Modified polyvinyl alcohol-based resin, release agent and laminate

Abstract

To provide a modified polyvinyl alcohol-based resin having both excellent light peelability and peeling antistatic property, a release agent having the same, and a laminate.SOLUTION: A modified polyvinyl alcohol-based resin has fluorine at a side chain of a polyvinyl alcohol-based resin.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a modified polyvinyl alcohol resin, a release agent, and a laminate, and more particularly to a modified polyvinyl alcohol resin, a release agent, and a laminate having excellent easy releasability and antistatic properties against peeling. [Background technology]

[0002] Conventionally, known release agents used in release films include silicone resins, long-chain alkyl vinyl monomer polymers, fluoroalkyl vinyl monomer polymers, polyvinyl alcohol, and the like. For example, from the viewpoint of preventing a decrease in release performance at high temperatures, a release agent containing, as an active ingredient, a reaction product between an active hydrogen-containing polymer such as polyvinyl alcohol and an isocyanate compound having an aliphatic group is known (e.g., Patent Documents 1 and 2).

[0003] Furthermore, as a release film in which a release agent is applied to a base film as a release layer, there is also known a release film in which a release material containing a silicone-based release agent and / or a fluorine-based release agent and an addition-polymerizable compound is formed into a film by a vacuum film-forming method, and the film is then subjected to addition polymerization to form the release layer, in order to suppress the migration of the release components in the release layer (for example, Patent Document 3). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-057511 [Patent Document 2] Japanese Patent Application Publication No. 6-65341 [Patent Document 3] Japanese Patent Application Laid-Open No. 2005-319723 Summary of the Invention [Problem to be solved by the invention]

[0005] On the other hand, polyester film is a typical example of a base film for release films. However, polyester film has a common problem with plastic films in that it easily generates static electricity and becomes charged up, which can cause problems at processing sites due to the adhesion or entrapment of foreign matter, etc.

[0006] In the above-mentioned Patent Documents 1 and 2, when a release film using a reaction product with an isocyanate compound as a release agent is attached to a silicone-based adhesive layer and then the release film is peeled off, peeling static electricity is generated, which can cause problems such as adhesion or entrapment of foreign matter.

[0007] In addition, in the case of Patent Document 3, peeling electrification is suppressed and antistatic properties are improved by containing a fluorine-based release agent, but since a film of a release material is formed on a substrate film by a vacuum film forming method and the release material is polymerized after the film formation, not only is productivity poor, but the suppression of migration of the release component is not sufficient, and there are also problems such as difficulty in peeling due to migration of the release component over time.

[0008] Therefore, under the above circumstances, an object of the present invention is to provide a modified polyvinyl alcohol-based resin having both excellent easy releasability and antistatic properties at the time of release, and a release agent and a laminate using the same. [Means for solving the problem]

[0009] However, in view of these circumstances, the present inventors have conducted extensive research and discovered that by using a modified polyvinyl alcohol resin having fluorine in the side chain of the polyvinyl alcohol resin, a release layer having both excellent easy releasability and antistatic properties on peeling can be obtained, and have completed the present invention.

[0010] That is, the present invention has the following aspects. [1] A modified polyvinyl alcohol resin having fluorine in the side chain of the polyvinyl alcohol resin. [2] The modified polyvinyl alcohol resin according to [1], wherein the side chain has a group represented by the following formula (1): [ka] (In the formula (1), X1 represents an ester bond, an ether bond, a urethane bond, an amide bond, or a structural unit represented by the following formula (2), and R1 represents a fluorine group, a fluorine-containing aromatic group, a fluorine-containing hydrocarbon group, a fluorine-containing alkoxyalkyl group, a fluorine-containing alkoxyaromatic group, a fluorine-containing aminoalkyl group, or a fluorine-containing aminoaromatic group.) [ka] [3] The modified polyvinyl alcohol resin according to [2], wherein R1 in the formula (1) is at least one selected from the group consisting of a fluorophenyl group, a trifluoromethoxyphenyl group, and a pentafluoropropionyl group. [4] The modified polyvinyl alcohol resin according to any one of [1] to [3], wherein the side chain has a group represented by the following formula (3): [ka] (In the formula (3), X2 represents an ester bond, an ether bond, a urethane bond, an amide bond, or a structural unit represented by the following formula (2), and R2 represents a hydrocarbon group.) [ka] [5] The modified polyvinyl alcohol resin according to [4], wherein R2 in the formula (3) is an alkyl group having 8 or more carbon atoms. [6] The modified polyvinyl alcohol resin according to any one of [1] to [5], which has a structural unit represented by the following formula (4): [ka] (In the formula (4), X1 represents an ester bond, an ether bond, a urethane bond, an amide bond, or a structural unit represented by the following formula (2); R1 represents a fluorine group, a fluorine-containing aromatic group, a fluorine-containing hydrocarbon group, a fluorine-containing alkoxyalkyl group, a fluorine-containing alkoxyaromatic group, a fluorine-containing aminoalkyl group, or a fluorine-containing aminoaromatic group; and R3 represents a hydrogen atom or a hydrocarbon group.) [ka] [7] The modified polyvinyl alcohol resin according to any one of [1] to [6], wherein the resin having fluorine in the side chain has a structural unit represented by the following formula (5): [ka] (In the formula (5), X2 represents an ester bond, an ether bond, a urethane bond, an amide bond, or a structural unit represented by the following formula (2), R2 represents a hydrocarbon group, and R3 represents a hydrogen atom or a hydrocarbon group.) [ka] [8] The modified polyvinyl alcohol resin according to [6] or [7], wherein the content of the structural unit represented by the formula (4) is 1 to 10 mol %. [9] The modified polyvinyl alcohol resin according to [7] or [8], wherein the content of the structural unit represented by the formula (5) is 30 to 90 mol %.

[10] The modified polyvinyl alcohol resin according to any one of [6] to [9], which has a structural unit represented by the formula (4) and a structural unit represented by the following formula (5), and the ratio of the content of the structural unit represented by the formula (4) to the content of the structural unit represented by the following formula (5) (formula (4) / formula (5)) is 0.01 to 10. [ka] (In the formula (5), X2 represents an ester bond, an ether bond, a urethane bond, an amide bond, or a structural unit represented by the following formula (2), R2 represents a hydrocarbon group, and R3 represents a hydrogen atom or a hydrocarbon group.) [ka]

[11] The modified polyvinyl alcohol resin according to any one of [7] to

[10] , wherein R2 in the formula (5) is an alkyl group having 8 or more carbon atoms.

[12] The modified polyvinyl alcohol-based resin according to any one of [1] to

[11] , wherein the modified polyvinyl alcohol-based resin is a reaction product of a polyvinyl alcohol-based resin with a fluorine-containing isocyanate and / or an alkyl isocyanate.

[13] The modified polyvinyl alcohol-based resin according to any one of [1] to

[12] , wherein the modified polyvinyl alcohol-based resin is a reaction product of a polyvinyl alcohol-based resin with a fluorine-containing carboxylic acid and / or an alkyl isocyanate.

[14] A release agent containing the modified polyvinyl alcohol resin according to any one of [1] to

[13] .

[15] A laminate comprising a base film and a release layer on at least one surface thereof, the release layer containing the modified polyvinyl alcohol resin according to any one of [1] to

[14] .

[16] The laminate according to

[15] , wherein the base film is a polyester film.

[17] The laminate according to

[15] or

[16] , wherein the laminate is a release film.

[18] The laminate according to any one of

[15] to

[17] , wherein the peel strength of the release layer under the following condition α is 20 mN / cm or less. (Condition α) A 5 μm thick silicone adhesive layer is formed on the surface of the film, the release layer is attached to the silicone adhesive layer, and the film is cut into a piece 5 cm wide x 10 cm long. This piece is left to stand at 23°C for 24 hours, and then the release layer is peeled from the silicone adhesive layer at 180° using a peel tester at a pulling rate of 5 m / min. The peel strength is measured.

[19] The laminate according to

[18] , wherein the absolute value of the peel charge of the release layer under the following condition β is 430 V or less. (Condition β) During peeling under the condition α, the surface potential is measured with a potential measuring device at a position 1 cm away from the peeling surface at the center of the silicone adhesive layer, and this is taken as the peeling charge.

[20] The laminate according to

[18] or

[19] , wherein the adhesive forming the silicone-based adhesive layer is a silicone adhesive "KR-3704" manufactured by Shin-Etsu Chemical Co., Ltd. [Effects of the Invention]

[0011] According to the present invention, there are provided a modified polyvinyl alcohol-based resin having excellent easy releasability and antistatic properties upon peeling, particularly excellent easy releasability and antistatic properties upon peeling against silicone-based pressure-sensitive adhesives, as well as a release agent and a laminate using the same, which have great industrial utility value. DETAILED DESCRIPTION OF THE INVENTION

[0012] The present invention will be described below based on examples of embodiments for carrying out the present invention, but the present invention is not limited to the embodiments described below.

[0013] In this specification, "x and / or y (x and y are optional configurations)" means at least one of x and y, and can mean three possibilities: x only, y only, or x and y. In this specification, when the expression "X to Y" (X and Y are any numbers) is used, unless otherwise specified, it means "X or more and Y or less," as well as "preferably larger than X" or "preferably smaller than Y." In this specification, when it is expressed as "X or more" (X is any number) or "Y or less" (Y is any number), it also means that "it is preferably greater than X" or "it is preferably less than Y." In the present specification, when numerical ranges are described in stages, the upper or lower limit of a certain numerical range can be arbitrarily combined with the upper or lower limit of another numerical range. In addition, in the numerical ranges described in this specification, the upper or lower limit of the numerical range can also be replaced with the values ​​shown in the examples.

[0014] In this specification, the term "film" includes "tape" and "sheet." In this specification, "(meth)acrylic" means acrylic and / or methacrylic, "(meth)acryloyl" means acryloyl and / or methacryloyl, and "(meth)acrylate" means acrylate and / or methacrylate.

[0015] In this specification, the term "main component" means a component that has a significant effect on the properties of the target object, and the content of the component is usually 50% by mass or more, preferably 55% by mass or more, more preferably 60% by mass or more, and even more preferably 70% by mass or more, and may be 100% by mass. In this specification, the term "mainly" refers to the component that accounts for the largest proportion in the target object, and typically, it is preferably 50% by mass or more of the target object, more preferably 60% by mass or more, even more preferably 70% by mass or more, particularly preferably 80% by mass or more, and especially preferably 90% by mass or more, and may be 100% by mass.

[0016] The modified polyvinyl alcohol-based resin according to one embodiment of the present invention is used to form a release layer by laminating the resin on at least one surface of a substrate film, thereby constituting a laminate including the substrate film and the release layer. The laminate will be described in detail below.

[0017] <<<Laminate>>> A laminate according to one embodiment of the present invention (hereinafter sometimes referred to as "the laminate") preferably has a release layer containing a modified polyvinyl alcohol resin having fluorine in the side chain on at least one surface of the base film.

[0018] The laminate structure of the present laminate may be such that a release layer is formed on one side of the substrate film and the surface of the substrate film is left as is on the other side, or such that another layer is formed on the other side. Alternatively, the laminate may be such that release layers are formed on both sides of the substrate film. Furthermore, the release layer may be formed directly on the substrate film, or another layer may be provided between the substrate film and the release layer.

[0019] The total thickness of the present laminate is not particularly limited, but is usually in the range of 10 to 350 μm, preferably 25 to 250 μm, and more preferably 38 to 125 μm.

[0020] Each of the members constituting the present laminate will be described below.

[0021] <<Base film>> The base film constituting the present laminate is not particularly limited in material as long as it is film-like. For example, it may be made of paper, resin, metal, etc., but among these, resin is preferred from the viewpoints of mechanical strength and flexibility.

[0022] Examples of resin substrate films include resin films formed from polymers such as polyethylene, polypropylene, cycloolefin polymer (COP), polyester, polystyrene, (meth)acrylic resin, polycarbonate, polyurethane, triacetyl cellulose (TAC), polyvinyl chloride, polyethersulfone, polyamide, polyimide, polyamideimide, etc. Furthermore, as long as they can be formed into a film, mixtures of these materials (polymer blends) or composites of structural units (copolymers) may also be used.

[0023] The base film may have a single layer structure or a multilayer structure. When the base film has a multilayer structure, the base film may have a two-layer structure, a three-layer structure, or a four-layer structure or more, without departing from the gist of the present invention, and the number of layers is not particularly limited.

[0024] The thickness of the substrate film is not particularly limited as long as it is within a range that allows film formation, but is usually in the range of 10 to 350 μm, preferably 25 to 250 μm, and more preferably 38 to 125 μm.

[0025] Among the above-mentioned substrate films, polyester films are particularly preferred because they have excellent physical properties such as heat resistance, flatness, optical properties, and strength. The polyester film may be a non-stretched film (sheet) or a stretched film. A uniaxially or biaxially stretched film is preferred. Among these, a biaxially stretched polyester film is preferred from the viewpoints of thinning and dimensional stability.

[0026] The polyester used may be a homopolyester or a copolymer polyester. In the case of homopolyesters, those obtained by polycondensation of aromatic dicarboxylic acids and aliphatic glycols are preferred. Examples of aromatic dicarboxylic acids include terephthalic acid and 2,6-naphthalenedicarboxylic acid, and examples of aliphatic glycols include ethylene glycol, diethylene glycol, and 1,4-cyclohexanedimethanol. A typical example of a polyester is polyethylene terephthalate. On the other hand, examples of the dicarboxylic acid component of the copolymer polyester include one or more of isophthalic acid, phthalic acid, terephthalic acid, 2,6-naphthalenedicarboxylic acid, adipic acid, sebacic acid, and oxycarboxylic acid. Examples of the glycol component include one or more of propylene glycols such as ethylene glycol, diethylene glycol, 2,2-diethyl-1,3-propanediol, 2-n-butyl-2-ethyl-1,3-propanediol, 2,2-isopropyl-1,3-propanediol, and 2,2-di-n-1,3-propanediol, butanediol, 4-cyclohexanedimethanol, hexadiol, and neopentyl glycol. The intrinsic viscosity of the polyester is not particularly limited, but is preferably 0.5 to 1 dL / g, more preferably 0.53 to 0.9 dL / g, even more preferably 0.56 to 0.8 dL / g, and even more preferably 0.6 to 0.75 dL / g.

[0027] The polyester polymerization catalyst is not particularly limited, and any conventionally known compound can be used, such as a titanium compound, a germanium compound, an antimony compound, a manganese compound, an aluminum compound, a magnesium compound, and a calcium compound.

[0028] Depending on the processing conditions, oligomer components may precipitate from the polyester film upon heating, causing contamination of the processing process. To suppress the amount of oligomer component precipitation, the film may be produced using a polyester with a low oligomer component content as the raw material. Various known methods can be used to produce polyester with a low oligomer component content, such as a method of solid-phase polymerization after polyester production. The amount of oligomer component precipitation may also be suppressed by forming a polyester film with three or more layers, with the outer layer (surface layer) of the polyester film being a layer made from a polyester raw material with a low oligomer component content. Furthermore, the polyester may be obtained by esterification or transesterification, followed by melt polycondensation under reduced pressure at a higher reaction temperature.

[0029] The polyester film may contain an ultraviolet absorber to improve the weather resistance of the film and prevent deterioration of the adherend (e.g., liquid crystal), etc. The ultraviolet absorber is a compound that absorbs ultraviolet light and is not particularly limited as long as it can withstand the heat applied in the polyester film production process.

[0030] The ultraviolet absorber includes organic ultraviolet absorbers and inorganic ultraviolet absorbers, and organic ultraviolet absorbers are preferred from the viewpoint of transparency.The organic ultraviolet absorbers are not particularly limited, but examples thereof include cyclic imino esters, benzotriazoles, benzophenones, etc.From the viewpoint of durability, cyclic imino esters and benzotriazoles are more preferred.In addition, the ultraviolet absorbers can be used alone or in combination of two or more.

[0031] Particles can be blended into the polyester film primarily for the purposes of imparting lubricity and preventing scratches during each process. The type of particles to be blended is not particularly limited as long as they are capable of imparting lubricity, and specific examples include inorganic particles such as silica, calcium carbonate, magnesium carbonate, barium carbonate, calcium sulfate, calcium phosphate, magnesium phosphate, kaolin, aluminum oxide, and titanium oxide, and organic particles such as (meth)acrylic resin, styrene resin, urea resin, phenolic resin, epoxy resin, and benzoguanamine resin. Furthermore, precipitated particles obtained by precipitating and finely dispersing a portion of a metal compound such as a catalyst during the polyester production process can also be used.

[0032] There is no particular limitation on the shape of the particles used, and any of spherical, blocky, rod-like, flat, etc. There is also no particular limitation on the hardness, specific gravity, color, etc. Two or more types of particles of this series may be used in combination as needed.

[0033] The average particle size of the particles used is usually 5 μm or less, preferably 0.01 to 4 μm, preferably 0.1 to 3.5 μm, and more preferably 0.5 to 3 μm. A particle size of 5 μm or less is preferred because it prevents the surface roughness of the film from becoming too rough, which is less likely to cause problems when various surface functional layers are formed in subsequent processes. The average particle size of the particles can be calculated, for example, by observing the film with a transmission electron microscope and averaging the particle sizes of 10 particles.

[0034] Furthermore, the particle content in the polyester film is usually less than 5% by mass, preferably in the range of 0.0003 to 3% by mass. When there are no particles or only a small amount of particles, the film becomes highly transparent and a good film is obtained, but the slipperiness may be insufficient, so it may be necessary to improve the slipperiness by adding particles to the release layer. Furthermore, when the particle content is less than 5% by mass, the transparency of the film is easily ensured. The lower limit of the particle content is usually 0.01% by mass, preferably 0.1% by mass. When particles are contained, it is preferable to provide a surface layer and an intermediate layer and contain particles in the surface layer, for example. In this case, it is more preferable to have a multilayer structure having a particle-containing surface layer, an intermediate layer, and another particle-containing surface layer in this order.

[0035] The method of adding particles to a polyester film is not particularly limited, and any conventionally known method can be used. For example, in the case of a multi-layer polyester film, the particles can be added at any stage in the production of the polyester constituting each layer, but it is preferable to add the particles after the completion of the esterification or transesterification reaction.

[0036] In addition to the above-mentioned particles, conventionally known antioxidants, antistatic agents, heat stabilizers, lubricants, dyes, pigments, etc. may be added to the polyester film as needed.

[0037] Next, specific examples of polyester film production will be described, but the present invention is not limited to these examples. For example, when producing a biaxially stretched polyester film, a preferred method is to extrude dried pellets of the polyester raw material described above from a die using an extruder as a molten sheet, and then cool and solidify the molten sheet on a cooling roll such as a rotating cooling drum to obtain an unstretched sheet. In this case, it is preferable to increase the adhesion between the sheet and the rotating cooling drum to improve the flatness of the sheet, and an electrostatic adhesion method and / or a liquid application adhesion method are preferably used.

[0038] The unstretched sheet is then biaxially stretched. In this case, the unstretched sheet is first stretched in one direction using a roll or tenter-type stretching machine. The stretching temperature is usually 70 to 120°C, preferably 80 to 110°C, and the stretching ratio is usually 2.5 to 7 times, preferably 3 to 6 times. Next, the sheet is stretched in a direction perpendicular to the first-stage stretching direction, at a stretching temperature of usually 70 to 170°C, and a stretching ratio of usually 3 to 7 times, preferably 3.5 to 6 times. Subsequently, the film is heat-treated under tension or relaxation of 30% or less at a temperature of 180 to 270°C to obtain a biaxially oriented film. The stretching may be performed in one direction in two or more stages. In this case, it is preferable to perform the stretching so that the final stretch ratios in both directions are within the above-mentioned ranges.

[0039] A simultaneous biaxial stretching method can also be used to produce polyester films. In the simultaneous biaxial stretching method, the unstretched sheet is simultaneously stretched and oriented in the machine direction (longitudinal direction) and width direction (transverse direction) under temperature control, typically at 70 to 120°C, and preferably at 80 to 110°C, with the area stretching ratio being typically 4 to 50 times, preferably 7 to 35 times, and more preferably 10 to 25 times. Subsequently, the film is subjected to a heat treatment under tension or relaxation of 30% or less at a temperature of typically 170 to 250°C to obtain a stretched and oriented film. Regarding the simultaneous biaxial stretching device employing the above-mentioned stretching method, any conventionally known stretching method such as a screw method, a pantograph method, or a linear drive method can be employed.

[0040] <<Release layer>> The present laminate has a release layer on at least one surface of the substrate film. The release layer is formed from a resin composition containing a modified polyvinyl alcohol resin having fluorine in the side chain. The release layer may be a cured resin layer. The release layer used in the present laminate is formed from the resin composition described below.

[0041] The release layer preferably has a peel strength of 20 mN / cm or less, more preferably 15 mN / cm or less, even more preferably 10 mN / cm or less, particularly preferably 8 mN / cm or less, and especially preferably 5 mN / cm or less under the following condition α. ​​The lower limit is usually 0.1 mN / cm, but may be 0.5 mN / cm or 1 mN / cm. (Condition α) A 5 μm thick silicone adhesive layer is formed on the surface of the film, the release layer is attached to the silicone adhesive layer, and the film is cut into a piece 5 cm wide x 10 cm long. This piece is left to stand at 23°C for 24 hours, and then the release layer is peeled from the silicone adhesive layer at 180° using a peel tester at a pulling rate of 5 m / min. The peel strength is measured.

[0042] The film forming the silicone-based adhesive layer under condition α is a film for measuring peel strength, and is a different film from the base film that is a constituent member of this laminate, but is a resin film of the same composition as the base film that constitutes this laminate.

[0043] The release layer preferably has an absolute value of peel charge under the following condition β of 430 V or less, more preferably 400 V or less, even more preferably 380 V or less, and particularly preferably 350 V or less. The lower limit is usually 0 V, but may be 10 V, 30 V, 50 V, or 70 V. (Condition β) During peeling under the condition α, the surface potential is measured with a potential measuring device at a position 1 cm away from the center of the silicone adhesive layer and the peeling surface, and this is taken as the peeling charge.

[0044] The adhesive that forms the silicone adhesive layer under the conditions α and β may be any addition-curing silicone adhesive, but is preferably the addition-curing silicone adhesive "KR-3704" manufactured by Shin-Etsu Chemical Co., Ltd.

[0045] The thickness of the release layer is preferably 0.002 μm or more and 1 μm or less, more preferably 0.005 μm or more and 0.25 μm or less, and even more preferably 0.02 μm or more and 0.1 μm or less. The coating amount of the release layer is preferably 1 to 100 mg / m 2 , more preferably 5 to 80 mg / m 2 , and more preferably 10 to 60 mg / m 2 , and even more preferably 15 to 50 mg / m 2The thinner the release layer thickness or coating amount, the better the transparency and coating appearance, but the worse the antistatic properties tend to be. The thicker the release layer, the better the antistatic properties become, but at a certain thickness or more, the resistance value saturates and the transparency and coating appearance tend to worsen, and the paint cost tends to increase relative to the antistatic properties. Therefore, if the thickness of the release layer is within the above range, the transparency, coating appearance, paint cost, etc. tend to be good. It can be assumed that the release layer contains unreacted compounds of the various compounds in the resin composition, reacted compounds, or a mixture thereof.

[0046] <Resin composition> The resin composition that forms the release layer contains the following compound (A), and may also contain the following compounds (B), (C), and (D) as needed. That is, the release layer is formed from a resin composition that contains the following compound (A), and may also contain the following compounds (B), (C), and (D) as needed. (A) Modified polyvinyl alcohol resin with fluorine in the side chain (B) One or more selected from (b1) a polymer obtained by doping a compound made of thiophene or a thiophene derivative with another anionic compound, and (b2) a self-doped polymer having an anionic group in a compound made of thiophene or a thiophene derivative. (C) One or more compounds selected from (c1) polyglycerin and (c2) alkylene oxide adducts of polyglycerin, or derivatives thereof (D) Wax component

[0047] [Compound (A)] The compound (A), i.e., the modified polyvinyl alcohol-based resin (A) having fluorine in the side chain, is not particularly limited as long as it is a modified polyvinyl alcohol-based resin having fluorine in the side chain, but it is preferable that the side chain has a group represented by the following formula (1): [ka] (In the formula (1), X1 represents an ester bond, an ether bond, a urethane bond, an amide bond, or a structural unit represented by the following formula (2), and R1 represents a fluorine group, a fluorine-containing aromatic group, a fluorine-containing hydrocarbon group, a fluorine-containing alkoxyalkyl group, a fluorine-containing alkoxyaromatic group, a fluorine-containing aminoalkyl group, or a fluorine-containing aminoaromatic group.) [ka]

[0048] The modified polyvinyl alcohol resin having fluorine in the side chain preferably has a structural unit represented by the following formula (4): The functional group "-X1-R1" in the following formula (4) is the same as the group represented by the formula (1). [ka] (In the formula (4), X1 represents an ester bond, an ether bond, a urethane bond, an amide bond, or a structural unit represented by the following formula (2); R1 represents a fluorine group, a fluorine-containing aromatic group, a fluorine-containing hydrocarbon group, a fluorine-containing alkoxyalkyl group, a fluorine-containing alkoxyaromatic group, a fluorine-containing aminoalkyl group, or a fluorine-containing aminoaromatic group; and R3 represents a hydrogen atom or a hydrocarbon group.) [ka]

[0049] In the formulas (1) and (4), X1 represents an ester bond, an ether bond, a urethane bond, an amide bond, or a structural unit represented by the formula (2), and among these, an ester bond or a urethane bond is preferred, and a urethane bond is more preferred. In the formulas (1) and (4), R1 represents a fluorine group, a fluorine-containing aromatic group, a fluorine-containing hydrocarbon group, a fluorine-containing alkoxyalkyl group, a fluorine-containing alkoxyaromatic group, a fluorine-containing aminoalkyl group, or a fluorine-containing aminoaromatic group. Among these, the fluorine-containing aromatic group, the fluorine-containing alkoxyaromatic group, and the fluorine-containing aminoaromatic group preferably have 6 to 24 carbon atoms, more preferably 7 to 20 carbon atoms, and even more preferably 7 to 16 carbon atoms, and the fluorine-containing hydrocarbon group, the fluorine-containing alkoxyalkyl group, and the fluorine-containing aminoalkyl group preferably have 1 to 18 carbon atoms, more preferably 2 to 16 carbon atoms, and even more preferably 2 to 12 carbon atoms. Among these, at least one selected from the group consisting of a fluorophenyl group, a difluorophenyl group, a trifluorophenyl group, a trifluoromethylphenyl group, a bistrifluoromethylphenyl group, a chlorotrifluoromethylphenyl group, a bromotrifluoromethylphenyl group, a trifluoromethoxyphenyl group, a pentafluoropropionyl group, and a pentafluoroethyl group is preferred, and at least one selected from the group consisting of a fluorophenyl group, a trifluoromethoxyphenyl group, and a pentafluoropropionyl group is more preferred. Furthermore, in the formula (4), R3 represents a hydrogen atom or a hydrocarbon group, and the number of carbon atoms in the hydrocarbon group of R3 is preferably 8 or less, more preferably 6 or less, even more preferably 4 or less, and still more preferably 2 or less. R3 is particularly preferably a hydrogen atom or a methyl group, and most preferably a hydrogen atom.

[0050] The content of the structural unit represented by the formula (4) is preferably 1 to 30 mol %, more preferably 2 to 25 mol %, even more preferably 3 to 20 mol %, still more preferably 4 to 15 mol %, and even more preferably 5 to 10 mol %, relative to the modified polyvinyl alcohol resin (A) having fluorine in the side chain. When it is within the above range, excellent antistatic properties against peeling tend to be obtained.

[0051] The modified polyvinyl alcohol resin (A) having fluorine in the side chain preferably has a hydrocarbon group such as an alkyl group in the side chain, for example, a group represented by the following formula (3). [ka] (In the formula (3), X2 represents an ester bond, an ether bond, a urethane bond, an amide bond, or a structural unit represented by the following formula (2), and R2 represents a hydrocarbon group.) [ka]

[0052] The modified polyvinyl alcohol resin having fluorine in the side chain preferably has a structural unit represented by the following formula (5): The functional group "-X2-R2" in the following formula (5) is the same as the group represented by the formula (3). [ka] (In the formula (5), X2 represents an ester bond, an ether bond, a urethane bond, an amide bond, or a structural unit represented by the following formula (2), R2 represents a hydrocarbon group, and R3 represents a hydrogen atom or a hydrocarbon group.) [ka]

[0053] In the formulas (3) and (5), X2 represents an ester bond, an ether bond, a urethane bond, an amide bond, or a structural unit represented by the formula (2), and is preferably a urethane bond. Furthermore, in the formulas (3) and (5), R2 represents a hydrocarbon group, and is preferably a saturated or unsaturated aliphatic group such as alkyl, alkenyl, or cycloalkyl, and is preferably an alkyl group. Such an alkyl group may be linear or branched, and is more preferably an alkyl group having 8 or more carbon atoms, even more preferably 12 or more, even more preferably 14 or more, and particularly preferably 16 or more. The upper limit of the carbon number is usually 40 or less, preferably 31 or less, even more preferably 25 or less, and even more preferably 23 or less. Furthermore, in the formula (5), R3 represents a hydrogen atom or a hydrocarbon group, and the number of carbon atoms in the hydrocarbon group of R3 is preferably 8 or less, more preferably 6 or less, even more preferably 4 or less, and still more preferably 2 or less. R3 is particularly preferably a hydrogen atom or a methyl group, and most preferably a hydrogen atom.

[0054] The content of the structural unit represented by the formula (5) is preferably 30 to 90 mol %, more preferably 40 to 85 mol %, even more preferably 50 to 80 mol %, and particularly preferably 55 to 75 mol %, based on the modified polyvinyl alcohol resin (A) having fluorine in the side chain.

[0055] The ratio of the content of the structural unit represented by formula (4) to the content of the structural unit represented by formula (5) (formula (4) / formula (5)) is preferably 0.001 to 10, more preferably 0.01 to 5, even more preferably 0.05 to 1, still more preferably 0.07 to 0.8, and even more preferably 0.09 to 0.5. Within the above range, it becomes easy to achieve both easy releasability and antistatic properties at the time of peeling.

[0056] (Method for producing compound (A)) ~Modification by adding fluorine to the side chain~ The modified polyvinyl alcohol resin (A) having fluorine in the side chain can be produced by a conventionally known method for modifying a resin by adding fluorine to the side chain. For example, the resin that forms the main chain of the raw material for production has a reactive group (mainly a hydroxyl group), and the resin can be obtained by reacting a fluorine-containing compound that can react with the reactive group of the resin.

[0057] Examples of the reactive group include a hydroxyl group, an amino group, a carboxyl group, and an acid anhydride group, and the hydroxyl group is preferred. The resin having the reactive group is polyvinyl alcohol.

[0058] That is, the main chain of the modified polyvinyl alcohol-based resin (A) having fluorine in the side chain is preferably derived from a polyvinyl alcohol-based resin, in other words, the main skeleton of the modified polyvinyl alcohol-based resin (A) having fluorine in the side chain is preferably a polyvinyl alcohol skeleton.

[0059] Here, examples of methods for producing the modified polyvinyl alcohol-based resin (A) having fluorine in the side chain include (i) a method of producing it as a condensation reaction product by a condensation reaction between a hydroxyl group of a resin and a fluorine-containing compound (for example, a method of producing a reaction product between a resin that forms the main chain and a fluorine-containing carboxylic acid and / or an alkyl isocyanate), and (ii) a method of producing it as a reaction product by a urethanization reaction between a hydroxyl group of a resin and a fluorine-containing isocyanate (for example, a method of producing a reaction product between a resin that forms the main chain and a fluorine-containing isocyanate and / or an alkyl isocyanate).

[0060] Modification by adding alkyl groups to the side chains The modified polyvinyl alcohol resin (A) having fluorine in the side chain preferably has an alkyl group in the side chain of the resin, for example, to have a structural unit represented by the above formula (5). The alkyl group may be linear or branched, and is more preferably a long-chain alkyl group. The long-chain alkyl group more preferably has 8 or more carbon atoms, even more preferably 10 or more, more preferably 13 or more, and particularly preferably 15 or more. The upper limit of the carbon number is usually 40 or less, preferably 31 or less, even more preferably 25 or less, and even more preferably 23 or less.

[0061] As a method for adding an alkyl group to such a side chain, a resin having a reactive group can be obtained by reacting a compound having an alkyl group capable of reacting with the reactive group to obtain a resin having an alkyl group in the side chain. For example, a method is also possible in which a monomer having a hydroxyl group is copolymerized with a resin and then alkylated. As the "reactive group" and "resin having a reactive group", the same "reactive group" and "resin having a reactive group" as described in the above "Modification by adding fluorine to the side chain" can be used.

[0062] A preferred method for obtaining a resin having an alkyl group in its side chain is one in which the reactive group is a hydroxyl group and the compound having the alkyl group is an alkyl isocyanate, from the viewpoint of easy peelability. This allows the alkyl group to be added to the side chain by a urethane reaction between the hydroxyl group of the resin and the alkyl isocyanate. The alkyl isocyanate is preferably an isocyanate having an alkyl group having 8 or more carbon atoms, more preferably 10 or more carbon atoms, even more preferably 13 or more carbon atoms, and particularly preferably 15 or more carbon atoms. The upper limit is usually 40 or less carbon atoms, preferably 31 or less carbon atoms, even more preferably 25 or less carbon atoms, and even more preferably 23 or less carbon atoms.

[0063] The modified polyvinyl alcohol resin (A) having fluorine in the side chain is preferably modified by both the "modification by adding fluorine to the side chain" and the "modification by adding a long-chain alkyl group to the side chain", and the case where both modifications are performed will be described below.

[0064] In the method (i) of producing a condensation reaction product by a condensation reaction between the hydroxyl groups of a resin and a fluorine-containing compound, for example, a fluorine-containing carboxylic acid such as pentafluoropropionic acid (PFA) is used as the fluorine-containing compound, and is subjected to a condensation reaction with the hydroxyl groups of the resin that forms the main chain to obtain a condensation reaction product, and the hydroxyl groups of the condensation reaction product are then subjected to a urethanization reaction with an alkyl isocyanate, thereby producing a modified polyvinyl alcohol-based resin (A) having fluorine in the side chain as the reaction product.

[0065] In the method (ii) for producing a reaction product by a urethane reaction between a hydroxyl group of a resin and a fluorine-containing isocyanate, it is preferable that the alkyl isocyanate, together with the fluorine-containing isocyanate, undergo a urethane reaction with the hydroxyl group of the resin that forms the main chain.

[0066] The fluorine-containing isocyanate is preferably an isocyanate containing at least one fluorine-containing group selected from the group consisting of a fluorine group, a fluorine-containing aromatic group, a fluorine-containing hydrocarbon group, a fluorine-containing alkoxyalkyl group, and a fluorine-containing aminoalkyl group, and is more preferably an isocyanate containing at least one fluorine-containing group selected from the group consisting of a fluorophenyl group, a fluorophenyl group, a difluorophenyl group, a trifluorophenyl group, a trifluoromethylphenyl group, a bistrifluoromethylphenyl group, a chloro-trifluoromethylphenyl group, a bromotrifluoromethylphenyl group, a trifluoromethoxyphenyl group, and a pentafluoropropionyl group, and particularly preferably 4-fluorophenyl isocyanate (4FPI), 2,4-difluorophenyl isocyanate, 4-trifluoromethyl isocyanate, 4-chloro-3-trifluoromethylphenyl isocyanate, and 4-trifluoromethoxyphenyl isocyanate (4OCF3PI).

[0067] The reaction product (ii) is produced as follows: The hydroxyl-containing resin that forms the main chain is dissolved or dispersed in a solvent inert to isocyanate groups, such as toluene, xylene, or dimethyl sulfoxide (DMSO), and then reacted with an isocyanate compound (the fluorine-containing isocyanate and / or alkyl isocyanate) at, for example, 80 to 150°C. The reaction ratio of the isocyanate groups is typically 0.3 to 1.2 equivalents, preferably 0.5 to 1 equivalent, per equivalent of hydroxyl groups in the main chain resin. If too many hydroxyl groups remain, the resulting release layer tends to have poor releasability. The reaction is continued for another 0.5 to 2 hours after the reaction raw materials have dissolved in the solvent or after the absorption spectrum due to the isocyanate groups in the reaction mixture has disappeared (usually resulting in a brown solution), and then stopped. The reaction mixture is cooled to about 40 to 80°C and poured into a 3 to 6 times amount of a poor solvent such as acetone, methanol, or isopropanol to precipitate the reaction product, which is then filtered and separated and dried to obtain the target product. The reaction product thus obtained has excellent easy releasability and residual adhesiveness, and in particular, retains excellent easy releasability and residual adhesiveness even after being heated at high temperatures.

[0068] The methods for producing the modified polyvinyl alcohol resin (A) having fluorine in the side chain include the above-mentioned methods (i) and (ii), but perfluoroalkyl compounds (PFAS) are hardly decomposed in nature, and in recent years, there have been concerns about their persistence in marine and soil environments, their bioaccumulation, and their toxicity, leading to the establishment of restrictions on their use in various countries. Since the perfluoroalkyl compound used in the above-mentioned method (i) is a type of PFAS, it is preferable to use the above-mentioned method (ii) as a method that does not use such PFAS.

[0069] Next, preferred examples of the resin that forms the main chain of the modified polyvinyl alcohol-based resin (A) having fluorine in the side chain include polyvinyl alcohol-based resins, (meth)acrylic resins, polyurethane resins, and polyester resins. These resins are described below. However, the "modification" described below for the main chain resin does not include "modification by adding fluorine to the side chain" or "modification by adding an alkyl group to the side chain" in the modified polyvinyl alcohol-based resin (A) having fluorine in the side chain.

[0070] (Polyvinyl alcohol resin) The polyvinyl alcohol resin (hereinafter, sometimes referred to as "PVA resin") used in the present embodiment is a resin mainly composed of vinyl alcohol structural units, which is obtained by saponifying a polyvinyl ester resin obtained by polymerizing a vinyl ester monomer, and is composed of vinyl alcohol structural units and vinyl ester structural units in amounts corresponding to the degree of saponification.

[0071] Examples of the vinyl ester monomer include vinyl formate, vinyl acetate, vinyl propionate, vinyl valerate, vinyl butyrate, vinyl isobutyrate, vinyl pivalate, vinyl caprate, vinyl laurate, vinyl stearate, vinyl benzoate, and vinyl versatate, with vinyl acetate being economically preferred. These may be used alone or in combination of two or more.

[0072] The average degree of polymerization of the PVA resin used in this embodiment (measured in accordance with JIS K6726-1994) is preferably 200 to 1,800, more preferably 300 to 1,500, and even more preferably 300 to 1,000.

[0073] When the average degree of polymerization is equal to or greater than the lower limit, the PVA-based resin layer has sufficient mechanical strength, whereas when the average degree of polymerization is equal to or less than the upper limit, the viscosity during dissolution can be reduced, which is preferable because it makes it easier to coat the release layer.

[0074] The saponification degree of the PVA resin used in the present embodiment (measured in accordance with JIS K6726-1994) is preferably 80 to 100 mol%, more preferably 90 to 99.9 mol%, and even more preferably 98 to 99.9 mol%. When the saponification degree is equal to or greater than the lower limit, it is easier to introduce a large amount of the structural units represented by the formula (4) or (5), which is preferable.

[0075] In addition, in this embodiment, the PVA-based resin may be one obtained by copolymerizing various monomers during the production of a polyvinyl ester-based resin and then saponifying the copolymer, or various modified PVA-based resins obtained by introducing various functional groups into unmodified PVA by post-modification.

[0076] Examples of other monomers that can be copolymerized with vinyl ester monomers include olefins such as ethylene, propylene, isobutylene, α-octene, α-dodecene, and α-octadecene; hydroxyl group-containing α-olefins such as 3-buten-1-ol, 4-penten-1-ol, 5-hexen-1-ol, and 3,4-dihydroxy-1-butene, and derivatives thereof such as acylated products; unsaturated acids such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, maleic anhydride, and itaconic acid, their salts, monoesters, or dialkyl esters; nitriles such as acrylonitrile and methacrylonitrile; and diacetone acrylate. Examples of suitable vinyl compounds include amides such as allylamides, acrylamides, and methacrylamides, olefin sulfonic acids such as ethylene sulfonic acid, allyl sulfonic acid, and methallylsulfonic acid, or salts thereof, alkyl vinyl ethers, dimethylallyl vinyl ketone, N-vinylpyrrolidone, vinyl chloride, vinyl ethylene carbonate, 2,2-dialkyl-4-vinyl-1,3-dioxolane, glycerin monoallyl ether, and vinyl compounds such as 3,4-diacetoxy-1-butene, substituted vinyl acetates such as isopropenyl acetate and 1-methoxyvinyl acetate, vinylidene chloride, 1,4-diacetoxy-2-butene, and vinylene carbonate. These may be used alone or in combination of two or more.

[0077] The proportion of structural units derived from other monomers in the polyvinyl ester resin is preferably 15 mol% or less, more preferably 5 mol% or less, based on the number of moles of all structural units constituting the polyvinyl ester resin, from the viewpoint of the strength of the resulting polyvinyl alcohol resin film, etc. Incidentally, ethylene is a preferred example of the other monomer, and when ethylene is contained, the proportion of ethylene units is preferably 15 mol% or less, more preferably 10 mol% or less, and even more preferably 5 mol% or less, based on the number of moles of all structural units constituting the vinyl ester resin. The lower limit is usually 0 mol%, but may be 1 mol% or more.

[0078] In addition, examples of modified PVA-based resins into which functional groups have been introduced by post-modification include those having acetoacetyl groups through reaction with diketene, those having polyalkylene oxide groups through reaction with ethylene oxide, those having hydroxyalkyl groups through reaction with epoxy compounds, and those obtained by reacting PVA with aldehyde compounds having various functional groups.

[0079] The content of modified species in such modified PVA-based resins, i.e., structural units derived from various monomers in the copolymer or functional groups introduced by post-reaction, cannot be generalized because the properties vary greatly depending on the modified species, but is preferably in the range of 0.5 to 20 mol %, more preferably 1 to 10 mol %.

[0080] Among these various modified PVA-based resins, in this embodiment, a PVA-based resin having a structural unit having a 1,2-diol structure in a side chain, as represented by the following general formula (6) (hereinafter, sometimes referred to as a "1,2-diol structural unit"), is preferably used because it facilitates melt molding in the manufacturing method of the present laminate described below.

[0081] [ka]

[0082] In addition, R in the 1,2-diol structural unit represented by the general formula (6) 1 ~R 4 each independently represents a hydrogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms.

[0083] Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, and a tert-butyl group, and the alkyl group may have a functional group such as a halogen group, a hydroxyl group, an ester group, a carboxylic acid group, a sulfonic acid group, etc. These may be used alone or in combination of two or more.

[0084] Furthermore, X in the 1,2-diol structural unit represented by general formula (6) represents a single bond or a bonding chain. Examples of such a bonding chain include hydrocarbons such as linear or branched alkylene groups having 1 to 6 carbon atoms, linear or branched alkenylene groups having 1 to 6 carbon atoms, linear or branched alkynylene groups having 1 to 6 carbon atoms, phenylene groups, and naphthylene groups (these hydrocarbons may be substituted with halogens such as fluorine, chlorine, and bromine), as well as -O-, -(CHO) t -, -(OCH2) t -, -(CHO) t CH2-, -CO-, -COCO-, -CO(CH2) t Examples thereof include CO-, -CO(CH)CO-, -S-, -CS-, -SO-, -SO-, -NR-, -CONR-, -NRCO-, -CSNR-, -NRCS-, -NRNR-, -HPO-, -Si(OR)-, -OSi(OR)-, -OSi(OR)O-, -Ti(OR)-, -OTi(OR)-, -OTi(OR)O-, -Al(OR)-, -OAl(OR)-, -OAl(OR)O-, and the like (each R independently represents an arbitrary substituent and represents a hydrogen atom or a linear or branched alkyl group having 1 to 6 carbon atoms, and t represents an integer of 1 to 5). These may be used alone or in combination of two or more. Among these, from the viewpoint of stability during production or use, the linking chain is preferably a linear or branched alkylene group having 1 to 6 carbon atoms, particularly a methylene group, or -CH2OCH2-.

[0085] X is most preferably a single bond in terms of thermal stability and stability at high temperatures and under acidic conditions.

[0086] Among the 1,2-diol structural units represented by general formula (6), R 1 ~R 4 A structural unit represented by the following general formula (6'), in which all of are hydrogen atoms and X is a single bond, is most preferred.

[0087] [ka]

[0088] Examples of a method for producing such a PVA resin having a 1,2-diol structural unit in the side chain include the method described in paragraphs

[0026] to

[0034] of JP-A No. 2015-143356.

[0089] The content of 1,2-diol structural units contained in such PVA resins having 1,2-diol structural units in their side chains is preferably 0.5 to 20 mol%, more preferably 1 to 10 mol%, even more preferably 2 to 9 mol%, and still more preferably 3 to 8 mol%. If the content is equal to or greater than the lower limit, the number of hydroxyl groups that can be modified increases, making it easier to fully obtain the effects of the 1,2-diol structure in the side chain.

[0090] The content of 1,2-diol structural units in PVA resin is the same as that of a completely saponified PVA resin. 1 The content can be determined from H-NMR spectrum (solvent: DMSO-d6, internal standard: tetramethylsilane). Specifically, the content can be calculated from the peak areas derived from hydroxyl group protons, methine protons, and methylene protons in the 1,2-diol structural unit, methylene protons in the main chain, and protons of hydroxyl groups linked to the main chain.

[0091] The PVA-based resin used in this embodiment may be one type or a mixture of two or more types. When the PVA-based resin is a mixture of two or more types, the following combinations may be used: unmodified PVAs, unmodified PVA and a PVA-based resin having a structural unit represented by general formula (6), PVA-based resins having structural units represented by general formula (6) with different degrees of saponification, polymerization, modification, etc., unmodified PVA, or a PVA-based resin having a structural unit represented by general formula (6) and another modified PVA-based resin.

[0092] [Compound (B)] Compound (B) is (b1) a polymer in which a compound made of thiophene or a thiophene derivative is doped with another anionic compound, or (b2) a self-doped polymer in which an anionic group is contained in a compound made of thiophene or a thiophene derivative. These compounds exhibit excellent conductivity and are suitable. Examples of compound (B) include those obtained by polymerizing a compound of the following formula (7) or (8) in the presence of a polyanion. Polymer (b1) and polymer (b2) may be used in combination.

[0093] [ka]

[0094] In the formula (7), R 5 and R 6 each independently represents a hydrogen atom or an aliphatic hydrocarbon group, alicyclic hydrocarbon group, aromatic hydrocarbon group, or the like having 1 to 20 carbon atoms.

[0095] [ka]

[0096] In the formula (8), n represents an integer of 1 to 4.

[0097] Examples of polyanions used in polymerization include poly(meth)acrylic acid, polymaleic acid, polystyrene sulfonic acid, polyvinyl sulfonic acid, etc. As a method for producing such a polymer, for example, a method such as that disclosed in JP-A-7-90060 can be used.

[0098] In this embodiment, a compound of the formula (8) in which n is 2 and polystyrene sulfonic acid is used as the polyanion is preferably used.

[0099] When these polyanions are acidic, they may be partially or completely neutralized. Preferred bases for neutralization include ammonia, organic amines, and alkali metal hydroxides.

[0100] [Compound (C)] The compound (C) is one or more compounds selected from (c1) polyglycerin and (c2) alkylene oxide adducts of polyglycerin, or derivatives thereof. Polyglycerin is a compound represented by the following general formula (9):

[0101] [ka]

[0102] In the formula (9), n is 2 or more, and in this embodiment, n in the formula is usually in the range of 2 to 20, preferably 3 to 15, and more preferably 3 to 12.

[0103] The alkylene oxide adduct of polyglycerin has a structure in which alkylene oxide is addition polymerized to the hydroxyl group of polyglycerin represented by the general formula (9).

[0104] Here, the structure of the alkylene oxide added to each hydroxyl group in the polyglycerol skeleton may be different, and it is sufficient that the alkylene oxide is added to at least one hydroxyl group in the molecule, and it is not necessary that the alkylene oxide or its derivative is added to all hydroxyl groups.

[0105] The alkylene oxide added to polyglycerin is preferably ethylene oxide or propylene oxide. If the alkylene chain of the alkylene oxide is too long, the hydrophobicity becomes strong, dispersibility in the coating liquid deteriorates, and the antistatic property and transparency of the release layer tend to deteriorate. Ethylene oxide is particularly preferred. The number of additions is preferably in the range of 200 to 2,000, more preferably 300 to 1,000, and even more preferably 400 to 900, in terms of the number average molecular weight of the final compound.

[0106] The polyglycerin or the alkylene oxide adduct of polyglycerin may be used alone or in combination of two or more kinds.

[0107] [Compound (D)] Compound (D) is a wax component. The wax component is a wax selected from natural waxes, synthetic waxes, and blends thereof. These may be used alone or in combination of two or more types.

[0108] The natural waxes include vegetable waxes, animal waxes, mineral waxes, and petroleum waxes. Vegetable waxes include candelilla wax, carnauba wax, rice wax, Japan wax, and jojoba oil. Animal waxes include beeswax, lanolin, and spermaceti. Mineral waxes include montan wax, ozokerite, and ceresin. Petroleum waxes include paraffin wax, microcrystalline wax, and petrolatum.

[0109] Examples of the synthetic wax include synthetic hydrocarbons, modified waxes, hydrogenated waxes, fatty acids, acid amides, amines, imides, ester waxes, and ketones.

[0110] Well-known synthetic hydrocarbons include Fischer-Tropsch wax (also known as Sazowar wax) and polyethylene wax, but also include the following low-molecular-weight polymers (specifically, polymers with viscosity number average molecular weights of 500 to 20,000): polypropylene, ethylene-acrylic acid copolymer, polyethylene glycol, polypropylene glycol, and block or graft conjugates of polyethylene glycol and polypropylene glycol.

[0111] Specific examples of modified waxes include montan wax derivatives, paraffin wax derivatives, and microcrystalline wax derivatives, where the derivatives are compounds obtained by any one of purification, oxidation, esterification, and saponification, or a combination thereof.

[0112] Specific examples of hydrogenated waxes include hydrogenated castor oil and hydrogenated castor oil derivatives.

[0113] Among these waxes, synthetic hydrocarbon waxes are preferred because they provide stable performance and are easily available. Polyethylene wax, polypropylene wax, oxidized polyethylene wax, and oxidized polypropylene wax are more preferred, with polyethylene wax and oxidized polyethylene wax being particularly preferred.

[0114] The softening point of the wax in this embodiment is preferably 90°C or higher and 170°C or lower, more preferably 100°C or higher and 160°C or lower, and even more preferably 120°C or higher and 150°C or lower. By using a wax with a softening point within this range, for example, when used as a protective film for processing, it is possible to improve easy releasability and suppress processing contamination due to oligomer components contained in the polyester film. The softening point of the wax can be measured and calculated in accordance with JIS-K2207.

[0115] [Crosslinking agent] The resin composition according to this embodiment may contain a crosslinking agent (referred to as compound (E)) for the purpose of improving the durability of the release layer, particularly the durability of antistatic performance. Various known crosslinking agents can be used as the crosslinking agent, including, for example, oxazoline compounds, epoxy compounds, isocyanate compounds, carbodiimide compounds, melamine compounds, and silane coupling compounds. Among these, oxazoline compounds, epoxy compounds, isocyanate compounds, and carbodiimide compounds are preferred because of their good antistatic properties and stable coating appearance even when stored under high humidity. That is, it is preferred to include one or more crosslinking agents selected from oxazoline compounds, epoxy compounds, isocyanate compounds, carbodiimide compounds, and melamine compounds.

[0116] (Oxazoline compounds) An oxazoline compound is a compound having an oxazoline group in the molecule. A polymer containing an oxazoline group is particularly preferred. The compound can be prepared by polymerizing an addition-polymerizable oxazoline group-containing monomer alone or with other monomers. Examples of the addition-polymerizable oxazoline group-containing monomer include 2-vinyl-2-oxazoline, 2-vinyl-4-methyl-2-oxazoline, 2-vinyl-5-methyl-2-oxazoline, 2-isopropenyl-2-oxazoline, 2-isopropenyl-4-methyl-2-oxazoline, and 2-isopropenyl-5-ethyl-2-oxazoline. These monomers can be used alone or in combination. Among these, 2-isopropenyl-2-oxazoline is preferred because it is readily available industrially.

[0117] The other monomer is not limited as long as it is copolymerizable with the addition-polymerizable oxazoline group-containing monomer, and examples thereof include (meth)acrylic acid esters such as alkyl(meth)acrylate (the alkyl group can be methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl, 2-ethylhexyl, and cyclohexyl); unsaturated carboxylic acids such as acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid, crotonic acid, styrenesulfonic acid, and salts thereof (sodium salt, potassium salt, ammonium salt, tertiary amine salt, etc.); unsaturated nitriles such as acrylonitrile and methacrylonitrile; (meth)acrylamide, N-alkyl(meth)acrylate, N-methyl-N ... Examples of suitable monomers include unsaturated amides such as t)acrylamide and N,N-dialkyl(meth)acrylamide (the alkyl group can be a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a t-butyl group, a 2-ethylhexyl group, a cyclohexyl group, and the like); vinyl esters such as vinyl acetate and vinyl propionate; vinyl ethers such as methyl vinyl ether and ethyl vinyl ether; α-olefins such as ethylene and propylene; halogen-containing α,β-unsaturated monomers such as vinyl chloride and vinylidene chloride; and α,β-unsaturated aromatic monomers such as styrene and α-methylstyrene, and one or more of these monomers can be used. From the viewpoint of improving adhesion, the amount of oxazoline groups in the oxazoline compound is preferably in the range of 0.5 to 10 mmol / g, more preferably 1 to 9 mmol / g, still more preferably 3 to 8 mmol / g, and particularly preferably 4 to 6 mmol / g.

[0118] (epoxy compounds) The epoxy compound is a compound having an epoxy group in the molecule, and examples thereof include condensation products of epichlorohydrin, ethylene glycol, polyethylene glycol, glycerin, polyglycerin, bisphenol A, etc. with a hydroxyl group or an amino group, polyepoxy compounds, diepoxy compounds, monoepoxy compounds, and glycidylamine compounds. Examples of polyepoxy compounds include sorbitol polyglycidyl ether, polyglycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, diglycerol polyglycidyl ether, triglycidyl tris(2-hydroxyethyl)isocyanate, glycerol polyglycidyl ether, and trimethylolpropane polyglycidyl ether. Examples of diepoxy compounds include neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, resorcinol diglycidyl ether, ethylene glycol diglycidyl ether, and propylene glycol diglycidyl ether. Examples of monoepoxy compounds include allyl glycidyl ether, 2-ethylhexyl glycidyl ether, and phenyl glycidyl ether. Examples of glycidylamine compounds include N,N,N',N'-tetraglycidyl-m-xylylenediamine and 1,3-bis(N,N-diglycidylamino)cyclohexane. These may be used alone or in combination of two or more. From the viewpoint of improving adhesion, polyether-based epoxy compounds are preferred. In terms of the number of epoxy groups, polyepoxy compounds having three or more functional groups are preferred over those having two functional groups.

[0119] (Isocyanate compounds) The isocyanate compound refers to a compound having an isocyanate or an isocyanate derivative structure, such as a blocked isocyanate. Examples of the isocyanate include aromatic isocyanates such as tolylene diisocyanate, xylylene diisocyanate, methylene diphenyl diisocyanate, phenylene diisocyanate, and naphthalene diisocyanate, aliphatic isocyanates having an aromatic ring such as α,α,α',α'-tetramethylxylylene diisocyanate, aliphatic isocyanates such as methylene diisocyanate, propylene diisocyanate, lysine diisocyanate, trimethylhexamethylene diisocyanate, and hexamethylene diisocyanate, and alicyclic isocyanates such as cyclohexane diisocyanate, methylcyclohexane diisocyanate, isophorone diisocyanate, methylenebis(4-cyclohexyl isocyanate), and isopropylidenedicyclohexyl diisocyanate. Further examples include polymers and derivatives of these isocyanates, such as biuretized products, isocyanurated products, urethodionated products, and carbodiimide-modified products. These may be used alone or in combination of two or more. Among the above isocyanates, aliphatic isocyanates or alicyclic isocyanates are more preferred than aromatic isocyanates in order to prevent yellowing due to ultraviolet rays.

[0120] When used in the form of a blocked isocyanate, examples of the blocking agent include bisulfites, phenolic compounds such as phenol, cresol, and ethylphenol, alcoholic compounds such as propylene glycol monomethyl ether, ethylene glycol, benzyl alcohol, methanol, and ethanol, active methylene compounds such as methyl isobutanoylacetate, dimethyl malonate, diethyl malonate, methyl acetoacetate, ethyl acetoacetate, and acetylacetone, mercaptan compounds such as butyl mercaptan and dodecyl mercaptan, lactam compounds such as ε-caprolactam and δ-valerolactam, amine compounds such as diphenylaniline, aniline, and ethyleneimine, acid amide compounds of acetanilide and acetic acid amide, and oxime compounds such as formaldehyde, acetaldoxime, acetoneoxime, methyl ethyl ketoneoxime, and cyclohexanoneoxime. These may be used alone or in combination of two or more.

[0121] The isocyanate compound may be used alone or as a mixture or bond with various polymers. In order to improve the dispersibility and crosslinkability of the isocyanate compound, it is preferable to use a mixture or bond with a polyester resin or a urethane resin.

[0122] (Carbodiimide compounds) A carbodiimide compound is a compound having a carbodiimide structure, and is a compound having one or more carbodiimide structures in the molecule. For better adhesion, etc., a polycarbodiimide compound having two or more carbodiimide structures in the molecule is more preferred.

[0123] Carbodiimide compounds can be synthesized by conventionally known techniques, and generally involve the condensation reaction of a diisocyanate compound. The diisocyanate compound is not particularly limited, and both aromatic and aliphatic compounds can be used. Specific examples include tolylene diisocyanate, xylene diisocyanate, diphenylmethane diisocyanate, phenylene diisocyanate, naphthalene diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, cyclohexane diisocyanate, methylcyclohexane diisocyanate, isophorone diisocyanate, dicyclohexyl diisocyanate, and dicyclohexylmethane diisocyanate. These compounds may be used alone or in combination of two or more.

[0124] The content of carbodiimide groups contained in the carbodiimide compound, in terms of carbodiimide equivalent (weight [g] of carbodiimide compound required to provide 1 mol of carbodiimide groups), is usually in the range of 100 to 1000, preferably 250 to 800, and more preferably 300 to 700. Use in this range tends to improve the durability of the coating film.

[0125] Furthermore, within the scope of the present invention, in order to improve the water solubility or water dispersibility of the polycarbodiimide-based compound, a surfactant may be added, or a hydrophilic monomer such as a polyalkylene oxide, a quaternary ammonium salt of a dialkylamino alcohol, or a hydroxyalkyl sulfonate may be added.

[0126] (melamine compounds) The melamine compound refers to a compound having a melamine skeleton within the compound. Examples of such compounds include alkylolated melamine derivatives, compounds obtained by reacting alkylolated melamine derivatives with alcohols to partially or completely etherify them, and mixtures thereof. Suitable alcohols for etherification include methyl alcohol, ethyl alcohol, isopropyl alcohol, n-butanol, and isobutanol. The melamine compound may be a monomer or a dimer or higher polymer, or a mixture thereof. Furthermore, melamine may be partially co-condensed with urea or the like, and a catalyst may be used to increase the reactivity of the melamine compound.

[0127] (Silane coupling compounds) A silane coupling compound is an organosilicon compound that has an organic functional group and a hydrolyzable group such as an alkoxy group in one molecule. For example, epoxy group-containing compounds such as 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, and 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane; vinyl group-containing compounds such as vinyltrimethoxysilane and vinyltriethoxysilane; styryl group-containing compounds such as p-styryltrimethoxysilane and p-styryltriethoxysilane; (meth)acrylic group-containing compounds such as 3-(meth)acryloxypropyltrimethoxysilane, 3-(meth)acryloxypropyltriethoxysilane, 3-(meth)acryloxypropylmethyldimethoxysilane, and 3-(meth)acryloxypropylmethyldiethoxysilane; 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-2-(aminoethyl)- Examples of suitable compounds include amino group-containing compounds such as 3-aminopropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropyltriethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldiethoxysilane, 3-triethoxysilyl-N-(1,3-dimethylbutylidene)propylamine, N-phenyl-3-aminopropyltrimethoxysilane, and N-phenyl-3-aminopropyltriethoxysilane; isocyanurate group-containing compounds such as tris(trimethoxysilylpropyl)isocyanurate and tris(triethoxysilylpropyl)isocyanurate; and mercapto group-containing compounds such as 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-mercaptopropylmethyldimethoxysilane, and 3-mercaptopropylmethyldiethoxysilane. These compounds may be used alone or in combination of two or more.

[0128] [binder] The resin composition according to this embodiment may contain a binder (referred to as compound (F)) for the purpose of improving coating appearance and transparency. Various known polymers, such as polyester resin, acrylic resin, and urethane resin, may also be used in combination as the binder. Furthermore, particles may also be used in combination for the purpose of improving anti-blocking properties and slip properties, within the scope of the present invention.

[0129] As the binder, from the viewpoint of improving the durability of the release layer, an acrylic resin is preferred, and in particular, a (meth)acrylic polymer having a styrene structure is more preferred. The styrene structure refers to styrene and styrene derivatives, and for example, styrene may have an alkyl group such as a methyl group or an ethyl group, a phenyl group, or the like introduced as a substituent. From the viewpoint of the effect of preventing oligomer precipitation by heat treatment, styrene substituted with an alkyl group having 4 or less carbon atoms or styrene without a substituent is preferred, and styrene is more preferred.

[0130] The (meth)acrylic polymer is a polymer having (meth)acrylic acid or a (meth)acrylic acid alkyl ester as a constituent unit, and the compound (F) is a copolymer of styrene or a styrene derivative and (meth)acrylic acid or a (meth)acrylic acid alkyl ester. In the present invention, the term "(meth)acrylic acid" refers to either or both of "acrylic acid" and "methacrylic acid." Similarly, "(meth)acrylate" refers to either or both of "acrylate" and "methacrylate," and "(meth)acryloyl" refers to either or both of "acryloyl" and "methacryloyl."

[0131] Examples of the (meth)acrylic acid alkyl ester include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, sec-butyl (meth)acrylate, t-butyl (meth)acrylate, n-pentyl (meth)acrylate, n-hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, and lauryl (meth)acrylate. Hydroxyl group-containing (meth)acrylic acid alkyl esters such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate may also be used. These may be used alone or in combination of two or more. Among these, (meth)acrylic acid is preferred, and acrylic acid is more preferred, from the viewpoint of preventing oligomer precipitation due to heat treatment. That is, the acrylic structure of the (meth)acrylic polymer is preferably a (meth)acrylic acid structure. The (meth)acrylic polymer may have a radically polymerizable double bond.

[0132] In addition, (meth)acrylic polymers having a styrene structure can also be combined with other polymerizable monomers copolymerizable therewith. Examples of copolymerizable monomers include hydroxyl group-containing dibasic acid ester compounds such as monobutylhydroxyfumarate and monobutylhydroxyitaconate, various nitrogen-containing compounds such as (meth)acrylamide, diacetoneacrylamide, N-methylolacrylamide, and (meth)acrylonitrile, various vinyl esters such as vinyl propionate and vinyl acetate, various silicon-containing polymerizable monomers such as γ-methacryloxypropyltrimethoxysilane and vinyltrimethoxysilane, phosphorus-containing vinyl monomers, various vinyl halides such as vinyl chloride and vinylidene chloride, and various conjugated dienes such as butadiene.

[0133] [Other ingredients] The resin composition of the release layer may contain other components within a range that does not impair the gist of the present invention (e.g., 5% by mass or less of the resin composition). For example, particles may be used in combination for the purpose of improving blocking properties or slippage. Examples of such particles include those exemplified as particles that can be incorporated into polyester films. In addition to the above-mentioned particles, additives that are generally incorporated into resin compositions may be contained as needed, such as heat stabilizers, antioxidants, antistatic agents, colorants, ultraviolet absorbers, lubricants, plasticizers, light stabilizers, surfactants, antibacterial agents, desiccants, antiblocking agents, flame retardants, crosslinking agents, curing agents, foaming agents, crystal nucleating agents, antifogging agents, biodegradable additives, silane coupling agents, and oxygen absorbers. These may be used alone or in combination of two or more.

[0134] The content of compound (A) in the resin composition is preferably 0.1 to 50 mass%, more preferably 0.3 to 40 mass%, even more preferably 0.6 to 30 mass%, still more preferably 0.8 to 20 mass%, even more preferably 1 to 15 mass%, and still more preferably 1.2 to 10 mass%, as a proportion of all nonvolatile components in the resin composition. When the content of compound (A) is the upper limit or less, the release layer tends to have good easy releasability, antistatic properties, and transparency. On the other hand, when the content of the compound (A) is equal to or greater than the lower limit, the resistance to scratches and abrasions tends to be better.

[0135] The content of compound (B) in the resin composition is preferably 2 to 30 mass%, more preferably 3 to 15 mass%, and even more preferably 5 to 12 mass%, based on the total nonvolatile components in the resin composition. When the content of compound (B) is equal to or less than the upper limit, the strength and transparency of the release layer tend to be good. On the other hand, when the content of compound (B) is equal to or more than the lower limit, the antistatic performance tends to be good.

[0136] The content of compound (C) in the resin composition is preferably 10 to 85% by mass, more preferably 20 to 80% by mass, even more preferably 30 to 75% by mass, even more preferably 35 to 70% by mass, and even more preferably 40 to 65% by mass, as a proportion of all nonvolatile components in the resin composition. When the content of compound (C) is below the upper limit, the proportions of other components are increased, and the antistatic properties and film-forming properties of the release layer tend to be good. On the other hand, when the content of compound (C) is above the lower limit, the transparency of the release layer tends to be good.

[0137] The content of compound (D) in the resin composition is preferably 0.1 to 15 mass%, more preferably 0.5 to 10 mass%, and even more preferably 1 to 8 mass%, based on the total nonvolatile components in the resin composition. When the content of compound (D) is equal to or less than the upper limit, the release layer tends to have good antistatic properties and transparency. On the other hand, when the content of compound (D) is equal to or more than the lower limit, the release layer tends to have good resistance to scratches and abrasions.

[0138] When the resin composition contains a crosslinking agent (compound (E)), the content of compound (E) in the resin composition is preferably 25% by mass or less, more preferably in the range of 3 to 20% by mass, as a proportion of all non-volatile components in the resin composition. When the content of compound (E) is equal to or less than the upper limit, the release layer tends to have good antistatic properties and transparency. On the other hand, when the content of compound (E) is equal to or more than the lower limit, the resistance to scratches and abrasions tends to be better.

[0139] When the resin composition contains a binder (compound (F)), the content of compound (F) in the resin composition is preferably 35% by mass or less, more preferably 3 to 30% by mass, even more preferably 5 to 25% by mass, and even more preferably 7 to 20% by mass, as a proportion of all non-volatile components in the resin composition. When the content of compound (F) is equal to or less than the upper limit, the release layer tends to have good antistatic properties. On the other hand, when the content of compound (F) is equal to or more than the lower limit, the release layer tends to have better resistance to scratches and abrasions.

[0140] The resin composition for forming the release layer can be used as a release agent, and such a release agent can be used to produce the present laminate, such as a release film, in which a release layer is formed on a substrate film.

[0141] <Method for forming release layer> Next, a method for forming the release layer that constitutes the present laminate will be described. Examples of methods for forming the release layer include a method using a solution or dispersion (coating liquid) of the resin composition, a method using an extruder to melt-mold a pellet-shaped composition containing the resin composition, etc. When a solution or dispersion (coating liquid) of the resin composition is used, the solid content (total non-volatile components) is preferably about 0.1 to 50% by mass, more preferably 0.5 to 30% by weight, and even more preferably 5 to 20% by weight.

[0142] The method for coating the release layer is not particularly limited, and any conventionally known coating method can be used, such as reverse gravure coating, direct gravure coating, roll coating, die coating, bar coating, curtain coating, and the like. The release layer can be applied by in-line coating or off-line coating. The drying and curing conditions are not particularly limited. For example, when the release layer is formed by off-line coating, the heat treatment is typically carried out at 80 to 200°C for 3 to 40 seconds, preferably at 100 to 180°C for 3 to 40 seconds. On the other hand, when the release layer is formed by in-line coating, the heat treatment is typically carried out at 70 to 280°C for 3 to 200 seconds.

[0143] In this embodiment, it is preferable to form the protective layer by in-line coating, which treats the film surface during the film-forming process of the substrate film. Inline coating is a method of coating within the base film production process. Specifically, it is a method of coating at any stage between melt extrusion of polyester, stretching, heat setting, and winding up. Typically, coating is performed on an unstretched sheet obtained by melting and quenching, a stretched uniaxially stretched film, a biaxially stretched film before heat setting, or a film after heat setting and before winding up. While not limited to the following, for example, in sequential biaxial stretching, a method in which coating is performed on a uniaxially stretched film stretched in the longitudinal direction (machine direction) and then stretched in the transverse direction is particularly advantageous. This method offers advantages in terms of production cost, as film formation and release layer formation can be performed simultaneously. Furthermore, since stretching is performed after coating, the thickness of the release layer can be changed by adjusting the stretch ratio, making thin film coating easier than offline coating. Furthermore, by providing a release layer on the film before stretching, the release layer can be stretched together with the base film, thereby firmly adhering the release layer to the base film. Furthermore, in the production of biaxially stretched polyester films, by stretching the film while holding the film edges with clips or the like, the film can be restrained in both the longitudinal and transverse directions, and in the heat setting process, high temperatures can be applied while maintaining flatness and without wrinkles, etc. Therefore, the heat treatment performed after coating can be performed at high temperatures that cannot be achieved by other methods, improving the film-forming properties of the release layer and enabling stronger adhesion between the release layer and the polyester film.Furthermore, a strong release layer can be formed, and performance such as adhesion to various functional layers that can be formed on the release layer and resistance to moisture and heat can be improved.

[0144] When providing a release layer by inline coating, it is preferable to manufacture the laminate in such a manner that the above-mentioned series of compounds are made into a solution or dispersion (coating liquid) and a resin composition with an adjusted solid content concentration is applied onto a substrate film.

[0145] Regardless of whether off-line coating or in-line coating is used, heat treatment and irradiation with active energy rays such as ultraviolet radiation may be used in combination as needed. The substrate film constituting the present laminate may be previously subjected to a surface treatment such as a corona treatment or a plasma treatment.

[0146] The various components in the release layer can be analyzed by, for example, TOF-SIMS, ESCA, fluorescent X-ray analysis, or the like.

[0147] <<Applications of laminates>> From the viewpoint that the present laminate has excellent easy release properties as a release film for pressure sensitive adhesives, particularly silicone-based pressure sensitive adhesives, it can be suitably used as an easy release film for silicone-based pressure sensitive adhesives in the following forms, although the present invention is not limited to such uses.

[0148] In this laminate, which is configured by laminating the present laminate (light release film) on one side of a silicone adhesive layer made of a silicone adhesive, and laminating a release film (hereinafter referred to as a "heavy release film") with a higher peel strength than the present laminate (light release film) on the other side of the silicone adhesive layer, the present laminate (light release film) can be peeled off, the exposed surface of the silicone adhesive layer can be attached to an "adherend," the silicone adhesive layer can be cured, and then the heavy release film can be peeled off. However, the method of use is not limited to this.

[0149] As the adhesive, for example, known adhesive resins such as silicone-based, acrylic-based, and rubber-based adhesives can be used. In the present invention, silicone-based adhesives are preferred, and addition-curing silicone-based adhesives are more preferred.

[0150] The adherend may be an optical member, such as a resin film selected from a polyester film, a polyimide film, or a cyclic polyolefin film, or a glass substrate, as described above. The laminate can be suitably used for silicone-based pressure-sensitive adhesives that have good durability and transparency. Therefore, by taking advantage of the heat resistance, cold resistance, weather resistance and high transparency inherent in the silicone-based pressure-sensitive adhesive itself, the laminate can be suitably used in the manufacture of displays such as touch panels, and in particular in the manufacture of in-vehicle displays such as car navigation systems.

[0151] <<Physical properties of laminates>> The present laminate has a release layer having the above-mentioned excellent easy releasability and antistatic properties upon peeling, on at least one surface of the substrate film. Therefore, the present laminate also has properties similar to those of the release layer described above, and has excellent easy releasability and antistatic properties upon peeling. [Example]

[0152] The present invention will be explained in more detail below by way of examples, but the present invention is not limited to the following examples as long as it does not depart from the gist of the invention. The measurement and evaluation methods used in the present invention are as follows.

[0153] <Evaluation method> (1) Intrinsic viscosity of polyester 1 g of polyester, from which components incompatible with the polyester had been removed, was precisely weighed and dissolved in 100 mL of a 50 / 50 (mass ratio) phenol / tetrachloroethane mixed solvent. The viscosity (IV) was measured at 30°C using a viscosity (IV) measuring device (Rigo Co., Ltd., "VMS-022UPC·F10").

[0154] (2) Average particle size The films of the examples and comparative examples were observed using a transmission electron microscope (TEM) (Hitachi High-Technologies Corporation, "H-7650", acceleration voltage 100 kV), and the average particle size of 10 particles was taken as the average particle size.

[0155] (3) Coating amount of release layer The concentration of nonvolatile components in the coating solution was calculated from the coating amount before drying, which was derived from the amount of coating solution consumed.

[0156] (4) Peeling strength of release layer The following silicone adhesive composition was applied to the surface of a film not provided with a release layer (the film of Comparative Example 4 described below), and heat-treated at 120°C for 6 minutes to form a 5 μm-thick silicone adhesive layer. After aging at room temperature (23°C) for 24 hours, the adhesive layer side of the film was attached to the release layer surface of the release film of the Examples and Comparative Examples, pressed with a rubber roller, and cut into a piece 5 cm wide x 10 cm long. This was left to stand at room temperature (23°C) for 12 hours to obtain an evaluation sample. The peel force when peeling the release film from the silicone adhesive layer of the evaluation sample was measured, and this was taken as the peel force of the release layer. The peel strength was measured using a high-speed peel tester (manufactured by Tester Sangyo Co., Ltd., "High-Speed ​​Peel Tester TE-702") at a pulling speed of 5 m / min and a 180° peel angle. (Silicone pressure-sensitive adhesive composition) 50 parts by weight of silicone adhesive (Shin-Etsu Chemical Co., Ltd., "KR-3704") 0.25 parts by mass of curing catalyst (Shin-Etsu Chemical Co., Ltd., "PL-50T") Toluene 50 parts by mass

[0157] (5) Measurement method for peeling charge During peeling in the method for measuring peel force (4) above, the surface potential was measured using a potential meter (Kasuga Electric Co., Ltd., "Digital Low Potential Meter KSD-3000") at a position 1 cm away from the peel surface at the center of the silicone adhesive layer, and this was taken as the peel charge.

[0158] The polyester raw materials for the base films used in the examples and comparative examples are as follows:

[0159] <Polyester (1)> Substantially particle-free polyethylene terephthalate with an intrinsic viscosity of 0.64 dL / g

[0160] <Polyester (2)> Polyethylene terephthalate with an intrinsic viscosity of 0.65 dL / g containing 0.2% by mass of amorphous silica with an average particle size of 2.4 μm

[0161] The following coating liquid raw materials were used to form the release layer.

[0162] <Coating liquid raw material 1> (Synthesis example of 4FPI modified PVA) 10 g of PVA (Mitsubishi Chemical Corporation, "NL-05"; degree of polymerization: 500, degree of saponification: 99 mol%, ethylene content: 0 mol%) and 104 g of toluene were weighed into a round-bottom separable flask, and the aluminum block bath temperature was set to 120 °C for 30 minutes to perform azeotropic dehydration. 104 g of DMSO was then added and azeotropic dehydration was continued for 30 minutes. The temperature was then lowered to 100 °C and the mixture was stirred for 15 minutes. 42.7 g of octadecyl isocyanate was then added and stirred for 120 minutes. 2.5 g of 4-fluorophenyl isocyanate (4FPI) was then added and stirred for 60 minutes. At this point, the reaction mixture had become a brown homogeneous solution. The reaction mixture was transferred to a 2 L beaker, and 1 kg of acetone was added with vigorous stirring. A milky white granular solid was precipitated, which was then separated by suction filtration. The solid was further washed twice with 300 g of acetone, and then vacuum dried at 60°C for 24 hours to obtain a sample as a milky white granular solid.

[0163] The amount of modification of the obtained 4FPI-modified PVA was 1 Measurements were performed using H-NMR (solvent: orthodichlorobenzene-d4), and the amount of 4FPI modification was 6 mol% (calculated from methine protons at 7.7-8.0 ppm and methylene protons in the vinyl alcohol main chain), and the amount of octadecyl modification was 60 mol% (calculated from methyl protons at 1.0-1.3 ppm and methylene protons in the vinyl alcohol main chain).

[0164] <Coating liquid raw material 2> (Synthesis example of 4OCF3PI modified PVA) 10 g of PVA (Mitsubishi Chemical Corporation, "NL-05"; degree of polymerization: 500, degree of saponification: 99 mol%, ethylene content: 0 mol%) and 104 g of toluene were weighed into a round-bottom separable flask, and the aluminum block bath temperature was set to 120 °C for 30 minutes to perform azeotropic dehydration. 104 g of DMSO was added and azeotropic dehydration was continued for 30 minutes. The temperature was then lowered to 100 °C and the mixture was stirred for 15 minutes. 42.7 g of octadecyl isocyanate was added and stirred for 120 minutes. 3.6 g of 4-trifluoromethoxyphenyl isocyanate (4OCF3PI) was then added and stirred for 60 minutes. At this point, the reaction mixture had become a brown homogeneous solution. The reaction mixture was transferred to a 2 L beaker, and 1 kg of acetone was added with vigorous stirring to reprecipitate a milky-white granular solid, which was then separated by suction filtration. The solid was further washed twice with 300 g of acetone, and then vacuum dried at 60°C for 24 hours to obtain a sample as a milky white granular solid.

[0165] The amount of modification of the obtained 4OCF3PI-modified PVA was 1 Measurements were performed using H-NMR (solvent: orthodichlorobenzene-d4), and the amount of 4FPI modification was 6 mol% (calculated from methine protons at 7.7-8.0 ppm and methylene protons in the vinyl alcohol main chain), and the amount of octadecyl modification was 60 mol% (calculated from methyl protons at 1.0-1.3 ppm and methylene protons in the vinyl alcohol main chain).

[0166] <Coating liquid raw material 3> (Example of synthesis of PFA-modified PVA) 53.1 g of pentafluoropropionic acid (PFA), 30.0 g of water, and 0.6 g of p-toluenesulfonic acid were weighed into a round-bottom flask, placed in an aluminum block bath, and 10 g of PVA (Mitsubishi Chemical Corporation, "NL-05"; degree of polymerization: 500, degree of saponification: 99 mol%, ethylene content: 0 mol%) was added while stirring. The temperature was set to 90 °C and the mixture was stirred for 180 minutes. At this point, a pale yellow solution was obtained. After cooling to 23 °C, 100 g of ethyl acetate was added to reprecipitate a gel-like solid, and the supernatant was removed. This process of adding 100 g of ethyl acetate and removing the supernatant was repeated twice, followed by overnight vacuum drying at 60 °C to obtain pentafluoropropionyl PVA as a milky-white resin mass. 10.9 g of the pentafluoropropionyl PVA and 104 g of xylene were weighed into a round-bottom separable flask, and the aluminum block bath was set to 140 °C and refluxed. Further, 47.8 g of octadecyl isocyanate was added and stirred for 360 minutes. At this point, the solution became brown, containing some dark brown solids. The solids were removed using a metal mesh and transferred to a 2 L beaker. 1 kg of acetone was added with vigorous stirring to reprecipitate a brown granular solid, which was then separated by suction filtration. The solid was washed twice with 300 g of acetone, and vacuum dried at 60°C for 24 hours to obtain a sample as a brown granular solid. The degree of modification of the obtained pentafluoroethylene-modified PVA was confirmed by NMR, and the degree of pentafluoroethylene modification was 10 mol % and the degree of octadecyl modification was 79 mol %.

[0167] <Coating liquid raw material 4> (non-fluorine-modified PVA) A compound containing a long-chain alkyl group, in which octadecyl isocyanate is added to polyvinyl alcohol with an average degree of polymerization of 500 and a degree of saponification of 88 mol% ("Rezem T-738" manufactured by Chukyo Yushi Co., Ltd.)

[0168] <Coating liquid raw material 5> Aqueous dispersion of a copolymer compound whose main components are perfluoroalkyl group-containing acrylate and long-chain alkyl group-containing acrylate (AGC Corporation, "Asahiguard E400")

[0169] <Coating liquid raw material 6> Aqueous dispersion of a copolymer compound whose main components are a branched perfluoroalkyl group-containing acrylate and a long-chain alkyl group-containing acrylate (NEOS Corporation, "Flease 6012")

[0170] A laminate having a release layer on the surface of a substrate film was prepared as follows.

[0171] [Example 1] A 92 / 8 mass blend of polyester (1) and polyester (2) was used as the raw material for Layer A, and polyester (1) alone was used as the raw material for Layer B. The materials were fed into an extruder, heated and melted at 285°C, and the A layer was divided into two layers, forming an outermost layer (surface layer), and the B layer was used as the middle layer. The resulting mixture was co-extruded to a thickness ratio of A / B / A = 5 / 90 / 5. The resulting film was then cooled and solidified while in close contact with a mirror-finished cooling drum at a surface temperature of 40-50°C to produce an unstretched film. This film was stretched 3.7 times in the longitudinal direction while passing through a group of heated rolls at 85°C to produce a uniaxially stretched film. The film was then introduced into a tenter stretching machine, stretched 4.3 times in the width direction at 100°C, and further heat-treated at 230°C. After that, the film was relaxed 2% in the width direction to produce a biaxially stretched film with a thickness of 50 μm. Coating solution raw material 1 diluted with toluene to a solids concentration of 1% was applied to this polyester film and dried at 120°C for 30 seconds, resulting in a coating weight of 45 mg / m after drying. 2 A release film of Example 1 having the release layer of the above formula was obtained. The evaluation results of this release film are shown in Table 1 below.

[0172] [Examples 2 to 3, Comparative Examples 1 to 3] The same procedure as in Example 1 was carried out to obtain release films of Examples 2 to 3 and Comparative Examples 1 to 3, except that the coating liquid raw materials and solvents for forming the release layer were changed to those shown in Table 1. The evaluation results are shown in Table 1 below.

[0173] Comparative Example 4 Except for not providing a release layer, a release film of Comparative Example 4 was obtained in the same manner as in Example 1. The evaluation results are shown in Table 1 below.

[0174] [Table 1]

[0175] The release films obtained in Examples 1 to 3 of the present invention had both excellent easy releasability and antistatic properties. In Comparative Example 1, in which a resin having no fluorine in the side chain was used as the release layer, not only was the peeling force greater than in Examples 1 to 3, but the absolute value of the peeling charge was also greater, resulting in poor peeling charge prevention properties. In addition, in Comparative Examples 2 and 3, in which the compound used in the release layer was replaced with an acrylic skeleton-containing compound commonly used in release layers, the peel force was as high as that of Comparative Example 4, which did not have a release layer, and it was not possible to obtain sufficiently light peelability. [Industrial Applicability]

[0176] The modified polyvinyl alcohol-based resin of the present invention exhibits excellent easy releasability and antistatic properties against peeling even with an extremely small amount of conductive agent, and in particular, has excellent easy releasability and antistatic properties against peeling with silicone pressure-sensitive adhesives, making it excellent in productivity and economy and highly promising as a release film.

Claims

1. A modified polyvinyl alcohol resin having fluorine in the side chain of the polyvinyl alcohol resin.

2. The modified polyvinyl alcohol resin according to claim 1 , wherein the side chain has a group represented by the following formula (1): 【Chemical 1】 (In the formula (1), X1 represents an ester bond, an ether bond, a urethane bond, an amide bond, or a structural unit represented by the following formula (2), and R1 represents a fluorine group, a fluorine-containing aromatic group, a fluorine-containing hydrocarbon group, a fluorine-containing alkoxyalkyl group, a fluorine-containing alkoxyaromatic group, a fluorine-containing aminoalkyl group, or a fluorine-containing aminoaromatic group.) 【Chemistry 2】

3. 3. The modified polyvinyl alcohol resin according to claim 2, wherein R1 in the formula (1) is at least one selected from the group consisting of a fluorophenyl group, a trifluoromethoxyphenyl group, and a pentafluoropropionyl group.

4. The modified polyvinyl alcohol resin according to claim 1 or 2, wherein the side chain has a group represented by the following formula (3): 【Chemistry 3】 (In the formula (3), X2 represents an ester bond, an ether bond, a urethane bond, an amide bond, or a structural unit represented by the following formula (2), and R2 represents a hydrocarbon group.) 【Chemistry 4】

5. The modified polyvinyl alcohol resin according to claim 4, wherein R2 in the formula (3) is an alkyl group having 8 or more carbon atoms.

6. The modified polyvinyl alcohol resin according to claim 1 or 2, having a structural unit represented by the following formula (4): 【Chemistry 5】 (In the formula (4), X1 represents an ester bond, an ether bond, a urethane bond, an amide bond, or a structural unit represented by the following formula (2); R1 represents a fluorine group, a fluorine-containing aromatic group, a fluorine-containing hydrocarbon group, a fluorine-containing alkoxyalkyl group, a fluorine-containing alkoxyaromatic group, a fluorine-containing aminoalkyl group, or a fluorine-containing aminoaromatic group; and R3 represents a hydrogen atom or a hydrocarbon group.) 【Chemistry 6】

7. The modified polyvinyl alcohol resin according to claim 1 or 2, wherein the resin having fluorine in a side chain has a structural unit represented by the following formula (5): 【Chemistry 7】 (In the formula (5), X2 represents an ester bond, an ether bond, a urethane bond, an amide bond, or a structural unit represented by the following formula (2), R2 represents a hydrocarbon group, and R3 represents a hydrogen atom or a hydrocarbon group.) 【Chemistry 8】

8. The modified polyvinyl alcohol resin according to claim 6, wherein the content of the structural unit represented by the formula (4) is 1 to 10 mol %.

9. The modified polyvinyl alcohol resin according to claim 7, wherein the content of the structural unit represented by the formula (5) is 30 to 90 mol %.

10. The modified polyvinyl alcohol resin according to claim 6, which has a structural unit represented by the formula (4) and a structural unit represented by the following formula (5), and the ratio of the content of the structural unit represented by the formula (4) to the content of the structural unit represented by the following formula (5) (formula (4) / formula (5)) is 0.01 to 10. 【Chemistry 9】 (In the formula (5), X2 represents an ester bond, an ether bond, a urethane bond, an amide bond, or a structural unit represented by the following formula (2), R2 represents a hydrocarbon group, and R3 represents a hydrogen atom or a hydrocarbon group.) 【Chemistry 10】

11. The modified polyvinyl alcohol resin according to claim 7, wherein R2 in the formula (5) is an alkyl group having 8 or more carbon atoms.

12. 3. The modified polyvinyl alcohol-based resin according to claim 1, wherein the modified polyvinyl alcohol-based resin is a reaction product of a polyvinyl alcohol-based resin with a fluorine-containing isocyanate and / or an alkyl isocyanate.

13. 3. The modified polyvinyl alcohol resin according to claim 1, wherein the modified polyvinyl alcohol resin is a reaction product of a polyvinyl alcohol resin with a fluorine-containing carboxylic acid and / or an alkyl isocyanate.

14. A release agent comprising the modified polyvinyl alcohol resin according to claim 1 or 2.

15. A laminate comprising a base film and a release layer comprising the modified polyvinyl alcohol resin according to claim 1 or 2 on at least one surface of the base film.

16. The laminate according to claim 15, wherein the substrate film is a polyester film.

17. The laminate of claim 15, wherein the laminate is a release film.

18. 16. The laminate according to claim 15, wherein the peel strength of the release layer under the following condition a is 20 mN / cm or less. (Condition α) A 5 μm-thick silicone adhesive layer is formed on the surface of the film, the release layer is bonded to the silicone adhesive layer, and the film is cut into a piece 5 cm wide x 10 cm long. This piece is left to stand at 23°C for 24 hours, and then the release layer is peeled from the silicone adhesive layer at 180° using a peel tester at a pulling rate of 5 m / min. The peel strength is measured.

19. 19. The laminate according to claim 18, wherein the absolute value of peel charge of the release layer under the following condition β is 430 V or less. (Condition β) During peeling under the condition α, the surface potential is measured with a potential measuring device at a position 1 cm away from the peeling surface at the center of the silicone adhesive layer, and this is taken as the peeling charge.

20. The laminate according to claim 18, wherein the adhesive forming the silicone-based adhesive layer is a silicone adhesive "KR-3704" manufactured by Shin-Etsu Chemical Co., Ltd.

Images