JP2016168691A - Release sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a release sheet which has excellent releasability, can suppress the glossiness of the surface of an object to be released, and can prevent glare.SOLUTION: A release sheet has a resin layer comprising an acid-modified ethylene-α-olefin copolymer and a crosslinking agent on a base material, the crosslinking agent is a carbodiimide compound and/or an oxazoline compound, and 60° glossiness of the resin layer surface is 50% or less.SELECTED DRAWING: None

Description

  The present invention relates to a release sheet.

  In recent years, release sheets have been widely used industrially. Applications of the release sheet include, for example, use of adhesive materials such as adhesive sheets and adhesive tapes, adhesive / protection surface protection materials, use of process materials for the production of the adhesive materials, printed wiring boards, flexible printed wiring boards, and multilayers. The process material use for manufacture of a printed wiring board etc., the protective material use of the polarizing plate and phase difference plate which are components for liquid crystal displays, Furthermore, the shaping | molding use of a sheet-like structure etc. are mentioned.

  Examples of the general configuration of the release sheet include those obtained by forming a resin having releasability into a film, or those obtained by laminating a release layer containing a release agent on a substrate such as a film or paper. . The release sheets of Patent Documents 1 to 3 exhibit good release properties with respect to the pressure-sensitive adhesive sheet.

  The release sheet may be used for forming a sheet made of rubber or FRP (fiber reinforced plastic), a sheet made of unsaturated polyester, or the like. In such a case, a release sheet using a matted fluorine film, a satin polyvinyl alcohol film, a sand mat, or the like is used for the purpose of obtaining a matte peeled surface by transferring the uneven shape. used. That is, when the release sheet is peeled off from the sheet after the sheet is formed, the uneven shape is transferred to the peeled surface, and a matte surface is obtained. Such a sheet having a matte surface is excellent in adhesiveness with other resins, and in addition, when used for building materials, it can express a high-class feeling and anti-glare property. There are advantages. However, in such a case, the release sheet itself is expensive, or the polyvinyl alcohol is affected by humidity, so that it may be difficult to process, or foreign matter may adhere to the release sheet. .

JP 2010-162900 A JP 2004-162048 A JP 2012-152965 A JP 2012-040707 A

  However, since the release sheets described in Patent Documents 1 and 2 have low heat resistance, when stored at a high temperature in a state of being bonded to the pressure-sensitive adhesive sheet, the release sheet strongly adheres to the pressure-sensitive adhesive sheet, and handling properties are reduced. There was a thing. In particular, when heat is applied at the time of drying after application of the pressure-sensitive adhesive or at the time of transfer of the pressure-sensitive adhesive sheet, the release sheet tends to change its releasability, which is undesirable in handling.

  In the release sheet described in Patent Document 3, since the release layer is soft, when the release sheet is wound into a roll shape, the sheet may be blocked and cannot be unwound from the roll.

  Moreover, since the roughened film described in Patent Document 4 is heavy, when the soft resin sheet is peeled off, the sheet may be stretched or torn.

  In view of the above problems, the present invention intends to provide a release sheet that can suppress the gloss of the surface of an object to be peeled and prevent glare.

  As a result of intensive studies to solve the above problems, the present inventors have reached the present invention by laminating a resin layer having a specific composition on a sheet.

That is, the gist of the present invention is as follows.
(1) A release sheet having a resin layer containing the following (i) and (ii) on a substrate and having a 60 ° gloss on the surface of the resin layer of 50% or less.
(I) Acid-modified ethylene-α-olefin copolymer (ii) Carbodiimide compound and / or oxazoline compound (2) Mass ratio of ethylene component and α-olefin component constituting acid-modified ethylene-α-olefin copolymer (Ethylene component / α-olefin component) is 60/40 to 99/1, The release sheet according to (1).
(3) The release sheet according to (1) or (2), wherein the α-olefin component is propylene or 1-butene.
(4) The content of the acid-modified component constituting the acid-modified ethylene-α-olefin copolymer is less than 1% by mass with respect to the total of the ethylene component and the α-olefin component ( The release sheet according to any one of 1) to (3).
(5) The release sheet according to any one of (1) to (4), wherein the resin layer contains fine particles having an average particle diameter of 0.1 to 10 μm.
(6) The release sheet according to (5), wherein the fine particles are non-crosslinked thermoplastic resin fine particles.

  Since the release sheet of the present invention has a low peel resistance, the surface of the material to be peeled that has been so far peeled off and could not be used like the protective film for pressure-sensitive adhesive sheets is formed with a matte effect. be able to. Therefore, in the release sheet, both high speed peelability and antiglare properties can be achieved. Moreover, since it is excellent in heat resistance, it is excellent in releasability even after heat treatment after bonding with an adhesive material or the like. Furthermore, even when wound in a roll shape, the blocking resistance is excellent.

  Therefore, when a rubber sheet, an FRP sheet, or the like is formed using the release sheet of the present invention, there is an effect that the surface of the rubber sheet, the FRP sheet, etc. after being peeled is excellent in antiglare property. In addition, a decrease in visibility can be suppressed. That is, after peeling off the release sheet of the present invention, there is an effect that printing and images on the surface of the rubber sheet and the like are not obscured.

  Hereinafter, the present invention will be described in detail.

  The release sheet of the present invention is obtained by providing a resin layer on a substrate.

The resin layer contains the following (i) and (ii).
(I) Acid-modified ethylene-α-olefin copolymer (ii) Including carbodiimide compound and / or oxazoline compound (i) is described below.

  The acid-modified ethylene-α-olefin copolymer is obtained by acid-modifying an ethylene-α-olefin copolymer, and the ethylene-α-olefin copolymer comprises an ethylene component and one or more α-olefin components. Containing.

  Examples of the α-olefin include propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene, 1-dodecene and the like can be mentioned. Among these, propylene and 1-butene are preferable from the viewpoints of economy and availability.

  In the ethylene-α-olefin copolymer, the mass ratio of the ethylene component to the α-olefin component (ethylene component / α-olefin component) is preferably 60/40 to 99/1, and 70/30 to 97. / 3 is more preferable, and 80/20 to 95/5 is still more preferable. If the mass ratio of the ethylene component and the α-olefin component is outside this range, the resulting release sheet may have poor release properties and may have high-speed peelability.

  The ethylene-α-olefin copolymer is preferably produced using a metallocene catalyst. The ethylene-α-olefin copolymer produced by this method has a narrow molecular weight distribution, a small amount of low molecular weight components, and a uniform copolymer.

  In the present invention, the ethylene-α-olefin copolymer is acid-modified from the viewpoint of improving the adhesion between the resulting resin layer and the substrate and improving the heat resistance by reacting with a crosslinking agent. is necessary. The acid modification of the ethylene-α-olefin copolymer can be performed, for example, by introducing an unsaturated carboxylic acid component into the ethylene-α-olefin copolymer.

  In the present invention, the content of the acid-modified component constituting the acid-modified ethylene-α-olefin copolymer is less than 1% by mass with respect to the total amount of the olefin component, that is, the total of the ethylene component and the α-olefin component. Is preferably 0.01% by mass or more and less than 1% by mass, more preferably 0.05% by mass or more and less than 1% by mass, and further preferably 0.1% by mass or more and less than 1% by mass. It is particularly preferable that the content is 0.2% by mass or more and less than 1% by mass. When the content of the acid-modified component is less than 0.01% by mass, the adhesion to the substrate may be insufficient, or the reaction with the crosslinking agent may be insufficient, resulting in poor heat resistance. On the other hand, when the content of the acid-modifying component is 1% by mass or more, the releasability tends to decrease. When a polyolefin resin that normally contains an ethylene component is acid-modified, the cross-linking reaction proceeds in concert. Therefore, it may be substantially difficult to produce a product having a high acid modification amount from the viewpoint of operability.

  Specific examples of the unsaturated carboxylic acid component introduced into the ethylene-α-olefin copolymer include acrylic acid, methacrylic acid, maleic acid, maleic anhydride, itaconic acid, itaconic anhydride, aconitic acid, aconitic anhydride, In addition to fumaric acid, crotonic acid, citraconic acid, mesaconic acid, allyl succinic acid, etc., at least one carboxyl group or acid anhydride in the molecule (in the monomer unit) such as half ester or half amide of unsaturated dicarboxylic acid The compound which has a physical group is mentioned. Of these, maleic anhydride, acrylic acid and methacrylic acid are preferred, and maleic anhydride is more preferred from the viewpoint of ease of introduction into the ethylene-α-olefin copolymer.

  The unsaturated carboxylic acid component only needs to be copolymerized in the ethylene-α-olefin copolymer, and the form thereof is not limited, and examples thereof include random copolymerization, block copolymerization, and graft copolymerization. It is done.

  The method for introducing the unsaturated carboxylic acid unit into the ethylene-α-olefin copolymer is not particularly limited. For example, in the presence of a radical generator, an ethylene-α-olefin copolymer and an unsaturated carboxylic acid are heated and melted to a temperature equal to or higher than the melting point of the ethylene-α-olefin copolymer, or an ethylene-α-olefin is reacted. After dissolving the copolymer and the unsaturated carboxylic acid in an organic solvent, the unsaturated carboxylic acid is added to the ethylene-α-olefin copolymer by a method of reacting by heating and stirring in the presence of a radical generator. A method of graft copolymerization may be mentioned. The former method is preferable because the operation is simple.

  Examples of the radical generator used for graft copolymerization include di-tert-butyl peroxide, dicumyl peroxide, tert-butyl hydroperoxide, tert-butyl cumyl peroxide, benzoyl peroxide, dilauryl peroxide, Examples thereof include organic peroxides such as cumene hydroperoxide, tert-butyl peroxybenzoate, ethyl ethyl ketone peroxide, and di-tert-butyl diperphthalate, and azonitriles such as azobisisobutyronitrile. These may be appropriately selected and used depending on the reaction temperature.

  In the present invention, the melt flow rate of the acid-modified ethylene-α-olefin copolymer as the resin layer production raw material is not particularly limited, but is preferably 0.01 to 500 g / 10 min at 230 ° C. and 2160 g load. 0.1 to 100 g / 10 min is more preferable, and 0.3 to 10 g / 10 min is further preferable. An acid-modified ethylene-α-olefin copolymer having a melt flow rate of less than 0.01 g / 10 min is difficult to dissolve in a solvent, whereas the melt flow rate of the acid-modified ethylene-α-olefin copolymer is difficult. Is 500 g / 10 min or more, the resulting resin layer may have poor adhesion to the substrate, and migration of low molecular weight components tends to occur on the adherend such as an adhesive.

  A commercially available ethylene-α-olefin copolymer can be used as the ethylene-α-olefin copolymer for acid modification. Examples of commercially available ethylene-α-olefin copolymers include Esprene series manufactured by Sumitomo Chemical Co., Ltd. and Tuffmer series manufactured by Mitsui Chemicals. An acid-modified ethylene-α-olefin copolymer can be obtained by performing acid modification by the above-described method using such a commercially available ethylene-α-olefin copolymer.

  A commercially available acid-modified ethylene-α-olefin copolymer may be used. Examples of commercially available acid-modified ethylene-α-olefin copolymers include MP-0620, MH-7020, MA-8510, etc., manufactured by Mitsui Chemicals, Inc.

(Ii) will be described below.
The resin layer of the release sheet of the present invention contains a crosslinking agent. As the crosslinking agent, a compound having in its molecule a plurality of functional groups that react with the acid-modified ethylene-α-olefin copolymer is used, and at least one crosslinking selected from oxazoline compounds and carbodiimide compounds from the viewpoint of reactivity. It is necessary to be an agent. When a compound other than an oxazoline compound or a carbodiimide compound is used as the cross-linking agent, the resulting resin layer has a reduced heat resistance and a tendency to lower the releasability after heat treatment.

  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, an oxazoline group-containing polymer, and the like. 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.

  Examples of commercially available products of the oxazoline group-containing polymer include EPOCROSS series manufactured by Nippon Shokubai Co., Ltd., and specifically, water-soluble type “WS-500”, “WS-700”, and solid type “RPS-”. 1005 "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.

  Examples of commercially available products of polycarbodiimide include carbodilite series manufactured by Nisshinbo Co., Ltd. Specifically, water-soluble types “SV-02”, “V-02”, “V-02-L2”, “ V-04 ", organic solution type" V-01 "," V-03 "," V-07 "," V-09 ", solventless type" V-05 ", and the like.

  The content of the crosslinking agent comprising the oxazoline compound and / or carbodiimide compound is preferably 0.1 to 50 parts by mass, and 1 to 30 parts by mass with respect to 100 parts by mass of the acid-modified ethylene-α-olefin copolymer. More preferably, it is 2 to 20 parts by mass. When the content of the cross-linking agent is less than 0.1 parts by mass, the effect of addition is poor, the releasability may deteriorate with time, and sufficient heat resistance may not be obtained. If the content exceeds 50 parts by mass, the releasability may decrease. A plurality of types of crosslinking agents can be used at the same time. When used at the same time, the total amount of the crosslinking agent only needs to satisfy the range of the content of the crosslinking agent.

  As described above, the resin layer constituting the release sheet of the present invention contains an acid-modified ethylene-α-olefin copolymer and a crosslinking agent. If necessary, a leveling agent and an antifoaming agent are used. Further, it may contain various agents such as anti-waxing agents, antistatic agents, pigment dispersants, ultraviolet absorbers, and pigments or dyes such as titanium oxide, zinc white and carbon black. In addition, organic or inorganic compounds other than those described above can be added to the liquid material and contained in the resin layer as long as the stability of the liquid material for forming the resin layer described later is not impaired.

  In the release sheet of the present invention, the thickness of the resin layer is preferably 0.01 to 5.0 μm, more preferably 0.03 to 3.0 μm, and 0.05 to 1.0 μm. Is more preferable. If the thickness of the resin layer is less than 0.01 μm, sufficient releasability may not be obtained. On the other hand, if the thickness exceeds 5.0 μm, the cost increases, which is not preferable.

  In the present invention, the method for providing the resin layer on the substrate is not particularly limited. For example, a method of preparing a liquid material containing an acid-modified ethylene-α-olefin copolymer, a crosslinking agent, and a medium, applying the liquid material on a substrate, and drying the medium is the thickness of the resin layer. It is preferable in that it can be easily made uniform and mass production is possible. Alternatively, a resin layer may be formed by melt-extruding a mixture of an acid-modified ethylene-α-olefin copolymer and a crosslinking agent on a substrate. Moreover, you may obtain a release sheet by coextruding the resin material which comprises a base material, and resin layer forming material.

  As a method of producing a liquid material containing an acid-modified ethylene-α-olefin copolymer, a crosslinking agent, and a medium, an acid-modified ethylene-α-olefin copolymer and a crosslinking agent are added to an organic solvent serving as a medium. The method of dissolving is mentioned.

  Moreover, as a method for producing a liquid material, a method in which an acid-modified ethylene-α-olefin copolymer is made into an aqueous dispersion and a crosslinking agent is mixed can be mentioned. A method for dispersing the acid-modified ethylene-α-olefin copolymer in an aqueous medium to obtain an aqueous dispersion is not particularly limited. For example, the acid-modified ethylene-α-olefin copolymer, 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 the pamphlet of International Publication No. 02/0555598 can be mentioned, and a good aqueous dispersion can be obtained by neutralizing an acid-modified ethylene-α-olefin copolymer with a basic compound in an aqueous medium. Is obtained.

  The solid content in the liquid material can be appropriately selected depending on the formation conditions, thickness, performance, and the like of the resin layer, and is not particularly limited. In order to form a layer, 1-60 mass% is preferable and 2-20 mass% is more preferable.

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

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

  As the organic filler, non-crosslinked thermoplastic resin particles are preferable. Non-crosslinked thermoplastic resin particles have the property of being deformed by heat above the glass transition temperature (Tg). In particular, fluidity is exhibited by heating to a temperature exceeding the melting point. Therefore, when non-crosslinked thermoplastic resin particles are used, the surface of the resin layer is in a state where gentle protrusions are connected, and the anti-glare property of the adherend after the release sheet is peeled off is exhibited. , Visibility is improved.

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

  When an inorganic filler, particularly amorphous inorganic particles, is used, the glossiness of the resin layer decreases, but there may be a large number of flat portions in which the inorganic particles are not present in the resin layer. Therefore, the gloss of the adherend obtained after peeling off the release sheet becomes soft. That is, it is in an appropriate state where the gloss is not too high and not too low. Specifically, the 60 ° gloss is about 30 to 50%. However, even if the glossiness of the resin layer is about the same as when using a filler other than an inorganic filler, the glossiness of the adherend obtained after peeling the release sheet may increase, In the effect of the present invention to improve the antiglare property of the wearing body, it may not be preferable.

  The content of the matting agent in the resin layer is not particularly limited and is appropriately adjusted according to the surface roughness of the base film, but with respect to 100 parts by mass of the acid-modified ethylene-α-olefin copolymer, It is preferably 5 to 30 parts by mass, and more preferably 10 to 30 parts by mass. When the content of the matting agent is less than 5 parts by mass, the glossiness of the resin layer increases, and the adherend may not exhibit antiglare properties. On the other hand, when the content of the matting agent exceeds 30 parts by mass, the matting agent may aggregate and impair the releasability of the coating film (resin layer).

  The average particle size of the matting agent in the resin layer is preferably 0.1 to 10 μm, and more preferably 0.1 to 5 μm. When the average particle size is less than 0.1 μm, the glossiness does not decrease, and the adherend may not exhibit antiglare properties. On the other hand, when it exceeds 10 μm, the dispersibility is deteriorated, and in the case of obtaining a resin layer, it may be precipitated in the coating liquid.

  The resin layer may contain a silicone compound, a fluorine compound, waxes, a surfactant and the like as long as the effects of the present invention are not impaired. In that case, the total content of the silicone compound, the fluorine compound, the wax, and the surfactant is preferably 1 part by mass or less with respect to 100 parts by mass of the acid-modified ethylene-α-olefin copolymer. The smaller the content, the better the adhesion between the resin layer and the substrate, and the contamination of the adherend is suppressed. Therefore, the content is more preferably 0.5 parts by mass or less, and 0.1 parts by mass. It is more preferable that it is as follows, and it is particularly preferable that it is not contained.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

  The 60 ° glossiness of the release sheet of the present invention having the above-described configuration needs to be 50% or less, preferably 30 to 50%, more preferably 40 to 50%. preferable. When the 60 ° glossiness exceeds 50%, the protrusion shape is not sufficiently transferred to the adherend after the release sheet is bonded to the adherend and peeled off. Therefore, the glossiness of the adherend increases and the antiglare property decreases. As a result, when this adherend is used as, for example, a building material, the appearance of a fluorescent lamp is reflected so that the printing of the base becomes invisible, or when it is used as a liquid crystal display component, the display on the touch panel surface becomes difficult to see. . That is, visibility is reduced. Even when the glossiness is too low, the visibility may be lowered.

  As a method of suppressing the gloss (glossiness) of the release sheet, a method of coating a resin layer on a substrate with large irregularities such as cloth, sand mat, coating mat, embossed sheet, etc., a resin layer on the substrate And a method of roughening the surface by adding a matting agent or a foaming agent to the resin layer, etc. It is done.

  Among the above methods, in order to suppress the gloss of the release sheet of the present invention and reduce the 60 ° gloss to 50% or less, the method of coating a resin layer on a substrate having large irregularities is most preferable. . By using such a method, an increase in cost can be suppressed and glossiness can be easily adjusted.

  In the present invention, by appropriately adjusting the type, particle size and content of the matting agent contained in the resin layer, and the thickness of the resin layer, the 60 ° gloss can be reduced to 50% or less, and the gloss is effective. Can be suppressed.

  A method for producing the release sheet of the present invention will be described below.

  The method for producing the release sheet of the present invention is not particularly limited. For example, a liquid material containing an acid-modified ethylene-α-olefin copolymer and a carbodiimide compound and / or an oxazoline compound is coated on a substrate. The manufacturing method which laminates | stacks a resin layer by drying later is mentioned. According to this method, a release sheet can be obtained industrially easily.

The method for producing a liquid material containing an acid-modified ethylene-α-olefin copolymer and a carbodiimide compound and / or an oxazoline compound is particularly limited as long as each component is uniformly mixed in a liquid medium. It is not a thing. For example, the following methods (A) and (B) can be mentioned.
(A): A method of adding a dispersion or solution of a carbodiimide compound and / or an oxazoline compound to an acid-modified ethylene-α-olefin copolymer dispersion or solution and mixing them to obtain a liquid.
(B): A method of liquefying a mixture of an acid-modified ethylene-α-olefin copolymer and a carbodiimide compound and / or an oxazoline compound.

  In the case of using the method (A), the solute concentration of the dispersion or solution of the carbodiimide compound and / or oxazoline compound is not particularly limited, but is preferably 5 to 10% by mass from the viewpoint of ease of handling. .

  When the method (B) is used, a carbodiimide compound and / or an oxazoline compound may be added when the acid-modified ethylene-α-olefin copolymer is liquefied.

  When a component other than the acid-modified ethylene-α-olefin copolymer, carbodiimide compound and / or oxazoline compound (for example, the matting agent described above) is blended, at any stage in the method of (A) or (B) Can be blended.

  When producing the release sheet of the present invention, a solvent for obtaining a dispersion or solution of an acid-modified ethylene-α-olefin copolymer, a solvent for obtaining a dispersion or solution of a carbodiimide compound and / or an oxazoline compound The solvent for making the acid-modified ethylene-α-olefin copolymer and the carbodiimide compound and / or the oxazoline compound into a liquid material is not particularly limited as long as it can be applied onto the substrate. Examples of the solvent include water, an organic solvent, or an aqueous medium containing water and an amphiphilic organic solvent. Especially, it is preferable to use water or an aqueous medium from a viewpoint of environmental impact reduction.

  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 chill, 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.

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

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

  The method for dispersing the acid-modified ethylene-α-olefin copolymer in the aqueous medium as described above is not particularly limited, and examples thereof include the method described in WO 02/055598.

  The dispersed particle size of the acid-modified ethylene-α-olefin copolymer in the aqueous medium has a number average particle size of 1 μm or less from the viewpoint of stability when mixed with other components and storage stability after mixing. Is preferably 0.8 μm or less. Such a number average particle diameter can be achieved by the production method described in the pamphlet of International Publication No. 02/055598.

  In the methods (A) and (B) described above, the solid content of the liquid material can be appropriately selected depending on the lamination conditions of the resin layer and the substrate, the thickness of the target resin layer, the performance, etc., and is particularly limited. Although not intended, 1-60 mass% is preferable and 5-30 mass% is more preferable in order to keep the viscosity of the liquid material moderate and to form a good resin layer.

  In the method of forming a resin layer by applying 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, dipping A uniform resin layer is obtained by uniformly applying a liquid material to the surface of the substrate by coating, brushing, etc., setting it at around room temperature as necessary, and then subjecting it to drying treatment or heat treatment for drying. Can be formed in close contact with the substrate.

  After the resin layer is formed on the substrate, an aging treatment may be performed in an environment controlled at a constant temperature in order to promote the reaction between the acid-modified ethylene-α-olefin copolymer and the crosslinking agent. . By performing the aging treatment, it is possible to improve the cohesiveness of the resin layer and the adhesion to the base material, and to stabilize the mold release performance. The aging temperature is preferably relatively low from the viewpoint of reducing damage to the substrate, but it is preferable to treat at a high temperature from the viewpoint of allowing the reaction to proceed sufficiently and rapidly. The aging treatment is preferably performed at 20 to 100 ° C, more preferably at 30 to 70 ° C, and further preferably at 40 to 60 ° C.

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

  The release sheet used for the pressure-sensitive adhesive material is required to have excellent releasability in handling, for example, a sheet having a peel strength of 0.5 N / cm or less from the acrylic pressure-sensitive adhesive material. It has been demanded. When the release sheet of the present invention is used for an acrylic pressure-sensitive adhesive material, the peel strength between the resin layer and the acrylic pressure-sensitive adhesive material after the acrylic pressure-sensitive adhesive material is pasted and allowed to stand is 0.5 N / cm or less, more preferably 0.4 N / cm or less, and still more preferably 0.3 N / cm or less. When the peel strength with an acrylic adhesive material exceeds 0.5 N / cm, when the release sheet is peeled from the adhesive material, resistance is felt or the adhesive surface is roughened, resulting in a decrease in adhesiveness Therefore, it may be difficult to use as a release sheet for acrylic adhesive materials.

  Moreover, it is possible to use the release sheet of this invention also with respect to the silicone type adhesive material which is a representative of the adhesive material with strong adhesive force. When a conventional silicone release sheet is used for the silicone-based adhesive material, the adhesion between the adhesive layer and the resin layer is high, so that the adhesion is increased and it is difficult to peel off. On the other hand, the release sheet of the present invention can maintain good peelability even with respect to the silicone-based adhesive material.

  Since the release sheet of the present invention is excellent in heat resistance, even if the adhesive material to which the release sheet is attached is exposed to a high temperature for a long time in the process of storage and distribution, the peel strength changes over time. No change in the peel strength between the resin layer and the adhesive material can be kept small even after a long time has elapsed after pasting.

  For example, the peel strength from the acrylic pressure-sensitive adhesive after attaching the acrylic pressure-sensitive adhesive and leaving it for 20 hours under an atmosphere of 2 kPa load and 70 ° C. can be set to 0.5 N / cm or less. The peel strength is preferably 0.4 N / cm or less, and more preferably 0.3 N / cm or less. If the peel strength exceeds 0.5 N / cm, it may be extended and deformed or torn when a soft resin such as a substrate-less pressure-sensitive adhesive sheet is peeled off.

  In the process of peeling the release sheet industrially, the release sheet is peeled at a speed generally exceeding 10 m / min as the work line speeds up. There is a need for mold sheets. Since the release sheet of the present invention has sufficient releasability, even if it is peeled from the adhesive material at a high speed, it can be peeled without sound and without feeling of resistance. That is, the release sheet of the present invention can suppress a decrease in transparency and adhesiveness due to a rough surface condition of the adhesive material due to a phenomenon called “zipping or stick-slip” during high-speed peeling. .

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

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

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

  Among the above, the release sheet of the present invention is suitably used for applications such as protective materials such as pressure-sensitive adhesive materials and liquid crystal display parts and building materials that require anti-glare properties and visibility.

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

Measurement or evaluation method (1) Unsaturated carboxylic acid component content of acid-modified ethylene-α-olefin copolymer The content of unsaturated carboxylic acid component relative to the total amount of olefin component is the method (A) or (B) shown below. Was determined using.
(A): The acid value of the acid-modified ethylene-α-olefin copolymer was measured in accordance with JIS K5407, and the content (graft ratio) of the unsaturated carboxylic acid was determined from the following formula.
Content (mass%) = (mass of grafted unsaturated carboxylic acid) / (mass of raw material polyolefin resin) × 100
(B): Infrared absorption spectrum analysis (Perkin Elmer Fourier transform infrared spectrophotometer System-2000, resolution 4 cm ⁻¹ ) was performed to determine the content of the unsaturated carboxylic acid component.

(2) Structure of acid-modified ethylene-α-olefin copolymer other than unsaturated carboxylic acid component ¹ H-NMR, ¹³ C-NMR analysis (manufactured by Varian, Inc.) in orthodichlorobenzene (d ₄ ) at 120 ° C. , 300 MHz). ^{In 13} C-NMR analysis, measurement was performed using a gated decoupling method in consideration of quantitativeness.

(3) Melt flow rate of acid-modified ethylene-α-olefin copolymer It was measured by a method based on JIS K7210 (230 ° C., 2160 g load).

(4) Peel strength for acrylic adhesive (25 ° C)
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 20 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.
Practically, the peel strength is less than 1.0 N / cm, so that the film can be peeled without resistance, and it is particularly preferably 0.5 N / cm or less.

(5) Peel strength for acrylic adhesive (70 ° C)
A sample for measuring peel strength was obtained by the method described in (4) above, except that the condition for leaving the sample was changed from an atmosphere of 25 ° C. to an atmosphere of 70 ° C. The peel strength between the adhesive tape and the release sheet of the peel strength measurement sample was measured by the method described in (4) above.
Practically, the peel strength is less than 1.0 N / cm, so that the film can be peeled without resistance, and it is particularly preferably 0.5 N / cm or less.

(6) High-speed peelability Using the sample for measuring peel strength obtained by the method described in (4) above, the release sheet portion is fixed to a stainless steel plate with a double-sided tape, and the end of the adhesive tape is attached The evaluation was performed using the following indices with the hand feeling and the sound generated at the time of peeling when held by hand and peeled at once (peeling speed of about 30 m / min).
○: No sound, no resistance, and peeling
Δ: A noise due to zipping occurs, and resistance is felt at the time of peeling, but peeling is possible.
X: A loud sound is generated by zipping, and the resistance at the time of peeling is large, so that peeling at a peeling speed of about 30 m / min is not possible.

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

(8) Number average particle size of acid-modified ethylene-α-olefin copolymer particles Microtrac particle size distribution meter (manufactured by Nikkiso Co., Ltd., trade name “UPA150”) (MODEL No. 9340, dynamic light scattering method) The number average particle size was determined. The refractive index of the resin used for particle diameter calculation was 1.57.

(9) Thickness of resin layer The thickness of the base material is determined from the total thickness of the release sheet obtained by coating the liquid material on the base material with a contact-type film thickness meter and drying to laminate the resin layer. Sought to reduce.

(10) Center plane average roughness The center plane average roughness (Sa) was measured using a light interference type non-contact surface roughness meter (made by Taylor Hobson, trade name “CCI6000”).

(11) Blocking resistance Two pieces of the obtained release sheet were cut into a size of 50 mm × 50 mm, overlapped so that the resin layer and the opposite surface of the resin layer were in contact, and a load of 10 kPa was applied at 60 ° C. Then, after leaving still for 24 hours, the load was removed and the mixture was cooled to room temperature, and then the adhesion state between the resin layer and the opposite surface of the resin layer was examined.
○: Adhesion is not observed between the two films, or the two films are easily peeled off, and no change such as whitening is observed in the resin layer.
X: The resin layer causes cohesive failure, or the resin layer after the two films are peeled off is entirely white.

(12) Antiglare property 2 g / m ^{2 of} polyester amide resin having an amino group (softening point: 160 ° C.) was applied to the surface of a melamine resin-impregnated decorative paper on which a black line having a width of 0.1 mm was printed at a pitch of 20 mm. A decorative sheet on which a polyesteramide resin layer was formed was prepared. On the polyesteramide resin layer of this decorative sheet, the following composition (a) was applied. Next, the release sheet prepared in the examples or comparative examples was used to cover the application surface of the composition (a), and the resin was cured by extending and degassing with a roller. Thereafter, the release sheet was peeled and removed to obtain a resin sheet. In addition, the thickness of the composition (a) layer after hardening was 100 micrometers.
In the obtained resin sheet, the light of the fluorescent lamp was irradiated from 30 cm directly above the surface from which the release sheet was peeled off, and the reflection of the fluorescent lamp was visually confirmed and evaluated according to the following criteria.
○: The reflected light of the fluorescent lamp is not observed as a linear band, but appears blurred.
X: The reflected light of the fluorescent lamp is clearly confirmed as a linear band.
In addition, the composition of the composition (a) is as follows.
Epoxy methacrylate (containing 20% by mass of styrene monomer) 100 parts by weight, 55% by mass
1.5 parts by weight of methyl ethyl ketone peroxide, 0.15 parts by weight of 8% by weight cobalt octylate

(13) Visibility In the resin sheet prepared in the antiglare evaluation of (11), the perpendicular line connecting the fluorescent lamp and the irradiated surface is irradiated with light from the fluorescent lamp from 30 cm directly above the release sheet. The irradiated surface was observed from a direction forming an angle of 45 °. The visibility of the black line printed on the surface of the melamine resin-impregnated decorative paper constituting the resin sheet was visually confirmed and evaluated according to the following criteria: ○: The black line is clearly visible in a straight line.
Δ: The presence of a black line can be confirmed, but it appears blurred.
X: The presence of a black line cannot be confirmed.

(14) Glossiness Using a gloss meter (trade name “True GlOSS GM-26PRO” manufactured by Murakami Color Research Laboratory), the 60 ° glossiness of the resin layer surface was measured.

(Matting agent)
Polypropylene filler (manufactured by Trial, “TRL-PP-101”, average particle size: 1.8 μm) (hereinafter sometimes referred to as “TRL-PP”)
(Base material)
-Biaxially stretched polyester film (manufactured by Unitika, “Emblet S-38”, thickness: 38 μm, center plane average roughness: 0.035 μm) (hereinafter sometimes referred to as “S-38”)
Polyester film (manufactured by Unitika Ltd., “Emblet PTH-38”, thickness: 38 μm, center plane average roughness: 0.200 μm) (hereinafter sometimes referred to as “PTH-38”)
Polyester film (manufactured by Unitika Ltd., “Embret PTHA-25”, thickness: 25 μm, center plane average roughness: 0.240 μm) (hereinafter sometimes referred to as “PTHA-25”)
・ Sandmat film (product of Unitika, “Emblet SM-38”, thickness: 38 μm, center surface average roughness: 0.360 μm) (hereinafter sometimes referred to as “SM-38”)
The following were used as the resin constituting the resin layer.

P-1:
100 g of an ethylene-propylene copolymer (ethylene / propylene = 75/25% by mass) was dissolved in 400 g of xylene heated to 130 ° C. in a four-necked flask under a nitrogen atmosphere. Next, 10 g of a toluene solution of maleic anhydride (5% by mass) and 5 g of a toluene solution of dicumyl peroxide (10% by mass) were respectively added to this solution over 30 minutes, and then the system was kept at 130 ° C. The reaction was performed for 4 hours. After completion of the reaction, the obtained reaction product was put into a large amount of acetone to precipitate a resin. The resin was further washed several times with acetone to remove unreacted maleic anhydride and then dried under reduced pressure, and acid-modified ethylene-α-olefin copolymer P-1 obtained by drying under reduced pressure was used.

P-2:
In the production of P-1, the same except that the ethylene-propylene copolymer (ethylene / propylene = 75/25% by mass) was changed to the ethylene-propylene copolymer (ethylene / propylene = 55/45% by mass). The acid-modified ethylene-α-olefin copolymer P-2 obtained by the operation was used.

P-3:
In the production of P-1, except that the ethylene-propylene copolymer (ethylene / propylene = 75/25 mass%) was changed to the ethylene-butene copolymer (ethylene / 1-butene = 70/30 mass%), The acid-modified ethylene-α-olefin copolymer P-3 obtained by performing the same operation was used.

P-4:
In the production of P-1, the same operation was carried out except that the ethylene-propylene copolymer (ethylene / propylene = 75/25% by mass) was changed to ethylene- (ethylene / propylene = 90/10% by mass). The obtained acid-modified ethylene-α-olefin copolymer P-4 was used.

P-5:
In the production of P-1, an acid-modified ethylene-α-olefin copolymer P-5 obtained by performing the same operation except that the amount of the maleic anhydride toluene solution (5% by mass) was changed to 20 g. It was used.

P-6:
In the production of P-1, an acid-modified ethylene-α-olefin resin P-6 obtained by performing the same operation except that the amount of the maleic anhydride toluene solution (5% by mass) was changed to 3 g was used. did.

P-7:
In the production of P-1, the same operation was carried out except that the amount of the maleic anhydride toluene solution (5% by mass) was changed to 40 g and the amount of the dicumyl peroxide toluene solution (10% by mass) was changed to 7 g. The acid-modified ethylene-α-olefin copolymer P-7 obtained above was used.

P-8:
In the production of P-1, except that the ethylene-propylene copolymer (ethylene / propylene = 75/25% by mass) was changed to the propylene-1-butene copolymer (propylene / butene = 70/30% by mass), An acid-modified propylene-α-olefin copolymer P-8 obtained by performing the same operation was used.

P-9:
Bondine “LX-4110” (maleic anhydride-modified polyethylene resin) manufactured by Arkema Inc. was used.

P-10:
A non-acid-modified ethylene-propylene copolymer (ethylene / propylene = 70/30% by mass) was used.

P-11:
Claprene “LIR-403” (acid-modified polyisoprene, number average molecular weight 34000, acid value 9 to 11 mgKOH / g) manufactured by Kuraray Co., Ltd. was used.

  Table 1 shows the compositions and characteristics of the resins P-1 to P-11 constituting the resin layer.

Example 1
The acid-modified ethylene-α-olefin copolymer P-1 was dissolved in toluene to prepare a 2% by mass solution. An acid-modified ethylene-α-olefin copolymer and a solution of an oxazoline compound (manufactured by Nippon Shokubai Co., Ltd., Epocros “WS-500”, solid content concentration: 39% by mass, diluted with isopropanol), Using a Meyer bar on the corona-treated surface of the polyester film PTH-38, a liquid material obtained by mixing 2 parts by mass with respect to 100 parts by mass of the acid-modified ethylene-α-olefin copolymer. After coating, the film was dried at 150 ° C. for 90 seconds to form a 0.2 μm thick resin layer on the film, and then subjected to aging at 70 ° C. for 7 days to obtain a release sheet.

Examples 2-13, Comparative Examples 1, 3, 5, 6
Except for changing the type of acid-modified ethylene-α-olefin copolymer, the type and content of the crosslinking agent, and the type of the base film as shown in Table 2, the same operation as in Example 1 was performed, A release sheet was obtained. In addition, carbodilite “V-03” (solid content concentration: 50 mass%) manufactured by Nisshinbo Co., Ltd. was used as a crosslinking agent composed of a carbodiimide compound.

Example 14
The same operation as in Example 1 except that TRL-PP-101 was used as a matting agent and a toluene solution was prepared so that the solid content was 20 parts by mass relative to 100 parts by mass of the acid-modified ethylene-α-olefin copolymer. To obtain a release sheet.

Comparative Example 2
60.0 g of maleic anhydride-modified polyethylene resin P-9 (manufactured by Arkema, Bondine “LX-4110”), 90.0 g Isopropanol, 3.0 g of triethylamine and 147.0 g of distilled water were charged into a glass container, and the rotation speed of the stirring blade was set to 300 rpm. Then, the system temperature was kept at 140 to 145 ° C. and further stirred for 30 minutes. Then, after putting in a water bath and cooling to room temperature (about 25 ° C.) while stirring at a rotational speed of 300 rpm, pressure filtration (air pressure 0.2 MPa) with a 300 mesh stainless steel filter (wire diameter 0.035 mm, plain weave) Thus, a milky white uniform acid-modified polyethylene resin aqueous dispersion E-1 was obtained.
Other than mixing the obtained acid-modified polyethylene resin aqueous dispersion E-1 and the solution of the oxazoline compound so that the solid content of the oxazoline compound is 5 parts by mass with respect to 100 parts by mass of the acid-modified polyethylene resin. Performed the same operation as Example 1 to obtain a release sheet.

Comparative Example 4
60.0 g of acid-modified polyisoprene P-11 (manufactured by Kuraray Co., Ltd., Claprene “LIR-403”), 60.0 g of isopropanol, 15 g of triethylamine and 165 g of distilled water were charged into a glass container and heated while stirring at a rotation speed of a stirring blade of 300 rpm, and 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 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 was obtained. Except that the obtained acid-modified polyisoprene aqueous dispersion and oxazoline compound solution were mixed so that the solid content of the oxazoline compound was 5 parts by mass with respect to 100 parts by mass of the acid-modified polyethylene resin. The same operation as 1 was performed to obtain a release sheet.

Comparative Example 7
In Example 1, instead of the solution of the oxazoline compound, a solution obtained by diluting an isocyanate compound (BASF Corporation, Basonat “HW-100”, solid content concentration: 100 mass%) with isopropanol was used, and acid-modified ethylene-α- A release sheet was obtained in the same manner as described above except that the mixture was mixed to 100 parts by mass with respect to 100 parts by mass of the olefin copolymer.

Comparative Example 8
In Example 1, instead of the solution of the oxazoline compound, an epoxy compound (manufactured by DIC, EPICLON “860-90X”, solid concentration: 90% by mass) diluted with isopropanol was used, and acid-modified ethylene-α -A release sheet was obtained in the same manner as described above except that the mixture was mixed with 100 parts by mass of the olefin copolymer so as to be 5 parts by mass.

Comparative Example 9
In Example 1, instead of the solution of the oxazoline compound, a solution obtained by diluting a melamine compound (Nippon Cytec Industries, Cymel “325”, solid content concentration: 80% by mass) with isopropanol was used. -A release sheet was obtained in the same manner as described above except that the mixture was mixed to 100 parts by mass with respect to 100 parts by mass of the olefin copolymer.

  Table 2 shows the sheet configurations and evaluation results of Examples and Comparative Examples.

  A release sheet provided with a resin layer containing an acid-modified ethylene-α-olefin copolymer and an amount of a crosslinking agent specified in the present invention on Examples 1 to 14 on a base film is It was excellent in blocking property, releasability and high-speed peelability. Furthermore, since the 60 ° glossiness of the resin layer surface was 50% or less, the antiglare property and the visibility were good.

On the other hand, when a resin that does not contain an ethylene component and an α-olefin component at the same time is used as the resin constituting the resin layer (Comparative Examples 1 and 2), the obtained release sheet has a release property and a high-speed release property. It was inferior to. Moreover, when what was not acid-modified is used as resin which comprises a resin layer (comparative example 3), the obtained release sheet was inferior in heat resistance, and the release property fell remarkably by heat processing.
When acid-modified polyisoprene is used as the resin constituting the resin layer (Comparative Example 4), the obtained release sheet has excellent release properties, heat resistance, and residual adhesiveness, but has blocking resistance. Remarkably reduced. When the resin layer did not contain a crosslinking agent (Comparative Example 5), the release property of the release sheet was remarkably lowered by the heat treatment.
Moreover, when the 60 degree glossiness of the resin layer surface did not satisfy the range prescribed in the present invention (Comparative Example 6), the antiglare property was inferior.
When a crosslinking agent not specified in the present invention was used (Comparative Examples 7 to 9), the obtained release sheets were inferior in heat resistance, and the release properties were lowered by heat treatment.

Claims (6)

A release sheet having a resin layer containing the following (i) and (ii) on a substrate and having a 60 ° glossiness of 50% or less on the surface of the resin layer.
(I) Acid-modified ethylene-α-olefin copolymer (ii) Carbodiimide compound and / or oxazoline compound The mass ratio (ethylene component / α-olefin component) of the ethylene component and the α-olefin component constituting the acid-modified ethylene-α-olefin copolymer is 60/40 to 99/1. Item 1. The release sheet according to Item 1. The release sheet according to claim 1 or 2, wherein the α-olefin component is propylene or 1-butene. The content of the acid-modified component constituting the acid-modified ethylene-α-olefin copolymer is less than 1% by mass with respect to the total of the ethylene component and the α-olefin component. 3. The release sheet according to any one of 3. The release sheet according to any one of claims 1 to 4, wherein the resin layer contains fine particles having an average particle diameter of 0.1 to 10 µm. 6. The release sheet according to claim 5, wherein the fine particles are non-crosslinked thermoplastic resin fine particles.