Classifications

• • 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
  • 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
  • C09J133/08—Homopolymers or copolymers of acrylic acid 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
• • 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
  • C09J133/10—Homopolymers or copolymers of methacrylic acid 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
  • C09J7/00—Adhesives in the form of films or foils
• • G—PHYSICS
  • G06—COMPUTING; CALCULATING OR COUNTING
  • G06F—ELECTRIC DIGITAL DATA PROCESSING
  • G06F3/00—Input arrangements for transferring data to be processed into a form capable of being handled by the computer; Output arrangements for transferring data from processing unit to output unit, e.g. interface arrangements
  • G06F3/01—Input arrangements or combined input and output arrangements for interaction between user and computer
  • G06F3/03—Arrangements for converting the position or the displacement of a member into a coded form
  • G06F3/041—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
• • 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
  • C09J2203/00—Applications of adhesives in processes or use of adhesives in the form of films or foils
  • C09J2203/318—Applications of adhesives in processes or use of adhesives in the form of films or foils for the production of liquid crystal displays
• • 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
  • C09J2301/00—Additional features of adhesives in the form of films or foils
  • C09J2301/10—Additional features of adhesives in the form of films or foils characterized by the structural features of the adhesive tape or sheet
  • C09J2301/12—Additional features of adhesives in the form of films or foils characterized by the structural features of the adhesive tape or sheet by the arrangement of layers
  • C09J2301/124—Additional features of adhesives in the form of films or foils characterized by the structural features of the adhesive tape or sheet by the arrangement of layers the adhesive layer being present on both sides of the carrier, e.g. double-sided adhesive tape

Definitions

• the present invention relates to a pressure-sensitive adhesive composition, a pressure-sensitive adhesive, a pressure-sensitive adhesive sheet, a double-sided pressure-sensitive adhesive sheet, a pressure-sensitive adhesive for transparent electrodes, a touch panel, and an image display device, and more specifically, a pressure-sensitive adhesive used for an active energy ray-curable pressure-sensitive adhesive. It relates to compositions and the like.
• Adhesives used for touch panels and the like are mainly used for bonding a support plate having an ITO (indium tin oxide) surface and a cover panel or a liquid crystal (LCD) module.
• ITO indium tin oxide
• Conventional touch panels have a glass / adhesive / glass structure. Adhesives have excellent shock absorption and visibility, and prevent accurate detection and malfunction due to touch. Therefore, various adhesives have been developed that require a low dielectric constant. For example, it has been studied to satisfy these requirements by increasing the thickness of the adhesive layer.
• the present applicant has disclosed an adhesive composition containing an acrylic resin, an organic solvent having a specific flash point, and an ethylenically unsaturated compound having a specific flash point as an acrylic adhesive suitable for thick coating.
• an adhesive sheet with low dielectric constant and high transparency an adhesive layer containing stearyl (meth) acrylate and a lower alkyl group N, N-dialkyl (meth) acrylamide as a monomer or monomer unit is provided.
• An adhesive sheet has been proposed (Patent Document 2).
• Patent Document 2 is not yet satisfactory in terms of adhesive properties and good handleability at a low viscosity as well as a low dielectric constant, and further improvement is required as in Patent Document 1. It was a thing.
• An object of the present invention is to provide an adhesive, a touch panel, and an image display device.
• the present inventor has used a (meth) acrylate (b1) having one dioxane skeleton and one (meth) acryloyl group as a dilution monomer.
• the inventors have found that a reduction in viscosity can be achieved while maintaining good adhesive properties, and have reached the present invention.
• the present invention is a pressure-sensitive adhesive composition containing a (meth) acrylic resin (A) and an ethylenically unsaturated compound (B) containing one ethylenically unsaturated group, the ethylenically unsaturated group
• the first gist of the present invention is a pressure-sensitive adhesive composition containing (meth) acrylate (b1) in which one ethylenically unsaturated compound (B) has one dioxane skeleton and one (meth) acryloyl group.
• the present invention provides a pressure-sensitive adhesive sheet comprising a pressure-sensitive adhesive composition comprising the cross-linked product of the pressure-sensitive adhesive composition of the first gist and a pressure-sensitive adhesive sheet containing a pressure-sensitive adhesive layer containing the pressure-sensitive adhesive of the second gist.
• the double-sided pressure-sensitive adhesive sheet containing the pressure-sensitive adhesive layer containing the pressure-sensitive adhesive according to the second aspect is the fourth aspect, and the pressure-sensitive adhesive for transparent electrodes using the pressure-sensitive adhesive according to the second aspect is the first.
• An image display comprising a pressure-sensitive adhesive layer containing a pressure-sensitive adhesive layer containing the pressure-sensitive adhesive for a transparent electrode according to the fifth aspect, and a pressure-sensitive adhesive layer containing a pressure-sensitive adhesive layer containing the pressure-sensitive adhesive according to the second aspect.
• the device is a seventh aspect.
• the pressure-sensitive adhesive composition of the present invention comprises (meth) acrylic resin (A) and an ethylenically unsaturated group containing (meth) acrylate (b1) having one dioxane skeleton and one (meth) acryloyl group as essential components. It contains the ethylenically unsaturated compound (B) containing one. For this reason, low viscosity is implement
• the dielectric constant can be reduced. The improvement effect is achieved.
• (meth) acryl means acryl or methacryl
• (meth) acryloyl means acryloyl or methacryloyl
• (meth) acrylate means acrylate or methacrylate.
• the pressure-sensitive adhesive composition of the present invention is obtained using a (meth) acrylic resin (A) and an ethylenically unsaturated compound (B) containing one ethylenically unsaturated group containing a specific monomer component. It is done.
• (meth) acrylic resin (A) used in the present invention for example, a (meth) acrylic acid alkyl ester monomer (a1) is used as a polymerization component, and if necessary, a later-described crosslinking agent (E) and Examples thereof include (meth) acrylic resins obtained by polymerizing the functional group-containing monomer (a2) that can become a crosslinking point by reacting as a copolymerization component.
• Active energy ray-reactive (meth) acrylic having a reactive structural site capable of reacting with a part of (meth) acrylic resin or other curing component contained in the pressure-sensitive adhesive composition by irradiation with active energy ray Resin can also be used.
• the (meth) acrylic resin contains a (meth) acrylic acid alkyl ester monomer (a1) as a polymerization component, and further contains a functional group-containing monomer (a2) as a copolymerization component as necessary. Further, if necessary, other copolymerizable monomer (a3) can be contained as a copolymerization component.
• the (meth) acrylic resin uses the functional group-containing monomer (a2) as a copolymerization component, the (meth) acrylic resin becomes a cross-linking point of the (meth) acrylic resin and adheres to the substrate or the adherend. Sex can be further increased.
• the alkyl group usually has 1 to 20, particularly 1 to 12, more preferably 1 to 8, particularly 4 to 8 carbon atoms.
• the content of the (meth) acrylic acid alkyl ester monomer (a1) in the copolymerization component is preferably 10 to 100% by weight, particularly preferably 30 to 95% by weight, more preferably 50 to 90% by weight, The content is particularly preferably 60 to 85% by weight. If the content of the (meth) acrylic acid alkyl ester monomer (a1) is too small, the adhesive strength when used as an adhesive tends to be lowered.
• the functional group-containing monomer (a2) may be any monomer containing a functional group that can become a crosslinking point by reacting with a cross-linking agent (E) described later.
• a hydroxyl group-containing monomer, a carboxyl group-containing monomer, amino Examples thereof include a group-containing monomer, an acetoacetyl group-containing monomer, an isocyanate group-containing monomer, and a glycidyl group-containing monomer.
• a hydroxyl group-containing monomer and a carboxyl group-containing monomer are preferably used in that a crosslinking reaction can be efficiently performed.
• hydroxyl group-containing monomer examples include 2-hydroxyethyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 5-hydroxypentyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 8-hydroxyoctyl ( Hydroxyalkyl esters of acrylic acid such as (meth) acrylate, caprolactone-modified monomers such as caprolactone-modified 2-hydroxyethyl (meth) acrylate; oxyalkylene-modified monomers such as diethylene glycol (meth) acrylate and polyethylene glycol (meth) acrylate; Primary hydroxyl group-containing monomers such as acryloyloxyethyl-2-hydroxyethylphthalic acid; 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (methyl ) Acrylate, secondary hydroxyl group-containing monomers such as 3-chloro-2-hydroxypropyl (meth) acrylate; can be mentioned 2,
• 2-hydroxyethyl acrylate and 4-hydroxybutyl acrylate are particularly preferably used from the viewpoint of excellent reactivity with the crosslinking agent.
• hydroxyl group-containing monomer used in the present invention it is also preferable to use an impurity having a content of di (meth) acrylate of 0.5% by weight or less, more preferably 0.2% by weight or less. Is preferably 0.1% by weight or less. Specifically, 2-hydroxyethyl acrylate and 4-hydroxybutyl acrylate are preferable.
• carboxyl group-containing monomer examples include (meth) acrylic acid, acrylic acid dimer, crotonic acid, maleic acid, maleic anhydride, fumaric acid, citraconic acid, glutaconic acid, itaconic acid, acrylamide-N-glycolic acid, silica
• (meth) acrylic acid is preferably used.
• amino group-containing monomer examples include t-butylaminoethyl (meth) acrylate, ethylaminoethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, and the like.
• acetoacetyl group-containing monomer examples include 2- (acetoacetoxy) ethyl (meth) acrylate and allyl acetoacetate.
• isocyanate group-containing monomer examples include 2-acryloyloxyethyl isocyanate, 2-methacryloyloxyethyl isocyanate and their alkylene oxide adducts.
• glycidyl group-containing monomer examples include glycidyl (meth) acrylate, allyl glycidyl (meth) acrylate, and the like. These functional group-containing monomers (a2) may be used alone or in combination of two or more.
• the content of the functional group-containing monomer (a2) in the copolymerization component is preferably 0 to 90% by weight, particularly preferably 5 to 60% by weight, more preferably 10 to 55% by weight, and particularly preferably 15%. ⁇ 50% by weight. If the content of the functional group-containing monomer (a2) is too small, the heat-and-moisture whitening resistance and cohesive force tend to decrease, and if it is too large, the viscosity tends to increase and the stability of the resin tends to decrease. .
• Examples of the other copolymerizable monomer (a3) include phenyl (meth) acrylate, benzyl (meth) acrylate, phenoxyethyl (meth) acrylate, phenyldiethylene glycol (meth) acrylate, 2-hydroxy-3-phenoxypropyl ( Monomers containing one aromatic ring such as (meth) acrylate, styrene, ⁇ -methylstyrene; biphenyloxy structure-containing (meth) acrylate monomers such as biphenyloxyethyl (meth) acrylate; ethoxymethyl (meth) acrylamide, n-Butoxymethyl (meth) acrylamide, (meth) acryloylmorpholine, dimethyl (meth) acrylamide, diethyl (meth) acrylamide, dimethylaminopropyl acrylamide, (meth) acryl (Meth) acrylamide monomers such as amide N-methylol (meth
• the content of the other copolymerizable monomer (a3) in the copolymerization component is preferably 0 to 40% by weight, particularly preferably 0 to 30% by weight, and further preferably 0 to 25% by weight.
• the content of the other copolymerizable monomer (a3) in the copolymerization component is preferably 0 to 40% by weight, particularly preferably 0 to 30% by weight, and further preferably 0 to 25% by weight.
• the (meth) acrylic acid alkyl ester monomer (a1) preferably the functional group-containing monomer (a2), and other copolymerizable monomer (a3) as necessary are polymerized as copolymerization components.
• the (meth) acrylic resin (A) is produced by this, but in such polymerization, it is possible to produce it by solution polymerization in a safe and stable manner with any monomer composition (meth) acrylic resin ( A) is preferable in that it can be produced.
• a monomer component such as a (meth) acrylic acid alkyl ester monomer (a1), a functional group-containing monomer (a2), and other copolymerizable monomer (a3) in an organic solvent, a polymerization initiator. May be mixed or dropped and polymerized at reflux or at 50 to 98 ° C. for 0.1 to 20 hours.
• polymerization initiator examples include azo-based polymerization initiators such as azobisisobutyronitrile and azobisdimethylvaleronitrile, which are usual radical polymerization initiators, benzoyl peroxide, lauroyl peroxide, and di-t-butyl peroxide. Specific examples include peroxide-based polymerization initiators such as cumene hydroperoxide.
• organic solvent examples include alcohols such as methanol, ethanol, propanol, n-butanol and i-butanol, ketones such as acetone, methyl isobutyl ketone, methyl ethyl ketone and cyclohexanone, cellosolves such as ethyl cellosolve, toluene, xylene And the like, glycol ethers such as propylene glycol monomethyl ether and propylene glycol monomethyl ether acetate, acetates such as ethyl acetate and butyl acetate, and diacetone alcohol. These may be used alone or in combination of two or more.
• alcohols such as methanol, ethanol, propanol, n-butanol and i-butanol
• ketones such as acetone, methyl isobutyl ketone, methyl ethyl ketone and cyclohexanone
• the (meth) acrylic resin (A) when the (meth) acrylic resin (A) is produced by solution polymerization, the (meth) acrylic resin (A) is preferably produced through a step of distilling off the organic solvent after polymerization.
• the distillation method include a method of distilling off the organic solvent by heating, a method of distilling off the organic solvent by reducing the pressure, and the like.
• a solvent-free (meth) acrylic resin that does not substantially contain an organic solvent as the (meth) acrylic resin (A) in that a thick film of an adhesive sheet can be formed.
• “Substantially no organic solvent” means that the content of the organic solvent in the (meth) acrylic resin (A) is usually 1% by weight or less, preferably 0.1% by weight or less, particularly preferably 0. The lower limit is usually 0.0001% by weight.
• the weight average molecular weight of the (meth) acrylic resin (A) is usually 50,000 to 5,000,000, preferably 100,000 to 1,500,000, particularly preferably 200,000 to 1,000,000. If the weight average molecular weight is too small, the durability performance tends to decrease, and if it is too large, the production tends to be difficult.
• the dispersity (weight average molecular weight / number average molecular weight) of the (meth) acrylic resin (A) is preferably 20 or less, particularly preferably 10 or less, more preferably 7 or less, especially Is preferably 5 or less.
• the lower limit of the degree of dispersion is usually 1.1 from the viewpoint of production limit.
• the glass transition temperature of the (meth) acrylic resin (A) is preferably ⁇ 80 to 10 ° C., particularly preferably ⁇ 60 to ⁇ 10 ° C., more preferably ⁇ 50 to ⁇ 20 ° C. If it is too high, tack tends to be insufficient, and if it is too low, heat resistance tends to decrease.
• the weight average molecular weight of the said (meth) acrylic-type resin (A), a dispersion degree, and a glass transition temperature are calculated
• the weight average molecular weight is a weight average molecular weight in terms of standard polystyrene molecular weight, and the column: Shodex GPC KF is used in high performance liquid chromatography (manufactured by Japan Waters, “Waters 2695 (main body)” and “Waters 2414 (detector)”). -806L (exclusion limit molecular weight: 2 ⁇ 10 7 , separation range: 100 to 2 ⁇ 10 7 , theoretical plate number: 10,000 plates / piece, filler material: styrene-divinylbenzene copolymer, filler particle size: 10 ⁇ m )), And the number average molecular weight can be measured using the same method. The degree of dispersion is determined from the weight average molecular weight and the number average molecular weight.
• the adhesive composition of the present invention is used for information labels used for bonding to transparent electrodes such as for touch panels and other electronic members, particularly precision electronic members, and for fixing electronic members, it is corrosion resistant.
• the (meth) acrylic resin (A) does not contain an acidic group.
• the pressure-sensitive adhesive composition of the present invention comprises, in addition to the (meth) acrylic resin (A), an ethylenically unsaturated compound (B) containing one ethylenically unsaturated group containing a specific monomer component (hereinafter referred to as “the (meth) acrylic resin (A)”). , which may be simply referred to as “ethylenically unsaturated compound (B)”) as a dilution monomer.
• the ethylenically unsaturated compound (B) used in the present invention contains (meth) acrylate (b1) having one dioxane skeleton and one (meth) acryloyl group as essential components.
• Examples of the (meth) acrylate (b1) each having one dioxane skeleton and one (meth) acryloyl group include trimethylolpropane formal acrylate represented by the following structural formula (1), and the following structural formula (2). (2-methyl-2-ethyl-1,3-dioxolan-4-yl) methyl acrylate represented by the formula: These can be used alone or in combination. Especially, it is preferable to use the trimethylol propane formal acrylate represented by following Structural formula (1) from the point of giving favorable adhesive physical property and having a high glass transition temperature (Tg).
• Tg glass transition temperature
• the weight average molecular weight of the (meth) acrylate (b1) having one dioxane skeleton and one (meth) acryloyl group is preferably 100 to 500, more preferably 150 to 400, and particularly preferably 150 to 300. It is. If the weight average molecular weight is too small, the heat resistance tends to decrease, and if the weight average molecular weight is too large, the photopolymerization tends to decrease. In addition, the weight average molecular weight of said (b1) is calculated
• the above (b1) is present as a polymer in the pressure-sensitive adhesive layer by being cured by at least one of irradiation with active energy rays and heating as described later.
• the glass transition temperature (Tg) is preferably ⁇ 20 to 50 ° C., more preferably ⁇ 15 to 40 ° C., and particularly preferably ⁇ 10 to 30 ° C.
• the blending amount of (meth) acrylate (b1) having one dioxane skeleton and one (meth) acryloyl group is from the point of viscosity to 100 parts by weight of (meth) acrylic resin (A).
• the amount is preferably 15 to 150 parts by weight, particularly 20 to 125 parts by weight, more preferably 20 to 100 parts by weight, and particularly preferably 20 to 80 parts by weight.
• the viscosity tends to be high, and when it is too large, the adhesive performance tends to decrease.
• the ethylenically unsaturated compound (B) preferably contains an alkyl (meth) acrylate (b2) having an alkyl group with 8 to 30 carbon atoms from the viewpoint of reducing the dielectric constant. .
• the number of carbon atoms in the alkyl group of the alkyl (meth) acrylate (b2) is more preferably 10 to 26, and particularly preferably 13 to 24.
• the carbon number is too small, the dielectric constant of the pressure-sensitive adhesive composition tends to increase, and when it is too large, the adhesive strength tends to decrease.
• Specific examples include decane (meth) acrylate, dodecyl (meth) acrylate, tridecyl (meth) acrylate, myristyl (meth) acrylate, pentadecyl (meth) acrylate, cetyl (meth) acrylate, and n-stearyl (meth) acrylate.
• Aliphatic (meth) acrylates having a linear alkyl chain such as: isodecyl (meth) acrylate, isotridecyl (meth) acrylate, isomyristyl (meth) acrylate, isopentadecyl (meth) acrylate, isocetyl (meth) acrylate, Isostearyl (meth) acrylate, isotetracosyl (meth) acrylate, 2-dodecyl-hexadecanyl (meth) acrylate, 2-tetradecyl-octadecanyl (meth) acrylate, isobehenyl ( Data) acrylate, 2-decyl tetradecanyl (meth) long chain aliphatic having a branched chain containing alkyl chains such as acrylates (meth) acrylate; and the like.
• isostearyl (meth) acrylate isotridecyl (meth) acrylate, isotetracosyl (meth) acrylate, etc. from the point that the dielectric constant of an adhesive layer can be lowered
• the blending amount of the alkyl (meth) acrylate (b2) having 8 to 30 carbon atoms in the alkyl group is based on 100 parts by weight of the (meth) acrylic resin (A) from the viewpoint of dielectric constant.
• the amount is preferably 10 to 200 parts by weight, particularly preferably 25 to 175 parts by weight, and more preferably 50 to 150 parts by weight. If the amount is too small, the dielectric constant tends to increase, and if too large, the adhesion tends to decrease.
• the ethylenically unsaturated compound (B) containing one ethylenically unsaturated group has 8 to 30 carbon atoms in the (meth) acrylate (b1) having one dioxane skeleton and one (meth) acryloyl group, and an alkyl group.
• the (meth) acrylate (b1) having one each of the dioxane skeleton and one (meth) acryloyl group and the alkyl group has 8 to 30 carbon atoms.
• the ethylenically unsaturated compound (B) can be blended with other ethylenically unsaturated compounds other than the above (b1) and (b2) within the range not inhibiting the effects of the present invention. .
• Examples of the other ethylenically unsaturated compounds include alicyclic (meth) acrylate and aromatic (meth) acrylate.
• Examples of the alicyclic (meth) acrylate include isobornyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, and the like.
• aromatic (meth) acrylate examples include benzyl (meth) acrylate, biphenyl (meth) acrylate, naphthalene (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, and 3-chloro-2-hydroxy And propyl (meth) acrylate. These may be used alone or in combination of two or more.
• the blending ratio when blending the other ethylenically unsaturated compound is preferably set to 50% by weight or less of the entire ethylenically unsaturated compound (B).
• the ethylenically unsaturated compound (B) is present as a polymer in the pressure-sensitive adhesive layer by being cured by at least one of irradiation with active energy rays and heating as described later. It is preferable to select (b1) and (b2), which are essential components constituting the ethylenically unsaturated compound (B), so that the glass transition temperature (Tg) is ⁇ 80 to 80 ° C.
• the glass transition temperature (Tg) of the polymer is particularly preferably ⁇ 60 to 40 ° C., more preferably ⁇ 30 to 20 ° C., particularly preferably ⁇ 10 to 10 ° C., and the glass transition temperature is high. If it is too high, the adhesive performance tends to be difficult to obtain, and if it is too low, the cohesive force tends to decrease.
• the glass transition temperature is calculated from the Fox equation described above.
• the content of the ethylenically unsaturated compound (B) is preferably 50 to 300 parts by weight, particularly preferably 60 to 250 parts by weight, based on 100 parts by weight of the (meth) acrylic resin (A). Parts, particularly preferably 70 to 200 parts by weight, more preferably 110 to 180 parts by weight. If the content of the ethylenically unsaturated compound (B) is too small, the viscosity tends to be high and the handleability tends to be lowered. If the content is too large, the viscosity becomes too low to be applied to a desired thickness, and further Tends to reduce the reliability of the adhesive.
• the content ratio of the (meth) acrylic resin (A) in the whole pressure-sensitive adhesive composition of the present invention is usually 5 to 70% by weight, preferably 10 to 60% by weight, particularly preferably 25 to 50% by weight. If the content of (A) is too large, the viscosity tends to increase too much and the coating suitability tends to decrease. If the content is too small, the viscosity decreases too much and the coating suitability decreases, and further the reliability of the adhesive decreases. Tend to.
• the pressure-sensitive adhesive composition of the present invention preferably has a viscosity of 40000 (mPa ⁇ s / 25 ° C.) or less from the viewpoint of handleability, particularly preferably 30000 (mPa ⁇ s / 25 ° C.) or less, more preferably It is 20000 (mPa ⁇ s / 25 ° C.) or less, particularly preferably 10,000 (mPa ⁇ s / 25 ° C.) or less.
• the lower limit of the viscosity is 100 (mPa ⁇ s / 25 ° C.).
• the viscosity (25 degreeC) of the adhesive composition of this invention adjusts temperature to 25 degreeC, and is measured using a Brookfield type
• the pressure-sensitive adhesive composition does not substantially contain an organic solvent in that a thick film of the pressure-sensitive adhesive sheet can be formed.
• “Substantially no organic solvent” means that the content of the organic solvent in the pressure-sensitive adhesive composition is usually 1% by weight or less, preferably 0.1% by weight or less, particularly preferably 0.01% by weight or less. The lower limit is usually 0.0001% by weight.
• the pressure-sensitive adhesive composition of the present invention after producing the (meth) acrylic resin (A), simultaneously adding the (meth) acrylic resin (A) and the ethylenically unsaturated compound (B), or It is preferable to produce the mixture by adding the other to one and stirring.
• an ethylenically unsaturated compound (C) containing two or more ethylenically unsaturated groups (hereinafter, “ It may be abbreviated as “polyfunctional unsaturated compound (C)”) in that the cohesive force of the entire pressure-sensitive adhesive layer can be adjusted, and it is preferable that a polymerization initiator (D) is further contained. This is preferable in that at least one reaction at the time of energy beam irradiation and heating can be stabilized.
• the ethylenically unsaturated compound (B) and the polyfunctional unsaturated compound (C) are polymerized (polymerized) by at least one of active energy ray irradiation and heating, and are cured.
• a cross-linking reaction can be performed by adding a cross-linking agent (E) to the pressure-sensitive adhesive composition.
• a crosslinking agent (E) it is preferable that (meth) acrylic-type resin (A) has a functional group, and this functional group and crosslinking agent (E) react, and crosslinking ( Curing).
• curing by at least one of the above-mentioned [ ⁇ ] active energy ray irradiation and heating is possible in that the aging time is not required and the gel fraction of the pressure-sensitive adhesive layer can be increased in a short time. preferable.
• a method of curing by at least one of [ ⁇ ] active energy ray irradiation and heating and a crosslinking agent are used. And a method of combining with the method of cross-linking.
• polyfunctional unsaturated compound (C) for example, an ethylenically unsaturated monomer containing two or more ethylenically unsaturated groups in one molecule, for example, a bifunctional monomer, a trifunctional or higher monomer, Urethane (meth) acrylate compounds, epoxy (meth) acrylate compounds, and polyester (meth) acrylate compounds can be used.
• a bifunctional monomer for example, a trifunctional or higher monomer
• Urethane (meth) acrylate compounds for example, epoxy (meth) acrylate compounds, and polyester (meth) acrylate compounds
• the bifunctional monomer may be any monomer containing two ethylenically unsaturated groups.
• the tri- or higher functional monomer may be any monomer containing three or more ethylenically unsaturated groups.
• the urethane (meth) acrylate compound is a (meth) acrylate compound having a urethane bond in the molecule, a (meth) acrylic compound containing a hydroxyl group and a polyvalent isocyanate compound (if necessary, a polyol What is necessary is just to use what is obtained by making it react by a well-known general method, and what is necessary is just to use the thing of 300-4000 normally as the weight average molecular weight.
• the content of the polyfunctional unsaturated compound (C) is desirably 0.01 to 100 parts by weight, preferably 0.05 to 100 parts by weight with respect to 100 parts by weight of the (meth) acrylic resin (A).
• the amount is 10 parts by weight, more preferably 0.1 to 5 parts by weight. If the content of the polyfunctional unsaturated compound (C) is too large, the cohesive force is excessively increased, so that the adhesive performance tends to be lowered. If the content is too small, the holding power tends to be insufficient.
• the content of the polyfunctional unsaturated compound (C) is desirably 0.01 to 99 parts by weight, preferably 0.05 to 99 parts by weight with respect to 100 parts by weight of the ethylenically unsaturated compound (B).
• the amount is 10 parts by weight, more preferably 0.1 to 5 parts by weight.
• polymerization initiator (D) for example, various polymerization initiators such as a photopolymerization initiator (d1) and a thermal polymerization initiator (d2) can be used. It is preferable to use d1) in that it can be cured by irradiation with active energy rays such as ultraviolet rays for a very short time.
• the pressure-sensitive adhesive composition is cured by irradiation with active energy rays
• the thermal polymerization initiator (d2) is used, the pressure-sensitive adhesive composition is cured by heating.
• Examples of the photopolymerization initiator (d1) include diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzyldimethyl ketal, 4- (2-hydroxyethoxy) phenyl- (2 -Hydroxy-2-propyl) ketone, 1-hydroxycyclohexylphenylketone, 2-methyl-2-morpholino (4-thiomethylphenyl) propan-1-one, 2-benzyl-2-dimethylamino-1- (4- Acetophenones such as morpholinophenyl) butanone and 2-hydroxy-2-methyl-1- [4- (1-methylvinyl) phenyl] propanone oligomers; benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl Ether etc.
• auxiliary agents include triethanolamine, triisopropanolamine, 4,4′-dimethylaminobenzophenone (Michler ketone), 4,4′-diethylaminobenzophenone, 2-dimethylaminoethylbenzoic acid, 4-dimethylaminobenzoic acid.
• Ethyl, ethyl 4-dimethylaminobenzoate (n-butoxy), isoamyl 4-dimethylaminobenzoate, 2-ethylhexyl 4-dimethylaminobenzoate, 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone Etc. can be used in combination.
• benzyl dimethyl ketal 1-hydroxycyclohexyl phenyl ketone, benzoin isopropyl ether, 4- (2-hydroxyethoxy) phenyl- (2-hydroxy-2-propyl) ketone, 2-hydroxy-2-methyl-1- It is preferable to use phenylpropan-1-one.
• thermal polymerization initiator (d2) examples include methyl ethyl ketone peroxide, cyclohexanone peroxide, methyl cyclohexanone peroxide, methyl acetoacetate peroxide, acetyl acetate peroxide, 1,1-bis (t-hexyl peroxide).
• the total amount is preferably from 0.01 to 50 parts by weight, particularly preferably from 0.1 to 20 parts by weight, more preferably from 0.3 to 12 parts by weight, and particularly preferably from 0.1 to 50 parts by weight.
• the amount is preferably 5 to 3 parts by weight. If the content of the polymerization initiator (D) is too small, the curability tends to be poor and the physical properties tend to become unstable, and if it is too much, no further effect can be obtained.
• UV ray irradiation far ultraviolet rays, ultraviolet rays, near ultraviolet rays, infrared rays and other electromagnetic waves, X rays, ⁇ rays and other electromagnetic waves, as well as electron beams, proton rays, neutron rays, etc.
• Curing by ultraviolet irradiation is advantageous from the standpoint of availability of the device and price.
• electron beam irradiation it can harden
• a high pressure mercury lamp for example, 5 ⁇ 3000mJ / cm 2, preferably at a 50 ⁇ 2000mJ / cm 2 conditions.
• the electrodeless lamp for example, it is performed under the conditions of 2 to 2000 mJ / cm 2 , preferably 10 to 1000 mJ / cm 2 .
• the irradiation time varies depending on the type of light source, the distance between the light source and the coating surface, the coating thickness, and other conditions, but it may be usually from several seconds to several tens of seconds, and in some cases, a fraction of a second.
• the electron beam irradiation for example, an electron beam having an energy in the range of 50 to 1000 Kev is used, and the irradiation amount is preferably 2 to 50 Mrad.
• the polymerization initiator (D) may not be blended.
• the thermal polymerization initiator (d2) when used as the polymerization initiator (D), the polymerization reaction is started by heating and allowed to proceed.
• the treatment temperature and treatment time at the time of curing by heating vary depending on the type of the thermal polymerization initiator (d2) to be used, and are usually calculated from the half-life of the initiator, but the treatment temperature is usually It is preferably 70 ° C. to 170 ° C., and the treatment time is usually preferably 0.2 to 20 minutes, particularly preferably 0.5 to 10 minutes.
• the crosslinking agent (E) exhibits an excellent adhesive force by reacting with a functional group derived from the functional group-containing monomer (a2) which is a constituent monomer of the (meth) acrylic resin (A).
• a functional group derived from the functional group-containing monomer (a2) which is a constituent monomer of the (meth) acrylic resin (A) examples thereof include isocyanate crosslinking agents, epoxy crosslinking agents, aziridine crosslinking agents, melamine crosslinking agents, aldehyde crosslinking agents, amine crosslinking agents, and metal chelate crosslinking agents.
• an isocyanate-based crosslinking agent is preferably used from the viewpoint of improving the adhesion to the substrate and the reactivity with the (meth) acrylic resin (A).
• isocyanate crosslinking agent examples include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, hydrogenated tolylene diisocyanate, 1,3-xylylene diisocyanate, 1,4-xylylene diisocyanate, hexamethylene.
• epoxy-based crosslinking agent examples include bisphenol A / epichlorohydrin type epoxy resin, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, glycerin diglycidyl ether, glycerin triglycidyl ether, and 1,6-hexanediol diglycidyl ether. , Trimethylolpropane triglycidyl ether, sorbitol polyglycidyl ether, polyglycerol polyglycidyl ether, pentaerythritol polyglycidyl erythritol, diglycerol polyglycidyl ether and the like.
• aziridine-based crosslinking agent examples include tetramethylolmethane-tri- ⁇ -aziridinylpropionate, trimethylolpropane-tri- ⁇ -aziridinylpropionate, N, N′-diphenylmethane-4,4.
• Examples of the melamine-based crosslinking agent include hexamethoxymethyl melamine, hexaethoxymethyl melamine, hexapropoxymethyl melamine, hexaptoxymethyl melamine, hexapentyloxymethyl melamine, hexahexyloxymethyl melamine, and melamine resin. .
• aldehyde-based crosslinking agent examples include glyoxal, malondialdehyde, succindialdehyde, maleindialdehyde, glutardialdehyde, formaldehyde, acetaldehyde, benzaldehyde and the like.
• amine-based crosslinking agent examples include hexamethylenediamine, triethyldiamine, polyethyleneimine, hexamethylenetetraamine, diethylenetriamine, triethyltetraamine, isophoronediamine, amino resin, and polyamide.
• metal chelate-based crosslinking agent examples include acetylacetone and acetoacetyl ester coordination compounds of polyvalent metals such as aluminum, iron, copper, zinc, tin, titanium, nickel, antimony, magnesium, vanadium, chromium, and zirconium. can give.
• cross-linking agents (E) may be used alone or in combination of two or more.
• the content of the crosslinking agent (E) is usually preferably 0.01 to 10 parts by weight, more preferably 0.05 to 10 parts by weight with respect to 100 parts by weight of the (meth) acrylic resin (A). 5 parts by weight, particularly preferably 0.1 to 2 parts by weight. If the amount of the crosslinking agent (E) is too small, the cohesive force tends to decrease, and sufficient durability cannot be obtained. If the amount is too large, the flexibility and the adhesive strength decrease, and the durability decreases. Therefore, the use as an optical member tends to be difficult.
• the pressure-sensitive adhesive composition of the present invention includes a silane coupling agent, an antistatic agent, other acrylic pressure-sensitive adhesives, other pressure-sensitive adhesives, urethane resin, rosin, and rosin ester as long as the effects of the present invention are not impaired.
• Conventionally known additives such as ultraviolet absorbers and functional dyes, and compounds that cause coloration or discoloration upon irradiation with ultraviolet rays or radiation can be blended.
• the amount of these additives is preferably 30% by weight or less, particularly preferably 20% by weight or less of the entire pressure-sensitive adhesive composition, and low molecular components having a molecular weight lower than 10,000 are included as much as possible as additives. It is preferable that there is no durability in terms of excellent durability.
• a small amount of impurities and the like contained in the raw materials for producing the constituent components of the pressure-sensitive adhesive composition may be contained.
• the pressure-sensitive adhesive composition obtained above is cured or cross-linked to obtain a (meth) acrylic pressure-sensitive adhesive.
• the adhesive of this invention is used as an adhesive layer containing laminated body containing the adhesive layer which consists of the said adhesive, and a base material sheet, a release sheet, or an optical member, specifically, Is used as an adhesive sheet having an adhesive layer provided on a base sheet, a double-sided adhesive sheet having an adhesive layer provided on a release sheet, and an optical member with an adhesive layer having an adhesive layer provided on an optical member. It is preferable.
• the method for producing the pressure-sensitive adhesive sheet it can be produced according to a known method for producing a pressure-sensitive adhesive sheet.
• the pressure-sensitive adhesive composition layer is formed by coating the pressure-sensitive adhesive composition on a substrate sheet.
• the pressure-sensitive adhesive layer can be formed by performing treatment with at least one of active energy ray irradiation and heating, and curing as necessary.
• polyester resins such as polyethylene naphthalate, polyethylene terephthalate, polybutylene terephthalate, and polyethylene terephthalate / isophthalate copolymer
• polyolefins such as polyethylene, polypropylene, and polymethylpentene.
• Polyfluorinated ethylene resins such as polyvinyl fluoride, polyvinylidene fluoride, and polyfluorinated ethylene
• Polyamides such as nylon 6 and nylon 6, 6
• cellulose resins such as cellulose triacetate and cellophane
• Acrylic resins such as chill, polyethyl acrylate, polybutyl acrylate, etc .
• polystyrene polycarbonate; polyarylate
• synthetic resin sheets such as polyimide, aluminum, copper, iron metal foil, fine paper, glassine paper, etc., glass Examples thereof include woven fabrics and nonwoven fabrics made of fibers, natural fibers, synthetic fibers and the like.
• said double-sided adhesive sheet what is necessary is just a double-sided adhesive sheet of the well-known general structure using the said (meth) acrylic-type adhesive, and especially it is excellent in transparency, and the adhesive force with respect to the thickness which comprises. From a high point, it is preferable to make a double-sided pressure-sensitive adhesive sheet.
• the substrate-less double-sided pressure-sensitive adhesive sheet for example, after coating the pressure-sensitive adhesive composition on a release sheet to form a pressure-sensitive adhesive composition layer, on the side where there is no release sheet of the pressure-sensitive adhesive composition layer, Furthermore, another pressure-sensitive adhesive layer can be formed by pasting another release sheet, performing treatment with at least one of active energy ray irradiation and heating, and curing as necessary.
• the other release sheet may be peeled off and bonded to the adherend.
• the pressure-sensitive adhesive is preferably used as a pressure-sensitive adhesive for optical members, and the pressure-sensitive adhesive layer is formed by laminating and forming a pressure-sensitive adhesive layer made of the (meth) acrylic pressure-sensitive adhesive on the optical member. An attached optical member can be obtained.
• the above optical members include ITO electrode films, organic conductive films such as polythiophene, transparent electrode films such as metal meshes such as copper and silver, polarizing plates, retardation plates, elliptically polarizing plates, optical compensation films, and brightness enhancement.
• examples thereof include a film, an electromagnetic wave shielding film, a near-infrared absorbing film, and an AR (anti-reflection) film.
• the optical member is a transparent electrode film, the effect of the present invention can be remarkably exhibited and high adhesive force is obtained, and an ITO electrode film is particularly preferable.
• the ITO electrode film is often formed as a thin film on a substrate such as glass or PET.
• (meth) acrylic-type resin (A) and an ethylenically unsaturated compound (B) do not contain an acidic group. Furthermore, it is more preferable that the entire pressure-sensitive adhesive composition does not contain an acidic group.
• the acid value is preferably 10 mgKOH / g or less, particularly preferably 1 mgKOH / g or less, more preferably 0.1 mgKOH / g or less.
• a release sheet on the surface opposite to the optical member surface of the pressure-sensitive adhesive layer.
• An adhesive layer and an adherend will be bonded.
• a silicon release sheet is preferably used as the release sheet.
• the pressure-sensitive adhesive that bonds the pressure-sensitive adhesive layer and the adherend (other optical members) after peeling the release sheet.
• a method of bonding optical members to each other using the above-mentioned double-sided pressure-sensitive adhesive sheet may be used.
• the pressure-sensitive adhesive layer contained in the pressure-sensitive adhesive sheet, the double-sided pressure-sensitive adhesive sheet, and the optical member with the pressure-sensitive adhesive layer will be described.
• the pressure-sensitive adhesive layer is coated with a pressure-sensitive adhesive composition on a base sheet, release sheet, or optical member to form a pressure-sensitive adhesive composition layer, and then treated with at least one of active energy ray irradiation and heating. And is preferably produced by a method of performing an aging treatment if necessary.
• the pressure-sensitive adhesive composition In the application of the pressure-sensitive adhesive composition, a conventional method such as roll coating, die coating, gravure coating, comma coating or screen printing is performed.
• the pressure-sensitive adhesive composition layer thus obtained is subjected to treatment by at least one of active energy ray irradiation and heating, and an adhesive layer is formed by performing an aging treatment to balance the pressure-sensitive adhesive properties as necessary.
• the pressure-sensitive adhesive sheet, the double-sided pressure-sensitive adhesive sheet and the optical layered body (optical member) with the pressure-sensitive adhesive layer are produced.
• the active energy ray irradiation conditions are as described above.
• the aging treatment is preferably carried out particularly when the crosslinking agent (E) is used in the pressure-sensitive adhesive composition.
• the conditions for the aging treatment are as follows: the temperature is usually from room temperature (25 ° C.) to 70 ° C., and the time is usually 1 day. Specifically, for example, the treatment may be performed at 23 ° C. for 1 day to 20 days, preferably at 23 ° C. for 3 to 10 days, at 40 ° C. for 1 to 7 days, and the like.
• the gel fraction of the pressure-sensitive adhesive sheet, the double-sided pressure-sensitive adhesive sheet, and the pressure-sensitive adhesive layer of the optical member with the pressure-sensitive adhesive layer is preferably 30 to 100%, particularly 40 to 95% from the viewpoint of durability performance and adhesive strength. In particular, 50 to 90% is preferable.
• the gel fraction is too low, durability tends to be reduced due to a decrease in cohesive force.
• the adhesive force tends to decrease due to an increase in cohesive force.
• the gel fraction to the above range, for example, it is achieved by adjusting the type and amount of the crosslinking agent (E), the type and amount of the polyfunctional acrylate, and the like.
• the gel fraction is a measure of the degree of crosslinking (curing degree) and is calculated by the following method. That is, a pressure-sensitive adhesive sheet (without a separator) formed by forming a pressure-sensitive adhesive layer on a polymer sheet (eg, polyethylene terephthalate (PET) film) as a base material is wrapped in a 200 mesh SUS wire mesh, and toluene It is immersed in the solution at 23 ° C. for 24 hours, and the weight percentage of the insoluble adhesive component remaining in the wire mesh is defined as the gel fraction. However, the weight of the substrate is subtracted.
• a pressure-sensitive adhesive sheet without a separator
• a polymer sheet eg, polyethylene terephthalate (PET) film
• PET polyethylene terephthalate
• the thickness of the pressure-sensitive adhesive sheet, the double-sided pressure-sensitive adhesive sheet, and the pressure-sensitive adhesive layer of the optical member with the pressure-sensitive adhesive layer is usually preferably 50 to 3000 ⁇ m, more preferably 80 to 1000 ⁇ m, and particularly preferably 100 to It is preferable that it is 350 micrometers. If the thickness of the pressure-sensitive adhesive layer is too thin, the impact absorbability tends to decrease, and if it is too thick, the thickness of the entire optical member tends to increase too much.
• the thickness of the pressure-sensitive adhesive layer in the present invention is measured using the “ID-C112B” manufactured by Mitutoyo Co., Ltd. from the measured thickness of the entire pressure-sensitive adhesive layer-containing laminate. The value obtained by subtracting the value.
• the adhesive strength of the pressure-sensitive adhesive sheet, the double-sided pressure-sensitive adhesive sheet, and the pressure-sensitive adhesive layer of the optical member with the pressure-sensitive adhesive layer is appropriately determined according to the material of the adherend.
• it When sticking to a methyl methacrylate plate or a PET sheet having an ITO layer deposited thereon, it preferably has an adhesive strength of 5 N / 25 mm to 500 N / 25 mm, more preferably 10 N / 25 mm to 100 N / 25 mm.
• the above adhesive strength is calculated as follows.
• An easy-adhesive PET (polyethylene terephthalate) film with a thickness of 125 ⁇ m is peeled off from the pressure-sensitive adhesive layer (thickness: 80 ⁇ m) of the substrate-less double-sided pressure-sensitive adhesive sheet using a polyester-based release sheet (polyethylene terephthalate sheet).
• the PET film with the pressure-sensitive adhesive layer is cut into a width of 25 mm ⁇ a length of 100 mm, the release sheet is peeled off, the pressure-sensitive adhesive layer side is brought into close contact with the adherend, and the atmosphere is at 23 ° C. and a relative humidity of 50%.
• the total light transmittance of the pressure-sensitive adhesive sheet, the double-sided pressure-sensitive adhesive sheet, and the pressure-sensitive adhesive layer of the optical member with a pressure-sensitive adhesive layer is preferably 85% or more, and particularly preferably 90% or more. Preferably it is 92% or more. If the total light transmittance is too low, the light transmittance is low, so that it tends to be difficult to use in display applications.
• the upper limit of the total light transmittance is usually 95%.
• the haze value of the pressure-sensitive adhesive sheet, the double-sided pressure-sensitive adhesive sheet, and the pressure-sensitive adhesive layer of the optical member with a pressure-sensitive adhesive layer is preferably 10% or less, particularly preferably 2% or less, and still more preferably. 1% or less. If the haze value is too high, the image tends to be unclear when used for display.
• the lower limit of the haze value is usually 0.00%.
• the above total light transmittance and haze value are values measured using a haze meter in accordance with JIS K7361-1.
• the color difference b * value of the pressure-sensitive adhesive sheet, the double-sided pressure-sensitive adhesive sheet, and the pressure-sensitive adhesive layer of the optical member with the pressure-sensitive adhesive layer is preferably 1 or less, and particularly preferably 0.5 or less. If the color difference b * value is too high, the original color tends to be difficult to appear when used for display.
• the lower limit of the color difference b * value is normally -1.
• the color difference b * value is measured in accordance with JIS K7105, and the measurement is performed under a predetermined transmission condition using a spectral color difference meter (SE6000: manufactured by Nippon Denshoku Industries Co., Ltd.).
• the pressure-sensitive adhesive composed of the pressure-sensitive adhesive composition of the present invention includes glass, ITO transparent electrode sheet, polyethylene terephthalate (PET), polycarbonate (PC), optical sheets such as polymethyl methacrylate (PMMA), polarizing plate, retardation plate, Useful for attaching optical members such as optical compensation films and brightness enhancement films. Furthermore, it can be suitably used for an image display device such as a touch panel comprising these optical members.
• Acrylic resin (A-1) A four-necked round bottom flask equipped with a reflux condenser, a stirrer, a nitrogen gas inlet and a thermometer was charged with 300 parts of acetone and 2,2'-azobis (2,4-dimethylvaleronitrile as a polymerization initiator). ) (ADVN) 0.15 part was added, the temperature was raised with stirring, and a mixture of 70 parts 2-ethylhexyl acrylate (2EHA) and 30 parts 2-hydroxyethyl acrylate (HEA) was added dropwise over 2 hours at reflux temperature. .
• EHA 2-ethylhexyl acrylate
• HOA 2-hydroxyethyl acrylate
• Acrylic resin (A-2) A four-necked round bottom flask equipped with a reflux condenser, a stirrer, a nitrogen gas inlet and a thermometer was charged with 300 parts of acetone and 2,2'-azobis (2,4-dimethylvaleronitrile as a polymerization initiator). ) (ADVN) 0.15 part was added, the temperature was raised with stirring, and a mixture of 70 parts 2-ethylhexyl acrylate (2EHA) and 30 parts 2-hydroxyethyl acrylate (HEA) was added dropwise over 2 hours at reflux temperature. .
• EHA 2-ethylhexyl acrylate
• HOA 2-hydroxyethyl acrylate
• Acrylic resin (A-3) A four-necked round bottom flask equipped with a reflux condenser, a stirrer, a nitrogen gas inlet and a thermometer was charged with 400 parts of acetone and 2,2'-azobis (2,4-dimethylvaleronitrile as a polymerization initiator). ) (ADVN) 0.15 part, heated with stirring, 50 parts 2-ethylhexyl acrylate (2EHA), 30 parts 2-hydroxyethyl acrylate (HEA) and t-butyl methacrylate (tBMA) at reflux temperature 20 parts of the mixture was added dropwise over 2 hours.
• EHA 2-ethylhexyl acrylate
• HOA 2-hydroxyethyl acrylate
• tBMA t-butyl methacrylate
• the monomer components, weight average molecular weight (Mw), glass transition temperature (Tg), and dispersity of the acrylic resins (A-1) to (A-3) produced as described above are shown in Table 1 below. .
• B′-1 Methoxyethyl acrylate (MEA)
• B′-2 acryloylmorpholine (ACMO)
• B′-3 ethyl carbitol acrylate (CBA)
• B'-4 2-ethylhexyl acrylate (2EHA)
• TMPTA Trimethylolpropane triacrylate
• Example 1 A 4-neck round bottom flask equipped with a reflux condenser, a stirrer, a nitrogen gas inlet and a thermometer was charged with 100 parts (resin content) of acrylic resin (A-1).
• Examples 2 to 8 Comparative Examples 1 to 5
• the blending components prepared and prepared as described above were blended in the proportions shown in Table 2 below, and a pressure-sensitive adhesive composition solution was prepared in the same manner as in Example 1 except that.
• the adhesive composition solution obtained above was apply
• the obtained pressure-sensitive adhesive composition layer is sandwiched between polyester release sheets and irradiated with ultraviolet rays at a peak illuminance of 150 mW / cm 2 and an integrated exposure amount of 1000 mJ / cm 2 using a high-pressure mercury UV irradiation device (500 mJ / cm 2 ⁇ 2 pass) and a pressure-sensitive adhesive layer (film thickness of 80 ⁇ m: film thickness of 185 ⁇ m only in Example 8) was obtained, thereby obtaining a substrate-less double-sided pressure-sensitive adhesive sheet.
• the film thickness of the pressure-sensitive adhesive layer was determined by measuring the thickness of the entire substrate-less double-sided pressure-sensitive adhesive sheet on which the pressure-sensitive adhesive layer was formed using “ID-C112B” manufactured by Mitutoyo Corporation. This is a value obtained by subtracting the measured value of the thickness of the member.
• the gel fraction, adhesive strength, and dielectric constant were measured and evaluated according to the following methods. Further, the viscosity of the pressure-sensitive adhesive composition obtained above and the optical properties (optical measurement) of the pressure-sensitive adhesive layer were measured and evaluated according to the methods described below. These results are also shown in Table 3 below.
• optical measurement (haze value, color difference b * value, total light transmittance) in the obtained pressure-sensitive adhesive layer (glue only) was measured according to the method described above. That is, the total light transmittance and haze value were measured using a haze meter in accordance with JIS K7361-1.
• the color difference b * value was measured in accordance with JIS K7105, and the measurement was performed using a spectral color difference meter (SE6000: manufactured by Nippon Denshoku Industries Co., Ltd.) under predetermined transmission conditions.
• the release sheet on one side was peeled off from the pressure-sensitive adhesive layer of the substrate-less double-sided pressure-sensitive adhesive sheet, and pressed onto an easily adhesive PET (polyethylene terephthalate) film having a thickness of 125 ⁇ m to obtain a PET film with a pressure-sensitive adhesive layer.
• PET film with pressure-sensitive adhesive layer it is cut into 25mm width x 25mm length, the release sheet is peeled off, and the pressure-sensitive adhesive layer side is placed on optical glass ("Corning EagleXG") in an atmosphere of 23 ° C and 50% relative humidity. Then, after applying pressure by two reciprocations of a 2 kg rubber roller, an autoclave treatment of 0.5 MPa ⁇ 50 ° C.
• the release sheet on one side was peeled off from the pressure-sensitive adhesive layer of the substrate-less double-sided pressure-sensitive adhesive sheet, and pressed onto an easily adhesive PET (polyethylene terephthalate) film having a thickness of 125 ⁇ m to obtain a PET film with a pressure-sensitive adhesive layer.
• PET polyethylene terephthalate
• the release sheet is peeled off, and the pressure-sensitive adhesive layer side is placed on soda glass at a temperature of 23 ° C. and a relative humidity of 50% with a 2 kg rubber roller.
• the sample was reciprocated twice, pressed and stuck, left in the same atmosphere for 30 minutes, and then measured for 180 ° peel strength (N / 25 mm) at a peel rate of 300 mm / min at room temperature (23 ° C.).
• the evaluation criteria are as follows. (Evaluation criteria) A: 30 N / 25 mm or more. ⁇ : 15 N / 25 mm or more and less than 30 N / 25 mm. X: Less than 15 N / 25 mm.
• the PET film with the pressure-sensitive adhesive layer is cut into a 7 cm ⁇ 7 cm square and used as a test piece, and the test piece is sandwiched between electrodes using an HP4284A Precision LCR meter (manufactured by Agilent) under an atmosphere of 23 ° C. and 50% relative humidity.
• the electric capacity was measured by applying an electric field at a frequency of 1 MHz, and the relative dielectric constant of the adhesive layer was calculated from the change in the electric capacity between the electrodes.
• the evaluation criteria are as follows. (Evaluation criteria) ⁇ : 3.5 or less. X: Greater than 3.5.
• the adhesive layer) showed high adhesive strength but high viscosity (Comparative Example 1), low viscosity and low dielectric constant, but low adhesive strength and poor adhesive properties (Comparative Examples 2 to 2). 5).
• the pressure-sensitive adhesive comprising the pressure-sensitive adhesive composition of the present invention can be suitably used as a pressure-sensitive adhesive sheet, particularly a double-sided pressure-sensitive adhesive sheet, particularly a double-sided pressure-sensitive adhesive sheet having no base material (base material-less).
• a pressure-sensitive adhesive sheet particularly a double-sided pressure-sensitive adhesive sheet, particularly a double-sided pressure-sensitive adhesive sheet having no base material (base material-less).
• glass ITO transparent electrode sheet
• PET polyethylene terephthalate
• PC polycarbonate
• optical sheet such as polymethyl methacrylate (PMMA), polarizing plate, retardation plate
• PMMA polymethyl methacrylate
• polarizing plate polarizing plate
• retardation plate Useful for attaching optical members such as optical compensation films and brightness enhancement films.
• it can be suitably used for a touch panel including these optical members.

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