Method for manufacturing adhesive sheet, method for manufacturing laminate, and method for manufacturing optical film with adhesive sheet

Abstract

Provided is a technique suitable for producing an adhesive sheet with low environmental burden. Provided is a method for producing an adhesive sheet, comprising: irradiating a first laminate comprising a first substrate sheet, a first coating layer containing a first photocurable composition, and a first release liner in this order with light to form a first adhesive sheet from the first coating layer; and forming a second adhesive sheet from a second coating layer by irradiating a second laminate, which is formed using the first release liner peeled off from the first adhesive sheet as a second substrate sheet, and which sequentially comprises the second substrate sheet, the second coating layer containing the second photocurable composition, and the second release liner. The second base material sheet has a greater peeling force than the second peeling liner with respect to the second adhesive sheet.

Description

Technical Field

[0001] The present invention relates to a method for producing a pressure-sensitive adhesive sheet, a method for producing a laminate, and a method for producing an optical film with a pressure-sensitive adhesive sheet. Background Art

[0002] Various image display devices represented by liquid crystal display devices and electroluminescent (EL) display devices generally have an optical laminate including an optical film such as a polarizing film and an adhesive sheet. Adhesive sheets are usually used for the bonding between the optical films contained in the optical laminate and the bonding between the optical laminate and the image display panel. As an adhesive sheet, a typical sheet is obtained by curing a monomer group including an acrylic monomer, a silicone monomer, etc. through polymerization and crosslinking. Patent document 1 discloses a method of irradiating a laminate including a substrate sheet, a coating layer containing a photocurable composition, and a release liner in sequence to form an adhesive sheet from the coating layer. In this method, the two main surfaces of the coating layer are covered by the substrate sheet and the release liner, so that the hindrance of the photocuring reaction caused by oxygen can be suppressed.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2016-155981 Summary of the invention

[0006] Problems to be solved by the invention

[0007] When forming an adhesive sheet by curing, heat, light and other energies are usually required. According to the method using light (photocuring method), compared with the method (thermal curing method) in which, for example, a coating layer comprising an adhesive composition and a solvent is thermally cured by an oven, the energy required for the formation of the adhesive sheet can be reduced. However, from the viewpoint of reducing the environmental burden during the manufacture of the adhesive sheet, it is insufficient to focus only on the energy required for the curing of the coating layer.

[0008] An object of the present invention is to provide a technology suitable for producing a PSA sheet with a low environmental burden.

[0009] Solutions to the problem

[0010] The present invention provides a method for manufacturing an adhesive sheet, the method comprising:

[0011] irradiating a first laminate including a first substrate sheet, a first coating layer containing a first photocurable composition, and a first release liner in this order with light to form a first adhesive sheet from the first coating layer; and

[0012] irradiating a second laminate comprising a second substrate sheet, a second coating layer containing a second photocurable composition, and a second release liner in this order with light, thereby forming a second adhesive sheet from the second coating layer, wherein the second laminate is formed by using the first release liner peeled from the first adhesive sheet as the second substrate sheet,

[0013] The second base sheet has a greater release force with respect to the second pressure-sensitive adhesive sheet than the second release liner.

[0014] In another aspect, the present invention provides a method for manufacturing a laminate, the method comprising:

[0015] irradiating a first laminate including a first substrate sheet, a first coating layer containing a first photocurable composition, and a first release liner in this order with light to form a first adhesive sheet from the first coating layer; and

[0016] The first release liner peeled from the first pressure-sensitive adhesive sheet is used as a second substrate sheet to form a second laminate including the second substrate sheet, a second coating layer containing a second photocurable composition, and a second release liner in this order.

[0017] In another aspect, the present invention provides a method for manufacturing an optical film with an adhesive sheet, the method comprising:

[0018] An optical film with a pressure-sensitive adhesive sheet is formed by placing an optical film on the exposed surface of the pressure-sensitive adhesive sheet formed by the method for producing a pressure-sensitive adhesive sheet of the present invention.

[0019] Effects of the Invention

[0020] According to the present invention, a technique suitable for producing a PSA sheet with a low environmental burden can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic diagram for explaining an example of the method for producing the pressure-sensitive adhesive sheet of the present invention.

[0022] Figure 2 This is a cross-sectional view schematically showing an example of a release liner that can be used in the method for producing the pressure-sensitive adhesive sheet of the present invention.

[0023] Figure 3 This is a schematic diagram for explaining an example of the method for producing the pressure-sensitive adhesive sheet of the present invention.

[0024] Figure 4 This is a schematic diagram for explaining an example of the method for producing the pressure-sensitive adhesive sheet of the present invention.

[0025] Figure 5 This is a schematic diagram for explaining an example of the method for producing the optical film with a pressure-sensitive adhesive sheet of the present invention.

[0026] Figure 6 This is a schematic diagram for explaining an example of the method for producing the optical film with a pressure-sensitive adhesive sheet of the present invention.

[0027] Figure 7 This is a schematic diagram for explaining an example of the method for producing the optical film with a pressure-sensitive adhesive sheet of the present invention. DETAILED DESCRIPTION

[0028] The method for producing a pressure-sensitive adhesive sheet according to the first aspect of the present invention includes:

[0029] irradiating a first laminate including a first substrate sheet, a first coating layer containing a first photocurable composition, and a first release liner in this order with light to form a first adhesive sheet from the first coating layer; and

[0030] irradiating light onto a second laminated body including the second substrate sheet, a second coating layer containing a second photocurable composition, and a second release liner in this order, which is formed by using the first release liner peeled from the first adhesive sheet as a second substrate sheet, to form a second adhesive sheet from the second coating layer;

[0031] The second base sheet has a greater release force with respect to the second pressure-sensitive adhesive sheet than the second release liner.

[0032] In the second aspect of the present invention, for example, in the method for producing a pressure-sensitive adhesive sheet according to the first aspect,

[0033] The first laminate is irradiated with the light from the first release liner side.

[0034] In a third aspect of the present invention, for example, in the method for producing a pressure-sensitive adhesive sheet according to the first or second aspect,

[0035] The second substrate sheet and the second release liner each have a release layer on the surface facing the second coating layer.

[0036] The release layer included in the second base sheet and the release layer included in the second release liner are layers formed of a release agent composition containing the same release agent as a main component.

[0037] In a fourth aspect of the present invention, for example, in the method for producing a pressure-sensitive adhesive sheet according to any one of the first to third aspects,

[0038] The peeling force between the second base sheet and the second pressure-sensitive adhesive sheet is greater than the peeling force between the first release liner and the first pressure-sensitive adhesive sheet.

[0039] In a fifth aspect of the present invention, for example, in the method for producing a pressure-sensitive adhesive sheet according to any one of the first to fourth aspects,

[0040] The first photocurable composition and the second photocurable composition are the same composition.

[0041] In a sixth aspect of the present invention, for example, in the method for producing a pressure-sensitive adhesive sheet according to any one of the first to fifth aspects,

[0042] The first photocurable composition and the second photocurable composition contain a monomer group including a (meth)acrylic monomer and / or a partial polymer of the monomer group.

[0043] In a seventh aspect of the present invention, for example, in the method for producing a pressure-sensitive adhesive sheet according to the sixth aspect,

[0044] The (meth)acrylic monomer includes a carboxyl group-containing monomer.

[0045] The method for producing a laminate according to an eighth aspect of the present invention includes:

[0046] irradiating a first laminate including a first substrate sheet, a first coating layer containing a first photocurable composition, and a first release liner in this order with light to form a first adhesive sheet from the first coating layer; and

[0047] The first release liner peeled from the first pressure-sensitive adhesive sheet is used as a second substrate sheet to form a second laminate including the second substrate sheet, a second coating layer containing a second photocurable composition, and a second release liner in this order.

[0048] A method for producing an optical film with a pressure-sensitive adhesive sheet according to a ninth aspect of the present invention includes:

[0049] An optical film with a pressure-sensitive adhesive sheet is formed by placing an optical film on the exposed surface of the pressure-sensitive adhesive sheet formed by the method for producing a pressure-sensitive adhesive sheet according to any one of the first to seventh aspects.

[0050] In a tenth aspect of the present invention, for example, in the method for producing an optical film with a pressure-sensitive adhesive sheet according to the ninth aspect,

[0051] The optical film includes at least one film selected from the group consisting of a polarizing film and a retardation film.

[0052] Hereinafter, the present invention will be described in detail, but the present invention is not limited to the following embodiments and can be implemented with arbitrary modifications within the scope not departing from the gist of the present invention.

[0053] The inventors of the present invention have thought of further reducing the environmental burden in the manufacturing process of the adhesive sheet by reusing the release liner that is discarded immediately after peeling, and have conducted research based on this idea to complete the present invention. The release force of the release liner after peeling from the adhesive sheet becomes greater than that of the unused state. If the release liner with increased release force is reused as a substrate sheet, the release liner to be discarded is reduced, which can reduce the environmental burden.

[0054] [Method for producing adhesive sheet]

[0055] Reference Figure 1 , an example of a method for manufacturing an adhesive sheet of the present invention is described. In this example, the first laminate 10, which sequentially includes a first substrate sheet 11A, a first coating layer 12A containing a first photocurable composition, and a first release liner 13A, is irradiated with light 14A, and the first adhesive sheet 1A is formed from the first coating layer 12A. The light 14A passes through the first release liner 13A and reaches the first coating layer 12A, so that the first coating layer 12A is cured. The formed first adhesive sheet 1A is sandwiched by the first substrate sheet 11A and the first release liner 13A to form a part of the laminate (third laminate) 17 until the first release liner 13A is peeled off. Next, the first release liner 13A is peeled off from the first adhesive sheet 1A. The first release liner 13A after peeling is used as the second substrate sheet 11B to form the second laminate 20 which includes the second substrate sheet 11B, the second coating layer 12B containing the second photocurable composition, and the second release liner 13B in sequence. The formed second laminate 20 is irradiated with light 14B to form the second adhesive sheet 1B from the second coating layer 12B. The light 14B passes through the second release liner 13B and reaches the second coating layer 12B, so that the second coating layer 12B is cured. The formed second adhesive sheet 1B is sandwiched between the second substrate sheet 11B and the second release liner 13B to constitute a part of the laminate (the fourth laminate 27) until the second release liner 13B is peeled off. The second substrate sheet 11B has a greater peeling force relative to the second adhesive sheet 1B than the second release liner 13B. The second release liner 13B can also use the release liner used as the first release liner 13A. The laminate 27 that satisfies the above relationship in terms of the peeling force with respect to the second pressure-sensitive adhesive sheet 1B is suitable for stable peeling of the second release liner 13B.

[0056] It can be inferred that the increase in the release force of the first release liner 13A is due to the increase in the amount of functional groups and free radicals present on the surface of the first release liner 13A on the first coating layer 12A side due to the irradiation of light 14A. The above increase may occur due to the following reasons: a chemical bond is generated between the first release liner 13A and the first adhesive sheet 1A by irradiation with light 14A, and a part of it or a group formed by the decomposition of the bond remains on the above surface after the first adhesive sheet 1A is peeled off. The degree of increase in the release force may change due to the following factors: for example, the composition of the photocurable composition, the composition, formation conditions and thickness of the formed first adhesive sheet 1A, the material, thickness and state of the release surface of the first release liner 13A, and the composition, formation conditions and thickness of the release layer that the first release liner 13A may have.

[0057] The formation of the second adhesive sheet 1B generally increases the peeling force of the second release liner 13B. The formation of an adhesive sheet by irradiating light to a laminated body including a substrate sheet, a coating layer containing a photocurable composition, and a release liner in this order can be repeatedly performed using the second release liner 13B peeled off from the laminated body 27 as a substrate sheet.

[0058] (Release liner)

[0059] An example of the substrate of the first release liner 13A (hereinafter referred to as "substrate") is a resin film. Examples of resins that may be included in the substrate are polyesters such as polyethylene terephthalate and polyethylene naphthalate, acetate resins, polyether sulfones, polycarbonates, polyamides, polyimides, polyolefins, (meth)acrylic resins, polyvinyl chloride, polyvinylidene chloride, polystyrene, polyvinyl alcohol, polyarylates, and polyphenylene sulfide. The resin is preferably a polyester such as polyethylene terephthalate.

[0060] The first release liner 13A preferably has excellent transmittance of light 14A.

[0061] The thickness of the first release liner 13A may be, for example, 10 to 200 μm, or 25 to 150 μm.

[0062] The first release liner 13A may include a layer other than the base material. The first release liner 13A may include a release layer. Figure 2 The first release liner 13A shown includes a backing substrate 131 and a release layer 132 formed on one surface of the backing substrate 131. The first release liner 13A including the release layer 132 can be used so that the release layer 132 faces the first coating layer 12A side.

[0063] Typically, the release layer 132 is a solidified layer of a release agent composition containing a release agent. The release agent can use various release agents such as silicone release agents, fluorine release agents, long-chain alkyl release agents, fatty acid amide release agents, and silica powder. The first release liner 13A can have a solidified layer of a release agent composition containing a silicone release agent as a main component (hereinafter, "silicone release layer"). The silicone release layer is particularly suitable for balancing the adhesion and releasability of acrylic adhesive sheets. It should be noted that in this specification, the main component refers to the component with the largest content.

[0064] Silicone release agents include various curable silicone materials such as addition reaction type, condensation reaction type, ultraviolet curing type, electron beam curing type, solvent-free type, etc., preferably addition reaction curing type silicone materials. Addition reaction curing type silicone materials are particularly suitable for forming a release layer that takes into account both adhesion and peelability with respect to acrylic adhesive sheets. Curable silicone materials can be silicone modified resins obtained by introducing reactive silicone into organic resins such as urethane, epoxy, and alkyd resins through graft polymerization or the like.

[0065] Examples of addition reaction curing silicone materials are polyorganosiloxanes having vinyl or alkenyl groups in the molecule. Addition reaction curing silicone materials may not have hydrosilyl groups. Examples of alkenyl groups are 3-butenyl, 4-pentenyl, 5-hexenyl, 6-heptenyl, 7-octenyl, 8-nonenyl, 9-decenyl, 10-undecenyl and 11-dodecenyl. Examples of polyorganosiloxanes are copolymers of polyalkylalkylsiloxanes such as polydimethylsiloxane, polydiethylsiloxane and polymethylethylsiloxane, polyalkylarylsiloxane, and poly(dimethylsiloxane-diethylsiloxane) and other monomers containing Si atoms. Polyorganosiloxane is preferably polydimethylsiloxane.

[0066] A mold release composition containing a silicone-based mold release agent as a main component (hereinafter, "silicone mold release composition") generally contains a crosslinking agent. An example of the crosslinking agent is a polyorganosiloxane having a hydrosilyl group. The crosslinking agent may have two or more hydrosilyl groups in one molecule.

[0067] The silicone release agent composition may also contain a curing catalyst. Examples of the curing catalyst are platinum catalysts. Examples of platinum catalysts are chloroplatinic acid, olefin complexes of platinum, and olefin complexes of chloroplatinic acid. The amount of the platinum catalyst used is, for example, 10 to 1000 ppm (weight basis, converted to platinum) relative to the total solid content of the composition.

[0068] The silicone release agent composition may also contain additives. Examples of additives are release control agents and adhesion improvers. Examples of release control agents are unreactive silicone resins, and more specifically, organosiloxanes such as octamethylcyclotetrasiloxane and MQ resins. The total amount of release control agents and adhesion improvers is, for example, 1 to 30% by weight relative to the total solid content of the composition. Other examples of additives are fillers, antistatic agents, antioxidants, ultraviolet absorbers, plasticizers, and colorants. The total amount of other additives is, for example, 10% by weight or less relative to the total solid content of the composition.

[0069] The silicone release agent composition may also contain an organic solvent. Examples of organic solvents are hydrocarbon solvents such as cyclohexane, n-hexane, and n-heptane; aromatic solvents such as toluene and xylene; ester solvents such as ethyl acetate and methyl acetate; ketone solvents such as acetone and methyl ethyl ketone; and alcohol solvents such as methanol, ethanol, and butanol. Two or more organic solvents may also be contained. The amount of organic solvent used is preferably 80 to 99.9% by weight of the silicone release agent composition.

[0070] The release layer 132 can be formed, for example, by heating and drying a coating film containing a release agent composition formed on the lining substrate 131. The release agent composition can be applied by various coating methods such as roller coating, roller lick coating, gravure coating, reverse coating, roller brush, spray coating, dip roller coating, rod coating, blade coating, air knife coating, shower coating, die lip coating, and die coating. Heating and drying can be performed by hot air drying, for example. The heating temperature and time vary depending on the heat resistance of the lining substrate, and are generally 80 to 150° C. and about 10 seconds to 10 minutes. As required, irradiation with active energy rays such as ultraviolet rays can also be used in combination.

[0071] The thickness of the release layer 132 is, for example, 10 to 300 nm. The upper limit of the thickness may be 200 nm or less, 150 nm or less, 120 nm or less, 110 nm or less, 100 nm or less, less than 100 nm, 90 nm or less, 80 nm or less, 70 nm or less, less than 70 nm, and further may be 65 nm or less. The lower limit of the thickness may be 15 nm or more, 20 nm or more, 25 nm or more, 30 nm or more, 35 nm or more, 40 nm or more, 45 nm or more, and further may be 50 nm or more.

[0072] The first release liner 13A may be in a single sheet or in a long strip.

[0073] The example of the second release liner 13B including the preferred example is the same as the example of the first release liner 13A. However, for the second release liner 13B, the transmittance of the light 14A is replaced by the transmittance of the light 14B. The second release liner 13B having the release layer 132 can be used in a manner such that the release layer 132 is on the second coating layer 12B side.

[0074] (Base sheet)

[0075] An example of the first base sheet 11A is a resin film. Examples of the resin contained in the first base sheet 11A are the same as examples of the resin that can be contained in the backing base.

[0076] The first base sheet 11A may have the transmittance of the light 14A, or may have the transmittance of the light 14A to the same degree as that of the first release liner 13A.

[0077] The thickness of the first base sheet 11A is, for example, 10 to 200 μm, or 25 to 150 μm.

[0078] The first substrate sheet 11A may have a release layer on the surface of the first coating layer 12A. The examples of the release layer and its preparation method that the first substrate sheet 11A may have are the same as the examples of the release layer and its preparation method that the first release liner 13A may have. The first release liner 13A and the first substrate sheet 11A may both have a release layer. In this case, the release layers of the two may be formed by a release agent composition containing the same release agent as a main component. In addition, the thickness of the release layers of the two may also be different, for example, the release layer of the first substrate sheet 11A may be thicker.

[0079] The first base sheet 11A can generally be selected to have a greater release force with the first pressure-sensitive adhesive sheet 1A than the first release liner 13A.

[0080] The first base sheet 11A may be in a single sheet shape or in a long strip shape.

[0081] The first base sheet 11A may be the first release liner 13A peeled off from the first pressure-sensitive adhesive sheet 1A, or the second release liner 13B peeled off from the second pressure-sensitive adhesive sheet 1B.

[0082] (Photocurable composition)

[0083] The first photocurable composition is a composition that can form the first adhesive sheet 1A from the first coating layer 12A by irradiation with light 14A. The first photocurable composition, for example, contains a monomer group containing a (meth)acrylic monomer and / or a partial polymer of the monomer group. The content of the (meth)acrylic component in the first photocurable composition, that is, the (meth)acrylic monomer and its partial polymer, can be 50% by weight or more, 60% by weight or more, 70% by weight or more, and further can be 80% by weight or more. In this case, an acrylic adhesive sheet with (meth)acrylic polymer and its cross-linked product as the main component can be formed. However, the first photocurable composition is not limited to the above examples. In this specification, (meth)acrylic acid refers to acrylic acid and methacrylic acid. (Meth)acrylate refers to acrylate and methacrylate.

[0084] Examples of (meth)acrylic monomers include (meth)acrylic acid alkyl esters having an alkyl group having 1 to 20 carbon atoms in a side chain. The number of carbon atoms in the alkyl group may be 7 or less, 6 or less, 5 or less, or 4 or less. The alkyl group may be linear or branched. Examples of the alkyl (meth)acrylates are methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, sec-butyl (meth)acrylate, tert-butyl (meth)acrylate, isobutyl (meth)acrylate, n-pentyl (meth)acrylate, isopentyl (meth)acrylate, n-hexyl (meth)acrylate, isohexyl (meth)acrylate, isoheptyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, n-nonyl (meth)acrylate, isononyl (meth)acrylate, n-decyl (meth)acrylate, isodecyl (meth)acrylate, n-dodecyl (meth)acrylate (lauryl (meth)acrylate), n-tridecyl (meth)acrylate, n-tetradecyl (meth)acrylate, pentadecyl (meth)acrylate, hexadecyl (meth)acrylate, heptadecyl (meth)acrylate, and octadecyl (meth)acrylate. The alkyl (meth)acrylate may be n-butyl (meth)acrylate.

[0085] The content of the alkyl (meth)acrylate in the monomer group may be, for example, 40% by weight or more, 50% by weight or more, 60% by weight or more, 70% by weight or more, 80% by weight or more, 85% by weight or more, 90% by weight or more, or even 95% by weight or more. It should be noted that when calculating the content, the weight of the partial polymer is converted into the weight of each monomer before polymerization.

[0086] The monomer group may include a carboxyl-containing monomer. The carboxyl-containing monomer may be a (meth) acrylic monomer, in other words, the (meth) acrylic monomer may include a carboxyl-containing monomer. Examples of carboxyl-containing monomers are (meth) acrylic acid, (meth) carboxylethyl acrylate, (meth) carboxylpentyl acrylate, itaconic acid, maleic acid, fumaric acid and crotonic acid. The content of the carboxyl-containing monomer in the monomer group may be, for example, less than 10% by weight, less than 9% by weight, less than 8% by weight, less than 7% by weight, less than 6% by weight, less than 5.5% by weight, and further less than 5% by weight. The lower limit of the content may be, for example, more than 0.1% by weight, more than 0.5% by weight, and further more than 1% by weight. The monomer group may also not include a carboxyl-containing monomer.

[0087] The monomer group may include a hydroxyl-containing monomer. The hydroxyl-containing monomer may be a (meth) acrylic monomer, in other words, the (meth) acrylic monomer may include a hydroxyl-containing monomer. Examples of hydroxyl-containing monomers are 2-hydroxyethyl (meth) acrylate, 2-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. The hydroxyl-containing monomer is preferably 2-hydroxyethyl (meth) acrylate and 4-hydroxybutyl (meth) acrylate. The content of the hydroxyl-containing monomer in the monomer group may be, for example, 5% by weight or less, 4% by weight or less, 3% by weight or less, 2% by weight or less, 1% by weight or less, 0.8% by weight or less, 0.5% by weight or less, 0.3% by weight or less, 0.2% by weight or less, and further may be 0.1% by weight or less. The lower limit of the content may be, for example, 0.01% by weight or more, 0.03% by weight or more, or further 0.05% by weight or more. The monomer group may not contain a hydroxyl group-containing monomer.

[0088] The first photocurable composition may contain the above-mentioned monomers in the form of a partial polymer. The partial polymer may be any polymer of a homopolymer and a copolymer. The partial polymer may contribute to the stable formation of the first coating layer 12A by appropriately increasing the viscosity of the photocurable composition.

[0089] The first photocurable composition usually contains a photopolymerization initiator. Examples of the photopolymerization initiator include a photoradical generator that generates radicals by visible light and / or ultraviolet light having a wavelength shorter than 450 nm.

[0090] Examples of photopolymerization initiators include benzoin ethers such as benzoin methyl ether, benzoin isopropyl ether, and benzoin dimethyl ether; substituted benzoin ethers such as anisole methyl ether; substituted acetophenones such as 2,2-diethoxyacetophenone and 2,2-dimethoxy-2-phenylacetophenone; α-hydroxyalkyl phenones such as 1-hydroxycyclohexyl phenyl ketone; substituted α-ol ketones such as 2-methyl-2-hydroxypropiophenone; aromatic sulfonyl chlorides such as 2-naphthalenesulfonyl chloride; photoactive oximes such as 1-phenyl-1,1-propanedione-2-(o-ethoxycarbonyl)-oxime; benzophenone, benzoylbenzoic acid, benzoylbenzoic acid, Benzophenone compounds such as methyl benzoate, 4-phenylbenzophenone, hydroxybenzophenone, acryloyl benzophenone, 4-benzoyl-4'-methyldiphenyl sulfide, 3,3',4,4'-tetra(tert-butylperoxycarbonyl)benzophenone; thioxanthone compounds such as thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, isopropylthioxanthone, 2,4-diisopropylthioxanthone, 2,4-diethylthioxanthone; 2,4,6-trichloro-s-triazine, 2-phenyl-4,6-bis(trichloromethyl)-s-triazine, 2-(p-methoxyphenyl)-4,6 -bis(trichloromethyl)-s-triazine, 2-(p-tolyl)-4,6-bis(trichloromethyl)-s-triazine, 2-piperonyl-4,6-bis(trichloromethyl)-s-triazine, 2,4-bis(trichloromethyl)-6-phenylvinyl-s-triazine, 2-(naphthalene-1-yl)-4,6-bis(trichloromethyl)-s-triazine, 2-(4-methoxy-naphthalene-1-yl)-4,6-bis(trichloromethyl)-s-triazine, 2,4-trichloromethyl-(piperonyl)-6-triazine, 2,4-trichloromethyl-(4'-methoxyphenylvinyl)-6-triazine, etc. Oxime ester compounds such as 1,2-octanedione, 1-[4-(phenylthio)-, 2-(O-benzoyloxime)], O-(acetyl)-N-(1-phenyl-2-oxo-2-(4'-methoxy-naphthyl)ethylidene)hydroxylamine; phosphine compounds such as bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide and 2,4,6-trimethylbenzoyldiphenylphosphine oxide; quinone compounds such as 9,10-phenanthrenequinone, camphorquinone, and ethylanthraquinone; borate ester compounds; carbazole compounds; imidazole compounds; and titanocene compounds. The photocurable composition may contain one or more photopolymerization initiators.

[0091] The amount of the photopolymerization initiator in the first photocurable composition may be, for example, 0.02 to 10 parts by weight, or 0.05 to 5 parts by weight, relative to 100 parts by weight of the total of the monomer group and the partially polymerized product thereof.

[0092] The first photocurable composition may contain a crosslinking agent. An example of the crosslinking agent is a multifunctional monomer having two or more polymerizable functional groups in one molecule. The multifunctional monomer may be a (meth)acrylic monomer. An example of the multifunctional monomer is a monomer having two or more C=C bonds in one molecule, and a monomer having one or more C=C bonds and one or more epoxy groups, aziridine groups, The polyfunctional monomer preferably has two or more C═C bonds in one molecule.

[0093] Examples of the crosslinking agent include: polyfunctional acrylates (ester compounds formed by polyols and (meth)acrylic acid, etc.) such as (poly)ethylene glycol di(meth)acrylate, (poly)propylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, pentaerythritol di(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, 1,2-ethylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol diacrylate (NDDA), 1,12-dodecanediol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, and tetramethylolmethane tri(meth)acrylate; allyl (meth)acrylate, vinyl (meth)acrylate, divinylbenzene, epoxy acrylate, polyester acrylate, urethane acrylate, butyl di(meth)acrylate, and hexyl di(meth)acrylate. The polyfunctional monomer is preferably a polyfunctional acrylate, and more preferably trimethylolpropane tri(meth)acrylate, hexanediol di(meth)acrylate, or dipentaerythritol hexa(meth)acrylate.

[0094] The amount of the crosslinking agent varies depending on the molecular weight, the number of functional groups, etc., and is, for example, 5 parts by weight or less, 3 parts by weight or less, 2 parts by weight or less, 1 part by weight or less, and further 0.5 parts by weight or less per 100 parts by weight of the total of the monomer group and its partial polymer. The lower limit of the amount of the crosslinking agent is, for example, 0.01 parts by weight or more, and further 0.05 parts by weight or more.

[0095] The first photocurable composition may also contain additives other than those mentioned above. Examples of the additives include chain transfer agents, silane coupling agents, viscosity modifiers, tackifiers, plasticizers, softeners, antioxidants, fillers, colorants, antioxidants, surfactants, antistatic agents, and ultraviolet absorbers.

[0096] The content of the solvent in the first photocurable composition is, for example, 5% by weight or less, 4% by weight or less, 3% by weight or less, 2% by weight or less, 1% by weight or less, and further 0.5% by weight or less. The first photocurable composition may contain substantially no solvent. Substantially containing no solvent means that a solvent derived from an additive or the like is allowed to be contained at a content of, for example, 0.1% by weight or less, preferably 0.05% by weight or less, and more preferably 0.01% by weight or less.

[0097] The viscosity of the first photocurable composition is preferably 5 to 100 poise. The first photocurable composition having a viscosity within the above range is particularly suitable for forming the first coating layer 12A.

[0098] The second photocurable composition is a composition that can form the second adhesive sheet 1B from the second coating layer 12B by irradiation with light 14B. Examples of the second photocurable composition, including preferred examples, are the same as those of the first photocurable composition. The first photocurable composition and the second photocurable composition may be the same composition. In addition, the same composition may be used as the first photocurable composition and the second photocurable composition to form the same adhesive sheet as the first adhesive sheet 1A and the second adhesive sheet 1B.

[0099] (First and Second Laminated Bodies and Formation thereof)

[0100] The first substrate sheet 11A and the first release liner 13A can be selected from a sheet having a relatively large release force relative to the first adhesive sheet 1A and a sheet having a relatively small release force, respectively. In other words, the release force between the first substrate sheet 11A and the first adhesive sheet 1A can be greater than the release force between the first release liner 13A and the first adhesive sheet 1A.

[0101] The first substrate sheet 11A and the first release liner 13A may both have a release layer on the surface on the first coating layer 12A side. In this case, the release layer of the first substrate sheet 11A and the release layer of the first release liner 13A may be a layer formed of a release agent composition containing the same release agent as a main component, or may be a layer formed of the same release agent composition. In addition, the thickness of the release layers of both may be the same.

[0102] The first laminate 10 can be formed, for example, by forming the first coating layer 12A on the first substrate sheet 11A (or the first release liner 13A), and disposing the first release liner 13A (or the first substrate sheet 11A) on the formed first coating layer 12A. Alternatively, the first laminate 10 can be formed by coating the photocurable composition so as to flow into a space between the first substrate sheet 11A and the first release liner 13A, the main surfaces of which are facing each other and maintained at a predetermined distance.

[0103] The first laminate 10 may include a first elongated substrate sheet 11A, a first elongated coating layer 12A, and a first elongated release liner 13A. In other words, it may be in an elongated shape. The first elongated laminate 10 may be obtained by, for example, conveying the first substrate sheet 11A and the first release liner 13A continuously unwound from a roll while forming the first coating layer 12A therebetween.

[0104] The first laminate 10 may include another layer in addition to the first substrate sheet 11A, the first coating layer 12A, and the first release liner 13A. The above-mentioned other layer may be arranged on the side opposite to the first coating layer 12A side of the first substrate sheet 11A and / or the first release liner 13A. The first coating layer 12A is preferably in contact with the first substrate sheet 11A and the first release liner 13A.

[0105] The second release liner 13B can be selected from a sheet having a smaller release force with respect to the second pressure-sensitive adhesive sheet 1B than the second base sheet 11B. The second release liner 13B can be selected from the same sheet as the first release liner 13A.

[0106] The peeling force between the second base sheet 11B and the second pressure-sensitive adhesive sheet 1B may be greater than the peeling force between the first release liner 13A and the first pressure-sensitive adhesive sheet 1A.

[0107] The second substrate sheet 11B and the second release liner 13B may both have a release layer on the surface on the second coating layer 12B side. In this case, the release layer of the second substrate sheet 11B and the release layer of the second release liner 13B may be a layer formed of a release agent composition containing the same release agent as a main component, or may be a layer formed of the same release agent composition. In addition, the thickness of the release layers of both may be the same.

[0108] The second laminate 20 can be formed, for example, by forming the second coating layer 12B on the second substrate sheet 11B (or the second release liner 13B), and disposing the second release liner 13B (or the second substrate sheet 11B) on the formed second coating layer 12B. Alternatively, the second laminate 20 can be formed by coating the photocurable composition so as to flow into the space between the second substrate sheet 11B and the second release liner 13B, which are held at a predetermined interval so that their main surfaces face each other. The second substrate sheet 11B can be used so that the surface on the first coating layer 12A side, for example, the surface on the release layer 132 side, before peeling becomes the second coating layer 12B side.

[0109] The second laminate 20 may include a second long-strip base sheet 11B, a second long-strip coating layer 12B, and a second long-strip release liner 13B. In other words, it may be long-strip. The second long-strip laminate 20 may be obtained by, for example, conveying the second base sheet 11B and the second release liner 13B continuously unwound from a roll while forming the second coating layer 12B therebetween.

[0110] The second laminate 20 may also include another layer in addition to the second substrate sheet 11B, the second coating layer 12B and the second release liner 13B. The above-mentioned other layer may be arranged on the side opposite to the second coating layer 12B side of the second substrate sheet 11B and / or the second release liner 13B. The second coating layer 12B is preferably in contact with the second substrate sheet 11B and the second release liner 13B.

[0111] The first coating layer 12A and the second coating layer 12B can be formed by various coating methods such as roll coating, lick roll coating, gravure coating, reverse coating, roll brushing, spray coating, dip roll coating, rod coating, blade coating, air knife coating, shower coating, die lip coating, and die coating.

[0112] The thickness of the first coating layer 12A and the second coating layer 12B can be adjusted according to the desired thickness of the first adhesive sheet 1A and the second adhesive sheet 1B, for example, 5 to 100 μm, 5 to 50 μm, 5 to 25 μm, or further 5 to 20 μm, 5 to 60 μm, 5 to 80 μm, 5 to 100 μm, 5 to 25 μm, 5 to 30 μm, 5 to 50 μm, 5 to 25 μm, 5 to 30 μm, 5 to 100 μm, 5 to 20 ...50 μm, 5 to 25 μm, 5 to 25 μm, 5 to 20 μm, 5 to

[0113] (Radiation of light)

[0114] Light 14A, 14B is, for example, visible light or ultraviolet light having a wavelength shorter than 450 nm. Light 14A, 14B may include light of a wavelength in the same region as the absorption wavelength of the photopolymerization initiator contained in the photocurable composition. Light 14A, 14B obtained by cutting off short-wavelength light with a wavelength of less than 300 nm through an optical filter or the like may be irradiated, and cutting off short-wavelength light is suitable for suppressing the degradation of the release liner caused by light 14A, 14B. The light source of light 14A, 14B is, for example, an irradiation device having an ultraviolet irradiation lamp. Examples of ultraviolet irradiation lamps are ultraviolet LEDs, low-pressure mercury lamps, medium-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, metal halide lamps, xenon lamps, microwave-excited mercury lamps, black light lamps, chemical lamps, germicidal lamps, low-pressure discharge mercury lamps, and excimer lasers. Two or more ultraviolet irradiation lamps may also be combined. Light 14A and light 14B may have the same spectrum, or may be irradiated under the same irradiation conditions (irradiation intensity and cumulative light amount).

[0115] exist Figure 1In the example of , light 14A, 14B respectively passes through the release liner and reaches the coating layer, so that the coating layer is cured. However, it should be noted that the irradiation of light 14A, 14B can be implemented from one side of the substrate sheet, and can also be implemented from both sides of the release liner and the substrate sheet.

[0116] The irradiation of light 14A, 14B may be continuous or intermittent.

[0117] The irradiation intensity of the light beams 14A and 14B is, for example, 1 to 20 mW / cm 2 The accumulated light intensity of the light 14A and 14B on the first stack 10 and the second stack 20 is, for example, 100 to 5000 mJ / cm 2 .

[0118] (peel off)

[0119] The first release liner 13A is peeled off from the photocured laminate 17. The laminate 17 includes the first base sheet 11A, the first adhesive sheet 1A, and the first release liner 13A in this order. By the above peeling, a laminate (fifth laminate) 15 including the first base sheet 11A and the first adhesive sheet 1A is obtained.

[0120] The peeling force of the first release liner 13A relative to the first adhesive sheet 1A is, for example, 0.01 to 3 N / 50 mm. The upper limit of the peeling force may be 2 N / 50 mm or less, 1.5 N / 50 mm or less, 1 N / 50 mm or less, 0.5 N / 50 mm or less, 0.25 N / 50 mm or less, 0.2 N / 50 mm or less, and further may be 0.1 N / 50 mm or less. The lower limit of the peeling force may be 0.02 N / 50 mm or more, 0.03 N / 50 mm or more, and further may be 0.04 N / 50 mm or more.

[0121] The peeling force of the first substrate sheet 11A relative to the first adhesive sheet 1A is, for example, 0.05 to 10 N / 50 mm. The upper limit of the peeling force may be 8 N / 50 mm or less, 5 N / 50 mm or less, 2.5 N / 50 mm or less, 2 N / 50 mm or less, 1 N / 50 mm or less, 0.75 N / 50 mm or less, 0.5 N / 50 mm or less, 0.3 N / 50 mm or less, and further may be 0.2 N / 50 mm or less. The lower limit of the peeling force may be 0.07 N / 50 mm or more, 0.1 N / 50 mm or more, and further may be 0.2 N / 50 mm or more.

[0122] The peeled first release liner 13A can be wound up to form a roll and then reused for the second base sheet 11B.

[0123] The second release liner 13B can be peeled off from the photocured laminate 27. The laminate 27 includes the second base sheet 11B, the second adhesive sheet 1B, and the second release liner 13B in this order. By peeling off as described above, a laminate (sixth laminate) 25 including the second base sheet 11B and the second adhesive sheet 1B can be obtained.

[0124] The peeling force of the second release liner 13B with respect to the second adhesive sheet 1B is, for example, 0.01 to 3 N / 50 mm. The upper limit of the peeling force may be 2 N / 50 mm or less, 1.5 N / 50 mm or less, 1 N / 50 mm or less, 0.5 N / 50 mm or less, 0.25 N / 50 mm or less, 0.2 N / 50 mm or less, and further may be 0.1 N / 50 mm or less. The lower limit of the peeling force may be 0.02 N / 50 mm or more, 0.03 N / 50 mm or more, and further may be 0.04 N / 50 mm or more.

[0125] The peeling force of the second substrate sheet 11B relative to the second adhesive sheet 1B is, for example, 0.05 to 10 N / 50 mm. The upper limit of the peeling force may be 8 N / 50 mm or less, 5 N / 50 mm or less, 2.5 N / 50 mm or less, 2 N / 50 mm or less, 1 N / 50 mm or less, 0.75 N / 50 mm or less, 0.5 N / 50 mm or less, 0.3 N / 50 mm or less, and further may be 0.2 N / 50 mm or less. The lower limit of the peeling force may be 0.07 N / 50 mm or more, 0.1 N / 50 mm or more, and further may be 0.2 N / 50 mm or more.

[0126] The ratio β / α of the peeling force β of the second substrate sheet 11B with respect to the second adhesive sheet 1B and the peeling force α of the first release liner 13A with respect to the first adhesive sheet 1A may be 1.05 or more, 1.1 or more, 1.3 or more, and further may be 1.5 or more. The upper limit of the ratio β / α is, for example, 40 or less, 35 or less, 30 or less, 25 or less, 20 or less, 15 or less, 10 or less, 5 or less, 4 or less, 3 or less, 2 or less, and further may be 1.8 or less.

[0127] The peeling force of the release liner and the substrate sheet relative to the adhesive sheet can be prepared by cutting a laminate containing an adhesive sheet, a release liner and / or a substrate sheet into a width of 50 mm to prepare a test piece, and implementing a 180° peeling test in which only the release liner or the substrate sheet is peeled off from the prepared test piece. The peeling test is implemented after about 0.5 to 1 hour has passed since the formation of the adhesive sheet. From the formation of the adhesive sheet to the implementation of the peeling test, the laminate and the test piece are placed in an atmosphere of 23°C ± 5°C. The peeling speed of the peeling test is set to 300mm / min, and the test temperature is set to 23°C ± 5°C. In the case where the width of the laminate does not meet 50mm, the measured value under the original width can be converted to a value when the width is 50mm. In the case where the formation direction of the coating layer containing the photocurable composition can be distinguished, the TD facing perpendicular to the direction, i.e. MD, can be determined as the width direction of the test piece. In the case where the release liner and / or the substrate sheet is in the shape of a strip, its width direction can be used as the width direction of the test piece.

[0128] The second release liner 13B after the peeling can be reused as a base sheet, and can be reused after winding it into a roll.

[0129] (Adhesive Sheet)

[0130] The thickness of the first adhesive sheet 1A and the second adhesive sheet 1B may be, for example, 2 to 70 μm, 2 to 50 μm, 5 to 40 μm, 10 to 30 μm, 10 to 25 μm, or even 10 to 20 μm.

[0131] The polymerization rate of the monomer group in the first adhesive sheet 1A and the second adhesive sheet 1B is preferably 90% or more. The polymerization rate may be 95% or more, 98% or more, or even 99% or more.

[0132] The gel fraction of the first adhesive sheet 1A and the second adhesive sheet 1B may be, for example, 50% or more, 75% or more, 80% or more, or even 85% or more.

[0133] The first adhesive sheet 1A and the second adhesive sheet 1B may be formed of the same adhesive sheet.

[0134] The first adhesive sheet 1A and the second adhesive sheet 1B can be used, for example, for an optical laminate including an optical film. In other words, the first adhesive sheet 1A and the second adhesive sheet 1B can be adhesive sheets for optical laminates. The optical laminate can be an optical film with an adhesive sheet. It should be noted that the uses of the first adhesive sheet 1A and the second adhesive sheet 1B are not limited to the above examples.

[0135] Reference Figure 3, another example of the method for manufacturing the adhesive sheet of the present invention is described. In this example, a first coating layer 12A is formed by a coating device 32 on one side of a first long-strip substrate sheet 11A continuously unrolled from a winding body 31. Next, a first long-strip release liner 13A continuously unrolled from a winding body 33A is arranged on the first coating layer 12A to form a first long-strip laminate 10. Next, the first laminate 10 is irradiated with light 14A from a lighting device 34 to form a first long-strip adhesive sheet 1A. Next, the first release liner 13A is peeled off from the laminate 17 containing the first adhesive sheet 1A and wound up on a winding body 35A. The wound first release liner 13A is reused as the second substrate sheet 11B. The above steps are implemented while conveying the first substrate sheet 11A and the first release liner 13A. The laminate 15 formed by peeling off the first release liner 13A can be used, for example, for an optical film with a pressure-sensitive adhesive sheet or for its production.

[0136] Next, the second coating layer 12B is formed by the coating device 32 on one side of the second long-strip substrate sheet 11B continuously unrolled from the winding body 35A. Next, the second long-strip release liner 13B continuously unrolled from the winding body 33B is arranged on the second coating layer 12B to form the second long-strip laminate 20. Next, the second laminate 20 is irradiated with light 14B from the lighting device 34 to form the second long-strip adhesive sheet 1B. Next, the second release liner 13B is peeled off from the laminate 27 containing the second adhesive sheet 1B and wound up on the winding body 35B. The above steps are carried out while the second substrate sheet 11B and the second release liner 13B are transported. The laminate 25 formed by peeling the second release liner 13B can be used, for example, for an optical film with an adhesive sheet or its manufacture. Figure 3 The method is particularly suitable for mass production of adhesive sheets.

[0137] Reference Figure 4 Another example of the method for producing the adhesive sheet of the present invention is described below. This example is similar to the method of producing the adhesive sheet of the present invention except that the first release liner 13A after being peeled off from the laminate 17 is not wound up into a roll 35A and reused as the second substrate sheet 11B. Figure 3 Same as the example. Figure 4 The method is particularly suitable for mass production of adhesive sheets.

[0138] [Release liner]

[0139] According to a different aspect from the above, the present invention provides a release liner used in the method for producing a PSA sheet of the present invention. Examples of the release liner are the same as those described above in the description of the method for producing a PSA sheet.

[0140] [Method for producing laminated body]

[0141] According to an aspect different from the above, the present invention provides a method for manufacturing a laminate, the method comprising:

[0142] irradiating the first laminate 10 including the first substrate sheet 11A, the first coating layer 12A containing the first photocurable composition, and the first release liner 13A in this order with light 14A to form the first adhesive sheet 1A from the first coating layer 12A; and

[0143] The first release liner 13A peeled from the first pressure-sensitive adhesive sheet 1A is used as the second base sheet 11B to form the second laminate 20 including the second base sheet 11B, the second coating layer 12B containing the second photocurable composition, and the second release liner 13B in this order.

[0144] Examples of the layers and photocurable compositions included in the first stack 10 and the second stack 20 , examples of the lights 14A and 14B (including irradiation conditions), and examples of the first adhesive sheet 1A and the second adhesive sheet 1B are the same as those described above in the explanation of the method for producing the adhesive sheet.

[0145] [Method for producing optical film with pressure-sensitive adhesive sheet]

[0146] Reference Figure 5 , an example of a method for manufacturing an optical film with an adhesive sheet of the present invention is described. In this example, an optical film 2 is arranged on the exposed surface 18 of the first adhesive sheet 1A formed by peeling off the first release liner 13A from a laminate 17 sequentially including the first substrate sheet 11A, the first adhesive sheet 1A and the first release liner 13A, to form an optical film 41 with an adhesive sheet. The optical film 41 with an adhesive sheet sequentially includes the first substrate sheet 11A, the first adhesive sheet 1A and the optical film 2. The optical film 41 with an adhesive sheet can be used in an image display device, etc. directly or after peeling off the first substrate sheet 11A, for example, in the form of an optical laminate having the first adhesive sheet 1A and the optical film 2. The optical laminate can be attached to an object (such as an image forming panel) via the first adhesive sheet 1A. However, it should be noted that the use of the optical film 41 with an adhesive sheet is not limited to the above example. Another member such as an optical film may be arranged on the exposed surface 18 formed by peeling the first substrate sheet 11A from the optical film 41 with an adhesive sheet. For example, an optical film 42 with an adhesive sheet including the optical film 2A, the first adhesive sheet 1A, and the optical film 2B in this order may be formed (see Figure 6 ). The optical films 2A and 2B may be the same or different from each other.

[0147] The optical film 2 may be arranged on the exposed surface 18 of the second adhesive sheet 1B formed by peeling the second release liner 13B from the laminate 27 including the second base sheet 11B, the second adhesive sheet 1B and the second release liner 13B in sequence, to form an optical film with an adhesive sheet. In addition, the second base sheet 11B may be peeled off to form an optical film with an adhesive sheet including the optical film 2A, the second adhesive sheet 1B and the optical film 2B in sequence.

[0148] The optical film 2 may be disposed directly or indirectly on the exposed surface 18. In other words, the optical film 2 may be disposed in contact with the exposed surface 18 or in a state where another layer is sandwiched between the exposed surface 18.

[0149] Reference Figure 7 Another example of the method for producing an optical film with an adhesive sheet of the present invention is described. In this example, Figure 3 The exposed surface 18 of the first adhesive sheet 1A in the laminate 15 formed by the method is provided with a long optical film 2, thereby forming a long optical film 41 with an adhesive sheet. The optical film 2 is continuously unwound from the roll 36 and provided on the exposed surface 18. Figure 7 As shown, the formation of the pressure-sensitive adhesive sheet and the formation of the optical film with the pressure-sensitive adhesive sheet can be performed continuously. Figure 7 The method is particularly suitable for mass production of optical films with adhesive sheets. Figure 3 By similarly disposing the optical film 2 on the laminated body 25 formed by the method, an optical film with a pressure-sensitive adhesive sheet can be formed.

[0150] The optical film 2 is, for example, a film including at least one selected from a polarizing film and a phase difference film. The optical film 2 may be a laminated film including a polarizing film and / or a phase difference film. The optical film 2 may include a film made of glass. However, the optical film 2 is not limited to the above examples.

[0151] The polarizing film includes a polarizer. Typically, the polarizing film includes a polarizer and a protective film (transparent protective film). The protective film is, for example, arranged in contact with the main surface (surface with the widest area) of the polarizer. The polarizer can be arranged between two protective films. The protective film can be arranged on at least one side of the polarizer.

[0152] The polarizer is not particularly limited, and examples thereof include: a polarizer obtained by adsorbing a dichroic substance such as iodine and a dichroic dye on a hydrophilic polymer film such as a polyvinyl alcohol film, a partially formalized polyvinyl alcohol film, and a partially saponified film of an ethylene-vinyl acetate copolymer, and then uniaxially stretching the film; a polyene oriented film such as a dehydrated product of polyvinyl alcohol and a dehydrochlorinated product of polyvinyl chloride, etc. Typically, the polarizer is formed of a polyvinyl alcohol film (polyvinyl alcohol films include partially saponified films of ethylene-vinyl acetate copolymers) and a dichroic substance such as iodine.

[0153] The thickness of the polarizer is not particularly limited, for example, it is 80 μm or less, it can be 50 μm or less, 30 μm or less, 25 μm or less, and further, it can be 20 μm or less. The lower limit of the thickness of the polarizer is not particularly limited, for example, it is 1 μm or more, it can be 5 μm or more, 10 μm or more, and further, it can be 15 μm or more. The dimensional change of the thin polarizer (for example, the thickness is 20 μm or less) is suppressed, which can contribute to the durability of the optical laminate, especially the durability at high temperature.

[0154] As the material of the protective film, for example, a thermoplastic resin having excellent transparency, mechanical strength, thermal stability, moisture barrier, isotropy, etc. can be used. Specific examples of such thermoplastic resins include cellulose resins such as cellulose triacetate, polyester resins, polyethersulfone resins, polysulfone resins, polycarbonate resins, polyamide resins, polyimide resins, polyolefin resins, (meth)acrylic resins, cyclic polyolefin resins (norbornene resins), polyarylate resins, polystyrene resins, polyvinyl alcohol resins, and mixtures thereof. The material of the protective film can be a thermosetting resin or ultraviolet curing resin such as (meth)acrylic acid, urethane, acrylic urethane, epoxy, silicone, etc. In the case where the polarizing film has two protective films, the materials of the two protective films can be the same or different from each other. For example, a protective film formed of a thermoplastic resin can be bonded to one main surface of the polarizer via an adhesive, and a protective film formed of a thermosetting resin or an ultraviolet curing resin can be bonded to the other main surface of the polarizer. The protective film can contain one or more arbitrary additives. Examples of the additive include ultraviolet absorbers, antioxidants, lubricants, plasticizers, release agents, anti-coloring agents, flame retardants, nucleating agents, antistatic agents, pigments, and colorants.

[0155] The thickness of the protective film can be appropriately determined, and is generally about 10 to 200 μm from the perspectives of strength, workability such as handling properties, and thin film properties.

[0156] The polarizer and the protective film are usually bonded together via a water-based adhesive or the like. Examples of the water-based adhesive include isocyanate adhesives, polyvinyl alcohol adhesives, gelatin adhesives, vinyl latex, water-based polyurethane, and water-based polyester. Other adhesives other than the above-mentioned adhesives include ultraviolet curing adhesives and electron beam curing adhesives. Electron beam curing polarizer adhesives show suitable adhesion to various protective films. The adhesive may also contain a metal compound filler.

[0157] In the polarizing film, a retardation film or the like may be formed on the polarizer instead of the protective film. Another protective film or a retardation film or the like may be provided on the protective film.

[0158] The protective film may be provided with a hard coating layer on the surface opposite to the surface bonded to the polarizer, and may be subjected to treatment for the purpose of anti-reflection, anti-blocking, diffusion, anti-glare, etc.

[0159] The polarizing film may be a circular polarizing film.

[0160] As the retardation film, a film obtained by stretching a polymer film or a film obtained by orienting and fixing a liquid crystal material can be used. The retardation film has birefringence in the plane and / or in the thickness direction, for example.

[0161] The phase difference film includes a phase difference film for antireflection (refer to Japanese Patent Application Publication No. 2012-133303

[0221] ,

[0222] , and

[0228] ), a phase difference film for viewing angle compensation (refer to Japanese Patent Application Publication No. 2012-133303

[0225] and

[0226] ), and a tilted orientation phase difference film for viewing angle compensation (refer to Japanese Patent Application Publication No. 2012-133303

[0227] ).

[0162] The specific structure of the retardation film, such as the retardation value, the arrangement angle, the three-dimensional birefringence, whether it is a single layer or a multilayer, etc., is not particularly limited, and a known retardation film can be used.

[0163] The thickness of the retardation film is preferably 20 μm or less, more preferably 10 μm or less, further preferably 1 to 9 μm, particularly preferably 3 to 8 μm.

[0164] The phase difference film may include, for example, a quarter wave plate and / or a half wave plate in which a liquid crystal material is oriented and fixed.

[0165] An image display device can be formed using an optical film with an adhesive sheet formed by the above-mentioned method. The image display device can be formed by, for example, bonding optical films 41 and 42 with adhesive sheets to an image display panel. The bonding can be performed by the first adhesive sheet 1A or the second adhesive sheet 1B. The image display device can be an organic EL display or a liquid crystal display. However, the image display device is not limited to the above examples. The image display device can also be a field luminescence (EL) display, a plasma display (PD), a field emission display (FED: Field Emission Display), etc. The image display device can be used for household appliances, in-vehicle applications, public information displays (PID), etc.

[0166] Example

[0167] Hereinafter, the present invention will be described in more detail by way of examples. However, the present invention is not limited to the examples shown below.

[0168] (Manufacturing Example 1: Preparation of a photocurable composition)

[0169] 100 parts by weight of n-butyl acrylate (BA), 5 parts by weight of acrylic acid (AA), 0.1 parts by weight of 2-hydroxyethyl acrylate (2HEA), and 0.05 parts by weight of Omnirad184 and Omnirad651 (both made by IGM Resins) as photopolymerization initiators were placed in a four-necked flask and irradiated with ultraviolet light in a nitrogen atmosphere to obtain a partially photopolymerized monomer slurry. The ultraviolet irradiation was carried out until the viscosity of the solution in the flask (measurement conditions: BH viscometer No. 5 rotor, 10 rpm, measurement temperature 30°C) reached about 20 Pa·s. Next, 0.1 parts by weight of 1,9-nonanediol diacrylate (NDDA) as a crosslinking agent was uniformly mixed with 100 parts by weight of the monomer slurry to obtain a photocurable composition.

[0170] (Manufacturing Example 2: Preparation of Release Liner A)

[0171] 100 parts by weight of an addition reaction curable silicone (LTC761 containing hexenyl group-containing polyorganosiloxane, 30% by weight toluene solution, manufactured by Dow Corning Toray), 0.9 parts by weight of a release control agent (BY24-850 containing unreacted silicone resin, manufactured by Dow Corning Toray), 2 parts by weight of a curing catalyst (SRX212 containing a platinum catalyst, manufactured by Dow Corning Toray), and a toluene / hexane mixed solvent (volume ratio 1:1) as a diluent were mixed to obtain a silicone-based release agent composition A. The concentration of the silicone solid content in the release agent composition A was 1.0% by weight. Next, the release agent composition A was applied to one side of a liner substrate (Lumirror 38R75 as a polyester film, thickness 38 μm) by a wire bar, and heated at 130° C. for 1 minute to prepare a release liner A having a release layer (thickness 60 nm) on one side.

[0172] (Manufacturing Example 3: Preparation of Release Liner B)

[0173] A release liner B having a release layer (thickness 120 nm) on one surface was prepared in the same manner as in Production Example 2 except that the thickness of the release agent composition A applied to the lining substrate was changed.

[0174] (Manufacturing Example 4: Preparation of Release Liner C)

[0175] 33.3 parts by weight of addition reaction curable silicone (KS-847T containing vinyl polysiloxane, 30% by weight toluene solution, manufactured by Shin-Etsu Chemical) and 1 part by weight of a curing catalyst (CAT-PL-50T containing a platinum catalyst, manufactured by Shin-Etsu Chemical) were mixed with a toluene / hexane mixed solvent (volume ratio 1:1) as a diluent to obtain a silicone-based release agent composition C. The concentration of the silicone solid content in the release agent composition C was 1.0% by weight. Next, the release agent composition C was applied to one side of a liner substrate (Lumirror 38R75 as a polyester film, thickness 38 μm) by a wire bar, and heated at 130° C. for 1 minute to prepare a release liner C having a release layer (thickness 100 nm) on one side.

[0176] [Formation of Adhesive Sheet]

[0177] (Sample 1)

[0178] The photocurable composition of Manufacturing Example 1 was applied to one side of the first substrate sheet (Lumirror 38R75, a polyester film without a release layer, with a thickness of 38 μm) using an applicator to form a first coating layer. Next, the release liner A of Manufacturing Example 2 was arranged on the first coating layer to obtain a first laminate. The release liner A was arranged so that the release layer and the first coating layer were in contact. Next, the first coating layer was exposed to light at an illumination of 2.4 mW / cm 2 And the accumulated light intensity is 2880mJ / cm 2 Under the conditions of , ultraviolet rays (black light source) are irradiated from the release liner A side of the first laminate to photocure the first coating layer, thereby forming a laminate 17 consisting of the first substrate sheet, the first adhesive sheet (thickness 20 μm) and the release liner A.

[0179] A test piece of 220 mm in length and 50 mm in width was cut out from the formed laminate 17 (the length direction was the coating direction of the photocurable composition). A 180° peeling test was performed on the test piece using a tensile tester, in which only the release liner A was peeled off along the length direction, and the peeling force of the release liner A relative to the first adhesive sheet was evaluated. The conditions of the peeling test were as described above. The peeling force was 0.07 N / 50 mm.

[0180] After a portion of the laminate 17 in the longitudinal direction is removed by cutting in a manner that does not include the sampling site of the test piece, the release liner A is peeled off. The release liner A is peeled off by peeling the release liner A 180° from the end in the longitudinal direction while the first substrate sheet side of the laminate 17 is fixed by a double-sided adhesive tape. Next, the peeled release liner A is used for the second substrate sheet to form a second laminate. The second laminate is formed by coating the photocurable composition of Manufacturing Example 1 on the release layer side of the second substrate sheet using an applicator to form a second coating layer, and then arranging the release liner A (unused product) of Manufacturing Example 2 on the second coating layer. Next, under an illumination of 2.4 mW / cm 2 And the accumulated light intensity is 2880mJ / cm 2 Under the conditions of , ultraviolet rays (black light source) were irradiated from the release liner A side of the second laminate to photocure the second coating layer, thereby forming a laminate 27 consisting of a second substrate sheet, a second adhesive sheet (thickness 20 μm) and a release liner A. It should be noted that the second adhesive sheet formed is the same as the first adhesive sheet.

[0181] A test piece of 220 mm in length and 50 mm in width was cut out from the formed laminate 27 (the length direction is the coating direction of the photocurable composition). For the test piece, a 180° peeling test in which only the release liner A was peeled off along the length direction was carried out using a tensile testing machine, and then a 180° peeling test in which only the second substrate sheet was peeled off along the length direction was carried out, and the peeling force of the release liner A and the second substrate sheet relative to the second adhesive sheet was evaluated. The conditions of the peeling test are as described above. The peeling force of the release liner A is 0.07 N / 50 mm, and the peeling force of the second substrate sheet is 0.11 N / 50 mm. It should be noted that the peeling of only the release liner A from the test piece can be carried out without peeling the second substrate sheet.

[0182] (Sample 2)

[0183] The first adhesive sheet and the second adhesive sheet were formed in the same manner as in Sample 1 except that the release liner B of Manufacturing Example 3 was used instead of the release liner A. The release force of the release liner B relative to the first adhesive sheet was 0.04N / 50mm. The release forces of the release liner B and the second substrate sheet (the reused product of the release liner B) relative to the second adhesive sheet were 0.04N / 50mm and 0.51N / 50mm, respectively. It should be noted that only the release liner B can be peeled off from the test piece without peeling off the second substrate sheet.

[0184] (Sample 3)

[0185] The first adhesive sheet and the second adhesive sheet were formed in the same manner as in Sample 1 except that the release liner C of Manufacturing Example 4 was used instead of the release liner A. The release force of the release liner C relative to the first adhesive sheet was 0.22 N / 50 mm. The release forces of the release liner C and the second substrate sheet (a recycled product of the release liner C) relative to the second adhesive sheet were 0.22 N / 50 mm and 7.57 N / 50 mm, respectively. It should be noted that only the release liner C can be peeled off from the test piece without peeling off the second substrate sheet.

[0186] (Sample 4)

[0187] The second adhesive sheet was formed in the same manner as Sample 1 except that the release liner A (unused product) of Production Example 2 was also used for the second base sheet instead of the release liner A peeled off from the first adhesive sheet. It was intended to peel off only one side of the release liner A from the test piece collected from the laminate including the second adhesive sheet, but the release liners A on both sides peeled off, and the second adhesive sheet alone was exposed.

[0188] (Sample 5)

[0189] A second adhesive sheet was formed in the same manner as in Sample 1, except that the release liner A peeled from the first adhesive sheet was used as the second release liner instead of the release liner A (unused product) in Production Example 2. Although it was intended to peel off only one side of the release liner A from the test piece collected from the laminate including the second adhesive sheet, the release liners A on both sides peeled off, and the second adhesive sheet alone was exposed.

[0190] (Sample 6)

[0191] The second adhesive sheet was formed in the same manner as Sample 2 except that the release liner B (unused product) of Production Example 3 was also used for the second base sheet instead of the release liner B peeled off from the first adhesive sheet. It was intended to peel off only one side of the release liner B from the test piece collected from the laminate containing the second adhesive sheet, but the release liners B on both sides peeled off, and the second adhesive sheet alone was exposed.

[0192] Industrial Applicability

[0193] The pressure-sensitive adhesive sheet obtained by the production method of the present invention can be used for, for example, an optical layered body or an image display device.

Claims

1. A method for manufacturing an adhesive sheet, the method comprising: irradiating a first laminate including a first substrate sheet, a first coating layer containing a first photocurable composition, and a first release liner in this order with light to form a first adhesive sheet from the first coating layer; and irradiating a second laminate comprising a second substrate sheet, a second coating layer containing a second photocurable composition, and a second release liner in this order with light, thereby forming a second adhesive sheet from the second coating layer, wherein the second laminate is formed by using the first release liner peeled from the first adhesive sheet as the second substrate sheet, The second base sheet has a greater release force with respect to the second pressure-sensitive adhesive sheet than the second release liner.

2. The method for producing a pressure-sensitive adhesive sheet according to claim 1, wherein: The first laminate is irradiated with the light from the first release liner side.

3. The method for producing a pressure-sensitive adhesive sheet according to claim 1, wherein: The second base sheet and the second release liner each have a release layer on the surface on the second coating layer side. The release layer included in the second base sheet and the release layer included in the second release liner are layers formed of a release agent composition containing the same release agent as a main component.

4. The method for producing a pressure-sensitive adhesive sheet according to claim 1, wherein: The peeling force between the second substrate sheet and the second adhesive sheet is greater than the peeling force between the first release liner and the first adhesive sheet.

5. The method for producing a pressure-sensitive adhesive sheet according to claim 1, wherein: The first photocurable composition and the second photocurable composition are the same composition.

6. The method for producing a pressure-sensitive adhesive sheet according to claim 1, wherein: The first photocurable composition and the second photocurable composition include a monomer group containing a (meth)acrylic monomer and / or a partial polymer of the monomer group.

7. The method for producing a pressure-sensitive adhesive sheet according to claim 6, wherein: The (meth)acrylic monomer includes a carboxyl group-containing monomer.

8. A method for manufacturing a laminate, the method comprising: irradiating a first laminate including a first substrate sheet, a first coating layer containing a first photocurable composition, and a first release liner in this order with light to form a first adhesive sheet from the first coating layer; and The first release liner peeled from the first pressure-sensitive adhesive sheet is used as a second substrate sheet to form a second laminate including the second substrate sheet, a second coating layer containing a second photocurable composition, and a second release liner in this order.

9. A method for manufacturing an optical film with an adhesive sheet, the method comprising: An optical film with a pressure-sensitive adhesive sheet is formed by placing an optical film on the exposed surface of the pressure-sensitive adhesive sheet formed by the production method according to any one of claims 1 to 7.

10. The method for producing an optical film with a pressure-sensitive adhesive sheet according to claim 9, wherein: The optical film includes at least one film selected from a polarizing film and a phase difference film.

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