JP2013184461A - Release sheet and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a release sheet in which release layers of each of heavy and light peeling are formed separately on respective surfaces of a substrate, the release layers exhibit favorable releasability relative to an adherend, and the lowering of adhesion of a pressure-sensitive adhesive by migration of a releasing agent can be fundamentally solved by formation of a release layer without using a silicone-based releasing agent which has been used so far.SOLUTION: A release sheet includes a release layer 1 on one surface of a substrate and a release layer 2 on the other surface of the substrate. At least one release layer includes an acid-modified polybutadiene and/or an acid-modified polyisoprene and a cross-linking agent including at least one selected from oxazoline compounds, carbodiimide compounds and melamine compounds in which the total content of the oxazoline compound, the carbodiimide compound and the melamine compound is from 1 to 50 pts.mass relative to 100 pts.mass of the sum of the acid-modified polybutadiene and the acid-modified polyisoprene, the release strength F1 between the release layer 1 and an acrylic pressure sensitive adhesive material is 0.5 N/cm or less, the release strength F2 between the release layer 2 and the acrylic pressure sensitive adhesive material is 1.0 N/cm or less, and the relation: F1<F2 is satisfied.

Description

  The present invention relates to a release sheet and a manufacturing method thereof.

The pressure-sensitive adhesive sheet is used in various fields, and a double-sided pressure-sensitive adhesive sheet is used for bonding two objects. As the double-sided pressure-sensitive adhesive sheet, a sheet having a pressure-sensitive adhesive layer formed on both surfaces of a base material, or a pressure-sensitive adhesive sheet having both surfaces having adhesiveness and having no base material is used. Generally, in order to protect the surface of an adhesive sheet, a release sheet is bonded to the surface until it is used.
When the pressure-sensitive adhesive sheet is a double-sided pressure-sensitive adhesive sheet, one side of the pressure-sensitive adhesive layer has a relatively low release force, that is, a light-release release sheet is laminated, and the other side of the pressure-sensitive adhesive layer has a relative release force. Is high, that is, a release sheet of heavy release is laminated to protect both sides. When the object 1 and the object 2 are bonded using the double-sided pressure-sensitive adhesive sheet, the light release release sheet is first peeled off, and the exposed pressure-sensitive adhesive layer surface is bonded to the object 1. Thereafter, the heavy release release sheet is peeled off to expose the other adhesive layer surface, and then the object 2 is bonded to this surface to bond the object 1 and the object 2 together.

  When the double-sided pressure-sensitive adhesive sheet is wound up and provided in the form of a roll, as described above, one of the double-sided pressure-sensitive adhesive sheets is used by using two release sheets, a light-release release sheet and a heavy-release release sheet. A light release release sheet is bonded to the other surface, and a heavy release release sheet is bonded to the other surface and wound into a roll. Also, using a single release sheet that has been subjected to light release release treatment on one side and heavy release release treatment on the other side, this release sheet is applied to a double-sided adhesive sheet. It is provided by being rolled up in a bonded state. From the viewpoint of reducing waste after use, an increasing number of cases use a release sheet that has been subjected to light release and heavy release release treatments with different release forces on a single sheet.

  As such a release sheet subjected to the release treatment on both sides, Patent Literature 1 and Patent Literature 2 propose a release sheet having a silicone release treatment on both sides. However, when a silicone release agent is used, the low molecular weight silicone compound contained in the silicone release agent migrates to the adhesive surface of the adhesive sheet and remains, thereby causing the adhesive strength of the adhesive. It has been pointed out that there is a risk that the electronic components bonded by the pressure-sensitive adhesive sheet may cause trouble.

JP 2006-7550 A JP 2010-234604 A

  In view of these problems, the subject of the present invention is that a release layer for each heavy and light release is separately formed on each surface of the base material, and these exhibit good release properties with respect to the adhesive material, An object of the present invention is to provide a release sheet that can fundamentally solve a decrease in adhesive strength of an adhesive due to transfer of a release agent by forming a release layer without using a conventionally used silicone release agent.

As a result of intensive studies to solve the above-mentioned problems, the present inventor has release layers on both surfaces of a substrate, and at least one of the release layers is an acid-modified polybutadiene and / or acid-modified polyisoprene, and an oxazoline. It has been found that a compound having a crosslinking agent containing at least one selected from a compound, a carbodiimide compound and a melamine compound is effective as a release sheet for a double-sided pressure-sensitive adhesive sheet, and has reached the present invention.
That is, the gist of the present invention is as follows.
(1) A release sheet having a release layer 1 on one surface of a base material and a release layer 2 on the other surface of the base material, wherein at least one release layer comprises acid-modified polybutadiene and / or Or it has acid-modified polyisoprene and a crosslinking agent containing at least one selected from oxazoline compound, carbodiimide compound, and melamine compound, and the total content of oxazoline compound, carbodiimide compound and melamine compound is acid-modified polybutadiene and acid-modified 1 to 50 parts by mass with respect to 100 parts by mass in total of polyisoprene, the peel strength F1 between the release layer 1 and the acrylic adhesive material is 0.5 N / cm or less, and the release layer 2 and acrylic A release sheet having a peel strength F2 with respect to an adhesive material of 1.0 N / cm or less and F1 <F2.
(2) The release sheet according to (1), wherein the release layer 2 contains a long-chain alkyl compound and / or an acid-modified polyolefin resin.
(3) The release sheet according to (1) or (2), wherein the substrate is any one of a resin material, paper, synthetic paper, cloth, metal material, and glass material.
(4) The release sheet according to (3), wherein the resin material is a polyester resin film.
(5) A method for producing the release sheet according to (1) above, wherein at least one selected from acid-modified polybutadiene and / or acid-modified polyisoprene, an oxazoline compound, a carbodiimide compound, and a melamine compound The cross-linking agent is dispersed in an aqueous medium, and the total content of the oxazoline compound, carbodiimide compound and melamine compound is 1 to 50 parts by mass with respect to 100 parts by mass in total of the acid-modified polybutadiene and the acid-modified polyisoprene. A release material is formed by applying the liquid material on the at least one surface of the base material and then drying, to form a release layer.
(6) A method for producing the release sheet according to (4) above, comprising at least one selected from acid-modified polybutadiene and / or acid-modified polyisoprene, an oxazoline compound, a carbodiimide compound, and a melamine compound. The cross-linking agent is dispersed in an aqueous medium, and the total content of the oxazoline compound, carbodiimide compound and melamine compound is 1 to 50 parts by mass with respect to 100 parts by mass in total of the acid-modified polybutadiene and the acid-modified polyisoprene. A release sheet, characterized in that a release layer is formed by applying the liquid material on the at least one surface of an unstretched or uniaxially stretched polyester resin film, and then drying and orientation stretching with the film. Manufacturing method.

In the release sheet of the present invention, since the release layer is composed of a specific composition, it is possible to avoid problems caused by the release layer forming component moving to the pressure-sensitive adhesive surface of the pressure-sensitive adhesive sheet and remaining.
In addition, the release sheet of the present invention can be easily manufactured by applying and drying a liquid material in which a resin is dispersed in an aqueous medium on both sides of the substrate, and by changing the composition of the release layer. The peel strength on both sides of the release sheet can be easily adjusted.
Moreover, by using the release sheet of the present invention, it is possible to easily peel the adhesive sheet having a pressure-sensitive adhesive layer on both sides without impairing the quality of the pressure-sensitive adhesive material.

Hereinafter, the present invention will be described in detail.
The release sheet of the present invention has a base material and a release layer provided on the base material, and at least one release layer comprises acid-modified polybutadiene and / or acid-modified polyisoprene and an oxazoline compound. And a crosslinking agent containing at least one selected from carbodiimide compounds and melamine compounds.

  The butadiene skeleton in the acid-modified polybutadiene may have any structure of 1,2-vinyl type, 1,4-trans type, or 1,4-cis type, or a mixture thereof. The ratio is not particularly limited.

As the acid-modified component of the acid-modified polybutadiene, an unsaturated carboxylic acid can be used, and specifically, acrylic acid, methacrylic acid, maleic acid, maleic anhydride, itaconic acid, and itaconic anhydride are preferable and easily available. To maleic acid and maleic anhydride are particularly preferred.
The content of the unsaturated carboxylic acid in the acid-modified polybutadiene is 1 to 400 mgKOH / g as the acid value of the acid-modified polybutadiene, from the viewpoint of reaction with the crosslinking agent and from the viewpoint of easily obtaining an aqueous dispersion of acid-modified polybutadiene described later. Is preferable, 30 to 300 mgKOH / g is more preferable, 50 to 300 mgKOH / g is more preferable, and 70 to 250 mgKOH / g is particularly preferable from the viewpoint of adhesion to a substrate and releasability.
When the acid value of the acid-modified polybutadiene is less than 1 mgKOH / g, the release layer not only has a possibility of transferring to the surface of the pressure-sensitive adhesive due to a decrease in adhesion to the substrate, but also an acid-modified polybutadiene described later. It may be difficult to obtain an aqueous dispersion. On the other hand, when the acid value exceeds 400 mgKOH / g, there is a possibility that the releasability is lowered due to strong adhesion with the adhesive.
The unsaturated carboxylic acid component only needs to be copolymerized in the acid-modified polybutadiene, and the form thereof is not limited, and examples thereof include random copolymerization, block copolymerization, and graft copolymerization (graft modification). .

  The number average molecular weight of the acid-modified polybutadiene is preferably 200 to 20000, and more preferably 500 to 10,000. The number average molecular weight can be measured using gel permeation chromatography (GPC).

  The acid-modified polybutadiene is obtained by modifying polybutadiene with an unsaturated carboxylic acid, but it is convenient to use a commercially available one. Examples of commercially available products include maleated butadiene manufactured by Nippon Soda Co., Ltd. (BN-1010, etc.), maleated butadiene manufactured by JX Nippon Oil & Energy Corporation (M-1000-20, M-1000-80, M-2000-20). , M-2000-80, etc.) and maleated butadiene (polyvest OC800S, etc.) manufactured by Evonik Degussa.

  On the other hand, the skeleton of isoprene in the acid-modified polyisoprene may have any structure of 1,2-vinyl type, 3,4-vinyl type, 1,4-cis type, 1,4-trans type. It may be a mixture of

As an acid-modified component of the acid-modified polyisoprene, an unsaturated carboxylic acid can be used. Specifically, acrylic acid, methacrylic acid, maleic acid, maleic anhydride, itaconic acid, and itaconic anhydride are preferable and easily available. Therefore, maleic acid and maleic anhydride are particularly preferable.
The content of the unsaturated carboxylic acid in the acid-modified polyisoprene is 1 to 1 as the acid value of the acid-modified polyisoprene, from the viewpoint of reaction with the crosslinking agent and from the viewpoint of easily obtaining an aqueous dispersion of acid-modified polyisoprene described later. 400 mgKOH / g is preferable, 3-300 mgKOH / g is more preferable, 4-200 mgKOH / g is more preferable, and 5-100 mgKOH / g is especially preferable from a viewpoint of adhesiveness with a base material or mold release property.
When the acid value of the acid-modified polyisoprene is less than 1 mgKOH / g, the release layer not only has a possibility of transferring to the pressure-sensitive adhesive surface due to a decrease in adhesion to the base material, but also the acid-modified polyisoprene. It may be difficult to obtain an aqueous dispersion. On the other hand, when the acid value exceeds 400 mgKOH / g, there is a possibility that the releasability is lowered due to strong adhesion with the adhesive.
Further, the unsaturated carboxylic acid component only needs to be copolymerized in the acid-modified polyisoprene, and the form thereof is not limited, and examples thereof include random copolymerization, block copolymerization, and graft copolymerization (graft modification). It is done.

  The number average molecular weight of the acid-modified polyisoprene is preferably 200 to 100,000, more preferably 3000 to 70000, and still more preferably 10,000 to 50000. The number average molecular weight can be measured using gel permeation chromatography (GPC).

  The acid-modified polyisoprene is obtained by modifying polyisoprene with an unsaturated carboxylic acid, but it is easy to use a commercially available one. As a commercially available product, for example, maleic anhydride-modified polyisoprene “LIR-403”, “LIR-410” manufactured by Kuraray Co., Ltd. can be used.

  As described above, in the present invention, by using the acid-modified polybutadiene and / or acid-modified polyisoprene, a release layer can be formed without using a conventionally used silicone release agent. However, in the present invention, the use of a silicone release agent is not excluded, and a release layer containing a silicone release agent may be used as long as the effects of the present invention are not impaired. A release layer containing a known release agent that is widely used, such as a fluorine-based compound or an alkyd-based compound, may also be used as long as the effects of the present invention are not impaired.

  Furthermore, at least one release layer of the release sheet of the present invention contains a crosslinking agent together with the acid-modified polybutadiene and / or acid-modified polyisoprene. As the crosslinking agent, a compound having a plurality of functional groups in the molecule that react with the acid-modified component of acid-modified polybutadiene and / or acid-modified polyisoprene is used. From the viewpoint of reactivity, an oxazoline compound, a carbodiimide compound, a melamine compound It is necessary that the crosslinking agent contains at least one selected from the group consisting of:

The oxazoline compound is not particularly limited as long as it has two or more oxazoline groups in the molecule. For example, 2,2'-bis (2-oxazoline), 2,2'-ethylene-bis (4,4'-dimethyl-2-oxazoline), 2,2'-p-phenylene-bis (2-oxazoline) , A compound having an oxazoline group such as bis (2-oxazolinylcyclohexane) sulfide, and an oxazoline group-containing polymer. These 1 type (s) or 2 or more types can be used. Among these, an oxazoline group-containing polymer is preferable because of ease of handling.
The oxazoline group-containing polymer is obtained by polymerizing an addition polymerizable oxazoline such as 2-vinyl-2-oxazoline, 2-vinyl-4-methyl-2-oxazoline, 2-isopropenyl-2-oxazoline. Other monomers may be copolymerized as necessary. The polymerization method of the oxazoline group-containing polymer is not particularly limited, and various known polymerization methods can be employed. An example of a commercially available oxazoline group-containing polymer is EPOCROSS series manufactured by Nippon Shokubai Co., Ltd. Specific product names include, for example, 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 carbodiimide compound is not particularly limited as long as it has at least two or more carbodiimide groups in the molecule. For example, compounds having a carbodiimide group such as p-phenylene-bis (2,6-xylylcarbodiimide), tetramethylene-bis (t-butylcarbodiimide), cyclohexane-1,4-bis (methylene-t-butylcarbodiimide) And polycarbodiimide which is a polymer having a carbodiimide group. These 1 type (s) or 2 or more types can be used. Among these, polycarbodiimide is preferable from the viewpoint of ease of handling.
The method for producing polycarbodiimide is not particularly limited. Polycarbodiimide can be produced, for example, by a condensation reaction involving decarbonization of an isocyanate compound. The isocyanate compound is not limited, and any of aliphatic isocyanate, alicyclic isocyanate, and aromatic isocyanate may be used. The isocyanate compound may be copolymerized with a polyfunctional liquid rubber or polyalkylene diol as necessary. As a commercially available product of polycarbodiimide, there is a carbodilite series manufactured by Nisshinbo. Specific products include, for example, 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 "; solvent-free type" V-05 "and the like.

A melamine compound is a compound in which an amino group is bonded to three carbon atoms of a triazine ring, and the amino group of so-called melamine [1,3,5-triazine-2,4,6-triamine] is subjected to various modifications. And includes those in which a plurality of triazine rings are condensed. As the type of modification, one in which some of the hydrogen atoms of three amino groups are alkylated or methylolated is widely used. In general, methylolated or unsubstituted hydrogen atoms are more reactive than alkylated ones, and an appropriate type of melamine compound can be selected depending on the application. Among them, the average number of condensation of triazine rings is 3 or less, and at least one amino group is methylol-substituted. These are dispersibility in an aqueous medium and reactivity with a resin described later. Is excellent in terms of.
Examples of commercially available melamine compounds include Cymel series manufactured by Nippon Cytec Industries, Sumima manufactured by Sumitomo Chemical Co., and becamine manufactured by DIC.

  The content of the oxazoline compound, carbodiimide compound, and melamine compound as the crosslinking agent needs to be 1 to 50 parts by mass with respect to 100 parts by mass in total of the acid-modified polybutadiene and the acid-modified polyisoprene, and 2 to 30 More preferably, it is 3 parts by mass, and still more preferably 3-20 parts by mass. When the content is less than 1 part by mass, the effect of addition is poor, and the releasability may decrease with time, and when the content exceeds 50 parts by mass, the releasability may decrease. Two or more kinds of oxazoline compounds, carbodiimide compounds, and melamine compounds can be selected and used at the same time. When they are used at the same time, it is sufficient that the total amount thereof satisfies the above-described content range. In the release sheet of the present invention, the releasability between the release layer and the adhesive material can be easily adjusted by changing the addition amount of the crosslinking agent and the type of the crosslinking agent.

  In the release sheet of the present invention, for the purpose of adjusting releasability and preventing blocking of the release layer, the release layer 2 contains a long-chain alkyl compound or an acid-modified polyolefin resin as other components. It may be included. Among these, it is desirable that a long-chain alkyl-based compound is included because it is easy to adjust the peel strength between the release layer and the pressure-sensitive adhesive.

  The long-chain alkyl compound referred to in the present invention refers to a compound having a long-chain alkyl group, and is not particularly limited as long as it is a compound having a long-chain alkyl group, but has a long-chain alkyl group in the side chain of the main chain polymer. Things.

In a compound having a long-chain alkyl group in the side chain of the main chain polymer, the main chain polymer may be an acrylate polymer or copolymer, polyvinyl alcohol (including partially saponified polyvinyl acetate), ethylene-vinyl alcohol. Copolymer (including partially saponified ethylene-vinyl acetate copolymer), vinyl alcohol-acrylic acid copolymer (including partially saponified vinyl acetate-acrylic acid copolymer), polyethyleneimine, polyvinylamine, Examples thereof include styrene-maleic anhydride copolymer and polyurethane.
On the other hand, the long-chain alkyl group in the side chain preferably has 6 or more carbon atoms, more preferably 10 to 30, and still more preferably 12 to 30. When the number of carbon atoms in the side chain long chain alkyl group is small, the effect of preventing blocking may be small. On the other hand, a long chain alkyl group compound having a long chain alkyl group with a large number of carbon atoms in the side chain is actually obtained. May be difficult.

  A long-chain alkyl compound having an acrylate polymer or copolymer as a main chain polymer can be obtained by radical polymerization of an unsaturated monomer having a long-chain alkyl group. Specifically, unsaturated monomers having a long chain alkyl group such as decyl (meth) acrylate, lauryl (meth) acrylate, cetyl (meth) acrylate, stearyl (meth) acrylate, and behenyl (meth) acrylate are polymerized. Or those copolymerized with other monomers. (Meth) acrylate refers to acrylate and / or methacrylate.

In addition, long-chain alkyl compounds having a main chain polymer of polyvinyl alcohol, ethylene-vinyl alcohol copolymer, vinyl alcohol-acrylic acid copolymer, polyethyleneimine, polyvinylamine, styrene-maleic anhydride copolymer, polyurethane, etc. These can be obtained by introducing a long chain alkyl group into the main chain polymer. That is, by reacting the main chain polymer having a functional group such as a hydroxyl group, an amino group, or a carboxyl group with a compound having a functional group capable of reacting with these functional groups and a long chain alkyl group, the main chain polymer is converted into a main chain polymer. Long chain alkyl groups can be introduced.
Examples of the functional group capable of reacting with the functional group contained in the main chain polymer include an isocyanate group, a carboxylic acid group, an acid halide group, a ketene group, an aldehyde group, and an epoxy group, and a long chain alkyl group together with these functional groups. Are used in the reaction with the main chain polymer.
Examples of the compound having an isocyanate group and a long-chain alkyl group include hexyl isocyanate, octyl isocyanate, dodecyl isocyanate, octadecyl isocyanate, and docosanyl isocyanate. The compound having a carboxylic acid group and a long-chain alkyl group includes octane. Acid, dodecanoic acid, octadecanoic acid, docosanoic acid and the like. Examples of the compound having an acid halide group and a long chain alkyl group include octanoyl chloride, dodecanoyl chloride, docosanoyl chloride, etc. Examples of the compound having a chain alkyl group include octyl ketene dimer, dodecyl ketene dimer, octadecyl ketene dimer, docosanyl ketene dimer, etc., and compounds having an aldehyde group and a long chain alkyl group Octyl aldehyde, dodecyl aldehyde, octadecyl aldehyde, docosanyl aldehyde, etc., and compounds having an epoxy group and a long chain alkyl group include octyl glycidyl ether, dodecyl glycidyl ether, octadecyl glycidyl ether, docosanyl glycidyl ether, etc. Can be mentioned.

  If the ratio of the long-chain alkyl group in the long-chain alkyl compound is decreased, the release performance may be deteriorated and the anti-blocking effect may not be obtained. On the other hand, the compound having a long-chain alkyl group is preferably introduced in an amount of 0.5 equivalent or more, and more preferably 0.6 equivalent or more.

  Commercially available long-chain alkyl compounds may be used. Specifically, “K-256” and “N-” of the Resem series, which are aqueous dispersions of long-chain alkyl compounds manufactured by Chukyo Yushi Co., Ltd. “137”, “P-677”, “Q-472”, Ashioresin series “RA-95H”, “RA-585S”, long chain alkyl compounds manufactured by Ashio Sangyo Co., Ltd. "HT", "1050", "1010", "1070", "406" of the pyroyl series which is a chain alkyl compound, "ZF-15", which is a long chain alkyl compound manufactured by Nihon Ventures-Poval. ZF-15H "and the like.

  In forming the release layer to be described later, a long-chain alkyl compound dissolved in an aqueous medium may be used, or a dispersed compound may be used. An emulsifier may be used for dispersing the long-chain alkyl compound. As the emulsifier, a commonly used emulsifier may be used, and among them, a high molecular weight surfactant is preferably used.

On the other hand, with respect to the acid-modified polyolefin resin contained in the release layer, the acid-modified component is 1 to 10% by mass of the acid-modified polyolefin resin from the viewpoint of improving adhesion to the substrate and promoting aqueous dispersion. It is preferable that it is 1-7 mass%, and it is especially preferable that it is 2-5 mass%. When the amount of the acid-modified component is less than 1% by mass, sufficient adhesion to the substrate may not be obtained, and the pressure-sensitive adhesive surface may be contaminated. Furthermore, it tends to be difficult to disperse this resin in water. On the other hand, when the amount of the acid-modified component exceeds 10% by mass, the peel strength between the release layer and the adhesive material may increase.
Examples of the acid-modifying component 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 from the viewpoint of dispersion stability of the resin, and acrylic acid, methacrylic acid, and maleic anhydride are particularly preferable.

  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 and 1-hexene is preferable. . A mixture thereof may be used. Among these, alkene having 2 to 4 carbon atoms such as ethylene, propylene, isobutylene and 1-butene is more preferable, ethylene and propylene are further preferable, and ethylene is most preferable.

  The acid-modified polyolefin resin preferably contains a (meth) acrylic acid ester component for the purpose of improving the adhesion to the substrate. When the (meth) acrylic acid ester component is included, the content is preferably 0.5 to 40% by mass, and in order to have good adhesion to various thermoplastic resin film substrates, The range is more preferably 1 to 20% by mass, and further preferably 3 to 10% by 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, and (meth) acrylic acid and carbon number 1 from the viewpoint of easy availability. Esterified products with ˜20 alcohols are preferred. Specific examples of such compounds include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, hexyl (meth) acrylate, (meth) acrylic acid. Examples include octyl, decyl (meth) acrylate, lauryl (meth) acrylate, octyl (meth) acrylate, dodecyl (meth) acrylate, stearyl (meth) acrylate, and the like. Mixtures of these may be used. Among these, from the viewpoint of adhesion to the substrate, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, hexyl acrylate, octyl acrylate are more preferable, ethyl acrylate, More preferred is butyl acrylate, and particularly preferred is ethyl acrylate. In addition, “(meth) acrylic acid˜” means “acrylic acid˜ or methacrylic acid˜”.

  Each component constituting the acid-modified polyolefin may be copolymerized in the acid-modified polyolefin resin, and its form is not limited. Examples of the state 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 high temperature treatment is required for forming the release layer, and when the melting point is less than 80 ° C., the releasability is significantly lowered.
The Vicat softening point of the acid-modified polyolefin resin is preferably 50 to 130 ° C, more preferably 53 to 110 ° C, and more preferably 55 to 90 ° C. When the Vicat softening point is less than 50 ° C., the releasability decreases, and when it exceeds 130 ° C., a treatment at a high temperature is required for forming the release layer.
The melt flow rate 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 minutes. Is more preferable, and 2 to 200 g / 10 min is particularly preferable. When the amount is less than 1 g / 10 minutes, it is difficult to produce a resin and it is difficult to obtain an aqueous dispersion. When the amount exceeds 1000 g / 10 minutes, the adhesiveness of the release layer to the substrate is lowered, and the release layer tends to migrate to the adherend.

  Examples of the trade name of the acid-modified polyolefin resin that can be used in the present invention include Bondine series, which is a maleic anhydride polyolefin resin manufactured by Arkema. Specific product names include “LX-4110”, “HX-8210”, “HX-8290”, “AX-8390”, and the like.

  The acid-modified polyolefin resin can be made into an aqueous dispersion by the same method as that for obtaining an aqueous dispersion of acid-modified polybutadiene or acid-modified polyisoprene described later.

  The long-chain alkyl compound may be used alone to form the release layer 2, and the long-chain alkyl compound or the acid-modified polyolefin may be used in combination with acid-modified polybutadiene and / or acid-modified polyisoprene. The release layer 2 may be formed. When used in combination with acid-modified polybutadiene and / or acid-modified polyisoprene, the content of the long-chain alkyl compound or acid-modified polyolefin is 1 to 100 parts by mass with respect to 100 parts by mass in total of acid-modified polybutadiene and acid-modified polyisoprene. It is preferable that it is 1-50 mass parts, It is more preferable that it is 2-30 mass parts, It is especially preferable that it is 3-20 mass parts. When the content of the long-chain alkyl compound or the acid-modified polyolefin is less than 1 part by mass, the effect of addition is poor, and there is a possibility of blocking when wound into a roll. If the content exceeds 100 parts by mass, the releasability may decrease. In addition, a long-chain alkyl type compound or acid-modified polyolefin can also use several types simultaneously, and when it uses simultaneously, those total amount should just satisfy | fill the range of said content.

  The release sheet of the present invention is a release sheet having a release layer 1 on one surface of a substrate and a release layer 2 on the other surface of the substrate, and at least one release layer is It has the acid-modified polybutadiene and / or acid-modified polyisoprene and the crosslinking agent. When only one release layer of the release sheet has the acid-modified polybutadiene and / or acid-modified polyisoprene and the crosslinking agent, the other release layer moves to the pressure-sensitive adhesive surface of the pressure-sensitive adhesive sheet. It is preferable to select and apply a difficult component.

  Examples of the base material of the release sheet include those formed of resin material, paper, synthetic paper, cloth, metal material, glass material and the like. 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, 10-200 micrometers is more preferable, and 25-100 micrometers is especially preferable.

  Examples of resin materials that can be used for the substrate include polyester resins such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and polylactic acid (PLA) as thermoplastic resins; polyolefin resins such as polypropylene; polystyrene resins; Polyamide resin such as nylon 6, poly-m-xylylene adipamide (MXD6 nylon); polycarbonate resin; polyacrylonitrile resin; polyimide resin; multilayer of these resins (for example, nylon 6 / MXD6 nylon / nylon 6) , Nylon 6 / ethylene-vinyl alcohol copolymer / nylon 6) and mixtures. The resin material may be stretched. Among them, the base material is preferably a polyester resin film excellent in mechanical properties and thermal properties, and is preferably a polyethylene terephthalate film from the viewpoint of being inexpensive and easily available.

  The film made of the thermoplastic resin may contain a known additive or stabilizer, such as an antistatic agent, a plasticizer, a lubricant, or an antioxidant. The thermoplastic resin film may have a surface subjected to a corona treatment, a plasma treatment, an ozone treatment, a chemical treatment, a solvent treatment, or the like as a pretreatment in order to improve adhesion when laminated with other materials. Moreover, silica, alumina, etc. may be vapor-deposited, and other layers, such as a barrier layer, an easily bonding layer, an antistatic layer, and an ultraviolet absorption layer, may be laminated.

Examples of paper that can be used as the substrate include Japanese paper, kraft paper, liner paper, art paper, coated paper, carton paper, glassine paper, and semi-glassine paper. The paper may be provided with a sealing layer or the like.
The structure of the synthetic paper that can be used as 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. Each layer may or may not contain an inorganic or organic filler. A microporous synthetic paper having a large number of fine voids can also be used.
Examples of the cloth that can be used as the substrate include fibers made of the above-described synthetic resin, nonwoven fabrics made of natural fibers such as cotton, silk, and linen, woven cloth, and knitted cloth.
Examples of the metal material that can be used as 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 that can be used as the substrate include a glass plate and a cloth made of glass fiber.

The release layer 1 of the release sheet of the present invention requires that the peel strength F1 between the release layer 1 and the acrylic adhesive material be 0.5 N / cm or less, and 0.4 N / cm or less. Is more preferably 0.3 N / cm or less, and most preferably 0.2 N / cm or less. When the peel strength F1 is 0.5 N / cm or more, it is difficult to unwind easily when the pressure-sensitive adhesive sheet is unwound from the roll wound with the pressure-sensitive adhesive sheet attached to the release sheet. Yes, not preferred for use.
The release layer 2 of the release sheet of the present invention preferably has a peel strength F2 between the release layer 2 and the acrylic pressure-sensitive adhesive material of 1.0 N / cm or less, and 0.7 N / cm or less. More preferably, it is more preferably 0.5 N / cm or less, and most preferably 0.3 N / cm or less. When the peel strength F2 is 1.0 N / cm or more, the adhesive sheet is attached to the adherend, and it is difficult to peel off when the release sheet is peeled off. When doing so, the smoothness of the pressure-sensitive adhesive surface may be impaired.
Further, the peel strength F1 and the peel strength F2 need to satisfy F1 <F2. Thereby, when unwinding and using an adhesive sheet from the roll which stuck and adhered the adhesive sheet to the release sheet, it peels first between the release layer 1 and the adhesive sheet of the release sheet, and then The pressure-sensitive adhesive sheet can be attached to an adherend, and the release layer 2 and the pressure-sensitive adhesive sheet can be peeled off to be used suitably. When the relationship between the peel strengths does not satisfy F1 <F2, it is difficult to stably unwind the pressure-sensitive adhesive sheet, and it is difficult to suitably use the pressure-sensitive adhesive sheet.
Note that the peel strengths F1 and F2 indicate peel strengths obtained by attaching an adhesive tape, which will be described later, to each surface and pulling the adhesive tape at a rate of 300 mm / min in a 180 ° direction for peeling.

  The thickness of the release layer in the release sheet is preferably 0.01 to 5 μm, more preferably 0.02 to 1 μm, still more preferably 0.03 to 0.5 μm, and It is especially preferable that it is 05-0.3 micrometer. If the thickness of the release layer is less than 0.01 μm, sufficient releasability cannot be obtained. If the thickness exceeds 5 μm, not only the cost increases, but the releasability decreases or the release sheet is rolled. There is a case of blocking when wound on.

  In the present invention, the method for laminating the release layer on the substrate is not particularly limited. For example, a liquid material containing acid-modified polybutadiene and / or acid-modified polyisoprene, a crosslinking agent, and a medium is prepared, and this liquid A method of applying an object to a substrate and drying the medium is preferable in that the thickness of the release layer is easily uniformed and mass production is possible. Furthermore, it is preferable to use an aqueous medium as a medium from the viewpoint of improving the working environment.

  The method of mixing the acid-modified polybutadiene and / or acid-modified polyisoprene and the crosslinking agent is not particularly limited as long as each component is uniformly mixed in the liquid medium. For example, a dispersion or solution of a crosslinking agent is added to a dispersion of acid-modified polybutadiene and / or modified polyisoprene and mixed, or a mixture of acid-modified polybutadiene and / or acid-modified polyisoprene and a crosslinking agent is liquid. The method of making it.

  A method for obtaining an aqueous dispersion in which acid-modified polybutadiene and / or acid-modified polyisoprene is dispersed in an aqueous medium is not particularly limited. For example, acid-modified polybutadiene and / or acid-modified polyisoprene, organic Examples thereof include a method of preparing an aqueous dispersion by introducing raw materials such as a solvent and water and stirring while keeping the temperature in the tank at about 40 to 150 ° C. For example, the method described in International Publication No. 02/055598 pamphlet is mentioned, and good aqueous dispersion is obtained by neutralizing acid-modified polybutadiene and / or acid-modified polyisoprene with a basic compound in an aqueous medium. Is obtained.

It is preferable that the said basic compound is volatile from the point of the water resistance of the coating film after mold release layer formation. In the present invention, “volatile” means that the boiling point at normal pressure is 250 ° C. or less. When the boiling point exceeds 250 ° C., it becomes difficult to disperse the basic compound from the resin coating film by drying, and the water resistance of the coating film may decrease.
Volatile basic compounds include ammonia, triethylamine, N, N-dimethylethanolamine, aminoethanolamine, N-methyl-N, N-diethanolamine, isopropylamine, iminobispropylamine, ethylamine, diethylamine, 3-ethoxy. Propylamine, 3-diethylaminopropylamine, sec-butylamine, propylamine, methylaminopropylamine, methyliminobispropylamine, 3-methoxypropylamine, monoethanolamine, diethanolamine, triethanolamine, morpholine, N-methylmorpholine, N-ethylmorpholine etc. can be mentioned.

The aqueous medium as used in the field of this invention is a medium which has water as a main component, and may contain the organic solvent and the water-soluble basic compound as needed.
Examples of organic solvents include diethyl ketone (3-pentanone), methyl propyl ketone (2-pentanone), methyl isobutyl ketone (4-methyl-2-pentanone), 2-hexanone, 5-methyl-2-hexanone, and 2-to. Ketones such as butanone, 3-heptanone, 4-heptanone, cyclopentanone, cyclohexanone, aromatic hydrocarbons such as toluene, xylene, benzene, Solvesso 100, Solvesso 150, butane, pentane, hexane, cyclohexane, heptane Aliphatic hydrocarbons such as octane and nonane, methylene chloride, chloroform, carbon tetrachloride, 1,2-dichloroethane, 1,1,2,2-tetrachloroethane, chlorobenzene, o-dichlorobenzene, m-dichlorobenzene, Halogen-containing compounds such as p-dichlorobenzene, acetic acid Esters such as chill, isopropyl acetate, n-butyl acetate, isobutyl acetate, sec-butyl acetate, 3-methoxybutyl acetate, methyl propionate, ethyl propionate, diethyl carbonate, γ-butyrolactone, isophorone, etc. Examples include hydrophilic organic solvents described below.

Specific examples of the hydrophilic organic solvent include methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, tert-butanol, n-amyl alcohol, isoamyl alcohol, sec-amyl alcohol, tert. -Amyl alcohol, 1-ethyl-1-propanol, 2-methyl-1-butanol, n-hexanol, cyclohexanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, etc. Alcohols, ethers such as tetrahydrofuran and 1,4-dioxane, ketones such as acetone and methyl ethyl ketone, methyl acetate, acetic acid-n-propyl, ethyl acetate Propyl acetate -tert- butyl, methyl propionate, ethyl propionate, dimethyl carbonate, etc., dimethylformamide, dimethylacetamide, diacetone alcohol, acetonitrile, and the like.
Specific examples of the water-soluble basic compound include ammonia, diethylamine, triethylamine, diethanolamine, triethanolamine, N, N-dimethylethanolamine, N, N-diethylethanolamine, N-diethanolamine, 3-methoxypropyl. Examples thereof include organic amine compounds such as amine, 3-diethylaminopropylamine, and dimethylaminopropylamine.

  The number average particle diameter (hereinafter referred to as mn) of the acid-modified polybutadiene and / or acid-modified polyisoprene particles in the aqueous dispersion is the storage stability of the aqueous dispersion, the transparency of the coating film, and the structure at a low temperature of 30 ° C. or less. In view of improving the film properties, 0.5 μm or less is preferable, 0.005 to 0.3 μm is more preferable, 0.01 to 0.2 μm is further preferable, and 0.01 to 0.1 μm is particularly preferable. Furthermore, regarding a weight average particle diameter (henceforth, mw), 1 micrometer or less is preferable, 0.01-0.5 micrometer is more preferable, 0.01-0.2 micrometer is especially preferable.

A dispersion or solution of a crosslinking agent is added to an aqueous dispersion of acid-modified polybutadiene and / or modified polyisoprene obtained by the above method, and a dispersion of a long-chain alkyl compound or an acid-modified polyolefin resin is added if necessary. Alternatively, a liquid can be obtained by adding and mixing solutions.
The solid content in the liquid used in the present invention can be appropriately selected depending on the lamination conditions, the target thickness and performance, and is not particularly limited. However, the solid content is preferably 1 to 60% by mass and more preferably 5 to 30% by mass in order to keep the viscosity of the liquid material moderate and to form a good release layer.

  Furthermore, in liquids, various agents such as leveling agents, antifoaming agents, anti-waxing agents, antistatic agents, pigment dispersants, UV absorbers, pigments such as titanium oxide, zinc white, carbon black, etc. A dye may be added. In addition, organic or inorganic compounds other than those described above can be added to the liquid as long as the stability of the liquid is not impaired.

The release sheet of the present invention is industrially easily obtained by a production method in which a liquid material containing acid-modified polybutadiene and / or acid-modified polyisoprene and a crosslinking agent is applied on a substrate and then dried. be able to.
In other words, using the above-mentioned liquid material, known methods such as gravure roll coating, reverse roll coating, wire bar coating, lip coating, air knife coating, curtain flow coating, spray coating, dip coating, brush coating, etc. Apply uniformly to the surface of the base material, set it near room temperature as necessary, and then subject it to drying treatment or heat treatment for drying to form a uniform release layer in close contact with the base material Can do.
After forming the release layer on the substrate, in order to promote the reaction between the acid-modified polybutadiene and / or acid-modified polyisoprene and the crosslinking agent, an aging treatment may be performed in an environment controlled at a constant temperature. Good. The aging temperature is preferably relatively low from the viewpoint of reducing damage to the substrate, and is preferably treated at a high temperature from the viewpoint of allowing the reaction to proceed sufficiently and quickly. Aging is preferably performed at 20 to 100 ° C, more preferably at 30 to 70 ° C, and even more preferably at 40 to 60 ° C.

  When applying a liquid material to a thermoplastic resin film such as a polyester resin film, the film may be dried and heat-treated after being applied to a biaxially stretched film. The film may be coated with a liquid and dried and then heated and stretched, or heated and stretched simultaneously with drying to complete the orientation. The method of applying the liquid to the latter unstretched film or the film after completion of uniaxial stretching, followed by drying and stretching orientation can laminate the release layer at the same time as the formation of the thermoplastic resin film. To preferred. Moreover, it is also preferable from the viewpoint that the reaction between the acid-modified polybutadiene and / or acid-modified polyisoprene and the crosslinking agent can be efficiently advanced by applying high temperature heat to the release layer in the stretching step. In addition, it is more preferable to use an aqueous dispersion as the liquid material from the viewpoint that an explosion-proof facility is unnecessary in the production process.

  The release sheet of the present invention is applied to a pressure-sensitive adhesive material in which a pressure-sensitive adhesive is laminated on both surfaces of a base material, or a pressure-sensitive adhesive material having a base material and not having a base material (base material-less pressure-sensitive adhesive sheet). And may be applied to an adhesive material in which an adhesive is laminated on one side of a substrate. In practice, it can be applied to those used in the form of pressure-sensitive adhesive sheets, adhesive sheets, pressure-sensitive adhesive tapes, adhesive tapes and the like. The component and base material of an adhesive are not specifically limited. Examples of the adhesive include acrylic adhesives, natural rubber adhesives, synthetic rubber adhesives, silicone adhesives, urethane adhesives, and the like. The pressure-sensitive adhesive may contain a tackifier such as rosin, coumarone-indene, terpene, petroleum, styrene, phenol, xylene. Moreover, additives, such as a softening agent, a crosslinking agent, anti-aging agent, and a filler, may be included as needed. Examples of the base material in the adhesive material include the above-described paper, cloth, and resin material.

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

(1) Acid value of resin 0.15 g of resin was dissolved in 20 ml of tetrahydrofuran, titrated with KOH aqueous solution using cresol red as an indicator, and the acid value (mg KOH / mg) of resin was calculated from the number of mg of KOH consumed for neutralization. g) was determined.

(2) Solid Content Concentration of Aqueous Dispersion An appropriate amount of the aqueous dispersion was weighed and heated at 150 ° C. until the mass of the residue (solid content) reached a constant weight to obtain the solid content concentration.

(3) Average particle diameter of aqueous dispersion Using a Microtrac particle size distribution analyzer UPA150 (MODEL No. 9340, dynamic light scattering method) manufactured by Nikkiso Co., Ltd., the number average particle diameter (mn) and the weight average particle diameter (mw) Asked. Here, the refractive index of the resin used for calculating the particle diameter was set to 1.50.

(4) Release layer thickness The total thickness of the obtained release sheet was measured with a contact-type film thickness meter, and the thickness of the substrate film was subtracted from the measured value.

(5) Peel strength (normal temperature-after 24 hours)
A polyester adhesive tape (Nitto Denko Corporation, No. 31B / acrylic adhesive) having a width of 50 mm and a length of 150 mm was pressure-bonded to the release layer 1 of the obtained release sheet with a rubber roll to prepare a sample. The sample was sandwiched in the form of a metal plate / rubber plate / sample / rubber plate / metal plate and allowed to stand in an atmosphere of 2 kPa load and 25 ° C. for 24 hours to obtain a sample for peel strength measurement. The peel strength between the adhesive tape and the release sheet of this peel strength measurement sample was measured with a tensile tester (manufactured by Intesco, precision universal material tester, type 2020) in a thermostatic chamber at 25 ° C. The peeling angle was 180 ° C. and the peeling speed was 300 mm / min. The same evaluation was performed on the release layer 2.

Reference example 1
(Production of acid-modified polybutadiene aqueous dispersion T-1)
60.0 g of acid-modified polybutadiene (manufactured by Evonik Degussa, polyvest OC800S, number average molecular weight 2400, acid value 70 to 90 mgKOH / g) using a stirrer equipped with a heater and a pressure-resistant 1 liter glass container , 60.0 g of isopropanol (manufactured by Wako Pure Chemical Industries, Ltd., hereinafter referred to as IPA), 15 g of triethylamine (manufactured by Wako Pure Chemical Industries, Ltd., hereinafter referred to as TEA) and 165 g of distilled water were charged in a glass container, When stirred at 300 rpm, the system became milky white. Therefore, while maintaining this state, the heater was turned on and heated after 10 minutes. Then, the system temperature was kept at 80 ° C. and further stirred for 20 minutes. Then, after cooling to room temperature (about 25 ° C.) while stirring with air rotation at 300 rpm, pressure filtration (air pressure 0.2 MPa) with a 300 mesh stainless steel filter (wire diameter 0.035 mm, plain weave) Thus, a milky white uniform acid-modified polybutadiene aqueous dispersion T-1 was obtained.

Reference example 2
(Production of acid-modified polyisoprene aqueous dispersion T-2)
60.0 g of acid-modified polyisoprene (manufactured by Kuraray Co., Ltd., Kuraprene LIR-403, number average molecular weight 34000, acid value 9-11 mg KOH / g) using a stirrer equipped with a heater and a pressure-resistant 1 liter glass container equipped with a heater. ), 60.0 g of IPA, 15 g of TEA and 165 g of distilled water were charged into a glass container and heated while stirring at a rotation speed of 300 rpm, and the system temperature was kept at 120 ° C. for another 60 minutes. Stir. Then, after cooling to room temperature (about 25 ° C.) while stirring with air cooling, pressure filtration (air pressure 0.2 MPa) with a 300 mesh stainless steel filter (wire diameter 0.035 mm, plain weave), milky white uniform An acid-modified polyisoprene aqueous dispersion T-2 was obtained.

Reference example 3
(Production of acid-modified polyisoprene aqueous dispersion T-3)
60.0 g of acid-modified polyisoprene (manufactured by Kuraray Co., Ltd., Kuraprene LIR-410, number average molecular weight 30000, acid value 23-30 mgKOH / g) ), 60.0 g of IPA, 15 g of TEA and 165 g of distilled water were charged into a glass container and stirred at a rotation speed of the stirring blade of 300 rpm. The system became milky white. Therefore, while maintaining this state, the heater was turned on and heated after 10 minutes. Then, the system temperature was kept at 120 ° C. and further stirred for 60 minutes. Then, after cooling to room temperature (about 25 ° C.) while stirring with air rotation at 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 polyisoprene aqueous dispersion T-3 was obtained.

Reference example 4
(Production of acid-modified polyisoprene aqueous dispersion T-4)
60.0 g of acid-modified polyisoprene (manufactured by Kuraray Co., Ltd., Kuraprene LIR-403, number average molecular weight 34000, acid value 9-11 mg KOH / g) using a stirrer equipped with a heater and a pressure-resistant 1 liter glass container with a heater ), 60.0 g of IPA, 9.0 g of N, N-dimethylethanolamine (manufactured by Wako Pure Chemical Industries, Ltd., hereinafter referred to as DMEA) and 165 g of distilled water are charged into a glass container, and the rotation speed of the stirring blade is 300 rpm. While stirring, the mixture was heated and the system temperature was kept at 120 ° C., and further stirred for 60 minutes. Then, it cooled to room temperature (about 25 degreeC), stirring with air cooling with the rotational speed of 300 rpm. Thereafter, in order to remove IPA from the aqueous dispersion, the solvent was distilled off at a bath temperature of 80 ° C. while adding water using a rotary evaporator. Then, after cooling to room temperature (about 25 ° C.) by air cooling, pressure filtration (air pressure 0.2 MPa) with a 300 mesh stainless steel filter (wire diameter 0.035 mm, plain weave), milky white uniform acid-modified poly An isoprene aqueous dispersion T-4 was obtained.

Reference Example 5
(Production of acid-modified polyolefin aqueous dispersion E-1)
Using a stirrer equipped with a hermetic pressure-resistant 1 liter glass container with a heater, 60.0 g of maleic anhydride-modified polyolefin resin (Arkema, Bondine LX-4110), 90.0 g of IPA, 3.0 g Of TEA and 147.0 g of distilled water were charged into a glass container. And it stirred for 30 minutes, setting the rotational speed of a stirring blade to 300 rpm, maintaining system temperature at 140-145 degreeC. Then, it put on the water bath and cooled to room temperature (about 25 degreeC), stirring with a rotational speed of 300 rpm. Furthermore, pressure filtration (air pressure 0.2 MPa) was performed 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 E-1 was obtained.

  Table 1 shows the compositions and average particle diameters of the aqueous dispersions produced in Reference Examples 1 to 5.

Example 1
Acid-modified polybutadiene aqueous dispersion T-1 and an aqueous solution of an oxazoline compound (manufactured by Nippon Shokubai Co., Ltd., Epocros WS-500, solid content concentration 40% by mass, hereinafter referred to as WS-500) are added to 100 parts by mass of acid-modified polybutadiene. On the other hand, it mixed so that the quantity of oxazoline compound solid content might be 15 mass parts, and obtained the liquid material. This liquid material was applied to the corona-treated surface of a biaxially stretched polyester resin film (manufactured by Unitika, Emblet S-50, thickness 50 μm, hereinafter referred to as S-50) using a Mayer bar, and then at 120 ° C. for 15 seconds. The release layer 1 having a thickness of 0.1 μm was formed on the film by drying.
Furthermore, the acid-modified polybutadiene aqueous dispersion T-1 and the aqueous solution WS-500 of the oxazoline compound are mixed with respect to 100 parts by mass of the acid-modified polybutadiene so that the amount of solid content of the oxazoline compound is 30 parts by mass. To obtain a liquid product. After applying this to the opposite surface of the release layer 1 of the film using a Meyer bar, the release layer 2 having a thickness of 0.1 μm is formed on the film by drying at 120 ° C. for 15 seconds. A release film was obtained.

Example 2
The acid-modified polyisoprene aqueous dispersion T-2 and the aqueous solution WS-500 of the oxazoline compound are mixed with respect to 100 parts by mass of the acid-modified polyisoprene so that the solid content of the oxazoline compound is 5 parts by mass. To obtain a liquid product. This liquid material was applied to the corona-treated surface of the biaxially stretched polyester resin film S-50 using a Meyer bar, and then dried at 120 ° C. for 15 seconds, whereby a release layer 1 having a thickness of 0.1 μm was formed on the film. Formed.
Furthermore, the acid-modified polybutadiene aqueous dispersion T-1 and the aqueous solution WS-500 of the oxazoline compound are mixed so that the amount of the solid content of the oxazoline compound is 15 parts by mass with respect to 100 parts by mass of the acid-modified polybutadiene. To obtain a liquid product. After applying this to the opposite surface of the release layer 1 of the film using a Meyer bar, the release layer 2 having a thickness of 0.1 μm is formed on the film by drying at 120 ° C. for 15 seconds. A release film was obtained.

Example 3
In Example 2, when forming the release layer 2, in addition to the acid-modified polybutadiene aqueous dispersion T-1 and the oxazoline-based compound, an aqueous dispersion of a long-chain alkyl-based compound (Rezem K-256, manufactured by Chukyo Yushi Co., Ltd.) Hereinafter, K-256) was separated by performing the same operation except that a liquid material in which the solid content of the long-chain alkyl compound was 20 parts by mass with respect to 100 parts by mass of the acid-modified polybutadiene was used. A mold film was obtained.

Example 4
In Example 3, the same operation was performed except that the solid content of the long-chain alkyl compound was 50 parts by mass with respect to 100 parts by mass of the acid-modified polybutadiene to obtain a release film.

Example 5
In Example 2, when the release layer 2 was formed, the acid-modified polyisoprene aqueous dispersion T-2 and the aqueous solution WS-500 of the oxazoline-based compound were mixed with oxazoline-based compound solids with respect to 100 parts by mass of the acid-modified polyisoprene. A release film was obtained by performing the same operation except that the liquid material mixed so that the amount of the minute became 15 parts by mass was used.

Example 6
In Example 2, when the release layer 1 is formed, the solid content of the oxazoline-based compound is 10 parts by weight with respect to 100 parts by weight of the acid-modified polyisoprene, and when the release layer 2 is formed, the acid modification is performed. Using an aqueous polyisoprene dispersion T-2 and an aqueous dispersion of a carbodiimide compound (Nisshinbo Co., Ltd., Carbodilite E-02 solid concentration 40 mass%), the carbodiimide compound solid content with respect to 100 parts by mass of the acid-modified polyisoprene. A release film was obtained in the same manner as above except that the liquid material mixed so that the amount of the product became 15 parts by mass was used.

Example 7
In Example 2, when the release layer 2 was formed, the acid-modified polyisoprene aqueous dispersion T-3 and the aqueous solution WS-500 of the oxazoline compound were mixed with the oxazoline compound solid content with respect to 100 parts by mass of the acid-modified polyisoprene. A release film was obtained by carrying out the same operation except that the liquid material mixed so that the amount of was 10 parts by mass was used.

Example 8
In Example 7, when forming the release layer 2, in addition to the acid-modified polyisoprene aqueous dispersion T-3 and the oxazoline-based compound, the long-chain alkyl compound K-256 was added to 100 parts by mass of the acid-modified polyisoprene. A release film was obtained in the same manner as above except that the liquid material mixed so that the solid content of the long-chain alkyl compound was 50 parts by mass was used.

Example 9
In Example 7, when forming the release layer 2, in addition to the acid-modified polyisoprene aqueous dispersion T-3 and the oxazoline-based compound, the acid-modified polyolefin resin aqueous dispersion E-1 was added to 100 parts by mass of the acid-modified polyisoprene. On the other hand, a release film was obtained by performing the same operation except that a liquid material mixed so that the acid-modified polyolefin resin was 15 parts by mass was used.

Example 10
A release film was obtained in the same manner as in Example 8 except that only the long-chain alkyl compound aqueous dispersion K-256 was used when forming the release layer 2.

Example 11
In Example 8, a release film was obtained by performing the same operation except that the amount of the oxazoline compound solid content was 50 parts by mass with respect to 100 parts by mass of the acid-modified polyisoprene when the release layer 1 was formed. It was.

Example 12
In Example 10, a release film was obtained by performing the same operation except that the amount of the oxazoline compound solid content was 1 part by mass with respect to 100 parts by mass of the acid-modified polyisoprene when the release layer 1 was formed. It was.

Example 13
Using a polyethylene terephthalate resin (manufactured by Nihon Ester Co., Ltd., intrinsic viscosity 0.6) with an extruder (75 mm diameter, slow compression type single screw with L / D of 45) equipped with a T die, a cylinder temperature of 260 ° C., T Extruded into a sheet at a die temperature of 280 ° C., brought into close contact with a cooling roll adjusted to a surface temperature of 25 ° C., and rapidly cooled to obtain an unstretched film having a thickness of 500 μm.
Subsequently, the unstretched film was stretched 3.4 times in the longitudinal direction at 90 ° C., and then, using a gravure coater, an acid-modified polyisoprene aqueous dispersion T-4 and an aqueous solution of an oxazoline compound (Nippon Shokubai Co., Ltd.) Manufactured, Epocros WS-700, solid content concentration of 25% by mass) with 100 parts by mass of acid-modified polyisoprene so that the amount of oxazoline compound solids is 5 parts by mass, dried, The film was applied so that the coating amount after stretching was 0.1 g / m ² , then preheated at a temperature of 90 ° C. for 2 seconds, and then stretched at a magnification of 3.5 times in the transverse direction at 240 ° C. 1 was formed. The total thickness of the obtained polyester film and the release layer was 50 μm, and the thickness of the release layer was 0.05 μm.
Furthermore, the acid-modified polybutadiene aqueous dispersion T-1 and the aqueous solution WS-500 of the oxazoline compound have an oxazoline compound solid content of 15 parts by mass with respect to 100 parts by mass of the acid-modified polybutadiene. The aqueous dispersion K-256 of the compound was mixed with 100 parts by mass of the acid-modified polybutadiene so that the solid content of the long-chain alkyl compound was 25 parts by mass to obtain a liquid. After applying this to the opposite surface of the release layer 1 of the film using a Meyer bar, the release layer 2 having a thickness of 0.1 μm is formed on the film by drying at 120 ° C. for 15 seconds. A release film was obtained.

Example 14
In Example 13, when the release layer 1 was formed, instead of the aqueous solution of the oxazoline compound, a melamine compound-containing solution (DIC, Becamine J-101, solid content concentration 71% by mass) was used. A release sheet was obtained by performing the same operation except that the amount of the melamine compound solid content was 30 parts by mass with respect to 100 parts by mass of isoprene.

Comparative Example 1
In Example 1, when the release layer 1 was formed, instead of the acid-modified polybutadiene aqueous dispersion, an acid-modified polyolefin resin aqueous dispersion E-1 was used, with respect to 100 parts by mass of the acid-modified polyolefin resin aqueous dispersion. A release sheet was obtained by performing the same operation except that the amount of solid content of the oxazoline-based compound was changed to 5 parts by mass.

Comparative Example 2
In Example 1, only the release layer 1 was formed, and the release layer 2 was not formed to obtain a release sheet.

Comparative Example 3
In Example 1, the amount of solid content of the oxazoline compound is 0.5 parts by mass with respect to 100 parts by mass of the acid-modified polybutadiene when the release layer 1 is formed, and the acid-modified polybutadiene 100 is formed when the release layer 2 is formed. A release sheet was obtained by performing the same operation except that the solid content of the oxazoline-based compound was 60 parts by mass with respect to part by mass.

Comparative Example 4
In Example 2, it was the same except that only the acid-modified polyisoprene aqueous dispersion T-2 was used when forming the release layer 1, and only the acid-modified polybutadiene aqueous dispersion T-1 was used when forming the release layer 2. A release sheet was obtained by performing the above operations.

Comparative Example 5
In Example 1, when the release layer 2 was formed, the same operation was carried out except that the acid-modified polybutadiene (Nippon Soda Co., Ltd., B-1000) was dissolved in toluene to form the release layer 2. To obtain a release sheet.

  Table 2 shows the results of measuring the peel strength of the release sheets obtained in Examples and Comparative Examples.

  Release sheets obtained in Examples 1 to 14, that is, having release layers on both sides of the base material, and at least one release layer comprises 100 parts by mass of acid-modified polybutadiene and / or acid-modified polyisoprene, A crosslinking agent containing at least one selected from an oxazoline compound, a carbodiimide compound, and a melamine compound, and the content of the oxazoline compound, carbodiimide compound, and melamine compound is 100 parts by mass of acid-modified polybutadiene and acid-modified polyisoprene. The release sheet satisfying the peel strength relationship in which the release layer 1 and the release layer 2 are defined in an amount of 1 to 50 parts by mass was excellent in release properties. Among them, a release layer using acid-modified polyisoprene is preferable because it does not show a great change in peel strength even after being left at high temperature, and a combination of this and a small amount of an oxazoline compound is excellent. It showed releasability and was particularly preferable.

As shown in Comparative Example 1, those using a resin other than acid-modified polybutadiene or acid-modified polyisoprene had high release strength and insufficient release properties for use as a release sheet for an adhesive material. As shown in Comparative Example 2, in the case where the release layer is formed only on one surface, the opposite surface has a very high peel strength with respect to the adhesive material, and the adhesive sheet has adhesiveness on both surfaces. It was difficult to use. As shown in Comparative Example 3, when an amount of the crosslinking agent exceeding the range of the present invention was used, the releasability was not good. As shown in Comparative Example 4, even when no crosslinking agent was added, the releasability was poor. As shown in Comparative Example 5, when polybutadiene that has not been acid-modified is used, the adhesiveness to the base material is very low, so that the base layer and the release layer peel off, and the release layer is It was completely transferred to the adhesive tape side and could not be used as a release sheet.

Claims (6)

  A release sheet having a release layer 1 on one side of a substrate and a release layer 2 on the other side of the substrate, wherein at least one release layer is acid-modified polybutadiene and / or acid-modified A polyisoprene and a crosslinking agent containing at least one selected from an oxazoline compound, a carbodiimide compound, and a melamine compound, and the total content of the oxazoline compound, the carbodiimide compound, and the melamine compound is an acid-modified polybutadiene and an acid-modified polyisoprene. 1 to 50 parts by mass with respect to 100 parts by mass in total, the peel strength F1 between the release layer 1 and the acrylic adhesive material is 0.5 N / cm or less, and the release layer 2 and the acrylic adhesive material The release sheet | seat whose peeling strength F2 is 1.0 N / cm or less, and is F1 <F2.   The release sheet according to claim 1, wherein the release layer 2 contains a long-chain alkyl compound and / or an acid-modified polyolefin resin.   The release sheet according to claim 1 or 2, wherein the substrate is any one of a resin material, paper, synthetic paper, cloth, metal material, and glass material.   The release sheet according to claim 3, wherein the resin material is a polyester resin film.   A method for producing a release sheet according to claim 1, wherein the crosslinking agent contains acid-modified polybutadiene and / or acid-modified polyisoprene and at least one selected from an oxazoline compound, a carbodiimide compound, and a melamine compound. Is dispersed in an aqueous medium, and the total content of the oxazoline compound, carbodiimide compound and melamine compound is 1 to 50 parts by mass with respect to 100 parts by mass in total of the acid-modified polybutadiene and acid-modified polyisoprene. Is applied onto at least one surface of the base material, and then dried to form a release layer. A method for producing the release sheet according to claim 4, wherein the crosslinking agent contains acid-modified polybutadiene and / or acid-modified polyisoprene and at least one selected from an oxazoline compound, a carbodiimide compound, and a melamine compound. Is dispersed in an aqueous medium, and the total content of the oxazoline compound, carbodiimide compound and melamine compound is 1 to 50 parts by mass with respect to 100 parts by mass in total of the acid-modified polybutadiene and acid-modified polyisoprene. Is applied onto at least one surface of an unstretched or uniaxially stretched polyester resin film, dried, and oriented and stretched together with the film to form a release layer, and a method for producing a release sheet.