Method for producing pressure-sensitive adhesive sheet and method for producing optical film with pressure-sensitive adhesive sheet

Abstract

To provide a manufacturing method of a pressure sensitive adhesive sheet capable of further lowering an environmental load in a manufacturing process of a pressure sensitive adhesive sheet.SOLUTION: A manufacturing method of a pressure sensitive adhesive sheet includes: a step A of irradiating with light a first laminate including a first base material sheet, a first coating layer containing a first photo-curable composition and a first release liner in this order to form a first pressure sensitive adhesive sheet; a step B of removing the first release liner; and a step C of irradiating with light a second laminate including a second base material sheet, a second coating layer containing a second photo-curable composition and a second release liner in this order to form a second pressure sensitive adhesive sheet. In the step C, the first release liner removed at the step B is used as the second base material sheet and / or the second release liner. At least one selected from a group composed of the first photo-curable composition and the second photo-curable composition includes an antioxidant.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] Various image display devices, such as liquid crystal display devices and electroluminescence (EL) display devices, generally include an optical laminate including an optical film such as a polarizing film and an adhesive sheet. An adhesive sheet is usually used for bonding between the optical films included in the optical laminate and for bonding between the optical laminate and an image display panel. A typical adhesive sheet is a sheet obtained by polymerizing and crosslinking a monomer group including an acrylic monomer, a silicone monomer, and the like to harden the monomer group.

[0003] Patent Document 1 discloses an example of a pressure-sensitive adhesive sheet, which is produced by irradiating a coating layer of a pressure-sensitive adhesive composition disposed between two release liners with light. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6688054 Summary of the Invention [Problem to be solved by the invention]

[0005] Formation of an adhesive sheet by curing usually requires energy such as heat or light. According to a method that utilizes light (photocuring method), the amount of energy required to form an adhesive sheet can be reduced compared to, for example, a method (thermal curing method) in which a coating layer containing an adhesive composition and a solvent is thermally cured in an oven. However, from the viewpoint of reducing the environmental load during the production of an adhesive sheet, it is not sufficient to only focus on the amount of energy required to cure the coating layer.

[0006] Therefore, an object of the present invention is to provide a method for producing a pressure-sensitive adhesive sheet, which can further reduce the environmental impact of the pressure-sensitive adhesive sheet production process by making it possible to reuse release liners that were previously discarded immediately after peeling. [Means for solving the problem]

[0007] The present invention relates to A step A of irradiating light to a first laminate including, in this order, a first base sheet, a first coating layer including a first photocurable composition, and a first release liner to form a first pressure-sensitive adhesive sheet from the first coating layer; A step B of peeling the first release liner from the first pressure-sensitive adhesive sheet; a step C of irradiating light to a second laminate including, in this order, a second substrate sheet, a second coating layer including a second photocurable composition, and a second release liner to form a second pressure-sensitive adhesive sheet from the second coating layer; Including, In the step C, the first release liner peeled off in the step B is used as the second base sheet and / or the second release liner, The present invention provides a method for producing a pressure-sensitive adhesive sheet, wherein at least one selected from the group consisting of the first photocurable composition in the step A and the second photocurable composition in the step C contains an antioxidant.

[0008] Further, the present invention relates to The present invention provides a method for producing an optical film with a pressure-sensitive adhesive sheet, the method comprising: forming an optical film with a pressure-sensitive adhesive sheet by disposing an optical film on an exposed surface of the pressure-sensitive adhesive sheet formed by the above-described production method. Effect of the Invention

[0009] According to the present invention, a method for producing a pressure-sensitive adhesive sheet can be provided that makes it possible to reuse release liners that have previously been discarded immediately after peeling, thereby further reducing the environmental impact of the pressure-sensitive adhesive sheet production process. [Brief description of the drawings]

[0010] [Figure 1] 1A to 1C are schematic diagrams illustrating an example of a method for producing a pressure-sensitive adhesive sheet of the present invention. [Diagram 2] FIG. 1 is a cross-sectional view that illustrates a schematic example of a release liner that can be used in the method for producing a pressure-sensitive adhesive sheet of the present invention. [Figure 3A] FIG. 2 is a schematic diagram for explaining a method for measuring the amount of creep for a pressure-sensitive adhesive sheet. [Figure 3B] FIG. 2 is a schematic diagram for explaining a method for measuring the amount of creep for a pressure-sensitive adhesive sheet. [Figure 4] 1A to 1C are schematic diagrams illustrating an example of a method for producing a pressure-sensitive adhesive sheet of the present invention. [Diagram 5] 1A to 1C are schematic diagrams illustrating an example of a method for producing a pressure-sensitive adhesive sheet of the present invention. [Figure 6] FIG. 2 is a schematic diagram for explaining an example of a method for producing an optical film with a pressure-sensitive adhesive sheet of the present invention. [Figure 7] FIG. 2 is a schematic diagram for explaining an example of a method for producing an optical film with a pressure-sensitive adhesive sheet of the present invention. [Figure 8] FIG. 2 is a schematic diagram for explaining an example of a method for producing an optical film with a pressure-sensitive adhesive sheet of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] A method for producing a pressure-sensitive adhesive sheet according to a first aspect of the present invention includes the steps of: A step A of irradiating light to a first laminate including, in this order, a first base sheet, a first coating layer including a first photocurable composition, and a first release liner to form a first pressure-sensitive adhesive sheet from the first coating layer; A step B of peeling the first release liner from the first pressure-sensitive adhesive sheet; a step C of irradiating light to a second laminate including, in this order, a second substrate sheet, a second coating layer including a second photocurable composition, and a second release liner to form a second pressure-sensitive adhesive sheet from the second coating layer; Including, In the step C, the first release liner peeled off in the step B is used as the second base sheet and / or the second release liner, At least one selected from the group consisting of the first photocurable composition in the step A and the second photocurable composition in the step C contains an antioxidant.

[0012] In a second aspect of the present invention, for example, in the manufacturing method according to the first aspect, in the step C, the first release liner released in the step B is used as the second release liner.

[0013] In a third aspect of the present invention, for example, the production method according to the second aspect includes the steps of: a step D of peeling the second release liner from the second pressure-sensitive adhesive sheet; a step E of irradiating a third laminate including, in this order, a third base sheet, a third coating layer including a third photocurable composition, and a third release liner with light to form a third pressure-sensitive adhesive sheet from the third coating layer; Further comprising: In step E, the second release liner peeled off in step D is used as the third base sheet and / or the third release liner, or the first release liner peeled off in step B is used as the third base sheet and / or the third release liner.

[0014] In a fourth aspect of the present invention, for example, in the manufacturing method according to the second or third aspect, the peel strength PS1 between the second release liner and the second pressure sensitive adhesive sheet is 1.0 N / 50 mm or less.

[0015] In a fifth aspect of the present invention, for example in the manufacturing method according to any one of the first to fourth aspects, the peel strength PS0 between the first release liner and the first pressure-sensitive adhesive sheet is 0.01 N / 50 mm or more.

[0016] In a sixth aspect of the present invention, for example, in the production method according to any one of the first to fifth aspects, each of the first photocurable composition and the second photocurable composition contains the antioxidant.

[0017] In a seventh aspect of the present invention, for example, in the production method according to any one of the first to sixth aspects, the antioxidant includes at least one selected from the group consisting of hindered phenol compounds and hindered amine compounds.

[0018] In an eighth aspect of the present invention, for example, in the production method according to any one of the first to seventh aspects, the molecular weight of the antioxidant is 1,500 or less.

[0019] In a ninth aspect of the present invention, for example, in the production method according to any one of the first to eighth aspects, each of the first photocurable composition and the second photocurable composition contains a monomer group including a (meth)acrylic monomer and / or a partial polymer of the monomer group.

[0020] In a tenth aspect of the present invention, for example, in the production method according to the ninth aspect, the group of monomers includes a carboxyl group-containing monomer.

[0021] A method for producing an optical film with a pressure-sensitive adhesive sheet according to an eleventh aspect of the present invention comprises the steps of: The method includes forming an optical film with a pressure-sensitive adhesive sheet by disposing an optical film on an exposed surface of the pressure-sensitive adhesive sheet formed by the manufacturing method according to any one of the first to tenth aspects.

[0022] In a twelfth aspect of the present invention, for example, in the production method according to the eleventh aspect, the optical film includes at least one film selected from the group consisting of a polarizing film and a retardation film.

[0023] The present invention will be described in detail below, but the present invention is not limited to the following embodiments and can be modified in any manner without departing from the gist of the present invention.

[0024] The inventors came up with the idea of ​​further reducing the environmental impact of the PSA sheet manufacturing process by reusing release liners that were previously discarded immediately after peeling, and continued their research based on this idea, resulting in the completion of the present invention.

[0025] [Embodiment of the method for producing the pressure-sensitive adhesive sheet] The method for producing the pressure-sensitive adhesive sheet of this embodiment will be described with reference to FIG. The manufacturing method of this embodiment is as follows: a step A of irradiating a first laminate 10a, which includes, in this order, a first base sheet 11a, a first coating layer 12a containing a first photocurable composition, and a first release liner 13a, with light 14 to form a first pressure-sensitive adhesive sheet 1a from the first coating layer 12a; A step B of peeling the first release liner 13a from the first pressure-sensitive adhesive sheet 1a; a step C of irradiating light 14 to a second laminate 10b including, in this order, a second base sheet 11b, a second coating layer 12b containing a second photocurable composition, and a second release liner 13b to form a second pressure-sensitive adhesive sheet 1b from the second coating layer 12b; Includes.

[0026] In step C, the first release liner 13a peeled off in step B is used as the second base sheet 11b and / or the second release liner 13b. In other words, the first release liner 13a peeled off from the first pressure-sensitive adhesive sheet 1a in step B is not discarded but is reused in step C. In this manner, in the manufacturing method of the present embodiment, a pressure-sensitive adhesive sheet can be manufactured with low environmental impact by performing steps A to C without discarding the first release liner 13a. In step C, it is preferable to use the first release liner 13a peeled off in step B as the second release liner 13b.

[0027] In addition, "using the first release liner 13a peeled off in step B as the second base sheet 11b and the second release liner 13b" specifically means that some of the multiple first release liners 13a peeled off in step B are used as the second base sheet 11b, and the other parts are used as the second release liners 13b. In this case, at least one of the first release liner 13a used as the second base sheet 11b and the first release liner 13a used as the second release liner 13b may be subjected to a modification treatment such as a surface treatment.

[0028] The manufacturing method of this embodiment further includes, for example, step D of peeling the second release liner 13b from the second pressure-sensitive adhesive sheet 1b. Furthermore, in the manufacturing method of this embodiment, the second release liner 13b reused from the first release liner 13a may be peeled off in step D, and then step E similar to step A may be performed using it as the third base sheet 11c and / or the third release liner 13c. In other words, the reused release liner 13b may be used for a third time without being discarded. In step E, the third laminate 10c including the third base sheet 11c, the third coating layer 12c containing the third photocurable composition, and the third release liner 13c in this order is irradiated with light to form the third pressure-sensitive adhesive sheet 1c from the third coating layer 12c. In addition, in step E, the first release liner 13a peeled off in step B may be used as the third base sheet 11c and / or the third release liner 13c. By repeatedly using first release liner 13a as a release liner rather than discarding it, a pressure sensitive adhesive sheet can be produced with less environmental impact.

[0029] In the manufacturing method of this embodiment, at least one selected from the group consisting of the first photocurable composition in step A and the second photocurable composition in step C contains an antioxidant. As described below, the antioxidant is a component suitable for suppressing an increase in the peel strength between the release liner and the pressure-sensitive adhesive sheet. In particular, it is preferable that the first photocurable composition and the second photocurable composition each contain an antioxidant. The third photocurable composition in step E may also contain an antioxidant.

[0030] <Process A> In step A, the light 14 is typically applied from the side of the first base sheet 11a. At this time, the light 14 passes through the first base sheet 11a to reach the first coating layer 12a and cure the first coating layer 12a. However, the light 14 may be applied from the side of the first release liner 13a, or from both the side of the first release liner 13a and the first base sheet 11a. The first pressure-sensitive adhesive sheet 1a formed in step A is sandwiched between the first base sheet 11a and the first release liner 13a until the first release liner 13a is peeled off, and constitutes a part of the laminate 17a.

[0031] (First photocurable composition) The first photocurable composition is a pressure-sensitive adhesive composition that forms the first adhesive sheet 1a from the first coating layer 12a by irradiation with light 14. The first photocurable composition contains, for example, 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, i.e., the (meth)acrylic monomer and its partial polymer, may be 50% by weight or more, 60% by weight or more, 70% by weight or more, or even 80% by weight or more. In this case, an acrylic first adhesive sheet 1a containing a (meth)acrylic polymer and its crosslinked product as the main components can be formed. However, the first photocurable composition is not limited to the above example. In this specification, (meth)acrylic means acrylic and methacrylic. (Meth)acrylate means acrylate and methacrylate.

[0032] An example of the (meth)acrylic monomer is a (meth)acrylic acid alkyl ester having an alkyl group having 1 to 20 carbon atoms on the side chain. The number of carbon atoms in the alkyl group may be 7 or less, 6 or less, 5 or less, or even 4 or less. The alkyl group may be linear or branched. Examples of the (meth)acrylic acid alkyl ester are methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, s-butyl (meth)acrylate, t-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, and the like. 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 (meth)acrylic acid alkyl ester may be n-butyl (meth)acrylate.

[0033] The content of the (meth)acrylic acid alkyl ester in the monomer group is, for example, 40% by weight or more, and may be 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. In calculating the content, the weight of the partially polymerized product is converted into the weight of each monomer before polymerization.

[0034] The monomer group may contain a carboxyl group-containing monomer. The carboxyl group-containing monomer may be a (meth)acrylic monomer, in other words, the (meth)acrylic monomer may contain a carboxyl group-containing monomer. Examples of the carboxyl group-containing monomer are (meth)acrylic acid, carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, itaconic acid, maleic acid, fumaric acid, and crotonic acid. The content of the carboxyl group-containing monomer in the monomer group may be, for example, 10% by weight or less, 9% by weight or less, 8% by weight or less, 7% by weight or less, 6% by weight or less, 5.5% by weight or less, or even 5% by weight or less. The lower limit of the content may be, for example, 0.1% by weight or more, 0.5% by weight or more, or even 1% by weight or more. The monomer group may not contain a carboxyl group-containing monomer.

[0035] The monomer group may contain a hydroxyl group-containing monomer. The hydroxyl group-containing monomer may be a (meth)acrylic monomer, in other words, the (meth)acrylic monomer may contain a hydroxyl group-containing monomer. The hydroxyl group-containing monomer may contribute to improving the cohesive strength of the adhesive sheet. Examples of the hydroxyl group-containing monomer 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 group-containing monomer is preferably 2-hydroxyethyl (meth)acrylate or 4-hydroxybutyl (meth)acrylate. The content of the hydroxyl group-containing monomer in the monomer group is, for example, 10% by weight or less, and may be 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, or even 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 even 0.05% by weight or more. The monomer group may not contain a hydroxyl group-containing monomer.

[0036] In the first photocurable composition, each of the above-mentioned monomers may be contained as a partial polymer. The partial polymer may be either a homopolymer or a copolymer. The partial polymer can contribute to the stable formation of a coating layer by appropriately increasing the viscosity of the first photocurable composition.

[0037] The first photocurable composition usually contains a photopolymerization initiator. An example of the photopolymerization initiator is a photoradical generator that generates radicals when exposed to visible light and / or ultraviolet light having a wavelength shorter than 450 nm.

[0038] Examples of photopolymerization initiators include benzoin ethers such as benzoin methyl ether, benzoin isopropyl ether, and benzil dimethyl ketal; substituted benzoin ethers such as anisole methyl ether; substituted acetophenones such as 2,2-diethoxyacetophenone and 2,2-dimethoxy-2-phenylacetophenone; α-hydroxyalkylphenones such as 1-hydroxycyclohexyl-phenyl ketone; substituted alpha-ketol 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; and benzophenone compounds such as benzoylbenzoic acid, methyl benzoylbenzoate, 4-phenylbenzophenone, hydroxybenzophenone, acrylated benzophenone, 4-benzoyl-4'-methyldiphenyl sulfide, and 3,3',4,4'-tetra(t-butylperoxycarbonyl)benzophenone. Thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, isopropylthioxanthone, 2,4-diisopropylthioxanthone, 2,4-diethylthioxanthone and other thioxanthone compounds; 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-styryl-s-triazine, 2-(naphth-1-yl)-4,6-bis(trichloromethyl)-s-triazine, 2-(4-methoxy-naphth-1-yl)-4,6-bis(trichloromethyl)-s-triazine, 2,4-trichloromethyl-(piperonyl)-6-triazine, 2,4-trichloromethyl-(4'-methoxystyryl)-6-triazine and other triazine-based compounds;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, 2,4,6-trimethylbenzoyldiphenylphosphine oxide; quinone compounds such as 9,10-phenanthrenequinone, camphorquinone, ethylanthraquinone; borate compounds; carbazole compounds; imidazole compounds; and titanocene compounds. The first photocurable composition may contain one or more photopolymerization initiators.

[0039] The amount of the photopolymerization initiator in the first photocurable composition is, for example, 0.02 to 10 parts by weight, and may be 0.05 to 5 parts by weight, based on 100 parts by weight in total of the monomer group and its partial polymer.

[0040] As described above, the first photocurable composition may further contain an antioxidant. When the first photocurable composition contains an antioxidant, when the first release liner 13a is used as the second release liner 13b in step C, the peel strength between the second release liner 13b and the second adhesive sheet 1b tends to be adjusted to a small value. In detail, in step A, a chemical bond is formed between the first release liner 13a and the first adhesive sheet 1a by irradiation with light 14, and a part of the bond or a functional group formed by decomposition of the bond may remain on the surface of the first release liner 13a even after the first adhesive sheet 1a is peeled off. Due to this functional group, the peel strength of the second release liner 13b (first release liner 13a) against the second adhesive sheet 1b tends to increase. The antioxidant tends to suppress the formation of a chemical bond between the first release liner 13a and the first adhesive sheet 1a. Furthermore, the antioxidant tends to prevent the surface of first release liner 13a from being contaminated by the material of first adhesive sheet 1a, regardless of the manufacturing conditions of first adhesive sheet 1a (such as light exposure time).

[0041] Examples of the antioxidant include phenolic compounds (particularly hindered phenolic compounds), amine compounds (particularly hindered amine compounds), and phosphorus compounds. The antioxidant preferably contains at least one selected from the group consisting of hindered phenolic compounds and hindered amine compounds, and more preferably contains a hindered phenolic compound. The compound contained in the antioxidant may not contain a sulfur atom. The first photocurable composition may contain one or more antioxidants.

[0042] Examples of the hindered phenol compounds include dibutylhydroxytoluene (BHT), pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] (BASF "Irganox 1010"), octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate (BASF "Irganox 1076"), isooctyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate (BASF "Irganox 1135"), 3,3',3'',5,5',5''-hexa-tert-butyl-a,a',a''-(mesitylene-2,4,6-triyl)tri-p-cresol (BASF "Irganox 1135"). 1330"), 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione (BASF "Irganox 3114"), tris[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyloxyethyl]isocyanurate (BASF "Irganox 3125"), pentaerythritol tetrakis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate] (ADEKA "ADEKA STAB AO-60"), 3,9-bis{2-[3-(3-t-butyl-4-hydroxy-5-methylphenyl)propionyloxy]-1,1-dimethylethyl}-2,4,8,10-tetraoxaspiro[5.5]undecane (ADEKA "ADEKA STAB AO-80"), 2-[1-(2-hydroxy-3,5-di-tert-pentylphenyl)ethyl]-4,6-di-tert-pentylphenyl acrylate (Sumitomo Chemical "Sumilizer GS"), 2-tert-butyl-4-methyl-6-(2-hydroxy-3-tert-butyl-5-methylbenzyl)phenyl acrylate (Sumitomo Chemical "Sumilizer GM"), 2,2'-dimethyl-2,2'-(2,4,8,10-tetraoxaspiro[5.5]undecane-3,9-diyl)dipropane-1,1'-diyl=bis[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propanoate] (Sumitomo Chemical's "Sumilizer GA-80"), 1,3,5-tris(3-hydroxy-4-tert-butyl-2,6-dimethylbenzyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione (Cyanox 1790) from Cytec, etc. The hindered phenol compound is preferably Irganox 1010 or Irganox 1135, more preferably Irganox 1135. .

[0043] Examples of hindered amine compounds include bis-(1-octyloxy-2,2,6,6-tetramethyl-4-piperidyl) sebacate (BASF's "Tinuvin 123"), tetrakis(1,2,2,6,6-pentamethyl-4-piperidyl)butane-1,2,3,4-tetracarboxylate (ADEKA's "Adeka STAB LA-52"), tetrakis(2,2,6,6-tetramethyl-4-piperidyl)butane-1,2,3,4-tetracarboxylate (ADEKA's "Adeka STAB LA-57"), 1,2,3,4-butane tetracarboxylic acid tetramethyl ester 1,2,2,6,6-pentamethyl-4-piperidinol β,β,β',β'-Tetramethyl-2,4,8,10-tetraoxaspiro[5,5]undecane-3,9-diethanol (ADEKA "ADEKA STAB LA-63P"), 1,2,3,4-butanetetracarboxylic acid tetramethyl ester 2,2,6,6-pentamethyl-4-piperidinol β,β,β',β'-Tetramethyl-2,4,8,10-tetraoxaspiro[5,5]undecane-3,9-diethanol (ADEKA Corp. "ADEKA STAB LA-68"), bis(1,2,2,6,6-pentamethyl-4-piperidyl)sebacate (ADEKA Corp. "ADEKA STAB LA-72"), bis(2,2,6,6-tetramethyl-4-piperidyl)sebacate (ADEKA Corp. "ADEKA STAB LA-77Y"), bis(2,2,6,6-tetramethyl-4-piperidyl)sebacate (ADEKA Corp. "ADEKA STAB LA-77G"), bis(1-undecanoxy-2,2,6,6-tetramethyl-4-piperidyl)sebacate (ADEKA Corp. "ADEKA STAB LA-77G"), tetramethylpiperidin-4-yl) carbonate (ADEKA "ADEKA STAB LA-81"), 1,2,2,6,6-pentamethyl-4-piperidyl methacrylate (ADEKA "ADEKA STAB LA-82"), 2,2,6,6-tetramethyl-4-piperidyl methacrylate (ADEKA "ADEKA STAB LA-87"), SONGLIGHT1190 (SONGWON), SONGLIGHT1230 (SONGWON), bis(1,2,2,6,6-pentamethyl-4-piperidyl) sebacate (SONGWON "SONGLIGHT2920"), bis(2,2,6,6-tetramethyl-4-piperidyl)sebacate (SONGWON "SONGLIGHT7700"), poly(4-hydroxy-2,2,6,6-tetramethyl-1-piperidineethanol-ortho-1,4-butanediic acid) (BASF "Uvinul5062H"), Uvinul5050H (BASF), N,N'-bisformyl-N,N'-bis(2,2,6,6-tetramethyl-4-piperidinyl)-hexamethylenediamine (BASF "Uvinul4050H"), bis(2,2,6,6-tetramethyl-4-piperidyl)sebacate (BASF "Uvinul4077H"), etc. are included. The hindered amine compound is preferably Adeka STAB LA-52.

[0044] Examples of phosphorus compounds include trioctyl phosphite, trilauryl phosphite, tris tridecyl phosphite, tris isodecyl phosphite, phenyl diisooctyl phosphite, phenyl diisodecyl phosphite, phenyl di(tridecyl)phosphite, diphenyl isooctyl phosphite, diphenyl isodecyl phosphite, diphenyl tridecyl phosphite, triphenyl phosphite, tris(nonylphenyl)phosphite, tris(2,4-di-t-butylphenyl)phosphite, tris(butylphenyl)phosphite, (toxyethyl) phosphite, tetratridecyl-4,4'-butylidenebis(3-methyl-6-t-butylphenol)-diphosphite, 4,4'-isopropylidene-diphenol alkyl phosphite (wherein the alkyl has 12 to 15 carbon atoms), 4,4'-isopropylidenebis(2-t-butylphenol)-di(nonylphenyl)phosphite, tris(biphenyl)phosphite, tetra(tridecyl)-1,1,3-tris(2-methyl-5-t-butyl-4-hydroxyphenyl)butane diphosphite, Tris(3,5-di-t-butyl-4-hydroxyphenyl)phosphite, hydrogenated 4,4'-isopropylidenediphenol polyphosphite, bis(octylphenyl)·bis[4,4'-butylidenebis(3-methyl-6-t-butylphenol)]·1,6-hexanediol diphosphite, hexatridecyl-1,1,3-tris(2-methyl-4-hydroxy-5-t-butylphenol) diphosphite, tris[4,4'-isopropylidenebis(2-t-butylphenol)]phosphite, tris(1 ,3-distearoyloxyisopropyl)phosphite, 9,10-dihydro-9-phosphaphenanthrene-10-oxide, tetrakis(2,4-di-t-butylphenyl)-4,4'-biphenylene diphosphonite, distearyl pentaerythritol diphosphite, di(nonylphenyl)pentaerythritol diphosphite, phenyl-4,4'-isopropylidenediphenol-pentaerythritol diphosphite, bis(2,4-di-t-butylphenyl)pentaerythritol diphosphite, bis(2,6-di-t-butyl-4-methylphenyl)pentaerythritol diphosphite, phenyl bisphenol-A-pentaerythritol diphosphite, etc.

[0045] The antioxidant preferably has a small molecular weight. When the first release liner 13a is used as the second release liner 13b in step C, an antioxidant with a small molecular weight makes it easier to adjust the peel strength between the second release liner 13b and the second adhesive sheet 1b to a small value. The antioxidant is preferably liquid at room temperature (25°C) due to its small molecular weight. The molecular weight of the antioxidant is, for example, 1500 or less, and may be 1000 or less, 800 or less, 500 or less, or even 400 or less. The lower limit of the molecular weight of the antioxidant is not particularly limited, and may be, for example, 100 or more, 200 or more, or even 300 or more.

[0046] The amount of the antioxidant is, for example, 0.01 parts by weight or more, and may be 0.05 parts by weight or more, 0.1 parts by weight or more, or even 0.3 parts by weight or more, based on 100 parts by weight in total of the monomer group and its partial polymer. The upper limit of the amount of the antioxidant is, for example, 5 parts by weight or less, and may be 3 parts by weight or less, 2 parts by weight or less, 1 part by weight or less, or even 0.5 parts by weight or less.

[0047] The first photocurable composition may contain a crosslinking agent. An example of the crosslinking agent is a polyfunctional monomer having two or more polymerizable functional groups in one molecule. The polyfunctional monomer may be a (meth)acrylic monomer. An example of the polyfunctional 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 polymerizable functional groups such as epoxy groups, aziridine groups, oxazoline groups, hydrazine groups, methylol groups, etc. in one molecule. The polyfunctional monomer is preferably a monomer having two or more C=C bonds in one molecule.

[0048] Examples of crosslinking agents include (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 (NDD A), polyfunctional acrylates such as 1,12-dodecanediol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, and tetramethylolmethane tri(meth)acrylate (such as ester compounds of polyhydric alcohols and (meth)acrylic acid); 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, and dipentaerythritol hexa(meth)acrylate.

[0049] The amount of the crosslinking agent to be added varies depending on the molecular weight, the number of functional groups, etc., but may be, 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, or even 0.5 parts by weight or less, relative to 100 parts by weight in total of the monomer group and its partial polymer. The lower limit of the amount to be added is, for example, 0.01 parts by weight or more, or may be 0.05 parts by weight or more.

[0050] The first photocurable composition may contain additives other than those described above. Examples of the additives include a chain transfer agent, a silane coupling agent, a viscosity modifier, a tackifier, a plasticizer, a softener, an antiaging agent, a filler, a colorant, a surfactant, an antistatic agent, and an ultraviolet absorbing agent.

[0051] The content of the solvent in the first photocurable composition is, for example, 5% by weight or less, and may be 4% by weight or less, 3% by weight or less, 2% by weight or less, 1% by weight or less, or even 0.5% by weight or less. The first photocurable composition may be substantially free of a solvent. The phrase "substantially free of a solvent" means that the solvent derived from additives and the like is allowed to have 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.

[0052] The viscosity of the first photocurable composition is preferably 5 to 100 poise. A first photocurable composition having a viscosity in the above range is particularly suitable for forming the first coating layer 12a.

[0053] (First release liner) An example of the substrate of the first release liner 13a (hereinafter, "liner substrate") is a resin film. Examples of resins that may be included in the liner substrate include polyesters such as polyethylene terephthalate and polyethylene naphthalate, acetate resins, polyethersulfone, polycarbonate, polyamide, polyimide, polyolefin, (meth)acrylic resins, polyvinyl chloride, polyvinylidene chloride, polystyrene, polyvinyl alcohol, polyarylate, and polyphenylene sulfide. The resin is preferably a polyester such as polyethylene terephthalate.

[0054] The first release liner 13a may have transparency to the light 14 irradiated in step A, and may have the same degree of transparency to the light 14 as the first base sheet 11a.

[0055] The thickness of the first release liner 13a is, for example, 10 to 200 μm, and may be 25 to 150 μm.

[0056] The first release liner 13a may include a layer other than the liner substrate. The first release liner 13a may include a release layer. The first release liner 13a in Fig. 2 includes a liner substrate 131 and a release layer 132 formed on one surface of the liner substrate 131. The first release liner 13a in Fig. 2 can be used such that the release layer 132 is on the side of the first coating layer 12a.

[0057] The release layer 132 is typically a cured layer of a release agent composition containing a release agent. Various types of release agents can be used as the release agent, such as silicone-based release agents, fluorine-based release agents, long-chain alkyl-based release agents, fatty acid amide-based release agents, and silica powder. The first release liner 13a may have a cured layer of a release agent composition containing a silicone-based release agent as a main component (hereinafter, "silicone release layer"). The silicone release layer is particularly suitable for achieving both adhesion to the first pressure-sensitive adhesive sheet 1a and releasability. In this specification, the main component means the component with the largest content.

[0058] The silicone-based release agent is, for example, various curable silicone materials such as addition reaction type, condensation reaction type, ultraviolet curable type, electron beam curable type, and solventless type, and addition reaction curable silicone materials are preferred. The addition reaction curable silicone material is particularly suitable for forming a release layer that has both adhesion and releasability to the first adhesive sheet 1a. The curable silicone material may be a silicone-modified resin in which reactive silicone is introduced into an organic resin such as urethane, epoxy, or alkyd resin by graft polymerization or the like.

[0059] An example of the addition reaction curing silicone material is a polyorganosiloxane having a vinyl group or an alkenyl group in the molecule. The addition reaction curing silicone material may not have a hydrosilyl group. Examples of the alkenyl group are 3-butenyl, 4-pentenyl, 5-hexenyl, 6-heptenyl, 7-octenyl, 8-nonenyl, 9-decenyl, 10-undecenyl, and 11-dodecenyl. Examples of the polyorganosiloxane are polyalkylalkylsiloxanes such as polydimethylsiloxane, polydiethylsiloxane, and polymethylethylsiloxane, polyalkylarylsiloxane, and copolymers of multiple types of Si atom-containing monomers such as poly(dimethylsiloxane-diethylsiloxane). The polyorganosiloxane is preferably polydimethylsiloxane.

[0060] A release agent composition containing a silicone-based release agent as a main component (hereinafter referred to as "silicone release agent composition") usually contains a crosslinking agent. An example of the crosslinking agent is polyorganosiloxane having a hydrosilyl group. The crosslinking agent may have two or more hydrosilyl groups in one molecule.

[0061] The silicone release agent composition may contain a curing catalyst. An example of the curing catalyst is a platinum catalyst. An example of the platinum catalyst is chloroplatinic acid, an olefin complex of platinum, or an olefin complex of chloroplatinic acid. The amount of the platinum catalyst used is, for example, 10 to 1000 ppm (weight basis, platinum equivalent) based on the total solid content of the composition.

[0062] The silicone release agent composition may contain additives. Examples of additives are release control agents and adhesion promoters. Examples of release control agents are unreactive silicone resins, and more specific examples are organosiloxanes such as octamethylcyclotetrasiloxane, and MQ resins. The amount of the release control agent and adhesion promoter used is, for example, 1 to 30% by weight in total based on the total solid content of the composition. Further examples of additives are fillers, antistatic agents, antioxidants, ultraviolet absorbers, plasticizers, and colorants. The amount of the further additives used is, for example, 10% by weight or less in total based on the total solid content of the composition.

[0063] The silicone release agent composition may contain an organic solvent. Examples of the organic solvent include 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 be contained. The amount of the organic solvent used is preferably 80 to 99.9% by weight of the silicone release agent composition.

[0064] The release layer 132 can be formed, for example, by heating and drying a coating film containing a release agent composition formed on the liner substrate 131. For coating the release agent composition, various coating methods such as 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 die coating can be applied. For heating and drying, for example, hot air drying can be applied. The heating temperature and time vary depending on the heat resistance of the liner substrate, but are usually about 80 to 150°C and 10 seconds to 10 minutes. If necessary, irradiation with active energy rays such as ultraviolet rays may be used in combination.

[0065] 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, or even 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, or even 50 nm or more. The thickness of the release layer 132 may be 110 nm or less, in other words, the first release liner 13a may have the release layer 132 on the surface on the side of the first coating layer 12a, and the thickness of the release layer 132 may be 110 nm or less.

[0066] The first release liner 13a may be in the form of a sheet or a continuous sheet.

[0067] The peel force PS0 between the first release liner 13a, particularly the unused first release liner 13a, and the first adhesive sheet 1a is not particularly limited and may be, for example, 1.0 N / 50 mm or less, 0.5 N / 50 mm or less, 0.2 N / 50 mm or less, 0.15 N / 50 mm or less, 0.12 N / 50 mm or less, 0.1 N / 50 mm or less, 0.08 N / 50 mm or less, or even 0.05 N / 50 mm or less. The peel force PS0 may be 0.01 N / 50 mm or more, 0.02 N / 50 mm or more, or even 0.03 N / 50 mm or more.

[0068] The peel strength PS0 can be evaluated by cutting the laminate 17a formed by carrying out the step A to a width of 50 mm to prepare a test piece, and carrying out a 180° peel test in which only the first release liner 13a is peeled off from the prepared test piece. The peel test is carried out about 0.5 to 1 hour after the formation of the first adhesive sheet 1a. From the formation of the first adhesive sheet 1a until the peel test is carried out, the laminate 17a and the test piece are placed in an air atmosphere at 23°C ± 5°C. The peel speed of the peel test is 300 mm / min, and the test temperature is 23°C ± 5°C. If the width of the laminate 17a is less than 50 mm, the measured value in the original width may be converted to a value per 50 mm width. If the formation direction of the first coating layer 12a can be determined, the TD perpendicular to the plane of that direction, MD, can be determined as the width direction of the test piece. When the first base sheet 11a and the first release liner 13a are long, the width direction thereof can be set as the width direction of the test piece.

[0069] (First base sheet) 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 the examples of the resin that can be contained in the liner base material.

[0070] It is preferable that the first base sheet 11a has excellent transmittance for the light 14 irradiated in the step A.

[0071] The thickness of the first base sheet 11a is, for example, 10 to 200 μm, and may be 25 to 150 μm.

[0072] The first base sheet 11a may have a release layer on the surface on the side of the first coating layer 12a. Examples of the release layer that the first base sheet 11a may have and the manufacturing method thereof are the same as the examples of the release layer that the first release liner 13a may have and the manufacturing method thereof. Both the first release liner 13a and the first base sheet 11a may have a release layer. In this case, both release layers may be formed from a release agent composition containing the same release agent as a main component. In addition, the thicknesses of both release layers may be different, for example, the release layer provided on the first base sheet 11a may be thicker.

[0073] For first base sheet 11a, a sheet that has a greater peel strength from first adhesive sheet 1a than first release liner 13a can usually be selected.

[0074] The first base sheet 11a may be in the form of a sheet or a continuous sheet.

[0075] (First laminate and its formation) The first laminate 10a may include an additional layer other than the first base sheet 11a, the first coating layer 12a, and the first release liner 13a. The additional layer may be disposed on the side of the first base sheet 11a and / or the first release liner 13a opposite to the side of the first coating layer 12a. The first coating layer 12a is preferably in contact with the first base sheet 11a and the first release liner 13a.

[0076] The first laminate 10a can be formed, for example, by forming a first coating layer 12a on a first base sheet 11a (or a first release liner 13a) and arranging a first release liner 13a (or a first base sheet 11a) on the formed first coating layer 12a. Alternatively, the first laminate 10a may be formed by applying a photocurable composition in a poured manner into the space between the first base sheet 11a and the first release liner 13a, which are held at a predetermined distance so that their main surfaces face each other. In step C, the peeled first release liner 13a may be used so that the surface that was on the side of the first coating layer 12a in step A immediately before peeling, for example the surface on the release layer 132 side, becomes the side of the second coating layer 12b.

[0077] The first coating layer 12a can be formed by various coating methods such as roll coating, kiss roll coating, gravure coating, reverse coating, roll brush, spray coating, dip roll coating, bar coating, knife coating, air knife coating, curtain coating, lip coating, and die coating.

[0078] The thickness of the first coating layer 12a can be adjusted according to the desired thickness of the first adhesive sheet 1a, and may be, for example, 5 to 100 μm, 5 to 50 μm, 5 to 25 μm, or even 5 to 20 μm.

[0079] The first laminate 10a may include a long first base sheet 11a, a long first coating layer 12a, and a long first release liner 13a, in other words, may be long. The long first laminate 10a can be obtained, for example, by forming the first coating layer 12a between the first base sheet 11a and the first release liner 13a that are unwound from a roll while conveying them.

[0080] (Light irradiation) The light 14 irradiated to the first laminate 10a is, for example, visible light or ultraviolet light having a wavelength shorter than 450 nm. The light 14 may contain light having a wavelength in the same range as the absorption wavelength of the photopolymerization initiator contained in the first photocurable composition. The light 14 may be irradiated with light having a short wavelength of 300 nm or less cut by a filter or the like, and cutting the short wavelength light is suitable for suppressing deterioration of the first base sheet 11a caused by the light 14. The light source of the light 14 is, for example, a light irradiation device equipped with an ultraviolet irradiation lamp. Examples of the ultraviolet irradiation lamp are ultraviolet LED, low pressure mercury lamp, medium pressure mercury lamp, high pressure mercury lamp, ultra-high pressure mercury lamp, metal halide lamp, xenon lamp, microwave excited mercury lamp, black light lamp, chemical lamp, germicidal lamp, low pressure discharge mercury lamp, and excimer laser. Two or more ultraviolet irradiation lamps may be combined.

[0081] The illumination with light 14 may be continuous or intermittent.

[0082] The illuminance of the light 14 is, for example, 1 to 20 mW / cm 2 The irradiation time of the light 14 is, for example, 5 minutes to 5 hours. The integrated amount of the light 14 on the first laminate 10a is, for example, 100 to 5000 mJ / cm 2 2 It is.

[0083] (First adhesive sheet) The polymerization rate of the monomer group in the first adhesive sheet 1a formed from the first photocurable composition is preferably 90% or more, and may be 95% or more, 98% or more, or even 99% or more.

[0084] The gel fraction of the first adhesive sheet 1a is, for example, 50% or more, and may be 75% or more, 80% or more, or even 85% or more.

[0085] The creep amount of the first pressure-sensitive adhesive sheet 1a is, for example, 180 μm or less, and may be 160 μm or less. The lower limit of the creep amount is, for example, 5 μm or more, and may be 10 μm or more.

[0086] The creep amount of the first adhesive sheet 1a can be evaluated as follows (see FIG. 3A and FIG. 3B). First, a laminate of the first adhesive sheet 1a to be evaluated and a support film 51 is cut into a rectangular shape of 10 mm×50 mm to prepare a test piece 52. The support film 51 is arranged for the purpose of suppressing deformation of the portion of the first adhesive sheet 1a to which a load is applied during testing, thereby enabling more accurate measurement of the creep amount. For the support film 51, for example, a resin film such as a polyethylene terephthalate (PET) film can be used. The support film 51 may be an optical film or a laminate including an optical film. The thickness of the support film 51 may be any thickness that does not deform itself under the load, and is, for example, 20 to 200 μm. Next, as shown in FIG. 3A and FIG. 3B, the test piece 52 is attached to the surface of a stainless steel test plate 53 at a joint surface of 10 mm long×10 mm wide by the first adhesive sheet 1a. FIG. 3B shows the cross section BB of FIG. 3A. The test piece 52 is attached to the test plate 53 so that no air bubbles are mixed between the test plate 53 and the first adhesive sheet 1a. After attachment, the test plate 53 and the first adhesive sheet 1a are placed in an autoclave at 50°C and 5 atm (absolute pressure) for 15 minutes to homogenize the bond between the test plate 53 and the first adhesive sheet 1a. Next, the test plate 53 and the test piece 52 are held vertically with the test plate 53 facing upward and left in an atmosphere at 25°C for at least 5 minutes, and then a weight of 500g is fixed to the center of the lower end of the test piece 52 with the test plate 53 fixed, and a load 54 of 500gf is applied vertically downward. The creep amount (displacement amount) of the first adhesive sheet 1a with respect to the test plate 53 at a time 3600 seconds after the load 54 starts to be applied is measured as the fall amount of the weight. A laser displacement meter can be used to measure the fall amount of the weight.

[0087] The thickness of the first adhesive sheet 1a is, for example, 2 to 70 μm, and may be 2 to 50 μm, 5 to 40 μm, 10 to 30 μm, 10 to 25 μm, or even 10 to 20 μm.

[0088] <Process B> In step B, the first release liner 13a is peeled off from the cured laminate 17a. The laminate 17a includes a first base sheet 11a, a first pressure-sensitive adhesive sheet 1a, and a first release liner 13a, in this order. The peeling process provides a laminate 15a including the first release liner 13a, the first base sheet 11a, and the first pressure-sensitive adhesive sheet 1a.

[0089] The peel strength between first release liner 13a and first adhesive sheet 1a is smaller than the peel strength between first base sheet 11a and first adhesive sheet 1a, for example. The peel strength of first base sheet 11a from first adhesive sheet 1a is, for example, 0.1 to 10 N / 50 mm, and may be 1 to 8 N / 50 mm, 2 to 7 N / 50 mm, or even 3 to 5 N / 50 mm.

[0090] The peeled first release liner 13a may be wound into a roll and then used in step C.

[0091] <Process C> In step C, the light 14 is typically applied from the side of the second base sheet 11b. At this time, the light 14 passes through the second base sheet 11b to reach the second coating layer 12b, and cures the second coating layer 12b. However, the light 14 may be applied from the side of the second release liner 13b, or from both the side of the second release liner 13b and the second base sheet 11b. The second pressure-sensitive adhesive sheet 1b formed in step C is sandwiched between the second base sheet 11b and the second release liner 13b, and constitutes a part of the laminate 17b, until the second release liner 13b is peeled off.

[0092] (Second Photocurable Composition) The second photocurable composition is a pressure-sensitive adhesive composition that forms the second adhesive sheet 1b from the second coating layer 12b by irradiation with light 14. As the material of the second photocurable composition, the above-mentioned materials for the first photocurable composition can be used. That is, the second photocurable composition contains, for example, a monomer group containing a (meth)acrylic monomer and / or a partial polymer of the monomer group, and a photopolymerization initiator, and further contains an antioxidant as necessary. The second photocurable composition may further contain a crosslinking agent and other additives. The composition of the second photocurable composition may be the same as or different from that of the first photocurable composition. As an example, each of the first photocurable composition and the second photocurable composition preferably contains a monomer group containing a (meth)acrylic monomer and / or a partial polymer of the monomer group. In addition, as described above, each of the first photocurable composition and the second photocurable composition preferably contains an antioxidant.

[0093] As described above, the second photocurable composition may further contain an antioxidant. As with the first photocurable composition, when the second photocurable composition contains an antioxidant, when the second release liner 13b is used as the third release liner 13c to perform step E, the peel strength between the third release liner 13c and the third adhesive sheet 1c tends to be adjusted to a small value. The antioxidant also tends to prevent the surface of the second release liner 13b from being contaminated by the material of the second adhesive sheet 1b, regardless of the manufacturing conditions of the second adhesive sheet 1b (such as the light irradiation time).

[0094] As with the first photocurable composition, the solvent content in the second photocurable composition is, for example, 5% by weight or less, and may be 4% by weight or less, 3% by weight or less, 2% by weight or less, 1% by weight or less, or even 0.5% by weight or less. The second photocurable composition may be substantially free of solvent.

[0095] The viscosity of the second photocurable composition is preferably 5 to 100 poise. The second photocurable composition having a viscosity in the above range is particularly suitable for forming the second coating layer 12b.

[0096] (Second release liner) The second release liner 13b may be any of the above-mentioned first release liner 13a. The second release liner 13b may be the first release liner 13a that was peeled off from the first pressure-sensitive adhesive sheet 1a in step B.

[0097] The peel force PS1 between second release liner 13b, particularly first release liner 13a peeled from first adhesive sheet 1a in step B, and second adhesive sheet 1b is preferably 1.0 N / 50 mm or less, and may be 0.9 N / 50 mm or less, 0.8 N / 50 mm or less, 0.7 N / 50 mm or less, 0.6 N / 50 mm or less, 0.5 N / 50 mm or less, 0.4 N / 50 mm or less, 0.3 N / 50 mm or less, 0.2 N / 50 mm or less, or even 0.15 N / 50 mm or less. The lower limit of peel force PS1 is, for example, 0.01 N / 50 mm or more, and may be 0.03 N / 50 mm or more, 0.05 N / 50 mm or more, 0.08 N / 50 mm or more, or even 0.1 N / 50 mm or more.

[0098] The ratio PS1 / PS0 of the peel force PS1 to the peel force PS0 may be 10 or less, 8 or less, 6 or less, or even 5 or less. The lower limit of the ratio PS1 / PS0 is, for example, 1.1 or more, and may be 2.0 or more.

[0099] (Second base sheet) The second base sheet 11b may be the same as the first base sheet 11a described above. The second base sheet 11b may be the first release liner 13a that was peeled off from the first pressure-sensitive adhesive sheet 1a in step B.

[0100] (Second laminate and its formation) The second laminate 10b may include an additional layer other than the second base sheet 11b, the second coating layer 12b, and the second release liner 13b. The additional layer may be disposed on the side of the second base sheet 11b and / or the second release liner 13b opposite to the side of the second coating layer 12b. The second coating layer 12b is preferably in contact with the second base sheet 11b and the second release liner 13b.

[0101] The second laminate 10b can be formed by the method described above for the first laminate 10a.

[0102] The second laminate 10b may include a long second base sheet 11b, a long second coating layer 12b, and a long second release liner 13b, in other words, may be long. The long second laminate 10b can be obtained, for example, by forming the second coating layer 12b between the second base sheet 11b and the second release liner 13b that are unwound from a roll while conveying them.

[0103] (Light irradiation) The light 14 irradiated to the second laminate 10b and the irradiation conditions of the light 14 may be those described above for the step A.

[0104] (Second adhesive sheet) The polymerization rate of the monomer group in the second adhesive sheet 1b formed from the second photocurable composition is preferably 90% or more, and may be 95% or more, 98% or more, or even 99% or more.

[0105] The gel fraction of second adhesive sheet 1b is, for example, 50% or more, and may be 75% or more, 80% or more, or even 85% or more.

[0106] The creep amount of the second adhesive sheet 1b is, for example, 180 μm or less, and may be 160 μm or less. The lower limit of the creep amount is, for example, 5 μm or more, and may be 10 μm or more.

[0107] The thickness of the second adhesive sheet 1b is, for example, 2 to 70 μm, and may be 2 to 50 μm, 5 to 40 μm, 10 to 30 μm, 10 to 25 μm, or even 10 to 20 μm.

[0108] <Process D> In step D, second release liner 13b is peeled off from cured laminate 17b. Laminate 17b includes second base sheet 11b, second adhesive sheet 1b, and second release liner 13b in this order. By the above peeling, laminate 15b including second release liner 13b, second base sheet 11b, and second adhesive sheet 1b is obtained.

[0109] The peel strength between second release liner 13b and second adhesive sheet 1b is smaller than the peel strength between second base sheet 11b and second adhesive sheet 1b, for example. The peel strength of second base sheet 11b from second adhesive sheet 1b is, for example, 0.1 to 10 N / 50 mm, and may be 1 to 8 N / 50 mm, 2 to 7 N / 50 mm, or even 3 to 5 N / 50 mm.

[0110] The peeled second release liner 13b may be wound into a wound body and then used in step E.

[0111] <Process E> Step E can be carried out in the same manner and under the same conditions as step A. In detail, the third release liner 13c, the third photocurable composition, the third adhesive sheet 1c, and the third base sheet 11c can be the liners, compositions, or sheets described as the first release liner 13a, the first photocurable composition, the first adhesive sheet 1a, and the first base sheet 11a, respectively. As described above, in step D, the second release liner 13b peeled off from the second adhesive sheet 1b is used as, for example, the third base sheet 11c and / or the third release liner 13c. In other words, at least one of the third release liner 13c and the third base sheet 11c is the second release liner 13b itself peeled off from the second adhesive sheet 1b in step D. In step B, first release liner 13a peeled off from first pressure-sensitive adhesive sheet 1a may be used as third base sheet 11c and / or third release liner 13c. In other words, at least one of third release liner 13c and third base sheet 11c may be the first release liner 13a itself peeled off from first pressure-sensitive adhesive sheet 1a in step B.

[0112] Next, referring to FIG. 4, another example of a method for manufacturing a pressure-sensitive adhesive sheet will be described. In this example, a first coating layer 12a of a first photocurable composition is formed on one side of a long-shaped first base sheet 11a unwound from a roll 31 by a coating device 32. Next, a long-shaped first release liner 13a unwound from a roll 33 is placed on the first coating layer 12a to form a long-shaped first laminate 10a. Next, a light irradiator 34 irradiates the first laminate 10a with light 14 to form a long-shaped first pressure-sensitive adhesive sheet 1a. Next, the first release liner 13a is peeled from a laminate 17a including the first pressure-sensitive adhesive sheet 1a and wound up on a roll 35. The above steps are performed while the first base sheet 11a and the first release liner 13a are being transported. In this way, the above-mentioned steps A and B are performed. The wound first release liner 13a is reused in step C. Steps C and D may also be performed in the same manner as in Fig. 4. The method of Fig. 4 is particularly suitable for mass production of pressure-sensitive adhesive sheets.

[0113] Another example of the method for producing a pressure-sensitive adhesive sheet will be described with reference to FIG. 5. In this example, the first release liner 13a peeled off from the laminate 17a is used to produce a second pressure-sensitive adhesive sheet 1b without being wound up into a roll 35. The second pressure-sensitive adhesive sheet 1b is produced by the same method as the first pressure-sensitive adhesive sheet 1a. Except for the above, the example of FIG. 5 is the same as the example of FIG. 4. The method of FIG. 5 is particularly suitable for mass production of pressure-sensitive adhesive sheets. In FIG. 5, the first release liner 13a peeled off from the laminate 17a is used as the second release liner 13b. However, as described above, the first release liner 13a may be used as the second base sheet 11b.

[0114] [Method of manufacturing optical film with adhesive sheet] An example of a method for producing an optical film with a pressure-sensitive adhesive sheet according to this embodiment will be described with reference to Fig. 6. In the following example, a method for producing an optical film with a pressure-sensitive adhesive sheet using a first pressure-sensitive adhesive sheet 1a will be described. However, it is also possible to use a second pressure-sensitive adhesive sheet 1b or a third pressure-sensitive adhesive sheet 1c instead of the first pressure-sensitive adhesive sheet 1a.

[0115] In the example of FIG. 6, the optical film 2 is disposed on the exposed surface 18 of the first adhesive sheet 1a formed by peeling the first release liner 13a from the laminate 17a including the first base sheet 11a, the first adhesive sheet 1a, and the first release liner 13a in this order, to form an optical film 21 with an adhesive sheet. The optical film 21 with an adhesive sheet includes the first base sheet 11a, the first adhesive sheet 1a, and the optical film 2 in this order. The laminate 17a can be formed by the above-mentioned step A. The peeling of the first release liner 13a may be performed as the above-mentioned step B. The optical film 21 with an adhesive sheet can be used as it is or after peeling the first base sheet 11a, for example, as an optical laminate including the first adhesive sheet 1a and the optical film 2 in an image display device or the like. The optical laminate may be attached to an object (for example, an image forming panel) via the first adhesive sheet 1a. However, the use of the optical film 21 with an adhesive sheet is not limited to the above-mentioned example. An additional member such as an optical film may be disposed on exposed surface 18 formed by peeling first base sheet 11a from adhesive sheet-attached optical film 21. As an example, adhesive sheet-attached optical film 22 including optical film 2A, first adhesive sheet 1a, and optical film 2B in this order can be formed (see FIG. 7). Optical films 2A and 2B may be the same or different from each other.

[0116] 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 so as to be in contact with the exposed surface 18, or may be disposed with another layer sandwiched between the optical film 2 and the exposed surface 18.

[0117] With reference to Fig. 8, another example of the method for producing an optical film with a pressure-sensitive adhesive sheet of this embodiment will be described. In this example, a long optical film 2 is arranged on the exposed surface 18 of the first pressure-sensitive adhesive sheet 1a in the laminate 15a formed by the method of Fig. 4 to form a long optical film with a pressure-sensitive adhesive sheet 21. The optical film 2 is unwound from a roll 36 and arranged on the exposed surface 18. As shown in Fig. 8, the formation of the first pressure-sensitive adhesive sheet 1a and the formation of the optical film with a pressure-sensitive adhesive sheet 21 may be carried out continuously. The method of Fig. 8 is particularly suitable for mass production of the optical film with a pressure-sensitive adhesive sheet 21.

[0118] The optical film 2 is, for example, a film including at least one selected from the group consisting of a polarizing film and a retardation film. The optical film 2 may be a laminated film including a polarizing film and / or a retardation film. The optical film 2 may include a glass film. However, the optical film 2 is not limited to the above examples.

[0119] The polarizing film includes a polarizer. The polarizing film typically includes a polarizer and a protective film (transparent protective film). The protective film is disposed, for example, in contact with the main surface (surface having the widest area) of the polarizer. The polarizer may be disposed between two protective films. The protective film may be disposed on at least one surface of the polarizer.

[0120] The polarizer is not particularly limited, and examples thereof 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 dichroic substances such as iodine and dichroic dyes; polyene-based oriented films such as dehydrated polyvinyl alcohol and dehydrochlorinated polyvinyl chloride; etc. Polarizers are typically made of polyvinyl alcohol films (polyvinyl alcohol films include partially saponified ethylene-vinyl acetate copolymer films) and dichroic substances such as iodine.

[0121] The thickness of the polarizer is not particularly limited, and may be, for example, 80 μm or less, 50 μm or less, 30 μm or less, 25 μm or less, or even 20 μm or less. The lower limit of the thickness of the polarizer is not particularly limited, and may be, for example, 1 μm or more, 5 μm or more, 10 μm or more, or even 15 μm or more. A thin polarizer (for example, a thickness of 20 μm or less) is suppressed in dimensional change, and can contribute to improving the durability of the optical laminate, particularly the durability at high temperatures.

[0122] As the material of the protective film, for example, a thermoplastic resin excellent in transparency, mechanical strength, thermal stability, moisture blocking property, isotropy, etc. is used. 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. The material of the protective film may be a thermosetting resin or an ultraviolet-curing resin such as a (meth)acrylic, urethane, acrylic urethane, epoxy, or silicone-based resin. When the polarizing film has two protective films, the materials of the two protective films may be the same or different from each other. For example, a protective film made of a thermoplastic resin may be bonded to one main surface of the polarizer via an adhesive, and a protective film made of a thermosetting resin or an ultraviolet-curing resin may be bonded to the other main surface of the polarizer. The protective film may contain one or more types of optional additives, such as ultraviolet absorbers, antioxidants, lubricants, plasticizers, release agents, color inhibitors, flame retardants, nucleating agents, antistatic agents, pigments, and colorants.

[0123] The thickness of the protective film can be appropriately determined, but is generally about 10 to 200 μm in terms of strength, workability such as handleability, thinness, and the like.

[0124] The polarizer and the protective film are usually adhered to each other via a water-based adhesive or the like. Examples of the water-based adhesive include an isocyanate-based adhesive, a polyvinyl alcohol-based adhesive, a gelatin-based adhesive, a vinyl-based latex, a water-based polyurethane, and a water-based polyester. Examples of adhesives other than the above-mentioned adhesives include an ultraviolet-curable adhesive and an electron beam-curable adhesive. The electron beam-curable polarizing plate adhesive exhibits suitable adhesion to various protective films. The adhesive may contain a metal compound filler.

[0125] In the polarizing film, a retardation film or the like can be formed on the polarizer instead of the protective film. Another protective film or a retardation film or the like can be further provided on the protective film.

[0126] The protective film may have a hard coat layer on the surface opposite to the surface bonded to the polarizer, and may also be subjected to treatments for the purposes of anti-reflection, anti-sticking, diffusion, anti-glare, etc.

[0127] The polarizing film may be a circular polarizing film.

[0128] The retardation film may be one obtained by stretching a polymer film or one obtained by aligning and fixing a liquid crystal material. The retardation film has birefringence, for example, in the in-plane and / or thickness direction.

[0129] Retardation films include anti-reflection retardation films (see JP 2012-133303 A,

[0221] ,

[0222] ,

[0228] ), viewing angle compensation retardation films (see JP 2012-133303 A,

[0225] ,

[0226] ), and tilted orientation retardation films for viewing angle compensation (see JP 2012-133303 A,

[0227] ).

[0130] The specific configuration of the retardation film, for example, the retardation value, arrangement angle, three-dimensional birefringence, whether it is a single layer or a multilayer, and the like, are not particularly limited, and any known retardation film can be used.

[0131] The thickness of the retardation film is preferably 20 μm or less, more preferably 10 μm or less, further preferably 1 to 9 μm, and particularly preferably 3 to 8 μm.

[0132] The retardation 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.

[0133] An image display device may be formed using the optical film with adhesive sheet formed by the above-mentioned manufacturing method. The image display device may be formed, for example, by bonding the optical film 21, 22 with adhesive sheet to an image display panel. The bonding may be performed by a first adhesive sheet 1a. The image display device may 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 may be an electroluminescence (EL) display, a plasma display (PD), a field emission display (FED: Field Emission Display), or the like. The image display device may be used for home appliances, in-vehicle applications, public information displays (PID), and the like. EXAMPLES

[0134] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the examples shown below.

[0135] Example 1 [Preparation of release liner A] Addition reaction curing type silicone (LTC761 containing hexenyl group-containing polyorganosiloxane, 30 wt% toluene solution, manufactured by Dow Corning Toray) 30 parts by weight, release control agent (BY24-850 containing unreactive silicone resin, manufactured by Dow Corning Toray) 0.9 parts by weight, and curing catalyst (SRX212 containing platinum catalyst, manufactured by Dow Corning Toray) 2 parts by weight, and toluene / hexane mixed solvent (volume ratio 1: 1) as a dilution solvent were mixed to obtain a silicone-based release agent composition A. The concentration of silicone solids in the release agent composition A was 1.0 wt%. Next, the release agent composition A was applied to one side of a liner substrate (Lumirror XD500P, a polyester film, thickness 75 μm) with 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.

[0136] [Preparation of Photocurable Composition A] 95.1 parts by weight of n-butyl acrylate (BA), 4.8 parts by weight of acrylic acid (AA), 0.1 parts by weight of 4-hydroxybutyl acrylate (HBA), 0.05 parts by weight of 2,2-dimethoxy-1,2-diphenylethan-1-one (Omnirad651, IGM Resins BV) as photopolymerization initiators, and 0.05 parts by weight of bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide (Omnirad819, IGM Resins BV) were placed in a four-bottom flask and irradiated with ultraviolet light under a nitrogen atmosphere to obtain a partially photopolymerized monomer syrup. The ultraviolet light irradiation was continued until the viscosity of the liquid in the flask (measurement conditions: BH viscometer No. 5 rotor, 10 rpm, measurement temperature 30°C) reached approximately 20 Pa·s. Next, 0.09 parts by weight of 1,9-nonanediol diacrylate (NDDA) as a crosslinking agent and 0.3 parts by weight of isooctyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate (BASF's "Irganox 1135") as an antioxidant were added to 100 parts by weight of the monomer syrup, and the mixture was mixed uniformly to obtain a photocurable composition A.

[0137] [Preparation of the first adhesive sheet] Photocurable composition A was applied to one side of a first base sheet (Lumirror XD500P, a polyester film without a release layer, thickness 75 μm) using an applicator to form a first coating layer (thickness 20 μm). Next, release liner A was placed as a first release liner on top of the formed first coating layer to obtain a first laminate. The first release liner was placed so that the release layer was in contact with the first coating layer. Next, a light beam with an illuminance of 2.42 mW / cm was applied from the side of the first base sheet in the first laminate. 2 The first coating layer was photocured by irradiating it with ultraviolet light (black light source) for 10 minutes to form a laminate consisting of a first base sheet, a first adhesive sheet (thickness 20 μm), and a first release liner.

[0138] A test piece 220 mm long and 50 mm wide (the length direction was the application direction of the photocurable composition) was cut out from the formed laminate. A 180° peel test was performed on the test piece using a tensile tester to peel only the first release liner in the length direction, and the peel force PS0 was evaluated. The peel test conditions were as described above.

[0139] [Preparation of second adhesive sheet] A laminate including a first pressure-sensitive adhesive sheet was prepared by the above-mentioned method, and the first release liner was peeled off from the first pressure-sensitive adhesive sheet. Next, the photocurable composition A was applied to one side of a second base sheet (Lumirror XD500P, a polyester film without a release layer, 75 μm thick) with an applicator to form a second coating layer (20 μm thick). Next, a second release liner was placed on the formed second coating layer to obtain a second laminate. As the second release liner, the first release liner peeled off from the first pressure-sensitive adhesive sheet was used. The second release liner was placed so that the release layer was in contact with the second coating layer. Next, the second laminate was irradiated with ultraviolet light under the same conditions as when the first pressure-sensitive adhesive sheet was prepared, and the second coating layer was photocured to form a laminate composed of the second base sheet, the second pressure-sensitive adhesive sheet (20 μm thick), and the second release liner.

[0140] A test piece 220 mm long and 50 mm wide (the length direction was the coating direction of the photocurable composition) was cut out from the formed laminate. A 180° peel test was performed on the test piece using a tensile tester to peel only the second release liner in the length direction, and the peel force PS1 was evaluated. The peel test conditions were as described above.

[0141] Example 2 [Preparation of release liner B] Release liner B having a release layer (thickness 120 nm) on one side was prepared in the same manner as release liner A, except that the thickness of release agent composition A applied to the liner substrate was changed.

[0142] [Preparation of the first adhesive sheet] Except for using release liner B as the first release liner, a first PSA sheet was produced in the same manner as in Example 1. Furthermore, the peel strength PS0 was evaluated using a laminate including the first PSA sheet in the same manner as in Example 1.

[0143] [Preparation of second adhesive sheet] A laminate including a first pressure-sensitive adhesive sheet was prepared by the above-mentioned method, and the first release liner was peeled off from the first pressure-sensitive adhesive sheet. Next, the first release liner peeled off from the first pressure-sensitive adhesive sheet was used as a second release liner to prepare a second pressure-sensitive adhesive sheet by the same method as in Example 1. Furthermore, the peel force PS1 was evaluated by the same method as in Example 1 using the laminate including the second pressure-sensitive adhesive sheet.

[0144] Example 3 [Preparation of Photocurable Composition B] Photocurable composition B was prepared in the same manner as photocurable composition A, except that no antioxidant was used.

[0145] [Preparation of the first adhesive sheet] A first pressure-sensitive adhesive sheet was produced by the same method as in Example 1, except that release liner B was used as the first release liner and photocurable composition B was used. Furthermore, by the same method as in Example 1, the peel force PS0 was evaluated using a laminate including the first pressure-sensitive adhesive sheet.

[0146] [Preparation of second adhesive sheet] A laminate including a first pressure-sensitive adhesive sheet was prepared by the above-mentioned method, and the first release liner was peeled off from the first pressure-sensitive adhesive sheet. Next, the first release liner peeled off from the first pressure-sensitive adhesive sheet was used as a second release liner to prepare a second pressure-sensitive adhesive sheet by the same method as in Example 1. Furthermore, the peel force PS1 was evaluated by the same method as in Example 1 using the laminate including the second pressure-sensitive adhesive sheet.

[0147] Example 4 [Preparation of the first adhesive sheet] Except for using release liner B as the first release liner, a first PSA sheet was produced in the same manner as in Example 1. Furthermore, the peel strength PS0 was evaluated using a laminate including the first PSA sheet in the same manner as in Example 1.

[0148] [Preparation of second adhesive sheet] A laminate including a first pressure-sensitive adhesive sheet was prepared by the above-mentioned method, and the first release liner was peeled off from the first pressure-sensitive adhesive sheet. Next, a second pressure-sensitive adhesive sheet was prepared by the same method as in Example 1, except that the first release liner peeled off from the first pressure-sensitive adhesive sheet was used as the second release liner, and the photocurable composition B prepared in Example 3 was used. Furthermore, the peel force PS1 was evaluated using the laminate including the second pressure-sensitive adhesive sheet by the same method as in Example 1.

[0149] (Examples 5 to 7) The first and second adhesive sheets of Examples 5 to 7 were produced by the same method as in Example 2, except that the ultraviolet irradiation conditions when producing the first and second adhesive sheets were changed as shown in Table 1. Furthermore, by the same method as in Example 1, the peel force PS0 was evaluated using a laminate including the first adhesive sheet, and further, the peel force PS1 was evaluated using a laminate including the second adhesive sheet.

[0150] (Examples 8 to 10) A first pressure-sensitive adhesive sheet and a second pressure-sensitive adhesive sheet were prepared for each of Examples 8 to 10 by the same method as Example 2, except that a compound shown in Table 1 was used as the antioxidant contained in the photocurable composition A. Furthermore, by the same method as Example 1, a peel force PS0 was evaluated using a laminate including the first pressure-sensitive adhesive sheet, and a peel force PS1 was evaluated using a laminate including the second pressure-sensitive adhesive sheet.

[0151] Comparative Example 1 A first pressure-sensitive adhesive sheet and a second pressure-sensitive adhesive sheet were produced by the same method as in Example 2, except that the photocurable composition B prepared in Example 3 was used when producing the first pressure-sensitive adhesive sheet and the second pressure-sensitive adhesive sheet. Furthermore, by the same method as in Example 1, a peel force PS0 was evaluated using a laminate including the first pressure-sensitive adhesive sheet, and a peel force PS1 was evaluated using a laminate including the second pressure-sensitive adhesive sheet.

[0152] [Table 1]

[0153] The abbreviations in Table 1 are as follows. Irg1135: Isooctyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate (BASF "Irganox 1135", molecular weight 390) Irg1010: Pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] (BASF "Irganox 1010", molecular weight 1178) LA-52: Tetrakis(1,2,2,6,6-pentamethyl-4-piperidyl)butane-1,2,3,4-tetracarboxylate (ADEKA "ADEKA STAB LA-52", molecular weight 847) 2112: Tris(2,4-di-t-butylphenyl)phosphite (ADEKA "ADEKA STAB 2112", molecular weight 647)

[0154] As can be seen from Table 1, in the Examples in which at least one selected from the group consisting of the photocurable composition for forming the first pressure-sensitive adhesive sheet (first photocurable composition) and the photocurable composition for forming the second pressure-sensitive adhesive sheet (second photocurable composition) contained an antioxidant, the peel force PS1 was smaller than in the Comparative Examples. From this result, it is presumed that the conditions of the Examples are suitable for repeated use of the release liner.

[0155] In all of the Examples, the first release liner peeled off from the first pressure-sensitive adhesive sheet is reused as the second release liner, but by appropriately setting the production conditions for the second pressure-sensitive adhesive sheet, the first release liner can also be reused as the second base sheet. [Industrial Applicability]

[0156] The pressure-sensitive adhesive sheet obtained by the production method of the present invention can be used, for example, in optical laminates and image display devices. [Explanation of symbols]

[0157] 1a First adhesive sheet 1b Second adhesive sheet 1c Third adhesive sheet 2. Optical Film 10a First laminate 10b Second laminate 10c Third laminate 11a First base sheet 11b Second base sheet 11c Third base sheet 12a First coating layer 12b Second coating layer 12c Third Coating Layer 13a First release liner 13b Second release liner 13c Third release liner 14 light 18 Exposed surface 21,22 Optical film with adhesive sheet

Claims

1. A step A includes irradiating a first laminate including, in this order, a first base sheet, a first coating layer including a first photocurable composition, and a first release liner with light to form a first pressure-sensitive adhesive sheet from the first coating layer; a step B of peeling the first release liner from the first pressure-sensitive adhesive sheet; a step C of irradiating light to a second laminate including, in this order, a second base sheet, a second coating layer including a second photocurable composition, and a second release liner to form a second pressure-sensitive adhesive sheet from the second coating layer; Including, In the step C, the first release liner peeled off in the step B is used as the second base sheet and / or the second release liner, A method for producing a pressure-sensitive adhesive sheet, wherein at least one selected from the group consisting of the first photocurable composition in the step A and the second photocurable composition in the step C contains an antioxidant.

2. The method according to claim 1 , wherein in the step C, the first release liner released in the step B is used as the second release liner.

3. a step D of peeling the second release liner from the second pressure-sensitive adhesive sheet; a step E of irradiating a third laminate including, in this order, a third base sheet, a third coating layer including a third photocurable composition, and a third release liner with light to form a third pressure-sensitive adhesive sheet from the third coating layer; Further comprising:

3. The manufacturing method according to claim 2, wherein in step E, the second release liner peeled off in step D is used as the third base sheet and / or the third release liner, or the first release liner peeled off in step B is used as the third base sheet and / or the third release liner.

4. The peel strength PS between the second release liner and the second pressure-sensitive adhesive sheet 1 The manufacturing method according to claim 2, wherein the tension is 1.0 N / 50 mm or less.

5. The peel strength PS between the first release liner and the first pressure-sensitive adhesive sheet 0 The manufacturing method according to claim 1, wherein the tension is 0.01 N / 50 mm or more.

6. The method of claim 1 , wherein each of the first photohardenable composition and the second photohardenable composition includes the antioxidant.

7. The method according to claim 1 , wherein the antioxidant comprises at least one selected from the group consisting of hindered phenol compounds and hindered amine compounds.

8. The method according to claim 1 , wherein the molecular weight of the antioxidant is 1,500 or less.

9. The method according to claim 1 , wherein each of the first photocurable composition and the second photocurable composition contains a monomer group including a (meth)acrylic monomer and / or a partial polymer of the monomer group.

10. The method according to claim 9 , wherein the monomer group includes a carboxyl group-containing monomer.

11. A method for producing an optical film with a pressure-sensitive adhesive sheet, comprising: arranging an optical film on an exposed surface of the pressure-sensitive adhesive sheet formed by the manufacturing method according to any one of claims 1 to 10 to form an optical film with a pressure-sensitive adhesive sheet.

12. The method according to claim 11 , wherein the optical film comprises at least one film selected from the group consisting of a polarizing film and a retardation film.

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