JP5737964B2 - Release sheet and manufacturing method thereof - Google Patents

Description

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

In recent years, pressure-sensitive adhesive sheets have been used in the manufacturing process of electronic parts such as semiconductor devices and precision equipment. In order to protect the surface of such an adhesive sheet, a release sheet is laminated and laminated until it is used. The release sheet is provided with a release layer in which a release agent is applied to the surface of a substrate.
As a release agent for a release sheet, a silicone release agent is generally used. 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. There was a risk that the deterioration of electronic components and troubles in electronic parts.
As a non-silicone release sheet, Patent Document 1 proposes a release sheet coated with a release agent using acid-modified polyolefin, and Patent Document 2 applies a release agent containing polybutadiene, A release sheet in which a release agent layer is formed by irradiation with ultraviolet rays has been proposed.

However, although the release sheet of Patent Document 1 shows good release properties with respect to various adherends, the release tends to be somewhat heavy with respect to the pressure-sensitive adhesive, which is handled when peeling the pressure-sensitive adhesive sheet. When the adhesive sheet is bad or when the adhesive sheet is peeled off at a high speed, zipping may occur, and the smoothness of the adhesive sheet surface may be impaired.
Moreover, although the release sheet of Patent Document 2 has good release properties with respect to the pressure-sensitive adhesive, it is necessary to cure the release layer by ultraviolet irradiation, and only special equipment and processes are required in production. In addition, since the adhesion between the base material and the release layer is poor, it is necessary to provide an anchor coat layer between the base material and the release layer. . Further, in order to provide a release layer, a liquid material in which a resin is dissolved in an organic solvent is used, which is not preferable from the viewpoint of the environment.

JP 2009-101680 A JP-A-2005-212121

  In view of these problems, the present invention is intended to provide a release sheet that is easy to manufacture and excellent in releasability from an adhesive material.

As a result of intensive studies to solve the above problems, the present inventor has found that a resin layer containing acid-modified polybutadiene and / or acid-modified polyisoprene and a crosslinking agent containing an oxazoline compound and / or a carbodiimide compound is separated. It was found that the moldability was excellent and the adhesiveness to the substrate was also good, and it was found that the resin layer was effective as a release sheet by laminating the resin layer on the substrate.
That is, the gist of the present invention is as follows.
(1) A release sheet in which a resin layer is provided on a substrate, wherein the resin layer contains 100 parts by mass of acid-modified polybutadiene and / or acid-modified polyisoprene and an oxazoline compound and / or carbodiimide compound . A release sheet comprising 1 to 50 parts by mass of an agent.
(2) The release sheet according to (1), wherein the release sheet is used for an adhesive material, and the peel strength between the resin layer and the adhesive material is 0.5 N / cm or less.
(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) above (1) to a method for producing a release sheet according to any one of (4), and acid-modified polybutadiene and / or acid-modified polyisoprene 100 parts by weight of an oxazoline compound and / or a carbodiimide compound A release sheet characterized by forming a resin layer by coating a liquid material containing 1 to 50 parts by mass of a cross-linking agent and dispersed in an aqueous medium on a substrate, followed by drying. Manufacturing method.
(6) The method for producing a release sheet according to the above (4), wherein 1 to 50 mass of a crosslinking agent containing 100 parts by mass of acid-modified polybutadiene and / or acid-modified polyisoprene and an oxazoline compound and / or carbodiimide compound And a liquid material dispersed in an aqueous medium is applied onto an unstretched or uniaxially stretched polyester resin film, and then dried and oriented and stretched together with the film to form a resin layer. A method for producing a release sheet.

  The release sheet of the present invention can be easily produced by applying a liquid material in which a resin is dispersed in an aqueous medium to a substrate and drying. Further, by using the release sheet of the present invention, the pressure-sensitive adhesive surface of the pressure-sensitive adhesive material can be protected, and the quality of the pressure-sensitive adhesive material is not easily impaired even when the release sheet is peeled off when the pressure-sensitive adhesive material is used. Can be peeled off.

Hereinafter, the present invention will be described in detail.
The release sheet of this invention has a base material and the resin layer provided on this base material. The resin layer contains acid-modified polybutadiene and / or acid-modified polyisoprene and a crosslinking agent.

  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, and may be 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 resin layer not only has a possibility of transferring to the adhesive surface due to a decrease in adhesion to the base material, but also an aqueous dispersion of the acid-modified polybutadiene. Getting a body can be difficult. 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 resin 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 of 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.

  The resin layer of the release sheet of the present invention contains acid-modified polybutadiene and / or acid-modified polyisoprene and a crosslinking agent. 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 condensed triazine rings is 3 or less, and at least one amino group is methylol-substituted, and these are dispersible in an aqueous medium and reactive with a resin. Is excellent.
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 cross-linking agent needs to be 1 to 50 parts by mass, more preferably 2 to 30 parts by mass with respect to 100 parts by mass of the acid-modified polybutadiene and / or acid-modified polyisoprene. More preferably, it is -20 mass parts. When the content of the crosslinking agent is less than 1 part by mass, the effect of addition is poor, and the releasability may decrease over time, and when the content exceeds 50 parts by mass, the releasability may decrease. In addition, a several kind of crosslinking agent can also be used simultaneously, and when it is used simultaneously, the total amount of a crosslinking agent should just satisfy | fill the range of content of said crosslinking agent.

  The method for laminating the resin layer of the present invention 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 the liquid material The method of coating the substrate on the substrate and drying the medium is preferable in that the thickness of the resin layer can be easily uniformed and mass production is possible. Furthermore, it is preferable to use an aqueous dispersion in which acid-modified polybutadiene and / or acid-modified polyisoprene and a cross-linking agent are dispersed in an aqueous medium as a liquid material in consideration of the global environment and the health of workers.

  The method for dispersing the acid-modified polybutadiene and / or acid-modified polyisoprene in an aqueous medium to obtain an aqueous dispersion is not particularly limited. For example, the acid-modified polybutadiene and / or acid-modified polyisoprene, an organic solvent, Examples thereof include a method of introducing an aqueous dispersion by charging raw materials such as water and stirring while maintaining the temperature in the tank at a temperature of 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 resin 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 referred to in the present invention is a medium containing water as a main component and may contain an organic solvent or a water-soluble basic compound.
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 Specific examples of water-soluble basic compounds include propyl, tert-butyl acetate, methyl propionate, ethyl propionate, esters such as dimethyl carbonate, dimethylformamide, dimethylacetamide, diacetone alcohol, acetonitrile, and the like. , Including ammonia, diethylamine, triethylamine, diethanolamine, triethanolamine, N, N-dimethylethanolamine, N, N-diethylethanolamine, N-diethanolamine, 3-methoxypropylamine, 3-diethylaminopropylamine, dimethylaminopropyl Examples thereof include organic amine compounds such as amines.

  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.

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.
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, more preferably 5 to 30% by mass in order to keep the viscosity of the liquid material moderate and to form a good resin 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. By uniformly applying to the surface of the substrate and setting it near room temperature as necessary, it can be formed by adhering a uniform resin layer to the substrate by subjecting it to drying treatment or heat treatment for drying. it can.
After the resin layer is formed on the substrate, an aging treatment may be performed in an environment controlled at a certain temperature in order to promote the reaction between the acid-modified polybutadiene and / or acid-modified polyisoprene and the crosslinking agent. . 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.

  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; , 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.

  When a liquid material is applied to a thermoplastic resin film, it may be dried and heat-treated after being applied to a biaxially stretched film, or it may be liquid on an unstretched film before or after completion of uniaxial stretching. The product may be applied and dried and heated to stretch, 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 uniaxial stretching, followed by drying and stretching orientation allows the resin layer to be laminated simultaneously with the formation of the thermoplastic resin film. 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 resin 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 thermoplastic resin film 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 thickness of the resin layer in the release sheet is preferably 0.01 to 5 μm, more preferably 0.02 to 1 μm, further preferably 0.03 to 0.5 μm, 0.05 It is especially preferable that it is -0.3 micrometer. When the thickness of the resin layer is less than 0.01 μm, sufficient releasability cannot be obtained, and when the thickness exceeds 5 μm, not only the cost increases, but also the releasability decreases or the release sheet is rolled. Blocking may occur when wound.

Since the release sheet of the present invention has a good releasability for various materials, it can be used for various materials, but can be preferably used particularly for adhesive materials. .
Examples of the pressure-sensitive adhesive material include those in which a pressure-sensitive adhesive is laminated on a base material. In practice, the pressure-sensitive adhesive material is used in the form of a pressure-sensitive adhesive sheet, an adhesive sheet, a pressure-sensitive adhesive tape, an adhesive tape, or the like. The component and base material of an adhesive are not specifically limited. Examples of the pressure-sensitive adhesive include acrylic pressure-sensitive adhesives, natural rubber-based pressure-sensitive adhesives, and synthetic rubber-based pressure-sensitive adhesives. The pressure-sensitive adhesive may contain a tackifier such as rosin, coumarone-indene, terpene, petroleum, styrene, phenol, xylene. Examples of the substrate include the above-described paper, cloth, and resin material.
When the release sheet of the present invention is used for an adhesive material, the peel strength between the resin layer and the adhesive material after the adhesive material is pasted and allowed to stand may be 0.5 N / cm or less. More preferably, it can be 0.4 N / cm or less, more preferably 0.3 N / cm or less, and most preferably 0.2 N / cm or less. When the peel strength with the adhesive material exceeds 0.5 N / cm, it may be difficult to use as a release sheet for the adhesive material.
Moreover, when the release sheet of this invention is used with respect to an adhesive material, the change of the peeling strength of a resin layer and an adhesive material can be restrained small even after a long time passes after sticking. The adhesive material with the release sheet attached may be exposed to high temperatures for a long time in the process of storage and distribution, and if the change in peel strength over time is large, it becomes difficult to use as a release sheet. This is not preferable.

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 The number average particle diameter (mn) and the weight average particle diameter (mw) using a Microtrac particle size distribution analyzer UPA150 (MODEL No. 9340, dynamic light scattering method) manufactured by Nikkiso Co., Ltd. ) Here, the refractive index of the resin used for calculating the particle diameter was set to 1.50.
(4) Thickness of resin layer The total thickness of the obtained release sheet was measured with a contact-type film thickness meter, and the thickness of the base film was subtracted from the measured value.
(5) Peel strength (at room temperature)
A polyester pressure-sensitive adhesive tape having a width of 50 mm and a length of 150 mm (No. 31B / acrylic pressure-sensitive adhesive, manufactured by Nitto Denko Corporation) is pressure-bonded to the resin layer side of the obtained release sheet with a rubber roll, did. 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.
(6) 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 resin layer side 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.
(7) Peel strength (after 70 ° C-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 resin layer side 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 70 ° 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.

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 into a glass container, and the rotational speed of the stirring blade was adjusted. 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 polybutadiene aqueous dispersion T-4)
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 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 were charged in a glass container and stirred at a rotation speed of 300 rpm. As a result, the system became milky white. Therefore, while maintaining this state, the heater was turned on and heated. Then, the system temperature was kept at 80 ° C. and further stirred for 20 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 partially 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) through a 300 mesh stainless steel filter (wire diameter 0.035 mm, plain weave), milky white uniform acid-modified polybutadiene An aqueous dispersion T-4 was obtained.

Reference Example 5
(Production of acid-modified polyisoprene aqueous dispersion T-5)
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, 9.0 g of DMEA and 165 g of distilled water were charged into a glass container and heated while stirring at a rotation speed of the stirring blade of 300 rpm, and the system temperature was kept at 120 ° C. Stir 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 partially 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-5 was obtained.

Reference Example 6
(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 1-6.

Example 1
An acid-modified polybutadiene aqueous dispersion T-1 and an aqueous solution of an oxazoline compound (Nippon Shokubai Co., Ltd., Epocros WS-500, solid content concentration 40% by mass) are mixed with an oxazoline compound solid based on 100 parts by mass of the acid-modified polybutadiene. The mixture was mixed so that the amount of the minute became 15 mass to obtain a liquid material. By applying this liquid material to the corona-treated surface of a biaxially stretched polyester resin film (manufactured by Unitika Ltd., Emblet S-50, thickness 50 μm) using a Mayer bar, it is dried at 120 ° C. for 15 seconds, A release sheet having a 0.2 μm resin layer formed on the film was obtained.

Example 2
In Example 1, a release sheet was obtained by performing the same operation except that the amount of the oxazoline compound solid content was 20 parts by mass with respect to 100 parts by mass of the acid-modified polybutadiene.

Example 3
In Example 1, a release sheet 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 polybutadiene.

Example 4
In Example 1, instead of the aqueous solution of the oxazoline compound, an aqueous dispersion of a carbodiimide compound (Nisshinbo Co., Ltd., Carbodilite E-02, solid content concentration 40% by mass) was used, and 100 parts by mass of acid-modified polybutadiene. A release sheet was obtained by performing the same operation except that the amount of the carbodiimide compound solid content was 20 parts by mass.

Example 5
In Example 4, a release sheet was obtained by performing the same operation except that the amount of solid content of the carbodiimide compound was 50 parts by mass with respect to 100 parts by mass of the acid-modified polybutadiene.

Reference Example 7
In Example 2, instead of the aqueous solution of the oxazoline compound, a melamine compound-containing solution (DIC Corporation, Becamine J-101, solid content concentration: 71% by mass) was dried at 170 ° C. for 30 seconds to release the mold. A sheet was obtained.

Example 7
In Example 3, a release sheet was obtained by performing the same operation except that the acid-modified polyisoprene aqueous dispersion T-2 was used in place of the acid-modified polybutadiene aqueous dispersion T-1.

Example 8
In Example 7, a release sheet was obtained by performing the same operation except that the amount of the oxazoline compound solid content was 5 parts by mass with respect to 100 parts by mass of the acid-modified polyisoprene.

Example 9
In Example 8, a release sheet was obtained by performing the same operation except that the acid-modified polyisoprene aqueous dispersion T-3 was used instead of the acid-modified polyisoprene aqueous dispersion T-2.

Example 10
In Example 9, instead of an aqueous solution of the oxazoline compound, an aqueous dispersion of a carbodiimide compound (Nisshinbo Co., Ltd., Carbodilite E-02, solid content concentration: 40% by mass) was used, and 100 parts by mass of acid-modified polyisoprene. A release sheet was obtained by performing the same operation except that the amount of the carbodiimide compound solid content was 10 parts by mass.

Example 11
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 polybutadiene aqueous dispersion T-4 and an aqueous solution of an oxazoline compound (manufactured by Nippon Shokubai Co., Ltd.) , Epocros WS-700, solid content concentration of 25% by mass) with respect to 100 parts by mass of acid-modified polybutadiene, and after drying and stretching, a liquid material in which the amount of oxazoline compound solid content is 20 parts by mass the coating amount was applied so that 0.1 g / m ^2, was then preheated 2 seconds at 90 ° C., and stretched 3.5-fold magnification in the transverse direction at 240 ° C., to obtain a release sheet It was. The total thickness of the obtained polyester film and the resin layer was 50 μm, and the thickness of the resin layer was 0.05 μm.

Example 12
In Example 11, instead of the aqueous solution of the oxazoline compound, an aqueous dispersion of a carbodiimide compound (Nisshinbo Co., Ltd., Carbodilite E-02, solid content concentration 40% by mass) was used, and 100 parts by mass of acid-modified polybutadiene. A release sheet was obtained by performing the same operation except that the amount of the carbodiimide compound solid content was 20 parts by mass.

Example 13
In Example 11, instead of the acid-modified polybutadiene aqueous dispersion T-4, an acid-modified polyisoprene aqueous dispersion T-5 was used, and the solid content of the oxazoline compound was 100 parts by mass with respect to 100 parts by mass of the acid-modified polyisoprene. A release sheet was obtained by performing the same operation except that the amount was 5 parts by mass.

Example 14
In Example 13, a release sheet 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.

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

Comparative Example 2
The acid-modified polybutadiene aqueous dispersion T-1 is applied to the corona-treated surface of a biaxially stretched polyester resin film (Embret S-50, manufactured by Unitika) using a Mayer bar, and then dried at 120 ° C. for 15 seconds. Thus, a release sheet having a 0.2 μm resin layer formed on the film was obtained.

Comparative Example 3
In Example 2, the same operation was performed except that the acid-modified polyisoprene aqueous dispersion T-2 was used instead of the acid-modified polybutadiene aqueous dispersion T-1, thereby obtaining a release sheet.

Comparative Example 4
In Example 1, a release sheet was obtained by performing the same operation except that the amount of the oxazoline compound solid content was 60 parts by mass with respect to 100 parts by mass of the acid-modified polybutadiene.

Comparative Example 5
In Example 4, a release sheet was obtained by performing the same operation except that the amount of solid content of the carbodiimide compound was 60 parts by mass with respect to 100 parts by mass of the acid-modified polybutadiene.

Comparative Example 6
Resin layer of non-acid-modified polybutadiene (Nippon Soda Co., Ltd., B-1000) on the corona-treated surface of a biaxially stretched polyester resin film (Unitika Ltd., Emblet S-50) to a thickness of 0.2 μm A release sheet was obtained.

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

The release sheet in which a resin layer containing 1 to 50 parts by mass of a crosslinking agent with respect to 100 parts by mass of acid-modified polybutadiene or acid-modified polyisoprene obtained in Examples 1 to 5 and 7 to 14 was released. It was excellent in properties. Among them, those using acid-modified polyisoprene are preferable because they do not show a great change in peel strength even after being left at high temperature, and those that combine this with a small amount of oxazoline compound are excellent mold release. It was particularly preferable.
As shown in Comparative Example 1, those using resins other than acid-modified polybutadiene and acid-modified polyisoprene had a somewhat high peel strength, and were insufficiently releasable for use as a release sheet for adhesive materials. . As shown in Comparative Examples 2 and 3, when no crosslinking agent was used, the releasability was particularly likely to change over time. Furthermore, as shown in Comparative Examples 4 and 5, when an amount of the crosslinking agent exceeding the range specified in the present invention was used, the releasability was low. As shown in Comparative Example 6, when polybutadiene that has not been acid-modified is used, the adhesiveness to the base material is very low, and thus the base layer and the resin layer are separated, and the resin layer is an adhesive tape. The entire surface shifted to the side and could not be used as a release sheet.

Claims (6)

A release sheet comprising a resin layer provided on a substrate, the resin layer is an acid modified polybutadiene and / or acid-modified polyisoprene 100 parts by weight, crosslinking agent 1 containing an oxazoline compound and / or a carbodiimide compound A release sheet containing 50 parts by mass.   The release sheet according to claim 1, wherein the release sheet is used for an adhesive material and has a peel strength of 0.5 N / cm or less between the resin layer and the adhesive material.   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 of manufacturing a release sheet according to any one of claims 1 to 4, and acid-modified polybutadiene and / or acid-modified polyisoprene 100 parts by weight, crosslinking agent 1 containing an oxazoline compound and / or a carbodiimide compound A method for producing a release sheet, wherein a resin layer is formed by applying a liquid material containing 50 parts by mass and dispersed in an aqueous medium onto a substrate and then drying. It is a manufacturing method of the mold release sheet | seat of Claim 4, Comprising: 100 mass parts of acid-modified polybutadiene and / or acid-modified polyisoprene, and 1-50 mass parts of crosslinking agents containing an oxazoline compound and / or a carbodiimide compound are contained. A release material characterized by forming a resin layer by applying a liquid material dispersed in an aqueous medium onto an unstretched or uniaxially stretched polyester resin film, followed by drying and orientation stretching with the film. Production method.