JP6363772B2 - Adhesive composition, adhesive layer, polarizing film with adhesive layer, and image display device - Google Patents

Description

  The present invention relates to a pressure-sensitive adhesive composition and a pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition. Moreover, this invention relates to the image display apparatus containing the polarizing film with an adhesive layer which has the said adhesive layer, and the said polarizing film with an adhesive layer.

  In a liquid crystal panel used for a liquid crystal display device or the like, a polarizing film is usually laminated on both sides of a liquid crystal cell formed from a liquid crystal layer disposed between a pair of transparent substrates via an adhesive layer. Such an adhesive layer is required to have high durability. For example, in an endurance test such as heating and humidification that is usually performed as an environmental promotion test, defects such as peeling or floating due to the adhesive layer may not occur. Desired.

  Various pressure-sensitive adhesive compositions for such optical use have been studied. For example, a pressure-sensitive adhesive composition that does not cause peeling or foaming even when placed under high-humidity heat conditions after applying an optical film is proposed. (For example, refer to Patent Document 1).

JP 2009-242767 A

  A transparent conductive film such as an indium tin oxide (ITO) thin film is formed on one transparent substrate of the liquid crystal cell constituting the liquid crystal panel, and the adhesive layer in contact with the transparent conductive film is a glass substrate. Compared with the pressure-sensitive adhesive layer that comes into contact with a transparent substrate, etc., there was a tendency for peeling and floating to occur, and the durability tends to be low.

  The pressure-sensitive adhesive layer may be used after long-term storage for 6 months or more, and excellent durability is required even after such long-term storage.

  The pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition of Patent Document 1 was not sufficient from the viewpoint of heat durability when bonded to a transparent conductive film.

  Accordingly, the present invention provides a pressure-sensitive adhesive composition for forming a pressure-sensitive adhesive layer that can maintain high durability even when exposed to a heating environment or after standing for a long period of time. Objective. Another object of the present invention is to provide an adhesive layer formed from the pressure-sensitive adhesive composition, a polarizing film with a pressure-sensitive adhesive layer having the pressure-sensitive adhesive layer, and an image display device including the polarizing film with a pressure-sensitive adhesive layer. To do.

  As a result of intensive studies to solve the above problems, the present inventors have found the following pressure-sensitive adhesive composition and have completed the present invention.

  That is, the present invention relates to a pressure-sensitive adhesive composition comprising a (meth) acrylic polymer and an oligomer type epoxy group-containing silane coupling agent having an epoxy equivalent of 250 to 600 g / mol.

  The silane coupling agent preferably has two or more alkoxysilyl groups in the molecule.

  It is preferable that the compounding quantity of the said silane coupling agent is 0.01-3 weight part with respect to 100 weight part of said (meth) acrylic-type polymers.

  The (meth) acrylic polymer contains, as a monomer unit, two or more types of monomers selected from the group consisting of alkyl (meth) acrylates, carboxyl group-containing monomers, hydroxyl group-containing monomers, and amide group-containing monomers. Preferably, an alkyl (meth) acrylate, a carboxyl group-containing monomer, a hydroxyl group-containing monomer, and an amide group-containing monomer are more preferably included as monomer units.

  The pressure-sensitive adhesive composition of the present invention is suitably used as a pressure-sensitive adhesive composition for forming a pressure-sensitive adhesive layer that is used by being bonded to the transparent conductive layer of a transparent conductive substrate having a transparent conductive layer on a transparent substrate. be able to.

  The present invention relates to a pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition.

  The present invention relates to a polarizing film and a polarizing film with a pressure-sensitive adhesive layer comprising the pressure-sensitive adhesive layer. Moreover, it is preferable that the said polarizing film with an adhesive layer is bonded together and used for the said transparent conductive layer of the transparent conductive base material which has a transparent conductive layer on a transparent base material.

Furthermore, the present invention is an image display device comprising a liquid crystal cell comprising the polarizing film with an adhesive layer, and a transparent conductive substrate having a transparent conductive layer on the transparent substrate,
The pressure-sensitive adhesive layer of the pressure-sensitive adhesive layer-attached polarizing film is bonded to the transparent conductive layer of the liquid crystal cell.

  The pressure-sensitive adhesive composition of the present invention can form a pressure-sensitive adhesive layer that can maintain high durability even when exposed to a heating environment or after standing for a long period of time. Moreover, this invention can provide the image display apparatus which has the adhesive layer formed from the said adhesive composition, the polarizing film with an adhesive layer which has the said adhesive layer, and the said polarizing film with an adhesive layer. .

It is sectional drawing which shows typically one Embodiment of the liquid crystal panel which can be used by this invention.

1. Pressure-sensitive adhesive composition The pressure-sensitive adhesive composition of the present invention comprises a (meth) acrylic polymer and an oligomer type epoxy group-containing silane coupling agent having an epoxy equivalent of 250 to 600 g / mol. Hereinafter, the composition of the pressure-sensitive adhesive composition of the present invention will be described.

(1) (Meth) acrylic polymer The pressure-sensitive adhesive composition of the present invention comprises a (meth) acrylic polymer and an oligomer type epoxy group-containing silane coupling agent having an epoxy equivalent of 250 to 600 g / mol, It is preferable to contain a (meth) acrylic polymer as a main component. Here, the main component refers to a component having the highest content ratio among the total solids contained in the pressure-sensitive adhesive composition, and occupies more than 50% by weight of the total solids contained in the pressure-sensitive adhesive composition, for example. It is a component, and further refers to a component occupying more than 70% by weight.

  The (meth) acrylic polymer usually contains an alkyl (meth) acrylate as a main component as a monomer unit. Note that (meth) acrylate refers to acrylate and / or methacrylate, and (meth) of the present invention has the same meaning.

  Examples of the alkyl (meth) acrylate constituting the main skeleton of the (meth) acrylic polymer include linear or branched alkyl groups 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. The average carbon number of these alkyl groups is preferably 3-9.

  Examples of the monomer constituting the (meth) acrylic polymer include a carboxyl group-containing monomer, a hydroxyl group-containing monomer, an amide group-containing monomer, and an aromatic ring-containing (meth) acrylate, in addition to the alkyl (meth) acrylate. it can.

  The carboxyl group-containing monomer is a compound containing a carboxyl group in its structure and a polymerizable unsaturated double bond such as a (meth) acryloyl group or a vinyl group. Specific 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 the like. Among the carboxyl group-containing monomers, acrylic acid is preferable from the viewpoints of copolymerizability, cost, and adhesive properties.

  The hydroxyl group-containing monomer is a compound containing a hydroxyl group in its structure and a polymerizable unsaturated double bond such as a (meth) acryloyl group or a vinyl group. Specific examples of the hydroxyl group-containing monomer include, for example, 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 8- Examples include hydroxyalkyl (meth) acrylate and (4-hydroxymethylcyclohexyl) -methyl acrylate, such as hydroxyoctyl (meth) acrylate, 10-hydroxydecyl (meth) acrylate, and 12-hydroxylauryl (meth) acrylate. Among the hydroxyl group-containing monomers, 2-hydroxyethyl (meth) acrylate and 4-hydroxybutyl (meth) acrylate are preferable from the viewpoint of durability, and 4-hydroxybutyl (meth) acrylate is particularly preferable.

  The amide group-containing monomer is a compound containing an amide group in its structure and a polymerizable unsaturated double bond such as a (meth) acryloyl group or a vinyl group. Specific examples of the amide group-containing monomer include (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, N-isopropylacrylamide, N-methyl (meth) acrylamide, N- Butyl (meth) acrylamide, N-hexyl (meth) acrylamide, N-methylol (meth) acrylamide, N-methylol-N-propane (meth) acrylamide, aminomethyl (meth) acrylamide, aminoethyl (meth) acrylamide, mercaptomethyl Acrylamide monomers such as (meth) acrylamide and mercaptoethyl (meth) acrylamide; N-actyl such as N- (meth) acryloylmorpholine, N- (meth) acryloylpiperidine and N- (meth) acryloylpyrrolidine Royle heterocyclic monomers; N- vinylpyrrolidone, N- vinyl-containing lactam monomers such as N- vinyl -ε- caprolactam. The amide group-containing monomer is preferable for satisfying the durability, and among the amide group-containing monomers, the N-vinyl group-containing lactam monomer is particularly preferable for satisfying the durability for the transparent conductive layer.

  The aromatic ring-containing (meth) acrylate is a compound containing an aromatic ring structure in its structure and a (meth) acryloyl group. Examples of the aromatic ring include a benzene ring, a naphthalene ring, and a biphenyl ring. The aromatic ring-containing (meth) acrylate can satisfy durability (particularly durability against the transparent conductive layer).

  Specific examples of the aromatic ring-containing (meth) acrylate include, for example, benzyl (meth) acrylate, phenyl (meth) acrylate, o-phenylphenol (meth) acrylate, phenoxy (meth) acrylate, phenoxyethyl (meth) acrylate, phenoxy Propyl (meth) acrylate, phenoxydiethylene glycol (meth) acrylate, ethylene oxide modified nonylphenol (meth) acrylate, ethylene oxide modified cresol (meth) acrylate, phenol ethylene oxide modified (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) ) Acrylate, methoxybenzyl (meth) acrylate, chlorobenzyl (meth) acrylate, cresyl (meth) acrylate, polystyryl Having a benzene ring such as (meth) acrylate; hydroxyethylated β-naphthol acrylate, 2-naphthoethyl (meth) acrylate, 2-naphthoxyethyl acrylate, 2- (4-methoxy-1-naphthoxy) ethyl (meth) acrylate And those having a naphthalene ring such as biphenyl (meth) acrylate.

  The carboxyl group-containing monomer, hydroxyl group-containing monomer, amide group-containing monomer, and aromatic ring-containing (meth) acrylate serve as a reaction point with the crosslinking agent when the pressure-sensitive adhesive composition contains a crosslinking agent. In particular, the carboxyl group-containing monomer and the hydroxyl group-containing monomer are preferably used for improving the cohesiveness and heat resistance of the resulting pressure-sensitive adhesive layer because they are highly reactive with the intermolecular crosslinking agent. These monomers may be used in combination of two or more, and it is particularly preferable to use in combination two kinds selected from the group consisting of a carboxyl group-containing monomer, a hydroxyl group-containing monomer, and an amide group-containing monomer. , Carboxyl group-containing monomer, hydroxyl group-containing monomer, and amide group-containing monomer are particularly preferably used in combination. Combining these monomers is preferable because the long-term durability of the pressure-sensitive adhesive can be improved.

  The (meth) acrylic polymer used in the present invention preferably contains each monomer as a monomer unit in the following amount in the weight ratio of all constituent monomers (100% by weight).

  The weight ratio of the alkyl (meth) acrylate can be set as the remainder of the monomer other than the alkyl (meth) acrylate, and specifically, it is preferably 70% by weight or more. Setting the weight ratio of the alkyl (meth) acrylate within the above range is preferable for securing adhesiveness.

  The weight ratio of the carboxyl group-containing monomer is preferably 2% by weight or less, more preferably 0.01 to 2% by weight, further preferably 0.05 to 1.5% by weight, -1% by weight is more preferable, and 0.05-0.5% by weight is particularly preferable. When the weight ratio of the carboxyl group-containing monomer is less than 0.01% by weight, the durability tends not to be satisfied. On the other hand, if it exceeds 2% by weight, the durability tends to be unsatisfactory, which is not preferable.

  The weight ratio of the hydroxyl group-containing monomer is preferably 3% by weight or less, more preferably 0.01 to 3% by weight, further preferably 0.1 to 2% by weight, and 0.2 to 2% by weight. % Is particularly preferred. When the weight ratio of the hydroxyl group-containing monomer is less than 0.01% by weight, the pressure-sensitive adhesive layer is insufficiently crosslinked, and there is a tendency that durability and pressure-sensitive adhesive properties cannot be satisfied. On the other hand, if it exceeds 3% by weight, the durability tends not to be satisfied.

  The weight ratio of the amide group-containing monomer is preferably 8% by weight or less, more preferably 0.1 to 8% by weight, further preferably 0.3 to 5% by weight, and 0.3 to 4% by weight. % Is more preferable, and 0.7 to 2.5% by weight is particularly preferable. When the weight ratio of the amide group-containing monomer is less than 0.1% by weight, the durability particularly with respect to the transparent conductive layer tends not to be satisfied. On the other hand, if it exceeds 8% by weight, the durability tends to decrease, which is not preferable.

  The weight ratio of the aromatic ring-containing (meth) acrylate is preferably 25% by weight or less, more preferably 0 to 22% by weight, and further preferably 0 to 18% by weight. When the weight ratio of the aromatic ring-containing (meth) acrylate exceeds 25% by weight, durability tends to decrease.

  In the (meth) acrylic polymer, in addition to the monomer unit, it is not particularly necessary to contain other monomer units, but for the purpose of improving adhesiveness and heat resistance, (meth) acryloyl groups Alternatively, one or more copolymerization monomers having a polymerizable functional group having an unsaturated double bond such as a vinyl group can be introduced by copolymerization.

  The ratio of the copolymerization monomer in the (meth) acrylic polymer is preferably about 0 to 10% by weight in the weight ratio of all the constituent monomers (100% by weight) of the (meth) acrylic polymer. It is more preferably about 7% by weight, and further preferably about 0 to 5% by weight.

  As the (meth) acrylic polymer of the present invention, those having a weight average molecular weight of 1,000,000 to 2,500,000 are usually used. Considering durability, particularly heat resistance, the weight average molecular weight is preferably 1.2 million to 2 million. When the weight average molecular weight is less than 1,000,000, it is not preferable from the viewpoint of heat resistance. On the other hand, when the weight average molecular weight is larger than 2.5 million, the pressure-sensitive adhesive tends to be hard and peeling is likely to occur. Further, the weight average molecular weight (Mw) / number average molecular weight (Mn) indicating the molecular weight distribution is preferably 1.8 or more and 10 or less, more preferably 1.8 to 7, and more preferably 1.8 to More preferably, it is 5. When the molecular weight distribution (Mw / Mn) exceeds 10, it is not preferable in terms of durability. The weight average molecular weight and molecular weight distribution (Mw / Mn) are determined by GPC (gel permeation chromatography) and calculated from polystyrene.

  For the production of such a (meth) acrylic polymer, known production methods such as solution polymerization, bulk polymerization, emulsion polymerization, and various radical polymerizations can be appropriately selected. Further, the (meth) acrylic polymer obtained may be any of a random copolymer, a block copolymer, a graft copolymer, and the like.

  In solution polymerization, for example, ethyl acetate, toluene or the like is used as a polymerization solvent. As a specific example of solution polymerization, the reaction is performed under 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.

  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.

  Examples of the polymerization initiator include 2,2′-azobisisobutyronitrile, 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'-dimethyleneisobutylamidine), 2,2 Azo initiator such as' -azobis [N- (2-carboxyethyl) -2-methylpropionamidine] hydrate (trade name: VA-057, manufactured by Wako Pure Chemical Industries, Ltd.), potassium persulfate, Persulfates such as ammonium sulfate, di (2-ethylhexyl) peroxydicarbonate, di (4-t-butylcyclohexyl) peroxydicarbonate, di-s c-butyl peroxydicarbonate, t-butyl peroxyneodecanoate, t-hexyl peroxypivalate, t-butyl peroxypivalate, 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) peroxide initiators such as cyclohexane, t-butyl hydroperoxide, hydrogen peroxide, peroxides such as a combination of persulfate and sodium bisulfite, a combination of peroxide and sodium ascorbate, Examples include redox initiators combined with reducing agents. The present invention is not limited to.

  The polymerization initiator may be used alone or in combination of two or more, but the total content is 0.005 with respect to 100 parts by weight of the total amount of monomer components. It is preferably about 1 to 1 part by weight, and more preferably about 0.02 to 0.5 part by weight.

  In order to produce the (meth) acrylic polymer having the weight average molecular weight using, for example, 2,2′-azobisisobutyronitrile as the polymerization initiator, the amount of the polymerization initiator used is: The amount is preferably about 0.06 to 0.2 parts by weight and more preferably about 0.08 to 0.175 parts by weight with respect to 100 parts by weight of the total amount of monomer components.

  Moreover, conventionally well-known things can be used suitably as a continuous agent transfer agent, an emulsifier, etc. These addition amounts can also be appropriately determined within a range not impairing the effects of the present invention.

(2) Epoxy group-containing silane coupling agent

In the present invention, the pressure-sensitive adhesive composition includes an oligomer type epoxy group-containing silane coupling agent having an epoxy equivalent of 250 to 600 g / mol. By including an oligomer type epoxy group-containing silane coupling agent having an epoxy equivalent of 250 to 600 g / mol in the pressure-sensitive adhesive composition, the durability of the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition can be improved. In particular, high durability can be maintained even when exposed to a heating environment or after being left for a long period of time. Here, the oligomer type refers to a polymer of a monomer dimer or more and less than about 100 mer, and the weight average molecular weight of the oligomer type silane coupling agent is preferably about 300 to 30000.

The epoxy equivalent of the epoxy group-containing silane coupling agent is 250 to 600 g / mol, preferably 250 to 500 g / mol, and more preferably 280 to 400 g / mol. When the epoxy equivalent of the epoxy group-containing silane coupling agent is within the above range, the durability of the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition can be improved, particularly when exposed to a heated environment. In addition, high durability can be maintained even after standing for a long time.

  The epoxy group-containing silane coupling agent preferably has two or more alkoxysilyl groups in the molecule. The amount of the alkoxy group in the epoxy group-containing silane coupling agent is preferably 10 to 60% by weight, more preferably 20 to 50% by weight in the silane coupling agent, and more preferably 20 to 40% by weight. % Is more preferable.

  Although the kind of alkoxy group is not limited, For example, C1-C6 alkoxy groups, such as methoxy, ethoxy, propoxy, butoxy, pentyloxy, hexyloxy, can be mentioned. Among these, methoxy and ethoxy are preferable, and methoxy is more preferable. It is also preferred that both methoxy and ethoxy are contained in one molecule.

  In the present invention, as the epoxy group-containing silane coupling agent, it is preferable to use an oligomer type epoxy group-containing silane coupling agent having two or more alkoxysilyl groups in the molecule. Specific examples include X-41-1059A (epoxy equivalent: 350 g / mol) and X-41-1056 (epoxy equivalent: 280 g / mol) manufactured by Shin-Etsu Chemical Co., Ltd. These coupling agents are preferable because the epoxy equivalent is less likely to volatilize and has a plurality of alkoxysilyl groups, which is effective in improving durability.

  The epoxy group-containing silane coupling agent may be used alone or in combination of two or more, but the total content is 100 parts by weight of the (meth) acrylic polymer. On the other hand, it is preferably 0.01 to 6 parts by weight, more preferably 0.01 to 3 parts by weight, still more preferably 0.02 to 2 parts by weight, still more preferably 0.05 to 1 part by weight, and 0.05 to 0. .5 parts by weight is particularly preferred. By including an epoxy group-containing silane coupling agent in the above range, it is possible to improve the durability of the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition, particularly when exposed to a heating environment, Even after being left for a long time, high durability can be maintained.

  Moreover, silane coupling agents other than the said epoxy group containing silane coupling agent can also be added to the adhesive composition used by this invention. Other coupling agents include 3-aminopropyltrimethoxysilane, N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-triethoxysilyl-N- (1,3-dimethylbutylidene) Amino group-containing silane coupling agents such as propylamine and N-phenyl-γ-aminopropyltrimethoxysilane, (meth) acryl group-containing silanes such as 3-acryloxypropyltrimethoxysilane and 3-methacryloxypropyltriethoxysilane Examples thereof include coupling agents and isocyanate group-containing silane coupling agents such as 3-isocyanatopropyltriethoxysilane.

  Silane coupling agents other than the epoxy group-containing silane coupling agent can be added within a range not impairing the effects of the present invention, and the addition amount is not particularly limited.

(3) Crosslinking agent The pressure-sensitive adhesive composition used in the present invention preferably contains a crosslinking agent. As the crosslinking agent, an organic crosslinking agent or a polyfunctional metal chelate can be used. 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 polyvalent metal atoms include Al, Cr, Zr, Co, Cu, Fe, Ni, V, Zn, In, Ca, Mg, Mn, Y, Ce, Sr, Ba, Mo, La, Sn, Ti, and the like. Can be mentioned. Examples of the atom in the organic compound to be covalently bonded or coordinated include an oxygen atom, and examples of the organic compound include alkyl esters, alcohol compounds, carboxylic acid compounds, ether compounds, and ketone compounds.

  As a crosslinking agent, an isocyanate type crosslinking agent and / or a peroxide type crosslinking agent are preferable, and it is more preferable to use together an isocyanate type crosslinking agent and a peroxide type crosslinking agent.

  As the isocyanate-based crosslinking agent, a compound having at least two isocyanate groups can be used. For example, known aliphatic polyisocyanate, alicyclic polyisocyanate, aromatic polyisocyanate and the like generally used for urethanization reaction are used.

  Examples of the aliphatic polyisocyanate include trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, 1,2-propylene diisocyanate, 1,3-butylene diisocyanate, dodecamethylene diisocyanate, 2,4,4-trimethyl. And hexamethylene diisocyanate.

  Examples of the alicyclic isocyanate include 1,3-cyclopentene diisocyanate, 1,3-cyclohexane diisocyanate, 1,4-cyclohexane diisocyanate, isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate, hydrogenated xylylene diisocyanate, hydrogenated tolylene diisocyanate hydrogen. Examples include added tetramethylxylylene diisocyanate.

  Examples of the aromatic diisocyanate include phenylene diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 2,2′-diphenylmethane diisocyanate, 4,4′-diphenylmethane diisocyanate, 4,4 Examples include '-toluidine diisocyanate, 4,4'-diphenyl ether diisocyanate, 4,4'-diphenyl diisocyanate, 1,5-naphthalene diisocyanate, and xylylene diisocyanate.

  Examples of the isocyanate-based crosslinking agent include the above-mentioned diisocyanate multimers (dimers, trimers, pentamers, etc.), urethane-modified products reacted with polyhydric alcohols such as trimethylolpropane, urea-modified products, and biurets. Examples include modified products, alphanate modified products, isocyanurate modified products, and carbodiimide modified products.

  Examples of commercially available isocyanate-based crosslinking agents include trade names “Millionate MT”, “Millionate MTL”, “Millionate MR-200”, “Millionate MR-400”, and “Coronate L” manufactured by Nippon Polyurethane Industry Co., Ltd. ”,“ Coronate HL ”,“ Coronate HX ”, trade names“ Takenate D-110N ”,“ Takenate D-120N ”,“ Takenate D-140N ”,“ Takenate D-160N ”, manufactured by Mitsui Chemicals, Inc. “Takenate D-165N”, “Takenate D-170HN”, “Takenate D-178N”, “Takenate 500”, “Takenate 600” and the like can be mentioned. These compounds may be used alone or in combination of two or more.

  As the isocyanate-based crosslinking agent, aliphatic polyisocyanate and an aliphatic polyisocyanate-based compound which is a modified product thereof are preferable. Aliphatic polyisocyanate compounds are more flexible in cross-linking structures than other isocyanate cross-linking agents, tend to relieve stress associated with the expansion / contraction of optical films, and do not easily peel off in durability tests. As the aliphatic polyisocyanate compound, hexamethylene diisocyanate and modified products thereof are particularly preferable.

  Any peroxide can be used as long as it generates radical active species by heating or light irradiation to promote crosslinking of the base polymer ((meth) acrylic polymer) of the pressure-sensitive adhesive composition. In view of the property and stability, it is preferable to use a peroxide having a half-life temperature of 80 ° C. to 160 ° C., more preferably a peroxide having a temperature of 90 ° C. to 140 ° C.

  Examples of the peroxide that can be used 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 0.5 ° 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 ( 1 minute half-life temperature: 116.4 ° C), di-n-octanoyl peroxide (1 minute half-life temperature: 117.4 ° C), 1,1,3,3-tetramethylbutylper Xyl-2-ethylhexanoate (1 minute half-life temperature: 124.3 ° C), di (4-methylbenzoyl) peroxide (1 minute half-life temperature: 128.2 ° C), dibenzoyl peroxide (half-minute for 1 minute) Period temperature: 130.0 ° C.), t-butyl peroxyisobutyrate (1 minute half-life temperature: 136.1 ° C.), 1,1-di (t-hexylperoxy) cyclohexane (1 minute half-life temperature: 149.2 ° C.) and the like. Especially, since the crosslinking reaction efficiency is excellent, di (4-t-butylcyclohexyl) peroxydicarbonate (1 minute half-life temperature: 92.1 ° C.), dilauroyl peroxide (1 minute half-life temperature: 116. 4 ° C.), dibenzoyl peroxide (1 minute half-life temperature: 130.0 ° C.) and the like are preferably used.

  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. 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 3 parts by weight, more preferably 0.02 to 2 parts by weight, and further 0.03 to 1 part by weight with respect to 100 parts by weight of the (meth) acrylic polymer. preferable. If the cross-linking agent is less than 0.01 parts by weight, the pressure-sensitive adhesive layer may be insufficiently cross-linked and the durability and adhesive properties may not be satisfied. On the other hand, if it exceeds 3 parts by weight, the pressure-sensitive adhesive layer becomes too hard. The durability tends to decrease.

  The isocyanate-based crosslinking agent may be used alone or in combination of two or more, but the total content is 100 parts by weight of the (meth) acrylic polymer. On the other hand, it is preferably 0.01 to 2 parts by weight, more preferably 0.02 to 2 parts by weight, and even more preferably 0.05 to 1.5 parts by weight. It can be appropriately contained in consideration of cohesive force, prevention of peeling in a durability test, and the like.

  The peroxide may be used alone or as a mixture of two or more, but the total content is based on 100 parts by weight of the (meth) acrylic polymer. The content is preferably 0.01 to 2 parts by weight, more preferably 0.04 to 1.5 parts by weight, and still more preferably 0.05 to 1 part by weight. In order to adjust processability, cross-linking stability, etc., it is appropriately selected within this range.

(4) Ionic Compound The pressure-sensitive adhesive composition of the present invention can further contain an ionic compound. As the ionic compound, an alkali metal salt and / or an organic cation-anion salt can be preferably used. As the alkali metal salt, an organic salt or inorganic salt of an alkali metal can be used. The “organic cation-anion salt” in the present invention refers to an organic salt whose cation part is composed of an organic substance, and the anion part may be an organic substance or an inorganic substance. There may be. “Organic cation-anion salt” is also called an ionic liquid or ionic solid. The ionic compound is not particularly limited, and those used in this field can be suitably used. Examples thereof include those described in JP-A No. 2015-4861, among which (perfluoroalkylsulfonyl) imide lithium salt is preferable, and bis (trifluoromethanesulfonylimide) lithium is more preferable. Further, the ratio of the ionic compound is not particularly limited, and can be within a range not impairing the effects of the present invention. For example, the ratio of the ionic compound is 10 with respect to 100 parts by weight of the (meth) acrylic polymer. Parts by weight or less, preferably 5 parts by weight or less, more preferably 3 parts by weight or less, and particularly preferably 1 part by weight or less.

(5) Others In the pressure-sensitive adhesive composition used in the present invention, a polyether compound having a reactive silyl group can be blended. Polyether compounds are preferred because they can improve reworkability. As the polyether compound, for example, those disclosed in JP 2010-275522 A can be used. Moreover, the addition amount can be appropriately determined within a range not impairing the effects of the present invention.

  Furthermore, the pressure-sensitive adhesive composition of the present invention may contain other known additives, for example, a polyalkylene glycol polyether compound such as polypropylene glycol, a colorant, a powder such as a pigment, a dye, Surfactant, plasticizer, tackifier, surface lubricant, leveling agent, softener, antioxidant, anti-aging agent, light stabilizer, UV absorber, polymerization inhibitor, inorganic or organic filler, metal It can be added as appropriate according to the intended use of powder, particles, foils and the like. Moreover, you may employ | adopt the redox system which added a reducing agent within the controllable range. These additives are preferably used in an amount of 5 parts by weight or less, further 3 parts by weight or less, and further 1 part by weight or less based on 100 parts by weight of the (meth) acrylic polymer.

  The pressure-sensitive adhesive composition of the present invention is suitably used as a pressure-sensitive adhesive composition for forming a pressure-sensitive adhesive layer that is used by being bonded to the transparent conductive layer of a transparent conductive substrate having a transparent conductive layer on a transparent substrate. be able to.

2. Pressure-sensitive adhesive layer The pressure-sensitive adhesive layer of the present invention is formed from the pressure-sensitive adhesive composition.

  As described above, the pressure-sensitive adhesive layer of the present invention can maintain high durability even when exposed to a heating environment or after being left for a long period of time. Even if the transparent conductive substrate having a layer is used by being bonded to the transparent conductive layer, high durability can be exhibited, which is preferable.

  In forming the pressure-sensitive adhesive layer, it is preferable to fully consider the influence of the crosslinking treatment temperature and the crosslinking treatment time as well as adjusting the addition amount of the entire crosslinking agent.

  The crosslinking treatment temperature and the crosslinking treatment time can be adjusted depending on the crosslinking agent used. The crosslinking treatment temperature is preferably 170 ° C. or lower. Moreover, this crosslinking process may be performed at the temperature at the time of the drying process of an adhesive layer, and you may carry out by providing a crosslinking process process separately after a drying process. The crosslinking treatment time can be set in consideration of productivity and workability, but is usually about 0.2 to 20 minutes, preferably about 0.5 to 10 minutes.

  The method for forming the pressure-sensitive adhesive layer is not particularly limited, but the pressure-sensitive adhesive composition is applied on various substrates, dried with a dryer such as a heat oven to volatilize the solvent, etc. A method of transferring the pressure-sensitive adhesive layer onto a polarizing film or a transparent conductive substrate, which will be described later, by forming a pressure-sensitive adhesive layer by crosslinking treatment, may be used. The pressure-sensitive adhesive composition may be directly applied to form a pressure-sensitive adhesive layer. In this invention, the method of producing the polarizing film with an adhesive layer which formed the adhesive layer on the polarizing film previously, and sticking the said polarizing film with an adhesive layer on a transparent conductive base material is preferable.

  The substrate is not particularly limited, and examples thereof include various substrates such as a release film, a transparent resin film substrate, and a polarizing film described later.

  Various methods are used as a method of applying the pressure-sensitive adhesive composition to the substrate or polarizing film. Specifically, for example, fountain coater, 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, Daiko A method such as an extrusion coating method using a tar or the like.

  The drying conditions (temperature, time) are not particularly limited, and can be appropriately set depending on the composition, concentration, etc. of the pressure-sensitive adhesive composition. For example, about 80 to 170 ° C., preferably 90 to 200 ° C. 1 to 60 minutes, preferably 2 to 30 minutes.

  Moreover, after drying, a crosslinking treatment can be performed as necessary, and the conditions are as described above.

  The thickness (after drying) of the pressure-sensitive adhesive layer is, for example, preferably 5 to 100 μm, more preferably 7 to 70 μm, and further preferably 10 to 50 μm. When the thickness of the pressure-sensitive adhesive layer is less than 5 μm, the adhesion to the adherend tends to be poor, and the durability under humidified conditions tends to be insufficient. On the other hand, when the thickness of the pressure-sensitive adhesive layer exceeds 100 μm, the pressure-sensitive adhesive composition is not sufficiently dried during the application and drying of the pressure-sensitive adhesive layer, and bubbles remain or the surface of the pressure-sensitive adhesive layer. There is a tendency that unevenness in thickness occurs and problems in appearance tend to become apparent.

  Examples of the constituent material of the release film include resin films such as polyethylene, polypropylene, polyethylene terephthalate, and polyester films, porous materials such as paper, cloth, and nonwoven fabric, nets, foam sheets, metal foils, and laminates thereof. Suitable thin leaf bodies and the like can be mentioned, but a resin film is suitably used from the viewpoint of excellent surface smoothness.

  Examples of the resin 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, ethylene- A vinyl acetate copolymer film etc. are mentioned.

  The thickness of the release film is usually 5 to 200 μm, preferably about 5 to 100 μm. For the release film, if necessary, release agent and antifouling treatment with a silicone-based, fluorine-based, long-chain alkyl-based or fatty acid amide-based release agent, silica powder, etc., coating type, kneading type, An antistatic treatment such as a vapor deposition type can also be performed. 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 release film.

  The transparent resin film substrate is not particularly limited, and various resin films having transparency are used. The resin film is formed of a single layer film. For example, the materials include polyester resins such as polyethylene terephthalate and polyethylene naphthalate, acetate resins, polyethersulfone resins, polycarbonate resins, polyamide resins, polyimide resins, polyolefin resins, (meth) acrylic resins. , Polyvinyl chloride resin, polyvinylidene chloride resin, polystyrene resin, polyvinyl alcohol resin, polyarylate resin, polyphenylene sulfide resin, and the like. Of these, polyester resins, polyimide resins and polyethersulfone resins are particularly preferable.

  The thickness of the film substrate is preferably 15 to 200 μm.

3. The polarizing film with an adhesive layer The polarizing film with an adhesive layer of this invention has the said adhesive layer in the at least one surface of a polarizing film, It is characterized by the above-mentioned.

  The method for forming the pressure-sensitive adhesive layer is as described above.

  Although it does not specifically limit as a polarizing film, The thing which has a transparent protective film on the single side | surface of a polarizer or both surfaces is generally used.

  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, and an iodine polarizer containing iodine and / or iodine ions is more preferable. The thickness of these polarizers is not particularly limited, but is generally about 5 to 80 μm.

  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 solution of iodine 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.

  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 film can be reduced.

  As the thin polarizer, typically, Japanese Patent Laid-Open No. 51-069644, Japanese Patent Laid-Open No. 2000-338329, International Publication No. 2010/100917, International Publication No. 2010/100917, or a patent. The thin polarizing film described in the specification of 4751481 and Unexamined-Japanese-Patent No. 2012-0753563 can be mentioned. 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.

  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. , WO 2010/100917 pamphlet, or patent 4751481 specification or JP 2012-073563 A is obtained by a manufacturing method including a step of stretching in a boric acid aqueous solution, particularly patents What is obtained by the manufacturing method including the process of extending | stretching in the air auxiliary before extending | stretching in the boric-acid aqueous solution which is described in the specification of 4751481 or Unexamined-Japanese-Patent No. 2012-073563 is preferable.

  As a material for forming the transparent protective film provided on one side or both sides of the polarizer, for example, a thermoplastic resin excellent in transparency, mechanical strength, thermal stability, moisture barrier property, isotropy, and the like is used. . Specific examples of such thermoplastic resins include cellulose resins such as triacetyl cellulose, polyester resins, polyethersulfone resins, polysulfone resins, polycarbonate resins, polyamide resins, polyimide resins, polyolefin resins, (meth) acrylic resins, cyclic Examples thereof include polyolefin resins (norbornene resins), polyarylate resins, polystyrene resins, polyvinyl alcohol resins, and mixtures thereof. A transparent protective film is bonded to one side of the polarizer by an adhesive layer. On the other side, as a transparent protective film, (meth) acrylic, urethane-based, acrylurethane-based, epoxy-based, silicone A thermosetting resin such as a system or an ultraviolet curable resin can be used. One or more kinds of arbitrary appropriate additives may be contained in the transparent protective film. Examples of the additive include an ultraviolet absorber, an antioxidant, a lubricant, a plasticizer, a mold release agent, a coloring inhibitor, a flame retardant, a nucleating agent, an antistatic agent, a pigment, and a coloring agent. The content of the thermoplastic resin in the transparent protective film is preferably 50 to 100% by weight, more preferably 50 to 99% by weight, still more preferably 60 to 98% by weight, and particularly preferably 70 to 97% by weight. . When content of the said thermoplastic resin in a transparent protective film is 50 weight% or less, there exists a possibility that the high transparency etc. which a thermoplastic resin originally has cannot fully be expressed.

  Although the thickness of a protective film can be determined suitably, generally it is about 1-500 micrometers from points, such as workability | operativity, such as intensity | strength and handleability, and thin film property.

  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.

  In the present invention, a retardation film or the like can be formed on the polarizer instead of the transparent protective film of the polarizing film. Further, another transparent protective film or a retardation film can be provided on the transparent protective film.

  The surface of the transparent protective film to which the polarizer is not adhered may be subjected to a treatment for the purpose of hard coat layer, antireflection treatment, sticking prevention, diffusion or antiglare.

  Moreover, you may have an anchor layer between a polarizing film and an adhesive layer. The material for forming the anchor layer is not particularly limited, and examples thereof include various polymers, metal oxide sols, and silica sols. Among these, polymers are particularly preferably used. The polymer may be used in any of a solvent-soluble type, a water-dispersed type, and a water-soluble type.

  Examples of the polymers include polyurethane resins, polyester resins, acrylic resins, polyether resins, cellulose resins, polyvinyl alcohol resins, polyvinyl pyrrolidone, polystyrene resins, and the like.

  Moreover, when the adhesive layer of the said polarizing film with an adhesive layer is exposed, you may protect an adhesive layer with a release film (separator) until it uses for practical use. The above-mentioned thing can be mentioned as a release film. When a release film is used as a base material in the production of the above-mentioned pressure-sensitive adhesive layer, the release film is polarized with a pressure-sensitive adhesive layer by laminating the pressure-sensitive adhesive layer on the release film and the polarizing film. It can be used as a release film for the pressure-sensitive adhesive layer of the film, and the process can be simplified.

  The polarizing film with the pressure-sensitive adhesive layer of the present invention is used by bonding so that the pressure-sensitive adhesive layer of the polarizing film is in contact with the transparent conductive layer of the transparent conductive substrate having a transparent conductive layer on the transparent substrate. Can do. The transparent conductive substrate will be described later.

4). Image display device The image display device of the present invention is an image display device comprising a liquid crystal cell comprising the polarizing film with an adhesive layer, and a transparent conductive substrate having a transparent conductive layer on the transparent substrate,
The pressure-sensitive adhesive layer of the polarizing film with the pressure-sensitive adhesive layer is bonded to the transparent conductive layer of the liquid crystal cell.

  The polarizing film with the pressure-sensitive adhesive layer is as described above.

  The constituent material of the transparent conductive layer of the transparent conductive substrate is not particularly limited and is composed of indium, tin, zinc, gallium, antimony, titanium, silicon, zirconium, magnesium, aluminum, gold, silver, copper, palladium, tungsten. A metal oxide of at least one metal selected from the group is used. The metal oxide may further contain a metal atom shown in the above group, if necessary. For example, indium oxide (ITO) containing tin oxide, tin oxide containing antimony, or the like is preferably used, and ITO is particularly preferably used. As ITO, it is preferable to contain 80 to 99 weight% of indium oxide and 1 to 20 weight% of tin oxide.

  Examples of the ITO include crystalline ITO and non-crystalline (amorphous) ITO, both of which can be suitably used.

  The thickness of the transparent conductive layer is not particularly limited, but is preferably 10 nm or more, more preferably 15 to 40 nm, and even more preferably 20 to 30 nm.

  It does not specifically limit as a formation method of the said transparent conductive layer, A conventionally well-known method is employable. Specifically, for example, a vacuum deposition method, a sputtering method, and an ion plating method can be exemplified. In addition, an appropriate method can be adopted depending on the required film thickness.

  The transparent substrate is not particularly limited as long as it is a transparent substrate, and examples thereof include glass and a transparent resin film substrate. Examples of the transparent resin film substrate include those described above.

  Moreover, an undercoat layer, an oligomer prevention layer, etc. can be provided between a transparent conductive layer and a transparent substrate as needed.

  The liquid crystal cell used in the image display device of the present invention is provided with the transparent conductive substrate, and the transparent conductive substrate is usually provided on the surface on the viewing side of the liquid crystal cell. A liquid crystal panel including a liquid crystal cell that can be used in the present invention will be described with reference to FIG. However, the present invention is not limited to FIG.

  As one embodiment of the liquid crystal panel 1 that can be included in the image display device of the present invention, from the viewing side, the viewing side transparent protective film 2 / polarizer 3 / liquid crystal cell side transparent protective film 4 / adhesive layer 5 / transparent conductive material. The structure which consists of layer 6 / transparent base material 7 / liquid crystal layer 8 / transparent base material 9 / adhesive layer 10 / liquid crystal cell side transparent protective film 11 / polarizer 12 / light source side transparent protective film 13 can be mentioned. In FIG. 1, the polarizing film with an adhesive layer of this invention corresponds to the visual recognition side transparent protective film 2 / polarizer 2 / liquid crystal cell side transparent protective film 3 / adhesive layer 5. Moreover, in FIG. 1, the transparent conductive base material used by this invention is comprised by the transparent conductive layer 6 / transparent base material 7. FIG. Moreover, in FIG. 1, the liquid crystal cell provided with the transparent conductive base material used by this invention is comprised by transparent conductive layer 6 / transparent base material 7 / liquid crystal layer 8 / transparent base material 9. In FIG.

  Further, in addition to the above configuration, the liquid crystal panel 1 can be appropriately provided with an optical film such as a retardation film, a viewing angle compensation film, and a brightness enhancement film.

  The liquid crystal layer 8 is not particularly limited, and for example, an arbitrary type such as an arbitrary type such as a TN type, an STN type, a π type, a VA type, and an IPS type can be used. The transparent substrate 9 (light source side) may be a transparent substrate, and the material thereof is not particularly limited, and examples thereof include glass and a transparent resin film substrate. Examples of the transparent resin film substrate include those described above.

  Further, as the pressure-sensitive adhesive layer 10 on the light source side, the liquid crystal cell-side transparent protective film 11, the polarizer 12, and the light source-side transparent protective film 13, those conventionally used in this field can be used. Those described in the book can also be suitably used.

  The liquid crystal panel 1 includes the polarizing film with the adhesive layer of the present invention on the transparent conductive layer 6 formed on the outermost layer on the viewing side of the liquid crystal cell, and the transparent conductive layer 6 of the liquid crystal cell and the polarizing film with the adhesive layer. The adhesive layer 5 is laminated so as to be in contact with it.

  The image display apparatus of this invention should just contain the liquid crystal cell provided with the polarizing film with an adhesive layer of this invention, and the transparent conductive base material which has a transparent conductive layer on a transparent base material. It is preferable to include. Hereinafter, a liquid crystal display device will be described as an example, but the present invention is not limited thereto.

  Specific examples of the image display device to which the liquid crystal panel can be applied include a liquid crystal display device, an electroluminescence (EL) display, a plasma display (PD), a field emission display (FED), and the like.

  The image display apparatus of this invention should just contain the liquid crystal cell provided with the polarizing film with an adhesive layer of this invention, and the transparent conductive base material which has a transparent conductive layer on a transparent base material, Other structures are This is the same as the conventional image display device.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. Note that the room temperature standing conditions not particularly specified are all 23 ° C. and 65% R.S. H. It is.

<Measurement of weight average molecular weight of (meth) acrylic polymer>
The weight average molecular weight (Mw) of the (meth) acrylic polymer was measured by GPC (gel permeation chromatography). It measured similarly about Mw / Mn.
・ Analyzer: HLC-8120GPC, manufactured by Tosoh Corporation ・ Column: G7000HXL + GMHXL + GMHXL, manufactured by Tosoh Corporation ・ Column size: 7.8 mmφ × 30 cm each 90 cm in total
-Column temperature: 40 ° C
・ Flow rate: 0.8mL / min
・ Injection volume: 100 μL
・ Eluent: Tetrahydrofuran ・ Detector: Differential refractometer (RI)
Standard sample: polystyrene

Production Example 1 (Preparation of polarizing film)
A 80 μm-thick polyvinyl alcohol film was stretched up to 3 times while being dyed in an iodine solution of 0.3 wt% concentration at 30 ° C. between rolls having different speed ratios. Thereafter, the total draw ratio was stretched up to 6 times while being immersed in an aqueous solution containing boric acid at 4% by weight at 60 ° C. and 10% by weight potassium iodide for 0.5 minutes. Next, after washing by immersing in an aqueous solution containing potassium iodide at 30 ° C. and 1.5 wt% concentration for 10 seconds, drying was performed at 50 ° C. for 4 minutes to obtain a polarizer having a thickness of 30 μm. A saponified 80 μm thick triacetyl cellulose film was bonded to both sides of the polarizer with a polyvinyl alcohol adhesive to produce a polarizing film.

Production Example 2 (Preparation of solution of acrylic polymer (a-1))
A monomer mixture containing 99 parts by weight of butyl acrylate and 1 part by weight of 4-hydroxybutyl acrylate was charged into a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas inlet tube, and a condenser. Furthermore, with respect to 100 parts by weight of the monomer mixture (solid content), 0.1 part by weight of 2,2′-azobisisobutyronitrile as a polymerization initiator was charged together with 100 parts by weight of ethyl acetate, while gently stirring. After introducing nitrogen gas and substituting with nitrogen, the temperature of the liquid in the flask was kept at around 55 ° C. for 8 hours to conduct a polymerization reaction, and an acrylic polymer having a weight average molecular weight (Mw) of 1560,000 and Mw / Mn3.2 ( A solution of a-1) was prepared.

Production Examples 3-5
In Production Example 2, as shown in Table 1, the acrylic polymer (a-2) was prepared in the same manner as in Production Example 2 except that the type of monomer used for the preparation of the acrylic polymer and the use ratio thereof were changed. A solution of (a-4) was prepared.

表１中の略記は、それぞれ以下の通りである。
ＢＡ：ブチルアクリレート
ＮＶＰ：Ｎ−ビニル−２−ピロリドン
ＡＡ：アクリル酸
ＨＢＡ：４−ヒドロキシブチルアクリレート

Abbreviations in Table 1 are as follows.
BA: butyl acrylate NVP: N-vinyl-2-pyrrolidone AA: acrylic acid HBA: 4-hydroxybutyl acrylate

Example 1
(Adjustment of acrylic adhesive composition)
For 100 parts by weight of the solid content of the acrylic polymer (a-1) solution obtained in Production Example 2, an isocyanate crosslinking agent (trade name: Takenate D160N, trimethylolpropane hexamethylene diisocyanate, manufactured by Mitsui Chemicals, Inc.) ) 0.1 part, 0.3 part of benzoyl peroxide (Niper BMT 40SV, manufactured by NOF Corporation), and an oligomer type epoxy group-containing silane coupling agent (trade name: X-41-1059A, amount of alkoxy group) : 43 wt%, epoxy equivalent: 350 g / mol, manufactured by Shin-Etsu Chemical Co., Ltd.) 0.3 part was prepared to prepare an acrylic pressure-sensitive adhesive composition solution.

(Preparation of polarizing film with adhesive layer)
A solution of an acrylic adhesive composition is coated on one side of a polyethylene terephthalate film (separator film, trade name: MRF38, manufactured by Mitsubishi Chemical Polyester Film Co., Ltd.) treated with a silicone release agent. The film was applied to a thickness of 23 μm and dried at 155 ° C. for 1 minute to form an adhesive layer on the surface of the separator film. Next, the pressure-sensitive adhesive layer formed on the separator film was transferred to the polarizing film produced in Production Example 1 to produce a pressure-sensitive adhesive layer-attached polarizing film.

Examples 2-10, Comparative Examples 1-8
In Example 1, as shown in Table 2, the acrylic pressure-sensitive adhesive composition was changed in the same manner as in Example 1 except that the type of acrylic polymer, the type of silane coupling agent, and the amount added were changed. A solution was prepared. In Example 10, ionic compounds were blended in the proportions shown in Table 2. Using the obtained acrylic pressure-sensitive adhesive composition solution, a polarizing film with a pressure-sensitive adhesive layer was produced in the same manner as in Example 1.

  The following evaluation was performed about the polarizing film with an adhesive layer obtained by the said Example and comparative example. The evaluation results are shown in Table 2.

<Durability test immediately after coating>
Samples obtained by cutting the polarizing film with pressure-sensitive adhesive layer obtained in Examples and Comparative Examples into 15-inch sizes were used as samples. The sample was attached to an ITO layer of a glass with an ITO layer having an amorphous ITO layer on a non-alkali glass (trade name: EG-XG, manufactured by Corning) having a thickness of 0.7 mm using a laminator. Subsequently, the sample was autoclaved at 50 ° C. and 0.5 MPa for 15 minutes to completely adhere the sample to the glass with an ITO layer. After the sample subjected to such treatment was treated for 500 hours in each atmosphere at 80 ° C. and 85 ° C. (heating test), the appearance between the polarizing film and the glass with the ITO layer was visually evaluated according to the following criteria. did. The ITO layer was formed by sputtering. The composition of ITO was 3 wt% Sn ratio, and a heating step of 140 ° C. × 60 minutes was performed before the samples were bonded. The Sn ratio of ITO was calculated from the weight of Sn atoms / (weight of Sn atoms + weight of In atoms).
(Evaluation criteria)
A: No change in appearance such as peeling.
○: Slightly peeled off at the end, but no problem in practical use.
Δ: Although there is peeling at the end, there is no practical problem unless it is a special use.
X: Remarkably peeled off at the end, causing practical problems.

<Durability test after long-term storage (12 months)>
The polarizing film with a pressure-sensitive adhesive layer obtained in Examples and Comparative Examples was obtained at 23 ° C./55% R.D. H. It was stored for 12 months under the above conditions. A durability test after long-term storage was conducted in the same manner as in the above <Durability test immediately after coating> except that the polarizing film with the pressure-sensitive adhesive layer stored for 12 months was used. Moreover, it evaluated on the same evaluation criteria as the above <Durability test immediately after coating>.

表２中の略記は、それぞれ以下の通りである。
（ａ−１）：製造例２で得られたアクリル系ポリマー（ａ−１）
（ａ−２）：製造例３で得られたアクリル系ポリマー（ａ−２）
（ａ−３）：製造例４で得られたアクリル系ポリマー（ａ−３）
（ａ−４）：製造例５で得られたアクリル系ポリマー（ａ−４）
イソシアネート系：商品名：タケネートＤ１６０Ｎ、トリメチロールプロパンヘキサメチレンジイソシアネート、三井化学（株）製
過酸化物系：商品名：ナイパーＢＭＴ ４０ＳＶ、ベンゾイルパーオキサイド、日本油脂（株）製
Ｘ−４１−１０５６：オリゴマー型のエポキシ基含有シランカップリング剤、アルコキシ基量：１７重量％、エポキシ当量：２８０ｇ／ｍｏｌ、信越化学工業（株）製
Ｘ−４１−１０５９Ａ：オリゴマー型のエポキシ基含有シランカップリング剤、アルコキシ基量：４３重量％、エポキシ当量：３５０ｇ／ｍｏｌ、信越化学工業（株）製
Ｘ−４１−１０５３：オリゴマー型のエポキシ基含有シランカップリング剤、アルコキシ基量：５０重量％、エポキシ当量：８３０ｇ／ｍｏｌ、信越化学工業（株）製
ＫＢＭ４０３：γ−グリシドキシプロピルメトキシシラン、エポキシ当量：２３６ｇ／ｍｏｌ、信越化学工業（株）製
Ｘ−４１−１８１０：オリゴマー型のメルカプト基含有シランカップリング剤、信越化学工業（株）製
イオン性化合物：ビス（トリフルオロメタンスルホニルイミド）リチウム、三菱マテリアル（株）製

Abbreviations in Table 2 are as follows.
(A-1): Acrylic polymer (a-1) obtained in Production Example 2
(A-2): Acrylic polymer (a-2) obtained in Production Example 3
(A-3): Acrylic polymer (a-3) obtained in Production Example 4
(A-4): Acrylic polymer (a-4) obtained in Production Example 5
Isocyanate type: Trade name: Takenate D160N, trimethylolpropane hexamethylene diisocyanate, manufactured by Mitsui Chemicals, Ltd. Oligomer type epoxy group-containing silane coupling agent, alkoxy group amount: 17% by weight, epoxy equivalent: 280 g / mol, Shin-Etsu Chemical Co., Ltd. X-41-1059A: oligomer type epoxy group-containing silane coupling agent, Alkoxy group amount: 43 wt%, epoxy equivalent: 350 g / mol, Shin-Etsu Chemical Co., Ltd. X-41-1053: oligomer type epoxy group-containing silane coupling agent, alkoxy group amount: 50 wt%, epoxy equivalent: 830g / mol, Shin-Etsu Chemical KBM4 3: γ-glycidoxypropylmethoxysilane, epoxy equivalent: 236 g / mol, X-41-1810 manufactured by Shin-Etsu Chemical Co., Ltd .: oligomeric mercapto group-containing silane coupling agent, ion manufactured by Shin-Etsu Chemical Co., Ltd. Compound: bis (trifluoromethanesulfonylimide) lithium, manufactured by Mitsubishi Materials Corporation

DESCRIPTION OF SYMBOLS 1 Liquid crystal panel 2 Viewing side transparent protective film 3 Polarizer 4 Liquid crystal cell side transparent protective film 5 Adhesive layer 6 Transparent conductive layer 7 Transparent base material 8 Liquid crystal layer 9 Transparent base material 10 Adhesive layer 11 Liquid crystal cell side transparent protective film 12 Polarizer 13 Light source side transparent protective film

Claims (9)

A (meth) acrylic polymer and an oligomer type epoxy group-containing silane coupling agent having an epoxy equivalent of 250 to 600 g / mol,
(Meth) acrylic polymer, alkyl (meth) acrylate, see-containing carboxyl group-containing monomers, hydroxyl group-containing monomer, and an amide group-containing monomer as a monomer unit, and the amide group-containing monomers, N- vinyl group-containing lactam A pressure-sensitive adhesive composition comprising a system monomer .   The pressure-sensitive adhesive composition according to claim 1, wherein the silane coupling agent has two or more alkoxysilyl groups in the molecule.   The pressure-sensitive adhesive composition according to claim 1 or 2, wherein the amount of the silane coupling agent is 0.01 to 3 parts by weight with respect to 100 parts by weight of the (meth) acrylic polymer. . The pressure-sensitive adhesive composition according to claim 1, wherein the pressure-sensitive adhesive composition is used for forming a pressure-sensitive adhesive layer to be bonded to the transparent conductive layer of a transparent conductive substrate having a transparent conductive layer on a transparent substrate. . It forms from the adhesive composition in any one of Claims 1-4 , The adhesive layer characterized by the above-mentioned. The pressure-sensitive adhesive layer according to claim 5, wherein the pressure-sensitive adhesive layer is used by being bonded to the transparent conductive layer of a transparent conductive substrate having a transparent conductive layer on a transparent substrate. It has a polarizing film and the adhesive layer of Claim 5 or 6 , The polarizing film with an adhesive layer characterized by the above-mentioned. The polarizing film with a pressure-sensitive adhesive layer according to claim 7 , wherein the transparent conductive substrate having a transparent conductive layer on a transparent substrate is used by being bonded to the transparent conductive layer. An image display device comprising a polarizing film with a pressure-sensitive adhesive layer according to claim 7 or 8 , and a liquid crystal cell comprising a transparent conductive substrate having a transparent conductive layer on the transparent substrate,
An image display device, wherein the pressure-sensitive adhesive layer of the polarizing film with the pressure-sensitive adhesive layer is bonded to the transparent conductive layer of the liquid crystal cell.

Images