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

Abstract

Provided is a technique suitable for producing an adhesive sheet with low environmental burden. Provided is a method for producing an adhesive sheet, comprising: laminating an elongated release liner on an elongated coating layer while conveying the elongated release liner in the longitudinal direction in order to form an elongated laminate comprising an elongated substrate sheet, an elongated coating layer containing a photocurable composition, and an elongated release liner in this order; and irradiating the laminated body with light to form the adhesive sheet from the coating layer. The release liner is a sheet having a release force with the adhesive sheet of 1.0 N / 50 mm or less as measured in a state of being exposed for 24 hours in an atmosphere in which the release liner is laminated on the coating layer, and a release force with the adhesive sheet of 0.1 N / 50 mm or less as measured before the exposure for 24 hours is performed.

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] In order to form an elongated laminated body including an elongated substrate sheet, an elongated coating layer containing a photocurable composition, and an elongated release liner in this order, the elongated release liner is laminated on the elongated coating layer while being conveyed in the longitudinal direction; and

[0012] irradiating the laminate with light to form a pressure-sensitive adhesive sheet from the coating layer;

[0013] The release liner used herein has a peeling force with the adhesive sheet of 1.0 N / 50 mm or less measured when the release liner is laminated on the coating layer and exposed to the atmosphere for 24 hours, and a peeling force with the adhesive sheet of 0.1 N / 50 mm or less measured before the 24-hour exposure.

[0014] In another aspect, the present invention provides a method for manufacturing an optical film with an adhesive sheet, the method comprising:

[0015] 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.

[0016] Effects of the Invention

[0017] 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

[0018] 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.

[0019] 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.

[0020] Figure 3 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.

[0021] Figure 4 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.

[0022] 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. DETAILED DESCRIPTION

[0023] The method for producing a pressure-sensitive adhesive sheet according to the first aspect of the present invention includes:

[0024] In order to form an elongated laminated body including an elongated substrate sheet, an elongated coating layer containing a photocurable composition, and an elongated release liner in this order, the elongated release liner is laminated on the elongated coating layer while being conveyed in the longitudinal direction; and

[0025] irradiating the laminate with light to form a pressure-sensitive adhesive sheet from the coating layer;

[0026] The release liner used herein has a peeling force with the adhesive sheet of 1.0 N / 50 mm or less measured when the release liner is laminated on the coating layer and exposed to the atmosphere for 24 hours, and a peeling force with the adhesive sheet of 0.1 N / 50 mm or less measured before the 24-hour exposure.

[0027] In a second aspect of the present invention, for example, the method for producing a pressure-sensitive adhesive sheet according to the first aspect further comprises:

[0028] While the side of the long strip of release liner in contact with the long strip of coating layer is exposed to the atmosphere, lamination of the release liner to the coating layer is interrupted for 1 to 24 hours; and

[0029] After the interruption, lamination of the release liner onto the coating layer is restarted without removing the portion including the surface exposed to the atmosphere from the release liner.

[0030] 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,

[0031] The long release liner is continuously unwound from a roll and laminated on the coating layer.

[0032] 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,

[0033] The photocurable composition includes a monomer group containing a (meth)acrylic monomer and / or a partial polymer of the monomer group.

[0034] In a fifth aspect of the present invention, for example, in the method for producing a pressure-sensitive adhesive sheet according to the fourth aspect,

[0035] The (meth)acrylic monomer includes a carboxyl group-containing monomer.

[0036] The method for producing an optical film with a pressure-sensitive adhesive sheet according to a sixth aspect of the present invention includes:

[0037] 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 fifth aspects.

[0038] In a seventh aspect of the present invention, for example, in the method for producing an optical film with a pressure-sensitive adhesive sheet according to the sixth aspect,

[0039] The optical film includes at least one film selected from the group consisting of a polarizing film and a retardation film.

[0040] 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.

[0041] If long strip substrate sheet and release liner are used to manufacture long strip adhesive sheet, it is effective. However, when the manufacturing line stops due to a fault, etc., the quality of the adhesive sheet may be reduced sometimes after restarting. In order to maintain quality, each time the manufacturing line stops, all or part of the substrate sheet, coating layer, release liner and their laminates have to be removed and discarded. The inventor has thought of further reducing the environmental burden in the manufacturing process of the adhesive sheet by avoiding the above-mentioned waste caused by the long-term stop of the manufacturing line, and has studied and completed the present invention based on this idea. According to the research of the inventor, the release liner of the side (hereinafter, "release surface") connected to the coating layer is exposed to the manufacturing atmosphere for a long time relative to the release force of the adhesive sheet. Therefore, it is easy to cause the poor release of the quality of the adhesive sheet. It can be inferred that the increase in release force is attributed to the functional groups and free radicals of the release surface due to continuous exposure to the manufacturing atmosphere. The release liner whose release force is suppressed due to exposure to the manufacturing atmosphere is not only suitable for reducing the waste amount of the release liner, but also suitable for reducing the waste amount of the coating layer and the substrate sheet stacked therewith. Specifically, the peeling force PS from the pressure-sensitive adhesive sheet measured after exposure for 24 hours was confirmed. 24 A release liner having a peel force PS0 of 1.0 N / 50 mm or less and a peel force PS0 with the adhesive sheet of 0.1 N / 50 mm or less measured before the above exposure is suitable for avoiding the above disposal.

[0042] [Method for producing adhesive sheet]

[0043] Reference Figure 1An example of a method for manufacturing an adhesive sheet of the present invention is described. In this example, a long coating layer 12 containing a photocurable composition is formed by a coating device 32 on one side of a long substrate sheet 11 continuously unrolled from a winding body 31. The coating layer 12 is formed while the substrate sheet 11 is conveyed in the length direction. Next, the long release liner 13 continuously unrolled from the winding body 33 is conveyed in the length direction while being stacked on the coating layer 12. Thus, a long first laminate 10 is formed, which includes a substrate sheet 11, a coating layer 12 and a release liner 13 in sequence. During the period from when the release liner 13 is continuously unrolled from the winding body 33 until it is stacked on the coating layer 12, the release surface 133 of the release liner 13 is exposed to the manufacturing atmosphere. Next, the first laminate 10 is irradiated with light 14 from a lighting device 34, and a long adhesive sheet 1 is formed from the coating layer 12. The light 14 passes through the release liner 13 and reaches the coating layer 12, thereby curing the coating layer 12. However, it should be noted that the irradiation of the 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. The formed adhesive sheet 1 is sandwiched between the substrate sheet 11 and the release liner 13 to constitute a part of the second laminate 17 until the release liner 13 is peeled off. The third laminate 15 formed by peeling off the release liner 13 can be used, for example, for an optical film with an adhesive sheet or its production.

[0044] (Release liner)

[0045] The release liner 13 used was the following sheet: the release force PS with the pressure-sensitive adhesive sheet 1 measured in a state where the release liner 13 was exposed to an atmosphere in which the release liner 13 was laminated on the coating layer 12 (hereinafter, “lamination atmosphere”) for 24 hours. 24 A sheet having a peeling force PS0 of 1.0 N / 50 mm or less and a peeling force PS0 with the pressure-sensitive adhesive sheet 1 measured before the above-mentioned 24-hour exposure is 0.1 N / 50 mm or less.

[0046] Release force PS of release liner 13 24 The peel force PS may be 0.8 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, 0.15 N / 50 mm or less, 0.1 N / 50 mm or less, and may be 0.08 N / 50 mm or less. 24 The lower limit of is, for example, 0.01 N / 50 mm or more, may be 0.03 N / 50 mm or more, and may be 0.05 N / 50 mm or more.

[0047] The release force PS0 of the release liner 13 may be 0.09 N / 50 mm or less, 0.08 N / 50 mm or less, 0.07 N / 50 mm or less, 0.06 N / 50 mm or less, or even 0.05 N / 50 mm or less. The lower limit of the release force PS0 is, for example, 0.01 N / 50 mm or more, 0.02 N / 50 mm or more, or even 0.03 N / 50 mm or more.

[0048] Release force PS of release liner 13 24 Ratio PS to peel force PS0 24 / PS0 can be 10 or less, 8 or less, 6 or less, 5 or less, 4 or less, 3 or less, 2.5 or less, 2 or less, 1.7 or less, 1.5 or less, and further can be 1.4 or less. 24 The lower limit of / PS0 is, for example, 1.01 or more, and may be 1.05 or more, 1.1 or more, 1.15 or more, 1.2 or more, or further may be 1.25 or more.

[0049] Peel force PS 24 Evaluation can be performed as follows: a test piece with a width of 50 mm is prepared by cutting out the second laminate 17 formed by using the release liner after being exposed to the lamination atmosphere for 24 hours, and a 180° peeling test is performed in which only the release liner 13 is peeled off from the prepared test piece. The peeling force PS0 can be evaluated by comparing the peeling force PS0 with the test piece prepared by using the release liner before the above-mentioned 24-hour exposure. 24 The evaluation is performed in the same manner. The peel test is performed after about 0.5 to 1 hour has passed since the adhesive sheet 1 was formed. From the formation of the adhesive sheet 1 until the peel test is performed, the second laminate 17 and the test piece are placed in an atmosphere of 23°C ± 5°C. The peeling speed of the peel test is set to 300 mm / min, and the test temperature is set to 23°C ± 5°C. In the case where the width of the second laminate 17 does not meet 50 mm, the measured value at the original width can be converted to a value when the width is 50 mm. The width direction of the substrate sheet 11 and the release liner 13 can be used as the width direction of the test piece.

[0050] For determination of peel force PS 24The exposure of the release liner can be carried out by bringing the release liner in a state where the release surface is not exposed, typically in the state of a roll, so that the release surface is in contact with the stacking atmosphere, typically by continuously unwinding it from the roll in the stacking atmosphere. The second stack 17 is formed after the exposure is completed, preferably within 1 hour, and more preferably within 30 minutes. The formation of the second stack 17 for measuring the release force PS0 is carried out using a release liner in a state where the release surface is not exposed, typically in the state of a roll, and limiting the time from contact with the stacking atmosphere to lamination on the coating layer 12 to preferably within 5 minutes. In normal operation of the manufacturing line, the time that the release surface of the release liner is exposed to the stacking atmosphere is generally within 5 minutes. The stoppage of the manufacturing line caused by a malfunction or the like is generally eliminated within a period of about 1 to 24 hours.

[0051] Typically, the stacking atmosphere is an air atmosphere. The air atmosphere may be a clean atmosphere after foreign matter such as dust is removed by an air filter or the like. The clean atmosphere is represented by the cleanliness level specified in Japanese Industrial Standard (JIS) B9920, which may be below level 8, below level 7, below level 6, and further below level 5. The temperature of the stacking atmosphere is usually 23±10°C, and may be 23±5°C.

[0052] Peeling force PS0, PS 24 PS 24 / PS0 may change 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.

[0053] An example of the base material of the release liner 13 (hereinafter, "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.

[0054] The release liner 13 preferably has excellent light 14 transmittance.

[0055] The thickness of the release liner 13 is, for example, 10 to 200 μm, or 25 to 150 μm.

[0056] 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 2The release liner 13 can be used in such a manner that the release layer 132 constitutes a release surface.

[0057] 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.

[0058] 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.

[0059] 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.

[0060] 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.

[0061] 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.

[0062] 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.

[0063] 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.

[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 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.

[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, 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.

[0066] (Base sheet)

[0067] 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 can be contained in the backing base.

[0068] The base sheet 11 may have the transmittance of the light 14 or may have the same degree of transmittance of the light 14 as the release liner 13 .

[0069] The thickness of the base sheet 11 is, for example, 10 to 200 μm, or 25 to 150 μm.

[0070] 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.

[0071] 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 .

[0072] (Photocurable composition)

[0073] 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.

[0074] 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.

[0075] 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.

[0076] 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.

[0077] 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 used. 24 The release liner 13 having a PS0 below the above-given value is particularly advantageous when the photocurable composition contains a carboxyl group-containing monomer.

[0078] 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 may 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.

[0079] 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.

[0080] 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.

[0081] 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.

[0082] 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.

[0083] 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, Monomers having polymerizable functional groups such as oxazoline group, hydrazine group, methylol group, etc. Polyfunctional monomers are preferably monomers having two or more C═C bonds in one molecule.

[0084] 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.

[0085] 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.

[0086] 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.

[0087] 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.

[0088] 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 .

[0089] (First Laminated Body and Formation thereof)

[0090] exist Figure 1 In the example, after forming the elongated coating layer 12 on the elongated substrate sheet 11, the elongated release liner 13 is arranged on the formed coating layer 12, thereby forming the first laminate 10. As long as the elongated first laminate 10 including the elongated substrate sheet 11, the elongated coating layer 12 and the elongated release liner 13 in sequence and the release liner 13 is stacked on the coating layer 12 can be formed, the method of forming the first laminate 10 is not limited to this example. The first laminate 10 can also be formed by forming the elongated coating layer 12 on the elongated release liner 13 and then arranging the elongated substrate sheet 11 on the formed coating layer 12. In addition, the first laminate 10 can be formed by coating the photocurable composition in a manner that allows it to flow into the following space, which is a space between the elongated substrate sheet 11 and the elongated release liner 13 that are maintained at a given interval in a manner that the main surfaces face each other. In these methods as well, the long release liner 13 is laminated on the long coating layer 12 while being conveyed in the longitudinal direction.

[0091] The long strip coating layer 12 can be formed by various coating methods such as roll coating, lick roll coating, gravure coating, reverse coating, roller brush, spray coating, dip roll coating, rod coating, blade coating, air knife coating, shower coating, die lip coating, die coating, etc. The coating device 32 can be a device capable of implementing these coating methods.

[0092] 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.

[0093] exist Figure 1In the example of , the long strip release liner 13 is continuously unwound from the state of the roll 33 and is provided for the formation of the long strip first laminate 10. In other words, the long strip release liner 13 is continuously unwound from the state of the roll 33 and is laminated on the long strip coating layer 12. In addition, the long strip base sheet 11 is continuously unwound from the state of the roll 31 and is provided for the formation of the long strip first laminate 10. These methods are particularly suitable for mass production of the adhesive sheet 1.

[0094] In the release liner 13, the increase in the release force caused by the release surface 133 being exposed to the laminating atmosphere is suppressed, so that after the production line is stopped due to a fault or the like, the formation of the first laminate 10 can be restarted without removing the portion including the release surface exposed to the laminating atmosphere from the release liner 13. From this aspect, the production method of the present invention may further include: interrupting the lamination of the release liner 13 onto the coating layer 12 for 1 to 24 hours in a state where the surface of the long-strip release liner 13 in contact with the long-strip coating layer 12 is exposed to the laminating atmosphere; and restarting the lamination of the release liner 13 onto the coating layer 12 without removing the portion including the surface exposed to the laminating atmosphere from the release liner 13 after the interruption.

[0095] The length of the first laminate 10 formed may be 1000 m or longer, 2000 m or longer, or even 3000 m or longer. To form the first laminate 10 having the above length, a base sheet 11 and a release liner 13 having a corresponding length or longer may be used.

[0096] 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.

[0097] (Radiation of light)

[0098] 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 34 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.

[0099] The irradiation of the light 14 may be continuous or intermittent.

[0100] 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 .

[0101] (Second laminate)

[0102] In the second laminate 17 formed by irradiation with the light 14, the release force of the release liner 13 with respect to the adhesive sheet 1 may be smaller than the release force of the substrate sheet 11 with respect to the adhesive sheet 1. The release force of the substrate sheet 11 with respect to the adhesive sheet 1 may be, 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.

[0103] The length of the formed second stack 17 may be 1000 m or longer, 2000 m or longer, or even 3000 m or longer. The second stack 17 may be distributed in the form of a wound body or in the form of a processed sheet, for example.

[0104] (Adhesive sheet 1)

[0105] 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.

[0106] 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.

[0107] 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.

[0108] The length of the formed pressure-sensitive adhesive sheet 1 may be 1000 m or longer, 2000 m or longer, or even 3000 m or longer. The pressure-sensitive adhesive sheet 1 may be distributed in the form of, for example, the second laminate 17 or a pressure-sensitive adhesive sheet-attached optical film.

[0109] 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.

[0110] [Release liner]

[0111] 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.

[0112] [Method for producing optical film with pressure-sensitive adhesive sheet]

[0113] Reference Figure 3 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, to form 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 manufacturing method of the above-mentioned adhesive sheet 1. The second laminate 17 can be in the form of a long strip or a single sheet. 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 disposed 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 an optical film 2A, an adhesive sheet 1, and an optical film 2B in this order may be formed (see Figure 4 ). The optical films 2A and 2B may be the same or different from each other.

[0114] 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.

[0115] Reference Figure 5 Another example of the method for producing the optical film with the adhesive sheet of the present invention is described. Figure 1 The exposed surface 18 of the adhesive sheet 1 in the elongated third laminate 15 formed by the method is provided with the elongated optical film 2, thereby forming an elongated 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 5 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 5 The method is particularly suitable for mass production of the optical film 21 with an adhesive sheet.

[0116] 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.

[0117] 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.

[0118] 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.

[0119] 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.

[0120] 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.

[0121] 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.

[0122] 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.

[0123] 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.

[0124] 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.

[0125] The polarizing film may be a circular polarizing film.

[0126] 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.

[0127] 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] ).

[0128] 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.

[0129] 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.

[0130] 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.

[0131] 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.

[0132] Example

[0133] 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.

[0134] (Manufacturing Example 1: Preparation of a photocurable composition)

[0135] 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.

[0136] (Manufacturing Example 2: Preparation of Release Liner A)

[0137] 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 long 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 long release liner A having a release layer (thickness 60 nm) on one side. The produced release liner A was put into a state of a roll so that the surface on the release layer side used as the release surface was not exposed until the release force was evaluated.

[0138] (Manufacturing Example 3: Preparation of Release Liner B)

[0139] A long release liner B having a release layer (thickness 120 nm) on one side was prepared in the same manner as in Production Example 2 except that the thickness of the release agent composition A applied to the liner was changed. The prepared release liner B was wound up so that the surface on the release layer side used as the release surface was not exposed until the release force was evaluated.

[0140] (Manufacturing Example 4: Preparation of Release Liner C)

[0141] 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 curing catalyst (CAT-PL-50T containing platinum catalyst, manufactured by Shin-Etsu Chemical) and a toluene / hexane mixed solvent (volume ratio 1:1) as a diluent were mixed 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 long strip of backing substrate (Lumirror 38R75 as a polyester film, 38 μm thick) by a wire bar, and heated at 130° C. for 1 minute to prepare a long strip of release liner C having a release layer (100 nm thick) on one side. The prepared release liner C was wound in a state so that the surface on the release layer side used as the release surface was not exposed until it was subjected to the evaluation of the release force.

[0142] (Manufacturing Example 5: Preparation of Release Liner D)

[0143] 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) and a toluene / hexane mixed solvent (volume ratio 1:1) as a diluent were mixed 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 long liner substrate (Lumirror 38R75 as a polyester film, 38 μm thick) by a wire bar, and heated at 130° C. for 1 minute to prepare a long release liner D having a release layer (100 nm thick) on one side. The prepared release liner D was wound in a state so that the surface on the release layer side used as the release surface was not exposed until it was subjected to the evaluation of the release force.

[0144] [Peeling force PS0 and PS 24 's evaluation]

[0145] The photocurable composition of Manufacturing Example 1 was applied to one side of a long strip of substrate sheet (Lumirror 38R75 as a polyester film without a release layer, thickness 38 μm) using a coater to form a long strip of coating layer. Next, each release liner of Manufacturing Examples 2 to 5 was arranged on the formed coating layer to obtain a long strip of the first laminate. The release liner was arranged in such a way that the release layer and the coating layer were in contact. The formation of the coating layer and the arrangement of the release liner were carried out in an atmosphere of 23°C. Each release liner used a release liner just after being continuously unwound from a roll (for evaluation of release force PS0) and a release liner after being exposed to an atmosphere of 23°C for 24 hours in a state where the surface on the release layer side was exposed after being continuously unwound from a roll (for evaluation of release force PS0). 24 Next, at an illuminance of 2.4 mW / cm 2 And the accumulated light intensity is 2880mJ / cm 2 The first laminate was irradiated with ultraviolet light (black light source) from the release liner side under the conditions of , so that the coating layer was photocured to form a second laminate consisting of a substrate sheet, an adhesive sheet (thickness 20 μm) and a release liner. For the second laminate used to evaluate the release force PS0, the time when the release liner was continuously unwound from the roll until it was arranged on the coating layer was within 5 minutes of the time when the surface on the release layer side was in contact with the atmosphere. In addition, for the laminate used to evaluate the release force PS0, the release liner was continuously unwound from the roll until it was arranged on the coating layer. 24 The second laminate was formed within 30 minutes after the release liner was exposed to the atmosphere. Next, a test piece of 220 mm in length and 50 mm in width was cut out from the formed second laminate. A 180° peeling test was performed on the test piece using a tensile testing machine, in which the release liner was peeled off only in the longitudinal direction. The peeling forces PS0 and PS 24 The conditions of the peel test were as described above.

[0146] The evaluation results of the release force of each release liner are shown in Table 1 below.

[0147] [Table 1]

[0148]

[0149] Industrial Applicability

[0150] 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: In order to form a long laminated body including a long substrate sheet, a long coating layer containing a photocurable composition, and a long release liner in this order, the long release liner is laminated on the long coating layer while being conveyed in the longitudinal direction; and irradiating the laminate with light to form a pressure-sensitive adhesive sheet from the coating layer; The release liner used herein has a peeling force with the adhesive sheet of 1.0 N / 50 mm or less measured when the release liner is laminated on the coating layer and exposed to the atmosphere for 24 hours, and a peeling force with the adhesive sheet of 0.1 N / 50 mm or less measured before the 24-hour exposure.

2. The method for producing an adhesive sheet according to claim 1, further comprising: While the side of the long strip of release liner in contact with the long strip of coating layer is exposed to the atmosphere, laminating the release liner on the coating layer is interrupted for 1 to 24 hours; and After the interruption, lamination of the release liner onto the coating layer is restarted without removing the portion including the surface exposed to the atmosphere from the release liner.

3. The method for producing a pressure-sensitive adhesive sheet according to claim 1, wherein: The long release liner is continuously unwound from a roll and laminated on the coating layer.

4. 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.

5. The method for producing a pressure-sensitive adhesive sheet according to claim 4, wherein: The (meth)acrylic monomer includes a carboxyl group-containing monomer.

6. A method for manufacturing an optical film with an adhesive sheet, the method comprising: An optical film with a pressure-sensitive adhesive sheet is formed by placing an optical film on the exposed surface of the pressure-sensitive adhesive sheet formed by the production method according to any one of claims 1 to 5 to form an optical film with a pressure-sensitive adhesive sheet.

7. The method for producing an optical film with a pressure-sensitive adhesive sheet according to claim 6, wherein: The optical film includes at least one film selected from a polarizing film and a phase difference film.

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