TW201522042A - Release sheet - Google Patents

Abstract

This invention provides a release sheet constituted by providing a resin layer on substrate, wherein, the resin layer includes an acid-modified ethylene-[alpha]-olefin copolymer 100 parts by mass and a crosslinker 0.1 to 50 parts by mass, the crosslinker being constituted by an oxazoline compound and/or a carbodiimide compound.

Description

Release sheet

The present invention relates to a release sheet.

The adhesive sheet is used in various types of applications, including the manufacturing steps of electronic components such as semiconductor devices and precision machines. The adhesive sheet is such that the surface of the adhesive sheet is adhered to the laminated sheet until it is used.

The surface of the base material constituting the release sheet is provided with a resin layer containing a release agent in order to be easily peeled off from the adhesive sheet. A release agent for release sheets is most often used as a release agent. However, when a polyoxynitride type release agent is used, the low molecular weight polyoxynitride contained in the polyoxygen type release agent may move to the surface of the adhesive sheet of the adhesive sheet and remain. It has been pointed out that the polyoxynitride compound remaining on the surface of the adhesive of the adhesive sheet not only causes a decrease in the adhesive force of the adhesive, but also vaporizes slowly, for example, on the surface of an electronic component using an adhesive sheet, and thus Its performance has an adverse effect.

In the non-polyoxyl-based release agents for release sheets, it has been proposed to use olefin-based elastomers in Patent Documents 1 and 2, and it has been proposed to use acid-modified polyolefins in Patent Documents 3 and 4. Further, Patent Document 5 has proposed the use of acid-modified polybutadiene or acid-modified polyisoprene.

The release sheets of Patent Documents 1 and 2 exhibit good release properties for the adhesive sheet. However, since such a release sheet is low in heat resistance, it may be strongly adhered to the adhesive sheet when it is stored at a high temperature in a state of being bonded to the adhesive sheet, and the workability may be lowered. In particular, when drying after applying the adhesive, or when transferring the adhesive sheet, if the heat is applied, the release property of the release sheet is liable to change, and the operation is not preferable.

On the other hand, in the release sheets of Patent Documents 3 and 4, an acid-modified ethylene-based polymer is used as a release agent, and good release properties are exhibited for various types of adherends. However, since the peeling strength of the adhesive sheet is slightly large, the workability in peeling off the adhesive sheet may be poor, and in particular, when the release sheet is peeled off at a high speed from the adhesive sheet, peeling may occur, and adhesion may be caused. Smoothness or transparency of the surface of the sheet.

The release sheet of Patent Document 5 is excellent in release property to the adhesive, but the release layer is soft. Therefore, when the release sheet is wound into a roll, the sheet is pressed, and there is a fear that it cannot be rolled from the roll. Out of production problems.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent No. 4907724

[Patent Document 2] Japanese Patent No. 4367082

[Patent Document 3] Japanese Patent Laid-Open Publication No. 2009-101680

[Patent Document 4] Japanese International Publication No. 2009/025063

[Patent Document 5] Japanese Patent Laid-Open Publication No. 2012-152965

In view of the above problems, the present invention is intended to provide a release sheet which is excellent in release property from an adhesive material, has excellent workability even at high speed, and is excellent in heat resistance and pressure resistance.

The present inventors have solved the above problems, and as a result of intensive research, it has been found that an acid-modified ethylene-α-olefin copolymer is used as a release agent, and a resin layer containing the specific crosslinking agent is provided on the substrate. The above-mentioned release sheet can solve the above problems, and the present invention is finally completed.

That is, the gist of the present invention is as follows.

(1) A release sheet which is a release sheet provided with a resin layer on a substrate, and the resin layer contains 100 parts by mass of an acid-modified ethylene-α-olefin copolymer and a crosslinking agent 0.1 to 50 parts by mass, cross-linking agent It is composed of an oxazoline compound and/or a carbodiimide compound.

(2) The release sheet according to item (1), wherein 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.

(3) The release sheet according to item (1) or (2), wherein the α-olefin component is propylene or 1-butene.

(4) The release sheet according to any one of (1) to (3) wherein the content of the acid-modified component constituting the acid-modified ethylene-α-olefin copolymer is relative to the ethylene component and α- The total of the olefin components is less than 1% by mass.

(5) The release sheet according to any one of (1) to (4), wherein the substrate is any one of a resin material, paper, synthetic paper, cloth, metal material, and glass material. By.

(6) The release sheet according to item (5), wherein the resin material is a polyester resin film.

The release sheet of any one of (1) to (6), wherein the peeling strength of the resin layer and the acrylic pressure-sensitive adhesive material is 0.5 N/cm or less.

By using the release sheet of the present invention, the surface of the adhesive of the adhesive material can be protected, and when the adhesive material is used, even if the release sheet is peeled off at a high speed, the quality of the adhesive material can be easily peeled off without damaging the quality of the adhesive material. Since the release sheet of the present invention is excellent in heat resistance, it is excellent in release property after heat treatment after bonding with an adhesive material or the like. Further, the release sheet of the present invention is excellent in blocking resistance even when wound into a roll shape.

Hereinafter, the present invention will be described in detail.

The release sheet of the present invention is composed of a substrate and a resin layer provided thereon. Then, the resin layer contains an acid-modified ethylene-α-olefin copolymer and a crosslinking agent.

The acid-modified ethylene-α-olefin copolymer is an acid-modified ethylene-α-olefin copolymer, and the ethylene-α-olefin copolymer contains an ethylene component and one or more α-olefin components.

The α-olefin may, for example, be propylene, 1-butene, 1-pentene or 1-hexene. 4-methyl-1-pentene, 1-heptene, 1-octene, 1-decene, 1-decene, 1-undecene, 1-dodecene, and the like. Among these, propylene and 1-butene are preferred from the viewpoint of economy or ease of availability.

The mass ratio of the ethylene component to the α-olefin component (ethylene component/α-olefin component) in the ethylene-α-olefin copolymer is preferably from 60/40 to 99/1, more preferably from 70/30 to 97/3. 80/20 to 95/5 is the best. When the mass ratio of the ethylene component to the α-olefin component is outside this range, the release sheet obtained may have a reduced release property, and the high-speed peelability may be lowered.

The ethylene-α-olefin copolymer is preferably produced by using a ferrocene-based 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 uniform copolymerization.

In the present invention, the ethylene-α-olefin copolymer is required to improve the heat resistance of the resin layer obtained by the adhesion between the resin layer and the substrate and to improve the heat resistance by reacting with the crosslinking agent. The acid modification of the ethylene-α-olefin copolymer can be carried out, 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, that is, the total amount of the ethylene component and the α-olefin component, is less than 1% by mass based on the total amount of the olefin component. Preferably, it 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 particularly preferably 0.1% by mass or more and less than 1% by mass. The mass% or more and less than 1 mass% are the most preferable. When the content of the acid-modified component is less than 0.01% by mass, the adhesion to the substrate may be insufficient, the reaction with the crosslinking agent may be insufficient, and the heat resistance may be poor. on the other hand, When the content of the acid-modified component is 1% by mass or more, the release property tends to be lowered. When the polyolefin resin containing a general ethylene component is acid-modified, the crosslinking reaction is also carried out at the same time. Therefore, in order to produce a high acid-modified quality, it may be substantially difficult from the viewpoint of workability.

Specific examples of the unsaturated carboxylic acid component to be introduced into the ethylene-α-olefin copolymer include, for example, acrylic acid, methacrylic acid, maleic acid, maleic anhydride, itaconic acid, itaconic anhydride, aconitic acid, and aconite. In addition to anhydrides, fumaric acid, crotonic acid, citraconic acid, mesaconic acid, allyl succinic acid, etc., such as semi-esters of unsaturated dicarboxylic acids, hemi-amines, etc., in the molecule (in monomer units) A compound having at least one carboxyl group or an acid anhydride group. Among them, maleic anhydride, acryl acid, and methacrylic acid are preferred from the viewpoint of easiness of introduction into the ethylene-α-olefin copolymer, and maleic anhydride is more preferable.

The unsaturated carboxylic acid component is not particularly limited as long as it is copolymerized in the ethylene-α-olefin copolymer, and examples thereof include random copolymerization, block copolymerization, and branched copolymerization.

The method of introducing the unsaturated carboxylic acid unit into the ethylene-α-olefin copolymer is not particularly limited. For example, a method of heating and melting an ethylene-α-olefin copolymer and an unsaturated carboxylic acid to a melting point or higher of an ethylene-α-olefin copolymer in the presence of a radical generating agent, or ethylene-α - a method in which an olefin copolymer and an unsaturated carboxylic acid are dissolved in an organic solvent, heated, stirred, and reacted in the presence of a radical generating agent, whereby an ethylene-α-olefin copolymer and an unsaturated carboxylic acid are separated. The method of branch copolymerization. From the point of ease of operation, the former method is preferred.

The radical generator used in the branch copolymerization may, for example, be peroxidized Di-tert-butyl, dicumyl peroxide, tert-butyl hydroperoxide, tributyl cumyl peroxide, benzammonium peroxide, dilauryl peroxide, hydroperoxide Organic peroxides such as cumene, butyl peroxybenzoate, ethyl ethyl ketone peroxide, di-tert-butyl dihalide, or azo such as azobisisobutyronitrile Nitrile. These are preferably selected depending on the reaction temperature.

In the present invention, the melt flow rate of the acid-modified ethylene-α-olefin copolymer of the resin layer production raw material is not particularly limited, and is preferably 0.01 to 500 g/10 min at 230 ° C and 2160 g load, and 0.1. It is more preferably 100 g/10 min, and most preferably 0.3 to 10 g/10 min. The acid-modified ethylene-α-olefin copolymer having a melt flow rate of less than 0.01 g/10 minutes is hardly soluble in the solvent, and on the other hand, the melt flow rate of the acid-modified ethylene-α-olefin copolymer is 500 g. When the resin layer obtained is at least /10 minutes or more, the adhesion to the substrate may be lowered, and the adherend such as an adhesive may easily cause movement of the low molecular weight component.

Commercially available ethylene-α-olefin copolymers can be used for the acid-modified ethylene-α-olefin copolymer. The ethylene-α-olefin copolymer of the market is, for example, the ESPRENE series manufactured by Sumitomo Chemical Co., Ltd., and the TAFMER series manufactured by Mitsui Chemicals Co., Ltd., and the like. The acid-modified ethylene-α-olefin copolymer can be obtained by acid modification using the commercially available ethylene-α-olefin copolymer by the above method.

Acid-modified ethylene-α-olefin copolymers can also be used by marketers. The commercially available acid-modified ethylene-α-olefin copolymer may, for example, be MP-0620, MH-7020 or MA-8510 of the TAFMER series manufactured by Mitsui Chemicals.

The resin layer of the release sheet of the present invention contains a crosslinking agent. The crosslinking agent can be used for a compound having a plurality of functional groups reactive with the acid-modified ethylene-α-olefin copolymer in the molecule, and must be selected from the viewpoint of reactivity. At least one crosslinking agent of the oxazoline compound or the carbodiimide compound. If the crosslinker is used Since the cross-linking reaction is insufficient in the cross-linking agent other than the oxazoline compound or the carbodiimide compound, the heat resistance of the obtained resin layer is lowered, and the release property after heat treatment tends to be lowered.

The oxazoline compound has two or more molecules in the molecule. The oxazoline group is not particularly limited. For example, 2,2'-double (2- Oxazoline), 2,2'-ethylene-bis(4,4'-dimethyl-2- Oxazoline), 2,2'-p-phenylene-bis(2- Oxazoline), double (2- Oxazolinylcyclohexane) thioether An oxazolyl compound or a compound An oxazoline-based polymer. One or two or more of these may be used. Among these, it is easy to handle to contain An oxazoline group polymer is preferred.

contain An oxazolyl-based polymer can be obtained by making 2-vinyl-2- Oxazoline, 2-vinyl-4-methyl-2- Oxazoline, 2-isopropenyl-2- Addition polymerization of oxazoline The oxazoline is obtained by polymerization. Other monomers may also be copolymerized as needed. contain The polymerization method of the oxazoline group polymer is not particularly limited, and various known polymerization methods can be employed.

contain For example, the Epocros series manufactured by Nippon Shokubai Co., Ltd. may be, for example, a water-soluble type "WS-500", "WS-700", or a solid type "RPS-1005".

The carbodiimide compound is not particularly limited as long as it has at least two or more carbonyldiamine imine groups in the molecule. Can be cited Such as p-phenyl-bis(2,6-dimethylphenylcarbodiimide), tetramethylene-bis(t-butylcarbonyldiimide), cyclohexane-1,4-bis ( A carbodiimide group-containing compound such as methylene-tert-butylcarbonyldiimide or a polycarbodiimide having a carbonyldiamine-imine group. One or two or more of these may be used. Among these, from the viewpoint of easy handling, polycarbodiimide is preferred.

The production method of polycarbodiimide is not particularly limited. The polycarbodiimide is produced, for example, by a condensation reaction involving decarbonation of an isocyanate compound. The isocyanate compound is not limited, and any of an aliphatic isocyanate, an alicyclic isocyanate, and an aromatic isocyanate may be used. The isocyanate compound may be copolymerized with a polyfunctional liquid rubber or a polyalkylene glycol or the like as needed.

For example, the Carbodilite series manufactured by Nisshinbo Co., Ltd., for example, "SV-02", "V-02", "V-02-L2", and "V-", which are water-soluble types, may be mentioned. 04", "V-01", "V-03", "V-07", "V-09", and "V-05" without solvent.

100 parts by mass relative to the acid-modified ethylene-α-olefin copolymer The content of the crosslinking agent composed of the oxazoline compound and/or the carbodiimide compound must be 0.1 to 50 parts by mass, preferably 1 to 30 parts by mass, more preferably 2 to 20 parts by mass. When the content of the crosslinking agent is less than 0.1 part by mass, the addition effect may be insufficient, the release property may be lowered with time, or sufficient heat resistance may not be obtained, and if the content exceeds 50 parts by mass, the release property may be lowered. The cross-linking agent may be used in a plurality of types at the same time, and at the same time, as long as the total amount of the cross-linking agent satisfies the range of the above-mentioned cross-linking agent content.

The resin layer constituting the release sheet of the present invention contains an acid-modified ethylene-α-olefin copolymer and a crosslinking agent as described above, but may also contain a leveling agent, an antifoaming agent, and anti-foaming as needed. Various agents such as a solvent, an antistatic agent, a pigment dispersant, and an ultraviolet absorber, or a pigment or dye such as titanium oxide, zinc white or carbon black. The organic or inorganic compound other than the above may be added to the liquid material in the range of the stability of the liquid material for forming the resin layer to be described later, and may be contained in the resin layer.

The thickness of the resin layer in the release sheet of the present invention is preferably 0.01 to 5.0 μm, more preferably 0.03 to 3.0 μm, and most preferably 0.05 to 1.0 μm. When the thickness of the resin layer is less than 0.01 μm, sufficient release property may not be obtained. On the other hand, if the thickness exceeds 5.0 μm, the cost will increase, which is not preferable.

In the present invention, a method of providing a resin layer on a substrate is not particularly limited. For example, by preparing a liquid material containing an acid-modified ethylene-α-olefin copolymer, a crosslinking agent and a medium, and applying the liquid to a substrate to dry the medium, the thickness of the resin layer is uniform. And can be mass produced, preferably. Alternatively, a mixture of an acid-modified ethylene-α-olefin copolymer and a crosslinking agent may be melted onto a substrate to form a resin layer. A release sheet can also be obtained by coextruding a resin material constituting the substrate with a resin layer forming material.

The medium for preparing the liquid material containing the acid-modified ethylene-α-olefin copolymer and the crosslinking agent can be used as an organic solvent capable of dissolving or dispersing the acid-modified ethylene-α-olefin and the crosslinking agent. The process of film formation is dried, whereby it is removed. From the viewpoint of efficient removal from the coating film, The boiling point of the organic solvent is preferably 150 ° C or lower. An organic solvent having a boiling point of more than 150 ° C tends to be difficult to disperse from the coating film by drying, and in particular, the adhesion of the coating film or the physical properties of the coating film may be lowered.

The organic solvent may, for example, be acetone, methyl ethyl ketone, diethyl ketone (3-pentanone), methyl propyl ketone (2-pentanone), isobutyl ketone or methyl isobutyl ketone (4). Ketones such as -methyl-2-pentanone), 2-hexanone, 5-methyl-2-hexanone, 2-heptanone, 3-heptanone, 4-heptanone, cyclopentanone, cyclohexanone Oral hydrocarbons such as toluene, xylene, benzene, Solvesso 100, Solvesso 150; aliphatic hydrocarbons such as butane, pentane, hexane, cyclohexane, heptane, octane, decane; Methyl chloride, chloroform, carbon tetrachloride, 1,2-dichloroethane, 1,1,2,2-tetrachloroethane, chlorobenzene, o-dichlorobenzene, m-dichlorobenzene, p-di Halogen-containing such as chlorobenzene; methyl acetate, ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, acetic acid-second butyrate, acetic acid-third Ester, 3-methyloxybutyl acetate, methyl propionate, ethyl propionate, dimethyl carbonate, diethyl carbonate, γ-butyrolactone, isophorone, etc.; methanol, ethanol, N-propanol, isopropanol, n-butanol, isobutanol, second-butanol, third-butanol, n-pentanol, isoamyl alcohol, second-pentanol Third-pentanol, 1-ethyl-1-propanol, 2-methyl-1-butanol, n-hexanol, cyclohexanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, B Alcohols such as diol monopropyl ether and ethylene glycol monobutyl ether; tetrahydrofuran, 1,4-two Ethers such as alkane; dimethylformamide, dimethylacetamide, diacetone alcohol, acetonitrile, others, diethylamine containing ammonia, triethylamine, diethanolamine, triethanolamine, N, N - dimethylethanolamine, N,N-diethylethanolamine, N-diethanolamine, 3-methoxypropylamine, 3-diethylaminopropylamine, dimethylaminopropylamine, etc. Organic amine compounds; and the like.

Among them, aromatic hydrocarbons such as toluene, xylene, benzene, Solvesso 100, and Solvesso 150, butane, pentane, hexane, and cyclohexane are used from the viewpoint of obtaining a stable liquid material and facilitating coating. An aliphatic hydrocarbon such as heptane, octane or decane is preferred, and toluene is particularly preferred from the viewpoint of solubility.

In addition, from the viewpoints of the improvement of the stability of the liquid material, the improvement of the solubility, the coating property of the substrate, and the improvement of the coating appearance, two or more kinds of the above organic solvents may be used in combination. When two or more types of organic solvents are used, it is preferred to use an aromatic hydrocarbon, an alcohol, and/or a ketone in combination. When two or more types of organic solvents are used, the aromatic hydrocarbons are preferably toluene, xylene or the like, and the alcohols are preferably methanol, ethanol, n-propanol, isopropanol, n-butanol or isobutanol. The ketone is preferably acetone, methyl ethyl ketone, isobutyl ketone, methyl isobutyl ketone or the like.

By using these solvents in combination, the leveling property can be improved, the interference fringes of the coating film can be solved, and a release sheet excellent in coating appearance can be obtained. When a release sheet having interference fringes is used, there is a possibility that the interference fringe is transferred to the surface of the adhesive or the like, and it may not be used for the optical material.

The mixing ratio in the case of mixing two or more kinds of organic solvents is not particularly limited, and the mass ratio of the aromatic hydrocarbon solvent to the alcohol and/or the ketone ((aromatic hydrocarbon solvent) / (alcohol and/or ketone) It is preferably from 99/1 to 50/50, more preferably from 97/3 to 70/30, and most preferably from 95/5 to 80/20.

The method of applying a liquid to a substrate to form a resin layer is carried out by a known method such as gravure roll coating, reverse roll coating, Wire bar coating, lip coating, air knife coating, curtain coating, spray coating, dip coating, blade coating, etc., so that the liquid is uniformly applied to the surface of the substrate, and after being placed at room temperature as needed, It is supplied to a drying process or a heat treatment for drying, whereby a uniform resin layer can be formed by adhering to a substrate.

After the resin layer is formed on the substrate, in order to promote the reaction between the acid-modified ethylene-α-olefin copolymer and the crosslinking agent, the aging treatment may be carried out under an environment controlled to a certain temperature. The aging temperature is preferably from the viewpoint of reducing the damage to the substrate, and is preferably a high temperature treatment from the viewpoint of allowing the reaction to proceed sufficiently and rapidly. The aging treatment is preferably carried out at 20 to 100 ° C, more preferably 30 to 70 ° C, and most preferably 40 to 60 ° C.

A method for producing a liquid containing an acid-modified ethylene-α-olefin copolymer, a crosslinking agent and a medium, for example, dissolving an acid-modified ethylene-α-olefin copolymer and a crosslinking agent in an organic solvent serving as a medium The method.

Further, a method for producing a liquid material may, for example, be a method in which an acid-modified ethylene-α-olefin copolymer is an aqueous dispersion and a crosslinking agent is mixed. The method of dispersing the acid-modified ethylene-α-olefin copolymer in an aqueous medium and obtaining the aqueous dispersion is not particularly limited, and for example, an acid-modified ethylene-α-olefin copolymer or an organic solvent is introduced into a container that can be sealed. A method of forming an aqueous dispersion by maintaining the temperature in the tank at a temperature of about 40 to 150 ° C while stirring the raw material such as water. For example, a method described in International Publication No. 02/055598 can be used to neutralize an acid-modified ethylene-α-olefin copolymer by using a basic compound in an aqueous medium to obtain a good aqueous dispersion.

The content of the solid component in the liquid can be based on the resin layer The formation conditions, thickness, performance, and the like are appropriately selected, and are not particularly limited, but the viscosity of the liquid material is moderately maintained, and a good resin layer is formed, preferably from 1 to 60% by mass, and from 2 to 20% by mass. For better.

The base material constituting the release sheet may be formed, for example, of a resin material, paper, synthetic paper, cloth, metal material, glass material or the like. The thickness of the substrate is not particularly limited and is generally preferably from 1 to 1000 μm, more preferably from 1 to 500 μm, still more preferably from 10 to 200 μm, still more preferably from 25 to 100 μm.

The resin material to be used for the substrate may, for example, be a polyester resin such as polyethylene terephthalate (PET), polyethylene terephthalate (PEN) or polylactic acid (PLA) as a thermoplastic resin. Polyolefin resin such as polypropylene; polystyrene resin; polyamine resin such as nylon 6, poly-m-phenylphenyl hexamethylenediamine (MXD6 nylon); polycarbonate resin; polyacrylonitrile resin; A quinone imine resin; a laminate of such resins (for example, nylon 6/MXD6 nylon/nylon 6, nylon 6/ethylene-vinyl alcohol copolymer/nylon 6) or a mixture.

The resin material can also be subjected to elongation treatment. Among them, the base material is preferably a polyester resin film excellent in mechanical properties and thermal properties, and is inexpensive and easily available, and a polyethylene terephthalate film is preferable.

When the liquid crystal is applied to the thermoplastic resin film, it may be dried or heat-treated after being applied to the film which is biaxially stretched, or may be applied to the unstretched film before the end of the alignment or the film which is terminated by the one-axis extension. After drying, it is heated to extend, or heated to extend and terminate the alignment simultaneously with drying. The latter unstretched film, or one-axis extension After the liquid material is applied to the film, the method of drying and stretching is preferably carried out by laminating the resin layer simultaneously with the film formation of the thermoplastic resin film, which is preferable in terms of cost.

The thermoplastic resin film may also contain a known additive or stabilizer, such as an antistatic agent, a plasticizer, a lubricant, an antioxidant, or the like. The thermoplastic resin film may be vapor-deposited with cerium oxide, aluminum oxide, or the like, or may be laminated with another layer such as a barrier layer or an easy-adhesion layer, an antistatic layer, or an ultraviolet absorbing layer. The adhesion to other materials may be good, and the surface of the thermoplastic resin film may be subjected to corona treatment, plasma treatment, ozone treatment, pharmaceutical treatment, solvent treatment, or the like as a pretreatment.

Papers which can be used as a substrate include, for example, paper, kraft paper, liner paper, art paper, coated paper, cardboard paper, transparent paper, translucent paper, and the like. A peeling layer or the like may also be provided on the paper.

The structure of the synthetic paper which can be used as a base material is not particularly limited, and may be a single layer structure or a multilayer structure. The multilayer structure is, for example, a two-layer structure of a base material layer and a surface layer, a three-layer structure in which a surface layer is present on the surface of the base material layer, and a multilayer structure in which another resin film layer exists between the base material layer and the surface layer. Each layer may contain inorganic or organic fillers or may not. Microporous synthetic paper having a plurality of fine pores can also be used.

Examples of the fabric which can be used as the substrate include non-woven fabrics, woven fabrics, woven fabrics, and the like which are composed of the above-mentioned synthetic resin or natural fibers such as wood wool, crepe, and hemp.

The metal material which can be used as the base material is, for example, a metal foil such as an aluminum foil or a copper foil, or a metal plate such as an aluminum plate or a copper plate.

A glass material which can be used as a substrate is, for example, a cloth made of a glass plate or a glass fiber.

The release sheet of the present invention has a good release property for a wide variety of materials, and can be used for a wide variety of materials, so that the release sheet of the present invention can be laminated to the adhesive layer through the resin layer. Body, forming a layered body.

Specifically, the release sheet of the present invention can be used as a protective material for an adhesive material or a component for a liquid crystal display, a step material for a prepreg used as a material for a stamping step of a printed circuit board, or a structural material such as an aircraft. A base substrate at the time of production of a sheet-like structure, and a release sheet for transfer printing. It is particularly suitable for use with adhesive materials.

Examples of the adhesive material include an adhesive sheet, a sheet, an adhesive tape, and an adhesive tape. More specifically, it is attached to a substrate-laden adhesive. The component or the substrate of the adhesive is not particularly limited, and examples of the adhesive include an acrylic adhesive, a natural rubber adhesive, a synthetic rubber adhesive, and a polyoxygen adhesive. Here, the adhesive may also contain a rosin-based adhesive. A tackifier such as coumarin-terpene, terpene, petroleum, styrene, phenol or xylene. Examples of the substrate include paper, cloth, and a resin material described above.

The release sheet used for the adhesive material is preferably one which is excellent in release property in handling, for example, the peel strength of the acrylic adhesive is 0.5 N/cm or less. When the release sheet of the present invention is used for the acrylic adhesive material, the acrylic adhesive material is adhered to make the peel strength between the resin layer after standing and the acrylic adhesive material 0.5 N/cm or less, more preferably 0.4. Below N/cm, more preferably 0.3N/cm or less, the best system is 0.2N/cm the following. When the peeling strength with the acrylic adhesive material exceeds 0.5 N/cm, when the release sheet is peeled off from the adhesive material, the adhesive may be felt, or the surface of the adhesive material may be rough, and the adhesiveness may be lowered, so that it is difficult to use it as an acrylic adhesive. Release sheet for materials.

The release sheet of the present invention can be used even for a polyoxygen-based adhesive material which is a representative of an adhesive material having a strong adhesion. When a conventional polyfluorene-based release sheet is used for a polyadoxic adhesive material, since the adhesive layer and the release layer have high affinity, the adhesion is high and peeling is difficult. On the other hand, the release sheet of the present invention can maintain good peelability even for a polyoxynitride-based adhesive material. When used in the case of a polyoxygen-based adhesive material, the adhesive layer is adhered to the polyoxygen-based adhesive material, and the peeling strength of the resin layer and the polyoxyn-based adhesive material after the placement is preferably 1.0 N/cm or less, more preferably 0.8 N. Below /cm, the optimum system is 0.7 N/cm or less.

Since the release sheet of the present invention is excellent in heat resistance, the adhesive material adhered to the release sheet is stored and circulated, and even when exposed to a high temperature for a long time, the peel strength does not change over time. After a long period of time after sticking, the change in peel strength between the resin layer and the adhesive material can also be suppressed to a small extent.

In the industrial step of peeling off the release sheet, the release sheet is peeled off at a speed of more than 10 m/min as the speed of the production line is increased. Therefore, a release sheet which can be peeled off from the adhesive material at a high speed is sought. Since the release sheet of the present invention has sufficient release property, even if it is peeled off from the adhesive material at a high speed, it can be peeled off without sound and without a feeling of resistance. That is, the release sheet of the present invention can be so-called stripping or hard slipping at high speed peeling. The phenomenon of the sound of (stick-slip) is suppressed by the surface state of the adhesive material to suppress transparency or adhesion.

Examples of the liquid crystal display device which can use the release sheet of the present invention as a protective material include a polarizing plate, a phase difference polarizing plate, and a phase difference plate.

The release sheet of the present invention can also be used as a step material for the prepreg, and can be suitably used, for example, as a solution containing a resin such as an epoxy resin or a phenol resin, a curing agent, or the like, and dried to form a solution. Carrier sheet when the sheet is used.

The release sheet of the present invention also has heat resistance, so that the release property can be maintained even after the high temperature treatment in the hardening step. The prepreg is a reinforcing material such as a fabric such as carbon fiber or glass fiber for improving the reinforcing effect. The steps of using the prepreg include, for example, a stamping step of a printed circuit board, a forming step of a structural member such as an aircraft, a bicycle, a windmill, and the like, and a forming step of a sports and leisure article such as a golf club or a tennis racket. The printed circuit board can be, for example, a single-sided printed circuit board, a double-sided printed circuit board, a flexible printed circuit board, a multilayer printed circuit board, or the like.

Examples of the sheet-like structure which can be produced by using the release sheet of the present invention as a base material include rubber sheets such as polyoxyethylene rubber, fluororubber, urethane rubber, vinyl chloride or the like. An ion exchange membrane composed of a synthetic leather composed of a urethane, a polymer electrolyte such as a semi-fluorosulfonic acid resin, or a ceramic sheet composed of a dielectric ceramic or glass, or the like, and a heat dissipating material. Heat sink sheet, etc.

In the manufacturing steps of the present invention, the mold of the present invention which can be used as a substrate On the sheet, a raw material in the form of a paste or a slurry is applied with a solvent, and dried to form a sheet-like structure. Or, a resin which melts is extruded on the release sheet to form a sheet-like structure.

When the release sheet of the present invention is used for transfer printing, by applying it to the release sheet of the present invention, various functional layers such as a printed layer, an electrode, and a protective layer can be formed. The functional layer on the mold sheet is heated and crimped to the transfer target, and the functional layer is transferred onto the transfer target, and then the release sheet is peeled off from the functional layer. Thus, the release sheet of the present invention can be used in those also referred to as imprinted foils. The functional layer may, for example, be a metal foil, a pigment foil, a multicolor printing foil, a hologram film, an electrostatic destruction foil, a semi-specular metal foil or the like.

[Examples]

Hereinafter, the present invention will be described by way of Examples, but the present invention is not limited thereto.

(1) The content of unsaturated carboxylic acid component of acid-modified ethylene-α-olefin copolymer

The content of the unsaturated carboxylic acid component is determined by the method (A) or (B) shown below with respect to the total amount of the olefin component.

(A): The acid value of the acid-modified ethylene-α-olefin copolymer was measured in accordance with JIS K5407, and the content (branched ratio) of the unsaturated carboxylic acid was determined from the following formula. Content (% by mass) = (mass of branched unsaturated carboxylic acid) / (mass of raw material polyolefin resin) × 100

(B): Infrared absorption spectrum analysis (Fourier-converted infrared spectrophotometer System-2000, manufactured by Perkin Elymer Co., Ltd., analytical energy: 4 cm ^-1 ) was carried out, and the content of the unsaturated carboxylic acid component was determined.

(2) Composition of acid-modified ethylene-α-olefin copolymer other than unsaturated carboxylic acid component

In the o-dichlorobenzene (d ₄ ), ¹ H-NMR and ¹³ C-NMR analysis (manufactured by Varian Co., Ltd., 300 MHz) were carried out at 120 °C. The ¹³ C-NMR analysis was carried out using a decantation method in which a quantitative gate was considered.

(3) Melt flow rate of acid-modified ethylene-α-olefin copolymer

It was measured by the method according to JIS K 7210 (230 ° C, 2160 g load).

(4) Peel strength (normal temperature) for acrylic adhesive

On the resin layer side of the obtained release sheet, an acrylic pressure-sensitive adhesive tape (manufactured by Nitto Denko Corporation, No. 31B/acrylic adhesive) having a width of 50 mm and a length of 150 mm was pressure-bonded to a rubber roller to form a sample. The sample was sandwiched between a metal plate/rubber plate/sample/rubber plate/metal plate, and placed in an environment of 2 kPa load and 25° C. for 24 hours to obtain a sample for measuring the peel strength. The peel strength of the adhesive tape and the release sheet of the peel strength measurement sample was measured by a tensile tester (manufactured by Intesco Co., Ltd., precision universal material testing machine, Model 2020) in a constant temperature room at 25 °C. The peeling angle was 180 ° C, and the peeling speed was 300 mm/min.

(5) Peel strength for acrylic adhesive (70 ° C)

A sample for measuring the peel strength was obtained by the method described in the above (4), except that the conditions for placing the sample were changed from an environment of 25 ° C to an environment of 70 ° C. The peel strength of the adhesive tape and the release sheet of the sample for peel strength measurement was measured by the method described in the above (4).

(6) High speed peelability

The peeling strength measurement sample obtained by the method described in the above (4) was used, and the release sheet portion was fixed to a stainless steel plate with a double-sided tape, and the end portion of the adhesive tape was grasped by hand, and all of the release tape was peeled off at a time (peeling speed was about At 30 m/min), the feeling of the hand and the sound of peeling off were evaluated by the following indicators.

○: It can be peeled off without sound or with a sense of impedance.

△: Peeling produces sound, and the impedance is felt when peeling off.

X: Since a large sound was developed due to peeling, the impedance at the time of peeling was large, and it was impossible to peel off at a peeling speed of about 30 m/min.

(7) Residual adhesion rate

According to the peel strength test (normal temperature) of (4), the peel strength test of (5) (70 °C) and the high speed peeling test of (6), the polyester having a width of 50 mm and a length of 150 mm peeled off from the surface of the release sheet Adhesive tape (No. 31B/acrylic adhesive manufactured by Nitto Denko Corporation) was adhered to a stainless steel plate (SUS 304 thickness: 1 mm), and allowed to stand at a load of 2 kPa at room temperature for 20 hours. Then, the peeling strength of the polyester adhesive tape and the stainless steel plate was measured by a tensile tester (manufactured by Intesco Co., Ltd., precision universal material testing machine, Model 2020) under a constant temperature chamber at 25 °C. The peeling angle was 180 degrees, and the peeling speed was 300 mm/min. The peel strengths obtained by this measurement were set to F1 ₍₄₎ , F1 ₍₅₎ , and F1 _{(6), respectively} .

A polyester adhesive tape (No. 31B/acrylic adhesive manufactured by Nitto Denko Corporation) having a thickness of 50 mm and a length of 150 mm was applied to a stainless steel plate (SUS304 thickness: 1 mm), and allowed to stand at a load of 2 kPa at room temperature for 20 hours. Then, the peel strength of the polyester adhesive tape and the film was measured by a tensile tester (manufactured by Intesco Co., Ltd., precision universal material testing machine, Model 2020) under a constant temperature chamber at 25 ° C (the peeling angle was 180 degrees, and the peeling speed was 300mm / min), the resulting The peel strength was set to F2.

The residual adhesion rate of the adhesive tape was obtained by the following formula.

Residual adhesion rate after standing at room temperature (%) = (F1 ₍₄₎ / F2) × 100

Residual adhesion rate after placement at 70 ° C (%) = (F1 ₍₅₎ / F2) × 100

Residual adhesion rate after high-speed peeling (%) = (F1 ₍₆₎ / F2) × 100

The surface of the adhesive of the adhesive tape is contaminated by the release sheet, or when the surface of the adhesive tape is significantly thickened when peeled off, the re-adhesiveness of the adhesive tape is lowered to impair the performance of the adhesive tape. Therefore, the higher the residual adhesion rate, the better.

(8) Peel strength (normal temperature, 70 ° C), high-speed peelability, and residual adhesion rate of the polyoxygen-based adhesive

In the above (4) to (7), an acrylic adhesive tape having a width of 50 mm and a length of 150 mm was used, and a polyoxynoxy adhesive tape having a width of 25 mm and a length of 150 mm (manufactured by Nitto Denko Corporation, No. 336/polyoxyl) was used. In the same manner as in the above (4) to (7), the peel strength (normal temperature, 70 ° C) was measured for the polyoxynoxy adhesive, and the high-speed peelability was evaluated, and the residual adhesion ratio was measured.

(9) Evaluation of coating appearance (interference fringes)

The biaxially stretched polyester resin film of the obtained release sheet was bonded to a enamel gloss tape (ethylene tape 200-50-21 manufactured by Yamato Co., Ltd.), and was irradiated at three wavelengths in a dark room (FPL 27EX-N manufactured by Panasonic). Immediately below the distance of 30 cm, the degree of interference fringes was visually observed while changing the angle, and the appearance of the coating was evaluated.

◎: There is almost no interference fringe.

○: The interference fringes are slightly seen.

△: Weak interference fringes can be seen.

×: The interference fringes are clearly seen.

(10) Pressure resistance

The obtained release sheet was cut into two pieces of 50 mm × 50 mm in size, and the resin layer was superposed so as to be in contact with the opposite surface of the resin layer, and a load of 10 kPa was applied at 60 ° C, and after being left for 24 hours, the load was removed. After cooling to room temperature, the state of adhesion of the resin layer to the opposite side of the resin layer was examined, and the pressure resistance was evaluated.

○: The two sheets were not in close contact with each other, or two sheets were simply peeled off, and no change in whitening or the like was observed in the resin layer.

X: The resin layer was agglomerated, or the resin layers after peeling off two sheets were all white.

The resin constituting the resin layer is as follows.

P-1:

100 g of an ethylene-propylene copolymer (ethylene/propylene = 75/25 mass%) was placed in a 4-necked flask, and dissolved in 400 g of xylene heated to 130 ° C under a nitrogen atmosphere. Then, 10 g of a toluene solution (5 mass%) of maleic anhydride and 5 g of a toluene solution (10 mass%) of dicumyl peroxide were added to the solution for 30 minutes, respectively, and then held in the system until It was allowed to react at 130 ° C for 4 hours. After the reaction was terminated, the obtained reactant was placed in a large amount of acetone to precipitate a resin. This resin was further washed with acetone several times to remove unreacted maleic anhydride, and then dried under reduced pressure to obtain an acid-modified ethylene-α-olefin copolymer P-1. The resulting acid was used to modify the ethylene-α-olefin copolymer P-1.

P-2:

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

P-3:

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

P-4:

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

P-5:

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

P-6:

In the production of P-1, the acid-modified ethylene-α-olefin copolymer P-6 was obtained by the same operation except that the amount of the toluene solution (5 mass%) of maleic anhydride was changed to 20 g. The resulting acid is modified with an ethylene-α-olefin copolymer P-6.

P-7:

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

P-8:

In the production of P-1, except that the ethylene-propylene copolymer (ethylene/propylene = 75/25 mass%) was changed to a propylene-1-butene copolymer (propylene/butene = 70/30 mass%), The same operation was carried out to obtain an acid-modified ethylene-α-olefin copolymer P-8, and the obtained acid-modified ethylene-α-olefin copolymer P-8 was used.

P-9:

Bordine "LX-4110" (maleic anhydride modified polyethylene resin) manufactured by Arkema Co., Ltd. was used.

P-10

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

P-11:

An ethylene-propylene copolymer (ethylene/propylene = 70/30% by mass) which was not acid-modified was used.

a group of the above resins P-1 to P-11 constituting the resin layer The composition and characteristics are shown in Table 1.

Example 1

The acid-modified ethylene-α-olefin copolymer P-1 was dissolved in toluene to prepare a 2% by mass solution. Acid-modified ethylene-α-olefin copolymer and A solution of an oxazoline compound (manufactured by Nippon Shokubai Co., Ltd., Epocros "WS-500", solid concentration: 39% by mass, diluted with isopropanol) A liquid material obtained by mixing a solid content of an oxazoline compound in an amount of 2 parts by mass based on 100 parts by mass of the acid-modified ethylene-α-olefin copolymer, and a biaxially stretched polyester resin film (EmbletPET manufactured by Unitika Co., Ltd.) The corona-treated surface of -38" and thickness 38 μm) was coated with a wire bar, dried at 140 ° C for 15 seconds, and a resin layer having a thickness of 0.2 μm was formed on the film, and then aged at 50 ° C for 2 days to obtain a separation. Mold sheet.

Examples 2 to 10, Comparative Examples 1, 4 to 6

Except that the type of the acid-modified ethylene-α-olefin copolymer and the type and content of the crosslinking agent were changed as described in Table 2, the same procedure as in Example 1 was carried out. In the same operation, a release sheet was obtained. Further, Carbodilite "V-03" manufactured by Nisshinbo Co., Ltd. was used as a crosslinking agent composed of a carbodiimide compound.

Examples 11 to 15

In the same manner as in Example 1, except that the medium in which the acid-modified ethylene-α-olefin copolymer P-1 was dissolved was used as the medium in which the acid-modified ethylene-α-olefin copolymer P-1 was dissolved, the same procedure as in Example 1 was carried out. Sheet.

Comparative example 2

60.0 g of maleic anhydride modified polyethylene resin P-9 (Bondine "LX-4110" manufactured by Arkema Co., Ltd.) and 90.0 g were used in a mixer equipped with a heat-resistant 1 liter capacity glass container with a heater. Isopropanol, 3.0 g of triethylamine, and 147.0 g of distilled water were fed into a glass vessel to set the rotation speed of the stirring blade to 300 rpm. Then, the temperature in the system was maintained at 140 to 145 ° C and further stirred for 30 minutes. Thereafter, the mixture was placed in a water bath, cooled to room temperature (about 25 ° C) while stirring at a rotation speed of 300 rpm, and then filtered under a pressure of 300 mesh stainless steel filter (wire diameter 0.035 mm, plain weave) (air pressure 0.2 MPa). ), a milky white homo-acid modified polyethylene resin aqueous dispersion E-1 was obtained.

The obtained acid-modified polyethylene resin aqueous dispersion E-1 and a solution of an oxazoline compound A mold release sheet was obtained in the same manner as in Example 1 except that the solid content of the oxazoline compound was mixed in an amount of 5 parts by mass based on 100 parts by mass of the acid-modified polyethylene resin.

Comparative example 3

60.0 g of acid-modified polyisoprene P-10 (Kuraprene "LIR-403"), 60.0 g, was used in a mixer equipped with a heat-resistant 1 liter capacity glass container with a heater. Isopropanol, 15 g of triethylamine, and 165 g of distilled water were fed into a glass vessel, and the stirring blade was rotated at a rotation speed of 300 rpm while stirring, and the internal temperature was maintained at 120 ° C and further stirred for 60 minutes. Thereafter, the mixture was cooled to room temperature (about 25 ° C) while stirring with air cooling, and then filtered under a pressure of 300 mesh stainless steel filter (wire diameter: 0.035 mm, plain weave) (air pressure: 0.2 MPa) to obtain a milky white homogenous acid. A modified polyisoprene aqueous dispersion. The resulting acid-modified polyisoprene aqueous dispersion and a solution of an oxazoline compound A mold release sheet was obtained in the same manner as in Example 1 except that the solid content of the oxazoline compound was mixed in an amount of 5 parts by mass based on 100 parts by mass of the acid-modified polyethylene resin.

Comparative Example 7

In the embodiment 1, instead A solution of an oxazoline compound, which is obtained by diluting an isocyanate compound (Basonat "HW-100", solid content concentration: 100% by mass) with isopropanol, with respect to the acid-modified ethylene-α- The same operation was carried out except that 100 parts by mass of the olefin copolymer was mixed in an amount of 10 parts by mass to obtain a release sheet.

Comparative Example 8

In the embodiment 1, instead A solution of an oxazoline compound, an epoxy compound (manufactured by DIC Corporation, EPICLON "860-90X", solid content concentration: 90% by mass), a liquid diluted with isopropanol, and an acid-modified ethylene-α The same operation was carried out except that 100 parts by mass of the olefin copolymer was mixed in an amount of 5 parts by mass to obtain a release sheet.

Comparative Example 9

In the embodiment 1, instead As a solution of the oxazoline compound, a liquid obtained by diluting a melamine-based compound (Cymel "325" manufactured by Cytecs Industrials Co., Ltd., solid concentration: 80% by mass) with isopropanol was used to modify ethylene-α- with respect to acid. The same operation was carried out except that 100 parts by mass of the olefin copolymer was mixed in an amount of 10 parts by mass to obtain a release sheet.

The results of evaluation of the release sheets obtained in the examples and the comparative examples are shown in Table 2.

Provided with the acid-modified ethylene obtained in Examples 1 to 15 - The release sheet of the resin layer of the α-olefin copolymer and the cross-linking agent of the type and amount specified in the present invention is excellent in release property, heat resistance, high-speed peelability, and pressure-resistant adhesiveness. As shown in Examples 11 to 15, when a mixture of toluene and an alcohol or a mixture of toluene and a ketone was used as a medium for the liquid, the coating appearance was also excellent. In the second embodiment, the mass ratio of the ethylene component to the α-olefin component constituting the acid-modified ethylene-α-olefin copolymer is not in a preferable range, so that the release property and the high-speed peelability are slightly lowered. In Example 7, the content of the acid-modified component constituting the acid-modified ethylene-α-olefin copolymer was not in a preferable range, so that the release property was slightly lowered.

On the other hand, when the resin constituting the resin layer contains an ethylene component and an α-olefin component at different times (Comparative Examples 1 and 2), the obtained release sheet is inferior in release property and high-speed peelability. Further, when the resin constituting the resin layer is an acid-modified polyisoprene (Comparative Example 3), the obtained release sheet has excellent mold release property, heat resistance, and residual adhesion, but is resistant to pressure. obviously decased.

When the resin constituting the resin layer was used without being acid-modified (Comparative Example 4), the obtained release sheet was inferior in heat resistance and the release property by heat treatment was remarkably lowered.

When the resin layer contained a crosslinking agent (Comparative Example 5), the release property of the release sheet by heat treatment was remarkably lowered. When the content of the crosslinking agent in the resin layer was more than the range specified in the present invention (Comparative Example 6), the obtained release sheet was inferior in leaving property at normal temperature, and the release property by heat treatment was further lowered.

When the crosslinking agent not specified in the present invention was used (Comparative Examples 7 to 9), the obtained release sheet was inferior in heat resistance and the release property by heat treatment was remarkably lowered.

Claims (7)

A release sheet which is a release sheet provided with a resin layer on a substrate, wherein the resin layer contains 100 parts by mass of an acid-modified ethylene-α-olefin copolymer and a crosslinking agent of 0.1 to 50 Part by mass, the cross-linking agent is It is composed of an oxazoline compound and/or a carbodiimide compound. The release sheet according to the first aspect of the invention, wherein the mass ratio of the ethylene component to the α-olefin component (ethylene component/α-olefin component) constituting the acid-modified ethylene-α-olefin copolymer is 60/40. To 99/1. The release sheet according to claim 1 or 2, wherein the α-olefin component is propylene or 1-butene. The release sheet according to any one of claims 1 to 3, wherein the content of the acid-modified component constituting the acid-modified ethylene-α-olefin copolymer is relative to the ethylene component and the α-olefin component. In total, it is less than 1% by mass. The release sheet according to any one of claims 1 to 4, wherein the substrate is any one of a resin material, paper, synthetic paper, cloth, metal material, and glass material. The release sheet according to claim 5, wherein the resin material is a polyester resin film. The release sheet according to any one of claims 1 to 6, wherein the peeling strength of the resin layer and the acrylic adhesive is 0.5 N/cm or less.