WO2024019159A1 - Adhesive sheet and optical layered product - Google Patents

Adhesive sheet and optical layered product Download PDF

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Publication number
WO2024019159A1
WO2024019159A1 PCT/JP2023/026820 JP2023026820W WO2024019159A1 WO 2024019159 A1 WO2024019159 A1 WO 2024019159A1 JP 2023026820 W JP2023026820 W JP 2023026820W WO 2024019159 A1 WO2024019159 A1 WO 2024019159A1
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WO
WIPO (PCT)
Prior art keywords
adhesive sheet
weight
group
monomer
parts
Prior art date
Application number
PCT/JP2023/026820
Other languages
French (fr)
Japanese (ja)
Inventor
赳彦 三嶋
智之 木村
普史 形見
Original Assignee
日東電工株式会社
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Filing date
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Publication of WO2024019159A1 publication Critical patent/WO2024019159A1/en

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00—Layered products comprising a layer of synthetic resin
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00—Layered products comprising a layer of synthetic resin
    • B32B27/40—Layered products comprising a layer of synthetic resin comprising polyurethanes
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B7/00—Layered products characterised by the relation between layers; Layered products characterised by the relative orientation of features between layers, or by the relative values of a measurable parameter between layers, i.e. products comprising layers having different physical, chemical or physicochemical properties; Layered products characterised by the interconnection of layers
    • B32B7/02—Physical, chemical or physicochemical properties
    • B32B7/023—Optical properties
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J133/00—Adhesives based on homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by only one carboxyl radical, or of salts, anhydrides, esters, amides, imides, or nitriles thereof; Adhesives based on derivatives of such polymers
    • C09J133/04—Homopolymers or copolymers of esters
    • C09J133/14—Homopolymers or copolymers of esters of esters containing halogen, nitrogen, sulfur or oxygen atoms in addition to the carboxy oxygen
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J175/00—Adhesives based on polyureas or polyurethanes; Adhesives based on derivatives of such polymers
    • C09J175/04—Polyurethanes
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J201/00—Adhesives based on unspecified macromolecular compounds
    • C09J201/02—Adhesives based on unspecified macromolecular compounds characterised by the presence of specified groups, e.g. terminal or pendant functional groups
    • C09J201/06—Adhesives based on unspecified macromolecular compounds characterised by the presence of specified groups, e.g. terminal or pendant functional groups containing oxygen atoms
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J4/00—Adhesives based on organic non-macromolecular compounds having at least one polymerisable carbon-to-carbon unsaturated bond ; adhesives, based on monomers of macromolecular compounds of groups C09J183/00 - C09J183/16
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J7/00—Adhesives in the form of films or foils
    • C09J7/30—Adhesives in the form of films or foils characterised by the adhesive composition
    • C09J7/38—Pressure-sensitive adhesives [PSA]
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/30—Polarising elements
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B33/00—Electroluminescent light sources
    • H05B33/02—Details
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K50/00—Organic light-emitting devices
    • H10K50/10—OLEDs or polymer light-emitting diodes [PLED]
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K59/00—Integrated devices, or assemblies of multiple devices, comprising at least one organic light-emitting element covered by group H10K50/00
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K59/00—Integrated devices, or assemblies of multiple devices, comprising at least one organic light-emitting element covered by group H10K50/00
    • H10K59/10—OLED displays

Definitions

  • the present invention relates to an adhesive sheet and an optical laminate.
  • Various image display devices typified by liquid crystal display devices and electroluminescent (EL) display devices, generally include an optical laminate that includes an optical film such as a polarizing film and an adhesive sheet.
  • Adhesive sheets are usually used for bonding between optical films included in an optical laminate and for bonding an optical laminate and an image display panel.
  • a typical pressure-sensitive adhesive sheet is a sheet obtained by curing a group of monomers including acrylic monomers, silicone monomers, etc. by polymerization and crosslinking.
  • Patent Document 1 discloses an example of an adhesive sheet.
  • a pressure-sensitive adhesive sheet is produced by irradiating a pressure-sensitive adhesive composition with light.
  • a typical pressure-sensitive adhesive sheet is manufactured, for example, by the following thermosetting method.
  • a crosslinking agent and the like are added to a polymer produced by polymerizing a polymerizable monomer in an organic solvent to prepare an adhesive composition.
  • This adhesive composition is applied to a base material such as a release liner, and the organic solvent is removed by heating to form a sheet.
  • a pressure-sensitive adhesive sheet can be manufactured by performing heat aging as necessary to complete crosslinking. In this manufacturing process, it is necessary to burn a large amount of fuel such as LNG in order to generate the thermal energy necessary for heat removal of the solvent and heat aging. Furthermore, if the organic solvent that has been removed by heating is released into the atmosphere as it is, it may have a significant negative impact on the surrounding environment.
  • organic solvents are often burned in a deodorizing furnace or the like before being released.
  • the organic solvent itself will also be converted into CO 2 and released into the atmosphere through combustion, resulting in a manufacturing process with extremely large CO 2 emissions. be.
  • thermosetting method an isocyanate-based crosslinking agent is usually blended into the adhesive composition, and the anchoring force between the adhesive sheet and the optical film tends to improve due to the isocyanate-based crosslinking agent.
  • an optical laminate is produced using a pressure-sensitive adhesive sheet formed by a photocuring method, the anchoring force between the pressure-sensitive adhesive sheet and the optical film is small, and peeling tends to occur between the pressure-sensitive adhesive sheet and the optical film.
  • the present invention provides a pressure-sensitive adhesive sheet that is formed from a photocurable composition and is suitable for adjusting the anchoring force with an optical film to a large value.
  • the gap between the pressure-sensitive adhesive sheet and the optical film is greater than when using a pressure-sensitive adhesive sheet formed by a thermosetting method.
  • peeling is explained by the fact that when an adhesive sheet formed by a thermosetting method is laminated with an optical film, the adhesive sheet hardens further on the surface of the optical film. This is presumed to be due to the fact that curing hardly progresses after bonding. This problem can occur particularly prominently when the optical film includes a uniaxially stretched film such as a polarizer or when the thickness of the adhesive sheet is 30 ⁇ m or less.
  • the present inventors further investigated based on the above findings, and even in a photocurable composition containing almost no isocyanate-based crosslinking agent, the amount of the ether group-containing monomer and the formula of FOX can be changed.
  • the present inventors have discovered that by appropriately adjusting the glass transition temperature calculated using the above-mentioned method, the anchoring force between the adhesive sheet and the optical film formed from the photocurable composition can be adjusted to a large value, and the present invention has been completed based on this finding. Ta.
  • the present invention A pressure-sensitive adhesive sheet formed from a photocurable composition containing a monomer group and/or a partial polymer of the monomer group,
  • the amount of the isocyanate crosslinking agent in the photocurable composition is less than 0.05 parts by weight based on the total of 100 parts by weight of the monomer group and the partial polymer
  • the monomer group includes an ether group-containing monomer, Out of 100 parts by weight of the monomer group, the amount of the ether group-containing monomer is 25 parts by weight or more,
  • the present invention provides a pressure-sensitive adhesive sheet in which, when a polymer is synthesized from the monomer group, the glass transition temperature of the polymer calculated from the FOX formula is higher than -60°C.
  • an optical film containing at least one selected from the group consisting of a polarizing film and a retardation film an optical laminate comprising:
  • a pressure-sensitive adhesive sheet that is formed from a photocurable composition and is suitable for adjusting the anchoring force with an optical film to a large value.
  • FIG. 1 is a cross-sectional view schematically showing an example of a pressure-sensitive adhesive sheet of the present invention.
  • FIG. 3 is a schematic diagram for explaining a method for measuring the amount of creep on a pressure-sensitive adhesive sheet.
  • FIG. 3 is a schematic diagram for explaining a method for measuring the amount of creep on a pressure-sensitive adhesive sheet.
  • BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram for explaining an example of a method for manufacturing a pressure-sensitive adhesive sheet of the present invention.
  • BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram for explaining an example of a method for manufacturing a pressure-sensitive adhesive sheet of the present invention.
  • BRIEF DESCRIPTION OF THE DRAWINGS FIG.
  • FIG. 1 is a schematic diagram for explaining an example of a method for manufacturing a pressure-sensitive adhesive sheet of the present invention.
  • FIG. 1 is a cross-sectional view schematically showing an example of an optical laminate of the present invention.
  • FIG. 1 is a cross-sectional view schematically showing an example of an optical laminate of the present invention.
  • the adhesive sheet according to the first aspect of the present invention is A pressure-sensitive adhesive sheet formed from a photocurable composition containing a monomer group and/or a partial polymer of the monomer group,
  • the amount of the isocyanate crosslinking agent in the photocurable composition is less than 0.05 parts by weight based on the total of 100 parts by weight of the monomer group and the partial polymer
  • the monomer group includes an ether group-containing monomer, Out of 100 parts by weight of the monomer group, the amount of the ether group-containing monomer is 25 parts by weight or more,
  • the glass transition temperature of the polymer calculated from the FOX formula is higher than -60°C.
  • the relative permittivity of the partial polymer at a frequency of 100 Hz is 3.8 or more.
  • the ether group-containing monomer includes an alkoxy group-containing monomer.
  • the alkoxy group-containing monomer is represented by the following formula (1).
  • R 1 is a hydrogen atom or a methyl group
  • R 2 is an alkyl group
  • n is an integer from 1 to 30.
  • the alkoxy group-containing monomer includes 2-methoxyethyl acrylate.
  • the ether group-containing monomer has a ring structure.
  • the glass transition temperature is 0° C. or lower.
  • the photocurable composition does not contain an isocyanate-based crosslinking agent.
  • the content of the solvent in the photocurable composition is 5% by weight or less.
  • the adhesive sheet according to any one of the first to ninth aspects has a surface that has been subjected to surface modification treatment.
  • the optical laminate according to the eleventh aspect of the present invention is An adhesive sheet according to any one of the first to tenth aspects, an optical film containing at least one selected from the group consisting of a polarizing film and a retardation film; Equipped with.
  • the anchoring force between the adhesive sheet and the optical film is 10.0 N/25 mm or more.
  • the adhesive sheet 1 in FIG. 1 is formed from a photocurable composition containing a monomer group and/or a partial polymer of the monomer group.
  • the amount of the isocyanate crosslinking agent in the photocurable composition is less than 0.05 parts by weight based on the total of 100 parts by weight of the monomer group and the partial polymer.
  • the photocurable composition does not contain 0.05 parts by weight or more of an isocyanate-based crosslinking agent based on a total of 100 parts by weight of the monomer group and the partial polymer.
  • the monomer group includes an ether group-containing monomer, and the blending amount of the ether group-containing monomer is 25 parts by weight or more out of 100 parts by weight of the monomer group.
  • the glass transition temperature Tg of the polymer A calculated from the FOX formula is higher than -60°C.
  • the glass transition temperature Tg of the polymer A tends to correlate with the glass transition temperature of the adhesive sheet 1.
  • the glass transition temperature Tg is, for example, -55°C or higher, and may be -50°C or higher.
  • the upper limit of the glass transition temperature Tg is not particularly limited, and is, for example, 0°C or lower, may be -20°C or lower, or may be -40°C or lower.
  • Tg is the glass transition temperature (K) of polymer A.
  • w 1 , w 2 , . . . w m are each the weight fraction of each monomer in the monomer group.
  • Tg 1 , Tg 2 , . . . Tg m are the glass transition temperatures (K) of a homopolymer of each monomer, respectively.
  • w 1 is the weight fraction of the first monomer in the monomer group
  • Tg 1 is the glass transition temperature (K) of a homopolymer of the first monomer.
  • the glass transition temperature Tg (° C.) of the polymer A can be determined by calculating the glass transition temperature (K) of the polymer A from the formula (I) and converting it into units.
  • the adhesive sheet 1 has surfaces 1a and 1b facing each other.
  • the adhesive sheet 1 is attached to an optical film via the surface 1a, and the adhesive sheet 1 is attached to an image display panel via the surface 1b.
  • the surface 1a of the adhesive sheet 1 that contacts the optical film may or may not be subjected to a surface modification treatment.
  • the surface 1a subjected to the surface modification treatment there is a tendency that the anchoring force between the adhesive sheet 1 and the optical film can be improved.
  • the surface 1b of the adhesive sheet 1 is preferably not subjected to surface modification treatment. Examples of surface modification treatments include corona treatment, plasma treatment, excimer treatment, and flame treatment.
  • the surface 1a is preferably subjected to corona treatment as surface modification treatment.
  • the surface modification treatment may be performed in an inert gas atmosphere.
  • the risk of ignition of the remaining monomer can be reduced.
  • Specific examples of the inert gas include nitrogen and argon.
  • the surface modification treatment may be carried out under normal pressure (1 atmosphere).
  • the conditions for the surface modification treatment are, for example, 0.6 to 100 kJ/m 2 in terms of discharge amount.
  • the lower limit of discharge amount is 1kJ/ m2 or more, 2kJ/ m2 or more, 5kJ/m2 or more, 7kJ/ m2 or more, 10kJ/ m2 or more, 13kJ/m2 or more, 15kJ/m2 or more, 20kJ/ m2 or more.
  • the upper limit of the discharge amount is 70 kJ/m 2 or less, 60 kJ/m 2 or less, 50 kJ/m 2 or less, 45 kJ/m 2 or less, 40 kJ/m 2 or less, 30 kJ/m 2 or less, 20 kJ/m 2 or less, and even It may be 18 kJ/m 2 or less.
  • the discharge amount may be 1 to 18 kJ/m 2 .
  • the discharge amount may be 1 to 60 kJ/m 2 .
  • the adhesive sheet 1 is formed from a photocurable composition.
  • the photocurable composition is an adhesive composition that forms the adhesive sheet 1 when irradiated with light.
  • the monomer group includes, for example, a (meth)acrylic monomer.
  • the content of the (meth)acrylic component in the photocurable composition that is, the (meth)acrylic monomer and its partial polymer, is 50% by weight or more, 60% by weight or more, 70% by weight or more, and even The content may be 80% by weight or more, and in this case, an acrylic pressure-sensitive adhesive sheet 1 containing a (meth)acrylic polymer and a crosslinked product thereof as main components can be formed.
  • the photocurable composition is not limited to the above example.
  • (meth)acrylic means acrylic and methacryl.
  • (Meth)acrylate means acrylate and methacrylate.
  • An example of the (meth)acrylic monomer is a (meth)acrylic acid alkyl ester having an alkyl group having 1 to 20 carbon atoms in the side chain.
  • the number of carbon atoms in the alkyl group may be 7 or less, 6 or less, 5 or less, or even 4 or less.
  • the alkyl group may be linear or branched.
  • Examples of (meth)acrylic acid alkyl esters are methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, s-butyl (meth)acrylate.
  • t-butyl (meth)acrylate isobutyl (meth)acrylate, n-pentyl (meth)acrylate, isopentyl (meth)acrylate, n-hexyl (meth)acrylate, isohexyl (meth)acrylate, isoheptyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, 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
  • the amount of alkyl (meth)acrylate is, for example, 75 parts by weight or less, 60 parts by weight or less, 50 parts by weight or less, 40 parts by weight or less, and even 30 parts by weight. The following may be sufficient.
  • the lower limit of the blending amount is, for example, 10 parts by weight or more.
  • the monomer group does not need to contain (meth)acrylic acid alkyl ester.
  • the weight of the partially polymerized product is converted to the weight of each monomer before polymerization.
  • the monomer group may include a carboxyl group-containing monomer.
  • the carboxyl group-containing monomer may be a (meth)acrylic monomer, or in other words, the (meth)acrylic monomer may include a carboxyl group-containing monomer.
  • Examples of carboxyl group-containing monomers are (meth)acrylic acid, carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, itaconic acid, maleic acid, fumaric acid and crotonic acid.
  • the amount of the carboxyl group-containing monomer is, for example, 10 parts by weight or less, 9 parts by weight or less, 8 parts by weight or less, 7 parts by weight or less, 6 parts by weight or less, 5 parts by weight or less. It may be less than 4.8 parts by weight, less than 4 parts by weight, less than 3 parts by weight, less than 2 parts by weight, less than 1 part by weight, and even less than 0.5 parts by weight.
  • the lower limit of the blending amount is, for example, 0.1 part by weight or more, and in some cases may be 0.5 part by weight or more.
  • the monomer group does not need to contain carboxyl group-containing monomers.
  • the monomer group may include a hydroxy group-containing monomer.
  • the hydroxy group-containing monomer may be a (meth)acrylic monomer, or in other words, the (meth)acrylic monomer may include a hydroxy group-containing monomer.
  • the hydroxy group-containing monomer can contribute to improving the cohesive force of the pressure-sensitive adhesive sheet.
  • hydroxy group-containing monomers examples include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, They are 8-hydroxyoctyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, 12-hydroxylauryl (meth)acrylate, and (4-hydroxymethylcyclohexyl)-methyl acrylate.
  • the hydroxy group-containing monomer is preferably 2-hydroxyethyl (meth)acrylate or 4-hydroxybutyl (meth)acrylate.
  • the amount of the hydroxy group-containing monomer is, for example, 20 parts by weight or less, 15 parts by weight or less, 10 parts by weight or less, 7.5 parts by weight or less, 5 parts by weight or less. , 4 parts by weight or less, 3 parts by weight or less, 2 parts by weight or less, 1 part by weight or less, or even 0.5 parts by weight or less.
  • the lower limit of the blending amount may be, for example, 0.01 part by weight or more, 0.03 part by weight or more, and even 0.05 part by weight or more.
  • the monomer group does not need to contain hydroxy group-containing monomers.
  • the monomer group includes ether group-containing monomers.
  • the ether group-containing monomer may be a (meth)acrylic monomer, or in other words, the (meth)acrylic monomer may include an ether group-containing monomer.
  • the ether group-containing monomer can contribute to improving the anchoring force between the adhesive sheet 1 and the optical film.
  • the ether group-containing monomer preferably includes an alkoxy group-containing monomer.
  • the alkoxy group-containing monomer is, for example, an alkylene oxide adduct represented by the following formula (1).
  • R 1 in formula (1) is a hydrogen atom or a methyl group.
  • R 2 in formula (1) is an alkyl group.
  • the alkyl group may be linear or branched.
  • R 2 is preferably a linear alkyl group. Examples of R 2 are methyl and ethyl groups.
  • n in formula (1) is an integer of 1 to 30, preferably an integer of 1 to 12, and may be an integer of 1 to 5.
  • alkylene oxide adducts shown in formula (1) include 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, 2-(2-ethoxyethoxy)ethyl (meth)acrylate, and methoxytriethylene glycol. (meth)acrylate and methoxypolyethylene glycol (meth)acrylate.
  • the alkoxy group-containing monomer preferably includes 2-methoxyethyl acrylate (MEA).
  • the ether group-containing monomer is not limited to the above alkylene oxide adduct.
  • the ether group-containing monomer may have a ring structure, and the ring structure may have an ether group.
  • the ring structure does not need to contain any functional groups other than ether groups.
  • Examples of the ring structure having an ether group include a tetrahydrofuran ring and a dioxane ring.
  • Examples of ether group-containing monomers having a ring structure are cyclic trimethylolpropane formal (meth)acrylate and tetrahydrofurfuryl (meth)acrylate.
  • the amount of the ether group-containing monomer is 25 parts by weight or more, preferably 30 parts by weight or more, 40 parts by weight or more, 50 parts by weight or more. , 60 parts by weight or more, 70 parts by weight or more, 80 parts by weight or more, or even 90 parts by weight or more.
  • the upper limit of the blending amount is, for example, 99 parts by weight or less.
  • the amount of the ether group-containing monomer is too large, the water absorbency of the pressure-sensitive adhesive sheet 1 may increase. When the adhesive sheet 1 with high water absorption is used in an image display device, metal parts included in the image display device tend to be easily corroded.
  • the upper limit of the amount of the ether group-containing monomer may be 80 parts by weight or less, or 70 parts by weight or less. It is particularly preferable that the ether group-containing monomer be blended in an amount of 50 to 70 parts by weight out of 100 parts by weight of the monomer group.
  • the monomer group may contain other monomers than the (meth)acrylic acid alkyl ester, the carboxyl group-containing monomer, the hydroxy group-containing monomer, and the ether group-containing monomer, but Preferably not.
  • examples of other monomers include aromatic ring-containing monomers such as benzyl (meth)acrylate.
  • each of the above-mentioned monomers may be included as a partial polymer.
  • the partial polymer may be either a single polymer or a copolymer.
  • the partial polymer can contribute to stable formation of the coating layer described below by appropriately increasing the viscosity of the photocurable composition.
  • the relative dielectric constant P of the partially polymerized product at a frequency of 100 Hz is 3.8 or more.
  • the dielectric constant P is as high as this, even if an optical film with a low dielectric constant, especially a polarizing film, and the adhesive sheet 1 are used in combination, the sensitivity of the touch sensor included in the image display device will decrease. There is a tendency to suppress it.
  • the dielectric constant P can be measured by the following method. First, a test piece with a thickness of 30 ⁇ m made of only a partially polymerized material is prepared. Regarding this test piece, the dielectric constant at a frequency of 100 Hz is measured in accordance with JIS K6911:1995. The obtained measured value can be regarded as the relative dielectric constant P. Details of the measurement conditions for the dielectric constant are as follows. ⁇ Measurement conditions Measurement method: Capacitive method (Equipment: 4294A Precision Impedance Analyzer manufactured by Agilent Technologies) Electrode configuration: Aluminum plate with a diameter of 12.1 mm and a thickness of 0.5 mm Counter electrode: 3 oz copper plate Measurement environment: 23 ⁇ 1°C, 52 ⁇ 1% RH
  • the dielectric constant P is preferably 3.8 or more, and may be 4.0 or more, 5.0 or more, 6.0 or more, 7.0 or more, or even 8.0 or more.
  • the upper limit of the dielectric constant P is not particularly limited, and is, for example, 10.0 or less.
  • the photocurable composition usually contains a photopolymerization initiator.
  • a photopolymerization initiator is a photoradical generator that generates radicals using visible light and/or ultraviolet light having a wavelength shorter than 450 nm.
  • photopolymerization initiators include benzoin ethers such as benzoin methyl ether, benzoin isopropyl ether, and benzyl dimethyl ketal; substituted benzoin ethers such as anisole methyl ether; 2,2-diethoxyacetophenone, 2,2-dimethoxy-2- Substituted acetophenones such as phenylacetophenone; ⁇ -hydroxyalkylphenones such as 1-hydroxycyclohexyl-phenylketone; substituted alphaketols 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, methyl benzoylbenzoate, 4-phenylbenzophenone, hydroxybenzophenone
  • the amount of the photopolymerization initiator in the photocurable composition is, for example, 0.02 to 10 parts by weight, and 0.05 to 5 parts by weight, based on a total of 100 parts by weight of the monomer group and its partial polymer. It may be a department.
  • the photocurable composition may contain a crosslinking agent.
  • a crosslinking agent is a polyfunctional monomer having two or more polymerizable functional groups in one molecule.
  • the polyfunctional monomer may be a (meth)acrylic monomer.
  • the polyfunctional monomer is preferably a monomer having two or more C ⁇ C bonds in one molecule.
  • polyfunctional monomers examples include (poly)ethylene glycol di(meth)acrylate, (poly)propylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, pentaerythritol di(meth)acrylate, pentaerythritol Tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, 1,2-ethylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol diacrylate (NDDA) , 1,12-dodecanediol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, tetramethylolmethane tri(meth)acrylate, and other polyfunctional acrylates (ester compounds of polyhydric alcohol and (meth)acrylic acid, etc.) ); allyl (meth)acrylate,
  • the polyfunctional monomer is preferably a polyfunctional acrylate, more preferably trimethylolpropane tri(meth)acrylate, hexanediol di(meth)acrylate, or dipentaerythritol hexa(meth)acrylate.
  • the crosslinking agent may contain a crosslinking agent other than the above-mentioned polyfunctional monomer.
  • Other crosslinking agents include isocyanate crosslinking agents.
  • the photocurable composition may contain an isocyanate-based crosslinking agent as a crosslinking agent, or may contain both the above-mentioned polyfunctional monomer and isocyanate-based crosslinking agent.
  • the isocyanate-based crosslinking agent can contribute to improving the anchoring force between the adhesive sheet 1 and the optical film.
  • isocyanate crosslinking agent a compound having at least two isocyanate groups (isocyanate compound) can be used.
  • the number of isocyanate groups contained in the isocyanate compound is preferably 3 or more.
  • the upper limit of the number of isocyanate groups is not particularly limited, and is, for example, 5.
  • examples of the isocyanate compound include aromatic isocyanate compounds, alicyclic isocyanate compounds, and aliphatic isocyanate compounds.
  • aromatic isocyanate compounds include phenylene diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 2,2'-diphenylmethane diisocyanate, 4,4'-diphenylmethane diisocyanate, and 4,4'-toluidine.
  • aromatic isocyanate compounds include diisocyanate, 4,4'-diphenyl ether diisocyanate, 4,4'-diphenyl diisocyanate, 1,5-naphthalene diisocyanate, and xylylene diisocyanate.
  • alicyclic isocyanate compounds include 1,3-cyclopentene diisocyanate, 1,3-cyclohexane diisocyanate, 1,4-cyclohexane diisocyanate, isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate, hydrogenated xylylene diisocyanate, and hydrogenated tolylene diisocyanate. , hydrogenated tetramethylxylylene diisocyanate, and the like.
  • aliphatic isocyanate compounds include trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), pentamethylene diisocyanate (PDI), 1,2-propylene diisocyanate, 1,3-butylene diisocyanate, dodecamethylene diisocyanate, 2,4 , 4-trimethylhexamethylene diisocyanate and the like.
  • isocyanate crosslinking agent examples include multimers (dimers, trimers, pentamers, etc.) of the above isocyanate compounds, adducts obtained by adding to polyhydric alcohols such as trimethylolpropane, urea modified products, Also included are urethane prepolymers obtained by adding to biuret modified products, allophanate modified products, isocyanurate modified products, carbodiimide modified products, polyether polyols, polyester polyols, acrylic polyols, polybutadiene polyols, polyisoprene polyols, and the like.
  • the isocyanate-based crosslinking agent preferably contains an aliphatic isocyanate compound and/or a derivative of an aliphatic isocyanate compound.
  • the isocyanate-based crosslinking agent may be at least one selected from the group consisting of pentamethylene diisocyanate (PDI)-based crosslinking agents (PDI and its derivatives) and hexamethylene diisocyanate (HDI)-based crosslinking agents (HDI and its derivatives). Particularly preferred.
  • PDI-based crosslinking agent include isocyanurate-modified PDI.
  • Specific examples of HDI-based crosslinking agents include isocyanurate-modified HDI and biuret-modified products.
  • the blending amount of the crosslinking agent in the photocurable composition varies depending on the molecular weight, the number of functional groups, etc., but is, for example, 5 parts by weight or less, and 3 parts by weight based on the total of 100 parts by weight of the monomer group and its partial polymer. 1 part by weight or less, 2 parts by weight or less, 1 part by weight or less, or even 0.5 parts by weight or less.
  • the lower limit of the blending amount is, for example, 0.01 part by weight or more, and may even be 0.05 part by weight or more.
  • the photocurable composition does not contain an isocyanate crosslinking agent in an amount of 0.05 parts by weight or more based on 100 parts by weight of the monomer group and partial polymer.
  • the amount of the isocyanate-based crosslinking agent is less than 0.05 parts by weight, less than 0.03 parts by weight, and even less than 0.01 parts by weight, based on a total of 100 parts by weight of the monomer group and the partial polymer. It may be.
  • the photocurable composition does not need to contain an isocyanate crosslinking agent.
  • the photocurable composition hardly contains an isocyanate-based crosslinking agent, the anchoring force between the adhesive sheet 1 formed from the photocurable composition and the optical film can be adjusted to a large value. Tend.
  • the photocurable composition may contain additives other than those mentioned above.
  • additives are chain transfer agents, rework improvers, corrosion inhibitors, silane coupling agents, viscosity modifiers, tackifiers, plasticizers, softeners, anti-aging agents, fillers, colorants, antioxidants. , surfactants, antistatic agents and ultraviolet absorbers.
  • 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 even 0.5% by weight or less. You can.
  • the photocurable composition may be substantially free of solvent. "Substantially free of solvent” means that the content of solvents derived from additives etc. is, for example, 0.1% by weight or less, preferably 0.05% by weight or less, more preferably 0.01% by weight or less. The intention is to allow it.
  • the viscosity of the photocurable composition is preferably 5 to 150 poise.
  • a photocurable composition having a viscosity within the above range is particularly suitable for forming the coating layer described below.
  • the polymerization rate of the monomer group in the adhesive sheet 1 is preferably 90% or more.
  • the polymerization rate may be 95% or more, 98% or more, or even 99% or more.
  • the gel fraction of the adhesive sheet 1 is, for example, 50% or more, and may be 70% or more, 75% or more, 80% or more, or even 85% or more.
  • the upper limit of the gel fraction of the adhesive sheet 1 is, for example, 95% or less, and may be 80% or less or 75% or less depending on the case. When the gel fraction of the adhesive sheet 1 is 75% or less, the adhesive sheet 1 tends to be in close contact with the optical film, and the anchoring force with the optical film tends to be further improved.
  • the creep amount of the adhesive sheet 1 is, for example, 500 ⁇ m or less, and may be 300 ⁇ m or less, 180 ⁇ m or less, 160 ⁇ m or less, 150 ⁇ m or less, 100 ⁇ m or less, or even 50 ⁇ m or less.
  • the lower limit of the creep amount may be, for example, 5 ⁇ m or more, 10 ⁇ m or more, or even 20 ⁇ m or more.
  • the amount of creep of the adhesive sheet 1 can be evaluated as follows (see FIGS. 2A and 2B).
  • a test piece 52 is obtained by cutting a laminate of the adhesive sheet 1 and the support film 51 to be evaluated into a strip of 10 mm x 50 mm.
  • the support film 51 is disposed for the purpose of suppressing deformation of the load-applied portion of the pressure-sensitive adhesive sheet 1 during a test, and thereby measuring the amount of creep with higher accuracy.
  • a resin film such as a polyethylene terephthalate (PET) film can be used.
  • PET polyethylene terephthalate
  • the support film 51 may be an optical film or a laminate including an optical film.
  • the thickness of the support film 51 may be such that it does not deform itself under the above load, and is, for example, 20 to 200 ⁇ m.
  • the test piece 52 is attached to the surface of the stainless steel test plate 53 using the adhesive sheet 1 at a joint surface measuring 10 mm in length and 10 mm in width.
  • FIG. 2B is a cross section BB in FIG. 2A.
  • the test piece 52 is attached to the test plate 53 so that air bubbles are not mixed between the test plate 53 and the adhesive sheet 1.
  • the test plate 53 and the adhesive sheet 1 are placed in an autoclave at 50° C. and 5 atm (absolute pressure) for 15 minutes to homogenize the bond between the test plate 53 and the adhesive sheet 1.
  • test plate 53 and the test piece 52 are held vertically with the test plate 53 facing upward and left in an atmosphere of 25°C for at least 5 minutes.
  • a weight with a mass of 500 g is fixed at the center of the lower end, and a load 54 of 500 gf is applied vertically downward.
  • the amount of creep (deviation amount) of the adhesive sheet 1 with respect to the test plate 53 at the time point 3600 seconds after the start of applying the load 54 is measured as the amount of fall of the weight.
  • a laser displacement meter can be used to measure the amount of weight fall.
  • the thickness of the adhesive sheet 1 is, for example, 500 ⁇ m or less, and may be 250 ⁇ m or less, 150 ⁇ m or less, 100 ⁇ m or less, 50 ⁇ m or less, 30 ⁇ m or less, 25 ⁇ m or less, or even 20 ⁇ m or less.
  • the lower limit of the thickness of the adhesive sheet 1 is, for example, 2 ⁇ m or more, and may be 5 ⁇ m or more.
  • the adhesive sheet 1 can be manufactured, for example, by the following method. First, as shown in FIGS. 3A and 3B, a first laminate 15 including a base sheet 21, a coating layer 22 containing a photocurable composition, and a release liner 23 in this order is produced. The adhesive sheet 1 can be formed from the coating layer 22 by irradiating the first laminate 15 with the light 14 (FIG. 3C).
  • the first laminate 15 is typically irradiated with the light 14 from the base sheet 21 side (FIG. 3A). At this time, the light 14 passes through the base sheet 21, reaches the coating layer 22, and cures the coating layer 22. However, the irradiation with the light 14 may be performed from the release liner 23 side, or from both sides of the release liner 23 and the base sheet 21 (FIG. 3B).
  • the adhesive sheet 1 formed from the coating layer 22 is sandwiched between the base sheet 21 and the release liner 23 and constitutes a part of the second laminate 16 until the release liner 23 is peeled off.
  • the base material of the release liner 23 is a resin film.
  • resins that can be included in the liner base material are polyesters such as polyethylene terephthalate and polyethylene naphthalate, acetate resins, polyether sulfones, polycarbonates, polyamides, polyimides, polyolefins, (meth)acrylic resins, polyvinyl chloride, polyvinylidene chloride. , polystyrene, polyvinyl alcohol, polyarylate, and polyphenylene sulfide.
  • the resin is preferably a polyester such as polyethylene terephthalate.
  • the release liner 23 may have a light 14 transmittance, or may have a light 14 transmittance comparable to that of the base sheet 21.
  • the thickness of the release liner 23 is, for example, 10 to 200 ⁇ m, and may be 25 to 150 ⁇ m.
  • the release liner 23 may include layers other than the liner base material.
  • the release liner 23 may include a release layer.
  • the release liner 23 includes, for example, a liner base material and a release layer formed on one surface of the liner base material. This release liner 23 can be used so that the release layer is on the coating layer 22 side.
  • the release layer is typically a cured layer of a release agent composition containing a release agent.
  • Various mold release agents can be used as the mold release agent, such as a silicone mold release agent, a fluorine mold release agent, a long chain alkyl mold release agent, a fatty acid amide mold release agent, and silica powder.
  • the release liner 23 may include a cured layer of a release agent composition containing a silicone release agent as a main component (hereinafter referred to as "silicone release layer").
  • the silicone release layer is particularly suitable for achieving both adhesion and releasability to the pressure-sensitive adhesive sheet 1.
  • the main component means the component with the largest content rate.
  • the silicone mold release agent is, for example, various types of curable silicone materials such as addition reaction type, condensation reaction type, ultraviolet curable type, electron beam curable type, and solvent-free type, with addition reaction curable silicone materials being preferred.
  • the addition reaction-curable silicone material is particularly suitable for forming a release layer that has both adhesion and releasability to the pressure-sensitive adhesive sheet 1.
  • the curable silicone material may be a silicone-modified resin in which reactive silicone is introduced into an organic resin such as urethane, epoxy, or alkyd resin by graft polymerization or the like.
  • An example of an addition reaction-curable silicone material is a polyorganosiloxane having a vinyl group or an alkenyl group in the molecule.
  • the addition reaction curable silicone material does not need to have a hydrosilyl group.
  • alkenyl groups are 3-butenyl, 4-pentenyl, 5-hexenyl, 6-heptenyl, 7-octenyl, 8-nonenyl, 9-decenyl, 10-undecenyl, and 11-dodecenyl. It is the basis.
  • polyorganosiloxanes examples include polyalkylalkylsiloxanes such as polydimethylsiloxane, polydiethylsiloxane, and polymethylethylsiloxane, polyalkylarylsiloxanes, and a plurality of Si atom-containing monomers such as poly(dimethylsiloxane-diethylsiloxane). It is a copolymer.
  • the polyorganosiloxane is preferably polydimethylsiloxane.
  • a mold release agent composition containing a silicone mold release agent as a main component usually contains a crosslinking agent.
  • crosslinking agents are polyorganosiloxanes containing hydrosilyl groups.
  • the crosslinking agent may have two or more hydrosilyl groups in one molecule.
  • the silicone mold release agent composition may contain a curing catalyst.
  • a curing catalyst is a platinum-based catalyst.
  • platinum-based catalysts are chloroplatinic acid, olefin complexes of platinum, and olefin complexes of chloroplatinic acid.
  • the amount of the platinum-based catalyst used is, for example, 10 to 1000 ppm (by weight, in terms of platinum) based on the total solid content of the composition.
  • the silicone mold release agent composition may contain additives.
  • additives are release control agents and adhesion promoters.
  • release control agents are unreacted silicone resins, and more specific examples are organosiloxanes such as octamethylcyclotetrasiloxane, and MQ resins.
  • the total amount of the peel control agent and adhesion improver used is, for example, 1 to 30% by weight based on the total solid content of the composition.
  • Further examples of additives are fillers, antistatic agents, antioxidants, UV absorbers, plasticizers and colorants.
  • the amount of further additives used is, for example, up to 10% by weight in total, based on the total solids content of the composition.
  • the silicone mold release agent composition may contain an organic solvent.
  • organic solvents include hydrocarbon solvents such as cyclohexane, n-hexane, and n-heptane; aromatic solvents such as toluene and xylene; ester solvents such as ethyl acetate and methyl acetate; ketone solvents such as acetone and methyl ethyl ketone.
  • Solvent Alcohol solvent such as methanol, ethanol, butanol. Two or more types of organic solvents may be included. The amount of organic solvent used is preferably 80 to 99.9% by weight of the silicone mold release agent composition.
  • the release layer can be formed, for example, by heating and drying a coating film containing a release agent composition formed on a liner base material.
  • Application of the release agent composition includes roll coating, kiss roll coating, gravure coating, reverse coating, roll brushing, spray coating, dip roll coating, bar coating, knife coating, air knife coating, curtain coating, lip coating, and die coating.
  • Various coating methods such as can be applied. For example, hot air drying can be used for heating and drying.
  • the heating temperature and time vary depending on the heat resistance of the liner base material, but are usually about 80 to 150°C and about 10 seconds to 10 minutes. If necessary, irradiation with active energy rays such as ultraviolet rays may be used in combination.
  • the thickness of the release layer is, for example, 10 to 300 nm.
  • the upper limit of the thickness may be 200 nm or less, 150 nm or less, 120 nm or less, 110 nm or less, 100 nm or less, less than 100 nm, 90 nm or less, 80 nm or less, 70 nm or less, less than 70 nm, or even 65 nm or less.
  • the lower limit of the thickness may be 15 nm or more, 20 nm or more, 25 nm or more, 30 nm or more, 35 nm or more, 40 nm or more, 45 nm or more, or even 50 nm or more.
  • the release liner 23 may be sheet-shaped or elongated.
  • An example of the base sheet 21 is a resin film.
  • Examples of resins included in the base sheet 21 are the same as examples of resins that can be included in the liner base material.
  • the base sheet 21 has excellent transparency for the light 14.
  • the thickness of the base sheet 21 is, for example, 10 to 200 ⁇ m, and may be 25 to 150 ⁇ m.
  • the base sheet 21 may include a release layer on the surface facing the coating layer 22.
  • Examples of the release layer that the base sheet 21 can include and its manufacturing method are the same as the examples of the release layer that the release liner 23 can include and its manufacturing method.
  • Both the release liner 23 and the base sheet 21 may be provided with a release layer.
  • both mold release layers may be formed from mold release agent compositions containing the same mold release agent as a main component. Further, the thicknesses of both release layers may be different, and for example, the release layer included in the base sheet 21 may be thicker.
  • a sheet can usually be selected that has a greater peeling force with the adhesive sheet 1 than the release liner 23.
  • the base sheet 21 may be sheet-shaped or elongated.
  • the first laminate 15 is constructed by, for example, forming a coating layer 22 on a base sheet 21 (or a release liner 23), and disposing a release liner 23 (or a base sheet 21) on the formed coating layer 22. It can be formed by Further, the first laminate 15 is formed by pouring and applying the photocurable composition into the space between the base sheet 21 and the release liner 23 which are held at a predetermined interval so that their main surfaces face each other. You may.
  • the coating layer 22 can be formed using a roll coat, a kiss roll coat, a gravure coat, a reverse coat, a roll brush, a spray coat, a dip roll coat, a bar coat, a knife coat, an air knife coat, a curtain coat, a lip coat, a die coat, etc.
  • Various application methods can be applied.
  • the thickness of the coating layer 22 can be adjusted depending on the desired thickness of the adhesive sheet 1, and is, for example, 5 to 500 ⁇ m, 5 to 250 ⁇ m, 5 to 150 ⁇ m, 5 to 100 ⁇ m, 5 to 50 ⁇ m, 5 to 30 ⁇ m, It may be 5 to 25 ⁇ m, or even 5 to 20 ⁇ m.
  • the light 14 irradiated onto the first laminate 15 is, for example, visible light or ultraviolet light having a wavelength shorter than 450 nm.
  • the light 14 may include light with a wavelength in the same region as the absorption wavelength of the photopolymerization initiator included in the photocurable composition.
  • the light 14 may be irradiated by cutting short wavelength light with a wavelength of 300 nm or less using a filter or the like, and cutting off the short wavelength light is suitable for suppressing deterioration of the base sheet 21 due to the light 14.
  • the light source of the light 14 is, for example, a light irradiation device including an ultraviolet irradiation lamp.
  • ultraviolet irradiation lamps examples include ultraviolet LEDs, low-pressure mercury lamps, medium-pressure mercury lamps, high-pressure mercury lamps, extra-high-pressure mercury lamps, metal halide lamps, xenon lamps, microwave-excited mercury lamps, black light lamps, chemical lamps, germicidal lamps, and low-pressure discharge mercury lamps. , an excimer laser. Two or more ultraviolet irradiation lamps may be combined.
  • Irradiation of the light 14 may be continuous or intermittent.
  • the illuminance of the light 14 is, for example, 1 to 20 mW/cm 2 .
  • the irradiation time of the light 14 is, for example, 5 minutes to 5 hours.
  • the cumulative amount of light 14 to the first laminate 15 is, for example, 100 to 5000 mJ/cm 2 .
  • the release liner 23 may be peeled off from the second laminate 16 to expose the surface (for example, the surface 1a) of the adhesive sheet 1, and the surface may be subjected to surface modification treatment.
  • the optical laminate 10 in FIG. 4 includes the adhesive sheet 1 described above and at least one optical film 2 selected from the group consisting of a polarizing film and a retardation film. It is preferable that the adhesive sheet 1 is in direct contact with the optical film 2. In the example of FIG. 4, the surface 1a of the adhesive sheet 1 is in contact with the optical film 2.
  • the optical laminate 10 may have a structure in which the base sheet used in producing the adhesive sheet 1 is laminated on the adhesive sheet 1.
  • the optical laminate 10 can be used as an optical film with an adhesive sheet.
  • Optical film 2 has a surface 2 a facing adhesive sheet 1 .
  • the surface 2a is in contact with the surface 1a of the adhesive sheet 1.
  • the surface 2a of the optical film 2 may be subjected to a surface modification treatment. According to the surface 2a subjected to the surface modification treatment, there is a tendency that the anchoring force between the adhesive sheet 1 and the optical film 2 can be improved. Examples of the surface modification treatment include those described above for the adhesive sheet 1.
  • the surface 2a is preferably subjected to corona treatment as surface modification treatment.
  • conditions such as the amount of discharge can be adjusted as appropriate within the range described above for the adhesive sheet 1, for example.
  • the optical film 2 includes at least one selected from the group consisting of a polarizing film and a retardation film.
  • the optical film 2 may be a laminated film including a polarizing film and/or a retardation film.
  • the optical film 2 may include a glass film.
  • the optical film 2 is not limited to the above example.
  • the polarizing film includes a polarizer.
  • a polarizing film typically includes a polarizer and a protective film (transparent protective film).
  • the protective film is placed, for example, in contact with the main surface (the surface with the widest area) of the polarizer.
  • a polarizer may be placed between two protective films.
  • the protective film may be placed on at least one surface of the polarizer.
  • the polarizer is not particularly limited, and examples include hydrophilic polymer films such as polyvinyl alcohol films, partially formalized polyvinyl alcohol films, partially saponified ethylene/vinyl acetate copolymer films, iodine, and dichroism. Examples include those obtained by adsorbing dichroic substances such as dyes and uniaxially stretched; polyene-based oriented films such as dehydrated polyvinyl alcohol and dehydrochloric acid treated polyvinyl chloride.
  • a polarizer typically consists of a polyvinyl alcohol film (polyvinyl alcohol films include partially saponified ethylene/vinyl acetate copolymer films) and a dichroic substance such as iodine.
  • the thickness of the polarizer is not particularly limited, and may be, for example, 80 ⁇ m or less, 50 ⁇ m or less, 30 ⁇ m or less, 25 ⁇ m or less, or even 20 ⁇ m or less.
  • the lower limit of the thickness of the polarizer is not particularly limited, and may be, for example, 1 ⁇ m or more, 5 ⁇ m or more, 10 ⁇ m or more, or even 15 ⁇ m or more.
  • a thin polarizer (for example, 20 ⁇ m or less in thickness) has suppressed dimensional changes and can contribute to improving the durability of the optical laminate, especially the durability under high temperatures.
  • thermoplastic resin having excellent transparency, mechanical strength, thermal stability, moisture barrier properties, isotropy, etc.
  • thermoplastic resins include cellulose resins such as triacetylcellulose, polyester resins, polyethersulfone resins, polysulfone resins, polycarbonate resins, polyamide resins, polyimide resins, polyolefin resins, (meth)acrylic resins, and cyclic resins.
  • examples include polyolefin resins (norbornene resins), polyarylate resins, polystyrene resins, polyvinyl alcohol resins, and mixtures thereof.
  • the material of the protective film may be a thermosetting resin or an ultraviolet curing resin such as (meth)acrylic, urethane, acrylic urethane, epoxy, or silicone.
  • the materials of the two protective films may be the same or different.
  • a protective film made of a thermoplastic resin is attached to one main surface of a polarizer via an adhesive
  • a protective film made of a thermosetting resin or an ultraviolet curable resin is attached to the other main surface of the polarizer.
  • a protective film made of molded resin may be attached.
  • the protective film may contain one or more types of arbitrary additives. Examples of additives include ultraviolet absorbers, antioxidants, lubricants, plasticizers, mold release agents, color inhibitors, flame retardants, nucleating agents, antistatic agents, pigments, colorants, and the like.
  • films containing (meth)acrylic resin tend to have low adhesive strength with adhesive sheets.
  • the anchoring force with the optical film 2 can be adjusted to a sufficiently high value even when it is in contact with the surface of the protective film containing (meth)acrylic resin. be able to.
  • the thickness of the protective film can be determined as appropriate, but is generally about 10 to 200 ⁇ m from the viewpoint of strength, workability such as handleability, thin film property, etc.
  • a polarizer and a protective film are usually attached to each other via a water-based adhesive or the like.
  • water-based adhesives include isocyanate adhesives, polyvinyl alcohol adhesives, gelatin adhesives, vinyl latex, water-based polyurethanes, and water-based polyesters.
  • adhesives other than the above adhesives include ultraviolet curable adhesives and electron beam curable adhesives.
  • Electron beam-curable adhesives for polarizing plates exhibit suitable adhesion to various types of protective films.
  • the adhesive may include a metal compound filler.
  • a retardation film or the like can also be formed on the polarizer instead of the protective film. It is also possible to provide another protective film, a retardation film, etc. on the protective film.
  • a hard coat layer may be provided on the surface opposite to the surface bonded to the polarizer, and treatments for the purpose of anti-reflection, anti-sticking, diffusion, anti-glare, etc. can also be applied. .
  • the polarizing film may be a circularly polarizing film.
  • the retardation film one obtained by stretching a polymer film or one obtained by aligning and fixing a liquid crystal material can be used.
  • the retardation film has, for example, birefringence in the plane and/or in the thickness direction.
  • the retardation film includes a retardation film for antireflection (see JP-A-2012-133303 [0221], [0222], and [0228]) and a retardation film for viewing angle compensation (see JP-A 2012-133303 [0221], [0222], and [0228]). 0225], [0226]), an obliquely oriented retardation film for viewing angle compensation (see JP-A-2012-133303 [0227]), and the like.
  • the specific structure of the retardation film for example, retardation value, arrangement angle, three-dimensional birefringence, single layer or multilayer, etc., is not particularly limited, and any known retardation film can be used.
  • the thickness of the retardation film is preferably 20 ⁇ m or less, more preferably 10 ⁇ m or less, still more preferably 1 to 9 ⁇ m, particularly preferably 3 to 8 ⁇ m.
  • the retardation film may include, for example, a quarter-wave plate and/or a half-wave plate in which a liquid crystal material is oriented and fixed.
  • the anchoring force F between the adhesive sheet 1 and the optical film 2 tends to be large.
  • the anchoring force F is, for example, 7.0 N/25 mm or more, 8.0 N/25 mm or more, 9.0 N/25 mm or more, 10.0 N/25 mm or more, 11.0 N/25 mm or more, 12.0 N/25 mm or more, It may be 15.0 N/25 mm or more, 20.0 N/25 mm or more, 22.0 N/25 mm or more, 23.0 N/25 mm or more, 24.0 N/25 mm or more, or even 25.0 N/25 mm or more.
  • the upper limit of the anchoring force F is not particularly limited, and may be, for example, 50 N/25 mm or less, and may be 30 N/25 mm or less.
  • the anchoring force F between the adhesive sheet 1 and the optical film 2 can be measured by the following method.
  • the optical laminate 10 to be evaluated is cut out into a piece having a width of 25 mm and a length of 150 mm to form a test piece.
  • the entire surface of the optical film 2 included in the test piece was superimposed on a stainless steel test plate via double-sided tape, and a 2 kg roller was moved back and forth once to press them together.
  • the adhesive sheet 1 included in the test piece is superimposed on the evaluation sheet, and a 2 kg roller is moved back and forth once to press them together.
  • the evaluation sheet has a size of 30 mm width x 150 mm length, and is not particularly limited as long as it does not peel off from the adhesive sheet 1 during the test.
  • an ITO film 125 Tetraite OES (manufactured by Oike Kogyo Co., Ltd.), etc.
  • the adhesive sheet 1 was peeled off from the optical film 2 at a peeling angle of 180° and a pulling speed of 300 mm/min while holding the evaluation sheet.
  • the value is specified as the anchoring force F between the adhesive sheet 1 and the optical film 2. Note that the above test is conducted in an atmosphere at 23°C.
  • the optical laminate 11 in FIG. 5 has a laminated structure in which an adhesive sheet 1A, an optical film 2A, an adhesive sheet 1B, and an optical film 2B are laminated in this order.
  • the optical laminate 11 may have a structure in which the base sheet used in producing the adhesive sheet 1A is laminated on the adhesive sheet 1A.
  • the optical film 2A is a retardation film
  • the optical film 2B is a polarizing film.
  • the adhesive sheet 1B functions as an interlayer adhesive between the optical films 2A and 2B.
  • the adhesive sheet 1B may be one using a known adhesive.
  • the optical laminate of this embodiment can be distributed and stored, for example, as a roll of a band-shaped optical laminate or as a sheet-shaped optical laminate.
  • the optical laminate of this embodiment is typically used in an image display device.
  • the image display device can be formed by, for example, joining the optical laminate 10 or 11 and an image display panel. The bonding is performed using the adhesive sheet 1, for example.
  • the image display device may be an organic EL display or a liquid crystal display. However, the image display device is not limited to the above example.
  • the image display device may be an electroluminescence (EL) display, a plasma display (PD), a field emission display (FED), or the like.
  • EL electroluminescence
  • PD plasma display
  • FED field emission display
  • the image display device can be used for household appliances, in-vehicle applications, public information displays (PID), and the like.
  • a polyvinyl alcohol film having a thickness of 80 ⁇ m was stretched up to 3 times the length between rolls having different speed ratios while being dyed for 1 minute in an iodine solution having a concentration of 0.3% at a temperature of 30°C.
  • the film was stretched while being immersed for 0.5 minutes in an aqueous solution containing boric acid at a concentration of 4% and potassium iodide at a concentration of 10% at a temperature of 60°C until the total stretching ratio became 6 times.
  • a polarizer with a thickness of 28 ⁇ m was obtained by immersing it in an aqueous solution containing potassium iodide at a concentration of 1.5% and washing it for 10 seconds at a temperature of 30°C, and then drying it at 50°C for 4 minutes.
  • Ta A 30 ⁇ m thick transparent protective film made of a modified acrylic polymer having a lactone ring structure was attached to one side of the polarizer using a polyvinyl alcohol adhesive.
  • a 47 ⁇ m thick transparent protective film made of a triacetyl cellulose film (manufactured by Konica Minolta, product name "KC4UY”) with a hard coat layer (HC) is attached using a polyvinyl alcohol adhesive.
  • a polarizing film was produced by heating and drying it for 5 minutes in an oven set at 70°C. Further, the surface of the polarizing film on the side of the transparent protective film made of a modified acrylic polymer was subjected to corona treatment at a discharge amount of 63 W/m 2 ⁇ min.
  • Release liner B which has a release layer (thickness: 120 nm) on one side, was prepared by the same method as release liner A, except that the thickness of the release agent composition applied to the liner base material was changed.
  • BA n-butyl acrylate
  • HBA 4-hydroxybutyl acrylate
  • MEA 2-methoxyethyl acrylate
  • 1-hydroxycyclohexyl-phenyl ketone 1-hydroxycyclohexyl-phenyl ketone
  • the monomer syrup A1 which was partially photopolymerized, was obtained by charging the mixture into a flask and irradiating it with ultraviolet rays under a nitrogen atmosphere. The ultraviolet irradiation was carried out until the viscosity of the liquid in the flask (measurement conditions: BH viscometer No. 5 rotor, 10 rpm, measurement temperature 30° C.) reached approximately 20 Pa ⁇ s.
  • Table 1 The abbreviations in Table 1 are as follows.
  • BA n-butyl acrylate 2EHA: 2-ethylhexyl acrylate HBA: 4-hydroxybutyl acrylate
  • MEA 2-methoxyethyl acrylate
  • Omnirad184 1-hydroxycyclohexyl-phenyl ketone (Omnirad184, manufactured by IGM Resins BV)
  • Omnirad651 2,2-dimethoxy-1,2-diphenylethan-1-one (Omnirad651, manufactured by IGM Resins BV)
  • Photocurable compositions C1 to C8 Next, monomer syrup and additives were mixed to obtain photocurable compositions C1 to C8 so as to have the compositions shown in Table 2 below.
  • NDDA 1,9-nonanediol diacrylate
  • A-100 Acetoacetyl group-containing silane coupling agent (A-100, manufactured by Soken Chemical Co., Ltd.)
  • Photocurable composition C1 was applied to the surface of the release layer of release liner A using an applicator to form a coating layer (thickness: 20 ⁇ m).
  • the above-described release liner B was placed on the formed coating layer to obtain a first laminate.
  • Release liner B was arranged so that the release layer was in contact with the coating layer.
  • ultraviolet light black light source
  • a second laminate consisting of liner A, adhesive sheet (thickness: 20 ⁇ m), and release liner B was formed.
  • the release liner B was peeled off from the second laminate, and the above-mentioned polarizing film was placed on the exposed surface of the adhesive sheet to obtain the optical laminate of Example 1.
  • the polarizing film was placed so that the surface of the transparent protective film made of a modified acrylic polymer was in contact with the adhesive sheet.
  • Examples 2-3, 5, 7-8 and Comparative Examples 1-2 The optical laminates of Examples 2-3, 5, 7-8 and Comparative Examples 1-2 were prepared by the same method as Example 1, except that the photocurable composition used was changed as shown in Table 3. Obtained.
  • Example 4 A second laminate was formed in the same manner as in Example 1, except that photocurable composition C3 was used. Next, the release liner B was peeled off from the second laminate, and the exposed surface of the adhesive sheet was subjected to corona treatment at a discharge amount of 63 W/m 2 ⁇ min. The optical laminate of Example 4 was obtained by disposing the above-mentioned polarizing film on this exposed surface. The polarizing film was placed so that the surface of the transparent protective film made of a modified acrylic polymer was in contact with the adhesive sheet.
  • Example 6 A second laminate was formed in the same manner as in Example 1, except that photocurable composition C4 was used. Next, the release liner B was peeled off from the second laminate, and the exposed surface of the adhesive sheet was subjected to corona treatment at a discharge amount of 63 W/m 2 ⁇ min. The optical laminate of Example 6 was obtained by disposing the above-mentioned polarizing film on this exposed surface. The polarizing film was placed so that the surface of the transparent protective film made of a modified acrylic polymer was in contact with the adhesive sheet.
  • (Reference example 1) [Preparation of (meth)acrylic polymer] 99.0 parts by weight of BA and 1 part by weight of HBA were charged into a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas inlet tube, and a condenser. Next, 0.1 part by weight of AIBN was added as a polymerization initiator to 100 parts by weight of the mixture of BA and HBA, and nitrogen gas was introduced while stirring gently to replace the inside of the flask with nitrogen. The polymerization reaction was allowed to proceed for 7 hours while maintaining the liquid temperature at around 55°C.
  • the weight average molecular weight (Mw) of the (meth)acrylic polymer was 1.65 million.
  • thermosetting (solvent type) adhesive composition Per 100 parts by weight of the solid content of the above (meth)acrylic polymer, 0.3 parts by weight of peroxide crosslinking agent (dibenzoyl peroxide, manufactured by NOF Corporation, trade name "Niper BMT”), 0 .1 part by weight of an isocyanate-based crosslinking agent (trimethylolpropane xylene diisocyanate, manufactured by Mitsui Takeda Chemical Co., Ltd., trade name "Takenate D110N”), and 0.2 part by weight of an acetoacetyl group-containing silane coupling agent (Soken Chemical Co., Ltd.) (trade name: "A-100”) was mixed to obtain a thermosetting (solvent type) adhesive composition.
  • peroxide crosslinking agent dibenzoyl peroxide, manufactured by NOF Corporation, trade name "Niper BMT
  • isocyanate-based crosslinking agent trimethylolpropane xylene diisocyanate,
  • the above adhesive composition is applied to the release surface of a 38 ⁇ m thick PET film (manufactured by Mitsubishi Chemical Polyester Film, MRF38), which is a release film whose release surface has been subjected to silicone treatment.
  • a pressure-sensitive adhesive sheet having a thickness of 20 ⁇ m was formed.
  • An optical laminate of Reference Example 1 was obtained by disposing the above polarizing film on the exposed surface of the adhesive sheet. The polarizing film was placed so that the surface of the transparent protective film made of a modified acrylic polymer was in contact with the adhesive sheet.
  • Glass-transition temperature When a polymer was synthesized from the monomer syrup or the monomer group used for producing the (meth)acrylic polymer of Reference Example 1, the glass transition temperature Tg of the polymer was calculated from the FOX formula.
  • the gel fraction of the produced pressure-sensitive adhesive sheet was measured by the following method. First, a portion of the adhesive sheet was scraped off to obtain a small piece of about 0.2 g. Next, the obtained small piece was wrapped in a polytetrafluoroethylene stretched porous membrane (NTF1122 manufactured by Nitto Denko (average pore diameter: 0.2 ⁇ m)) and tied with a kite string to obtain a test piece. Next, the total weight (weight A) of the small pieces of the adhesive sheet, the stretched porous membrane, and the kite string was measured. The total weight of the stretched porous membrane and kite string used was defined as weight B.
  • the test piece was immersed in a container filled with ethyl acetate and left at 23° C. for one week. After standing still, the test piece was taken out from the container and dried for 2 hours in a dryer set at 130°C, and then the weight C of the test piece was measured.
  • the anchoring force F between the pressure-sensitive adhesive sheet and the polarizing film was measured by the method described above.
  • product name "No. 531" manufactured by Nitto Denko Corporation was used.
  • stainless steel test plate a SUS304 plate (width 40 mm x length 120 mm) was used.
  • an ITO film 125 Tetraite OES, manufactured by Oike Kogyo
  • Autograph SHIMAZU AG-I 10KN manufactured by Shimadzu Corporation
  • the anchoring force F between the adhesive sheet and the optical film (polarizing film) was larger than that of the comparative example.
  • the value of the anchoring force F was higher than that of Reference Example 1 using a pressure-sensitive adhesive sheet made from a thermosetting pressure-sensitive adhesive composition containing an isocyanate-based crosslinking agent. It was at least the same level as the optical laminate.
  • the anchoring force F was a significantly high value. This result is presumed to be due to the fact that in Examples 1 and 7, the gel fraction of the adhesive sheet was relatively low, and the adhesive sheet easily adhered to the optical film.
  • the results of Examples 3 to 6 show that the anchoring force F increases by performing surface modification treatment on the adhesive sheet.
  • the relative permittivity P of the partial polymer contained in the monomer syrup used in the examples at a frequency of 100 Hz was 3.8 or more. From this result, it is estimated that the adhesive sheet used in the example can suppress the decrease in sensitivity of the touch sensor included in the image display device even when used in combination with an optical film with a low dielectric constant. Ru.
  • the pressure-sensitive adhesive sheet of the present invention can be used, for example, in optical laminates and image display devices.

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Abstract

The present invention provides an adhesive sheet which is formed from a photocurable composition and which is suitable for increasing the value of anchoring strength to an optical film. This adhesive sheet 1 is formed from a photocurable composition containing a monomer group and/or a partial polymer of said monomer group. The blending quantity of an isocyanate-based crosslinking agent in the photocurable composition is less than 0.05 parts by weight relative to a total of 100 parts by weight of the monomer group and partial polymer thereof. In the adhesive sheet 1, the monomer group includes an ether group-containing monomer, and the blending quantity of said ether group-containing monomer is 25 parts by weight or more relative to 100 parts by weight of the monomer group. In a case where a polymer is synthesized from the monomer group, the glass transition temperature of said polymer, as calculated from the Fox equation, is higher than -60ºC.

Description

粘着シート及び光学積層体Adhesive sheets and optical laminates
　本発明は、粘着シート及び光学積層体に関する。 The present invention relates to an adhesive sheet and an optical laminate.
　液晶表示装置及びエレクトロルミネセンス（ＥＬ）表示装置に代表される各種の画像表示装置は、一般に、偏光フィルム等の光学フィルムと粘着シートとを含む光学積層体を備えている。光学積層体に含まれる光学フィルム間の接合や、光学積層体と画像表示パネルとの接合には、通常、粘着シートが使用される。粘着シートとしては、アクリル単量体やシリコーン単量体等を含む単量体群を重合及び架橋により硬化させたシートが典型的である。 Various image display devices, typified by liquid crystal display devices and electroluminescent (EL) display devices, generally include an optical laminate that includes an optical film such as a polarizing film and an adhesive sheet. Adhesive sheets are usually used for bonding between optical films included in an optical laminate and for bonding an optical laminate and an image display panel. A typical pressure-sensitive adhesive sheet is a sheet obtained by curing a group of monomers including acrylic monomers, silicone monomers, etc. by polymerization and crosslinking.
　特許文献１は、粘着シートの一例を開示している。特許文献１において、粘着シートは、粘着剤組成物に光を照射することによって作製されている。 Patent Document 1 discloses an example of an adhesive sheet. In Patent Document 1, a pressure-sensitive adhesive sheet is produced by irradiating a pressure-sensitive adhesive composition with light.
特許第３０５２９７２号公報Patent No. 3052972
　一般的な粘着シートは、例えば、次の熱硬化法によって製造される。まず、重合性単量体を有機溶剤中で重合して製造したポリマーに、架橋剤等を配合して粘着剤組成物を調製する。この粘着剤組成物をはく離ライナー等の基材に塗工し、有機溶剤を加熱除去してシート化する。必要に応じて加熱エージングを施し、架橋を完了させることで、粘着シートを製造できる。この製造プロセスでは、溶剤の加熱除去や加熱エージングに必要な熱エネルギーを生み出すために、ＬＮＧ等の燃料を多量に燃焼させる必要がある。また、加熱除去した有機溶剤をそのまま大気放出すると、周辺環境に著しい悪影響を及ぼす恐れがある。そのため、有機溶剤については、脱臭炉等で燃焼させてから放出することが多い。この場合、脱臭炉での燃焼のための燃料がさらに必要になるだけでなく、有機溶剤自体も燃焼によりＣＯ2に変換されて大気放出されることとなり、ＣＯ2排出量が極めて大きい製造プロセスである。 A typical pressure-sensitive adhesive sheet is manufactured, for example, by the following thermosetting method. First, a crosslinking agent and the like are added to a polymer produced by polymerizing a polymerizable monomer in an organic solvent to prepare an adhesive composition. This adhesive composition is applied to a base material such as a release liner, and the organic solvent is removed by heating to form a sheet. A pressure-sensitive adhesive sheet can be manufactured by performing heat aging as necessary to complete crosslinking. In this manufacturing process, it is necessary to burn a large amount of fuel such as LNG in order to generate the thermal energy necessary for heat removal of the solvent and heat aging. Furthermore, if the organic solvent that has been removed by heating is released into the atmosphere as it is, it may have a significant negative impact on the surrounding environment. Therefore, organic solvents are often burned in a deodorizing furnace or the like before being released. In this case, not only will more fuel be required for combustion in the deodorizing furnace, but the organic solvent itself will also be converted into CO 2 and released into the atmosphere through combustion, resulting in a manufacturing process with extremely large CO 2 emissions. be.
　近年、温室効果ガスによる気候変動が喫緊の課題であり、各国政府が数値目標を掲げてＣＯ2削減に取り組んでいる。粘着シートの製造においても、有機溶剤を用いることなく、ＣＯ2排出量の少ない製造プロセスを選択することが求められている。 In recent years, climate change caused by greenhouse gases has become an urgent issue, and governments around the world are working to reduce CO2 by setting numerical targets. In the production of pressure-sensitive adhesive sheets, there is a need to select a production process that does not use organic solvents and has low CO 2 emissions.
　光を利用して粘着シートを作製する方法（光硬化法）によれば、上記の熱硬化法に比べて、粘着シートの形成に必要なエネルギーの量やＣＯ2排出量を削減できる。しかし、熱硬化法では、通常、イソシアネート系架橋剤が粘着剤組成物に配合されており、当該イソシアネート系架橋剤に起因して、粘着シートと光学フィルムとの投錨力が向上する傾向がある。一方、光硬化法で形成した粘着シートを用いて光学積層体を作製した場合、粘着シートと光学フィルムとの投錨力が小さく、粘着シートと光学フィルムとの間で剥がれが生じやすい傾向がある。 According to a method of producing a pressure-sensitive adhesive sheet using light (photocuring method), the amount of energy and CO 2 emissions required for forming the pressure-sensitive adhesive sheet can be reduced compared to the above-mentioned thermosetting method. However, in the thermosetting method, an isocyanate-based crosslinking agent is usually blended into the adhesive composition, and the anchoring force between the adhesive sheet and the optical film tends to improve due to the isocyanate-based crosslinking agent. On the other hand, when an optical laminate is produced using a pressure-sensitive adhesive sheet formed by a photocuring method, the anchoring force between the pressure-sensitive adhesive sheet and the optical film is small, and peeling tends to occur between the pressure-sensitive adhesive sheet and the optical film.
　そこで本発明は、光硬化性組成物から形成され、光学フィルムとの投錨力を大きい値に調整することに適した粘着シートを提供する。 Therefore, the present invention provides a pressure-sensitive adhesive sheet that is formed from a photocurable composition and is suitable for adjusting the anchoring force with an optical film to a large value.
　上述のとおり、本発明者らの検討によると、光硬化法で形成した粘着シートを用いた場合、熱硬化法で形成した粘着シートを用いた場合と比べて、粘着シートと光学フィルムとの間での剥がれが生じやすい傾向がある。この傾向は、熱硬化法で形成した粘着シートを光学フィルムと貼り合わせた場合に、光学フィルムの表面上で粘着シートの硬化がさらに進行する一方、光硬化法で形成した粘着シートでは、光学フィルムと貼り合わせた後に硬化がほとんど進行しないことに起因していると推定される。この問題は、光学フィルムが偏光子等の一軸延伸フィルムを含む場合や、粘着シートの厚みが３０μｍ以下の場合に、特に顕著に生じうる。 As mentioned above, according to the inventors' studies, when using a pressure-sensitive adhesive sheet formed by a photo-curing method, the gap between the pressure-sensitive adhesive sheet and the optical film is greater than when using a pressure-sensitive adhesive sheet formed by a thermosetting method. There is a tendency for peeling to occur easily. This tendency is explained by the fact that when an adhesive sheet formed by a thermosetting method is laminated with an optical film, the adhesive sheet hardens further on the surface of the optical film. This is presumed to be due to the fact that curing hardly progresses after bonding. This problem can occur particularly prominently when the optical film includes a uniaxially stretched film such as a polarizer or when the thickness of the adhesive sheet is 30 μm or less.
　本発明者らは、上記の知見に基づいてさらに検討を進め、イソシアネート系架橋剤をほとんど含まない光硬化性組成物であっても、エーテル基含有単量体の配合量や、ＦＯＸの式を利用して算出されるガラス転移温度を適切に調整すれば、光硬化性組成物から形成された粘着シートと光学フィルムとの投錨力を大きい値に調整できることを見出し、本発明を完成するに至った。 The present inventors further investigated based on the above findings, and even in a photocurable composition containing almost no isocyanate-based crosslinking agent, the amount of the ether group-containing monomer and the formula of FOX can be changed. The present inventors have discovered that by appropriately adjusting the glass transition temperature calculated using the above-mentioned method, the anchoring force between the adhesive sheet and the optical film formed from the photocurable composition can be adjusted to a large value, and the present invention has been completed based on this finding. Ta.
　本発明は、
　単量体群及び／又は前記単量体群の部分重合物を含む光硬化性組成物から形成された粘着シートであって、
　前記光硬化性組成物におけるイソシアネート系架橋剤の配合量が、前記単量体群及び前記部分重合物の合計１００重量部に対して０．０５重量部未満であり、
　前記単量体群は、エーテル基含有単量体を含み、
　前記単量体群１００重量部のうち、前記エーテル基含有単量体の配合量が２５重量部以上であり、
　前記単量体群から重合体を合成した場合に、ＦＯＸの式から算出した前記重合体のガラス転移温度が－６０℃より大きい、粘着シートを提供する。 The present invention
A pressure-sensitive adhesive sheet formed from a photocurable composition containing a monomer group and/or a partial polymer of the monomer group,
The amount of the isocyanate crosslinking agent in the photocurable composition is less than 0.05 parts by weight based on the total of 100 parts by weight of the monomer group and the partial polymer,
The monomer group includes an ether group-containing monomer,
Out of 100 parts by weight of the monomer group, the amount of the ether group-containing monomer is 25 parts by weight or more,
The present invention provides a pressure-sensitive adhesive sheet in which, when a polymer is synthesized from the monomer group, the glass transition temperature of the polymer calculated from the FOX formula is higher than -60°C.
　さらに本発明は、
　上記の粘着シートと、
　偏光フィルム及び位相差フィルムからなる群より選ばれる少なくとも１つを含む光学フィルムと、
を備えた、光学積層体を提供する。 Furthermore, the present invention
The above adhesive sheet,
an optical film containing at least one selected from the group consisting of a polarizing film and a retardation film;
An optical laminate comprising:
　本発明によれば、光硬化性組成物から形成され、光学フィルムとの投錨力を大きい値に調整することに適した粘着シートを提供できる。 According to the present invention, it is possible to provide a pressure-sensitive adhesive sheet that is formed from a photocurable composition and is suitable for adjusting the anchoring force with an optical film to a large value.
本発明の粘着シートの一例を模式的に示す断面図である。FIG. 1 is a cross-sectional view schematically showing an example of a pressure-sensitive adhesive sheet of the present invention. 粘着シートに対するクリープ量の測定方法を説明するための模式図である。FIG. 3 is a schematic diagram for explaining a method for measuring the amount of creep on a pressure-sensitive adhesive sheet. 粘着シートに対するクリープ量の測定方法を説明するための模式図である。FIG. 3 is a schematic diagram for explaining a method for measuring the amount of creep on a pressure-sensitive adhesive sheet. 本発明の粘着シートの製造方法の一例を説明するための模式図である。BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram for explaining an example of a method for manufacturing a pressure-sensitive adhesive sheet of the present invention. 本発明の粘着シートの製造方法の一例を説明するための模式図である。BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram for explaining an example of a method for manufacturing a pressure-sensitive adhesive sheet of the present invention. 本発明の粘着シートの製造方法の一例を説明するための模式図である。BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram for explaining an example of a method for manufacturing a pressure-sensitive adhesive sheet of the present invention. 本発明の光学積層体の一例を模式的に示す断面図である。FIG. 1 is a cross-sectional view schematically showing an example of an optical laminate of the present invention. 本発明の光学積層体の一例を模式的に示す断面図である。FIG. 1 is a cross-sectional view schematically showing an example of an optical laminate of the present invention.
　本発明の第１態様にかかる粘着シートは、
　単量体群及び／又は前記単量体群の部分重合物を含む光硬化性組成物から形成された粘着シートであって、
　前記光硬化性組成物におけるイソシアネート系架橋剤の配合量が、前記単量体群及び前記部分重合物の合計１００重量部に対して０．０５重量部未満であり、
　前記単量体群は、エーテル基含有単量体を含み、
　前記単量体群１００重量部のうち、前記エーテル基含有単量体の配合量が２５重量部以上であり、
　前記単量体群から重合体を合成した場合に、ＦＯＸの式から算出した前記重合体のガラス転移温度が－６０℃より大きい。 The adhesive sheet according to the first aspect of the present invention is
A pressure-sensitive adhesive sheet formed from a photocurable composition containing a monomer group and/or a partial polymer of the monomer group,
The amount of the isocyanate crosslinking agent in the photocurable composition is less than 0.05 parts by weight based on the total of 100 parts by weight of the monomer group and the partial polymer,
The monomer group includes an ether group-containing monomer,
Out of 100 parts by weight of the monomer group, the amount of the ether group-containing monomer is 25 parts by weight or more,
When a polymer is synthesized from the monomer group, the glass transition temperature of the polymer calculated from the FOX formula is higher than -60°C.
　本発明の第２態様において、例えば、第１態様にかかる粘着シートでは、前記部分重合物の周波数１００Ｈｚにおける比誘電率が３．８以上である。 In the second aspect of the present invention, for example, in the adhesive sheet according to the first aspect, the relative permittivity of the partial polymer at a frequency of 100 Hz is 3.8 or more.
　本発明の第３態様において、例えば、第１又は第２態様にかかる粘着シートでは、前記エーテル基含有単量体は、アルコキシ基含有単量体を含む。 In the third aspect of the present invention, for example, in the adhesive sheet according to the first or second aspect, the ether group-containing monomer includes an alkoxy group-containing monomer.
　本発明の第４態様において、例えば、第３態様にかかる粘着シートでは、前記アルコキシ基含有単量体が下記式（１）で表される。
Figure JPOXMLDOC01-appb-C000002
 　前記式（１）において、Ｒ1は、水素原子又はメチル基であり、Ｒ2は、アルキル基であり、ｎは、１～３０の整数である。 In the fourth aspect of the present invention, for example, in the adhesive sheet according to the third aspect, the alkoxy group-containing monomer is represented by the following formula (1).
Figure JPOXMLDOC01-appb-C000002
 In the formula (1), R 1 is a hydrogen atom or a methyl group, R 2 is an alkyl group, and n is an integer from 1 to 30.
　本発明の第５態様において、例えば、第３又は第４態様にかかる粘着シートでは、前記アルコキシ基含有単量体は、２－メトキシエチルアクリレートを含む。 In the fifth aspect of the present invention, for example, in the pressure-sensitive adhesive sheet according to the third or fourth aspect, the alkoxy group-containing monomer includes 2-methoxyethyl acrylate.
　本発明の第６態様において、例えば、第１又は第２態様にかかる粘着シートでは、前記エーテル基含有単量体は、環構造を有する。 In the sixth aspect of the present invention, for example, in the adhesive sheet according to the first or second aspect, the ether group-containing monomer has a ring structure.
　本発明の第７態様において、例えば、第１～第６態様のいずれか１つにかかる粘着シートでは、前記ガラス転移温度が０℃以下である。 In the seventh aspect of the present invention, for example, in the adhesive sheet according to any one of the first to sixth aspects, the glass transition temperature is 0° C. or lower.
　本発明の第８態様において、例えば、第１～第７態様のいずれか１つにかかる粘着シートでは、前記光硬化性組成物は、イソシアネート系架橋剤を含まない。 In the eighth aspect of the present invention, for example, in the pressure-sensitive adhesive sheet according to any one of the first to seventh aspects, the photocurable composition does not contain an isocyanate-based crosslinking agent.
　本発明の第９態様において、例えば、第１～第８態様のいずれか１つにかかる粘着シートでは、前記光硬化性組成物における溶剤の含有率が５重量％以下である。 In the ninth aspect of the present invention, for example, in the adhesive sheet according to any one of the first to eighth aspects, the content of the solvent in the photocurable composition is 5% by weight or less.
　本発明の第１０態様において、例えば、第１～第９態様のいずれか１つにかかる粘着シートは、表面改質処理が施された表面を有する。 In the tenth aspect of the present invention, for example, the adhesive sheet according to any one of the first to ninth aspects has a surface that has been subjected to surface modification treatment.
　本発明の第１１態様にかかる光学積層体は、
　第１～第１０態様のいずれか１つにかかる粘着シートと、
　偏光フィルム及び位相差フィルムからなる群より選ばれる少なくとも１つを含む光学フィルムと、
を備える。 The optical laminate according to the eleventh aspect of the present invention is
An adhesive sheet according to any one of the first to tenth aspects,
an optical film containing at least one selected from the group consisting of a polarizing film and a retardation film;
Equipped with.
　本発明の第１２態様において、例えば、第１１態様にかかる光学積層体では、前記粘着シートと前記光学フィルムとの投錨力が１０．０Ｎ／２５ｍｍ以上である。 In the twelfth aspect of the present invention, for example, in the optical laminate according to the eleventh aspect, the anchoring force between the adhesive sheet and the optical film is 10.0 N/25 mm or more.
　以下に本発明を詳細に説明するが、本発明は以下の実施形態に限定されるものではなく、本発明の要旨を逸脱しない範囲において、任意に変形して実施することができる。 The present invention will be described in detail below, but the present invention is not limited to the following embodiments, and can be implemented with arbitrary modifications within the scope of the gist of the present invention.
［粘着シートの実施形態］
　本実施形態の粘着シートの一例を図１に示す。図１の粘着シート１は、単量体群及び／又は当該単量体群の部分重合物を含む光硬化性組成物から形成されている。光硬化性組成物におけるイソシアネート系架橋剤の配合量は、単量体群及び部分重合物の合計１００重量部に対して０．０５重量部未満である。言い換えると、光硬化性組成物は、イソシアネート系架橋剤を、単量体群及び部分重合物の合計１００重量部に対して０．０５重量部以上含まない。単量体群は、エーテル基含有単量体を含み、単量体群１００重量部のうち、当該エーテル基含有単量体の配合量が２５重量部以上である。 [Embodiment of adhesive sheet]
An example of the adhesive sheet of this embodiment is shown in FIG. The adhesive sheet 1 in FIG. 1 is formed from a photocurable composition containing a monomer group and/or a partial polymer of the monomer group. The amount of the isocyanate crosslinking agent in the photocurable composition is less than 0.05 parts by weight based on the total of 100 parts by weight of the monomer group and the partial polymer. In other words, the photocurable composition does not contain 0.05 parts by weight or more of an isocyanate-based crosslinking agent based on a total of 100 parts by weight of the monomer group and the partial polymer. The monomer group includes an ether group-containing monomer, and the blending amount of the ether group-containing monomer is 25 parts by weight or more out of 100 parts by weight of the monomer group.
　本実施形態では、上記の単量体群から重合体Ａを合成した場合に、ＦＯＸの式から算出した当該重合体Ａのガラス転移温度Ｔｇが－６０℃より大きい。重合体Ａのガラス転移温度Ｔｇは、粘着シート１のガラス転移温度と相関する傾向がある。ガラス転移温度Ｔｇは、例えば－５５℃以上であり、－５０℃以上であってもよい。ガラス転移温度Ｔｇの上限は、特に限定されず、例えば０℃以下であり、－２０℃以下であってもよく、－４０℃以下であってもよい。なお、ＦＯＸの式は、以下の式（Ｉ）で表される。
１／Ｔｇ＝ｗ1／Ｔｇ1＋ｗ2／Ｔｇ2＋・・・＋ｗm／Ｔｇm　　（Ｉ） In this embodiment, when a polymer A is synthesized from the above monomer group, the glass transition temperature Tg of the polymer A calculated from the FOX formula is higher than -60°C. The glass transition temperature Tg of the polymer A tends to correlate with the glass transition temperature of the adhesive sheet 1. The glass transition temperature Tg is, for example, -55°C or higher, and may be -50°C or higher. The upper limit of the glass transition temperature Tg is not particularly limited, and is, for example, 0°C or lower, may be -20°C or lower, or may be -40°C or lower. Note that the FOX formula is represented by the following formula (I).
1/Tg=w 1 /Tg 1 +w 2 /Tg 2 +...+w m /Tg m (I)
　上記の式（Ｉ）において、Ｔｇは、重合体Ａのガラス転移温度（Ｋ）である。ｗ1、ｗ2、・・・ｗmは、それぞれ、単量体群における各単量体の重量分率である。Ｔｇ1、Ｔｇ2、・・・Ｔｇmは、それぞれ、各単量体の単一重合体のガラス転移温度（Ｋ）である。一例として、ｗ1は、単量体群における第１単量体の重量分率であり、Ｔｇ1は、当該第１単量体の単一重合体のガラス転移温度（Ｋ）である。式（Ｉ）から、重合体Ａのガラス転移温度（Ｋ）を算出し、単位換算することによって、重合体Ａのガラス転移温度Ｔｇ（℃）を特定することができる。 In the above formula (I), Tg is the glass transition temperature (K) of polymer A. w 1 , w 2 , . . . w m are each the weight fraction of each monomer in the monomer group. Tg 1 , Tg 2 , . . . Tg m are the glass transition temperatures (K) of a homopolymer of each monomer, respectively. As an example, w 1 is the weight fraction of the first monomer in the monomer group, and Tg 1 is the glass transition temperature (K) of a homopolymer of the first monomer. The glass transition temperature Tg (° C.) of the polymer A can be determined by calculating the glass transition temperature (K) of the polymer A from the formula (I) and converting it into units.
　図１に示すとおり、粘着シート１は、互いに対向する表面１ａ及び１ｂを有する。一例として、表面１ａを介して粘着シート１が光学フィルムに貼り付けられ、表面１ｂを介して粘着シート１が画像表示パネルに貼り付けられる。光学フィルムと接触する粘着シート１の表面１ａには、表面改質処理が施されていてもよく、表面改質処理が施されていなくてもよい。表面改質処理が施された表面１ａによれば、粘着シート１と光学フィルムとの投錨力を向上できる傾向がある。一方、粘着シート１の表面１ｂには、表面改質処理が施されていないことが好ましい。表面改質処理としては、コロナ処理、プラズマ処理、エキシマ処理、フレーム処理などが挙げられる。表面１ａは、表面改質処理として、コロナ処理が施されていることが好ましい。 As shown in FIG. 1, the adhesive sheet 1 has surfaces 1a and 1b facing each other. As an example, the adhesive sheet 1 is attached to an optical film via the surface 1a, and the adhesive sheet 1 is attached to an image display panel via the surface 1b. The surface 1a of the adhesive sheet 1 that contacts the optical film may or may not be subjected to a surface modification treatment. According to the surface 1a subjected to the surface modification treatment, there is a tendency that the anchoring force between the adhesive sheet 1 and the optical film can be improved. On the other hand, the surface 1b of the adhesive sheet 1 is preferably not subjected to surface modification treatment. Examples of surface modification treatments include corona treatment, plasma treatment, excimer treatment, and flame treatment. The surface 1a is preferably subjected to corona treatment as surface modification treatment.
　表面改質処理は、不活性ガス雰囲気で実施してもよい。不活性ガスにより酸素濃度を低減した状態で表面改質処理を行うことで、残存モノマーへの着火リスクを低減することができる。具体的には、酸素濃度が８体積％以下で表面改質処理を行うことが好ましい。より好ましくは６体積％以下、さらに好ましくは３体積％以下である。酸素濃度が低すぎると、表面改質処理による粘着シート表面への官能基の導入が不十分になる場合があるため、酸素濃度は０．０１体積％以上が好ましく、０．１体積％以上がより好ましく、０．５体積％以上が特に好ましい。不活性ガスの具体例としては、窒素やアルゴンが挙げられる。表面改質処理は、常圧（１気圧）下で実施してもよい。 The surface modification treatment may be performed in an inert gas atmosphere. By performing the surface modification treatment with the oxygen concentration reduced using an inert gas, the risk of ignition of the remaining monomer can be reduced. Specifically, it is preferable to perform the surface modification treatment at an oxygen concentration of 8% by volume or less. More preferably it is 6% by volume or less, and still more preferably 3% by volume or less. If the oxygen concentration is too low, the introduction of functional groups to the surface of the pressure-sensitive adhesive sheet by surface modification treatment may become insufficient. Therefore, the oxygen concentration is preferably 0.01% by volume or more, and 0.1% by volume or more. More preferably, 0.5% by volume or more is particularly preferred. Specific examples of the inert gas include nitrogen and argon. The surface modification treatment may be carried out under normal pressure (1 atmosphere).
　コロナ処理である表面改質処理の条件は、放電量により表して、例えば、０．６～１００ｋＪ／ｍ2である。放電量の下限は、１ｋＪ／ｍ2以上、２ｋＪ／ｍ2以上、５ｋＪ／ｍ2以上、７ｋＪ／ｍ2以上、１０ｋＪ／ｍ2以上、１３ｋＪ／ｍ2以上、１５ｋＪ／ｍ2以上、２０ｋＪ／ｍ2以上、２５ｋＪ／ｍ2以上、３０ｋＪ／ｍ2以上、さらには３５ｋＪ／ｍ2以上であってもよい。放電量の上限は、７０ｋＪ／ｍ2以下、６０ｋＪ／ｍ2以下、５０ｋＪ／ｍ2以下、４５ｋＪ／ｍ2以下、４０ｋＪ／ｍ2以下、３０ｋＪ／ｍ2以下、２０ｋＪ／ｍ2以下、さらには１８ｋＪ／ｍ2以下であってもよい。酸素濃度１０体積％以上２０．９体積％以下の雰囲気でコロナ処理を実施する場合は、放電量は１～１８ｋＪ／ｍ2であってもよい。酸素濃度０．０１体積％以上１０体積％未満の雰囲気でコロナ処理を実施する場合は、放電量は１～６０ｋＪ／ｍ2であってもよい。コロナ処理の放電量を適切に調整することによって、粘着シート１と光学フィルムとの投錨力がより向上する傾向がある。 The conditions for the surface modification treatment, which is corona treatment, are, for example, 0.6 to 100 kJ/m 2 in terms of discharge amount. The lower limit of discharge amount is 1kJ/ m2 or more, 2kJ/ m2 or more, 5kJ/m2 or more, 7kJ/ m2 or more, 10kJ/ m2 or more, 13kJ/m2 or more, 15kJ/m2 or more, 20kJ/ m2 or more. m 2 or more, 25 kJ/m 2 or more, 30 kJ/m 2 or more, or even 35 kJ/m 2 or more. The upper limit of the discharge amount is 70 kJ/m 2 or less, 60 kJ/m 2 or less, 50 kJ/m 2 or less, 45 kJ/m 2 or less, 40 kJ/m 2 or less, 30 kJ/m 2 or less, 20 kJ/m 2 or less, and even It may be 18 kJ/m 2 or less. When performing corona treatment in an atmosphere with an oxygen concentration of 10% by volume or more and 20.9% by volume or less, the discharge amount may be 1 to 18 kJ/m 2 . When performing corona treatment in an atmosphere with an oxygen concentration of 0.01% by volume or more and less than 10% by volume, the discharge amount may be 1 to 60 kJ/m 2 . By appropriately adjusting the amount of discharge in the corona treatment, the anchoring force between the adhesive sheet 1 and the optical film tends to be further improved.
（光硬化性組成物）
　上述のとおり、粘着シート１は、光硬化性組成物から形成されている。光硬化性組成物は、光が照射されることによって粘着シート１を形成する粘着剤組成物である。光硬化性組成物において、単量体群は、例えば、（メタ）アクリル系単量体を含む。光硬化性組成物における（メタ）アクリル系成分、すなわち（メタ）アクリル系単量体及びその部分重合物、の含有率は、５０重量％以上、６０重量％以上、７０重量％以上、さらには８０重量％以上であってもよく、この場合、（メタ）アクリル重合体及びその架橋物を主成分とするアクリル系の粘着シート１を形成できる。ただし、光硬化性組成物は上記例に限定されない。本明細書において（メタ）アクリルとは、アクリル及びメタクリルを意味する。（メタ）アクリレートとは、アクリレート及びメタクリレートを意味する。 (Photocurable composition)
As mentioned above, the adhesive sheet 1 is formed from a photocurable composition. The photocurable composition is an adhesive composition that forms the adhesive sheet 1 when irradiated with light. In the photocurable composition, the monomer group includes, for example, a (meth)acrylic monomer. The content of the (meth)acrylic component in the photocurable composition, that is, the (meth)acrylic monomer and its partial polymer, is 50% by weight or more, 60% by weight or more, 70% by weight or more, and even The content may be 80% by weight or more, and in this case, an acrylic pressure-sensitive adhesive sheet 1 containing a (meth)acrylic polymer and a crosslinked product thereof as main components can be formed. However, the photocurable composition is not limited to the above example. In this specification, (meth)acrylic means acrylic and methacryl. (Meth)acrylate means acrylate and methacrylate.
　（メタ）アクリル系単量体の例は、炭素数１～２０のアルキル基を側鎖に有する（メタ）アクリル酸アルキルエステルである。アルキル基の炭素数は、７以下、６以下、５以下、さらには４以下であってもよい。アルキル基は、直鎖状であっても分岐を有していてもよい。（メタ）アクリル酸アルキルエステルの例は、メチル（メタ）アクリレート、エチル（メタ）アクリレート、プロピル（メタ）アクリレート、イソプロピル（メタ）アクリレート、ｎ－ブチル（メタ）アクリレート、ｓ－ブチル（メタ）アクリレート、ｔ－ブチル（メタ）アクリレート、イソブチル（メタ）アクリレート、ｎ－ペンチル（メタ）アクリレート、イソペンチル（メタ）アクリレート、ｎ－へキシル（メタ）アクリレート、イソヘキシル（メタ）アクリレート、イソヘプチル（メタ）アクリレート、２－エチルヘキシル（メタ）アクリレート、ｎ－オクチル（メタ）アクリレート、イソオクチル（メタ）アクリレート、ｎ－ノニル（メタ）アクリレート、イソノニル（メタ）アクリレート、ｎ－デシル（メタ）アクリレート、イソデシル（メタ）アクリレート、ｎ－ドデシル（メタ）アクリレート（ラウリル（メタ）アクリレート）、ｎ－トリデシル（メタ）アクリレート、ｎ－テトラデシル（メタ）アクリレート、ペンタデシル（メタ）アクリレート、ヘキサデシル（メタ）アクリレート、ヘプタデシル（メタ）アクリレート及びオクタデシル（メタ）アクリレートである。（メタ）アクリル酸アルキルエステルは、ｎ－ブチル（メタ）アクリレートであってもよい。 An example of the (meth)acrylic monomer is a (meth)acrylic acid alkyl ester having an alkyl group having 1 to 20 carbon atoms in the side chain. The number of carbon atoms in the alkyl group may be 7 or less, 6 or less, 5 or less, or even 4 or less. The alkyl group may be linear or branched. Examples of (meth)acrylic acid alkyl esters are methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, s-butyl (meth)acrylate. , t-butyl (meth)acrylate, isobutyl (meth)acrylate, n-pentyl (meth)acrylate, isopentyl (meth)acrylate, n-hexyl (meth)acrylate, isohexyl (meth)acrylate, isoheptyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, n-nonyl (meth)acrylate, isononyl (meth)acrylate, n-decyl (meth)acrylate, isodecyl (meth)acrylate, n-dodecyl (meth)acrylate (lauryl (meth)acrylate), n-tridecyl (meth)acrylate, n-tetradecyl (meth)acrylate, pentadecyl (meth)acrylate, hexadecyl (meth)acrylate, heptadecyl (meth)acrylate and octadecyl (meth)acrylate. The (meth)acrylic acid alkyl ester may be n-butyl (meth)acrylate.
　単量体群１００重量部のうち、（メタ）アクリル酸アルキルエステルの配合量は、例えば７５重量部以下であり、６０重量部以下、５０重量部以下、４０重量部以下、さらには３０重量部以下であってもよい。配合量の下限は、例えば１０重量部以上である。単量体群は、（メタ）アクリル酸アルキルエステルを含んでいなくてもよい。なお、特定の単量体の配合量の計算にあたり、部分重合物の重量は、重合前の各単量体としての重量に換算する。 Out of 100 parts by weight of the monomer group, the amount of alkyl (meth)acrylate is, for example, 75 parts by weight or less, 60 parts by weight or less, 50 parts by weight or less, 40 parts by weight or less, and even 30 parts by weight. The following may be sufficient. The lower limit of the blending amount is, for example, 10 parts by weight or more. The monomer group does not need to contain (meth)acrylic acid alkyl ester. In addition, when calculating the blending amount of a specific monomer, the weight of the partially polymerized product is converted to the weight of each monomer before polymerization.
　単量体群は、カルボキシル基含有単量体を含んでいてもよい。カルボキシル基含有単量体は（メタ）アクリル系単量体であってもよく、換言すれば、（メタ）アクリル系単量体がカルボキシル基含有単量体を含んでいてもよい。カルボキシル基含有単量体の例は、（メタ）アクリル酸、カルボキシエチル（メタ）アクリレート、カルボキシペンチル（メタ）アクリレート、イタコン酸、マレイン酸、フマール酸及びクロトン酸である。単量体群１００重量部のうち、カルボキシル基含有単量体の配合量は、例えば１０重量部以下であり、９重量部以下、８重量部以下、７重量部以下、６重量部以下、５重量部以下、４．８重量部以下、４重量部以下、３重量部以下、２重量部以下、１重量部以下、さらには０．５重量部以下であってもよい。配合量の下限は、例えば０．１重量部以上であり、場合によっては、０．５重量部以上であってもよい。単量体群は、カルボキシル基含有単量体を含んでいなくてもよい。 The monomer group may include a carboxyl group-containing monomer. The carboxyl group-containing monomer may be a (meth)acrylic monomer, or in other words, the (meth)acrylic monomer may include a carboxyl group-containing monomer. Examples of carboxyl group-containing monomers are (meth)acrylic acid, carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, itaconic acid, maleic acid, fumaric acid and crotonic acid. Out of 100 parts by weight of the monomer group, the amount of the carboxyl group-containing monomer is, for example, 10 parts by weight or less, 9 parts by weight or less, 8 parts by weight or less, 7 parts by weight or less, 6 parts by weight or less, 5 parts by weight or less. It may be less than 4.8 parts by weight, less than 4 parts by weight, less than 3 parts by weight, less than 2 parts by weight, less than 1 part by weight, and even less than 0.5 parts by weight. The lower limit of the blending amount is, for example, 0.1 part by weight or more, and in some cases may be 0.5 part by weight or more. The monomer group does not need to contain carboxyl group-containing monomers.
　単量体群は、ヒドロキシ基含有単量体を含んでいてもよい。ヒドロキシ基含有単量体は（メタ）アクリル系単量体であってもよく、換言すれば、（メタ）アクリル系単量体がヒドロキシ基含有単量体を含んでいてもよい。ヒドロキシ基含有単量体は、粘着シートの凝集力向上に寄与しうる。ヒドロキシ基含有単量体の例は、（メタ）アクリル酸２－ヒドロキシエチル、（メタ）アクリル酸２－ヒドロキシプロピル、（メタ）アクリル酸４－ヒドロキシブチル、（メタ）アクリル酸６－ヒドロキシヘキシル、（メタ）アクリル酸８－ヒドロキシオクチル、（メタ）アクリル酸１０－ヒドロキシデシル、（メタ）アクリル酸１２－ヒドロキシラウリル及び（４－ヒドロキシメチルシクロヘキシル）－メチルアクリレートである。ヒドロキシ基含有単量体は、好ましくは、（メタ）アクリル酸２－ヒドロキシエチル、（メタ）アクリル酸４－ヒドロキシブチルである。単量体群１００重量部のうち、ヒドロキシ基含有単量体の配合量は、例えば２０重量部以下であり、１５重量部以下、１０重量部以下、７．５重量部以下、５重量部以下、４重量部以下、３重量部以下、２重量部以下、１重量部以下、さらには０．５重量部以下であってもよい。配合量の下限は、例えば０．０１重量部以上であり、０．０３重量部以上、さらには０．０５重量部以上であってもよい。単量体群は、ヒドロキシ基含有単量体を含んでいなくてもよい。 The monomer group may include a hydroxy group-containing monomer. The hydroxy group-containing monomer may be a (meth)acrylic monomer, or in other words, the (meth)acrylic monomer may include a hydroxy group-containing monomer. The hydroxy group-containing monomer can contribute to improving the cohesive force of the pressure-sensitive adhesive sheet. Examples of hydroxy group-containing monomers include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, They are 8-hydroxyoctyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, 12-hydroxylauryl (meth)acrylate, and (4-hydroxymethylcyclohexyl)-methyl acrylate. The hydroxy group-containing monomer is preferably 2-hydroxyethyl (meth)acrylate or 4-hydroxybutyl (meth)acrylate. Out of 100 parts by weight of the monomer group, the amount of the hydroxy group-containing monomer is, for example, 20 parts by weight or less, 15 parts by weight or less, 10 parts by weight or less, 7.5 parts by weight or less, 5 parts by weight or less. , 4 parts by weight or less, 3 parts by weight or less, 2 parts by weight or less, 1 part by weight or less, or even 0.5 parts by weight or less. The lower limit of the blending amount may be, for example, 0.01 part by weight or more, 0.03 part by weight or more, and even 0.05 part by weight or more. The monomer group does not need to contain hydroxy group-containing monomers.
　上述のとおり、単量体群は、エーテル基含有単量体を含む。エーテル基含有単量体は（メタ）アクリル系単量体であってもよく、換言すれば、（メタ）アクリル系単量体がエーテル基含有単量体を含んでいてもよい。エーテル基含有単量体は、粘着シート１と光学フィルムとの投錨力の向上に寄与しうる。 As mentioned above, the monomer group includes ether group-containing monomers. The ether group-containing monomer may be a (meth)acrylic monomer, or in other words, the (meth)acrylic monomer may include an ether group-containing monomer. The ether group-containing monomer can contribute to improving the anchoring force between the adhesive sheet 1 and the optical film.
　エーテル基含有単量体は、アルコキシ基含有単量体を含むことが好ましい。アルコキシ基含有単量体は、例えば、下記式（１）で表されるアルキレンオキサイド付加物である。式（１）のＲ1は、水素原子又はメチル基である。式（１）のＲ2は、アルキル基である。アルキル基は、直鎖状であっても分岐を有していてもよい。Ｒ2は、好ましくは直鎖状のアルキル基である。Ｒ2の例は、メチル基及びエチル基である。式（１）のｎは、１～３０の整数であり、好ましくは１～１２の整数であり、１～５の整数であってもよい。
Figure JPOXMLDOC01-appb-C000003
 The ether group-containing monomer preferably includes an alkoxy group-containing monomer. The alkoxy group-containing monomer is, for example, an alkylene oxide adduct represented by the following formula (1). R 1 in formula (1) is a hydrogen atom or a methyl group. R 2 in formula (1) is an alkyl group. The alkyl group may be linear or branched. R 2 is preferably a linear alkyl group. Examples of R 2 are methyl and ethyl groups. n in formula (1) is an integer of 1 to 30, preferably an integer of 1 to 12, and may be an integer of 1 to 5.
Figure JPOXMLDOC01-appb-C000003
　式（１）に示すアルキレンオキサイド付加物の例は、２－メトキシエチル（メタ）アクリレート、２－エトキシエチル（メタ）アクリレート、２－（２－エトキシエトキシ）エチル（メタ）アクリレート、メトキシトリエチレングリコール（メタ）アクリレート及びメトキシポリエチレングリコール（メタ）アクリレートである。アルコキシ基含有単量体は、２－メトキシエチルアクリレート（ＭＥＡ）を含むことが好ましい。 Examples of alkylene oxide adducts shown in formula (1) include 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, 2-(2-ethoxyethoxy)ethyl (meth)acrylate, and methoxytriethylene glycol. (meth)acrylate and methoxypolyethylene glycol (meth)acrylate. The alkoxy group-containing monomer preferably includes 2-methoxyethyl acrylate (MEA).
　エーテル基含有単量体は、上記のアルキレンオキサイド付加物に限定されない。エーテル基含有単量体は、環構造を有していてもよく、当該環構造がエーテル基を有していてもよい。環構造は、エーテル基以外の官能基を含んでいなくてもよい。エーテル基を有する環構造としては、テトラヒドロフラン環、ジオキサン環などが挙げられる。環構造を有するエーテル基含有単量体の例は、環状トリメチロールプロパンホルマール（メタ）アクリレート及びテトラヒドロフルフリル（メタ）アクリレートである。 The ether group-containing monomer is not limited to the above alkylene oxide adduct. The ether group-containing monomer may have a ring structure, and the ring structure may have an ether group. The ring structure does not need to contain any functional groups other than ether groups. Examples of the ring structure having an ether group include a tetrahydrofuran ring and a dioxane ring. Examples of ether group-containing monomers having a ring structure are cyclic trimethylolpropane formal (meth)acrylate and tetrahydrofurfuryl (meth)acrylate.
　上述のとおり、単量体群１００重量部のうち、エーテル基含有単量体の配合量は、２５重量部以上であり、好ましくは３０重量部以上であり、４０重量部以上、５０重量部以上、６０重量部以上、７０重量部以上、８０重量部以上、さらには９０重量部以上であってもよい。配合量の上限は、例えば９９重量部以下である。ただし、エーテル基含有単量体の配合量が多すぎると、粘着シート１の吸水性が上昇することがある。吸水性が高い粘着シート１を画像表示装置に用いた場合、画像表示装置に含まれる金属部品が腐食しやすい傾向がある。この観点から、エーテル基含有単量体の配合量の上限は、８０重量部以下であってもよく、７０重量部以下であってもよい。単量体群１００重量部のうち、エーテル基含有単量体の配合量は、５０～７０重量部であることが特に好ましい。 As mentioned above, out of 100 parts by weight of the monomer group, the amount of the ether group-containing monomer is 25 parts by weight or more, preferably 30 parts by weight or more, 40 parts by weight or more, 50 parts by weight or more. , 60 parts by weight or more, 70 parts by weight or more, 80 parts by weight or more, or even 90 parts by weight or more. The upper limit of the blending amount is, for example, 99 parts by weight or less. However, if the amount of the ether group-containing monomer is too large, the water absorbency of the pressure-sensitive adhesive sheet 1 may increase. When the adhesive sheet 1 with high water absorption is used in an image display device, metal parts included in the image display device tend to be easily corroded. From this point of view, the upper limit of the amount of the ether group-containing monomer may be 80 parts by weight or less, or 70 parts by weight or less. It is particularly preferable that the ether group-containing monomer be blended in an amount of 50 to 70 parts by weight out of 100 parts by weight of the monomer group.
　単量体群は、（メタ）アクリル酸アルキルエステル、カルボキシル基含有単量体、ヒドロキシ基含有単量体及びエーテル基含有単量体以外の他の単量体を含んでいてもよいが、含まないことが好ましい。他の単量体としては、例えば、ベンジル（メタ）アクリレートなどの芳香環含有単量体が挙げられる。 The monomer group may contain other monomers than the (meth)acrylic acid alkyl ester, the carboxyl group-containing monomer, the hydroxy group-containing monomer, and the ether group-containing monomer, but Preferably not. Examples of other monomers include aromatic ring-containing monomers such as benzyl (meth)acrylate.
　光硬化性組成物において、上述した各単量体は部分重合物として含まれていてもよい。部分重合物は、単一重合体及び共重合体のいずれであってもよい。部分重合物は、光硬化性組成物の粘度を適度に増大させることで、後述する塗布層の安定した形成に寄与しうる。 In the photocurable composition, each of the above-mentioned monomers may be included as a partial polymer. The partial polymer may be either a single polymer or a copolymer. The partial polymer can contribute to stable formation of the coating layer described below by appropriately increasing the viscosity of the photocurable composition.
　部分重合物の周波数１００Ｈｚにおける比誘電率Ｐは、３．８以上であることが好ましい。比誘電率Ｐがこの程度に高い場合、比誘電率が低い光学フィルム、特に偏光フィルムと粘着シート１とを組み合わせて用いた場合であっても、画像表示装置が備えるタッチセンサの感度の低下を抑制できる傾向がある。 It is preferable that the relative dielectric constant P of the partially polymerized product at a frequency of 100 Hz is 3.8 or more. When the dielectric constant P is as high as this, even if an optical film with a low dielectric constant, especially a polarizing film, and the adhesive sheet 1 are used in combination, the sensitivity of the touch sensor included in the image display device will decrease. There is a tendency to suppress it.
　比誘電率Ｐは、次の方法によって測定することができる。まず、部分重合物のみから構成された、厚さ３０μｍの試験片を作製する。この試験片について、ＪＩＳ　Ｋ６９１１：１９９５に準拠して、周波数１００Ｈｚにおける比誘電率を測定する。得られた測定値を比誘電率Ｐとみなすことができる。比誘電率の測定条件の詳細は、以下のとおりである。
・測定条件
　測定方法：容量法（装置：Agilent Technologies社製の4294A Precision Impedance Analyzer）
　電極構成：直径１２．１ｍｍ、厚さ０．５ｍｍのアルミニウム板
　対向電極：３ｏｚ　銅板
　測定環境：２３±１℃、５２±１％ＲＨ The dielectric constant P can be measured by the following method. First, a test piece with a thickness of 30 μm made of only a partially polymerized material is prepared. Regarding this test piece, the dielectric constant at a frequency of 100 Hz is measured in accordance with JIS K6911:1995. The obtained measured value can be regarded as the relative dielectric constant P. Details of the measurement conditions for the dielectric constant are as follows.
・Measurement conditions Measurement method: Capacitive method (Equipment: 4294A Precision Impedance Analyzer manufactured by Agilent Technologies)
Electrode configuration: Aluminum plate with a diameter of 12.1 mm and a thickness of 0.5 mm Counter electrode: 3 oz copper plate Measurement environment: 23 ± 1°C, 52 ± 1% RH
　比誘電率Ｐは、好ましくは３．８以上であり、４．０以上、５．０以上、６．０以上、７．０以上、さらには８．０以上であってもよい。比誘電率Ｐの上限は、特に限定されず、例えば１０．０以下である。 The dielectric constant P is preferably 3.8 or more, and may be 4.0 or more, 5.0 or more, 6.0 or more, 7.0 or more, or even 8.0 or more. The upper limit of the dielectric constant P is not particularly limited, and is, for example, 10.0 or less.
　光硬化性組成物は、通常、光重合開始剤を含有する。光重合開始剤の例は、波長４５０ｎｍよりも短い波長の可視光及び／又は紫外線によりラジカルを発生する光ラジカル発生剤である。 The photocurable composition usually contains a photopolymerization initiator. An example of the photopolymerization initiator is a photoradical generator that generates radicals using visible light and/or ultraviolet light having a wavelength shorter than 450 nm.
　光重合開始剤の例は、ベンゾインメチルエーテル、ベンゾインイソプロピルエーテル、ベンジルジメチルケタール等のベンゾインエーテル類；アニソールメチルエーテル等の置換ベンゾインエーテル；２，２－ジエトキシアセトフェノン、２，２－ジメトキシ－２－フェニルアセトフェノン等の置換アセトフェノン；１－ヒドロキシシクロヘキシル－フェニルケトン等のα－ヒドロキシアルキルフェノン；２－メチル－２－ヒドロキシプロピオフェノン等の置換アルファーケトール；２－ナフタレンスルホニルクロライド等の芳香族スルホニルクロライド；１－フェニル－１，１－プロパンジオン－２－（ｏ－エトキシカルボニル）－オキシム等の光活性オキシム；ベンゾフェノン、ベンゾイル安息香酸、ベンゾイル安息香酸メチル、４－フェニルベンゾフェノン、ヒドロキシベンゾフェノン、アクリル化ベンゾフェノン、４－ベンゾイル－４’－メチルジフェニルサルファイド、３，３’，４，４’－テトラ（ｔ－ブチルパーオキシカルボニル）ベンゾフェノン等のベンゾフェノン系化合物；チオキサントン、２－クロルチオキサントン、２－メチルチオキサントン、イソプロピルチオキサントン、２，４－ジイソプロピルチオキサントン、２，４－ジエチルチオキサントン等のチオキサントン系化合物；２，４，６－トリクロロ－ｓ－トリアジン、２－フェニル－４，６－ビス（トリクロロメチル）－ｓ－トリアジン、２－（ｐ－メトキシフェニル）－４，６－ビス（トリクロロメチル）－ｓ－トリアジン、２－（ｐ－トリル）－４，６－ビス（トリクロロメチル）－ｓ－トリアジン、２－ピペロニル－４，６－ビス（トリクロロメチル）－ｓ－トリアジン、２，４－ビス（トリクロロメチル）－６－スチリル－ｓ－トリアジン、２－（ナフト－１－イル）－４，６－ビス（トリクロロメチル）－ｓ－トリアジン、２－（４－メトキシ－ナフト－１－イル）－４，６－ビス（トリクロロメチル）－ｓ－トリアジン、２，４－トリクロロメチル－（ピペロニル）－６－トリアジン、２，４－トリクロロメチル－（４’－メトキシスチリル）－６－トリアジン等のトリアジン系化合物；１，２－オクタンジオン，１－〔４－（フェニルチオ）－，２－（Ｏ－ベンゾイルオキシム）〕、Ｏ－（アセチル）－Ｎ－（１－フェニル－２－オキソ－２－（４’－メトキシ－ナフチル）エチリデン）ヒドロキシルアミン等のオキシムエステル系化合物；ビス（２，４，６－トリメチルベンゾイル）フェニルホスフィンオキサイド、２，４，６－トリメチルベンゾイルジフェニルホスフィンオキサイド等のホスフィン系化合物；９，１０－フェナンスレンキノン、カンファーキノン、エチルアントラキノン等のキノン系化合物；ボレート系化合物；カルバゾール系化合物；イミダゾール系化合物；並びにチタノセン系化合物である。光硬化性組成物は、１種又は２種以上の光重合開始剤を含んでいてもよい。 Examples of photopolymerization initiators include benzoin ethers such as benzoin methyl ether, benzoin isopropyl ether, and benzyl dimethyl ketal; substituted benzoin ethers such as anisole methyl ether; 2,2-diethoxyacetophenone, 2,2-dimethoxy-2- Substituted acetophenones such as phenylacetophenone; α-hydroxyalkylphenones such as 1-hydroxycyclohexyl-phenylketone; substituted alphaketols 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, methyl benzoylbenzoate, 4-phenylbenzophenone, hydroxybenzophenone, acrylated benzophenone, Benzophenone compounds such as 4-benzoyl-4'-methyldiphenyl sulfide, 3,3',4,4'-tetra(t-butylperoxycarbonyl)benzophenone; thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, isopropyl Thioxanthone compounds such as thioxanthone, 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-styryl-s-triazine, 2-(naphth-1-yl)-4,6-bis(trichloromethyl )-s-triazine, 2-(4-methoxy-naphth-1-yl)-4,6-bis(trichloromethyl)-s-triazine, 2,4-trichloromethyl-(piperonyl)-6-triazine, 2 , 4-trichloromethyl-(4'-methoxystyryl)-6-triazine and other triazine compounds; 1,2-octanedione, 1-[4-(phenylthio)-,2-(O-benzoyloxime)], Oxime ester compounds such as O-(acetyl)-N-(1-phenyl-2-oxo-2-(4'-methoxy-naphthyl)ethylidene) hydroxylamine; bis(2,4,6-trimethylbenzoyl)phenyl Phosphine compounds such as phosphine oxide and 2,4,6-trimethylbenzoyldiphenylphosphine oxide; Quinone compounds such as 9,10-phenanthrenequinone, camphorquinone, and ethyl anthraquinone; Borate compounds; Carbazole compounds; Imidazole compounds compounds; and titanocene compounds. The photocurable composition may contain one or more photopolymerization initiators.
　光硬化性組成物における光重合開始剤の配合量は、単量体群及びその部分重合物の合計１００重量部に対して、例えば０．０２～１０重量部であり、０．０５～５重量部であってもよい。 The amount of the photopolymerization initiator in the photocurable composition is, for example, 0.02 to 10 parts by weight, and 0.05 to 5 parts by weight, based on a total of 100 parts by weight of the monomer group and its partial polymer. It may be a department.
　光硬化性組成物は、架橋剤を含んでいてもよい。架橋剤の例は、１分子中に２以上の重合性官能基を有する多官能単量体である。多官能単量体は（メタ）アクリル系単量体であってもよい。多官能単量体の例は、１分子中に２以上のＣ＝Ｃ結合を有する単量体、及び１分子中に１以上のＣ＝Ｃ結合と、１以上のエポキシ基、アジリジン基、オキサゾリン基、ヒドラジン基、メチロール基等の重合性官能基とを有する単量体である。多官能単量体は、好ましくは、１分子中に２以上のＣ＝Ｃ結合を有する単量体である。 The photocurable composition may contain a crosslinking agent. An example of a crosslinking agent is a polyfunctional monomer having two or more polymerizable functional groups in one molecule. The polyfunctional monomer may be a (meth)acrylic monomer. Examples of polyfunctional monomers include monomers having two or more C=C bonds in one molecule, and one or more C=C bonds in one molecule and one or more epoxy groups, aziridine groups, and oxazolines. It is a monomer having a polymerizable functional group such as a hydrazine group, a hydrazine group, or a methylol group. The polyfunctional monomer is preferably a monomer having two or more C═C bonds in one molecule.
　多官能単量体の例は、（ポリ）エチレングリコールジ（メタ）アクリレート、（ポリ）プロピレングリコールジ（メタ）アクリレート、ネオペンチルグリコールジ（メタ）アクリレート、ペンタエリスリトールジ（メタ）アクリレート、ペンタエリスリトールトリ（メタ）アクリレート、ジペンタエリスリトールヘキサ（メタ）アクリレート、１，２－エチレングリコールジ（メタ）アクリレート、１，６－ヘキサンジオールジ（メタ）アクリレート、１，９－ノナンジオールジアクリレート（ＮＤＤＡ）、１，１２－ドデカンジオールジ（メタ）アクリレート、トリメチロールプロパントリ（メタ）アクリレート、テトラメチロールメタントリ（メタ）アクリレート等の多官能アクリレート（多価アルコールと（メタ）アクリル酸とのエステル化合物等）；アリル（メタ）アクリレート、ビニル（メタ）アクリレート、ジビニルベンゼン、エポキシアクリレート、ポリエステルアクリレート、ウレタンアクリレート、ブチルジ（メタ）アクリレート、ヘキシルジ（メタ）アクリレートである。多官能単量体は、好ましくは、多官能アクリレートであり、より好ましくは、トリメチロールプロパントリ（メタ）アクリレート、ヘキサンジオールジ（メタ）アクリレート、ジペンタエリスリトールヘキサ（メタ）アクリレートである。 Examples of polyfunctional monomers are (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, tetramethylolmethane tri(meth)acrylate, and other polyfunctional acrylates (ester compounds of polyhydric alcohol and (meth)acrylic acid, etc.) ); 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, more preferably trimethylolpropane tri(meth)acrylate, hexanediol di(meth)acrylate, or dipentaerythritol hexa(meth)acrylate.
　架橋剤は、上記の多官能単量体以外の他の架橋剤を含んでいてもよい。他の架橋剤としては、イソシアネート系架橋剤が挙げられる。光硬化性組成物は、架橋剤として、イソシアネート系架橋剤を含んでいてもよく、上記の多官能単量体及びイソシアネート系架橋剤の両方を含んでいてもよい。イソシアネート系架橋剤は、粘着シート１と光学フィルムとの投錨力の向上に寄与しうる。 The crosslinking agent may contain a crosslinking agent other than the above-mentioned polyfunctional monomer. Other crosslinking agents include isocyanate crosslinking agents. The photocurable composition may contain an isocyanate-based crosslinking agent as a crosslinking agent, or may contain both the above-mentioned polyfunctional monomer and isocyanate-based crosslinking agent. The isocyanate-based crosslinking agent can contribute to improving the anchoring force between the adhesive sheet 1 and the optical film.
　イソシアネート系架橋剤としては、少なくとも２個のイソシアネート基を有する化合物（イソシアネート化合物）を用いることができる。イソシアネート化合物に含まれるイソシアネート基の数は、３以上であることが好ましい。イソシアネート基の数の上限値は、特に限定されず、例えば５である。イソシアネート化合物としては、芳香族イソシアネート化合物、脂環族イソシアネート化合物、脂肪族イソシアネート化合物などが挙げられる。 As the isocyanate crosslinking agent, a compound having at least two isocyanate groups (isocyanate compound) can be used. The number of isocyanate groups contained in the isocyanate compound is preferably 3 or more. The upper limit of the number of isocyanate groups is not particularly limited, and is, for example, 5. Examples of the isocyanate compound include aromatic isocyanate compounds, alicyclic isocyanate compounds, and aliphatic isocyanate compounds.
　芳香族イソシアネート化合物としては、例えば、フェニレンジイソシアネート、２，４－トリレンジイソシアネート、２，６－トリレンジイソシアネート、２，２’－ジフェニルメタンジイソシアネート、４，４’－ジフェニルメタンジイソシアネート、４，４’－トルイジンジイソシアネート、４，４’－ジフェニルエーテルジイソシアネート、４，４’－ジフェニルジイソシアネート、１，５－ナフタレンジイソシアネート、キシリレンジイソシアネートなどが挙げられる。 Examples of aromatic isocyanate compounds include phenylene diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 2,2'-diphenylmethane diisocyanate, 4,4'-diphenylmethane diisocyanate, and 4,4'-toluidine. Examples include diisocyanate, 4,4'-diphenyl ether diisocyanate, 4,4'-diphenyl diisocyanate, 1,5-naphthalene diisocyanate, and xylylene diisocyanate.
　脂環族イソシアネート化合物としては、例えば、１，３－シクロペンテンジイソシアネート、１，３－シクロヘキサンジイソシアネート、１，４－シクロヘキサンジイソシアネート、イソホロンジイソシアネート、水素添加ジフェニルメタンジイソシアネート、水素添加キシリレンジイソシアネート、水素添加トリレンジイソシアネート、水素添加テトラメチルキシリレンジイソシアネートなどが挙げられる。 Examples of alicyclic isocyanate compounds include 1,3-cyclopentene diisocyanate, 1,3-cyclohexane diisocyanate, 1,4-cyclohexane diisocyanate, isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate, hydrogenated xylylene diisocyanate, and hydrogenated tolylene diisocyanate. , hydrogenated tetramethylxylylene diisocyanate, and the like.
　脂肪族イソシアネート化合物としては、トリメチレンジイソシアネート、テトラメチレンジイソシアネート、ヘキサメチレンジイソシアネート（ＨＤＩ）、ペンタメチレンジイソシアネート（ＰＤＩ）、１，２－プロピレンジイソシアネート、１，３－ブチレンジイソシアネート、ドデカメチレンジイソシアネート、２，４，４－トリメチルヘキサメチレンジイソシアネートなどが挙げられる。 Examples of aliphatic isocyanate compounds include trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), pentamethylene diisocyanate (PDI), 1,2-propylene diisocyanate, 1,3-butylene diisocyanate, dodecamethylene diisocyanate, 2,4 , 4-trimethylhexamethylene diisocyanate and the like.
　イソシアネート系架橋剤としては、上記イソシアネート化合物の多量体（２量体、３量体、５量体など）、トリメチロールプロパンなどの多価アルコールに付加して得られた付加物、ウレア変性体、ビウレット変性体、アロファネート変性体、イソシアヌレート変性体、カルボジイミド変性体、ポリエーテルポリオール、ポリエステルポリオール、アクリルポリオール、ポリブタジエンポリオール、ポリイソプレンポリオールなどに付加して得られたウレタンプレポリマーなども挙げられる。 Examples of the isocyanate crosslinking agent include multimers (dimers, trimers, pentamers, etc.) of the above isocyanate compounds, adducts obtained by adding to polyhydric alcohols such as trimethylolpropane, urea modified products, Also included are urethane prepolymers obtained by adding to biuret modified products, allophanate modified products, isocyanurate modified products, carbodiimide modified products, polyether polyols, polyester polyols, acrylic polyols, polybutadiene polyols, polyisoprene polyols, and the like.
　イソシアネート系架橋剤は、好ましくは脂肪族イソシアネート化合物及び／又は脂肪族イソシアネート化合物の誘導体を含む。イソシアネート系架橋剤は、ペンタメチレンジイソシアネート（ＰＤＩ）系架橋剤（ＰＤＩ及びその誘導体）及びヘキサメチレンジイソシアネート（ＨＤＩ）系架橋剤（ＨＤＩ及びその誘導体）からなる群より選ばれる少なくとも１つであることが特に好ましい。ＰＤＩ系架橋剤の具体例は、ＰＤＩのイソシアヌレート変性体などである。ＨＤＩ系架橋剤の具体例は、ＨＤＩのイソシアヌレート変性体やビウレット変性体などである。 The isocyanate-based crosslinking agent preferably contains an aliphatic isocyanate compound and/or a derivative of an aliphatic isocyanate compound. The isocyanate-based crosslinking agent may be at least one selected from the group consisting of pentamethylene diisocyanate (PDI)-based crosslinking agents (PDI and its derivatives) and hexamethylene diisocyanate (HDI)-based crosslinking agents (HDI and its derivatives). Particularly preferred. Specific examples of the PDI-based crosslinking agent include isocyanurate-modified PDI. Specific examples of HDI-based crosslinking agents include isocyanurate-modified HDI and biuret-modified products.
　光硬化性組成物における架橋剤の配合量は、分子量や官能基数等により異なるが、単量体群及びその部分重合物の合計１００重量部に対して、例えば５重量部以下であり、３重量部以下、２重量部以下、１重量部以下、さらには０．５重量部以下であってもよい。配合量の下限は、例えば０．０１重量部以上であり、さらには０．０５重量部以上であってもよい。 The blending amount of the crosslinking agent in the photocurable composition varies depending on the molecular weight, the number of functional groups, etc., but is, for example, 5 parts by weight or less, and 3 parts by weight based on the total of 100 parts by weight of the monomer group and its partial polymer. 1 part by weight or less, 2 parts by weight or less, 1 part by weight or less, or even 0.5 parts by weight or less. The lower limit of the blending amount is, for example, 0.01 part by weight or more, and may even be 0.05 part by weight or more.
　ただし、上述のとおり、光硬化性組成物は、イソシアネート系架橋剤を、単量体群及び部分重合物の合計１００重量部に対して０．０５重量部以上含まない。イソシアネート系架橋剤の配合量は、単量体群及び部分重合物の合計１００重量部に対して、０．０５重量部未満であり、０．０３重量部未満、さらには０．０１重量部未満であってもよい。光硬化性組成物は、イソシアネート系架橋剤を含んでいなくてもよい。本実施形態では、光硬化性組成物がイソシアネート系架橋剤をほとんど含んでいないにも関わらず、光硬化性組成物から形成された粘着シート１と光学フィルムとの投錨力を大きい値に調整できる傾向がある。 However, as described above, the photocurable composition does not contain an isocyanate crosslinking agent in an amount of 0.05 parts by weight or more based on 100 parts by weight of the monomer group and partial polymer. The amount of the isocyanate-based crosslinking agent is less than 0.05 parts by weight, less than 0.03 parts by weight, and even less than 0.01 parts by weight, based on a total of 100 parts by weight of the monomer group and the partial polymer. It may be. The photocurable composition does not need to contain an isocyanate crosslinking agent. In this embodiment, although the photocurable composition hardly contains an isocyanate-based crosslinking agent, the anchoring force between the adhesive sheet 1 formed from the photocurable composition and the optical film can be adjusted to a large value. Tend.
　光硬化性組成物は、上述した以外の添加剤を含んでいてもよい。添加剤の例は、連鎖移動剤、リワーク向上剤、腐食防止剤、シランカップリング剤、粘度調整剤、粘着付与剤、可塑剤、軟化剤、老化防止剤、充填剤、着色剤、酸化防止剤、界面活性剤、帯電防止剤及び紫外線吸収剤である。 The photocurable composition may contain additives other than those mentioned above. Examples of additives are chain transfer agents, rework improvers, corrosion inhibitors, silane coupling agents, viscosity modifiers, tackifiers, plasticizers, softeners, anti-aging agents, fillers, colorants, antioxidants. , surfactants, antistatic agents and ultraviolet absorbers.
　光硬化性組成物における溶剤の含有率は、例えば５重量％以下であり、４重量％以下、３重量％以下、２重量％以下、１重量％以下、さらには０．５重量％以下であってもよい。光硬化性組成物は、溶剤を実質的に含まなくてもよい。溶剤を実質的に含まないとは、添加剤等に由来する溶剤等を、例えば０．１重量％以下、好ましくは０．０５重量％以下、より好ましくは０．０１重量％以下の含有率で許容する趣旨である。 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 even 0.5% by weight or less. You can. The photocurable composition may be substantially free of solvent. "Substantially free of solvent" means that the content of solvents derived from additives etc. is, for example, 0.1% by weight or less, preferably 0.05% by weight or less, more preferably 0.01% by weight or less. The intention is to allow it.
　光硬化性組成物の粘度は、好ましくは、５～１５０ポイズである。上記範囲の粘度を有する光硬化性組成物は、後述する塗布層の形成に特に適している。 The viscosity of the photocurable composition is preferably 5 to 150 poise. A photocurable composition having a viscosity within the above range is particularly suitable for forming the coating layer described below.
（粘着シートの物性及び特性）
　粘着シート１における単量体群の重合率は、好ましくは９０％以上である。重合率は、９５％以上、９８％以上、さらには９９％以上であってもよい。 (Physical properties and characteristics of adhesive sheet)
The polymerization rate of the monomer group in the adhesive sheet 1 is preferably 90% or more. The polymerization rate may be 95% or more, 98% or more, or even 99% or more.
　粘着シート１のゲル分率は、例えば５０％以上であり、７０％以上、７５％以上、８０％以上、さらには８５％以上であってもよい。粘着シート１のゲル分率の上限は、例えば９５％以下であり、場合によっては、８０％以下、７５％以下であってもよい。粘着シート１のゲル分率が７５％以下である場合、粘着シート１が光学フィルムと密着しやすく、光学フィルムとの投錨力がより向上する傾向がある。 The gel fraction of the adhesive sheet 1 is, for example, 50% or more, and may be 70% or more, 75% or more, 80% or more, or even 85% or more. The upper limit of the gel fraction of the adhesive sheet 1 is, for example, 95% or less, and may be 80% or less or 75% or less depending on the case. When the gel fraction of the adhesive sheet 1 is 75% or less, the adhesive sheet 1 tends to be in close contact with the optical film, and the anchoring force with the optical film tends to be further improved.
　粘着シート１のクリープ量は、例えば５００μｍ以下であり、３００μｍ以下、１８０μｍ以下、１６０μｍ以下、１５０μｍ以下、１００μｍ以下、さらには５０μｍ以下であってもよい。クリープ量の下限は、例えば５μｍ以上であり、１０μｍ以上、さらには２０μｍ以上であってもよい。 The creep amount of the adhesive sheet 1 is, for example, 500 μm or less, and may be 300 μm or less, 180 μm or less, 160 μm or less, 150 μm or less, 100 μm or less, or even 50 μm or less. The lower limit of the creep amount may be, for example, 5 μm or more, 10 μm or more, or even 20 μm or more.
　粘着シート１のクリープ量は、以下のように評価できる（図２Ａ及び図２Ｂ参照）。まず、評価対象である粘着シート１とサポートフィルム５１との積層体を１０ｍｍ×５０ｍｍの短冊状に切り出して試験片５２とする。サポートフィルム５１は、試験時に荷重が加えられる粘着シート１における当該荷重の印加部分の変形を抑え、これにより、クリープ量をより精度よく測定することを目的として配置する。サポートフィルム５１には、例えば、ポリエチレンテレフタレート（ＰＥＴ）フィルム等の樹脂フィルムを使用できる。サポートフィルム５１は、光学フィルム、あるいは光学フィルムを含む積層体であってもよい。サポートフィルム５１の厚さは、上記荷重により自らが変形しない厚さであればよく、例えば、２０～２００μｍである。次に、図２Ａ及び図２Ｂに示すように、縦１０ｍｍ×横１０ｍｍの接合面にて、ステンレス製試験板５３の表面に試験片５２を粘着シート１により貼り付ける。なお、図２Ｂは、図２Ａの断面Ｂ－Ｂである。試験板５３への試験片５２の貼り付けは、試験板５３と粘着シート１との間に気泡が混入しないように実施する。また、貼り付けた後、５０℃及び５気圧（絶対圧）のオートクレーブ内に１５分収容して試験板５３と粘着シート１との接合を均質化させる。次に、試験板５３及び試験片５２を、試験板５３が上方となるように垂直に保持して２５℃の雰囲気に少なくとも５分放置した後、試験板５３を固定した状態で試験片５２の下端中央に質量５００ｇの錘を固定して５００ｇｆの荷重５４を鉛直下方に加える。荷重５４を加え始めてから３６００秒後の時点における試験板５３に対する粘着シート１のクリープ量（ずれ量）を錘の落下量として測定する。錘の落下量の測定には、レーザー変位計を使用できる。 The amount of creep of the adhesive sheet 1 can be evaluated as follows (see FIGS. 2A and 2B). First, a test piece 52 is obtained by cutting a laminate of the adhesive sheet 1 and the support film 51 to be evaluated into a strip of 10 mm x 50 mm. The support film 51 is disposed for the purpose of suppressing deformation of the load-applied portion of the pressure-sensitive adhesive sheet 1 during a test, and thereby measuring the amount of creep with higher accuracy. For the support film 51, for example, a resin film such as a polyethylene terephthalate (PET) film can be used. The support film 51 may be an optical film or a laminate including an optical film. The thickness of the support film 51 may be such that it does not deform itself under the above load, and is, for example, 20 to 200 μm. Next, as shown in FIGS. 2A and 2B, the test piece 52 is attached to the surface of the stainless steel test plate 53 using the adhesive sheet 1 at a joint surface measuring 10 mm in length and 10 mm in width. Note that FIG. 2B is a cross section BB in FIG. 2A. The test piece 52 is attached to the test plate 53 so that air bubbles are not mixed between the test plate 53 and the adhesive sheet 1. Further, after pasting, the test plate 53 and the adhesive sheet 1 are placed in an autoclave at 50° C. and 5 atm (absolute pressure) for 15 minutes to homogenize the bond between the test plate 53 and the adhesive sheet 1. Next, the test plate 53 and the test piece 52 are held vertically with the test plate 53 facing upward and left in an atmosphere of 25°C for at least 5 minutes. A weight with a mass of 500 g is fixed at the center of the lower end, and a load 54 of 500 gf is applied vertically downward. The amount of creep (deviation amount) of the adhesive sheet 1 with respect to the test plate 53 at the time point 3600 seconds after the start of applying the load 54 is measured as the amount of fall of the weight. A laser displacement meter can be used to measure the amount of weight fall.
　粘着シート１の厚さは、例えば５００μｍ以下であり、２５０μｍ以下、１５０μｍ以下、１００μｍ以下、５０μｍ以下、３０μｍ以下、２５μｍ以下、さらには２０μｍ以下であってもよい。粘着シート１の厚さの下限は、例えば２μｍ以上であり、５μｍ以上であってもよい。 The thickness of the adhesive sheet 1 is, for example, 500 μm or less, and may be 250 μm or less, 150 μm or less, 100 μm or less, 50 μm or less, 30 μm or less, 25 μm or less, or even 20 μm or less. The lower limit of the thickness of the adhesive sheet 1 is, for example, 2 μm or more, and may be 5 μm or more.
（粘着シートの製造方法）
　粘着シート１は、例えば、次の方法によって製造できる。まず、図３Ａや図３Ｂに示すように、基材シート２１、光硬化性組成物を含む塗布層２２、及びはく離ライナー２３をこの順に含む第１の積層体１５を作製する。第１の積層体１５に光１４を照射することによって塗布層２２から粘着シート１を形成することができる（図３Ｃ）。 (Method for manufacturing adhesive sheet)
The adhesive sheet 1 can be manufactured, for example, by the following method. First, as shown in FIGS. 3A and 3B, a first laminate 15 including a base sheet 21, a coating layer 22 containing a photocurable composition, and a release liner 23 in this order is produced. The adhesive sheet 1 can be formed from the coating layer 22 by irradiating the first laminate 15 with the light 14 (FIG. 3C).
　第１の積層体１５に対する光１４の照射は、典型的には、基材シート２１の側から実施する（図３Ａ）。このとき、光１４は、基材シート２１を透過して塗布層２２に到達し、塗布層２２を硬化させる。ただし、光１４の照射は、はく離ライナー２３の側から実施してもよいし、はく離ライナー２３及び基材シート２１の双方の側から実施してもよい（図３Ｂ）。塗布層２２から形成された粘着シート１は、はく離ライナー２３が剥離されるまでは、基材シート２１及びはく離ライナー２３によって挟持されて、第２の積層体１６の一部を構成している。 The first laminate 15 is typically irradiated with the light 14 from the base sheet 21 side (FIG. 3A). At this time, the light 14 passes through the base sheet 21, reaches the coating layer 22, and cures the coating layer 22. However, the irradiation with the light 14 may be performed from the release liner 23 side, or from both sides of the release liner 23 and the base sheet 21 (FIG. 3B). The adhesive sheet 1 formed from the coating layer 22 is sandwiched between the base sheet 21 and the release liner 23 and constitutes a part of the second laminate 16 until the release liner 23 is peeled off.
　はく離ライナー２３の基材（以下、「ライナー基材」）の例は、樹脂フィルムである。ライナー基材に含まれうる樹脂の例は、ポリエチレンテレフタレート及びポリエチレンナフタレート等のポリエステル、アセテート樹脂、ポリエーテルスルホン、ポリカーボネート、ポリアミド、ポリイミド、ポリオレフィン、（メタ）アクリル樹脂、ポリ塩化ビニル、ポリ塩化ビニリデン、ポリスチレン、ポリビニルアルコール、ポリアリレート、並びにポリフェニレンサルファイドである。樹脂は、好ましくは、ポリエチレンテレフタレート等のポリエステルである。 An example of the base material of the release liner 23 (hereinafter referred to as "liner base material") is a resin film. Examples of resins that can be included in the liner base material are polyesters such as polyethylene terephthalate and polyethylene naphthalate, acetate resins, polyether sulfones, polycarbonates, polyamides, polyimides, polyolefins, (meth)acrylic resins, polyvinyl chloride, polyvinylidene chloride. , polystyrene, polyvinyl alcohol, polyarylate, and polyphenylene sulfide. The resin is preferably a polyester such as polyethylene terephthalate.
　はく離ライナー２３は、光１４の透過性を有していてもよく、基材シート２１と同程度の光１４の透過性を有していてもよい。 The release liner 23 may have a light 14 transmittance, or may have a light 14 transmittance comparable to that of the base sheet 21.
　はく離ライナー２３の厚さは、例えば１０～２００μｍであり、２５～１５０μｍであってもよい。 The thickness of the release liner 23 is, for example, 10 to 200 μm, and may be 25 to 150 μm.
　はく離ライナー２３は、ライナー基材以外の層を備えていてもよい。はく離ライナー２３は、離型層を備えていてもよい。はく離ライナー２３は、例えば、ライナー基材と、ライナー基材の一方の面に形成された離型層とを備える。このはく離ライナー２３は、離型層が塗布層２２の側となるように使用できる。 The release liner 23 may include layers other than the liner base material. The release liner 23 may include a release layer. The release liner 23 includes, for example, a liner base material and a release layer formed on one surface of the liner base material. This release liner 23 can be used so that the release layer is on the coating layer 22 side.
　離型層は、典型的には、離型剤を含む離型剤組成物の硬化層である。離型剤には、シリコーン系離型剤、フッ素系離型剤、長鎖アルキル系離型剤、脂肪酸アミド系離型剤、シリカ粉等の種々の離型剤を使用できる。はく離ライナー２３は、シリコーン系離型剤を主成分として含む離型剤組成物の硬化層（以下「シリコーン離型層」）を備えていてもよい。シリコーン離型層は、粘着シート１に対する密着性及び剥離性の両立に特に適している。なお、本明細書において主成分とは、最も含有率の大きな成分を意味する。 The release layer is typically a cured layer of a release agent composition containing a release agent. Various mold release agents can be used as the mold release agent, such as a silicone mold release agent, a fluorine mold release agent, a long chain alkyl mold release agent, a fatty acid amide mold release agent, and silica powder. The release liner 23 may include a cured layer of a release agent composition containing a silicone release agent as a main component (hereinafter referred to as "silicone release layer"). The silicone release layer is particularly suitable for achieving both adhesion and releasability to the pressure-sensitive adhesive sheet 1. In addition, in this specification, the main component means the component with the largest content rate.
　シリコーン系離型剤は、例えば、付加反応型、縮合反応型、紫外線硬化型、電子線硬化型、無溶媒型等の各種の硬化型シリコーン材料であり、付加反応硬化型シリコーン材料が好ましい。付加反応硬化型シリコーン材料は、粘着シート１に対する密着性及び剥離性の両立した離型層の形成に特に適している。硬化型シリコーン材料は、ウレタン、エポキシ、アルキッド樹脂等の有機樹脂にグラフト重合等により反応性シリコーンを導入したシリコーン変性樹脂であってもよい。 The silicone mold release agent is, for example, various types of curable silicone materials such as addition reaction type, condensation reaction type, ultraviolet curable type, electron beam curable type, and solvent-free type, with addition reaction curable silicone materials being preferred. The addition reaction-curable silicone material is particularly suitable for forming a release layer that has both adhesion and releasability to the pressure-sensitive adhesive sheet 1. The curable silicone material may be a silicone-modified resin in which reactive silicone is introduced into an organic resin such as urethane, epoxy, or alkyd resin by graft polymerization or the like.
　付加反応硬化型シリコーン材料の例は、ビニル基又はアルケニル基を分子内に有するポリオルガノシロキサンである。付加反応硬化型シリコーン材料は、ヒドロシリル基を有さなくてもよい。アルケニル基の例は、３－ブテニル基、４－ペンテニル基、５－ヘキセニル基、６－ヘプテニル基、７－オクテニル基、８－ノネニル基、９－デセニル基、１０－ウンデセニル基、及び１１－ドデセニル基である。ポリオルガノシロキサンの例は、ポリジメチルシロキサン、ポリジエチルシロキサン及びポリメチルエチルシロキサン等のポリアルキルアルキルシロキサン、ポリアルキルアリールシロキサン、並びにポリ（ジメチルシロキサン－ジエチルシロキサン）等の複数種のＳｉ原子含有モノマーの共重合体である。ポリオルガノシロキサンは、好ましくはポリジメチルシロキサンである。 An example of an addition reaction-curable silicone material is a polyorganosiloxane having a vinyl group or an alkenyl group in the molecule. The addition reaction curable silicone material does not need to have a hydrosilyl group. Examples of alkenyl groups are 3-butenyl, 4-pentenyl, 5-hexenyl, 6-heptenyl, 7-octenyl, 8-nonenyl, 9-decenyl, 10-undecenyl, and 11-dodecenyl. It is the basis. Examples of polyorganosiloxanes include polyalkylalkylsiloxanes such as polydimethylsiloxane, polydiethylsiloxane, and polymethylethylsiloxane, polyalkylarylsiloxanes, and a plurality of Si atom-containing monomers such as poly(dimethylsiloxane-diethylsiloxane). It is a copolymer. The polyorganosiloxane is preferably polydimethylsiloxane.
　シリコーン系離型剤を主成分として含む離型剤組成物（以下「シリコーン離型剤組成物」）は、通常、架橋剤を含む。架橋剤の例は、ヒドロシリル基を有するポリオルガノシロキサンである。架橋剤は、一分子中に２以上のヒドロシリル基を有していてもよい。 A mold release agent composition containing a silicone mold release agent as a main component (hereinafter referred to as "silicone mold release agent composition") usually contains a crosslinking agent. Examples of crosslinking agents are polyorganosiloxanes containing hydrosilyl groups. The crosslinking agent may have two or more hydrosilyl groups in one molecule.
　シリコーン離型剤組成物は、硬化触媒を含んでいてもよい。硬化触媒の例は、白金系触媒である。白金系触媒の例は、塩化白金酸、白金のオレフィン錯体、塩化白金酸のオレフィン錯体である。白金系触媒の使用量は、組成物の全固形分に対して、例えば１０～１０００ｐｐｍ（重量基準、白金換算）である。 The silicone mold release agent composition may contain a curing catalyst. An example of a curing catalyst is a platinum-based catalyst. Examples of platinum-based catalysts are chloroplatinic acid, olefin complexes of platinum, and olefin complexes of chloroplatinic acid. The amount of the platinum-based catalyst used is, for example, 10 to 1000 ppm (by weight, in terms of platinum) based on the total solid content of the composition.
　シリコーン離型剤組成物は、添加剤を含んでいてもよい。添加剤の例は、剥離コントロール剤及び密着性向上剤である。剥離コントロール剤の例は未反応性のシリコーン樹脂であり、より具体的な例は、オクタメチルシクロテトラシロキサン等のオルガノシロキサン、及びＭＱレジンである。剥離コントロール剤及び密着性向上剤の使用量は、組成物の全固形分に対して合計で、例えば１～３０重量％である。添加剤のさらなる例は、充填剤、帯電防止剤、酸化防止剤、紫外線吸収剤、可塑剤及び着色剤である。さらなる添加剤の使用量は、組成物の全固形分に対して合計で、例えば１０重量％以下である。 The silicone mold release agent composition may contain additives. Examples of additives are release control agents and adhesion promoters. Examples of release control agents are unreacted silicone resins, and more specific examples are organosiloxanes such as octamethylcyclotetrasiloxane, and MQ resins. The total amount of the peel control agent and adhesion improver used is, for example, 1 to 30% by weight based on the total solid content of the composition. Further examples of additives are fillers, antistatic agents, antioxidants, UV absorbers, plasticizers and colorants. The amount of further additives used is, for example, up to 10% by weight in total, based on the total solids content of the composition.
　シリコーン離型剤組成物は、有機溶媒を含んでいてもよい。有機溶媒の例は、シクロヘキサン、ｎ－ヘキサン、ｎ－ヘプタン等の炭化水素系溶媒；トルエン、キシレン等の芳香族系溶媒；酢酸エチル、酢酸メチル等のエステル系溶媒；アセトン、メチルエチルケトン等のケトン系溶媒；メタノール、エタノール、ブタノール等のアルコール系溶媒である。２種以上の有機溶媒が含まれていてもよい。有機溶媒の使用量は、好ましくは、シリコーン離型剤組成物の８０～９９．９重量％である。 The silicone mold release agent composition may contain an organic solvent. Examples of organic solvents include hydrocarbon solvents such as cyclohexane, n-hexane, and n-heptane; aromatic solvents such as toluene and xylene; ester solvents such as ethyl acetate and methyl acetate; ketone solvents such as acetone and methyl ethyl ketone. Solvent: Alcohol solvent such as methanol, ethanol, butanol. Two or more types of organic solvents may be included. The amount of organic solvent used is preferably 80 to 99.9% by weight of the silicone mold release agent composition.
　離型層は、例えば、ライナー基材上に形成した離型剤組成物を含む塗布膜を加熱及び乾燥して形成できる。離型剤組成物の塗布には、ロールコート、キスロールコート、グラビアコート、リバースコート、ロールブラッシュ、スプレーコート、ディップロールコート、バーコート、ナイフコート、エアーナイフコート、カーテンコート、リップコート、ダイコート等の各種の塗布方法を適用できる。加熱及び乾燥には、例えば熱風乾燥を適用できる。加熱温度及び時間は、ライナー基材の耐熱性により異なるが、通常、８０～１５０℃及び１０秒～１０分程度である。必要に応じて、紫外線等の活性エネルギー線の照射を併用してもよい。 The release layer can be formed, for example, by heating and drying a coating film containing a release agent composition formed on a liner base material. Application of the release agent composition includes roll coating, kiss roll coating, gravure coating, reverse coating, roll brushing, spray coating, dip roll coating, bar coating, knife coating, air knife coating, curtain coating, lip coating, and die coating. Various coating methods such as can be applied. For example, hot air drying can be used for heating and drying. The heating temperature and time vary depending on the heat resistance of the liner base material, but are usually about 80 to 150°C and about 10 seconds to 10 minutes. If necessary, irradiation with active energy rays such as ultraviolet rays may be used in combination.
　離型層の厚さは、例えば１０～３００ｎｍである。厚さの上限は、２００ｎｍ以下、１５０ｎｍ以下、１２０ｎｍ以下、１１０ｎｍ以下、１００ｎｍ以下、１００ｎｍ未満、９０ｎｍ以下、８０ｎｍ以下、７０ｎｍ以下、７０ｎｍ未満、さらには６５ｎｍ以下であってもよい。厚さの下限は、１５ｎｍ以上、２０ｎｍ以上、２５ｎｍ以上、３０ｎｍ以上、３５ｎｍ以上、４０ｎｍ以上、４５ｎｍ以上、さらには５０ｎｍ以上であってもよい。 The thickness of the release layer is, for example, 10 to 300 nm. The upper limit of the thickness may be 200 nm or less, 150 nm or less, 120 nm or less, 110 nm or less, 100 nm or less, less than 100 nm, 90 nm or less, 80 nm or less, 70 nm or less, less than 70 nm, or even 65 nm or less. The lower limit of the thickness may be 15 nm or more, 20 nm or more, 25 nm or more, 30 nm or more, 35 nm or more, 40 nm or more, 45 nm or more, or even 50 nm or more.
　はく離ライナー２３は、枚葉状であっても長尺状であってもよい。 The release liner 23 may be sheet-shaped or elongated.
　基材シート２１の例は、樹脂フィルムである。基材シート２１に含まれる樹脂の例は、ライナー基材に含まれうる樹脂の例と同じである。 An example of the base sheet 21 is a resin film. Examples of resins included in the base sheet 21 are the same as examples of resins that can be included in the liner base material.
　基材シート２１は、光１４の透過性に優れることが好ましい。 It is preferable that the base sheet 21 has excellent transparency for the light 14.
　基材シート２１の厚さは、例えば１０～２００μｍであり、２５～１５０μｍであってもよい。 The thickness of the base sheet 21 is, for example, 10 to 200 μm, and may be 25 to 150 μm.
　基材シート２１は、塗布層２２の側の面に離型層を備えていてもよい。基材シート２１が備えうる離型層及びその製法の例は、はく離ライナー２３が備えうる離型層及びその製法の例と同じである。はく離ライナー２３及び基材シート２１の双方が離型層を備えていてもよい。この場合、双方の離型層は、同じ離型剤を主成分として含む離型剤組成物から形成されていてもよい。また、双方の離型層の厚さは異なっていてもよく、例えば、基材シート２１が備える離型層の方が厚くてもよい。 The base sheet 21 may include a release layer on the surface facing the coating layer 22. Examples of the release layer that the base sheet 21 can include and its manufacturing method are the same as the examples of the release layer that the release liner 23 can include and its manufacturing method. Both the release liner 23 and the base sheet 21 may be provided with a release layer. In this case, both mold release layers may be formed from mold release agent compositions containing the same mold release agent as a main component. Further, the thicknesses of both release layers may be different, and for example, the release layer included in the base sheet 21 may be thicker.
　基材シート２１には、通常、粘着シート１との剥離力がはく離ライナー２３に比べて大きなシートを選択できる。 For the base sheet 21, a sheet can usually be selected that has a greater peeling force with the adhesive sheet 1 than the release liner 23.
　基材シート２１は、枚葉状であっても長尺状であってもよい。 The base sheet 21 may be sheet-shaped or elongated.
　第１の積層体１５は、例えば、基材シート２１（又ははく離ライナー２３）の上に塗布層２２を形成し、形成した塗布層２２の上にはく離ライナー２３（又は基材シート２１）を配置して形成できる。また、互いの主面が向き合うように所定の間隔に保持された基材シート２１及びはく離ライナー２３の間の空間に光硬化性組成物を流しこむように塗布して第１の積層体１５を形成してもよい。 The first laminate 15 is constructed by, for example, forming a coating layer 22 on a base sheet 21 (or a release liner 23), and disposing a release liner 23 (or a base sheet 21) on the formed coating layer 22. It can be formed by Further, the first laminate 15 is formed by pouring and applying the photocurable composition into the space between the base sheet 21 and the release liner 23 which are held at a predetermined interval so that their main surfaces face each other. You may.
　塗布層２２の形成には、ロールコート、キスロールコート、グラビアコート、リバースコート、ロールブラッシュ、スプレーコート、ディップロールコート、バーコート、ナイフコート、エアーナイフコート、カーテンコート、リップコート、ダイコート等の各種の塗布方法を適用できる。 The coating layer 22 can be formed using a roll coat, a kiss roll coat, a gravure coat, a reverse coat, a roll brush, a spray coat, a dip roll coat, a bar coat, a knife coat, an air knife coat, a curtain coat, a lip coat, a die coat, etc. Various application methods can be applied.
　塗布層２２の厚さは、目的とする粘着シート１の厚さに応じて調整でき、例えば５～５００μｍであり、５～２５０μｍ、５～１５０μｍ、５～１００μｍ、５～５０μｍ、５～３０μｍ、５～２５μｍ、さらには５～２０μｍであってもよい。 The thickness of the coating layer 22 can be adjusted depending on the desired thickness of the adhesive sheet 1, and is, for example, 5 to 500 μm, 5 to 250 μm, 5 to 150 μm, 5 to 100 μm, 5 to 50 μm, 5 to 30 μm, It may be 5 to 25 μm, or even 5 to 20 μm.
　第１の積層体１５に照射する光１４は、例えば、波長４５０ｎｍよりも短い波長を有する可視光又は紫外線である。光１４は、光硬化性組成物が含む光重合開始剤の吸収波長と同じ領域の波長の光を含んでいてもよい。波長３００ｎｍ以下の短波長光をフィルター等でカットした光１４を照射してもよく、短波長光をカットすることは、光１４による基材シート２１の劣化の抑制に適している。光１４の光源は、例えば紫外線照射ランプを備える光照射装置である。紫外線照射ランプの例は、紫外光ＬＥＤ、低圧水銀灯、中圧水銀灯、高圧水銀灯、超高圧水銀灯、メタルハライドランプ、キセノンランプ、マイクロウエーブ励起水銀灯、ブラックライトランプ、ケミカルランプ、殺菌ランプ、低圧放電水銀ランプ、エキシマレーザーである。２以上の紫外線照射ランプが組み合わされていてもよい。 The light 14 irradiated onto the first laminate 15 is, for example, visible light or ultraviolet light having a wavelength shorter than 450 nm. The light 14 may include light with a wavelength in the same region as the absorption wavelength of the photopolymerization initiator included in the photocurable composition. The light 14 may be irradiated by cutting short wavelength light with a wavelength of 300 nm or less using a filter or the like, and cutting off the short wavelength light is suitable for suppressing deterioration of the base sheet 21 due to the light 14. The light source of the light 14 is, for example, a light irradiation device including an ultraviolet irradiation lamp. Examples of ultraviolet irradiation lamps include ultraviolet LEDs, low-pressure mercury lamps, medium-pressure mercury lamps, high-pressure mercury lamps, extra-high-pressure mercury lamps, metal halide lamps, xenon lamps, microwave-excited mercury lamps, black light lamps, chemical lamps, germicidal lamps, and low-pressure discharge mercury lamps. , an excimer laser. Two or more ultraviolet irradiation lamps may be combined.
　光１４の照射は、連続的であっても断続的であってもよい。 Irradiation of the light 14 may be continuous or intermittent.
　光１４の照度は、例えば１～２０ｍＷ／ｃｍ2である。光１４の照射時間は、例えば５分～５時間である。第１の積層体１５に対する光１４の積算光量は、例えば１００～５０００ｍＪ／ｃｍ2である。 The illuminance of the light 14 is, for example, 1 to 20 mW/cm 2 . The irradiation time of the light 14 is, for example, 5 minutes to 5 hours. The cumulative amount of light 14 to the first laminate 15 is, for example, 100 to 5000 mJ/cm 2 .
　なお、必要に応じて、第２の積層体１６からはく離ライナー２３を剥離し、粘着シート１の表面（例えば表面１ａ）を露出させ、当該表面に対して表面改質処理を施してもよい。 Note that, if necessary, the release liner 23 may be peeled off from the second laminate 16 to expose the surface (for example, the surface 1a) of the adhesive sheet 1, and the surface may be subjected to surface modification treatment.
［光学積層体の実施形態］
　本実施形態の光学積層体の一例を図４に示す。図４の光学積層体１０は、上記の粘着シート１と、偏光フィルム及び位相差フィルムからなる群より選ばれる少なくとも１つの光学フィルム２とを含む。粘着シート１は、光学フィルム２と直接接していることが好ましい。図４の例では、粘着シート１の表面１ａが光学フィルム２と接触している。光学積層体１０は、粘着シート１の作製時に用いた基材シートが粘着シート１に積層された構造を有していてもよい。光学積層体１０は、粘着シート付き光学フィルムとして使用できる。 [Embodiment of optical laminate]
An example of the optical laminate of this embodiment is shown in FIG. The optical laminate 10 in FIG. 4 includes the adhesive sheet 1 described above and at least one optical film 2 selected from the group consisting of a polarizing film and a retardation film. It is preferable that the adhesive sheet 1 is in direct contact with the optical film 2. In the example of FIG. 4, the surface 1a of the adhesive sheet 1 is in contact with the optical film 2. The optical laminate 10 may have a structure in which the base sheet used in producing the adhesive sheet 1 is laminated on the adhesive sheet 1. The optical laminate 10 can be used as an optical film with an adhesive sheet.
（光学フィルム）
　光学フィルム２は、粘着シート１に対向する表面２ａを有する。例えば、表面２ａが粘着シート１の表面１ａと接している。光学フィルム２の表面２ａには、表面改質処理が施されていてもよい。表面改質処理が施された表面２ａによれば、粘着シート１と光学フィルム２との投錨力を向上できる傾向がある。表面改質処理としては、粘着シート１について上述したものが挙げられる。 (optical film)
Optical film 2 has a surface 2 a facing adhesive sheet 1 . For example, the surface 2a is in contact with the surface 1a of the adhesive sheet 1. The surface 2a of the optical film 2 may be subjected to a surface modification treatment. According to the surface 2a subjected to the surface modification treatment, there is a tendency that the anchoring force between the adhesive sheet 1 and the optical film 2 can be improved. Examples of the surface modification treatment include those described above for the adhesive sheet 1.
　表面２ａは、表面改質処理としてコロナ処理が施されていることが好ましい。表面２ａにコロナ処理が施される場合、放電量などの条件は、例えば、粘着シート１について上述した範囲で適宜調節することができる。 The surface 2a is preferably subjected to corona treatment as surface modification treatment. When the surface 2a is subjected to corona treatment, conditions such as the amount of discharge can be adjusted as appropriate within the range described above for the adhesive sheet 1, for example.
　上述のとおり、光学フィルム２は、偏光フィルム及び位相差フィルムからなる群から選ばれる少なくとも１つを含む。光学フィルム２は、偏光フィルム及び／又は位相差フィルムを含む積層フィルムであってもよい。光学フィルム２は、ガラス製のフィルムを含んでいてもよい。ただし、光学フィルム２は上記例に限定されない。 As described above, the optical film 2 includes at least one selected from the group consisting of a polarizing film and a retardation film. The optical film 2 may be a laminated film including a polarizing film and/or a retardation film. The optical film 2 may include a glass film. However, the optical film 2 is not limited to the above example.
　偏光フィルムは、偏光子を含む。偏光フィルムは、典型的には、偏光子及び保護フィルム（透明保護フィルム）を含む。保護フィルムは、例えば、偏光子の主面（最も広い面積を有する表面）に接して配置されている。偏光子は、２つの保護フィルムの間に配置されていてもよい。保護フィルムは、偏光子の少なくとも一方の面に配置されていてもよい。 The polarizing film includes a polarizer. A polarizing film typically includes a polarizer and a protective film (transparent protective film). The protective film is placed, for example, in contact with the main surface (the surface with the widest area) of the polarizer. A polarizer may be placed between two protective films. The protective film may be placed on at least one surface of the polarizer.
　偏光子としては、特に限定されず、例えば、ポリビニルアルコール系フィルム、部分ホルマール化ポリビニルアルコール系フィルム、エチレン・酢酸ビニル共重合体系部分ケン化フィルム等の親水性高分子フィルムに、ヨウ素、二色性染料等の二色性物質を吸着させて一軸延伸したもの；ポリビニルアルコールの脱水処理物、ポリ塩化ビニルの脱塩酸処理物等のポリエン系配向フィルム等が挙げられる。偏光子は、典型的には、ポリビニルアルコール系フィルム（ポリビニルアルコール系フィルムには、エチレン・酢酸ビニル共重合体系部分ケン化フィルムが含まれる）、及び、ヨウ素等の二色性物質からなる。 The polarizer is not particularly limited, and examples include hydrophilic polymer films such as polyvinyl alcohol films, partially formalized polyvinyl alcohol films, partially saponified ethylene/vinyl acetate copolymer films, iodine, and dichroism. Examples include those obtained by adsorbing dichroic substances such as dyes and uniaxially stretched; polyene-based oriented films such as dehydrated polyvinyl alcohol and dehydrochloric acid treated polyvinyl chloride. A polarizer typically consists of a polyvinyl alcohol film (polyvinyl alcohol films include partially saponified ethylene/vinyl acetate copolymer films) and a dichroic substance such as iodine.
　偏光子の厚さは、特に限定されず、例えば８０μｍ以下であり、５０μｍ以下、３０μｍ以下、２５μｍ以下、さらには２０μｍ以下であってもよい。偏光子の厚さの下限は、特に限定されず、例えば１μｍ以上であり、５μｍ以上、１０μｍ以上、さらには１５μｍ以上であってもよい。薄型の偏光子（例えば、厚さ２０μｍ以下）は、寸法変化が抑制されており、光学積層体の耐久性、特に高温下の耐久性、の向上に寄与しうる。 The thickness of the polarizer is not particularly limited, and may be, for example, 80 μm or less, 50 μm or less, 30 μm or less, 25 μm or less, or even 20 μm or less. The lower limit of the thickness of the polarizer is not particularly limited, and may be, for example, 1 μm or more, 5 μm or more, 10 μm or more, or even 15 μm or more. A thin polarizer (for example, 20 μm or less in thickness) has suppressed dimensional changes and can contribute to improving the durability of the optical laminate, especially the durability under high temperatures.
　保護フィルムの材料としては、例えば、透明性、機械的強度、熱安定性、水分遮断性、等方性等に優れる熱可塑性樹脂が用いられる。このような熱可塑性樹脂の具体例としては、トリアセチルセルロース等のセルロース樹脂、ポリエステル樹脂、ポリエーテルスルホン樹脂、ポリスルホン樹脂、ポリカーボネート樹脂、ポリアミド樹脂、ポリイミド樹脂、ポリオレフィン樹脂、（メタ）アクリル樹脂、環状ポリオレフィン樹脂（ノルボルネン系樹脂）、ポリアリレート樹脂、ポリスチレン樹脂、ポリビニルアルコール樹脂、及び、これらの混合物が挙げられる。保護フィルムの材料は、（メタ）アクリル系、ウレタン系、アクリルウレタン系、エポキシ系、シリコーン系等の熱硬化性樹脂又は紫外線硬化型樹脂であってもよい。偏光フィルムが２つの保護フィルムを有する場合、２つの保護フィルムの材料は、互いに同じであってもよく、異なっていてもよい。例えば、偏光子の一方の主面に対して、接着剤を介して、熱可塑性樹脂で構成された保護フィルムが貼り合わされ、偏光子の他方の主面に対して、熱硬化性樹脂又は紫外線硬化型樹脂で構成された保護フィルムが貼り合わされていてもよい。保護フィルムは、任意の添加剤を１種類以上含んでいてもよい。添加剤としては、例えば、紫外線吸収剤、酸化防止剤、滑剤、可塑剤、離型剤、着色防止剤、難燃剤、核剤、帯電防止剤、顔料、着色剤等が挙げられる。 As the material for the protective film, for example, a thermoplastic resin having excellent transparency, mechanical strength, thermal stability, moisture barrier properties, isotropy, etc. is used. Specific examples of such thermoplastic resins include cellulose resins such as triacetylcellulose, polyester resins, polyethersulfone resins, polysulfone resins, polycarbonate resins, polyamide resins, polyimide resins, polyolefin resins, (meth)acrylic resins, and cyclic resins. Examples include polyolefin resins (norbornene resins), polyarylate resins, polystyrene resins, polyvinyl alcohol resins, and mixtures thereof. The material of the protective film may be a thermosetting resin or an ultraviolet curing resin such as (meth)acrylic, urethane, acrylic urethane, epoxy, or silicone. When the polarizing film has two protective films, the materials of the two protective films may be the same or different. For example, a protective film made of a thermoplastic resin is attached to one main surface of a polarizer via an adhesive, and a protective film made of a thermosetting resin or an ultraviolet curable resin is attached to the other main surface of the polarizer. A protective film made of molded resin may be attached. The protective film may contain one or more types of arbitrary additives. Examples of additives include ultraviolet absorbers, antioxidants, lubricants, plasticizers, mold release agents, color inhibitors, flame retardants, nucleating agents, antistatic agents, pigments, colorants, and the like.
　なお、（メタ）アクリル樹脂を含むフィルムは、粘着シートとの接着強度が小さい傾向がある。しかし、本実施形態の粘着シート１によれば、（メタ）アクリル樹脂を含む保護フィルムの表面と接触している場合であっても、光学フィルム２との投錨力を十分に高い値に調整することができる。 Note that films containing (meth)acrylic resin tend to have low adhesive strength with adhesive sheets. However, according to the adhesive sheet 1 of the present embodiment, the anchoring force with the optical film 2 can be adjusted to a sufficiently high value even when it is in contact with the surface of the protective film containing (meth)acrylic resin. be able to.
　保護フィルムの厚さは、適宜に決定しうるが、一般には強度や取扱性等の作業性、薄膜性等の点より１０～２００μｍ程度である。 The thickness of the protective film can be determined as appropriate, but is generally about 10 to 200 μm from the viewpoint of strength, workability such as handleability, thin film property, etc.
　偏光子と保護フィルムとは通常、水系接着剤等を介して密着している。水系接着剤としては、イソシアネート系接着剤、ポリビニルアルコール系接着剤、ゼラチン系接着剤、ビニル系ラテックス、水系ポリウレタン、水系ポリエステル等を例示できる。上記の接着剤以外の他の接着剤としては、紫外線硬化型接着剤、電子線硬化型接着剤等が挙げられる。電子線硬化型偏光板用接着剤は、各種の保護フィルムに対して、好適な接着性を示す。接着剤は、金属化合物フィラーを含んでいてもよい。 A polarizer and a protective film are usually attached to each other via a water-based adhesive or the like. Examples of water-based adhesives include isocyanate adhesives, polyvinyl alcohol adhesives, gelatin adhesives, vinyl latex, water-based polyurethanes, and water-based polyesters. Examples of adhesives other than the above adhesives include ultraviolet curable adhesives and electron beam curable adhesives. Electron beam-curable adhesives for polarizing plates exhibit suitable adhesion to various types of protective films. The adhesive may include a metal compound filler.
　偏光フィルムでは、保護フィルムに代えて、位相差フィルム等を偏光子上に形成することもできる。保護フィルム上には、さらに別の保護フィルムを設けること、位相差フィルム等を設けること等もできる。 In the polarizing film, a retardation film or the like can also be formed on the polarizer instead of the protective film. It is also possible to provide another protective film, a retardation film, etc. on the protective film.
　保護フィルムについて、偏光子と接着している表面と対向する表面には、ハードコート層が設けられていてもよく、反射防止、スティッキング防止、拡散、アンチグレア等を目的とした処理を施すこともできる。 Regarding the protective film, a hard coat layer may be provided on the surface opposite to the surface bonded to the polarizer, and treatments for the purpose of anti-reflection, anti-sticking, diffusion, anti-glare, etc. can also be applied. .
　偏光フィルムは、円偏光フィルムであってもよい。 The polarizing film may be a circularly polarizing film.
　位相差フィルムとしては、高分子フィルムを延伸させて得られるものや液晶材料を配向、固定化させたものを用いることができる。位相差フィルムは、例えば、面内及び／又は厚さ方向に複屈折を有する。 As the retardation film, one obtained by stretching a polymer film or one obtained by aligning and fixing a liquid crystal material can be used. The retardation film has, for example, birefringence in the plane and/or in the thickness direction.
　位相差フィルムには、反射防止用位相差フィルム（特開２０１２－１３３３０３号公報〔０２２１〕、〔０２２２〕、〔０２２８〕参照）、視野角補償用位相差フィルム（特開２０１２－１３３３０３号公報〔０２２５〕、〔０２２６〕参照）、視野角補償用の傾斜配向位相差フィルム（特開２０１２－１３３３０３号公報〔０２２７〕参照）等が含まれる。 The retardation film includes a retardation film for antireflection (see JP-A-2012-133303 [0221], [0222], and [0228]) and a retardation film for viewing angle compensation (see JP-A 2012-133303 [0221], [0222], and [0228]). 0225], [0226]), an obliquely oriented retardation film for viewing angle compensation (see JP-A-2012-133303 [0227]), and the like.
　位相差フィルムの具体的な構成、例えば、位相差値、配置角度、３次元複屈折率、単層か多層か等は特に限定されず、公知の位相差フィルムを使用することができる。 The specific structure of the retardation film, for example, retardation value, arrangement angle, three-dimensional birefringence, single layer or multilayer, etc., is not particularly limited, and any known retardation film can be used.
　位相差フィルムの厚さは、好ましくは２０μｍ以下であり、より好ましくは１０μｍ以下であり、さらに好ましくは１～９μｍであり、特に好ましくは３～８μｍである。 The thickness of the retardation film is preferably 20 μm or less, more preferably 10 μm or less, still more preferably 1 to 9 μm, particularly preferably 3 to 8 μm.
　位相差フィルムは、例えば、液晶材料が配向、固定化された１／４波長板及び／又は１／２波長板を含んでいてもよい。 The retardation film may include, for example, a quarter-wave plate and/or a half-wave plate in which a liquid crystal material is oriented and fixed.
（光学積層体の特性）
　本実施形態では、粘着シート１と光学フィルム２との投錨力Ｆが大きい傾向がある。投錨力Ｆは、例えば７．０Ｎ／２５ｍｍ以上であり、８．０Ｎ／２５ｍｍ以上、９．０Ｎ／２５ｍｍ以上、１０．０Ｎ／２５ｍｍ以上、１１．０Ｎ／２５ｍｍ以上、１２．０Ｎ／２５ｍｍ以上、１５．０Ｎ／２５ｍｍ以上、２０．０Ｎ／２５ｍｍ以上、２２．０Ｎ／２５ｍｍ以上、２３．０Ｎ／２５ｍｍ以上、２４．０Ｎ／２５ｍｍ以上、さらには２５．０Ｎ／２５ｍｍ以上であってもよい。投錨力Ｆが大きければ大きいほど、粘着シート１と光学フィルム２との間での剥がれを十分に抑制することができる。投錨力Ｆの上限は、特に限定されず、例えば５０Ｎ／２５ｍｍ以下であり、３０Ｎ／２５ｍｍ以下であってもよい。 (Characteristics of optical laminate)
In this embodiment, the anchoring force F between the adhesive sheet 1 and the optical film 2 tends to be large. The anchoring force F is, for example, 7.0 N/25 mm or more, 8.0 N/25 mm or more, 9.0 N/25 mm or more, 10.0 N/25 mm or more, 11.0 N/25 mm or more, 12.0 N/25 mm or more, It may be 15.0 N/25 mm or more, 20.0 N/25 mm or more, 22.0 N/25 mm or more, 23.0 N/25 mm or more, 24.0 N/25 mm or more, or even 25.0 N/25 mm or more. The larger the anchoring force F is, the more fully the peeling between the adhesive sheet 1 and the optical film 2 can be suppressed. The upper limit of the anchoring force F is not particularly limited, and may be, for example, 50 N/25 mm or less, and may be 30 N/25 mm or less.
　粘着シート１と光学フィルム２との投錨力Ｆは、次の方法によって測定することができる。まず、評価対象である光学積層体１０を幅２５ｍｍ×長さ１５０ｍｍに切り出して試験片とする。次に、両面テープを介して、試験片が備える光学フィルム２の表面全体をステンレス製試験板に重ね合わせ、２ｋｇのローラを１往復させて、これらを圧着させる。次に、試験片が備える粘着シート１を評価用シートに重ね合わせ、２ｋｇのローラを１往復させて、これらを圧着させる。評価用シートは、幅３０ｍｍ×長さ１５０ｍｍのサイズを有し、試験中に粘着シート１から剥離しないものである限り特に限定されない。評価用シートとしては、例えば、ＩＴＯフィルム（１２５テトライトＯＥＳ（尾池工業社製）など）を用いることができる。次に、市販の引張試験機を用いて、評価用シートを把持した状態で、剥離角度１８０°、引張速度３００ｍｍ／ｍｉｎで粘着シート１を光学フィルム２から引きはがした際の剥離力の平均値を粘着シート１と光学フィルム２との投錨力Ｆとして特定する。なお、上記の試験は、２３℃の雰囲気下で行う。 The anchoring force F between the adhesive sheet 1 and the optical film 2 can be measured by the following method. First, the optical laminate 10 to be evaluated is cut out into a piece having a width of 25 mm and a length of 150 mm to form a test piece. Next, the entire surface of the optical film 2 included in the test piece was superimposed on a stainless steel test plate via double-sided tape, and a 2 kg roller was moved back and forth once to press them together. Next, the adhesive sheet 1 included in the test piece is superimposed on the evaluation sheet, and a 2 kg roller is moved back and forth once to press them together. The evaluation sheet has a size of 30 mm width x 150 mm length, and is not particularly limited as long as it does not peel off from the adhesive sheet 1 during the test. As the evaluation sheet, for example, an ITO film (125 Tetraite OES (manufactured by Oike Kogyo Co., Ltd.), etc.) can be used. Next, using a commercially available tensile tester, the adhesive sheet 1 was peeled off from the optical film 2 at a peeling angle of 180° and a pulling speed of 300 mm/min while holding the evaluation sheet. The value is specified as the anchoring force F between the adhesive sheet 1 and the optical film 2. Note that the above test is conducted in an atmosphere at 23°C.
　本実施形態の光学積層体の別の一例を図５に示す。図５の光学積層体１１は、粘着シート１Ａ、光学フィルム２Ａ、粘着シート１Ｂ及び光学フィルム２Ｂがこの順に積層された積層構造を有する。光学積層体１１は、粘着シート１Ａの作製時に用いた基材シートが粘着シート１Ａに積層された構造を有していてもよい。 Another example of the optical laminate of this embodiment is shown in FIG. The optical laminate 11 in FIG. 5 has a laminated structure in which an adhesive sheet 1A, an optical film 2A, an adhesive sheet 1B, and an optical film 2B are laminated in this order. The optical laminate 11 may have a structure in which the base sheet used in producing the adhesive sheet 1A is laminated on the adhesive sheet 1A.
　光学積層体１１において、典型的には、光学フィルム２Ａが位相差フィルムであり、光学フィルム２Ｂが偏光フィルムである。粘着シート１Ｂは、光学フィルム２Ａ及び２Ｂの層間粘着剤として機能する。粘着シート１Ｂは、公知の粘着剤を使用したものであってもよい。 In the optical laminate 11, typically, the optical film 2A is a retardation film, and the optical film 2B is a polarizing film. The adhesive sheet 1B functions as an interlayer adhesive between the optical films 2A and 2B. The adhesive sheet 1B may be one using a known adhesive.
　本実施形態の光学積層体は、例えば、帯状の光学積層体を巻回した巻回体として、あるいは枚葉状の光学積層体として、流通及び保管が可能である。 The optical laminate of this embodiment can be distributed and stored, for example, as a roll of a band-shaped optical laminate or as a sheet-shaped optical laminate.
　本実施形態の光学積層体は、典型的には、画像表示装置に用いられる。画像表示装置は、例えば、光学積層体１０又は１１と画像表示パネルとを接合して形成できる。接合は、例えば、粘着シート１により行う。画像表示装置は、有機ＥＬディスプレイであってもよく、液晶ディスプレイであってもよい。ただし、画像表示装置は上記例に限定されない。画像表示装置は、エレクトロルミネッセンス（ＥＬ）ディスプレイ、プラズマディスプレイ（ＰＤ）、電界放出ディスプレイ（ＦＥＤ：Field Emission Display）等であってもよい。画像表示装置は、家電用途、車載用途、パブリックインフォメーションディスプレイ（ＰＩＤ）用途等に用いることができる。 The optical laminate of this embodiment is typically used in an image display device. The image display device can be formed by, for example, joining the optical laminate 10 or 11 and an image display panel. The bonding is performed using the adhesive sheet 1, for example. The image display device may be an organic EL display or a liquid crystal display. However, the image display device is not limited to the above example. The image display device may be an electroluminescence (EL) display, a plasma display (PD), a field emission display (FED), or the like. The image display device can be used for household appliances, in-vehicle applications, public information displays (PID), and the like.
　以下、実施例により、本発明をさらに詳細に説明する。本発明は、以下に示す実施例に限定されない。 Hereinafter, the present invention will be explained in more detail with reference to Examples. The invention is not limited to the examples shown below.
［偏光フィルム］
　まず、厚さ８０μｍのポリビニルアルコールフィルムを、速度比の異なるロール間において、温度３０℃、濃度０．３％のヨウ素溶液中で１分間染色しながら、３倍まで延伸した。次に、濃度４％でホウ酸を含み、かつ濃度１０％でヨウ化カリウムを含む、温度６０℃の水溶液中に０．５分間浸漬しながら、総合延伸倍率が６倍になるまで延伸した。次に、濃度１．５％でヨウ化カリウムを含む、温度３０℃の水溶液中に１０秒間浸漬させて洗浄した後、５０℃で４分間乾燥を行うことによって、厚さ２８μｍの偏光子を得た。当該偏光子の片面に、ラクトン環構造を有する変性アクリル系ポリマーからなる厚さ３０μｍの透明保護フィルムをポリビニルアルコール系接着剤により貼り合せた。さらに、偏光子の他方の面に、トリアセチルセルロースフィルム（コニカミノルタ製、商品名「ＫＣ４ＵＹ」）にハードコート層（ＨＣ）を形成した厚さ４７μｍの透明保護フィルムをポリビニルアルコール系接着剤により貼り合せた。７０℃に設定されたオーブン内で５分間加熱乾燥させることによって偏光フィルムを作製した。さらに、変性アクリル系ポリマーからなる透明保護フィルム側の偏光フィルムの表面に対して、放電量６３Ｗ／ｍ2・ｍｉｎでコロナ処理を行った。 [Polarizing film]
First, a polyvinyl alcohol film having a thickness of 80 μm was stretched up to 3 times the length between rolls having different speed ratios while being dyed for 1 minute in an iodine solution having a concentration of 0.3% at a temperature of 30°C. Next, the film was stretched while being immersed for 0.5 minutes in an aqueous solution containing boric acid at a concentration of 4% and potassium iodide at a concentration of 10% at a temperature of 60°C until the total stretching ratio became 6 times. Next, a polarizer with a thickness of 28 μm was obtained by immersing it in an aqueous solution containing potassium iodide at a concentration of 1.5% and washing it for 10 seconds at a temperature of 30°C, and then drying it at 50°C for 4 minutes. Ta. A 30 μm thick transparent protective film made of a modified acrylic polymer having a lactone ring structure was attached to one side of the polarizer using a polyvinyl alcohol adhesive. Furthermore, on the other side of the polarizer, a 47 μm thick transparent protective film made of a triacetyl cellulose film (manufactured by Konica Minolta, product name "KC4UY") with a hard coat layer (HC) is attached using a polyvinyl alcohol adhesive. Combined. A polarizing film was produced by heating and drying it for 5 minutes in an oven set at 70°C. Further, the surface of the polarizing film on the side of the transparent protective film made of a modified acrylic polymer was subjected to corona treatment at a discharge amount of 63 W/m 2 ·min.
［はく離ライナーＡ］
　付加反応硬化型シリコーン（ヘキセニル基含有ポリオルガノシロキサンを含むＬＴＣ７６１、３０重量％トルエン溶液、東レ・ダウコーニング製）３０重量部、剥離コントロール剤（未反応性シリコーン樹脂を含むＢＹ２４－８５０、東レ・ダウコーニング製）０．９重量部、及び硬化触媒（白金触媒を含むＳＲＸ２１２、東レ・ダウコーニング製）２重量部、及び希釈溶媒としてトルエン／ヘキサン混合溶媒（体積比１：１）を混合して、シリコーン系離型剤組成物を得た。離型剤組成物におけるシリコーン固形分の濃度は、１．０重量％であった。次に、ライナー基材（ポリエステルフィルムであるルミラーＸＤ５００Ｐ、厚さ７５μｍ）の片面に離型剤組成物をワイヤーバーにより塗布し、１３０℃で１分間加熱して、離型層（厚さ６０ｎｍ）を片面に備えるはく離ライナーＡを作製した。 [Release liner A]
Addition reaction curing silicone (LTC761 containing hexenyl group-containing polyorganosiloxane, 30% by weight toluene solution, manufactured by Dow Corning Toray), 30 parts by weight, release control agent (BY24-850 containing unreactive silicone resin, Toray Dow) (manufactured by Corning), 2 parts by weight of a curing catalyst (SRX212 containing platinum catalyst, manufactured by Dow Corning Toray), and a mixed solvent of toluene/hexane (volume ratio 1:1) as a diluting solvent. A silicone mold release agent composition was obtained. The concentration of silicone solids in the mold release agent composition was 1.0% by weight. Next, a mold release agent composition was applied to one side of the liner base material (Lumirror Release liner A was prepared, which had one side of the release liner A.
［はく離ライナーＢ］
　ライナー基材に塗布する離型剤組成物の厚さを変更した以外は、はく離ライナーＡと同じ方法によって、離型層（厚さ１２０ｎｍ）を片面に備えるはく離ライナーＢを作製した。 [Release liner B]
Release liner B, which has a release layer (thickness: 120 nm) on one side, was prepared by the same method as release liner A, except that the thickness of the release agent composition applied to the liner base material was changed.
［モノマーシロップＡ１］
　ｎ－ブチルアクリレート（ＢＡ）４９重量部、４－ヒドロキシブチルアクリレート（ＨＢＡ）１重量部、及び２－メトキシエチルアクリレート（ＭＥＡ）５０重量部と、光重合開始剤としての１－ヒドロキシシクロヘキシル－フェニルケトン（Ｏｍｎｉｒａｄ１８４、IGM Resins B.V.社製）０．０５重量部、及び２，２－ジメトキシ－１，２－ジフェニルエタン－１－オン（Ｏｍｎｉｒａｄ６５１、IGM Resins B.V.社製）０．０５重量部とを４つロフラスコに投入し、窒素雰囲気下で紫外線を照射することによって、部分的に光重合したモノマーシロップＡ１を得た。紫外線の照射は、フラスコ内の液体の粘度（計測条件：ＢＨ粘度計Ｎｏ．５ローター、１０ｒｐｍ、測定温度３０℃）が約２０Ｐａ・ｓになるまで実施した。 [Monomer syrup A1]
49 parts by weight of n-butyl acrylate (BA), 1 part by weight of 4-hydroxybutyl acrylate (HBA), and 50 parts by weight of 2-methoxyethyl acrylate (MEA), and 1-hydroxycyclohexyl-phenyl ketone as a photopolymerization initiator. (Omnirad 184, manufactured by IGM Resins BV) 0.05 parts by weight, and 4 parts of 0.05 parts by weight of 2,2-dimethoxy-1,2-diphenylethan-1-one (Omnirad 651, manufactured by IGM Resins BV) The monomer syrup A1, which was partially photopolymerized, was obtained by charging the mixture into a flask and irradiating it with ultraviolet rays under a nitrogen atmosphere. The ultraviolet irradiation was carried out until the viscosity of the liquid in the flask (measurement conditions: BH viscometer No. 5 rotor, 10 rpm, measurement temperature 30° C.) reached approximately 20 Pa·s.
［モノマーシロップＡ２～Ａ６］
　使用するモノマーを表１のように変更したことを除き、モノマーシロップＡ１と同じ方法によって、モノマーシロップＡ２～Ａ６を調製した。 [Monomer syrup A2-A6]
Monomer syrups A2 to A6 were prepared by the same method as monomer syrup A1, except that the monomers used were changed as shown in Table 1.
Figure JPOXMLDOC01-appb-T000004
Figure JPOXMLDOC01-appb-T000004
　表１中の略称は以下のとおりである。
　ＢＡ：ｎ－ブチルアクリレート
　２ＥＨＡ：２－エチルヘキシルアクリレート
　ＨＢＡ：４－ヒドロキシブチルアクリレート
　ＭＥＡ：２－メトキシエチルアクリレート
　Ｏｍｎｉｒａｄ１８４：１－ヒドロキシシクロヘキシル－フェニルケトン（Ｏｍｎｉｒａｄ１８４、IGM Resins B.V.社製）
　Ｏｍｎｉｒａｄ６５１：２，２－ジメトキシ－１，２－ジフェニルエタン－１－オン（Ｏｍｎｉｒａｄ６５１、IGM Resins B.V.社製） The abbreviations in Table 1 are as follows.
BA: n-butyl acrylate 2EHA: 2-ethylhexyl acrylate HBA: 4-hydroxybutyl acrylate MEA: 2-methoxyethyl acrylate Omnirad184: 1-hydroxycyclohexyl-phenyl ketone (Omnirad184, manufactured by IGM Resins BV)
Omnirad651: 2,2-dimethoxy-1,2-diphenylethan-1-one (Omnirad651, manufactured by IGM Resins BV)
［光硬化性組成物Ｃ１～Ｃ８］
　次に、以下の表２に示す組成となるように、モノマーシロップ及び添加剤を混合して、光硬化性組成物Ｃ１～Ｃ８を得た。 [Photocurable compositions C1 to C8]
Next, monomer syrup and additives were mixed to obtain photocurable compositions C1 to C8 so as to have the compositions shown in Table 2 below.
Figure JPOXMLDOC01-appb-T000005
Figure JPOXMLDOC01-appb-T000005
　表２中の略称は以下のとおりである。
　ＮＤＤＡ：１，９－ノナンジオールジアクリレート
　Ａ－１００：アセトアセチル基含有シランカップリング剤（Ａ－１００、綜研化学社製） The abbreviations in Table 2 are as follows.
NDDA: 1,9-nonanediol diacrylate A-100: Acetoacetyl group-containing silane coupling agent (A-100, manufactured by Soken Chemical Co., Ltd.)
（実施例１）
　はく離ライナーＡの離型層の面に、光硬化性組成物Ｃ１をアプリケーターにより塗布し、塗布層（厚さ２０μｍ）を形成した。次に、形成した塗布層の上に、上述のはく離ライナーＢを配置して第１の積層体を得た。はく離ライナーＢは、離型層が塗布層に接するように配置した。次に、第１の積層体におけるはく離ライナーＡの側から、照度２．５ｍＷ／ｃｍ2、照射時間６４０秒の条件で紫外線（Ｂｌａｃｋ　ｌｉｇｈｔ光源）を照射し、塗布層を光硬化させて、はく離ライナーＡ、粘着シート（厚さ２０μｍ）及びはく離ライナーＢにより構成される第２の積層体を形成した。 (Example 1)
Photocurable composition C1 was applied to the surface of the release layer of release liner A using an applicator to form a coating layer (thickness: 20 μm). Next, the above-described release liner B was placed on the formed coating layer to obtain a first laminate. Release liner B was arranged so that the release layer was in contact with the coating layer. Next, from the release liner A side of the first laminate, ultraviolet light (black light source) is irradiated at an illuminance of 2.5 mW/cm 2 and an irradiation time of 640 seconds to photocure the coating layer and release it. A second laminate consisting of liner A, adhesive sheet (thickness: 20 μm), and release liner B was formed.
　次に、第２の積層体からはく離ライナーＢを剥離し、粘着シートの露出面に上述の偏光フィルムを配置することによって実施例１の光学積層体を得た。なお、偏光フィルムは、変性アクリル系ポリマーからなる透明保護フィルム側の表面が粘着シートに接するように配置した。 Next, the release liner B was peeled off from the second laminate, and the above-mentioned polarizing film was placed on the exposed surface of the adhesive sheet to obtain the optical laminate of Example 1. The polarizing film was placed so that the surface of the transparent protective film made of a modified acrylic polymer was in contact with the adhesive sheet.
（実施例２～３、５、７～８及び比較例１～２）
　使用する光硬化性組成物を表３に示すように変更したことを除き、実施例１と同じ方法によって、実施例２～３、５、７～８及び比較例１～２の光学積層体を得た。 (Examples 2-3, 5, 7-8 and Comparative Examples 1-2)
The optical laminates of Examples 2-3, 5, 7-8 and Comparative Examples 1-2 were prepared by the same method as Example 1, except that the photocurable composition used was changed as shown in Table 3. Obtained.
（実施例４）
　光硬化性組成物Ｃ３を用いたことを除き、実施例１と同じ方法によって、第２の積層体を形成した。次に、第２の積層体からはく離ライナーＢを剥離し、粘着シートの露出面に対して、放電量６３Ｗ／ｍ2・ｍｉｎでコロナ処理を行った。この露出面に上述の偏光フィルムを配置することによって実施例４の光学積層体を得た。なお、偏光フィルムは、変性アクリル系ポリマーからなる透明保護フィルム側の表面が粘着シートに接するように配置した。 (Example 4)
A second laminate was formed in the same manner as in Example 1, except that photocurable composition C3 was used. Next, the release liner B was peeled off from the second laminate, and the exposed surface of the adhesive sheet was subjected to corona treatment at a discharge amount of 63 W/m 2 ·min. The optical laminate of Example 4 was obtained by disposing the above-mentioned polarizing film on this exposed surface. The polarizing film was placed so that the surface of the transparent protective film made of a modified acrylic polymer was in contact with the adhesive sheet.
（実施例６）
　光硬化性組成物Ｃ４を用いたことを除き、実施例１と同じ方法によって、第２の積層体を形成した。次に、第２の積層体からはく離ライナーＢを剥離し、粘着シートの露出面に対して、放電量６３Ｗ／ｍ2・ｍｉｎでコロナ処理を行った。この露出面に上述の偏光フィルムを配置することによって実施例６の光学積層体を得た。なお、偏光フィルムは、変性アクリル系ポリマーからなる透明保護フィルム側の表面が粘着シートに接するように配置した。 (Example 6)
A second laminate was formed in the same manner as in Example 1, except that photocurable composition C4 was used. Next, the release liner B was peeled off from the second laminate, and the exposed surface of the adhesive sheet was subjected to corona treatment at a discharge amount of 63 W/m 2 ·min. The optical laminate of Example 6 was obtained by disposing the above-mentioned polarizing film on this exposed surface. The polarizing film was placed so that the surface of the transparent protective film made of a modified acrylic polymer was in contact with the adhesive sheet.
（参考例１）
［（メタ）アクリル系ポリマーの作製］
　撹拌羽根、温度計、窒素ガス導入管、及び冷却器を備えた４つ口フラスコに、ＢＡ９９．０重量部、及びＨＢＡ１重量部を仕込んだ。次に、ＢＡ、及びＨＢＡの混合物１００重量部に対して、重合開始剤としてＡＩＢＮ０．１重量部を加え、緩やかに撹拌しながら窒素ガスを導入してフラスコ内を窒素置換した後、フラスコ内の液温を５５℃付近に保って重合反応を７時間進行させた。次に、得られた反応液に酢酸エチルを加えて固形分濃度１２重量％に調整して、（メタ）アクリル系ポリマーの溶液を得た。（メタ）アクリル系ポリマーの重量平均分子量（Ｍｗ）は１６５万であった。 (Reference example 1)
[Preparation of (meth)acrylic polymer]
99.0 parts by weight of BA and 1 part by weight of HBA were charged into a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas inlet tube, and a condenser. Next, 0.1 part by weight of AIBN was added as a polymerization initiator to 100 parts by weight of the mixture of BA and HBA, and nitrogen gas was introduced while stirring gently to replace the inside of the flask with nitrogen. The polymerization reaction was allowed to proceed for 7 hours while maintaining the liquid temperature at around 55°C. Next, ethyl acetate was added to the obtained reaction solution to adjust the solid content concentration to 12% by weight to obtain a (meth)acrylic polymer solution. The weight average molecular weight (Mw) of the (meth)acrylic polymer was 1.65 million.
［光学積層体の作製］
　上記の（メタ）アクリル系ポリマーの固形分１００重量部に対して、０．３重量部の過酸化物系架橋剤（ジベンゾイルパーオキシド、日本油脂社製、商品名「ナイパーＢＭＴ」）、０．１重量部のイソシアネート系架橋剤（トリメチロールプロパンキシレンジイソシアネート、三井武田ケミカル社製、商品名「タケネートＤ１１０Ｎ」）、及び、０．２重量部のアセトアセチル基含有シランカップリング剤（綜研化学社製、商品名「Ａ－１００」）を混合して、熱硬化型（溶剤型）の粘着剤組成物を得た。 [Preparation of optical laminate]
Per 100 parts by weight of the solid content of the above (meth)acrylic polymer, 0.3 parts by weight of peroxide crosslinking agent (dibenzoyl peroxide, manufactured by NOF Corporation, trade name "Niper BMT"), 0 .1 part by weight of an isocyanate-based crosslinking agent (trimethylolpropane xylene diisocyanate, manufactured by Mitsui Takeda Chemical Co., Ltd., trade name "Takenate D110N"), and 0.2 part by weight of an acetoacetyl group-containing silane coupling agent (Soken Chemical Co., Ltd.) (trade name: "A-100") was mixed to obtain a thermosetting (solvent type) adhesive composition.
　次に、剥離面にシリコーン処理が施された剥離フィルムである、厚さ３８μｍのＰＥＴフィルム（三菱化学ポリエステルフィルム製、ＭＲＦ３８）の剥離面に対して、上記の粘着剤組成物を塗布して塗布膜を形成し、これを２３℃の環境下にて予備加熱まで放置した後、基材フィルム及び塗布膜を搬送しながら空気循環式恒温オーブンにて予備加熱及び本加熱を連続的に実施して、２０μｍの厚さを有する粘着シートを形成した。粘着シートの露出面に上述の偏光フィルムを配置することによって参考例１の光学積層体を得た。なお、偏光フィルムは、変性アクリル系ポリマーからなる透明保護フィルム側の表面が粘着シートに接するように配置した。 Next, the above adhesive composition is applied to the release surface of a 38 μm thick PET film (manufactured by Mitsubishi Chemical Polyester Film, MRF38), which is a release film whose release surface has been subjected to silicone treatment. After forming a film and leaving it in an environment of 23°C until preheating, preheating and main heating are continuously carried out in an air circulating constant temperature oven while transporting the base film and coating film. , a pressure-sensitive adhesive sheet having a thickness of 20 μm was formed. An optical laminate of Reference Example 1 was obtained by disposing the above polarizing film on the exposed surface of the adhesive sheet. The polarizing film was placed so that the surface of the transparent protective film made of a modified acrylic polymer was in contact with the adhesive sheet.
［ガラス転移温度］
　モノマーシロップや、参考例１の（メタ）アクリル系ポリマーの作製に用いた単量体群から重合体を合成した場合における当該重合体のガラス転移温度ＴｇをＦＯＸの式から算出した。 [Glass-transition temperature]
When a polymer was synthesized from the monomer syrup or the monomer group used for producing the (meth)acrylic polymer of Reference Example 1, the glass transition temperature Tg of the polymer was calculated from the FOX formula.
［ゲル分率］
　作製した粘着シートについて、次の方法によって、ゲル分率を測定した。まず、粘着シートの一部を掻き取って小片約０．２ｇを得た。次に、得られた小片を、ポリテトラフルオロエチレンの延伸多孔質膜（日東電工製ＮＴＦ１１２２（平均孔径０．２μｍ））で包んで凧糸で縛り、試験片を得た。次に、粘着シートの小片、延伸多孔質膜及び凧糸の重量の合計（重量Ａ）を測定した。使用した延伸多孔質膜及び凧糸の合計は、重量Ｂと定義した。次に、酢酸エチルで満たされた容器に試験片を浸漬して、２３℃で１週間静置した。静置後、容器から試験片を取り出し、１３０℃に設定した乾燥機中で２時間乾燥させた後、試験片の重量Ｃを測定した。下記式に基づいて、重量Ａ、重量Ｂ及び重量Ｃから粘着シートのゲル分率を算出した。
　ゲル分率（重量％）＝（Ｃ－Ｂ）／（Ａ－Ｂ）×１００ [Gel fraction]
The gel fraction of the produced pressure-sensitive adhesive sheet was measured by the following method. First, a portion of the adhesive sheet was scraped off to obtain a small piece of about 0.2 g. Next, the obtained small piece was wrapped in a polytetrafluoroethylene stretched porous membrane (NTF1122 manufactured by Nitto Denko (average pore diameter: 0.2 μm)) and tied with a kite string to obtain a test piece. Next, the total weight (weight A) of the small pieces of the adhesive sheet, the stretched porous membrane, and the kite string was measured. The total weight of the stretched porous membrane and kite string used was defined as weight B. Next, the test piece was immersed in a container filled with ethyl acetate and left at 23° C. for one week. After standing still, the test piece was taken out from the container and dried for 2 hours in a dryer set at 130°C, and then the weight C of the test piece was measured. The gel fraction of the adhesive sheet was calculated from weight A, weight B, and weight C based on the following formula.
Gel fraction (wt%) = (CB)/(AB) x 100
［投錨力］
　作製した光学積層体について、上述の方法によって、粘着シートと偏光フィルムとの投錨力Ｆを測定した。両面テープとしては、日東電工社製の商品名「Ｎｏ．５３１」を用いた。ステンレス製試験板としては、ＳＵＳ３０４の板（幅４０ｍｍ×長さ１２０ｍｍ）を用いた。評価用シートとしては、ＩＴＯフィルム（１２５テトライトＯＥＳ、尾池工業製）を用いた。引張試験機としては、オートグラフＳＨＩＭＡＺＵ　ＡＧ-Ｉ　１０ＫＮ（島津製作所製）を用いた。 [Anchoring power]
Regarding the produced optical laminate, the anchoring force F between the pressure-sensitive adhesive sheet and the polarizing film was measured by the method described above. As the double-sided tape, product name "No. 531" manufactured by Nitto Denko Corporation was used. As the stainless steel test plate, a SUS304 plate (width 40 mm x length 120 mm) was used. As the evaluation sheet, an ITO film (125 Tetraite OES, manufactured by Oike Kogyo) was used. As the tensile tester, Autograph SHIMAZU AG-I 10KN (manufactured by Shimadzu Corporation) was used.
［比誘電率］
　モノマーシロップに含まれる部分重合物や、参考例１の（メタ）アクリル系ポリマーについて、上述の方法によって、周波数１００Ｈｚにおける比誘電率Ｐを測定した。 [Relative dielectric constant]
Regarding the partial polymer contained in the monomer syrup and the (meth)acrylic polymer of Reference Example 1, the dielectric constant P at a frequency of 100 Hz was measured by the method described above.
Figure JPOXMLDOC01-appb-T000006
Figure JPOXMLDOC01-appb-T000006
　表３からわかるとおり、エーテル基含有単量体の配合量やＦＯＸの式を利用して算出されるガラス転移温度Ｔｇが上述した範囲に調整された光硬化性組成物から形成された粘着シートを用いた実施例の光学積層体では、比較例と比べて、粘着シートと光学フィルム（偏光フィルム）との投錨力Ｆが大きい値であった。特に、実施例１、２、４、及び６～８では、投錨力Ｆの値が、イソシアネート系架橋剤を含む熱硬化型の粘着剤組成物から作製された粘着シートを用いた参考例１の光学積層体と同程度以上であった。 As can be seen from Table 3, a pressure-sensitive adhesive sheet formed from a photocurable composition in which the glass transition temperature Tg calculated using the blending amount of the ether group-containing monomer and the FOX formula was adjusted to the above-mentioned range. In the optical laminate of the example used, the anchoring force F between the adhesive sheet and the optical film (polarizing film) was larger than that of the comparative example. In particular, in Examples 1, 2, 4, and 6 to 8, the value of the anchoring force F was higher than that of Reference Example 1 using a pressure-sensitive adhesive sheet made from a thermosetting pressure-sensitive adhesive composition containing an isocyanate-based crosslinking agent. It was at least the same level as the optical laminate.
　実施例１及び７では、投錨力Ｆが顕著に高い値であった。この結果は、実施例１及び７では、粘着シートのゲル分率が比較的低く、粘着シートが光学フィルムに密着しやすいことに起因していると推定される。実施例３～６の結果からは、粘着シートに対して表面改質処理を行うことによって、投錨力Ｆが増加することがわかる。 In Examples 1 and 7, the anchoring force F was a significantly high value. This result is presumed to be due to the fact that in Examples 1 and 7, the gel fraction of the adhesive sheet was relatively low, and the adhesive sheet easily adhered to the optical film. The results of Examples 3 to 6 show that the anchoring force F increases by performing surface modification treatment on the adhesive sheet.
　さらに、表３からわかるとおり、実施例で用いたモノマーシロップに含まれる部分重合物の周波数１００Ｈｚにおける比誘電率Ｐは、３．８以上であった。この結果から、実施例で用いた粘着シートによれば、比誘電率が低い光学フィルムと組み合わせて用いた場合であっても、画像表示装置が備えるタッチセンサの感度の低下を抑制できることが推定される。 Furthermore, as can be seen from Table 3, the relative permittivity P of the partial polymer contained in the monomer syrup used in the examples at a frequency of 100 Hz was 3.8 or more. From this result, it is estimated that the adhesive sheet used in the example can suppress the decrease in sensitivity of the touch sensor included in the image display device even when used in combination with an optical film with a low dielectric constant. Ru.
　本発明の粘着シートは、例えば、光学積層体や画像表示装置に利用できる。
  The pressure-sensitive adhesive sheet of the present invention can be used, for example, in optical laminates and image display devices.

Claims (12)

  1. 　単量体群及び／又は前記単量体群の部分重合物を含む光硬化性組成物から形成された粘着シートであって、
    　前記光硬化性組成物におけるイソシアネート系架橋剤の配合量が、前記単量体群及び前記部分重合物の合計１００重量部に対して０．０５重量部未満であり、
    　前記単量体群は、エーテル基含有単量体を含み、
    　前記単量体群１００重量部のうち、前記エーテル基含有単量体の配合量が２５重量部以上であり、
    　前記単量体群から重合体を合成した場合に、ＦＯＸの式から算出した前記重合体のガラス転移温度が－６０℃より大きい、粘着シート。     A pressure-sensitive adhesive sheet formed from a photocurable composition containing a monomer group and/or a partial polymer of the monomer group,
    The amount of the isocyanate crosslinking agent in the photocurable composition is less than 0.05 parts by weight based on the total of 100 parts by weight of the monomer group and the partial polymer,
    The monomer group includes an ether group-containing monomer,
    Out of 100 parts by weight of the monomer group, the amount of the ether group-containing monomer is 25 parts by weight or more,
    A pressure-sensitive adhesive sheet, wherein when a polymer is synthesized from the monomer group, the glass transition temperature of the polymer calculated from the FOX formula is higher than -60°C.
  2. 　前記部分重合物の周波数１００Ｈｚにおける比誘電率が３．８以上である、請求項１に記載の粘着シート。 The adhesive sheet according to claim 1, wherein the partial polymer has a dielectric constant of 3.8 or more at a frequency of 100 Hz.
  3. 　前記エーテル基含有単量体は、アルコキシ基含有単量体を含む、請求項１に記載の粘着シート。 The adhesive sheet according to claim 1, wherein the ether group-containing monomer includes an alkoxy group-containing monomer.
  4. 　前記アルコキシ基含有単量体が下記式（１）で表される、請求項３に記載の粘着シート。
    Figure JPOXMLDOC01-appb-C000001
     　前記式（１）において、Ｒ1は、水素原子又はメチル基であり、Ｒ2は、アルキル基であり、ｎは、１～３０の整数である。     The adhesive sheet according to claim 3, wherein the alkoxy group-containing monomer is represented by the following formula (1).
    Figure JPOXMLDOC01-appb-C000001
     In the formula (1), R 1 is a hydrogen atom or a methyl group, R 2 is an alkyl group, and n is an integer from 1 to 30.
  5. 　前記アルコキシ基含有単量体は、２－メトキシエチルアクリレートを含む、請求項３に記載の粘着シート。 The adhesive sheet according to claim 3, wherein the alkoxy group-containing monomer includes 2-methoxyethyl acrylate.
  6. 　前記エーテル基含有単量体は、環構造を有する、請求項１に記載の粘着シート。 The adhesive sheet according to claim 1, wherein the ether group-containing monomer has a ring structure.
  7. 　前記ガラス転移温度が０℃以下である、請求項１に記載の粘着シート。 The pressure-sensitive adhesive sheet according to claim 1, wherein the glass transition temperature is 0°C or lower.
  8. 　前記光硬化性組成物は、イソシアネート系架橋剤を含まない、請求項１に記載の粘着シート。 The pressure-sensitive adhesive sheet according to claim 1, wherein the photocurable composition does not contain an isocyanate-based crosslinking agent.
  9. 　前記光硬化性組成物における溶剤の含有率が５重量％以下である、請求項１に記載の粘着シート。 The pressure-sensitive adhesive sheet according to claim 1, wherein the content of the solvent in the photocurable composition is 5% by weight or less.
  10. 　表面改質処理が施された表面を有する、請求項１に記載の粘着シート。 The pressure-sensitive adhesive sheet according to claim 1, having a surface that has been subjected to surface modification treatment.
  11. 　請求項１～１０のいずれか１項に記載の粘着シートと、
    　偏光フィルム及び位相差フィルムからなる群より選ばれる少なくとも１つを含む光学フィルムと、
    を備えた、光学積層体。     The adhesive sheet according to any one of claims 1 to 10,
    an optical film containing at least one selected from the group consisting of a polarizing film and a retardation film;
    An optical laminate with
  12. 　前記粘着シートと前記光学フィルムとの投錨力が１０．０Ｎ／２５ｍｍ以上である、請求項１１に記載の光学積層体。
          The optical laminate according to claim 11, wherein the anchoring force between the adhesive sheet and the optical film is 10.0 N/25 mm or more.
PCT/JP2023/026820 2022-07-22 2023-07-21 Adhesive sheet and optical layered product WO2024019159A1 (en)

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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2013129813A (en) * 2011-08-19 2013-07-04 Sumitomo Chemical Co Ltd Adhesive composition, adhesive sheet, optical film with adhesive, and optical laminate
JP2018022135A (en) * 2016-07-20 2018-02-08 住友化学株式会社 Optical film having separator film laminate adhesive layer
WO2019065375A1 (en) * 2017-09-28 2019-04-04 日東電工株式会社 Reinforced film
JP2020101814A (en) * 2020-02-13 2020-07-02 日東電工株式会社 Polarization film with adhesive layer on both sides, and image formation apparatus

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2013129813A (en) * 2011-08-19 2013-07-04 Sumitomo Chemical Co Ltd Adhesive composition, adhesive sheet, optical film with adhesive, and optical laminate
JP2018022135A (en) * 2016-07-20 2018-02-08 住友化学株式会社 Optical film having separator film laminate adhesive layer
WO2019065375A1 (en) * 2017-09-28 2019-04-04 日東電工株式会社 Reinforced film
JP2020101814A (en) * 2020-02-13 2020-07-02 日東電工株式会社 Polarization film with adhesive layer on both sides, and image formation apparatus

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