JP2011126043A - Release sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a release sheet suitably used in manufacturing a rubber sheet, and having appropriate releasability even after crosslinking treatment of the rubber. <P>SOLUTION: The release sheet is used for a manufacturing process of a rubber sheet and/or protection of the rubber sheet. A releasing layer is laminated on at least on side of a base material. The releasing layer is formed of a composition containing an acid-modified polyolefinic resin with an acid-modified component of 1-10 mass%, and 1-50 pts.mass of a crosslinking agent for 100 pts.mass of the acid-modified polyolefinic resin. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a release sheet, and more particularly to a release sheet used for a rubber sheet manufacturing process and product surface protection.

  Rubber sheets are used in a wide range of industrial fields because they have excellent cushioning properties and stretchability.

  As a method for producing a rubber sheet, for example, there is a method in which an uncrosslinked rubber component is extrusion cast or coated on a release sheet and dried to form a sheet-like molded body, followed by curing / crosslinking treatment in a subsequent step. is there. When the rubber sheet is finally made into a product, the release sheet is peeled off.

  In general, an adhesive phenomenon occurs when rubber is crosslinked. In order to cope with this, as a release sheet that is difficult to adhere to a rubber component, a release sheet formed from a polyolefin resin (Patent Document 1), a release sheet formed from a fluororesin, or a polyester film A release sheet (Patent Document 2) having a surface treated with a silicone compound or a fluorine compound has been proposed and used.

JP 2006-77238 A International Publication No. WO03 / 099556 Pamphlet

  However, polyolefin resin films such as polypropylene are insufficient in strength and heat resistance, and troubles such as film breakage are likely to occur in the manufacturing process. In addition, the high temperature treatment for crosslinking the rubber component is often performed at a temperature higher than the melting point of the resin, and in this case, the rubber sheet is strongly bonded, and troubles are likely to occur in the peeling operation.

  The fluororesin film is not only expensive because the resin itself is very expensive, but it is also difficult to burn and generate toxic gas in the waste incineration treatment after use.

  The release sheet treated with a silicone compound is inferior in wettability of the surface, so that when the rubber component is applied onto the release sheet, it tends to be repelled and uniform especially when trying to form a thin rubber sheet layer. It is difficult to manufacture a rubber sheet. In addition to this, the adhesion with the rubber sheet is poor, and it does not adhere well with the rubber sheet before cross-linking, so it may be peeled off during the manufacturing process or transportation of the product, causing trouble. .

  An object of the present invention is to provide a release sheet that can be suitably used in the production of a rubber sheet and that has an appropriate releasability even after a rubber crosslinking treatment.

  As a result of intensive studies to solve the above problems, the present inventor is a resin composition comprising an acid-modified polyolefin resin having an acid-modified component of 1 to 10% by mass and a crosslinking agent on at least one side of a substrate. The present inventors have found that a release sheet in which the formed release layers are laminated can be suitably used as a release sheet in a rubber sheet manufacturing process, and have reached the present invention.

  The gist of the present invention is as follows.

  (1) A release sheet used for the production process of a rubber sheet and / or protection of the rubber sheet, wherein a release layer is laminated on at least one surface of a substrate, and the release layer is an acid-modified component. Is formed of a resin composition containing 1 to 10% by mass of an acid-modified polyolefin resin and 1 to 50 parts by mass of a crosslinking agent with respect to 100 parts by mass of the acid-modified polyolefin resin. Mold sheet.

  (2) The release sheet according to (1), wherein the resin composition forming the release layer contains 1-1000 parts by mass of polyvinyl alcohol with respect to 100 parts by mass of the acid-modified polyolefin resin.

  (3) The peel strength between the release sheet and the crosslinked rubber sheet formed on the release sheet is 0.05 to 1.0 N / cm (1) or ( The release sheet of 2).

  (4) The release sheet according to any one of (1) to (3), wherein the substrate is a polyester film.

  (5) Rubber sheet containing as component at least one selected from urethane rubber, silicone rubber, fluoro rubber, natural rubber, styrene butadiene rubber, ethylene propylene rubber, ethylene propylene diene rubber, acrylonitrile butadiene rubber, chloroprene rubber, acrylic rubber The release sheet according to any one of (1) to (4), wherein the release sheet is used in the above.

  According to the present invention, the release layer includes a resin composition containing an acid-modified polyolefin resin having an acid-modified component of 1 to 10% by mass and a crosslinking agent of 1 to 50 parts by mass with respect to 100 parts by mass of the acid-modified polyolefin resin. Therefore, it is possible to provide a release sheet that can be suitably used in the production of a rubber sheet and that has an appropriate releasability even after the rubber is crosslinked.

Hereinafter, the present invention will be described in detail.
The acid-modified polyolefin resin contained in the release layer needs to have an acid-modified component of 1 to 10% by mass of the acid-modified polyolefin resin. 1-7 mass% is preferable, 2-5 mass% is more preferable, and 2-3 mass% is especially preferable. When the mass ratio of the acid-modifying component, that is, the modification amount is less than 1% by mass, not only sufficient adhesion to the substrate may not be obtained, but also the rubber sheet as the adherend may be contaminated. is there. Furthermore, it tends to be difficult to disperse this resin in water and laminate it on a substrate. On the other hand, when it exceeds 10 mass%, mold release property may fall.

  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 stabilization of the resin, and acrylic acid, methacrylic acid, and maleic anhydride are particularly preferable.

  The olefin component which is the main component of the acid-modified polyolefin resin is not particularly limited, but an alkene having 2 to 6 carbon atoms such as ethylene, propylene, isobutylene, 2-butene, 1-butene, 1-pentene, 1-hexene is preferable. A mixture of these may also 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 substrates, this range is 1 to 1%. The content is more preferably 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 adhesiveness with the substrate film, 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. ("(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 temperature exceeds 150 ° C., a high temperature treatment is required for forming the release layer, and when the temperature is less than 80 ° C., the releasability is remarkably deteriorated.

  The Vicat softening point of the acid-modified polyolefin resin is preferably 50 to 130 ° C, more preferably 53 to 110 ° C, and still more preferably 55 to 90 ° C. When the Vicat softening point is less than 50 ° C., the releasability is lowered, and when it exceeds 130 ° C., a high temperature treatment 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 to make an aqueous dispersion. On the other hand, if it exceeds 1000 g / 10 minutes, the adhesion to the substrate is lowered, and the transition to the rubber sheet as the adherend tends to occur.

  The release layer in the release sheet of the present invention contains a crosslinking agent. The content needs to be 1-50 mass parts with respect to 100 mass parts of acid-modified polyolefin resin. It is more preferably 3 to 30 parts by mass, and further preferably 5 to 20 parts by mass. If it is less than 1 part by mass, the effect of addition is poor, and if it exceeds 50 parts by mass, the releasability may decrease. By cross-linking the acid-modified polyolefin resin using a cross-linking agent, there is an effect that even when the rubber sheet is cross-linked, even when a treatment at high temperature is performed, the change in the peeling force of the release sheet is small and can be easily peeled off. be able to.

  Examples of the crosslinking agent for crosslinking the acid-modified polyolefin resin include carbodiimide compounds, oxazoline group-containing compounds, isocyanate compounds, melamine compounds, urea compounds, epoxy compounds, aziridine compounds, zirconium salt compounds, and silane coupling agents. Of these, carbodiimide compounds and oxazoline group-containing compounds are effective and preferable, and oxazoline group-containing compounds are particularly preferable.

  The oxazoline group-containing compound is not particularly limited as long as it has at least two 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 can use 1 type (s) or 2 or more types. 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. More specifically, water-soluble type “WS-500”, “WS-700”, emulsion type “K-1010E”, “K-1020E”, “K-1030E”, “K-2010E”, "K-2020E", "K-2030E", etc. are mentioned.

  In the case of a carbodiimide compound, it is not particularly limited as long as it has at least two or more carbodiimide groups in the molecule. For example, p-phenylene-bis (2,6-xylylcarbodiimide), Examples thereof include compounds having a carbodiimide group such as tetramethylene-bis (t-butylcarbodiimide) and cyclohexane-1,4-bis (methylene-t-butylcarbodiimide), and polycarbodiimide which is a polymer having a carbodiimide group. These can use 1 type (s) or 2 or more types. Among these, polycarbodiimide is preferable from the viewpoint of ease of handling. Although the manufacturing method of polycarbodiimide is not specifically limited, For example, it can manufacture by the condensation reaction accompanied by the carbon dioxide removal of an isocyanate compound.

  As a commercially available product of polycarbodiimide, there is a carbodilite series manufactured by Nisshinbo. More specifically, water-soluble type “SV-02”, “V-02”, “V-02-L2”, “V-04”, emulsion type “E-” 01 ”,“ E-02 ”, organic solution type“ V-01 ”,“ V-03 ”,“ V-07 ”,“ V-09 ”, and solventless type“ V-05 ”.

  The isocyanate compound is not limited, and any of aliphatic isocyanate, alicyclic isocyanate, and aromatic isocyanate may be used. Moreover, polyfunctional liquid rubber, polyalkylene diol, etc. may be copolymerized as needed.

  The release layer in the release sheet of the present invention preferably contains polyvinyl alcohol. When it contains, the content needs to be 1-1000 mass parts with respect to 100 mass parts of acid-modified polyolefin resin. It is preferably 10 to 600 parts by mass, more preferably 20 to 400 parts by mass, and most preferably 30 to 300 parts by mass. By containing polyvinyl alcohol in this range, it is possible to prevent the release layer from softening even when the rubber sheet is cross-linked, and the change in the release force of the release sheet is small and easy. The effect that it can peel is produced. If the content is less than 1 part by mass, the effect of addition is poor, and even if it exceeds 1000 parts by mass, the effect of addition is poor. When the amount exceeds 1000 parts by mass, the rubber sheet and the release layer are strongly adhered to each other, and not only the release property is not obtained, but also the liquid stability may be lowered when used as a liquid material. .

  The kind of polyvinyl alcohol is not particularly limited. For example, a completely or partially saponified polymer of vinyl ester can be mentioned. Examples of the saponification method include known alkali saponification methods and acid saponification methods. Of these, a method of alcoholysis using an alkali hydroxide in methanol is preferred. As will be described later, it is preferable to have water solubility for use as a liquid material.

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

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

  The average degree of polymerization of polyvinyl alcohol is not particularly limited, but is preferably 300 to 2,000.

  Examples of commercially available polyvinyl alcohol include “JC-05”, “VC-10”, “ASC-05X”, “UMR-10HH” of “J-Poval” by Nippon Vine Poval Co., Ltd .; “Kuraray Poval” “PQA-103”, “PVA-105”, “Exeval” “AQ4104”, “HR3010”; Denki Poval “PC-1000”, “PC-2000”, etc.

  Since the release sheet of the present invention has a release layer having the above-described configuration, it has good adhesion to various substrates. Furthermore, it has moderate releasability with respect to the rubber sheet. Furthermore, since it also has heat resistance, the releasability can be maintained even after high temperature treatment in the rubber sheet crosslinking step. Therefore, by using the release sheet of the present invention, the release sheet and the rubber sheet are sufficiently adhered in the rubber sheet manufacturing process, and after the rubber sheet is subjected to a crosslinking treatment, the rubber sheet and the release layer Can exhibit good releasability.

Examples of the base material of the release sheet include resin material, paper, synthetic paper, cloth, metal material, and glass material.
Examples of resin materials that can be used for the substrate include thermoplastic resins such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polylactic acid (PLA), and the like; polystyrene resins; nylon 6, poly-m Polyamide resins such as xylylene adipamide (MXD6 nylon); polycarbonate resins; polyacrylonitrile resins; polyimide resins; multilayers of these resins (for example, nylon 6 / MXD / nylon 6, nylon 6 / ethylene-vinyl) Examples thereof include alcohol copolymers / nylon 6) and mixtures. The base material preferably has a melting point higher than the crosslinking temperature of the rubber sheet. Among these, a polyester resin is preferable, and a polyethylene terephthalate resin that is relatively inexpensive and excellent in heat resistance and dimensional stability is more preferable. The resin material may be stretched.

  The resin material may contain known additives and stabilizers such as antistatic agents, plasticizers, lubricants, antioxidants, etc., and in order to improve the adhesion to the release layer, Corona treatment, plasma treatment, ozone treatment, chemical treatment, solvent treatment and the like may be performed as treatment. Moreover, silica, alumina, etc. may be vapor-deposited, and other layers, such as a barrier layer, an easily bonding layer, an antistatic layer, an ultraviolet absorption layer, and an adhesive layer, may be laminated.

Examples of paper that can be used for the substrate include Japanese paper, craft paper, liner paper, art paper, coated paper, carton paper, glassine paper, semi-glassine paper, and the like.
The structure of the synthetic paper that can be used for the substrate is not particularly limited, and may be, for example, a single layer structure or a multilayer structure. As a multilayer structure, for example, a two-layer structure of a base material layer and a surface layer, a three-layer structure in which a surface layer exists on the front and back surfaces of the base material layer, and another resin film layer exists between the base material layer and the surface layer. A multilayer structure can be exemplified. Moreover, each layer may contain the inorganic or organic filler, and does not need to contain it. A microporous synthetic paper having a large number of fine voids can also be used.

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

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

The base material using the resin material may be a paper, synthetic paper, cloth, other resin material, metal material, or the like laminated on the side opposite to the release layer in the base material. .
The release sheet of the present invention is used for the purpose of preventing blocking between the opposite surface of the release sheet and the rubber sheet when the laminate of the release sheet and the rubber sheet is rolled. You may perform the process which forms the same mold release layer also on the surface on the opposite side to the mold release layer of a type | mold sheet | seat. In other words, the base material may be sandwiched between a pair of release layers.

  In the present invention, the surface roughness (properties) of the substrate is not particularly limited. However, when it is desired to give a special shape to the surface of the rubber sheet, it is desirable to give a special shape to the surface of the release sheet correspondingly. The method for controlling the surface roughness is not particularly limited. For example, as a method for controlling the surface roughness of the polyester film, for example, a film is formed using a polyester resin raw material to which several mass% of inorganic particles or organic particles are added. (Kneading mat), spraying fine inorganic sand on the surface to roughen the surface (sand mat), chemically eroding the polyester film surface with chemicals (chemical mat), embossing the substrate For example, a method of embossing the surface by pressing against a roll. A special shape can be imparted to the surface of the rubber sheet by forming a release layer on the substrate having such a controlled surface roughness. Moreover, when forming a release layer on the substrate surface, a method (coat mat) for controlling the surface shape by adding inorganic particles or organic particles to the release layer may be used.

  The control of the surface roughness is based on the purpose of preventing blocking between the opposite surface of the release sheet and the rubber sheet when the laminate of the release sheet and the rubber sheet is rolled. You may give to the surface on the opposite side to the side which provides the release layer in a material.

  The thickness of the release layer in the release sheet is preferably in the range of 0.01 to 5 μm, more preferably 0.1 to 2 μm, still more preferably 0.2 to 1 μm. A thickness of 3 to 0.7 μm is particularly preferable. When the thickness is less than 0.01 μm, sufficient releasability may not be obtained. When the thickness exceeds 5 μm, not only the cost is increased, but the releasability may be lowered.

  The thickness of the base material in the release sheet is not particularly limited. However, it is preferably 10 to 1000 μm, more preferably 50 to 300 μm, still more preferably 70 to 200 μm, and most preferably 75 to 150 μm. In particular, when a resin material is used as a base material, it becomes a film. Therefore, if the thickness is small, the film may shrink and tear due to heat at the time of crosslinking, or it may cause uneven thickness. In addition, since the film itself is not strong, it may be easily broken at the time of peeling and may be difficult to handle. When the thickness of the substrate exceeds 1000 μm, the cost increases.

  The release sheet of the present invention is industrially simple by a production method in which a liquid material containing an acid-modified polyolefin resin, a crosslinking agent, and polyvinyl alcohol used as necessary is coated on a substrate and then dried. Can get to.

  The method for producing a liquid material containing an acid-modified polyolefin resin, a crosslinking agent and, if necessary, polyvinyl alcohol is not particularly limited as long as each component is uniformly mixed in a liquid medium. For example, the following method is mentioned.

  (A): A method of adding and mixing a dispersion or solution of a crosslinking agent and a dispersion or solution of polyvinyl alcohol used as necessary to a dispersion or solution of an acid-modified polyolefin resin.

(B): A method of liquefying a mixture of an acid-modified polyolefin resin, a crosslinking agent, and polyvinyl alcohol used as necessary.
In the case of the method (A), a dispersion or a solution may be mixed as appropriate. The solute concentration of the dispersion or solution of polyvinyl alcohol is not particularly limited, but is preferably 5 to 10% by mass from the viewpoint of ease of handling. In the case of the method (B), when the acid-modified polyolefin resin is liquefied, a crosslinking agent and polyvinyl alcohol required as necessary may be added.

  In addition, when other components are added, they can be added at any stage in the production method (A) or (B).

  In the production of the release sheet of the present invention, the solvent in the liquid containing the acid-modified polyolefin resin, the cross-linking agent and, if necessary, polyvinyl alcohol is not particularly limited as long as it can be applied on the substrate. Can be used. Examples thereof include water, an organic solvent, or an aqueous medium containing water and an amphiphilic organic solvent. Especially, it is preferable to use water or an aqueous medium from an environmental viewpoint and the solubility viewpoint of polyvinyl alcohol.

  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, 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 til, isopropyl acetate, n-butyl acetate, isobutyl acetate, sec-butyl acetate, 3-methoxybutyl acetate, methyl propionate, ethyl propionate, diethyl carbonate, γ-butyrolactone, isophorone; Examples include amphiphilic organic solvents described below.

  Here, the aqueous medium containing water and an amphiphilic organic solvent means a solvent having a water content of 2% by mass or more. The amphiphilic organic solvent herein refers to an organic solvent having a water solubility of 5% by mass or more at 20 ° C. [For the solubility of water in an organic solvent at 20 ° C., for example, “Solvent Handbook” (It is described in documents such as Kodansha Scientific, 1990, 10th edition)]. Specifically, alcohols such as methanol, ethanol, n-propanol and isopropanol; ethers such as tetrahydrofuran, 1,4-dioxane and ethylene glycol-n-butyl ether; ketones such as acetone and methyl ethyl ketone; methyl acetate and acetic acid -Esters such as n-propyl, isopropyl acetate, methyl propionate, ethyl propionate, dimethyl carbonate; in addition, ammonia, diethylamine, triethylamine, diethanolamine, triethanolamine, N, N-dimethylethanolamine, N, N -Organic amine compounds such as diethylethanolamine and N-diethanolamine; lactams such as 2-pyrrolidone and N-methyl-2-pyrrolidone.

  The method for dispersing the acid-modified polyolefin resin in the aqueous medium as described above is not particularly limited. For example, what was described in the international publication WO02 / 055598 pamphlet is mentioned.

  The dispersed particle size of the acid-modified polyolefin resin in an aqueous medium containing water and an amphiphilic organic solvent has a number average particle size from the viewpoint of stability when mixed with other components and storage stability after mixing. It is preferably 1 μm or less, and more preferably 0.8 μm or less. Such a particle size can be achieved by the production method described in the pamphlet of International Publication No. WO02 / 055598.

  The solid content of the liquid can be appropriately selected depending on the lamination conditions, the thickness and performance of the target release layer, and is not particularly limited. However, in order to keep the viscosity of the liquid material moderate and to form a good release layer, the content is preferably 1 to 60% by mass, and more preferably 5 to 30% by mass.

  When coating a liquid material on a substrate, 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, brushing method Apply uniformly on the surface of the base material, etc. after setting it at around room temperature if necessary, and then subject it to drying treatment or heat treatment for drying, forming a uniform release layer in close contact with the base material can do.

  The rubber component for forming a rubber sheet using the release sheet of the present invention is not particularly limited. For example, any rubber such as silicone rubber, fluorine rubber, urethane rubber, natural rubber, styrene butadiene rubber, ethylene propylene rubber, ethylene propylene diene rubber, acrylonitrile butadiene rubber, chloroprene rubber, acrylic rubber, or a mixture thereof can be used. These rubber components may be appropriately selected and used depending on the required characteristics according to the purpose of use. Two or more kinds of these rubber components may be included.

  The rubber sheet has various functions such as a cross-linking initiator, a cross-linking aid, a cross-linking regulator, etc .; a conductive agent, an electromagnetic wave absorber, a colorant, an optical property modifier, a hydrophilizing agent, a flame retardant, etc. Agents; reinforcing fillers, anti-aging agents, antioxidants, mold release agents, thixotropy imparting agents, filler dispersants and other fillers; even if additives such as adhesion improvers are included Good. Two or more of these additives may be used simultaneously.

  In general, a rubber is often added with a cross-linking agent to improve physical properties such as elasticity, strength, and solvent resistance, and after a rubber sheet is formed, it is often made into a product through a cross-linking step. For this purpose, the crosslinking agent used in the rubber sheet is not particularly limited. For example, sulfur such as powdered sulfur, precipitated sulfur, colloidal sulfur, and insoluble sulfur; sulfur chloride such as sulfur monochloride and sulfur dichloride; tetramethylthiuram Disulfides; sulfur-containing compounds; acyl peroxides and alkyl peroxides are known.

  For example, benzoyl peroxide, monochlorobenzoyl peroxide, 2,4-dichlorobenzoyl peroxide, t-butylcumyl peroxide, 2,5-dimethyl-2,5-bis (t-butylperoxy) hexane, 1,1 -Organization of di-t-butylperoxy-3,3,5-trimethylcyclohexane, 1,1-bis-t-butylperoxy-3,3,5-trimethylcyclohexane, di-t-butyl peroxide, etc. Oxides; Metal oxides such as magnesium oxide, zinc oxide, and lead oxide; Organic polyamines such as triethylenetetramine, hexamethylenediamine carbamate, and 4,4'-methylene-bis-orthochloroaniline; Modifications such as alkylphenol resins Phenol resin; p-quinone dioxime; p, p'-diben Dioxime; tetrachloro--p- benzoquinone; Isoshiana - DOO acids; lead peroxide; red light bright; Benzokurorido like. Two or more of these crosslinking agents may be used simultaneously.

  Furthermore, a crosslinking accelerator may be added for the purpose of shortening the crosslinking time of the rubber, lowering the crosslinking temperature, reducing the amount of the crosslinking agent, and the like. The crosslinking accelerator is not particularly limited, but 2-mercaptobenzothiazole (MBT), dibenzothiazyl disulfide (MBTS), zinc salt of 2-mercaptobenzothiazole (ZnMBT), sodium salt of 2-mercaptobenzothiazole (NaMBT) ), Cyclohexylamine salts of 2-mercaptobenzothiazole (CMBT), 2- (2,4-dinitrophenylthio) benzothiazole (DPBT) and the like thiazole crosslinking accelerators; N-cyclohexyl-2-benzothiazole sulfenamide (CBS), Nt-butyl-2-benzothiazolesulfenamide (TBBS), N-oxyethylene-2-benzothiazolesulfenamide (OBS), N, N′-diisopropyl-2-benzothiazolesulfen Amide ( PBS) and other sulfenamide crosslinking accelerators; tetramethylthiuram monosulfide (TMTM), tetramethylthiuram disulfide (TMTD), tetraethylthiuram disulfide (TETD), tetrabutylthiuram disulfide (TBTD), dipentamethylenethiuram tetrasulfide (DPTT) and other thiuram crosslinking accelerators; sodium dimethyldithiocarbamate (NaMDC), sodium diethyldithiocarbamate (NaEDC), sodium di-n-butyldithiocarbamate (NaBDC), lead dimethyldithiocarbamate (PbMDC), dimethyldithiocarbamic acid Zinc (ZnMDC), zinc diethyldithiocarbamate (ZnEDC), zinc di-n-butyldithiocarbamate (ZnBDC), pen Zinc methylenedithiocarbamate (ZnPDC), zinc ethylphenyldithiocarbamate (ZnEPDC), tellurium diethyldithiocarbamate (TeEDC), selenium dimethyldithiocarbamate (SeMDC), selenium diethyldithiocarbamate (SeEDC), copper dimethyldithiocarbamate (CuMDC), dimethyl Dithioacid-based crosslinking accelerators such as iron dithiocarbamate (FeMDC), diethylamine diethyldithiocarbamate (EAEDC), piperidine pentamethylenedithiocarbamate (PPDC), pipecoline methylpentamethylenedithiocarbamate (PMPDC); diphenylguanidine (DPG), di Promotion of guanidine-based crosslinking such as ortho-tolyl guanidine (DOTG) and ortho-tolyl biguanide (OTBG) Agents: Thiourea-based crosslinking accelerators such as thiocarboanilide (CA), diortolylthiourea (DOTU), ethylenethiourea (EU), diethylthiourea (DEU), trimethylthiourea (TMU); hexamethylenetetramine (H), acetaldehyde・ Aldehyde-ammonia crosslinking accelerators such as ammonia (AA); Organic crosslinking accelerators such as aldehyde-amine crosslinking accelerators such as n-butyraldehyde and aniline reaction products (BAA), slaked lime, magnesium oxide And inorganic crosslinking accelerators such as Resurge. Two or more of these crosslinking accelerators may be used simultaneously.

  Although the compounding quantity of a crosslinking agent and a crosslinking accelerator is not specifically limited, It is preferable to set it as 0.1-50 mass parts with respect to 100 mass parts of said rubber components, respectively, More preferably, it is 0.2-30 masses. Part, more preferably 0.5 to 20 parts by mass. When the blending amount is less than 0.1 parts by mass, it is difficult to obtain sufficient physical properties of the rubber. On the other hand, even if it exceeds 50 parts by mass, it is difficult to obtain sufficient rubber properties, but the rubber properties may be deteriorated. When two or more kinds of crosslinking agents and crosslinking accelerators are used, the total amount of the crosslinking agents is preferably within the above range.

  The method for blending the rubber component and additive of the rubber sheet is not particularly limited. For example, it may be blended using a known kneading machine such as a two-roll, Banbury mixer, dough mixer (kneader), etc., and various kinds of materials are prepared when the rubber component is dissolved in a solvent or after it is made into a solution. A compounding agent may be added.

  The method for producing the rubber sheet is not particularly limited, and a conventionally known method can be used. For example, a solution in which a rubber component is dissolved in an organic solvent is applied to the surface of the release sheet and dried to form a rubber layer and cured, or a rubber component melted at high temperature is applied to the release sheet. And a method of forming a sheet with a predetermined thickness with a calendar or an extruder and curing the sheet.

  In the case of obtaining a rubber sheet using a solution of the rubber component, the solvent for preparing the rubber solution is not particularly limited as long as it can dissolve the rubber, and can be arbitrarily used. For example, the organic solvent mentioned above can be used. Although the density | concentration of a rubber solution is arbitrary and changes with kinds of rubber | gum and a composition of a compound, it is preferable that a density | concentration is the range of 5-90 mass%, and it is more preferable that it is 10-50 mass%.

  The method for crosslinking the rubber sheet is not particularly limited, and a known crosslinking method can be used. Examples thereof include thermal crosslinking and crosslinking with energy active rays such as ultraviolet rays, electron beams, and γ rays. When performing thermal crosslinking, the treatment temperature is not particularly limited, and may be appropriately selected according to the rubber component, the crosslinking agent, and the crosslinking accelerator used. Specifically, 80 to 250 ° C is preferable, 100 to 200 ° C is more preferable, and 120 to 180 is more preferable. The crosslinking treatment with heat may be performed in several steps as necessary. For example, after performing primary crosslinking for 1 minute to 30 minutes, secondary crosslinking is performed for about 1 to 20 hours.

  The peel strength between the release sheet of the present invention and the rubber sheet after the crosslinking treatment is such that when the rubber sheet is held and peeled from the release sheet, the T-type peel is performed at a temperature of 20 ° C., and the pulling speed is 300 mm. It is preferable that the average value when the peel strength is stable when measured at 1 / min is 0.05 to 1.0 N / cm. More preferably, it is 0.05 to 0.8 N / cm, more preferably 0.1 to 0.6 N / cm, and most preferably 0.1 to 0.5 N / cm. When the peel strength is in the above range, it is possible to suppress the release sheet from being lifted when the rubber sheet is wound, stored or transported in the rubber sheet manufacturing process, thereby improving the product yield. In addition, the quality can be kept high, and when the release sheet is peeled off, it can be peeled off without stress and without adversely affecting the surface of the rubber sheet layer. When the peel strength is less than 0.05 N / cm, the release sheet and the rubber sheet are easily peeled off during the production process, during storage and during transportation, and cannot serve as a protection, There is a possibility of deteriorating the quality of the rubber sheet. Moreover, when peeling strength is larger than 1.0 N / cm, when using a rubber sheet, a release sheet cannot peel easily and there exists a possibility of damaging the rubber sheet surface.

Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited by these.
Various characteristics in the following examples and comparative examples were measured or evaluated by the following methods.

(1) Configuration of acid-modified polyolefin resin The configuration of the acid-modified polyolefin resin was determined by ¹ H-NMR analysis using a high-resolution nuclear magnetic resonance apparatus (manufactured by Varian, trade name “GEMINI 2000/300”). .

The analysis conditions are shown below.
Frequency: 300MHz
Solvent: orthodichlorobenzene (d ₄ )
Temperature: 120 ° C

(2) Organic solvent content of acid-modified polyolefin resin dispersion (% by mass)
Using an FID detector (manufactured by Shimadzu Corporation, trade name “Gas Chromatograph GC-8A”), an acid-modified polyolefin resin dispersion or an acid-modified polyolefin resin dispersion diluted with water was directly put into the apparatus, The content of the organic solvent was determined. The detection limit was 0.01% by mass.

The measurement conditions are shown below.
Carrier gas: nitrogen Column filler: GL Sciences, trade name "PEG-HT (5%)-Uniport HP (60/80 mesh)"
Column size: 3mm diameter x 3m
Sample charging temperature (injection temperature): 150 ° C
Column temperature: 60 ° C
Internal standard: n-butanol

(3) Solid content concentration (mass%) of acid-modified polyolefin resin dispersion
An appropriate amount (for example, 5 g) of the acid-modified polyolefin resin dispersion was weighed, and this was heated at 150 ° C. until the mass of the residue (solid content) became a constant amount (that is, an amount in which the residue did not decrease any more). And solid content concentration was computed according to the following formula | equation.

      Solid content concentration (mass%) = mass after heating / mass before heating × 100

(4) Thickness of release layer The thickness of the substrate was measured with a contact-type film thickness meter (manufactured by HEIDENNHAIN, trade name “MT12B”). Subsequently, the release layer-forming liquid material was applied to the substrate and dried to laminate the release layer. The thickness of the obtained laminate was measured with a contact-type film thickness meter, and the thickness of the release layer was determined by subtracting the thickness before coating the release layer from the thickness of the laminate.

(5) Releasability between release sheet and rubber sheet By a method described later, a rubber sheet is formed on the release sheet and then crosslinked to form a laminate composed of the release sheet and the rubber sheet. Obtained. A sample obtained by cutting this laminate into a size of 15 mm in width and 10 cm in length was used as a sample.

  With respect to this sample, the peel strength was measured with a tensile tester (manufactured by Intesco, precision universal material tester, type 2020) under the conditions of a temperature of 20 ° C., T-type peeling, and a pulling speed of 300 mm / min. evaluated. The measurement results are shown in units of N / cm.

Preparation Example 1 (Preparation of acid-modified polyolefin resin P-1)
4 280 g of propylene-butene-ethylene terpolymer (manufactured by Huls Japan, trade name “Best Plast 708”, propylene / butene / ethylene = 64.8 / 23.9 / 11.3 (mass ratio)) It was put into a one-necked flask and heated and melted under a nitrogen atmosphere. Next, while maintaining the system temperature at 170 ° C. and stirring, 32.0 g of maleic anhydride as an unsaturated carboxylic acid and 6.0 g of dicumyl peroxide as a radical generator were added over 1 hour, respectively, and then stirred. The reaction was carried out for 1 hour. After completion of the reaction, the obtained reaction product was put into a large amount of acetone to precipitate an acid-modified polyolefin resin. This acid-modified polyolefin resin was further washed several times with acetone to remove unreacted maleic anhydride, and then dried under reduced pressure in a vacuum dryer to obtain acid-modified polyolefin resin P-1.

Preparation Example 2 (Preparation of acid-modified polyolefin resin P-2)
A propylene-butene-ethylene terpolymer (manufactured by Huls Japan, trade name “Best Plast 408”, propylene / butene / ethylene = 12.3 / 82.2 / 5.5% by mass) was used. Otherwise in the same manner as in Preparation Example 1, polyolefin resin P-2 was obtained.

Preparation Example 3 (Preparation of polyolefin resin P-3)
280 g of a propylene-ethylene copolymer (propylene / ethylene = 81.8 / 18.2% by mass, weight average molecular weight 85,000) was heated and melted in a four-necked flask under a nitrogen atmosphere. Next, while stirring the system temperature at 180 ° C., 35.0 g of maleic anhydride as an unsaturated carboxylic acid and 6.0 g of di-tert-butyl peroxide as a radical generator were added over 2 hours, respectively. Thereafter, the reaction was allowed to proceed for 1 hour. After completion of the reaction, the obtained reaction product was put into a large amount of acetone to precipitate a resin. This resin was further washed several times with acetone to remove unreacted maleic anhydride and then dried under reduced pressure in a vacuum dryer to obtain polyolefin resin P-3.

  Table 1 shows the characteristics of the resins of Preparation Examples 1 to 3 and other acid-modified polyolefin resins used in the following Examples and Comparative Examples.

Preparation Example 4 (Preparation of acid-modified polyolefin resin aqueous dispersion E-1)
In a sealed 1 liter glass container with a heater, 60.0 g of acid-modified polyolefin resin (P-1), 45.0 g of ethylene glycol-n-butyl ether (manufactured by Wako Pure Chemical Industries, special grade, boiling point 171 ° C., Hereafter referred to as “Bu-EG”), 6.9 g of N, N-dimethylethanolamine (manufactured by Wako Pure Chemical Industries, special grade, boiling point 134 ° C., based on the carboxyl group of the maleic anhydride unit in the resin) 1.08.1 equivalents, hereinafter may be referred to as “DMEA”) 188.1 g of distilled water was poured, and the stirring blade provided in the vessel was stirred at a rotational speed of 300 rpm. During stirring, no resin precipitation was observed at the bottom of the container, confirming that it was in a floating state. Therefore, while maintaining this state, the heater was turned on and heated after 10 minutes. Then, the system temperature was kept at 140 ° C. and further stirred for 60 minutes. Then, while stirring at a rotational speed of 300 rpm, it was cooled to room temperature (25 ° C.) by air cooling, and pressure filtered (air pressure 0.2 MPa) with a 300 mesh stainless steel filter (wire diameter: 0.035 mm, plain weave). A milky yellow uniform acid-modified polyolefin resin dispersion E-1 was obtained. There was almost no residual resin on the filter.

Preparation Example 5 (Preparation of acid-modified polyolefin resin dispersion E-2)
Instead of the acid-modified polyolefin resin (P-1) in Preparation Example 4, an acid-modified polyolefin resin (P-2) was used. Otherwise by performing the same operations as in Preparation Example 4, an acid-modified polyolefin resin aqueous dispersion E-2 was obtained.

Preparation Example 6 (Preparation of acid-modified polyolefin resin aqueous dispersion E-3)
Instead of the acid-modified polyolefin resin (P-1) in Preparation Example 4, an acid-modified polyolefin resin (P-3) was used. Otherwise by performing the same operations as in Preparation Example 4, an acid-modified polyolefin resin aqueous dispersion E-3 was obtained.

Preparation Example 7 (Preparation of acid-modified polyolefin resin dispersion E-4)
A hermetic pressure resistant 1 liter glass container with a heater was prepared. In this container, 60.0 g of maleic anhydride-modified polyolefin resin (manufactured by Arkema, trade name “Bondaine LX-4110”), 90.0 g of isopropanol (manufactured by Wako Pure Chemical Industries, Ltd., hereinafter referred to as “IPA”) ), 3.0 g of triethylamine (manufactured by Wako Pure Chemical Industries, Ltd., hereinafter sometimes referred to as “TEA”), 147.0 g of distilled water was injected, and the stirring blade provided in the vessel was stirred at a rotational speed of 300 rpm. did. During stirring, no resin precipitation was observed at the bottom of the container, confirming that it was in a floating state. Therefore, while maintaining this state, the heater was turned on and heated after 10 minutes. Then, the system temperature was kept at 140 to 145 ° C. and further stirred for 30 minutes. Thereafter, it was placed in a water bath and cooled to room temperature (about 25 ° C.) while stirring at a rotational speed of 300 rpm. Furthermore, pressure filtration (air pressure 0.2 MPa) was performed through a 300 mesh stainless steel filter (wire diameter 0.035 mm, plain weave) to obtain a milky white uniform acid-modified polyolefin resin dispersion E-4. There was almost no residual resin on the filter.

Preparation Example 8 (Preparation of acid-modified polyolefin resin aqueous dispersion E-5)
Instead of the acid-modified polyolefin resin “Bondaine LX-4110” in Preparation Example 7, an acid-modified polyolefin resin “Bondaine HX-8210” (manufactured by Arkema) was used. Otherwise by performing the same operations as in Preparation Example 7, acid-modified polyolefin resin aqueous dispersion E-5 was obtained.

Preparation Example 9 (Preparation of acid-modified polyolefin resin aqueous dispersion E-6)
Using a stirrer equipped with a heat-resistant 1-liter glass container with a heater, 60.0 g of “Primacol 5980I” (manufactured by Dow Chemical Co., acrylic acid-modified polyolefin resin), 16.8 g of TEA, and 223 .2 g of distilled water was 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) to obtain a slightly cloudy aqueous dispersion E-6. At this time, almost no resin remained on the filter.

  Table 2 shows the compositions of the acid-modified polyolefin resin aqueous dispersions E-1 to E-6 obtained in Preparation Examples 4 to 9 and the particle diameters of the resins.

Preparation Example 10 (Preparation of urethane rubber sheet)
8 parts by mass of Ketjen black (EC300J made by Lion Corporation), 2 parts by mass of organic peroxide (Park Mill D made by NOF Corporation), 100 parts by mass of millable urethane rubber (Adiprene CM made by DuPont), stearic acid (Kao) Lunac S30 (0.55 parts by mass) was added and kneaded thoroughly with a Banbury mixer to prepare a urethane rubber component.

  This urethane rubber component was extruded onto a release sheet, formed into a sheet shape, press molded, and then subjected to secondary crosslinking. The press molding at this time was performed at a temperature of 180 ° C. for 10 minutes. Secondary crosslinking was performed at 120 ° C. for 15 hours.

Preparation Example 11 (Preparation of fluororubber sheet)
A vinylidene fluoride / hexafluoropropylene copolymer binary fluororubber (Daikin G801, manufactured by Daikin) was dissolved in methyl ethyl ketone, and carbon black (Asahi Carbon Co., Ltd., Asahi # 50H) 1 was added to 100 parts by mass of fluororubber. Part by mass, 0.5 part by mass of stearic acid (Lunac S30 manufactured by Kao Corporation), 2 parts by mass of organic peroxide (Perhexa 25B-40 manufactured by NOF Corporation), triallyl isocyanurate (TAIK M-60 manufactured by Nippon Kasei Co., Ltd.) 2 parts by mass was added to prepare a fluororubber solution. This fluororubber solution was applied onto a release sheet using a roll coater so that the thickness after drying was 0.5 mm, and dried at 80 ° C. to form a rubber layer. And after pressing on 160 degreeC and the conditions for 10 minutes, secondary bridge | crosslinking was performed. The conditions for secondary crosslinking were 180 ° C. and 4 hours.

Preparation Example 12 (Preparation of silicone rubber sheet)
0.4 parts by mass of organic peroxide (TC-8 manufactured by Momentive Performance Materials Japan GK) per 100 parts by mass of polyorganosiloxane polymer (TME2527U manufactured by Momentive Performance Materials Japan GK) , 4 parts by mass of iron oxide (ME-41F manufactured by Momentive Performance Materials Japan LLC), 5 parts by mass of carbon black (ME-41B manufactured by Momentive Performance Materials Japan LLC) were added, and Banbury mixer A silicone rubber component was prepared by sufficiently kneading with the use of the above.

  This silicone rubber component was extruded onto a release sheet to form a sheet, press-molded, and then subjected to secondary crosslinking. The press molding conditions at this time were a temperature of 170 ° C. and 10 minutes. Secondary crosslinking was performed under the conditions of 200 ° C. and 4 hours.

Example 1
An aqueous solution of acid-modified polyolefin resin aqueous dispersion E-1 and an oxazoline compound (Epocross WS manufactured by Nippon Shokubai Co., Ltd.) is applied to the corona-treated surface of a biaxially stretched polyester film (Embret S-75, thickness 75 μm manufactured by Unitika) as a base material. -500 solid content concentration of 40% by mass, hereinafter referred to as “OX”) is added so that the oxazoline compound solid content is 10 parts by mass with respect to 100 parts by mass of the acid-modified polyolefin resin solid content. The film was coated using a Mayer bar and dried at 120 ° C. for 30 seconds to form a release layer having a thickness of 0.3 μm. Then, the release sheet was obtained by performing aging at 50 degreeC for 2 days.

Example 2
Instead of the acid-modified polyolefin resin aqueous dispersion E-1 in Example 1, an acid-modified polyolefin resin aqueous dispersion E-2 was used. Otherwise, the same operation as in Example 1 was performed to obtain a release sheet.

Example 3
Instead of the acid-modified polyolefin resin aqueous dispersion E-1 in Example 1, an acid-modified polyolefin resin aqueous dispersion E-3 was used. Otherwise, the same operation as in Example 1 was performed to obtain a release sheet.

Example 4
Instead of the acid-modified polyolefin resin aqueous dispersion E-1 in Example 1, an acid-modified polyolefin resin aqueous dispersion E-4 was used. Moreover, it changed so that an oxazoline compound solid content might be 5 mass parts with respect to 100 mass parts of acid-modified polyolefin resin solid content. Otherwise, the same operation as in Example 1 was performed to obtain a release sheet.

Example 5
Instead of the acid-modified polyolefin resin aqueous dispersion E-4 in Example 4, an acid-modified polyolefin resin aqueous dispersion E-5 was used. Otherwise by performing the same operations as in Example 4, a release sheet was obtained.

Example 6
With respect to the acid-modified polyolefin resin aqueous dispersion E-1, an aqueous solution of an oxazoline compound (Epocross WS-500 manufactured by Nippon Shokubai Co., Ltd., solid content concentration 40% by mass) and polyvinyl alcohol (VC-10 manufactured by Nippon Vinegar Pover Co., Ltd.) 8 mass% aqueous solution with a polymerization degree of 1000 (hereinafter sometimes referred to as “PVA”) is 10 parts by mass with respect to 100 parts by mass of the acid-modified polyolefin resin, and 100 parts by mass of the acid-modified polyolefin resin. On the other hand, the liquid substance added so that polyvinyl alcohol might be 50 mass parts was obtained. This liquid material is coated on a corona-treated surface of a biaxially stretched polyester film (Embret S-75, thickness 75 μm, manufactured by Unitika Co.) as a substrate using a Mayer bar, and dried at 120 ° C. for 30 seconds to obtain a thickness. A release layer of 0.3 μm was formed on the film. Then, the release sheet was obtained by performing aging at 50 degreeC for 2 days.

Example 7
Instead of the acid-modified polyolefin resin aqueous dispersion E-1 in Example 6, an acid-modified polyolefin resin aqueous dispersion E-2 was used. Otherwise by performing the same operations as in Example 6, a release sheet was obtained.

Example 8
Instead of the acid-modified polyolefin resin aqueous dispersion E-1 in Example 6, an acid-modified polyolefin resin aqueous dispersion E-3 was used. Otherwise by performing the same operations as in Example 6, a release sheet was obtained.

Example 9
Instead of the acid-modified polyolefin resin aqueous dispersion E-1 in Example 6, an acid-modified polyolefin resin aqueous dispersion E-4 was used. And oxazoline compound solid content was made into 5 mass parts with respect to 100 mass parts of acid-modified polyolefin resin. Otherwise by performing the same operations as in Example 6, a release sheet was obtained.

Example 10
Instead of the acid-modified polyolefin resin aqueous dispersion E-4 in Example 9, an acid-modified polyolefin resin aqueous dispersion E-5 was used. Otherwise by performing the same operations as in Example 9, a release sheet was obtained.

Example 11
Compared with Example 6, it changed so that polyvinyl alcohol might be 1 mass part with respect to 100 mass parts of acid-modified polyolefin resin. Otherwise by performing the same operations as in Example 6, a release sheet was obtained.

Example 12
Compared with Example 6, it changed so that polyvinyl alcohol might be 100 mass parts with respect to 100 mass parts of acid-modified polyolefin resin. Otherwise by performing the same operations as in Example 6, a release sheet was obtained.

Example 13
Compared with Example 6, it changed so that polyvinyl alcohol might be 300 mass parts with respect to 100 mass parts of acid-modified polyolefin resin. Otherwise by performing the same operations as in Example 6, a release sheet was obtained.

Example 14
Compared with Example 6, it changed so that polyvinyl alcohol might be 500 mass parts with respect to 100 mass parts of acid-modified polyolefin resin. Otherwise by performing the same operations as in Example 6, a release sheet was obtained.

Example 15
Compared with Example 6, it changed so that polyvinyl alcohol might be 1000 mass parts with respect to 100 mass parts of acid-modified polyolefin resin. Otherwise by performing the same operations as in Example 6, a release sheet was obtained.

Example 16
Compared with Example 9, it changed so that polyvinyl alcohol might be 300 mass parts with respect to 100 mass parts of acid-modified polyolefin resin. Otherwise by performing the same operations as in Example 9, a release sheet was obtained.

Example 17
Compared with Example 9, it changed so that polyvinyl alcohol might be 1000 mass parts with respect to 100 mass parts of acid-modified polyolefin resin. Otherwise by performing the same operations as in Example 9, a release sheet was obtained.

Example 18
Compared with Example 6, it changed so that an oxazoline compound might be 50 mass parts with respect to 100 mass parts of acid-modified polyolefin resin. Otherwise by performing the same operations as in Example 6, a release sheet was obtained.

Example 19
Compared with Example 16, it changed so that an oxazoline compound might be 1 mass part with respect to 100 mass parts of acid-modified polyolefin resin. Otherwise by performing the same operations as in Example 16, a release sheet was obtained.

Example 20
Instead of the aqueous solution “WS-500” of the oxazoline compound in Example 6, an aqueous solution of a polycarbodiimide compound (“V-02” manufactured by Nisshinbo Co., Ltd., solid concentration 40 mass%, hereinafter sometimes referred to as “CI”) ) Was used. And it changed so that a polycarbodiimide compound might be 30 mass parts with respect to 100 mass parts of acid-modified polyolefin resin. Otherwise by performing the same operations as in Example 6, a release sheet was obtained.

Example 21
Instead of the aqueous solution “WS-500” of the oxazoline compound in Example 9, an aqueous solution CI of a polycarbodiimide compound was used. And it changed so that a polycarbodiimide compound might be 10 mass parts with respect to 100 mass parts of acid-modified polyolefin resin. Otherwise by performing the same operations as in Example 9, a release sheet was obtained.

Example 22
Instead of the biaxially stretched polyester film (Embret S-75, thickness 75 μm, manufactured by Unitika) as the base material in Example 6, a biaxially stretched polyester kneaded mat film (PTH-50, thickness 50 μm, manufactured by Unitika) was used. . Otherwise by performing the same operations as in Example 6, a release sheet was obtained.

Example 23
Instead of the biaxially stretched polyester film in Example 16 (Embret S-75, thickness 75 μm, manufactured by Unitika), a biaxially stretched polyester kneaded mat film (PTH-50, thickness 50 μm, manufactured by Unitika) was used. Otherwise by performing the same operations as in Example 16, a release sheet was obtained.

Example 24
Instead of the biaxially stretched polyester film (Embret S-75, thickness 75 μm, manufactured by Unitika Ltd.) as the base material in Example 6, a polyester sand mat film (SM-75, thickness 75 μm manufactured by Unitika Ltd.) was used. Otherwise by performing the same operations as in Example 6, a release sheet was obtained.

Example 25
Instead of the biaxially stretched polyester film (Embret S-75, thickness 75 μm manufactured by Unitika) as the base material in Example 9, a polyester sand mat film (SM-75, thickness 75 μm manufactured by Unitika) was used. Otherwise by performing the same operations as in Example 9, a release sheet was obtained.

  The evaluation result about each release sheet of Examples 1-25 is shown in Tables 3-5.

Comparative Example 1
Without forming a release layer on a biaxially stretched polyester resin film (Embret S-75, thickness 75 μm, manufactured by Unitika Ltd.), the corona-untreated surface of the film was evaluated.

Comparative Example 2
The biaxially stretched polypropylene film (FOK-P thickness 30 μm manufactured by Futamura Chemical Co., Ltd.) was evaluated.

Comparative Example 3
Compared to Example 1, a silicone release agent (manufactured by Toshiba Silicone Co., Ltd., trade name “ TSM6341 ”, solid content concentration: 40% by mass) was coated to a thickness of 0.3 μm to obtain a release sheet.

Comparative Example 4
Instead of the acid-modified polyolefin resin dispersion E-1 in Example 1, an acid-modified polyolefin resin aqueous dispersion E-6 was used. Otherwise, the same operation as in Example 1 was performed to obtain a release sheet.

Comparative Example 5
Instead of the acid-modified polyolefin resin aqueous dispersion E-1 in Example 6, an acid-modified polyolefin resin aqueous dispersion E-6 was used. Otherwise by performing the same operations as in Example 6, a release sheet was obtained.

Comparative Example 6
Compared with Example 1, the addition amount of the oxazoline compound was changed to 60 parts by mass with respect to 100 parts by mass of the acid-modified polyolefin resin. Otherwise, the same operation as in Example 1 was performed to obtain a release sheet.

Comparative Example 7
A corona-treated surface of a biaxially stretched polyester film (trade name “Emblet S-75” manufactured by Unitika Ltd.) is coated with acid-modified polyolefin E-1 to a thickness of 0.3 μm, and a release sheet. Got.

Comparative Example 8
In the acid-modified polyolefin resin aqueous dispersion E-1, an aqueous solution of polyvinyl alcohol (VC-10, degree of polymerization 1000, manufactured by Nippon Vinegar Poval Co., Ltd.) was added to 50 parts by mass of polyvinyl alcohol with respect to 100 parts by mass of the acid-modified polyolefin resin. Was added to obtain a liquid. This liquid material is coated on the corona-treated surface of a biaxially stretched polyester film (trade name “Embret S-75”, manufactured by Unitika Co., Ltd.) as a substrate using a Mayer bar, and dried at 120 ° C. for 30 seconds. Then, a release layer having a thickness of 0.3 μm was formed on the film. Then, the release sheet was obtained by performing aging at 50 degreeC for 2 days.

  Table 6 shows the evaluation results for the release sheets of Comparative Examples 1 to 8.

実施例１〜２５は、酸変性成分が１〜１０質量％の酸変性ポリオレフィン樹脂と、架橋剤と、任意的に含まれるポリビニルアルコールとを本発明で規定する範囲に含有する離型層を、基材の上に形成した離型シートであった。このため、離型シート上にゴムをシート状に形成し、このゴムを架橋した後も、適度な離型性を有していた。

In Examples 1 to 25, a release layer containing an acid-modified polyolefin resin having an acid-modified component of 1 to 10% by mass, a crosslinking agent, and optionally included polyvinyl alcohol in a range specified in the present invention, It was the release sheet formed on the base material. For this reason, rubber was formed into a sheet shape on the release sheet, and even after this rubber was crosslinked, it had an appropriate release property.

On the other hand, since the comparative example 1 used the polyester film which has not provided the mold release layer, the rubber sheet was not able to be peeled after the crosslinking process.
Since the comparative example 2 used the polyolefin resin film which does not provide the mold release layer, it was not able to peel a rubber sheet similarly after bridge | crosslinking treatment.

  Comparative Example 3 was a release sheet in which a silicone-type release agent was coated on a polyester film. Therefore, it cannot be said that the peel strength is too small to have an appropriate release property. When a rubber sheet was created, there was a high possibility of peeling during the manufacturing process or during product storage. Furthermore, when it was used for a silicone rubber sheet, it could not be peeled off.

Since Comparative Example 4 and Comparative Example 5 used an acid-modified polyolefin resin having a modified amount outside of the present invention, they adhered strongly to the rubber sheet and could not be peeled off.
In Comparative Example 6, since the addition amount of the crosslinking agent was out of the range of the present invention, it could be peeled off, but it was hard to say that it could be suitably used because it adhered strongly to the rubber sheet. .

Since Comparative Example 7 did not add a cross-linking agent, it adhered strongly to the rubber sheet and could not be peeled off.
Comparative Example 8 contains polyvinyl alcohol but does not contain a cross-linking agent. Therefore, although the release sheet can be peeled from the rubber sheet, the peel strength is very large and it cannot be said that it can be suitably used. Met.

Claims (5)

  A release sheet used for the production process of a rubber sheet and / or protection of the rubber sheet, wherein a release layer is laminated on at least one side of a substrate, and the release layer has an acid-modified component of 1 to A release sheet, which is formed of a resin composition containing 10% by mass of an acid-modified polyolefin resin and 1 to 50 parts by mass of a crosslinking agent with respect to 100 parts by mass of the acid-modified polyolefin resin.   The release sheet according to claim 1, wherein the resin composition forming the release layer contains 1-1000 parts by mass of polyvinyl alcohol with respect to 100 parts by mass of the acid-modified polyolefin resin.   The release strength according to claim 1 or 2, wherein the peel strength between the release sheet and the crosslinked rubber sheet formed on the release sheet is 0.05 to 1.0 N / cm. Mold sheet.   The release sheet according to any one of claims 1 to 3, wherein the substrate is a polyester film.   Used as a rubber sheet containing at least one selected from urethane rubber, silicone rubber, fluorine rubber, natural rubber, styrene butadiene rubber, ethylene propylene rubber, ethylene propylene diene rubber, acrylonitrile butadiene rubber, chloroprene rubber, and acrylic rubber as components. The release sheet according to any one of claims 1 to 4, wherein the release sheet is one.