocyanate, etc.
- Modified products of the above-mentioned polyisocyanate compounds may also be used as the polyisocyanate compound.
- modified polyisocyanate compound examples include biuret modified polyisocyanate compounds, isocyanurate modified polyisocyanate compounds, adducts obtained by reacting the polyisocyanate compounds with polyols obtained by addition polymerization of glycerin, trimethylolpropane, or alkylene oxides such as propylene oxide and ethylene oxide with these compounds, and polymethylene polyphenyl polyisocyanate, also called polymeric MDI.
- polyisocyanate compounds containing aromatic groups are preferred from the viewpoint of excellent compatibility with the above-mentioned compound (C1) and vinyl monomer polymers having structural units derived from the above-mentioned compound (C1), high reworkability, and high adhesive strength, and among these, modified diphenylmethane diisocyanate compounds such as diphenylmethane diisocyanate and liquid modified diphenylmethane diisocyanate are more preferred.
- modified diphenylmethane diisocyanate compounds such as diphenylmethane diisocyanate and liquid modified diphenylmethane diisocyanate are more preferred.
- These polyisocyanate compounds may be used alone or in combination of two or more.
- the polyisocyanate compound preferably contains an isocyanate compound having three or more isocyanate groups.
- the preferred lower limit of the content ratio of the structural unit derived from an isocyanate compound having 3 or more isocyanate groups in the urethane polymer is 0.1% by mass, and the preferred upper limit is 20% by mass.
- the pressure-sensitive adhesive obtained from the pressure-sensitive adhesive composition of the present invention can achieve both higher adhesive strength and better reworkability.
- the more preferred lower limit is 0.5% by mass, and the more preferred upper limit is 10% by mass.
- the urethane polymer preferably has a structural unit derived from an aromatic group-containing compound.
- the urethane polymer has a structural unit derived from an aromatic group-containing compound, the reworkability of the pressure-sensitive adhesive of the present invention is further improved.
- the aromatic group-containing compound include the above-mentioned polyol compounds containing an aromatic group and the above-mentioned polyisocyanate compounds containing an aromatic group.
- the preferred lower limit of the weight-average molecular weight (Mw) of the urethane polymer is 3,000, and the preferred upper limit is 300,000.
- Mw weight-average molecular weight
- the reworkability of the pressure-sensitive adhesive of the present invention is further improved.
- the weight-average molecular weight of the urethane polymer is 300,000 or less, the adhesive strength of the pressure-sensitive adhesive obtained from the pressure-sensitive adhesive composition of the present invention is further improved.
- a more preferred lower limit of the weight-average molecular weight of the urethane polymer is 5,000, a more preferred upper limit is 250,000, an even more preferred lower limit is 7,000, and an even more preferred upper limit is 200,000.
- the preferred lower limit of the content of the urethane polymer in 100 parts by mass of the total of the vinyl monomer polymer and the urethane polymer is 5 parts by mass, and the preferred upper limit is 90 parts by mass.
- the content of the urethane polymer being within the above range, the pressure-sensitive adhesive obtained from the pressure-sensitive adhesive composition of the present invention can achieve both higher adhesive strength and better reworkability.
- the more preferred lower limit of the content of the urethane polymer is 10 parts by mass
- the more preferred upper limit is 70 parts by mass
- the even more preferred lower limit is 15 parts by mass
- the even more preferred upper limit is 60 parts by mass.
- the crosslinking agent when the urethane polymer and the vinyl monomer polymer in the crosslinked product are crosslinked by a crosslinking agent, examples of the crosslinking agent include an isocyanate-based crosslinking agent, an aziridine-based crosslinking agent, an epoxy-based crosslinking agent, and a metal chelate-type crosslinking agent.
- an isocyanate-based crosslinking agent is preferred because it can selectively crosslink hydroxyl groups and is easy to control the crosslinked structure.
- isocyanate-based crosslinking agent examples include Coronate HX and Millionate MR200 (both manufactured by Tosoh Corporation).
- the preferred lower limit of the content of the crosslinking agent in the total of the adhesive composition and the crosslinker is 0.1 mass %, and the preferred upper limit is 20 mass %.
- the content of the crosslinking agent is 0.1 mass % or more, the adhesive can be cured more, and the reworkability of the adhesive obtained from the adhesive composition of the present invention is further improved.
- the content of the crosslinking agent is 20 mass % or less, the adhesive obtained from the adhesive composition of the present invention does not become too hard, and the adhesive tape of the present invention can exhibit higher adhesive strength.
- the pressure-sensitive adhesive composition of the present invention may further contain a tackifier resin.
- a tackifier resin By containing a tackifier resin, the pressure-sensitive adhesive composition of the present invention has improved adhesive strength.
- the tackifier resin in the pressure-sensitive adhesive composition of the present invention may be, for example, a rosin-based resin such as a rosin ester-based resin, a terpene-based resin such as a terpene phenol resin, or a petroleum-based resin.
- a rosin-based resin such as a rosin ester-based resin
- a terpene-based resin such as a terpene phenol resin
- a petroleum-based resin rosin-based resins and terpene phenol resins are preferred because they have relatively high polarity and excellent compatibility with the vinyl monomer polymer and the urethane polymer.
- These tackifier resins may be used alone or in combination of two or more.
- the rosin ester resin in the pressure-sensitive adhesive composition of the present invention is a resin obtained by esterifying a rosin resin mainly composed of abietic acid, a disproportionated rosin resin, a hydrogenated rosin resin, a dimer of a resin acid such as abietic acid (polymerized rosin resin), etc., with an alcohol.
- a part of the hydroxyl group of the alcohol used for esterification is not used for esterification and is contained in the resin, so that the hydroxyl value is adjusted to the above-mentioned range.
- the alcohol include polyhydric alcohols such as ethylene glycol, glycerin, and pentaerythritol.
- a resin obtained by esterifying a rosin resin is a rosin ester resin
- a resin obtained by esterifying a disproportionated rosin resin is a disproportionated rosin ester resin
- a resin obtained by esterifying a hydrogenated rosin resin is a hydrogenated rosin ester resin
- a resin obtained by esterifying a polymerized rosin resin is a polymerized rosin ester resin.
- the terpene phenol resin in the pressure-sensitive adhesive composition of the present invention is a resin obtained by polymerizing terpene in the presence of phenol.
- the preferred lower limit of the content of the tackifier resin in the adhesive composition of the present invention is 1 mass%, and the preferred upper limit is 60 mass%.
- the adhesive obtained from the adhesive composition of the present invention can exhibit higher adhesive strength.
- the content of the tackifier resin is 60 mass% or less, the adhesive strength of the adhesive obtained from the adhesive composition of the present invention is not too high, and the reworkability of the adhesive obtained from the adhesive composition of the present invention is further improved.
- a more preferred lower limit of the content of the tackifier resin is 3 mass%, a more preferred upper limit is 50 mass%, an even more preferred lower limit is 5 mass%, and an even more preferred upper limit is 40 mass%.
- the pressure-sensitive adhesive composition of the present invention may further contain additives such as silane coupling agents, plasticizers, softeners, fillers, pigments, dyes, etc., as necessary, within the scope of the invention's effects.
- additives such as silane coupling agents, plasticizers, softeners, fillers, pigments, dyes, etc., as necessary, within the scope of the invention's effects.
- the pressure-sensitive adhesive composition of the present invention also includes a pressure-sensitive adhesive containing the crosslinked product of the vinyl monomer polymer and the urethane polymer.
- the adhesive of the present invention contains the crosslinked product of the urethane polymer and the vinyl monomer polymer in the adhesive composition, and the crosslinked product has a urethane polymer structure, which makes the adhesive of the present invention excellent in reworkability, while the crosslinked product has a vinyl monomer polymer structure, which makes the adhesive of the present invention high in adhesion.
- the crosslinked product has a structure in which the vinyl monomer polymer structure and the urethane polymer structure are crosslinked, so the adhesive becomes hard and the reworkability is improved.
- the adhesive of the present invention can achieve both high adhesion and excellent reworkability.
- the vinyl monomer polymer and the urethane polymer in the pressure-sensitive adhesive composition may be crosslinked with a crosslinking agent or may be crosslinked with a polymerization initiator.
- the vinyl monomer polymer and the urethane polymer are crosslinked with a crosslinking agent.
- the method for producing the pressure-sensitive adhesive is not particularly limited, and the pressure-sensitive adhesive can be produced by a conventionally known method, etc.
- the pressure-sensitive adhesive can be produced by adding a crosslinking agent to a pressure-sensitive adhesive composition obtained by adding a urethane polymer, a vinyl monomer polymer, or the compound (C1), and optionally a tackifier resin, etc., to a solvent, and then thoroughly stirring the mixture.
- an adhesive tape that combines high adhesive strength and excellent reworkability.
- an adhesive composition that can combine high adhesive strength and excellent reworkability.
- an adhesive obtained from the adhesive composition it is possible to provide an adhesive obtained from the adhesive composition.
- polycarbonate-based polyurethane U2 was obtained in the same manner as in the polycarbonate-based polyurethane U1, except that diphenylmethane diisocyanate (manufactured by Nisso Shoji Co., Ltd., "Pure MDI") was used in an amount of 23.5 parts by mass.
- the weight average molecular weight of the obtained polycarbonate-based polyurethane U2 was 70,000.
- polyester-based polyurethane U3 was obtained in the same manner as in the polycarbonate-based polyurethane U1, except that 100 parts by mass of polyester diol (manufactured by Ube Industries, Ltd., "Ethanacole 3010") was used as the polyol compound. The weight average molecular weight of the obtained polyester-based polyurethane U3 was 17,000.
- a polyether-based polyurethane U4 was obtained in the same manner as in the polycarbonate-based polyurethane U1, except that 100 parts by mass of polyether diol (manufactured by Hodogaya Chemical Co., Ltd., "PTC-L3500") was used as the polyol compound.
- the weight average molecular weight of the obtained polyether-based polyurethane U4 was 17,000.
- the obtained adhesive compositions were applied to the release-treated surface of a release PET film using an applicator, and the release-treated surface of a release PET film (manufactured by Nippa, "1-E", thickness 50 ⁇ m) was laminated so as to face the coated surface and sealed.
- the obtained coated material was simultaneously irradiated with ultraviolet light having a wavelength of 365 nm and an illuminance of 20 mW/cm 2 and ultraviolet light having a wavelength of 405 nm and an illuminance of 40 mW/cm 2 for 15 seconds using a batch-type UV LED curing device (manufactured by ITEC, "M UVBA") so that the total irradiation amount was 900 mJ/cm 2 , and the adhesive composition was cured.
- a batch-type UV LED curing device manufactured by ITEC, "M UVBA
- a pressure-sensitive adhesive containing a crosslinked product having a vinyl monomer polymer structure and a urethane polymer structure, and a pressure-sensitive adhesive layer containing the pressure-sensitive adhesive and having the thickness shown in Tables 2 to 5 were formed, and the obtained pressure-sensitive adhesive layer was used as a pressure-sensitive adhesive tape.
- the urethane polymers shown in Tables 2 to 5 were added to the resulting solutions containing the acrylic copolymers A, F, G, H, I, and N to obtain solutions containing a pressure-sensitive adhesive composition. Furthermore, the crosslinking agents shown in Tables 2 to 5 were added to the solutions containing the pressure-sensitive adhesive composition, and the resulting solutions of pressure-sensitive adhesive containing crosslinked products having a vinyl monomer polymer structure and a urethane polymer structure were prepared by thoroughly stirring the resulting solutions of pressure-sensitive adhesive. The resulting solutions of pressure-sensitive adhesive were applied to a release PET film having a thickness of 50 ⁇ m so that the thickness after drying would be 100 ⁇ m, and then dried at 110° C.
- a pressure-sensitive adhesive tape having a pressure-sensitive adhesive layer was obtained by overlapping the release-treated surface of a release PET film having a thickness of 38 ⁇ m so as to face the pressure-sensitive adhesive layer formed thereon.
- Examples 1-16 to 1-17 Manufacturing of adhesives and adhesive tapes
- the release PET film was peeled off to expose one side of a pressure-sensitive adhesive layer having the same composition and thickness as in Example 2.
- the exposed pressure-sensitive adhesive layer was attached to one side of a substrate shown in Table 3.
- a similar pressure-sensitive adhesive layer was also attached to the other side of the substrate shown in Table 3 in the same manner to obtain a double-sided pressure-sensitive adhesive tape having a substrate and pressure-sensitive adhesive layers on both sides of the substrate.
- Each adhesive tape obtained in the Examples and Comparative Examples was cut into a flat rectangular shape with a width of 25 mm and a length of 80 mm, and the release PET film on one side (the side not to be measured) of the cut adhesive tape was peeled off, and then a test specimen was prepared by backing it with a 50 ⁇ m thick PET film ("Cosmoshine A4100" manufactured by Toyobo Co., Ltd.).
- the release PET film on the other side (the side to be measured) of the prepared test specimen was peeled off, and the specimen was attached to a SUS plate (a SUS304 plate washed with ethanol and then wiped dry) by one reciprocating motion at a speed of 10 mm/min using a 2 kg rubber roller, and then aged for 24 hours at 23° C. and 50% RH to obtain a measurement sample.
- a SUS plate a SUS304 plate washed with ethanol and then wiped dry
- the obtained measurement samples were subjected to a peel test in accordance with JIS Z0237 using a tensile tester (manufactured by A&D Co., Ltd., "RTI-1310") at 23°C, 50% RH, a peel speed of 300 mm/min, and a peel angle of 180° to obtain the 180° peel strength (N/inch) of the pressure-sensitive adhesive tape against SUS at a peel speed of 300 mm/min at 23°C.
- RTI-1310 tensile tester
- the stress at which the adhesive layer broke was defined as the tensile stress at break (MPa), and the ratio of the length of the long side of the adhesive layer sample at the time the adhesive layer broke to the length of the long side of the adhesive layer sample before the tensile test was defined as the breaking elongation (%).
- the results are shown in Tables 2 to 5.
- the length of the long side of the pressure-sensitive adhesive layer means the distance between the chucks of a tensile tester that grips a sample of the pressure-sensitive adhesive layer in a tensile test.
- a tensile test was performed using a sample of the pressure-sensitive adhesive layer obtained by punching out the pressure-sensitive adhesive layer with a No. 4 dumbbell before laminating it on the substrate.
- the other release PET film of the adhesive tape in the test sample was peeled off to expose the adhesive layer, and the end of the adhesive layer was pulled at an angle of 30° from the horizontal direction at a speed of 300 mm/min to peel off from the SUS plate.
- the reworkability of the adhesive tape was evaluated three times for each sample according to the following criteria. ⁇ : The adhesive tape was peeled off cleanly without breaking during the test all three times. ⁇ : The adhesive tape could be peeled off cleanly without breaking during two tests, but the adhesive tape broke during peeling once. x: The number of tests in which the adhesive tape could be peeled cleanly without breaking was less than two.
- adhesive tapes without a substrate or adhesive tapes with a substrate having sufficient elasticity such as a foam substrate tend to break as the peel angle increases due to stress concentration at the peel point. Therefore, adhesive tapes other than those of Example 1-17, which are adhesive tapes without a substrate or adhesive tapes having a foam substrate as a substrate, have sufficient reworkability even if they are evaluated as " ⁇ ” in the evaluation of "(1) Reworkability of adhesive tape at a peel angle of 30°" as described above, if they are evaluated as “ ⁇ ” or “ ⁇ ” in the evaluation of "(2) Reworkability of adhesive tape at a peel angle of 0°" as described above.
- the adhesive tape of Example 1-17 which is an adhesive tape having a resin film as a substrate, has sufficient reworkability if it is rated as " ⁇ " or " ⁇ " in the above-mentioned "(1) Reworkability of the adhesive tape at a peel angle of 30°", even if it is rated as " ⁇ ” in the above-mentioned "(2) Reworkability of the adhesive tape at a peel angle of 0°".
- the better the evaluation in the above-mentioned "(1) Reworkability of the adhesive tape at a peel angle of 30°" the more excellent the reworkability of the adhesive tape.
- the monomer symbols shown in Table 1 represent the following: BA: n-butyl acrylate; 2-EHA: 2-ethylhexyl acrylate; Aac: acrylic acid; HEA: 2-hydroxyethyl acrylate; 4-HBA: 4-hydroxybutyl acrylate; IBOA: isobornyl acrylate; BzA: benzyl acrylate
- an adhesive tape that combines high adhesive strength and excellent reworkability.
- an adhesive composition that can combine high adhesive strength and excellent reworkability.
- an adhesive obtained from the adhesive composition it is possible to provide an adhesive obtained from the adhesive composition.
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Health & Medical Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Adhesive Tapes (AREA)
- Adhesives Or Adhesive Processes (AREA)
Abstract
Description
本発明は、粘着テープに関する。また、本発明は、粘着剤組成物に関する。更に、本発明は該粘着剤組成物から得られる粘着剤に関する。 The present invention relates to an adhesive tape. The present invention also relates to an adhesive composition. The present invention further relates to an adhesive obtained from the adhesive composition.
従来から、電子部品、車輌、住宅及び建材において部品を固定する際に、粘着剤組成物を含有する粘着剤層を有する粘着テープが広く用いられている(例えば、特許文献1~3)。具体的には例えば、携帯電子機器の表面を保護するためのカバーパネルをタッチパネルモジュール又はディスプレイパネルモジュールに接着したり、タッチパネルモジュールとディスプレイパネルモジュールとを接着したりするために粘着テープが用いられている。 Adhesive tapes having an adhesive layer containing an adhesive composition have been widely used to fasten components in electronic components, vehicles, housing, and building materials (e.g., Patent Documents 1 to 3). Specifically, for example, adhesive tapes are used to adhere a cover panel for protecting the surface of a portable electronic device to a touch panel module or a display panel module, or to adhere a touch panel module to a display panel module.
エレクトロニクス分野で用いられる粘着テープには、長期信頼性を発現するための高い粘着力が求められる一方、貼合後に剥離したい場合に、被着体に残渣なく剥離できるリワーク性も同様に求められる。通常、粘着力を向上させるには粘着剤層に含まれる粘着剤を柔軟にして密着性を向上させる必要がある一方、リワーク性を向上させるには粘着剤層に含まれる粘着剤を硬くして、引き剥がし時に粘着剤層が破断しないようにする必要がある。そのため、粘着力とリワーク性を向上するためには、粘着剤の柔らかさと硬さという相反する特性を両立する必要がある。 Adhesive tapes used in the electronics field require high adhesive strength to ensure long-term reliability, but also reworkability, which allows them to be peeled off after application without leaving any residue on the adherend. Normally, to improve adhesive strength, it is necessary to soften the adhesive contained in the adhesive layer to improve adhesion, while to improve reworkability, it is necessary to harden the adhesive contained in the adhesive layer so that the adhesive layer does not break when peeled off. Therefore, to improve both adhesive strength and reworkability, it is necessary to achieve both the contradictory properties of softness and hardness of the adhesive.
本発明は、高い粘着力と優れたリワーク性とを両立する粘着テープを提供することを目的とする。また、本発明は、高い粘着力と優れたリワーク性とを両立して発現できる粘着剤組成物を提供することを目的とする。更に、本発明は、該粘着剤組成物から得られる粘着剤を提供することを目的とする。 The present invention aims to provide an adhesive tape that combines high adhesive strength and excellent reworkability. In addition, the present invention aims to provide an adhesive composition that can combine high adhesive strength and excellent reworkability. Furthermore, the present invention aims to provide an adhesive obtained from the adhesive composition.
本開示1は、粘着剤を含有する粘着剤層を有し、下記の第1の構成、及び、第2の構成からなる群より選択される少なくとも1種の構成を満たす粘着テープである。
第1の構成:上記粘着剤は、ビニルモノマー重合体構造、及び、ウレタンポリマー構造を有する架橋生成物を含有し、上記架橋生成物において上記ビニルモノマー重合体と上記ウレタンポリマーとは、架橋剤によって架橋されており、上記ビニルモノマー重合体は、下記(a)、(b)、又は、(c)から選択される化合物(C1)に由来する構成単位を有する
(a)芳香族基含有(メタ)アクリレートと窒素原子含有(メタ)アクリレート
(b)芳香族基含有(メタ)アクリレートに由来する構成単位及び窒素原子含有(メタ)アクリレートに由来する構成単位を有するポリマー
(c)芳香族基含有(メタ)アクリレートに由来する構成単位を有するポリマーと窒素原子含有(メタ)アクリレートに由来する構成単位を有するポリマー
第2の構成:上記粘着剤層の厚みが、50μm以上であり、上記粘着剤層の23℃における引張破断点応力が、0.50MPa以上であり、上記粘着テープの23℃での剥離速度300mm/minにおけるSUSに対する180°剥離力が、5.0N/inch以上30.0N/inch以下である
本開示2は、上記粘着剤層は、周波数1Hzで測定したときの-10℃以上30℃以下の温度領域における損失正接(tanδ)のピークが1つで、かつ、該損失正接のピークの半値幅が40℃以下であり、上記粘着剤層の25℃におけるせん断貯蔵弾性率(G’)が1.0MPa以下である本開示1の粘着テープである。
本開示3は、上記第1の構成において、上記粘着剤層の厚みが50μm以上であり、上記粘着剤層の23℃における引張破断点応力が、0.50MPa以上であり、上記粘着テープの23℃での剥離速度300mm/minにおけるSUSに対する180°剥離力が、5.0N/inch以上30.0N/inch以下である本開示1又は2の粘着テープである。
本開示4は、上記第2の構成において、上記粘着剤は、ビニルモノマー重合体構造、及び、ウレタンポリマー構造を有する架橋生成物を含有し、上記架橋生成物において上記ビニルモノマー重合体と上記ウレタンポリマーとは、架橋剤によって架橋されており、上記ビニルモノマー重合体は、下記(a)、(b)、又は、(c)から選択される化合物(C1)に由来する構成単位を有する本開示1又は2の粘着テープである。
(a)芳香族基含有(メタ)アクリレートと窒素原子含有(メタ)アクリレート
(b)芳香族基含有(メタ)アクリレートに由来する構成単位及び窒素原子含有(メタ)アクリレートに由来する構成単位を有するポリマー
(c)芳香族基含有(メタ)アクリレートに由来する構成単位を有するポリマーと窒素原子含有(メタ)アクリレートに由来する構成単位を有するポリマー
本開示5は、上記窒素原子含有(メタ)アクリレートが、ウレタン結合含有(メタ)アクリレート及びイミド結合含有(メタ)アクリレートからなる群より選択される少なくとも1種を含む本開示1、2、3又は4の粘着テープである。
本開示6は、上記窒素原子含有(メタ)アクリレートが、ウレタン結合含有(メタ)アクリレートを含む本開示5の粘着テープである。
本開示7は、上記芳香族基含有(メタ)アクリレートに由来する構成単位と上記窒素原子含有(メタ)アクリレートに由来する構成単位との合計100質量部中における上記芳香族基含有(メタ)アクリレートに由来する構成単位の含有量が、5質量部以上95質量部以下である本開示1、2、3、4、5又は6の粘着テープである。
本開示8は、上記ビニルモノマー重合体が、更に、水酸基含有(メタ)アクリレートに由来する構成単位を有する本開示1、2、3、4、5、6又は7の粘着テープである。
本開示9は、上記ビニルモノマー重合体が、更に、アルキル(メタ)アクリレートに由来する構成単位を有する本開示1、2、3、4、5、6、7又は8の粘着テープである。
本開示10は、上記ウレタンポリマーが、ポリエーテルジオールに由来する構成単位、ポリエステルジオールに由来する構成単位、及び、ポリカーボネートジオールに由来する構成単位からなる群より選択される少なくとも1種を有する本開示1、2、3、4、5、6、7、8又は9の粘着テープである。
本開示11は、上記ウレタンポリマーが、ポリエステルジオールに由来する構成単位、及び、ポリカーボネートジオールに由来する構成単位からなる群より選択される少なくとも1種を有する本開示10の粘着テープである。
本開示12は、上記ウレタンポリマーが、ポリカーボネートジオールに由来する構成単位を有する本開示11の粘着テープである。
本開示13は、上記ウレタンポリマーが、芳香族基含有化合物に由来する構成単位を有する本開示1、2、3、4、5、6、7、8、9、10、11又は12の粘着テープである。
本開示14は、上記ビニルモノマー重合体と上記ウレタンポリマーとの合計100質量部中における上記ウレタンポリマーの含有量が、5質量部以上90質量部以下である本開示1、2、3、4、5、6、7、8、9、10、11、12又は13の粘着テープである。
本開示15は、上記粘着剤が、更に、粘着付与樹脂を含有する本開示1、2、3、4、5、6、7、8、9、10、11、12、13又は14の粘着テープである。
本開示16は、上記粘着剤層の23℃における破断伸長率が、300%以上である本開示1、2、3、4、5、6、7、8、9、10、11、12、13、14又は15の粘着テープである。
本開示17は、上記粘着剤層のゲル分率が、30質量%以上99質量%以下である本開示1、2、3、4、5、6、7、8、9、10、11、12、13、14、15又は16の粘着テープである。
本開示18は、上記粘着剤層の23℃におけるヤング率が、0.010MPa以上10MPa以下である本開示1、2、3、4、5、6、7、8、9、10、11、12、13、14、15、16又は17の粘着テープである。
本開示19は、基材を有し、上記基材の少なくとも一方の面に上記粘着剤層を有する本開示1、2、3、4、5、6、7、8、9、10、11、12、13、14、15、16、17又は18の粘着テープである。
本開示20は、上記基材が、発泡体基材を含む本開示19の粘着テープである。
本開示21は、基材を有しない本開示1、2、3、4、5、6、7、8、9、10、11、12、13、14、15、16、17又は18の粘着テープである。
本開示22は、ビニルモノマー重合体、及び、ウレタンポリマーを含有し、上記ビニルモノマー重合体は、下記(a)、(b)、又は、(c)から選択される化合物(C1)に由来する構成単位を有する粘着剤組成物である。
(a)芳香族基含有(メタ)アクリレートと窒素原子含有(メタ)アクリレート
(b)芳香族基含有(メタ)アクリレートに由来する構成単位及び窒素原子含有(メタ)アクリレートに由来する構成単位を有するポリマー
(c)芳香族基含有(メタ)アクリレートに由来する構成単位を有するポリマーと窒素原子含有(メタ)アクリレートに由来する構成単位を有するポリマー
本開示23は、上記窒素原子含有(メタ)アクリレートが、ウレタン結合含有(メタ)アクリレート及びイミド結合含有(メタ)アクリレートからなる群より選択される少なくとも1種を含む本開示22の粘着剤組成物である。
本開示24は、上記窒素原子含有(メタ)アクリレートが、ウレタン結合含有(メタ)アクリレートを含む本開示23の粘着剤組成物である。
本開示25は、上記芳香族基含有(メタ)アクリレートに由来する構成単位と上記窒素原子含有(メタ)アクリレートに由来する構成単位との合計100質量部中における上記芳香族基含有(メタ)アクリレートに由来する構成単位の含有量が、5質量部以上95質量部以下である本開示22、23又は24の粘着剤組成物である。
本開示26は、上記ビニルモノマー重合体が、更に、水酸基含有(メタ)アクリレートに由来する構成単位を有する本開示22、23、24又は25の粘着剤組成物である。
本開示27は、上記ビニルモノマー重合体が、更に、アルキル(メタ)アクリレートに由来する構成単位を有する本開示22、23、24、25又は26の粘着剤組成物である。
本開示28は、上記ウレタンポリマーが、ポリエーテルジオールに由来する構成単位、ポリエステルジオールに由来する構成単位、及び、ポリカーボネートジオールに由来する構成単位からなる群より選択される少なくとも1種を有する本開示22、23、24、25、26又は27の粘着剤組成物である。
本開示29は、上記ウレタンポリマーが、ポリエステルジオールに由来する構成単位、及び、ポリカーボネートジオールに由来する構成単位からなる群より選択される少なくとも1種を有する本開示28の粘着剤組成物である。
本開示30は、上記ウレタンポリマーが、ポリカーボネートジオールに由来する構成単位を有する本開示29の粘着剤組成物である。
本開示31は、上記ウレタンポリマーが、芳香族基含有化合物に由来する構成単位を有する本開示22、23、24、25、26、27、28、29又は30の粘着剤組成物である。
本開示32は、上記ビニルモノマー重合体と上記ウレタンポリマーとの合計100質量部中における上記ウレタンポリマーの含有量が、5質量部以上90質量部以下である本開示22、23、24、25、26、27、28、29、30又は31の粘着剤組成物である。
本開示33は、更に、粘着付与樹脂を含有する本開示22、23、24、25、26、27、28、29、30、31又は32の粘着剤組成物である。
本開示34は、本開示22、23、24、25、26、27、28、29、30、31、32又は33の粘着剤組成物における上記ビニルモノマー重合体と上記ウレタンポリマーとの架橋生成物を含有する粘着剤である。
本開示35は、上記架橋生成物において上記ビニルモノマー重合体と上記ウレタンポリマーとは、架橋剤によって架橋されている本開示34の粘着剤である。
以下、本発明を詳述する。
なお、本発明の粘着テープにおいて、上記第1の構成と上記第2の構成とに共通する事項については、特に指定しないものとして記載する。
The present disclosure 1 is an adhesive tape having an adhesive layer containing an adhesive and satisfying at least one configuration selected from the group consisting of the following first configuration and second configuration.
First configuration: the pressure-sensitive adhesive contains a crosslinked product having a vinyl monomer polymer structure and a urethane polymer structure, and in the crosslinked product, the vinyl monomer polymer and the urethane polymer are crosslinked with a crosslinking agent, and the vinyl monomer polymer has a structural unit derived from a compound (C1) selected from the following (a), (b), or (c): (a) an aromatic group-containing (meth)acrylate and a nitrogen atom-containing (meth)acrylate; (b) a polymer having a structural unit derived from an aromatic group-containing (meth)acrylate and a structural unit derived from a nitrogen atom-containing (meth)acrylate; (c) a polymer having a structural unit derived from an aromatic group-containing (meth)acrylate and a nitrogen atom-containing (meth)acrylate; A polymer having a structural unit derived from a meth)acrylate. Second configuration: The pressure-sensitive adhesive layer has a thickness of 50 μm or more, a tensile stress at break of the pressure-sensitive adhesive layer at 23° C. of 0.50 MPa or more, and a 180° peel strength of the pressure-sensitive adhesive tape from SUS at 23° C. and a peel speed of 300 mm/min of 5.0 N/inch or more and 30.0 N/inch or less. Disclosure 2 is a pressure-sensitive adhesive tape according to Disclosure 1, in which the pressure-sensitive adhesive layer has one peak of loss tangent (tan δ) in a temperature range of -10° C. or more and 30° C. or less when measured at a frequency of 1 Hz, and the half-width of the loss tangent peak is 40° C. or less, and the pressure-sensitive adhesive layer has a shear storage modulus (G') at 25° C. of 1.0 MPa or less.
Disclosure 3 is the pressure-sensitive adhesive tape of Disclosure 1 or 2, wherein, in the first configuration, the thickness of the pressure-sensitive adhesive layer is 50 μm or more, the tensile stress at break of the pressure-sensitive adhesive layer at 23° C. is 0.50 MPa or more, and the 180° peel force of the pressure-sensitive adhesive tape from SUS at a peel speed of 300 mm/min at 23° C. is 5.0 N/inch or more and 30.0 N/inch or less.
The present disclosure 4 is the pressure-sensitive adhesive tape of the present disclosure 1 or 2, wherein in the second configuration, the pressure-sensitive adhesive contains a crosslinked product having a vinyl monomer polymer structure and a urethane polymer structure, and in the crosslinked product, the vinyl monomer polymer and the urethane polymer are crosslinked with a crosslinking agent, and the vinyl monomer polymer has a structural unit derived from a compound (C1) selected from the following (a), (b), or (c):
(a) an aromatic group-containing (meth)acrylate and a nitrogen atom-containing (meth)acrylate; (b) a polymer having a structural unit derived from an aromatic group-containing (meth)acrylate and a structural unit derived from a nitrogen atom-containing (meth)acrylate; (c) a polymer having a structural unit derived from an aromatic group-containing (meth)acrylate and a structural unit derived from a nitrogen atom-containing (meth)acrylate. Disclosure 5 is the pressure-sensitive adhesive tape of Disclosure 1, 2, 3, or 4, wherein the nitrogen atom-containing (meth)acrylate comprises at least one selected from the group consisting of urethane bond-containing (meth)acrylates and imide bond-containing (meth)acrylates.
The present disclosure 6 is the pressure-sensitive adhesive tape of the present disclosure 5, wherein the nitrogen atom-containing (meth)acrylate contains a urethane bond-containing (meth)acrylate.
The present disclosure 7 is a pressure-sensitive adhesive tape according to the present disclosure 1, 2, 3, 4, 5, or 6, in which the content of the structural units derived from the aromatic group-containing (meth)acrylate is 5 parts by mass or more and 95 parts by mass or less per 100 parts by mass of the total of the structural units derived from the aromatic group-containing (meth)acrylate and the structural units derived from the nitrogen atom-containing (meth)acrylate.
The present disclosure 8 is the pressure-sensitive adhesive tape of the present disclosure 1, 2, 3, 4, 5, 6, or 7, wherein the vinyl monomer polymer further has a structural unit derived from a hydroxyl group-containing (meth)acrylate.
The present disclosure 9 is the pressure-sensitive adhesive tape of the present disclosure 1, 2, 3, 4, 5, 6, 7, or 8, wherein the vinyl monomer polymer further has a structural unit derived from an alkyl (meth)acrylate.
The present disclosure 10 is a pressure-sensitive adhesive tape according to the present disclosure 1, 2, 3, 4, 5, 6, 7, 8, or 9, wherein the urethane polymer has at least one selected from the group consisting of a structural unit derived from a polyether diol, a structural unit derived from a polyester diol, and a structural unit derived from a polycarbonate diol.
The present disclosure 11 is the pressure-sensitive adhesive tape of the present disclosure 10, wherein the urethane polymer has at least one selected from the group consisting of a structural unit derived from a polyester diol and a structural unit derived from a polycarbonate diol.
Disclosure 12 is the pressure-sensitive adhesive tape of Disclosure 11, wherein the urethane polymer has a structural unit derived from a polycarbonate diol.
The present disclosure 13 is the pressure-sensitive adhesive tape of the present disclosure 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12, wherein the urethane polymer has a structural unit derived from an aromatic group-containing compound.
The present disclosure 14 is the pressure-sensitive adhesive tape of the present disclosure 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, or 13, wherein the content of the urethane polymer is 5 parts by mass or more and 90 parts by mass or less per 100 parts by mass of the vinyl monomer polymer and the urethane polymer in total.
The present disclosure 15 is the pressure-sensitive adhesive tape of the present disclosure 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, or 14, wherein the pressure-sensitive adhesive further contains a tackifier resin.
The present disclosure 16 is a pressure-sensitive adhesive tape according to the present disclosure 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15, wherein the pressure-sensitive adhesive layer has a breaking elongation at 23° C. of 300% or more.
The present disclosure 17 is the pressure-sensitive adhesive tape of the present disclosure 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, or 16, wherein the pressure-sensitive adhesive layer has a gel fraction of 30 mass% or more and 99 mass% or less.
The present disclosure 18 is the pressure-sensitive adhesive tape of the present disclosure 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, or 17, wherein the pressure-sensitive adhesive layer has a Young's modulus at 23° C. of 0.010 MPa or more and 10 MPa or less.
The present disclosure 19 is the pressure-sensitive adhesive tape of the present disclosure 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, or 18, having a substrate and the pressure-sensitive adhesive layer on at least one surface of the substrate.
Disclosure 20 is the pressure-sensitive adhesive tape of Disclosure 19, wherein the substrate comprises a foam substrate.
The present disclosure 21 is the adhesive tape of the present disclosure 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, or 18, which does not have a substrate.
The present disclosure 22 is a pressure-sensitive adhesive composition containing a vinyl monomer polymer and a urethane polymer, wherein the vinyl monomer polymer has a structural unit derived from a compound (C1) selected from the following (a), (b), or (c):
(a) an aromatic group-containing (meth)acrylate and a nitrogen atom-containing (meth)acrylate; (b) a polymer having a structural unit derived from an aromatic group-containing (meth)acrylate and a structural unit derived from a nitrogen atom-containing (meth)acrylate; (c) a polymer having a structural unit derived from an aromatic group-containing (meth)acrylate and a structural unit derived from a nitrogen atom-containing (meth)acrylate. Disclosure 23 is a pressure-sensitive adhesive composition according to Disclosure 22, wherein the nitrogen atom-containing (meth)acrylate comprises at least one selected from the group consisting of urethane bond-containing (meth)acrylates and imide bond-containing (meth)acrylates.
The present disclosure 24 is the pressure-sensitive adhesive composition according to the present disclosure 23, wherein the nitrogen atom-containing (meth)acrylate contains a urethane bond-containing (meth)acrylate.
The present disclosure 25 is a pressure-sensitive adhesive composition according to the present disclosure 22, 23, or 24, in which the content of the structural units derived from the aromatic group-containing (meth)acrylate is 5 parts by mass or more and 95 parts by mass or less per 100 parts by mass of the total of the structural units derived from the aromatic group-containing (meth)acrylate and the structural units derived from the nitrogen atom-containing (meth)acrylate.
The present disclosure 26 is the pressure-sensitive adhesive composition according to the present disclosure 22, 23, 24, or 25, wherein the vinyl monomer polymer further has a structural unit derived from a hydroxyl group-containing (meth)acrylate.
The present disclosure 27 is the pressure-sensitive adhesive composition according to the present disclosure 22, 23, 24, 25, or 26, wherein the vinyl monomer polymer further has a structural unit derived from an alkyl(meth)acrylate.
The present disclosure 28 is a pressure-sensitive adhesive composition according to the present disclosure 22, 23, 24, 25, 26, or 27, wherein the urethane polymer has at least one selected from the group consisting of a structural unit derived from a polyether diol, a structural unit derived from a polyester diol, and a structural unit derived from a polycarbonate diol.
The present disclosure 29 is a pressure-sensitive adhesive composition according to the present disclosure 28, wherein the urethane polymer has at least one selected from the group consisting of a structural unit derived from a polyester diol and a structural unit derived from a polycarbonate diol.
Disclosure 30 is the pressure-sensitive adhesive composition of Disclosure 29, wherein the urethane polymer has a structural unit derived from a polycarbonate diol.
The present disclosure 31 is the pressure-sensitive adhesive composition according to the present disclosure 22, 23, 24, 25, 26, 27, 28, 29, or 30, wherein the urethane polymer has a structural unit derived from an aromatic group-containing compound.
The present disclosure 32 is a pressure-sensitive adhesive composition according to the present disclosure 22, 23, 24, 25, 26, 27, 28, 29, 30, or 31, wherein the content of the urethane polymer is 5 parts by mass or more and 90 parts by mass or less per 100 parts by mass of the total of the vinyl monomer polymer and the urethane polymer.
The present disclosure 33 is a pressure-sensitive adhesive composition according to the present disclosure 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, or 32, further comprising a tackifier resin.
The present disclosure 34 is a pressure-sensitive adhesive comprising a crosslinked product of the vinyl monomer polymer and the urethane polymer in the pressure-sensitive adhesive composition of the present disclosure 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32 or 33.
Disclosure 35 is the pressure-sensitive adhesive of Disclosure 34, wherein in the crosslinked product, the vinyl monomer polymer and the urethane polymer are crosslinked with a crosslinking agent.
The present invention will be described in detail below.
In the pressure-sensitive adhesive tape of the present invention, matters common to the first configuration and the second configuration will be described without being particularly specified.
本発明者らは、粘着剤を含有する粘着剤層を有する粘着テープについて、粘着剤層の組成、並びに、粘着剤層及び粘着テープの物性について、検討した。
粘着剤層の組成については、特定のウレタンポリマー構造、及び、ビニルモノマー重合体構造を有する架橋生成物を含有する粘着剤を用いることを検討した。更に、当該ビニルモノマー重合体について、芳香族基含有(メタ)アクリレートと窒素原子含有(メタ)アクリレート、芳香族基含有(メタ)アクリレートに由来する構成単位及び窒素原子含有(メタ)アクリレートに由来する構成単位を有するポリマー、又は、芳香族基含有(メタ)アクリレートに由来する構成単位を有するポリマーと窒素原子含有(メタ)アクリレートに由来する構成単位を有するポリマーに由来する構成単位を有するものとすることを検討した。
また、粘着剤層及び粘着テープの物性については、粘着剤層の厚み及び引張破断点応力、並びに、粘着テープのSUSに対する180°剥離力を調整することを検討した。
その結果、高い粘着力と優れたリワーク性とを両立する粘着テープを得ることができることを見出し、本発明を完成させるに至った。
The present inventors have investigated the composition of the adhesive layer of an adhesive tape having an adhesive layer containing an adhesive, as well as the physical properties of the adhesive layer and the adhesive tape.
Regarding the composition of the adhesive layer, it was considered to use an adhesive containing a crosslinked product having a specific urethane polymer structure and a vinyl monomer polymer structure.Furthermore, it was considered to use an adhesive containing an aromatic group-containing (meth)acrylate and a nitrogen atom-containing (meth)acrylate, a polymer having a structural unit derived from an aromatic group-containing (meth)acrylate and a structural unit derived from a nitrogen atom-containing (meth)acrylate, or a polymer having a structural unit derived from an aromatic group-containing (meth)acrylate and a structural unit derived from a nitrogen atom-containing (meth)acrylate, as the vinyl monomer polymer.
Regarding the physical properties of the adhesive layer and the adhesive tape, adjustment of the thickness and tensile stress at break of the adhesive layer, as well as the 180° peel strength of the adhesive tape against SUS were investigated.
As a result, they found that it was possible to obtain an adhesive tape that combines high adhesive strength with excellent reworkability, which led to the completion of the present invention.
本発明の粘着テープは、粘着剤を含有する粘着剤層を有する。
本発明の粘着テープは、下記の第1の構成、及び、第2の構成からなる群より選択される少なくとも1種の構成を満たす。
第1の構成:上記粘着剤は、ビニルモノマー重合体構造、及び、ウレタンポリマー構造を有する架橋生成物を含有し、上記架橋生成物において上記ビニルモノマー重合体と上記ウレタンポリマーとは、架橋剤によって架橋されており、上記ビニルモノマー重合体は、下記(a)、(b)、又は、(c)から選択される化合物(C1)に由来する構成単位を有する
(a)芳香族基含有(メタ)アクリレートと窒素原子含有(メタ)アクリレート
(b)芳香族基含有(メタ)アクリレートに由来する構成単位及び窒素原子含有(メタ)アクリレートに由来する構成単位を有するポリマー
(c)芳香族基含有(メタ)アクリレートに由来する構成単位を有するポリマーと窒素原子含有(メタ)アクリレートに由来する構成単位を有するポリマー
第2の構成:上記粘着剤層の厚みが、50μm以上であり、上記粘着剤層の23℃における引張破断点応力が、0.50MPa以上であり、上記粘着テープの23℃での剥離速度300mm/minにおけるSUSに対する180°剥離力が、5.0N/inch以上30.0N/inch以下である
本発明の粘着テープが上記第1の構成、及び、第2の構成からなる群より選択される少なくとも1種の構成を満たすことにより、本発明の粘着テープは高い粘着力と優れたリワーク性とを両立することができるようになる。
The pressure-sensitive adhesive tape of the present invention has a pressure-sensitive adhesive layer containing a pressure-sensitive adhesive.
The pressure-sensitive adhesive tape of the present invention satisfies at least one constitution selected from the group consisting of the following first constitution and second constitution.
First configuration: the pressure-sensitive adhesive contains a crosslinked product having a vinyl monomer polymer structure and a urethane polymer structure, and in the crosslinked product, the vinyl monomer polymer and the urethane polymer are crosslinked with a crosslinking agent, and the vinyl monomer polymer has a structural unit derived from a compound (C1) selected from the following (a), (b), or (c): (a) an aromatic group-containing (meth)acrylate and a nitrogen atom-containing (meth)acrylate; (b) a polymer having a structural unit derived from an aromatic group-containing (meth)acrylate and a structural unit derived from a nitrogen atom-containing (meth)acrylate; (c) a polymer having a structural unit derived from an aromatic group-containing (meth)acrylate; and a polymer having a structural unit derived from a nitrogen atom-containing (meth)acrylate. Second configuration: the thickness of the pressure-sensitive adhesive layer is 50 μm or more, the tensile stress at break of the pressure-sensitive adhesive layer is 0.50 MPa or more at 23° C., and the 180° peel strength of the pressure-sensitive adhesive tape from SUS at a peel speed of 300 mm/min at 23° C. is 5.0 N/inch or more and 30.0 N/inch or less. When the pressure-sensitive adhesive tape of the present invention satisfies at least one configuration selected from the group consisting of the first configuration and the second configuration, the pressure-sensitive adhesive tape of the present invention can achieve both high adhesive strength and excellent reworkability.
上記第1の構成において、上記粘着剤は、ビニルモノマー重合体構造、及び、ウレタンポリマー構造を有する架橋生成物を含有する。上記第1の構成において、上記粘着剤が上記架橋生成物を含有することにより、上記架橋生成物が有するウレタンポリマー構造によって、本発明の粘着テープはリワーク性に優れ、一方、上記架橋生成物が有するビニルモノマー重合体構造によって、本発明の粘着テープが高い粘着力を有するものになる。また、上記架橋生成物はビニルモノマー重合体構造とウレタンポリマー構造とを架橋している構造であるため、上記粘着剤が硬くなり、本発明の粘着テープのリワーク性が向上する。即ち、上記第1の構成において、上記粘着剤が上記架橋生成物を含有することにより、本発明の粘着テープは高い粘着力と優れたリワーク性とを両立することができるようになる。
また、上記第2の構成において、上記粘着剤は、ビニルモノマー重合体構造、及び、ウレタンポリマー構造を有する架橋生成物を含有することが好ましい。上記第2の構成において、上記粘着剤が上記架橋生成物を含有することにより、上記架橋生成物が有するウレタンポリマー構造によって、本発明の粘着テープはリワーク性により優れ、一方、上記架橋生成物が有するビニルモノマー重合体構造によって、本発明の粘着テープがより高い粘着力を有するものになる。また、上記架橋生成物はビニルモノマー重合体構造とウレタンポリマー構造とを架橋している構造であるため、上記粘着剤がより硬くなり、本発明の粘着テープのリワーク性がより向上する。即ち、上記第2の構成において、上記粘着剤が上記架橋生成物を含有することにより、本発明の粘着テープは、より高い粘着力とより優れたリワーク性とを両立することができるようになる。
In the first configuration, the pressure-sensitive adhesive contains a crosslinked product having a vinyl monomer polymer structure and a urethane polymer structure. In the first configuration, the pressure-sensitive adhesive contains the crosslinked product, and the urethane polymer structure of the crosslinked product makes the pressure-sensitive adhesive tape of the present invention excellent in reworkability, while the vinyl monomer polymer structure of the crosslinked product makes the pressure-sensitive adhesive tape of the present invention have high adhesive strength. In addition, since the crosslinked product has a structure in which the vinyl monomer polymer structure and the urethane polymer structure are crosslinked, the pressure-sensitive adhesive becomes hard, and the reworkability of the pressure-sensitive adhesive tape of the present invention is improved. That is, in the first configuration, the pressure-sensitive adhesive contains the crosslinked product, and the pressure-sensitive adhesive tape of the present invention can achieve both high adhesive strength and excellent reworkability.
In the second configuration, the adhesive preferably contains a crosslinked product having a vinyl monomer polymer structure and a urethane polymer structure. In the second configuration, the adhesive contains the crosslinked product, and the crosslinked product has a urethane polymer structure, which makes the adhesive tape of the present invention more excellent in reworkability, while the crosslinked product has a vinyl monomer polymer structure, which makes the adhesive tape of the present invention have a higher adhesive strength. In addition, since the crosslinked product has a structure in which the vinyl monomer polymer structure and the urethane polymer structure are crosslinked, the adhesive becomes harder, and the reworkability of the adhesive tape of the present invention is further improved. That is, in the second configuration, the adhesive contains the crosslinked product, and the adhesive tape of the present invention can achieve both higher adhesive strength and better reworkability.
上記第1の構成において、上記ビニルモノマー重合体は、下記(a)、(b)、又は、(c)から選択される化合物(C1)に由来する構成単位を有する。
(a)芳香族基含有(メタ)アクリレートと窒素原子含有(メタ)アクリレート
(b)芳香族基含有(メタ)アクリレートに由来する構成単位及び窒素原子含有(メタ)アクリレートに由来する構成単位を有するポリマー
(c)芳香族基含有(メタ)アクリレートに由来する構成単位を有するポリマーと窒素原子含有(メタ)アクリレートに由来する構成単位を有するポリマー
上記化合物(C1)は、ウレタンポリマーとの相溶性に優れるため、上記第1の構成において、上記ビニルモノマー重合体が上記(a)、(b)、又は、(c)から選択される化合物(C1)に由来する構成単位を有することにより、上記ビニルモノマー重合体が後述するウレタンポリマーとの相溶性に優れる。そのため、上記化合物(C1)及び上記化合物(C1)に由来する構成単位を有するビニルモノマー重合体と後述するウレタンポリマーとの架橋が均一に進行するようになる。その結果、上記架橋生成物はビニルモノマー重合体構造とウレタンポリマー構造とを有し、本発明の粘着テープが高い粘着力と優れたリワーク性とを両立することができるようになる。また、上記化合物(C1)と上記ウレタンポリマーとの相溶性が優れることで、上記粘着剤層はミクロ相分離による界面形成を抑制することができ、引張り時に粘着剤層が破断しにくくなる結果、本発明の粘着テープはリワーク性に優れるものとなる。
また、上記第2の構成において、上記ビニルモノマー重合体は、下記(a)、(b)、又は、(c)から選択される化合物(C1)に由来する構成単位を有することが好ましい。
(a)芳香族基含有(メタ)アクリレートと窒素原子含有(メタ)アクリレート
(b)芳香族基含有(メタ)アクリレートに由来する構成単位及び窒素原子含有(メタ)アクリレートに由来する構成単位を有するポリマー
(c)芳香族基含有(メタ)アクリレートに由来する構成単位を有するポリマーと窒素原子含有(メタ)アクリレートに由来する構成単位を有するポリマー
上記化合物(C1)は、ウレタンポリマーとの相溶性に優れるため、上記第2の構成において、上記ビニルモノマー重合体が上記(a)、(b)、又は、(c)から選択される化合物(C1)に由来する構成単位を有することにより、上記ビニルモノマー重合体が後述するウレタンポリマーとの相溶性により優れる。そのため、上記化合物(C1)及び上記化合物(C1)に由来する構成単位を有するビニルモノマー重合体と後述するウレタンポリマーとの架橋がより均一に進行するようになる。その結果、上記架橋生成物はビニルモノマー重合体構造とウレタンポリマー構造とを有し、本発明の粘着テープがより高い粘着力とより優れたリワーク性とを両立することができるようになる。また、上記化合物(C1)と上記ウレタンポリマーとの相溶性が優れることで、上記粘着剤層はミクロ相分離による界面形成をより抑制することができ、引張り時に粘着剤層が破断しにくくなる結果、本発明の粘着テープはリワーク性により優れるものとなる。
なお、本明細書中において、「(メタ)アクリレート」とは、アクリレート又はメタクリレートのことを意味する。
In the first configuration, the vinyl monomer polymer has a structural unit derived from a compound (C1) selected from the following (a), (b), or (c):
(a) aromatic group-containing (meth)acrylate and nitrogen atom-containing (meth)acrylate (b) polymer having a structural unit derived from aromatic group-containing (meth)acrylate and a structural unit derived from nitrogen atom-containing (meth)acrylate (c) polymer having a structural unit derived from aromatic group-containing (meth)acrylate and a structural unit derived from nitrogen atom-containing (meth)acrylate The compound (C1) has excellent compatibility with urethane polymers, so that in the first configuration, the vinyl monomer polymer has a structural unit derived from the compound (C1) selected from (a), (b), or (c), and thus the vinyl monomer polymer has excellent compatibility with the urethane polymer described below. Therefore, the crosslinking between the vinyl monomer polymer having the structural unit derived from the compound (C1) and the compound (C1) and the urethane polymer described below proceeds uniformly. As a result, the crosslinked product has a vinyl monomer polymer structure and a urethane polymer structure, and the pressure-sensitive adhesive tape of the present invention can achieve both high adhesion and excellent reworkability. In addition, since the compatibility between the compound (C1) and the urethane polymer is excellent, the pressure-sensitive adhesive layer can suppress interface formation due to microphase separation, making the pressure-sensitive adhesive layer less likely to break when pulled, and as a result, the pressure-sensitive adhesive tape of the present invention has excellent reworkability.
In the second configuration, the vinyl monomer polymer preferably has a structural unit derived from a compound (C1) selected from the following (a), (b), or (c):
(a) aromatic group-containing (meth)acrylate and nitrogen atom-containing (meth)acrylate (b) polymer having a structural unit derived from aromatic group-containing (meth)acrylate and a structural unit derived from nitrogen atom-containing (meth)acrylate (c) polymer having a structural unit derived from aromatic group-containing (meth)acrylate and a structural unit derived from nitrogen atom-containing (meth)acrylate The compound (C1) has excellent compatibility with urethane polymers, so that in the second configuration, the vinyl monomer polymer has a structural unit derived from the compound (C1) selected from the above (a), (b), or (c), and thus the vinyl monomer polymer has better compatibility with the urethane polymer described below. Therefore, the crosslinking between the vinyl monomer polymer having the structural unit derived from the compound (C1) and the compound (C1) and the urethane polymer described below proceeds more uniformly. As a result, the crosslinked product has a vinyl monomer polymer structure and a urethane polymer structure, and the pressure-sensitive adhesive tape of the present invention can achieve both higher adhesion and better reworkability. In addition, since the compatibility between the compound (C1) and the urethane polymer is excellent, the pressure-sensitive adhesive layer can further suppress interface formation due to microphase separation, making the pressure-sensitive adhesive layer less likely to break when pulled, and as a result, the pressure-sensitive adhesive tape of the present invention has excellent reworkability.
In this specification, the term "(meth)acrylate" means acrylate or methacrylate.
上記芳香族基含有(メタ)アクリレートとしては、例えば、ベンジルアクリレート、フェノキシエチル(メタ)アクリレート、フェノキシジエチレングリコールアクリレート、メチルフェノキシエチルアクリレート、2-ヒドロキシ-3-フェノキシプロピルアクリレート、2-([1,1’―ビフェニル]-2-イルオキシ)エチル(メタ)アクリレート等が挙げられる。なかでも、粘着特性の観点から、フェノキシエチル(メタ)アクリレート、フェノキシジエチレングリコールアクリレートが好ましい。 Examples of the aromatic group-containing (meth)acrylate include benzyl acrylate, phenoxyethyl (meth)acrylate, phenoxydiethylene glycol acrylate, methylphenoxyethyl acrylate, 2-hydroxy-3-phenoxypropyl acrylate, 2-([1,1'-biphenyl]-2-yloxy)ethyl (meth)acrylate, etc. Among these, from the viewpoint of adhesive properties, phenoxyethyl (meth)acrylate and phenoxydiethylene glycol acrylate are preferred.
上記ビニルモノマー重合体全体中における上記芳香族基含有(メタ)アクリレートに由来する構成単位の含有割合の好ましい下限は5質量%であり、好ましい上限は95質量%である。上記芳香族基含有(メタ)アクリレートに由来する構成単位の含有割合が5質量%以上であることにより、上記粘着剤がより硬くなるため、リワーク性がより向上する。上記芳香族基含有(メタ)アクリレートに由来する構成単位の含有割合が95質量%以下であることにより、上記粘着剤が硬くなりすぎず、本発明の粘着テープはより高い粘着力を発揮できるようになる。上記芳香族基含有(メタ)アクリレートに由来する構成単位の含有割合のより好ましい下限は10質量%、より好ましい上限は90質量%、更に好ましい下限は15質量%、更に好ましい上限は85質量%である。 The preferred lower limit of the content of the constituent units derived from the aromatic group-containing (meth)acrylate in the entire vinyl monomer polymer is 5% by mass, and the preferred upper limit is 95% by mass. When the content of the constituent units derived from the aromatic group-containing (meth)acrylate is 5% by mass or more, the adhesive becomes harder, and the reworkability is further improved. When the content of the constituent units derived from the aromatic group-containing (meth)acrylate is 95% by mass or less, the adhesive does not become too hard, and the adhesive tape of the present invention can exhibit higher adhesive strength. The more preferred lower limit of the content of the constituent units derived from the aromatic group-containing (meth)acrylate is 10% by mass, the more preferred upper limit is 90% by mass, the even more preferred lower limit is 15% by mass, and the even more preferred upper limit is 85% by mass.
上記窒素原子含有(メタ)アクリレートとしては、例えば、ウレタン結合含有(メタ)アクリレート、イミド結合含有(メタ)アクリレート、(メタ)アクリルアミド等が挙げられる。なかでも、後述するウレタンポリマーとの相溶性により優れる観点から、上記窒素原子含有(メタ)アクリレートは、ウレタン結合含有(メタ)アクリレート及びイミド結合含有(メタ)アクリレートからなる群より選択される少なくとも1種を含むことが好ましく、ウレタン結合含有(メタ)アクリレートを含むことがより好ましい。 The nitrogen atom-containing (meth)acrylate may, for example, be a urethane bond-containing (meth)acrylate, an imide bond-containing (meth)acrylate, or a (meth)acrylamide. In particular, from the viewpoint of having better compatibility with the urethane polymer described below, the nitrogen atom-containing (meth)acrylate preferably contains at least one selected from the group consisting of a urethane bond-containing (meth)acrylate and an imide bond-containing (meth)acrylate, and more preferably contains a urethane bond-containing (meth)acrylate.
上記ウレタン結合含有(メタ)アクリレートとしては、例えば、1,2-エタンジオール1-アクリラート2-(N-ブチルカルバマート)等が挙げられる。
上記イミド結合含有(メタ)アクリレートとしては、例えば、N-[2-(アクリロイルオキシ)エチル]フタルイミド等が挙げられる。
Examples of the urethane bond-containing (meth)acrylate include 1,2-ethanediol 1-acrylate 2-(N-butylcarbamate).
The imide bond-containing (meth)acrylate may, for example, be N-[2-(acryloyloxy)ethyl]phthalimide.
上記ビニルモノマー重合体全体中における上記窒素原子含有(メタ)アクリレートに由来する構成単位の含有割合の好ましい下限は5質量%であり、好ましい上限は95質量%である。上記窒素原子含有(メタ)アクリレートに由来する構成単位の含有割合が5質量%以上であることにより、上記粘着剤がより硬くなるため、本発明の粘着テープのリワーク性がより向上する。上記窒素原子含有(メタ)アクリレートに由来する構成単位の含有割合が95質量%以下であることにより、上記粘着剤が硬くなりすぎず、本発明の粘着テープはより高い粘着力を発揮できるようになる。上記窒素原子含有(メタ)アクリレートに由来する構成単位の含有割合のより好ましい下限は10質量%、より好ましい上限は90質量%、更に好ましい下限は15質量%、更に好ましい上限は85質量%である。 The preferred lower limit of the content ratio of the constituent units derived from the nitrogen atom-containing (meth)acrylate in the entire vinyl monomer polymer is 5% by mass, and the preferred upper limit is 95% by mass. When the content ratio of the constituent units derived from the nitrogen atom-containing (meth)acrylate is 5% by mass or more, the adhesive becomes harder, and the reworkability of the adhesive tape of the present invention is further improved. When the content ratio of the constituent units derived from the nitrogen atom-containing (meth)acrylate is 95% by mass or less, the adhesive does not become too hard, and the adhesive tape of the present invention can exhibit higher adhesive strength. The more preferred lower limit of the content ratio of the constituent units derived from the nitrogen atom-containing (meth)acrylate is 10% by mass, the more preferred upper limit is 90% by mass, the even more preferred lower limit is 15% by mass, and the even more preferred upper limit is 85% by mass.
上記芳香族基含有(メタ)アクリレートに由来する構成単位と上記窒素原子含有(メタ)アクリレートに由来する構成単位との合計100質量部中における上記芳香族基含有(メタ)アクリレートに由来する構成単位の含有量の好ましい下限は5質量部であり、好ましい上限は95質量部である。上記芳香族基含有(メタ)アクリレートに由来する構成単位の含有量が上記範囲内であることにより、上記化合物(C1)及び上記化合物(C1)に由来する構成単位を有するビニルモノマー重合体が後述するウレタンポリマーとの相溶性により優れるようになるため、本発明の粘着テープがより高い粘着力とより優れたリワーク性とを両立することができるようになる。上記芳香族基含有(メタ)アクリレートに由来する構成単位の含有量のより好ましい下限は10質量部、より好ましい上限は90質量部、更に好ましい下限は15質量部、更に好ましい上限は85質量部である。 The preferred lower limit of the content of the structural unit derived from the aromatic group-containing (meth)acrylate in the total of 100 parts by mass of the structural unit derived from the aromatic group-containing (meth)acrylate and the structural unit derived from the nitrogen atom-containing (meth)acrylate is 5 parts by mass, and the preferred upper limit is 95 parts by mass. When the content of the structural unit derived from the aromatic group-containing (meth)acrylate is within the above range, the vinyl monomer polymer having the structural unit derived from the compound (C1) and the compound (C1) has better compatibility with the urethane polymer described below, so that the adhesive tape of the present invention can achieve both higher adhesive strength and better reworkability. The more preferred lower limit of the content of the structural unit derived from the aromatic group-containing (meth)acrylate is 10 parts by mass, the more preferred upper limit is 90 parts by mass, the even more preferred lower limit is 15 parts by mass, and the even more preferred upper limit is 85 parts by mass.
上記ビニルモノマー重合体は、更に、水酸基含有(メタ)アクリレートに由来する構成単位を有することが好ましい。
上記ビニルモノマー重合体が水酸基含有(メタ)アクリレートに由来する構成単位を有することにより、後述する架橋剤による上記化合物(C1)及び上記化合物(C1)に由来する構成単位を有するビニルモノマー重合体がと後述するウレタンポリマーとの架橋がより進行しやすくなる。その結果、上記粘着剤がより硬化し破断強度がより向上するため、本発明の粘着テープのリワーク性がより向上する。
なお、本明細書中において、芳香族基と水酸基とを含有する(メタ)アクリレートに由来する構成単位は、芳香族基含有(メタ)アクリレートに由来する構成単位とする。
また、本明細書中において、窒素原子と水酸基とを含有する(メタ)アクリレートに由来する構成単位は、窒素原子含有(メタ)アクリレートに由来する構成単位とする。
The vinyl monomer polymer preferably further contains a structural unit derived from a hydroxyl group-containing (meth)acrylate.
The vinyl monomer polymer has a structural unit derived from a hydroxyl group-containing (meth)acrylate, and thus crosslinking between the compound (C1) and the vinyl monomer polymer having a structural unit derived from the compound (C1) and the urethane polymer described below by a crosslinking agent described below is facilitated. As a result, the pressure-sensitive adhesive is further cured and the breaking strength is further improved, and the reworkability of the pressure-sensitive adhesive tape of the present invention is further improved.
In this specification, a structural unit derived from a (meth)acrylate containing an aromatic group and a hydroxyl group is referred to as a structural unit derived from an aromatic group-containing (meth)acrylate.
In this specification, a structural unit derived from a (meth)acrylate containing a nitrogen atom and a hydroxyl group is referred to as a structural unit derived from a nitrogen-atom-containing (meth)acrylate.
上記水酸基含有(メタ)アクリレートとしては、例えば、2-ヒドロキシエチル(メタ)アクリレート、4-ヒドロキシブチル(メタ)アクリレート、3-ヒドロキシプロピル(メタ)アクリレート、テトラヒドロキシフルフリル(メタ)アクリレート等が挙げられる。 Examples of the hydroxyl group-containing (meth)acrylate include 2-hydroxyethyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, and tetrahydroxyfurfuryl (meth)acrylate.
上記ビニルモノマー重合体全体中における上記水酸基含有(メタ)アクリレートに由来する構成単位の含有割合の好ましい下限は0.01質量%であり、好ましい上限は20質量%である。上記水酸基含有(メタ)アクリレートに由来する構成単位の含有割合が0.01質量%以上であることにより、本発明の粘着テープのリワーク性がより向上する。上記水酸基含有(メタ)アクリレートに由来する構成単位の含有割合が20質量%以下であることにより、上記粘着剤が硬くなりすぎず、本発明の粘着テープがより高い粘着力を発揮できるようになる。上記水酸基含有(メタ)アクリレートに由来する構成単位の含有割合のより好ましい下限は0.1質量%、より好ましい上限は10質量%、更に好ましい下限は0.5質量%、更に好ましい上限は5.0質量%である。 The preferred lower limit of the content of the structural unit derived from the hydroxyl group-containing (meth)acrylate in the entire vinyl monomer polymer is 0.01% by mass, and the preferred upper limit is 20% by mass. When the content of the structural unit derived from the hydroxyl group-containing (meth)acrylate is 0.01% by mass or more, the reworkability of the adhesive tape of the present invention is further improved. When the content of the structural unit derived from the hydroxyl group-containing (meth)acrylate is 20% by mass or less, the adhesive does not become too hard, and the adhesive tape of the present invention can exhibit higher adhesive strength. The more preferred lower limit of the content of the structural unit derived from the hydroxyl group-containing (meth)acrylate is 0.1% by mass, the more preferred upper limit is 10% by mass, the even more preferred lower limit is 0.5% by mass, and the even more preferred upper limit is 5.0% by mass.
上記ビニルモノマー重合体は、更に、アルキル(メタ)アクリレートに由来する構成単位を有していてもよい。 The vinyl monomer polymer may further have a structural unit derived from an alkyl (meth)acrylate.
上記アルキル(メタ)アクリレートとしては、例えば、メチル(メタ)アクリレート、エチル(メタ)アクリレート、n-プロピル(メタ)アクリレート、イソプロピル(メタ)アクリレート、n-ブチル(メタ)アクリレート、n-ヘプチル(メタ)アクリレート、2-エチルヘキシル(メタ)アクリレート、2-オクチル(メタ)アクリレート、イソオクチル(メタ)アクリレート、n-ノニル(メタ)アクリレート、イソノニル(メタ)アクリレート、ラウリル(メタ)アクリレート、ミリスチル(メタ)アクリレート、セチル(メタ)アクリレート、イソステアリルアクリレート、アラキジル(メタ)アクリレート等が挙げられる。なかでも、後述するウレタンポリマーとの相溶性の観点から、アルキル鎖長の短いアルキル(メタ)アクリレートが好ましく、具体的にはn-ブチル(メタ)アクリレート、2-エチルヘキシル(メタ)アクリレートが好ましい。 Examples of the alkyl (meth)acrylate include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, n-heptyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, 2-octyl (meth)acrylate, isooctyl (meth)acrylate, n-nonyl (meth)acrylate, isononyl (meth)acrylate, lauryl (meth)acrylate, myristyl (meth)acrylate, cetyl (meth)acrylate, isostearyl acrylate, and arachidyl (meth)acrylate. Among these, from the viewpoint of compatibility with the urethane polymer described below, alkyl (meth)acrylates with short alkyl chain lengths are preferred, specifically n-butyl (meth)acrylate and 2-ethylhexyl (meth)acrylate.
上記ビニルモノマー重合体は、更に、上記芳香族基含有(メタ)アクリレートに由来する構成単位、上記窒素原子含有(メタ)アクリレートに由来する構成単位、上記水酸基含有(メタ)アクリレートに由来する構成単位、及び、上記アルキル(メタ)アクリレートに由来する構成単位以外のその他のモノマーに由来する構成単位を有していてもよい。 The vinyl monomer polymer may further have a structural unit derived from the aromatic group-containing (meth)acrylate, a structural unit derived from the nitrogen atom-containing (meth)acrylate, a structural unit derived from the hydroxyl group-containing (meth)acrylate, and a structural unit derived from a monomer other than the structural unit derived from the alkyl (meth)acrylate.
上記ビニルモノマー重合体が上記(b)に由来する構成単位を有する場合、上記芳香族基含有(メタ)アクリレートに由来する構成単位及び窒素原子含有(メタ)アクリレートに由来する構成単位を有するポリマーの重量平均分子量(Mw)の好ましい下限は20万であり、好ましい上限は200万である。上記芳香族基含有(メタ)アクリレートに由来する構成単位及び窒素原子含有(メタ)アクリレートに由来する構成単位を有するポリマーの重量平均分子量が20万以上であることにより、本発明の粘着テープのリワーク性がより向上する。上記芳香族基含有(メタ)アクリレートに由来する構成単位及び窒素原子含有(メタ)アクリレートに由来する構成単位を有するポリマーの重量平均分子量が200万以下であることにより、本発明の粘着テープの粘着力がより向上する。上記芳香族基含有(メタ)アクリレートに由来する構成単位及び窒素原子含有(メタ)アクリレートに由来する構成単位を有するポリマーの重量平均分子量のより好ましい下限は40万、より好ましい上限は150万、更に好ましい下限は60万、更に好ましい上限は100万である。 When the vinyl monomer polymer has a structural unit derived from (b), the weight average molecular weight (Mw) of the polymer having a structural unit derived from the aromatic group-containing (meth)acrylate and a structural unit derived from the nitrogen atom-containing (meth)acrylate is preferably 200,000 in lower limit and 2,000,000 in upper limit. When the weight average molecular weight of the polymer having a structural unit derived from the aromatic group-containing (meth)acrylate and a structural unit derived from the nitrogen atom-containing (meth)acrylate is 200,000 or more, the reworkability of the adhesive tape of the present invention is further improved. When the weight average molecular weight of the polymer having a structural unit derived from the aromatic group-containing (meth)acrylate and a structural unit derived from the nitrogen atom-containing (meth)acrylate is 2,000,000 or less, the adhesive strength of the adhesive tape of the present invention is further improved. The weight average molecular weight of the polymer having a structural unit derived from the aromatic group-containing (meth)acrylate and a structural unit derived from the nitrogen atom-containing (meth)acrylate is more preferably 400,000 in lower limit and 1,500,000 in upper limit, more preferably 600,000 in lower limit and even more preferably 1,000,000 in upper limit.
上記ビニルモノマー重合体が上記(c)に由来する構成単位を有する場合、上記芳香族基含有(メタ)アクリレートに由来する構成単位を有するポリマーの重量平均分子量(Mw)の好ましい下限は20万であり、好ましい上限は200万である。上記芳香族基含有(メタ)アクリレートに由来する構成単位を有するポリマーの重量平均分子量が20万以上であることにより、本発明の粘着テープのリワーク性がより向上する。上記芳香族基含有(メタ)アクリレートに由来する構成単位を有するポリマーの重量平均分子量が200万以下であることにより、本発明の粘着テープの粘着力がより向上する。上記芳香族基含有(メタ)アクリレートに由来する構成単位を有するポリマーの重量平均分子量のより好ましい下限は40万、より好ましい上限は150万、更に好ましい下限は60万、更に好ましい上限は100万である。 When the vinyl monomer polymer has a structural unit derived from (c), the weight average molecular weight (Mw) of the polymer having a structural unit derived from the aromatic group-containing (meth)acrylate is preferably 200,000 in lower limit and 2,000,000 in upper limit. When the weight average molecular weight of the polymer having a structural unit derived from the aromatic group-containing (meth)acrylate is 200,000 or more, the reworkability of the adhesive tape of the present invention is further improved. When the weight average molecular weight of the polymer having a structural unit derived from the aromatic group-containing (meth)acrylate is 2,000,000 or less, the adhesive strength of the adhesive tape of the present invention is further improved. The weight average molecular weight of the polymer having a structural unit derived from the aromatic group-containing (meth)acrylate is more preferably 400,000 in lower limit and 1,500,000 in upper limit, even more preferably 600,000 in lower limit and even more preferably 1,000,000 in upper limit.
上記ビニルモノマー重合体が上記(c)に由来する構成単位を有する場合、上記窒素原子含有(メタ)アクリレートに由来する構成単位を有するポリマーの重量平均分子量(Mw)の好ましい下限は20万であり、好ましい上限は200万である。上記窒素原子含有(メタ)アクリレートに由来する構成単位を有するポリマーの重量平均分子量が20万以上であることにより、本発明の粘着テープのリワーク性がより向上する。上記窒素原子含有(メタ)アクリレートに由来する構成単位を有するポリマーの重量平均分子量が200万以下であることにより、本発明の粘着テープの粘着力がより向上する。上記窒素原子含有(メタ)アクリレートに由来する構成単位を有するポリマーの重量平均分子量のより好ましい下限は40万、より好ましい上限は150万、更に好ましい下限は60万、更に好ましい上限は100万である。 When the vinyl monomer polymer has a structural unit derived from (c), the weight average molecular weight (Mw) of the polymer having a structural unit derived from the nitrogen atom-containing (meth)acrylate is preferably 200,000 in lower limit and 2,000,000 in upper limit. When the weight average molecular weight of the polymer having a structural unit derived from the nitrogen atom-containing (meth)acrylate is 200,000 or more, the reworkability of the adhesive tape of the present invention is further improved. When the weight average molecular weight of the polymer having a structural unit derived from the nitrogen atom-containing (meth)acrylate is 2,000,000 or less, the adhesive strength of the adhesive tape of the present invention is further improved. The weight average molecular weight of the polymer having a structural unit derived from the nitrogen atom-containing (meth)acrylate is more preferably 400,000 in lower limit and 1,500,000 in upper limit, even more preferably 600,000 in lower limit and even more preferably 1,000,000 in upper limit.
本明細書中において、重量平均分子量(Mw)とは、ゲルパーミエーションクロマトグラフィー(GPC)測定による標準ポリスチレン換算による重量平均分子量である。具体的には、例えば、測定機器としてWaters社製「2690 Separations Module」、カラムとして昭和電工社製「GPC KF-806L」、溶媒としてテトラヒドロフランを用い、サンプル流量1mL/min、カラム温度40℃の条件で測定することができる。 In this specification, the weight average molecular weight (Mw) is the weight average molecular weight calculated based on standard polystyrene by gel permeation chromatography (GPC). Specifically, for example, the measurement can be performed using a Waters 2690 Separations Module as the measuring instrument, a Showa Denko GPC KF-806L column, tetrahydrofuran as the solvent, a sample flow rate of 1 mL/min, and a column temperature of 40°C.
上記化合物(C1)が上記(b)又は上記(c)である場合、上記ビニルモノマー重合体を製造する方法としては、例えば、上記芳香族基含有(メタ)アクリレート及び上記窒素原子含有(メタ)アクリレート、必要に応じて上記水酸基含有(メタ)アクリレート、上記アルキル(メタ)アクリレート、上記その他のモノマー等の原料となるモノマー混合物を重合開始剤の存在下にてラジカル反応させて重合すること等によって得ることができる。
また、上記化合物(C1)が上記(a)である場合は、上述した方法により上記ビニルモノマー重合体を製造する方法に加えて、上記モノマー混合物、光重合開始剤、及び、上記ウレタンポリマー等を混合した混合物を、アプリケーターを用いて離型PETフィルムや基材上に塗工し、塗工した上面を離型PETフィルムにて封止又は窒素雰囲気下として塗工面が空気に触れないようにしたうえでUV照射する方法にて重合を行うことにより、ビニルモノマー重合体を得ると同時に粘着剤を得ることもできる。
上記モノマー混合物を重合する方法としては、従来公知の方法を用いることができ、例えば、溶液重合(沸点重合又は定温重合)、UV重合、エマルジョン重合、懸濁重合、塊状重合等が挙げられる。なかでも、得られる粘着テープの粘着力がより高くなることから、溶液重合、UV重合が好ましい。
上記モノマー混合物を重合する方法として溶液重合を用いる場合、反応溶剤としては、例えば、酢酸エチル、トルエン、メチルエチルケトン、ジメチルスルホキシド、エタノール、アセトン、ジエチルエーテル等が挙げられる。これらの反応溶剤は、単独で用いられてもよいし、2種以上が組み合わせて用いられてもよい。
When the compound (C1) is the compound (b) or (c), the vinyl monomer polymer can be produced, for example, by polymerizing a monomer mixture serving as raw materials, such as the aromatic group-containing (meth)acrylate and the nitrogen atom-containing (meth)acrylate, and, if necessary, the hydroxyl group-containing (meth)acrylate, the alkyl (meth)acrylate, and the other monomers, through a radical reaction in the presence of a polymerization initiator.
Furthermore, when the compound (C1) is the compound (a), in addition to the method for producing the vinyl monomer polymer by the method described above, a mixture of the monomer mixture, photopolymerization initiator, and the urethane polymer, etc., can be applied to a release PET film or a substrate using an applicator, and the upper surface of the applied film is sealed with a release PET film or placed under a nitrogen atmosphere to prevent the coated surface from coming into contact with air, and then UV irradiation is performed to polymerize the mixture, thereby obtaining a vinyl monomer polymer and a pressure-sensitive adhesive at the same time.
The method for polymerizing the monomer mixture may be a conventionally known method, such as solution polymerization (boiling point polymerization or constant temperature polymerization), UV polymerization, emulsion polymerization, suspension polymerization, bulk polymerization, etc. Among these, solution polymerization and UV polymerization are preferred because the adhesive strength of the resulting adhesive tape is higher.
When solution polymerization is used as a method for polymerizing the monomer mixture, examples of the reaction solvent include ethyl acetate, toluene, methyl ethyl ketone, dimethyl sulfoxide, ethanol, acetone, diethyl ether, etc. These reaction solvents may be used alone or in combination of two or more kinds.
上記重合開始剤としては、例えば、溶液重合する場合は、アゾ化合物、有機過酸化物等が挙げられ、UV重合する場合は、ベンゾフェノン系化合物、アセトフェノン系化合物、アルキルフェノン系化合物、アシルフォスフィンオキサイド系化合物、チタノセン系化合物、オキシムエステル系化合物、ベンゾインエーテル系化合物、チオキサントン等の光重合開始剤等が挙げられる。
上記アゾ化合物としては、例えば、2,2’-アゾビス(イソブチロニトリル)、2,2’-アゾビス(2-メチルブチロニトリル)、2,2’-アゾビス(2,4-ジメチルバレロニトリル)、2,2’-アゾビス(4-メトキシ-2,4-ジメチルバレロニトリル)、1,1-アゾビス(シクロヘキサン-1-カルボニトリル)、1-((1-シアノ-1-メチルエチル)アゾ)ホルムアミド、4,4’-アゾビス(4-シアノバレリアン酸)、ジメチル-2,2’-アゾビス(2-メチルプロピオネート)、ジメチル-1,1’-アゾビス(1-シクロヘキサンカルボキシレート)、2,2’-アゾビス(2-メチル-N-(1,1’-ビス(ヒドロキシメチル)-2-ヒドロキシエチル)プロピオンアミド)、2,2’-アゾビス(2-メチル-N-(2-ヒドロキシエチル)プロピオンアミド)、2,2’-アゾビス(N-(2-プロペニル)-2-メチルプロピオンアミド)、2,2’-アゾビス(N-ブチル-2-メチルプロピオンアミド)、2,2’-アゾビス(N-シクロヘキシル-2-メチルプロピオンアミド)、2,2’-アゾビス(2-(2-イミダゾリン-2-イル)プロパン)二塩酸塩、2,2’-アゾビス(2-(1-(2-ヒドロキシエチル)-2-イミダゾリン-2-イル)プロパン)二塩酸塩、2,2’-アゾビス(2-(2-イミダゾリン-2-イル)プロパン)、2,2’-アゾビス(2-アミジノプロパン)二塩酸塩、2,2’-アゾビス(N-(2-カルボキシエチル)-2-メチルプロピオンアミジン)四水和物、2,2’-アゾビス(1-イミノ-1-ピロリジノ-2-メチルプロパン)二塩酸塩、2,2’-アゾビス(2,4,4-トリメチルペンタン)等が挙げられる。これらのアゾ化合物は、単独で用いられてもよいし、2種以上が組み合わせて用いられてもよい。
上記有機過酸化物としては、例えば、1,1-ビス(t-ヘキシルパーオキシ)-3,3,5-トリメチルシクロヘキサン、t-ヘキシルパーオキシピバレート、t-ブチルパーオキシピバレート、2,5-ジメチル-2,5-ビス(2-エチルヘキサノイルパーオキシ)ヘキサン、t-ヘキシルパーオキシ-2-エチルヘキサノエート、t-ブチルパーオキシ-2-エチルヘキサノエート、t-ブチルパーオキシイソブチレート、t-ブチルパーオキシ-3,5,5-トリメチルヘキサノエート、t-ブチルパーオキシラウレート等が挙げられる。これらの有機過酸化物は、単独で用いられてもよいし、2種以上が組み合わせて用いられてもよい。
上記光重合開始剤としては、例えば、Omnirad 184、Omnirad 369、Omnirad 379、Omnirad 379EG、Omnirad 651、Omnirad 784、Omnirad 819、Omnirad 907、Omnirad 2959、Omnirad TPO(いずれもIGM Resins社製)、Omnirad OXE01(BASF社製)、ベンゾインメチルエーテル、ベンゾインエチルエーテル、ベンゾインイソプロピルエーテル(いずれも東京化成工業社製)等が挙げられる。これらの光重合開始剤は、単独で用いられてもよいし、2種以上が組み合わせて用いられてもよい。
Examples of the polymerization initiator include, in the case of solution polymerization, azo compounds and organic peroxides, and in the case of UV polymerization, photopolymerization initiators such as benzophenone compounds, acetophenone compounds, alkylphenone compounds, acylphosphine oxide compounds, titanocene compounds, oxime ester compounds, benzoin ether compounds, and thioxanthone can be used.
Examples of the azo compound include 2,2'-azobis(isobutyronitrile), 2,2'-azobis(2-methylbutyronitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), 1,1-azobis(cyclohexane-1-carbonitrile), 1-((1-cyano-1-methylethyl)azo)formamide, 4,4'-azobis(4-cyanovaleric acid), dimethyl-2,2'-azobis(2-methylpropionate), dimethyl-1,1'-azobis(1-cyclohexanecarboxylate), 2,2'-azobis(2-methyl-N-(1,1'-bis(hydroxymethyl)-2-hydroxyethyl)propionamide), 2,2'-azobis(2-methyl-N-(2-hydroxyethyl)propionamide), 2,2 '-Azobis(N-(2-propenyl)-2-methylpropionamide), 2,2'-azobis(N-butyl-2-methylpropionamide), 2,2'-azobis(N-cyclohexyl-2-methylpropionamide), 2,2'-azobis(2-(2-imidazolin-2-yl)propane) dihydrochloride, 2,2'-azobis(2-(1-(2-hydroxyethyl)-2-imidazolin-2-yl)propane) ) dihydrochloride, 2,2'-azobis(2-(2-imidazolin-2-yl)propane), 2,2'-azobis(2-amidinopropane) dihydrochloride, 2,2'-azobis(N-(2-carboxyethyl)-2-methylpropionamidine) tetrahydrate, 2,2'-azobis(1-imino-1-pyrrolidino-2-methylpropane) dihydrochloride, 2,2'-azobis(2,4,4-trimethylpentane), and the like. These azo compounds may be used alone or in combination of two or more.
Examples of the organic peroxides include 1,1-bis(t-hexylperoxy)-3,3,5-trimethylcyclohexane, t-hexylperoxypivalate, t-butylperoxypivalate, 2,5-dimethyl-2,5-bis(2-ethylhexanoylperoxy)hexane, t-hexylperoxy-2-ethylhexanoate, t-butylperoxy-2-ethylhexanoate, t-butylperoxyisobutyrate, t-butylperoxy-3,5,5-trimethylhexanoate, t-butylperoxylaurate, etc. These organic peroxides may be used alone or in combination of two or more.
Examples of the photopolymerization initiator include Omnirad 184, Omnirad 369, Omnirad 379, Omnirad 379EG, Omnirad 651, Omnirad 784, Omnirad 819, Omnirad 907, Omnirad 2959, Omnirad TPO (all manufactured by IGM Resins), Omnirad OXE01 (manufactured by BASF), benzoin methyl ether, benzoin ethyl ether, and benzoin isopropyl ether (all manufactured by Tokyo Chemical Industry Co., Ltd.). These photopolymerization initiators may be used alone or in combination of two or more.
上記ウレタンポリマーは、ポリオール化合物とポリイソシアネート化合物との反応により得られる化合物である。
上記ポリオール化合物が炭素数の少ないポリオールジオールの場合、上記ウレタンポリマーの構成単位として極性が高いハードセグメントが得られる。上記ウレタンポリマーが上記ハードセグメントを含むことにより、得られるウレタンポリマーは水素結合を介する物理架橋によって凝集力がより向上し、本発明の粘着テープのリワーク性がより向上する。
一方、上記ポリオール化合物が炭素数の多いポリオールの場合、上記ウレタンポリマーの構成単位として極性の低いソフトセグメントが得られる。上記ウレタンポリマーが上記ソフトセグメントを含むことにより、得られるウレタンポリマーの変形に対する自由度がより向上する結果、本発明の粘着テープの粘着力がより向上する。
なかでも、上記化合物(C1)及び上記化合物(C1)に由来する構成単位を有するビニルモノマー重合体との相溶性に優れる観点から、上記ウレタンポリマーは上記ハードセグメントを含有することが好ましい。
The urethane polymer is a compound obtained by reacting a polyol compound with a polyisocyanate compound.
When the polyol compound is a polyol diol having a small number of carbon atoms, a hard segment having high polarity is obtained as a constituent unit of the urethane polymer. By including the hard segment in the urethane polymer, the cohesive strength of the obtained urethane polymer is improved by physical crosslinking via hydrogen bonds, and the reworkability of the pressure-sensitive adhesive tape of the present invention is improved.
On the other hand, when the polyol compound is a polyol having a large number of carbon atoms, a soft segment having low polarity is obtained as a constituent unit of the urethane polymer. By including the soft segment in the urethane polymer, the degree of freedom of deformation of the obtained urethane polymer is further improved, and as a result, the adhesive strength of the pressure-sensitive adhesive tape of the present invention is further improved.
In particular, from the viewpoint of excellent compatibility with the compound (C1) and a vinyl monomer polymer having a structural unit derived from the compound (C1), it is preferable that the urethane polymer contains the hard segment.
上記ウレタンポリマーの製造方法は特に限定されないが、例えば、ポリオール化合物とポリイソシアネート化合物とを混合して撹拌すること等によって得られる。なお、ポリオール化合物とポリイソシアネート化合物との反応は、ウレタンポリマーの製造に採用される任意の適切な方法によって行い得る。また、この反応において、必要に応じて、イソシアネート基が反応し得る活性水素を持たない有機溶媒(例えば、酢酸エチル、メチルエチルケトン、クロロホルム等)と、触媒(例えば、スズ塩化物や有機スズ化合物等の有機金属触媒類、3級アミン化合物等の有機塩基類、酢酸やアクリル酸等の有機酸類等)とを加え、反応を行うこともできる。 The method for producing the urethane polymer is not particularly limited, but for example, the urethane polymer can be obtained by mixing and stirring a polyol compound and a polyisocyanate compound. The reaction between the polyol compound and the polyisocyanate compound can be carried out by any suitable method used in the production of urethane polymers. In addition, in this reaction, if necessary, an organic solvent that does not have an active hydrogen with which the isocyanate group can react (e.g., ethyl acetate, methyl ethyl ketone, chloroform, etc.) and a catalyst (e.g., organometallic catalysts such as tin chloride and organotin compounds, organic bases such as tertiary amine compounds, organic acids such as acetic acid and acrylic acid, etc.) can be added to carry out the reaction.
上記ポリオール化合物としては、例えば、ポリエステルポリオール(2価のアルコールとアジピン酸、アゼライン酸、セパチン酸等の2価の塩基酸との重縮合物等)、ポリエーテルポリオール(エチレンオキサイド、テトラヒドロフラン等を付加重合して得られるもの等)、ポリアクリレートポリオール、ポリカーボネートポリオール、ポリオレフィンポリオール、ポリブタジエンポリオール又はその水添物、ポリイソプレンポリオール又はその水添物、フェノーリックポリオール、エポキシポリオール、カプロラクトンポリオール、ポリスルホンポリオール等が挙げられる。また、ポリオール化合物として、ポリエステル・ポリエーテルポリオールのような共重合体ポリオールも挙げられる。
なかでも、得られるウレタンポリマーの極性がより向上し、上記化合物(C1)及び上記化合物(C1)に由来する構成単位を有するビニルモノマー重合体との相溶性に優れる観点から、ポリエーテルジオール、ポリエステルジオール、及び、ポリカーボネートジオールからなる群より選択される少なくとも1種を含むことが好ましい。そのなかでも、凝集力並びに上記化合物(C1)及び上記化合物(C1)に由来する構成単位を有するビニルモノマー重合体との相溶性の観点から、ポリエステルジオール、及び、ポリカーボネートジオールからなる群より選択される1種を含むことがより好ましく、ポリカーボネートジオールを含むことが更に好ましい。即ち、上記ウレタンポリマーは、ポリエーテルジオールに由来する構成単位、ポリエステルジオールに由来する構成単位、及び、ポリカーボネートジオールに由来する構成単位からなる群より選択される少なくとも1種を有することが好ましい。また、上記ウレタンポリマーは、ポリエステルジオールに由来する構成単位、及び、ポリカーボネートジオールに由来する構成単位からなる群より選択される少なくとも1種を有することがより好ましく、上記ウレタンポリマーは、ポリカーボネートジオールに由来する構成単位を有することが更に好ましい。
これらのポリオール化合物は1種のみを用いても、2種以上併用してもよい。
Examples of the polyol compound include polyester polyols (polycondensates of dihydric alcohols and divalent basic acids such as adipic acid, azelaic acid, and sepatic acid), polyether polyols (those obtained by addition polymerization of ethylene oxide, tetrahydrofuran, and the like), polyacrylate polyols, polycarbonate polyols, polyolefin polyols, polybutadiene polyols or hydrogenated products thereof, polyisoprene polyols or hydrogenated products thereof, phenolic polyols, epoxy polyols, caprolactone polyols, polysulfone polyols, etc. Polyol compounds also include copolymer polyols such as polyester-polyether polyols.
Among them, from the viewpoint of further improving the polarity of the obtained urethane polymer and excellent compatibility with the vinyl monomer polymer having the structural unit derived from the compound (C1) and the compound (C1), it is preferable to include at least one selected from the group consisting of polyether diol, polyester diol, and polycarbonate diol. Among them, from the viewpoint of cohesive force and compatibility with the vinyl monomer polymer having the structural unit derived from the compound (C1) and the compound (C1), it is more preferable to include one selected from the group consisting of polyester diol and polycarbonate diol, and it is even more preferable to include polycarbonate diol. That is, it is preferable that the urethane polymer has at least one selected from the group consisting of structural units derived from polyether diol, structural units derived from polyester diol, and structural units derived from polycarbonate diol. In addition, it is more preferable that the urethane polymer has at least one selected from the group consisting of structural units derived from polyester diol and structural units derived from polycarbonate diol, and it is even more preferable that the urethane polymer has structural units derived from polycarbonate diol.
These polyol compounds may be used alone or in combination of two or more.
上記ポリカーボネートジオール合成に用いられるジオール化合物としては、例えば、上述したポリオール化合物のうち、水酸基の価数が2であるもの等が挙げられる。これらのジオール化合物は1種のみを用いても、2種以上併用してもよい。 The diol compound used in the synthesis of the polycarbonate diol may be, for example, one of the polyol compounds described above in which the hydroxyl group has a valence of 2. These diol compounds may be used alone or in combination of two or more.
上記ウレタンポリマー中における上記ポリカーボネートジオールに由来する構成単位の含有割合の好ましい下限は3質量%であり、好ましい上限は70質量%である。上記ポリカーボネートジオールに由来する構成単位の含有割合が3質量%以上であることにより、得られるウレタンポリマーの凝集力がより向上し、本発明の粘着テープのリワーク性がより向上する。上記ポリカーボネートジオールに由来する構成単位の含有割合が70質量%以下であることにより、得られるウレタンポリマーの変形に対する自由度がより向上する結果、本発明の粘着テープの粘着力がより向上する。上記ポリカーボネートジオールに由来する構成単位の含有割合のより好ましい下限は5質量%、より好ましい上限は60質量%、更に好ましい下限は7質量%、更に好ましい上限は50質量%である。 The preferred lower limit of the content of the structural unit derived from the polycarbonate diol in the urethane polymer is 3% by mass, and the preferred upper limit is 70% by mass. When the content of the structural unit derived from the polycarbonate diol is 3% by mass or more, the cohesive strength of the obtained urethane polymer is further improved, and the reworkability of the adhesive tape of the present invention is further improved. When the content of the structural unit derived from the polycarbonate diol is 70% by mass or less, the degree of freedom of deformation of the obtained urethane polymer is further improved, and as a result, the adhesive strength of the adhesive tape of the present invention is further improved. The more preferred lower limit of the content of the structural unit derived from the polycarbonate diol is 5% by mass, and the more preferred upper limit is 60% by mass, and even more preferred lower limit is 7% by mass, and even more preferred upper limit is 50% by mass.
上記ウレタンポリマー中における上記ポリエステルジオールに由来する構成単位の含有割合の好ましい下限は3質量%であり、好ましい上限は70質量%である。上記ポリエステルジオールに由来する構成単位の含有割合が3質量%以上であることにより、得られるウレタンポリマーの凝集力がより向上し、本発明の粘着テープのリワーク性がより向上する。上記ポリエステルジオールに由来する構成単位の含有割合が70質量%以下であることにより、得られるウレタンポリマーの変形に対する自由度がより向上する結果、本発明の粘着テープの粘着力がより向上する。上記ポリエステルジオールに由来する構成単位の含有割合のより好ましい下限は5質量%、より好ましい上限は60質量%、更に好ましい下限は7質量%、更に好ましい上限は50質量%である。 The preferred lower limit of the content of the constituent units derived from the polyester diol in the urethane polymer is 3% by mass, and the preferred upper limit is 70% by mass. When the content of the constituent units derived from the polyester diol is 3% by mass or more, the cohesive strength of the obtained urethane polymer is further improved, and the reworkability of the pressure-sensitive adhesive tape of the present invention is further improved. When the content of the constituent units derived from the polyester diol is 70% by mass or less, the degree of freedom of deformation of the obtained urethane polymer is further improved, and as a result, the adhesive strength of the pressure-sensitive adhesive tape of the present invention is further improved. The more preferred lower limit of the content of the constituent units derived from the polyester diol is 5% by mass, and the more preferred upper limit is 60% by mass, and even more preferred lower limit is 7% by mass, and even more preferred upper limit is 50% by mass.
上記ウレタンポリマー中における上記ポリエーテルジオールに由来する構成単位の含有割合の好ましい下限は3質量%であり、好ましい上限は70質量%である。上記ポリエーテルジオールに由来する構成単位の含有割合が3質量%以上であることにより、得られるウレタンポリマーの凝集力がより向上し、本発明の粘着テープのリワーク性がより向上する。上記ポリエーテルジオールに由来する構成単位の含有割合が70質量%以下であることにより、得られるウレタンポリマーの変形に対する自由度がより向上する結果、本発明の粘着テープの粘着力がより向上する。上記ポリエーテルジオールに由来する構成単位の含有割合のより好ましい下限は5質量%、より好ましい上限は60質量%、更に好ましい下限は7質量%、更に好ましい上限は50質量%である。 The preferred lower limit of the content of the structural unit derived from the polyether diol in the urethane polymer is 3% by mass, and the preferred upper limit is 70% by mass. When the content of the structural unit derived from the polyether diol is 3% by mass or more, the cohesive strength of the obtained urethane polymer is further improved, and the reworkability of the pressure-sensitive adhesive tape of the present invention is further improved. When the content of the structural unit derived from the polyether diol is 70% by mass or less, the degree of freedom of deformation of the obtained urethane polymer is further improved, and as a result, the adhesive strength of the pressure-sensitive adhesive tape of the present invention is further improved. The more preferred lower limit of the content of the structural unit derived from the polyether diol is 5% by mass, and the more preferred upper limit is 60% by mass, and even more preferred lower limit is 7% by mass, and even more preferred upper limit is 50% by mass.
上記ポリエーテルジオールに由来する構成単位を有するウレタンポリマーとしては、例えば、AG8451(ルーブリゾール社製)等が挙げられる。 An example of a urethane polymer having structural units derived from the above polyether diol is AG8451 (manufactured by Lubrizol Corporation).
本発明の粘着テープのリワーク性の観点からは、上記ポリオール化合物は水酸基の数が3以上のアルコール化合物を含んでいてもよい。 From the viewpoint of the reworkability of the adhesive tape of the present invention, the above polyol compound may contain an alcohol compound having three or more hydroxyl groups.
上記ポリイソシアネート化合物としては、例えば、ジフェニルメタンジイソシアネート、トリレンジイソシアネート、ナフタレン-1,5-ジイソシアネート、ヘキサメチレンジイソシアネート、トリメチルヘキサメチレンジイソシアネート、リジンジイソシアネート、ノルボルナンジイソシアネート、トランスシクロヘキサン-1,4-ジイソシアネート、イソホロンジイソシアネート、水添キシリレンジイソシアネート、水添ジフェニルメタンジイソシアネート、シクロヘキサンジイソシアネート、ビス(イソシアネートメチル)シクロヘキサン、ジシクロヘキシルメタンジイソシアネート等が挙げられる。また、上記ポリイソシアネート化合物として、上述したポリイソシアネート化合物の変性体を用いてもよい。上記ポリイソシアネート化合物の変性体としては、例えば、上述したポリイソシアネート化合物のビュレット変性体、上述したポリイソシアネート化合物のイソシアヌレート変性体や、グリセリン、トリメチロールプロパン、又は、これらにプロピレンオキサイド、エチレンオキサイド等のアルキレンオキサイドを付加重合したポリオールに、上述したポリイソシアネート化合物を反応させて得たアダクト体、ポリメリックMDIとも呼ばれるポリメチレンポリフェニルポリイソシアネート等が挙げられる。なかでも、上記化合物(C1)及び上記化合物(C1)に由来する構成単位を有するビニルモノマー重合体との相溶性に優れ、より高いリワーク性を発揮することができ、かつ、より高い粘着力を発揮することができる観点から、芳香族基を含有するポリイソシアネート化合物が好ましく、なかでも、ジフェニルメタンジイソシアネート、ジフェニルメタンジイソシアネートの液状変性物等のジフェニルメタンジイソシアネートの変性体がより好ましい。
これらのポリイソシアネート化合物は1種のみを用いても、2種以上を併用してもよい。
Examples of the polyisocyanate compound include diphenylmethane diisocyanate, tolylene diisocyanate, naphthalene-1,5-diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, lysine diisocyanate, norbornane diisocyanate, transcyclohexane-1,4-diisocyanate, isophorone diisocyanate, hydrogenated xylylene diisocyanate, hydrogenated diphenylmethane diisocyanate, cyclohexane diisocyanate, bis(isocyanatemethyl)cyclohexane, dicyclohexylmethane diisocyanate, etc. Furthermore, modified products of the above-mentioned polyisocyanate compounds may be used as the polyisocyanate compound. Examples of the modified polyisocyanate compound include the biuret modified polyisocyanate compound described above, the isocyanurate modified polyisocyanate compound described above, the adduct obtained by reacting the polyisocyanate compound described above with glycerin, trimethylolpropane, or a polyol obtained by addition polymerization of an alkylene oxide such as propylene oxide or ethylene oxide to these, and polymethylene polyphenyl polyisocyanate also called polymeric MDI. Among them, polyisocyanate compounds containing aromatic groups are preferred from the viewpoint of excellent compatibility with the above compound (C1) and vinyl monomer polymers having structural units derived from the above compound (C1), exhibiting higher reworkability, and exhibiting higher adhesive strength, and among them, modified diphenylmethane diisocyanate such as diphenylmethane diisocyanate and liquid modified diphenylmethane diisocyanate are more preferred.
These polyisocyanate compounds may be used alone or in combination of two or more.
本発明の粘着テープのリワーク性の観点からは、上記ポリイソシアネート化合物はイソシアネート基の数が3以上のイソシアネート化合物を含むことが好ましい。
上記ウレタンポリマー中におけるイソシアネート基の数が3以上のイソシアネート化合物に由来する構成単位の含有割合の好ましい下限は0.1質量%であり、好ましい上限は20質量%である。上記イソシアネート基の数が3以上のイソシアネート化合物に由来する構成単位の含有割合が上記範囲内であることにより、本発明の粘着テープはより高い粘着力とより優れたリワーク性とを両立することができるようになる。より好ましい下限は0.5質量%、より好ましい上限は10質量%である。
From the viewpoint of the reworkability of the pressure-sensitive adhesive tape of the present invention, the polyisocyanate compound preferably contains an isocyanate compound having three or more isocyanate groups.
The preferred lower limit of the content ratio of the structural unit derived from the isocyanate compound having 3 or more isocyanate groups in the urethane polymer is 0.1% by mass, and the preferred upper limit is 20% by mass. By having the content ratio of the structural unit derived from the isocyanate compound having 3 or more isocyanate groups within the above range, the pressure-sensitive adhesive tape of the present invention can achieve both higher adhesive strength and better reworkability. The more preferred lower limit is 0.5% by mass, and the more preferred upper limit is 10% by mass.
上記ウレタンポリマーは、芳香族基含有化合物に由来する構成単位を有することが好ましい。上記ウレタンポリマーが、芳香族基含有化合物に由来する構成単位を有することにより、本発明の粘着テープのリワーク性がより向上する。
上記芳香族基含有化合物としては、例えば、上述したポリオール化合物のうち芳香族基を含有する化合物や上述した芳香族基を含有するポリイソシアネート化合物等が挙げられる。
The urethane polymer preferably has a structural unit derived from an aromatic group-containing compound. When the urethane polymer has a structural unit derived from an aromatic group-containing compound, the reworkability of the pressure-sensitive adhesive tape of the present invention is further improved.
Examples of the aromatic group-containing compound include the above-mentioned polyol compounds containing an aromatic group and the above-mentioned polyisocyanate compounds containing an aromatic group.
上記ウレタンポリマーの重量平均分子量(Mw)の好ましい下限は3000であり、好ましい上限は30万である。上記ウレタンポリマーの重量平均分子量が3000以上であることにより、本発明の粘着テープのリワーク性がより向上する。上記ウレタンポリマーの重量平均分子量が30万以下であることにより、本発明の粘着テープの粘着力がより向上する。上記ウレタンポリマーの重量平均分子量のより好ましい下限は5000、より好ましい上限は25万、更に好ましい下限は7000、更に好ましい上限は20万である。 The preferred lower limit of the weight average molecular weight (Mw) of the urethane polymer is 3,000, and the preferred upper limit is 300,000. When the weight average molecular weight of the urethane polymer is 3,000 or more, the reworkability of the adhesive tape of the present invention is further improved. When the weight average molecular weight of the urethane polymer is 300,000 or less, the adhesive strength of the adhesive tape of the present invention is further improved. A more preferred lower limit of the weight average molecular weight of the urethane polymer is 5,000, a more preferred upper limit is 250,000, an even more preferred lower limit is 7,000, and an even more preferred upper limit is 200,000.
上記ビニルモノマー重合体と上記ウレタンポリマーとの合計100質量部中における上記ウレタンポリマーの含有量の好ましい下限は5質量部であり、好ましい上限は90質量部である。
上記ウレタンポリマーの含有量が上記範囲内にあることにより、本発明の粘着テープがより高い粘着力とより優れたリワーク性とを両立することができるようになる。上記ウレタンポリマーの含有量のより好ましい下限は10質量部、より好ましい上限は70質量部、更に好ましい下限は15質量部、更に好ましい上限は60質量部である。
The preferred lower limit of the amount of the urethane polymer per 100 parts by mass of the combined total of the vinyl monomer polymer and the urethane polymer is 5 parts by mass, and the preferred upper limit is 90 parts by mass.
By setting the content of the urethane polymer within the above range, the pressure-sensitive adhesive tape of the present invention can achieve both higher adhesive strength and better reworkability. The lower limit of the content of the urethane polymer is more preferably 10 parts by mass, the upper limit is more preferably 70 parts by mass, the further lower limit is 15 parts by mass, and the further upper limit is more preferably 60 parts by mass.
本明細書において、上記架橋生成物とは、粘着剤組成物を架橋して得られた生成物のことを意味する。
上記第1の構成において、上記架橋生成物において上記ビニルモノマー重合体と上記ウレタンポリマーとは、架橋剤によって架橋されている。
また、上記第2の構成において、上記架橋生成物において上記ビニルモノマー重合体と上記ウレタンポリマーとは、架橋剤によって架橋されていることが好ましい。
上記架橋剤としては、例えば、イソシアネート系架橋剤、アジリジン系架橋剤、エポキシ系架橋剤、金属キレート型架橋剤等が挙げられる。なかでも、水酸基に対して選択的に架橋することができ、架橋構造を制御しやすいことから、イソシアネート系架橋剤が好ましい。
In this specification, the crosslinked product means a product obtained by crosslinking a pressure-sensitive adhesive composition.
In the first aspect, in the crosslinked product, the vinyl monomer polymer and the urethane polymer are crosslinked with a crosslinking agent.
In the second aspect, the vinyl monomer polymer and the urethane polymer in the crosslinked product are preferably crosslinked with a crosslinking agent.
Examples of the crosslinking agent include an isocyanate-based crosslinking agent, an aziridine-based crosslinking agent, an epoxy-based crosslinking agent, a metal chelate-type crosslinking agent, etc. Among these, an isocyanate-based crosslinking agent is preferred because it can selectively crosslink with a hydroxyl group and the crosslinked structure can be easily controlled.
上記イソシアネート系架橋剤としては、例えば、コロネートHX、ミリオネートMR200(いずれも東ソー社製)等が挙げられる。 Examples of the isocyanate-based crosslinking agent include Coronate HX and Millionate MR200 (both manufactured by Tosoh Corporation).
上記粘着剤組成物及び架橋剤の合計中における上記架橋剤の含有割合の好ましい下限は0.1質量%であり、好ましい上限は20質量%である。上記架橋剤の含有割合が0.1質量%以上であることにより、上記粘着剤がより硬化ができ、本発明の粘着テープのリワーク性がより向上する。上記架橋剤の含有割合が20質量%以下であることにより、上記粘着剤が硬くなりすぎず、本発明の粘着テープはより高い粘着力を発揮することができるようになる。 The preferred lower limit of the content of the crosslinking agent in the total of the pressure-sensitive adhesive composition and the crosslinking agent is 0.1% by mass, and the preferred upper limit is 20% by mass. When the content of the crosslinking agent is 0.1% by mass or more, the pressure-sensitive adhesive can be cured more, and the reworkability of the pressure-sensitive adhesive tape of the present invention is further improved. When the content of the crosslinking agent is 20% by mass or less, the pressure-sensitive adhesive does not become too hard, and the pressure-sensitive adhesive tape of the present invention can exert a higher adhesive strength.
上記粘着剤は、更に、粘着付与樹脂(タッキファイア)を含有していてもよい。上記粘着剤が粘着付与樹脂を含有することにより、本発明の粘着テープの粘着力がより向上する。 The adhesive may further contain a tackifier resin. By containing a tackifier resin in the adhesive, the adhesive strength of the adhesive tape of the present invention is further improved.
上記粘着付与樹脂としては、例えば、ロジンエステル系樹脂等のロジン系樹脂、テルペンフェノール樹脂等のテルペン系樹脂、石油系樹脂等が挙げられる。なかでも、極性が比較的高く、上記ビニルモノマー重合体や上記ウレタンポリマーとの相溶性に優れるロジン系樹脂、テルペンフェノール樹脂が好ましい。
これらの粘着付与樹脂は、単独で用いられてもよいし、2種以上が組み合わせて用いられてもよい。
Examples of the tackifier resin include rosin-based resins such as rosin ester-based resins, terpene-based resins such as terpene phenol resins, petroleum-based resins, etc. Among these, rosin-based resins and terpene phenol resins are preferred because they have relatively high polarity and are highly compatible with the vinyl monomer polymer and the urethane polymer.
These tackifier resins may be used alone or in combination of two or more kinds.
上記ロジンエステル系樹脂とは、アビエチン酸を主成分とするロジン樹脂、不均化ロジン樹脂、水添ロジン樹脂、アビエチン酸等の樹脂酸の二量体(重合ロジン樹脂)等を、アルコールによってエステル化させて得られた樹脂である。エステル化に用いたアルコールの水酸基の一部がエステル化に使用されずに樹脂内に含有されることで、水酸基価が上述した範囲に調整される。アルコールとしては、エチレングリコール、グリセリン、ペンタエリスリトール等の多価アルコールが挙げられる。
なお、ロジン樹脂をエステル化した樹脂がロジンエステル樹脂、不均化ロジン樹脂をエステル化した樹脂が不均化ロジンエステル樹脂、水添ロジン樹脂をエステル化した樹脂が水添ロジンエステル樹脂、重合ロジン樹脂をエステル化した樹脂が重合ロジンエステル樹脂である。
The rosin ester resin is a resin obtained by esterifying, with an alcohol, a rosin resin mainly composed of abietic acid, a disproportionated rosin resin, a hydrogenated rosin resin, a dimer of a resin acid such as abietic acid (polymerized rosin resin), etc. A part of the hydroxyl group of the alcohol used for esterification is not used for esterification and is contained in the resin, so that the hydroxyl value is adjusted to the above-mentioned range. Examples of the alcohol include polyhydric alcohols such as ethylene glycol, glycerin, and pentaerythritol.
In addition, a resin obtained by esterifying a rosin resin is a rosin ester resin, a resin obtained by esterifying a disproportionated rosin resin is a disproportionated rosin ester resin, a resin obtained by esterifying a hydrogenated rosin resin is a hydrogenated rosin ester resin, and a resin obtained by esterifying a polymerized rosin resin is a polymerized rosin ester resin.
上記テルペンフェノール樹脂は、フェノールの存在下においてテルペンを重合させて得られた樹脂である。 The above terpene phenol resin is a resin obtained by polymerizing terpene in the presence of phenol.
上記粘着剤中における粘着付与樹脂の含有割合の好ましい下限は1質量%であり、好ましい上限は60質量%である。上記粘着付与樹脂の含有割合が1質量%以上であることにより、本発明の粘着テープがより高い粘着力を発揮できるようになる。上記粘着付与樹脂の含有割合が60質量%以下であることにより、本発明の粘着テープの粘着力が高くなりすぎず、リワーク性がより向上する。上記粘着付与樹脂の含有割合のより好ましい下限は3質量%、より好ましい上限は50質量%、更に好ましい下限は5質量%、更に好ましい上限は40質量%である。 The preferred lower limit of the content of the tackifier resin in the adhesive is 1% by mass, and the preferred upper limit is 60% by mass. When the content of the tackifier resin is 1% by mass or more, the adhesive tape of the present invention can exhibit higher adhesive strength. When the content of the tackifier resin is 60% by mass or less, the adhesive strength of the adhesive tape of the present invention does not become too high, and reworkability is further improved. A more preferred lower limit of the content of the tackifier resin is 3% by mass, a more preferred upper limit is 50% by mass, an even more preferred lower limit is 5% by mass, and an even more preferred upper limit is 40% by mass.
上記粘着剤は、本発明の効果を損なわない範囲において、更に、必要に応じて、シランカップリング剤、可塑剤、軟化剤、充填剤、顔料、染料等の添加剤等を含有していてもよい。 The above adhesive may further contain additives such as silane coupling agents, plasticizers, softeners, fillers, pigments, dyes, etc., as necessary, within the scope of the invention.
上記粘着剤を製造する方法は特に限定されず、従来公知の方法等により製造することができる。具体的には例えば、ウレタンポリマー、ビニルモノマー重合体又は上記化合物(C1)、架橋剤等を溶剤に加えた後、充分に撹拌することにより、製造することができる。
また、上記化合物(C1)が上記(a)である場合は、上述したモノマー混合物、上述した光重合開始剤、及び、上記ウレタンポリマーを混合し、アプリケーターを用いて離型PETフィルムや基材上に塗工し、塗工した上面を離型PETフィルムにて封止又は窒素雰囲気下として塗工面が空気に触れないようにしたうえでUV照射する方法にて重合を行うことにより粘着剤を得ることもできる。
The method for producing the pressure-sensitive adhesive is not particularly limited, and the pressure-sensitive adhesive can be produced by a conventionally known method, etc. Specifically, for example, the pressure-sensitive adhesive can be produced by adding a urethane polymer, a vinyl monomer polymer, or the compound (C1), a crosslinking agent, etc. to a solvent and then thoroughly stirring the mixture.
In addition, when the compound (C1) is the compound (a), the above-mentioned monomer mixture, the above-mentioned photopolymerization initiator, and the above-mentioned urethane polymer are mixed, and the mixture is applied onto a release PET film or a substrate using an applicator. The upper surface of the coated layer is sealed with a release PET film or placed under a nitrogen atmosphere to prevent the coated surface from coming into contact with air, and then polymerized by UV irradiation to obtain a pressure-sensitive adhesive.
上記第1の構成において、上記粘着剤層の厚みの好ましい下限は50μmである。上記第1の構成において、上記粘着剤層の厚みが50μm以上である場合、本発明の粘着テープのリワーク性がより向上する。上記粘着剤層の厚みのより好ましい下限は60μm、更に好ましい下限は70μmである。
上記第2の構成において、上記粘着剤層の厚みの下限は50μmである。上記第2の構成において、上記粘着剤層の厚みが50μm以上である場合、本発明の粘着テープのリワーク性が向上する。上記粘着剤層の厚みの好ましい下限は60μm、より好ましい下限は70μmである。
In the first configuration, the preferred lower limit of the thickness of the pressure-sensitive adhesive layer is 50 μm. In the first configuration, when the thickness of the pressure-sensitive adhesive layer is 50 μm or more, the reworkability of the pressure-sensitive adhesive tape of the present invention is further improved. The more preferred lower limit of the thickness of the pressure-sensitive adhesive layer is 60 μm, and the even more preferred lower limit is 70 μm.
In the second configuration, the lower limit of the thickness of the pressure-sensitive adhesive layer is 50 μm. In the second configuration, when the thickness of the pressure-sensitive adhesive layer is 50 μm or more, the reworkability of the pressure-sensitive adhesive tape of the present invention is improved. The lower limit of the thickness of the pressure-sensitive adhesive layer is preferably 60 μm, and more preferably 70 μm.
また、上記粘着剤層の厚みの好ましい上限は300μmである。上記粘着剤層の厚みが300μm以下であることにより、本発明の粘着テープの粘着力がより高くなる。上記粘着剤層の厚みのより好ましい上限は250μm、更に好ましい上限は200μmである。 The preferred upper limit of the thickness of the adhesive layer is 300 μm. By setting the thickness of the adhesive layer to 300 μm or less, the adhesive strength of the adhesive tape of the present invention is increased. The more preferred upper limit of the thickness of the adhesive layer is 250 μm, and the even more preferred upper limit is 200 μm.
上記第1の構成において、上記粘着剤層の23℃における引張破断点応力の好ましい下限は0.50MPaである。上記第1の構成において、上記粘着剤層の23℃における引張破断点応力が0.50MPa以上であることにより、本発明の粘着テープはリワーク性により優れるものとなる。上記第1の構成において、上記粘着剤層の23℃における引張破断点応力のより好ましい下限は0.60MPa、更に好ましい下限は0.70MPaである。
上記第2の構成において、上記粘着剤層の23℃における引張破断点応力の下限は0.50MPaである。上記第2の構成において、上記粘着剤層の23℃における引張破断点応力が0.50MPa以上であることにより、本発明の粘着テープはリワーク性に優れるものとなる。上記第2の構成において、上記粘着剤層の23℃における引張破断点応力の好ましい下限は0.60MPa、より好ましい下限は0.70MPaである。
In the first configuration, the preferred lower limit of the tensile stress at break of the pressure-sensitive adhesive layer at 23° C. is 0.50 MPa. In the first configuration, the pressure-sensitive adhesive layer has a tensile stress at break of 0.50 MPa or more at 23° C., so that the pressure-sensitive adhesive tape of the present invention has better reworkability. In the first configuration, the more preferred lower limit of the tensile stress at break of the pressure-sensitive adhesive layer at 23° C. is 0.60 MPa, and the even more preferred lower limit is 0.70 MPa.
In the second configuration, the lower limit of the tensile stress at break of the pressure-sensitive adhesive layer at 23° C. is 0.50 MPa. In the second configuration, the pressure-sensitive adhesive layer has a tensile stress at break of 0.50 MPa or more at 23° C., so that the pressure-sensitive adhesive tape of the present invention has excellent reworkability. In the second configuration, the lower limit of the tensile stress at break of the pressure-sensitive adhesive layer at 23° C. is preferably 0.60 MPa, and more preferably 0.70 MPa.
また、上記粘着剤層の23℃における引張破断点応力の好ましい上限は20MPaである。上記粘着剤層の23℃における引張破断点応力が20MPa以下であることにより、本発明の粘着テープは粘着力がより高くなる。本発明の粘着テープの23℃における引張破断点応力のより好ましい上限は15MPa、更に好ましい上限は10MPaである。 The preferred upper limit of the tensile stress at break of the adhesive layer at 23°C is 20 MPa. When the tensile stress at break of the adhesive layer at 23°C is 20 MPa or less, the adhesive tape of the present invention has higher adhesive strength. The more preferred upper limit of the tensile stress at break of the adhesive tape of the present invention at 23°C is 15 MPa, and the even more preferred upper limit is 10 MPa.
上記粘着剤層の23℃における破断伸長率の好ましい下限は300%である。上記粘着剤層の23℃における破断伸長率が300%以上であることにより、本発明の粘着テープはリワーク性により優れるものとなる。上記粘着剤層の23℃における破断伸長率のより好ましい下限は350%、更に好ましい下限は400%である。
また、上記粘着剤層の破断伸長率の好ましい上限は3000%である。本発明の粘着テープの破断伸長率が3000%以下であることにより、本発明の粘着テープは粘着力がより高くなる。本発明の粘着テープの破断伸長率のより好ましい上限は2500%、更に好ましい上限は2000%である。
The lower limit of the breaking elongation percentage of the pressure-sensitive adhesive layer at 23° C. is preferably 300%. When the breaking elongation percentage of the pressure-sensitive adhesive layer at 23° C. is 300% or more, the pressure-sensitive adhesive tape of the present invention has better reworkability. The lower limit of the breaking elongation percentage of the pressure-sensitive adhesive layer at 23° C. is more preferably 350%, and even more preferably 400%.
The upper limit of the breaking elongation of the pressure-sensitive adhesive layer is preferably 3000%. When the breaking elongation of the pressure-sensitive adhesive tape of the present invention is 3000% or less, the pressure-sensitive adhesive tape of the present invention has higher adhesive strength. The upper limit of the breaking elongation of the pressure-sensitive adhesive tape of the present invention is more preferably 2500%, and even more preferably 2000%.
上記引張破断点応力及び上記破断伸長率の測定は、例えば、JIS K7161に準拠して、引張試験機(エー・アンド・デイ社製、「TBS-1225S」等)を用い、23℃、50%RH、引張速度200mm/minの条件下で粘着剤層を長辺方向に引っ張る引張試験を行うこと等により測定する。そして、粘着剤層が破断したときにおける応力を引張破断点応力、引張試験前の粘着剤層の長辺の長さに対する粘着剤層が破断したときにおける粘着剤層の長辺の長さの比率を破断伸長率として、それぞれ得ることができる。なお、上記粘着剤層の長辺の長さは、引張試験において粘着剤層を掴む引張試験機のチャック間距離を意味する。 The tensile stress at break and the elongation at break are measured, for example, in accordance with JIS K7161, by performing a tensile test in which the adhesive layer is pulled in the long side direction using a tensile tester (such as "TBS-1225S" manufactured by A&D Co., Ltd.) under conditions of 23°C, 50% RH, and a tensile speed of 200 mm/min. The stress at break when the adhesive layer breaks can be obtained as the tensile stress at break, and the ratio of the length of the long side of the adhesive layer when it breaks to the length of the long side of the adhesive layer before the tensile test can be obtained as the elongation at break. The length of the long side of the adhesive layer refers to the distance between the chucks of the tensile tester that grip the adhesive layer in the tensile test.
上記引張破断点応力を上述した範囲内に調整する方法としては、例えば、上記ビニルモノマー重合体や上記ウレタンポリマーの組成を変更する方法、上記架橋剤の種類や含有量を変更する方法、粘着付与樹脂等の添加物の種類や含有量を変更する方法等が挙げられる。
具体的には例えば、上記ビニルモノマーや上記ウレタンポリマーの組成を変更することにより、上記ビニルモノマーや上記ウレタンポリマーのガラス転移温度を高くさせる方法等が挙げられる。
Examples of methods for adjusting the tensile stress at break within the above-mentioned range include a method of changing the composition of the vinyl monomer polymer or the urethane polymer, a method of changing the type or content of the crosslinking agent, a method of changing the type or content of an additive such as a tackifier resin, and the like.
Specifically, for example, the composition of the vinyl monomer or the urethane polymer may be changed to increase the glass transition temperature of the vinyl monomer or the urethane polymer.
上記破断伸長率を上述した範囲内に調整する方法としては、例えば、上記ビニルモノマーや上記ウレタンポリマーの組成を変更する方法、上記架橋剤の種類や含有量を変更する方法、粘着付与樹脂等の添加物の種類や含有量を変更する方法等が挙げられる。
具体的には例えば、上記架橋生成物中における上記ウレタンポリマーの含有割合を大きくすること等が挙げられる。
Examples of methods for adjusting the breaking elongation rate within the above-mentioned range include a method of changing the composition of the vinyl monomer or the urethane polymer, a method of changing the type or content of the crosslinking agent, a method of changing the type or content of an additive such as a tackifier resin, and the like.
Specifically, for example, the content of the urethane polymer in the crosslinked product may be increased.
上記粘着剤層の25℃におけるせん断貯蔵弾性率の好ましい下限は0.05MPaであり、好ましい上限は1.0MPaである。上記粘着剤層の25℃におけるせん断貯蔵弾性率が0.05MPa以上であることにより、上記粘着剤層が硬くなり、本発明の粘着テープのリワーク性がより向上する。上記粘着剤層の25℃におけるせん断貯蔵弾性率が1.0MPa以下であることにより、本発明の粘着テープがより高い粘着力を発揮できるようになる。上記粘着剤層の25℃におけるせん断貯蔵弾性率のより好ましい下限は0.07MPa、より好ましい上限は0.9MPa、更に好ましい下限は0.1MPa、更に好ましい上限は0.8MPaである。 The preferred lower limit of the shear storage modulus of the adhesive layer at 25°C is 0.05 MPa, and the preferred upper limit is 1.0 MPa. When the shear storage modulus of the adhesive layer at 25°C is 0.05 MPa or more, the adhesive layer becomes hard, and the reworkability of the adhesive tape of the present invention is further improved. When the shear storage modulus of the adhesive layer at 25°C is 1.0 MPa or less, the adhesive tape of the present invention can exert higher adhesive strength. The more preferred lower limit of the shear storage modulus of the adhesive layer at 25°C is 0.07 MPa, the more preferred upper limit is 0.9 MPa, the even more preferred lower limit is 0.1 MPa, and the even more preferred upper limit is 0.8 MPa.
上記粘着剤層は、周波数1Hzで測定したときの-10℃以上30℃以下の温度領域における損失正接(tanδ)のピークが1つであることが好ましい。上記周波数1Hzで測定したときの-10℃以上30℃以下の温度領域における損失正接(tanδ)のピークが1つである場合、上記粘着剤層はより均一であることから、上記粘着剤層中の成分同士の相溶性がより優れるため、本発明の粘着テープはより高い粘着力とより優れたリワーク性とを両立することができるものとなる。
なお、本明細書中において、「ピークが1つ」とは、動的粘弾性測定にて得られる損失正接(tanδ)のスペクトルチャートの-10℃から30℃の温度領域において、損失正接(tanδ)の極大値が1つであることを意味する。
The pressure-sensitive adhesive layer preferably has one peak in loss tangent (tan δ) in the temperature range of -10° C. or more and 30° C. or less when measured at a frequency of 1 Hz. When there is one peak in loss tangent (tan δ) in the temperature range of -10° C. or more and 30° C. or less when measured at a frequency of 1 Hz, the pressure-sensitive adhesive layer is more uniform, and therefore the compatibility between the components in the pressure-sensitive adhesive layer is more excellent, so that the pressure-sensitive adhesive tape of the present invention can achieve both higher adhesive strength and better reworkability.
In this specification, "one peak" means that there is one maximum value of loss tangent (tan δ) in the temperature range from -10°C to 30°C on a spectrum chart of loss tangent (tan δ) obtained by dynamic viscoelasticity measurement.
上記粘着剤層は、周波数1Hzで測定したときの-10℃以上30℃以下の温度領域における損失正接(tanδ)のピークが1つである場合、該損失正接のピークの半値幅(以下、単に「損失正接のピークの半値幅」ということもある。)の好ましい上限は40℃である。上記損失正接のピークの半値幅が40℃以下である場合、上記粘着剤層はより均一であることから、上記粘着剤層の成分同士の相溶性がより優れるため、本発明の粘着テープはより高い粘着力とより優れたリワーク性とを両立することができるものとなる。上記損失正接のピークの半値幅のより好ましい上限は35℃、更に好ましい上限は30℃である。
また、上記損失正接のピークの半値幅の好ましい下限は特にないが、実質的には5℃程度が下限である。
なお、本明細書中において、「損失正接のピークの半値幅」は、損失正接のピークの半値全幅のことを意味する。
When the pressure-sensitive adhesive layer has one loss tangent (tan δ) peak in the temperature range of -10°C to 30°C when measured at a frequency of 1 Hz, the half-width of the loss tangent peak (hereinafter, sometimes simply referred to as "half-width of the loss tangent peak") is preferably 40°C. When the half-width of the loss tangent peak is 40°C or less, the pressure-sensitive adhesive layer is more uniform, and therefore the compatibility between the components of the pressure-sensitive adhesive layer is more excellent, so that the pressure-sensitive adhesive tape of the present invention can achieve both higher adhesive strength and better reworkability. The more preferable upper limit of the half-width of the loss tangent peak is 35°C, and the even more preferable upper limit is 30°C.
There is no particular preferred lower limit for the half-width of the peak of the loss tangent, but the lower limit is substantially about 5°C.
In this specification, the "half width of the peak of the loss tangent" means the full width at half maximum of the peak of the loss tangent.
上記粘着剤層の25℃におけるせん断貯蔵弾性率、上記周波数1Hzで測定したときの-10℃以上30℃以下の温度領域における損失正接(tanδ)、及び、周波数1Hzで測定したときの損失正接(tanδ)のピークの半値幅は、動的粘弾性測定により求めることができる。
即ち、得られた粘着剤層について、動的粘弾性測定装置(例えば、アイティー計測制御社製、「DVA-200」等)を用い、窒素雰囲気下、せん断方向、周波数1Hz、昇温速度10℃/min、温度範囲-50℃から150℃までの条件で動的粘弾性スペクトルを測定することにより、25℃におけるせん断貯蔵弾性率、周波数1Hzで測定したときの損失正接(tanδ)のピークを得ることができる。また、得られた損失正接(tanδ)のスペクトルチャートから損失正接(tanδ)のピークの半値幅を算出することができる。
なお、粘着剤層の厚みが500μm未満である場合は、厚みが500μm以上となるように粘着剤層を積層した測定用の粘着剤層を作製し、動的粘弾性測定を行う。
The shear storage modulus of the pressure-sensitive adhesive layer at 25°C, the loss tangent (tan δ) in the temperature range of -10°C or more and 30°C or less when measured at a frequency of 1 Hz, and the half-value width of the peak of the loss tangent (tan δ) when measured at a frequency of 1 Hz can be determined by dynamic viscoelasticity measurement.
That is, the dynamic viscoelasticity spectrum of the obtained pressure-sensitive adhesive layer is measured using a dynamic viscoelasticity measuring device (e.g., "DVA-200" manufactured by IT Measurement & Control Co., Ltd.) under conditions of a nitrogen atmosphere, a shear direction, a frequency of 1 Hz, a heating rate of 10°C/min, and a temperature range of -50°C to 150°C, thereby obtaining the shear storage modulus at 25°C and the peak of the loss tangent (tan δ) measured at a frequency of 1 Hz. In addition, the half-width of the peak of the loss tangent (tan δ) can be calculated from the obtained spectrum chart of the loss tangent (tan δ).
When the thickness of the pressure-sensitive adhesive layer is less than 500 μm, a pressure-sensitive adhesive layer for measurement is prepared by laminating pressure-sensitive adhesive layers so as to have a thickness of 500 μm or more, and dynamic viscoelasticity measurement is performed on the pressure-sensitive adhesive layer.
上記粘着剤層の25℃におけるせん断貯蔵弾性率や上記粘着剤層の周波数1Hzで測定したときの損失正接(tanδ)のピークの半値幅を、上述した範囲に調整する方法としては、例えば、上記ビニルモノマー重合体や上記ウレタンポリマーの組成を変更する方法、上記架橋剤の種類や含有量を変更する方法等が挙げられる。
具体的には例えば、上記粘着剤層の25℃におけるせん断貯蔵弾性率を低下させる場合には、上記ビニルモノマー重合体中における、ホモポリマーとしたときのガラス転移温度が低い(メタ)アクリレートモノマーに由来する構成単位の含有割合を大きくする方法等が挙げられる。一方、上記粘着剤層の25℃におけるせん断貯蔵弾性率を増加させる場合には、上記ビニルモノマー重合体中における、ホモポリマーとしたときのガラス転移温度が高い(メタ)アクリレートモノマーに由来する構成単位の含有割合を大きくする方法等が挙げられる。
なお、本明細書中において、「ホモポリマーとしたときのガラス転移温度」とは、(メタ)アクリレートを重量平均分子量10万以上200万以下としたときのホモポリマーを示差走査熱量測定により、測定したガラス転移温度のことを意味する。また、上記ホモポリマーとしたときのガラス転移温度の測定方法としては、例えば、窒素雰囲気下(窒素フロー、流量50mL/min)、示差走査熱量計(セイコーインスツルメンツ社製、「220C」等)を用いて、JIS K6240:2011に準拠した方法で、測定温度-100℃~200℃、昇温速度10℃/分の条件下で測定を行うこと等が挙げられる。
Methods for adjusting the shear storage modulus at 25°C of the pressure-sensitive adhesive layer or the half-value width of the peak of the loss tangent (tan δ) when measured at a frequency of 1 Hz of the pressure-sensitive adhesive layer to within the above-mentioned ranges include, for example, a method of changing the composition of the vinyl monomer polymer or the urethane polymer, a method of changing the type or content of the crosslinking agent, etc.
Specifically, for example, in order to reduce the shear storage modulus of the pressure-sensitive adhesive layer at 25° C., a method may be used in which the content ratio of a constituent unit derived from a (meth)acrylate monomer having a low glass transition temperature when made into a homopolymer is increased in the vinyl monomer polymer, while in order to increase the shear storage modulus of the pressure-sensitive adhesive layer at 25° C., a method may be used in which the content ratio of a constituent unit derived from a (meth)acrylate monomer having a high glass transition temperature when made into a homopolymer is increased in the vinyl monomer polymer.
In this specification, the term "glass transition temperature when made into a homopolymer" refers to the glass transition temperature measured by differential scanning calorimetry of a homopolymer when the (meth)acrylate has a weight average molecular weight of 100,000 to 2,000,000. The glass transition temperature when made into the homopolymer may be measured, for example, in a nitrogen atmosphere (nitrogen flow, flow rate 50 mL/min) using a differential scanning calorimeter (manufactured by Seiko Instruments Inc., "220C" or the like) in accordance with JIS K6240:2011 at a measurement temperature of -100°C to 200°C and a heating rate of 10°C/min.
上記粘着剤層の周波数1Hzで測定したときの損失正接(tanδ)のピークの半値幅を、上述した範囲に調整する方法としては、例えば、上記ビニルモノマー重合体や上記ウレタンポリマーの組成を変更する方法、上記架橋剤の種類や含有量を変更する方法等が挙げられる。 Methods for adjusting the half-width of the peak of the loss tangent (tan δ) when measured at a frequency of 1 Hz of the pressure-sensitive adhesive layer to the above-mentioned range include, for example, changing the composition of the vinyl monomer polymer or the urethane polymer, or changing the type or content of the crosslinking agent.
上記粘着剤層のゲル分率の好ましい下限は30質量%であり、好ましい上限は99質量%である。上記粘着剤層のゲル分率が30質量%以上であることにより、上記粘着剤層が硬くなり、本発明の粘着テープのリワーク性がより向上する。上記粘着剤層のゲル分率が99質量%以下であることにより、本発明の粘着テープがより高い粘着力を発揮できるようになる。上記粘着剤層のゲル分率のより好ましい下限は32質量%、より好ましい上限は90質量%、更に好ましい下限は35質量%、更に好ましい上限は80質量%である。
なお、上記粘着剤層のゲル分率は、以下の方法により測定される。
即ち、まず、上記粘着剤層を有する粘着テープを幅30mm×長さ30mmの平面正方形状に裁断して試験片を作製し、試験片をテトラヒドロフラン(THF)中に23℃にて24時間浸漬した後、金属メッシュを用いてろ過し、110℃の条件下で1時間乾燥させる。乾燥後の試験片の質量を測定し、下記式(I)を用いてゲル分率を算出する。なお、試験片には、上記粘着剤層を保護するための離型フィルムは積層されていないものとする。また、粘着テープが基材を有さない場合、W0=0としてゲル分率を算出する。
ゲル分率(質量%)=100×(W2-W0)/(W1-W0) (I)
(W0:基材の質量、W1:浸漬前の試験片の質量、W2:浸漬、乾燥後の試験片の質量)
The preferred lower limit of the gel fraction of the pressure-sensitive adhesive layer is 30% by mass, and the preferred upper limit is 99% by mass. When the gel fraction of the pressure-sensitive adhesive layer is 30% by mass or more, the pressure-sensitive adhesive layer becomes hard, and the reworkability of the pressure-sensitive adhesive tape of the present invention is further improved. When the gel fraction of the pressure-sensitive adhesive layer is 99% by mass or less, the pressure-sensitive adhesive tape of the present invention can exhibit higher adhesive strength. The more preferred lower limit of the gel fraction of the pressure-sensitive adhesive layer is 32% by mass, the more preferred upper limit is 90% by mass, the even more preferred lower limit is 35% by mass, and the even more preferred upper limit is 80% by mass.
The gel fraction of the pressure-sensitive adhesive layer is measured by the following method.
That is, first, the adhesive tape having the adhesive layer is cut into a planar square shape of 30 mm wide x 30 mm long to prepare a test piece, and the test piece is immersed in tetrahydrofuran (THF) at 23°C for 24 hours, filtered using a metal mesh, and dried under the condition of 110°C for 1 hour. The mass of the test piece after drying is measured, and the gel fraction is calculated using the following formula (I). Note that the test piece is not laminated with a release film for protecting the adhesive layer. In addition, when the adhesive tape does not have a substrate, the gel fraction is calculated assuming W0 = 0.
Gel fraction (mass%)=100×(W 2 −W 0 )/(W 1 −W 0 ) (I)
(W 0 : Mass of the substrate, W 1 : Mass of the test piece before immersion, W 2 : Mass of the test piece after immersion and drying)
上記粘着剤層のゲル分率を上述した範囲に調整する方法としては、例えば、上記ビニルモノマー重合体や上記ウレタンポリマーの組成を変更する方法、上記架橋剤の種類や含有量を変更する方法、粘着付与樹脂等の添加物の種類や含有量を変更する方法等が挙げられる。 Methods for adjusting the gel fraction of the pressure-sensitive adhesive layer to the above-mentioned range include, for example, changing the composition of the vinyl monomer polymer or the urethane polymer, changing the type or content of the crosslinking agent, and changing the type or content of additives such as tackifier resins.
上記粘着剤層の23℃におけるヤング率の好ましい下限は0.010MPaであり、好ましい上限は10MPaである。上記粘着剤層の23℃におけるヤング率が0.010MPa以上であることにより、本発明の粘着テープの剥離時に引張に対してより大きな応力が加わることにより、本発明の粘着テープのリワーク性がより向上する。上記粘着剤層の23℃におけるヤング率が10MPa以下であることにより、上記粘着剤層は硬くなりすぎず、本発明の粘着テープは粘着力がより高くなる。上記粘着剤層の23℃におけるヤング率のより好ましい下限は0.012MPa、より好ましい上限は7MPa、更に好ましい下限は0.014MPa、更に好ましい上限は5MPaである。
なお、上記粘着剤層のヤング率の測定方法としては、例えば、以下の方法等が挙げられる。
即ち、粘着剤層について、上述した引張破断点応力及び破断伸長率を測定する引張試験を行うことにより、得られた応力-ひずみ曲線(S-S曲線)の線形領域(弾性領域)における傾きを算出する方法から、上記粘着剤層のヤング率を得ることができる。
The Young's modulus of the pressure-sensitive adhesive layer at 23° C. is preferably 0.010 MPa at its lower limit, and 10 MPa at its upper limit. The Young's modulus of the pressure-sensitive adhesive layer at 23° C. is 0.010 MPa or more, so that a larger stress is applied to the tension when the pressure-sensitive adhesive tape of the present invention is peeled off, and the reworkability of the pressure-sensitive adhesive tape of the present invention is further improved. The Young's modulus of the pressure-sensitive adhesive layer at 23° C. is 10 MPa or less, so that the pressure-sensitive adhesive layer does not become too hard, and the pressure-sensitive adhesive tape of the present invention has a higher adhesive strength. The Young's modulus of the pressure-sensitive adhesive layer at 23° C. is more preferably 0.012 MPa at its lower limit, 7 MPa at its upper limit, 0.014 MPa at its lower limit, and 5 MPa at its upper limit.
The Young's modulus of the pressure-sensitive adhesive layer can be measured, for example, by the following method.
That is, by carrying out a tensile test on the pressure-sensitive adhesive layer to measure the above-mentioned tensile stress at break and elongation at break, the Young's modulus of the pressure-sensitive adhesive layer can be obtained by calculating the slope in the linear region (elastic region) of the obtained stress-strain curve (S-S curve).
上記粘着剤層の23℃におけるヤング率を上述した範囲内に調整する方法としては、例えば、上記ビニルモノマー重合体や上記ウレタンポリマーの組成を変更する方法、上記架橋剤の種類や含有量を変更する方法、粘着付与樹脂等の添加物の種類や含有量を変更する方法等が挙げられる。 Methods for adjusting the Young's modulus at 23°C of the pressure-sensitive adhesive layer to fall within the above-mentioned range include, for example, changing the composition of the vinyl monomer polymer or the urethane polymer, changing the type or amount of the crosslinking agent, and changing the type or amount of additives such as tackifier resin.
本発明の粘着テープは基材を有さないノンサポートタイプの粘着テープであってもよいし、基材上に粘着剤層が形成されたサポートタイプの粘着テープであってもよい。なお、本発明の粘着テープが基材を有する場合、本発明の粘着テープは、上記基材の少なくとも一方の面に上記粘着剤層を有していればよく、即ち、基材の一方の面に上記粘着剤層を有する片面粘着テープであってもよく、基材の両面に上記粘着剤層を有する両面粘着テープであってもよい。 The adhesive tape of the present invention may be a non-support type adhesive tape that does not have a substrate, or a supported type adhesive tape in which an adhesive layer is formed on a substrate. When the adhesive tape of the present invention has a substrate, the adhesive tape of the present invention only needs to have the adhesive layer on at least one side of the substrate, that is, it may be a single-sided adhesive tape having the adhesive layer on one side of the substrate, or a double-sided adhesive tape having the adhesive layers on both sides of the substrate.
本発明の粘着テープが基材を有する場合、上記基材は特に限定されず、例えば、アクリル、オレフィン、ポリカーボネート、塩化ビニル、ABS、ポリエチレンテレフタレート(PET)、ナイロン、ウレタン、ポリイミド等の樹脂からなる樹脂シートや樹脂フィルム、網目状の構造を有するシートやフィルム、孔が開けられたシートやフィルム(発泡体シートや発泡体フィルム)等が挙げられる。なかでも、応力緩和性や段差追従性が優れるようになる観点から、上記基材は発泡体シートや発泡体フィルム等の発泡体基材を含むことが好ましい。
上記粘着剤を用いると、リワーク時に破断しやすい発泡体シート等の発泡体基材を基材として用いた場合であっても、リワーク性に優れた粘着テープを得ることができる。
When the pressure-sensitive adhesive tape of the present invention has a substrate, the substrate is not particularly limited, and examples thereof include resin sheets and films made of resins such as acrylic, olefin, polycarbonate, vinyl chloride, ABS, polyethylene terephthalate (PET), nylon, urethane, polyimide, etc., sheets and films having a mesh-like structure, sheets and films having holes (foam sheets and foam films), etc. Among these, from the viewpoint of achieving excellent stress relaxation properties and step conformability, it is preferable that the substrate contains a foam substrate such as a foam sheet or foam film.
By using the above pressure-sensitive adhesive, a pressure-sensitive adhesive tape with excellent reworkability can be obtained even when a foam substrate such as a foam sheet that is prone to breaking during rework is used as the substrate.
上記基材の厚みは、好ましい下限が5μmであり、好ましい上限が1000μmである。上記基材の厚みがこの範囲内であると、適度なコシがあって、取り扱い性に優れる粘着テープとすることができる。上記基材の厚みのより好ましい下限は10μm、より好ましい上限は500μm、更に好ましい上限は200μm、更により好ましい上限は150μmである。 The thickness of the substrate is preferably 5 μm at the lower limit and 1000 μm at the upper limit. If the thickness of the substrate is within this range, the adhesive tape will have appropriate stiffness and excellent handling properties. A more preferred lower limit of the thickness of the substrate is 10 μm, a more preferred upper limit is 500 μm, an even more preferred upper limit is 200 μm, and an even more preferred upper limit is 150 μm.
本発明の粘着テープの製造方法は特に限定されず、従来公知の製造方法により製造することができる。例えば、基材を有する両面粘着テープの場合には、以下の方法等が挙げられる。
まず、ビニルモノマー重合体、ウレタンポリマー、及び、架橋剤、更に必要に応じて粘着付与樹脂等を加えて、充分に撹拌することにより、粘着剤aの溶液を得る。得られた粘着剤aを基材の一方の面に塗布し、溶液中の溶剤を完全に乾燥除去して粘着剤層aを形成する。次に、形成された粘着剤層aの上に離型フィルムをその離型処理面が粘着剤層aに対向した状態で重ね合わせる。なお、上記化合物(C1)が上記(a)である場合は、上述したモノマー混合物、上述した光重合開始剤、上述したウレタンポリマー、及び、必要に応じて架橋剤等を混合し、アプリケーターを用いて離型PETフィルムに塗工し、塗工した上面を離型PETフィルムにて封止又は窒素雰囲気下として塗工面が空気に触れないようにしたうえでUV照射する方法にて重合を行うことにより粘着剤を得ながら粘着剤層を形成してもよい。
次いで、上記離型フィルムとは別の離型フィルムを用意し、この離型フィルムの離型処理面に、上記と同様の要領で調製した粘着剤bの溶液を塗布し、溶液中の溶剤を完全に乾燥除去することにより、離型フィルムの表面に粘着剤層bが形成された積層フィルムを作製する。得られた積層フィルムを一方の面に粘着剤層aが形成された基材の他方の面に、粘着剤層bが対向した状態に重ね合わせて積層体を作製する。そして、上記積層体をゴムローラ等によって加圧することによって、基材の両面に粘着剤層を有し、かつ、該粘着剤層の表面が離型フィルムで覆われた両面粘着テープを得ることができる。
The method for producing the pressure-sensitive adhesive tape of the present invention is not particularly limited, and the tape can be produced by a conventionally known production method. For example, in the case of a double-sided pressure-sensitive adhesive tape having a substrate, the following method can be mentioned.
First, a vinyl monomer polymer, a urethane polymer, and a crosslinking agent, and further a tackifier resin, etc., are added as necessary, and thoroughly stirred to obtain a solution of adhesive a. The obtained adhesive a is applied to one side of a substrate, and the solvent in the solution is completely dried and removed to form an adhesive layer a. Next, a release film is superimposed on the formed adhesive layer a with its release-treated surface facing the adhesive layer a. In addition, when the compound (C1) is the above (a), the above-mentioned monomer mixture, the above-mentioned photopolymerization initiator, the above-mentioned urethane polymer, and if necessary, a crosslinking agent, etc. are mixed and applied to a release PET film using an applicator, and the coated upper surface is sealed with a release PET film or placed under a nitrogen atmosphere so that the coated surface does not come into contact with air, and then polymerization is performed by UV irradiation to form an adhesive layer while obtaining an adhesive.
Next, a release film other than the above release film is prepared, and a solution of adhesive b prepared in the same manner as above is applied to the release-treated surface of this release film, and the solvent in the solution is completely dried and removed to produce a laminated film in which adhesive layer b is formed on the surface of the release film. The obtained laminated film is superimposed on the other surface of a substrate on one side of which adhesive layer a is formed, with adhesive layer b facing each other, to produce a laminate. Then, by pressing the laminate with a rubber roller or the like, a double-sided adhesive tape can be obtained that has adhesive layers on both sides of the substrate and the surface of the adhesive layer is covered with a release film.
また、同様の要領で積層フィルムを2組作製し、これらの積層フィルムを基材の両面のそれぞれに、積層フィルムの粘着剤層を基材に対向させた状態に重ね合わせて積層体を作製し、この積層体をゴムローラ等によって加圧することによって、基材の両面に粘着剤層を有し、かつ、該粘着剤層の表面が離型フィルムで覆われた両面粘着テープを得てもよい。 Alternatively, two sets of laminate films may be prepared in a similar manner, and these laminate films may be superimposed on both sides of a substrate with the adhesive layer of the laminate film facing the substrate to produce a laminate. By pressing this laminate with a rubber roller or the like, a double-sided adhesive tape having adhesive layers on both sides of the substrate and the surface of the adhesive layer covered with a release film may be obtained.
上記第1の構成において、本発明の粘着テープの23℃での剥離速度300mm/minにおけるSUSに対する180°剥離力の好ましい下限は5.0N/inchであり、好ましい上限は30.0N/inchである。本発明の粘着テープの23℃での剥離速度300mm/minにおけるSUSに対する180°剥離力が上記の範囲内にあることにより、本発明の粘着テープはより高い粘着力とより優れたリワーク性とを両立することができる。本発明の粘着テープの23℃での剥離速度300mm/minにおけるSUSに対する180°剥離力のより好ましい下限は7.0N/inch、より好ましい上限は25.0N/inch、更に好ましい下限は10.0N/inch、更に好ましい上限は20.0N/inchである。
上記第2の構成において、本発明の粘着テープの23℃での剥離速度300mm/minにおけるSUSに対する180°剥離力の下限は5.0N/inchであり、上限は30.0N/inchである。本発明の粘着テープの23℃での剥離速度300mm/minにおけるSUSに対する180°剥離力が上記の範囲内にあることにより、本発明の粘着テープはより高い粘着力とより優れたリワーク性とを両立することができる。本発明の粘着テープの23℃での剥離速度300mm/minにおけるSUSに対する180°剥離力の好ましい下限は7.0N/inch、好ましい上限は25.0N/inch、より好ましい下限は10.0N/inch、より好ましい上限は20.0N/inchである。
なお、上記23℃での剥離速度300mm/minにおけるSUSに対する180°剥離力の測定は、例えば、JIS Z0237に準拠して、引張試験機(エー・アンド・デイ社製、「RTI-1310」等)を用い、23℃、50%RH、剥離速度300mm/min、剥離角度180°の剥離試験を行うこと等により測定することができる。また、本発明の粘着テープが基材を有さないノンサポートタイプの粘着テープである場合、又は、本発明の粘着テープが基材を有する両面粘着テープである場合には、粘着テープの180°剥離力を測定しない面をPETフィルム等により裏打ちした試験片を作製し、作製した試験片を用いて剥離試験を行う。
In the first configuration, the preferred lower limit of the 180° peel strength of the pressure-sensitive adhesive tape of the present invention against SUS at a peel speed of 300 mm/min at 23° C. is 5.0 N/inch, and the preferred upper limit is 30.0 N/inch. When the 180° peel strength of the pressure-sensitive adhesive tape of the present invention against SUS at a peel speed of 300 mm/min at 23° C. is within the above range, the pressure-sensitive adhesive tape of the present invention can achieve both higher adhesive strength and better reworkability. The more preferred lower limit of the 180° peel strength of the pressure-sensitive adhesive tape of the present invention against SUS at a peel speed of 300 mm/min at 23° C. is 7.0 N/inch, and the more preferred upper limit is 25.0 N/inch, and the even more preferred lower limit is 10.0 N/inch, and the even more preferred upper limit is 20.0 N/inch.
In the second configuration, the lower limit of the 180° peel strength of the pressure-sensitive adhesive tape of the present invention against SUS at a peel speed of 300 mm/min at 23° C. is 5.0 N/inch, and the upper limit is 30.0 N/inch. When the 180° peel strength of the pressure-sensitive adhesive tape of the present invention against SUS at a peel speed of 300 mm/min at 23° C. is within the above range, the pressure-sensitive adhesive tape of the present invention can achieve both higher adhesive strength and better reworkability. The preferred lower limit of the 180° peel strength of the pressure-sensitive adhesive tape of the present invention against SUS at a peel speed of 300 mm/min at 23° C. is 7.0 N/inch, the preferred upper limit is 25.0 N/inch, the more preferred lower limit is 10.0 N/inch, and the more preferred upper limit is 20.0 N/inch.
The 180° peel strength against SUS at a peel speed of 300 mm/min at 23°C can be measured, for example, in accordance with JIS Z0237 using a tensile tester (such as "RTI-1310" manufactured by A&D Co., Ltd.) at 23°C, 50% RH, a peel speed of 300 mm/min, and a peel angle of 180°. When the pressure-sensitive adhesive tape of the present invention is a non-support type pressure-sensitive adhesive tape having no substrate, or when the pressure-sensitive adhesive tape of the present invention is a double-sided pressure-sensitive adhesive tape having a substrate, a test piece is prepared in which the surface of the pressure-sensitive adhesive tape on which the 180° peel strength is not measured is backed with a PET film or the like, and the peel test is performed using the prepared test piece.
上記23℃での剥離速度300mm/minにおけるSUSに対する180°剥離力を上述した範囲内に調整する方法としては、例えば、上記ビニルモノマー重合体や上記ウレタンポリマーの組成を変更する方法、上記架橋剤の種類や含有量を変更する方法、粘着付与樹脂等の添加物の種類や含有量を変更する方法、25℃以下の範囲で上記粘着剤のガラス転移温度を高くする方法等が挙げられる。 Methods for adjusting the 180° peel force against SUS at 23°C and a peel speed of 300 mm/min within the above range include, for example, changing the composition of the vinyl monomer polymer or urethane polymer, changing the type or amount of the crosslinking agent, changing the type or amount of additives such as tackifier resin, and increasing the glass transition temperature of the adhesive within a range of 25°C or less.
本発明の粘着テープの用途は特に限定されないが、電子部品又は車載部品の固定に用いられることが好ましい。具体的には、大型の携帯電子機器における電子部品の固定、車載部品(例えば、車載用パネル)の固定等に、本発明の粘着テープを好適に用いることができる。 The application of the adhesive tape of the present invention is not particularly limited, but it is preferably used to fasten electronic components or in-vehicle components. Specifically, the adhesive tape of the present invention can be suitably used for fastening electronic components in large portable electronic devices, fastening in-vehicle components (e.g., in-vehicle panels), etc.
ビニルモノマー重合体、及び、ウレタンポリマーを含有し、上記ビニルモノマー重合体は、下記(a)、(b)、又は、(c)から選択される化合物(C1)に由来する構成単位を有する粘着剤組成物もまた、本発明の1つである。
(a)芳香族基含有(メタ)アクリレートと窒素原子含有(メタ)アクリレート
(b)芳香族基含有(メタ)アクリレートに由来する構成単位及び窒素原子含有(メタ)アクリレートに由来する構成単位を有するポリマー
(c)芳香族基含有(メタ)アクリレートに由来する構成単位を有するポリマーと窒素原子含有(メタ)アクリレートに由来する構成単位を有するポリマー
本発明の粘着剤組成物は、高い粘着力と優れたリワーク性とを両立して発現することができる。
The present invention also provides a pressure-sensitive adhesive composition comprising a vinyl monomer polymer and a urethane polymer, the vinyl monomer polymer having a structural unit derived from a compound (C1) selected from the following (a), (b), or (c):
(a) an aromatic group-containing (meth)acrylate and a nitrogen atom-containing (meth)acrylate; (b) a polymer having a structural unit derived from an aromatic group-containing (meth)acrylate and a structural unit derived from a nitrogen atom-containing (meth)acrylate; (c) a polymer having a structural unit derived from an aromatic group-containing (meth)acrylate and a structural unit derived from a nitrogen atom-containing (meth)acrylate. The pressure-sensitive adhesive composition of the present invention can exhibit both high adhesive strength and excellent reworkability.
本発明の粘着剤組成物において、上記ビニルモノマー重合体は、下記(a)、(b)、又は、(c)から選択される化合物(C1)に由来する構成単位を有する。
(a)芳香族基含有(メタ)アクリレートと窒素原子含有(メタ)アクリレート
(b)芳香族基含有(メタ)アクリレートに由来する構成単位及び窒素原子含有(メタ)アクリレートに由来する構成単位を有するポリマー
(c)芳香族基含有(メタ)アクリレートに由来する構成単位を有するポリマーと窒素原子含有(メタ)アクリレートに由来する構成単位を有するポリマー
上記化合物(C1)は、ウレタンポリマーとの相溶性に優れるため、本発明の粘着剤組成物において、上記ビニルモノマー重合体が上記(a)、(b)、又は、(c)から選択される化合物(C1)に由来する構成単位を有することにより、上記ビニルモノマー重合体が後述するウレタンポリマーとの相溶性に優れる。そのため、上記化合物(C1)及び上記化合物(C1)に由来する構成単位を有するビニルモノマー重合体と後述するウレタンポリマーとの架橋が均一に進行するようになる。その結果、本発明の粘着剤組成物から得られる粘着剤に含有される架橋生成物はビニルモノマー重合体構造とウレタンポリマー構造とを有し、本発明の粘着剤組成物から得られる粘着剤が高い粘着力と優れたリワーク性とを両立することができるようになる。また、上記化合物(C1)と上記ウレタンポリマーとの相溶性が優れることで、本発明の粘着剤組成物から得られる粘着剤はミクロ相分離による界面形成を抑制することができ、引張り時に樹脂破断しにくくなる結果、リワーク性に優れるものとなる。
In the pressure-sensitive adhesive composition of the present invention, the vinyl monomer polymer has a structural unit derived from a compound (C1) selected from the following (a), (b), or (c):
(a) aromatic group-containing (meth)acrylate and nitrogen atom-containing (meth)acrylate (b) polymer having a structural unit derived from aromatic group-containing (meth)acrylate and a structural unit derived from nitrogen atom-containing (meth)acrylate (c) polymer having a structural unit derived from aromatic group-containing (meth)acrylate and a structural unit derived from nitrogen atom-containing (meth)acrylate The compound (C1) has excellent compatibility with urethane polymers, so that in the pressure-sensitive adhesive composition of the present invention, the vinyl monomer polymer has a structural unit derived from the compound (C1) selected from the above (a), (b), or (c), and thus the vinyl monomer polymer has excellent compatibility with the urethane polymer described below. Therefore, crosslinking between the vinyl monomer polymer having the structural unit derived from the compound (C1) and the compound (C1) and the urethane polymer described below proceeds uniformly. As a result, the crosslinked product contained in the pressure-sensitive adhesive obtained from the pressure-sensitive adhesive composition of the present invention has a vinyl monomer polymer structure and a urethane polymer structure, and the pressure-sensitive adhesive obtained from the pressure-sensitive adhesive composition of the present invention can achieve both high adhesion and excellent reworkability. In addition, since the compatibility between the compound (C1) and the urethane polymer is excellent, the pressure-sensitive adhesive obtained from the pressure-sensitive adhesive composition of the present invention can suppress interface formation due to microphase separation, and the resin is less likely to break when pulled, resulting in excellent reworkability.
本発明の粘着剤組成物における、上記芳香族基含有(メタ)アクリレートとしては、例えば、ベンジルアクリレート、フェノキシエチル(メタ)アクリレート、フェノキシジエチレングリコールアクリレート、メチルフェノキシエチルアクリレート、2-ヒドロキシ-3-フェノキシプロピルアクリレート、2-([1,1’―ビフェニル]-2-イルオキシ)エチル(メタ)アクリレート等が挙げられる。なかでも、粘着特性の観点から、フェノキシエチル(メタ)アクリレート、フェノキシジエチレングリコールアクリレートが好ましい。 In the pressure-sensitive adhesive composition of the present invention, examples of the aromatic group-containing (meth)acrylate include benzyl acrylate, phenoxyethyl (meth)acrylate, phenoxydiethylene glycol acrylate, methylphenoxyethyl acrylate, 2-hydroxy-3-phenoxypropyl acrylate, 2-([1,1'-biphenyl]-2-yloxy)ethyl (meth)acrylate, etc. Among these, from the viewpoint of adhesive properties, phenoxyethyl (meth)acrylate and phenoxydiethylene glycol acrylate are preferred.
本発明の粘着剤組成物において、上記ビニルモノマー重合体全体中における上記芳香族基含有(メタ)アクリレートに由来する構成単位の含有割合の好ましい下限は5質量%であり、好ましい上限は95質量%である。上記芳香族基含有(メタ)アクリレートに由来する構成単位の含有割合が5質量%以上であることにより、本発明の粘着剤組成物から得られる粘着剤がより硬くなるため、リワーク性がより向上する。上記芳香族基含有(メタ)アクリレートに由来する構成単位の含有割合が95質量%以下であることにより、本発明の粘着剤組成物から得られる粘着剤が硬くなりすぎず、より高い粘着力を発揮できるようになる。上記芳香族基含有(メタ)アクリレートに由来する構成単位の含有割合のより好ましい下限は10質量%、より好ましい上限は90質量%、更に好ましい下限は15質量%、更に好ましい上限は85質量%である。 In the pressure-sensitive adhesive composition of the present invention, the preferred lower limit of the content ratio of the constituent units derived from the aromatic group-containing (meth)acrylate in the entire vinyl monomer polymer is 5% by mass, and the preferred upper limit is 95% by mass. When the content ratio of the constituent units derived from the aromatic group-containing (meth)acrylate is 5% by mass or more, the adhesive obtained from the pressure-sensitive adhesive composition of the present invention becomes harder, and the reworkability is further improved. When the content ratio of the constituent units derived from the aromatic group-containing (meth)acrylate is 95% by mass or less, the adhesive obtained from the pressure-sensitive adhesive composition of the present invention does not become too hard, and can exhibit higher adhesive strength. A more preferred lower limit of the content ratio of the constituent units derived from the aromatic group-containing (meth)acrylate is 10% by mass, a more preferred upper limit is 90% by mass, an even more preferred lower limit is 15% by mass, and an even more preferred upper limit is 85% by mass.
本発明の粘着剤組成物における、上記窒素原子含有(メタ)アクリレートとしては、例えば、ウレタン結合含有(メタ)アクリレート、イミド結合含有(メタ)アクリレート、(メタ)アクリルアミド等が挙げられる。なかでも、後述するウレタンポリマーとの相溶性により優れる観点から、上記窒素原子含有(メタ)アクリレートは、ウレタン結合含有(メタ)アクリレート及びイミド結合含有(メタ)アクリレートからなる群より選択される少なくとも1種を含むことが好ましく、ウレタン結合含有(メタ)アクリレートを含むことがより好ましい。 In the pressure-sensitive adhesive composition of the present invention, examples of the nitrogen atom-containing (meth)acrylate include urethane bond-containing (meth)acrylate, imide bond-containing (meth)acrylate, (meth)acrylamide, and the like. In particular, from the viewpoint of having better compatibility with the urethane polymer described below, the nitrogen atom-containing (meth)acrylate preferably contains at least one selected from the group consisting of urethane bond-containing (meth)acrylate and imide bond-containing (meth)acrylate, and more preferably contains urethane bond-containing (meth)acrylate.
上記ウレタン結合含有(メタ)アクリレートとしては、例えば、1,2-エタンジオール1-アクリラート2-(N-ブチルカルバマート)等が挙げられる。
上記イミド結合含有(メタ)アクリレートとしては、例えば、N-[2-(アクリロイルオキシ)エチル]フタルイミド等が挙げられる。
Examples of the urethane bond-containing (meth)acrylate include 1,2-ethanediol 1-acrylate 2-(N-butylcarbamate).
The imide bond-containing (meth)acrylate may, for example, be N-[2-(acryloyloxy)ethyl]phthalimide.
本発明の粘着剤組成物において、上記ビニルモノマー重合体全体中における上記窒素原子含有(メタ)アクリレートに由来する構成単位の含有割合の好ましい下限は5質量%であり、好ましい上限は95質量%である。上記窒素原子含有(メタ)アクリレートに由来する構成単位の含有割合が5質量%以上であることにより、本発明の粘着剤組成物から得られる粘着剤がより硬くなるため、リワーク性がより向上する。上記窒素原子含有(メタ)アクリレートに由来する構成単位の含有割合が95質量%以下であることにより、本発明の粘着剤組成物から得られる粘着剤が硬くなりすぎず、より高い粘着力を発揮できるようになる。上記窒素原子含有(メタ)アクリレートに由来する構成単位の含有割合のより好ましい下限は10質量%、より好ましい上限は90質量%、更に好ましい下限は15質量%、更に好ましい上限は85質量%である。 In the adhesive composition of the present invention, the preferred lower limit of the content ratio of the constituent units derived from the nitrogen atom-containing (meth)acrylate in the entire vinyl monomer polymer is 5% by mass, and the preferred upper limit is 95% by mass. When the content ratio of the constituent units derived from the nitrogen atom-containing (meth)acrylate is 5% by mass or more, the adhesive obtained from the adhesive composition of the present invention becomes harder, and the reworkability is further improved. When the content ratio of the constituent units derived from the nitrogen atom-containing (meth)acrylate is 95% by mass or less, the adhesive obtained from the adhesive composition of the present invention does not become too hard, and can exhibit higher adhesive strength. The more preferred lower limit of the content ratio of the constituent units derived from the nitrogen atom-containing (meth)acrylate is 10% by mass, the more preferred upper limit is 90% by mass, the even more preferred lower limit is 15% by mass, and the even more preferred upper limit is 85% by mass.
本発明の粘着剤組成物において、上記芳香族基含有(メタ)アクリレートに由来する構成単位と上記窒素原子含有(メタ)アクリレートに由来する構成単位との合計100質量部中における上記芳香族基含有(メタ)アクリレートに由来する構成単位の含有量の好ましい下限は5質量部であり、好ましい上限は95質量部である。上記芳香族基含有(メタ)アクリレートに由来する構成単位の含有量が上記範囲内であることにより、上記化合物(C1)及び上記化合物(C1)に由来する構成単位を有するビニルモノマー重合体が後述するウレタンポリマーとの相溶性により優れるようになるため、本発明の粘着剤組成物から得られる粘着剤がより高い粘着力とより優れたリワーク性とを両立することができるようになる。上記芳香族基含有(メタ)アクリレートに由来する構成単位の含有量のより好ましい下限は10質量部、より好ましい上限は90質量部、更に好ましい下限は15質量部、更に好ましい上限は85質量部である。 In the pressure-sensitive adhesive composition of the present invention, the preferred lower limit of the content of the structural unit derived from the aromatic group-containing (meth)acrylate in the total of 100 parts by mass of the structural unit derived from the aromatic group-containing (meth)acrylate and the structural unit derived from the nitrogen atom-containing (meth)acrylate is 5 parts by mass, and the preferred upper limit is 95 parts by mass. When the content of the structural unit derived from the aromatic group-containing (meth)acrylate is within the above range, the compound (C1) and the vinyl monomer polymer having the structural unit derived from the compound (C1) have better compatibility with the urethane polymer described below, so that the pressure-sensitive adhesive obtained from the pressure-sensitive adhesive composition of the present invention can achieve both higher adhesive strength and better reworkability. The more preferred lower limit of the content of the structural unit derived from the aromatic group-containing (meth)acrylate is 10 parts by mass, the more preferred upper limit is 90 parts by mass, the even more preferred lower limit is 15 parts by mass, and the even more preferred upper limit is 85 parts by mass.
本発明の粘着剤組成物における、上記ビニルモノマー重合体は、更に、水酸基含有(メタ)アクリレートに由来する構成単位を有することが好ましい。
上記ビニルモノマー重合体が水酸基含有(メタ)アクリレートに由来する構成単位を有することにより、後述する架橋剤による上記化合物(C1)と後述するウレタンポリマーとの架橋がより進行しやすくなる。その結果、本発明の粘着剤組成物がより硬化するため、破断強度がより向上し、本発明の粘着剤組成物から得られる粘着剤のリワーク性がより向上する。
なお、本明細書中において、芳香族基と水酸基とを含有する(メタ)アクリレートに由来する構成単位は、芳香族基含有(メタ)アクリレートに由来する構成単位とする。
また、本明細書中において、窒素原子と水酸基とを含有する(メタ)アクリレートに由来する構成単位は、窒素原子含有(メタ)アクリレートに由来する構成単位とする。
In the pressure-sensitive adhesive composition of the present invention, the vinyl monomer polymer preferably further has a structural unit derived from a hydroxyl group-containing (meth)acrylate.
The vinyl monomer polymer has a structural unit derived from a hydroxyl group-containing (meth)acrylate, which facilitates crosslinking between the compound (C1) and the urethane polymer by a crosslinking agent described below. As a result, the adhesive composition of the present invention is cured more, so that the breaking strength is improved and the reworkability of the adhesive obtained from the adhesive composition of the present invention is improved.
In this specification, a structural unit derived from a (meth)acrylate containing an aromatic group and a hydroxyl group is referred to as a structural unit derived from an aromatic group-containing (meth)acrylate.
In this specification, a structural unit derived from a (meth)acrylate containing a nitrogen atom and a hydroxyl group is referred to as a structural unit derived from a nitrogen-atom-containing (meth)acrylate.
本発明の粘着剤組成物における、上記水酸基含有(メタ)アクリレートとしては、例えば、2-ヒドロキシエチル(メタ)アクリレート、4-ヒドロキシブチル(メタ)アクリレート、3-ヒドロキシプロピル(メタ)アクリレート、テトラヒドロキシフルフリル(メタ)アクリレート等が挙げられる。 Examples of the hydroxyl group-containing (meth)acrylate in the pressure-sensitive adhesive composition of the present invention include 2-hydroxyethyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, and tetrahydroxyfurfuryl (meth)acrylate.
本発明の粘着剤組成物において、上記ビニルモノマー重合体全体中における上記水酸基含有(メタ)アクリレートに由来する構成単位の含有割合の好ましい下限は0.01質量%であり、好ましい上限は20質量%である。上記水酸基含有(メタ)アクリレートに由来する構成単位の含有割合が0.01質量%以上であることにより、本発明の粘着剤組成物から得られる粘着剤のリワーク性がより向上する。上記水酸基含有(メタ)アクリレートに由来する構成単位の含有割合が20質量%以下であることにより、本発明の粘着剤組成物から得られるが硬くなりすぎず、粘着剤がより高い粘着力を発揮できるようになる。上記水酸基含有(メタ)アクリレートに由来する構成単位の含有割合のより好ましい下限は0.1質量%、より好ましい上限は10質量%、更に好ましい下限は0.5質量%、更に好ましい上限は5.0質量%である。 In the adhesive composition of the present invention, the preferred lower limit of the content ratio of the structural unit derived from the hydroxyl group-containing (meth)acrylate in the entire vinyl monomer polymer is 0.01% by mass, and the preferred upper limit is 20% by mass. When the content ratio of the structural unit derived from the hydroxyl group-containing (meth)acrylate is 0.01% by mass or more, the reworkability of the adhesive obtained from the adhesive composition of the present invention is further improved. When the content ratio of the structural unit derived from the hydroxyl group-containing (meth)acrylate is 20% by mass or less, the adhesive obtained from the adhesive composition of the present invention is not too hard, and the adhesive can exhibit higher adhesive strength. A more preferred lower limit of the content ratio of the structural unit derived from the hydroxyl group-containing (meth)acrylate is 0.1% by mass, a more preferred upper limit is 10% by mass, an even more preferred lower limit is 0.5% by mass, and an even more preferred upper limit is 5.0% by mass.
本発明の粘着剤組成物における、上記ビニルモノマー重合体は、更に、アルキル(メタ)アクリレートに由来する構成単位を有していてもよい。 The vinyl monomer polymer in the pressure-sensitive adhesive composition of the present invention may further have a structural unit derived from an alkyl (meth)acrylate.
本発明の粘着剤組成物における、上記アルキル(メタ)アクリレートとしては、例えば、メチル(メタ)アクリレート、エチル(メタ)アクリレート、n-プロピル(メタ)アクリレート、イソプロピル(メタ)アクリレート、n-ブチル(メタ)アクリレート、n-ヘプチル(メタ)アクリレート、2-エチルヘキシル(メタ)アクリレート、2-オクチル(メタ)アクリレート、イソオクチル(メタ)アクリレート、n-ノニル(メタ)アクリレート、イソノニル(メタ)アクリレート、ラウリル(メタ)アクリレート、ミリスチル(メタ)アクリレート、セチル(メタ)アクリレート、イソステアリルアクリレート、アラキジル(メタ)アクリレート等が挙げられる。なかでも、後述するウレタンポリマーとの相溶性の観点から、アルキル鎖長の短いアルキル(メタ)アクリレートが好ましく、具体的にはn-ブチル(メタ)アクリレート、2-エチルヘキシル(メタ)アクリレートが好ましい。 Examples of the alkyl (meth)acrylate in the adhesive composition of the present invention include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, n-heptyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, 2-octyl (meth)acrylate, isooctyl (meth)acrylate, n-nonyl (meth)acrylate, isononyl (meth)acrylate, lauryl (meth)acrylate, myristyl (meth)acrylate, cetyl (meth)acrylate, isostearyl acrylate, and arachidyl (meth)acrylate. Among these, from the viewpoint of compatibility with the urethane polymer described below, alkyl (meth)acrylates with short alkyl chain lengths are preferred, specifically n-butyl (meth)acrylate and 2-ethylhexyl (meth)acrylate.
本発明の粘着剤組成物における、上記ビニルモノマー重合体は、更に、上記芳香族基含有(メタ)アクリレートに由来する構成単位、上記窒素原子含有(メタ)アクリレートに由来する構成単位、上記水酸基含有(メタ)アクリレートに由来する構成単位、及び、上記アルキル(メタ)アクリレートに由来する構成単位以外のその他のモノマーに由来する構成単位を有していてもよい。 The vinyl monomer polymer in the pressure-sensitive adhesive composition of the present invention may further have a structural unit derived from the aromatic group-containing (meth)acrylate, a structural unit derived from the nitrogen atom-containing (meth)acrylate, a structural unit derived from the hydroxyl group-containing (meth)acrylate, and a structural unit derived from a monomer other than the structural unit derived from the alkyl (meth)acrylate.
本発明の粘着剤組成物において、上記ビニルモノマー重合体が上記(b)に由来する構成単位を有する場合、上記芳香族基含有(メタ)アクリレートに由来する構成単位及び窒素原子含有(メタ)アクリレートに由来する構成単位を有するポリマーの重量平均分子量(Mw)の好ましい下限は20万であり、好ましい上限は200万である。上記芳香族基含有(メタ)アクリレートに由来する構成単位及び窒素原子含有(メタ)アクリレートに由来する構成単位を有するポリマーの重量平均分子量が20万以上であることにより、本発明の粘着剤組成物から得られる粘着剤のリワーク性がより向上する。上記芳香族基含有(メタ)アクリレートに由来する構成単位及び窒素原子含有(メタ)アクリレートに由来する構成単位を有するポリマーの重量平均分子量が200万以下であることにより、本発明の粘着剤組成物から得られる粘着剤の粘着力がより向上する。上記芳香族基含有(メタ)アクリレートに由来する構成単位及び窒素原子含有(メタ)アクリレートに由来する構成単位を有するポリマーの重量平均分子量のより好ましい下限は40万、より好ましい上限は150万、更に好ましい下限は60万、更に好ましい上限は100万である。 In the pressure-sensitive adhesive composition of the present invention, when the vinyl monomer polymer has a structural unit derived from the above (b), the weight-average molecular weight (Mw) of the polymer having a structural unit derived from the aromatic group-containing (meth)acrylate and a structural unit derived from the nitrogen atom-containing (meth)acrylate is preferably 200,000 in lower limit and 2,000,000 in upper limit. When the weight-average molecular weight of the polymer having a structural unit derived from the aromatic group-containing (meth)acrylate and a structural unit derived from the nitrogen atom-containing (meth)acrylate is 200,000 or more, the reworkability of the pressure-sensitive adhesive obtained from the pressure-sensitive adhesive composition of the present invention is further improved. When the weight-average molecular weight of the polymer having a structural unit derived from the aromatic group-containing (meth)acrylate and a structural unit derived from the nitrogen atom-containing (meth)acrylate is 2,000,000 or less, the adhesive strength of the pressure-sensitive adhesive obtained from the pressure-sensitive adhesive composition of the present invention is further improved. The weight average molecular weight of the polymer having a structural unit derived from the aromatic group-containing (meth)acrylate and a structural unit derived from the nitrogen atom-containing (meth)acrylate is more preferably 400,000 in lower limit, 1,500,000 in upper limit, 600,000 in even more preferred lower limit, and 1,000,000 in even more preferred upper limit.
本発明の粘着剤組成物において、本発明の粘着剤組成物において、上記ビニルモノマー重合体が上記(c)に由来する構成単位を有する場合、上記芳香族基含有(メタ)アクリレートに由来する構成単位を有するポリマーの重量平均分子量(Mw)の好ましい下限は20万であり、好ましい上限は200万である。上記芳香族基含有(メタ)アクリレートに由来する構成単位を有するポリマーの重量平均分子量が20万以上であることにより、本発明の粘着剤組成物から得られる粘着剤のリワーク性がより向上する。上記芳香族基含有(メタ)アクリレートに由来する構成単位を有するポリマーの重量平均分子量が200万以下であることにより、本発明の粘着剤組成物から得られる粘着剤の粘着力がより向上する。上記芳香族基含有(メタ)アクリレートに由来する構成単位を有するポリマーの重量平均分子量のより好ましい下限は40万、より好ましい上限は150万、更に好ましい下限は60万、更に好ましい上限は100万である。 In the pressure-sensitive adhesive composition of the present invention, when the vinyl monomer polymer has a structural unit derived from the above (c), the weight-average molecular weight (Mw) of the polymer having a structural unit derived from the aromatic group-containing (meth)acrylate is preferably 200,000 in lower limit and 2,000,000 in upper limit. When the weight-average molecular weight of the polymer having a structural unit derived from the aromatic group-containing (meth)acrylate is 200,000 or more, the reworkability of the pressure-sensitive adhesive obtained from the pressure-sensitive adhesive composition of the present invention is further improved. When the weight-average molecular weight of the polymer having a structural unit derived from the aromatic group-containing (meth)acrylate is 2,000,000 or less, the adhesive strength of the pressure-sensitive adhesive obtained from the pressure-sensitive adhesive composition of the present invention is further improved. The weight-average molecular weight of the polymer having a structural unit derived from the aromatic group-containing (meth)acrylate is more preferably 400,000 in lower limit and 1,500,000 in upper limit, even more preferably 600,000 in lower limit and even more preferably 1,000,000 in upper limit.
本発明の粘着剤組成物において、上記ビニルモノマー重合体が上記(c)に由来する構成単位を有する場合、上記窒素原子含有(メタ)アクリレートに由来する構成単位を有するポリマーの重量平均分子量(Mw)の好ましい下限は20万であり、好ましい上限は200万である。上記窒素原子含有(メタ)アクリレートに由来する構成単位を有するポリマーの重量平均分子量が20万以上であることにより、本発明の粘着剤組成物から得られる粘着剤のリワーク性がより向上する。上記窒素原子含有(メタ)アクリレートに由来する構成単位を有するポリマーの重量平均分子量が200万以下であることにより、本発明の粘着剤組成物から得られる粘着剤の粘着力がより向上する。上記窒素原子含有(メタ)アクリレートに由来する構成単位を有するポリマーの重量平均分子量のより好ましい下限は40万、より好ましい上限は150万、更に好ましい下限は60万、更に好ましい上限は100万である。 In the pressure-sensitive adhesive composition of the present invention, when the vinyl monomer polymer has a structural unit derived from (c), the weight-average molecular weight (Mw) of the polymer having a structural unit derived from the nitrogen-containing (meth)acrylate is preferably 200,000 in lower limit and 2,000,000 in upper limit. When the weight-average molecular weight of the polymer having a structural unit derived from the nitrogen-containing (meth)acrylate is 200,000 or more, the reworkability of the pressure-sensitive adhesive obtained from the pressure-sensitive adhesive composition of the present invention is further improved. When the weight-average molecular weight of the polymer having a structural unit derived from the nitrogen-containing (meth)acrylate is 2,000,000 or less, the adhesive strength of the pressure-sensitive adhesive obtained from the pressure-sensitive adhesive composition of the present invention is further improved. The weight-average molecular weight of the polymer having a structural unit derived from the nitrogen-containing (meth)acrylate is more preferably 400,000 in lower limit and 1,500,000 in upper limit, even more preferably 600,000 in lower limit and even more preferably 1,000,000 in upper limit.
本発明の粘着剤組成物における、上記化合物(C1)が上記(b)又は上記(c)である場合、上記ビニルモノマー重合体を製造する方法としては、例えば、上記芳香族基含有(メタ)アクリレート及び上記窒素原子含有(メタ)アクリレート、必要に応じて上記水酸基含有(メタ)アクリレート、上記アルキル(メタ)アクリレート、上記その他のモノマー等の原料となるモノマー混合物を重合開始剤の存在下にてラジカル反応させて重合すること等によって得ることができる。
上記モノマー混合物を重合する方法としては、従来公知の方法を用いることができ、例えば、溶液重合(沸点重合又は定温重合)、UV重合、エマルジョン重合、懸濁重合、塊状重合等が挙げられる。なかでも、本発明の粘着剤組成物から得られる粘着剤の粘着力がより高くなることから、溶液重合、UV重合が好ましい。
上記モノマー混合物を重合する方法として溶液重合を用いる場合、反応溶剤としては、例えば、酢酸エチル、トルエン、メチルエチルケトン、ジメチルスルホキシド、エタノール、アセトン、ジエチルエーテル等が挙げられる。これらの反応溶剤は、単独で用いられてもよいし、2種以上が組み合わせて用いられてもよい。
When the compound (C1) in the pressure-sensitive adhesive composition of the present invention is the compound (b) or (c), the vinyl monomer polymer can be produced, for example, by polymerizing a monomer mixture serving as raw materials such as the aromatic group-containing (meth)acrylate and the nitrogen atom-containing (meth)acrylate, and if necessary the hydroxyl group-containing (meth)acrylate, the alkyl (meth)acrylate, and the other monomers by radical reaction in the presence of a polymerization initiator.
The method for polymerizing the monomer mixture may be a conventionally known method, such as solution polymerization (boiling point polymerization or constant temperature polymerization), UV polymerization, emulsion polymerization, suspension polymerization, bulk polymerization, etc. Among these, solution polymerization and UV polymerization are preferred because they result in higher adhesive strength of the adhesive obtained from the adhesive composition of the present invention.
When solution polymerization is used as a method for polymerizing the monomer mixture, examples of the reaction solvent include ethyl acetate, toluene, methyl ethyl ketone, dimethyl sulfoxide, ethanol, acetone, diethyl ether, etc. These reaction solvents may be used alone or in combination of two or more kinds.
上記重合開始剤としては、例えば、溶液重合する場合は、アゾ化合物、有機過酸化物等が挙げられ、UV重合する場合は、ベンゾフェノン系化合物、アセトフェノン系化合物、アルキルフェノン系化合物、アシルフォスフィンオキサイド系化合物、チタノセン系化合物、オキシムエステル系化合物、ベンゾインエーテル系化合物、チオキサントン等の光重合開始剤等が挙げられる。
上記アゾ化合物としては、例えば、2,2’-アゾビス(イソブチロニトリル)、2,2’-アゾビス(2-メチルブチロニトリル)、2,2’-アゾビス(2,4-ジメチルバレロニトリル)、2,2’-アゾビス(4-メトキシ-2,4-ジメチルバレロニトリル)、1,1-アゾビス(シクロヘキサン-1-カルボニトリル)、1-((1-シアノ-1-メチルエチル)アゾ)ホルムアミド、4,4’-アゾビス(4-シアノバレリアン酸)、ジメチル-2,2’-アゾビス(2-メチルプロピオネート)、ジメチル-1,1’-アゾビス(1-シクロヘキサンカルボキシレート)、2,2’-アゾビス(2-メチル-N-(1,1’-ビス(ヒドロキシメチル)-2-ヒドロキシエチル)プロピオンアミド)、2,2’-アゾビス(2-メチル-N-(2-ヒドロキシエチル)プロピオンアミド)、2,2’-アゾビス(N-(2-プロペニル)-2-メチルプロピオンアミド)、2,2’-アゾビス(N-ブチル-2-メチルプロピオンアミド)、2,2’-アゾビス(N-シクロヘキシル-2-メチルプロピオンアミド)、2,2’-アゾビス(2-(2-イミダゾリン-2-イル)プロパン)二塩酸塩、2,2’-アゾビス(2-(1-(2-ヒドロキシエチル)-2-イミダゾリン-2-イル)プロパン)二塩酸塩、2,2’-アゾビス(2-(2-イミダゾリン-2-イル)プロパン)、2,2’-アゾビス(2-アミジノプロパン)二塩酸塩、2,2’-アゾビス(N-(2-カルボキシエチル)-2-メチルプロピオンアミジン)四水和物、2,2’-アゾビス(1-イミノ-1-ピロリジノ-2-メチルプロパン)二塩酸塩、2,2’-アゾビス(2,4,4-トリメチルペンタン)等が挙げられる。これらのアゾ化合物は、単独で用いられてもよいし、2種以上が組み合わせて用いられてもよい。
上記有機過酸化物としては、例えば、1,1-ビス(t-ヘキシルパーオキシ)-3,3,5-トリメチルシクロヘキサン、t-ヘキシルパーオキシピバレート、t-ブチルパーオキシピバレート、2,5-ジメチル-2,5-ビス(2-エチルヘキサノイルパーオキシ)ヘキサン、t-ヘキシルパーオキシ-2-エチルヘキサノエート、t-ブチルパーオキシ-2-エチルヘキサノエート、t-ブチルパーオキシイソブチレート、t-ブチルパーオキシ-3,5,5-トリメチルヘキサノエート、t-ブチルパーオキシラウレート等が挙げられる。これらの有機過酸化物は、単独で用いられてもよいし、2種以上が組み合わせて用いられてもよい。
上記光重合開始剤としては、例えば、Omnirad 184、Omnirad 369、Omnirad 379、Omnirad 379EG、Omnirad 651、Omnirad 784、Omnirad 819、Omnirad 907、Omnirad 2959、Omnirad TPO(いずれもIGM Resins社製)、Omnirad OXE01(BASF社製)、ベンゾインメチルエーテル、ベンゾインエチルエーテル、ベンゾインイソプロピルエーテル(いずれも東京化成工業社製)等が挙げられる。これらの光重合開始剤は、単独で用いられてもよいし、2種以上が組み合わせて用いられてもよい。
Examples of the polymerization initiator include, in the case of solution polymerization, azo compounds and organic peroxides, and in the case of UV polymerization, photopolymerization initiators such as benzophenone compounds, acetophenone compounds, alkylphenone compounds, acylphosphine oxide compounds, titanocene compounds, oxime ester compounds, benzoin ether compounds, and thioxanthone can be used.
Examples of the azo compound include 2,2'-azobis(isobutyronitrile), 2,2'-azobis(2-methylbutyronitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), 1,1-azobis(cyclohexane-1-carbonitrile), 1-((1-cyano-1-methylethyl)azo)formamide, 4,4'-azobis(4-cyanovaleric acid), dimethyl-2,2'-azobis(2-methylpropionate), dimethyl-1,1'-azobis(1-cyclohexanecarboxylate), 2,2'-azobis(2-methyl-N-(1,1'-bis(hydroxymethyl)-2-hydroxyethyl)propionamide), 2,2'-azobis(2-methyl-N-(2-hydroxyethyl)propionamide), 2,2 '-Azobis(N-(2-propenyl)-2-methylpropionamide), 2,2'-azobis(N-butyl-2-methylpropionamide), 2,2'-azobis(N-cyclohexyl-2-methylpropionamide), 2,2'-azobis(2-(2-imidazolin-2-yl)propane) dihydrochloride, 2,2'-azobis(2-(1-(2-hydroxyethyl)-2-imidazolin-2-yl)propane) ) dihydrochloride, 2,2'-azobis(2-(2-imidazolin-2-yl)propane), 2,2'-azobis(2-amidinopropane) dihydrochloride, 2,2'-azobis(N-(2-carboxyethyl)-2-methylpropionamidine) tetrahydrate, 2,2'-azobis(1-imino-1-pyrrolidino-2-methylpropane) dihydrochloride, 2,2'-azobis(2,4,4-trimethylpentane), and the like. These azo compounds may be used alone or in combination of two or more.
Examples of the organic peroxides include 1,1-bis(t-hexylperoxy)-3,3,5-trimethylcyclohexane, t-hexylperoxypivalate, t-butylperoxypivalate, 2,5-dimethyl-2,5-bis(2-ethylhexanoylperoxy)hexane, t-hexylperoxy-2-ethylhexanoate, t-butylperoxy-2-ethylhexanoate, t-butylperoxyisobutyrate, t-butylperoxy-3,5,5-trimethylhexanoate, t-butylperoxylaurate, etc. These organic peroxides may be used alone or in combination of two or more.
Examples of the photopolymerization initiator include Omnirad 184, Omnirad 369, Omnirad 379, Omnirad 379EG, Omnirad 651, Omnirad 784, Omnirad 819, Omnirad 907, Omnirad 2959, Omnirad TPO (all manufactured by IGM Resins), Omnirad OXE01 (manufactured by BASF), benzoin methyl ether, benzoin ethyl ether, and benzoin isopropyl ether (all manufactured by Tokyo Chemical Industry Co., Ltd.). These photopolymerization initiators may be used alone or in combination of two or more.
本発明の粘着剤組成物における、上記ウレタンポリマーは、ポリオール化合物とポリイソシアネート化合物との反応により得られる化合物である。
上記ポリオール化合物が炭素数の少ないポリオールジオールの場合、上記ウレタンポリマーの構成単位として極性が高いハードセグメントが得られる。上記ウレタンポリマーが上記ハードセグメントを含むことにより、得られるウレタンポリマーは水素結合を介する物理架橋によって凝集力がより向上し、本発明の粘着剤組成物から得られる粘着剤のリワーク性がより向上する。
一方、上記ポリオール化合物が炭素数の多いポリオールの場合、上記ウレタンポリマーの構成単位として極性の低いソフトセグメントが得られる。上記ウレタンポリマーが上記ソフトセグメントを含むことにより、得られるウレタンポリマーの変形に対する自由度がより向上する結果、本発明の粘着剤組成物から得られる粘着剤の粘着力がより向上する。
なかでも、上記化合物(C1)及び上記化合物(C1)に由来する構成単位を有するビニルモノマー重合体との相溶性に優れる観点から、上記ウレタンポリマーは上記ハードセグメントを含有することが好ましい。
The urethane polymer in the pressure-sensitive adhesive composition of the present invention is a compound obtained by reacting a polyol compound with a polyisocyanate compound.
When the polyol compound is a polyol diol having a small number of carbon atoms, a hard segment having high polarity is obtained as a constituent unit of the urethane polymer. By including the hard segment in the urethane polymer, the cohesive strength of the obtained urethane polymer is improved by physical crosslinking via hydrogen bonds, and the reworkability of the pressure-sensitive adhesive obtained from the pressure-sensitive adhesive composition of the present invention is improved.
On the other hand, when the polyol compound is a polyol having a large number of carbon atoms, a soft segment having low polarity is obtained as a constituent unit of the urethane polymer. By including the soft segment in the urethane polymer, the degree of freedom of deformation of the obtained urethane polymer is further improved, and as a result, the adhesive strength of the adhesive obtained from the adhesive composition of the present invention is further improved.
In particular, from the viewpoint of excellent compatibility with the compound (C1) and a vinyl monomer polymer having a structural unit derived from the compound (C1), it is preferable that the urethane polymer contains the hard segment.
本発明の粘着剤組成物における、上記ウレタンポリマーの製造方法は特に限定されないが、例えば、ポリオール化合物とポリイソシアネート化合物とを混合して撹拌すること等によって得られる。なお、ポリオール化合物とポリイソシアネート化合物との反応は、ウレタンポリマーの製造に採用される任意の適切な方法によって行い得る。また、この反応において、必要に応じて、イソシアネート基が反応し得る活性水素を持たない有機溶媒(例えば、酢酸エチル、メチルエチルケトン、クロロホルム等)と、触媒(例えば、スズ塩化物や有機スズ化合物等の有機金属触媒類、3級アミン化合物等の有機塩基類、酢酸やアクリル酸等の有機酸類等)とを加え、反応を行うこともできる。 The method for producing the urethane polymer in the pressure-sensitive adhesive composition of the present invention is not particularly limited, but may be, for example, obtained by mixing and stirring a polyol compound and a polyisocyanate compound. The reaction between the polyol compound and the polyisocyanate compound may be carried out by any suitable method employed in the production of urethane polymers. In addition, in this reaction, if necessary, an organic solvent that does not have active hydrogen with which the isocyanate group can react (e.g., ethyl acetate, methyl ethyl ketone, chloroform, etc.) and a catalyst (e.g., organometallic catalysts such as tin chloride and organotin compounds, organic bases such as tertiary amine compounds, organic acids such as acetic acid and acrylic acid, etc.) may be added to carry out the reaction.
本発明の粘着剤組成物における、上記ポリオール化合物としては、例えば、ポリエステルポリオール(2価のアルコールとアジピン酸、アゼライン酸、セパチン酸等の2価の塩基酸との重縮合物等)、ポリエーテルポリオール(エチレンオキサイド、テトラヒドロフラン等を付加重合して得られるもの等)、ポリアクリレートポリオール、ポリカーボネートポリオール、ポリオレフィンポリオール、ポリブタジエンポリオール又はその水添物、ポリイソプレンポリオール又はその水添物、フェノーリックポリオール、エポキシポリオール、カプロラクトンポリオール、ポリスルホンポリオール等が挙げられる。また、ポリオール化合物として、ポリエステル・ポリエーテルポリオールのような共重合体ポリオールも挙げられる。
なかでも、得られるウレタンポリマーの極性がより向上し、上記化合物(C1)及び上記化合物(C1)に由来する構成単位を有するビニルモノマー重合体との相溶性に優れる観点から、ポリエーテルジオール、ポリエステルジオール、及び、ポリカーボネートジオールからなる群より選択される少なくとも1種を含むことが好ましい。そのなかでも、凝集力並びに上記化合物(C1)及び上記化合物(C1)に由来する構成単位を有するビニルモノマー重合体との相溶性の観点から、ポリエステルジオール、及び、ポリカーボネートジオールからなる群より選択される1種を含むことがより好ましく、ポリカーボネートジオールを含むことが更に好ましい。即ち、上記ウレタンポリマーは、ポリエーテルジオールに由来する構成単位、ポリエステルジオールに由来する構成単位、及び、ポリカーボネートジオールに由来する構成単位からなる群より選択される少なくとも1種を有することが好ましい。また、上記ウレタンポリマーは、ポリエステルジオールに由来する構成単位、及び、ポリカーボネートジオールに由来する構成単位からなる群より選択される少なくとも1種を有することがより好ましく、上記ウレタンポリマーは、ポリカーボネートジオールに由来する構成単位を有することが更に好ましい。
これらのポリオール化合物は1種のみを用いても、2種以上併用してもよい。
Examples of the polyol compound in the pressure-sensitive adhesive composition of the present invention include polyester polyols (polycondensates of dihydric alcohols and divalent basic acids such as adipic acid, azelaic acid, sepatic acid, etc.), polyether polyols (those obtained by addition polymerization of ethylene oxide, tetrahydrofuran, etc.), polyacrylate polyols, polycarbonate polyols, polyolefin polyols, polybutadiene polyols or hydrogenated products thereof, polyisoprene polyols or hydrogenated products thereof, phenolic polyols, epoxy polyols, caprolactone polyols, polysulfone polyols, etc. Also included as polyol compounds are copolymer polyols such as polyester-polyether polyols.
Among them, from the viewpoint of further improving the polarity of the obtained urethane polymer and excellent compatibility with the vinyl monomer polymer having the structural unit derived from the compound (C1) and the compound (C1), it is preferable to include at least one selected from the group consisting of polyether diol, polyester diol, and polycarbonate diol. Among them, from the viewpoint of cohesive force and compatibility with the vinyl monomer polymer having the structural unit derived from the compound (C1) and the compound (C1), it is more preferable to include one selected from the group consisting of polyester diol and polycarbonate diol, and it is even more preferable to include polycarbonate diol. That is, it is preferable that the urethane polymer has at least one selected from the group consisting of structural units derived from polyether diol, structural units derived from polyester diol, and structural units derived from polycarbonate diol. In addition, it is more preferable that the urethane polymer has at least one selected from the group consisting of structural units derived from polyester diol and structural units derived from polycarbonate diol, and it is even more preferable that the urethane polymer has structural units derived from polycarbonate diol.
These polyol compounds may be used alone or in combination of two or more.
本発明の粘着剤組成物における、上記ポリカーボネートジオール合成に用いられるジオール化合物としては、例えば、上述したポリオール化合物のうち、水酸基の価数が2であるもの等が挙げられる。これらのジオール化合物は1種のみを用いても、2種以上併用してもよい。 In the pressure-sensitive adhesive composition of the present invention, the diol compound used in the synthesis of the polycarbonate diol may be, for example, one of the polyol compounds described above in which the hydroxyl group has a valence of 2. These diol compounds may be used alone or in combination of two or more.
本発明の粘着剤組成物において、上記ウレタンポリマー中における上記ポリカーボネートジオールに由来する構成単位の含有割合の好ましい下限は3質量%であり、好ましい上限は70質量%である。上記ポリカーボネートジオールに由来する構成単位の含有割合が3質量%以上であることにより、得られるウレタンポリマーの凝集力がより向上し、本発明の粘着剤組成物から得られる粘着剤のリワーク性がより向上する。上記ポリカーボネートジオールに由来する構成単位の含有割合が70質量%以下であることにより、得られるウレタンポリマーの変形に対する自由度がより向上する結果、本発明の粘着剤組成物から得られる粘着剤の粘着力がより向上する。上記ポリカーボネートジオールに由来する構成単位の含有割合のより好ましい下限は5質量%、より好ましい上限は60質量%、更に好ましい下限は7質量%、更に好ましい上限は50質量%である。 In the pressure-sensitive adhesive composition of the present invention, the preferred lower limit of the content of the structural unit derived from the polycarbonate diol in the urethane polymer is 3% by mass, and the preferred upper limit is 70% by mass. When the content of the structural unit derived from the polycarbonate diol is 3% by mass or more, the cohesive strength of the obtained urethane polymer is further improved, and the reworkability of the adhesive obtained from the pressure-sensitive adhesive composition of the present invention is further improved. When the content of the structural unit derived from the polycarbonate diol is 70% by mass or less, the degree of freedom of deformation of the obtained urethane polymer is further improved, and as a result, the adhesive strength of the adhesive obtained from the pressure-sensitive adhesive composition of the present invention is further improved. A more preferred lower limit of the content of the structural unit derived from the polycarbonate diol is 5% by mass, a more preferred upper limit is 60% by mass, an even more preferred lower limit is 7% by mass, and an even more preferred upper limit is 50% by mass.
上記ウレタンポリマー中における上記ポリエステルジオールに由来する構成単位の含有割合の好ましい下限は3質量%であり、好ましい上限は70質量%である。上記ポリエステルジオールに由来する構成単位の含有割合が3質量%以上であることにより、得られるウレタンポリマーの凝集力がより向上し、本発明の粘着剤組成物から得られる粘着剤のリワーク性がより向上する。上記ポリエステルジオールに由来する構成単位の含有割合が70質量%以下であることにより、得られるウレタンポリマーの変形に対する自由度がより向上する結果、本発明の粘着剤組成物から得られる粘着剤の粘着力がより向上する。上記ポリエステルジオールに由来する構成単位の含有割合のより好ましい下限は5質量%、より好ましい上限は60質量%、更に好ましい下限は7質量%、更に好ましい上限は50質量%である。 The preferred lower limit of the content of the constituent units derived from the polyester diol in the urethane polymer is 3% by mass, and the preferred upper limit is 70% by mass. When the content of the constituent units derived from the polyester diol is 3% by mass or more, the cohesive strength of the resulting urethane polymer is improved, and the reworkability of the adhesive obtained from the adhesive composition of the present invention is improved. When the content of the constituent units derived from the polyester diol is 70% by mass or less, the degree of freedom of deformation of the resulting urethane polymer is improved, and as a result, the adhesive strength of the adhesive obtained from the adhesive composition of the present invention is improved. The more preferred lower limit of the content of the constituent units derived from the polyester diol is 5% by mass, the more preferred upper limit is 60% by mass, the even more preferred lower limit is 7% by mass, and the even more preferred upper limit is 50% by mass.
本発明の粘着剤組成物において、上記ウレタンポリマー中における上記ポリエーテルジオールに由来する構成単位の含有割合の好ましい下限は3質量%であり、好ましい上限は70質量%である。上記ポリエーテルジオールに由来する構成単位の含有割合が3質量%以上であることにより、得られるウレタンポリマーの凝集力がより向上し、本発明の粘着剤組成物から得られる粘着剤のリワーク性がより向上する。上記ポリエーテルジオールに由来する構成単位の含有割合が70質量%以下であることにより、得られるウレタンポリマーの変形に対する自由度がより向上する結果、本発明の粘着剤組成物から得られる粘着剤の粘着力がより向上する。上記ポリエーテルジオールに由来する構成単位の含有割合のより好ましい下限は5質量%、より好ましい上限は60質量%、更に好ましい下限は7質量%、更に好ましい上限は50質量%である。 In the pressure-sensitive adhesive composition of the present invention, the preferred lower limit of the content of the structural unit derived from the polyether diol in the urethane polymer is 3% by mass, and the preferred upper limit is 70% by mass. When the content of the structural unit derived from the polyether diol is 3% by mass or more, the cohesive strength of the obtained urethane polymer is further improved, and the reworkability of the adhesive obtained from the pressure-sensitive adhesive composition of the present invention is further improved. When the content of the structural unit derived from the polyether diol is 70% by mass or less, the degree of freedom of deformation of the obtained urethane polymer is further improved, and as a result, the adhesive strength of the adhesive obtained from the pressure-sensitive adhesive composition of the present invention is further improved. A more preferred lower limit of the content of the structural unit derived from the polyether diol is 5% by mass, a more preferred upper limit is 60% by mass, an even more preferred lower limit is 7% by mass, and an even more preferred upper limit is 50% by mass.
本発明の粘着剤組成物における、上記ポリエーテルジオールに由来する構成単位を有するウレタンポリマーとしては、例えば、AG8451(ルーブリゾール社製)等が挙げられる。 In the pressure-sensitive adhesive composition of the present invention, examples of the urethane polymer having structural units derived from the above polyether diol include AG8451 (manufactured by Lubrizol Corporation).
本発明の粘着剤組成物から得られる粘着剤のリワーク性の観点からは、上記ポリオール化合物は水酸基の数が3以上のアルコール化合物を含んでいてもよい。 From the viewpoint of the reworkability of the adhesive obtained from the adhesive composition of the present invention, the above polyol compound may contain an alcohol compound having three or more hydroxyl groups.
本発明の粘着剤組成物における、上記ポリイソシアネート化合物としては、例えば、ジフェニルメタンジイソシアネート、トリレンジイソシアネート、ナフタレン-1,5-ジイソシアネート、ヘキサメチレンジイソシアネート、トリメチルヘキサメチレンジイソシアネート、リジンジイソシアネート、ノルボルナンジイソシアネート、トランスシクロヘキサン-1,4-ジイソシアネート、イソホロンジイソシアネート、水添キシリレンジイソシアネート、水添ジフェニルメタンジイソシアネート、シクロヘキサンジイソシアネート、ビス(イソシアネートメチル)シクロヘキサン、ジシクロヘキシルメタンジイソシアネート等が挙げられる。また、上記ポリイソシアネート化合物として、上述したポリイソシアネート化合物の変性体を用いてもよい。ポリイソシアネート化合物の変性体としては、例えば、上述したポリイソシアネート化合物のビュレット変性体、上述したポリイソシアネート化合物のイソシアヌレート変性体や、グリセリン、トリメチロールプロパン、又は、これらにプロピレンオキサイド、エチレンオキサイド等のアルキレンオキサイドを付加重合したポリオールに、上述したポリイソシアネート化合物を反応させて得たアダクト体、ポリメリックMDIとも呼ばれるポリメチレンポリフェニルポリイソシアネート等が挙げられる。なかでも、上記化合物(C1)及び上記化合物(C1)に由来する構成単位を有するビニルモノマー重合体との相溶性に優れ、より高いリワーク性を発揮することができ、かつ、より高い粘着力を発揮することができる観点から、芳香族基を含有するポリイソシアネート化合物が好ましく、なかでも、ジフェニルメタンジイソシアネート、ジフェニルメタンジイソシアネートの液状変性物等のジフェニルメタンジイソシアネートの変性体がより好ましい。これらのポリイソシアネート化合物は1種のみを用いても、2種以上を併用してもよい。 Examples of the polyisocyanate compound in the adhesive composition of the present invention include diphenylmethane diisocyanate, tolylene diisocyanate, naphthalene-1,5-diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, lysine diisocyanate, norbornane diisocyanate, transcyclohexane-1,4-diisocyanate, isophorone diisocyanate, hydrogenated xylylene diisocyanate, hydrogenated diphenylmethane diisocyanate, cyclohexane diisocyanate, bis(isocyanatemethyl)cyclohexane, dicyclohexylmethane diisocyanate, etc. Modified products of the above-mentioned polyisocyanate compounds may also be used as the polyisocyanate compound. Examples of the modified polyisocyanate compound include biuret modified polyisocyanate compounds, isocyanurate modified polyisocyanate compounds, adducts obtained by reacting the polyisocyanate compounds with polyols obtained by addition polymerization of glycerin, trimethylolpropane, or alkylene oxides such as propylene oxide and ethylene oxide with these compounds, and polymethylene polyphenyl polyisocyanate, also called polymeric MDI. Among these, polyisocyanate compounds containing aromatic groups are preferred from the viewpoint of excellent compatibility with the above-mentioned compound (C1) and vinyl monomer polymers having structural units derived from the above-mentioned compound (C1), high reworkability, and high adhesive strength, and among these, modified diphenylmethane diisocyanate compounds such as diphenylmethane diisocyanate and liquid modified diphenylmethane diisocyanate are more preferred. These polyisocyanate compounds may be used alone or in combination of two or more.
本発明の粘着剤組成物において、本発明の粘着剤組成物から得られる粘着剤のリワーク性の観点からは、上記ポリイソシアネート化合物はイソシアネート基の数が3以上のイソシアネート化合物を含むことが好ましい。
本発明の粘着剤組成物において、上記ウレタンポリマー中におけるイソシアネート基の数が3以上のイソシアネート化合物に由来する構成単位の含有割合の好ましい下限は0.1質量%であり、好ましい上限は20質量%である。上記イソシアネート基の数が3以上のイソシアネート化合物に由来する構成単位の含有割合が上記範囲内であることにより、本発明の粘着剤組成物から得られる粘着剤はより高い粘着力とより優れたリワーク性とを両立することができるようになる。より好ましい下限は0.5質量%、より好ましい上限は10質量%である。
In the pressure-sensitive adhesive composition of the present invention, from the viewpoint of the reworkability of the pressure-sensitive adhesive obtained from the pressure-sensitive adhesive composition of the present invention, the polyisocyanate compound preferably contains an isocyanate compound having three or more isocyanate groups.
In the pressure-sensitive adhesive composition of the present invention, the preferred lower limit of the content ratio of the structural unit derived from an isocyanate compound having 3 or more isocyanate groups in the urethane polymer is 0.1% by mass, and the preferred upper limit is 20% by mass. By having the content ratio of the structural unit derived from an isocyanate compound having 3 or more isocyanate groups within the above range, the pressure-sensitive adhesive obtained from the pressure-sensitive adhesive composition of the present invention can achieve both higher adhesive strength and better reworkability. The more preferred lower limit is 0.5% by mass, and the more preferred upper limit is 10% by mass.
本発明の粘着剤組成物において、上記ウレタンポリマーは、芳香族基含有化合物に由来する構成単位を有することが好ましい。上記ウレタンポリマーが、芳香族基含有化合物に由来する構成単位を有することにより、本発明の粘着剤のリワーク性がより向上する。
上記芳香族基含有化合物としては、例えば、上述したポリオール化合物のうち芳香族基を含有する化合物や上述した芳香族基を含有するポリイソシアネート化合物等が挙げられる。
In the pressure-sensitive adhesive composition of the present invention, the urethane polymer preferably has a structural unit derived from an aromatic group-containing compound. When the urethane polymer has a structural unit derived from an aromatic group-containing compound, the reworkability of the pressure-sensitive adhesive of the present invention is further improved.
Examples of the aromatic group-containing compound include the above-mentioned polyol compounds containing an aromatic group and the above-mentioned polyisocyanate compounds containing an aromatic group.
本発明の粘着剤組成物において、上記ウレタンポリマーの重量平均分子量(Mw)の好ましい下限は3000であり、好ましい上限は30万である。上記ウレタンポリマーの重量平均分子量が3000以上であることにより、本発明の粘着剤のリワーク性がより向上する。上記ウレタンポリマーの重量平均分子量が30万以下であることにより、本発明の粘着剤組成物から得られる粘着剤の粘着力がより向上する。上記ウレタンポリマーの重量平均分子量のより好ましい下限は5000、より好ましい上限は25万、更に好ましい下限は7000、更に好ましい上限は20万である。 In the pressure-sensitive adhesive composition of the present invention, the preferred lower limit of the weight-average molecular weight (Mw) of the urethane polymer is 3,000, and the preferred upper limit is 300,000. When the weight-average molecular weight of the urethane polymer is 3,000 or more, the reworkability of the pressure-sensitive adhesive of the present invention is further improved. When the weight-average molecular weight of the urethane polymer is 300,000 or less, the adhesive strength of the pressure-sensitive adhesive obtained from the pressure-sensitive adhesive composition of the present invention is further improved. A more preferred lower limit of the weight-average molecular weight of the urethane polymer is 5,000, a more preferred upper limit is 250,000, an even more preferred lower limit is 7,000, and an even more preferred upper limit is 200,000.
本発明の粘着剤組成物において、上記ビニルモノマー重合体と上記ウレタンポリマーとの合計100質量部中における上記ウレタンポリマーの含有量の好ましい下限は5質量部であり、好ましい上限は90質量部である。
上記ウレタンポリマーの含有量が上記範囲内にあることにより、本発明の粘着剤組成物から得られる粘着剤がより高い粘着力とより優れたリワーク性とを両立することができるようになる。上記ウレタンポリマーの含有量のより好ましい下限は10質量部、より好ましい上限は70質量部、更に好ましい下限は15質量部、更に好ましい上限は60質量部である。
In the pressure-sensitive adhesive composition of the present invention, the preferred lower limit of the content of the urethane polymer in 100 parts by mass of the total of the vinyl monomer polymer and the urethane polymer is 5 parts by mass, and the preferred upper limit is 90 parts by mass.
By the content of the urethane polymer being within the above range, the pressure-sensitive adhesive obtained from the pressure-sensitive adhesive composition of the present invention can achieve both higher adhesive strength and better reworkability. The more preferred lower limit of the content of the urethane polymer is 10 parts by mass, the more preferred upper limit is 70 parts by mass, the even more preferred lower limit is 15 parts by mass, and the even more preferred upper limit is 60 parts by mass.
本発明の粘着剤組成物において、上記架橋生成物において上記ウレタンポリマーと上記ビニルモノマー重合体とは、架橋剤によって架橋されている場合、上記架橋剤としては、例えば、イソシアネート系架橋剤、アジリジン系架橋剤、エポキシ系架橋剤、金属キレート型架橋剤等が挙げられる。なかでも、水酸基に対して選択的に架橋することができ、架橋構造を制御しやすいことから、イソシアネート系架橋剤が好ましい。 In the pressure-sensitive adhesive composition of the present invention, when the urethane polymer and the vinyl monomer polymer in the crosslinked product are crosslinked by a crosslinking agent, examples of the crosslinking agent include an isocyanate-based crosslinking agent, an aziridine-based crosslinking agent, an epoxy-based crosslinking agent, and a metal chelate-type crosslinking agent. Among these, an isocyanate-based crosslinking agent is preferred because it can selectively crosslink hydroxyl groups and is easy to control the crosslinked structure.
上記イソシアネート系架橋剤としては、例えば、コロネートHX、ミリオネートMR200(いずれも東ソー社製)等が挙げられる。 Examples of the isocyanate-based crosslinking agent include Coronate HX and Millionate MR200 (both manufactured by Tosoh Corporation).
本発明の粘着剤組成物における、上記粘着剤組成物及び架橋との合計中における上記架橋剤の含有割合の好ましい下限は0.1質量%であり、好ましい上限は20質量%である。上記架橋剤の含有割合が0.1質量%以上であることにより、上記粘着剤がより硬化ができ、本発明の粘着剤組成物から得られる粘着剤のリワーク性がより向上する。上記架橋剤の含有割合が20質量%以下であることにより、本発明の粘着剤組成物から得られる粘着剤が硬くなりすぎず、本発明の粘着テープはより高い粘着力を発揮することができるようになる。 In the adhesive composition of the present invention, the preferred lower limit of the content of the crosslinking agent in the total of the adhesive composition and the crosslinker is 0.1 mass %, and the preferred upper limit is 20 mass %. When the content of the crosslinking agent is 0.1 mass % or more, the adhesive can be cured more, and the reworkability of the adhesive obtained from the adhesive composition of the present invention is further improved. When the content of the crosslinking agent is 20 mass % or less, the adhesive obtained from the adhesive composition of the present invention does not become too hard, and the adhesive tape of the present invention can exhibit higher adhesive strength.
本発明の粘着剤組成物は、更に、粘着付与樹脂(タッキファイア)を含有していてもよい。本発明の粘着剤組成物が粘着付与樹脂を含有することにより、粘着力がより向上する。 The pressure-sensitive adhesive composition of the present invention may further contain a tackifier resin. By containing a tackifier resin, the pressure-sensitive adhesive composition of the present invention has improved adhesive strength.
本発明の粘着剤組成物における、上記粘着付与樹脂としては、例えば、ロジンエステル系樹脂等のロジン系樹脂、テルペンフェノール樹脂等のテルペン系樹脂、石油系樹脂等が挙げられる。なかでも、極性が比較的高く、上記ビニルモノマー重合体や上記ウレタンポリマーとの相溶性に優れるロジン系樹脂、テルペンフェノール樹脂が好ましい。これらの粘着付与樹脂は、単独で用いられてもよいし、2種以上が組み合わせて用いられてもよい。 The tackifier resin in the pressure-sensitive adhesive composition of the present invention may be, for example, a rosin-based resin such as a rosin ester-based resin, a terpene-based resin such as a terpene phenol resin, or a petroleum-based resin. Among these, rosin-based resins and terpene phenol resins are preferred because they have relatively high polarity and excellent compatibility with the vinyl monomer polymer and the urethane polymer. These tackifier resins may be used alone or in combination of two or more.
本発明の粘着剤組成物における、上記ロジンエステル系樹脂とは、アビエチン酸を主成分とするロジン樹脂、不均化ロジン樹脂、水添ロジン樹脂、アビエチン酸等の樹脂酸の二量体(重合ロジン樹脂)等を、アルコールによってエステル化させて得られた樹脂である。エステル化に用いたアルコールの水酸基の一部がエステル化に使用されずに樹脂内に含有されることで、水酸基価が上述した範囲に調整される。アルコールとしては、エチレングリコール、グリセリン、ペンタエリスリトール等の多価アルコールが挙げられる。
なお、ロジン樹脂をエステル化した樹脂がロジンエステル樹脂、不均化ロジン樹脂をエステル化した樹脂が不均化ロジンエステル樹脂、水添ロジン樹脂をエステル化した樹脂が水添ロジンエステル樹脂、重合ロジン樹脂をエステル化した樹脂が重合ロジンエステル樹脂である。
The rosin ester resin in the pressure-sensitive adhesive composition of the present invention is a resin obtained by esterifying a rosin resin mainly composed of abietic acid, a disproportionated rosin resin, a hydrogenated rosin resin, a dimer of a resin acid such as abietic acid (polymerized rosin resin), etc., with an alcohol. A part of the hydroxyl group of the alcohol used for esterification is not used for esterification and is contained in the resin, so that the hydroxyl value is adjusted to the above-mentioned range. Examples of the alcohol include polyhydric alcohols such as ethylene glycol, glycerin, and pentaerythritol.
In addition, a resin obtained by esterifying a rosin resin is a rosin ester resin, a resin obtained by esterifying a disproportionated rosin resin is a disproportionated rosin ester resin, a resin obtained by esterifying a hydrogenated rosin resin is a hydrogenated rosin ester resin, and a resin obtained by esterifying a polymerized rosin resin is a polymerized rosin ester resin.
本発明の粘着剤組成物における、上記テルペンフェノール樹脂は、フェノールの存在下においてテルペンを重合させて得られた樹脂である。 The terpene phenol resin in the pressure-sensitive adhesive composition of the present invention is a resin obtained by polymerizing terpene in the presence of phenol.
本発明の粘着剤組成物において、本発明の粘着剤組成物中における粘着付与樹脂の含有割合の好ましい下限は1質量%であり、好ましい上限は60質量%である。上記粘着付与樹脂の含有割合が1質量%以上であることにより、本発明の粘着剤組成物から得られる粘着剤がより高い粘着力を発揮できるようになる。上記粘着付与樹脂の含有割合が60質量%以下であることにより、本発明の粘着剤組成物から得られる粘着剤の粘着力が高くなりすぎず、本発明の粘着剤組成物から得られる粘着剤のリワーク性がより向上する。上記粘着付与樹脂の含有割合のより好ましい下限は3質量%、より好ましい上限は50質量%、更に好ましい下限は5質量%、更に好ましい上限は40質量%である。 In the adhesive composition of the present invention, the preferred lower limit of the content of the tackifier resin in the adhesive composition of the present invention is 1 mass%, and the preferred upper limit is 60 mass%. When the content of the tackifier resin is 1 mass% or more, the adhesive obtained from the adhesive composition of the present invention can exhibit higher adhesive strength. When the content of the tackifier resin is 60 mass% or less, the adhesive strength of the adhesive obtained from the adhesive composition of the present invention is not too high, and the reworkability of the adhesive obtained from the adhesive composition of the present invention is further improved. A more preferred lower limit of the content of the tackifier resin is 3 mass%, a more preferred upper limit is 50 mass%, an even more preferred lower limit is 5 mass%, and an even more preferred upper limit is 40 mass%.
本発明の粘着剤組成物は、本発明の効果を損なわない範囲において、更に、必要に応じて、シランカップリング剤、可塑剤、軟化剤、充填剤、顔料、染料等の添加剤等を含有していてもよい。 The pressure-sensitive adhesive composition of the present invention may further contain additives such as silane coupling agents, plasticizers, softeners, fillers, pigments, dyes, etc., as necessary, within the scope of the invention's effects.
本発明の粘着剤組成物における上記ビニルモノマー重合体、及び、上記ウレタンポリマーの架橋生成物を含有する粘着剤もまた、本発明の1つである。
本発明の粘着剤が、上記粘着剤組成物における上記ウレタンポリマー、及び、上記ビニルモノマー重合体の架橋生成物を含有することにより、上記架橋生成物が有するウレタンポリマー構造によって、本発明の粘着剤はリワーク性に優れ、一方、上記架橋生成物が有するビニルモノマー重合体構造によって、本発明の粘着剤が高い粘着力を有するものになる。また、上記架橋生成物はビニルモノマー重合体構造とウレタンポリマー構造とを架橋している構造であるため、粘着剤が硬くなり、リワーク性が向上する。即ち、上記架橋生成物を含有することにより、本発明の粘着剤は、高い粘着力と優れたリワーク性とを両立することができるようになる。
上記粘着剤組成物におけるビニルモノマー重合体、及び、ウレタンポリマーの架橋生成物は、上記ビニルモノマー重合体、及び、上記ウレタンポリマーが架橋剤によって架橋されていてもよく、重合開始剤によって架橋されていてもよいが、なかでも、被着体へのより優れた密着性を発揮できるようになる観点から、上記ビニルモノマー重合体、及び、上記ウレタンポリマーが架橋剤によって架橋されていることが好ましい。
The pressure-sensitive adhesive composition of the present invention also includes a pressure-sensitive adhesive containing the crosslinked product of the vinyl monomer polymer and the urethane polymer.
The adhesive of the present invention contains the crosslinked product of the urethane polymer and the vinyl monomer polymer in the adhesive composition, and the crosslinked product has a urethane polymer structure, which makes the adhesive of the present invention excellent in reworkability, while the crosslinked product has a vinyl monomer polymer structure, which makes the adhesive of the present invention high in adhesion. In addition, the crosslinked product has a structure in which the vinyl monomer polymer structure and the urethane polymer structure are crosslinked, so the adhesive becomes hard and the reworkability is improved. That is, by containing the crosslinked product, the adhesive of the present invention can achieve both high adhesion and excellent reworkability.
In the crosslinked product of the vinyl monomer polymer and the urethane polymer in the pressure-sensitive adhesive composition, the vinyl monomer polymer and the urethane polymer may be crosslinked with a crosslinking agent or may be crosslinked with a polymerization initiator. In particular, from the viewpoint of exhibiting better adhesion to the adherend, it is preferred that the vinyl monomer polymer and the urethane polymer are crosslinked with a crosslinking agent.
上記粘着剤を製造する方法は特に限定されず、従来公知の方法等により製造することができる。具体的には例えば、ウレタンポリマー、ビニルモノマー重合体又は上記化合物(C1)、及び、必要に応じて粘着付与樹脂等を溶剤に加えて得た粘着剤組成物に対して、架橋剤を加えた後、充分に撹拌することにより、製造することができる。
また、上記化合物(C1)が上記(a)である場合は、上述したモノマー混合物、上述した光重合開始剤、及び、上記ウレタンポリマーを混合し、アプリケーターを用いて離型PETフィルムや基材上に塗工し、塗工した上面を離型PETフィルムにて封止又は窒素雰囲気下として塗工面が空気に触れないようにしたうえでUV照射する方法にて重合を行うことにより粘着剤を得ることもできる。
The method for producing the pressure-sensitive adhesive is not particularly limited, and the pressure-sensitive adhesive can be produced by a conventionally known method, etc. Specifically, for example, the pressure-sensitive adhesive can be produced by adding a crosslinking agent to a pressure-sensitive adhesive composition obtained by adding a urethane polymer, a vinyl monomer polymer, or the compound (C1), and optionally a tackifier resin, etc., to a solvent, and then thoroughly stirring the mixture.
In addition, when the compound (C1) is the compound (a), the above-mentioned monomer mixture, the above-mentioned photopolymerization initiator, and the above-mentioned urethane polymer are mixed, and the mixture is applied onto a release PET film or a substrate using an applicator. The upper surface of the coated layer is sealed with a release PET film or placed under a nitrogen atmosphere to prevent the coated surface from coming into contact with air, and then polymerized by UV irradiation to obtain a pressure-sensitive adhesive.
本発明によれば、高い粘着力と優れたリワーク性とを両立する粘着テープを提供することができる。また、本発明によれば、高い粘着力と優れたリワーク性とを両立して発現できる粘着剤組成物を提供することができる。更に、本発明によれば、該粘着剤組成物から得られる粘着剤を提供することができる。 According to the present invention, it is possible to provide an adhesive tape that combines high adhesive strength and excellent reworkability. In addition, according to the present invention, it is possible to provide an adhesive composition that can combine high adhesive strength and excellent reworkability. Furthermore, according to the present invention, it is possible to provide an adhesive obtained from the adhesive composition.
以下に実施例を挙げて本発明の態様を更に詳しく説明するが、本発明はこれら実施例のみに限定されない。 The following examples further illustrate aspects of the present invention, but the present invention is not limited to these examples.
(ウレタンポリマーの製造)
(ポリカーボネート系ポリウレタンU1の製造)
ポリオール化合物として100質量部のポリカーボネートジオール(クラレ社製、「Kuraraypolyol C-1090」)と、0.01質量部のジブチルスズジラウレートとを500mL容量のセパラブルフラスコに入れた。フラスコ内を真空下(20mmHg以下)、100℃で30分間撹拌して混合した。その後常圧とし、更に、ポリイソシアネート化合物として19質量部のジフェニルメタンジイソシアネート(日曹商事社製、「Pure MDI」)を加えて、80℃で3時間撹拌して反応させ、ポリカーボネート系ポリウレタンU1を得た。得られたポリカーボネート系ポリウレタンU1の重量平均分子量は17000であった。
(Production of urethane polymer)
(Production of polycarbonate-based polyurethane U1)
100 parts by mass of polycarbonate diol (Kuraray Co., Ltd., "Kuraraypolyol C-1090") as a polyol compound and 0.01 parts by mass of dibutyltin dilaurate were placed in a 500 mL separable flask. The flask was stirred and mixed for 30 minutes at 100°C under vacuum (20 mmHg or less). Thereafter, the pressure was returned to normal, and 19 parts by mass of diphenylmethane diisocyanate (Nisso Shoji Co., Ltd., "Pure MDI") as a polyisocyanate compound was added, and the mixture was stirred and reacted at 80°C for 3 hours to obtain polycarbonate-based polyurethane U1. The weight average molecular weight of the obtained polycarbonate-based polyurethane U1 was 17,000.
(ポリカーボネート系ポリウレタンU2の製造)
ジフェニルメタンジイソシアネート(日曹商事社製、「Pure MDI」)を23.5質量部とした以外は、ポリカーボネート系ポリウレタンU1と同様にしてポリカーボネート系ポリウレタンU2を得た。得られたポリカーボネート系ポリウレタンU2の重量平均分子量は70000であった。
(Production of polycarbonate-based polyurethane U2)
A polycarbonate-based polyurethane U2 was obtained in the same manner as in the polycarbonate-based polyurethane U1, except that diphenylmethane diisocyanate (manufactured by Nisso Shoji Co., Ltd., "Pure MDI") was used in an amount of 23.5 parts by mass. The weight average molecular weight of the obtained polycarbonate-based polyurethane U2 was 70,000.
(ポリエステル系ポリウレタンU3の製造)
ポリオール化合物として100質量部のポリエステルジオール(宇部興産社製、「エタナコール3010」)を用いたこと以外は、ポリカーボネート系ポリウレタンU1と同様にしてポリエステル系ポリウレタンU3を得た。得られたポリエステル系ポリウレタンU3の重量平均分子量は17000であった。
(Production of polyester-based polyurethane U3)
A polyester-based polyurethane U3 was obtained in the same manner as in the polycarbonate-based polyurethane U1, except that 100 parts by mass of polyester diol (manufactured by Ube Industries, Ltd., "Ethanacole 3010") was used as the polyol compound. The weight average molecular weight of the obtained polyester-based polyurethane U3 was 17,000.
(ポリエーテル系ポリウレタンU4の製造)
ポリオール化合物として100質量部のポリエーテルジオール(保土谷化学社製、「PTC-L3500」)を用いたこと以外は、ポリカーボネート系ポリウレタンU1と同様にしてポリエーテル系ポリウレタンU4を得た。得られたポリエーテル系ポリウレタンU4の重量平均分子量は17000であった。
(Production of Polyether-Based Polyurethane U4)
A polyether-based polyurethane U4 was obtained in the same manner as in the polycarbonate-based polyurethane U1, except that 100 parts by mass of polyether diol (manufactured by Hodogaya Chemical Co., Ltd., "PTC-L3500") was used as the polyol compound. The weight average molecular weight of the obtained polyether-based polyurethane U4 was 17,000.
(実施例1-1~1-13、1-18~1-25、2-1~2-6、2-9~2-15、比較例1~2、14~17)
(粘着剤、粘着テープの製造)
表1に示したアクリル共重合体A~E、H~Mを構成するモノマー、並びに、表2~5に示したウレタンポリマー及び重合開始剤を混合し、粘着剤組成物を調製した。得られた粘着剤組成物に表2~5に示した架橋剤を加えた後、アプリケーターを用いて、得られた粘着剤組成物を離型PETフィルムの離型処理面上に塗工し、塗工した上面に対して離型PETフィルム(ニッパ社製、「1-E」、厚さ50μm)の離型処理面を対向するように重ねて封止した。得られた塗工物をバッチ式UV LED硬化装置(アイテック社製、「M UVBA」)を用いて、波長365nm、照度20mW/cm2の紫外線、及び、波長405nm、照度40mW/cm2の紫外線を、合計の照射量が900mJ/cm2となるように15秒間同時照射し、粘着剤組成物を硬化させた。その結果、ビニルモノマー重合体構造、及び、ウレタンポリマー構造を有する架橋生成物を含有する粘着剤、並びに、該粘着剤を含有する表2~5に示した厚みの粘着剤層を形成し、得られた粘着剤層を粘着テープとした。
(Examples 1-1 to 1-13, 1-18 to 1-25, 2-1 to 2-6, 2-9 to 2-15, Comparative Examples 1 to 2, 14 to 17)
(Manufacturing of adhesives and adhesive tapes)
Monomers constituting acrylic copolymers A to E and H to M shown in Table 1, and urethane polymers and polymerization initiators shown in Tables 2 to 5 were mixed to prepare adhesive compositions. After adding the crosslinking agents shown in Tables 2 to 5 to the obtained adhesive compositions, the obtained adhesive compositions were applied to the release-treated surface of a release PET film using an applicator, and the release-treated surface of a release PET film (manufactured by Nippa, "1-E", thickness 50 μm) was laminated so as to face the coated surface and sealed. The obtained coated material was simultaneously irradiated with ultraviolet light having a wavelength of 365 nm and an illuminance of 20 mW/cm 2 and ultraviolet light having a wavelength of 405 nm and an illuminance of 40 mW/cm 2 for 15 seconds using a batch-type UV LED curing device (manufactured by ITEC, "M UVBA") so that the total irradiation amount was 900 mJ/cm 2 , and the adhesive composition was cured. As a result, a pressure-sensitive adhesive containing a crosslinked product having a vinyl monomer polymer structure and a urethane polymer structure, and a pressure-sensitive adhesive layer containing the pressure-sensitive adhesive and having the thickness shown in Tables 2 to 5 were formed, and the obtained pressure-sensitive adhesive layer was used as a pressure-sensitive adhesive tape.
(実施例1-14~1-15、2-7~2-8、比較例3~13、18)
(アクリル共重合体A、F、G、H、I、Nの製造)
反応容器内に、重合溶媒として酢酸エチルを加え、窒素置換した後、窒素を流入しながら反応容器を加熱して還流を開始した。続いて、重合開始剤としてアゾビスイソブチロニトリル0.1質量部を酢酸エチルで10倍希釈した重合開始剤溶液を反応容器内に投入し、表1に示したモノマー混合物を2時間かけて滴下添加した。滴下終了後、重合開始剤としてアゾビスイソブチロニトリル0.1質量部を酢酸エチルで10倍希釈した重合開始剤溶液を反応容器内に再度投入し、4時間重合反応を行い、アクリル共重合体A、F、G、H、I、Nを含有する溶液を得た。
(Examples 1-14 to 1-15, 2-7 to 2-8, Comparative Examples 3 to 13, 18)
(Production of Acrylic Copolymers A, F, G, H, I, and N)
Ethyl acetate was added as a polymerization solvent into the reaction vessel, and the vessel was replaced with nitrogen. The vessel was then heated while flowing in nitrogen to start reflux. Subsequently, a polymerization initiator solution in which 0.1 parts by mass of azobisisobutyronitrile was diluted 10 times with ethyl acetate was added into the reaction vessel as a polymerization initiator, and the monomer mixture shown in Table 1 was added dropwise over 2 hours. After the dropwise addition was completed, a polymerization initiator solution in which 0.1 parts by mass of azobisisobutyronitrile was diluted 10 times with ethyl acetate was added again into the reaction vessel, and a polymerization reaction was carried out for 4 hours to obtain a solution containing acrylic copolymers A, F, G, H, I, and N.
(粘着剤、粘着テープの製造)
得られたアクリル共重合体A、F、G、H、I、Nを含有する溶液に、表2~5に示したウレタンポリマーを加え、粘着剤組成物を含有する溶液を得た。更に、粘着剤組成物を含有する溶液に表2~5に示した架橋剤を加えた後、充分に撹拌することにより、ビニルモノマー重合体構造、及び、ウレタンポリマー構造を有する架橋生成物を含有する粘着剤の溶液を調製し、得られた粘着剤の溶液を厚み50μmの離型PETフィルムに、乾燥後の厚みが100μmとなるように塗工した後、110℃で5分間乾燥させ粘着剤層を形成した。更に、厚み38μmの離型PETフィルムの離型処理面を形成した粘着剤層に対向するように重ねることにより、粘着剤層を有する粘着テープを得た。
(Manufacturing of adhesives and adhesive tapes)
The urethane polymers shown in Tables 2 to 5 were added to the resulting solutions containing the acrylic copolymers A, F, G, H, I, and N to obtain solutions containing a pressure-sensitive adhesive composition. Furthermore, the crosslinking agents shown in Tables 2 to 5 were added to the solutions containing the pressure-sensitive adhesive composition, and the resulting solutions of pressure-sensitive adhesive containing crosslinked products having a vinyl monomer polymer structure and a urethane polymer structure were prepared by thoroughly stirring the resulting solutions of pressure-sensitive adhesive. The resulting solutions of pressure-sensitive adhesive were applied to a release PET film having a thickness of 50 μm so that the thickness after drying would be 100 μm, and then dried at 110° C. for 5 minutes to form a pressure-sensitive adhesive layer. Furthermore, a pressure-sensitive adhesive tape having a pressure-sensitive adhesive layer was obtained by overlapping the release-treated surface of a release PET film having a thickness of 38 μm so as to face the pressure-sensitive adhesive layer formed thereon.
(実施例1-16~1-17)
(粘着剤、粘着テープの製造)
実施例2と同様の組成、厚みを有する粘着剤層の一方の面の離型PETフィルムを剥がし、露出させた。表3に示した基材の一方の面に、露出した粘着剤層を貼り合わせた。更に、表3に示した基材の他方の面にも同様にして、同様の粘着剤層を貼り合わせることにより、基材と、基材の両面に粘着剤層を有する両面粘着テープを得た。
(Examples 1-16 to 1-17)
(Manufacturing of adhesives and adhesive tapes)
The release PET film was peeled off to expose one side of a pressure-sensitive adhesive layer having the same composition and thickness as in Example 2. The exposed pressure-sensitive adhesive layer was attached to one side of a substrate shown in Table 3. A similar pressure-sensitive adhesive layer was also attached to the other side of the substrate shown in Table 3 in the same manner to obtain a double-sided pressure-sensitive adhesive tape having a substrate and pressure-sensitive adhesive layers on both sides of the substrate.
(粘着剤層のゲル分率)
実施例及び比較例で得られた各粘着テープを幅30mm×長さ30mmの平面長方形状に裁断した後、離型PETフィルムを剥離した試験片を作製し、作製した試験片をテトラヒドロフラン(THF)中に23℃にて24時間浸漬した後、金属メッシュを用いてろ過し、110℃の条件下で1時間乾燥させた。乾燥後の試験片の質量を測定し、下記式(I)を用いて粘着剤層のゲル分率を算出した。結果を表2~5に示した。
ゲル分率(質量%)=100×(W2-W0)/(W1-W0) (I)
(W0:基材の質量、W1:浸漬前の試験片の質量、W2:浸漬、乾燥後の試験片の質量)
(Gel fraction of pressure-sensitive adhesive layer)
Each pressure-sensitive adhesive tape obtained in the Examples and Comparative Examples was cut into a flat rectangular shape of 30 mm width x 30 mm length, and then the release PET film was peeled off to prepare a test piece. The prepared test piece was immersed in tetrahydrofuran (THF) at 23°C for 24 hours, filtered using a metal mesh, and dried at 110°C for 1 hour. The mass of the test piece after drying was measured, and the gel fraction of the pressure-sensitive adhesive layer was calculated using the following formula (I). The results are shown in Tables 2 to 5.
Gel fraction (mass%)=100×(W 2 −W 0 )/(W 1 −W 0 ) (I)
(W 0 : Mass of the substrate, W 1 : Mass of the test piece before immersion, W 2 : Mass of the test piece after immersion and drying)
(粘着剤層の23℃におけるヤング率)
実施例及び比較例で得られた各粘着剤層をダンベル4号で打ち抜いて得たサンプルを、23℃、50%RHの条件下で、引張試験機(エー・アンド・デイ社製、「STB―1225S」)を用いて引張速度200mm/min(チャック間距離50mm)の条件にて引張試験を行うことによって、粘着剤層の23℃におけるヤング率(%)を測定した。結果を表2~5に示した。
(Young's modulus of pressure-sensitive adhesive layer at 23° C.)
The pressure-sensitive adhesive layers obtained in the Examples and Comparative Examples were punched out with a No. 4 dumbbell to obtain samples, and a tensile test was carried out at 23° C. and 50% RH using a tensile tester (manufactured by A&D Co., Ltd., "STB-1225S") at a tensile speed of 200 mm/min (chuck distance 50 mm) to measure the Young's modulus (%) of the pressure-sensitive adhesive layer at 23° C. The results are shown in Tables 2 to 5.
(粘着剤層の25℃におけるせん断貯蔵弾性率)
実施例及び比較例で得られた各粘着剤層を厚みが500μmとなるように積層し測定用の粘着剤層を作製し、試験片を得た。得られた試験片について、動的粘弾性測定装置(アイティー計測制御社製、「DVA-200」)を用い、窒素雰囲気下、せん断方向、周波数1Hz、昇温速度10℃/min、温度範囲-50℃から150℃までの条件で動的粘弾性スペクトルを測定することにより、25℃におけるせん断貯蔵弾性率(MPa)を得た。結果を表2~5に示した。
(Shear storage modulus of pressure-sensitive adhesive layer at 25° C.)
Each pressure-sensitive adhesive layer obtained in the Examples and Comparative Examples was laminated to a thickness of 500 μm to prepare a pressure-sensitive adhesive layer for measurement, and a test piece was obtained. The dynamic viscoelasticity spectrum of the obtained test piece was measured using a dynamic viscoelasticity measuring device (manufactured by IT Measurement & Control Co., Ltd., "DVA-200") under conditions of a nitrogen atmosphere, shear direction, frequency of 1 Hz, heating rate of 10° C./min, and temperature range of -50° C. to 150° C., to obtain the shear storage modulus (MPa) at 25° C. The results are shown in Tables 2 to 5.
(粘着剤層の周波数1Hzで測定したときの-10℃以上30℃以下の温度領域における損失正接(tanδ)のピーク温度及び損失正接(tanδ)のピークの半値幅)
上述した「(粘着剤層の25℃におけるせん断貯蔵弾性率)」の測定により、得られた損失正接(tanδ)のスペクトルチャートから、-10℃以上30℃以下の温度領域における損失正接(tanδ)のピーク温度(℃)及び損失正接(tanδ)のピークの半値幅を得た。なお、損失正接のピーク温度(℃)が-10℃以上30℃以下ではなかった比較例3~13については、損失正接(tanδ)のピークの半値幅の導出は行わなかった。結果を表2~5に示した。
(Peak temperature of loss tangent (tan δ) and half-width of the peak of loss tangent (tan δ) in the temperature range of -10°C to 30°C when the pressure-sensitive adhesive layer is measured at a frequency of 1 Hz)
From the spectrum chart of the loss tangent (tan δ) obtained by measuring the above-mentioned "(shear storage modulus at 25°C of the pressure-sensitive adhesive layer)", the peak temperature (°C) of the loss tangent (tan δ) and the half-width of the peak of the loss tangent (tan δ) in the temperature range of -10°C to 30°C were obtained. Note that for Comparative Examples 3 to 13 in which the peak temperature (°C) of the loss tangent was not -10°C to 30°C, the half-width of the peak of the loss tangent (tan δ) was not derived. The results are shown in Tables 2 to 5.
(粘着テープの23℃での剥離速度300mm/minにおけるSUSに対する180°剥離力)
実施例及び比較例で得られた各粘着テープを幅25mm×長さ80mmの平面長方形状に裁断し、裁断した粘着テープの一方の面(測定しない面)の離型PETフィルムを剥離した後、厚み50μmのPETフィルム(東洋紡社製、「コスモシャインA4100」)を用いて裏打ちした試験片を作製した。作製した試験片の他方の面(測定する面)の離型PETフィルムを剥離し、2kgのゴムローラを用い速度10mm/minで1往復することにより、SUS板(エタノールで洗浄後乾拭きしたSUS304板)に貼り合わせ、23℃、50%RHで24時間養生することにより、測定サンプルを得た。
得られた測定サンプルについて、JIS Z0237に準拠して、引張試験機(エー・アンド・デイ社製、「RTI-1310」)を用い、23℃、50%RH、剥離速度300mm/min、剥離角度180°で剥離試験を行い、粘着テープの23℃での剥離速度300mm/minにおけるSUSに対する180°剥離力(N/inch)を得た。結果を表2~5に示した。
(180° peel strength of pressure-sensitive adhesive tape against SUS at a peel speed of 300 mm/min at 23° C.)
Each adhesive tape obtained in the Examples and Comparative Examples was cut into a flat rectangular shape with a width of 25 mm and a length of 80 mm, and the release PET film on one side (the side not to be measured) of the cut adhesive tape was peeled off, and then a test specimen was prepared by backing it with a 50 μm thick PET film ("Cosmoshine A4100" manufactured by Toyobo Co., Ltd.). The release PET film on the other side (the side to be measured) of the prepared test specimen was peeled off, and the specimen was attached to a SUS plate (a SUS304 plate washed with ethanol and then wiped dry) by one reciprocating motion at a speed of 10 mm/min using a 2 kg rubber roller, and then aged for 24 hours at 23° C. and 50% RH to obtain a measurement sample.
The obtained measurement samples were subjected to a peel test in accordance with JIS Z0237 using a tensile tester (manufactured by A&D Co., Ltd., "RTI-1310") at 23°C, 50% RH, a peel speed of 300 mm/min, and a peel angle of 180° to obtain the 180° peel strength (N/inch) of the pressure-sensitive adhesive tape against SUS at a peel speed of 300 mm/min at 23°C. The results are shown in Tables 2 to 5.
(粘着剤層の23℃における引張破断点応力及び粘着剤層の23℃における破断伸長率)
実施例及び比較例で得られた各粘着テープをダンベル4号(高分子計器社製)で打ち抜いて得た粘着剤層のサンプルを、23℃、湿度50%RHの条件下で、引張試験機(エー・アンド・デイ社製、「STB―1225S」)を用いて引張速度200mm/min(チャック間距離50mm)の条件にて、粘着剤層のサンプルを長辺方向に引っ張る引張試験を行った。そして、粘着剤層が破断したときにおける応力を引張破断点応力(MPa)、引張試験前の粘着剤層のサンプルの長辺の長さに対する粘着剤層が破断したときにおける粘着剤層のサンプルの長辺の長さの比率を破断伸長率(%)とした。結果を表2~5に示した。
なお、上記粘着剤層の長辺の長さは、引張試験において粘着剤層のサンプルを掴む引張試験機のチャック間距離を意味する。また、基材を有する実施例1-16及び実施例1-17については、基材に積層する前の粘着剤層をダンベル4号で打ち抜いて得た粘着剤層のサンプルを用いて、引張試験を行った。
(Tensile stress at break of pressure-sensitive adhesive layer at 23° C. and elongation at break of pressure-sensitive adhesive layer at 23° C.)
Each adhesive tape obtained in the Examples and Comparative Examples was punched out with a dumbbell No. 4 (manufactured by Kobunshi Keiki Co., Ltd.) to obtain a sample of the adhesive layer. A tensile test was performed by pulling the adhesive layer sample in the long side direction at a tensile speed of 200 mm/min (distance between chucks: 50 mm) using a tensile tester (manufactured by A&D Co., Ltd., "STB-1225S") under conditions of 23°C and 50% RH. The stress at which the adhesive layer broke was defined as the tensile stress at break (MPa), and the ratio of the length of the long side of the adhesive layer sample at the time the adhesive layer broke to the length of the long side of the adhesive layer sample before the tensile test was defined as the breaking elongation (%). The results are shown in Tables 2 to 5.
The length of the long side of the pressure-sensitive adhesive layer means the distance between the chucks of a tensile tester that grips a sample of the pressure-sensitive adhesive layer in a tensile test. For Examples 1-16 and 1-17 having a substrate, a tensile test was performed using a sample of the pressure-sensitive adhesive layer obtained by punching out the pressure-sensitive adhesive layer with a No. 4 dumbbell before laminating it on the substrate.
<評価>
実施例及び比較例で得られた粘着剤、粘着テープについて、以下の方法により評価を行った。結果を表2~5に示した。
<Evaluation>
The adhesives and adhesive tapes obtained in the Examples and Comparative Examples were evaluated by the following methods. The results are shown in Tables 2 to 5.
(粘着剤の透明性)
得られた粘着剤の透明性を目視にて観察し、以下の基準に沿って評価した。
〇:粘着剤が透明であった。
△:粘着剤がやや白濁していた。
×:粘着剤が白濁していた。
(Transparency of adhesive)
The transparency of the resulting pressure-sensitive adhesive was visually observed and evaluated according to the following criteria.
A: The adhesive was transparent.
Δ: The adhesive was slightly cloudy.
×: The adhesive was cloudy.
(粘着テープのリワーク性)
(1)剥離角度30°での粘着テープのリワーク性
得られた粘着テープを幅10mm×長さ80mmの大きさに切り出し、一方の離型PETフィルムを剥がしてSUS板(エタノールで洗浄後乾拭きしたSUS304板)に貼付した後、2kgのゴムローラを10mm/minの速度で一往復させることにより圧着し、23℃、相対湿度50%RHの環境下で24時間静置し、試験サンプルを作製した。次いで、試験サンプルにおける粘着テープのもう一方の離型PETフィルムを剥がして粘着剤層を露出させ、粘着剤層の端部を、水平方向から30°の角度方向に300mm/minの速度にて引っ張り、SUS板から剥離した。粘着テープのリワーク性については、1サンプルにつき3回行い、以下の基準により評価した。
〇:3回とも試験中に粘着テープが切れることなくきれいに剥離できた。
△:2回は試験中に粘着テープが切れることなくきれいに剥離できたが、1回は剥離途中に粘着テープが切れた。
×:粘着テープが切れることなくきれいに剥離できた試験回数が2回未満であった。
なお、比較例17~18については、上述した「(粘着テープの23℃での剥離速度300mm/minにおけるSUSに対する180°剥離力)」の測定結果から、粘着テープが粘着力を有さないものであったため、粘着テープのリワーク性の評価を行わなかった。
(Reworkability of adhesive tape)
(1) Reworkability of the adhesive tape at a peel angle of 30° The obtained adhesive tape was cut into a size of 10 mm wide x 80 mm long, one release PET film was peeled off, and the tape was attached to a SUS plate (SUS304 plate washed with ethanol and then wiped dry), and then the tape was pressed by reciprocating a 2 kg rubber roller at a speed of 10 mm/min, and the tape was left to stand for 24 hours under an environment of 23°C and a relative humidity of 50% RH to prepare a test sample. Next, the other release PET film of the adhesive tape in the test sample was peeled off to expose the adhesive layer, and the end of the adhesive layer was pulled at an angle of 30° from the horizontal direction at a speed of 300 mm/min to peel off from the SUS plate. The reworkability of the adhesive tape was evaluated three times for each sample according to the following criteria.
◯: The adhesive tape was peeled off cleanly without breaking during the test all three times.
Δ: The adhesive tape could be peeled off cleanly without breaking during two tests, but the adhesive tape broke during peeling once.
x: The number of tests in which the adhesive tape could be peeled cleanly without breaking was less than two.
In addition, for Comparative Examples 17 to 18, the measurement results of the above-mentioned "(180° peel force of adhesive tape from SUS at a peel speed of 300 mm/min at 23° C.)" showed that the adhesive tapes had no adhesive force, so the reworkability of the adhesive tapes was not evaluated.
(2)剥離角度0°での粘着テープのリワーク性
剥離角度について水平方向から30°を水平方向から0°に変更したこと以外は、上述した「(1)剥離角度30°での粘着テープのリワーク性」と同様の方法、同様の判断基準により、粘着テープのリワーク性の更なる評価を行った。
(2) Reworkability of the Adhesive Tape at a Peel Angle of 0° Further evaluation of the reworkability of the adhesive tape was carried out using the same method and criteria as in "(1) Reworkability of the Adhesive Tape at a Peel Angle of 30°" described above, except that the peel angle was changed from 30° from the horizontal to 0° from the horizontal.
通常、基材を有さない粘着テープ又は発泡体基材のような充分な伸縮性を持つ基材を有する粘着テープは、剥離角度が大きくなるにつれて剥離点に応力が集中することで破断しやすくなる。そのため、基材を有さない粘着テープ又は基材として発泡体基材を有する粘着テープである実施例1-17以外の粘着テープは、上述した「(2)剥離角度0°での粘着テープのリワーク性」の評価において、「○」又は「△」であれば、上述した「(1)剥離角度30°での粘着テープのリワーク性」の評価において「×」であっても充分なリワーク性を有するものとなる。また、上述した「(1)剥離角度30°での粘着テープのリワーク性」の評価において評価が良好であればあるほど、粘着テープはリワーク性により優れるものとなる。
一方、通常、樹脂フィルムのような伸縮性に乏しい基材を有する粘着テープは、剥離角度が小さくなるにつれて粘着剤層が変形しにくくなるため剥離力が大きくなる。そのため、基材として樹脂フィルム有する粘着テープである実施例1-17の粘着テープは、上述した「(1)剥離角度30°での粘着テープのリワーク性」の評価において、「○」又は「△」であれば、上述した「(2)剥離角度0°での粘着テープのリワーク性」の評価において「×」であっても充分なリワーク性を有するものとなる。また、上述した「(1)剥離角度30°での粘着テープのリワーク性」の評価において評価が良好であればあるほど、粘着テープはリワーク性により優れるものとなる。
Usually, adhesive tapes without a substrate or adhesive tapes with a substrate having sufficient elasticity such as a foam substrate tend to break as the peel angle increases due to stress concentration at the peel point. Therefore, adhesive tapes other than those of Example 1-17, which are adhesive tapes without a substrate or adhesive tapes having a foam substrate as a substrate, have sufficient reworkability even if they are evaluated as "×" in the evaluation of "(1) Reworkability of adhesive tape at a peel angle of 30°" as described above, if they are evaluated as "○" or "△" in the evaluation of "(2) Reworkability of adhesive tape at a peel angle of 0°" as described above. In addition, the better the evaluation in the evaluation of "(1) Reworkability of adhesive tape at a peel angle of 30°" as described above, the more excellent the reworkability of the adhesive tape is.
On the other hand, in general, in adhesive tapes having a substrate with poor elasticity such as a resin film, the adhesive layer becomes less likely to deform as the peel angle becomes smaller, and therefore the peel force becomes larger. Therefore, the adhesive tape of Example 1-17, which is an adhesive tape having a resin film as a substrate, has sufficient reworkability if it is rated as "○" or "△" in the above-mentioned "(1) Reworkability of the adhesive tape at a peel angle of 30°", even if it is rated as "×" in the above-mentioned "(2) Reworkability of the adhesive tape at a peel angle of 0°". In addition, the better the evaluation in the above-mentioned "(1) Reworkability of the adhesive tape at a peel angle of 30°", the more excellent the reworkability of the adhesive tape.
表1に示したモノマーの記号は以下のものを表す。
・BA:n-ブチルアクリレート
・2-EHA:2-エチルヘキシルアクリレート
・Aac:アクリル酸
・HEA:2-ヒドロキシエチルアクリレート
・4-HBA:4-ヒドロキシブチルアクリレート
・IBOA:イソボルニルアクリレート
・BzA:ベンジルアクリレート
The monomer symbols shown in Table 1 represent the following:
BA: n-butyl acrylate; 2-EHA: 2-ethylhexyl acrylate; Aac: acrylic acid; HEA: 2-hydroxyethyl acrylate; 4-HBA: 4-hydroxybutyl acrylate; IBOA: isobornyl acrylate; BzA: benzyl acrylate
本発明によれば、高い粘着力と優れたリワーク性とを両立する粘着テープを提供することができる。また、本発明によれば、高い粘着力と優れたリワーク性とを両立して発現できる粘着剤組成物を提供することができる。更に、本発明によれば、該粘着剤組成物から得られる粘着剤を提供することができる。 According to the present invention, it is possible to provide an adhesive tape that combines high adhesive strength and excellent reworkability. In addition, according to the present invention, it is possible to provide an adhesive composition that can combine high adhesive strength and excellent reworkability. Furthermore, according to the present invention, it is possible to provide an adhesive obtained from the adhesive composition.
Claims (35)
下記の第1の構成、及び、第2の構成からなる群より選択される少なくとも1種の構成を満たす
ことを特徴とする粘着テープ。
第1の構成:前記粘着剤は、ビニルモノマー重合体構造、及び、ウレタンポリマー構造を有する架橋生成物を含有し、
前記架橋生成物において前記ビニルモノマー重合体と前記ウレタンポリマーとは、架橋剤によって架橋されており、
前記ビニルモノマー重合体は、下記(a)、(b)、又は、(c)から選択される化合物(C1)に由来する構成単位を有する
(a)芳香族基含有(メタ)アクリレートと窒素原子含有(メタ)アクリレート
(b)芳香族基含有(メタ)アクリレートに由来する構成単位及び窒素原子含有(メタ)アクリレートに由来する構成単位を有するポリマー
(c)芳香族基含有(メタ)アクリレートに由来する構成単位を有するポリマーと窒素原子含有(メタ)アクリレートに由来する構成単位を有するポリマー
第2の構成:前記粘着剤層の厚みが、50μm以上であり、
前記粘着剤層の23℃における引張破断点応力が、0.50MPa以上であり、
前記粘着テープの23℃での剥離速度300mm/minにおけるSUSに対する180°剥離力が、5.0N/inch以上30.0N/inch以下である The adhesive layer includes a pressure-sensitive adhesive,
An adhesive tape characterized by satisfying at least one constitution selected from the group consisting of the following first constitution and second constitution:
First configuration: the pressure-sensitive adhesive contains a crosslinked product having a vinyl monomer polymer structure and a urethane polymer structure,
In the crosslinked product, the vinyl monomer polymer and the urethane polymer are crosslinked with a crosslinking agent,
The vinyl monomer polymer has a structural unit derived from a compound (C1) selected from the following (a), (b), or (c): (a) an aromatic group-containing (meth)acrylate and a nitrogen atom-containing (meth)acrylate; (b) a polymer having a structural unit derived from an aromatic group-containing (meth)acrylate and a structural unit derived from a nitrogen atom-containing (meth)acrylate; (c) a polymer having a structural unit derived from an aromatic group-containing (meth)acrylate and a structural unit derived from a nitrogen atom-containing (meth)acrylate. Second configuration: the pressure-sensitive adhesive layer has a thickness of 50 μm or more,
The pressure-sensitive adhesive layer has a tensile stress at break of 0.50 MPa or more at 23°C,
The pressure-sensitive adhesive tape has a 180° peel strength from SUS at a peel speed of 300 mm/min at 23° C. of 5.0 N/inch or more and 30.0 N/inch or less.
前記粘着剤層の25℃におけるせん断貯蔵弾性率(G’)が1.0MPa以下である
請求項1記載の粘着テープ。 the pressure-sensitive adhesive layer has one peak of loss tangent (tan δ) in a temperature range of −10° C. or more and 30° C. or less when measured at a frequency of 1 Hz, and the half-value width of the loss tangent peak is 40° C. or less;
2. The pressure-sensitive adhesive tape according to claim 1, wherein the pressure-sensitive adhesive layer has a shear storage modulus (G') at 25° C. of 1.0 MPa or less.
前記粘着剤層の23℃における引張破断点応力が、0.50MPa以上であり、
前記粘着テープの23℃での剥離速度300mm/minにおけるSUSに対する180°剥離力が、5.0N/inch以上30.0N/inch以下である
請求項1又は2記載の粘着テープ。 In the first configuration, the pressure-sensitive adhesive layer has a thickness of 50 μm or more,
The pressure-sensitive adhesive layer has a tensile stress at break of 0.50 MPa or more at 23°C,
3. The pressure-sensitive adhesive tape according to claim 1, wherein the 180° peel strength of the pressure-sensitive adhesive tape against SUS at 23° C. and a peel speed of 300 mm/min is 5.0 N/inch or more and 30.0 N/inch or less.
前記架橋生成物において前記ビニルモノマー重合体と前記ウレタンポリマーとは、架橋剤によって架橋されており、
前記ビニルモノマー重合体は、下記(a)、(b)、又は、(c)から選択される化合物(C1)に由来する構成単位を有する請求項1又は2記載の粘着テープ。
(a)芳香族基含有(メタ)アクリレートと窒素原子含有(メタ)アクリレート
(b)芳香族基含有(メタ)アクリレートに由来する構成単位及び窒素原子含有(メタ)アクリレートに由来する構成単位を有するポリマー
(c)芳香族基含有(メタ)アクリレートに由来する構成単位を有するポリマーと窒素原子含有(メタ)アクリレートに由来する構成単位を有するポリマー In the second configuration, the pressure-sensitive adhesive contains a crosslinked product having a vinyl monomer polymer structure and a urethane polymer structure,
In the crosslinked product, the vinyl monomer polymer and the urethane polymer are crosslinked with a crosslinking agent,
The pressure-sensitive adhesive tape according to claim 1 or 2, wherein the vinyl monomer polymer has a structural unit derived from a compound (C1) selected from the following (a), (b), or (c):
(a) an aromatic group-containing (meth)acrylate and a nitrogen atom-containing (meth)acrylate; (b) a polymer having a structural unit derived from an aromatic group-containing (meth)acrylate and a structural unit derived from a nitrogen atom-containing (meth)acrylate; (c) a polymer having a structural unit derived from an aromatic group-containing (meth)acrylate and a structural unit derived from a nitrogen atom-containing (meth)acrylate.
前記ビニルモノマー重合体は、下記(a)、(b)、又は、(c)から選択される化合物(C1)に由来する構成単位を有する
ことを特徴とする粘着剤組成物。
(a)芳香族基含有(メタ)アクリレートと窒素原子含有(メタ)アクリレート
(b)芳香族基含有(メタ)アクリレートに由来する構成単位及び窒素原子含有(メタ)アクリレートに由来する構成単位を有するポリマー
(c)芳香族基含有(メタ)アクリレートに由来する構成単位を有するポリマーと窒素原子含有(メタ)アクリレートに由来する構成単位を有するポリマー Contains a vinyl monomer polymer and a urethane polymer,
The pressure-sensitive adhesive composition, wherein the vinyl monomer polymer has a structural unit derived from a compound (C1) selected from the following (a), (b), or (c):
(a) an aromatic group-containing (meth)acrylate and a nitrogen atom-containing (meth)acrylate; (b) a polymer having a structural unit derived from an aromatic group-containing (meth)acrylate and a structural unit derived from a nitrogen atom-containing (meth)acrylate; (c) a polymer having a structural unit derived from an aromatic group-containing (meth)acrylate and a structural unit derived from a nitrogen atom-containing (meth)acrylate.
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Citations (7)
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JP2002146326A (en) * | 2000-11-02 | 2002-05-22 | Three M Innovative Properties Co | Adhesive sheet |
JP2009155532A (en) * | 2007-12-27 | 2009-07-16 | Nippon Carbide Ind Co Inc | Adhesive composition and adhesive sheet |
JP4443852B2 (en) * | 2002-04-19 | 2010-03-31 | 三洋化成工業株式会社 | Adhesive composition |
WO2013042560A1 (en) * | 2011-09-22 | 2013-03-28 | リンテック株式会社 | Flame retardant adhesive sheet |
US20130196120A1 (en) * | 2011-12-30 | 2013-08-01 | Liberman Distributing and Manufacturing Co. d/b/a Lidco Products ("Lidco") | Extendable Self-Supporting Material Composites and Manufacture Thereof |
WO2015135134A1 (en) * | 2014-03-11 | 2015-09-17 | 3M Innovative Properties Company | Stretch releasable adhesive article, usage and manufacturing the same |
JP2022047704A (en) * | 2020-09-14 | 2022-03-25 | 日東電工株式会社 | Adhesive sheet |
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2024
- 2024-06-27 WO PCT/JP2024/023429 patent/WO2025005201A1/en active Application Filing
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JP2002146326A (en) * | 2000-11-02 | 2002-05-22 | Three M Innovative Properties Co | Adhesive sheet |
JP4443852B2 (en) * | 2002-04-19 | 2010-03-31 | 三洋化成工業株式会社 | Adhesive composition |
JP2009155532A (en) * | 2007-12-27 | 2009-07-16 | Nippon Carbide Ind Co Inc | Adhesive composition and adhesive sheet |
WO2013042560A1 (en) * | 2011-09-22 | 2013-03-28 | リンテック株式会社 | Flame retardant adhesive sheet |
US20130196120A1 (en) * | 2011-12-30 | 2013-08-01 | Liberman Distributing and Manufacturing Co. d/b/a Lidco Products ("Lidco") | Extendable Self-Supporting Material Composites and Manufacture Thereof |
WO2015135134A1 (en) * | 2014-03-11 | 2015-09-17 | 3M Innovative Properties Company | Stretch releasable adhesive article, usage and manufacturing the same |
JP2022047704A (en) * | 2020-09-14 | 2022-03-25 | 日東電工株式会社 | Adhesive sheet |
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