JP2012171230A - Mold releasing sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mold releasing sheet ready in manufacturing, excellent in releasability, suppressed in transition of a release layer to an adherend in high temperature pressing, reduced in contamination of the adherend and environmental load upon discarding, and increased in water tightness.SOLUTION: In the mold releasing sheet constituted by forming the release layer containing an acid-modified polyolefin resin, polyvinyl alcohol and crosslinking agents on a base material. The crosslinking agent A selected from carbodiimide or oxazoline compounds and the crosslinking agent B selected from melamine compounds are contained as the crosslinking agents.

Description

In recent years, release sheets have been widely used industrially. Examples of the use of the release sheet include, for example, the use of pressure-sensitive adhesive materials such as pressure-sensitive adhesive sheets and pressure-sensitive adhesive tapes, the use of process materials for the production of the pressure-sensitive adhesive materials, printed wiring boards, flexible printed wiring boards, The process material use for manufacture of a multilayer printed wiring board etc., the protective material use of the polarizing plate and phase difference plate which are components for liquid crystal displays, Furthermore, the shaping | molding use of a sheet-like structure etc. are mentioned.
Patent Document 1 discloses that an acid-modified polyolefin and a specific cross-linking agent are used in a release layer as a release sheet having both coatability and release properties.

International Publication No. 2009/025063

  The release sheet of Patent Document 1 can also be used in a process of forming a sheet by coating and drying a low-viscosity varnish that would cause repellency with fluorine or silicone. However, the cohesive force and scratch resistance may not be sufficient. In particular, when performing high-temperature pressing at 150 ° C. or higher, the components of the release layer may move to the surface of the object to be peeled, and post-processing of the object to be peeled may be hindered, or the residual adhesion of the release layer itself A phenomenon such as a low rate can occur. In addition, in the release sheet of Patent Document 1, when polyvinyl alcohol is used for the release layer, the water resistance of the release layer, particularly the water rub resistance, may be lowered by the terminal hydroxyl group derived from this component. is there.

  As described above, the release sheet of Patent Document 1 is usually exposed to a high temperature of about 200 ° C. or used in contact with water, such as a substrate pressing application, a simultaneous molding transfer, or a hydraulic transfer application. There is a problem that it is difficult to use in applications such as simple transfer applications and sheet formation by application of aqueous resin.

  In view of these problems, the present invention is easy to manufacture and excellent in releasability, and the migration of the release layer to the adherend during high-temperature pressing is suppressed, and contamination of the adherend and the environment during disposal The present invention provides a release sheet having a low load and further improved water resistance.

As a result of intensive studies to solve the above problems, the present inventors have found that the above problems are remarkably improved when a combination of a specific crosslinking agent is used as a release layer in addition to an acid-modified polyolefin resin and polyvinyl alcohol. As a result, the present invention has been reached.
That is, the gist of the present invention is as follows.
(1) A release sheet formed by forming a release layer containing an acid-modified polyolefin resin, polyvinyl alcohol and a crosslinking agent on a substrate, and the crosslinking agent selected from carbodiimide or oxazoline compounds as the crosslinking agent A release sheet comprising A and a crosslinking agent B selected from melamine compounds.
(2) The release sheet according to (1), wherein the content of the crosslinking agent B is 1 to 100 parts by mass with respect to 100 parts by mass of the acid-modified polyolefin resin.

  The release sheet of the present invention has good releasability while having appropriate wettability, and the migration of the release layer to the adherend during high-temperature pressing is particularly suppressed. In addition, since the terminal hydroxyl groups are reduced due to an increase in the crosslinking density, the water resistance is also improved, and as a result, the water scratch resistance is improved. Therefore, even if it peels in the environment where moisture and humidity are high, such as application drying of water-based material and hydraulic transfer, stable releasability can be maintained.

  Further, the release sheet of the present invention has a simple process of laminating a release layer during production.

Hereinafter, the present invention will be described in detail.
The release sheet of the present invention is obtained by providing a release layer on a substrate.

In the release sheet of the present invention, the release layer contains an acid-modified polyolefin resin, polyvinyl alcohol, and a crosslinking agent.

  Although the olefin component which is the main component of the acid-modified polyolefin resin is not particularly limited, an alkene having 2 to 6 carbon atoms such as ethylene, propylene, isobutylene, 2-butene, 1-butene, 1-pentene, 1-hexene is preferable . Moreover, you may use these mixtures. Of these, alkenes having 2 to 4 carbon atoms such as ethylene, propylene, isobutylene and 1-butene are more preferable, ethylene and propylene are more preferable, and ethylene is most preferable.

  Examples of the acid-modified component in the acid-modified polyolefin resin include an unsaturated carboxylic acid component. Examples of unsaturated carboxylic acid components include acrylic acid, methacrylic acid, maleic acid, maleic anhydride, itaconic acid, itaconic anhydride, fumaric acid, crotonic acid, and the like, as well as unsaturated dicarboxylic acid half esters and half amides. It is done.

  Among these, acrylic acid, methacrylic acid, maleic acid, and maleic anhydride are preferable, and acrylic acid, methacrylic acid, and maleic anhydride are particularly preferable from the viewpoint of excellent dispersion stabilization.

  In the acid-modified polyolefin resin, the modification ratio of the acid-modified component is preferably 1 to 30% by mass of the acid-modified polyolefin resin, more preferably 1 to 10% by mass, and further preferably 3 to 10% by mass. When the modification ratio of the acid-modifying component is less than 1% by mass, sufficient adhesion between the release layer and the substrate may not be obtained, and the adherend may be contaminated. Furthermore, when an acid-modified polyolefin resin is used as an aqueous dispersion, aqueous dispersion may be difficult. On the other hand, when the modification ratio of the acid-modified component exceeds 30% by mass, the releasability may be deteriorated.

  The acid-modified polyolefin resin preferably contains a (meth) acrylic acid ester component for the purpose of improving the adhesion between the release layer and the substrate. When a (meth) acrylic acid ester component is included, the content is preferably 0.5 to 40% by mass and 1 to 20% by mass from the viewpoint of good adhesion to various substrates. Is more preferable, and it is further more preferable that it is 3-10 mass%.

  Examples of the (meth) acrylic acid ester component include an esterified product of (meth) acrylic acid and an alcohol having 1 to 30 carbon atoms. Especially, the esterified substance of (meth) acrylic acid and a C1-C20 alcohol is preferable from the point of availability.

  Specific examples of the (meth) acrylic acid ester component include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, hexyl (meth) acrylate, (meth ) Octyl acrylate, decyl (meth) acrylate, lauryl (meth) acrylate, octyl (meth) acrylate, dodecyl (meth) acrylate, stearyl (meth) acrylate, etc., and a mixture thereof. Also good. Of these, methyl (meth) acrylate (ethyl) (meth) acrylate, butyl (meth) acrylate, hexyl acrylate, and octyl acrylate are preferred from the viewpoint of excellent adhesion to the substrate. Ethyl acrylate, acrylic acid Butyl is more preferred, and ethyl acrylate is particularly preferred. In addition, “(meth) acrylic acid˜” means “acrylic acid˜ or methacrylic acid˜”.

  Each component constituting the acid-modified polyolefin resin may be copolymerized in the acid-modified polyolefin resin, and the form thereof is not limited. Examples of the form of copolymerization include random copolymerization, block copolymerization, and graft copolymerization (graft modification).

  The melting point of the acid-modified polyolefin resin is preferably 80 to 150 ° C, more preferably 85 to 130 ° C, and further preferably 90 to 100 ° C. When the melting point exceeds 150 ° C., a treatment at a high temperature may be required to form a release layer. On the other hand, when the melting point is less than 80 ° C., the releasability may be remarkably lowered.

  The Vicat softening point of the acid-modified polyolefin resin is preferably 50 to 130 ° C, more preferably 53 to 110 ° C, and still more preferably 55 to 90 ° C. If the Vicat softening point exceeds 130 ° C, a high temperature treatment may be required to form a release layer. On the other hand, if the Vicat softening point is less than 50 ° C, the releasability may be significantly reduced. It is not preferable.

  The melt flow rate (MFR) of the acid-modified polyolefin resin is preferably 1 to 1000 g / 10 minutes at 190 ° C. and 2160 g load, more preferably 1 to 500 g / 10 minutes, and 2 to 300 g / 10. It is more preferable that it is a minute, and it is especially preferable that it is 2-200 g / 10min. If the MFR is less than 1 g / 10 min, it may be difficult to produce an acid-modified polyolefin resin, and it may be difficult to make the acid-modified polyolefin resin into an aqueous dispersion. On the other hand, if the MFR exceeds 1000 g / 10 min, the adhesion between the release layer and the substrate may be lowered, and the transfer to the adherend may be more likely to occur.

  The release layer of the release sheet of the present invention contains, as a crosslinking agent, a crosslinking agent A selected from carbodiimide or oxazoline compounds and a crosslinking agent B selected from melamine compounds.

  The crosslinking agent A (carbodiimide compound or oxazoline compound) used for the release layer plays a role of crosslinking the acid-modified polyolefin resin, and the crosslinking agent B (melamine compound) plays a role of crosslinking polyvinyl alcohol.

  In the present invention, when other reactive compounds such as isocyanate compounds and epoxy resins are used in place of the crosslinking agent B (melamine compound), cohesiveness and water resistance that can withstand practical use cannot be expected.

  As the crosslinking agent A, a carbodiimide compound and an oxazoline compound may be used in combination. When either a carbodiimide compound or an oxazoline compound is used alone as the crosslinking agent A, it is more preferable to use the oxazoline compound alone from the viewpoint of excellent mixing stability and storage stability.

  The carbodiimide compound used in the present invention is not particularly limited as long as it has a carbodiimide compound having at least two carbodiimide groups in the molecule. Examples of such carbodiimide compounds include p-phenylene-bis (2,6-xylylcarbodiimide), tetramethylene-bis (t-butylcarbodiimide), cyclohexane-1,4-bis (methylene-t-butylcarbodiimide). And a compound having two or more carbodiimide groups, and a polycarbodiimide which is a polymer having two or more carbodiimide groups. These can use 1 type (s) or 2 or more types. Of these, polycarbodiimide is preferred from the viewpoint of ease of handling. The production method of polycarbodiimide is not particularly limited, and can be produced, for example, by a condensation reaction involving decarbonization of an isocyanate compound.

  As the carbodiimide compound, a commercially available product can be suitably used. For example, a carbodilite series manufactured by Nisshinbo Co., Ltd. can be used. More specifically, water-soluble type “SV-02”, “V-02”, “V-02-L2”, “V-04”, emulsion type “E-01”, “E-02” Organic solution type “V-01”, “V-03”, “V-07”, “V-09”, and solventless type “V-05”.

  The oxazoline compound used in the present invention is not particularly limited as long as it has at least two oxazoline groups in the molecule. Oxazoline compounds are preferred. Examples of such oxazoline compounds include 2,2'-bis (2-oxazoline), 2,2'-ethylene-bis (4,4'-dimethyl-2-oxazoline), 2,2'-p- A compound having two or more oxazoline groups such as phenylene-bis (2-oxazoline) or bis (2-oxazolinylcyclohexane) sulfide, or a polymer containing two or more oxazoline groups (hereinafter referred to as an oxazoline group-containing polymer) There are). These can use 1 type (s) or 2 or more types. Among these, an oxazoline group-containing polymer is preferable from the viewpoint of ease of handling.

  The production method of the oxazoline group-containing polymer is not particularly limited. For example, addition polymerization of 2-vinyl-2-oxazoline, 2-vinyl-4-methyl-2-oxazoline, 2-isopropenyl-2-oxazoline, etc. And a method of polymerizing a functional oxazoline. The polymerization method is not particularly limited, and various known polymerization methods can be employed. The oxazoline compound may be copolymerized with other monomers as necessary.

  Commercially available oxazoline compounds can also be suitably used, and examples thereof include Epocros series manufactured by Nippon Shokubai Co., Ltd. More specifically, water-soluble type “WS-500”, “WS-700”, emulsion type “K-1010E”, “K-1020E”, “K-1030E”, “K-2010E”, “ K-2020E "," K-2030E "and the like.

  The content of the crosslinking agent A is preferably 1 to 50 parts by mass, more preferably 3 to 30 parts by mass, and still more preferably 5 to 10 parts by mass with respect to 100 parts by mass of the acid-modified polyolefin resin. If it is less than 1 part by mass, the effect of addition may be poor. On the other hand, if it exceeds 50 parts by mass, the releasability may decrease. In addition, when using a carbodiimide compound and an oxazoline compound together, the total amount of a carbodiimide compound and an oxazoline compound should just satisfy | fill the range of content of the above-mentioned crosslinking agent A.

  The melamine compound as the crosslinking agent B contained in the release layer is not particularly limited, but is partially or completely reacted with melamine, a methylolated melamine derivative obtained by condensing melamine and formaldehyde, or a methylolated melamine reacted with a lower alcohol. And etherified compounds and mixtures thereof. The melamine resin may be a monomer or a condensate consisting of a dimer or higher polymer, or a mixture thereof. Examples of the lower alcohol used for etherification include methyl alcohol, ethyl alcohol, isopropyl alcohol, n-butanol, isobutanol and the like, and methyl alcohol is particularly preferable, but is not particularly limited. Melamine compounds are known to react with compounds containing hydroxyl groups, react with polyvinyl alcohol compounds in the release layer, and improve the cohesiveness and water resistance of the release layer by increasing crosslink density and reducing hydroxyl groups. .

  In the present invention, the melamine compound as the crosslinking agent B is not particularly limited, but a compound obtained by partially etherifying a methylolated melamine derivative and a mixture thereof are preferable from the viewpoint of water solubility, reactivity, storage stability, moisture resistance and the like. In particular, a compound obtained by etherifying 50% to 90% of the methylol group is preferable.

  The content of the melamine compound in the present invention is preferably 1 to 100 parts by mass, more preferably 1 to 50 parts by mass, with respect to 100 parts by mass of the polyvinyl alcohol. More preferably. When the amount is less than 1 part by mass, the polyvinyl alcohol is not sufficiently cross-linked and the water scratch resistance may be insufficient. Moreover, when it exceeds 100 mass parts, since an unreacted melamine compound remains in a coating film, peeling may become heavy.

  Polyvinyl alcohol reacts with the acidic group of the acid-modified polyolefin resin to form a crosslinked structure with an ester bond in the release layer. In the present invention, the polyvinyl alcohol used is not particularly limited, and examples thereof include those obtained by completely or partially saponifying a vinyl ester polymer. As the saponification method, a known alkali saponification method or acid saponification method can be used. Of these, a method of alcoholysis using an alkali hydroxide in methanol is preferred. As described later, the polyvinyl alcohol used in the present invention preferably has water solubility for use as a liquid.

  Examples of the vinyl ester include vinyl formate, vinyl acetate, vinyl propionate, vinyl pivalate, vinyl versatate, and the like. Of these, vinyl acetate is most preferred industrially.

  The vinyl ester described above may be copolymerized with other vinyl monomers as long as the effects of the present invention are not impaired. Other vinyl monomers include unsaturated monocarboxylic acids such as crotonic acid, acrylic acid and methacrylic acid, their esters, their salts, their anhydrides, their amides and their nitriles; maleic acid, itaconic acid, fumaric acid Examples thereof include unsaturated dicarboxylic acids such as acids and salts thereof; α-olefins having 2 to 30 carbon atoms; alkyl vinyl ethers; vinyl pyrrolidones and the like.

  The average degree of polymerization of polyvinyl alcohol is not particularly limited, but is preferably 300 to 2,000. If it is less than 300, the coating film is weakly cohesive, and if it exceeds 2000, the release agent itself thickens.

  In this invention, it is preferable that content of polyvinyl alcohol is 5-200 mass parts with respect to 100 mass parts of acid-modified polyolefin resin, 10-150 mass parts is more preferable, and 30-100 mass parts is the most preferable. . If the content is less than 5 parts by mass, the effect of addition may be poor. On the other hand, even if it exceeds 200 parts by mass, the effect of addition is poor, and when polyvinyl alcohol is used as a liquid, its liquid stability may be lowered.

  As the polyvinyl alcohol, a commercially available product can be suitably used. For example, “JC-05”, “VC-10”, “ASC-05X”, “UMR-10HH” of “J-Poval” of Nippon Vinegar Poval Co., Ltd. “PVA-103”, “PVA-105” of “Kuraray Poval”, “AQ4104”, “HR3010” of “Exeval”, “PC-1000”, “PC-1000” of Denka Poval 2000 "and the like.

  The release layer may contain fine particles such as an inorganic filler and an organic filler (hereinafter sometimes referred to as “matting agent”) for the purpose of improving the winding property. The shape of the fine particles is not particularly limited, and examples thereof include an irregular shape, a spherical shape, a chain shape, a hollow shape, a flat shape, a needle shape, and a flat plate shape. The fine particles can be used alone or in combination of two or more. Furthermore, the surface of the matting agent may be subjected to a surface treatment from the viewpoint of excellent affinity with the resin forming the release layer and excellent dispersion stability in a solvent when laminating the release layer. .

  Examples of the organic filler include, but are not limited to, polystyrene, polymethyl acrylate and polyacrylate ester copolymers, crosslinked fine particles such as rubber, and fine powder of thermoplastic resin. As a method for producing these organic fillers, a method in which a divalent or higher-valent ethylenically unsaturated compound is used together during emulsion / suspension polymerization and secondary crosslinking is performed between end groups, a thermoplastic polymer and a water-soluble polymer are mixed and heated. A physical melt dispersion method in which the thermoplastic polymer is finely divided by melting is mentioned. The physical melt dispersion method is preferable in that the particle size can be easily controlled and various thermoplastic resins can be finely divided.

  Examples of the inorganic filler include, but are not limited to, clay, mica, titanium oxide, calcium carbonate, kaolin, wet and dry silica, colloidal silica, calcium phosphate, barium sulfate, alumina, and zeolite. These may be used alone or in combination of two or more. The inorganic fine particles are preferably surface-treated with a silane coupling agent or the like for the purpose of improving dispersibility.

  The release layer may contain a silicone compound, a fluorine compound, waxes, a surfactant and the like as long as the effects of the present invention are not impaired. In that case, the total content of the silicone compound, fluorine compound, wax, and surfactant is preferably 1 part by mass or less with respect to 100 parts by mass of the acid-modified polyolefin resin. The smaller the content, the better the adhesion between the release layer and the substrate, and the more the contamination of the adherend is suppressed. It is more preferable that the amount is not more than part, and it is particularly preferable that the content is not contained.

  Examples of the waxes include plant waxes, animal waxes, mineral waxes and petrochemical waxes having a number average molecular weight of 10,000 or less. Specific examples of the wax include candelilla wax, carnauba wax, rice wax, wood wax, berry wax, jojoba wax, shea butter, beeswax, shellac wax, lanolin wax, whale wax, montan wax, ceresin wax, microcrystalline wax, and microcrystalline wax. Synthetic polyethylene wax, synthetic polypropylene wax, synthetic ethylene-vinyl acetate copolymer wax, and the like.

  Examples of the surfactant include a cationic surfactant, an anionic surfactant, a nonionic (nonionic) surfactant, an amphoteric surfactant, a fluorosurfactant, and a reactive surfactant. Surfactants include emulsifiers in addition to those generally used for emulsion polymerization.

  Anionic surfactants include higher alcohol sulfates, higher alkyl sulfonic acids and salts thereof, alkylbenzene sulfonic acids and salts thereof, polyoxyethylene alkyl sulfate salts, polyoxyethylene alkyl phenyl ether sulfate salts, vinyl sulfosuccinates. Etc.

  Nonionic surfactants include polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyethylene glycol fatty acid ester, ethylene oxide propylene oxide block copolymer, polyoxyethylene fatty acid amide, ethylene oxide-propylene oxide copolymer, etc. And a sorbitan derivative such as a polyoxyethylene sorbitan fatty acid ester and the like.

  Examples of amphoteric surfactants include lauryl betaine and lauryl dimethylamine oxide. Examples of reactive surfactants include alkylpropenylphenol polyethylene oxide adducts and their sulfate esters, allyl alkylphenol polyethylene oxide adducts and their sulfate esters, allyl dialkylphenol polyethylene oxide adducts and their sulfate esters, etc. Examples thereof include compounds having a reactive double bond.

  The thickness of the release layer in the release sheet is preferably from 0.01 to 5 μm, preferably from 0.1 to 2 μm, more preferably from 0.1 to 1 μm, and from 0.2 to More preferably, it is 0.7 μm. If it is less than 0.01 μm, sufficient releasability cannot be obtained, while if it exceeds 5 μm, the releasability may be lowered.

  The wetting tension on the surface of the release layer is preferably 30 mN / m or more, and more preferably 32 mN / m or more. If the wetting tension is less than 30 mN / m, it may be difficult to laminate another coating agent or liquid on the release layer. The wetting tension in the present invention indicates a critical surface tension by Zisman and can be measured by the method described in JIS K6768.

  Examples of the substrate in the release sheet include a resin material, paper, synthetic paper, cloth, metal material, and glass material. Although the thickness of a base material is not specifically limited, Usually, what is necessary is just 1-1000 micrometers, 1-500 micrometers is preferable, 1-100 micrometers is more preferable, and 1-50 micrometers is especially preferable.

  Examples of the resin material that can be used for the substrate include, as thermoplastic resins, polyester resins such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and polylactic acid (PLA); polyolefin resins such as polypropylene; polystyrene resins, Polyamide resin such as 6-nylon and poly-m-xylylene adipamide (MXD6 nylon); polycarbonate resin; polyacrylonitrile resin; polyimide resin, multilayer of these resins (for example, nylon 6 / MXD / nylon 6) And nylon 6 / ethylene-vinyl alcohol copolymer / nylon 6) and mixtures of these resins.

  The resin material may be stretched. Further, the resin material may contain a known additive or stabilizer, such as an antistatic agent, a plasticizer, a lubricant, or an antioxidant. Further, the resin material may be subjected to surface treatment such as corona treatment, plasma treatment, ozone treatment, chemical treatment, solvent treatment, etc. in order to improve adhesion when laminated with other materials. Further, silica, alumina, or the like may be deposited on the surface of the resin material, and other layers such as a barrier layer, an easy adhesion layer, an antistatic layer, an ultraviolet absorption layer, and an adhesive layer may be laminated.

  Examples of paper that can be used for the substrate include Japanese paper, craft paper, liner paper, art paper, coated paper, carton paper, glassine paper, semi-glassine paper, and the like.

  The structure of the synthetic paper that can be used for the substrate is not particularly limited, and may be a single layer structure or a multilayer structure. As a multilayer structure, for example, a two-layer structure of a base material layer and a surface layer, a three-layer structure in which a surface layer exists on the front and back surfaces of the base material layer, and another resin film layer exists between the base material layer and the surface layer. A multilayer structure can be exemplified. Moreover, each layer in the substrate may contain an inorganic or organic filler. Moreover, the microporous synthetic paper which has many fine voids may be sufficient.

  Examples of the cloth that can be used for the substrate include fibers made of the above-described resin materials, nonwoven fabrics made of natural fibers such as cotton, silk, and hemp, woven cloth, and knitted cloth.

  Examples of the metal material that can be used for the substrate include metal foils such as aluminum foil and copper foil, and metal plates such as aluminum plate and copper plate. Examples of the glass material include a glass plate and a cloth made of glass fiber.

  In the base material using the resin material, paper, synthetic paper, cloth, other resin materials, metal materials, and the like may be laminated on the opposite side on which the release layer is laminated.

  The release sheet of the present invention has good release properties. Therefore, the peel strength between the release layer and the adherend after leaving for 20 hours in an atmosphere of 2 kPa load and 70 ° C. can be, for example, 10 N / 50 mm or less. The peel strength is preferably 8 N / 50 mm or less, more preferably 7 N / 50 mm or less. If the peel strength exceeds 10 N / 50 mm, the releasability is insufficient and it may be difficult to use as a release sheet.

A method for producing the release sheet of the present invention will be described below.
The method for producing the release sheet of the present invention is not particularly limited. For example, a coating liquid obtained by mixing an acid-modified polyolefin resin, polyvinyl alcohol, crosslinking agent A and crosslinking agent B in a liquid medium is used as a base material. The manufacturing method which laminates | releases a mold release layer by drying after coating on top is mentioned. According to this method, a release sheet can be obtained industrially easily.

The method for producing the coating liquid is not particularly limited as long as each component is uniformly mixed in the liquid medium. For example, the following methods (1) and (2) may be mentioned.
Production method (1): A method in which a dispersion or solution of a crosslinking agent and polyvinyl alcohol is added to a dispersion or solution of an acid-modified polyolefin resin and mixed to form a liquid material.
Production method (2): A method of liquefying a mixture of an acid-modified polyolefin resin, a crosslinking agent and polyvinyl alcohol.

  In the case of using the production method (1), the solute concentration of the dispersion or solution of the crosslinking agent and polyvinyl alcohol is not particularly limited, but is preferably 5 to 10% by mass from the viewpoint of ease of handling.

  When the production method (2) is used, a crosslinking agent and polyvinyl alcohol may be added when the acid-modified polyolefin resin is liquefied.

  When a component (for example, the aforementioned matting agent) other than the acid-modified polyolefin resin, the crosslinking agent, or polyvinyl alcohol is blended, it can be blended at any stage in the production method (1) or (2).

  In the case of producing the release sheet of the present invention, a solvent for obtaining a dispersion or solution of an acid-modified polyolefin resin, a solvent for obtaining a dispersion or solution of a crosslinking agent and polyvinyl alcohol, an acid-modified polyolefin resin, The solvent for making the crosslinking agent and polyvinyl alcohol into a liquid is not particularly limited as long as it can be applied onto the substrate. Examples of the solvent include water, an organic solvent, or an aqueous medium containing water and an amphiphilic organic solvent. Of these, water or an aqueous medium is preferably used from the viewpoint of reducing environmental burden and from the viewpoint of excellent solubility of polyvinyl alcohol.

  Examples of the organic solvent used as the solvent include diethyl ketone (3-pentanone), methyl propyl ketone (2-pentanone), methyl isobutyl ketone (4-methyl-2-pentanone), 2-hexanone, and 5-methyl-2- Ketones such as hexanone, 2-heptanone, 3-heptanone, 4-heptanone, cyclopentanone, cyclohexanone; aromatic hydrocarbons such as toluene, xylene, benzene, Solvesso 100, Solvesso 150; butane, pentane, Aliphatic hydrocarbons such as hexane, cyclohexane, heptane, octane, nonane; methylene chloride, chloroform, carbon tetrachloride, 1,2-dichloroethane, 1,1,2,2-tetrachloroethane, chlorobenzene, o-dichlorobenzene, m-dichlorobenzene, p-dichlorobenzene Halogenated compounds such as ethyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, sec-butyl acetate, 3-methoxybutyl acetate, methyl propionate, ethyl propionate, diethyl carbonate, γ-butyrolactone, isophorone In addition, the following amphiphilic organic solvents are mentioned.

  The aqueous medium means a solvent composed of water and an amphiphilic organic solvent and having a water content of 2% by mass or more. The amphiphilic organic solvent means an organic solvent having a water solubility of 5% by mass or more with respect to the organic solvent at 20 ° C. The solubility of water in an organic solvent at 20 ° C. is described in documents such as “Solvent Handbook” (Kodansha Scientific, 1990, 10th edition).

  Specific examples of the aqueous medium include alcohols such as methanol, ethanol (hereinafter abbreviated as “EA”), n-propanol (hereinafter abbreviated as “NPA”), isopropanol (hereinafter abbreviated as “IPA”); Ethers such as 1,4-dioxane; ketones such as acetone and methyl ethyl ketone; esters such as methyl acetate, n-propyl acetate, isopropyl acetate, methyl propionate, ethyl propionate, and dimethyl carbonate; Including diethylamine, triethylamine (hereinafter abbreviated as “TEA”), diethanolamine, triethanolamine, N, N-dimethylethanolamine (hereinafter abbreviated as “DMEA”), N, N-diethylethanolamine, N-diethanolamine and the like Organic amination of Things; 2-pyrrolidone, etc. lactams such as N- methyl-2-pyrrolidone.

  The method for dispersing the acid-modified polyolefin resin in the aqueous medium as described above is not particularly limited, and examples thereof include a method described in International Publication No. 02/055598.

  It is desirable that the dispersion obtained by dispersing the acid-modified polyolefin resin in an aqueous medium is neutralized and stabilized with ammonia or an organic amine compound. The dispersion liquid stabilized with ammonia or an organic amine compound exhibits alkalinity, and the stability of the coating liquid is increased. Further, when these components are volatilized when the coating film is dried, the reactivity with the crosslinking agent is rapidly increased and the crosslinking density can be increased. On the other hand, when neutralized with a metal such as sodium or lithium, the ionic properties remain after drying, so that the reaction with the crosslinking agent, particularly oxazoline, does not proceed sufficiently, and the water resistance and releasability Improvement may not be seen.

  The dispersed particle size of the acid-modified polyolefin resin in the aqueous medium preferably has a number average particle size of 1 μm or less from the viewpoint of stability when mixed with other components and storage stability after mixing. More preferably, it is 8 μm or less. Such a number average particle diameter can be achieved by the production method described in the pamphlet of International Publication No. 02/055598.

  In the coating liquid production method of (1) or (2) above, the solid content of the coating liquid is appropriately selected depending on the lamination conditions of the release layer and the substrate, the thickness of the desired release layer, the performance, and the like. Although not particularly limited, it is preferably 1 to 60% by mass, more preferably 5 to 30% by mass in order to keep the viscosity of the coating solution moderate and to form a good release layer. .

  As a method for applying the coating liquid to the substrate, a known method may be mentioned. For example, apply to the substrate surface uniformly by gravure roll coating, reverse roll coating, wire bar coating, lip coating, air knife coating, curtain flow coating, spray coating, dip coating, brush coating, etc. There is a method in which after setting near room temperature, it is subjected to heat treatment and dried. In this way, a uniform resin layer can be formed in close contact with the substrate. The conditions for the heat treatment are not particularly limited, but the temperature is preferably 120 ° C. to 200 ° C., and the time is preferably 5 to 90 seconds.

  After the heat treatment, an aging treatment may be performed as necessary. By this treatment, it is possible to improve the cohesiveness of the release layer and the adhesion to the substrate, and to stabilize the release performance. The conditions for the aging treatment are not particularly limited, but about 40 hours to 80 ° C. and about 24 hours to 72 days are suitable.

  The release sheet of the present invention has a good release property for various adherends. Therefore, it is suitably used in an application in which a laminate is formed by laminating on another adherend via a release layer and then released. Specifically, protective materials such as adhesive materials and liquid crystal display parts, process materials when manufacturing printed wiring boards, process materials when transferring unsaturated polyester sheets and surface protective layers for building materials, in-mold It can be suitably used as a material for forming a sheet-like structure such as decoration (IMD), stamping, ink ribbon, or the like, a base film of a sheet for transferring a character, a design, or a character, an ion exchange membrane, or a ceramic green sheet.

  Examples of the adhesive material include an adhesive sheet, an adhesive sheet, an adhesive tape, and an adhesive tape. More specifically, an adhesive is laminated on a base material. The components and base material of the pressure-sensitive adhesive are not particularly limited, but examples of the pressure-sensitive adhesive include acrylic pressure-sensitive adhesives, natural rubber-based pressure-sensitive adhesives, and synthetic rubber-based pressure-sensitive adhesives. Here, rosin-based, coumarone-indene-based, A terpene, petroleum, styrene, phenol or xylene tackifier may be included. Examples of the substrate include the above-described paper, cloth, and resin material.

  Examples of the printed wiring board include a single-sided printed wiring board, a double-sided printed wiring board, a flexible printed wiring board, and a multilayer printed wiring board.

  Examples of the liquid crystal display component include a polarizing plate, a retardation polarizing plate, and a retardation plate.

  Examples of the sheet-like structure include an ion exchange membrane made of a polymer electrolyte such as perfluorosulfonic acid resin, and a ceramic green sheet made of dielectric ceramics or glass. These are formed by casting a raw material in a paste or slurry form with a solvent onto a release sheet.

  Among the above, the release sheet of the present invention is a process for producing a printed wiring board that is exposed to high temperature and high pressure such as IMD and press use, and a process that is susceptible to moisture such as sheet formation from emulsion and hydraulic transfer. In, it can use suitably.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited thereto.

<Measurement or evaluation method>
(1) Configuration of acid-modified polyolefin resin
^It calculated | required from < ¹ > H-NMR analysis (The product made by Varian, 300MHz). Orthodichlorobenzene (d4) was used as a solvent, and measurement was performed at 120 ° C.

(2) Melting point of acid-modified polyolefin resin 10 mg of resin is used as a sample, and measurement is performed using a DSC (Differential Scanning Calorimetry) apparatus (trade name “DSC7” manufactured by PerkinElmer Co., Ltd.) at a temperature rising rate of 10 ° C./min. The melting point was determined from the obtained temperature rise curve.

(3) Vicat softening point of acid-modified polyolefin resin Measured according to JIS K7206-1979.

(4) Melt flow rate (MFR) of acid-modified polyolefin resin
It measured according to JIS K6730 (190 degreeC, 2160g load).

(5) Organic solvent content of aqueous dispersion Gas chromatograph (manufactured by Shimadzu Corporation, trade name “GC-8A”) [using FID detector, carrier gas: nitrogen, column packing material (manufactured by GL Sciences): PEG- HT (5%)-Uniport HP (60/80 mesh), column size: diameter 3 mm × 3 m, sample charging temperature (injection temperature): 150 ° C., column temperature: 60 ° C., internal standard substance: n-butanol] Then, the aqueous dispersion or a solution obtained by diluting the aqueous dispersion with water was directly put into the apparatus, and the content of the organic solvent was determined. The detection limit was 0.01% by mass.

(6) Solid content concentration An appropriate amount of the liquid material was weighed and heated at 150 ° C. until the mass of the residue (solid content) reached a constant weight, and the solid content concentration was determined.

(7) Number average particle diameter of acid-modified polyolefin resin particles Using a Microtrac particle size distribution meter (trade name “UPA150” manufactured by Nikkiso Co., Ltd.) (MODEL No. 9340, dynamic light scattering method), the number average particle diameter is obtained. It was. The refractive index of the resin used for particle diameter calculation was 1.57.

(8) Release layer thickness Using a contact-type film thickness meter, the thickness of the substrate was determined by subtracting the thickness of the sheet (release sheet) obtained by laminating the release layer. .

(9) Peel strength On the release layer side of the obtained release sheet, a polyester adhesive tape having a width of 50 mm and a length of 150 mm (manufactured by Nitto Denko Corporation, “No. 31B”) (acrylic adhesive) is used with a rubber roll. A sample was prepared by pressure bonding. This sample is sandwiched in the form of metal plate / rubber plate / sample / rubber plate / metal plate, left in a 2 kPa load, 70 ° C. atmosphere for 20 hours, then cooled to room temperature for 30 minutes or more, for peel strength measurement A sample was obtained. The peel strength between the pressure-sensitive adhesive tape and the release sheet of the peel strength measurement sample was measured with a tensile tester (Intesco, “Precision Universal Material Tester Model 2020”) in a thermostatic chamber at 25 ° C. The peeling angle at the time of measurement was 180 °, and the peeling speed was 300 mm / min.

(10) Water scratch resistance Absorbent cotton, which was soaked in water and rolled to about 1 cm, was pinched with tweezers, and it was visually judged whether or not the coating layer was missing 10 times on the release layer.
○: Presence of a coating film is recognized.
X: The coating film is missing and the base is visible.

(11) Transfer resistance to coating film A hard coating agent UVT clear type F manufactured by DIC was applied on a release sheet so as to have a film thickness of 10 μm and dried at 120 ° C. for 30 seconds. A transfer sheet was prepared by coating an adhesive layer made of a thermoplastic acrylic resin (Paraloid B-66 manufactured by Rohm and Haas Co.) so that the dry film thickness was 5 μm. Then, after bonding together with a hot roll so that an acrylic board and an adhesive bond layer might contact (210 degreeC x 5 second), the release sheet was peeled off and the acrylic board with a protective layer was obtained. Then, white ink (Toyo Ink Finestar R650) was applied and dried with a Meyer bar (60 ° C. × 10 seconds) from the top of the protective layer, and then an adhesive tape (Nichiban Cellotape (registered trademark) LP-24) was used as the ink. When the material was applied to the coated surface and peeled off, the material from which the ink was taken on the adhesive tape was marked with x, and the material with no ink transferred was marked with ○ (the ink adhesion decreased when the release layer was transferred).

The materials used in the examples are shown below.
(1) Acid-modified polyolefin resin (composition is shown in Table 1)
・ Arkema Bondine LX-4110
・ Primacall 5980I manufactured by Dow Chemical

(2) Carbodiimide compound: “Carbodilite E-01” and “Carbodilite E-02” manufactured by Nisshinbo Co., Ltd. (both solid concentration: 40% by mass)

(3) Oxazoline compound: “Epocross WS-500” (solid content concentration: 40% by mass), “Epocross WS-700” (solid content concentration: 25% by mass) manufactured by Nippon Shokubai Co., Ltd.

(4) Melamine compound, manufactured by Nippon Cytec Co., Ltd., imino melamine resin “Cymel 325” (solid content concentration: 100 mass%)
-Sumitomo Chemical Co., Ltd. methylated melamine resin "Sumimar M-30W" (solid content: 100% by mass)
・ DIC-made hexa-type melamine resin “Beccamin J-101” (solid content: 100% by mass)

(5) Other reactive compounds / isocyanate compounds ("Basonat HW-100" manufactured by BASF) (solid content concentration: 100% by mass)
-Epoxy compound water dispersion (manufactured by Adeka, "Adeka Resin EM-051R") (solid content concentration: 50% by mass)

(6) “VC-10” (Polymerization degree: 1,000), manufactured by polyvinyl alcohol, Nippon Vinegar-Poval, Inc.

(7) Base film / biaxially stretched polyester film (Unitika, “Emblet S-38”) (thickness: 38 μm)

[Production of Aqueous Dispersion M-1]
60.0 g of acid-modified polyolefin resin (LX-4110 manufactured by Arkema Co.), 90.0 g of IPA (manufactured by Wako Pure Chemical Industries, Ltd.), 3.0 g of TEA (manufactured by Wako Pure Chemical Industries, Ltd.) and 147.0 g of distilled water were charged into a glass container, and the rotation speed of the stirring blade was 300 rpm. The system temperature was kept at 140 to 145 ° C., and the mixture was further stirred for 30 minutes. Then, after putting in a water bath and cooling to room temperature (about 25 ° C.) while stirring at a rotational speed of 300 rpm, pressure filtration (air pressure 0.2 MPa) with a 300 mesh stainless steel filter (wire diameter 0.035 mm, plain weave) As a result, a milky white uniform acid-modified polyolefin resin aqueous dispersion M-1 was obtained.

[Production of Aqueous Dispersion M-2]
Using a stirrer equipped with a hermetic pressure-resistant 1 liter glass container with a heater, 60.0 g of acid-modified polyolefin resin (5980I manufactured by Dow Chemical Company), 16.8 g of TEA, and 223.2 g of distilled water were added. The mixture was charged into a glass container and stirred at a rotation speed of the stirring blade of 300 rpm. The system temperature was kept at 140 to 145 ° C., and the mixture was further stirred for 30 minutes. Then, after putting in a water bath and cooling to room temperature (about 25 ° C.) while stirring at a rotational speed of 300 rpm, pressure filtration (air pressure 0.2 MPa) with a 300 mesh stainless steel filter (wire diameter 0.035 mm, plain weave) As a result, a slightly cloudy acid-modified polyolefin resin aqueous dispersion M-2 was obtained. At this time, almost no resin remained on the filter.

  The compositions of the aqueous dispersions M-1 and M-2 are shown in Table 2.

Example 1
M-1, WS-500, Cymel 325, and VC-10 were mixed to obtain a coating solution having a solid content concentration of 10% by mass. The blending amount was such that the solid content of WS-500 was 5 mass parts, the solid content of Cymel 325 was 5 mass parts, and VC-10 was 30 mass parts with respect to 100 mass parts of the solid content of M-1.

  The obtained coating solution was coated on the corona-treated surface of the base film using a Meyer bar so that the dry film thickness was 0.2 μm, and then dried at 180 ° C. for 90 seconds to form on the base film. A release layer was formed.

Examples 2 and 3
Using the coating solution prepared in Example 1, the same operation as in Example 1 was performed except that the dry film thickness was 0.5 μm (Example 2) and 0.8 μm (Example 3). Thus, a release layer was formed to obtain a release sheet.

Example 4
In the preparation of the coating liquid used in Example 1, a coating liquid having a solid content concentration of 10% by mass was prepared by performing the same operation as in Example 1 except that M-2 was used instead of M-1. Using this, the same operation as in Example 1 was performed to obtain a release sheet.

Examples 5-11 and Comparative Examples 1-8
Except for changing the composition of the coating liquid used in Example 1 as shown in Table 3 or Table 4, the same operation as in Example 1 was performed to prepare a coating liquid having a solid content concentration of 10% by mass, A release sheet was obtained using this.

  Tables 3 and 4 show the compositions of the coating liquids used in Examples and Comparative Examples and the evaluation results of the release sheet obtained therefrom.

  The release sheets of Examples 1 to 11 were excellent in water scratch resistance, coating film transfer resistance, and release properties.

  As is clear from Comparative Example 1, when the melamine compound defined in the present invention was not used, the water scratch resistance and the film transfer resistance were inferior. Further, as in Comparative Example 2 or 3, even when another cross-linking agent was used instead of the cross-linking agent B, the water rub resistance and the film transfer resistance were not improved.

As is clear from Comparative Examples 4 to 8, when any of polyvinyl alcohol, cross-linking agent A, and cross-linking agent B is not used, the release satisfying all of water rub resistance, film transfer resistance and mold release properties. A mold sheet could not be obtained.

Claims (2)

A release sheet formed by forming a release layer containing an acid-modified polyolefin resin, polyvinyl alcohol and a crosslinking agent on a substrate, and the crosslinking agent selected from carbodiimide or oxazoline compound as the crosslinking agent and melamine A release sheet comprising a crosslinking agent B selected from compounds. 2. The release sheet according to claim 1, wherein the content of the crosslinking agent B is 1 to 100 parts by mass with respect to 100 parts by mass of the acid-modified polyolefin resin.