WO2017033741A1 - Adhesive layer for optical members, adhesive layer-provided optical member, and image display device - Google Patents

Adhesive layer for optical members, adhesive layer-provided optical member, and image display device Download PDF

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Publication number
WO2017033741A1
WO2017033741A1 PCT/JP2016/073457 JP2016073457W WO2017033741A1 WO 2017033741 A1 WO2017033741 A1 WO 2017033741A1 JP 2016073457 W JP2016073457 W JP 2016073457W WO 2017033741 A1 WO2017033741 A1 WO 2017033741A1
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Prior art keywords
adhesive layer
sensitive adhesive
pressure
meth
optical member
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PCT/JP2016/073457
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French (fr)
Japanese (ja)
Inventor
淳 保井
翔 寳田
良平 澤▲崎▼
山本　真也
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日東電工株式会社
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Priority to CN201680047018.4A priority Critical patent/CN107922807B/en
Priority to KR1020177036994A priority patent/KR102543355B1/en
Publication of WO2017033741A1 publication Critical patent/WO2017033741A1/en

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    • 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
    • C09J7/10—Adhesives in the form of films or foils without carriers
    • 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
    • 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
    • C09J11/00—Features of adhesives not provided for in group C09J9/00, e.g. additives
    • C09J11/08—Macromolecular additives
    • 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
    • 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
    • C09J133/06—Homopolymers or copolymers of esters of esters containing only carbon, hydrogen and oxygen, the oxygen atom being present only as part of the carboxyl radical
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/02—Diffusing elements; Afocal elements

Definitions

  • the present invention relates to a pressure-sensitive adhesive layer for optical members having a light diffusion function, and an optical member with a pressure-sensitive adhesive layer having at least one pressure-sensitive adhesive layer for optical members on at least one surface of the optical member. Moreover, this invention relates to the image display apparatus containing the said optical member with an adhesive layer.
  • the backlight unit of the image display device generally includes a diffusion sheet in order to improve the visibility, but the diffusion sheet alone may not ensure sufficient visibility, In some cases, an adhesive layer having a light diffusion function is used.
  • Examples of such a light diffusing pressure-sensitive adhesive include a pressure-sensitive adhesive containing a base polymer containing a (meth) acrylic polymer, and light diffusing fine particles having a refractive index lower than that of the pressure-sensitive adhesive.
  • a light diffusion pressure-sensitive adhesive in which an acrylic polymer contains an aromatic ring-containing (meth) acrylic monomer as a monomer unit is disclosed (for example, see Patent Document 1).
  • the pressure-sensitive adhesive layer of Patent Document 1 has a light diffusing function, wrinkles and sagging may occur when various types of optical members having a large size or a thin film are bonded.
  • a step absorbability is required when bonding an optical member having a step (unevenness) on the surface, such as a prism sheet.
  • a step absorbability is required when bonding an optical member having a step (unevenness) on the surface, such as a prism sheet.
  • a step absorbability is required.
  • in terms of the step absorbability was not enough.
  • this invention aims at providing the adhesive layer for optical members which can bond the optical member which has various optical members thinned and thinned, and the optical member which has a level
  • this invention provides the image display apparatus containing the optical member with an adhesive layer which has at least 1 layer of the said adhesive layer for optical members on the at least one surface of an optical member, and the said optical member with an adhesive layer. Also aimed.
  • the present invention includes at least one light-diffusing pressure-sensitive adhesive layer formed from a base pressure-sensitive adhesive composition containing a (meth) acrylic polymer and a light-diffusing fine particle and having a thickness of 5 to 300 ⁇ m, The thickness of the entire pressure-sensitive adhesive layer is 20 ⁇ m or more,
  • the present invention relates to a pressure-sensitive adhesive layer for optical members, characterized by having a haze of 10 to 96%.
  • the light diffusing fine particles are preferably silicone resin fine particles.
  • the refractive index of the light diffusing fine particles is preferably lower than the refractive index of the base pressure-sensitive adhesive composition.
  • the volume average particle diameter of the light diffusing fine particles is preferably 1 to 5 ⁇ m.
  • the pressure-sensitive adhesive layer of the present invention can be formed by laminating a transparent pressure-sensitive adhesive layer having a haze of 0.01 to 5% on at least one surface of the light-diffusing pressure-sensitive adhesive layer.
  • the thickness of the transparent adhesive layer having a haze of 0.01 to 5% is preferably 50 to 300 ⁇ m.
  • the content of the light diffusing fine particles in the light diffusing pressure-sensitive adhesive layer is preferably 3 to 30% by weight.
  • the (meth) acrylic polymer preferably contains an alkyl (meth) acrylate and a carboxyl group-containing monomer as monomer components.
  • the transparent adhesive layer preferably contains a (meth) acrylic polymer containing an alkyl (meth) acrylate, a hydroxyl group-containing monomer, and a nitrogen-containing monomer as monomer components.
  • the (meth) acrylic polymer contained in the transparent adhesive layer does not contain a carboxyl group-containing monomer as a monomer component.
  • the present invention also relates to an optical member with an adhesive layer, characterized in that the optical member has at least one adhesive layer for an optical member on at least one surface of the optical member. Furthermore, this invention relates to the image display apparatus characterized by including the said optical member with an adhesive layer.
  • the pressure-sensitive adhesive layer for optical members of the present invention has a light diffusion pressure-sensitive adhesive layer having a specific thickness and has a specific thickness as the whole pressure-sensitive adhesive layer, various types of optical devices that have been made larger and thinner.
  • the members can be laminated without wrinkles or sagging.
  • the pressure-sensitive adhesive layer for optical members of the present invention has a specific thickness, for example, when a member having a step on the surface thereof, such as a prism sheet, is bonded, there is no gap following the step. Bonding can be performed.
  • the adhesive layer for optical members of this invention has a specific haze, it is excellent also in the display nonuniformity and durability requested
  • Such an optical member with an adhesive layer using the adhesive layer for an optical member of the present invention and an image display device including the optical member with an adhesive layer have high reliability.
  • the pressure-sensitive adhesive layer for an optical member of the present invention is formed of a base pressure-sensitive adhesive composition containing a (meth) acrylic polymer and light-diffusing fine particles, and has at least one light-diffusing pressure-sensitive adhesive layer having a thickness of 5 to 300 ⁇ m. Including The pressure-sensitive adhesive layer as a whole has a thickness of 20 ⁇ m or more and a haze of 10 to 96%.
  • the configuration of the pressure-sensitive adhesive layer for optical members of the present invention is not particularly limited, and it may have at least one light diffusion pressure-sensitive adhesive layer having a thickness of 5 to 300 ⁇ m, and the total thickness of the pressure-sensitive adhesive layer may be 20 ⁇ m or more. It is good. Although it does not specifically limit about a specific structure, For example, the following structures can be mentioned.
  • the thickness of the light diffusion pressure-sensitive adhesive layer is less than 20 ⁇ m, a transparent pressure-sensitive adhesive layer other than the light diffusion pressure-sensitive adhesive layer is bonded together with the light diffusion pressure-sensitive adhesive layer so that the total thickness becomes 20 ⁇ m or more.
  • the pressure-sensitive adhesive layer for optical members of the present invention can be formed.
  • the light diffusion pressure-sensitive adhesive layer or the other transparent pressure-sensitive adhesive layer may be one layer or two or more layers, for example, as shown in FIG.
  • the pressure-sensitive adhesive layer 1 for an optical member can be formed from the layer 2 and the transparent pressure-sensitive adhesive layer 3.
  • the transparent adhesive layer 3 can also be formed on both surfaces of the light-diffusion adhesive layer 2, and the light-diffusion adhesive layer 2 is shown in FIG.1 (c). And the transparent pressure-sensitive adhesive layer 3 can be alternately laminated. Further, when the thickness of the light diffusing pressure-sensitive adhesive layer is 20 ⁇ m or more, the same configuration as that shown in FIGS. 1 (a) to (c) can be obtained, but as shown in FIG. Only one diffusion adhesive layer 2 can be used as the optical member adhesive layer 1 of the present invention. 1A to 1D show a form in which the separator 4 is bonded to both surfaces of the optical member pressure-sensitive adhesive layer 1.
  • the thickness of the pressure-sensitive adhesive layer for optical members of the present invention is 20 ⁇ m or more, preferably 30 ⁇ m or more, more preferably 50 ⁇ m or more, and more preferably 100 ⁇ m or more. More preferably, it is more preferable to exceed 100 ⁇ m.
  • the upper limit of the thickness of the entire pressure-sensitive adhesive layer is not particularly limited, but is preferably about 300 ⁇ m or less, more preferably about 200 ⁇ m or less.
  • the light diffusion pressure-sensitive adhesive layer included in the pressure-sensitive adhesive layer for optical members of the present invention is formed from a base pressure-sensitive adhesive composition containing a (meth) acrylic polymer and light diffusing fine particles, The thickness is 5 to 300 ⁇ m.
  • the base pressure-sensitive adhesive composition used in the present invention contains a (meth) acrylic polymer (A) as a base polymer.
  • the (meth) acrylic polymer (A) contains an alkyl (meth) acrylate (a1) constituting the main skeleton of the (meth) acrylic polymer (A) as a monomer unit.
  • (Meth) acrylate refers to acrylate and / or methacrylate.
  • alkyl (meth) acrylate (a1) examples include those having a linear or branched alkyl group having 1 to 18 carbon atoms.
  • the alkyl group includes methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, amyl group, hexyl group, cyclohexyl group, heptyl group, 2-ethylhexyl group, isooctyl group, nonyl group, decyl group.
  • isodecyl group isodecyl group, dodecyl group, isomyristyl group, lauryl group, tridecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group and the like. These can be used alone or in combination.
  • the blending ratio of the alkyl (meth) acrylate (a1) is preferably 50% by weight or more with respect to all constituent monomers (100% by weight) constituting the (meth) acrylic polymer (A), It is more preferably 100% by weight, further preferably 60 to 100% by weight, and particularly preferably 70 to 90% by weight.
  • the (meth) acrylic polymer (A) is selected from the group consisting of a carboxyl group-containing monomer (a2), a hydroxyl group-containing monomer (a3), and a nitrogen-containing monomer (a4) for the purpose of improving adhesiveness and heat resistance. It is preferable to include one or more selected monomers as monomer components.
  • the carboxyl group-containing monomer (a2) a monomer having a polymerizable functional group having an unsaturated double bond such as a (meth) acryloyl group or a vinyl group and having a carboxyl group can be used without particular limitation.
  • the carboxyl group-containing monomer include (meth) acrylic acid, carboxyethyl (meth) acrylate, carboxypentyl (meth) acrylate, itaconic acid, maleic acid, fumaric acid, crotonic acid, and isocrotonic acid. Can be used alone or in combination. These anhydrides can be used for itaconic acid and maleic acid. Among these, acrylic acid and methacrylic acid are preferable, and acrylic acid is particularly preferable.
  • the blending ratio of the carboxyl group-containing monomer (a2) is preferably 10% by weight or less with respect to all constituent monomers (100% by weight) constituting the (meth) acrylic polymer (A), 0.05 It is more preferably from 10 to 10% by weight, further preferably from 0.1 to 10% by weight, particularly preferably from 0.5 to 5% by weight.
  • hydroxyl group-containing monomer (a3) a monomer having a polymerizable functional group having an unsaturated double bond such as a (meth) acryloyl group or a vinyl group and having a hydroxyl group can be used without particular limitation. .
  • hydroxyl group-containing monomer examples include 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl ( (4-hydroxymethylcyclohexyl) methyl (meth) acrylate, 8-hydroxyoctyl (meth) acrylate, 10-hydroxydecyl (meth) acrylate, hydroxyalkyl (meth) acrylate such as 12-hydroxylauryl (meth) acrylate; And hydroxyalkylcycloalkane (meth) acrylates such as (meth) acrylate.
  • hydroxyethyl (meth) acrylamide examples include hydroxyethyl (meth) acrylamide, allyl alcohol, 2-hydroxyethyl vinyl ether, 4-hydroxybutyl vinyl ether, diethylene glycol monovinyl ether, and the like. These can be used alone or in combination. Among these, hydroxyalkyl (meth) acrylate is preferable, and 2-hydroxyethyl (meth) acrylate is more preferable.
  • the blending ratio of the hydroxyl group-containing monomer (a3) is preferably 20% by weight or less with respect to all the constituent monomers (100% by weight) constituting the (meth) acrylic polymer (A). More preferably, it is ⁇ 20% by weight, more preferably 0.1 to 15% by weight, and particularly preferably 1 to 15% by weight.
  • the nitrogen-containing monomer (a4) a monomer having a polymerizable functional group having an unsaturated double bond such as a (meth) acryloyl group or a vinyl group and a functional group having a nitrogen atom is used without particular limitation. be able to.
  • the nitrogen-containing monomer (a4) include (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, N-isopropyl (meth) acrylamide, and N-butyl (meth).
  • (Meth) acrylamide monomers such as acrylamide, N-methylol (meth) acrylamide, N-methylolpropane (meth) acrylamide, (meth) acryloylmorpholine; for example, aminoethyl (meth) acrylate, (meth) acrylic acid N, N-dimethylaminoethyl, amino group-containing monomer having primary, secondary or tertiary at the terminal, such as t-butylaminoethyl (meth) acrylate; for example, cyano group-containing monomer such as acrylonitrile, methacrylonitrile; N -Vinylpyrrolidone, N- (1-methyl Nyl) pyrrolidone and other pyrrolidone monomers, N-vinylpyridine, N-vinylpiperidone, N-vinylpyrimidine, N-vinylpiperazine, N-vinylpyrazine, N-vinylpyrrole,
  • the blending ratio of the nitrogen-containing monomer (a4) is preferably 20% by weight or less with respect to all the constituent monomers (100% by weight) constituting the (meth) acrylic polymer (A), and is 0.05 to It is more preferably 20% by weight, further preferably 0.1 to 15% by weight, and particularly preferably 1 to 15% by weight.
  • the (meth) acrylic polymer (A) In addition to the alkyl (meth) acrylate (a1), the carboxyl group-containing monomer (a2), the hydroxyl group-containing monomer (a3), and the nitrogen-containing monomer (a4), the (meth) acrylic polymer (A) In order to improve adhesiveness and heat resistance, one or more copolymerization monomers having a polymerizable functional group having an unsaturated double bond such as a (meth) acryloyl group or a vinyl group are introduced by copolymerization. be able to.
  • copolymerization monomers include, for example, caprolactone adducts of acrylic acid; sulfonic acid groups containing styrene sulfonic acid, allyl sulfonic acid, sulfopropyl (meth) acrylate, (meth) acryloyloxynaphthalene sulfonic acid, etc.
  • Monomers Phosphoric acid group-containing monomers such as 2-hydroxyethylacryloyl phosphate.
  • vinyl monomers such as vinyl acetate and vinyl propionate; epoxy group-containing acrylic monomers such as glycidyl (meth) acrylate; polyethylene glycol (meth) acrylate, polypropylene glycol (meth) acrylate, ( Glycol acrylic ester monomers such as methacrylic acid methoxyethylene glycol and (meth) acrylic acid methoxypolypropylene glycol; (meth) acrylic acid tetrahydrofurfuryl, fluorine (meth) acrylate, silicone (meth) acrylate and 2-methoxyethyl acrylate Acrylic ester monomers such as can also be used. Furthermore, isoprene, butadiene, isobutylene, vinyl ether and the like can be mentioned.
  • examples of copolymerizable monomers other than the above include silane-based monomers containing silicon atoms.
  • examples of the silane monomer include 3-acryloxypropyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 4-vinylbutyltrimethoxysilane, 4-vinylbutyltriethoxysilane, and 8-vinyloctyltrimethoxysilane.
  • a polyfunctional monomer can be used as a copolymerization monomer as necessary in order to adjust the cohesive strength of the pressure-sensitive adhesive.
  • the monofunctional monomer means a monomer having one polymerizable functional group having an unsaturated double bond such as a (meth) acryloyl group or a vinyl group, and is a polyfunctional monomer. As described later, indicates a monomer having at least two polymerizable functional groups having an unsaturated double bond such as a (meth) acryloyl group or a vinyl group.
  • the polyfunctional monomer is a monomer having at least two polymerizable functional groups having an unsaturated double bond such as a (meth) acryloyl group or a vinyl group, such as (poly) ethylene glycol di (meth) acrylate, (Poly) propylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, pentaerythritol di (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, 1,2-ethylene Glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,12-dodecanediol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, tetramethylol methanetri (meth) acrylate Ester compounds of poly
  • the proportion of the copolymerization monomer other than the carboxyl group-containing monomer (a2), the hydroxyl group-containing monomer (a3), and the nitrogen-containing monomer (a4) is not particularly limited, but may be all of the (meth) acrylic polymer (A).
  • the monomer it is preferably 10% by weight or less, more preferably 0.1 to 10% by weight, and further preferably 0.1 to 5% by weight.
  • the (meth) acrylic polymer (A) can be obtained by polymerizing the above monomers appropriately in accordance with the purpose and desired properties.
  • the obtained (meth) acrylic polymer (A) may be any of a random copolymer, a block copolymer, and a graft copolymer.
  • the (meth) acrylic polymer (A) can be synthesized by any appropriate method. For example, it can be synthesized by referring to “Chemistry and Application of Adhesion / Adhesion” by Katsuhiko Nakamae, published by Dainippon Tosho Co., Ltd. .
  • any appropriate method can be adopted as a polymerization method of the (meth) acrylic polymer (A).
  • Specific examples include solution polymerization, bulk polymerization, emulsion polymerization, and various radical polymerizations.
  • the polymerization initiator, chain transfer agent, emulsifier and the like used for radical polymerization are not particularly limited and can be appropriately selected and used.
  • the weight average molecular weight of a (meth) acrylic-type polymer can be controlled by the usage-amount of a polymerization initiator and a chain transfer agent, and reaction conditions, The usage-amount is suitably adjusted according to these kinds.
  • solution polymerization for example, ethyl acetate, toluene or the like is used as a polymerization solvent.
  • the reaction is carried out in an inert gas stream such as nitrogen and a polymerization initiator is added, and the reaction is usually performed at about 50 to 70 ° C. under reaction conditions for about 5 to 30 hours.
  • thermal polymerization initiators used for solution polymerization include 2,2′-azobisisobutyronitrile, 2,2′-azobis-2-methylbutyronitrile, 2,2′-azobis (2 -Methylpropionic acid) dimethyl, 4,4'-azobis-4-cyanovaleric acid, azobisisovaleronitrile, 2,2'-azobis (2-amidinopropane) dihydrochloride, 2,2'-azobis [2- (5-Methyl-2-imidazolin-2-yl) propane] dihydrochloride, 2,2′-azobis (2-methylpropionamidine) disulfate, 2,2′-azobis (N, N′-dimethyleneisobutyl) Amidine), 2,2′-azobis [N- (2-carboxyethyl) -2-methylpropionamidine] hydrate (VA-057, Wako Pure Chemical Industries, Ltd.) Azo initiators such as potassium persulfate, ammonium persulfate,
  • Examples include oxide initiators, redox initiators that combine a peroxide and a reducing agent, such as a combination of persulfate and sodium bisulfite, and a combination of peroxide and sodium ascorbate. It is not limited to.
  • the said polymerization initiator may be used independently and may be used in mixture of 2 or more types, with respect to 100 weight part of all the monomer components which comprise a (meth) acrylic-type polymer (A).
  • the amount is preferably about 1 part by weight or less, more preferably about 0.005 to 1 part by weight, and still more preferably about 0.02 to 0.5 part by weight.
  • the amount of polymerization initiator used is the total amount of monomer components.
  • the amount is preferably about 0.2 parts by weight or less with respect to 100 parts by weight, and more preferably about 0.06 to 0.2 parts by weight.
  • chain transfer agent examples include lauryl mercaptan, glycidyl mercaptan, mercaptoacetic acid, 2-mercaptoethanol, thioglycolic acid, 2-ethylhexyl thioglycolate, and 2,3-dimercapto-1-propanol.
  • the chain transfer agent may be used alone or in combination of two or more, but the total content is 0.1 parts by weight with respect to 100 parts by weight of the total amount of monomer components. Less than or equal to
  • emulsifier used in emulsion polymerization examples include anionic emulsifiers such as sodium lauryl sulfate, ammonium lauryl sulfate, sodium dodecylbenzenesulfonate, ammonium polyoxyethylene alkyl ether sulfate, sodium polyoxyethylene alkylphenyl ether sulfate, and polyoxy Nonionic emulsifiers such as ethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene fatty acid ester, polyoxyethylene-polyoxypropylene block polymer and the like can be mentioned. These emulsifiers may be used alone or in combination of two or more.
  • a reactive emulsifier into which a radical polymerizable functional group such as a propenyl group or an allyl ether group is introduced can be used.
  • a reactive emulsifier into which a radical polymerizable functional group such as a propenyl group or an allyl ether group is introduced can be used.
  • Aqualon HS-10, HS-20, KH-10, BC-05, BC-10, BC-20 (all of which are manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), Adekaria soap SE10N (Made by ADEKA).
  • the amount of the emulsifier used is preferably 5 parts by weight or less, more preferably 0.3 to 5 parts by weight, based on 100 parts by weight of the total amount of the monomer components, and it has polymerization stability and mechanical stability. From the viewpoint, it is more preferably 0.5 to 1 part by weight.
  • the (meth) acrylic polymer (A) when produced by radiation polymerization, it can be produced by polymerizing the monomer component by irradiating with radiation such as electron beam or UV.
  • radiation polymerization When the radiation polymerization is performed with an electron beam, it is not particularly necessary to include a photopolymerization initiator in the monomer component.
  • the radiation polymerization is performed with UV polymerization, the polymerization time is particularly short.
  • a photopolymerization initiator can be contained in the monomer component because of the advantages that can be achieved.
  • a photoinitiator can be used individually by 1 type or in combination of 2 or more types.
  • the photopolymerization initiator is not particularly limited, but is not particularly limited as long as it initiates photopolymerization, and a commonly used photopolymerization initiator can be used.
  • a commonly used photopolymerization initiator can be used.
  • benzoin ether photopolymerization initiator acetophenone photopolymerization initiator, ⁇ -ketol photopolymerization initiator, aromatic sulfonyl chloride photopolymerization initiator, photoactive oxime photopolymerization initiator, benzoin photopolymerization initiator Agents, benzyl photopolymerization initiators, benzophenone photopolymerization initiators, ketal photopolymerization initiators, thioxanthone photopolymerization initiators, acylphosphine oxide photopolymerization initiators, and the like can be used.
  • examples of the benzoin ether photopolymerization initiator include benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, benzoin isopropyl ether, benzoin isobutyl ether, 2,2-dimethoxy-1,2-diphenylethane- Examples thereof include 1-one (trade name: Irgacure 651, manufactured by BASF), anisole methyl ether, and the like.
  • acetophenone photopolymerization initiator examples include 1-hydroxycyclohexyl phenyl ketone (trade name: Irgacure 184, manufactured by BASF), 4-phenoxydichloroacetophenone, 4-t-butyl-dichloroacetophenone, 1- [4- ( 2-hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propan-1-one (trade name: Irgacure 2959, manufactured by BASF), 2-hydroxy-2-methyl-1-phenyl-propane- Examples thereof include 1-one (trade name: Darocur 1173, manufactured by BASF), methoxyacetophenone, and the like.
  • Examples of the ⁇ -ketol photopolymerization initiator include 2-methyl-2-hydroxypropiophenone, 1- [4- (2-hydroxyethyl) -phenyl] -2-hydroxy-2-methylpropane-1- ON etc. are mentioned.
  • Examples of aromatic sulfonyl chloride photopolymerization initiators include 2-naphthalenesulfonyl chloride.
  • Examples of the photoactive oxime photopolymerization initiator include 1-phenyl-1,1-propanedione-2- (o-ethoxycarbonyl) -oxime.
  • the benzoin photopolymerization initiator includes, for example, benzoin.
  • Examples of the benzyl photopolymerization initiator include benzyl.
  • Examples of the benzophenone photopolymerization initiator include benzophenone, benzoylbenzoic acid, 3,3′-dimethyl-4-methoxybenzophenone, polyvinylbenzophenone, ⁇ -hydroxycyclohexyl phenyl ketone, and the like.
  • Examples of the ketal photopolymerization initiator include benzyl dimethyl ketal.
  • thioxanthone photopolymerization initiator examples include thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, 2,4-dichlorothioxanthone, 2,4-diethylthioxanthone, isopropylthioxanthone, 2,4-diisopropylthioxanthone, dodecylthioxanthone and the like are included.
  • acylphosphine photopolymerization initiator examples include bis (2,6-dimethoxybenzoyl) phenylphosphine oxide, bis (2,6-dimethoxybenzoyl) (2,4,4-trimethylpentyl) phosphine oxide, bis ( 2,6-dimethoxybenzoyl) -n-butylphosphine oxide, bis (2,6-dimethoxybenzoyl)-(2-methylpropan-1-yl) phosphine oxide, bis (2,6-dimethoxybenzoyl)-(1- Methylpropan-1-yl) phosphine oxide, bis (2,6-dimethoxybenzoyl) -t-butylphosphine oxide, bis (2,6-dimethoxybenzoyl) cyclohexylphosphine oxide, bis (2,6-dimethoxybenzoyl) octylphosphine Oxides, bis (2- T
  • the amount of the photopolymerization initiator used is not particularly limited, but is preferably 0.01 to 5 parts by weight with respect to 100 parts by weight of the total monomers constituting the (meth) acrylic polymer (A), for example, 0.05 Is more preferably 3 to 3 parts by weight, still more preferably 0.05 to 1.5 parts by weight, and particularly preferably 0.1 to 1 part by weight. If the usage-amount of a photoinitiator is in the said range, a polymerization reaction can fully be advanced. In addition, a photopolymerization initiator can be used individually by 1 type or in combination of 2 or more types.
  • the weight average molecular weight of the (meth) acrylic polymer (A) used in the present invention is preferably 400,000 to 2,500,000, and more preferably 600,000 to 2,200,000. By making the weight average molecular weight larger than 400,000, it is possible to satisfy the durability of the pressure-sensitive adhesive layer, or to suppress the occurrence of adhesive residue due to the reduced cohesive force of the pressure-sensitive adhesive layer.
  • the weight average molecular weight is a value measured by gel permeation chromatography (GPC) and calculated in terms of polystyrene. In addition, it is difficult to measure the molecular weight of the (meth) acrylic polymer obtained by radiation polymerization.
  • the base pressure-sensitive adhesive composition used in the present invention may contain a crosslinking agent.
  • the crosslinking agent include organic crosslinking agents and polyfunctional metal chelates.
  • the organic crosslinking agent include an isocyanate crosslinking agent, a peroxide crosslinking agent, an epoxy crosslinking agent, and an imine crosslinking agent.
  • a polyfunctional metal chelate is one in which a polyvalent metal is covalently or coordinately bonded to an organic compound.
  • the polyvalent metal include Al, Cr, Zr, Co, Cu, Fe, Ni, V, Zn, In, Ca, Mg, Mn, Y, Ce, Sr, Ba, Mo, La, Sn, and Ti. Can be mentioned.
  • organic compound examples include alkyl esters, alcohol compounds, carboxylic acid compounds, ether compounds, and ketone compounds.
  • an oxygen atom is mentioned, for example.
  • a crosslinking agent an isocyanate type crosslinking agent is preferable.
  • An isocyanate-based crosslinking agent typically refers to a compound having two or more isocyanate groups in one molecule.
  • isocyanate monomers such as tolylene diisocyanate, chlorophenylene diisocyanate, tetramethylene diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, and isocyanate compounds obtained by adding these isocyanate monomers to trimethylolpropane, etc.
  • Examples include isocyanurates, burette type compounds, and urethane prepolymer type isocyanates obtained by addition reaction with polyether polyols, polyester polyols, acrylic polyols, polybutadiene polyols, polyisoprene polyols, and the like.
  • a polyisocyanate compound which is one or a polyisocyanate compound derived from one selected from the group consisting of hexamethylene diisocyanate, hydrogenated xylylene diisocyanate, and isophorone diisocyanate.
  • hexamethylene diisocyanate, hydrogenated xylylene diisocyanate, isophorone diisocyanate, polyol modified with one or more polyisocyanate compounds selected from the group consisting of hexamethylene diisocyanate, hydrogenated xylylene diisocyanate, and isophorone diisocyanate examples include hexamethylene diisocyanate, polyol-modified hydrogenated xylylene diisocyanate, trimer-type hydrogenated xylylene diisocyanate, and polyol-modified isophorone diisocyanate.
  • the epoxy-based crosslinking agent typically refers to a compound having two or more epoxy groups (glycidyl groups) in one molecule.
  • examples of the epoxy-based crosslinking agent include ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, diglycidyl terephthalate, spiroglycol diglycidyl ether, diglycidylaminomethylcyclohexane, tetraglycidylxylenediamine, and polyglycidylmetaxylene. Examples include diamines.
  • any suitable compound capable of generating radical active species by heating or light irradiation to advance the crosslinking of the base polymer can be employed.
  • a peroxide having a 1 minute half-life temperature of 80 ° C. to 160 ° C. is preferable, and a peroxide having a 90 ° C. to 140 ° C. is more preferable.
  • peroxides include di (2-ethylhexyl) peroxydicarbonate (1 minute half-life temperature: 90.6 ° C.), di (4-t-butylcyclohexyl) peroxydicarbonate (1 minute half-life) Temperature: 92.1 ° C.), di-sec-butyl peroxydicarbonate (1 minute half-life temperature: 92.4 ° C.), t-butyl peroxyneodecanoate (1 minute half-life temperature: 103.5 ° C.) ), T-hexyl peroxypivalate (1 minute half-life temperature: 109.1 ° C.), t-butyl peroxypivalate (1 minute half-life temperature: 110.3 ° C.), dilauroyl peroxide (half minute for 1 minute) Phase temperature: 116.4 ° C.), di-n-octanoyl peroxide (1 minute half-life temperature: 117.4 ° C.), 1,1,3,3-tetramethylbutyl
  • the peroxide half-life is an index representing the decomposition rate of the peroxide, and means the time until the remaining amount of peroxide is reduced to half. Therefore, the 1-minute half-life temperature of peroxide refers to the temperature at which the remaining amount of peroxide is halved in 1 minute.
  • the decomposition temperature for obtaining a half-life at an arbitrary time and the half-life time at an arbitrary temperature are described in the manufacturer catalog, for example, “Organic Peroxide Catalog No. 9 of Nippon Oil & Fats Co., Ltd.” Edition ( May 2003) ".
  • the amount of the crosslinking agent used is preferably 0.01 to 20 parts by weight and more preferably 0.03 to 10 parts by weight with respect to 100 parts by weight of the (meth) acrylic polymer (A).
  • the amount of the crosslinking agent used is less than 0.01 parts by weight, the cohesive force of the pressure-sensitive adhesive tends to be insufficient, and foaming may occur during heating.
  • the amount of the crosslinking agent used exceeds 20 parts by weight, the moisture resistance is not sufficient, and peeling or the like may easily occur.
  • the base pressure-sensitive adhesive composition may contain any appropriate additive.
  • the additive include an antistatic agent, an antioxidant, and a coupling agent.
  • the kind of additive, the addition amount, the combination, and the like can be appropriately set according to the purpose.
  • the content of the base pressure-sensitive adhesive composition in the light diffusion pressure-sensitive adhesive layer used in the present invention is preferably 50 to 99.7% by weight, more preferably 52 to 97% by weight, and 70 to 97% by weight. More preferably.
  • the refractive index of the base pressure-sensitive adhesive composition is preferably 1.47 or more, more preferably 1.47 to 1.60, and further preferably 1.47 to 1.55. If the refractive index of a base adhesive composition is the said range, the refractive index difference with the light diffusible fine particle mentioned later can be made into a desired range. As a result, a light diffusion pressure-sensitive adhesive layer having a desired haze value after curing can be obtained, which is preferable.
  • the light diffusing pressure-sensitive adhesive layer is a layer in which light diffusing fine particles are dispersed in a pressure-sensitive adhesive layer formed from the base pressure-sensitive adhesive composition.
  • the light diffusing fine particles any appropriate one can be used as long as the effect of the present invention is obtained. Specific examples include inorganic fine particles and polymer fine particles. Among these, polymer fine particles are preferable.
  • the material of the polymer fine particles examples include silicone resin, methacrylic resin (for example, polymethyl methacrylate), polystyrene resin, polyurethane resin, and melamine resin. Since these resins have excellent dispersibility with respect to the base pressure-sensitive adhesive composition and an appropriate refractive index difference from the base pressure-sensitive adhesive composition, a light diffusion pressure-sensitive adhesive layer having excellent diffusion performance can be obtained. Among these, silicone resins and polymethyl methacrylate are particularly preferable.
  • the shape of the light diffusing fine particles can be, for example, a spherical shape, a flat shape, or an indefinite shape.
  • the light diffusing fine particles may be used alone or in combination of two or more.
  • the refractive index of the light diffusing fine particles used in the present invention is preferably lower than the refractive index of the base pressure-sensitive adhesive composition.
  • the refractive index of the light diffusing fine particles is preferably 1.30 to 1.70, and more preferably 1.40 to 1.65. If the refractive index of the light diffusing fine particles is in the above range, the difference in refractive index from the base pressure-sensitive adhesive composition can be set to a desired range, and as a result, the light diffusing pressure-sensitive adhesive layer having a desired haze value after curing. Is preferable.
  • the absolute value of the difference in refractive index between the light diffusing fine particles and the base pressure-sensitive adhesive composition is preferably more than 0 and 0.2 or less, more preferably more than 0 and 0.15 or less. More preferably, the ratio is 0.01 to 0.13.
  • the volume average particle diameter of the light diffusing fine particles is preferably about 1 to 5 ⁇ m, more preferably about 2 to 5 ⁇ m, and further preferably about 2 to 4 ⁇ m. If the volume average particle diameter of the light diffusing fine particles is within the above range, a light diffusing pressure-sensitive adhesive layer having a desired haze value can be obtained by combining with the base pressure-sensitive adhesive composition, which is preferable.
  • the volume average particle diameter can be measured using, for example, an ultracentrifugal automatic particle size distribution measuring apparatus.
  • the content of the light diffusing fine particles in the light diffusing pressure-sensitive adhesive layer is not particularly limited, but is preferably 0.3 to 50% by weight, more preferably 3 to 48% by weight. More preferably, it is ⁇ 30% by weight. By setting the blending amount of the light diffusing fine particles in the above range, a light diffusing pressure-sensitive adhesive layer having excellent light diffusing performance can be obtained.
  • the light diffusing pressure-sensitive adhesive layer is formed by, for example, applying a light diffusing pressure-sensitive adhesive composition in which light diffusing fine particles are dispersed in the base pressure-sensitive adhesive composition to a support. It can be formed by removing the solvent and the like by drying. In applying the light diffusion pressure-sensitive adhesive composition, one or more solvents may be appropriately added. Further, when the base pressure-sensitive adhesive composition is an active energy ray curable type, a light diffusion is produced by preparing a prepolymer obtained by polymerizing a part of the base pressure-sensitive adhesive composition, and dispersing light diffusing fine particles in the prepolymer.
  • a light-diffusion pressure-sensitive adhesive layer can be formed by applying the pressure-sensitive adhesive composition to a support and irradiating the coating layer with active energy rays such as ultraviolet rays.
  • the light diffusion pressure-sensitive adhesive layer can be formed by directly coating the light diffusion pressure-sensitive adhesive composition on an optical member such as a polarizing film described later.
  • the light diffusion pressure-sensitive adhesive layer has a thickness of 5 to 300 ⁇ m, preferably 5 to 250 ⁇ m, more preferably 50 to 250 ⁇ m, still more preferably 100 to 200 ⁇ m, more than 100 ⁇ m and not more than 200 ⁇ m. More preferably. It is preferable that the thickness of the light diffusing pressure-sensitive adhesive layer be in the above-mentioned range because the bonding can be performed following the fine unevenness of the material to be bonded or the uneven portion for imparting an optical function. In addition, when a transparent adhesive layer is bonded to the light diffusion adhesive layer, the thickness of the light diffusion adhesive layer is about 5 to 100 ⁇ m. It is preferable from the viewpoint of not affecting the bonding effect, and more preferably about 5 to 30 ⁇ m. Moreover, when a light-diffusion adhesive layer consists of two or more layers, the total value of the thickness of all the light-diffusion adhesive layers should just be in the said range.
  • Various methods are used as a method for applying the light diffusion adhesive composition. Specifically, for example, by roll coat, kiss roll coat, gravure coat, reverse coat, roll brush, spray coat, dip roll coat, bar coat, knife coat, air knife coat, curtain coat, lip coat, die coater, etc. Examples thereof include an extrusion coating method.
  • the heating and drying temperature is preferably about 30 ° C. to 200 ° C., more preferably 40 ° C. to 180 ° C., and further preferably 80 ° C. to 160 ° C. By setting the heating temperature in the above range, an adhesive layer having excellent adhesive properties can be obtained.
  • As the drying time an appropriate time can be adopted as appropriate.
  • the drying time is preferably about 5 seconds to 20 minutes, more preferably 30 seconds to 10 minutes, and further preferably 1 minute to 8 minutes.
  • a light diffusion pressure-sensitive adhesive layer can be formed by irradiating active energy rays such as ultraviolet rays.
  • active energy rays such as ultraviolet rays.
  • a high pressure mercury lamp, a low pressure mercury lamp, a metal halide lamp, a chemical light lamp, or the like can be used.
  • a peeled sheet can be used as the support.
  • a silicone release liner is preferably used as the release-treated sheet.
  • the pressure-sensitive adhesive layer When the pressure-sensitive adhesive layer is exposed on the release-treated sheet, the pressure-sensitive adhesive layer may be protected with a release-treated sheet (separator) until practical use. . In practical use, the peeled sheet is peeled off.
  • Examples of the constituent material of the separator may include porous materials such as plastic film, paper, cloth, and nonwoven fabric, nets, foam sheets, metal foils, and appropriate thin leaves such as laminates thereof.
  • a plastic film is preferably used from the viewpoint of excellent surface smoothness.
  • plastic film examples include polyethylene film, polypropylene film, polybutene film, polybutadiene film, polymethylpentene film, polyvinyl chloride film, vinyl chloride copolymer film, polyethylene terephthalate film, polybutylene terephthalate film, polyurethane film, and ethylene.
  • plastic film examples include polyethylene film, polypropylene film, polybutene film, polybutadiene film, polymethylpentene film, polyvinyl chloride film, vinyl chloride copolymer film, polyethylene terephthalate film, polybutylene terephthalate film, polyurethane film, and ethylene.
  • -Vinyl acetate copolymer film and the like.
  • the thickness of the separator is usually about 5 to 200 ⁇ m, preferably about 5 to 100 ⁇ m.
  • silicone type, fluorine type, long chain alkyl type or fatty acid amide type release agent, mold release and antifouling treatment with silica powder, coating type, kneading type, vapor deposition type, if necessary It is also possible to perform antistatic treatment such as.
  • the release property from the pressure-sensitive adhesive layer can be further improved by appropriately performing a release treatment such as silicone treatment, long-chain alkyl treatment, or fluorine treatment on the surface of the separator.
  • the haze value of the formed light diffusion pressure-sensitive adhesive layer is preferably 10 to 99%, more preferably 10 to 96%, further preferably 20 to 96%, and more preferably 40 to 80%. It is particularly preferred. By setting the haze value in the above range, desired diffusion performance can be obtained, and generation of moire and glare can be favorably suppressed, which is preferable.
  • the light diffusing performance of the light diffusing adhesive can be controlled by adjusting the constituent material of the matrix (adhesive), the constituent material of the light diffusing fine particles, the volume average particle diameter, the blending amount, and the like.
  • the total light transmittance of the light diffusion pressure-sensitive adhesive layer is preferably 75% or more, more preferably 80% or more, and further preferably 85% or more.
  • the adhesive layer for optical members of this invention can contain transparent adhesive layers other than the said light-diffusion adhesive layer as above-mentioned.
  • the transparent adhesive layer is not particularly limited, and examples thereof include those formed from an adhesive composition containing a base polymer and a crosslinking agent.
  • the pressure-sensitive adhesive composition may be an acrylic, synthetic rubber-based, rubber-based, or silicone-based pressure-sensitive adhesive, but from the viewpoint of transparency and heat resistance, a (meth) acrylic polymer is a base polymer. An acrylic pressure-sensitive adhesive is preferred.
  • the monomer component contained in the (meth) acrylic polymer those mentioned in the base pressure-sensitive adhesive composition can be preferably used, but the alkyl (meth) acrylate (a1), the hydroxyl group-containing monomer (a3), And a (meth) acrylic polymer containing the nitrogen-containing monomer (a4) as a monomer component is preferred. Moreover, it is preferable that the monomer component contained in the said (meth) acrylic-type polymer does not contain a carboxyl group-containing monomer.
  • the blending ratio of each monomer and the method for forming the transparent pressure-sensitive adhesive layer can include the same methods as in the case of the light diffusion pressure-sensitive adhesive layer.
  • the haze of the transparent pressure-sensitive adhesive layer is not particularly limited, but is preferably 0.01 to 5%, more preferably 0.05 to 5%, and 0.1 to 3%. More preferably. It is preferable that the haze of the transparent pressure-sensitive adhesive layer is in the above range because optical design such as haze becomes easy.
  • the thickness of the transparent pressure-sensitive adhesive layer is not particularly limited, and when the pressure-sensitive adhesive layer is formed by laminating with the light diffusion pressure-sensitive adhesive layer, the total thickness may be 20 ⁇ m or more. Although not limited, it is preferably 20 to 300 ⁇ m, more preferably 50 to 300 ⁇ m. It is preferable that the thickness of the transparent pressure-sensitive adhesive layer be in the above-mentioned range since the bonding can be performed following a minute unevenness of a material to be bonded or an uneven portion for imparting an optical function.
  • the optical member pressure-sensitive adhesive layer of the present invention may be formed of only one light diffusion pressure-sensitive adhesive layer, and at least one light diffusion pressure-sensitive adhesive layer and It may be formed from at least one transparent adhesive layer.
  • the pressure-sensitive adhesive layer for an optical member of the present invention is preferably applied to an optical member, and the optical member is as described later.
  • optical members it can be preferably used for a brightness enhancement film and a polarizing film.
  • the haze value of the pressure-sensitive adhesive layer for an optical member of the present invention is 10 to 96%, preferably 20 to 96%, more preferably 30 to 96%. If the haze value is less than 10%, display unevenness occurs because the light from the backlight and the prism sheet is biased and cannot be eliminated. Further, when the haze value of the pressure-sensitive adhesive layer exceeds 96%, it is necessary to add a large amount of particles to the pressure-sensitive adhesive layer. In that case, the stress relaxation property and adhesiveness of the pressure-sensitive adhesive layer are lowered, and the durability is inferior. .
  • optical member with pressure-sensitive adhesive layer has at least one pressure-sensitive adhesive layer for optical members on at least one surface of the optical member.
  • optical member those used for manufacturing various image display devices and the like are used, and the type thereof is not particularly limited, and examples thereof include a polarizing film, a retardation plate, a brightness enhancement film, or an antiglare sheet. Can do.
  • the optical member is a laminate of two or more optical materials, such as a laminate of a polarizing film and a retardation plate, a laminate of retardation plates, a laminate of a polarizing film and a brightness enhancement film, or an antiglare sheet. There may be. Among these, a brightness enhancement film and a polarizing film are preferable.
  • polarizing film one having a transparent protective film on one side or both sides of a polarizer is generally used.
  • the polarizer is not particularly limited, and various types can be used.
  • polarizers include dichroic iodine and dichroic dyes on hydrophilic polymer films such as polyvinyl alcohol films, partially formalized polyvinyl alcohol films, and ethylene / vinyl acetate copolymer partially saponified films.
  • hydrophilic polymer films such as polyvinyl alcohol films, partially formalized polyvinyl alcohol films, and ethylene / vinyl acetate copolymer partially saponified films.
  • examples thereof include polyene-based oriented films such as those obtained by adsorbing substances and uniaxially stretched, polyvinyl alcohol dehydrated products and polyvinyl chloride dehydrochlorinated products.
  • a polarizer composed of a polyvinyl alcohol film and a dichroic substance such as iodine is preferable.
  • the thickness of these polarizers is not particularly limited, but is generally about 5 to 80 ⁇ m.
  • a polarizer obtained by dyeing a polyvinyl alcohol film with iodine and uniaxially stretching it can be produced, for example, by dyeing polyvinyl alcohol in an aqueous iodine solution and stretching it 3 to 7 times the original length. If necessary, it can be immersed in an aqueous solution of potassium iodide or the like which may contain boric acid, zinc sulfate, zinc chloride or the like. Further, if necessary, the polyvinyl alcohol film may be immersed in water and washed before dyeing.
  • the polyvinyl alcohol film In addition to washing the polyvinyl alcohol film surface with stains and antiblocking agents by washing the polyvinyl alcohol film with water, the polyvinyl alcohol film is also swollen to prevent unevenness such as uneven coloring. is there. Stretching may be performed after dyeing with iodine, may be performed while dyeing, or may be dyed with iodine after stretching. The film can be stretched even in an aqueous solution of boric acid or potassium iodide or in a water bath.
  • a thin polarizer having a thickness of 10 ⁇ m or less can also be used.
  • the thickness is preferably 1 to 7 ⁇ m.
  • Such a thin polarizer is preferable in that the thickness unevenness is small, the visibility is excellent, the dimensional change is small, the durability is excellent, and the thickness of the polarizing plate can be reduced.
  • the thin polarizer typically, Japanese Patent Application Laid-Open No. 51-069644, Japanese Patent Application Laid-Open No. 2000-338329, International Publication No. 2010/100917, PCT / JP2010 / 001460, Examples thereof include thin polarizing films described in Japanese Patent Application Nos. 2010-269002 and 2010-263692.
  • These thin polarizing films can be obtained by a production method including a step of stretching and dyeing a polyvinyl alcohol-based resin (hereinafter also referred to as PVA-based resin) layer and a stretching resin substrate in the state of a laminate. With this production method, even if the PVA-based resin layer is thin, it can be stretched without problems such as breakage due to stretching by being supported by the stretching resin substrate.
  • PVA-based resin polyvinyl alcohol-based resin
  • polyester polymers such as polyethylene terephthalate and polyethylene naphthalate
  • cellulose polymers such as diacetyl cellulose and triacetyl cellulose
  • acrylic polymers such as polymethyl methacrylate
  • styrene such as polystyrene and acrylonitrile / styrene copolymer (AS resin)
  • AS resin acrylonitrile / styrene copolymer
  • polyethylene, polypropylene, polyolefins having a cyclo or norbornene structure polyolefin polymers such as ethylene / propylene copolymers, vinyl chloride polymers, amide polymers such as nylon and aromatic polyamide, imide polymers, sulfone polymers , Polyether sulfone polymer, polyether ether ketone polymer, polyphenylene sulfide polymer, vinyl alcohol polymer, vinylidene chloride polymer, vinyl butyral polymer, arylate polymer, polyoxymethylene polymer, epoxy polymer, or Examples of the polymer that forms the transparent protective film include polymer blends.
  • the transparent protective film can also be formed as a cured layer of thermosetting or ultraviolet curable resin such as acrylic, urethane, acrylurethane, epoxy, and silicone.
  • the thickness of the protective film can be determined as appropriate, but is generally about 1 to 500 ⁇ m from the viewpoints of workability such as strength and handleability, and thin film properties.
  • the polarizer and the protective film are usually in close contact with each other through an aqueous adhesive or the like.
  • the water-based adhesive include an isocyanate-based adhesive, a polyvinyl alcohol-based adhesive, a gelatin-based adhesive, a vinyl-based latex, a water-based polyurethane, and a water-based polyester.
  • examples of the adhesive between the polarizer and the transparent protective film include an ultraviolet curable adhesive and an electron beam curable adhesive.
  • the electron beam curable polarizing film adhesive exhibits suitable adhesiveness to the various transparent protective films.
  • the adhesive used in the present invention can contain a metal compound filler.
  • the surface of the transparent protective film to which the polarizer is not bonded may be subjected to a treatment for the purpose of hard coat layer, antireflection treatment, sticking prevention, diffusion or antiglare.
  • FIG. 2 An example of a specific usage pattern of the optical member with an adhesive layer of the present invention is shown in FIG.
  • the polarizing film 10 (optical member with an adhesive layer) having the adhesive layer 1 for an optical member of the present invention can be used by bonding the adhesive layer surface to the step surface of the prism sheet 20. Since the optical member with the pressure-sensitive adhesive layer of the present invention has the pressure-sensitive adhesive layer for the optical member of the present invention, the optical member can be bonded without following the step.
  • the polarizing film 10 has a protective film 12 on both sides of the polarizer 11, but may be a single-sided protective polarizing film having the protective film 12 on one side of the polarizer 11.
  • the prism sheet 20 typically includes a substrate 22 and a prism portion 21.
  • the pressure-sensitive adhesive layer 1 for an optical member of the present invention has a light diffusing function, it can usually be used instead of a diffusion sheet provided on the backlight side of an image display device.
  • Image display device The image display device of the present invention is characterized by including the optical member with an adhesive layer.
  • the image display device of the present invention only needs to include the optical member with the pressure-sensitive adhesive layer of the present invention, and other configurations can be the same as those of the conventional image display device.
  • the image display device of the present invention includes the optical member with the pressure-sensitive adhesive layer, it has high reliability.
  • the pressure-sensitive adhesive layer for optical members of the present invention has a light diffusion function
  • the optical member with the pressure-sensitive adhesive layer can be used instead of the diffusion sheet provided on the backlight side, and the image display device is thinned. be able to.
  • an isocyanate crosslinking agent (trade name: Coronate L, adduct of tolylene diisocyanate of trimethylolpropane, manufactured by Nippon Polyurethane Industry Co., Ltd.) is added to 100 parts of the obtained prepolymer composition.
  • a base pressure-sensitive adhesive composition (A-1) was obtained.
  • the obtained base adhesive composition (A-1) had a refractive index of 1.475.
  • silicone resin fine particles (trade name: Tospearl 145, volume average particle size: 4 ⁇ m, refractive index: 1.43, silicone, as light diffusing fine particles 14 parts of resin fine particles (manufactured by Momentive Performance Materials) were added to obtain a light diffusion adhesive composition (A-1).
  • Production Examples 2 to 5 (Production of light diffusion adhesive compositions (A-2) to (A-5))
  • the light diffusing pressure-sensitive adhesive compositions (A-2) to (A-5) were the same as Production Example 1 except that the addition amount of the light diffusing fine particles was changed. Manufactured.
  • Production Example 6 (Production of light diffusion adhesive composition (A-6))
  • 100 parts of butyl acrylate, 5 parts of acrylic acid, 1 part of hydroxyethyl acrylate, 2,2′-azobisiso as a polymerization initiator
  • 0.1 parts of butyronitrile with 100 parts of ethyl acetate (monomer concentration 50%) After charging 0.1 parts of butyronitrile with 100 parts of ethyl acetate (monomer concentration 50%), introducing nitrogen gas with gentle stirring and replacing with nitrogen, the liquid temperature in the flask was kept at around 55 ° C.
  • a polymerization reaction was carried out for 8 hours to prepare a solution of an acrylic polymer (A-6) having a weight average molecular weight (Mw) of 1.8 million.
  • Mw weight average molecular weight
  • an isocyanate-based crosslinking agent (trade name: Coronate L, trimethylolpropane / tolylene diisocyanate trimer adduct, Nippon Polyurethane Industry 0.66 part, 0.3 parts of benzoyl peroxide (Niper BMT, manufactured by NOF Corporation), silane coupling agent (trade name: KBM403, manufactured by Shin-Etsu Chemical Co., Ltd.) 0.2 Part was added to obtain a base pressure-sensitive adhesive composition (A-6).
  • an isocyanate-based crosslinking agent (trade name: Coronate L, trimethylolpropane / tolylene diisocyanate trimer adduct, Nippon Polyurethane Industry 0.66 part, 0.3 parts of benzoyl peroxide (Niper BMT, manufactured by NOF Corporation), silane coupling agent (trade name: KBM403, manufactured by Shin-Etsu Chemical Co., Ltd.) 0.2 Part was added to obtain a base pressure-sensitive adhesive composition (A
  • Silicone resin fine particles (trade name: Tospearl 145, volume average particle size: 4 ⁇ m, refractive index: 1. ⁇ m) as light diffusing fine particles with respect to 100 parts of solid content of the obtained base pressure-sensitive adhesive composition (A-6). 43, silicone resin fine particles, manufactured by Momentive Performance Materials Co., Ltd.) were blended to prepare a light diffusion adhesive composition (A-6).
  • Production Example 7 (Production of light diffusion adhesive composition (A-7))
  • Production Example 6 as shown in Table 1, a light diffusing pressure-sensitive adhesive composition (A-7) was produced in the same manner as in Production Example 6 except that the addition amount of the light diffusing fine particles was changed.
  • Production Examples 8 to 12 (Production of light diffusion adhesive compositions (A-8) to (A-12))
  • Production Example 1 As shown in Table 1, the light diffusing pressure-sensitive adhesive compositions (A-8) to (A-12) were produced in the same manner as in Production Example 1 except that the addition amount of the light diffusing fine particles was changed. Manufactured.
  • Example 1 (Production of light diffusion adhesive layer) Release treatment of a 38 ⁇ m-thick polyester film (trade name: Diafoil MRF, manufactured by Mitsubishi Plastics Co., Ltd.) obtained by removing the light-diffusing adhesive composition (A-1) obtained in Production Example 1 with silicone on one side. On the surface, the obtained light diffusion pressure-sensitive adhesive layer was applied so that the thickness was 23 ⁇ m, thereby forming a coating layer. Next, a 38 ⁇ m thick polyester film (trade name: Diafoil MRE, manufactured by Mitsubishi Resin Co., Ltd.) having one surface peeled with silicone is applied to the surface of the formed coating layer. It coat
  • a 38 ⁇ m-thick polyester film trade name: Diafoil MRF, manufactured by Mitsubishi Plastics Co., Ltd.
  • Examples 2 to 12 Comparative Examples 1 to 3, 6, 7
  • a pressure-sensitive adhesive sheet was prepared in the same manner as in Example 1 except that the light diffusion pressure-sensitive adhesive composition used and the thickness after drying were changed to those described in Table 2.
  • Example 13 Manufacture of first layer and third layer (transparent adhesive layer)
  • the transparent pressure-sensitive adhesive layer in the same manner as in Example 1, except that the light diffusion pressure-sensitive adhesive composition (A-8) obtained in Production Example 8 was used and the thickness of the pressure-sensitive adhesive layer obtained was 50 ⁇ m.
  • a pressure-sensitive adhesive sheet was prepared. Two identical pieces were produced.
  • One release sheet of the pressure-sensitive adhesive sheet for the transparent pressure-sensitive adhesive layer obtained above is peeled off, and a transparent pressure-sensitive adhesive layer is bonded to both surfaces of the light diffusion pressure-sensitive adhesive layer obtained above, and the pressure-sensitive adhesive layer for optical members Formed.
  • Example 14 A pressure-sensitive adhesive sheet was prepared in the same manner as in Example 13 except that the light diffusion pressure-sensitive adhesive composition used and the thickness after drying were changed to those described in Table 2.
  • Example 15 Manufacture of second layer (light diffusion adhesive layer) Release treatment of a 38 ⁇ m-thick polyester film (trade name: Diafoil MRF, manufactured by Mitsubishi Plastics Co., Ltd.) obtained by peeling off the light diffusing pressure-sensitive adhesive composition (A-10) obtained in Production Example 10 with silicone on one side On the surface, the obtained light diffusion pressure-sensitive adhesive layer was applied so that the thickness was 23 ⁇ m, thereby forming a coating layer. Next, a 38 ⁇ m thick polyester film (trade name: Diafoil MRE, manufactured by Mitsubishi Resin Co., Ltd.) having one surface peeled with silicone is applied to the surface of the formed coating layer. It coat
  • a 38 ⁇ m thick polyester film trade name: Diafoil MRE, manufactured by Mitsubishi Resin Co., Ltd.
  • the coating layer of the light diffusion adhesive composition was shielded from oxygen.
  • a chemical light lamp manufactured by Toshiba Corporation
  • ultraviolet rays having an illuminance of 100 mW / cm 2 measured with Topcon UVR-T1 having a maximum sensitivity of about 350 nm
  • Irradiation was performed for 30 seconds, the coating layer was cured to form a light diffusion pressure-sensitive adhesive layer, and a pressure-sensitive adhesive sheet was produced.
  • the polyester film coated on both sides of the pressure-sensitive adhesive layer functions as a release liner.
  • Example 13 A pressure-sensitive adhesive sheet was produced in the same manner as in Example 13 except that the pressure-sensitive adhesive layer was used as the second layer (light diffusion pressure-sensitive adhesive layer).
  • Examples 16 and 17, Comparative Examples 4 and 5 A pressure-sensitive adhesive sheet was prepared in the same manner as in Example 15 except that the light diffusing pressure-sensitive adhesive composition used and the thickness were changed to those shown in Table 2.
  • a polarizing film in which a brightness enhancement film (trade name: DBEF-Q, manufactured by 3M) was bonded onto a polarizing film (trade name: CVT, manufactured by Nitto Denko Corporation) was prepared.
  • One release film of the pressure-sensitive adhesive sheets obtained in Examples and Comparative Examples was peeled off and bonded to the brightness enhancement film side of the polarizing film.
  • the other release film of the pressure-sensitive adhesive sheet was peeled off, and bonded to a prism sheet having 50 ⁇ m or 5 ⁇ m unevenness with a hand roller, and autoclaved at 50 ° C. and 5 atm for 15 minutes. The state after bonding was visually confirmed and evaluated according to the following evaluation criteria.
  • a sample obtained by bonding the polarizing film to the pressure-sensitive adhesive sheets obtained in Examples and Comparative Examples was cut into a size of 400 mm long ⁇ 250 mm wide to prepare a sample.
  • This sample was bonded to a non-alkali glass plate having a thickness of 0.07 mm with a laminator, and a polarizing plate with a transparent adhesive layer was bonded to the opposite side so as to be in a crossed Nicol state, and then at 50 ° C., 5 atm for 15 minutes.
  • An autoclave treatment was performed to prepare an evaluation sample. Then, it put on the backlight of 10,000 candela, the light leak was observed visually, and the corner nonuniformity was evaluated on the following reference

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Abstract

A purpose of the present invention is to provide an adhesive layer for optical members, which can be used to attach large and thin optical members or uneven optical members to each other, and which has a light diffusing function. Another purpose of the present invention is to provide: an adhesive layer-provided optical member having at least one layer of the adhesive layer for optical members, on at least one surface of the optical member; and an image display device including the adhesive layer-provided optical member. The adhesive layer for optical members is characterized by: being formed of a base adhesive composition containing a (meth)acrylic polymer and light diffusing particles; including at least one layer of a light diffusing adhesive layer having a thickness of 5-300 μm; having an overall thickness of 20 μm or more; and having a haze of 10-96%.

Description

光学部材用粘着剤層、粘着剤層付光学部材、及び画像表示装置Adhesive layer for optical member, optical member with adhesive layer, and image display device
　本発明は、光拡散機能を有する光学部材用粘着剤層、光学部材の少なくとも一方の面に、前記光学部材用粘着剤層を少なくとも１層有する粘着剤層付光学部材に関する。また、本発明は、前記粘着剤層付光学部材を含む画像表示装置に関する。 The present invention relates to a pressure-sensitive adhesive layer for optical members having a light diffusion function, and an optical member with a pressure-sensitive adhesive layer having at least one pressure-sensitive adhesive layer for optical members on at least one surface of the optical member. Moreover, this invention relates to the image display apparatus containing the said optical member with an adhesive layer.
　近年、液晶表示装置等の画像表示装置においては、大型化や薄膜化が求められており、画像表示装置を構成する各光学部材においても同様の要求がされている。このように大型化、薄膜化された各光学部材を粘着剤により固定して積層する場合、光学部材に貼り合せ不良（しわやひずみ等）が発生しやすく、結果として、表示部の不具合が生じる場合があった。 In recent years, image display devices such as liquid crystal display devices have been required to be large and thin, and similar demands have been made for each optical member constituting the image display device. When each of the optical members that have been increased in size and thickness are fixed and laminated with an adhesive, bonding defects (wrinkles, strains, etc.) are likely to occur on the optical member, resulting in defects in the display unit. There was a case.
　また、前記画像表示装置のバックライトユニットには、一般的に、視認性を向上させるために拡散シートが含まれるが、当該拡散シートだけでは十分な視認性を確保できない場合があり、拡散シートと伴に光拡散機能を有する粘着剤層を用いる場合があった。 Further, the backlight unit of the image display device generally includes a diffusion sheet in order to improve the visibility, but the diffusion sheet alone may not ensure sufficient visibility, In some cases, an adhesive layer having a light diffusion function is used.
　このような光拡散粘着剤としては、例えば、（メタ）アクリル系ポリマーを含有するベースポリマーを含む粘着剤と、該粘着剤よりも低い屈折率を有する光拡散性微粒子を含み、該（メタ）アクリル系ポリマーが、モノマー単位として芳香族環含有（メタ）アクリル系モノマーを含む光拡散粘着剤が開示されている（例えば、特許文献１参照）。 Examples of such a light diffusing pressure-sensitive adhesive include a pressure-sensitive adhesive containing a base polymer containing a (meth) acrylic polymer, and light diffusing fine particles having a refractive index lower than that of the pressure-sensitive adhesive. A light diffusion pressure-sensitive adhesive in which an acrylic polymer contains an aromatic ring-containing (meth) acrylic monomer as a monomer unit is disclosed (for example, see Patent Document 1).
特開２０１４－２２４９６４号公報JP 2014-224964 A
　特許文献１の粘着剤層は光拡散機能を有するものの、大型化、薄膜化された各種光学部材を貼り合せる際には、しわやたるみが発生する場合があった。また、例えば、プリズムシートのように表面に段差（凹凸）がある光学部材を貼り合せる際には、段差吸収性が要求されるが、特許文献１の粘着剤層では、段差吸収性の点においても十分なものではなかった。 Although the pressure-sensitive adhesive layer of Patent Document 1 has a light diffusing function, wrinkles and sagging may occur when various types of optical members having a large size or a thin film are bonded. In addition, for example, when bonding an optical member having a step (unevenness) on the surface, such as a prism sheet, a step absorbability is required. However, in the pressure-sensitive adhesive layer of Patent Document 1, in terms of the step absorbability Was not enough.
　そこで、本発明は、大型化、薄膜化された各種光学部材や段差を有する光学部材を貼り合せることができ、かつ、光拡散機能を有する光学部材用粘着剤層を提供することを目的とする。また、本発明は、光学部材の少なくとも一方の面に、前記光学部材用粘着剤層を少なくとも１層有する粘着剤層付光学部材、前記粘着剤層付光学部材を含む画像表示装置を提供することも目的とする。 Then, this invention aims at providing the adhesive layer for optical members which can bond the optical member which has various optical members thinned and thinned, and the optical member which has a level | step difference, and has a light-diffusion function. . Moreover, this invention provides the image display apparatus containing the optical member with an adhesive layer which has at least 1 layer of the said adhesive layer for optical members on the at least one surface of an optical member, and the said optical member with an adhesive layer. Also aimed.
　本発明者らは前記課題を解決すべく鋭意検討を重ねた結果、下記光学部材用粘着剤層を見出し、本発明を完成するに至った。 As a result of intensive studies to solve the above problems, the present inventors have found the following pressure-sensitive adhesive layer for optical members and have completed the present invention.
　すなわち、本発明は、（メタ）アクリル系ポリマーを含有するベース粘着剤組成物及び光拡散性微粒子から形成され、厚みが５～３００μｍである光拡散粘着剤層を少なくとも１層含み、
　粘着剤層全体としての厚みが２０μｍ以上であり、
　ヘイズが１０～９６％であることを特徴とする光学部材用粘着剤層に関する。 That is, the present invention includes at least one light-diffusing pressure-sensitive adhesive layer formed from a base pressure-sensitive adhesive composition containing a (meth) acrylic polymer and a light-diffusing fine particle and having a thickness of 5 to 300 μm,
The thickness of the entire pressure-sensitive adhesive layer is 20 μm or more,
The present invention relates to a pressure-sensitive adhesive layer for optical members, characterized by having a haze of 10 to 96%.
　前記光拡散性微粒子が、シリコーン樹脂微粒子であることが好ましい。 The light diffusing fine particles are preferably silicone resin fine particles.
　前記光拡散性微粒子の屈折率が、前記ベース粘着剤組成物の屈折率よりも低いことが好ましい。 The refractive index of the light diffusing fine particles is preferably lower than the refractive index of the base pressure-sensitive adhesive composition.
　前記光拡散性微粒子の体積平均粒子径が、１～５μｍであることが好ましい。 The volume average particle diameter of the light diffusing fine particles is preferably 1 to 5 μm.
　本発明の粘着剤層は、前記光拡散粘着剤層の少なくとも片面に、ヘイズが０．０１～５％の透明粘着剤層を貼り合せて形成することができ、前記光拡散粘着剤層の厚みが５～３０μｍであり、ヘイズが０．０１～５％の透明粘着剤層の厚みが５０～３００μｍであることが好ましい。 The pressure-sensitive adhesive layer of the present invention can be formed by laminating a transparent pressure-sensitive adhesive layer having a haze of 0.01 to 5% on at least one surface of the light-diffusing pressure-sensitive adhesive layer. The thickness of the transparent adhesive layer having a haze of 0.01 to 5% is preferably 50 to 300 μm.
　前記光拡散粘着剤層における前記光拡散性微粒子の含有量が、３～３０重量％であることが好ましい。 The content of the light diffusing fine particles in the light diffusing pressure-sensitive adhesive layer is preferably 3 to 30% by weight.
　前記（メタ）アクリル系ポリマーが、モノマー成分として、アルキル（メタ）アクリレート及びカルボキシル基含有モノマーを含有することが好ましい。 The (meth) acrylic polymer preferably contains an alkyl (meth) acrylate and a carboxyl group-containing monomer as monomer components.
　前記透明粘着剤層が、アルキル（メタ）アクリレート、水酸基含有モノマー及び窒素含有モノマーをモノマー成分として含む（メタ）アクリル系ポリマーを含有することが好ましい。 The transparent adhesive layer preferably contains a (meth) acrylic polymer containing an alkyl (meth) acrylate, a hydroxyl group-containing monomer, and a nitrogen-containing monomer as monomer components.
　前記透明粘着剤層に含まれる（メタ）アクリル系ポリマーが、カルボキシル基含有モノマーをモノマー成分として含まないことが好ましい。 It is preferable that the (meth) acrylic polymer contained in the transparent adhesive layer does not contain a carboxyl group-containing monomer as a monomer component.
　また、本発明は、光学部材の少なくとも一方の面に、前記光学部材用粘着剤層を少なくとも１層有することを特徴とする粘着剤層付光学部材に関する。さらに、本発明は、前記粘着剤層付光学部材を含むことを特徴とする画像表示装置に関する。 The present invention also relates to an optical member with an adhesive layer, characterized in that the optical member has at least one adhesive layer for an optical member on at least one surface of the optical member. Furthermore, this invention relates to the image display apparatus characterized by including the said optical member with an adhesive layer.
　本発明の光学部材用粘着剤層は、特定の厚みの光拡散粘着剤層を有し、かつ、粘着剤層全体として特定の厚みを有するものであるため、大型化、薄膜化された各種光学部材を、しわやたるみなく積層することができるものである。また、本発明の光学部材用粘着剤層は、特定の厚みを有するため、例えば、プリズムシートのように、その表面に段差を有する部材を貼り合せる場合にも、前記段差に追従して空隙なく貼り合わせを行うことができる。また、本発明の光学部材用粘着剤層は、特定のヘイズを有するため、光学部材用粘着剤層に要求される表示ムラや耐久性にも優れるものである。このような本発明の光学部材用粘着剤層を用いた粘着剤層付光学部材や、当該粘着剤層付光学部材を含む画像表示装は、高い信頼性を有するものである。 Since the pressure-sensitive adhesive layer for optical members of the present invention has a light diffusion pressure-sensitive adhesive layer having a specific thickness and has a specific thickness as the whole pressure-sensitive adhesive layer, various types of optical devices that have been made larger and thinner. The members can be laminated without wrinkles or sagging. In addition, since the pressure-sensitive adhesive layer for optical members of the present invention has a specific thickness, for example, when a member having a step on the surface thereof, such as a prism sheet, is bonded, there is no gap following the step. Bonding can be performed. Moreover, since the adhesive layer for optical members of this invention has a specific haze, it is excellent also in the display nonuniformity and durability requested | required of the adhesive layer for optical members. Such an optical member with an adhesive layer using the adhesive layer for an optical member of the present invention and an image display device including the optical member with an adhesive layer have high reliability.
（ａ）～（ｄ）本発明の光学部材用粘着剤層の実施形態を模式的に示す断面図である。(A)-(d) It is sectional drawing which shows typically embodiment of the adhesive layer for optical members of this invention. 本発明の光学部材用粘着剤層の一使用形態を模式的に示す断面図である。It is sectional drawing which shows typically one usage pattern of the adhesive layer for optical members of this invention.
　本発明の光学部材用粘着剤層は、（メタ）アクリル系ポリマーを含有するベース粘着剤組成物及び光拡散性微粒子から形成され、厚みが５～３００μｍである光拡散粘着剤層を少なくとも１層含み、
　粘着剤層全体としての厚みが２０μｍ以上であり、ヘイズが１０～９６％であることを特徴とする。 The pressure-sensitive adhesive layer for an optical member of the present invention is formed of a base pressure-sensitive adhesive composition containing a (meth) acrylic polymer and light-diffusing fine particles, and has at least one light-diffusing pressure-sensitive adhesive layer having a thickness of 5 to 300 μm. Including
The pressure-sensitive adhesive layer as a whole has a thickness of 20 μm or more and a haze of 10 to 96%.
　本発明の光学部材用粘着剤層の構成は、特に限定されるものではなく、厚み５～３００μｍの光拡散粘着剤層を少なくとも１層有し、粘着剤層全体としての厚みが２０μｍ以上であればよいものである。具体的な構成については、特に限定されるものではないが、例えば、以下の構成を挙げることができる。 The configuration of the pressure-sensitive adhesive layer for optical members of the present invention is not particularly limited, and it may have at least one light diffusion pressure-sensitive adhesive layer having a thickness of 5 to 300 μm, and the total thickness of the pressure-sensitive adhesive layer may be 20 μm or more. It is good. Although it does not specifically limit about a specific structure, For example, the following structures can be mentioned.
　前記光拡散粘着剤層の厚みが２０μｍ未満である場合は、当該光拡散粘着剤層と伴に、光拡散粘着剤層以外の透明粘着剤層を貼り合せ、トータルの厚みが２０μｍ以上となるようにして、本発明の光学部材用粘着剤層を形成することができる。その場合、光拡散粘着剤層又はそれ以外の透明粘着剤層は、それぞれ１層であっても２層以上であってもよく、例えば、図１（ａ）に示すように、光拡散粘着剤層２と透明粘着剤層３から光学部材用粘着剤層１を形成することができる。また、図１（ｂ）に示すように、光拡散粘着剤層２の両面に透明粘着剤層３を形成することもできるし、図１（ｃ）に示すように、光拡散粘着剤層２と透明粘着剤層３を交互に積層することもできる。また、前記光拡散粘着剤層の厚みが２０μｍ以上である場合についても、図１（ａ）～（ｃ）と同様の形態とすることができるが、図１（ｄ）に示すように、光拡散粘着剤層２の１層のみで本発明の光学部材用粘着剤層１とすることもできる。なお、図１（ａ）～（ｄ）においては、光学部材用粘着剤層１の両面にセパレーター４が貼り合わされている形態を図示している。 When the thickness of the light diffusion pressure-sensitive adhesive layer is less than 20 μm, a transparent pressure-sensitive adhesive layer other than the light diffusion pressure-sensitive adhesive layer is bonded together with the light diffusion pressure-sensitive adhesive layer so that the total thickness becomes 20 μm or more. Thus, the pressure-sensitive adhesive layer for optical members of the present invention can be formed. In that case, the light diffusion pressure-sensitive adhesive layer or the other transparent pressure-sensitive adhesive layer may be one layer or two or more layers, for example, as shown in FIG. The pressure-sensitive adhesive layer 1 for an optical member can be formed from the layer 2 and the transparent pressure-sensitive adhesive layer 3. Moreover, as shown in FIG.1 (b), the transparent adhesive layer 3 can also be formed on both surfaces of the light-diffusion adhesive layer 2, and the light-diffusion adhesive layer 2 is shown in FIG.1 (c). And the transparent pressure-sensitive adhesive layer 3 can be alternately laminated. Further, when the thickness of the light diffusing pressure-sensitive adhesive layer is 20 μm or more, the same configuration as that shown in FIGS. 1 (a) to (c) can be obtained, but as shown in FIG. Only one diffusion adhesive layer 2 can be used as the optical member adhesive layer 1 of the present invention. 1A to 1D show a form in which the separator 4 is bonded to both surfaces of the optical member pressure-sensitive adhesive layer 1.
　１．光学部材用粘着剤層
　本発明の光学部材用粘着剤層は、粘着剤層全体としての厚みが２０μｍ以上であり、３０μｍ以上であることが好ましく、５０μｍ以上であることがより好ましく、１００μｍ以上であることがさらに好ましく、１００μｍを超えることが特に好ましい。粘着剤層全体としての厚みが２０μｍ以上であることで、被着体である光学部材が、プリズムシートのようにその表面に段差を有する部材であっても、前記段差に追従して空隙なく貼り合わせを行うことができるため好ましい。また、粘着剤層全体としての厚みの上限値については特に限定されないが、３００μｍ以下程度であることが好ましく、２００μｍ以下程度であることがより好ましい。 1. The pressure-sensitive adhesive layer for optical members The thickness of the pressure-sensitive adhesive layer for optical members of the present invention is 20 μm or more, preferably 30 μm or more, more preferably 50 μm or more, and more preferably 100 μm or more. More preferably, it is more preferable to exceed 100 μm. When the thickness of the entire pressure-sensitive adhesive layer is 20 μm or more, even if the optical member that is the adherend is a member having a step on its surface, such as a prism sheet, it is pasted without following a gap. It is preferable because they can be combined. The upper limit of the thickness of the entire pressure-sensitive adhesive layer is not particularly limited, but is preferably about 300 μm or less, more preferably about 200 μm or less.
　（１）光拡散粘着剤層
　本発明の光学部材用粘着剤層に含まれる光拡散粘着剤層は、（メタ）アクリル系ポリマーを含有するベース粘着剤組成物及び光拡散性微粒子から形成され、厚みが５～３００μｍである。 (1) Light diffusion pressure-sensitive adhesive layer The light diffusion pressure-sensitive adhesive layer included in the pressure-sensitive adhesive layer for optical members of the present invention is formed from a base pressure-sensitive adhesive composition containing a (meth) acrylic polymer and light diffusing fine particles, The thickness is 5 to 300 μm.
　（１－１）ベース粘着剤組成物
　本発明で用いるベース粘着剤組成物は、ベースポリマーとして（メタ）アクリル系ポリマー（Ａ）を含む。（メタ）アクリル系ポリマー（Ａ）は、モノマー単位として、（メタ）アクリル系ポリマー（Ａ）の主骨格を構成するアルキル（メタ）アクリレート（ａ１）を含む。なお、（メタ）アクリレートはアクリレート及び／又はメタクリレートをいう。 (1-1) Base pressure-sensitive adhesive composition The base pressure-sensitive adhesive composition used in the present invention contains a (meth) acrylic polymer (A) as a base polymer. The (meth) acrylic polymer (A) contains an alkyl (meth) acrylate (a1) constituting the main skeleton of the (meth) acrylic polymer (A) as a monomer unit. (Meth) acrylate refers to acrylate and / or methacrylate.
　前記アルキル（メタ）アクリレート（ａ１）としては、直鎖状又は分岐鎖状の炭素数１～１８のアルキル基を有するものを挙げることができる。例えば、前記アルキル基としては、メチル基、エチル基、プロピル基、イソプロピル基、ブチル基、イソブチル基、アミル基、ヘキシル基、シクロヘキシル基、ヘプチル基、２－エチルヘキシル基、イソオクチル基、ノニル基、デシル基、イソデシル基、ドデシル基、イソミリスチル基、ラウリル基、トリデシル基、ペンタデシル基、ヘキサデシル基、ヘプタデシル基、オクタデシル基等を例示できる。これらは単独であるいは組み合わせて使用することができる。 Examples of the alkyl (meth) acrylate (a1) include those having a linear or branched alkyl group having 1 to 18 carbon atoms. For example, the alkyl group includes methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, amyl group, hexyl group, cyclohexyl group, heptyl group, 2-ethylhexyl group, isooctyl group, nonyl group, decyl group. Group, isodecyl group, dodecyl group, isomyristyl group, lauryl group, tridecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group and the like. These can be used alone or in combination.
　前記アルキル（メタ）アクリレート（ａ１）の配合割合は、（メタ）アクリル系ポリマー（Ａ）を構成する全構成モノマー（１００重量％）に対して、５０重量％以上であることが好ましく、５０～１００重量％であることがより好ましく、６０～１００重量％であることがさらに好ましく、７０～９０重量％であることが特に好ましい。 The blending ratio of the alkyl (meth) acrylate (a1) is preferably 50% by weight or more with respect to all constituent monomers (100% by weight) constituting the (meth) acrylic polymer (A), It is more preferably 100% by weight, further preferably 60 to 100% by weight, and particularly preferably 70 to 90% by weight.
　前記（メタ）アクリル系ポリマー（Ａ）は、接着性や耐熱性の改善を目的に、カルボキシル基含有モノマー（ａ２）、ヒドロキシル基含有モノマー（ａ３）、及び窒素含有モノマー（ａ４）からなる群から選択される１種以上のモノマーをモノマー成分として含むことが好ましい。 The (meth) acrylic polymer (A) is selected from the group consisting of a carboxyl group-containing monomer (a2), a hydroxyl group-containing monomer (a3), and a nitrogen-containing monomer (a4) for the purpose of improving adhesiveness and heat resistance. It is preferable to include one or more selected monomers as monomer components.
　カルボキシル基含有モノマー（ａ２）としては、（メタ）アクリロイル基又はビニル基等の不飽和二重結合を有する重合性の官能基を有し、かつカルボキシル基を有するものを特に制限なく用いることができる。カルボキシル基含有モノマーとしては、例えば、（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、クロトン酸、イソクロトン酸等が挙げられ、これらは単独で又は組み合わせて使用できる。イタコン酸、マレイン酸はこれらの無水物を用いることができる。これらの中でも、アクリル酸、メタクリル酸が好ましく、特にアクリル酸が好ましい。 As the carboxyl group-containing monomer (a2), a monomer having a polymerizable functional group having an unsaturated double bond such as a (meth) acryloyl group or a vinyl group and having a carboxyl group can be used without particular limitation. . Examples of the carboxyl group-containing monomer include (meth) acrylic acid, carboxyethyl (meth) acrylate, carboxypentyl (meth) acrylate, itaconic acid, maleic acid, fumaric acid, crotonic acid, and isocrotonic acid. Can be used alone or in combination. These anhydrides can be used for itaconic acid and maleic acid. Among these, acrylic acid and methacrylic acid are preferable, and acrylic acid is particularly preferable.
　前記カルボキシル基含有モノマー（ａ２）の配合割合は、（メタ）アクリル系ポリマー（Ａ）を構成する全構成モノマー（１００重量％）に対して、１０重量％以下であることが好ましく、０．０５～１０重量％であることがより好ましく、０．１～１０重量％であることがさらに好ましく、０．５～５重量％が特に好ましい。 The blending ratio of the carboxyl group-containing monomer (a2) is preferably 10% by weight or less with respect to all constituent monomers (100% by weight) constituting the (meth) acrylic polymer (A), 0.05 It is more preferably from 10 to 10% by weight, further preferably from 0.1 to 10% by weight, particularly preferably from 0.5 to 5% by weight.
　ヒドロキシル基含有モノマー（ａ３）としては、（メタ）アクリロイル基又はビニル基等の不飽和二重結合を有する重合性の官能基を有し、かつヒドロキシル基を有するものを特に制限なく用いることができる。ヒドロキシル基含有モノマーとしては、例えば、２－ヒドロキシエチル（メタ）アクリレート、３－ヒドロキシプロピル（メタ）アクリレート、２－ヒドロキシブチル（メタ）アクリレート、４－ヒドロキシブチル（メタ）アクリレート、６－ヒドロキシヘキシル（メタ）アクリレート、８－ヒドロキシオクチル（メタ）アクリレート、１０－ヒドロキシデシル（メタ）アクリレート、１２－ヒドロキシラウリル（メタ）アクリレート等のヒドロキシアルキル（メタ）アクリレート；（４－ヒドロキシメチルシクロへキシル）メチル（メタ）アクリレート等のヒドロキシアルキルシクロアルカン（メタ）アクリレートが挙げられる。その他、ヒドロキシエチル（メタ）アクリルアミド、アリルアルコール、２－ヒドロキシエチルビニルエーテル、４－ヒドロキシブチルビニルエーテル、ジエチレングリコールモノビニルエーテル等が挙げられる。これらは単独で又は組み合わせて使用できる。これらの中でも、ヒドロキシアルキル（メタ）アクリレートが好ましく、２－ヒドロキシエチル（メタ）アクリレートがより好ましい。 As the hydroxyl group-containing monomer (a3), a monomer having a polymerizable functional group having an unsaturated double bond such as a (meth) acryloyl group or a vinyl group and having a hydroxyl group can be used without particular limitation. . Examples of the hydroxyl group-containing monomer include 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl ( (4-hydroxymethylcyclohexyl) methyl (meth) acrylate, 8-hydroxyoctyl (meth) acrylate, 10-hydroxydecyl (meth) acrylate, hydroxyalkyl (meth) acrylate such as 12-hydroxylauryl (meth) acrylate; And hydroxyalkylcycloalkane (meth) acrylates such as (meth) acrylate. Other examples include hydroxyethyl (meth) acrylamide, allyl alcohol, 2-hydroxyethyl vinyl ether, 4-hydroxybutyl vinyl ether, diethylene glycol monovinyl ether, and the like. These can be used alone or in combination. Among these, hydroxyalkyl (meth) acrylate is preferable, and 2-hydroxyethyl (meth) acrylate is more preferable.
　前記ヒドロキシル基含有モノマー（ａ３）の配合割合は、（メタ）アクリル系ポリマー（Ａ）を構成する全構成モノマー（１００重量％）に対して、２０重量％以下であることが好ましく、０．０５～２０重量％であることがより好ましく、０．１～１５重量％であることがさらに好ましく、１～１５重量％が特に好ましい。 The blending ratio of the hydroxyl group-containing monomer (a3) is preferably 20% by weight or less with respect to all the constituent monomers (100% by weight) constituting the (meth) acrylic polymer (A). More preferably, it is ˜20% by weight, more preferably 0.1 to 15% by weight, and particularly preferably 1 to 15% by weight.
　窒素含有モノマー（ａ４）としては、（メタ）アクリロイル基又はビニル基等の不飽和二重結合を有する重合性の官能基を有し、かつ窒素原子を有する官能基を有するものを特に制限なく用いることができる。窒素含有モノマー（ａ４）としては、例えば、（メタ）アクリルアミド、Ｎ，Ｎ－ジメチル（メタ）アクリルアミド、Ｎ，Ｎ－ジエチル（メタ）アクリルアミド、Ｎ－イソプロピル（メタ）アクリルアミド、Ｎ－ブチル（メタ）アクリルアミド、Ｎ－メチロール（メタ）アクリルアミド、Ｎ－メチロールプロパン（メタ）アクリルアミド、（メタ）アクリロイルモルホリン等の（メタ）アクリルアミド系モノマー；例えば、（メタ）アクリル酸アミノエチル、（メタ）アクリル酸Ｎ，Ｎ－ジメチルアミノエチル、（メタ）アクリル酸ｔ－ブチルアミノエチル等の末端に１級、２級又は３級を有するアミノ基含有モノマー；例えば、アクリロニトリル、メタクリロニトリル等のシアノ基含有モノマー；Ｎ－ビニルピロリドン、Ｎ－（１－メチルビニル）ピロリドン等のピロリドン系モノマー、その他、Ｎ－ビニルピリジン、Ｎ－ビニルピペリドン、Ｎ－ビニルピリミジン、Ｎ－ビニルピペラジン、Ｎ－ビニルピラジン、Ｎ－ビニルピロール、Ｎ－ビニルイミダゾール、Ｎ－ビニルオキサゾール、Ｎ－ビニルモルホリン等のビニル基含有複素環化合物；Ｎ－ビニルアセトアミド等のビニルカルボン酸アミド化合物；例えば、Ｎ－シクロヘキシルマレイミド、Ｎ－イソプロピルマレイミド、Ｎ－ラウリルマレイミド、Ｎ－フェニルマレイミド等のマレイミド系モノマー；例えば、Ｎ－メチルイタコンイミド、Ｎ－エチルイタコンイミド、Ｎ－ブチルイタコンイミド、Ｎ－オクチルイタコンイミド、Ｎ－２－エチルヘキシルイタコンイミド、Ｎ－シクロヘキシルイタコンイミド、Ｎ－ラウリルイタコンイミド等のイタコンイミド系モノマー；例えば、Ｎ－（メタ）アクリロイルオキシメチレンスクシンイミド、Ｎ－（メタ）アクリロイル－６－オキシヘキサメチレンスクシンイミド、Ｎ－（メタ）アクリロイル－８－オキシオクタメチレンスクシンイミド等のスクシンイミド系モノマー；その他、２－（メタ）アクリルアミド－２－メチルプロパンスルホン酸、（メタ）アクリルアミドプロパンスルホン酸等のスルホン酸基含有（メタ）アクリルアミド系モノマー、ダイアセトンアクリルアミド；等が挙げられる。これらの中でも、ビニル基含有複素環化合物が好ましく、Ｎ－ビニルピロリドンがより好ましい。 As the nitrogen-containing monomer (a4), a monomer having a polymerizable functional group having an unsaturated double bond such as a (meth) acryloyl group or a vinyl group and a functional group having a nitrogen atom is used without particular limitation. be able to. Examples of the nitrogen-containing monomer (a4) include (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, N-isopropyl (meth) acrylamide, and N-butyl (meth). (Meth) acrylamide monomers such as acrylamide, N-methylol (meth) acrylamide, N-methylolpropane (meth) acrylamide, (meth) acryloylmorpholine; for example, aminoethyl (meth) acrylate, (meth) acrylic acid N, N-dimethylaminoethyl, amino group-containing monomer having primary, secondary or tertiary at the terminal, such as t-butylaminoethyl (meth) acrylate; for example, cyano group-containing monomer such as acrylonitrile, methacrylonitrile; N -Vinylpyrrolidone, N- (1-methyl Nyl) pyrrolidone and other pyrrolidone monomers, N-vinylpyridine, N-vinylpiperidone, N-vinylpyrimidine, N-vinylpiperazine, N-vinylpyrazine, N-vinylpyrrole, N-vinylimidazole, N-vinyloxazole, Vinyl group-containing heterocyclic compounds such as N-vinylmorpholine; Vinylcarboxylic acid amide compounds such as N-vinylacetamide; for example, maleimides such as N-cyclohexylmaleimide, N-isopropylmaleimide, N-laurylmaleimide, N-phenylmaleimide Monomer; for example, N-methylitaconimide, N-ethylitaconimide, N-butylitaconimide, N-octylitaconimide, N-2-ethylhexylitaconimide, N-cyclohexylitaconimide, N-lauri Itaconimide monomers such as itaconimide; for example, succinimides such as N- (meth) acryloyloxymethylenesuccinimide, N- (meth) acryloyl-6-oxyhexamethylenesuccinimide, N- (meth) acryloyl-8-oxyoctamethylenesuccinimide Other monomers include sulfonic acid group-containing (meth) acrylamide monomers such as 2- (meth) acrylamide-2-methylpropanesulfonic acid and (meth) acrylamidepropanesulfonic acid, diacetone acrylamide, and the like. Among these, a vinyl group-containing heterocyclic compound is preferable, and N-vinylpyrrolidone is more preferable.
　前記窒素含有モノマー（ａ４）の配合割合は、（メタ）アクリル系ポリマー（Ａ）を構成する全構成モノマー（１００重量％）に対して、２０重量％以下であることが好ましく、０．０５～２０重量％であることがより好ましく、０．１～１５重量％であることがさらに好ましく、１～１５重量％が特に好ましい。 The blending ratio of the nitrogen-containing monomer (a4) is preferably 20% by weight or less with respect to all the constituent monomers (100% by weight) constituting the (meth) acrylic polymer (A), and is 0.05 to It is more preferably 20% by weight, further preferably 0.1 to 15% by weight, and particularly preferably 1 to 15% by weight.
　前記（メタ）アクリル系ポリマー（Ａ）には、さらに、前記アルキル（メタ）アクリレート（ａ１）、カルボキシル基含有モノマー（ａ２）、ヒドロキシル基含有モノマー（ａ３）、窒素含有モノマー（ａ４）以外にも、接着性や耐熱性の改善を目的に、（メタ）アクリロイル基又はビニル基等の不飽和二重結合を有する重合性の官能基を有する、１種類以上の共重合モノマーを共重合により導入することができる。そのような共重合モノマーの具体例としては、例えば、アクリル酸のカプロラクトン付加物；スチレンスルホン酸やアリルスルホン酸、スルホプロピル（メタ）アクリレート、（メタ）アクリロイルオキシナフタレンスルホン酸等のスルホン酸基含有モノマー；２－ヒドロキシエチルアクリロイルホスフェート等の燐酸基含有モノマー等が挙げられる。 In addition to the alkyl (meth) acrylate (a1), the carboxyl group-containing monomer (a2), the hydroxyl group-containing monomer (a3), and the nitrogen-containing monomer (a4), the (meth) acrylic polymer (A) In order to improve adhesiveness and heat resistance, one or more copolymerization monomers having a polymerizable functional group having an unsaturated double bond such as a (meth) acryloyl group or a vinyl group are introduced by copolymerization. be able to. Specific examples of such copolymerization monomers include, for example, caprolactone adducts of acrylic acid; sulfonic acid groups containing styrene sulfonic acid, allyl sulfonic acid, sulfopropyl (meth) acrylate, (meth) acryloyloxynaphthalene sulfonic acid, etc. Monomers: Phosphoric acid group-containing monomers such as 2-hydroxyethylacryloyl phosphate.
　さらに改質モノマーとして、酢酸ビニル、プロピオン酸ビニル等のビニル系モノマー；（メタ）アクリル酸グリシジル等のエポキシ基含有アクリル系モノマー；（メタ）アクリル酸ポリエチレングリコール、（メタ）アクリル酸ポリプロピレングリコール、（メタ）アクリル酸メトキシエチレングリコール、（メタ）アクリル酸メトキシポリプロピレングリコール等のグリコール系アクリルエステルモノマー；（メタ）アクリル酸テトラヒドロフルフリル、フッ素（メタ）アクリレート、シリコーン（メタ）アクリレートや２－メトキシエチルアクリレート等のアクリル酸エステル系モノマー等も使用することができる。さらには、イソプレン、ブタジエン、イソブチレン、ビニルエーテル等が挙げられる。 Furthermore, as the modifying monomer, vinyl monomers such as vinyl acetate and vinyl propionate; epoxy group-containing acrylic monomers such as glycidyl (meth) acrylate; polyethylene glycol (meth) acrylate, polypropylene glycol (meth) acrylate, ( Glycol acrylic ester monomers such as methacrylic acid methoxyethylene glycol and (meth) acrylic acid methoxypolypropylene glycol; (meth) acrylic acid tetrahydrofurfuryl, fluorine (meth) acrylate, silicone (meth) acrylate and 2-methoxyethyl acrylate Acrylic ester monomers such as can also be used. Furthermore, isoprene, butadiene, isobutylene, vinyl ether and the like can be mentioned.
　さらに、上記以外の共重合可能なモノマーとして、ケイ素原子を含有するシラン系モノマー等が挙げられる。シラン系モノマーとしては、例えば、３－アクリロキシプロピルトリエトキシシラン、ビニルトリメトキシシラン、ビニルトリエトキシシラン、４－ビニルブチルトリメトキシシラン、４－ビニルブチルトリエトキシシラン、８－ビニルオクチルトリメトキシシラン、８－ビニルオクチルトリエトキシシラン、１０－メタクリロイルオキシデシルトリメトキシシラン、１０－アクリロイルオキシデシルトリメトキシシラン、１０－メタクリロイルオキシデシルトリエトキシシラン、１０－アクリロイルオキシデシルトリエトキシシラン等が挙げられる。 Furthermore, examples of copolymerizable monomers other than the above include silane-based monomers containing silicon atoms. Examples of the silane monomer include 3-acryloxypropyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 4-vinylbutyltrimethoxysilane, 4-vinylbutyltriethoxysilane, and 8-vinyloctyltrimethoxysilane. , 8-vinyloctyltriethoxysilane, 10-methacryloyloxydecyltrimethoxysilane, 10-acryloyloxydecyltrimethoxysilane, 10-methacryloyloxydecyltriethoxysilane, 10-acryloyloxydecyltriethoxysilane, and the like.
　また、前記の単官能性モノマーの他に、粘着剤の凝集力を調整するために、必要に応じて多官能性モノマーを共重合モノマーとして使用することができる。ここで、本発明において、単官能性モノマーとは、（メタ）アクリロイル基又はビニル基等の不飽和二重結合を有する重合性の官能基を１つ有するモノマーのことを示し、多官能性モノマーとは、後述するように、（メタ）アクリロイル基又はビニル基等の不飽和二重結合を有する重合性の官能基を少なくとも２つ有するモノマーのことを示す。 Further, in addition to the above monofunctional monomer, a polyfunctional monomer can be used as a copolymerization monomer as necessary in order to adjust the cohesive strength of the pressure-sensitive adhesive. Here, in the present invention, the monofunctional monomer means a monomer having one polymerizable functional group having an unsaturated double bond such as a (meth) acryloyl group or a vinyl group, and is a polyfunctional monomer. As described later, indicates a monomer having at least two polymerizable functional groups having an unsaturated double bond such as a (meth) acryloyl group or a vinyl group.
　多官能性モノマーは、（メタ）アクリロイル基又はビニル基等の不飽和二重結合を有する重合性の官能基を少なくとも２つ有するモノマーであり、例えば、（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、１，１２－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価アルコールと（メタ）アクリル酸とのエステル化合物；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）アクリレート等が挙げられる。多官能性モノマーは、１種を単独で又は２種以上を組み合わせて使用することができる。 The polyfunctional monomer is a monomer having at least two polymerizable functional groups having an unsaturated double bond such as a (meth) acryloyl group or a vinyl group, such as (poly) ethylene glycol di (meth) acrylate, (Poly) propylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, pentaerythritol di (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, 1,2-ethylene Glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,12-dodecanediol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, tetramethylol methanetri (meth) acrylate Ester compounds of polyhydric alcohols such as carbonate and (meth) acrylic acid; allyl (meth) acrylate, vinyl (meth) acrylate, divinylbenzene, epoxy acrylate, polyester acrylate, urethane acrylate, butyl di (meth) acrylate, hexyl di ( And (meth) acrylate. A polyfunctional monomer can be used individually by 1 type or in combination of 2 or more types.
　前記カルボキシル基含有モノマー（ａ２）、ヒドロキシル基含有モノマー（ａ３）、窒素含有モノマー（ａ４）以外の共重合モノマーの割合は、特に制限されないが、（メタ）アクリル系ポリマー（Ａ）を構成する全モノマー中、１０重量％以下であることが好ましく、０．１～１０重量％がより好ましく、０．１～５重量％がさらに好ましい。 The proportion of the copolymerization monomer other than the carboxyl group-containing monomer (a2), the hydroxyl group-containing monomer (a3), and the nitrogen-containing monomer (a4) is not particularly limited, but may be all of the (meth) acrylic polymer (A). In the monomer, it is preferably 10% by weight or less, more preferably 0.1 to 10% by weight, and further preferably 0.1 to 5% by weight.
　（メタ）アクリル系ポリマー（Ａ）は、上記のモノマーを目的や所望の特性に応じて適切に組み合わせて重合することにより得られ得る。得られる（メタ）アクリル系ポリマー（Ａ）は、ランダム共重合体、ブロック共重合体、グラフト共重合体のいずれでもよい。（メタ）アクリル系ポリマー（Ａ）は、任意の適切な方法で合成することができ、例えば、大日本図書（株）発行　中前勝彦著「接着・粘着の化学と応用」を参考に合成できる。 The (meth) acrylic polymer (A) can be obtained by polymerizing the above monomers appropriately in accordance with the purpose and desired properties. The obtained (meth) acrylic polymer (A) may be any of a random copolymer, a block copolymer, and a graft copolymer. The (meth) acrylic polymer (A) can be synthesized by any appropriate method. For example, it can be synthesized by referring to “Chemistry and Application of Adhesion / Adhesion” by Katsuhiko Nakamae, published by Dainippon Tosho Co., Ltd. .
　例えば、（メタ）アクリル系ポリマー（Ａ）の重合方法としては、任意の適切な方法を採用することができる。具体例としては、溶液重合、塊状重合、乳化重合、各種ラジカル重合が挙げられる。 For example, any appropriate method can be adopted as a polymerization method of the (meth) acrylic polymer (A). Specific examples include solution polymerization, bulk polymerization, emulsion polymerization, and various radical polymerizations.
　ラジカル重合に用いられる重合開始剤、連鎖移動剤、乳化剤等は特に限定されず適宜選択して使用することができる。なお、（メタ）アクリル系ポリマーの重量平均分子量は、重合開始剤、連鎖移動剤の使用量、反応条件により制御可能であり、これらの種類に応じて適宜のその使用量が調整される。 The polymerization initiator, chain transfer agent, emulsifier and the like used for radical polymerization are not particularly limited and can be appropriately selected and used. In addition, the weight average molecular weight of a (meth) acrylic-type polymer can be controlled by the usage-amount of a polymerization initiator and a chain transfer agent, and reaction conditions, The usage-amount is suitably adjusted according to these kinds.
　例えば、溶液重合等においては、重合溶媒として、例えば、酢酸エチル、トルエン等が用いられる。具体的な溶液重合例としては、反応は窒素等の不活性ガス気流下で、重合開始剤を加え、通常、５０～７０℃程度で、５～３０時間程度の反応条件で行われる。 For example, in solution polymerization or the like, for example, ethyl acetate, toluene or the like is used as a polymerization solvent. As a specific example of solution polymerization, the reaction is carried out in an inert gas stream such as nitrogen and a polymerization initiator is added, and the reaction is usually performed at about 50 to 70 ° C. under reaction conditions for about 5 to 30 hours.
　溶液重合等に用いられる、熱重合開始剤としては、例えば、２，２’－アゾビスイソブチロニトリル、２，２’－アゾビス－２－メチルブチロニトリル、２，２’－アゾビス（２－メチルプロピオン酸）ジメチル、４，４’－アゾビス－４－シアノバレリアン酸、アゾビスイソバレロニトリル、２，２’－アゾビス（２－アミジノプロパン）ジヒドロクロライド、２，２’－アゾビス［２－（５－メチル－２－イミダゾリン－２－イル）プロパン］ジヒドロクロライド、２，２’－アゾビス（２－メチルプロピオンアミジン）二硫酸塩、２，２’－アゾビス（Ｎ，Ｎ’－ジメチレンイソブチルアミジン）、２，２’－アゾビス［Ｎ－（２－カルボキシエチル）－２－メチルプロピオンアミジン］ハイドレート（ＶＡ－０５７、和光純薬工業（株）製）等のアゾ系開始剤；過硫酸カリウム、過硫酸アンモニウム等の過硫酸塩、ジ（２－エチルヘキシル）パーオキシジカーボネート、ジ（４－ｔ－ブチルシクロヘキシル）パーオキシジカーボネート、ジ－ｓｅｃ－ブチルパーオキシジカーボネート、ｔ－ブチルパーオキシネオデカノエート、ｔ－ヘキシルパーオキシピバレート、ｔ－ブチルパーオキシピバレート、ジラウロイルパーオキシド、ジ－ｎ－オクタノイルパーオキシド、１，１，３，３－テトラメチルブチルパーオキシ－２－エチルヘキサノエート、ジ（４－メチルベンゾイル）パーオキシド、ジベンゾイルパーオキシド、ｔ－ブチルパーオキシイソブチレート、１，１－ジ（ｔ－ヘキシルパーオキシ）シクロヘキサン、ｔ－ブチルハイドロパーオキシド、過酸化水素等の過酸化物系開始剤、過硫酸塩と亜硫酸水素ナトリウムの組み合わせ、過酸化物とアスコルビン酸ナトリウムの組み合わせ等の過酸化物と還元剤とを組み合わせたレドックス系開始剤等を挙げることができるが、これらに限定されるものではない。 Examples of thermal polymerization initiators used for solution polymerization include 2,2′-azobisisobutyronitrile, 2,2′-azobis-2-methylbutyronitrile, 2,2′-azobis (2 -Methylpropionic acid) dimethyl, 4,4'-azobis-4-cyanovaleric acid, azobisisovaleronitrile, 2,2'-azobis (2-amidinopropane) dihydrochloride, 2,2'-azobis [2- (5-Methyl-2-imidazolin-2-yl) propane] dihydrochloride, 2,2′-azobis (2-methylpropionamidine) disulfate, 2,2′-azobis (N, N′-dimethyleneisobutyl) Amidine), 2,2′-azobis [N- (2-carboxyethyl) -2-methylpropionamidine] hydrate (VA-057, Wako Pure Chemical Industries, Ltd.) Azo initiators such as potassium persulfate, ammonium persulfate, di (2-ethylhexyl) peroxydicarbonate, di (4-t-butylcyclohexyl) peroxydicarbonate, di- sec-butyl peroxydicarbonate, t-butylperoxyneodecanoate, t-hexylperoxypivalate, t-butylperoxypivalate, dilauroyl peroxide, di-n-octanoyl peroxide, 1, 1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, di (4-methylbenzoyl) peroxide, dibenzoyl peroxide, t-butylperoxyisobutyrate, 1,1-di (t- Hexylperoxy) cyclohexane, t-butyl hydroperoxide, hydrogen peroxide, etc. Examples include oxide initiators, redox initiators that combine a peroxide and a reducing agent, such as a combination of persulfate and sodium bisulfite, and a combination of peroxide and sodium ascorbate. It is not limited to.
　前記重合開始剤は、単独で使用してもよく、また２種以上を混合して使用してもよいが、（メタ）アクリル系ポリマー（Ａ）を構成する全モノマー成分１００重量部に対して、１重量部以下程度であることが好ましく、０．００５～１重量部程度であることがより好ましく、０．０２～０．５重量部程度であることがさらに好ましい。 Although the said polymerization initiator may be used independently and may be used in mixture of 2 or more types, with respect to 100 weight part of all the monomer components which comprise a (meth) acrylic-type polymer (A). The amount is preferably about 1 part by weight or less, more preferably about 0.005 to 1 part by weight, and still more preferably about 0.02 to 0.5 part by weight.
　なお、重合開始剤として、例えば、２，２’－アゾビスイソブチロニトリルを用いて（メタ）アクリル系ポリマー（Ａ）を製造するには、重合開始剤の使用量は、モノマー成分の全量１００重量部に対して、０．２重量部以下程度であることが好ましく、０．０６～０．２重量部程度とするのがより好ましい。 In order to produce the (meth) acrylic polymer (A) using, for example, 2,2′-azobisisobutyronitrile as the polymerization initiator, the amount of polymerization initiator used is the total amount of monomer components. The amount is preferably about 0.2 parts by weight or less with respect to 100 parts by weight, and more preferably about 0.06 to 0.2 parts by weight.
　連鎖移動剤としては、例えば、ラウリルメルカプタン、グリシジルメルカプタン、メルカプト酢酸、２－メルカプトエタノール、チオグリコール酸、チオグルコール酸２－エチルヘキシル、２，３－ジメルカプト－１－プロパノール等が挙げられる。連鎖移動剤は、単独で使用してもよく、また２種以上を混合して使用してもよいが、全体としての含有量はモノマー成分の全量１００重量部に対して、０．１重量部程度以下である。 Examples of the chain transfer agent include lauryl mercaptan, glycidyl mercaptan, mercaptoacetic acid, 2-mercaptoethanol, thioglycolic acid, 2-ethylhexyl thioglycolate, and 2,3-dimercapto-1-propanol. The chain transfer agent may be used alone or in combination of two or more, but the total content is 0.1 parts by weight with respect to 100 parts by weight of the total amount of monomer components. Less than or equal to
　また、乳化重合する場合に用いる乳化剤としては、例えば、ラウリル硫酸ナトリウム、ラウリル硫酸アンモニウム、ドデシルベンゼンスルホン酸ナトリウム、ポリオキシエチレンアルキルエーテル硫酸アンモニウム、ポリオキシエチレンアルキルフェニルエーテル硫酸ナトリウム等のアニオン系乳化剤、ポリオキシエチレンアルキルエーテル、ポリオキシエチレンアルキルフェニルエーテル、ポリオキシエチレン脂肪酸エステル、ポリオキシエチレン－ポリオキシプロピレンブロックポリマー等のノニオン系乳化剤等が挙げられる。これらの乳化剤は、単独で用いてもよく２種以上を併用してもよい。 Examples of the emulsifier used in emulsion polymerization include anionic emulsifiers such as sodium lauryl sulfate, ammonium lauryl sulfate, sodium dodecylbenzenesulfonate, ammonium polyoxyethylene alkyl ether sulfate, sodium polyoxyethylene alkylphenyl ether sulfate, and polyoxy Nonionic emulsifiers such as ethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene fatty acid ester, polyoxyethylene-polyoxypropylene block polymer and the like can be mentioned. These emulsifiers may be used alone or in combination of two or more.
　さらに、プロペニル基、アリルエーテル基等のラジカル重合性官能基が導入された反応性乳化剤を用いることができる。具体的には、例えば、アクアロンＨＳ－１０、ＨＳ－２０、ＫＨ－１０、ＢＣ－０５、ＢＣ－１０、ＢＣ－２０（以上、いずれも第一工業製薬（株）製）、アデカリアソープＳＥ１０Ｎ（ＡＤＥＫＡ社製）等がある。 Furthermore, a reactive emulsifier into which a radical polymerizable functional group such as a propenyl group or an allyl ether group is introduced can be used. Specifically, for example, Aqualon HS-10, HS-20, KH-10, BC-05, BC-10, BC-20 (all of which are manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), Adekaria soap SE10N (Made by ADEKA).
　乳化剤の使用量は、モノマー成分の全量１００重量部に対して、５重量部以下であることが好ましく、０．３～５重量部であることがより好ましく、重合安定性や機械的安定性の観点から、０．５～１重量部であることがさらに好ましい。 The amount of the emulsifier used is preferably 5 parts by weight or less, more preferably 0.3 to 5 parts by weight, based on 100 parts by weight of the total amount of the monomer components, and it has polymerization stability and mechanical stability. From the viewpoint, it is more preferably 0.5 to 1 part by weight.
　また、（メタ）アクリル系ポリマー（Ａ）は、放射線重合により製造する場合には、前記モノマー成分を、電子線、ＵＶ等の放射線を照射することにより重合して製造することができる。前記放射線重合を電子線で行う場合には、前記モノマー成分には光重合開始剤を含有させることは特に必要ではないが、前記放射線重合をＵＶ重合で行う場合には、特に、重合時間を短くすることができる利点等から、モノマー成分に光重合開始剤を含有させることができる。光重合開始剤は１種を単独で又は２種以上を組み合わせて使用することができる。 Further, when the (meth) acrylic polymer (A) is produced by radiation polymerization, it can be produced by polymerizing the monomer component by irradiating with radiation such as electron beam or UV. When the radiation polymerization is performed with an electron beam, it is not particularly necessary to include a photopolymerization initiator in the monomer component. However, when the radiation polymerization is performed with UV polymerization, the polymerization time is particularly short. For example, a photopolymerization initiator can be contained in the monomer component because of the advantages that can be achieved. A photoinitiator can be used individually by 1 type or in combination of 2 or more types.
　光重合開始剤としては、特に制限されないが、光重合を開始するものであれば特に制限されず、通常用いられる光重合開始剤を用いることができる。例えば、ベンゾインエーテル系光重合開始剤、アセトフェノン系光重合開始剤、α－ケトール系光重合開始剤、芳香族スルホニルクロリド系光重合開始剤、光活性オキシム系光重合開始剤、ベンゾイン系光重合開始剤、ベンジル系光重合開始剤、ベンゾフェノン系光重合開始剤、ケタール系光重合開始剤、チオキサントン系光重合開始剤、アシルフォスフィンオキサイド系光重合開始剤等を用いることができる。 The photopolymerization initiator is not particularly limited, but is not particularly limited as long as it initiates photopolymerization, and a commonly used photopolymerization initiator can be used. For example, benzoin ether photopolymerization initiator, acetophenone photopolymerization initiator, α-ketol photopolymerization initiator, aromatic sulfonyl chloride photopolymerization initiator, photoactive oxime photopolymerization initiator, benzoin photopolymerization initiator Agents, benzyl photopolymerization initiators, benzophenone photopolymerization initiators, ketal photopolymerization initiators, thioxanthone photopolymerization initiators, acylphosphine oxide photopolymerization initiators, and the like can be used.
　具体的には、ベンゾインエーテル系光重合開始剤としては、例えば、ベンゾインメチルエーテル、ベンゾインエチルエーテル、ベンゾインプロピルエーテル、ベンゾインイソプロピルエーテル、ベンゾインイソブチルエーテル、２，２－ジメトキシ－１，２－ジフェニルエタン－１－オン（商品名：イルガキュア６５１、ＢＡＳＦ社製）、アニソールメチルエーテル等が挙げられる。アセトフェノン系光重合開始剤としては、例えば、１－ヒドロキシシクロヘキシルフェニルケトン（商品名：イルガキュア１８４、ＢＡＳＦ社製）、４－フェノキシジクロロアセトフェノン、４－ｔ－ブチル－ジクロロアセトフェノン、１－［４－(２－ヒドロキシエトキシ)－フェニル］－２－ヒドロキシ－２－メチル－１－プロパン－１－オン（商品名：イルガキュア２９５９、ＢＡＳＦ社製）、２－ヒドロキシ－２－メチル－１－フェニル－プロパン－１－オン（商品名：ダロキュア１１７３、ＢＡＳＦ社製）、メトキシアセトフェノン等が挙げられる。α－ケトール系光重合開始剤としては、例えば、２－メチル－２－ヒドロキシプロピオフェノン、１－［４－（２－ヒドロキシエチル）－フェニル］－２－ヒドロキシ－２－メチルプロパン－１－オン等が挙げられる。芳香族スルホニルクロリド系光重合開始剤としては、例えば、２－ナフタレンスルホニルクロライド等が挙げられる。光活性オキシム系光重合開始剤としては、例えば、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）－オキシム等が挙げられる。 Specifically, examples of the benzoin ether photopolymerization initiator include benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, benzoin isopropyl ether, benzoin isobutyl ether, 2,2-dimethoxy-1,2-diphenylethane- Examples thereof include 1-one (trade name: Irgacure 651, manufactured by BASF), anisole methyl ether, and the like. Examples of the acetophenone photopolymerization initiator include 1-hydroxycyclohexyl phenyl ketone (trade name: Irgacure 184, manufactured by BASF), 4-phenoxydichloroacetophenone, 4-t-butyl-dichloroacetophenone, 1- [4- ( 2-hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propan-1-one (trade name: Irgacure 2959, manufactured by BASF), 2-hydroxy-2-methyl-1-phenyl-propane- Examples thereof include 1-one (trade name: Darocur 1173, manufactured by BASF), methoxyacetophenone, and the like. Examples of the α-ketol photopolymerization initiator include 2-methyl-2-hydroxypropiophenone, 1- [4- (2-hydroxyethyl) -phenyl] -2-hydroxy-2-methylpropane-1- ON etc. are mentioned. Examples of aromatic sulfonyl chloride photopolymerization initiators include 2-naphthalenesulfonyl chloride. Examples of the photoactive oxime photopolymerization initiator include 1-phenyl-1,1-propanedione-2- (o-ethoxycarbonyl) -oxime.
　また、ベンゾイン系光重合開始剤には、例えば、ベンゾイン等が含まれる。ベンジル系光重合開始剤には、例えば、ベンジル等が含まれる。ベンゾフェノン系光重合開始剤には、例えば、ベンゾフェノン、ベンゾイル安息香酸、３，３’－ジメチル－４－メトキシベンゾフェノン、ポリビニルベンゾフェノン、α－ヒドロキシシクロヘキシルフェニルケトン等が含まれる。ケタール系光重合開始剤には、例えば、ベンジルジメチルケタール等が含まれる。チオキサントン系光重合開始剤には、例えば、チオキサントン、２－クロロチオキサントン、２－メチルチオキサントン、２，４－ジ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－ジクロロチオキサントン、２，４－ジエ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、ドデシルチオキサントン等が含まれる。 The benzoin photopolymerization initiator includes, for example, benzoin. Examples of the benzyl photopolymerization initiator include benzyl. Examples of the benzophenone photopolymerization initiator include benzophenone, benzoylbenzoic acid, 3,3′-dimethyl-4-methoxybenzophenone, polyvinylbenzophenone, α-hydroxycyclohexyl phenyl ketone, and the like. Examples of the ketal photopolymerization initiator include benzyl dimethyl ketal. Examples of the thioxanthone photopolymerization initiator include thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, 2,4-dichlorothioxanthone, 2,4-diethylthioxanthone, isopropylthioxanthone, 2,4-diisopropylthioxanthone, dodecylthioxanthone and the like are included.
　アシルフォスフィン系光重合開始剤としては、例えば、ビス（２，６－ジメトキシベンゾイル）フェニルホスフィンオキシド、ビス（２，６－ジメトキシベンゾイル）（２，４，４－トリメチルペンチル）ホスフィンオキシド、ビス（２，６－ジメトキシベンゾイル）－ｎ－ブチルホスフィンオキシド、ビス（２，６－ジメトキシベンゾイル）－（２－メチルプロパン－１－イル）ホスフィンオキシド、ビス（２，６－ジメトキシベンゾイル）－（１－メチルプロパン－１－イル）ホスフィンオキシド、ビス（２，６－ジメトキシベンゾイル）－ｔ－ブチルホスフィンオキシド、ビス（２，６－ジメトキシベンゾイル）シクロヘキシルホスフィンオキシド、ビス（２，６－ジメトキシベンゾイル）オクチルホスフィンオキシド、ビス（２－メトキシベンゾイル）（２－メチルプロパン－１－イル）ホスフィンオキシド、ビス（２－メトキシベンゾイル）（１－メチルプロパン－１－イル）ホスフィンオキシド、ビス（２，６－ジエトキシベンゾイル）（２－メチルプロパン－１－イル）ホスフィンオキシド、ビス（２，６－ジエトキシベンゾイル）（１－メチルプロパン－１－イル）ホスフィンオキシド、ビス（２，６－ジブトキシベンゾイル）（２－メチルプロパン－１－イル）ホスフィンオキシド、ビス（２，４－ジメトキシベンゾイル）（２－メチルプロパン－１－イル）ホスフィンオキシド、ビス（２，４，６－トリメチルベンゾイル）（２，４－ジペントキシフェニル）ホスフィンオキシド、ビス（２，６－ジメトキシベンゾイル）ベンジルホスフィンオキシド、ビス（２，６－ジメトキシベンゾイル）－２－フェニルプロピルホスフィンオキシド、ビス（２，６－ジメトキシベンゾイル）－２－フェニルエチルホスフィンオキシド、ビス（２，６－ジメトキシベンゾイル）ベンジルホスフィンオキシド、ビス（２，６－ジメトキシベンゾイル）－２－フェニルプロピルホスフィンオキシド、ビス（２，６－ジメトキシベンゾイル）－２－フェニルエチルホスフィンオキシド、２，６－ジメトキシベンゾイルベンジルブチルホスフィンオキシド、２，６－ジメトキシベンゾイルベンジルオクチルホスフィンオキシド、ビス（２，４，６－トリメチルベンゾイル）－２，５－ジイソプロピルフェニルホスフィンオキシド、ビス（２，４，６－トリメチルベンゾイル）－２－メチルフェニルホスフィンオキシド、ビス（２，４，６－トリメチルベンゾイル）－４－メチルフェニルホスフィンオキシド、ビス（２，４，６－トリメチルベンゾイル）－２，５－ジエチルフェニルホスフィンオキシド、ビス（２，４，６－トリメチルベンゾイル）－２，３，５，６－テトラメチルフェニルホスフィンオキシド、ビス（２，４，６－トリメチルベンゾイル）－２，４－ジ－ｎ－ブトキシフェニルホスフィンオキシド、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シド、ビス（２，６－ジメトキシベンゾイル）－２，４，４－トリメチルペンチルホスフィンオキシド、ビス（２，４，６－トリメチルベンゾイル）イソブチルホスフィンオキシド、２，６－ジメチトキシベンゾイル－２，４，６－トリメチルベンゾイル－ｎ－ブチルホスフィンオキシド、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シド、ビス（２，４，６－トリメチルベンゾイル）－２，４－ジブトキシフェニルホスフィンオキシド、１，１０－ビス［ビス（２，４，６－トリメチルベンゾイル）ホスフィンオキシド］デカン、トリ（２－メチルベンゾイル）ホスフィンオキシド、等が挙げられる。 Examples of the acylphosphine photopolymerization initiator include bis (2,6-dimethoxybenzoyl) phenylphosphine oxide, bis (2,6-dimethoxybenzoyl) (2,4,4-trimethylpentyl) phosphine oxide, bis ( 2,6-dimethoxybenzoyl) -n-butylphosphine oxide, bis (2,6-dimethoxybenzoyl)-(2-methylpropan-1-yl) phosphine oxide, bis (2,6-dimethoxybenzoyl)-(1- Methylpropan-1-yl) phosphine oxide, bis (2,6-dimethoxybenzoyl) -t-butylphosphine oxide, bis (2,6-dimethoxybenzoyl) cyclohexylphosphine oxide, bis (2,6-dimethoxybenzoyl) octylphosphine Oxides, bis (2- Toxibenzoyl) (2-methylpropan-1-yl) phosphine oxide, bis (2-methoxybenzoyl) (1-methylpropan-1-yl) phosphine oxide, bis (2,6-diethoxybenzoyl) (2-methyl Propan-1-yl) phosphine oxide, bis (2,6-diethoxybenzoyl) (1-methylpropan-1-yl) phosphine oxide, bis (2,6-dibutoxybenzoyl) (2-methylpropane-1- Yl) phosphine oxide, bis (2,4-dimethoxybenzoyl) (2-methylpropan-1-yl) phosphine oxide, bis (2,4,6-trimethylbenzoyl) (2,4-dipentoxyphenyl) phosphine oxide Bis (2,6-dimethoxybenzoyl) benzylphosphine oxide, bis 2,6-dimethoxybenzoyl) -2-phenylpropylphosphine oxide, bis (2,6-dimethoxybenzoyl) -2-phenylethylphosphine oxide, bis (2,6-dimethoxybenzoyl) benzylphosphine oxide, bis (2,6 -Dimethoxybenzoyl) -2-phenylpropylphosphine oxide, bis (2,6-dimethoxybenzoyl) -2-phenylethylphosphine oxide, 2,6-dimethoxybenzoylbenzylbutylphosphine oxide, 2,6-dimethoxybenzoylbenzyloctylphosphine oxide Bis (2,4,6-trimethylbenzoyl) -2,5-diisopropylphenylphosphine oxide, bis (2,4,6-trimethylbenzoyl) -2-methylphenylphosphine oxide, (2,4,6-trimethylbenzoyl) -4-methylphenylphosphine oxide, bis (2,4,6-trimethylbenzoyl) -2,5-diethylphenylphosphine oxide, bis (2,4,6-trimethylbenzoyl) ) -2,3,5,6-tetramethylphenylphosphine oxide, bis (2,4,6-trimethylbenzoyl) -2,4-di-n-butoxyphenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenyl Phosphine oxide, bis (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide, bis (2,4,6-trimethylbenzoyl) isobutylphosphine oxide, 2,6-dimethoxyoxybenzoyl-2,4 , 6-Trimethylbenzoyl-n-butylphosphine oxy Bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide, bis (2,4,6-trimethylbenzoyl) -2,4-dibutoxyphenylphosphine oxide, 1,10-bis [bis (2,4 , 6-trimethylbenzoyl) phosphine oxide] decane, tri (2-methylbenzoyl) phosphine oxide, and the like.
　光重合開始剤の使用量は、特に制限されないが、例えば、前記（メタ）アクリル系ポリマー（Ａ）を構成する全モノマー１００重量部に対して０．０１～５重量部が好ましく、０．０５～３重量部がより好ましく、０．０５～１．５重量部がさらに好ましく、０．１～１重量部が特に好ましい。光重合開始剤の使用量が上記範囲内であれば重合反応を十分に進行させることができる。なお、光重合性開始剤は１種を単独で又は２種以上を組み合わせて使用することができる。 The amount of the photopolymerization initiator used is not particularly limited, but is preferably 0.01 to 5 parts by weight with respect to 100 parts by weight of the total monomers constituting the (meth) acrylic polymer (A), for example, 0.05 Is more preferably 3 to 3 parts by weight, still more preferably 0.05 to 1.5 parts by weight, and particularly preferably 0.1 to 1 part by weight. If the usage-amount of a photoinitiator is in the said range, a polymerization reaction can fully be advanced. In addition, a photopolymerization initiator can be used individually by 1 type or in combination of 2 or more types.
　本発明で用いる（メタ）アクリル系ポリマー（Ａ）の重量平均分子量は、４０万～２５０万であることが好ましく、６０万～２２０万であることがより好ましい。重量平均分子量が４０万より大きくすることで、粘着剤層の耐久性を満足させたり、粘着剤層の凝集力が小さくなって糊残りが生じるのを抑えることができる。なお、重量平均分子量は、ゲルパーミネーション・クロマトグラフィー（ＧＰＣ）により測定し、ポリスチレン換算により算出された値をいう。なお、放射線重合で得られた（メタ）アクリル系ポリマーについては、分子量測定は困難である。 The weight average molecular weight of the (meth) acrylic polymer (A) used in the present invention is preferably 400,000 to 2,500,000, and more preferably 600,000 to 2,200,000. By making the weight average molecular weight larger than 400,000, it is possible to satisfy the durability of the pressure-sensitive adhesive layer, or to suppress the occurrence of adhesive residue due to the reduced cohesive force of the pressure-sensitive adhesive layer. The weight average molecular weight is a value measured by gel permeation chromatography (GPC) and calculated in terms of polystyrene. In addition, it is difficult to measure the molecular weight of the (meth) acrylic polymer obtained by radiation polymerization.
　本発明で用いるベース粘着剤組成物は、架橋剤を含有してもよい。架橋剤としては、例えば、有機系架橋剤、多官能性金属キレートが挙げられる。有機系架橋剤としては、例えば、イソシアネート系架橋剤、過酸化物系架橋剤、エポキシ系架橋剤、イミン系架橋剤が挙げられる。多官能性金属キレートは、多価金属が有機化合物と共有結合又は配位結合しているものである。多価金属としては、例えば、Ａｌ、Ｃｒ、Ｚｒ、Ｃｏ、Ｃｕ、Ｆｅ、Ｎｉ、Ｖ、Ｚｎ、Ｉｎ、Ｃａ、Ｍｇ、Ｍｎ、Ｙ、Ｃｅ、Ｓｒ、Ｂａ、Ｍｏ、Ｌａ、Ｓｎ、Ｔｉが挙げられる。有機化合物としては、例えば、アルキルエステル、アルコール化合物、カルボン酸化合物、エーテル化合物、ケトン化合物が挙げられる。共有結合又は配位結合する有機化合物中の原子としては、例えば酸素原子が挙げられる。これらの中でも、架橋剤としては、イソシアネート系架橋剤が好ましい。 The base pressure-sensitive adhesive composition used in the present invention may contain a crosslinking agent. Examples of the crosslinking agent include organic crosslinking agents and polyfunctional metal chelates. Examples of the organic crosslinking agent include an isocyanate crosslinking agent, a peroxide crosslinking agent, an epoxy crosslinking agent, and an imine crosslinking agent. A polyfunctional metal chelate is one in which a polyvalent metal is covalently or coordinately bonded to an organic compound. Examples of the polyvalent metal include Al, Cr, Zr, Co, Cu, Fe, Ni, V, Zn, In, Ca, Mg, Mn, Y, Ce, Sr, Ba, Mo, La, Sn, and Ti. Can be mentioned. Examples of the organic compound include alkyl esters, alcohol compounds, carboxylic acid compounds, ether compounds, and ketone compounds. As an atom in the organic compound which carries out a covalent bond or a coordinate bond, an oxygen atom is mentioned, for example. Among these, as a crosslinking agent, an isocyanate type crosslinking agent is preferable.
　イソシアネート系架橋剤は、代表的には、２個以上のイソシアネート基を１分子中に有する化合物をいう。例えば、トリレンジイソシアネート、クロルフェニレンジイソシアナート、テトラメチレンジイソシアナート、キシリレンジイソシアネート、ジフェニルメタンジイソシアネート、水添されたジフェニルメタンジイソシアネート等のイソシアネートモノマー及びこれらイソシアネートモノマーをトリメチロールプロパン等と付加したイソシアネート化合物やイソシアヌレート化物、ビュレット型化合物、さらにはポリエーテルポリオールや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等と付加反応させたウレタンプレポリマー型のイソシアネート等が挙げられる。特に好ましくは、ポリイソシアネート化合物であり、ヘキサメチレンジイソシアネート、水添キシリレンジイソシアネート、及びイソホロンジイソシアネートからなる群より選択される1種又はそれに由来するポリイソシアネート化合物である。ここで、ヘキサメチレンジイソシアネート、水添キシリレンジイソシアネート、及びイソホロンジイソシアネートからなる群より選択される1種又はそれに由来するポリイソシアネート化合物には、ヘキサメチレンジイソシアネート、水添キシリレンジイソシアネート、イソホロンジイソシアネート、ポリオール変性ヘキサメチレンジイソシアネート、ポリオール変性水添キシリレンジイソシアネート、トリマー型水添キシリレンジイソシアネート、及びポリオール変性イソホロンジイソシアネート等が含まれる。 An isocyanate-based crosslinking agent typically refers to a compound having two or more isocyanate groups in one molecule. For example, isocyanate monomers such as tolylene diisocyanate, chlorophenylene diisocyanate, tetramethylene diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, and isocyanate compounds obtained by adding these isocyanate monomers to trimethylolpropane, etc. Examples include isocyanurates, burette type compounds, and urethane prepolymer type isocyanates obtained by addition reaction with polyether polyols, polyester polyols, acrylic polyols, polybutadiene polyols, polyisoprene polyols, and the like. Particularly preferred is a polyisocyanate compound, which is one or a polyisocyanate compound derived from one selected from the group consisting of hexamethylene diisocyanate, hydrogenated xylylene diisocyanate, and isophorone diisocyanate. Here, hexamethylene diisocyanate, hydrogenated xylylene diisocyanate, isophorone diisocyanate, polyol modified with one or more polyisocyanate compounds selected from the group consisting of hexamethylene diisocyanate, hydrogenated xylylene diisocyanate, and isophorone diisocyanate Examples include hexamethylene diisocyanate, polyol-modified hydrogenated xylylene diisocyanate, trimer-type hydrogenated xylylene diisocyanate, and polyol-modified isophorone diisocyanate.
　エポキシ系架橋剤は、代表的には、２個以上のエポキシ基（グリシジル基）を１分子中に有する化合物をいう。エポキシ系架橋剤としては、例えば、エチレングリコールジグリシジルエーテル、プロピレングリコールジグリシジルエーテル、テレフタル酸ジグリシジルエステル、スピログリコールジグリシジルエーテル、ジグリシジルアミノメチルシクロへキサン、テトラグリシジルキシレンジアミン、ポリグリシジルメタキシレンジアミン等が挙げられる。 The epoxy-based crosslinking agent typically refers to a compound having two or more epoxy groups (glycidyl groups) in one molecule. Examples of the epoxy-based crosslinking agent include ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, diglycidyl terephthalate, spiroglycol diglycidyl ether, diglycidylaminomethylcyclohexane, tetraglycidylxylenediamine, and polyglycidylmetaxylene. Examples include diamines.
　過酸化物としては、加熱又は光照射によりラジカル活性種を発生してベースポリマーの架橋を進行させ得る任意の適切な化合物を採用することができる。作業性及び安定性を考慮すると、１分間半減期温度が８０℃～１６０℃である過酸化物が好ましく、９０℃～１４０℃である過酸化物がより好ましい。過酸化物の具体例としては、ジ（２－エチルヘキシル）パーオキシジカーボネート（１分間半減期温度：９０．６℃）、ジ（４－ｔ－ブチルシクロヘキシル）パーオキシジカーボネート（１分間半減期温度：９２．１℃）、ジ－ｓｅｃ－ブチルパーオキシジカーボネート（１分間半減期温度：９２．４℃）、ｔ－ブチルパーオキシネオデカノエート（１分間半減期温度：１０３．５℃）、ｔ－ヘキシルパーオキシピバレート（１分間半減期温度：１０９．１℃）、ｔ－ブチルパーオキシピバレート（１分間半減期温度：１１０．３℃）、ジラウロイルパーオキシド（１分間半減期温度：１１６．４℃）、ジ－ｎ－オクタノイルパーオキシド（１分間半減期温度：１１７．４℃）、１，１，３，３－テトラメチルブチルパーオキシ－２－エチルヘキサノエート（１分間半減期温度：１２４．３℃）、ジ（４－メチルベンゾイル）パーオキシド（１分間半減期温度：１２８．２℃）、ジベンゾイルパーオキシド（１分間半減期温度：１３０．０℃）、ｔ－ブチルパーオキシイソブチレート（１分間半減期温度：１３６．１℃）、１，１－ジ（ｔ－ヘキシルパーオキシ）シクロヘキサン（１分間半減期温度：１４９．２℃）等が挙げられる。なお、過酸化物の半減期とは、過酸化物の分解速度を表す指標であり、過酸化物の残存量が半分になるまでの時間をいう。したがって、過酸化物の１分間半減期温度とは、過酸化物の残存量が１分間で半分になる温度をいう。任意の時間で半減期を得るための分解温度や、任意の温度での半減期時間に関しては、メーカーカタログ等に記載されており、例えば、日本油脂（株）の「有機過酸化物カタログ第９版（２００３年５月）」等に記載されている。 As the peroxide, any suitable compound capable of generating radical active species by heating or light irradiation to advance the crosslinking of the base polymer can be employed. In consideration of workability and stability, a peroxide having a 1 minute half-life temperature of 80 ° C. to 160 ° C. is preferable, and a peroxide having a 90 ° C. to 140 ° C. is more preferable. Specific examples of peroxides include di (2-ethylhexyl) peroxydicarbonate (1 minute half-life temperature: 90.6 ° C.), di (4-t-butylcyclohexyl) peroxydicarbonate (1 minute half-life) Temperature: 92.1 ° C.), di-sec-butyl peroxydicarbonate (1 minute half-life temperature: 92.4 ° C.), t-butyl peroxyneodecanoate (1 minute half-life temperature: 103.5 ° C.) ), T-hexyl peroxypivalate (1 minute half-life temperature: 109.1 ° C.), t-butyl peroxypivalate (1 minute half-life temperature: 110.3 ° C.), dilauroyl peroxide (half minute for 1 minute) Phase temperature: 116.4 ° C.), di-n-octanoyl peroxide (1 minute half-life temperature: 117.4 ° C.), 1,1,3,3-tetramethylbutylperoxy-2-ethyl Xanoate (1 minute half-life temperature: 124.3 ° C), di (4-methylbenzoyl) peroxide (1 minute half-life temperature: 128.2 ° C), dibenzoyl peroxide (1 minute half-life temperature: 130.0 ° C) ), T-butylperoxyisobutyrate (1 minute half-life temperature: 136.1 ° C.), 1,1-di (t-hexylperoxy) cyclohexane (1 minute half-life temperature: 149.2 ° C.), etc. Can be mentioned. The peroxide half-life is an index representing the decomposition rate of the peroxide, and means the time until the remaining amount of peroxide is reduced to half. Therefore, the 1-minute half-life temperature of peroxide refers to the temperature at which the remaining amount of peroxide is halved in 1 minute. The decomposition temperature for obtaining a half-life at an arbitrary time and the half-life time at an arbitrary temperature are described in the manufacturer catalog, for example, “Organic Peroxide Catalog No. 9 of Nippon Oil & Fats Co., Ltd.” Edition (May 2003) ".
　架橋剤の使用量は、（メタ）アクリル系ポリマー（Ａ）１００重量部に対して、０．０１～２０重量部が好ましく、０．０３～１０重量部がより好ましい。架橋剤の使用量が０．０１重量部未満では、粘着剤の凝集力が不足する傾向があり、加熱時に発泡が生じる場合がある。架橋剤の使用量が２０重量部を超えると、耐湿性が十分ではなく、剥がれ等が生じやすく場合がある。 The amount of the crosslinking agent used is preferably 0.01 to 20 parts by weight and more preferably 0.03 to 10 parts by weight with respect to 100 parts by weight of the (meth) acrylic polymer (A). When the amount of the crosslinking agent used is less than 0.01 parts by weight, the cohesive force of the pressure-sensitive adhesive tends to be insufficient, and foaming may occur during heating. When the amount of the crosslinking agent used exceeds 20 parts by weight, the moisture resistance is not sufficient, and peeling or the like may easily occur.
　前記ベース粘着剤組成物は、任意の適切な添加剤を含んでいてもよい。添加剤としては、例えば、帯電防止剤、酸化防止剤、カップリング剤が挙げられる。添加剤の種類、添加量及び組み合わせ等は、目的に応じて適切に設定され得る。 The base pressure-sensitive adhesive composition may contain any appropriate additive. Examples of the additive include an antistatic agent, an antioxidant, and a coupling agent. The kind of additive, the addition amount, the combination, and the like can be appropriately set according to the purpose.
　本発明で用いる光拡散粘着剤層中におけるベース粘着剤組成物の含有量は、５０～９９．７重量％であることが好ましく、５２～９７重量％がより好ましく、７０～９７重量％であることがさらに好ましい。 The content of the base pressure-sensitive adhesive composition in the light diffusion pressure-sensitive adhesive layer used in the present invention is preferably 50 to 99.7% by weight, more preferably 52 to 97% by weight, and 70 to 97% by weight. More preferably.
　前記ベース粘着剤組成物の屈折率は、１．４７以上であることが好ましく、１．４７～１．６０であることがより好ましく、１．４７～１．５５であることがさらに好ましい。ベース粘着剤組成物の屈折率が前記範囲であれば、後述する光拡散性微粒子との屈折率差を所望の範囲とすることができる。その結果、硬化後に所望のヘイズ値を有する光拡散粘着剤層を得ることができるため好ましい。 The refractive index of the base pressure-sensitive adhesive composition is preferably 1.47 or more, more preferably 1.47 to 1.60, and further preferably 1.47 to 1.55. If the refractive index of a base adhesive composition is the said range, the refractive index difference with the light diffusible fine particle mentioned later can be made into a desired range. As a result, a light diffusion pressure-sensitive adhesive layer having a desired haze value after curing can be obtained, which is preferable.
　（１－２）光拡散性微粒子
　前記光拡散粘着剤層は、前記ベース粘着剤組成物から形成される粘着剤層中に光拡散性微粒子が分散しているものである。前記光拡散性微粒子としては、本発明の効果が得られる限りにおいて、任意の適切なものを用いることができる。具体例としては、無機微粒子、高分子微粒子等が挙げられるが、これらの中でも、高分子微粒子が好ましい。 (1-2) Light Diffusing Fine Particles The light diffusing pressure-sensitive adhesive layer is a layer in which light diffusing fine particles are dispersed in a pressure-sensitive adhesive layer formed from the base pressure-sensitive adhesive composition. As the light diffusing fine particles, any appropriate one can be used as long as the effect of the present invention is obtained. Specific examples include inorganic fine particles and polymer fine particles. Among these, polymer fine particles are preferable.
　前記高分子微粒子の材質としては、例えば、シリコーン樹脂、メタアクリル系樹脂（例えば、ポリメタクリル酸メチル）、ポリスチレン樹脂、ポリウレタン樹脂、メラミン樹脂が挙げられる。これらの樹脂は、前記ベース粘着剤組成物に対する優れた分散性及び前記ベース粘着剤組成物との適切な屈折率差を有するので、拡散性能に優れた光拡散粘着剤層が得られ得る。これらの中でも、シリコーン樹脂、ポリメタクリル酸メチルが特に好ましい。 Examples of the material of the polymer fine particles include silicone resin, methacrylic resin (for example, polymethyl methacrylate), polystyrene resin, polyurethane resin, and melamine resin. Since these resins have excellent dispersibility with respect to the base pressure-sensitive adhesive composition and an appropriate refractive index difference from the base pressure-sensitive adhesive composition, a light diffusion pressure-sensitive adhesive layer having excellent diffusion performance can be obtained. Among these, silicone resins and polymethyl methacrylate are particularly preferable.
　光拡散性微粒子の形状は、例えば、真球状、扁平状、不定形状であり得る。光拡散性微粒子は、単独で用いてもよく、２種以上を組み合わせて用いてもよい。 The shape of the light diffusing fine particles can be, for example, a spherical shape, a flat shape, or an indefinite shape. The light diffusing fine particles may be used alone or in combination of two or more.
　本発明で用いる光拡散性微粒子の屈折率は、前記ベース粘着剤組成物の屈折率よりも低いことが好ましい。光拡散性微粒子の屈折率は、１．３０～１．７０であることが好ましく、１．４０～１．６５であることがより好ましい。光拡散性微粒子の屈折率が前記範囲であれば、ベース粘着剤組成物との屈折率差を所望の範囲とすることができ、その結果、硬化後に所望のヘイズ値を有する光拡散粘着剤層を得ることができるため好ましい。 The refractive index of the light diffusing fine particles used in the present invention is preferably lower than the refractive index of the base pressure-sensitive adhesive composition. The refractive index of the light diffusing fine particles is preferably 1.30 to 1.70, and more preferably 1.40 to 1.65. If the refractive index of the light diffusing fine particles is in the above range, the difference in refractive index from the base pressure-sensitive adhesive composition can be set to a desired range, and as a result, the light diffusing pressure-sensitive adhesive layer having a desired haze value after curing. Is preferable.
　光拡散性微粒子とベース粘着剤組成物との屈折率差の絶対値は、０を超えて０．２以下であることが好ましく、０を超えて０．１５以下であることがより好ましく、０．０１～０．１３であることがさらに好ましい。 The absolute value of the difference in refractive index between the light diffusing fine particles and the base pressure-sensitive adhesive composition is preferably more than 0 and 0.2 or less, more preferably more than 0 and 0.15 or less. More preferably, the ratio is 0.01 to 0.13.
　光拡散性微粒子の体積平均粒子径は、１～５μｍ程度であることが好ましく、２～５μｍ程度であることがより好ましく、２～４μｍ程度であることがさらに好ましい。光拡散性微粒子の体積平均粒子径が前記範囲内であれば、前記ベース粘着剤組成物と組み合わせることにより、所望のヘイズ値を有する光拡散粘着剤層を得ることができるため好ましい。なお、体積平均粒子径は、例えば、超遠心式自動粒度分布測定装置を用いて測定することができる。 The volume average particle diameter of the light diffusing fine particles is preferably about 1 to 5 μm, more preferably about 2 to 5 μm, and further preferably about 2 to 4 μm. If the volume average particle diameter of the light diffusing fine particles is within the above range, a light diffusing pressure-sensitive adhesive layer having a desired haze value can be obtained by combining with the base pressure-sensitive adhesive composition, which is preferable. The volume average particle diameter can be measured using, for example, an ultracentrifugal automatic particle size distribution measuring apparatus.
　光拡散粘着剤層における光拡散性微粒子の含有量は、特に限定されるものではないが、０．３～５０重量％であることが好ましく、３～４８重量％であることがより好ましく、３～３０重量％であることがさらに好ましい。光拡散性微粒子の配合量を前記範囲にすることにより、優れた光拡散性能を有する光拡散粘着剤層を得ることができる。 The content of the light diffusing fine particles in the light diffusing pressure-sensitive adhesive layer is not particularly limited, but is preferably 0.3 to 50% by weight, more preferably 3 to 48% by weight. More preferably, it is ˜30% by weight. By setting the blending amount of the light diffusing fine particles in the above range, a light diffusing pressure-sensitive adhesive layer having excellent light diffusing performance can be obtained.
　（１－３）光拡散粘着剤層の形成方法
　前記光拡散粘着剤層は、例えば、前記ベース粘着剤組成物中に光拡散性微粒子を分散させた光拡散粘着剤組成物を支持体に塗布し、溶剤等を乾燥除去することにより形成することができる。光拡散粘着剤組成物の塗布にあたっては、適宜に一種以上の溶剤を加えてもよい。また、前記ベース粘着剤組成物が活性エネルギー線硬化型である場合、前記ベース粘着剤組成物の一部を重合したプレポリマーを作製し、当該プレポリマーに光拡散性微粒子を分散させた光拡散粘着剤組成物を支持体に塗布し、当該塗布層に紫外線等の活性エネルギー線を照射することにより光拡散粘着剤層を形成することができる。また、後述する偏光フィルム等の光学部材上に、前記光拡散粘着剤組成物を直接塗布して光拡散粘着剤層を形成することもできる。 (1-3) Method for forming light diffusing pressure-sensitive adhesive layer The light diffusing pressure-sensitive adhesive layer is formed by, for example, applying a light diffusing pressure-sensitive adhesive composition in which light diffusing fine particles are dispersed in the base pressure-sensitive adhesive composition to a support. It can be formed by removing the solvent and the like by drying. In applying the light diffusion pressure-sensitive adhesive composition, one or more solvents may be appropriately added. Further, when the base pressure-sensitive adhesive composition is an active energy ray curable type, a light diffusion is produced by preparing a prepolymer obtained by polymerizing a part of the base pressure-sensitive adhesive composition, and dispersing light diffusing fine particles in the prepolymer. A light-diffusion pressure-sensitive adhesive layer can be formed by applying the pressure-sensitive adhesive composition to a support and irradiating the coating layer with active energy rays such as ultraviolet rays. In addition, the light diffusion pressure-sensitive adhesive layer can be formed by directly coating the light diffusion pressure-sensitive adhesive composition on an optical member such as a polarizing film described later.
　前記光拡散粘着剤層の厚みは、５～３００μｍであり、５～２５０μｍであることが好ましく、５０～２５０μｍであることがより好ましく、１００～２００μｍであることがさらに好ましく、１００μｍを超え２００μｍ以下であることがさらに好ましい。光拡散粘着剤層の厚みが前記範囲であることで、貼り合せする材料の微小な凹凸、又は光学機能を付与するための凹凸部に追従して貼り合せすることができるため好ましい。また、光拡散粘着剤層に透明粘着剤層を貼り合せる場合には、前記光拡散粘着剤層の厚みは、５～１００μｍ程度であることが光拡散粘着剤の物性の影響が周辺部材への貼り合せ効果に影響しない点から好ましく、５～３０μｍ程度であることがより好ましい。また、光拡散粘着剤層が２層以上からなる場合は、全ての光拡散粘着剤層の厚みの合計値が前記範囲内であればよい。 The light diffusion pressure-sensitive adhesive layer has a thickness of 5 to 300 μm, preferably 5 to 250 μm, more preferably 50 to 250 μm, still more preferably 100 to 200 μm, more than 100 μm and not more than 200 μm. More preferably. It is preferable that the thickness of the light diffusing pressure-sensitive adhesive layer be in the above-mentioned range because the bonding can be performed following the fine unevenness of the material to be bonded or the uneven portion for imparting an optical function. In addition, when a transparent adhesive layer is bonded to the light diffusion adhesive layer, the thickness of the light diffusion adhesive layer is about 5 to 100 μm. It is preferable from the viewpoint of not affecting the bonding effect, and more preferably about 5 to 30 μm. Moreover, when a light-diffusion adhesive layer consists of two or more layers, the total value of the thickness of all the light-diffusion adhesive layers should just be in the said range.
　光拡散粘着剤組成物の塗布方法としては、各種方法が用いられる。具体的には、例えば、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、ダイコーター等による押出しコート法等の方法が挙げられる。 Various methods are used as a method for applying the light diffusion adhesive composition. Specifically, for example, by roll coat, kiss roll coat, gravure coat, reverse coat, roll brush, spray coat, dip roll coat, bar coat, knife coat, air knife coat, curtain coat, lip coat, die coater, etc. Examples thereof include an extrusion coating method.
　前記加熱乾燥温度は、３０℃～２００℃程度が好ましく、４０℃～１８０℃がより好ましく、８０℃～１６０℃がさらに好ましい。加熱温度を上記の範囲とすることによって、優れた粘着特性を有する粘着剤層を得ることができる。乾燥時間は、適宜、適切な時間が採用され得る。上記乾燥時間は、５秒～２０分程度が好ましく、３０秒～１０分がより好ましく、1分～８分がさらに好ましい。 The heating and drying temperature is preferably about 30 ° C. to 200 ° C., more preferably 40 ° C. to 180 ° C., and further preferably 80 ° C. to 160 ° C. By setting the heating temperature in the above range, an adhesive layer having excellent adhesive properties can be obtained. As the drying time, an appropriate time can be adopted as appropriate. The drying time is preferably about 5 seconds to 20 minutes, more preferably 30 seconds to 10 minutes, and further preferably 1 minute to 8 minutes.
　前記ベース粘着剤組成物が、活性エネルギー線硬化型粘着剤の場合には、紫外線等の活性エネルギー線を照射することにより光拡散粘着剤層を形成することができる。紫外線照射には、高圧水銀ランプ、低圧水銀ランプ、メタルハライドランプ、ケミカルライトランプ等を用いることができる。 When the base pressure-sensitive adhesive composition is an active energy ray-curable pressure-sensitive adhesive, a light diffusion pressure-sensitive adhesive layer can be formed by irradiating active energy rays such as ultraviolet rays. For ultraviolet irradiation, a high pressure mercury lamp, a low pressure mercury lamp, a metal halide lamp, a chemical light lamp, or the like can be used.
　前記支持体としては、例えば、剥離処理したシートを用いることができる。剥離処理したシートとしては、シリコーン剥離ライナーが好ましく用いられる。 As the support, for example, a peeled sheet can be used. A silicone release liner is preferably used as the release-treated sheet.
　剥離処理したシート上に粘着剤層を形成した粘着シートは、前記粘着剤層が露出する場合には、実用に供されるまで剥離処理したシート（セパレーター）で粘着剤層を保護してもよい。実用に際しては、前記剥離処理したシートは剥離される。 When the pressure-sensitive adhesive layer is exposed on the release-treated sheet, the pressure-sensitive adhesive layer may be protected with a release-treated sheet (separator) until practical use. . In practical use, the peeled sheet is peeled off.
　セパレーターの構成材料としては、例えば、プラスチックフィルム、紙、布、不織布等の多孔質材料、ネット、発泡シート、金属箔、及びこれらのラミネート体等の適宜な薄葉体等を挙げることができるが、表面平滑性に優れる点からプラスチックフィルムが好適に用いられる。 Examples of the constituent material of the separator may include porous materials such as plastic film, paper, cloth, and nonwoven fabric, nets, foam sheets, metal foils, and appropriate thin leaves such as laminates thereof. A plastic film is preferably used from the viewpoint of excellent surface smoothness.
　前記プラスチックフィルムとしては、例えば、ポリエチレンフィルム、ポリプロピレンフィルム、ポリブテンフィルム、ポリブタジエンフィルム、ポリメチルペンテンフイルム、ポリ塩化ビニルフィルム、塩化ビニル共重合体フィルム、ポリエチレンテレフタレートフィルム、ポリブチレンテレフタレートフィルム、ポリウレタンフィルム、エチレン－酢酸ビニル共重合体フィルム等が挙げられる。 Examples of the plastic film include polyethylene film, polypropylene film, polybutene film, polybutadiene film, polymethylpentene film, polyvinyl chloride film, vinyl chloride copolymer film, polyethylene terephthalate film, polybutylene terephthalate film, polyurethane film, and ethylene. -Vinyl acetate copolymer film and the like.
　前記セパレーターの厚みは、通常５～２００μｍ、好ましくは５～１００μｍ程度である。前記セパレーターには、必要に応じて、シリコーン系、フッ素系、長鎖アルキル系もしくは脂肪酸アミド系の離型剤、シリカ粉等による離型及び防汚処理や、塗布型、練り込み型、蒸着型等の帯電防止処理もすることもできる。特に、前記セパレーターの表面にシリコーン処理、長鎖アルキル処理、フッ素処理等の剥離処理を適宜行うことにより、前記粘着剤層からの剥離性をより高めることができる。 The thickness of the separator is usually about 5 to 200 μm, preferably about 5 to 100 μm. For the separator, silicone type, fluorine type, long chain alkyl type or fatty acid amide type release agent, mold release and antifouling treatment with silica powder, coating type, kneading type, vapor deposition type, if necessary It is also possible to perform antistatic treatment such as. In particular, the release property from the pressure-sensitive adhesive layer can be further improved by appropriately performing a release treatment such as silicone treatment, long-chain alkyl treatment, or fluorine treatment on the surface of the separator.
　形成された光拡散粘着剤層のヘイズ値は、１０～９９％であることが好ましく、１０～９６％であることがより好ましく、２０～９６％であることがさらに好ましく、４０～８０％であることが特に好ましい。ヘイズ値を前記範囲にすることで、所望の拡散性能が得られ、モアレ及びギラツキの発生を良好に抑制することができるため好ましい。光拡散粘着剤の光拡散性能は、マトリクス（粘着剤）の構成材料、ならびに、光拡散性微粒子の構成材料、体積平均粒子径及び配合量等を調整することにより制御することができる。 The haze value of the formed light diffusion pressure-sensitive adhesive layer is preferably 10 to 99%, more preferably 10 to 96%, further preferably 20 to 96%, and more preferably 40 to 80%. It is particularly preferred. By setting the haze value in the above range, desired diffusion performance can be obtained, and generation of moire and glare can be favorably suppressed, which is preferable. The light diffusing performance of the light diffusing adhesive can be controlled by adjusting the constituent material of the matrix (adhesive), the constituent material of the light diffusing fine particles, the volume average particle diameter, the blending amount, and the like.
　前記光拡散粘着剤層の全光線透過率は、７５％以上であることが好ましく、８０％以上であることがより好ましく、８５％以上であることがさらに好ましい。 The total light transmittance of the light diffusion pressure-sensitive adhesive layer is preferably 75% or more, more preferably 80% or more, and further preferably 85% or more.
　（２）透明粘着剤層
　本発明の光学部材用粘着剤層は、前述の通り、前記光拡散粘着剤層以外の透明粘着剤層を含むことができる。 (2) Transparent adhesive layer The adhesive layer for optical members of this invention can contain transparent adhesive layers other than the said light-diffusion adhesive layer as above-mentioned.
　前記透明粘着剤層としては、特に限定されるものではなく、ベースポリマー及び架橋剤を含む粘着剤組成物から形成されるものを挙げることができる。当該粘着剤組成物は、アクリル系、合成ゴム系、ゴム系、シリコーン系等の粘着剤等とすることができるが、透明性、耐熱性等の観点から、（メタ）アクリル系ポリマーをベースポリマーとするアクリル系粘着剤が好ましい。 The transparent adhesive layer is not particularly limited, and examples thereof include those formed from an adhesive composition containing a base polymer and a crosslinking agent. The pressure-sensitive adhesive composition may be an acrylic, synthetic rubber-based, rubber-based, or silicone-based pressure-sensitive adhesive, but from the viewpoint of transparency and heat resistance, a (meth) acrylic polymer is a base polymer. An acrylic pressure-sensitive adhesive is preferred.
　（メタ）アクリル系ポリマーに含まれるモノマー成分としては、前記ベース粘着剤組成物で挙げたものを好適に用いることができるが、アルキル（メタ）アクリレート（ａ１）、ヒドロキシル基含有モノマー（ａ３）、及び窒素含有モノマー（ａ４）をモノマー成分として含む（メタ）アクリル系ポリマーが好ましい。また、前記（メタ）アクリル系ポリマーに含まれるモノマー成分は、カルボキシル基含有モノマーを含まないことが好ましい。各モノマーの配合割合、透明粘着剤層の形成方法は、光拡散粘着剤層の場合と同様の方法を挙げることができる。 As the monomer component contained in the (meth) acrylic polymer, those mentioned in the base pressure-sensitive adhesive composition can be preferably used, but the alkyl (meth) acrylate (a1), the hydroxyl group-containing monomer (a3), And a (meth) acrylic polymer containing the nitrogen-containing monomer (a4) as a monomer component is preferred. Moreover, it is preferable that the monomer component contained in the said (meth) acrylic-type polymer does not contain a carboxyl group-containing monomer. The blending ratio of each monomer and the method for forming the transparent pressure-sensitive adhesive layer can include the same methods as in the case of the light diffusion pressure-sensitive adhesive layer.
　前記透明粘着剤層のヘイズは特に限定されるものではないが、０．０１～５％であることが好ましく、０．０５～５％であることがより好ましく、０．１～３％であることがさらに好ましい。透明粘着剤層のヘイズが前記範囲にあることで、ヘイズ等の光学設計が容易になるため好ましい。 The haze of the transparent pressure-sensitive adhesive layer is not particularly limited, but is preferably 0.01 to 5%, more preferably 0.05 to 5%, and 0.1 to 3%. More preferably. It is preferable that the haze of the transparent pressure-sensitive adhesive layer is in the above range because optical design such as haze becomes easy.
　また、前記透明粘着剤層の厚みは、特に限定されるものではなく、前記光拡散粘着剤層と貼り合せて粘着剤層を形成した際に、トータルの厚みが２０μｍ以上となればよく、特に限定されないが、２０～３００μｍであることが好ましく、５０～３００μｍであることがより好ましい。透明粘着剤層の厚みが前記範囲にあることで、貼り合せする材料の微小な凹凸、又は光学機能を付与するための凹凸部に追従して貼り合せすることができるため好ましい。 The thickness of the transparent pressure-sensitive adhesive layer is not particularly limited, and when the pressure-sensitive adhesive layer is formed by laminating with the light diffusion pressure-sensitive adhesive layer, the total thickness may be 20 μm or more. Although not limited, it is preferably 20 to 300 μm, more preferably 50 to 300 μm. It is preferable that the thickness of the transparent pressure-sensitive adhesive layer be in the above-mentioned range since the bonding can be performed following a minute unevenness of a material to be bonded or an uneven portion for imparting an optical function.
（３）光学部材用粘着剤層
　本発明の光学部材用粘着剤層は、前述の通り、光拡散粘着剤層１層のみから形成されていてもよく、少なくとも１層の光拡散粘着剤層と少なくとも１層の透明粘着剤層とから形成されていてもよい。 (3) Optical member pressure-sensitive adhesive layer As described above, the optical member pressure-sensitive adhesive layer of the present invention may be formed of only one light diffusion pressure-sensitive adhesive layer, and at least one light diffusion pressure-sensitive adhesive layer and It may be formed from at least one transparent adhesive layer.
　本発明の光学部材用粘着剤層は、光学部材への適用が好適であり、光学部材としては、後述する通りである。光学部材の中でも、輝度向上フィルムと偏光フィルムに好ましく用いることができる。 The pressure-sensitive adhesive layer for an optical member of the present invention is preferably applied to an optical member, and the optical member is as described later. Among optical members, it can be preferably used for a brightness enhancement film and a polarizing film.
　本発明の光学部材用粘着剤層全体としてのヘイズ値は、１０～９６％であり、２０～９６％であることが好ましく、３０～９６％であることがより好ましい。ヘイズ値が１０％未満であると、バックライト及びプリズムシートからの光に偏りがある状態に、その光の偏りを解消しきれないため表示ムラが発生してしまう。また、粘着剤層のヘイズ値が９６％を超える場合、粘着剤層に粒子を多量に添加する必要があり、その場合、粘着剤層の応力緩和性および接着性が低下し、耐久性が劣る。 The haze value of the pressure-sensitive adhesive layer for an optical member of the present invention is 10 to 96%, preferably 20 to 96%, more preferably 30 to 96%. If the haze value is less than 10%, display unevenness occurs because the light from the backlight and the prism sheet is biased and cannot be eliminated. Further, when the haze value of the pressure-sensitive adhesive layer exceeds 96%, it is necessary to add a large amount of particles to the pressure-sensitive adhesive layer. In that case, the stress relaxation property and adhesiveness of the pressure-sensitive adhesive layer are lowered, and the durability is inferior. .
　２．粘着剤層付光学部材
　本発明の粘着剤層付光学部材は、光学部材の少なくとも一方の面に、前記光学部材用粘着剤層を少なくとも１層有することを特徴とする。 2. Optical member with pressure-sensitive adhesive layer The optical member with pressure-sensitive adhesive layer of the present invention has at least one pressure-sensitive adhesive layer for optical members on at least one surface of the optical member.
　光学部材としては、各種の画像表示装置等の製造に用いられるものが使用され、その種類は特に制限されないが、例えば、偏光フィルム、位相差板、輝度向上フィルム、又は防眩シート等を挙げることができる。なお、光学部材は、偏光フィルムと位相差板を積層したものや位相差板の積層体、偏光フィルムと輝度向上フィルム又は防眩シートの積層体等、光学素材を２層以上種層したものであってもよい。これらの中でも輝度向上フィルムと偏光フィルムが好ましい。 As the optical member, those used for manufacturing various image display devices and the like are used, and the type thereof is not particularly limited, and examples thereof include a polarizing film, a retardation plate, a brightness enhancement film, or an antiglare sheet. Can do. The optical member is a laminate of two or more optical materials, such as a laminate of a polarizing film and a retardation plate, a laminate of retardation plates, a laminate of a polarizing film and a brightness enhancement film, or an antiglare sheet. There may be. Among these, a brightness enhancement film and a polarizing film are preferable.
　前記偏光フィルムとしては、偏光子の片面、又は、両面には透明保護フィルムを有するものが一般に用いられる。 As the polarizing film, one having a transparent protective film on one side or both sides of a polarizer is generally used.
　偏光子は、特に限定されず、各種のものを使用できる。偏光子としては、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、ヨウ素や二色性染料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やポリ塩化ビニルの脱塩酸処理物等ポリエン系配向フィルム等が挙げられる。これらの中でも、ポリビニルアルコール系フィルムとヨウ素等の二色性物質からなる偏光子が好適である。これらの偏光子の厚みは特に制限されないが、一般的に５～８０μｍ程度である。 The polarizer is not particularly limited, and various types can be used. Examples of polarizers include dichroic iodine and dichroic dyes on hydrophilic polymer films such as polyvinyl alcohol films, partially formalized polyvinyl alcohol films, and ethylene / vinyl acetate copolymer partially saponified films. Examples thereof include polyene-based oriented films such as those obtained by adsorbing substances and uniaxially stretched, polyvinyl alcohol dehydrated products and polyvinyl chloride dehydrochlorinated products. Among these, a polarizer composed of a polyvinyl alcohol film and a dichroic substance such as iodine is preferable. The thickness of these polarizers is not particularly limited, but is generally about 5 to 80 μm.
　ポリビニルアルコール系フィルムをヨウ素で染色し一軸延伸した偏光子は、例えば、ポリビニルアルコールをヨウ素の水溶液に浸漬することによって染色し、元長の３～７倍に延伸することで作製することができる。必要に応じてホウ酸や硫酸亜鉛、塩化亜鉛等を含んでいても良いヨウ化カリウム等の水溶液に浸漬することもできる。さらに必要に応じて染色前にポリビニルアルコール系フィルムを水に浸漬して水洗してもよい。ポリビニルアルコール系フィルムを水洗することでポリビニルアルコール系フィルム表面の汚れやブロッキング防止剤を洗浄することができるほかに、ポリビニルアルコール系フィルムを膨潤させることで染色のムラ等の不均一を防止する効果もある。延伸はヨウ素で染色した後に行っても良いし、染色しながら延伸しても良いし、また延伸してからヨウ素で染色しても良い。ホウ酸やヨウ化カリウム等の水溶液や水浴中でも延伸することができる。 A polarizer obtained by dyeing a polyvinyl alcohol film with iodine and uniaxially stretching it can be produced, for example, by dyeing polyvinyl alcohol in an aqueous iodine solution and stretching it 3 to 7 times the original length. If necessary, it can be immersed in an aqueous solution of potassium iodide or the like which may contain boric acid, zinc sulfate, zinc chloride or the like. Further, if necessary, the polyvinyl alcohol film may be immersed in water and washed before dyeing. In addition to washing the polyvinyl alcohol film surface with stains and antiblocking agents by washing the polyvinyl alcohol film with water, the polyvinyl alcohol film is also swollen to prevent unevenness such as uneven coloring. is there. Stretching may be performed after dyeing with iodine, may be performed while dyeing, or may be dyed with iodine after stretching. The film can be stretched even in an aqueous solution of boric acid or potassium iodide or in a water bath.
　また、本発明においては、厚みが１０μｍ以下の薄型偏光子も用いることができる。薄型化の観点から言えば当該厚みは１～７μｍであるのが好ましい。このような薄型の偏光子は、厚みムラが少なく、視認性が優れており、また寸法変化が少ないため耐久性に優れ、さらには偏光板としての厚みも薄型化が図れる点が好ましい。 In the present invention, a thin polarizer having a thickness of 10 μm or less can also be used. From the viewpoint of thinning, the thickness is preferably 1 to 7 μm. Such a thin polarizer is preferable in that the thickness unevenness is small, the visibility is excellent, the dimensional change is small, the durability is excellent, and the thickness of the polarizing plate can be reduced.
　薄型の偏光子としては、代表的には、特開昭５１－０６９６４４号公報や特開２０００－３３８３２９号公報や、国際公開第２０１０／１００９１７号パンフレット、ＰＣＴ／ＪＰ２０１０／００１４６０の明細書、又は特願２０１０－２６９００２号明細書や特願２０１０－２６３６９２号明細書に記載されている薄型偏光膜を挙げることができる。これら薄型偏光膜は、ポリビニルアルコール系樹脂（以下、ＰＶＡ系樹脂ともいう）層と延伸用樹脂基材を積層体の状態で延伸する工程と染色する工程を含む製法により得ることができる。この製法であれば、ＰＶＡ系樹脂層が薄くても、延伸用樹脂基材に支持されていることにより延伸による破断等の不具合なく延伸することが可能となる。 As the thin polarizer, typically, Japanese Patent Application Laid-Open No. 51-069644, Japanese Patent Application Laid-Open No. 2000-338329, International Publication No. 2010/100917, PCT / JP2010 / 001460, Examples thereof include thin polarizing films described in Japanese Patent Application Nos. 2010-269002 and 2010-263692. These thin polarizing films can be obtained by a production method including a step of stretching and dyeing a polyvinyl alcohol-based resin (hereinafter also referred to as PVA-based resin) layer and a stretching resin substrate in the state of a laminate. With this production method, even if the PVA-based resin layer is thin, it can be stretched without problems such as breakage due to stretching by being supported by the stretching resin substrate.
　前記薄型偏光膜としては、積層体の状態で延伸する工程と染色する工程を含む製法の中でも、高倍率に延伸できて偏光性能を向上させることのできる点で、国際公開第２０１０／１００９１７号パンフレット、ＰＣＴ／ＪＰ２０１０／００１４６０の明細書、又は特願２０１０－２６９００２号明細書や特願２０１０－２６３６９２号明細書に記載のあるようなホウ酸水溶液中で延伸する工程を含む製法で得られるものが好ましく、特に特願２０１０－２６９００２号明細書や特願２０１０－２６３６９２号明細書に記載のあるホウ酸水溶液中で延伸する前に補助的に空中延伸する工程を含む製法により得られるものが好ましい。 As the thin polarizing film, International Publication No. 2010/100917 pamphlet in that it can be stretched at a high magnification and the polarization performance can be improved among the production methods including the step of stretching in the state of a laminate and the step of dyeing. , PCT / JP2010 / 001460, or Japanese Patent Application No. 2010-269002 and Japanese Patent Application No. 2010-263699, which are obtained by a production method including a step of stretching in a boric acid aqueous solution. In particular, those obtained by a production method including an auxiliary step of stretching in the air before stretching in a boric acid aqueous solution described in Japanese Patent Application Nos. 2010-269002 and 2010-263692 are preferable.
　前記偏光子の片面、又は、両面に設けられる透明保護フィルムを形成する材料としては、透明性、機械的強度、熱安定性、水分遮断性、等方性等に優れるものが好ましい。例えば、ポリエチレンテレフタレートやポリエチレンナフタレート等のポリエステル系ポリマー、ジアセチルセルロースやトリアセチルセルロース等のセルロース系ポリマー、ポリメチルメタクリレート等のアクリル系ポリマー、ポリスチレンやアクリロニトリル・スチレン共重合体（ＡＳ樹脂）等のスチレン系ポリマー、ポリカーボネート系ポリマー等が挙げられる。また、ポリエチレン、ポリプロピレン、シクロ系ないしはノルボルネン構造を有するポリオレフィン、エチレン・プロピレン共重合体等のポリオレフィン系ポリマー、塩化ビニル系ポリマー、ナイロンや芳香族ポリアミド等のアミド系ポリマー、イミド系ポリマー、スルホン系ポリマー、ポリエーテルスルホン系ポリマー、ポリエーテルエーテルケトン系ポリマー、ポリフェニレンスルフィド系ポリマー、ビニルアルコール系ポリマー、塩化ビニリデン系ポリマー、ビニルブチラール系ポリマー、アリレート系ポリマー、ポリオキシメチレン系ポリマー、エポキシ系ポリマー、又は、前記ポリマーのブレンド物等も前記透明保護フィルムを形成するポリマーの例として挙げられる。透明保護フィルムは、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型、紫外線硬化型の樹脂の硬化層として形成することもできる。 As a material for forming a transparent protective film provided on one side or both sides of the polarizer, a material excellent in transparency, mechanical strength, thermal stability, moisture barrier property, isotropy and the like is preferable. For example, polyester polymers such as polyethylene terephthalate and polyethylene naphthalate, cellulose polymers such as diacetyl cellulose and triacetyl cellulose, acrylic polymers such as polymethyl methacrylate, styrene such as polystyrene and acrylonitrile / styrene copolymer (AS resin) And polymers based on polycarbonate and polycarbonate. In addition, polyethylene, polypropylene, polyolefins having a cyclo or norbornene structure, polyolefin polymers such as ethylene / propylene copolymers, vinyl chloride polymers, amide polymers such as nylon and aromatic polyamide, imide polymers, sulfone polymers , Polyether sulfone polymer, polyether ether ketone polymer, polyphenylene sulfide polymer, vinyl alcohol polymer, vinylidene chloride polymer, vinyl butyral polymer, arylate polymer, polyoxymethylene polymer, epoxy polymer, or Examples of the polymer that forms the transparent protective film include polymer blends. The transparent protective film can also be formed as a cured layer of thermosetting or ultraviolet curable resin such as acrylic, urethane, acrylurethane, epoxy, and silicone.
　保護フィルムの厚みは、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１～５００μｍ程度である。 The thickness of the protective film can be determined as appropriate, but is generally about 1 to 500 μm from the viewpoints of workability such as strength and handleability, and thin film properties.
　前記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系、水系ポリウレタン、水系ポリエステル等を例示できる。上記の他、偏光子と透明保護フィルムとの接着剤としては、紫外硬化型接着剤、電子線硬化型接着剤等が挙げられる。電子線硬化型偏光フィルム用接着剤は、上記各種の透明保護フィルムに対して、好適な接着性を示す。また本発明で用いる接着剤には、金属化合物フィラーを含有させることができる。 The polarizer and the protective film are usually in close contact with each other through an aqueous adhesive or the like. Examples of the water-based adhesive include an isocyanate-based adhesive, a polyvinyl alcohol-based adhesive, a gelatin-based adhesive, a vinyl-based latex, a water-based polyurethane, and a water-based polyester. In addition to the above, examples of the adhesive between the polarizer and the transparent protective film include an ultraviolet curable adhesive and an electron beam curable adhesive. The electron beam curable polarizing film adhesive exhibits suitable adhesiveness to the various transparent protective films. The adhesive used in the present invention can contain a metal compound filler.
　前記透明保護フィルムの偏光子を接着させない面には、ハードコート層や反射防止処理、スティッキング防止や、拡散ないしアンチグレアを目的とした処理を施したものであっても良い。 The surface of the transparent protective film to which the polarizer is not bonded may be subjected to a treatment for the purpose of hard coat layer, antireflection treatment, sticking prevention, diffusion or antiglare.
　本発明の粘着剤層付光学部材の具体的な使用形態の一例を図２で示す。本発明の光学部材用粘着剤層１を有する偏光フィルム１０（粘着剤層付光学部材）は、粘着剤層面を、プリズムシート２０の段差面に貼り合せて用いることができる。本発明の粘着剤層付光学部材は、本発明の光学部材用粘着剤層を有するため、前記段差に追従して空隙なく貼り合わせを行うことができる。図２においては、偏光フィルム１０は、偏光子１１の両面に保護フィルム１２を有するものを使用しているが、偏光子１１の片面に保護フィルム１２を有する片面保護偏光フィルムであってもよい。また、プリズムシート２０は、代表的には、基板２２とプリズム部２１とを有する。 An example of a specific usage pattern of the optical member with an adhesive layer of the present invention is shown in FIG. The polarizing film 10 (optical member with an adhesive layer) having the adhesive layer 1 for an optical member of the present invention can be used by bonding the adhesive layer surface to the step surface of the prism sheet 20. Since the optical member with the pressure-sensitive adhesive layer of the present invention has the pressure-sensitive adhesive layer for the optical member of the present invention, the optical member can be bonded without following the step. In FIG. 2, the polarizing film 10 has a protective film 12 on both sides of the polarizer 11, but may be a single-sided protective polarizing film having the protective film 12 on one side of the polarizer 11. The prism sheet 20 typically includes a substrate 22 and a prism portion 21.
　本発明の光学部材用粘着剤層１は光拡散機能を備えるため、通常、画像表示装置のバックライト側に設けられる拡散シートの代わりに用いることができる。 Since the pressure-sensitive adhesive layer 1 for an optical member of the present invention has a light diffusing function, it can usually be used instead of a diffusion sheet provided on the backlight side of an image display device.
　３．画像表示装置
　本発明の画像表示装置は、前記粘着剤層付光学部材を含むことを特徴とする。本発明の画像表示装置は、本発明の粘着剤層付光学部材を含むものであればよく、その他の構成については、従来の画像表示装置と同様のものを挙げることができる。 3. Image display device The image display device of the present invention is characterized by including the optical member with an adhesive layer. The image display device of the present invention only needs to include the optical member with the pressure-sensitive adhesive layer of the present invention, and other configurations can be the same as those of the conventional image display device.
　本発明の画像表示装置は、前記粘着剤層付光学部材を含むため、高い信頼性を有するものである。また、本発明の光学部材用粘着剤層は光拡散機能を備えるため、前記粘着剤層付光学部材をバックライト側に設けられる拡散シートの代わりに用いることができ、画像表示装置を薄膜化することができる。 Since the image display device of the present invention includes the optical member with the pressure-sensitive adhesive layer, it has high reliability. In addition, since the pressure-sensitive adhesive layer for optical members of the present invention has a light diffusion function, the optical member with the pressure-sensitive adhesive layer can be used instead of the diffusion sheet provided on the backlight side, and the image display device is thinned. be able to.
　以下に、実施例によって本発明を具体的に説明するが、本発明はこれら実施例によって限定されるものではない。なお、各例中の部及び％はいずれも重量基準である。実施例等における評価項目は下記のようにして測定を行った。 Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited to these examples. In addition, all the parts and% in each example are based on weight. Evaluation items in Examples and the like were measured as follows.
　製造例１（光拡散粘着剤組成物（Ａ－１）の製造）
　温度計、攪拌機、還流冷却管及び窒素ガス導入管を備えたセパラブルフラスコに、モノマー成分として、２－エチルヘキシルアクリレート（２ＥＨＡ）７０部、Ｎ－ビニル－２－ピロリドン（ＮＶＰ）１５部及び２－ヒドロキシエチルアクリレート（ＨＥＡ）１５部、光重合開始剤（商品名：イルガキュア１８４、ＢＡＳＦ社製）０．１部を配合した後、粘度（計測条件：ＢＨ粘度計Ｎｏ．ローター、１０ｒｐｍ、測定温度３０℃）が約２０Ｐａ・ｓになるまで紫外線を照射して、上記モノマー成分の一部が重合したプレポリマー組成物を得た。 Production Example 1 (Production of light diffusing pressure-sensitive adhesive composition (A-1))
In a separable flask equipped with a thermometer, a stirrer, a reflux condenser and a nitrogen gas introduction tube, 70 parts of 2-ethylhexyl acrylate (2EHA), 15 parts of N-vinyl-2-pyrrolidone (NVP) and 2- After blending 15 parts of hydroxyethyl acrylate (HEA) and 0.1 part of a photopolymerization initiator (trade name: Irgacure 184, manufactured by BASF), viscosity (measurement condition: BH viscometer No. rotor, 10 rpm, measurement temperature 30) The prepolymer composition in which a part of the monomer component was polymerized was obtained by irradiating with ultraviolet rays until the temperature was about 20 Pa · s.
　次に、得られたプレポリマー組成物１００部に対して、イソシアネート架橋剤（商品名：コロネートＬ、トリメチロールプロパンのトリレンジイソシアネートのアダクト体、日本ポリウレタン工業（株）製）０．２部を混合して、ベース粘着剤組成物（Ａ－１）を得た。得られたベース粘着剤組成物（Ａ－１）の屈折率は１．４７５であった。 Next, 0.2 part of an isocyanate crosslinking agent (trade name: Coronate L, adduct of tolylene diisocyanate of trimethylolpropane, manufactured by Nippon Polyurethane Industry Co., Ltd.) is added to 100 parts of the obtained prepolymer composition. By mixing, a base pressure-sensitive adhesive composition (A-1) was obtained. The obtained base adhesive composition (A-1) had a refractive index of 1.475.
　得られたベース粘着剤組成物（Ａ－１）１００部に対して、光拡散性微粒子として、シリコーン樹脂微粒子（商品名：トスパール１４５、体積平均粒子径：４μｍ、屈折率：１．４３、シリコーン樹脂系微粒子、モメンティブ・パフォーマンス・マテリアルズ社製）を１４部添加し、光拡散粘着剤組成物（Ａ－１）を得た。 With respect to 100 parts of the obtained base pressure-sensitive adhesive composition (A-1), silicone resin fine particles (trade name: Tospearl 145, volume average particle size: 4 μm, refractive index: 1.43, silicone, as light diffusing fine particles 14 parts of resin fine particles (manufactured by Momentive Performance Materials) were added to obtain a light diffusion adhesive composition (A-1).
　製造例２～５（光拡散粘着剤組成物（Ａ－２）～（Ａ－５）の製造）
　製造例１において、表１に示すように、光拡散性微粒子の添加量を変更した以外は、製造例１と同様にして、光拡散粘着剤組成物（Ａ－２）～（Ａ－５）を製造した。 Production Examples 2 to 5 (Production of light diffusion adhesive compositions (A-2) to (A-5))
In Production Example 1, as shown in Table 1, the light diffusing pressure-sensitive adhesive compositions (A-2) to (A-5) were the same as Production Example 1 except that the addition amount of the light diffusing fine particles was changed. Manufactured.
　製造例６（光拡散粘着剤組成物（Ａ－６）の製造）
　攪拌羽根、温度計、窒素ガス導入管、冷却器を備えた４つ口フラスコに、ブチルアクリレート１００部、アクリル酸５部、ヒドロキシエチルアクリレート１部、重合開始剤として２，２’－アゾビスイソブチロニトリル０．１部を酢酸エチル１００部と共に仕込み（モノマーの濃度５０％）、緩やかに攪拌しながら窒素ガスを導入して窒素置換した後、フラスコ内の液温を５５℃付近に保って８時間重合反応を行い、重量平均分子量（Ｍｗ）１８０万のアクリル系ポリマー（Ａ－６）の溶液を調製した。 Production Example 6 (Production of light diffusion adhesive composition (A-6))
In a four-necked flask equipped with a stirring blade, thermometer, nitrogen gas inlet tube, and condenser, 100 parts of butyl acrylate, 5 parts of acrylic acid, 1 part of hydroxyethyl acrylate, 2,2′-azobisiso as a polymerization initiator After charging 0.1 parts of butyronitrile with 100 parts of ethyl acetate (monomer concentration 50%), introducing nitrogen gas with gentle stirring and replacing with nitrogen, the liquid temperature in the flask was kept at around 55 ° C. A polymerization reaction was carried out for 8 hours to prepare a solution of an acrylic polymer (A-6) having a weight average molecular weight (Mw) of 1.8 million.
　上記で得られたアクリル系ポリマー（Ａ－６）溶液の固形分１００部に対して、イソシアネート系架橋剤（商品名：コロネートＬ、トリメチロールプロパン／トリレンジイソシアネート３量体付加物、日本ポリウレタン工業（株）製）０．６６部、ベンゾイルパーオキサイド（ナイパーＢＭＴ、日本油脂（株）製）０．３部、シランカップリング剤（商品名：ＫＢＭ４０３、信越化学工業（株）製）０．２部を添加し、ベース粘着剤組成物（Ａ－６）を得た。 For 100 parts of the solid content of the acrylic polymer (A-6) solution obtained above, an isocyanate-based crosslinking agent (trade name: Coronate L, trimethylolpropane / tolylene diisocyanate trimer adduct, Nippon Polyurethane Industry 0.66 part, 0.3 parts of benzoyl peroxide (Niper BMT, manufactured by NOF Corporation), silane coupling agent (trade name: KBM403, manufactured by Shin-Etsu Chemical Co., Ltd.) 0.2 Part was added to obtain a base pressure-sensitive adhesive composition (A-6).
　得られたベース粘着剤組成物（Ａ－６）の固形分１００部に対して、光拡散性微粒子として、シリコーン樹脂微粒子（商品名：トスパール１４５、体積平均粒子径：４μｍ、屈折率：１．４３、シリコーン樹脂系微粒子、モメンティブ・パフォーマンス・マテリアルズ社製）２６部を配合して、光拡散粘着剤組成物（Ａ－６）を調製した。 Silicone resin fine particles (trade name: Tospearl 145, volume average particle size: 4 μm, refractive index: 1.μm) as light diffusing fine particles with respect to 100 parts of solid content of the obtained base pressure-sensitive adhesive composition (A-6). 43, silicone resin fine particles, manufactured by Momentive Performance Materials Co., Ltd.) were blended to prepare a light diffusion adhesive composition (A-6).
　製造例７（光拡散粘着剤組成物（Ａ－７）の製造）
　製造例６において、表１に示すように、光拡散性微粒子の添加量を変更した以外は、製造例６と同様にして、光拡散粘着剤組成物（Ａ－７）を製造した。 Production Example 7 (Production of light diffusion adhesive composition (A-7))
In Production Example 6, as shown in Table 1, a light diffusing pressure-sensitive adhesive composition (A-7) was produced in the same manner as in Production Example 6 except that the addition amount of the light diffusing fine particles was changed.
　製造例８～１２（光拡散粘着剤組成物（Ａ－８）～（Ａ－１２）の製造）
　製造例１において、表１に示すように、光拡散性微粒子の添加量を変更した以外は、製造例１と同様にして、光拡散粘着剤組成物（Ａ－８）～（Ａ－１２）を製造した。 Production Examples 8 to 12 (Production of light diffusion adhesive compositions (A-8) to (A-12))
In Production Example 1, as shown in Table 1, the light diffusing pressure-sensitive adhesive compositions (A-8) to (A-12) were produced in the same manner as in Production Example 1 except that the addition amount of the light diffusing fine particles was changed. Manufactured.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
　実施例１（光拡散粘着剤層の製造）
　製造例１で得られた光拡散粘着剤組成物（Ａ－１）を、片面をシリコーンで剥離処理した厚み３８μｍのポリエステルフィルム（商品名：ダイアホイルＭＲＦ、三菱樹脂（株）製）の剥離処理面に、得られる光拡散粘着剤層の厚みが２３μｍになるように塗布して、塗布層を形成した。次いで、形成された塗布層の表面に、片面をシリコーンで剥離処理した厚み３８μｍのポリエステルフィルム（商品名：ダイアホイルＭＲＥ、三菱樹脂（株）製）を、当該フィルムの剥離処理面が塗布層側になるようにして被覆した。これにより、光拡散粘着剤組成物の塗布層を酸素から遮断した。このようにして得られた塗布層を有するシートにケミカルライトランプ（（株）東芝製）を用いて、照度１００ｍＷ／ｃｍ２（約３５０ｎｍに最大感度をもつトプコンＵＶＲ－Ｔ１で測定）の紫外線を３０秒間照射して、塗布層を硬化させて光拡散粘着剤層を形成し、粘着シートを作製した。粘着剤層の両面に被覆されたポリエステルフィルムは、剥離ライナーとして機能する。 Example 1 (Production of light diffusion adhesive layer)
Release treatment of a 38 μm-thick polyester film (trade name: Diafoil MRF, manufactured by Mitsubishi Plastics Co., Ltd.) obtained by removing the light-diffusing adhesive composition (A-1) obtained in Production Example 1 with silicone on one side. On the surface, the obtained light diffusion pressure-sensitive adhesive layer was applied so that the thickness was 23 μm, thereby forming a coating layer. Next, a 38 μm thick polyester film (trade name: Diafoil MRE, manufactured by Mitsubishi Resin Co., Ltd.) having one surface peeled with silicone is applied to the surface of the formed coating layer. It coat | covered so that it might become. Thereby, the coating layer of the light diffusion adhesive composition was shielded from oxygen. Using a chemical light lamp (manufactured by Toshiba Corporation) on the sheet having the coating layer thus obtained, ultraviolet rays having an illuminance of 100 mW / cm 2 (measured with Topcon UVR-T1 having a maximum sensitivity of about 350 nm) are used. Irradiation was performed for 30 seconds, the coating layer was cured to form a light diffusion pressure-sensitive adhesive layer, and a pressure-sensitive adhesive sheet was produced. The polyester film coated on both sides of the pressure-sensitive adhesive layer functions as a release liner.
　実施例２～１２、比較例１～３、６、７
　用いる光拡散粘着剤組成物、乾燥後の厚みを表２に記載に変更した以外は、実施例１と同様にして粘着シートを作製した。 Examples 2 to 12, Comparative Examples 1 to 3, 6, 7
A pressure-sensitive adhesive sheet was prepared in the same manner as in Example 1 except that the light diffusion pressure-sensitive adhesive composition used and the thickness after drying were changed to those described in Table 2.
　実施例１３
　（第１層、第３層（透明粘着剤層）の製造）
　製造例８で得られた光拡散粘着剤組成物（Ａ－８）を用い、得られる粘着剤層の厚みが５０μｍになるようにした以外は実施例１と同様にして、透明粘着剤層用の粘着シートを作製した。同じものを２枚作製した。 Example 13
(Manufacture of first layer and third layer (transparent adhesive layer))
For the transparent pressure-sensitive adhesive layer in the same manner as in Example 1, except that the light diffusion pressure-sensitive adhesive composition (A-8) obtained in Production Example 8 was used and the thickness of the pressure-sensitive adhesive layer obtained was 50 μm. A pressure-sensitive adhesive sheet was prepared. Two identical pieces were produced.
　（第２層（光拡散粘着剤層）の製造）
　製造例７で得られた光拡散粘着剤組成物（Ａ－７）を、片面をシリコーンで剥離処理した厚み３８μｍのポリエステルフィルム（商品名：ダイアホイルＭＲＦ、三菱樹脂（株）製）の剥離処理面に、得られる光拡散粘着剤層の厚みが２３μｍになるように塗布して、塗布層を形成し、１５５℃で１分間乾燥を行い、光拡散粘着剤層を形成した。 (Manufacture of second layer (light diffusion adhesive layer))
Release treatment of a 38 μm-thick polyester film (trade name: Diafoil MRF, manufactured by Mitsubishi Plastics Co., Ltd.) obtained by removing the light diffusion adhesive composition (A-7) obtained in Production Example 7 from one side with silicone. On the surface, the obtained light diffusion pressure-sensitive adhesive layer was applied so as to have a thickness of 23 μm to form a coating layer, and dried at 155 ° C. for 1 minute to form a light diffusion pressure-sensitive adhesive layer.
　上記で得られた透明粘着剤層用の粘着シートの一方の剥離シートを剥離し、上記で得られた光拡散粘着剤層の両面に、透明粘着剤層を貼り合せ、光学部材用粘着剤層を形成した。 One release sheet of the pressure-sensitive adhesive sheet for the transparent pressure-sensitive adhesive layer obtained above is peeled off, and a transparent pressure-sensitive adhesive layer is bonded to both surfaces of the light diffusion pressure-sensitive adhesive layer obtained above, and the pressure-sensitive adhesive layer for optical members Formed.
　実施例１４
　用いる光拡散粘着剤組成物、乾燥後の厚みを表２に記載に変更した以外は、実施例１３と同様にして粘着シートを作製した。 Example 14
A pressure-sensitive adhesive sheet was prepared in the same manner as in Example 13 except that the light diffusion pressure-sensitive adhesive composition used and the thickness after drying were changed to those described in Table 2.
　実施例１５
　（第２層（光拡散粘着剤層）の製造）
　製造例１０で得られた光拡散粘着剤組成物（Ａ－１０）を、片面をシリコーンで剥離処理した厚み３８μｍのポリエステルフィルム（商品名：ダイアホイルＭＲＦ、三菱樹脂（株）製）の剥離処理面に、得られる光拡散粘着剤層の厚みが２３μｍになるように塗布して、塗布層を形成した。次いで、形成された塗布層の表面に、片面をシリコーンで剥離処理した厚み３８μｍのポリエステルフィルム（商品名：ダイアホイルＭＲＥ、三菱樹脂（株）製）を、当該フィルムの剥離処理面が塗布層側になるようにして被覆した。これにより、光拡散粘着剤組成物の塗布層を酸素から遮断した。このようにして得られた塗布層を有するシートにケミカルライトランプ（（株）東芝製）を用いて、照度１００ｍＷ／ｃｍ２（約３５０ｎｍに最大感度をもつトプコンＵＶＲ－Ｔ１で測定）の紫外線を３０秒間照射して、塗布層を硬化させて光拡散粘着剤層を形成し、粘着シートを作製した。粘着剤層の両面に被覆されたポリエステルフィルムは、剥離ライナーとして機能する。 Example 15
(Manufacture of second layer (light diffusion adhesive layer))
Release treatment of a 38 μm-thick polyester film (trade name: Diafoil MRF, manufactured by Mitsubishi Plastics Co., Ltd.) obtained by peeling off the light diffusing pressure-sensitive adhesive composition (A-10) obtained in Production Example 10 with silicone on one side On the surface, the obtained light diffusion pressure-sensitive adhesive layer was applied so that the thickness was 23 μm, thereby forming a coating layer. Next, a 38 μm thick polyester film (trade name: Diafoil MRE, manufactured by Mitsubishi Resin Co., Ltd.) having one surface peeled with silicone is applied to the surface of the formed coating layer. It coat | covered so that it might become. Thereby, the coating layer of the light diffusion adhesive composition was shielded from oxygen. Using a chemical light lamp (manufactured by Toshiba Corporation) on the sheet having the coating layer thus obtained, ultraviolet rays having an illuminance of 100 mW / cm 2 (measured with Topcon UVR-T1 having a maximum sensitivity of about 350 nm) are used. Irradiation was performed for 30 seconds, the coating layer was cured to form a light diffusion pressure-sensitive adhesive layer, and a pressure-sensitive adhesive sheet was produced. The polyester film coated on both sides of the pressure-sensitive adhesive layer functions as a release liner.
　実施例１３において、第２層（光拡散粘着剤層）として、前記粘着剤層を用いる以外は実施例１３と同様にして粘着シートを作製した。 Example 13 A pressure-sensitive adhesive sheet was produced in the same manner as in Example 13 except that the pressure-sensitive adhesive layer was used as the second layer (light diffusion pressure-sensitive adhesive layer).
　実施例１６、１７、比較例４、５
　用いる光拡散粘着剤組成物、厚みを表２に記載に変更した以外は、実施例１５と同様にして粘着シートを作製した。 Examples 16 and 17, Comparative Examples 4 and 5
A pressure-sensitive adhesive sheet was prepared in the same manner as in Example 15 except that the light diffusing pressure-sensitive adhesive composition used and the thickness were changed to those shown in Table 2.
　実施例及び比較例で得られた粘着剤層について、以下の評価を行った。評価結果は、表２に示す。 The following evaluation was performed about the adhesive layer obtained by the Example and the comparative example. The evaluation results are shown in Table 2.
　＜ベース粘着剤組成物の屈折率＞
　アッベ屈折率計（商品名：ＤＲ－Ｍ２、（株）アタゴ製）により測定した。 <Refractive index of base adhesive composition>
It was measured with an Abbe refractometer (trade name: DR-M2, manufactured by Atago Co., Ltd.).
　＜ヘイズ値＞
　実施例及び比較例で用いた各光拡散粘着剤層、透明粘着剤層のヘイズ値、実施例及び比較例で得られた粘着剤層のトータルヘイズ値について、ＪＩＳ　７１３６で定める方法により、ヘイズメーター（消費名：ＨＮ－１５０、（株）村上色彩科学研究所製）を用いて測定した。 <Haze value>
About each light-diffusion adhesive layer used by the Example and the comparative example, the haze value of a transparent adhesive layer, and the total haze value of the adhesive layer obtained by the Example and the comparative example, by the method prescribed | regulated by JIS7136, a haze meter (Consumption name: HN-150, manufactured by Murakami Color Research Laboratory Co., Ltd.).
　＜貼り合わせ＞
　偏光フィルム（商品名：ＣＶＴ、日東電工（株）製）上に輝度向上フィルム（商品名：ＤＢＥＦ－Ｑ、スリーエム製）が貼り合せられている偏光フィルムを準備した。実施例及び比較例で得られた粘着シートの一方の剥離フィルムを剥離し、当該偏光フィルムの輝度向上フィルム側に貼り合せた。さらに、粘着シートの他方の剥離フィルムを剥離し、５０μｍ又は５μｍの凹凸があるプリズムシートに対しハンドローラーにて貼り合せ、５０℃、５ａｔｍで１５分間のオートクレーブ処理を行った。貼り合せた後の状態を目視で確認し、以下の評価基準で評価した。
　◎：５０μｍの凹凸があるプリズムシートを用いた場合であっても、２００μｍ以上の気泡が発生することなく貼り合せることができた。
　○：５０μｍの凹凸があるプリズムシートを用いた場合、２００μｍ以上の気泡が発生する場合があるが、５μｍの凹凸があるプリズムシートを用いた場合には、２００μｍ以上の気泡が発生することなく、貼り合せることができた。
　×：５μｍの凹凸があるプリズムシートを用いた場合であっても、２００μｍ以上の気泡を発生させることなく貼り合せることはできなかった。 <Lamination>
A polarizing film in which a brightness enhancement film (trade name: DBEF-Q, manufactured by 3M) was bonded onto a polarizing film (trade name: CVT, manufactured by Nitto Denko Corporation) was prepared. One release film of the pressure-sensitive adhesive sheets obtained in Examples and Comparative Examples was peeled off and bonded to the brightness enhancement film side of the polarizing film. Further, the other release film of the pressure-sensitive adhesive sheet was peeled off, and bonded to a prism sheet having 50 μm or 5 μm unevenness with a hand roller, and autoclaved at 50 ° C. and 5 atm for 15 minutes. The state after bonding was visually confirmed and evaluated according to the following evaluation criteria.
(Double-circle): Even if it was a case where a prism sheet with an unevenness | corrugation of 50 micrometers was used, it was able to bond together without generating a 200 micrometers or more bubble.
○: When a prism sheet with 50 μm irregularities is used, bubbles of 200 μm or more may be generated, but when a prism sheet with irregularities of 5 μm is used, bubbles of 200 μm or more are not generated, I was able to paste them together.
X: Even when a prism sheet having 5 μm irregularities was used, it could not be bonded without generating bubbles of 200 μm or more.
　＜表示ムラ＞
　実施例及び比較例で得られた粘着シートに、前記偏光フィルムを貼り合わせたものを、縦４００ｍｍ×横２５０ｍｍのサイズに切り出してサンプルとした。このサンプルを厚さ０．０７ｍｍの無アルカリガラス板にラミネーターにて貼り合せ、反対面に透明粘着剤層付偏光板をクロスニコルになるように貼り合せた後、５０℃、５ａｔｍで１５分間のオートクレーブ処理を行い、評価サンプルを作製した。その後、１万カンデラのバックライト上に置き、光漏れを目視により観察し、下記の基準でコーナームラを評価した。
　◎：ムラがなく、実用上問題ない
　○：ムラが発生して表示領域にわずかに表れているが、実用上問題ない。
　×：ムラが発生して表示領域に顕著に表れており、実用上問題がある。 <Display unevenness>
A sample obtained by bonding the polarizing film to the pressure-sensitive adhesive sheets obtained in Examples and Comparative Examples was cut into a size of 400 mm long × 250 mm wide to prepare a sample. This sample was bonded to a non-alkali glass plate having a thickness of 0.07 mm with a laminator, and a polarizing plate with a transparent adhesive layer was bonded to the opposite side so as to be in a crossed Nicol state, and then at 50 ° C., 5 atm for 15 minutes. An autoclave treatment was performed to prepare an evaluation sample. Then, it put on the backlight of 10,000 candela, the light leak was observed visually, and the corner nonuniformity was evaluated on the following reference | standard.
A: There is no unevenness and there is no problem in practical use. ○: An unevenness is generated and slightly appears in the display area, but there is no problem in practical use.
X: Unevenness appears and appears prominently in the display area, causing a problem in practical use.
　＜耐久性＞
　ガラス／偏光フィルム（商品名：ＣＶＴ、日東電工（株）製）／輝度向上フィルム（商品名：ＤＢＥＦ－Ｑ、スリーエム製）／実施例及び比較例で得られた粘着剤層／プリズムシートを貼り合せた状態で、８０℃、６０℃／９０％Ｒ．Ｈ．の環境下に２４０時間投入後の状態を目視で観察した。以下の評価基準により評価した。
　〇：１００μｍを超える発泡、剥がれの発生なし。
　×：１００μｍを超える発泡、剥がれの発生あり。 <Durability>
Glass / Polarizing film (trade name: CVT, manufactured by Nitto Denko Corporation) / Brightness enhancement film (trade name: DBEF-Q, manufactured by 3M) / Attached adhesive layer / prism sheet obtained in Examples and Comparative Examples In the combined state, 80 ° C., 60 ° C./90% R.D. H. In this environment, the state after 240 hours was visually observed. Evaluation was performed according to the following evaluation criteria.
A: No foaming or peeling exceeding 100 μm.
X: Occurrence of foaming and peeling exceeding 100 μm.
　＜加工性＞
　セパレータ付の実施例および比較例で得られた粘着剤層を、１０ｃｍ×２０ｃｍのサイズの打ち抜き刃で打ち抜いた。打ち抜きの際の状態を目視で確認し、以下の評価基準で評価した。
　○：問題なく打ち抜くことができた。
　×：刃にサンプルが付着し、打ち抜くことができなかった。 <Processability>
The pressure-sensitive adhesive layers obtained in Examples and Comparative Examples with separators were punched with a punching blade having a size of 10 cm × 20 cm. The state at the time of punching was confirmed visually and evaluated according to the following evaluation criteria.
○: I was able to punch without problems.
X: The sample adhered to the blade and could not be punched out.
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
　１　光学部材用粘着剤層
　２　光拡散粘着剤層
　３　透明粘着剤層
　４　セパレーター
　１０　偏光フィルム
　１１　偏光子
　１２　保護フィルム
　２０　プリズムシート
　２１　プリズム部
　２２　基板
  DESCRIPTION OF SYMBOLS 1 Adhesive layer for optical members 2 Light diffusion adhesive layer 3 Transparent adhesive layer 4 Separator 10 Polarizing film 11 Polarizer 12 Protective film 20 Prism sheet 21 Prismatic part 22 Substrate

Claims (12)

  1. 　（メタ）アクリル系ポリマーを含有するベース粘着剤組成物及び光拡散性微粒子から形成され、厚みが５～３００μｍである光拡散粘着剤層を少なくとも１層含み、
    　粘着剤層全体としての厚みが２０μｍ以上であり、
    　ヘイズが１０～９６％であることを特徴とする光学部材用粘着剤層。     Comprising at least one light-diffusing pressure-sensitive adhesive layer formed from a base pressure-sensitive adhesive composition containing a (meth) acrylic polymer and light-diffusing fine particles and having a thickness of 5 to 300 μm,
    The thickness of the entire pressure-sensitive adhesive layer is 20 μm or more,
    An adhesive layer for optical members, having a haze of 10 to 96%.
  2. 　前記光拡散性微粒子が、シリコーン樹脂微粒子であることを特徴とする請求項１に記載の光学部材用粘着剤層。 The pressure-sensitive adhesive layer for an optical member according to claim 1, wherein the light diffusing fine particles are silicone resin fine particles.
  3. 　前記光拡散性微粒子の屈折率が、前記ベース粘着剤組成物の屈折率よりも低いことを特徴とする請求項１又は２に記載の光学部材用粘着剤層。 The pressure-sensitive adhesive layer for an optical member according to claim 1 or 2, wherein a refractive index of the light diffusing fine particles is lower than a refractive index of the base pressure-sensitive adhesive composition.
  4. 　前記光拡散性微粒子の体積平均粒子径が、１～５μｍであることを特徴とする請求項１～３のいずれかに記載の光学部材用粘着剤層。 The pressure-sensitive adhesive layer for an optical member according to any one of claims 1 to 3, wherein the light diffusing fine particles have a volume average particle diameter of 1 to 5 µm.
  5. 　前記光拡散粘着剤層の少なくとも片面に、ヘイズが０．０１～５％の透明粘着剤層を有することを特徴とする請求項１～４のいずれかに記載の光学部材用粘着剤層。 The pressure-sensitive adhesive layer for optical members according to any one of claims 1 to 4, wherein a transparent pressure-sensitive adhesive layer having a haze of 0.01 to 5% is provided on at least one surface of the light diffusion pressure-sensitive adhesive layer.
  6. 　前記光拡散粘着剤層の厚みが５～３０μｍであり、ヘイズが０．０１～５％の透明粘着剤層の厚みが５０～３００μｍであることを特徴とする請求項５に記載の光学部材用粘着剤層。 6. The optical member according to claim 5, wherein the light diffusion adhesive layer has a thickness of 5 to 30 μm, and the transparent adhesive layer having a haze of 0.01 to 5% has a thickness of 50 to 300 μm. Adhesive layer.
  7. 　前記光拡散粘着剤層における前記光拡散性微粒子の含有量が、３～３０重量％であることを特徴とする請求項１～６のいずれかに記載の光学部材用粘着剤層。 The pressure-sensitive adhesive layer for optical members according to any one of claims 1 to 6, wherein the content of the light diffusing fine particles in the light diffusing pressure-sensitive adhesive layer is 3 to 30% by weight.
  8. 　前記（メタ）アクリル系ポリマーが、モノマー成分として、アルキル（メタ）アクリレート及びカルボキシル基含有モノマーを含有することを特徴とする請求項１～７のいずれかに記載の光学部材用粘着剤層。 The pressure-sensitive adhesive layer for an optical member according to any one of claims 1 to 7, wherein the (meth) acrylic polymer contains an alkyl (meth) acrylate and a carboxyl group-containing monomer as monomer components.
  9. 　前記透明粘着剤層が、アルキル（メタ）アクリレート、水酸基含有モノマー及び窒素含有モノマーをモノマー成分として含む（メタ）アクリル系ポリマーを含有することを特徴とする請求項５～８のいずれかに記載の光学部材用粘着剤層。 9. The transparent pressure-sensitive adhesive layer contains a (meth) acrylic polymer containing an alkyl (meth) acrylate, a hydroxyl group-containing monomer, and a nitrogen-containing monomer as monomer components. An adhesive layer for optical members.
  10. 　前記透明粘着剤層に含まれる（メタ）アクリル系ポリマーが、カルボキシル基含有モノマーをモノマー成分として含まないことを特徴とする請求項９に記載の光学部材用粘着剤層。 The pressure-sensitive adhesive layer for an optical member according to claim 9, wherein the (meth) acrylic polymer contained in the transparent pressure-sensitive adhesive layer does not contain a carboxyl group-containing monomer as a monomer component.
  11. 　光学部材の少なくとも一方の面に、請求項１～１０のいずれかに記載の光学部材用粘着剤層を少なくとも１層有することを特徴とする粘着剤層付光学部材。 An optical member with an adhesive layer, comprising at least one adhesive layer for an optical member according to any one of claims 1 to 10 on at least one surface of the optical member.
  12. 　請求項１１に記載の粘着剤層付光学部材を含むことを特徴とする画像表示装置。
          The image display apparatus characterized by including the optical member with an adhesive layer of Claim 11.
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