Method for producing adhesive sheet and method for producing optical film with adhesive sheet

Abstract

The present invention provides a technology suitable for manufacturing an adhesive sheet with a low environmental burden. The method for manufacturing an adhesive sheet provided comprises: using a release liner, irradiating light to a laminated body sequentially comprising a substrate sheet, a coating layer containing a photocurable composition, and a release liner, to form an adhesive sheet from the coating layer, step A; and step B of peeling the release liner from the adhesive sheet. In the above-mentioned manufacturing method, step A and step B are repeatedly implemented using the release liner peeled off in step B. The release liner is used and counted from the unused state. The peeling force PS measured from the adhesive sheet after being peeled off from the adhesive sheet three times is 3 Less than 1.0N / 50mm.

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 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] A step A of irradiating a laminate including a substrate sheet, a coating layer containing a photocurable composition, and the release liner in this order with light using a release liner to form a pressure-sensitive adhesive sheet from the coating layer; and

[0012] step B of peeling the release liner from the adhesive sheet,

[0013] The above steps A and B are repeatedly performed using the above release liner peeled off in the above step B,

[0014] As the release liner, the peeling force PS with the PSA sheet measured after peeling the liner from the PSA sheet three times, counting from the unused state, was used. 3 Less than 1.0N / 50mm.

[0015] In another aspect, the present invention provides a method for manufacturing an optical film with an adhesive sheet, the method comprising:

[0016] 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.

[0017] Effects of the Invention

[0018] 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

[0019] 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.

[0020] 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.

[0021] 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.

[0022] 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.

[0023] 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.

[0024] 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.

[0025] 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

[0026] The method for producing a pressure-sensitive adhesive sheet according to the first aspect of the present invention includes:

[0027] A step A of irradiating a laminate including a substrate sheet, a coating layer containing a photocurable composition, and the release liner in this order with light using a release liner to form a pressure-sensitive adhesive sheet from the coating layer; and

[0028] step B of peeling the release liner from the adhesive sheet,

[0029] Using the release liner peeled off in the step B, the steps A and B are repeatedly performed.

[0030] As the release liner, the following sheet was used: the peeling force PS from the PSA sheet measured after peeling the PSA sheet three times, counting from the unused state. 3 Less than 1.0N / 50mm.

[0031] 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,

[0032] The peeling force PS of the release liner measured in an unused state with the pressure-sensitive adhesive sheet is 0 It is 0.01N / 50mm or more.

[0033] 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,

[0034] The release force PS of the release liner 3 Relative to the peeling force PS of the above-mentioned adhesive sheet measured in the unused state 0 PS 3 / PS 0 Is below 10.

[0035] 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,

[0036] The peeling force PS of the release liner from the PSA sheet measured after the release liner has been peeled off from the PSA sheet once, starting from the unused state 1 Relative to the peeling force PS of the above-mentioned adhesive sheet measured in the unused state 0 PS 1 / PS 0 Is below 10.

[0037] 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,

[0038] The release liner has a release layer on the surface facing the coating layer.

[0039] The thickness of the release layer is 110 nm or less.

[0040] 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,

[0041] The peeling force between the release liner and the pressure-sensitive adhesive sheet is smaller than the peeling force between the substrate sheet and the pressure-sensitive adhesive sheet.

[0042] In a seventh 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 sixth aspects,

[0043] The photocurable composition includes a monomer group containing a (meth)acrylic monomer and / or a partial polymer of the monomer group.

[0044] In an eighth aspect of the present invention, for example, in the method for producing a pressure-sensitive adhesive sheet according to the seventh aspect,

[0045] The (meth)acrylic monomer includes a carboxyl group-containing monomer.

[0046] A method for producing an optical film with a pressure-sensitive adhesive sheet according to a ninth aspect of the present invention includes:

[0047] 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 eighth aspects.

[0048] 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,

[0049] The optical film includes at least one film selected from the group consisting of a polarizing film and a retardation film.

[0050] 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.

[0051] 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 directly discarded after peeling, and have conducted research based on this idea to complete the present invention. The peeling force of the release liner after peeling from the adhesive sheet becomes larger than that of the unused state. On the other hand, according to the inventors' research, the degree of increase in the peeling force tends to decrease with the number of repeated peelings. The peeling force PS after peeling from the adhesive sheet three times when counting from the unused state is 3 It is useful as an indicator reflecting the increase in peel force. Peel force PS 3 A release liner with a resistance of less than 1.0 N / 50 mm is suitable for repeated use. If it is reused, the amount of release liner to be discarded is reduced, which can reduce the environmental burden.

[0052] [Method for producing adhesive sheet]

[0053] Reference Figure 1 , an example of the method for manufacturing the adhesive sheet of the present invention is described. In this example, the first stack 10 including a substrate sheet 11, a coating layer 12 containing a photocurable composition, and a release liner 13 in sequence is irradiated with light 14, and the adhesive sheet 1 is formed from the coating layer 12 (process A). The light 14 passes through the release liner 13 and reaches the coating layer 12, so that the coating layer 12 is cured. However, it should be noted that the irradiation with light 14 can be implemented from one side of the substrate sheet 11, or from both sides of the release liner 13 and the substrate sheet 11. In process A, the adhesive sheet 1 is formed using the release liner 13. The formed adhesive sheet 1 is sandwiched by the substrate sheet 11 and the release liner 13 to form a part of the second stack 17 until the release liner 13 is peeled off. After process A, the release liner 13 is peeled off from the adhesive sheet 1 (process B). In Figure 1 In the method, the step A and the step B are repeatedly performed using the release liner 13 peeled off in the step B. The step A using the peeled release liner 13 is performed by forming a first laminate 10 including a substrate sheet 11, a coating layer 12, and the peeled release liner 13 in this order, and irradiating the formed first laminate 10 with light 14.

[0054] exist Figure 1 In the method, as the release liner 13, the release force PS is used 3 For sheets less than 1.0N / 50mm, the peel force PS 3 The peeling force from the adhesive sheet 1 is measured after peeling the adhesive sheet 1 three times when counting from the unused state. With the implementation of step A, the peeling force of the release liner 13 relative to the adhesive sheet 1 usually increases. The increase in the peeling force can be inferred to be due to the increase in the amount of functional groups and free radicals on the surface of the coating layer 12 side of the release liner 13 due to the irradiation of light 14. The above increase may occur due to the following reasons: due to the irradiation of light 14, a chemical bond is generated between the release liner 13 and the adhesive sheet 1, and a part of it or a group formed by the decomposition of the bond remains on the above surface after the adhesive sheet 1 is peeled off.

[0055] <Process A>

[0056] (Release liner)

[0057] Release force PS of release liner 13 3 The peel force PS 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, and may be 0.15 N / 50 mm or less. 3The lower limit of 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 further may be 0.1 N / 50 mm or more.

[0058] The peeling force PS of the release liner 13 measured when it is not used and the pressure-sensitive adhesive sheet 1 is 0 The peel force PS may be 0.01 N / 50 mm or more, 0.02 N / 50 mm or more, or 0.03 N / 50 mm or more. 0 The upper limit is, for example, 0.2 N / 50 mm or less, and may be 0.17 N / 50 mm or less, 0.15 N / 50 mm or less, 0.12 N / 50 mm or less, or further may be 0.1 N / 50 mm or less.

[0059] Release force PS of release liner 13 3 Relative to the peeling force PS of the adhesive sheet 1 measured in the unused state 0 PS 3 / PS 0 It may be 10 or less, 7 or less, 5 or less, 4 or less, 3 or less, 2 or less, and further 1.8 or less. 3 / PS 0 The lower limit of may be, for example, 1.1 or more, and further may be 1.2 or more.

[0060] The peeling force PS of the release liner 13 measured after it has been peeled off from the pressure-sensitive adhesive sheet 1 once, starting from the unused state, is 1 Relative to the peeling force PS of the adhesive sheet 1 measured in the unused state 0 PS 1 / PS 0 It may be 10 or less, 7 or less, 5 or less, 4 or less, 3 or less, 2 or less, 1.8 or less, and further 1.7 or less. 1 / PS 0 The lower limit of may be, for example, 1.05 or more, and further may be 1.1 or more.

[0061] The peeling force PS after peeling off the pressure-sensitive adhesive sheet 1 n times when counting from the unused state n (n is an integer greater than 0 corresponding to the number of peelings; when n=0, it is the peeling force PS in the unused state. 0) can be evaluated as follows: using the release liner of the evaluation object, process A and process B are carried out n times, and the second laminate 17 formed by further carrying out the (n+1)th process A is cut into a width of 50 mm to prepare a test piece, and a 180° peeling test is carried out to peel off only the release liner 13 from the prepared test piece for evaluation. The peeling test is carried out after about 0.5 to 1 hour has passed since the formation of the adhesive sheet 1. From the formation of the adhesive sheet 1 to the implementation of the peeling test, the second laminate 17 and the test piece are placed in an atmosphere of 23°C±5°C. The peeling test can be carried out using a tensile testing machine. More specifically, it can be carried out as follows: after fixing the entire surface of one side of the substrate sheet 11 of the test piece to a fixed plate (for example, a SUS plate) using a double-sided adhesive tape, one end of the fixed plate in the length direction is fixed to the upper chuck of the tensile testing machine, and the end of the upper chuck of the release liner 13 is peeled off, folded 180°, and fixed to the lower chuck of the tensile testing machine for implementation. The fixing plate can use a fixing plate with sufficient mechanical strength for realizing the stable implementation of the peel test. The double-sided adhesive tape can use a double-sided adhesive tape with sufficient adhesive force to prevent the substrate sheet 11 from peeling off from the fixing plate during the implementation of the peel test. The peeling speed of the peel test is set to 300mm / min, and the test temperature is set to 23℃±5℃. In the case where the width of the second laminate 17 does not meet 50mm, the measured value under the original width can be converted into a value when the width is 50mm. In the case where the formation direction of the coating layer 12 can be distinguished, the TD perpendicular to the direction, i.e. MD, in the plane can be determined as the width direction of the test piece. In the case where the substrate sheet 11 and the release liner 13 are in the shape of elongated strips, their width direction can be used as the width direction of the test piece.

[0062] Peel force PS 0 ,PS n and PS caused by repeated peeling n The degree of increase may vary due to the following factors: for example, the composition of the photocurable composition, the composition, formation conditions and thickness of the formed adhesive sheet 1, the material, thickness and state of the release surface of the release liner 13, and the composition, formation conditions and thickness of the release layer that the release liner 13 may have.

[0063] An example of the base material of the release liner 13 (hereinafter referred to as "base material") is a resin film. Examples of the resin that can be contained in the base material are polyesters such as polyethylene terephthalate and polyethylene naphthalate, acetate resins, polyether sulfone, polycarbonate, polyamide, polyimide, polyolefin, (meth) acrylic resin, polyvinyl chloride, polyvinylidene chloride, polystyrene, polyvinyl alcohol, polyarylate, and polyphenylene sulfide. The resin is preferably a polyester such as polyethylene terephthalate.

[0064] The release liner 13 preferably has excellent transmittance to the light 14 irradiated in the step A.

[0065] The thickness of the release liner 13 is, for example, 10 to 200 μm, or 25 to 150 μm.

[0066] The release liner 13 may include a layer other than the base material. The release liner 13 may include a release layer. Figure 2 The release liner 13 includes a backing substrate 131 and a release layer 132 formed on one surface of the backing substrate 131 . Figure 2 The release liner 13 may be used in such a manner that the release layer 132 faces the coating layer 12 side.

[0067] Typically, the release layer 132 is a cured 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 release liner 13 can have a cured 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 the acrylic adhesive sheet 1. It should be noted that in this specification, the main component refers to the component with the largest content.

[0068] The silicone release agent includes 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 the adhesion and peelability with respect to the acrylic adhesive sheet 1. The curable silicone material can be a silicone modified resin obtained by introducing reactive silicone into an organic resin such as urethane, epoxy, alkyd resin, etc. by graft polymerization.

[0069] 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.

[0070] 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.

[0071] 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.

[0072] 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.

[0073] 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.

[0074] 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.

[0075] 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. The thickness of the release layer 132 may be 110 nm or less. In other words, the release liner 13 has a release layer 132 on the surface of the coating layer 12, and the thickness of the release layer 132 may be 110 nm or less.

[0076] The release liner 13 may be in the form of a single sheet or in the form of a long strip.

[0077] (Base sheet)

[0078] An example of the base sheet 11 is a resin film. Examples of the resin contained in the base sheet 11 are the same as examples of the resin that may be contained in the backing base.

[0079] The base sheet 11 may have a transmittance to the light 14 irradiated in the step A, or may have a transmittance to the light 14 of the same degree as that of the release liner 13 .

[0080] The thickness of the base sheet 11 is, for example, 10 to 200 μm, or 25 to 150 μm.

[0081] The substrate sheet 11 may be provided with a release layer on the surface of the coating layer 12 side. The examples of the release layer and its preparation method that the substrate sheet 11 may have are the same as the examples of the release layer and its preparation method that the release liner 13 may have. The release layer may be provided on both the release liner 13 and the substrate sheet 11. 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 provided by the substrate sheet 11 may be thicker.

[0082] The base sheet 11 can generally be selected to have a greater release force with the pressure-sensitive adhesive sheet 1 than the release liner 13 .

[0083] The base sheet 11 may be in the form of a single sheet or in the form of a long strip.

[0084] (Photocurable composition)

[0085] The photocurable composition is a composition that can form an adhesive sheet 1 from a coating layer 12 by irradiation with light 14. The 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 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 1 with (meth)acrylic polymer and its cross-linked product as the main component can be formed. However, the 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.

[0086] 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.

[0087] 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.

[0088] 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.

[0089] The polymerization and curing speed of the carboxyl group-containing monomer based on the irradiation of light 14 is generally higher than that of the (meth) acrylate alkyl ester without a carboxyl group. The high speed means that the elastic modulus of the adhesive sheet 1 can be increased, thereby improving the dimensional stability with respect to the deformation force. On the other hand, the peeling force of the release liner with respect to the adhesive sheet 1 is likely to be increased. Therefore, the peeling force PS is suppressed. 3 The use of the release liner 13 is particularly advantageous in the case where the photocurable composition contains a carboxyl group-containing monomer.

[0090] 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. The hydroxyl-containing monomer can contribute to the improvement of the cohesive force of the adhesive sheet 1. 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 methyl acrylate (4-hydroxymethylcyclohexyl). 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.

[0091] In the photocurable composition, each of the above monomers may be included 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 coating layer 12 by appropriately increasing the viscosity of the photocurable composition.

[0092] The photocurable composition generally 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.

[0093] 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.

[0094] The amount of the photopolymerization initiator in the 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.

[0095] The photocurable composition may contain a crosslinking agent. An example of a 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 a 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.

[0096] 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.

[0097] 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.

[0098] The photocurable composition may 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.

[0099] The content of the solvent in the 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 photocurable composition may contain substantially no solvent. Substantially containing no solvent means that a solvent 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.

[0100] The viscosity of the photocurable composition is preferably 5 to 100 poise. A photocurable composition having a viscosity in the above range is particularly suitable for forming the coating layer 12 .

[0101] (First Laminated Body and Formation thereof)

[0102] The first laminate 10 may include another layer in addition to the base sheet 11, the coating layer 12, and the release liner 13. The other layer may be disposed on the side of the base sheet 11 and / or the release liner 13 opposite to the coating layer 12 side. The coating layer 12 is preferably in contact with the base sheet 11 and the release liner 13.

[0103] The first laminate 10 can be formed, for example, by forming a coating layer 12 on a substrate sheet 11 (or a release liner 13), and disposing a release liner 13 (or a substrate sheet 11) on the formed coating layer 12. Alternatively, the first laminate 10 can be formed by coating the photocurable composition so as to flow into a space between the substrate sheet 11 and the release liner 13 which are held at a predetermined interval so that their main surfaces face each other. The release liner 13 after release can be used so that the surface on the coating layer 12 side, for example, the surface on the release layer 132 side, in the step A immediately before release becomes the coating layer 12 side again.

[0104] The coating layer 12 can be formed by various coating methods such as roll coating, lick roll coating, gravure coating, reverse coating, roller brushing, spray coating, dip roll coating, rod coating, blade coating, air knife coating, shower coating, die lip coating, and die coating.

[0105] The thickness of the coating layer 12 can be adjusted according to the desired thickness of the pressure-sensitive adhesive sheet 1 , and may be, for example, 5 to 100 μm, 5 to 50 μm, 5 to 25 μm, or even 5 to 20 μm.

[0106] The first laminate 10 may include a long strip substrate sheet 11, a long strip coating layer 12, and a long strip release liner 13. In other words, it may be in a long strip shape. The long strip first laminate 10 may be obtained by, for example, conveying the substrate sheet 11 and the release liner 13 continuously unwound from a roll while forming the coating layer 12 therebetween.

[0107] (Radiation of light)

[0108] The light 14 irradiated to the first laminate 10 is, for example, visible light or ultraviolet light having a wavelength shorter than 450 nm. The light 14 may include light of a wavelength in the same region as the absorption wavelength of the photopolymerization initiator contained in the photocurable composition. The light 14 obtained by cutting off short-wavelength light having a wavelength of less than 300 nm through an optical filter or the like may be irradiated, and cutting off the short-wavelength light is suitable for suppressing the degradation of the release liner 13 caused by the light 14. The light source of the light 14 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, sterilization lamps, low-pressure discharge mercury lamps, and excimer lasers. Two or more ultraviolet irradiation lamps may also be combined.

[0109] The irradiation of the light 14 may be continuous or intermittent.

[0110] The irradiation intensity of the light 14 is, for example, 1 to 20 mW / cm 2 The accumulated light intensity of the light 14 on the first stacked body 10 is, for example, 100 to 5000 mJ / cm 2 .

[0111] The polymerization rate of the monomer group in the pressure-sensitive adhesive sheet 1 is preferably 90% or more. The polymerization rate may be 95% or more, 98% or more, or even 99% or more.

[0112] The gel fraction of the pressure-sensitive adhesive sheet 1 may be, for example, 50% or more, 75% or more, 80% or more, or even 85% or more.

[0113] <Process B>

[0114] In step B, the release liner 13 is peeled off from the cured second laminate 17. The second laminate 17 sequentially comprises the base sheet 11, the pressure-sensitive adhesive sheet 1, and the release liner 13. By the above peeling, the release liner 13 and the third laminate 15 comprising the base sheet 11 and the pressure-sensitive adhesive sheet 1 are obtained.

[0115] The peeling force between the release liner 13 and the pressure-sensitive adhesive sheet 1 may be smaller than the peeling force between the base sheet 11 and the pressure-sensitive adhesive sheet 1 .

[0116] The peeling force of the base sheet 11 with respect to the pressure-sensitive adhesive sheet 1 is, for example, 0.1 to 10 N / 50 mm, 1 to 8 N / 50 mm, 2 to 7 N / 50 mm, or 3 to 5 N / 50 mm.

[0117] There is no particular limit on the number of times the release liner 13 is peeled off and reused in the production of the adhesive sheet 1, and it can be, for example, 3 or more times, 5 or more times, or even 7 or more times. There is no particular limit on the upper limit of the number of times, and for example, the peeling force PS with the adhesive sheet 1 can be set to 1.n Continuous use within the range of no more than 3.0N / 50mm.

[0118] The release liner 13 after being peeled off can be recycled after being wound up into a roll.

[0119] The thickness of the pressure-sensitive adhesive sheet 1 is, for example, 2 to 70 μm, 2 to 50 μm, 5 to 40 μm, 10 to 30 μm, 10 to 25 μm, or further 10 to 20 μm.

[0120] The adhesive sheet 1 can be used, for example, in an optical laminate including an optical film. In other words, the adhesive sheet 1 can be an adhesive sheet for an optical laminate. The optical laminate can be an optical film with an adhesive sheet. It should be noted that the use of the adhesive sheet 1 is not limited to the above examples.

[0121] Reference Figure 3 Another example of the method for manufacturing the adhesive sheet of the present invention is described. In this example, a coating layer 12 of a photocurable composition is formed by a coating device 32 on one side of a long strip substrate sheet 11 continuously unrolled from a winding body 31. Next, a long strip release liner 13 continuously unrolled from a winding body 33 is arranged on the coating layer 12 to form a long strip of the first stack 10. Next, the first stack 10 is irradiated with light 14 from a lighting device 34 to form a long strip of adhesive sheet 1. Next, the release liner 13 is peeled off from the second stack 17 containing the adhesive sheet 1 and wound on a winding body 35. The above steps are implemented while conveying the substrate sheet 11 and the release liner 13. The release liner 13 after winding is reused. The third stack 15 formed by peeling the release liner 13 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 the adhesive sheet 1.

[0122] Reference Figure 4 Another example of the method for producing the adhesive sheet of the present invention is described. This example is similar to the method of producing the adhesive sheet of the present invention except that the release liner 13 after being peeled off from the second laminate 17 is not wound into a roll 35 but is reused in the production of the adhesive sheet 1. Figure 3 Same as the example. Figure 4 The method is particularly suitable for mass production of the adhesive sheet 1.

[0123] [Release liner]

[0124] 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.

[0125] [Method for producing optical film with pressure-sensitive adhesive sheet]

[0126] 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 adhesive sheet 1 formed by peeling off the release liner 13 from the second laminate 17 which sequentially includes a substrate sheet 11, an adhesive sheet 1 and a release liner 13, thereby forming an optical film 21 with an adhesive sheet. The optical film 21 with an adhesive sheet sequentially includes a substrate sheet 11, an adhesive sheet 1 and an optical film 2. The second laminate 17 can be formed by the above-mentioned process A. The peeling of the release liner 13 can be implemented in the form of the above-mentioned process B. The optical film 21 with an adhesive sheet can be used in an image display device, etc., directly or after peeling off the substrate sheet 11, for example, in the form of an optical laminate having an adhesive sheet 1 and an optical film 2. The optical laminate can be attached to an object (e.g., an image forming panel) via the adhesive sheet 1. However, it should be noted that the use of the optical film 21 with an adhesive sheet is not limited to the above-mentioned example. Another member such as an optical film may be arranged on the exposed surface 18 formed by peeling the substrate sheet 11 from the optical film 21 with an adhesive sheet. For example, an optical film 22 with an adhesive sheet including the optical film 2A, the adhesive sheet 1 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.

[0127] 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.

[0128] Reference Figure 7 Another example of the method for producing the optical film with the adhesive sheet of the present invention is described. Figure 3 The exposed surface 18 of the adhesive sheet 1 in the third laminate 15 formed by the method is provided with a long optical film 2, thereby forming a long optical film 21 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 1 and the formation of the pressure-sensitive adhesive sheet-attached optical film 21 can be performed continuously. Figure 7 The method is particularly suitable for mass production of the optical film 21 with an adhesive sheet.

[0129] 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.

[0130] 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.

[0131] 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.

[0132] 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.

[0133] 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.

[0134] 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.

[0135] 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.

[0136] 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.

[0137] 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.

[0138] The polarizing film may be a circular polarizing film.

[0139] 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.

[0140] 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] ).

[0141] 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.

[0142] 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.

[0143] 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.

[0144] 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 the optical films 21 and 22 with adhesive sheets to an image display panel. The bonding can be performed using the adhesive sheet 1. 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.

[0145] Example

[0146] 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.

[0147] (Manufacturing Example 1: Preparation of a photocurable composition)

[0148] 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.

[0149] (Manufacturing Example 2: Preparation of Release Liner A)

[0150] 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.

[0151] (Manufacturing Example 3: Preparation of Release Liner B)

[0152] 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.

[0153] (Manufacturing Example 4: Preparation of Release Liner C)

[0154] 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.

[0155] (Manufacturing Example 5: Preparation of Release Liner D)

[0156] 66.6 parts by weight of addition reaction curable silicone (KS-847H containing vinyl polysiloxane, 30% by weight toluene solution, manufactured by Shin-Etsu Chemical) and 0.2 parts by weight of curing catalyst (CAT-PL-50T containing 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 D. The concentration of the silicone solid content in the release agent composition D was 1.0% by weight. Next, the release agent composition D 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 D having a release layer (thickness 100 nm) on one side.

[0157] [Peel force PS 0 Evaluation]

[0158] The photocurable composition of Manufacturing Example 1 was applied to one side of a substrate sheet (Lumirror 38R75, a polyester film without a release layer, with a thickness of 38 μm) using an applicator to form a coating layer. Next, each release liner of Manufacturing Examples 2 to 5 was arranged on the formed coating layer to obtain a first laminate. The release liner was arranged so that the release layer and the coating layer were in contact. Next, the coating layer was exposed to light at an illumination of 2.4 mW / cm 2 And the accumulated light intensity is 2880mJ / cm 2 The coating layer was photocured by irradiating ultraviolet light (black light source) from the release liner side of the first laminate under the conditions of , thereby forming a second laminate a consisting of a substrate sheet, an adhesive sheet (thickness 20 μm) and a release liner.

[0159] A test piece of 220 mm in length and 50 mm in width was cut out from the formed second laminate a (the length direction was the coating direction of the photocurable composition). A 180° peeling test was performed using a tensile testing machine to peel off only the release liner in the length direction on the test piece in which one side of the substrate sheet was fixed as a whole to a SUS plate as a fixing plate. The peeling force PS 0 The conditions of the peel test were as described above.

[0160] [Peel force PS 1 ,PS 2 ,PS 3 Evaluation]

[0161] After a portion of the second laminate a in the longitudinal direction was removed by cutting so as not to include the sampling portion of the test piece, the release liner was peeled off for reuse. The second laminate b was formed in the same manner as the second laminate a except that the peeled release liner was used. The peel strength PS was the same as that of the second laminate a except that the test piece cut out from the second laminate b was used as the evaluation object.0 The evaluation of the peeling force PS 1 Next, the release liner was peeled off from the second laminate a, and the peeled release liner was reused to form a second laminate c (second reuse) from the second laminate b, and a second laminate d (third reuse) from the second laminate c in the same manner as the above method for forming the second laminate b. Except that the test pieces cut out from the second laminate c and the second laminate d were used as the evaluation objects, the peel force PS 0 The peeling force PS 2 and PS 3 An evaluation was conducted.

[0162] [Evaluation of Ease of Peeling of Release Liner in a State Where Only the Ends Are Fixed (Ease of Peeling)]

[0163] For the second laminate d, only the ends on both sides in the length direction were fixed to the fixed surface on one side of the substrate sheet using a double-sided adhesive tape, and the release liner was peeled off from the above-mentioned end on one side. Based on the state of this peeling, the ease of peeling was determined as follows.

[0164] A: The portion of the second laminate that was not fixed did not lift up from the fixed surface, and the release liner could be easily peeled off.

[0165] B: The portion of the second laminate that was not fixed was slightly lifted from the fixed surface, but the release liner could be peeled off.

[0166] C: The portion of the second laminate that was not fixed was lifted from the fixed surface, so it was difficult to peel off the release liner.

[0167] The evaluation results of the release force and the ease of release of each release liner are shown in Table 1 below.

[0168] [Table 1]

[0169]

[0170] Industrial Applicability

[0171] 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: A step A of irradiating a laminate including a substrate sheet, a coating layer containing a photocurable composition, and the release liner in this order with light using a release liner to form a pressure-sensitive adhesive sheet from the coating layer; and step B of peeling the release liner from the pressure-sensitive adhesive sheet, The step A and the step B are repeatedly performed using the release liner released in the step B, As the release liner, a sheet having a peeling force PS3 with the PSA sheet of less than 1.0 N / 50 mm measured after peeling from the PSA sheet three times, counting from an unused state, was used.

2. The method for producing a pressure-sensitive adhesive sheet according to claim 1, wherein: The release liner has a peeling force PS0 with the pressure-sensitive adhesive sheet measured in an unused state of not less than 0.01 N / 50 mm.

3. The method for producing a pressure-sensitive adhesive sheet according to claim 1, wherein: The ratio PS3 / PS0 of the release force PS3 to the release force PS0 of the release liner is 10 or less, and the release force PS0 is the release force with the pressure-sensitive adhesive sheet measured in an unused state.

4. The method for producing a pressure-sensitive adhesive sheet according to claim 1, wherein: The ratio PS1 / PS0 of the release force PS1 of the release liner to the release force PS0 is less than 10, the release force PS0 is the release force with the adhesive sheet measured in an unused state, and the release force PS1 is the release force with the adhesive sheet measured after being peeled off from the adhesive sheet once, counted from the unused state.

5. The method for producing a pressure-sensitive adhesive sheet according to claim 1, wherein: The release liner has a release layer on the surface of the coating layer. The release layer has a thickness of 110 nm or less.

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

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

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

9. A method for manufacturing an optical film with an adhesive sheet, the method comprising: An optical film is disposed on the exposed surface of the pressure-sensitive adhesive sheet formed by the production method according to any one of claims 1 to 8 to form an optical film with a pressure-sensitive adhesive sheet.

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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