Polarizing film with separator and adhesive layer

Abstract

To provide a polarization film with an adhesive layer having a separator which achieves both light peelability of a separator and high temperature durability of an adhesive layer.SOLUTION: A polarization film with an adhesive layer having a separator has an adhesive layer with a separator having an adhesive layer on a separator on one surface or both surfaces of a polarization film, wherein the separator has a release layer on a base material film, the release layer contains a reactive silicone resin having a reactive functional group, and a non-reactive silicone resin having a weight average molecular weight of 400,000 or more, in 100 mass% of the total content of the reactive silicone resin and the non-reactive silicone resin, a content of the reactive silicone resin is 50-70 mass%, a content of the non-reactive silicone resin is 30-50 mass%, an elastic modulus of the release layer is less than 1.5 MPa, the adhesive layer is provided on the release layer, and the adhesive layer contains a base polymer containing 0.5 mass% or more of a carboxy group-containing monomer as a monomer unit.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a polarizing film with a pressure-sensitive adhesive layer and a separator. [Background technology]

[0002] Polarizing films are used in image display devices such as liquid crystal display devices. When attaching a polarizing film to a display panel such as a liquid crystal panel, an adhesive is usually used. Generally, an adhesive-layered polarizing film is used, in which an adhesive is provided as an adhesive layer on one side of the polarizing film in advance, because this has the advantage of not requiring a drying process for attaching the polarizing film. Furthermore, an adhesive-layered polarizing film usually has a separator (also called a release film or release liner) provided on the surface of the adhesive layer to protect the adhesive layer before attachment.

[0003] In recent years, polarized films with pressure-sensitive adhesive layers have become thinner and less stiff, which has led to the problem of difficulty in peeling the separator from the pressure-sensitive adhesive layer. Therefore, separators with easier peeling properties are required. Meanwhile, the pressure-sensitive adhesive layer is required to have functionality such as conductivity and durability. Therefore, development of polarized films with pressure-sensitive adhesive layers and separators that combine the ease of peeling of the separator with the functionality of the pressure-sensitive adhesive layer has been promoted.

[0004] For example, Patent Document 1 describes a polyester film for substrate-less double-sided PSA sheets that minimizes peel speed dependency, has good releasability, and low migration, and A polyester film has been proposed that is characterized by having a reactive silicone resin having alkenyl groups and alkyl groups as functional groups, an unreactive silicone resin having a mass average molecular weight of 400,000 or more, and a silicone-based release layer containing a platinum-based catalyst.

[0005] Furthermore, Patent Document 2 discloses a release sheet that exhibits a very small release force and can be used as an ultra-light release sheet, The film comprises a substrate and a release agent layer provided on at least one surface of the substrate, the substrate is made of a plastic film, the release agent layer is formed from a release agent composition containing a polyorganosiloxane having a weight average molecular weight of 5,000 or more and 100,000 or less, A release sheet has been proposed in which the thickness of the release agent layer is 0.3 μm or more and 1.0 μm or less. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-208863 [Patent Document 2] Japanese Patent Application Laid-Open No. 2017-149048 Summary of the Invention [Problem to be solved by the invention]

[0007] However, even when a separator having a silicone-based release layer described in Patent Document 1 or a release agent layer described in Patent Document 2 is used, the problem of difficulty in peeling the separator from the adhesive layer of a thinned polarized film with an adhesive layer could not be solved.

[0008] An object of the present invention is to provide a polarizing film with a separator and a pressure-sensitive adhesive layer, which achieves both easy releasability of the separator and high-temperature durability of the pressure-sensitive adhesive layer. [Means for solving the problem]

[0009] As a result of extensive research into solving the above problems, the present inventors have found that the above problems can be solved by a polarizing film with a pressure-sensitive adhesive layer having the following separator, and have thus completed the present invention.

[0010] The present invention provides a separator-attached pressure-sensitive adhesive layer polarizing film, in which a separator-attached pressure-sensitive adhesive layer having a pressure-sensitive adhesive layer on a separator is provided on one or both sides of a polarizing film, the separator has a release layer on a substrate film, the release layer contains a reactive silicone resin having a reactive functional group and a non-reactive silicone resin having a weight average molecular weight of 400,000 or more; the content of the reactive silicone resin is 50 to 70 mass% and the content of the non-reactive silicone resin is 30 to 50 mass% relative to 100 mass% of the total content of the reactive silicone resin and the non-reactive silicone resin; The release layer has an elastic modulus of less than 1.5 MPa, the pressure-sensitive adhesive layer is provided on the release layer, The present invention relates to a polarizing film with a pressure-sensitive adhesive layer having a separator, wherein the pressure-sensitive adhesive layer contains a base polymer containing 0.5% by mass or more of a carboxyl group-containing monomer as a monomer unit.

[0011] The pressure-sensitive adhesive layer preferably contains a conductive agent.

[0012] The surface resistance of the pressure-sensitive adhesive layer is 1.0×10 12 It is preferably Ω / □ or less.

[0013] Furthermore, the peeling force when peeling the separator from the pressure-sensitive adhesive layer is preferably 0.12 N / 50 mm or less.

[0014] The thickness of the polarizing film is preferably 100 μm or less. [Effects of the Invention]

[0015] The separator of the present invention contains a specific ratio of a reactive silicone resin having a reactive functional group and a non-reactive silicone resin having a weight-average molecular weight of 400,000 or more, and has a release layer with an elastic modulus of less than 1.5 MPa. Therefore, even in a thin polarized film with a pressure-sensitive adhesive layer, the separator can be easily peeled from the pressure-sensitive adhesive layer. Furthermore, the pressure-sensitive adhesive layer of the present invention contains a base polymer containing 0.5% by mass or more of a carboxyl group-containing monomer as a monomer unit, and therefore has excellent high-temperature durability. By using the separator and the pressure-sensitive adhesive layer in combination, a polarized film with a separator and a pressure-sensitive adhesive layer can be obtained that combines the easy peelability of the separator with the high-temperature durability of the pressure-sensitive adhesive layer. DETAILED DESCRIPTION OF THE INVENTION

[0016] The separator-containing pressure-sensitive adhesive layer polarizing film of the present invention has a separator-containing pressure-sensitive adhesive layer, which has a pressure-sensitive adhesive layer on a separator, provided on one or both sides of the polarizing film. Each of the constituent members will be described in detail below.

[0017] <Separator-attached adhesive layer> The separator-attached pressure-sensitive adhesive layer of the present invention has a pressure-sensitive adhesive layer on a separator, and the separator has a release layer on a substrate film. The pressure-sensitive adhesive layer is provided on the release layer. The separator may also have an oligomer blocking layer between the substrate film and the release layer.

[0018] <Base film> The substrate film can be a plastic film. Examples of the plastic film include polyolefin films such as polyethylene film, polypropylene film, polybutene film, polybutadiene film, and polymethylpentene film; vinyl chloride films such as polyvinyl chloride film and vinyl chloride copolymer film; polyester films such as polyethylene terephthalate film, polybutylene terephthalate film, and polynaphthylene terephthalate film; and polyurethane films and ethylene-vinyl acetate copolymer films. Of the plastic films, polyester films are preferably used.

[0019] The thickness of the base film is usually 5 to 200 μm, preferably 5 to 100 μm, and more preferably 10 to 50 μm. The base film may be subjected to a surface treatment such as a corona treatment or a plasma treatment.

[0020] <Release layer> The release layer is provided to improve releasability from the pressure-sensitive adhesive layer. The release layer is formed from a silicone-based release agent, which contains a reactive silicone resin having a reactive functional group and a non-reactive silicone resin having a weight-average molecular weight of 400,000 or more. By using a reactive silicone resin having a reactive functional group, a crosslinked structure via the reactive functional group can be formed in the release layer by heating or irradiation with active energy rays, making it easier to adjust the elastic modulus of the release layer to the desired range. Furthermore, by using a non-reactive silicone resin having a weight-average molecular weight of 400,000 or more, easy releasability can be imparted. The release layer can be formed as a coating layer on a substrate film or an oligomer blocking layer. The release layer can also be formed by transfer.

[0021] Examples of reactive silicone resins having reactive functional groups include polyorganosiloxanes having reactive functional groups. Examples of polyorganosiloxanes include polydimethylsiloxane, polyphenylmethylsiloxane, and polydiphenylsiloxane. One type of polyorganosiloxane may be used alone, or two or more types may be used in combination. The reactive functional group may be introduced into one end of the polyorganosiloxane, both ends, or a side chain. Examples of the reactive functional group include alkenyl groups having 2 to 10 carbon atoms. Examples of the alkenyl group include vinyl groups, allyl groups, propenyl groups, butenyl groups, pentenyl groups, hexenyl groups, heptenyl groups, and octenyl groups.

[0022] Examples of reactive silicone resins having reactive functional groups include KS-774, KS-775, KS-778, KS-779H, KS-847H, KS-856, X-62-2422, X-62-2461, X-62-1387, X-62-5039, X-62-5040, KNS-3051, X-62-1496, KNS320A, KNS316, X-62-1574A / B, X-62-7052, X-62-7028A / B, X-62-7619, and X-62-7213 manufactured by Shin-Etsu Chemical Co., Ltd.; and YSR-3022, TPR-6700, TPR-6720, and TPR- 6721, TPR6500, TPR6501, UV9300, UV9425, XS56-A2775, XS56-A2982, XS56-C6010, XS56-C4880, UV9430, TPR6600, TPR6604, TPR6605; SRX357, SRX211 manufactured by Toray Dow Corning Co., Ltd. Examples include SD7220, SD7292, LTC750A, LTC760A, LTC303E, LTC300B, LTC856, SP7259, BY24-468C, SP7248S, BY24-452, DKQ3-202, DKQ3-203, DKQ3-204, DKQ3-205, and DKQ3-210.

[0023] Examples of non-reactive silicone resins having a weight average molecular weight of 400,000 or more include polyorganosiloxanes having a weight average molecular weight of 400,000 or more, and preferably polyorganosiloxanes represented by the following general formula (A). R3SiO(R2SiO) n SiR3(A) (In the formula, each R is independently a hydrocarbon group having no aliphatic unsaturated bonds, and n is a positive integer.)

[0024] The weight-average molecular weight of the non-reactive silicone resin is preferably 500,000 or more, more preferably 600,000 or more, from the viewpoint of imparting easy releasability to the release layer, and is preferably 1,000,000 or less, more preferably 900,000 or less, from the viewpoint of preventing the elastic modulus of the release layer from becoming too high. The weight-average molecular weight is measured by GPC (gel permeation chromatography) and calculated in terms of polystyrene.

[0025] In the release layer, from the viewpoint of adjusting the elastic modulus of the release layer to less than 1.5 MPa and imparting excellent easy releasability to the release layer, the content of the reactive silicone resin is 50 to 70 mass% and the content of the non-reactive silicone resin is 30 to 50 mass%, of which the total content of the reactive silicone resin and the non-reactive silicone resin is 100 mass%, preferably the content of the reactive silicone resin is 55 to 65 mass% and the content of the non-reactive silicone resin is 35 to 45 mass%, more preferably the content of the reactive silicone resin is 57 to 63 mass% and the content of the non-reactive silicone resin is 37 to 43 mass%.

[0026] The release layer may contain, in addition to the silicone resin, a crosslinking agent, a catalyst, a reaction inhibitor, an adhesion improver, and the like.

[0027] The release layer can be formed, for example, by applying a composition containing the above materials to the substrate film or the oligomer blocking layer by a conventional coating method such as reverse gravure coating, bar coating, or die coating, and then curing the composition by heat treatment, usually at about 120 to 200° C. for 30 seconds to 30 minutes. If necessary, the heat treatment may be combined with irradiation with active energy rays such as ultraviolet light.

[0028] The thickness of the release layer is usually 10 to 2000 nm, preferably 10 to 1000 nm, more preferably 10 to 500 nm, and even more preferably 50 to 300 nm.

[0029] The elastic modulus of the release layer is less than 1.5 MPa, preferably 1.4 MPa or less, more preferably 1.3 MPa or less, and even more preferably 1.2 MPa or less, from the viewpoint of imparting excellent easy releasability to the release layer. Furthermore, the elastic modulus of the release layer is preferably 0.5 MPa or more, more preferably 0.75 MPa or more, and even more preferably 0.9 MPa or more, from the viewpoint of preventing the release layer from falling off. The elastic modulus of the release layer is measured by the method described in the examples.

[0030] <Oligomer prevention layer> The oligomer blocking layer is a functional layer that prevents oligomers contained in the substrate film from eluting into the pressure-sensitive adhesive layer. Materials for forming the oligomer blocking layer can be inorganic or organic, or composites thereof. Examples of inorganic materials include silica-based materials, metals such as gold, silver, platinum, palladium, copper, aluminum, nickel, chromium, titanium, iron, cobalt, or tin, or alloys thereof, metal oxides such as indium oxide, tin oxide, titanium oxide, cadmium oxide, or mixtures thereof, and other metal compounds such as copper iodide. Examples of organic materials include polyvinyl alcohol-based resins, acrylic resins, urethane-based resins, melamine-based resins, UV-curable resins, and epoxy-based resins. Examples of composite materials include mixtures of the organic materials with inorganic particles such as alumina, silica, or mica.

[0031] The oligomer blocking layer is preferably formed from a composition containing a silica-based material and a polyvinyl alcohol-based resin.

[0032] <Silica-based materials> The silica-based material may, for example, be an organosiloxane represented by the following general formula (I). [ka]

[0033] In the general formula (I), R 1 and R 2 are each independently an organic group containing an epoxy group such as a γ-glycidoxypropyl group or a 3,4-epoxycyclohexylethyl group, or an alkoxy group such as a methoxy group or an ethoxy group, and R 3 is an alkoxy group such as a methoxy group or an ethoxy group, or a group represented by the following general formula (II): n and m are integers of 0 to 10. [ka]

[0034] In the general formula (II), R 4 is R 1 group or R 2 The epoxy group-containing organic group or alkoxy group is the same as the group.

[0035] Specific examples of the organosiloxane include monomers such as γ-glycidoxypropyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane, 5,6-epoxycyclohexyltriethoxysilane, and tetraethoxysilane, as well as hydrolysis products (oligomers) of these monomers or mixtures of these monomers.

[0036] The silica-based material may be a silane compound having an amino group, and the silane compound having an amino group is preferably an alkoxysilane represented by the following general formula (III): YR-Si-(X)3(III) (In the general formula (III), Y represents an amino group, R represents an alkylene group such as methylene, ethylene, or propylene, and X represents an alkoxy group such as a methoxy group or an ethoxy group, an alkyl group, or an organic functional group having any of these groups, and at least one of them is an alkoxy group.)

[0037] Specific examples of the silane compound having an amino group include N-β(aminoethyl)γ-aminopropyltrimethoxysilane, N-β(aminoethyl)γ-aminopropyltriethoxysilane, N-β(aminoethyl)γ-aminopropylmethyldimethoxysilane, γ-aminopropyltrimethoxysilane, and N-phenyl-γ-aminopropyltrimethoxysilane.

[0038] Other examples of the silica-based material include (meth)acrylic group-containing silane compounds such as 3-acryloxypropyltrimethoxysilane and 3-methacryloxypropyltriethoxysilane, and isocyanate group-containing silane compounds such as 3-isocyanatepropyltriethoxysilane.

[0039] Specific examples of the silica-based material include KR-401N, X-40-9227, X-40-9247, KR-510, KR-9218, KR-213, KR-217, X-41-1053, X-40-1056, X-41-1805, X-41-1810, X-40-2651, X-40-2652B, X-40-2655A, X-40-2761, and X-40-2672 manufactured by Shin-Etsu Chemical Co., Ltd.

[0040] The silica-based materials may be used alone or in combination of two or more.

[0041] The oligomer blocking layer formed from the silica-based material may contain, as necessary, an organic compound having a metal element (a metal compound such as a metal chelate), a catalyst, etc. Only one type of organic metal compound having a metal element may be used, or two or more types may be used.

[0042] Among the organic metal compounds containing the above metal elements, organic compounds containing aluminum, titanium, and zirconium, each having a chelate structure, are preferred because they have particularly good oligomer elution prevention properties. Such compounds are specifically described in "Crosslinking Agent Handbook" (edited by Yamashita Shinzo and Kaneko Tosuke, Taiseisha Co., Ltd., 1990 edition).

[0043] The oligomer blocking layer made of the silica-based material can be formed by dissolving the silica-based material in a solvent such as alcohol, applying the solution to a substrate film, and then drying the solution. The concentration of the solution containing the silica-based material is not particularly limited, but is preferably about 0.1 to 40% by weight. The drying temperature after application is not particularly limited, but is preferably about 100 to 150°C. The drying time after application is not particularly limited, but is preferably about 30 seconds to 30 minutes.

[0044] <Composition containing polyvinyl alcohol-based resin> The polyvinyl alcohol resin may be polyvinyl alcohol or a derivative thereof. Examples of polyvinyl alcohol derivatives include polyvinyl formal, polyvinyl acetal, and the like, as well as those modified with olefins such as ethylene and propylene, unsaturated carboxylic acids such as acrylic acid, methacrylic acid, and crotonic acid, and alkyl esters thereof, and acrylamide. Only one type of polyvinyl alcohol resin may be used, or two or more types may be used.

[0045] The degree of polymerization of the polyvinyl alcohol resin is not particularly limited, but is usually 100 or more, preferably 300 to 40000. On the other hand, the degree of saponification of the polyvinyl alcohol resin is not particularly limited, but is preferably 70 mol % or more, preferably 80 mol % or more and 99.9 mol % or less.

[0046] The composition containing the polyvinyl alcohol resin may contain a binder polymer. Examples of binder polymers include polyacrylamides, polyalkylene glycols, polyalkyleneimines, methylcellulose, hydroxycellulose, starches, polyurethanes, polyesters, polyacrylates, chlorine-based polymers (such as polyvinyl chloride and vinyl chloride-vinyl acetate copolymers), and polyolefins. Among these, organic polymers that can be used as nonionic, cationic, or amphoteric aqueous solutions or dispersions are preferred when the oligomer blocking layer is applied by a coating and stretching method. Among these, polyurethanes, polyesters, and polyacrylates provide excellent adhesion. These polymers can be made hydrophilic by copolymerizing a nonionic, cationic, or amphoteric hydrophilic component as one of their monomer components, making them water-dispersible.

[0047] The composition containing the polyvinyl alcohol resin may contain a crosslinking agent. Examples of the crosslinking agent include methylolated or alkylolated urea compounds, melamine compounds, guanamine compounds, acrylamide compounds, polyamide compounds, epoxy compounds, aziridine compounds, blocked polyisocyanates, silane coupling agents, titanium coupling agents, and zircoaluminate coupling agents. These crosslinking components may be bonded to the binder polymer in advance.

[0048] The composition containing the polyvinyl alcohol resin may contain inorganic particles, such as silica, alumina, kaolin, calcium carbonate, titanium oxide, and barium salts, for the purpose of improving the adhesion and slip properties of the oligomer prevention layer.

[0049] The oligomer blocking layer can be formed by applying a solution of the polyvinyl alcohol-based resin-containing composition dissolved in a solvent such as water or alcohol to a substrate film and then drying the solution. The solution may be stretched during drying. The concentration of the solution containing the polyvinyl alcohol-based resin-containing composition is not particularly limited, but is preferably about 0.1 to 40% by weight. The drying temperature after application is not particularly limited, but is preferably about 60 to 200°C. The drying time after application is not particularly limited, but is preferably about 3 to 60 seconds. If necessary, heat treatment and irradiation with active energy rays such as ultraviolet light may be used in combination.

[0050] The content of the polyvinyl alcohol resin in the oligomer blocking layer is not particularly limited, but is preferably in the range of 10 to 100% by weight, more preferably 20 to 90% by weight, and most preferably 30 to 80% by weight.

[0051] The method for forming the oligomer blocking layer is not particularly limited and may be appropriately selected depending on the material to be formed, and may include coating, spraying, spin coating, in-line coating, etc. Vacuum deposition, sputtering, ion plating, spray pyrolysis, chemical plating, electroplating, etc. may also be used.

[0052] The thickness of the oligomer blocking layer is preferably set appropriately in the range of 5 to 100 nm, and more preferably 10 to 70 nm.

[0053] <Adhesive layer> The pressure-sensitive adhesive layer is formed from a pressure-sensitive adhesive composition. Examples of the pressure-sensitive adhesive composition include a rubber-based pressure-sensitive adhesive composition, an acrylic-based pressure-sensitive adhesive composition, a silicone-based pressure-sensitive adhesive composition, a urethane-based pressure-sensitive adhesive composition, a vinyl alkyl ether-based pressure-sensitive adhesive composition, a polyvinyl alcohol-based pressure-sensitive adhesive composition, a polyvinylpyrrolidone-based pressure-sensitive adhesive composition, a polyacrylamide-based pressure-sensitive adhesive composition, and a cellulose-based pressure-sensitive adhesive composition. The pressure-sensitive adhesive composition preferably contains a base polymer.

[0054] <Base polymer> The base polymer is selected from adhesive base polymers depending on the type of the adhesive composition.

[0055] The base polymer contains 0.5% by mass or more, preferably 1% by mass or more, and more preferably 3% by mass or more of a carboxyl group-containing monomer as a monomer unit from the viewpoint of improving the high-temperature durability of the pressure-sensitive adhesive layer. On the other hand, the base polymer contains 10% by mass or less, more preferably 8% by mass or less, and even more preferably 5% by mass or less of a carboxyl group-containing monomer as a monomer unit from the viewpoint of reducing the peel force when peeling the separator from the pressure-sensitive adhesive layer.

[0056] Among the pressure-sensitive adhesive compositions, acrylic pressure-sensitive adhesive compositions are preferably used because they have excellent optical transparency, exhibit appropriate adhesive properties such as wettability, cohesion, and adhesion, and are excellent in weather resistance, heat resistance, etc. The acrylic pressure-sensitive adhesive composition preferably contains a (meth)acrylic polymer as the adhesive base polymer. The (meth)acrylic polymer usually contains alkyl (meth)acrylate as a main component as a monomer unit. Note that (meth)acrylate refers to acrylate and / or methacrylate, and (meth) in the present invention has the same meaning.

[0057] Examples of the alkyl (meth)acrylate constituting the main skeleton of the (meth)acrylic polymer include linear or branched alkyl groups having 1 to 18 carbon atoms. Examples of the alkyl group include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, amyl, hexyl, cyclohexyl, heptyl, 2-ethylhexyl, isooctyl, nonyl, decyl, isodecyl, dodecyl, isomyristyl, lauryl, tridecyl, pentadecyl, hexadecyl, heptadecyl, and octadecyl groups. One or more types of alkyl (meth)acrylate may be used. The average carbon number of these alkyl groups is preferably 3 to 9.

[0058] Furthermore, as the alkyl (meth)acrylate, alkyl (meth)acrylates containing an aromatic ring, such as phenoxyethyl (meth)acrylate and benzyl (meth)acrylate, can be used from the viewpoints of adhesive properties, durability, adjustment of phase difference, adjustment of refractive index, etc.

[0059] In order to improve adhesiveness and heat resistance, one or more copolymerizable monomers having a polymerizable functional group with an unsaturated double bond, such as a (meth)acryloyl group or a vinyl group, can be introduced into the (meth)acrylic polymer by copolymerization. Specific examples of copolymerizable monomers include hydroxyl group-containing monomers such as 2-hydroxyethyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 8-hydroxyoctyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, 12-hydroxylauryl (meth)acrylate, and (4-hydroxymethylcyclohexyl)-methyl acrylate; (meth)acrylic acid, carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, and the like. carboxyl group-containing monomers such as acrylate, itaconic acid, maleic acid, fumaric acid, and crotonic acid; acid anhydride group-containing monomers such as maleic anhydride and itaconic anhydride; caprolactone adducts of acrylic acid; sulfonic acid group-containing monomers such as styrenesulfonic acid, allylsulfonic acid, 2-(meth)acrylamido-2-methylpropanesulfonic acid, (meth)acrylamidopropanesulfonic acid, sulfopropyl (meth)acrylate, and (meth)acryloyloxynaphthalenesulfonic acid; and phosphoric acid group-containing monomers such as 2-hydroxyethyl acryloyl phosphate.

[0060] As described above, the (meth)acrylic polymer contains 0.5% by mass or more of the carboxy group-containing monomer as a monomer unit, from the viewpoint of improving the high-temperature durability of the pressure-sensitive adhesive layer. The preferred content is as described above.

[0061] The (meth)acrylic polymer has alkyl (meth)acrylate as the main component in the mass ratio of all constituent monomers, and the proportion of the copolymerization monomer is not particularly limited, but is preferably about 0 to 20%, about 0.1 to 15%, or even about 0.1 to 10% in the mass ratio of all constituent monomers.

[0062] The (meth)acrylic polymer typically has a weight-average molecular weight (Mw) in the range of 500,000 to 3,000,000. Considering durability, particularly heat resistance, a weight-average molecular weight (Mw) of 700,000 to 2,700,000 is preferred, with a weight-average molecular weight (Mw) of 800,000 to 2,500,000 being more preferred. A weight-average molecular weight (Mw) of less than 500,000 is undesirable in terms of heat resistance. Furthermore, a weight-average molecular weight (Mw) greater than 3,000,000 is undesirable because a large amount of dilution solvent is required to adjust the viscosity for application, resulting in increased costs. The weight-average molecular weight (Mw) is measured by GPC (gel permeation chromatography) and calculated in terms of polystyrene.

[0063] The (meth)acrylic polymer can be produced by any known production method, such as solution polymerization, bulk polymerization, emulsion polymerization, various radical polymerizations, etc. The resulting (meth)acrylic polymer may be any of a random copolymer, a block copolymer, a graft copolymer, etc.

[0064] The polymerization initiator, chain transfer agent, emulsifier, etc. used in the radical polymerization are not particularly limited and can be appropriately selected and used. The weight average molecular weight (Mw) of the (meth)acrylic polymer can be controlled by the amounts of the polymerization initiator and chain transfer agent used and the reaction conditions, and the amounts used are appropriately adjusted depending on the types of these.

[0065] In the solution polymerization, a polymerization solvent such as ethyl acetate or toluene is used. In a specific example of solution polymerization, the reaction is carried out under a stream of an inert gas such as nitrogen, with the addition of a polymerization initiator, usually at about 50 to 70°C for about 5 to 30 hours.

[0066] <Conductive agent> The pressure-sensitive adhesive composition preferably contains, in addition to the base polymer, a conductive agent, such as an ionic compound, an ionic surfactant, a conductive polymer, or a metal oxide.

[0067] As the ionic compound, alkali metal salts and / or organic cation-anion salts can be preferably used. The alkali metal salts can be organic salts and inorganic salts of alkali metals. In the present invention, the term "organic cation-anion salt" refers to an organic salt whose cation moiety is composed of an organic substance, and whose anion moiety may be either organic or inorganic. The "organic cation-anion salt" is also called an ionic liquid or an ionic solid. Only one type of ionic compound may be used, or two or more types may be used.

[0068] Examples of alkali metal ions constituting the cation moiety of the alkali metal salt include lithium ions, sodium ions, and potassium ions, with lithium ions being preferred among these alkali metal ions.

[0069] The anion moiety of the alkali metal salt may be composed of an organic substance or an inorganic substance. Examples of the anion moiety constituting the organic salt include CH3COO - , CF3COO - , CH3SO3 - , CF3SO3 - , (CF3SO2)3C - , C4F9SO3 - , C3F7COO - , (CF3SO2)(CF3CO)N - , - O3S(CF2)3SO3 - , PF6 - , CO3 2- , or the following general formulas (1) to (4): (1):(CnF 2n+1 SO2)2N - (where n is an integer from 1 to 10), (2):CF2(C m F 2m SO2)2N - (where m is an integer from 1 to 10), (3): - O3S(CF2) l SO3 - (where l is an integer from 1 to 10), (4):(Cp F 2p+1 SO2)N - (C q F 2q+1 SO2), (where p and q are integers of 1 to 10), etc. are used. In particular, an anion moiety containing a fluorine atom is preferably used because it can give an ionic compound with good ionic dissociation properties. Examples of an anion moiety constituting an inorganic salt include Cl - , Br - , I - , AlCl4 - , Al2Cl7 - , BF4 - , PF6 - , ClO4 - , NO3 - , AsF6 - , SbF6 - , NbF6 - , TaF6 - , (CN)2N - , etc. are used. As the anion part, (CF3SO2)2N - , (C2F5SO2)2N - (Perfluoroalkylsulfonyl)imides represented by the general formula (1) such as (CF3SO2)2N are preferred, and particularly (CF3SO2)2N - Preferred is (trifluoromethanesulfonyl)imide represented by the following formula:

[0070] Specific examples of organic salts of alkali metals include sodium acetate, sodium alginate, sodium lignosulfonate, sodium toluenesulfonate, LiCF3SO3, Li(CF3SO2)2N, Li(C2F5SO2)2N, Li(C4F9SO2)2N, Li(CF3SO2)3C, KO3S(CF2)3SO3K, LiO3S(CF2)3SO3K, and the like. Of these, LiCF3SO3, Li(CF3SO2)2N, Li(C2F5SO2)2N, Li(C4F9SO2)2N, Li(CF3SO2)3C, and the like are preferred, with fluorine-containing lithium imide salts such as Li(CF3SO2)2N, Li(C2F5SO2)2N, and Li(C4F9SO2)2N being more preferred, and (perfluoroalkylsulfonyl)imide lithium salts being particularly preferred.

[0071] Examples of inorganic salts of alkali metals include lithium perchlorate and lithium iodide.

[0072] The organic cation-anion salt is composed of a cation component and an anion component, and the cation component is an organic substance. Specific examples of the cation component include pyridinium cation, piperidinium cation, pyrrolidinium cation, cation having a pyrroline skeleton, cation having a pyrrole skeleton, imidazolium cation, tetrahydropyrimidinium cation, dihydropyrimidinium cation, pyrazolium cation, pyrazolinium cation, tetraalkylammonium cation, trialkylsulfonium cation, and tetraalkylphosphonium cation.

[0073] The anion component may be Cl - , Br - , I - , AlCl4 - , Al2Cl7 - , BF4 - , PF6 - , ClO4 - , NO3 - , CH3COO - , CF3COO - , CH3SO3 - , CF3SO3 - , (CF3SO2)3C - , AsF6 - , SbF6 - , NbF6 - , TaF6 - , (CN)2N - , C4F9SO3 - , C3F7COO - , ((CF3SO2)(CF3CO)N - , - O3S(CF2)3SO3 - , or the following general formulas (1) to (4): (1):(CnF 2n+1 SO2)2N - (where n is an integer from 1 to 10), (2):CF2(C m F2m SO2)2N - (where m is an integer from 1 to 10), (3): - O3S(CF2) l SO3 - (where l is an integer from 1 to 10), (4):(C p F 2p+1 SO2)N - (C q F 2q+1 SO2), (wherein p and q are integers of 1 to 10), etc. are used. Among these, an anion component containing a fluorine atom is particularly preferably used because it gives an ionic compound with good ionic dissociation properties.

[0074] In addition to the alkali metal salts and organic cation-anion salts, the ionic compounds may also include inorganic salts such as ammonium chloride, aluminum chloride, copper chloride, ferrous chloride, ferric chloride, and ammonium sulfate.

[0075] Examples of the ionic surfactant include cationic surfactants (quaternary ammonium salt type, phosphonium salt type, sulfonium salt type, etc.), anionic surfactants (carboxylic acid type, sulfonate type, sulfate type, phosphate type, phosphite type, etc.), amphoteric surfactants (sulfobetaine type, alkylbetaine type, alkylimidazolium betaine type, etc.), and nonionic surfactants (polyhydric alcohol derivatives, β-cyclodextrin inclusion compounds, sorbitan fatty acid monoesters / diesters, polyalkylene oxide derivatives, amine oxides, etc.). One or more types of ionic surfactants may be used.

[0076] Examples of the conductive polymer include polyaniline-based, polythiophene-based, polypyrrole-based, and polyquinoxaline-based polymers. Among these, polyaniline and polythiophene, which can easily become water-soluble or water-dispersible conductive polymers, are preferred. Polythiophene is particularly preferred. Only one type of conductive polymer may be used, or two or more types may be used.

[0077] Examples of the metal oxide include tin oxide, antimony oxide, indium oxide, and zinc oxide. Of these, tin oxide is preferred. Examples of tin oxide include tin oxide, antimony-doped tin oxide, indium-doped tin oxide, aluminum-doped tin oxide, tungsten-doped tin oxide, a titanium oxide-cerium oxide-tin oxide composite, and a titanium oxide-tin oxide composite. Only one type of metal oxide may be used, or two or more types may be used.

[0078] Further examples of conductive agents other than those mentioned above include acetylene black, ketjen black, natural graphite, artificial graphite, titanium black, homopolymers of monomers having ionic conductive groups of the cationic type (quaternary ammonium salts, etc.), amphoteric type (betaine compounds, etc.), anionic type (sulfonates, etc.), or nonionic type (glycerin, etc.), or copolymers of such monomers with other monomers, polymers having ionic conductivity such as polymers having a moiety derived from acrylate or methacrylate having a quaternary ammonium base, and permanent antistatic agents of the type in which a hydrophilic polymer such as a polyethylene methacrylate copolymer is alloyed with an acrylic resin or the like.

[0079] It is preferable to use an ionic compound as the conductive agent, from the viewpoints of high conductivity, excellent dispersibility and transparency in the adhesive, and storage stability in the adhesive.

[0080] The blending ratio of the conductive agent is preferably 0.0001 to 10 parts by mass per 100 parts by mass of the base polymer. If the conductive agent is less than 0.0001 part by mass, the effect of improving antistatic performance may not be sufficient. On the other hand, if the conductive agent is more than 10 parts by mass, durability may not be sufficient. The conductive agent is preferably 0.01 part by mass or more, more preferably 0.1 part by mass or more. Furthermore, the conductive agent is preferably 8 parts by mass or less, more preferably 6 parts by mass or less.

[0081] The pressure-sensitive adhesive composition may further contain a crosslinking agent. Examples of crosslinking agents that can be used include organic crosslinking agents and polyfunctional metal chelates. Examples of organic crosslinking agents include isocyanate crosslinking agents, peroxide crosslinking agents, epoxy crosslinking agents, and imine crosslinking agents. Polyfunctional metal chelates are compounds in which a polyvalent metal is covalently or coordinately bonded to an organic compound. Examples of polyvalent metal atoms include Al, Cr, Zr, Co, Cu, Fe, Ni, V, Zn, In, Ca, Mg, Mn, Y, Ce, Sr, Ba, Mo, La, Sn, and Ti. Examples of atoms in the organic compound that form covalent or coordinate bonds include oxygen atoms, and examples of organic compounds include alkyl esters, alcohol compounds, carboxylic acid compounds, ether compounds, and ketone compounds. Examples of crosslinking agents include isocyanate crosslinking agents and peroxide crosslinking agents. Only one crosslinking agent or two or more crosslinking agents may be used.

[0082] The blending ratio of the crosslinking agent is preferably 0.01 to 20 parts by mass, more preferably 0.03 to 10 parts by mass, per 100 parts by mass of the base polymer. If the crosslinking agent is less than 0.01 part by mass, the cohesive strength of the adhesive tends to be insufficient, and foaming may occur when heated. On the other hand, if the crosslinking agent is more than 20 parts by mass, moisture resistance is insufficient, and peeling is likely to occur during reliability tests, etc.

[0083] Furthermore, the pressure-sensitive adhesive composition may contain a silane coupling agent. Use of the silane coupling agent can improve durability. Only one type of silane coupling agent may be used, or two or more types may be used.

[0084] The blending ratio of the silane coupling agent is preferably 0.001 to 5 parts by mass, more preferably 0.01 to 1 part by mass, even more preferably 0.02 to 1 part by mass, and particularly preferably 0.05 to 0.6 parts by mass, relative to 100 parts by mass of the base polymer. The blending ratio is appropriately selected within this range in order to improve durability and maintain adequate adhesive strength to optical members such as liquid crystal panels.

[0085] Furthermore, the pressure-sensitive adhesive composition may contain other known additives, which can be appropriately added depending on the intended use, such as colorants, powders such as pigments, dyes, surfactants, plasticizers, tackifiers, surface lubricants, leveling agents, softeners, antioxidants, antiaging agents, light stabilizers, ultraviolet absorbers, polymerization inhibitors, inorganic or organic fillers, metal powders, particulate or foil-like materials, etc. Furthermore, a redox system may be employed by adding a reducing agent within a controllable range.

[0086] The separator-attached pressure-sensitive adhesive layer can be produced by applying a solution containing the pressure-sensitive adhesive composition onto the release layer of the separator, followed by drying to form a pressure-sensitive adhesive layer. When applying the pressure-sensitive adhesive composition, one or more solvents other than the polymerization solvent may be added as appropriate.

[0087] Various methods can be used to apply the pressure-sensitive adhesive composition, including roll coating, kiss roll coating, gravure coating, reverse coating, roll brushing, spray coating, dip roll coating, bar coating, knife coating, air knife coating, curtain coating, lip coating, and extrusion coating using a die coater or the like.

[0088] The thickness of the pressure-sensitive adhesive layer is not particularly limited and is about 1 to 100 μm, preferably 2 to 50 μm, more preferably 2 to 40 μm, and even more preferably 5 to 35 μm.

[0089] The surface resistance value of the pressure-sensitive adhesive layer is 1.0×10 from the viewpoint of imparting conductivity to the separator-attached pressure-sensitive adhesive layer and suppressing white unevenness in the liquid crystal panel. 12 It is preferable that the resistance is Ω / □ or less, and 1.0×10 11 It is more preferable that it is Ω / □ or less, and 1.0×10 10 It is more preferable that it is Ω / □ or less.

[0090] <Polarizing film with separator and pressure-sensitive adhesive layer> The separator-containing pressure-sensitive adhesive layer-attached polarizing film of the present invention is one in which the pressure-sensitive adhesive layer side of the separator-attached pressure-sensitive adhesive layer is attached to one or both surfaces of a polarizing film.

[0091] The polarizing film generally has a transparent protective film on one or both sides of the polarizer. The polarizer is not particularly limited, and various types can be used. Examples of polarizers include hydrophilic polymer films such as polyvinyl alcohol films, partially formalized polyvinyl alcohol films, and partially saponified ethylene-vinyl acetate copolymer films, which are uniaxially stretched after adsorbing a dichroic substance such as iodine or a dichroic dye, and polyene-based oriented films such as dehydrated polyvinyl alcohol and dehydrochlorinated polyvinyl chloride. Among these, polarizers made of a polyvinyl alcohol film and a dichroic substance such as iodine are preferred. The thickness of these polarizers is not particularly limited, but is generally about 80 μm or less.

[0092] The polarizer may be a thin polarizer having a thickness of 10 μm or less. From the viewpoint of thinning, the thickness is preferably 1 to 7 μm. Such a thin polarizer has less thickness unevenness, excellent visibility, and excellent durability due to less dimensional change, and is also preferable in that it can be made thinner as a polarizing film.

[0093] The material constituting the transparent protective film is a thermoplastic resin that is excellent in transparency, mechanical strength, thermal stability, moisture blocking properties, isotropy, etc. Specific examples of such thermoplastic resins include cellulose resins such as triacetyl cellulose, polyester resins, polyethersulfone resins, polysulfone resins, polycarbonate resins, polyamide resins, polyimide resins, polyolefin resins, (meth)acrylic resins, cyclic polyolefin resins (norbornene-based resins), polyarylate resins, polystyrene resins, polyvinyl alcohol resins, and mixtures thereof. A transparent protective film is attached to one side of the polarizer with an adhesive layer, and a thermosetting resin or ultraviolet-curable resin such as a (meth)acrylic, urethane, acrylic urethane, epoxy, or silicone resin can be used as the transparent protective film on the other side. The transparent protective film may contain one or more appropriate additives.

[0094] The adhesive used to bond the polarizer and the transparent protective film is not particularly limited as long as it is optically transparent, and various types of adhesives such as water-based, solvent-based, hot-melt, radical curing, and cation curing types can be used, but water-based adhesives or radical curing adhesives are preferred.

[0095] From the viewpoint of achieving a thinner film, the thickness of the polarizing film is preferably 100 μm or less, more preferably 90 μm or less, even more preferably 75 μm or less, and still more preferably 60 μm or less.

[0096] In the polarized film with a pressure-sensitive adhesive layer having a separator of the present invention, the peel force when peeling the separator from the pressure-sensitive adhesive layer is preferably 0.12 N / 50 mm or less, more preferably 0.10 N / 50 mm or less, and even more preferably 0.08 N / 50 mm or less, from the viewpoint of easy peelability of the separator.

[0097] The pressure-sensitive adhesive layer-attached polarizing film having the separator of the present invention has a pressure-sensitive adhesive layer with excellent high-temperature durability, and is therefore suitable for use in image displays used in high-temperature environments, such as in-vehicle image displays. [Example]

[0098] Examples of the present invention will be described below, but the embodiments of the present invention are not limited to these.

[0099] <Polarizer fabrication: Thickness 12 μm> A 30 μm-thick polyvinyl alcohol film with an average degree of polymerization of 2400 and a saponification degree of 99.9 mol% was immersed in warm water at 30°C and uniaxially stretched while swelling until the PVA-based resin film reached 2.0 times its original length. It was then immersed in a 0.3 wt% iodine solution (weight ratio: iodine / potassium iodide = 0.5 / 8) at 30°C and dyed while uniaxially stretching until the PVA-based resin film reached 3.0 times its original length. The PVA-based resin film was then stretched in an aqueous solution of 4 wt% boric acid and 5 wt% potassium iodide until the PVA-based resin film reached 6 times its original length. The film was then impregnated with iodine ions in an aqueous solution of 3 wt% potassium iodide (iodine impregnation bath) and dried in an oven at 60°C for 4 minutes to obtain a 12 μm-thick polarizer.

[0100] <First transparent protective film> The substrate film used was a 25 μm thick triacetyl cellulose film that had been subjected to a saponification treatment. The moisture permeability of the substrate film was 1200 g / m 2 The film was then coated on one side with a coating solution containing 25% solids by weight of an acrylic hard coat resin (Unidic 17-813, manufactured by Dainippon Ink and Chemicals, Inc.) dispersed in isopropyl alcohol, and dried at 80°C for 2 minutes. This was then treated with ultraviolet light to form a 7-μm-thick hard coat layer (pencil hardness 3H), which was then saponified before use. The resulting transparent protective film with a surface treatment layer had a thickness of 32 μm and a moisture permeability of 400 g / m². 2 -It was 24 hours.

[0101] <Second transparent protective film> A 13 μm thick cyclic polyolefin film (ZEONOR manufactured by Nippon Zeon Co., Ltd.) was used after corona treatment. The moisture permeability of the film was 12 g / m2 -It was 24 hours.

[0102] <Moisture permeability> Measurement was performed based on the moisture permeability test method (cup method) for moisture-proof packaging materials specified in JIS Z0208.

[0103] <Preparation of polarizing film> A polyvinyl alcohol-based adhesive was applied to both sides of the polarizer (thickness: 12 μm) so that the thickness of the aqueous adhesive layer was 0.1 μm, and the first transparent protective film (the side without the surface treatment layer) and the second transparent protective film were bonded to each other. The film was then dried at 50°C for 5 minutes to produce a polarized film (thickness: 57 μm).

[0104] <Preparation of Acrylic Polymer Solution (A)> A solution was prepared by adding 100 parts of butyl acrylate, 5 parts of acrylic acid, 0.075 parts of 2-hydroxyethyl acrylate, and 0.3 parts of 2,2'-azobisisobutyronitrile together with ethyl acetate to a reaction vessel equipped with a condenser, nitrogen inlet, thermometer, and stirrer. The solution was then stirred while blowing in nitrogen gas, and allowed to react at 60°C for 4 hours, yielding a solution containing an acrylic polymer with a weight-average molecular weight of 2.2 million. Ethyl acetate was then added to the solution containing the acrylic polymer, adjusting the solids concentration to 30%, yielding acrylic polymer solution (A).

[0105] <Preparation of Pressure-Sensitive Adhesive Compositions (A-1) to (A-4)> A pressure-sensitive adhesive composition (A-1) was prepared by blending, in this order, 0.6 parts of a crosslinking agent (manufactured by Nippon Polyurethane Co., Ltd., trade name "Coronate L") whose main component is a compound having an isocyanate group as a crosslinking agent, 0.075 parts of γ-glycidoxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., trade name "KMB-403") as a silane coupling agent, and 3 parts of lithium bis(trifluoromethanesulfonyl)imide (manufactured by Mitsubishi Materials Electronic Chemicals Co., Ltd.) as a conductive agent, per 100 parts of the solid content of the acrylic polymer solution (A). Furthermore, pressure-sensitive adhesive compositions (A-2) to (A-4) were prepared in the same manner as above, except that the blending amount of the conductive agent was changed to 6 parts, 0.3 parts, and 0 parts.

[0106] <Preparation of Acrylic Polymer Solution (B)> A four-neck flask equipped with a stirring blade, a thermometer, a nitrogen gas inlet tube, and a condenser was charged with a monomer mixture containing 79.7 parts of butyl acrylate, 16 parts of phenoxyethyl acrylate, 3 parts of N-vinyl-2-pyrrolidone, 0.3 parts of acrylic acid, and 1 part of 4-hydroxybutyl acrylate. Furthermore, 0.1 parts of 2,2'-azobisisobutyronitrile as a polymerization initiator and 100 parts of ethyl acetate were charged to 100 parts of the monomer mixture (solid content). Nitrogen gas was introduced with gentle stirring to replace the atmosphere. The temperature in the flask was maintained at around 55°C, and a polymerization reaction was carried out for 8 hours to prepare a solution (B) containing an acrylic polymer with a weight-average molecular weight (Mw) of 1.8 million.

[0107] <Preparation of Pressure-Sensitive Adhesive Composition (B)> A pressure-sensitive adhesive composition (B) was prepared by blending 100 parts of the solid content of the acrylic polymer solution (B) with 0.2 parts of an isocyanate crosslinking agent (Takenate D160N, trimethylolpropane hexamethylene diisocyanate, manufactured by Mitsui Chemicals, Inc.), 0.2 parts of benzoyl peroxide (Niper BMT, manufactured by Nippon Oil & Fats Corporation), 6 parts of lithium bis(trifluoromethanesulfonyl)imide (manufactured by Mitsubishi Materials Electronic Chemicals Co., Ltd.) as a conductive agent, and 0.2 parts of an acetoacetyl group-containing silane coupling agent (trade name: A-100, manufactured by Soken Chemical & Engineering Co., Ltd.).

[0108] <Preparation of separator X> [Formation of Oligomer Blocking Layer] A coating solution was prepared by diluting organosiloxane (Ethyl Silicate 48: Colcoat Co., Ltd.) as a silica-based material with isopropyl alcohol to a solids concentration of 1%. The resulting coating solution was applied to a polyester film (thickness: 38 μm) as a substrate film using a gravure coater so that the thickness after drying would be 50 nm, and then dried at 120°C for 30 seconds to form an oligomer blocking layer.

[0109] [Formation of Release Layer] A silicone-based release agent solution was prepared by diluting 20 parts of a reactive silicone resin (LTC856, manufactured by Dow Corning Toray Co., Ltd.) with reactive functional groups, 13.5 parts of a non-reactive silicone resin (BY24-850, manufactured by Dow Corning Toray Co., Ltd.) with a weight-average molecular weight of 400,000, and 0.2 parts of a curing agent (SRX-212cat, manufactured by Dow Corning Toray Co., Ltd.) with 350 parts of a methyl ethyl ketone / toluene mixed solvent (mixing ratio 1:1). The resulting silicone-based release agent solution was applied to the oligomer blocking layer using a gravure coater to a dry thickness of 120 nm, and then dried at 120°C for 30 seconds to form a release layer. Separator X, with a polyester film / oligomer blocking layer / release layer configuration, was produced. In the formed release layer, the total content of the reactive silicone resin and the non-reactive silicone resin is 100% by mass, and the content of the reactive silicone resin is 60% by mass and the content of the non-reactive silicone resin is 40% by mass.

[0110] <Preparation of separator Y> [Formation of Oligomer Blocking Layer] A coating solution was prepared by diluting organosiloxane (Ethyl Silicate 48: Colcoat Co., Ltd.) as a silica-based material with isopropyl alcohol to a solids concentration of 1%. The resulting coating solution was applied to a polyester film (thickness: 38 μm) as a substrate film using a gravure coater so that the thickness after drying would be 50 nm, and then dried at 120°C for 30 seconds to form an oligomer blocking layer.

[0111] [Formation of Release Layer] A silicone-based release agent solution was prepared by diluting 20 parts of a reactive silicone resin (KS-847H, manufactured by Shin-Etsu Chemical Co., Ltd.) having a reactive functional group and 0.2 parts of a curing agent (PL-50T, manufactured by Shin-Etsu Chemical Co., Ltd.) with 350 parts of a methyl ethyl ketone / toluene mixed solvent (mixing ratio 1:1). The obtained silicone-based release agent solution was applied to the oligomer prevention layer using a gravure coater so that the thickness after drying would be 100 nm, and then dried at 120°C for 30 seconds to form a release layer, thereby producing a separator Y having a polyester film / oligomer prevention layer / release layer configuration.

[0112] Example 1 <Preparation of a polarizing film with a separator and an adhesive layer> The pressure-sensitive adhesive composition (A-1) was uniformly applied to the surface of the release layer of separator X using a fountain coater, and then dried for 2 minutes in an air-circulating constant-temperature oven at 155°C to form a pressure-sensitive adhesive layer with a thickness of 20 µm, thereby producing a pressure-sensitive adhesive layer with a separator. Next, the pressure-sensitive adhesive layer of the pressure-sensitive adhesive layer with a separator prepared was attached to the second transparent protective film of the prepared polarizing film, thereby producing a polarizing film with a pressure-sensitive adhesive layer having a separator.

[0113] Examples 2 to 4, Comparative Examples 1 to 5 <Preparation of a polarizing film with a separator and an adhesive layer> A polarized film with a pressure-sensitive adhesive layer having a separator was produced in the same manner as in Example 1, except that the pressure-sensitive adhesive composition and separator shown in Table 1 were used.

[0114] <Measurement and evaluation methods> (Elastic modulus of release layer) The substrate film side of the prepared separator was attached to a stainless steel sample stage using double-sided adhesive tape. Next, a force curve was measured at 1 Hz on the release layer side of the separator using a probe microscope (Oxford Instruments, Asylum Research MFP-3D-SA) equipped with a silicon probe (Olympus, AC240TS, radius of curvature: 10 nm, spring constant: 3 N / m equivalent). A load-displacement curve was obtained from the resulting load-displacement curve using the JKR two-point method. The elastic modulus (MPa) of the release layer was calculated from the obtained load-displacement curve.

[0115] (Adhesive strength) The prepared polarized film with adhesive layer was cut into a 120 mm x 25 mm sample. The sample was attached to a 0.7 mm thick alkali-free glass plate (Corning EG-XG) using a laminator and then autoclaved at 50°C and 5 atm for 15 minutes to ensure complete adhesion. The adhesive strength of the sample was then measured. The adhesive strength was determined by measuring the adhesive strength (N / 25 mm, measurement length 80 mm) when the sample was peeled off at a peel angle of 90° and a peel rate of 300 mm / min using a tensile tester (Shimazu Autograph AG-1 1OKN). 200 samples were taken at intervals of 0.5 s, and the average value was used as the measured value. Three samples were used.

[0116] (Separator peeling force) The prepared polarizing film with a separator and adhesive layer was cut into a size of 50 mm x 100 mm to prepare a measurement sample. The measurement sample was attached to a flat peeling jig with the surface-treated side facing down via double-sided adhesive tape. The separator was then peeled 10 mm from the surface of the adhesive layer, chucked, and pulled using a tensile tester to measure the peel force (N / 50 mm) (pulling direction: 180° relative to the polarizing film surface, pulling speed: 300 mm / min). 200 samples were taken at intervals of 0.5 seconds, and the average value was used as the measurement value. Three samples were used. Evaluation was based on the following criteria. ◎: 0.08 or less 〇: More than 0.08 but less than 0.11 △: Over 0.11 and less than 0.13 ×: 0.13 or more

[0117] (Surface resistance of adhesive layer) The surface resistance value (Ω / □) of the pressure-sensitive adhesive layer was measured using MCP-HT450 manufactured by Mitsubishi Chemical Analytech Co., Ltd. The surface resistance value (Ω / □) was measured using MCP-HT450 manufactured by Mitsubishi Chemical Analytech Co., Ltd. The surface resistance value (Ω / □) of the pressure-sensitive adhesive layer ... ◎:10 10 below ○:10 11 ~10 12 ×:Over

[0118] (durability) The separator was removed from the prepared polarizing film (15 inches) with a separator and adhesive layer, and the film was attached to a 0.7 mm thick alkali-free glass (EG-XG, manufactured by Corning Incorporated) using a laminator. The film was then autoclaved at 50°C and 0.5 MPa for 15 minutes to completely adhere the polarizing film to the acrylic-free glass. The film was then placed in an 80°C heating oven (normal durability) and a 95°C heating oven (high-temperature durability), and the polarizing film was evaluated for peeling after 500 hours according to the following criteria. ○: No peeling was observed. △: Peeling was observed to an extent that was not visible to the naked eye. ×: Small peeling that can be visually confirmed was observed.

[0119] [Table 1]

[0120] Table 1 shows that the pressure-sensitive adhesive layer-attached polarizing films having separators of Examples 1 to 4 have a low elastic modulus of the release layer, a low peel force when peeling the separator from the pressure-sensitive adhesive layer, and excellent separator releasability and high-temperature durability of the pressure-sensitive adhesive layer. On the other hand, the pressure-sensitive adhesive layer-attached polarizing films having separators of Comparative Examples 1 to 4 have a high elastic modulus of the release layer, a high peel force when peeling the separator from the pressure-sensitive adhesive layer, and excellent separator releasability. Furthermore, the pressure-sensitive adhesive layer-attached polarizing film having a separator of Comparative Example 5 has a low content of carboxy group-containing monomer in the base polymer of the pressure-sensitive adhesive layer, and therefore has poor separator releasability. [Industrial Applicability]

[0121] The pressure-sensitive adhesive layer-attached polarizing film having the separator of the present invention is suitably used in image display devices used in high-temperature environments, for example, in-vehicle image display devices.

Claims

1. A polarizing film with a separator and a pressure-sensitive adhesive layer, in which a separator-attached pressure-sensitive adhesive layer having a pressure-sensitive adhesive layer on a separator is provided on one or both sides of the polarizing film, the separator has a release layer on a substrate film, the release layer contains a reactive silicone resin having a reactive functional group and a non-reactive silicone resin having a weight average molecular weight of 400,000 or more; the reactive functional group is an alkenyl group having 2 to 10 carbon atoms, the content of the reactive silicone resin is 50 to 70 mass% and the content of the non-reactive silicone resin is 30 to 50 mass% relative to 100 mass% of the total content of the reactive silicone resin and the non-reactive silicone resin; The release layer has an elastic modulus of less than 1.5 MPa, the pressure-sensitive adhesive layer is provided on the release layer, A polarizing film with a separator and a pressure-sensitive adhesive layer, wherein the pressure-sensitive adhesive layer contains a base polymer containing 0.5% by mass or more of a carboxyl group-containing monomer as a monomer unit.

2. The polarizing film with a pressure-sensitive adhesive layer having a separator according to claim 1 , wherein the pressure-sensitive adhesive layer contains a conductive agent.

3. The pressure-sensitive adhesive layer has a surface resistance of 1.0×10 １２ A polarizing film with a pressure-sensitive adhesive layer, comprising the separator according to claim 1 or 2, which has a resistivity of Ω / □ or less.

4. 4. A polarizing film with a pressure-sensitive adhesive layer comprising the separator according to claim 1, wherein the peeling force when peeling the separator from the pressure-sensitive adhesive layer is 0.12 N / 50 mm or less.

5. 5. A polarizing film with a pressure-sensitive adhesive layer, comprising the separator according to claim 1, wherein the polarizing film has a thickness of 100 μm or less.

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