JP2015203044A - Adhesive tape - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an adhesive tape used for fixing components constituting an automobile having an adhesive layer which is an aqueous adhesive, has excellent adhesiveness to a substrate (core) having a fine rugged surface, for example, like a foam substrate and has excellent shear adhesive force and excellent adhesion retention properties under ordinary temperature and high temperature environments.SOLUTION: There is provided an adhesive tape having an adhesive layer (B) on at least one surface of a foam substrate (A), where the adhesive layer (B) is formed using an acrylic adhesive containing an acrylic polymer emulsion (b-1) and an oxazoline crosslinking agent. Further, there is provided an adhesive tape formed using an acrylic adhesive containing an epoxy-based crosslinking agent and further a polymerized rosin ester-based tackifier.

Description

  The present invention relates to an adhesive tape that can be used exclusively for fixing parts constituting an automobile.

  The adhesive tape is used for the purpose of fixing components in the fields of OA equipment, home appliances, automobiles, and the like. Among them, the pressure-sensitive adhesive tape having the pressure-sensitive adhesive layer on both surfaces of the foam base material is excellent in step followability and adhesiveness, and is suitably used for, for example, an application for fixing a part such as an emblem to a curved surface portion of an automobile body. Has been.

  As the pressure-sensitive adhesive tape, for example, in a molded product adhesive fixing member having a foam as a core and a pressure-sensitive adhesive layer formed on both surfaces thereof, the long axis of the core is the length direction of the core. There is known a molded product adhesive fixing member characterized in that closed cells having an elliptical cross section extending in parallel are provided (for example, see Patent Document 1).

  On the other hand, in order to reduce the environmental burden, the industry has been demanding the development of an adhesive tape that suppresses the emission of volatile organic compounds (so-called VOC). Specifically, as a pressure-sensitive adhesive used for the production of the pressure-sensitive adhesive tape, replacement of a conventional solvent-type pressure-sensitive adhesive with a water-based pressure-sensitive adhesive is required.

  However, the pressure-sensitive adhesive layer formed using the water-based pressure-sensitive adhesive is often inferior in terms of adhesion as compared to the pressure-sensitive adhesive layer formed using the solvent-type pressure-sensitive adhesive, and thus constitutes a pressure-sensitive adhesive tape. In some cases, it is difficult to ensure sufficient adhesion to the core. In particular, the foam base material suitably used as the core is usually often provided with a surface having a fine uneven shape. For this reason, the pressure-sensitive adhesive layer formed using the water-based pressure-sensitive adhesive sometimes fails to exhibit practically sufficient adhesion to the foam substrate.

  In addition, the pressure-sensitive adhesive layer formed using the water-based pressure-sensitive adhesive is often inferior in terms of adhesion as compared with the pressure-sensitive adhesive layer formed using the solvent-type pressure-sensitive adhesive. In some cases, it has been difficult to develop a shear adhesive force and an adhesive retention force under a required high temperature environment.

Japanese Patent Application Laid-Open No. 7-090232

  The problem to be solved by the present invention is that even when a water-based pressure-sensitive adhesive is used instead of a solvent-type pressure-sensitive adhesive, for example, a substrate (core) having a fine uneven surface such as a foam substrate. Another object of the present invention is to provide a pressure-sensitive adhesive tape having a pressure-sensitive adhesive layer having excellent adhesiveness and having an excellent shearing adhesive force and adhesive holding force in a normal temperature and high temperature environment.

  The present inventor has found that the above problem can be solved by using an acrylic pressure-sensitive adhesive containing an acrylic polymer emulsion and an oxazoline crosslinking agent.

  That is, this invention is an adhesive tape used for fixation of the components which comprise a motor vehicle, Comprising: The said adhesive tape has an adhesive layer (B) in the at least one surface of a foam base material (A). The pressure-sensitive adhesive layer (B) is a pressure-sensitive adhesive layer formed using an acrylic pressure-sensitive adhesive containing an acrylic polymer emulsion (b-1) and an oxazoline crosslinking agent (b-2). It relates to an adhesive tape.

  Since the pressure-sensitive adhesive tape of the present invention uses an aqueous pressure-sensitive adhesive, adverse effects on the human body and the environment can be reduced. In addition, the pressure-sensitive adhesive tape of the present invention has excellent adhesion to a substrate having a fine uneven surface (core), and has excellent shear adhesive strength and adhesive retention strength at room temperature and high temperature. Therefore, it is suitable for applications such as fixing parts such as emblems to the body of an automobile, etc., or fixing on-vehicle devices such as electronic toll collection systems (electronic toll collection systems, so-called ETC) on-vehicle devices and car navigation systems. Can be used.

  The pressure-sensitive adhesive tape of the present invention has a pressure-sensitive adhesive layer (B) on at least one surface of the foam substrate (A), and the pressure-sensitive adhesive layer (B) is an acrylic polymer emulsion (b-1). And an oxazoline cross-linking agent (b-2), and is an adhesive tape that is an adhesive layer formed using an acrylic adhesive, and is exclusively used for fixing components constituting an automobile.

  Parts constituting the automobile include, for example, automobile bodies and interior / exterior materials, parts such as emblems and decorations fixed to the automobile, electronic toll collection system (electronic toll collection system, so-called ETC) on-board device, car navigation system, etc. Parts such as in-vehicle devices, electronic equipment parts, and the like. The pressure-sensitive adhesive tape of the present invention can be suitably used for fixing various parts as described above at predetermined positions.

  The pressure-sensitive adhesive tape of the present invention comprises a pressure-sensitive adhesive layer (B) formed using an acrylic pressure-sensitive adhesive containing a combination of an acrylic polymer emulsion (b-1) and an oxazoline crosslinking agent (b-2), and a foam base. By combining with the material (A), it is possible to develop excellent shear adhesive strength and adhesive retention strength at a normal temperature and high temperature environment at a level that can be used for fixing members for inside and outside of automobiles.

  The pressure-sensitive adhesive tape of the present invention has the specific pressure-sensitive adhesive layer (B) on one side or both sides of the foam substrate (A). The pressure-sensitive adhesive tape may have the specific pressure-sensitive adhesive layer (B) on one surface of the foam base material (A) and the other pressure-sensitive adhesive layer on the other surface. The adhesive tape may be a laminate of a plurality of different adhesive layers.

  As the adhesive tape of the present invention, it is preferable to use one having a thickness of 35 μm to 1,600 μm, more preferably one having a thickness of 80 μm to 860 μm, and a thickness of 150 μm to 600 μm. It is more preferable to use a material having a thickness of 220 μm to 450 μm. For example, a material having a three-dimensional curved surface portion of a member constituting an automobile interior and exterior has excellent followability and adhesion. It is particularly preferable for obtaining a pressure-sensitive adhesive tape having properties.

[Foam substrate (A)]
First, the foam base material used for manufacturing the pressure-sensitive adhesive tape of the present invention will be described.

  As a foam base material (A), for example, a foam base material obtained by using an olefin resin such as polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, or polystyrene is used. Foam base material obtained using polyurethane, foam base material obtained using polyvinyl chloride, foam base material obtained using acrylic rubber, other elastomers, etc. The foam base material obtained can be used. Among them, as the foam base material, a foam base material obtained using a polyolefin-based resin is used in order to obtain a pressure-sensitive adhesive tape having even better adhesion to the curved surface portion of the adherend. It is preferable to use a foam base material obtained by using polyethylene, and it is more preferable to use a polyethylene resin obtained by using a metallocene compound containing a tetravalent transition metal. It is more preferable to use a foam base material containing 40% by mass or more with respect to the adherend formed on the third-order curved surface in order to provide good base material followability and adhesiveness.

  As the foam base material (A), use of a foam base material having a structure elongated in the length direction of the foam base material has excellent followability and adhesion to the three-dimensional curved surface of the adherend. It is more preferable when obtaining the adhesive tape provided with.

  The average cell diameter in the flow direction of the foam substrate (A) is preferably 1.2 μm to 840 μm, more preferably 12 μm to 600 μm, and further preferably 60 μm to 360 μm. On the other hand, the average cell diameter in the width direction of the foam substrate (A) is preferably 1 μm to 700 μm, more preferably 10 μm to 500 μm, and further preferably 50 μm to 300 μm.

  As said foam base material (A), it is preferable to use what has ratio of the average length of a flow direction, and the average length of the width direction to 1.2-15, and uses what is 3-8. It is more preferable because flexibility in the flow direction and width direction of the foam base material and variations in tensile strength hardly occur.

  In addition, the average bubble diameter of the flow direction of the said foam base material (A) and the width direction points out the value measured in the following way.

  First, a foam base material (A) is cut | disconnected to the magnitude | size of the width method 1cm and the flow direction 1cm.

  Next, a digital microscope (trade name “KH-7700”, manufactured by HiROX) is set to a magnification of 200 times, and a cut surface in the width direction or the flow direction of the foam substrate is observed. In that case, the full length of the thickness direction of the cut surface of the said foam base material is observed. In the observation, all the bubble diameters of the bubbles existing in the range of 2 mm in the flow direction or the width direction of the cut surface are measured. Next, the range of 2 mm is changed, and all the bubble diameters of bubbles existing in arbitrary 10 ranges are measured. The value obtained by calculating the average value of the bubble diameters measured above was defined as the average bubble diameter.

  As said foam base material (A), what has the structure of any one or both of a closed-cell structure and an open-cell structure can be used.

  As said foam base material (A), it is preferable to use what has an expansion ratio of 1.5 times to 20 times, and it is more preferable to use what has an expansion ratio of 2 times to 10 times, In order to further improve the adhesion between the foam base material and the pressure-sensitive adhesive layer, it is more preferable to use a material having a foaming ratio of 2.5 to 8 times.

  Moreover, as the foam base material (A), it is possible to use a foam base having a foaming ratio of 3 to 6 times, which provides excellent adhesion between the foam base material and the pressure-sensitive adhesive layer, and good flexibility. It is preferable when obtaining an adhesive tape having properties and tensile strength.

As the foam substrate ^(A), is preferably in the the use of which has an apparent density of ^{0.1g / cm 3 ~0.7g / cm 3} , 0.2g / cm 3 ~0.6g / cm 3 it is more preferable to use those having an apparent ^densities, and more preferable to use one having an apparent density of ^{0.25g / cm 3 ~0.5g / cm 3} . The apparent density is a value obtained according to JIS K 6767, and a foam substrate cut into a square of 4 cm in length and 4 cm in width is prepared in an amount corresponding to about 15 cm ³ , and its mass is measured. The apparent density was obtained.

  The foam substrate (A) is prepared by, for example, supplying the polyolefin resin and a pyrolytic foaming agent to an extruder, melt-kneading, and forming the sheet into an electron beam or the like as necessary. After crosslinking by irradiation or the like, it can be produced by foaming and stretching and thinning as necessary.

  The foam substrate (A) was supplied by feeding the polyolefin resin and a pyrolytic foaming agent to an extruder, melted and kneaded to form a sheet, and sliced in the thickness direction. Later, it may be produced by drawing with a hot roll and putting it on the skin.

  As the foam substrate (A), it is preferable to use one having a thickness of 25 μm to 1200 μm, more preferably one having a thickness of 50 μm to 500 μm, and a thickness of 100 μm to 300 μm. It is more preferable to use a material having a thickness of 150 μm to 250 μm, for example, to have excellent followability with respect to a surface having a three-dimensional curved surface portion of a member constituting an automobile interior / exterior. It is preferable because the repulsive force derived from the foam base material generated when the adhesive tape is bent can be suppressed.

  As the foam substrate (A), corona treatment, flame treatment, plasma treatment, hot air treatment, ozone treatment, ultraviolet treatment, easy adhesion are performed for the purpose of further improving the adhesiveness with the pressure-sensitive adhesive layer and other layers. Those subjected to surface treatment such as application of a treatment agent can be used.

  As the foam substrate (A), if necessary, a filler (inorganic filler, organic filler, etc.), an antioxidant, an antioxidant, an ultraviolet absorber, a colorant (pigment, dye, etc.), What contains a slip agent, a plasticizer, etc. can be used.

[Adhesive layer (B)]
Next, the adhesive layer (B) which comprises the adhesive tape of this invention is demonstrated.

  The pressure-sensitive adhesive tape of the present invention comprises a pressure-sensitive adhesive layer (B) formed using an acrylic pressure-sensitive adhesive containing an acrylic polymer emulsion (b-1) and an oxazoline cross-linking agent (b-2). It has on one side or both sides of the material (A).

  The total thickness of the pressure-sensitive adhesive layer (B) is 10 μm or more in order to ensure even better adhesion to the surface of the foam substrate (A) having fine irregularities. It is preferably 20 μm to 400 μm, more preferably 60 μm to 360 μm, particularly preferably 100 μm to 300 μm, and particularly preferably 140 μm to 200 μm. The total thickness of the pressure-sensitive adhesive layer (B) refers to the total thickness of each pressure-sensitive adhesive layer (B) if the pressure-sensitive adhesive tape has the pressure-sensitive adhesive layer (B) on both sides, and the pressure-sensitive adhesive layer. If it is an adhesive tape which has a layer (B) on one side, it will refer to the thickness of an adhesive layer (B) alone.

  Examples of the acrylic polymer emulsion (b-1) constituting the pressure-sensitive adhesive layer (B) include those in which an acrylic polymer is dispersed in an aqueous medium such as water. Examples of the acrylic polymer include those obtained by polymerizing monomer components.

  As the monomer component, for example, alkyl (meth) acrylate can be used.

  Examples of the alkyl (meth) acrylate include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, and isobutyl (meth) acrylate. , T-butyl (meth) acrylate, n-pentyl (meth) acrylate, isopentyl (meth) acrylate, neopentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (Meth) acrylate, 2-ethylhexyl (meth) acrylate, n-nonyl (meth) acrylate, isononyl (meth) acrylate, n-decyl (meth) acrylate, isodecyl (meth) acrylate Undecyl (meth) acrylate, dodecyl (meth) acrylate, tridecyl (meth) acrylate, it is preferable to use a tetradecyl (meth) having an alkyl group of carbon number 1 to 14 such as acrylates (meth) acrylate.

  Among the above-mentioned alkyl (meth) acrylates, among those described above, n-butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, 2-ethylhexyl acrylate, isooctyl (meth) acrylate, n-octyl It is preferable to use (meth) acrylate, and more preferable to use n-butyl acrylate and 2-ethylhexyl acrylate in order to give much better adhesion to the foam substrate (A). The combined use of n-butyl acrylate and 2-ethylhexyl acrylate has much better adhesion to the foam substrate, and more excellent adhesion to the adherend and high heat resistance. In order to achieve both, it is even more preferable.

  The alkyl (meth) acrylate is preferably used in an amount of 50% by mass or more, more preferably 70% by mass or more, and more preferably 80% by mass or more based on the total amount of monomer components used in the production of the acrylic polymer. It is more preferable to use, more preferably 90% by mass or more, and more preferably 95% by mass or more to have more excellent adhesion to the foam substrate, and to the adherend. This is particularly preferable in order to achieve both excellent adhesion and high heat resistance.

  Moreover, as a monomer component used for the said acrylic polymer, the vinyl monomer which has a carboxyl group can be used.

  Examples of the vinyl monomer having a carboxyl group include acrylic acid, methacrylic acid, itaconic acid, maleic acid, crotonic acid, acrylic acid dimer, ethylene oxide-modified succinic acid acrylate, and the like.

  Among them, as the vinyl monomer having a carboxyl group, it is possible to use acrylic acid or methacrylic acid to easily react with an oxazoline cross-linking agent to form a cross-linked structure, and to provide excellent adhesion retention in a high temperature environment. This is preferable. Furthermore, it is preferable to use acrylic acid and methacrylic acid in combination in order to give a further excellent adhesive force to the adherend in addition to an excellent adhesive holding force in a high temperature environment.

  The vinyl monomer having a carboxyl group is preferably used in an amount of 0.1% by mass to 10% by mass, more preferably 0.5% by mass to 5% by mass, based on the total amount of the monomer components. More preferably, 1.5% to 4.5% by mass is further used, 2% to 4% by mass is particularly preferable, and 2.5% to 3.5% by mass is used. Is particularly preferred.

  Moreover, as a monomer component used for the said acrylic polymer, the vinyl monomer which has a hydroxyl group can be used as needed.

  As the vinyl monomer having a hydroxyl group, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate or the like is used. can do.

  Among these, 2-hydroxyethyl (meth) acrylate can be preferably used in that it easily reacts with the oxazoline cross-linking agent to form a cross-linked structure and imparts excellent adhesion retention in a high temperature environment.

  The vinyl monomer having a hydroxyl group is preferably used in an amount of 0% by mass to 5% by mass, more preferably 0.1% by mass to 4.5% by mass, based on the total amount of the monomer components. More preferably, 0.5% by mass to 4% by mass is further preferably used, 1% by mass to 3.5% by mass is particularly preferably used, and 1.5% by mass to 3% by mass is used. It is particularly preferable in that it easily reacts with a crosslinking agent to form a crosslinked structure and imparts excellent adhesion retention in a high temperature environment.

  Moreover, as a monomer component used for the said acrylic polymer, the vinyl monomer which has a nitrogen atom can be used.

  Examples of the vinyl monomer having a nitrogen atom include acrylamide, methacrylamide, diethylacrylamide, N-vinylpyrrolidone, N, N-dimethylacrylamide, N, N-dimethylmethacrylamide, N, N-diethylacrylamide, N, N-diethylmethacrylamide, N, N′-methylenebisacrylamide, N, N-dimethylaminopropylacrylamide, N, N-dimethylaminopropylmethacrylamide, diacetoneacrylamide, etc. can be used. It is preferable to use it because it is easy to realize an excellent cohesive force and the shear adhesive strength and the peel adhesive strength can be improved in a high temperature environment.

  The vinyl monomer having a nitrogen atom is preferably used in an amount of 0 to 5% by mass, more preferably 0.1 to 4% by mass, based on the total amount of the monomer components. It is more preferable to use 0.5% to 3% by mass, and 1% to 2% by mass is easy to realize excellent cohesive force, shearing adhesive strength in high temperature environment, peeling adhesion It is particularly preferable because the strength can be improved.

  In addition to the above-described monomer components, the monomer component may be a vinyl monomer having a sulfonic acid group, a glycol acrylic ester monomer, an olefin monomer, or a vinyl having an alkoxysilyl group, if necessary. A monomer or a vinyl monomer having a phosphate group may be used.

  The acrylic polymer can be produced, for example, by polymerizing the monomer component described above by an emulsion polymerization method.

  As an aqueous medium that can be used in the emulsion polymerization, water may be used alone, or a mixed solvent of water and a water-soluble solvent may be used. The “mixed solvent of water and a water-soluble solvent” is a mixed solvent of a water-soluble solvent mainly composed of water, and the content of the water-soluble solvent is preferably 10 with respect to the total amount of the mixed solvent. It is not more than mass%, more preferably 5 mass%. Examples of the water-soluble solvent include alcohols such as methyl alcohol, ethyl alcohol, isopropyl alcohol, ethyl carbitol, ethyl cellosolve, and butyl cellosolve, or polar solvents such as N-methylpyrrolidone, which are used alone. Two or more types may be used in combination.

  Examples of the polymerization initiator that can be used in the emulsion polymerization include 2,2 ′,-azobis (2-methylpropionamidine) dihydrochloride and 2,2′-azobis (2-methylpropionamidine) disulfate. 2,2′-azobis (2-amidinopropane) dihydrochloride, 2,2′-azobis [N- (2-alkoxyethyl) -2-methylpropionamidine] hydrate, 2,2′-azobis Azo initiators such as (N, N′-dimethyleneisobutylamidine) dihydrochloride, 2,2′-azobis [2- (2-imidazolin-2-yl) propane] dihydrochloride, potassium persulfate, Persulfate initiators such as ammonium sulfate and sodium persulfate, peroxide initiators such as benzoyl peroxide, t-butyl hydroperoxide, hydrogen peroxide, aromatic carbonyl compounds, etc. Carbonyl-based initiators, and the like. Moreover, a reducing agent can be used in combination with a polymerization initiator, for example, a combination of persulfate and sodium hydrogen sulfite, a combination of peroxide and sodium ascorbate, and the like.

  Examples of emulsifiers that can be used in the emulsion polymerization include anionic emulsifiers such as sodium lauryl sulfate, ammonium lauryl sulfate, sodium dodecylbenzene sulfonate, sodium polyoxyethylene alkyl ether sulfate, sodium polyoxyethylene alkyl phenyl ether sulfate, Nonionic emulsifiers such as polyoxyethylene alkyl ether and polyoxyethylene alkyl phenyl ether can be used.

  As the emulsifier, an emulsifier having a polymerizable unsaturated group generally called “reactive emulsifier” in the molecule is preferably used. For example, LATEMUL S-180 [manufactured by Kao Corporation], LATEMUL PD-104 [ Kao Corporation], Aqualon HS-10 [Daiichi Kogyo Seiyaku Co., Ltd.], Aqualon HS-20 [Daiichi Kogyo Seiyaku Co., Ltd.], Aqualon KH-10 [Daiichi Kogyo Seiyaku Co., Ltd.], Aqualon KH -1025 [Daiichi Kogyo Seiyaku Co., Ltd.], Aqualon KH-05 [Daiichi Kogyo Seiyaku Co., Ltd.], Aqualon RN-10 [Daiichi Kogyo Seiyaku Co., Ltd.], Aqualon RN-20 [Daiichi Kogyo Seiyaku Co., Ltd.] Company], Aqualon ER-10 [Daiichi Kogyo Seiyaku Co., Ltd.], Aqualon ER-20 [Daiichi Kogyo Seiyaku Co., Ltd.], New Frontier A-229E [ Made by Ichi Kogyo Seiyaku Co., Ltd.], Adekaria soap SE-10 [made by ADEKA Co., Ltd.], Adekaria soap SE-20 [made by ADEKA Co., Ltd.], Adekaria soap SR-10N [made by ADEKA Co., Ltd.], Adekaria soap SR-20N [manufactured by ADEKA Corporation] and the like.

  The emulsifier is preferably used in an amount of 10 parts by mass or less, more preferably 0.5 parts by mass to 10 parts by mass with respect to 100 parts by mass of the acrylic polymer. It is even more preferable to use it in an amount of 5 parts by mass to 5 parts by mass, and it is particularly preferable to use it in an amount of 1.5 parts by mass to 3 parts by mass because of excellent adhesiveness in a high humidity environment.

The acrylic polymer preferably has a weight average molecular weight of 600,000 to 1,500,000, more preferably 700,000 to 1,200,000, and even more preferably 800,000 to 1,000,000. Since a high cohesive force can be maintained without impairing the adhesion to the body substrate, a pressure-sensitive adhesive layer excellent in shearing adhesive force, holding force and the like in a high temperature environment can be formed.
The said weight average molecular weight is standard polystyrene conversion by a gel permeation chromatography (GPC). As measurement conditions, TSKgel GMHXL [manufactured by Tosoh Corporation] is used as the column, the column temperature is 40 ° C., the eluent is tetrahydrofuran, the flow rate is 1.0 mL / min, and the standard polystyrene is a value measured using TSK standard polystyrene. Point to.

  As an acrylic adhesive used for formation of the said adhesive layer (B), an oxazoline crosslinking agent (b-2) is used as a crosslinking agent with the said acrylic polymer emulsion (b-1).

  Examples of the oxazoline cross-linking agent (b-2) include Epocross WS-300 [manufactured by Nippon Shokubai Co., Ltd., water-soluble type], Epocross WS-500 [manufactured by Nippon Shokubai Co., Ltd., water-soluble type], Epocross WS-700. [Nippon Shokubai Co., Ltd., water-soluble type], Epocross K-2010E [Nippon Shokubai Co., Ltd., water dispersion type], Epocross K-2020E [Nippon Shokubai Co., Ltd., water dispersion type], Epocross K-2030E [Stock] Company Nippon Shokubai, water dispersion type] can be used. Among them, the oxazoline crosslinking agent that can be dissolved in an aqueous medium is excellent in adhesion to the foam base material (A), and the cohesive force between particles of the acrylic polymer emulsion is improved, so that it can be used in a high temperature environment. It is preferable because an excellent adhesive holding force can be imparted.

  As said oxazoline crosslinking agent (b-2), it is preferable to use in the range of 0.01 mass part-30 mass parts with respect to 100 mass parts of acrylic polymers, and 0.06 mass part-6 mass parts. It is more preferable to use within the range, and use within the range of 0.1 to 3 parts by mass provides excellent adhesion to the foam substrate (A) and an acrylic polymer emulsion ( It is particularly preferable since the cohesive force between the acrylic polymer particles constituting b-1) is improved, and a further excellent adhesion holding force can be imparted in a high temperature environment.

  As the oxazoline crosslinking agent (b-2), it is more preferable to use one having 0.01 to 0.4 mol of oxazoline group with respect to the total number of moles of carboxyl group and hydroxyl group of the acrylic polymer. It is even more preferable to use what has 0.04 to 0.6 mol, and to use what has 0.08 to 0.3 mol is, for example, made of polypropylene which is often used suitably for automobile interior members, for example. This is particularly preferable because it can provide an excellent adhesive holding force in a high temperature environment without impairing the adhesive strength to the member.

  Moreover, as said crosslinking agent, in addition to the said oxazoline crosslinking agent (b-2), another crosslinking agent can be used in combination with an oxazoline crosslinking agent (b-2) as needed.

  As said other crosslinking agent, an epoxy crosslinking agent, a carbodiimide crosslinking agent, a silane crosslinking agent, an aziridine crosslinking agent, an isocyanate crosslinking agent, a chelate crosslinking agent etc. can be used, for example.

  As the cross-linking agent, it is preferable to use an oxazoline cross-linking agent (b-2) and an epoxy cross-linking agent in combination because the adhesion retention in a high temperature environment can be further improved.

  Examples of the epoxy crosslinking agent include Denacol EX-832 [manufactured by Nagase Kasei Kogyo Co., Ltd.], Denacol EX-841 [manufactured by Nagase Kasei Kogyo Co., Ltd.], Tetrad C [manufactured by Mitsubishi Gas Chemical Co., Ltd.], Tetrad X [Mitsubishi Gas] Chemical Co., Ltd.] can be used. Among them, the use of Tetrad C as the epoxy cross-linking agent improves the cohesive strength inside the acrylic polymer particles, and as a result, for example, a polyolefin product that is suitably used as an automobile interior member such as a dashboard. It is preferable for the adherend because it is possible to achieve both excellent adhesiveness and even better adhesive retention in a high temperature environment.

  The other crosslinking agent is preferably used in an amount of 0.001 to 0.1 parts by mass with respect to 100 parts by mass of the acrylic polymer, and 0.005 to 0.05 parts by mass. The use of an amount, for example, for an adherend made of polyolefin that is suitably used as an automobile interior member such as a dashboard, has excellent adhesion and even better adhesion retention in a high temperature environment. It is preferable because it is compatible.

  The said other crosslinking agent and the said oxazoline crosslinking agent (b-2) are those in which the mass ratio [oxazoline crosslinking agent (b-2) / other crosslinking agents] becomes 0.5-5,000. More preferably, it is more preferably used in the range of 1 to 1,000, and particularly preferably used in the range of 2 to 600, for example, as an automobile interior member such as a dashboard. It is preferable for a member made of polyolefin, which is often used, because it can achieve both excellent adhesion and even better adhesion retention in a high temperature environment.

  As said acrylic adhesive, what contains other components, such as tackifying resin and a solvent, can be used as needed.

(Tackifying resin)
As the tackifying resin, it is easy to disperse in an aqueous medium constituting the acrylic polymer emulsion (b-1) by using an emulsion type tackifying resin, and workability when preparing the acrylic pressure-sensitive adhesive. Can be improved.

  Examples of the emulsion-type tackifying resin include rosin-based tackifying resins, rosin ester-based tackifying resins, modified rosin ester-based tackifying resins, polymerized rosin-based tackifying resins, polymerized rosin ester-based tackifying resins, and rosin phenol-based resins. Tackifying resin, stabilized rosin ester tackifying resin, disproportionated rosin ester tackifying resin, terpene tackifying resin, terpene phenol tackifying resin, petroleum resin tackifying resin, etc. alone or in combination Can be used. Among these, as the emulsion-type tackifying resin, it is preferable to use a polymerized rosin ester-based tackifier resin and a rosin phenol-based tackifier resin, and it is preferable to use a polymerized rosin ester-based tackifier resin. Adhesiveness between the base material (A) and the pressure-sensitive adhesive layer (B) can be further improved. For example, adhesion to a member made of polypropylene or the like often used for automobile interior members, shearing in a high temperature environment It is more preferable because the adhesive force and holding force can be further improved.

  Specific examples of the polymerized rosin ester-based tackifier resin include Superester E-720 (Arakawa Chemical Industries, softening point 100 ° C.), Superester E-625NT [Arakawa Chemical Industries, softening point. 125 ° C.], super ester E-650 [Arakawa Chemical Industries, softening point 160 ° C.], super ester E-730-55 [Arakawa Chemical Industries, softening point 125 ° C.], super ester E-788 [ Arakawa Chemical Industries, softening point 160 ° C], Super Ester E-865 [Arakawa Chemical Industries, softening point 160 ° C], Superester E-865NT [Arakawa Chemical Industries, softening point 160 ° C] , Harrier Star SK-508 [manufactured by Harima Chemical Co., Ltd., softening point 130 ° C.], Harrier Star SK-508H [Harima Chemical Made by a company, softening point 130 ° C.], Harrier Star SK-816E [Harima Kasei Co., Ltd., softening point 145 ° C.], Harrier Star SK-822E [Harima Kasei Co., Ltd., softening point 170 ° C.], Harrier Star SK- 218NS [manufactured by Harima Kasei Co., Ltd., softening point 100 ° C.], Harrier Star SK-218MT [manufactured by Harima Kasei Co., Ltd., softening point 100 ° C.], Harrier Star SK-385NS [manufactured by Harima Kasei Co., Ltd., softening point 85 ° C.], etc. Can be used.

  Specific examples of the rosin phenol-based tackifying resin include Tamanool E-100 [manufactured by Arakawa Chemical Industries, Ltd.], Tamanoru E-200 [manufactured by Arakawa Chemical Industries, Ltd., softening point 150 [deg.] C.], Tamanol E-200NT. [Arakawa Chemical Industries, Ltd., softening point 150 ° C.] can be used.

  As the emulsion type tackifying resin, those having a softening point of 100 ° C or higher are preferably used, those having a softening point of 120 ° C or higher are more preferable, and those having a softening point of 140 ° C or higher are used. It is even more preferable to use a material having a softening point of 155 ° C. or higher, since it is possible to improve the adhesion retention in a high temperature environment. The softening point here is a softening point according to the ring and ball method, and is a numerical value measured according to JIS K5601.

  As the emulsion-type tackifying resin, it is preferable to use a resin that does not substantially contain an aromatic hydrocarbon solvent such as toluene in order to reduce the environmental load. As a method of preparing an emulsion type tackifying resin using an organic solvent other than an aromatic hydrocarbon solvent, for example, the tackifying resin is dissolved in an alicyclic hydrocarbon solvent and then dispersed in water. Thereafter, a method of removing the alicyclic hydrocarbon solvent in a reduced pressure environment can be mentioned.

  Specific examples of the alicyclic hydrocarbon solvent include cyclohexane, methylcyclohexane, ethylcyclohexane, dimethylcyclohexane, methylethylcyclohexane, cyclopentane, methylcyclopentane, ethylcyclopentane, dimethylcyclopentane, and methylethylcyclopentane. , Cyclooctane, methylcyclooctane, ethylcyclooctane, dimethylcyclooctane, methylethylcyclooctane and the like. Of these, the use of cyclohexane and methylcyclohexane is highly effective in reducing the environmental burden, and is preferable for efficiently producing emulsion-type polymerized rosin ester-based tackifier resins and emulsion-type rosin phenol-based tackifier resins.

  The pressure-sensitive adhesive that can be used for forming the pressure-sensitive adhesive layer (B) is prepared by mixing, for example, the acrylic polymer emulsion (b-1) produced by the emulsion polymerization method and the like, the emulsion-type tackifying resin, and the like. It can manufacture by mixing crosslinking agents, such as the adhesive composition obtained by this, and the said oxazoline crosslinking agent (b-2).

  The pressure-sensitive adhesive tape of the present invention can be produced, for example, by applying the pressure-sensitive adhesive on one side or both sides of the predetermined foam base material (A) using a knife coater or a die coater and drying it ( So-called direct coating method). A release liner may be laminated on the surface of the pressure-sensitive adhesive layer (B) constituting the pressure-sensitive adhesive tape obtained by the above method.

  In addition, the pressure-sensitive adhesive tape of the present invention forms a pressure-sensitive adhesive layer (B) by applying the pressure-sensitive adhesive on the surface of the release liner in advance, using a knife coater or a die coater, and drying, The pressure-sensitive adhesive layer (B) can also be produced by a method of transferring to one side or both sides of the foam substrate (A) (so-called transfer method).

  In the case of using a foam base material that easily undergoes thermal shrinkage as the foam base material (A), it is preferable to produce an adhesive tape by a transfer method rather than a direct coating method.

  On the other hand, the pressure-sensitive adhesive tape obtained by the transfer method often tends to slightly decrease in followability and adhesiveness as compared with the pressure-sensitive adhesive tape obtained by the direct method. However, since the pressure-sensitive adhesive layer (B) constituting the present invention has excellent adhesion to the foam substrate (A) having fine irregularities on the surface, for example, the use environment such as fixing of automobile members With respect to the bottom, it is possible to achieve both an excellent adhesive force and an adhesive holding force.

  After the pressure-sensitive adhesive sheet is produced by the direct method, the transfer method, or the like, it is cured in a range of 20 ° C. to 50 ° C. for 48 hours or more to advance the cross-linking reaction of the pressure-sensitive adhesive layer (B). It is preferable for forming a pressure-sensitive adhesive layer excellent in shear adhesive strength and adhesive retention strength below.

(Gel fraction)
The degree of crosslinking of the pressure-sensitive adhesive layer (B) constituting the pressure-sensitive adhesive tape of the present invention is determined by immersing the pressure-sensitive adhesive tape after curing for 48 hours in a 40 ° C. environment in toluene for 24 hours in a 23 ° C. environment. It can be evaluated by the gel fraction based on the mass of the component that was insoluble in toluene.

  The gel fraction of the adhesive tape after curing is preferably 10% by mass to 70% by mass, more preferably 20% by mass to 60% by mass, and further preferably 25% by mass to 55% by mass. Preferably, 30% by mass to 50% by mass is excellent in adhesion to a member made of polypropylene or the like that is often used suitably for an automobile interior member, for example, in terms of shear adhesion and adhesion retention in a high temperature environment. It is preferable for obtaining an excellent adhesive tape.

  On the other hand, the gel fraction calculated based on the insoluble content after the adhesive tape before curing is immersed in toluene for 24 hours is preferably 0% by mass to 70% by mass, and 1% by mass to 50% by mass. It is more preferable that the content is 5% by mass to 25% by mass, which can further improve the adhesion to a foam base material having irregularities on the surface, and can improve the shear adhesive strength and adhesive retention strength in a high temperature environment. Therefore, it is particularly preferable.

  The pressure-sensitive adhesive tape of the present invention obtained by the above method has excellent shear adhesive force and holding force in a high-temperature environment.For example, in the automotive industry field, an emblem, a protective molding, etc. Applications for bonding and fixing resin moldings, applications for mounting electronic fare collection systems (electronic toll collection systems, so-called ETC) on-board devices and car navigation systems (so-called car navigation) on-board devices, etc. on dashboards in automobiles, etc. Can be used for

  Next, the present invention will be described in detail with reference to examples and comparative examples. The evaluation method of each characteristic of the double-sided adhesive tape obtained by the Example and the comparative example is as follows.

(Measurement of average particle size)
The value of the average particle diameter (50% median diameter on a volume basis) measured using a Nikkiso Co., Ltd. Microtrac UPA type particle size distribution measuring device was determined.

(Measurement of molecular weight)
Using a GPC measuring device HLC-8320 manufactured by Tosoh Corporation, using a column TSKgel GMHXL manufactured by Tosoh Corp., column temperature is 40 ° C., eluent is tetrahydrofuran, and flow rate is 1.0 mL / min. The weight average molecular weight was determined. In addition, a weight average molecular weight is standard polystyrene conversion, and TSK standard polystyrene was used for standard polystyrene.

(Measurement of gel fraction)
First, the mass (G0) of what cut the base material which comprises an adhesive tape into a 50 mm square was measured.

  Next, the pre-curing and post-curing pressure-sensitive adhesive tapes obtained in Examples and Comparative Examples were each cut into 50 mm squares and used as samples.

  Next, the mass (G1) of the sample was measured.

  Next, after the sample was immersed in toluene at room temperature for 24 hours, the residue in toluene (insoluble component in toluene) was filtered through a 300 mesh wire mesh and dried at 110 ° C. for 1 hour (G2) Was measured.

  The gel fraction of the pressure-sensitive adhesive layer was calculated based on the masses (G0), (G1) and (G2) and the following formula.

  Gel fraction (mass%) = [(G2-G0) / (G1-G0)] × 100

(Measurement of 180 degree peeling adhesion to stainless steel in a 23 ° C environment)
One release liner of the adhesive tape is peeled off, the adhesive layer is lined with 25 μm thick polyethylene terephthalate (PET film), cut into a rectangle with a length of 300 mm and a width of 20 mm, and then the other release liner is peeled off The agent layer was affixed to a stainless steel plate (SUS304 steel plate), subjected to one-time reciprocating pressure bonding with a 2 kg roller, and then allowed to stand in a 23 ° C. environment for 1 hour, which was used as a test piece. The adhesive strength when the adhesive tape was peeled off from the stainless steel plate at a speed of 300 mm / min in a 180 ° direction with a tensile tester (manufactured by A & D Co., Ltd., model: RTC-1210A) in a 23 ° C. environment. It was measured.

(Measurement of 180 degree peeling adhesion to stainless steel in an 80 ° C environment)
One release liner of the adhesive tape is peeled off, the adhesive layer is lined with 25 μm thick polyethylene terephthalate (PET film), cut into a rectangle with a length of 300 mm and a width of 20 mm, and then the other release liner is peeled off The agent layer was affixed to a stainless steel plate (SUS304 steel plate), subjected to one-time reciprocating pressure bonding with a 2 kg roller, and then allowed to stand in a 23 ° C. environment for 1 hour, which was used as a test piece. When the adhesive tape is peeled off from the stainless steel plate at a speed of 300 mm / min in a 180 degree direction by a tensile tester with a thermostatic chamber (manufactured by A & D Co., Ltd., model: RTG-1210) in an 80 ° C. environment. The adhesive force was measured.

(Measurement of 180 degree peeling adhesion to polypropylene in a 23 ° C environment)
One release liner of the adhesive tape is peeled off, the adhesive layer is lined with 25 μm thick polyethylene terephthalate (PET film), cut into a rectangle with a length of 300 mm and a width of 20 mm, and then the other release liner is peeled off The agent layer was affixed to a polypropylene plate (manufactured by Nippon Test Panel Co., Ltd.) and subjected to one-time reciprocating pressure bonding with a 2 kg roller, and then allowed to stand in a 23 ° C. environment for 1 hour to obtain a test piece. Adhesive strength when the adhesive tape is peeled off from the polypropylene plate at a speed of 300 mm / min in a 180 ° direction with a tensile tester (manufactured by A & D Co., Ltd., model: RTC-1210A) in an environment of 23 ° C. It was measured.

(Measurement of 180 degree peeling adhesion to polypropylene in an 80 ° C environment)
One release liner of the adhesive tape is peeled off, the adhesive layer is lined with 25 μm thick polyethylene terephthalate (PET film), cut into a rectangle with a length of 300 mm and a width of 20 mm, and then the other release liner is peeled off The agent layer was affixed to a polypropylene plate (manufactured by Nippon Test Panel Co., Ltd.) and subjected to one-time reciprocating pressure bonding with a 2 kg roller, and then allowed to stand in a 23 ° C. environment for 1 hour to obtain a test piece. When the adhesive tape is peeled off from the polypropylene plate at a speed of 300 mm / min in the direction of 180 degrees with a tensile tester with a thermostatic chamber (manufactured by A & D Co., Ltd., model: RTG-1210) in an 80 ° C. environment. The adhesive force was measured.

(Measurement of shear adhesive strength at 23 ° C)
After the adhesive tape is cut into squares with a length of 20 mm and a width of 20 mm, the release liners on both sides are peeled off, the adhesive layers on both sides are affixed to a stainless steel plate (SUS304 steel plate), and one-time reciprocating pressure bonding with a 2 kg roller After performing, it left still in 23 degreeC environment for 1 hour, and this was made into the test piece. Under a 23 ° C. environment, the adhesive strength when both stainless steel plates were pulled in the shear direction at a speed of 300 mm / min was measured with a tensile tester (manufactured by A & D Co., Ltd., model: RTC-1210A).

(Measurement of shear adhesive strength at 80 ° C)
After the adhesive tape is cut into squares with a length of 20 mm and a width of 20 mm, the release liners on both sides are peeled off, the adhesive layers on both sides are affixed to a stainless steel plate (SUS304 steel plate), and one-time reciprocating pressure bonding with a 2 kg roller After performing, it left still in 23 degreeC environment for 1 hour, and this was made into the test piece. Using a tensile tester with a thermostatic chamber (A & D Co., Ltd., model: RTG-1210), the adhesive strength when pulling both stainless plates in the shear direction at a speed of 300 mm / min in an 80 ° C environment. It was measured.

(Measurement of adhesion holding force in a 23 ° C environment)
One release liner of the adhesive tape is peeled off, the adhesive layer is lined with a 50 μm thick aluminum foil, cut into a rectangle with a length of 60 mm and a width of 20 mm, the other release liner is then peeled off, and the adhesive layer is made of a stainless steel plate (SUS304 steel plate) is pasted so that the pasting area is 400 mm ² (vertical 20 mm, lateral 20 mm), and after one-way pressure bonding with a 2 kg roller, it is allowed to stand in a 23 ° C. environment for 1 hour. This was used as a test piece. Using a holding force tester manufactured by Tester Sangyo Co., Ltd., a load was applied in the shearing direction in a 23 ° C. environment, and the time until dropping was measured. The load conditions were 500 g and 1 kg.

  Evaluation was made according to the following criteria. The evaluation results of ◎ or ○ were evaluated as having practically excellent holding power.

◎: Hold for 24 hours or more ○: Hold for 18 hours or more and dropped in less than 24 hours Δ: Hold for 12 hours or more and dropped in less than 18 hours ×: Dropped in less than 12 hours

(Measurement of adhesive retention in an 80 ° C environment)
One release liner of the adhesive tape is peeled off, the adhesive layer is lined with a 50 μm thick aluminum foil, cut into a rectangle with a length of 60 mm and a width of 20 mm, the other release liner is then peeled off, and the adhesive layer is made of a stainless steel plate (SUS304 steel plate) is pasted so that the pasting area is 400 mm ² (vertical 20 mm, lateral 20 mm), and after one-way pressure bonding with a 2 kg roller, it is allowed to stand in a 23 ° C. environment for 1 hour. This was used as a test piece. Using a holding force tester with a thermostatic chamber manufactured by Tester Sangyo Co., Ltd., a load was applied in the shearing direction in an 80 ° C. environment, and the time until dropping was measured. The load conditions were 500 g and 1 kg.

  Evaluation was made according to the following criteria. The evaluation results of ◎ or ○ were evaluated as having practically excellent holding power.

◎: Hold for 24 hours or more ○: Hold for 18 hours or more and dropped in less than 24 hours Δ: Hold for 12 hours or more and dropped in less than 18 hours ×: Dropped in less than 12 hours

(Measurement of elevated temperature holding force)
One release liner of the adhesive tape is peeled off, the adhesive layer is lined with a 50 μm thick aluminum foil, cut into a rectangle with a length of 60 mm and a width of 20 mm, the other release liner is then peeled off, and the adhesive layer is made of a stainless steel plate (SUS304 steel plate) is pasted so that the pasting area is 400 mm ² (vertical 20 mm, lateral 20 mm), and after one-way pressure bonding with a 2 kg roller, it is allowed to stand in a 23 ° C. environment for 1 hour. This was used as a test piece. Using a holding power tester with a thermostatic bath manufactured by Tester Sangyo Co., Ltd., a load was applied in the shearing direction, and the temperature when dropped was measured. The temperature raising condition was set to increase 1 ° C. every 30 minutes, and the starting temperature was 40 ° C. The load condition was 500 g.

(Example 1)
<Preparation of acrylic polymer emulsion (1)>
In a container, 75 g of deionized water and Aqualon KH-1025 as a surfactant (Daiichi Kogyo Seiyaku Co., Ltd .; active ingredient 25% by mass) and Latem PD-104 as a surfactant (Kao Corporation); Active ingredient 20% by mass] 37.5 g was added and dissolved uniformly. Emulsified by adding 227.5 g of n-butyl acrylate, 227.5 g of 2-ethylhexyl acrylate, 25 g of methyl methacrylate, 6 g of N-vinylpyrrolidone, 4 g of acrylic acid, 10 g of methacrylic acid, and 0.2 g of lauryl mercaptan as a chain transfer agent. As a result, 632.7 g of emulsion (1) was obtained.

  A reaction vessel equipped with a stirrer, a reflux condenser, a nitrogen inlet tube, a thermometer, and a dropping funnel was charged with 333.35 g of deionized water, and the temperature was raised to 60 ° C. while blowing nitrogen. While stirring, a part of emulsion (1) 7.59 g, ammonium persulfate aqueous solution 2.5 g [active ingredient 6% by mass], sodium hydrogen sulfite aqueous solution 2.5 g [active ingredient 2% by mass] were added, While maintaining, polymerization was carried out in 1 hour.

  Next, 625.11 g of the remaining emulsion (1) and 50 g of an aqueous solution of ammonium persulfate [active ingredient 1% by mass] were dropped and polymerized over 6 hours while keeping the reaction vessel at 60 ° C. using separate funnels. did.

  Next, 2.5 g of an aqueous solution of ammonium persulfate [active ingredient 6% by mass] and an aqueous solution of sodium bisulfite 2.5 g [active ingredient 2% by mass] were used for 1 hour while maintaining the reaction vessel at 60 ° C. using separate funnels. It was dripped over.

  After completion of dropping, the reaction vessel was stirred for 1 hour while maintaining the temperature at 60 ° C., and then the contents were cooled and adjusted with ammonia water [10% by mass of active ingredient] so that the pH was 7.2. This was filtered through a 200-mesh wire mesh to obtain an acrylic polymer emulsion (1). Here, the obtained acrylic polymer emulsion (1) had a solid content concentration of 50 mass%, an average particle size of 333 nm, and a weight average molecular weight of 800,000.

<Preparation of water-dispersed acrylic pressure-sensitive adhesive composition (1)>
To the acrylic polymer emulsion (1) 1000 g, Epocros WS-700 [manufactured by Nippon Shokubai Co., Ltd., water-soluble type, non-volatile content 25 mass%, oxazoline group amount 4.5 mmol / g (solid)] 40 g Superester E-865NT (Arakawa Chemical Industries, Ltd .; softening point: 160 ° C., solid content: 50% by mass) 200 g as a tackifying resin, Surfynol PSA- as a leveling agent 336 [manufactured by Air Products Japan Co., Ltd.] 2.5 g, and Surfynol DF-110D [manufactured by Air Products Japan Co., Ltd.] 2.5 g were added as an antifoaming agent. After stirring uniformly, it was filtered through a 200 mesh wire mesh. It was cured for 30 days in a 23 ° C. environment to obtain a water-dispersed acrylic pressure-sensitive adhesive composition (1).

<Manufacture of double-sided adhesive tape (1)>
The water-dispersed acrylic pressure-sensitive adhesive composition (1) is coated on a release liner using a knife coater so that the thickness after drying is 80 μm, and dried at 100 ° C. for 5 minutes. Thus, two laminated sheets each having an adhesive layer formed on the release liner were formed.

  Next, the laminated sheet is placed on both sides of Bora La XL-H # 05002 (black) [Sekisui Chemical Co., Ltd., thickness 200 μm, expansion ratio 5 times, polyethylene foam] as a foam base material at 60 ° C. After sticking together using a laminating roll warmed to 80 ° C., an adhesive tape was produced by curing for 72 hours in a 40 ° C. environment.

  In addition, the gel fraction of the adhesive layer before curing was 38.3 mass%, and the gel fraction of the adhesive layer after curing was 42.4 mass%.

(Example 2)
<Preparation of acrylic polymer emulsion (2)>
The amount of n-butyl acrylate was changed from 227.5 g to 227 g, the amount of 2-ethylhexyl acrylate was changed from 227.5 g to 227 g, the amount of acrylic acid was changed from 4 g to 0 g, An emulsion (2) was prepared in the same manner as described in Preparation Example 1 except that the amount used was changed from 10 g to 15 g.

  An acrylic polymer emulsion (2) was obtained in the same manner as in Preparation Example 1 except that the above emulsion (2) was used instead of the emulsion (1). The resulting acrylic polymer emulsion (2) had a solid content concentration of 50% by mass, an average particle size of 340 nm, and a weight average molecular weight of 750,000.

<Preparation of water-dispersed acrylic pressure-sensitive adhesive composition (2)>
A water-dispersed acrylic pressure-sensitive adhesive composition (2) in the same manner as in Preparation Example 1 except that the acrylic polymer emulsion (2) was used instead of the acrylic polymer emulsion (1). )

<Manufacture of double-sided adhesive tape (2)>
In the same manner as described in Preparation Example 1, except that the water-dispersed acrylic pressure-sensitive adhesive composition (2) was used instead of the water-dispersed acrylic pressure-sensitive adhesive composition (1). Tape (2) was produced. In addition, the gel fraction of the adhesive layer before curing was 40.8% by mass, and the gel fraction of the adhesive layer after curing was 47.0% by mass.

(Example 3)
<Preparation of acrylic polymer emulsion (3)>
The amount of n-butyl acrylate was changed from 227.5 g to 227 g, the amount of 2-ethylhexyl acrylate was changed from 227.5 g to 227 g, the amount of acrylic acid was changed from 4 g to 15 g, An emulsion (3) was prepared in the same manner as described in Preparation Example 1 except that the amount used was changed from 10 g to 0 g.

  An acrylic polymer emulsion (3) was obtained in the same manner as in Preparation Example 1 except that the above emulsion (3) was used instead of the emulsion (1). The resulting acrylic polymer emulsion (3) had a solid content concentration of 50% by mass, an average particle size of 325 nm, and a weight average molecular weight of 820,000.

<Preparation of water-dispersed acrylic pressure-sensitive adhesive composition (3)>
A water-dispersed acrylic pressure-sensitive adhesive composition (3) in the same manner as described in Preparation Example 1, except that the acrylic polymer emulsion (3) was used instead of the acrylic polymer emulsion (1). )

<Manufacture of double-sided adhesive tape (3)>
In the same manner as described in Preparation Example 1, except that the water-dispersed acrylic pressure-sensitive adhesive composition (3) was used instead of the water-dispersed acrylic pressure-sensitive adhesive composition (1). Tape (3) was produced. In addition, the gel fraction of the adhesive layer before curing was 39.1% by mass, and the gel fraction of the adhesive layer after curing was 41.5% by mass.

Example 4
<Preparation of acrylic polymer emulsion (4)>
The amount of n-butyl acrylate was changed from 227.5 g to 230 g, the amount of 2-ethylhexyl acrylate was changed from 227.5 g to 230 g, the amount of acrylic acid used was changed from 4 g to 15 g, An emulsion (4) was prepared in the same manner as described in Preparation Example 1 except that the amount used was changed from 10 g to 0 g.

  An acrylic polymer emulsion (4) was obtained in the same manner as in Preparation Example 1 except that the above emulsion (4) was used instead of the emulsion (1). The resulting acrylic polymer emulsion (4) had a solid content concentration of 50% by mass, an average particle size of 350 nm, and a weight average molecular weight of 700,000.

<Preparation of water-dispersed acrylic pressure-sensitive adhesive composition (4)>
A water-dispersed acrylic pressure-sensitive adhesive composition (4) in the same manner as described in Preparation Example 1 except that the acrylic polymer emulsion (4) was used instead of the acrylic polymer emulsion (1). )

<Manufacture of double-sided adhesive tape (4)>
In the same manner as described in Preparation Example 1, except that the water-dispersed acrylic pressure-sensitive adhesive composition (4) was used instead of the water-dispersed acrylic pressure-sensitive adhesive composition (1). Tape (4) was produced. In addition, the gel fraction of the adhesive layer before curing was 37.7% by mass, and the gel fraction of the adhesive layer after curing was 48.8% by mass.

(Example 5)
<Preparation of water-dispersed acrylic pressure-sensitive adhesive composition (5)>
A water-dispersed acrylic pressure-sensitive adhesive composition (5) in the same manner as described in Preparation Example 1, except that the amount of superester E-865NT, which is the tackifier resin, was changed from 200 g to 250 g. Got.

<Manufacture of double-sided adhesive tape (5)>
In the same manner as described in Preparation Example 1, except that the water-dispersed acrylic pressure-sensitive adhesive composition (5) was used instead of the water-dispersed acrylic pressure-sensitive adhesive composition (1). Tape (5) was produced. In addition, the gel fraction of the adhesive layer before curing was 37.5% by mass, and the gel fraction of the adhesive layer after curing was 43.3% by mass.

(Example 6)
<Preparation of water-dispersed acrylic pressure-sensitive adhesive composition (6)>
A water-dispersed acrylic pressure-sensitive adhesive composition (6) in the same manner as described in Preparation Example 1, except that the amount of superester E-865NT used as the tackifier resin is changed from 200 g to 300 g. Got.

<Manufacture of double-sided adhesive tape (6)>
Adhesion was carried out in the same manner as described in Preparation Example 1 except that the water-dispersed acrylic pressure-sensitive adhesive composition (6) was used instead of the water-dispersed acrylic pressure-sensitive adhesive composition (1). Tape (6) was produced. In addition, the gel fraction of the adhesive layer before curing was 37.0% by mass, and the gel fraction of the adhesive layer after curing was 41.1% by mass.

(Example 7)
<Preparation of water-dispersed acrylic pressure-sensitive adhesive composition (7)>
Water-dispersed acrylic pressure-sensitive adhesive composition (7) in the same manner as described in Preparation Example 1, except that the amount of superester E-865NT used as the tackifying resin was changed from 200 g to 400 g. Got.

<Manufacture of double-sided adhesive tape (7)>
In the same manner as described in Preparation Example 1, except that the water-dispersed acrylic pressure-sensitive adhesive composition (7) was used instead of the water-dispersed acrylic pressure-sensitive adhesive composition (1). Tape (7) was produced. In addition, the gel fraction of the adhesive layer before curing was 35.4% by mass, and the gel fraction of the adhesive layer after curing was 40.5% by mass.

(Example 8)
<Preparation of water-dispersed acrylic pressure-sensitive adhesive composition (8)>
Instead of Superester E-865NT, emulsion type rosin phenol-based tackifying resin Tamanol E-200NT [manufactured by Arakawa Chemical Industries, Ltd .; softening point 150 ° C., solid content 53 mass%] 188.68 g was used. Except for the above, a water-dispersed acrylic pressure-sensitive adhesive composition (8) was obtained in the same manner as described in Preparation Example 1.

<Manufacture of double-sided adhesive tape (8)>
In the same manner as described in Preparation Example 1, except that the water-dispersed acrylic pressure-sensitive adhesive composition (8) was used instead of the water-dispersed acrylic pressure-sensitive adhesive composition (1). Tape (8) was produced.

  In addition, the gel fraction of the adhesive layer before curing was 38.1% by mass, and the gel fraction of the adhesive layer after curing was 41.8% by mass.

Example 9
<Preparation of water-dispersed acrylic pressure-sensitive adhesive composition (9)>
A water-dispersed acrylic pressure-sensitive adhesive composition in the same manner as described in Preparation Example 1 except that the amount of Superester E-865NT used was changed from 200 g to 100 g and Tamanol E-200NT was used in an amount of 94.34 g. A product (9) was obtained.

<Manufacture of double-sided adhesive tape (9)>
In the same manner as described in Preparation Example 1, except that the water-dispersed acrylic pressure-sensitive adhesive composition (9) was used instead of the water-dispersed acrylic pressure-sensitive adhesive composition (1). Tape (9) was produced. In addition, the gel fraction of the adhesive layer before curing was 38.2% by mass, and the gel fraction of the adhesive layer after curing was 42.1% by mass.

(Example 10)
<Preparation of acrylic polymer emulsion (5)>
An emulsion (5) was prepared in the same manner as described in Preparation Example 1 except that the amount of lauryl mercaptan used was changed from 0.2 g to 0.15 g.

  An acrylic polymer emulsion (5) was obtained in the same manner as described in Preparation Example 1 except that the above emulsion (5) was used instead of the emulsion (1). The resulting acrylic polymer emulsion (5) had a solid content concentration of 50% by mass, an average particle size of 365 nm, and a weight average molecular weight of 950,000.

<Preparation of water-dispersed acrylic pressure-sensitive adhesive composition (10)>
A water-dispersed acrylic pressure-sensitive adhesive composition (10) in the same manner as described in Preparation Example 1 except that the acrylic polymer emulsion (5) was used instead of the acrylic polymer emulsion (1). )

<Manufacture of double-sided adhesive tape (10)>
In the same manner as described in Preparation Example 1, except that the water-dispersed acrylic pressure-sensitive adhesive composition (10) was used instead of the water-dispersed acrylic pressure-sensitive adhesive composition (1). Tape (10) was produced. In addition, the gel fraction of the adhesive layer before curing was 44.5% by mass, and the gel fraction of the adhesive layer after curing was 49.5% by mass.

(Example 11)
<Preparation of acrylic polymer emulsion (6)>
An emulsion (6) was prepared in the same manner as described in Preparation Example 1, except that the amount of lauryl mercaptan used was changed from 0.2 g to 0.1 g.

  An acrylic polymer emulsion (6) was obtained in the same manner as in Preparation Example 1 except that the above emulsion (6) was used instead of the emulsion (1). The resulting acrylic polymer emulsion (6) had a solid content concentration of 50% by mass, an average particle size of 328 nm, and a weight average molecular weight of 1.1 million.

<Preparation of water-dispersed acrylic pressure-sensitive adhesive composition (11)>
A water-dispersed acrylic pressure-sensitive adhesive composition (11) was prepared in the same manner as described in Preparation Example 1, except that the acrylic polymer emulsion (6) was used instead of the acrylic polymer emulsion (1). )

<Manufacture of double-sided adhesive tape (11)>
In the same manner as described in Preparation Example 1, except that the water-dispersed acrylic pressure-sensitive adhesive composition (11) was used instead of the water-dispersed acrylic pressure-sensitive adhesive composition (1). Tape (11) was produced. In addition, the gel fraction of the adhesive layer before curing was 51.3% by mass, and the gel fraction of the adhesive layer after curing was 62.2% by mass.

(Example 12)
<Preparation of acrylic polymer emulsion (7)>
An emulsion (7) was prepared in the same manner as described in Preparation Example 1 except that the amount of lauryl mercaptan used was changed from 0.2 g to 0.4 g.

  An acrylic polymer emulsion (7) was obtained in the same manner as in Preparation Example 1 except that the above emulsion (7) was used instead of the emulsion (1). The resulting acrylic polymer emulsion (7) had a solid content concentration of 50% by mass, an average particle size of 340 nm, and a weight average molecular weight of 550,000.

<Preparation of water-dispersed acrylic pressure-sensitive adhesive composition (12)>
A water-dispersed acrylic pressure-sensitive adhesive composition (12) in the same manner as described in Preparation Example 1 except that the acrylic polymer emulsion (12) was used instead of the acrylic polymer emulsion (1). )

<Manufacture of double-sided adhesive tape (12)>
In the same manner as described in Preparation Example 1, except that the water-dispersed acrylic pressure-sensitive adhesive composition (12) was used instead of the water-dispersed acrylic pressure-sensitive adhesive composition (1). Tape (12) was produced. In addition, the gel fraction of the adhesive layer before curing was 25.3 mass%, and the gel fraction of the adhesive layer after curing was 29.5 mass%.

(Example 13)
<Preparation of water-dispersed acrylic pressure-sensitive adhesive composition (13)>
A water-dispersed acrylic pressure-sensitive adhesive composition (13) was obtained in the same manner as described in Example 1 except that the amount of Epochros WS-700 used was changed from 40 g to 60 g.

<Manufacture of double-sided adhesive tape (13)>
In the same manner as described in Preparation Example 1, except that the water-dispersed acrylic pressure-sensitive adhesive composition (13) was used instead of the water-dispersed acrylic pressure-sensitive adhesive composition (1). Tape (13) was produced. In addition, the gel fraction of the adhesive layer before curing was 42.2% by mass, and the gel fraction of the adhesive layer after curing was 47.6% by mass.

(Example 14)
<Preparation of water-dispersed acrylic pressure-sensitive adhesive composition (14)>
A water-dispersed acrylic pressure-sensitive adhesive composition (14) was obtained by the same method as that described in Example 1, except that the amount of Epochros WS-700 used was changed from 40 g to 100 g.

<Manufacture of double-sided adhesive tape (14)>
Adhesion was carried out in the same manner as described in Preparation Example 1 except that the water-dispersed acrylic pressure-sensitive adhesive composition (14) was used instead of the water-dispersed acrylic pressure-sensitive adhesive composition (1). Tape (14) was produced. In addition, the gel fraction of the adhesive layer before curing was 45.4% by mass, and the gel fraction of the adhesive layer after curing was 59.8% by mass.

(Example 15)
<Preparation of water-dispersed acrylic pressure-sensitive adhesive composition (15)>
As described in Example 1, except that the amount of Epocros WS-700 used was changed from 40 g to 30 g and 1 g of a 10% by mass ethanol solution of Tetrad C [manufactured by Mitsubishi Gas Chemical Co., Ltd.] as an epoxy crosslinking agent was used. A water-dispersed acrylic pressure-sensitive adhesive composition (15) was obtained by the same method.

<Manufacture of double-sided adhesive tape (15)>
Adhesion was carried out in the same manner as described in Preparation Example 1, except that the water-dispersed acrylic pressure-sensitive adhesive composition (15) was used instead of the water-dispersed acrylic pressure-sensitive adhesive composition (1). Tape (15) was produced. In addition, the gel fraction of the adhesive layer before curing was 24.8% by mass, and the gel fraction of the adhesive layer after curing was 42.5% by mass.

(Example 16)
<Preparation of water-dispersed acrylic pressure-sensitive adhesive composition (16)>
A water-dispersed acrylic system was prepared in the same manner as described in Example 1 except that the amount of Epocros WS-700 was changed from 40 g to 30 g and 0.5 g of a 10 mass% ethanol solution of Tetrad C was used. A pressure-sensitive adhesive composition (16) was obtained.

<Manufacture of double-sided adhesive tape (16)>
In the same manner as described in Preparation Example 1, except that the water-dispersed acrylic pressure-sensitive adhesive composition (16) was used instead of the water-dispersed acrylic pressure-sensitive adhesive composition (1). Tape (16) was produced. In addition, the gel fraction of the adhesive layer before curing was 12.5% by mass, and the gel fraction of the adhesive layer after curing was 36.9% by mass.

(Example 17)
<Preparation of water-dispersed acrylic pressure-sensitive adhesive composition (17)>
Water-dispersed acrylic pressure-sensitive adhesive in the same manner as described in Example 1 except that the amount of Epocros WS-700 used was changed from 40 g to 14 g and 1 g of a 10% by mass ethanol solution of Tetrad C was used. A composition (17) was obtained.

<Manufacture of double-sided adhesive tape (17)>
In the same manner as described in Preparation Example 1, except that the water-dispersed acrylic pressure-sensitive adhesive composition (17) was used instead of the water-dispersed acrylic pressure-sensitive adhesive composition (1). A tape (17) was produced. In addition, the gel fraction of the adhesive layer before curing was 24.2% by mass, and the gel fraction of the adhesive layer after curing was 32.9% by mass.

(Comparative Example 1)
<Preparation of water-dispersed acrylic pressure-sensitive adhesive composition (H1)>
A water-dispersed acrylic pressure-sensitive adhesive composition (H1) was obtained by the same method as that described in Example 1, except that Epocros WS-700 was not used.

<Manufacture of double-sided adhesive tape (H1)>
Adhesion was carried out in the same manner as described in Preparation Example 1 except that the water-dispersed acrylic pressure-sensitive adhesive composition (H1) was used instead of the water-dispersed acrylic pressure-sensitive adhesive composition (1). Tape (H1) was produced. In addition, the gel fraction of the adhesive layer before curing was 0.1% by mass, and the gel fraction of the adhesive layer after curing was 0.1% by mass.

(Comparative Example 2)
<Preparation of water-dispersed acrylic pressure-sensitive adhesive composition (H2)>
A water-dispersed acrylic pressure-sensitive adhesive composition (H2) was obtained in the same manner as described in Example 1 except that 1 g of a 10% by mass ethanol solution of Tetrad C was used instead of Epocros WS-700. It was.

<Manufacture of double-sided adhesive tape (H2)>
Adhesion was carried out in the same manner as described in Preparation Example 1 except that the water-dispersed acrylic pressure-sensitive adhesive composition (H2) was used instead of the water-dispersed acrylic pressure-sensitive adhesive composition (1). A tape (H2) was produced. In addition, the gel fraction of the adhesive layer before curing was 19.8% by mass, and the gel fraction of the adhesive layer after curing was 31.1% by mass.

(Comparative Example 3)
<Preparation of water-dispersed acrylic pressure-sensitive adhesive composition (H3)>
A water-dispersed acrylic pressure-sensitive adhesive composition (H2) was obtained in the same manner as described in Example 1 except that 1 g of a 10% by mass ethanol solution of Tetrad C was used instead of Epocros WS-700. It was.

<Manufacture of double-sided adhesive tape (H3)>
Adhesion was carried out in the same manner as described in Preparation Example 1 except that the water-dispersed acrylic pressure-sensitive adhesive composition (H3) was used instead of the water-dispersed acrylic pressure-sensitive adhesive composition (1). A tape (H3) was produced. In addition, the gel fraction of the adhesive layer before curing was 17.9% by mass, and the gel fraction of the adhesive layer after curing was 30.4% by mass.

  The composition and evaluation results of the above examples are shown in the table below. “Mass%” described in the column of various monomers used for the production of the acrylic polymer represents the mass ratio of each monomer to the total amount of the monomer components used for the production of the acrylic polymer, and is a crosslinking agent. "Mass part" described in the column of the tackifying resin represents a mass part of the crosslinking agent and the tackifying resin with respect to 100 parts by mass of the acrylic polymer.

  As is clear from Tables 1 to 4, the adhesive tapes of Examples 1 to 17 have excellent adhesion between the foam base material and the adhesive layer, and are good for adherends made of stainless steel and polypropylene. It had adhesive strength and was excellent in shearing adhesive strength and adhesive retention in a high temperature environment. On the other hand, since the pressure-sensitive adhesive tapes of Comparative Examples 1 to 3 do not contain an oxazoline cross-linking agent, the adhesiveness between the foam substrate and the pressure-sensitive adhesive layer tends to be insufficient, and the shear adhesive strength in a high-temperature environment The result was poor adhesion retention.

Claims (7)

A pressure-sensitive adhesive tape used for fixing a part constituting an automobile, wherein the pressure-sensitive adhesive tape has a pressure-sensitive adhesive layer (B) on at least one surface of a foam substrate (A), and the pressure-sensitive adhesive layer ( A pressure-sensitive adhesive tape, wherein B) is a pressure-sensitive adhesive layer formed using an acrylic pressure-sensitive adhesive containing an acrylic polymer emulsion (b-1) and an oxazoline crosslinking agent (b-2). The pressure-sensitive adhesive tape according to claim 1, wherein the acrylic pressure-sensitive adhesive further contains an epoxy-based crosslinking agent. The pressure-sensitive adhesive tape according to claim 2, wherein a mass ratio of the oxazoline crosslinking agent to the epoxy crosslinking agent [the oxazoline crosslinking agent / epoxy crosslinking agent] is in the range of 2 to 600. The pressure-sensitive adhesive tape according to any one of claims 1 to 3, wherein the acrylic pressure-sensitive adhesive further contains a polymerized rosin ester-based tackifier resin. An automobile in which an automobile exterior member is fixed by the adhesive tape according to any one of claims 1 to 4. The vehicle by which the vehicle equipment of the electronic fee collection system and the interior material of the vehicle are fixed by the adhesive tape according to any one of claims 1 to 4. The vehicle by which the vehicle equipment of the car navigation system and the interior material of the vehicle are fixed by the adhesive tape according to any one of claims 1 to 4.