KR101162773B1 - Pressure-sensitive adhesive composition, and the preparation method and the use thereof - Google Patents

Abstract

In the present invention, even when the image display device is reused through the attachment and detachment of the optical member, no significant increase in adhesive force or contamination to the adherend is observed, and excellent durability does not occur even when stored at high temperature and high humidity. After the pressure-sensitive adhesive-attached optical member is produced, an adhesive composition and the like which is excellent in productivity that can be subjected to a punching processing quickly can be provided.

The present invention comprises 100 parts by weight of a (meth) acrylic polymer, 0.02 to 2 parts by weight of a peroxide, and 0.01 to 1 part by weight of a silane coupling agent, which contain 50% by weight or more of (meth) acrylate having an alkyl group having 4 or more carbon atoms as a monomer unit. The pressure-sensitive adhesive layer, characterized in that the pressure-sensitive adhesive composition for an optical member, the method for producing the pressure-sensitive adhesive composition, the pressure-sensitive adhesive layer formed by crosslinking the pressure-sensitive adhesive composition, and the pressure-sensitive adhesive layer are formed on one or both surfaces of the optical member. An optical member and an image display apparatus using at least one of the optical members.

Description

Adhesive composition, a manufacturing method, and its use {PRESSURE-SENSITIVE ADHESIVE COMPOSITION, AND THE PREPARATION METHOD AND THE USE THEREOF}

The present invention relates to a pressure-sensitive adhesive composition suitable for attaching and re-peeling an optical member and a method for producing the pressure-sensitive adhesive. The present invention also relates to a pressure-sensitive adhesive-attached optical member having a pressure-sensitive adhesive layer formed of the pressure-sensitive adhesive composition, and an image display apparatus such as a liquid crystal display device, an organic EL display device, a PDP, and the like.

The optical member used for a liquid crystal display device, for example, a polarizing plate, a retardation plate, etc. are affixed on a liquid crystal cell using an adhesive. Since the optical material used for such an optical member has elasticity under heating conditions and humidification conditions, it is easy to generate | occur | produce, peeling, etc. according to it after attachment. Therefore, the adhesive which can respond also to the adhesive for optical members is calculated | required also under the said conditions.

Moreover, when attaching the said optical member to a liquid crystal cell, various processing processes, such as a punching process or a slit process, are performed in the state by which the adhesive was bonded to the optical member. In this case, since the pressure-sensitive adhesive may be cut off or cut off from the cut surface, the aging treatment must be performed, thereby significantly inhibiting productivity. That is, it is very advantageous in terms of productivity that such a processing treatment can be quickly performed without an aging treatment after the pressure-sensitive adhesive optical member is manufactured.

As adhesives for attaching an optical member, acrylic adhesives are generally used because of advantages such as durability and transparency, and crosslinking treatment is usually performed to impart proper cohesion. Various crosslinking agents are selected and used as a crosslinking method of such an acrylic adhesive, and the general description of the functional group and crosslinking method of an acrylic polymer is published (adhesive handbook (2nd edition), adhesive tape industrial edition, October 12, 1995. page 147) Reference).

As a specific crosslinking agent of the adhesive for attaching an optical member, an isocyanate compound, an epoxy compound, an aldehyde compound, an amine compound, a metal salt, a metal alkoxide, an ammonium salt, a hydrazine compound and the like are known (see Japanese Patent Application Laid-Open No. 1996-199131). Lycidyl compounds, isocyanate compounds, aziridine compounds, metal chelates and the like are also known (see Japanese Patent Laid-Open No. 2003-49141).

On the other hand, the document "Adhesive Handbook (Second Edition), Adhesive Tape Industrial Edition, 1995.10.12. Page 121 and page 159 exemplify organic peroxides as crosslinking agents of rubber pressure sensitive adhesives and silicone pressure sensitive adhesives, but are not described as crosslinking agents of acrylic pressure sensitive adhesives.

As a peroxide crosslinking of an acrylic adhesive, the composition for tape sticking which consists of a heating reaction product of an acryl-type copolymer and the organic peroxide of 1 to 6weight% of a range is known (refer Japanese Unexamined-Japanese-Patent No. 1960-4876). In addition, Japanese Patent Application Laid-Open No. 2000-17237 discloses a pressure-sensitive adhesive layer having a gel fraction of less than 40% by weight, containing an acrylic pressure-sensitive adhesive and 0.01 to 10 parts by weight of an organic peroxide that does not undergo a crosslinking reaction at 60 to 100 ° C. The method of softening an adhesive by heating, impregnating a base material, and then further bridge | crosslinking and obtaining a breathable adhesive is disclosed. Japanese Patent Laid-Open Publication No. 2003-13027 discloses crosslinking an olefin portion by crosslinking an acrylic polymer obtained by copolymerizing a monomer having an olefinic polymer in a side chain with an acrylate using an organic peroxide of 110 ° C. or less with a half-life of 10 hours. A method of improving cohesion is disclosed.

However, in the adhesive bonded to an optical member, the example which stabilized a characteristic by bridge | crosslinking by a peroxide, there is little change with time, and productivity is also unknown.

In the case where an isocyanate compound, an epoxy compound, an aldehyde compound, an amine compound, a metal salt, a metal alkoxide, an ammonium salt, a hydrazine compound, an aziridine compound, or the like, which is generally used for crosslinking of an optical pressure sensitive adhesive, is used, Although it is finally exerted to have excellent curved adhesiveness without foaming or peeling under high temperature and high humidity and no polarization omission after attaching to the film, aging is necessary to become a crosslinked state that can exhibit sufficient properties. There are many cases. Since the aging treatment takes a long time to carry out a punching process or the like on the pressure-sensitive adhesive-attached optical member and ships it, the productivity is greatly reduced.

Moreover, when an isocyanate compound is used as a crosslinking agent, it is easy to color by long-term preservation, a heating state, and high temperature processing, and coloring may become remarkable especially when crosslinking by a peroxide exists.

Therefore, in the present invention, even when the optical member is attached to the image display device and then the optical member is peeled off to reuse the image display device, no significant increase in adhesive force or contamination to the adherend is observed, and the present invention is peeled off even if stored in a high temperature and high humidity state. And excellent durability because no lifting occurs, and after the pressure-sensitive adhesive-attached optical member is manufactured, the punching treatment can be performed quickly, so that the productivity is excellent. It aims at providing the adhesive composition and its manufacturing method which are excellent in transparency. Moreover, an object of this invention is to provide the optical member which has the said adhesive layer, and the image display apparatus using the same.

MEANS TO SOLVE THE PROBLEM As a result of earnestly examining in order to achieve the said subject, the present inventors obtained the adhesive composition which mix | blended the peroxide and silane coupling agent specific to a (meth) acrylic-type polymer, and discovered that the said subject can be achieved by using such a composition. The present invention has been completed. In addition, by using a specific amount of the pressure-sensitive adhesive composition for an optical member containing a specific isocyanate crosslinking agent, peroxide, and silane coupling agent in a high molecular weight (meth) acrylic polymer, it can be quickly punched after crosslinking treatment, The present inventors have found that an adhesive composition for an optical member which is excellent in adhesive properties (repeelability), excellent in long-term transparency and weather resistance, and which is difficult to be colored, has been completed.

That is, the adhesive composition for optical members of this invention contains 100 weight part of (meth) acrylic-type polymers (A) which contain 50 weight% or more of (meth) acrylates which have a C4 or more alkyl group as a monomer unit, and 0.02-2 weight of peroxides And 0.01 to 1 part by weight of the silane coupling agent. At this time, it is preferable to further contain 0.01-5 weight part of crosslinking agents. Moreover, it is preferable that the weight average molecular weight of the said (meth) acrylic-type polymer (A) is 1 million or more.

Moreover, the adhesive composition for optical members of this invention has a weight average molecular weight of 1 million or more (meth) containing 50 weight% or more of (meth) acrylate which has a C4 or more alkyl group as a monomer unit, and 0.2-10 weight% of unsaturated carboxylic acids. 0.01 to 5 parts by weight of aliphatic and / or alicyclic isocyanate crosslinking agent, 0.02 to 2 parts by weight of peroxide, and 0.01 to 1 part by weight of silane coupling agent, based on 100 parts by weight of the acrylic polymer (A1). It is done. At this time, it is preferable that the said isocyanate type crosslinking agent is a hexamethylene diisocyanate compound and / or an isophorone diisocyanate compound.

Moreover, the adhesive composition for optical members of this invention has a weight average molecular weight of 500,000 or more (meth) containing 50 weight% or more of (meth) acrylate which has a C4 or more alkyl group as monomer unit, and 0.2 to 2 weight% of unsaturated carboxylic acid. It is made by containing 70 weight% or more of (meth) acrylates and 1-7 weight% of unsaturated carboxylic acids as a monomeric unit with respect to 100 weight part of acrylic polymers (A2), and the carboxylic acid equivalent (meth) acrylic-type polymer (A2) It is characterized by containing 0.02-2 weight part of (meth) acrylic-type polymers (B) of the weight average molecular weights 2000-50000 larger than the carboxylic acid equivalent of 0.02-2 weight part of peroxides, and 0.01-1 weight part of a silane coupling agent. .

At this time, it is preferable to contain 0.01-5 weight part of crosslinking agents with respect to 100 weight part of said (meth) acrylic-type polymers (A2). Moreover, it is preferable that the said crosslinking agent is a polyisocyanate compound.

On the other hand, the manufacturing method of the adhesive for optical members of this invention is a process of apply | coating the adhesive composition for optical members as described in any one of said one to one side or both surfaces on the support body which peeled, drying, and performing a peroxide crosslinking process (here, a peroxide Gel fraction of the pressure-sensitive adhesive after the cross-linking treatment is 35 to 90% by weight).

Moreover, the manufacturing method of the adhesive for optical members of this invention is a process of forming the layer which consists of an adhesive composition for optical members as described in any one of said any on one side or both surfaces on the support body which peeled, and the peroxide in the said adhesive composition for optical members. It characterized by including the process of heat-processing the layer which consists of said adhesive composition for optical members so that the amount of decomposition | disassembly may be 75 weight% or more.

Moreover, the adhesive layer of this invention was obtained by peroxide crosslinking process of the adhesive composition for optical members as described in any one of the above. It is characterized by the above-mentioned. At this time, the gel fraction is preferably 35 to 90% by weight.

On the other hand, the pressure-sensitive adhesive optical member of the present invention is characterized in that any one pressure-sensitive adhesive layer is formed on one or both surfaces thereof. Moreover, the image display apparatus of this invention uses one or more adhesive-attached optical members as described in any one of the above, It is characterized by the above-mentioned.

The adhesive composition for optical members of this invention has a (meth) acrylic-type polymer (A) containing 50 weight% or more of (meth) acrylates which have a C4 or more alkyl group as a monomer unit as a main material. In addition, the (meth) acrylic-type polymer in this invention means an acryl-type polymer and / or a methacryl-type polymer, and is the same also about a structural monomer.

Although the alkyl group of the said (meth) acrylate will not be restrict | limited especially if it is a (meth) acrylic-type monomer which has a C4 or more alkyl group, C4-16 are preferable and it is more preferable that it is 4-10. In addition, although the alkyl group of 4 or more carbon atoms can use either a straight chain or a branched chain, it is preferable that it is a branched chain from a low glass transition point.

Examples of the (meth) acrylic monomer having an alkyl group having 4 to 16 carbon atoms include n-butyl (meth) acrylate, s-butyl (meth) acrylate, t-butyl (meth) acrylate, and isobutyl (meth) acryl. Latex, hexyl (meth) acrylate, isoamyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-pentyl (meth) acrylate, isopentyl (meth) acrylate, n-octyl (meth) Acrylate, isooctyl (meth) acrylate, n-nonyl (meth) acrylate, isononyl (meth) acrylate, n-decyl (meth) acrylate, isodecyl (meth) acrylate, n-dodec Sil (meth) acrylate, isomyristyl (meth) acrylate, n-tridecyl (meth) acrylate, n-tetradecyl (meth) acrylate, etc. are mentioned, Especially n-butyl (meth) acrylate 2-ethylhexyl (meth) acrylate, etc. It is preferably used.

The (meth) acrylic polymer contains 50% by weight or more, preferably 60 to 99% by weight of (meth) acrylate having an alkyl group having 4 or more carbon atoms. However, when the amount is too small, the stress relaxation property is insufficient, which is not preferable.

It is preferable that the said (meth) acrylic-type polymer (A) further contains unsaturated carboxylic acid as a monomeric unit. Unsaturated carboxylic acid is an essential component in the (meth) acrylic polymer (Al) and the (meth) acrylic polymer (A2). As unsaturated carboxylic acid, acrylic acid, methacrylic acid, itaconic acid, maleic acid, etc. are mentioned, Especially acrylic acid and methacrylic acid are used preferably.

The (meth) acrylic polymer (A) preferably contains 0.2 to 10% by weight of unsaturated carboxylic acid, more preferably 1.0 to 7.0% by weight. However, when the amount is too high, the adhesion to an image display device such as a liquid crystal cell becomes large and excessively small. If so, it will adversely affect the durability, which is undesirable.

In the case of the (meth) acrylic polymer (A1), the monomer unit contains 0.2 to 10% by weight of unsaturated carboxylic acid, preferably 0.4 to 7.0% by weight, more preferably 1.0 to 6.0% by weight. When the content of the unsaturated carboxylic acid is less than 0.2% by weight, the durability may be adversely affected. On the other hand, when the content of the unsaturated carboxylic acid exceeds 10% by weight, the adhesive force to the liquid crystal cell may be too large, which is not preferable.

In the case of the (meth) acrylic polymer (A2), the monomer unit contains 0.2 to 2% by weight of unsaturated carboxylic acid, preferably 0.3 to 1.5% by weight. When the content of the unsaturated carboxylic acid is less than 0.2% by weight, the stress relaxation property is lowered, which tends to adversely affect durability. On the other hand, when the content of the unsaturated carboxylic acid exceeds 2% by weight, the adhesion to the liquid crystal cell tends to be too large. It is not desirable.

The (meth) acrylic polymer may contain other monomers as long as the monomer unit contains (meth) acrylate and unsaturated carboxylic acid having an alkyl group having 4 or more carbon atoms in the above ratio. As another monomer, monomers without functional groups, such as methyl (meth) acrylate, ethyl (meth) acrylate, and propyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, and 2-hydroxypropyl (meth) Monomers having hydroxyl groups such as acrylate, acrylamide, dimethylaminomethylacrylamide, acryloyl morpholine, glycidyl acrylate and the like. These monomers can combine 1 type (s) or 2 or more types.

It is preferable that the said other monomer has a functional group which has reactivity with a crosslinking agent. When the (meth) acrylic polymer contains such a monomer, the content thereof is 0.02 to 1% by weight, preferably 0.04 to 0.4% by weight.

1 million or more are preferable, and, as for the weight average molecular weight of the (meth) acrylic-type polymer (A) of such a compounding, More preferably, they are 1.2 million-3 million. If the weight average molecular weight is less than 1 million, durability will be insufficient, and if too large, the workability tends to be lowered.

In the case of a (meth) acrylic-type polymer (A1), a weight average molecular weight is 1 million or more, Preferably it is 1.0 million-3 million, More preferably, it is 1.1 million-2.8 million. In the case where the weight average molecular weight is less than 1 million, durability may be insufficient, and debris may generate | occur | produce because cohesion force of an adhesive composition becomes small. On the other hand, from the viewpoint of workability, the weight average molecular weight is preferably 3 million or less.

In the case of a (meth) acrylic-type polymer (A2), it is preferable that a weight average molecular weight is 500,000 or more, Preferably it is 600,000 or more, More preferably, it is 1 million or more. When the weight average molecular weight is less than 500,000, durability is insufficient, and there exists a tendency for pool residue to arise because the cohesion force of an adhesive composition becomes small. On the other hand, from the viewpoint of workability, the weight average molecular weight is preferably 2 million or less.

The said weight average molecular weight is the value measured by GPC. The weight average molecular weight measured by GPC is a value calculated | required in polystyrene conversion. The measurement conditions of GPC were GPC apparatus: HLC-8120 GPC from Tosoh Corporation, column: G7000H _XL + GMH _XL + GMH _{XL from} Tosoh Corporation, solvent: tetrahydrofuran, temperature 40 ° C, flow rate 0.8 ml / min, detector: differential refractometer to be.

On the other hand, when using a (meth) acrylic-type polymer (B) together with a (meth) acrylic-type polymer (A2), as a (meth) acrylic-type polymer (B), 70 weight% or more of (meth) acrylate and unsaturated carboxylic acid as a monomeric unit (Meth) acrylic polymer (B) having a weight average molecular weight of 2000 to 50000, containing 1 to 7% by weight, and having a carboxylic acid equivalent greater than the carboxylic acid equivalent of the (meth) acrylic polymer (A2).

Although it does not specifically limit as a (meth) acrylate used for a (meth) acrylic-type polymer (B), Although a well-known thing can be used suitably, A (meth) acrylic-type monomer which has a C1-C4 alkyl group especially from a viewpoint of hydrophilicity and a softness | flexibility. Is preferred.

The (meth) acrylic polymer (B) used in the present invention is a monomer unit, which contains 1 to 7% by weight of unsaturated carbon, preferably 2 to 6% by weight. When the content of unsaturated carbon is less than 1% by weight, the stress relaxation property is lowered, and the durability tends to be adversely affected. On the other hand, when the content of unsaturated carbon is more than 7% by weight, the adhesion to the liquid crystal cell becomes excessively large. Tendency is undesirable.

As said unsaturated carboxylic acid, the thing similar to the said (meth) acrylic-type polymer (A) can be used. The (meth) acrylic polymer (B) uses a carboxylic acid equivalent that is larger than the carboxylic acid equivalent of the (meth) acrylic polymer (A2), but the adjustment of the carboxylic acid equivalent can be carried out by adjusting the content of the unsaturated carboxylic acid, for example. . When the carboxylic acid equivalent of the (meth) acrylic polymer (B) is smaller than the carboxylic acid equivalent of the (meth) acrylic polymer (A2), the adhesive force to the liquid crystal cell tends to be too large, which is not preferable.

In addition, the carboxylic acid equivalent in this invention means the quantity of the carboxylic acid group contained in 1 g of samples (polymer), For example, when carboxylic acid originates in acrylic acid, the value computed by dividing the acrylic acid weight in 1 g of samples (polymer) by the acrylic acid molecular weight. (Equivalent (eq) / g).

As other polymerizable monomers other than the said (meth) acrylic-type alkylester and the said unsaturated carboxylic acid, the polymerizable monomer for adjusting the glass transition point and peelability of a (meth) acrylic-type polymer (B), etc. impair the effect of this invention. Can be used in a range that does not.

As another polymerizable monomer used for a (meth) acrylic-type polymer (B), the cohesion force and heat resistance improvement component, such as a sulfonic acid group containing monomer, a phosphoric acid group containing monomer, a cyano group containing monomer, a vinyl ester monomer, an aromatic vinyl monomer, etc., and As a starting point for improving adhesion and crosslinking of acid anhydride group-containing monomers, hydroxyl group-containing monomers, amide group-containing monomers, amino group-containing monomers, imide group-containing monomers, epoxy group-containing monomers, N-acryloyl morpholine and vinyl ether monomers The component etc. which have a functional group which act can be used suitably. These monomer compounds may be used independently, and may mix and use 2 or more types.

Although the (meth) acrylic-type polymer (B) used for this invention uses the (meth) acrylic-type polymer which has a weight average molecular weight in the range of 2000-50000, 5000-40000 are more preferable, It is still more preferable that it is 10000-400000. . If the weight average molecular weight is less than 2000, the durability tends to be lowered. On the other hand, when a weight average molecular weight exceeds 50000, there exists a tendency for the adhesive force to a liquid crystal cell to increase. A weight average molecular weight says what is obtained by measuring by GPC (gel permeation chromatography).

Moreover, it is preferable that the glass transition temperature (Tg) of the said (meth) acrylic-type polymer (B) is 0 degrees C or less (usually -100 degrees C or more), Preferably it is -10 degrees C or less for the reason of being easy to balance adhesive performance. . When the glass transition temperature is higher than 0 ° C., the polymer hardly flows and the wettability to the polarizing plate is insufficient, which tends to cause swelling that occurs between the polarizing plate and the adhesive composition layers of the adhesive sheets. In addition, the glass transition temperature (Tg) of a (meth) acrylic-type polymer (B) can be adjusted in the said range by changing suitably the monomer component and composition ratio to be used.

The manufacture of such a (meth) acrylic-type polymer can select suitably well-known radical polymerization methods, such as solution polymerization, block polymerization, and emulsion polymerization. As a radical polymerization initiator, various well-known thing of azo type and a peroxide type can be used.

As solution polymerization, it is obtained by using 0.01-0.2 weight part of polymerization initiators, such as azobisisobutyronitrile, and making it react for 8 to 30 hours at 50-70 degreeC under nitrogen stream using a polymerization solvent. As said polymerization solvent, organic solvents, such as ethyl acetate and toluene, are used, for example. The solution concentration is usually about 20 to 80% by weight. Moreover, with the recent eco-friendly movement, the method which does not use organic solvents, such as suspension polymerization method and an emulsion polymerization method, is used preferably.

For example, the emulsion polymerization may be appropriately combined with a monomer component including (meth) acrylic acid ester as a main component in combination with a polymerization initiator, an emulsifier, and a chain transfer agent, if necessary, and more specifically, for example, a batch polymerization method. The well-known emulsion polymerization method, such as a continuous drop polymerization method and the division dripping polymerization method, can be employ | adopted. In addition, although reaction conditions etc. are suitably selected, polymerization temperature is about 20-100 degreeC, for example.

There is no restriction | limiting in particular as a polymerization initiator, The well-known radical polymerization initiator normally used for emulsion polymerization is used. For example, 2,2'-azobisisobutyronitrile, 2,2'-azobis (2-methylpropionamidine) disulfate, 2,2'-azobis (2-amidinopropane) dihydro Ride, 2,2'-azobis [2- (5-methyl-2-imidazolin-2-yl) propane] dihydrochloride, 2,2'-azobis (N, N'-dimethyleneiso Azo initiators such as butylamidine), such as persulfate initiators such as potassium persulfate and ammonium persulfate, such as benzoyl peroxide, t-butyl hydroperoxide and hydrogen peroxide, such as persulfate and hydrogen sulfite And redox initiators such as a combination of sodium, a combination of peroxide and sodium ascorbate, and the like.

These polymerization initiators are used alone or in combination as appropriate. In addition, the compounding quantity of a polymerization initiator is about 0.005-1 weight part with respect to 100 weight part of monomer components, for example.

There is no restriction | limiting in particular as an emulsifier, The well-known emulsifier normally used for emulsion polymerization is used, For example, sodium lauryl sulfate, ammonium lauryl sulfate, sodium dodecylbenzene sulfonate, sodium polyoxyethylene lauryl sulfate, sodium polyoxyethylene alkyl ether sulfate Anionic emulsifiers such as sodium polyoxyethylene lauryl sulfate, sodium polyoxyethylene alkyl ether sulfate, polyoxyethylene alkyl phenyl ether ammonium sulfate, sodium polyoxyethylene alkyl phenyl ether sulfate, and polyoxyethylene alkyl sulfosuccinate Nonionic emulsifiers such as polyoxyethylene alkyl ethers, polyoxyethylene alkylphenyl ethers, polyoxyethylene fatty acid esters, polyoxyethylene polyoxypropylene block polymers, and other radically polymerizable emulsifiers incorporating, for example, propenyl groups Etc. can be mentioned.

These emulsifiers are used alone or in combination as appropriate. In addition, the compounding quantity of an emulsifier is 0.2-10 weight part, Preferably it is about 0.5-5 weight part with respect to 100 weight part of monomer components.

The chain transfer agent is a chain transfer agent usually used for emulsion polymerization by adjusting the molecular weight of the copolymer, if necessary, for example, 1-dodecanethiol, mercaptoacetic acid, 2-mercaptoethanol, 2-ethylthioglycolate Mercaptans, such as hexyl and 2, 3- dimercapto- 1-propanol, etc. are mentioned.

These chain transfer agents are suitably used alone or in combination. In addition, the compounding quantity of a chain transfer agent is about 0.001-0.5 weight part with respect to 100 weight part of monomer components, for example.

And by such emulsion polymerization, the adhesive component containing the (meth) acrylic-type water dispersion type polymer, ie, an emulsifier, in which a (meth) acrylic-type polymer is disperse | distributed to water including an emulsifier can be obtained.

Further, the (meth) acrylic water-dispersible polymer containing an emulsifier may be, for example, polymerized by a method other than emulsion polymerization after the monomer component containing (meth) acrylic acid ester as a main component, and then dispersed in water by the emulsifier described above. It may also be obtained.

The obtained (meth) acrylic polymer is in a solution state, in a water dispersion state, or in a solid state capable of flowing by heating.

In the case where a peroxide is used as the polymerization initiator, the remaining peroxide can be used for the crosslinking reaction without being used for the polymerization reaction, but in this case, the remaining amount is quantified and re-added as necessary to be used as a predetermined amount of peroxide. .

The peroxide can be used as long as it can generate radicals by heating to achieve crosslinking of the pressure-sensitive adhesive polymer. However, in view of workability and stability, the half-life temperature is 80 ° C to 160 ° C, preferably 90 ° C to 140 ° C for 1 minute. Peroxide is used. If the half-life temperature is too low for 1 minute, the reaction may occur at the time of preservation before application drying, resulting in high viscosity, which may render the coating impossible. If too high, the temperature during crosslinking reaction may increase, resulting in side reactions or peroxide remaining, It is unpreferable since crosslinking may advance.

Examples of such peroxides include di (2-ethylhexyl) peroxydicarbonate (1 minute half life temperature 90.6 ° C.), di (4-t-butylcyclohexyl) peroxy dicarbonate (1 minute half life temperature 92.1 ° C.), and di-sec- Butyl peroxydicarbonate (1 minute half life temperature 92.4 ° C.), t-butyl peroxy neodecanoate (1 minute half life temperature 103.5 ° C.), t-hexyl peroxy pivalate, (1 minute half life temperature 109.1 ° C.), t Butyl peroxy pivalate (half life temperature 110.3 ° C. for 1 minute), dilauroyl peroxide (half life temperature 116.4 ° C. for 1 minute), di-n-octanoyl peroxide (half life temperature of 117.4 ° C. for 1 minute), 1,1, 3,3-tetramethylbutylperoxy-2-ethylhexanoate (1 minute half-life temperature 124.3 ° C), di (4-methylbenzoyl) peroxide (1 minute half-life temperature 128.2 ° C), dibenzoylperoxide (1 Minute half-life temperature 130.0 ° C), t-butylperoxybutylate (1 minute half-life temperature 136.1 ° C), and the like. , In particular cross-linking reaction efficiency is used as the good die (4-t- butyl cyclohexyl) peroxy dicarbonate and di-lauroyl peroxide, di-benzoyl peroxide preferred.

The peroxide is used in an amount of 0.02 to 2 parts by weight, preferably 0.05 to 1 part by weight based on 100 parts by weight of the (meth) acrylic polymer. When too little, the crosslinking reaction is insufficient, resulting in poor durability. It is not desirable because the sex is inferior.

The half-life of the peroxide is an indicator of the rate of decomposition of the peroxide, which is the time when the amount of peroxide decomposed is half, and the decomposition temperature for obtaining the half-life at any time or the half-life time at any temperature is described in the manufacturer's catalog or the like. For example, it is described in the organic peroxide catalog ninth edition (May 2003) of the Japan Oil and Fats Corporation.

Examples of the silane coupling agent include 3-glycidyloxypropyltrimethoxysilane, 3-glycidyloxypropylmethyldiethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, and the like. Epoxy group-containing silane coupling agent, 3-aminopropyltrimethoxysilane, N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-triethoxysilyl-N- (1 (Meth) acryl, such as amino-group-containing silane coupling agents, such as, 3-dimethyl butylidene) propylamine, 3-acrylooxypropyl trimethoxysilane, and 3-methacryloxy propyl triethoxysilane Isocyanate group containing silane coupling agents, such as group containing silane coupling agent and 3-iso cyanate propyl triethoxy silane, etc. are mentioned.

The silane coupling agent is added in an amount of 0.01 to 1 parts by weight, preferably 0.02 to 0.6 parts by weight, based on 100 parts by weight of the (meth) acrylic polymer. When the compounding quantity increases, the adhesive force to image display apparatuses, such as a liquid crystal cell, may increase, and re-peelability may be inferior, and when there are few compounding quantities, durability may fall.

The adhesive composition for optical members which mix | blends a peroxide and a silane coupling agent with a (meth) acrylic-type polymer is apply | coated on a support body, it is made to dry, and the gel fraction of the adhesive after crosslinking is 35 to 90 weight%, Preferably it is 40 to 85 The peroxide crosslinking treatment is carried out to be% by weight. If the gel fraction is too small, the workability is inferior, and if the gel fraction is too large, the adhesion tends to be inferior. It is natural to adjust the amount of peroxide in order to make the gel fraction in this range, but the crosslinking treatment temperature and time are also important, and the crosslinking treatment temperature and time are set so that the decomposition amount of the peroxide is 50% or more, preferably 75% or more. . If the amount of decomposition of the peroxide is small, the amount of residual peroxide increases and crosslinking reaction occurs over time, which is not preferable.

Specifically, for example, when the crosslinking temperature is 1 minute half-life temperature, the amount of decomposition is 50% for 1 minute, and the amount of decomposition is 75% for 2 minutes, and it is necessary to perform heat treatment for 1 minute or more, and the half-life time of the peroxide at the crosslinking temperature If it is this 30 second, the crosslinking process of 30 second or more is required, and if the peroxide half life time at a crosslinking process temperature is 5 minutes, the crosslinking process of 5 minutes or more is required.

In this way, the crosslinking treatment temperature and time are proportionally calculated and adjusted from the half-life time assuming that the peroxide is temporarily proportional to the peroxide to be used, but it is necessary to heat-treat up to 170 ° C. from the fear of side reactions. Naturally, this temperature may use the temperature at the time of drying as it is, and may process after drying. The treatment time is set in consideration of productivity and workability, but 0.2 to 20 minutes, preferably 0.5 to 10 minutes is used.

The adhesive composition for optical members of this invention may use together the crosslinking agent normally used for adjustment of adhesive characteristics. At this time, the gel fraction after crosslinking treatment by heating is used to be 35 to 90% by weight, preferably 40 to 70% by weight, and the gel fraction after treatment such as aging is 40 to 90% by weight, preferably 45 to Used to be 85% by weight. If the gel fraction is too large, the adhesion is inferior, and if the gel fraction is too small, the workability is inferior, which is not preferable.

The crosslinking agent is a multifunctional compound capable of reacting with a polymer to form a crosslinked structure, such as tolylene diisocyanate, diphenylmethane diisocyanate, and diisocyanate adducts to various polyols. Although a polyisocyanate compound, an epoxy compound, an aziridine compound, a melamine compound, a metal salt, a metal chelate compound, etc. are mentioned, A polyisocyanate compound is used preferably. In particular, hydroxyl group-containing monomers, such as 2-hydroxyethyl acrylate, are copolymerized during the preparation of the polymer to introduce hydroxyl groups into the polymer, and a polyisocyanate compound is used as a crosslinking agent. The amount of such crosslinking agent varies depending on the material used, but is usually used in the range of 0.01 to 5 parts by weight based on 100 parts by weight of the (meth) acrylic polymer.

In addition, it is preferable to use an aliphatic and / or alicyclic isocyanate type crosslinking agent about a (meth) acrylic-type polymer (Al). These crosslinking agents may be used independently, and may mix and use 2 or more types.

Aliphatic isocyanate type crosslinking agents include aliphatic isocyanate compounds. For example, butylenedi isocyanate, such as butylene-1,2-diisocyanate, butylene-1,3-diisocyanate, butylene-1,4-diisocyanate, Hexamethylene-1,2-diisocyanate, hexamethylene-1,3-diisocyanate, hexamethylene-1,4-diisocyanate, hexamethylene-1,5-diisocyanate Hexamethylene diisocyanate, trimethylolpropane / hexamethylene diisocyanate such as nate, hexamethylene-1,6-diisocyanate, hexamethylene-2,5-diisocyanate Diisocyanates, such as a trimer adduct (made by Japan Polyurethane Industry Co., brand name collate HL), and isocyanurate body (made by Japan Polyurethane Industry Co., brand name collate HX) of hexamethylene diisocyanate , Adducts with various polyols, And polyisocyanates polyfunctionalized with isocyanurate bonds, biuret bonds, allophanate bonds, and the like. In particular, the hexamethylene diisocyanate, the trimethylol propane / hexamethylene diisocyanate trimer adduct (the Japan Polyurethane Industry Co., brand name Colonate HL), the isocyanate of hexamethylene diisocyanate It is preferable to use hexamethylene diisocyanate compounds, such as an anurate body (made by Japan Polyurethane Industries, brand name Colonate HX). These compounds may be used alone, or may be used by mixing two or more kinds.

An alicyclic isocyanate compound is mentioned as an alicyclic (alicyclic) isocyanate type crosslinking agent. For example, cyclopentylene diisocyanate and cyclohex such as isophorone diisocyanate, cyclopentylene-1,2-diisocyanate, cyclopentylene-1,3-diisocyanate, etc. Cyclohexylene diisocyanates such as silylene-1,2-diisocyanate, cyclohexylene-1,3-diisocyanate, cyclohexylene-1,4-diisocyanate, Diisocyanates, such as norbornene diisocyanate, hydrogenated xylene diisocyanate, 4,4'- dicyclohexyl methane diisocyanate, adducts with various polyols, isocyanu And polyisocyanates polyfunctionalized by rate bonds, burette bonds, allophanate bonds, and the like. In particular, it is preferable to use isophorone diisocyanate and its adducts or trimers. These compounds may be used alone, or may be used by mixing two or more kinds.

In the pressure-sensitive adhesive composition obtained as described above, a ultraviolet absorber, an anti-aging agent, a softener, a dye, a pigment, a filler, and the like can be blended as necessary. Moreover, the redox system which added the reducing agent in the range which can be controlled can be employ | adopted.

The manufacturing method of the adhesive for optical members of this invention includes the process of apply | coating the said adhesive composition on the support body which peeled and dried, and carrying out peroxide crosslinking process. The process is as described above.

The pressure-sensitive adhesive formed by the above production method is transferred to the optical member, or the pressure-sensitive adhesive composition is applied directly to the optical member, dried, crosslinked to obtain an optical member. That is, an adhesive layer is formed on one side or both sides of an optical member, and becomes the optical member of this invention. As such a coating method, the pressure-sensitive adhesive thickness after normal drying is treated to 2 to 500 µm, preferably 5 to 100 µm by any coating method such as a roll coater such as a reverse coater or gravure coater, a curtain coater, a lip coater or a die coater. . When the adhesive layer is exposed on the surface, it is protected by a sheet subjected to peeling treatment until it is provided for practical use.

The pressure-sensitive adhesive optical member of the present invention has a pressure-sensitive adhesive layer crosslinked with a peroxide, and thus exhibits excellent productivity capable of quickly performing a punching process or a slit process without requiring aging after passing through a coating, drying, and crosslinking process. do. The reason for this is not clear, but it is considered as follows. Since the peroxide crosslinking takes the form of a crosslink in which radicals are generated and crosslinked in the polymer backbone by the hydrogen drawing reaction of the polymer backbone by radicals generated from the peroxide, the entire polymer backbone is incorporated into the crosslinked structure, and the entire pressure sensitive adhesive is uniformly crosslinked. Even if the processing such as punching is performed immediately after the crosslinking treatment, the adhesive may be attached to the cutting knife or the glue may not be pushed out after the processing, and the crosslinking reaction may not occur over time by the predetermined crosslinking treatment. It is assumed that the characteristics will stabilize.

As an optical member, what is used for formation of a liquid crystal display device etc. is used, The kind in particular is not restrict | limited. For example, a polarizing plate is mentioned as an optical member. It is generally used that the polarizing plate has a transparent protective film on one side or both sides of the polarizer.

A polarizer is not specifically limited, Various things can be used. As a polarizer, biaxial substances, such as iodine and a dichroic dye, are adsorb | sucked to hydrophilic polymer films, such as a polyvinyl alcohol-type film, a partially foamed polyvinyl alcohol-type film, and an ethylene vinyl acetate copolymerization partial saponification film, for example. Polyene oriented films, such as an extended thing, the dehydration process of polyvinyl alcohol, and the dehydrochlorination process of polyvinyl chloride, etc. are mentioned. Among these, the polarizer which consists of a divinyl substance, such as a polyvinyl alcohol-type film and iodine, is suitable. Although the thickness in particular of these polarizers is not restrict | limited, Generally, it is about 5-80 micrometers.

A polarizer obtained by uniaxially stretching a polyvinyl alcohol-based film by iodine can be produced by, for example, dyeing polyvinyl alcohol in an aqueous solution of iodine and stretching it to 3 to 7 times its original length. If necessary, it can also be immersed in aqueous solution, such as potassium iodide which may contain boric acid, zinc sulfate, zinc chloride, etc. In addition, if necessary, the polyvinyl alcohol-based film may be immersed in water and washed with water before dyeing. Besides washing the polyvinyl alcohol-based film with water, the contamination of the polyvinyl alcohol-based film and the blocking agent can be cleaned. In addition, swelling of the polyvinyl alcohol-based film also prevents unevenness such as staining. Stretching may be carried out after staining with iodine, stretching may be performed while dyeing, or dyeing with iodine after stretching. It can extend | stretch also in aqueous solution, such as a boric acid and potassium iodide, or in a water bath.

As a material which forms the transparent protective film with which one side or both sides of the said polarizer are equipped, what is excellent in transparency, mechanical strength, thermal stability, moisture shielding property, isotropy, etc. is preferable. For example, polyester polymers such as polyethylene terephthalate and polyethylene naphthalate, cellulose polymers such as diacetyl cellulose and triacetyl cellulose, (meth) acrylic polymers such as polymethyl methacrylate, polystyrene and acrylonitrile? Styrene-type polymers, such as a styrene copolymer (AS resin), a polycarbonate polymer, etc. are mentioned. In addition, polyethylene, polypropylene, polyolefin having a cyclo- or norbornene structure, polyolefin-based polymer such as ethylene-propylene copolymer, vinyl chloride-based polymer, amide-based polymer such as nylon and aromatic polyamide, imide-based polymer, sulfone-based Polymer, polyether sulfone polymer, polyether ether ketone polymer, polyphenylene sulfide polymer, vinyl alcohol polymer, vinylidene chloride polymer, vinyl butyral polymer, allylate polymer, polyoxymethylene polymer , An epoxy polymer, or a blend of the polymers may also be mentioned as examples of the polymer forming the transparent protective film. The transparent protective film can also be formed as a cured layer of thermosetting or ultraviolet curable resins such as acrylic, urethane, acrylic urethane, epoxy, and silicone.

Moreover, the polymer film of Unexamined-Japanese-Patent No. 2001-343529 (WO 01/37007), for example, (A) thermoplastic resin which has a substituted and / or unsubstituted imide group in the side chain, and (B) substituted in the side chain And / or a resin composition containing a thermoplastic resin having unsubstituted phenyl and nitrile groups. As a specific example, the film of the resin composition containing the alternating copolymer which consists of isobutylene and N-methyl maleimide, and an acrylonitrile styrene copolymer is mentioned. The film can be used as a mixed extruded product of the resin composition.

Although the thickness of a protective film can be suitably determined, it is generally about 1-500 micrometers from a viewpoint of workability, thinness, etc., such as strength and handleability. 1-300 micrometers is especially preferable, and 5-200 micrometers is more preferable.

In addition, it is preferable that a protective film does not have coloring as much as possible. Therefore, in the film thickness direction represented by Rth = [(nx + ny) / 2-nz] d (where nx and ny are principal refractive indices in the film plane, nz is a refractive index in the film thickness direction and d is a film thickness). The protective film whose retardation value is -90 nm-+75 nm is used preferably. By using the thing whose phase difference value Rth of such a thickness direction is -90 nm-+75 nm, coloring (optical coloring) of the polarizing plate resulting from a protective film can be almost eliminated. The thickness direction retardation value Rth is more preferably -80 nm to +60 nm, particularly -70 nm to +45 nm.

As a protective film, cellulose polymers, such as triacetyl cellulose, are preferable at the point of polarization characteristic, durability, etc. In particular, a triacetyl cellulose film is suitable. In addition, when providing a protective film in both sides of a polarizer, the protective film which consists of the same polymer material inside and outside can be used, and the protective film which consists of another polymer material etc. can be used. The polarizer and the protective film are usually in close contact with each other through an aqueous adhesive. As an aqueous adhesive, an isocyanate adhesive, a polyvinyl alcohol adhesive, a gelatin adhesive, a vinyl latex type, an aqueous polyurethane, an aqueous polyester, etc. can be illustrated.

The surface which does not adhere | attach the polarizer of the said transparent protective film may be the thing which performed the process for the purpose of a hard coat layer, an anti-reflective process, anti-sticking, diffusion | diffusion, or glare prevention.

The hard coating treatment is carried out for the purpose of preventing scratches on the surface of the polarizing plate, or the like, for example, by adding a cured film having excellent hardness, sliding properties, etc., by a suitable ultraviolet curable resin such as acrylic or silicone, to the surface of the transparent protective film. Can be formed. The antireflection treatment is performed for the purpose of preventing reflection of external light on the surface of the polarizing plate, and can be achieved by forming an antireflection film or the like according to the prior art. Incidentally, the anti-sticking treatment is performed for the purpose of preventing the adhesion with the adjacent layer.

The anti-glare treatment is performed for the purpose of preventing external light from reflecting off the surface of the polarizing plate and impairing the visibility of the polarizing plate transmitted light. For example, a sandblasting method or an embossing method, such as a roughening method or a compounding method of transparent fine particles, etc. It can form by giving a fine uneven structure to the surface of a transparent protective film in a suitable way of the following. Examples of the fine particles to be included in the formation of the surface fine uneven structure may include conductive fine particles of silica, alumina, titania, zirconia, tin oxide, indium oxide, cadmium oxide, antimony oxide, or the like having an average particle diameter of 0.5 to 50 µm, for example. And transparent fine particles such as organic fine particles made of a crosslinked or uncrosslinked polymer or the like. When forming a surface fine uneven structure, the usage-amount of microparticles | fine-particles is about 2-50 weight part generally with respect to 100 weight part of transparent resin which forms a surface fine uneven structure, and 5-25 weight part is preferable. The anti-glare layer may serve as a diffusion layer (visual magnification function, etc.) for diffusing the polarized plate transmitted light to enlarge the time and the like.

The anti-reflection layer, the anti-seizure layer, the diffusion layer, the anti-glare layer, and the like can be provided on the transparent protective film itself, and can be provided as a separate optical layer as a separate optical layer.

Moreover, as an optical member of this invention, it is used for formation of a liquid crystal display device, such as a reflecting plate, a semi-transmissive plate, a retardation plate (including wavelength plates, such as 1/2 or 1/4), an optical compensation film, a brightness enhancement film, etc., for example. The thing which becomes an optical layer which may become may be mentioned. In addition to being able to be used as the optical member of this invention independently, these can be laminated | stacked on the said polarizing plate at the time of use, and can use 1 layer or 2 or more layers.

In particular, a reflective polarizer or semi-transmissive polarizer in which a reflection plate or a semi-transmissive reflector is laminated on the polarizing plate, an elliptically polarizing plate or circular polarizer in which a retardation plate is further laminated on the polarizing plate, and a light in which a visual compensation film is further laminated on the polarizing plate The polarizing plate in which a brightness improving film is further laminated | stacked on a viewing angle polarizing plate or a polarizing plate is preferable.

The reflective polarizer is provided with a reflective layer on the polarizer to form a liquid crystal display device of a type that reflects and displays incident light from the viewing side (display side). It is advantageous in that the display device can be made thinner. Formation of a reflective polarizing plate can be performed by a suitable method, such as the method of laying a reflective layer which consists of metal etc. on one surface of a polarizing plate through a transparent protective layer etc. as needed.

As a specific example of a reflective polarizing plate, the thing which provided the reflective layer by laying the foil and vapor deposition film which consist of reflective metals, such as aluminum, on one surface of the transparent protective film which carried out the mat process as needed. Moreover, what contains microparticles | fine-particles in the said transparent protective film to make surface fine concavo-convex structure, and has a reflective layer of a fine concavo-convex structure on it, etc. are mentioned. The reflective layer of the fine concavo-convex structure has an advantage of preventing incident light from being diffused by diffuse reflection to prevent directionality and glare, and to suppress unevenness of light and dark. Moreover, the transparent protective film containing microparticles | fine-particles also has the advantage of being able to spread | diffuse when incident light and its reflection light permeate | transmit it, and to suppress a brightness nonuniformity more. Formation of a reflective layer having a fine concavo-convex structure reflecting the surface fine concavo-convex structure of the transparent protective film may be performed by forming a metal in a suitable manner such as a vapor deposition method such as a vacuum deposition method, an ion plating method, a sputtering method, or a plating method. It can carry out by the method of directly laying on a surface.

The reflecting plate can be used as a reflecting sheet or the like provided with a reflecting layer on a suitable film according to the transparent film instead of the method of directly applying to the transparent protective film of the polarizing plate. In addition, since the reflective layer is usually made of a metal, the use form in which the reflective surface is covered with a transparent protective film, a polarizing plate, or the like prevents the reduction of the reflectance due to oxidation, and furthermore, the viewpoint of long-term sustaining of the initial reflectance, and the protective layer. It is preferable from the standpoint of avoiding separate installation.

In addition, a semi-transmissive polarizing plate can be obtained by making it into the semi-transmissive reflecting layer, such as a half mirror which reflects and transmits light in a reflecting layer in the above. The semi-transmissive polarizing plate is usually provided on the rear side of the liquid crystal cell. When the liquid crystal display device is used in a relatively bright atmosphere, the semi-transmissive polarizing plate reflects the incident light from the viewing side (display side) to display an image. The liquid crystal display device of the type which displays an image using a built-in light source, such as a backlight built in the background side of the inside, can be formed. That is, the transflective polarizing plate can save energy of using a light source such as a backlight in a bright atmosphere, and is useful for forming a liquid crystal display device of a type that can be used using a built-in light source even in a relatively dark atmosphere.

An elliptical polarizing plate or circular polarizing plate in which a retardation plate is further laminated on the polarizing plate will be described. When the linearly polarized light is changed into elliptical polarization or circularly polarized light, the elliptical polarization or circularly polarized light is changed into linearly polarized light, or the polarization direction of the linearly polarized light is changed, a retardation plate or the like is used. In particular, a so-called quarter wave plate (also referred to as λ / 4 plate) is used as a phase difference plate for converting linearly polarized light into circularly polarized light or for converting circularly polarized light into linearly polarized light. The half wave plate (also referred to as λ / 2 plate) is usually used to change the polarization direction of linearly polarized light.

The elliptical polarizing plate is effectively used for compensating (preventing) coloration (blue or yellow color) caused by birefringence of the liquid crystal layer of an ultra-torsion nematic (STN) type liquid crystal display device to produce a monochrome display without the coloration. In addition, it is preferable to control the three-dimensional refractive index because it can compensate (prevent) coloring caused when the screen of the liquid crystal display device is viewed from an oblique direction. The circular polarizing plate is effectively used, for example, in the case of providing a color tone of an image of a reflective liquid crystal display device in which an image is color displayed, and also has an antireflection function.

Examples of the retardation plate include a birefringent film obtained by uniaxial or biaxial stretching of a polymer material, an alignment film of a liquid crystal polymer, and an alignment layer of a liquid crystal polymer as a film. Although the thickness of the retardation plate is not particularly limited, it is generally about 20 to 150 µm.

Examples of the polymer material include polyvinyl alcohol, polyvinyl butyral, polymethyl vinyl ether, polyhydroxyethyl acrylate, hydroxyethyl cellulose, hydroxypropyl cellulose, methyl cellulose, polycarbonate, polyallylate, polysulfone, Polyethylene terephthalate, polyethylene naphthalate, polyether sulfone, polyphenylene sulfide, polyphenylene oxide, polyallyl sulfone, polyvinyl alcohol, polyamide, polyimide, polyolefin, polyvinyl chloride, cellulose polymer, norbornene-based resin Or these binary or ternary various copolymers, graft copolymers, blends and the like. These high molecular materials become an orientation substance (stretched film) by extending | stretching etc.

Examples of the liquid crystalline polymer include various main chain and side chains in which the conjugated linear atomic group (mesogen) for imparting liquid crystal alignment is introduced into the main chain or side chain of the polymer. Specific examples of the main chain type liquid crystalline polymer include, for example, a nematic oriented polyester liquid crystalline polymer, a discotic polymer, a cholesteric polymer, and the like, in which a mesogenic group is bonded to a spacer portion providing flexibility. As a specific example of a branched liquid crystalline polymer, polysiloxane, polyacrylate, polymethacrylate, or polymalonate is used as a main chain skeleton, and as a side chain, a para-substituted cyclic compound unit of nematic orientation imparting property is provided through a spacer portion composed of a conjugated atomic group. The thing which has the mesogenic part which consists of these etc. is mentioned. These liquid crystalline polymers develop a solution of a liquid crystalline polymer on an alignment treatment surface such as rubbing a thin film surface such as polyimide or polyvinyl alcohol formed on a glass plate, or depositing silicon oxide obliquely. By heat treatment.

The retardation plate may have a suitable retardation according to the purpose of use, for example, for the purpose of compensating coloring or vision due to birefringence of various wavelength plates and liquid crystal layers, or the like. May be controlled by the optical properties of.

The elliptical polarizing plate and the reflective elliptic polarizing plate are laminated by appropriately combining a polarizing plate or a reflective polarizing plate with a phase difference plate. Such elliptical polarizing plates and the like can also be formed by sequentially stacking them separately in the manufacturing process of the liquid crystal display device so as to be a combination of a (reflective) polarizing plate and a retardation plate. There is an advantage that the stability of quality, lamination workability, etc. are excellent and the manufacturing efficiency of a liquid crystal display etc. can be improved.

The visual compensation film is a film for widening the viewing angle so that an image is relatively clear even when the screen of the liquid crystal display device is viewed from a slightly inclined direction rather than perpendicular to the screen. As such a visual compensation retardation plate, it consists of what supported an alignment layer, such as a liquid crystal polymer, on alignment films, such as a retardation plate and a liquid crystal polymer, or a transparent base material, etc., for example. Usually, a retardation plate is a polymer film having birefringence uniaxially stretched in its plane direction, whereas a retardation plate used as a visual compensation film is a polymer film having a birefringence oriented biaxially in the plane direction, or a plane direction. A bidirectional stretched film, such as a birefringent polymer or a diagonally oriented film, which is stretched in one axis and controlled in the thickness direction also in the thickness direction, is used. As a diagonal oriented film, the thing which carried out the extending | stretching process and / or shrinkage | contraction process of the polymer film under the action of the shrinkage force by heating, for example, adhere | attaching a heat-shrink film to a polymer film, the thing which orientated the liquid crystal polymer obliquely, etc. are mentioned. The raw material polymer of the retardation plate is the same as that of the polymer described above with the retardation plate, and is suitable for the purpose of preventing the coloring due to the change of the viewing angle based on the phase difference by the liquid crystal cell, or expanding the viewing angle of the good viewing. It is available.

Further, in view of achieving a wide viewing angle with good visibility, an optical compensation retardation plate supporting an optically anisotropic layer composed of an alignment layer of a liquid crystal polymer, particularly an oblique alignment layer of a discotic liquid crystal polymer, as a triacetylcellulose film can be preferably used. .

The polarizing plate which bonded the polarizing plate and the brightness enhancement film is usually provided and used on the back side of the liquid crystal cell. The brightness enhancing film reflects linearly polarized light on a predetermined polarization axis or circularly polarized light in a predetermined direction when natural light enters by a backlight such as a liquid crystal display device or reflection from the back side, and exhibits a property of transmitting other light. The polarizing plate laminated | stacked with a polarizing plate injects light from a light source, such as a backlight, and obtains the transmitted light of a predetermined polarization state, and reflects the light other than the said predetermined polarization state without transmitting. The light reflected from the surface of the brightness enhancing film is further inverted through a reflecting layer or the like provided on the back side thereof, and re-entered into the brightness enhancing film, and transmitted part or all of the light as light in a predetermined polarization state to transmit the brightness enhancing film. The luminance can be improved by increasing the amount of light and increasing the amount of light that can be used for liquid crystal display image display by supplying polarized light that is hardly absorbed by the polarizer. That is, when light is incident on the backside of the liquid crystal cell with a backlight or the like without using a brightness enhancement film, light having a polarization direction that does not coincide with the polarization axis of the polarizer is almost absorbed by the polarizer and transmitted through the polarizer. I never do that. That is, although it depends also on the characteristic of the polarizer used, about 50% of light is absorbed by a polarizer, and the quantity of light which can be used for a liquid crystal image display etc. by that amount reduces, and an image becomes dark. The brightness enhancement film repeatedly reflects light having a polarization direction absorbed by the polarizer into the brightness enhancement film without being incident on the polarizer, and is then inverted through a reflective layer or the like provided on the back side and re-injected into the brightness enhancement film. Since only the polarization direction in which the polarization direction of the light reflected and inverted between the two becomes the polarization direction that can pass through the polarizer is transmitted through the luminance enhancement film and is supplied to the polarizer, it is possible to efficiently transmit light such as a backlight and the like in the image of the liquid crystal display device. Can be used for display to brighten the screen.

A diffusion plate may be provided between the brightness enhancing film and the reflective layer. The light in the polarization state reflected by the brightness enhancement film is directed toward the reflection layer or the like, but the diffuser plate provided uniformly diffuses the light passing therethrough and at the same time eliminates the polarization state, resulting in a non-polarization state. In other words, the diffusion plate returns the polarized light to the original natural light state. Light in this non-polarized state, that is, natural light, is reflected through the reflecting layer or the like toward the reflecting layer or the like, and passes through the diffuser plate again and is reincident to the brightness enhancing film. Thus, by providing the diffuser plate which returns polarization to the original natural light state between the brightness improvement film and the said reflection layer, etc., the brightness of a display screen is maintained, and the deviation of the brightness of a display screen is reduced, and a uniform and bright screen is carried out. Can be provided. By providing such a diffuser plate, it is considered that the number of times of repeated reflection of the first incident light is moderately increased, so that a uniform and bright display screen can be provided in accordance with the diffuser function of the diffuser plate.

Examples of the brightness enhancement film include a film that transmits linearly polarized light of a predetermined polarization axis and reflects other light, such as a multilayer thin film of a dielectric film or a thin film film of a film having different refractive index anisotropy, or an alignment film of a cholesteric liquid crystal polymer. As the support of the alignment liquid crystal layer on the film substrate, a suitable one such as reflecting the circularly polarized light of either left or right diffraction and displaying other light can be used.

Therefore, as a luminance improvement film of the type which transmits the linearly polarized light of the said predetermined polarization axis, it can transmit efficiently, restraining the absorption loss by a polarizing plate by making the transmitted light into a polarizing plate side by side directly as it is. On the other hand, although the luminance-enhancing film of the type which drops circularly polarized light like a cholesteric liquid crystal layer can be made to enter a polarizer as it is, in order to suppress absorption loss, the circularly polarized light linearly polarizes through a retardation plate, and enters into a polarizing plate. It is preferable to be. In addition, by using a quarter wave plate as the retardation plate, circularly polarized light can be converted into linearly polarized light.

A retardation plate serving as a quarter wave plate in a wide wavelength range such as a visible light region is a retardation layer exhibiting retardation characteristics different from a retardation layer functioning as a quarter wave plate, for example, for pale color light having a wavelength of 550 nm. It can obtain by the method of superimposing the retardation layer which functions as a wave plate. Therefore, the phase difference plate arrange | positioned between a polarizing plate and a brightness improving film may consist of one layer or two or more phase difference layers.

In addition, also regarding the cholesteric liquid crystal layer, by using a combination of two or more reflection wavelengths in a batch structure in which two or more layers are superposed, it is possible to obtain the reflection of circularly polarized light in a wide wavelength range such as a visible light region. Thus, transmission circularly polarized light in a wide wavelength range can be obtained.

In addition, the polarizing plate may be formed by stacking a polarizing plate and two or three or more optical layers, like the polarization splitting polarizing plate. Therefore, the reflection type polarizing plate, the reflection type ellipsoidal polarizing plate or the semi-transparent ellipsoidal polarizing plate combined with the transflective polarizing plate, and the retardation plate may be used.

The optical member in which the optical layer is laminated on the polarizing plate may be formed in a manner of being separately laminated in a manufacturing process such as a liquid crystal display device. It is excellent and there exists an advantage that the manufacturing process of a liquid crystal display etc. can be improved. Suitable lamination means, such as an adhesion layer, can be used for lamination. In adhesion | attachment of the said polarizing plate and another optical layer, these optical axes can be made into a suitable arrangement angle according to the target phase difference characteristic etc ..

In addition, each layer, such as an optical member and an adhesive layer, of the pressure-sensitive adhesive-attached optical member of the present invention is, for example, a salicylic acid ester compound, a benzophenol compound, a benzotriazole compound, a cyanoacrylate compound, a nickel complex salt compound, or the like. The ultraviolet absorber may be provided by a method such as treatment with a ultraviolet absorber.

The adhesive-attached optical member of the present invention can be suitably used for forming various image display devices such as liquid crystal display devices. Formation of a liquid crystal display device can be performed according to the prior art. That is, a liquid crystal display device is generally formed by appropriately assembling a component such as a liquid crystal cell, an adhesive-attached optical member, and a lighting system as necessary, and incorporating a driving circuit. However, in the present invention, the optical member according to the present invention is used. It does not specifically limit except a point, and can follow conventionally. Also about a liquid crystal cell, what is arbitrary types, such as TN type, STN type, (pi) type, can be used, for example.

A suitable liquid crystal display device, such as a liquid crystal display device in which an adhesive-attached optical member is disposed on one or both of the liquid crystal cells, or a backlight or reflector used in an illumination system, can be formed. In that case, the optical member by this invention can be provided in one side or both sides of a liquid crystal cell. When the optical members are provided on both sides, they may be the same or may be different. In forming a liquid crystal display device, for example, a diffuser plate, an anti-glare layer, an anti-reflection film, a protective plate, a prism array, a lens array sheet, a light diffusion plate, a backlight, or the like may be provided with one or two or more layers at appropriate positions. Can be.

Next, the organic electroluminescent device (organic EL display device) will be described. In general, an organic EL display device forms a light emitting body (organic electroluminescent body) by sequentially stacking a transparent electrode, an organic light emitting layer, and a metal electrode on a transparent substrate. Here, the organic light emitting layer is a laminate of various organic thin films, for example, a laminate of a hole injection layer made of a triphenylamine derivative and the like and a light emitting layer made of a fluorescent organic solid such as anthracene, or such a light emitting layer and a perylene derivative. The structure which has various combinations, such as the laminated body of the electron injection layer which consists of these, or these hole injection layers, a light emitting layer, and the electron injection layer, is known.

In the organic EL display device, a voltage is applied to the transparent electrode and the metal electrode, so that holes and electrons are injected into the organic emission layer, and energy generated by the recombination of these holes and electrons excites the fluorescent material, and the excited fluorescent material is in a ground state. When it comes back to the light emitted by the principle of emitting light. The mechanism of intermediate recombination is the same as that of a normal diode, and as can be expected from this, the current and the luminescence intensity exhibit strong nonlinearity accompanied by rectification with respect to the applied voltage.

In the organic EL display device, in order to extract light emitted from the organic light emitting layer, at least one electrode must be transparent, and a transparent electrode usually formed of a transparent conductor such as indium tin oxide (ITO) is used as the anode. On the other hand, in order to facilitate electron injection and increase luminous efficiency, it is important to use a material having a small work function for the cathode, and metal electrodes such as Mg-Ag and Al-Li are usually used.

In the organic EL display device having such a configuration, the organic light emitting layer is formed of a very thin film having a thickness of about 10 nm. For this reason, the organic light emitting layer also transmits light almost completely like the transparent electrode. As a result, light incident on the surface of the transparent substrate during non-emission, and transmitted through the transparent electrode and the organic light emitting layer and reflected by the metal electrode again exits to the surface side of the transparent substrate, therefore, when viewed from the outside, the organic EL display device The display surface of looks like a mirror surface.

An organic EL display device comprising an organic electroluminescent light emitting body comprising a transparent electrode on the front side of an organic light emitting layer that emits light by applying a voltage and a metal electrode on the back side of the organic light emitting layer. A polarizing plate can be provided and a retardation plate can be provided between these transparent electrodes and a polarizing plate.

Since the retardation plate and the polarizing plate have a function of polarizing light incident on the outside and reflected from the metal electrode, there is an effect that the mirror surface of the metal electrode is not visually recognized by the polarization action. In particular, when the phase difference plate is constituted by a quarter wave plate, and the angle formed between the polarization direction of the polarizing plate and the phase difference plate is adjusted to? / 4, the mirror surface of the metal electrode can be completely shielded.

That is, only the linearly polarized light component transmits external light incident on the organic EL display device by the polarizing plate. This linearly polarized light is generally elliptically polarized by the retardation plate. In particular, the linearly polarized light becomes circularly polarized light when the retardation plate is a quarter wave plate and the angle between the polarizing plate and the retardation plate is π / 4.

The circularly polarized light penetrates the transparent substrate, the transparent electrode, and the organic thin film, is reflected by the metal electrode, passes through the organic thin film, the transparent electrode, and the transparent substrate, and is again linearly polarized on the retardation plate. And since this linearly polarized light is orthogonal to the polarization direction of a polarizing plate, it cannot pass through a polarizing plate. As a result, the mirror surface of a metal electrode can be shielded completely.

Example

Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited by these Examples. In addition, both parts and% in each example are based on a weight.

Example 1-1

Four-necked flask equipped with a nitrogen inlet tube and a cooling tube, 70 parts of isononyl acrylate, 25 parts of butyl acrylate, 5 parts of acrylic acid, and 0.1 part of 2,2-azobisisobutyronitrile and 200 parts of ethyl acetate It injected | thrown-in, and fully substituted by nitrogen, the polymerization reaction was performed at 55 degreeC for 20 hours, stirring under nitrogen stream, and the acrylic polymer of the weight average molecular weight 1.25 million was obtained.

38 micrometers which carried out the silicone peeling process of the adhesive composition which mix | blended 0.4 part of dibenzoyl peroxide (1 minute half life 130.0 degreeC), and 0.1 part of 3-glycidyloxypropyl trimethoxysilane with respect to 100 parts of solid content of a polymer solution. PET was applied so that the adhesive layer had a dry thickness of 25 µm, dried and crosslinked at 130 ° C. for 3 minutes (the amount of peroxide obtained in the calculation was about 88%), transferred to a polarizing film, and transferred to a polarizing film. It was set as the adhesive-attached optical member. In addition, the gel fraction of the adhesive was 71 weight%. Moreover, even if this adhesive was stored for one month at 60 degreeC, the increase of a gel fraction was not observed.

Examples 1-2

The adhesive composition of Example 1-1 was dried and crosslinked at 140 ° C. for 3 minutes (the amount of decomposition of the peroxide obtained by calculation was about 99%), and transferred to a polarizing film to obtain the pressure-sensitive adhesive optical member of the present invention. . In addition, the gel fraction of the adhesive was 71 weight%.

Example 1-3

The adhesive composition of Example 1-1 was dried and crosslinked at 120 ° C. for 9 minutes (the amount of decomposition of the peroxide obtained by calculation was about 90%), and transferred to the polarizing film to obtain the pressure-sensitive adhesive optical member of the present invention. . In addition, the gel fraction of the adhesive was 70 weight%.

Reference Example 1-1

Drying and crosslinking of the adhesive composition of Example 1-1 were performed at 110 degreeC for 3 minutes (the amount of decomposition of the peroxide obtained by calculation is about 19%), it was transferred to the polarizing film, and it was set as the adhesive-attached optical member of a reference example. In addition, the gel fraction of the adhesive was 5 weight%.

Comparative Example 1-1

In Example 1-1, the pressure-sensitive adhesive optical member of Comparative Example was obtained in the same manner as in Example 1-1 except that the dibenzoyl peroxide was 0.01 part. In addition, the gel fraction of the adhesive was 0 weight%.

Comparative Example 1-2

In Example 1-1, the pressure-sensitive adhesive optical member of Comparative Example was obtained in the same manner as in Example 1-1 except that three parts of dibenzoyl peroxide were used. In addition, the gel fraction of the adhesive was 95 weight%.

Comparative Example 1-3

In Example 1-1, 3 parts of dibenzoyl peroxide, and drying and crosslinking were carried out at 110 ° C. for 3 minutes (decomposition of peroxide obtained by calculation was about 19%) in the same manner as in Example 1-1. To obtain a pressure-sensitive adhesive optical member of the comparative example. In addition, the gel fraction of the adhesive was 82 weight%.

Comparative Example 1-4

In Example 1-1, it carried out similarly to Example 1-1 except having set 3-glycidyloxypropyl trimethoxysilane at 0.005 parts, and set it as the adhesive-attached optical member of a comparative example. In addition, the gel fraction of the adhesive was 71 weight%.

Comparative Example 1-5

In Example 1-1, except having made 3-glycidyloxypropyl trimethoxysilane into 2 parts, it carried out similarly to Example 1-1, and set it as the adhesive-attached optical member of a comparative example. In addition, the gel fraction of the adhesive was 71 weight%.

Example 1-4

Four parts equipped with a nitrogen inlet tube and a cooling tube, 70 parts of 2-ethylhexyl acrylate, 29 parts of butyl acrylate, 1.0 part of acrylic acid, and 0.05 parts of 2,2-azobisisobutyronitrile and 200 parts of ethyl acetate After putting in a flask and fully nitrogen-substituting, it superposed | polymerized at 55 degreeC for 20 hours, stirring under nitrogen stream, and obtained the acrylic polymer with a weight average molecular weight of 1,460,000.

The adhesive which mix | blended 0.2 parts of di (4-t-butylcyclohexyl) peroxydicarbonate (1 minute half life 92.1 degreeC), and 0.2 parts of 3-glycidyloxypropyl triethoxysilanes with respect to 100 parts of solid content of a polymer solution. The composition was apply | coated to 38 micrometers PET which carried out the silicone peeling process so that the adhesive layer may have a dry thickness of 25 micrometers, and it dried and crosslinked at 130 degreeC for 3 minutes (The amount of decomposition of the peroxide obtained by calculation is about 100%). Then, it transferred to the polarizing film and used as the adhesive-attached optical member of this invention. In addition, the gel fraction of the adhesive was 82 weight%.

Examples 1-5

95 parts of butyl acrylate, 5 parts of acrylic acid, 0.1 parts of 2-hydroxyethyl acrylate, and 0.05 parts of 2,2-azobisisobutyronitrile and 200 parts of ethyl acetate are provided with a nitrogen inlet tube and a cooling tube. The mixture was charged into an old flask and sufficiently substituted with nitrogen, followed by a polymerization reaction at 55 ° C. for 20 hours while stirring under a nitrogen stream to obtain an acrylic polymer having a weight average molecular weight of 1,570,000.

38 micrometers which carried out the silicone peeling process of the adhesive composition which mix | blended 0.2 parts of dibenzoyl peroxide (1 minute half life 130.0 degreeC) and 0.08 parts of 3-glycidyloxypropyl trimethoxysilane with respect to 100 parts of solid content of a polymer solution. PET was applied so that the adhesive layer had a dry thickness of 25 µm, dried and crosslinked at 140 ° C. for 3 minutes (the amount of decomposition of the peroxide obtained by calculation was about 99%), transferred to a polarizing film, and The adhesive-attached optical member was used. In addition, the gel fraction of the adhesive was 75 weight%.

Examples 1-6

0.1 part of dibenzoyl peroxide (1 minute half-life 130.0 ° C), 0.08 part of 3-glycidyloxypropyltrimethoxysilane, and trimethyl as a crosslinking agent with respect to 100 parts of solid content of the polymer solution of Example 1-5 Drying thickness of an adhesive layer is 25 micrometers to 38 micrometers PET which carried out the silicone peeling process of the adhesive composition which mixed 0.5 parts of polyisocyanate type crosslinking agents which consist of tolylene diisocyanate adducts of all propane uniformly. 3 minutes of drying and crosslinking (about 88% of the decomposition amount of peroxide obtained by calculation) were performed, it was made to transfer to a polarizing film, and it was set as the adhesive-attached optical member of this invention. In addition, the gel fraction of the adhesive was 68 weight%.

Comparative Example 1-6

In Example 1-6, except having used 0.8 parts of polyisocyanate crosslinking agents, without using a dibenzoyl peroxide, it carried out similarly to Example 1-6, and set it as the adhesive-attached optical member of a comparative example. In addition, the gel fraction of the adhesive was 6 weight%. In addition, the gel fraction became 68 weight% after aging at 30 degreeC for one week, but evaluation was performed before aging.

Example 1-7

In the polymer polymerization of Example 1-5, polymerization was carried out using 0.2 parts of dibenzoyl peroxide instead of 0.05 parts of 2,2-azobisisobutyronitrile to obtain a polymer having a weight average molecular weight of 1.3 million. Further, as a result of performing liquid chromatography to quantify the residual peroxide, 0.06 parts remained.

0.14 part of dibenzoyl peroxide was added with respect to 100 parts of solid content of a polymer solution, and operation similar to Example 1-5 was performed, and it was set as the adhesive-attached optical member of this invention. In addition, the gel fraction of the adhesive was 72 weight%.

Examples 1-8

Using a monomer mixture of 70 parts of butyl acrylate, 27 parts of 2-ethylhexyl acrylate, 2 parts of acrylic acid, and 1 part of 6-hydroxyhexyl acrylate, water 122 using 3 parts of polyoxyethylene distyrene phenyl ether ammonium sulfate as an emulsifier was used. The part was emulsified and subjected to polymerization reaction at 50 ° C for 3 hours using 0.05 parts of 2,2-azobis (2-amidinopropane) dihydrochloride as an initiator, and further reacted at 65 ° C for 2 hours, and ammonia water The viscosity was adjusted to obtain an aqueous dispersion of an acrylic polymer.

0.2 parts of dibenzoyl peroxide (1 minute half-life 130.0 ° C) and 0.1 part of 3-glycidyloxypropyltriethoxysilane dissolved in 5 parts of ethyl acetate were added to 100 parts of the solid content of the aqueous dispersion of the acrylic polymer, and uniformly added. The pressure-sensitive adhesive composition was applied to 38 μm PET, which had been subjected to silicone peeling, so that the pressure-sensitive adhesive layer had a dry thickness of 25 μm, and dried and crosslinked at 130 ° C. for 3 minutes (decomposition amount of the peroxide obtained by calculation was about 88 %) To transfer to a polarizing film to obtain a pressure-sensitive adhesive optical member of the present invention. In addition, the gel fraction of the adhesive was 78 weight%.

Example 1-9

A monomer mixture of 200 parts of water, 77 parts of butyl acrylate and 3 parts of 6-hydroxyhexyl acrylate was added to 50 parts (40.0% by weight of solid content) of polyurethane dispersion (Takerak W-511, manufactured by Mitsui Takeda Chemical Co., Ltd.). And absorbed into the urethane aqueous dispersion. Urethane which adds 0.08 parts of 2, 2- azobis (N- (2-carboxyethyl) -2-methyl- propionamidine, heats to 55 degreeC under nitrogen stream, and reacts for 5 hours, and does not use an emulsifier. An aqueous dispersion of an acrylic polymer was obtained.

In the same manner as in Example 1-8, a peroxide and a silane coupling agent were blended, applied, dried and crosslinked to obtain a pressure-sensitive adhesive optical member of the present invention. In addition, the gel fraction of the adhesive was 81 weight%.

(Measurement of gel fraction)

The dried and crosslinked adhesive (first weight W1) was immersed in an ethyl acetate solution and left to stand at room temperature for one week. Then, an insoluble component was taken out and the dried weight (W2) was measured to obtain the following formula.

Gel fraction (% by weight) = (W2 / W1) × 100

(Adhesion)

An optical member having a width of 25 mm obtained in Examples and Comparative Examples was attached to an alkali free glass plate by reciprocating once with a roll of 2 kg, and treated at 50 ° C. and 0.5 MPa autoclave for 30 minutes, and then at 23 ° C. and 50% conditions. After leaving for 3 hours, the peel adhesion was measured at a peel angle of 90 ° and a peel rate of 300 mm / min. After the autoclave treatment, the mixture was stored at 70 ° C. for 6 hours and allowed to stand at 23 ° C. and 50% for 3 hours, and then the peel adhesion strength was measured at a peel angle of 90 ° and a peel rate of 300 mm / min to obtain an adhesive strength after heating.

(durability)

The 12-inch optical members obtained in Examples and Comparative Examples were attached to an alkali-free glass having a thickness of 0.5 mm, treated for 30 minutes in an autoclave of 50 ° C and 0.5 MPa, and then at 60 ° C and 90% RH. It injected | thrown-in for 500 hours, it was set as (circle) when there was no peeling and lifting of an optical member, and it was set to x as there was.

(Processability)

The pressure-sensitive adhesive optical member of Examples and Comparative Examples was punched out using a press machine without performing an aging treatment. In that case, the case where the residual of an adhesive is not seen by the cutting knife was set to (circle), and when the adhesive remained or adhered, it was set to x.

From Table 1, the pressure-sensitive adhesive-attached optical member of the present invention exhibits high durability that does not occur peeling and foaming even after being stored in a high temperature and high humidity state after being attached, and even when the liquid crystal cell is reused by peeling off the optical member. It is excellent in punching workability without any contamination, no aging or the like after the coating, drying and crosslinking processes, and has a characteristic of satisfying all of them. In comparison, it can be seen that the optical member of the comparative example is not obtained to satisfy all the characteristics.

Next, although the Example etc. at the time of using an acryl-type polymer (A2) and an acryl-type polymer (B) together are demonstrated, this invention is not limited to these. In addition, the evaluation item in an Example etc. was measured as follows.

<Measurement of molecular weight>

Molecular weight was measured by GPC (gel permeation chromatography).

Analysis device: Tosoh Corporation, HLC-8120GPC

Data Processing Unit: Tosoh Corporation, GPC-8020

column:

Sample column;

(Meth) acrylic polymer (a);

Tososa products, G7000H _XL + GMH _XL + GMH _XL

(Meth) acrylic polymer (b);

Tosoh Corporation, GMH _HR -H + GMH _HR -H + G2000H _HR

Column size; 7.8 mm ψ × 30 cm (90 cm total)

Flow rate: 0.8 ml / min

Injection sample concentration: about 0.1% by weight

Injection volume: 100 μ1

Column temperature: 40 ℃

Eluent: Tetrahydrofuran

Detector: Differential Refractometer (RI)

In addition, molecular weight was computed by polystyrene conversion.

<Measurement of gel fraction>

Each of the examples and comparative examples by taking out the pressure-sensitive adhesive layer W ₁ g (about 0.1g) prepared in, followed by immersion for one week at room temperature (about 25 ℃) in ethyl acetate. Thereafter, the pressure-sensitive adhesive layer was taken out in ethyl acetate, the weight W ₂ g after drying for 2 hours at 130 ° C. was measured, and a value calculated as (W ₂ / W ₁ ) × 100 (% by weight) was obtained by gel. It was set as the fraction (weight%).

<Measurement of Adhesion (Initial Adhesion, Adhesion After 70 ° C Heating, and Adhesion After 90 ° C Storage)>

The manufactured optical member (width: 25 mm) was affixed on the alkali free glass plate (The Corning company make, 1737), and autoclave-processed for 15 minutes by the pressure of 50 degreeC and 0.5 MPa. Thereafter, storage was carried out at 23 ° C. × 60% RH for 3 hours to obtain a sample for evaluation (a).

The adhesive force (N / 25mm) at the time of peeling the said sample for evaluation (a) by peeling rate 300mm / min peeling angle 90 degrees with the universal tensile tester was measured. The measurement was performed under the environment of 23 ° C. × 60% RH.

After the autoclave treatment, the sample was subsequently stored at 70 ° C. for 48 hours and then stored at 23 ° C. × 60% RH for 3 hours to obtain a sample for evaluation (b).

The adhesive force (N / 25mm) after the heat processing at the time of peeling the said sample for evaluation (b) by peeling speed | rate 300mm / min peeling angle 90 degrees with the universal tensile tester was measured. The measurement was carried out under an environment of 23 ° C. × 60% RH.

Further, after the autoclave treatment, the sample was subsequently stored at 90 ° C. for 300 hours, and then stored at 23 ° C. × 60% RH for 3 hours to obtain a sample for evaluation (c).

The adhesive force (N / 25mm) after the heat processing at the time of peeling the said sample for evaluation (c) by peeling rate 300mm / min peeling angle 90 degrees with the universal tension tester was measured. The measurement was performed under the environment of 23 ° C. × 60% RH.

<Evaluation of Durability>

The prepared optical member was cut to a size of 200 mm in width x 260 mm in width, and attached to an alkali-free glass plate (1737, Corning Corporation, size: 250 x 350 mm, thickness: 0.7 mm), at a pressure of 50 ° C. and 0.5 MPa. The autoclave process was performed for 30 minutes. Thereafter, the sample was stored at 60 ° C for 500 hours and then returned to room temperature (about 25 ° C) to obtain a sample for evaluation.

The adhesion state to the glass plate of the said evaluation sample was observed and evaluated. Evaluation criteria are as follows.

No lifting or peeling of the optical member occurred:

Lifting or peeling of the optical member occurs: ×

<Evaluation of Color Deviation>

The optical member thus prepared was cut into a size of 200 mm in width x 260 mm in width, and attached to both sides of an alkali-free glass plate (1,737, manufactured by Corning Corporation, size: 250 x 350 mm, thickness: 0.7 mm) so that the absorption axis of the polarizing plate went straight. The autoclave process was performed for 30 minutes by the pressure of 50 degreeC and 0.5 Mpa. Thereafter, the sample was stored at 90 ° C for 500 hours and then returned to room temperature (about 25 ° C) to obtain a sample for evaluation.

The state of the color deviation of the said evaluation sample was visually observed and evaluated. Evaluation criteria are as follows.

If no occurrence of color deviation is observed: ○

When the occurrence of color deviation is observed: ×

<Full Survival Evaluation>

The state of the surface of the acrylic-free glass plate after peeling the said sample for evaluation (c) by peeling speed | rate 300mm / min peeling angle 90 degrees with the universal tensile tester was visually observed and evaluated. Evaluation criteria are as follows.

If no debris is observed: ○

When grass debris is observed: ×

<Evaluation of Machinability>

The punching process was performed on the manufactured optical member using the press machine, without performing an aging process.

The state of the cutting knife at the time of the said processing process was visually observed and evaluated. Evaluation criteria are as follows.

When no adhesion or damage of the pressure-sensitive adhesive layer is observed: ○

When adhesion or damage of the pressure-sensitive adhesive layer is observed: ×

<Production of (meth) acrylic polymer>

[Acrylic polymer (a1)]

100 parts by weight of 2-ethylhexyl acrylate, 0.5 part by weight of acrylic acid, 0.1 part by weight of 2-hydroxyethyl acrylate, and 2, as polymerization initiators in a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas introduction tube, and a cooler. 0.1 part by weight of 2'-azobisisobutyronitrile and 200 parts by weight of ethyl acetate were added thereto, nitrogen gas was introduced therein under gentle stirring for nitrogen substitution, and the liquid temperature in the flask was kept at about 55 ° C for 20 hours to polymerize. Was carried out to prepare an acrylic polymer (a1) solution. The weight average molecular weight of the said acrylic polymer (a1) was 1,320,000. The carboxylic acid equivalent of the obtained acrylic polymer (al) was 0.69 × 10 ^-4 equivalents (eq) / g.

[Acrylic polymer (a2)]

100 parts by weight of isooctyl acrylate, 0.3 parts by weight of acrylic acid, 0.1 parts by weight of 2-hydroxyethyl acrylate, and 2,2 as polymerization initiators in a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas introduction tube, and a cooler. 0.1 parts by weight of azobisisobutyronitrile and 200 parts by weight of ethyl acetate were added thereto, nitrogen gas was introduced and nitrogen was replaced with gentle stirring, and the liquid temperature in the flask was kept at about 55 ° C for 12 hours to carry out the polymerization reaction. It carried out and manufactured the acrylic polymer (a2) solution. The weight average molecular weight of the said acrylic polymer (a2) was 950,000. The carboxylic acid equivalent of the obtained acrylic polymer (a2) was 0.41x10 <^-4> equivalent (eq) / g.

[Acrylic polymer (a3)]

100 parts by weight of 2-ethylhexyl acrylate, 6 parts by weight of acrylic acid, 0.1 parts by weight of 2-hydroxyethyl acrylate, 2, as a polymerization initiator, into a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas introduction tube, and a cooler. 0.1 part by weight of 2'-azobisisobutyronitrile and 200 parts by weight of ethyl acetate were added thereto, nitrogen gas was introduced thereto under gentle agitation, followed by nitrogen substitution, and the liquid temperature in the flask was kept at about 55 ° C for 20 hours to polymerize. Was carried out to prepare an acrylic polymer (a3) solution. The weight average molecular weight of the said acrylic polymer (a3) was 128 million. The carboxylic acid equivalent of the obtained acrylic polymer (a3) was 8.22x10 <^-4> equivalent (eq) / g.

[Acrylic polymer (b1)]

In a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas introduction tube, and a cooler, 50 parts by weight of butyl acrylate, 50 parts by weight of 2-ethylhexyl acrylate, 5 parts by weight of acrylic acid, 0.8 parts by weight of lauryl mercaptan, and polymerization 0.1 part by weight of 2,2'-azobisisobutyronitrile was added as an initiator, nitrogen gas was introduced therein while the mixture was gently stirred with gentle stirring, and the polymerization was carried out for 12 hours while maintaining the liquid temperature in the flask at around 55 ° C. To prepare an acrylic polymer (b1) solution. The weight average molecular weight of the said acrylic polymer (b1) was 31000. The carboxylic acid equivalent of the obtained acrylic polymer (b1) was 6.89x10 <^-4> equivalent (eq) / g.

[Acrylic polymer (b2)]

In a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas introduction tube, and a cooler, 100 parts by weight of butyl acrylate, 7 parts by weight of acrylic acid, 1 part by weight of lauryl mercaptan, and 2,2'-azobisiso as a polymerization initiator 0.1 part by weight of butyronitrile was introduced, nitrogen gas was introduced with gentle stirring, and nitrogen was replaced. Then, the liquid temperature in the flask was maintained at around 55 ° C for a polymerization reaction for 12 hours to prepare an acrylic polymer (b2) solution. . The weight average molecular weight of the said acrylic polymer (b2) was 21000. The carboxylic acid equivalent of the obtained acrylic polymer (b2) was 9.59 × 10 ^-4 equivalents (eq) / g.

[Acrylic polymer (b3)]

In a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas introduction tube, and a cooler, 50 parts by weight of butyl acrylate, 50 parts by weight of 2-ethylhexyl acrylate, 1 part by weight of acrylic acid, 0.8 part by weight of lauryl mercaptan, and polymerization 0.1 part by weight of 2,2'-azobisisobutyronitrile was added as an initiator, nitrogen gas was introduced therein while the mixture was gently stirred with gentle stirring, and the polymerization was carried out for 12 hours while maintaining the liquid temperature in the flask at around 55 ° C. And the acrylic polymer (b3) solution was prepared. The weight average molecular weight of the said acrylic polymer (b3) was 850,000. The carboxylic acid equivalent of the obtained acrylic polymer (b3) was 1.45x10 <^-4> equivalent (eq) / g.

Example 2-1

(Manufacture of adhesive solution for optical members)

0.5 part by weight of the acrylic polymer (b1) solution (solid content), 100 parts by weight of the acrylic polymer (a1) solution (solid content), 0.1 part by weight of 3-glycidyloxypropyltrimethoxysilane as the silane coupling agent, As a crosslinking agent, 0.8 weight part of trimethylol propane / tolylene diisocyanate trimer adduct, and 0.35 weight part of dibenzoyl peroxides (half life temperature: 130.0 degreeC for 1 minute) are added, it is mixed and stirred uniformly, and an acrylic adhesive The solution (1) was prepared.

(Production of Adhesive-Attached Optical Member)

The acrylic pressure sensitive adhesive solution 1 was applied to one surface of a siliconized polyethylene terephthalate film (manufactured by Toray Corporation, thickness: 38 μm), and decomposed peroxide at 130 ° C. for 3 minutes (calculated by theory calculation). The amount heated about 88 weight%), and the adhesive layer of 25 micrometers in thickness after drying was formed.

Then, the said adhesive layer was bonded to the surface of a polarizing film, and the adhesive-adhered optical member was manufactured. In addition, the gel fraction of the said adhesive layer was 75 weight%.

Example 2-2

(Manufacture of adhesive solution for optical members)

An acrylic pressure-sensitive adhesive solution (2) was prepared in the same manner as in Example 2-1, except that 0.2 weight part of the acrylic polymer (bl) solution (solid content) was used instead of 0.5 weight part of the acrylic polymer (b1) solution (solid content). .

(Production of Adhesive-Attached Optical Member)

A pressure-sensitive adhesive optical member was manufactured in the same manner as in Example 2-1, except that the acrylic pressure-sensitive adhesive solution 2 was used instead of the acrylic pressure-sensitive adhesive solution 1. In addition, the gel fraction of the said adhesive layer was 68 weight%.

Example 2-3

(Manufacture of adhesive solution for optical members)

An acrylic pressure-sensitive adhesive solution (3) was prepared in the same manner as in Example 2-1, except that 0.9 parts by weight of the acrylic polymer (b1) solution (solid content) was used instead of 0.5 parts by weight of the acrylic polymer (b1) solution (solid content). .

(Production of Adhesive-Attached Optical Member)

A pressure-sensitive adhesive optical member was manufactured in the same manner as in Example 2-1, except that the acrylic pressure-sensitive adhesive solution 3 was used instead of the acrylic pressure-sensitive adhesive solution 1. In addition, the gel fraction of the said adhesive layer was 60 weight%.

Examples 2-4

(Production of Adhesive-Attached Optical Member)

The acrylic pressure-sensitive adhesive solution 1 was applied to one side of a siliconized polyethylene terephthalate film (manufactured by Toray Corporation, thickness: 38 μm) and decomposed peroxide at 140 ° C. for 3 minutes (calculated by theoretical calculation). The amount heated about 90 weight%), and the adhesive layer whose thickness after drying is 25 micrometers was formed.

Then, the said adhesive layer was bonded to the surface of a polarizing film, and the adhesive-adhered optical member was manufactured. In addition, the gel fraction of the said adhesive layer was 78 weight%.

Example 2-5

(Manufacture of adhesive solution for optical members)

0.3 weight part of said acrylic polymer (b2) solutions (solid content), 0.1 weight part of 3-acrylooxypropyl trimethoxysilane as a silane coupling agent, in 100 weight part of said acrylic polymer (a2) solutions (solid content), a crosslinking agent 1 part by weight of trimethylolpropane / tolylenediisocyanate trimer adduct and 0.35 part by weight of dibenzoyl peroxide (1 minute half-life temperature: 130.0 ° C.) were added to the mixture, followed by uniformly mixing and stirring. (4) was manufactured.

(Production of Adhesive-Attached Optical Member)

The acrylic pressure-sensitive adhesive solution 4 was applied to one side of a silicone-treated polyethylene terephthalate film (manufactured by Toray Corporation, thickness: 38 μm) and decomposed peroxide at 130 ° C. for 3 minutes (calculated by theoretical calculation). The amount was heated to about 8 to 8% by weight) to form a pressure-sensitive adhesive layer having a thickness of 25 µm after drying.

Then, the said adhesive layer was bonded to the surface of a polarizing film, and the adhesive-adhered optical member was manufactured. In addition, the gel fraction of the said adhesive layer was 74 weight%.

Examples 2-6

(Manufacture of adhesive solution for optical members)

An acrylic pressure-sensitive adhesive solution (5) was prepared in the same manner as in Example 2-1, except that 0.1 weight part of the acrylic polymer (b1) solution (solid content) was used instead of 0.5 weight part of the acrylic polymer (b1) solution (solid content).

(Production of Adhesive-Attached Optical Member)

A pressure-sensitive adhesive optical member was manufactured in the same manner as in Example 2-1, except that the acrylic pressure-sensitive adhesive solution 5 was used instead of the acrylic pressure-sensitive adhesive solution 1. In addition, the gel fraction of the said adhesive layer was 60 weight%.

Examples 2-7

(Manufacture of adhesive solution for optical members)

An acrylic pressure-sensitive adhesive solution 6 was prepared in the same manner as in Example 2-1, except that 2 parts by weight of the acrylic polymer (b1) solution (solid content) was used instead of 0.5 parts by weight of the acrylic polymer (b1) solution (solid content).

(Production of Adhesive-Attached Optical Member)

A pressure-sensitive adhesive optical member was manufactured in the same manner as in Example 2-1, except that the acrylic pressure-sensitive adhesive solution 6 was used instead of the acrylic pressure-sensitive adhesive solution 1. In addition, the gel fraction of the said adhesive layer was 54 weight%.

Comparative Example 2-1

(Manufacture of adhesive solution for optical members)

Except not using the said acrylic polymer (bl) solution (solid content), the acrylic adhesive solution 7 was manufactured by the method similar to Example 2-1.

(Production of Adhesive-Attached Optical Member)

A pressure-sensitive adhesive optical member was produced in the same manner as in Example 2-1 except that the acrylic pressure-sensitive adhesive solution 7 was used instead of the acrylic pressure-sensitive adhesive solution 1. In addition, the gel fraction of the said adhesive layer was 71 weight%.

Comparative Example 2-2

(Manufacture of adhesive solution for optical members)

An acrylic adhesive solution 8 was prepared in the same manner as in Example 2-1, except that 5 parts by weight of the acrylic polymer (b1) solution (solid content) was used instead of 0.5 parts by weight of the acrylic polymer (b1) solution (solid content). did.

(Production of Adhesive-Attached Optical Member)

A pressure-sensitive adhesive optical member was produced in the same manner as in Example 2-1 except that the acrylic pressure-sensitive adhesive solution 8 was used instead of the acrylic pressure-sensitive adhesive solution 1. In addition, the gel fraction of the said adhesive layer was 40 weight%.

Comparative Example 2-3

(Manufacture of adhesive solution for optical members)

Except not using the said silane coupling agent, the acrylic adhesive solution 9 was manufactured by the method similar to Example 2-1.

(Production of Adhesive-Attached Optical Member)

A pressure-sensitive adhesive optical member was manufactured in the same manner as in Example 2-1 except that the acrylic pressure-sensitive adhesive solution 9 was used instead of the acrylic pressure-sensitive adhesive solution 1. In addition, the gel fraction of the said adhesive layer was 71 weight%.

Comparative Example 2-4

(Manufacture of adhesive solution for optical members)

An acrylic pressure-sensitive adhesive according to the same method as in Example 2-1 except for using 3 parts by weight of the 3-glycidyloxypropyl trimethoxy silane instead of 0.1 part by weight of the 3-glycidyloxypropyl trimethoxy silane. Solution 10 was prepared.

(Production of Adhesive-Attached Optical Member)

A pressure-sensitive adhesive optical member was manufactured in the same manner as in Example 2-1, except that the acrylic pressure-sensitive adhesive solution 10 was used instead of the acrylic pressure-sensitive adhesive solution 1. In addition, the gel fraction of the said adhesive layer was 47 weight%.

Comparative Example 2-5

(Manufacture of adhesive solution for optical members)

An acrylic pressure-sensitive adhesive according to the same method as Example 2-1 except for using 0.01 parts by weight of the dibenzoyl peroxide (1 minute half-life temperature: 130.0 ° C) instead of 0.35 parts by weight of the dibenzoyl peroxide (1 minute half-life temperature: 130.0 ℃) Solution 11 was prepared.

(Production of Adhesive-Attached Optical Member)

A pressure-sensitive adhesive optical member was manufactured in the same manner as in Example 2-1, except that the acrylic pressure-sensitive adhesive solution 11 was used instead of the acrylic pressure-sensitive adhesive solution 1. In addition, the gel fraction of the said adhesive layer was 50 weight%.

Comparative Example 2-6

(Manufacture of adhesive solution for optical members)

Instead of 0.35 parts by weight of the dibenzoyl peroxide (1 minute half-life temperature: 130.0 ° C.), 0.01 parts by weight of the dibenzoyl peroxide (1 minute half-life temperature: 130.0 ° C.), and the trimethylolpropane / tolylene diiso The acrylic pressure-sensitive adhesive solution was prepared in the same manner as in Example 2-1 except that 0.15 parts by weight of the trimethylolpropane / tolylenediisocyanate trimer adduct was used instead of 0.8 parts by weight of the cyanate trimer adduct. ).

(Production of Adhesive-Attached Optical Member)

A pressure-sensitive adhesive optical member was manufactured in the same manner as in Example 2-1 except that the acrylic pressure-sensitive adhesive solution 12 was used instead of the acrylic pressure-sensitive adhesive solution 1. In addition, the gel fraction of the said adhesive layer was 35 weight%.

Comparative Example 2-7

(Production of Adhesive-Attached Optical Member)

The acrylic pressure-sensitive adhesive solution 1 was applied to one side of a silicon-treated polyethylene terephthalate film (manufactured by Toray Corporation, thickness: 38 μm) and decomposed peroxide at 110 ° C. for 3 minutes (calculated by theoretical calculation). The amount heated about 19 weight%), and the adhesive layer whose thickness after drying is 25 micrometers was formed.

Subsequently, the pressure-sensitive adhesive layer was bonded to the surface of the polarizing film to prepare a pressure-sensitive adhesive optical member. In addition, the gel fraction of the said adhesive layer was 55 weight%.

Comparative Example 2-8

(Manufacture of adhesive solution for optical members)

0.5 part by weight of the acrylic polymer (b3) solution (solid content), 100 parts by weight of the acrylic polymer (a3) solution (solid content), 0.1 part by weight of 3-glycidyloxypropyltrimethoxysilane as a silane coupling agent, As a crosslinking agent, 0.8 parts by weight of trimethylolpropane / tolylenediisocyanate trimer adduct and 0.35 parts by weight of dibenzoylperoxide (1 minute half-life temperature: 130.0 ° C.) were added, and the mixture was stirred uniformly to give an acrylic pressure-sensitive adhesive solution. (13) was manufactured.

(Production of Adhesive-Attached Optical Member)

The acrylic pressure sensitive adhesive solution 13 was applied to one surface of a siliconized polyethylene terephthalate film (manufactured by Toray Corporation, thickness: 38 μm), and decomposed peroxide at 130 ° C. for 3 minutes (calculated by theoretical calculation). The amount was about 88 weight%), and the adhesive layer which is 25 micrometers in thickness after drying was formed.

Then, the said adhesive layer was bonded to the surface of a polarizing film, and the adhesive-adhered optical member was manufactured. In addition, the gel fraction of the said adhesive layer was 52 weight%.

According to the above method, measurement of the adhesive force of the prepared adhesive-attached optical member (initial adhesive strength, adhesive strength after 70 ° C. heat treatment, and adhesive strength after 90 ° C. preservation treatment), and durability, color deviation, full residual property, and processability evaluation were evaluated. Carried out. The results obtained are shown in Table 2.

From the results of Table 2, in the case of using the pressure-sensitive adhesive-attached optical member produced according to the present invention (Examples 2-1 to 7), the difference between the initial adhesive force and the adhesive force after 70 ° C. heat treatment was small in any of the examples, It can be seen that there is almost no increase in adhesion force when attached to the liquid crystal cell. In addition, it is excellent in durability after peeling off long-term high-temperature and high-humidity treatment (no peeling and foaming), and relaxation of stress caused by the dimensional change of the optical member (polarizing plate), and the adverse effect (color deviation) to the liquid crystal display state. In addition, it became clear that the adhesive strength after a long-term high temperature, high humidity treatment was small, and excellent in pool | survival persistence. Moreover, in all the Examples, the punching workability was also excellent.

On the other hand, when using the adhesive-attached optical member which does not satisfy the structure of this invention (Comparative Examples 2-1-8), also in any comparative example, durability after high temperature, high humidity process, generation of a color deviation, suppression of the increase of adhesive force is suppressed. , And the result that the pool persistence cannot be coexisted, it became clear that it was not suitable for an adhesive-attached optical member.

As mentioned above, even if the adhesive-attached optical member of this invention is preserve | saved under severe processing conditions, it is excellent in re-peelability, durability, and stress relaxation property, and suppressed the increase of pool | survival persistence and adhesive force, and when discarding etc. It can be seen that the increase in adhesive force is suppressed even after a prolonged state of attachment. Therefore, by using the adhesive-attached optical member of the present invention, the recycling process for separating the glass portion and the optical member can be easily performed.

Next, although the Example etc. at the time of using an acryl-type polymer (Al) are demonstrated, this invention is not limited to these. In addition, the evaluation item in the Example etc. measured as follows.

<Measurement of molecular weight>

Molecular weight was measured by GPC (gel permeation chromatography).

Analysis device: Tosoh Corporation, HLC-8120 GPC

Data Processing Unit: Tosoh Corporation, GPC-8020

column:

Sample column;

Tososa products, G7000H _XL + GMH _XL + GMH _XL

Column size; 7.8mmψ × 30cm (90cm in total)

Flow rate: 0.8 ml / min

Injection sample concentration: about 0.1% by weight

Injection volume: 100 μl

Column temperature: 40 ℃

Eluent: Tetrahydrofuran

Detector: Differential Refractometer (RI)

In addition, molecular weight was computed by polystyrene conversion.

<Measurement of peroxide decomposition amount>

The amount of peroxide decomposition after the pyrolysis treatment was measured by HPLC (high performance liquid chromatography).

About 0.2 g of each pressure-sensitive adhesive composition before and after the decomposition treatment was taken out, immersed in 10 ml of ethyl acetate, shaken and extracted at 120 ° C. for 3 hours at 25 ° C. with a shaker, and then left at room temperature for 3 days. Subsequently, 10 acetonitrile was added, the mixture was shaken at 120 rpm for 30 minutes at 25 ° C., and about 10 μl of the extract obtained by filtration with a membrane filter (0.45 μm) was injected into HPLC, analyzed, and peroxide before and after the decomposition treatment. Reduction of quantity was made into the amount of peroxide decomposition.

Device: Tosoh Corporation, HPL CCPM / UV8000

column:

 Sample column; MACHEREY-NAGEL, NUCLEOSIL 7C18 (4.6mmψ × 250mm)

Flow rate: 1.0ml / min

Column pressure: 41kg / cm ²

Column temperature: 40 ℃

Eluent: water / acetonitrile = 30/70

Injection volume: 10 μl

Injection sample concentration: 0.01% by weight

Detector: UV detector (230 nm).

<Measurement of gel fraction>

The pressure-sensitive adhesive layer prepared in each of Examples and Comparative Examples was taken out of W ₁ g (about 0. lg) and immersed in ethyl acetate at room temperature (about 25 ° C.) for 1 week. Thereafter, the immersed pressure-sensitive adhesive layer was taken out in ethyl acetate, the weight W ₂ g after drying at 130 ° C. for 2 hours was measured, and the value calculated as (W ₂ / W ₁ ) × 100 (wt%) was determined by the gel fraction. It was set as (weight%).

<Measurement of adhesive force (initial peel adhesive force, peel adhesive force after 70 ° C. heat treatment)>

The prepared optical member (width: 25 mm) was attached to an alkali-free glass plate (Corning Corporation, 1737) once by reciprocating once with a roll of 2 kg, and subjected to autoclave treatment at a pressure of 50 MPa and 0.5 MPa for 30 minutes. Thereafter, storage was carried out at 23 ° C. × 50% RH for 3 hours to obtain a sample for evaluation (a).

The initial peeling adhesive force (N / 25mm) at the time of peeling the said sample for evaluation (a) by peeling rate 300mm / min peeling angle 90 degrees with the universal tensile tester was measured. The measurement was performed in an environment of 23 ° C. × 50% RH.

After the autoclave treatment, the sample was subsequently stored at 70 ° C. for 6 hours, and then stored at 23 ° C. × 50% RH for 3 hours to obtain a sample for evaluation (b).

The peeling adhesive force (N / 25mm) after the heat processing at the time of peeling the said sample for evaluation (b) by peeling rate 300mm / min peeling angle 90 degrees with the universal tension tester was measured. The measurement was performed in an environment of 23 ° C. × 50% RH.

<Evaluation of Durability>

The optical member thus prepared was cut into a size of 250 mm in width x 200 mm in width, and attached with an alkali-free glass plate (1,737, manufactured by Corning Corporation, size: 250 x 350 mm, thickness: 0.7 mm), at a temperature of 50 ° C. and 0.5 MPa. Autoclave treatment was performed for a minute. Then, after storing for 500 hours in 60 degreeC x 90% RH atmosphere, it returned to room temperature (about 25 degreeC) and obtained the sample for evaluation.

The adhesion state to the glass plate of the said evaluation sample was observed and evaluated. Evaluation criteria are as follows.

If no lifting or peeling of the optical member occurs: ○

When lifting or peeling of the optical member occurs: ×

<Evaluation of Machinability>

The punching process was performed on the manufactured optical member using the press machine, without performing an aging process.

The state of the cutting knife at the time of the said processing process was visually observed and evaluated. Evaluation criteria are as follows.

When no adhesion or damage of the pressure-sensitive adhesive layer is observed: ○

Adhesion or damage of adhesive layer is observed: ×

<Evaluation of coloring>

The prepared optical member (thickness of the adhesive layer: 140 micrometers) was cut | disconnected to the magnitude | size of 20 mm in width x 50 mm in width, and it was set as the sample for evaluation before heat processing.

Subsequently, heat processing were performed at 110 degreeC for 100 hours. Then, it returned to room temperature (about 25 degreeC), and obtained the sample for evaluation after heat processing.

The color difference of the said sample for evaluation was measured with the instantaneous multi-photometer (Otsuka Electronics Co., Ltd., MCPD3000, a standard light source: CIE-D65, viewing angle: 2 degrees), and chromaticity evaluation was performed using the sample for evaluation before and behind heat processing. did. In addition, the evaluation method of a color difference, and the evaluation criteria of colorability are as follows.

The color difference is a value expressed by ΔE ^* ab, and ΔE ^* ab = ((L ^* ₂ -L ^* ₁ ) ² + (a ^* ₂ -a ^* ₁ ) ² + (b ^* ₂ -b ^* ₁ ) ² ] ^It calculated by ^1/2 . Here, L ^* , a ^* , b ^* refer to the values defined by the CIE 1976 colorimeter, and L ^* ₂ , a ^* ₂ , b ^* ₂ refer to L ^* , of the sample for evaluation after heat processing at 110 degreeC for 100 hours, respectively. a ^* , b ^* , and L ^* ₁ , a ^* ₁ , b ^* ₁ are L ^* , a ^* , b ^* of the sample for evaluation before a heat processing at 110 degreeC, respectively, for 100 hours.

In addition, evaluation criteria of color difference and colorability are as follows.

When the color difference (ΔE ^* ab) is 2.0 or less: ○

If the color difference (ΔE ^* ab) exceeds 2.0: ×

<Production of (meth) acrylic polymer>

[Acrylic polymer (a)]

50 weight part of 2-ethylhexyl acrylate, 45 weight part of butyl acrylate, 5 weight part of acrylic acid, 0.3 weight of 2-hydroxybutyl acrylate to a four neck flask equipped with a stirring blade, a thermometer, a nitrogen gas introduction tube, and a cooler In addition, 0.1 weight part of 2,2'- azobis isobutyronitrile and 200 weight part of ethyl acetate were prepared as a polymerization initiator, nitrogen gas was introduce | transduced by nitrogen stirring, stirring gently, and the liquid temperature in a flask was near 55 degreeC. The polymerization reaction was performed for 20 hours, and the acrylic polymer (a) solution was prepared. The weight average molecular weight of the said acrylic polymer (a) was 1.25 million.

[Acrylic polymer (b)]

In a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas introduction tube, and a cooler, 60 parts by weight of isononyl acrylate, 40 parts by weight of butyl acrylate, 0.5 parts by weight of acrylic acid, and 0.2 parts by weight of 2-hydroxyethyl acrylate 0.1 parts by weight of 2,2'-azobisisobutyronitrile and 200 parts by weight of ethyl acetate were added as a polymerization initiator, nitrogen gas was introduced therein while being stirred with gentle stirring, and then the liquid temperature in the flask was brought to around 55 ° C. The polymerization reaction was carried out for 20 hours to prepare an acrylic polymer (b) solution. The weight average molecular weight of the said acrylic polymer (b) was 1,120,000.

[Acrylic polymer (c)]

95 weight part of butyl acrylate, 5 weight part of acrylic acid, 0.1 weight part of 2-hydroxyethyl acrylate, 0.2 weight of benzoyl peroxide as a polymerization initiator to the four neck flask equipped with the stirring blade, the thermometer, the nitrogen gas introduction tube, and the cooler. Then, 200 parts by weight of ethyl acetate was introduced, nitrogen gas was introduced with gentle stirring, and nitrogen was replaced. The liquid temperature in the flask was maintained at about 55 ° C. to carry out a polymerization reaction for 20 hours to prepare an acrylic polymer (c) solution. did. The weight average molecular weight of the said acrylic polymer (c) was 1.35 million. Moreover, 0.06 weight part remained as a result of performing quantification of residual peroxide by HPLC (high speed liquid chromatography).

Example 3-1

(Manufacture of adhesive solution for optical members)

0.1 parts by weight of 3-glycidyloxypropyltrimethoxysilane as the silane coupling agent and 100 parts by weight of the solid content of the acrylic polymer (a) solution, and trimethylolpropane of isophorone diisocyanate as the crosslinking agent. 0.5 weight part of adduct (Madei Takeda Chemical, Takenate D-140N), and 0.1 weight part of dibenzoyl peroxides (1 minute half life temperature: 130.0 degreeC) are added, it is mixed and stirred uniformly, and an acrylic adhesive solution (1) Prepared.

(Production of Adhesive-Attached Optical Member)

The acrylic pressure-sensitive adhesive solution 1 was applied to one side of a siliconized polyethylene terephthalate film (manufactured by Toray Corporation, thickness: 38 μm) and decomposed peroxide at 130 ° C. for 3 minutes (calculated by theory calculation). The amount heated about 88 weight%), and the adhesive layer whose thickness after drying is 25 micrometers was formed.

Subsequently, after impregnating and extending | stretching an iodine in a polyvinyl alcohol film, the said adhesive layer is transferred to the surface of the polarizing film manufactured by adhering a triacetyl cellulose film through the adhesive on both sides, and manufacturing an adhesive-adhering optical member. did. In addition, the gel fraction of the said adhesive layer was 76 weight%.

Example 3-2

(Production of Adhesive-Attached Optical Member)

The acrylic pressure-sensitive adhesive solution 1 was applied to one side of a siliconized polyethylene terephthalate film (manufactured by Toray Corporation, thickness: 38 μm) and decomposed peroxide at 140 ° C. for 3 minutes (calculated by theoretical calculation). The amount was heated to about 99% by weight) to form a pressure-sensitive adhesive layer having a thickness of 25 µm after drying.

Subsequently, the polyvinyl alcohol film is impregnated with iodine and stretched, and then the pressure-sensitive adhesive layer is transferred onto the surface of the polarizing film produced by adhering the triacetyl cellulose film through an adhesive on both sides, thereby obtaining the pressure-sensitive adhesive optical member. Manufactured. In addition, the gel fraction of the said adhesive layer was 82 weight%.

Example 3-3

(Manufacture of adhesive solution for optical members)

Trimethylolpropane adduct of hydrogenated xylenediisocyanate as a crosslinking agent instead of 0.5 parts by weight of the trimethylolpropane adduct of the isophorone diisocyanate (manufactured by Mitsui Takeda Chemical, Takenet D-120N ) An acrylic pressure-sensitive adhesive solution (2) was prepared in the same manner as in Example 3-1, except that 0.5 parts by weight was used.

(Production of Adhesive-Attached Optical Member)

An adhesive-attached optical member was produced in the same manner as in Example 3-1, except that the acrylic adhesive solution (2) was used instead of the acrylic adhesive solution (1). In addition, the gel fraction of the said adhesive layer was 69 weight%.

Comparative Example 3-1

(Manufacture of adhesive solution for optical members)

Instead of 0.5 parts by weight of the trimethylolpropane adduct of the isophorone diisocyanate, a trimethylolpropane adduct of tolylenediisocyanate (manufactured by Mitsui Takeda Chemical Co., Takenet D-) as a crosslinking agent. 101N) The acrylic adhesive solution 3 was manufactured by the method similar to Example 3-1 except having used 0.5 weight part.

(Production of Adhesive-Attached Optical Member)

A pressure-sensitive adhesive optical member was manufactured in the same manner as in Example 3-1, except that the acrylic pressure-sensitive adhesive solution 3 was used instead of the acrylic pressure-sensitive adhesive solution 1. In addition, the gel fraction of the said adhesive layer was 77 weight%.

Comparative Example 3-2

(Manufacture of adhesive solution for optical members)

Trimethylolpropane adduct of xylenediisocyanate as a crosslinking agent instead of 0.5 parts by weight of the trimethylolpropane adduct of the isophorone diisocyanate (manufactured by Mitsui Takeda Chemical, Takenet D-110N) Attempts were made to produce the acrylic pressure-sensitive adhesive solution 4 in the same manner as in Example 3-1, except that 0.5 parts by weight was used, but after 15 minutes had elapsed after the mixing, the viscosity rapidly increased and coating could not be performed.

Comparative Example 3-3

(Manufacture of adhesive solution for optical members)

Except not using the said dibenzoyl peroxide, the acrylic adhesive solution 5 was manufactured by the method similar to Example 3-1.

(Production of Adhesive-Attached Optical Member)

A pressure-sensitive adhesive optical member was manufactured in the same manner as in Example 3-1, except that the acrylic pressure-sensitive adhesive solution 5 was used instead of the acrylic pressure-sensitive adhesive solution 1. In addition, the gel fraction of the said adhesive layer was 61 weight%.

Comparative Example 3-4

(Manufacture of adhesive solution for optical members)

Except not using the trimethylolpropane adduct of the said isophorone diisocyanate, the acrylic adhesive solution 6 was manufactured by the method similar to Example 3-1.

(Production of Adhesive-Attached Optical Member)

A pressure-sensitive adhesive optical member was manufactured in the same manner as in Example 3-1, except that the acrylic pressure-sensitive adhesive solution 6 was used instead of the acrylic pressure-sensitive adhesive solution 1. In addition, the gel fraction of the said adhesive layer was 58 weight%.

Example 3-4

(Manufacture of adhesive solution for optical members)

0.1 weight part of 3-glycidyl oxypropyl trimethoxysilane as a silane coupling agent, and a trimer of hexamethylene diisocyanate as a crosslinking agent in 100 weight part of solid content of the said acryl-type polymer (b) solution Anurate) (0.2 parts by weight of Takeda Chemical Co., Ltd., Takenet D-170N), and 0.1 parts by weight of dibenzoyl peroxide (1 minute half-life temperature: 130.0 ° C) were added and uniformly mixed and stirred to obtain an acrylic pressure-sensitive adhesive solution ( 7) was prepared.

(Production of Adhesive-Attached Optical Member)

The acrylic pressure sensitive adhesive solution 7 was applied to one side of a siliconized polyethylene terephthalate film (manufactured by Toray Corporation, thickness: 38 μm) and decomposed peroxide at 130 ° C. for 3 minutes (calculated by theoretical calculation). The amount heated about 88 weight%), and the adhesive layer of 25 micrometers in thickness after drying was formed.

Subsequently, after the polyvinyl alcohol film is impregnated with iodine and stretched, the pressure-sensitive adhesive layer is transferred onto the surface of the polarizing film produced by adhering the triacetyl cellulose film through an adhesive on both sides, thereby obtaining the pressure-sensitive adhesive optical member. Manufactured. In addition, the gel fraction of the said adhesive layer was 78 weight%.

Example 3-5

(Manufacture of adhesive solution for optical members)

Trimethylolpropane of isophorone diisocyanate as 0.08 weight part of 3-glycidyloxypropyl trimethoxysilane as a silane coupling agent in 100 weight part of solid content of the said acryl-type polymer (c) solution 0.5 weight part of adduct (Madei Takeda Chemical, Takenet D-140N), and 0.14 weight part of dibenzoyl peroxide (1 minute half-life temperature: 130.0 degreeC) are added, it is mixed and stirred uniformly, and an acrylic adhesive solution (8) Prepared.

(Production of Adhesive-Attached Optical Member)

The acrylic pressure-sensitive adhesive solution 8 was applied to one side of a siliconized polyethylene terephthalate film (manufactured by Toray Corporation, thickness: 38 μm) and decomposed peroxide at 140 ° C. for 3 minutes (calculated by theoretical calculation). The amount was heated to about 99% by weight) to form a pressure-sensitive adhesive layer having a thickness of 25 µm after drying.

Subsequently, after impregnating and extending | stretching iodine to a polyvinyl alcohol film, the said adhesive layer was transferred to the surface of the polarizing film produced by adhering a triacetyl cellulose film through the adhesive on both sides, and the adhesive-adhering optical member was produced. . In addition, the gel fraction of the said adhesive layer was 82 weight%.

The measurement of the adhesive force (initial peeling adhesive force and the peeling adhesive force after 70 degreeC heat processing) of the adhesive-adhering optical member manufactured by the said method, and durability, workability, and coloring property were evaluated. The results obtained are shown in Table 3.

From the results in Table 3 above, in the case of using the pressure-sensitive adhesive-attached optical member produced according to the present invention (Examples 3-1 to 5), in any of the examples, the increase in the peel adhesion after the 70 ° C heat treatment was small and was applied to the liquid crystal cell. It can be seen that there is almost no increase in the peel adhesion force at the time of adhesion, and the re-peelability is excellent without contamination of the adherend. It also has long-term durability after high temperature and high humidity treatment (no peeling and foaming), does not require aging treatment after application, drying, crosslinking and transfer, and is excellent in punchability and at the same time the coloration of the adhesive layer. It became clear that I could not see.

On the other hand, when using the adhesive-attached optical member which does not satisfy the structure of this invention (Comparative Examples 3-1 to 4), also in any comparative example, durability after high temperature, high humidity treatment, generation | occurrence | production of coloring, suppression of the increase of adhesive force, and It became clear that punching workability was not possible, and it became clear that it was not suitable for an adhesive-attached optical member.

In view of the above, the pressure-sensitive adhesive-attached optical member of the present invention is excellent in re-peelability, durability, and long-term transparency and non-coloring property even when stored under severe processing conditions, thereby suppressing an increase in pooling persistence and adhesive force, and thus the pressure-sensitive adhesive optical member. After the member is manufactured, it can be punched out quickly so that the productivity is excellent.

In the pressure-sensitive adhesive composition of the present invention, a peroxide, a silane coupling agent, and a crosslinking agent are blended with a (meth) acrylic polymer, if necessary, to form a pressure-sensitive adhesive layer set to a predetermined gel fraction by coating, drying, and crosslinking the pressure-sensitive adhesive composition. Can be. After attaching the optical member in which the adhesive layer of this invention is formed to a liquid crystal cell, and storing in the high temperature, high humidity state, the high durability which does not produce peeling and foaming expresses. When re-peeling the optical member attached to the liquid crystal cell through the pressure-sensitive adhesive layer formed by the pressure-sensitive adhesive composition of the present invention by an attachment mistake or the like, it can be peeled off without damaging or contaminating the liquid crystal cell. The pressure-sensitive adhesive composition of the present invention can provide a pressure-sensitive adhesive and pressure-sensitive adhesive optical member excellent in productivity, since the punching processing and the slit processing can be performed quickly without the need for aging after the application, drying and crosslinking. .

Moreover, the optical containing the (meth) acrylic-type polymer (Al) which consists of a composition of the monomer unit of the specific unsaturated carboxylic acid whose weight average molecular weight is 1 million or more, a specific isocyanate type crosslinking agent, and a specific amount of peroxide and a silane coupling agent. The pressure-sensitive adhesive optical member using the pressure-sensitive adhesive composition for a member can be easily peeled from the liquid crystal cell even when stored in a severe state for a long time or under conditions of high temperature and high humidity, and particularly, even in a large liquid crystal cell. It is excellent in durability, excellent productivity (punching processability), and long-term transparency and non-coloring property, without damaging a liquid crystal cell.

Moreover, the (meth) acrylic-type polymer (A2) which consists of a composition of the monomeric unit of the specific unsaturated carboxylic acid whose weight average molecular weight is 500,000 or more, and the (meth) acrylic-type polymer which has a specific carboxylic acid equivalent whose weight average molecular weight is in the range of 2000-50000 ( B) and the pressure-sensitive adhesive optical member using the pressure-sensitive adhesive composition for an optical member comprising a small amount of peroxide and silane coupling agent are easily removed from the liquid crystal cell even when stored in severe long-term severe conditions or under high temperature and high humidity conditions. It can peel, especially a large liquid crystal cell is easy to peel, and it is excellent in durability, and excellent in the relaxation of the stress resulting from a dimensional change, such as a polarizing plate, without damaging or polluting a liquid crystal cell.

Moreover, the manufacturing method of the adhesive of this invention can easily provide the adhesive set so that it may become a predetermined gel fraction by performing a peroxide crosslinking process using the said adhesive composition.

In addition, the image display device of the present invention is a liquid crystal display device, an organic EL display device, a PDP and the like using the pressure-sensitive adhesive-attached optical member, and exhibits high durability without peeling and foaming even when stored in a high temperature and high humidity state, thereby providing optical Even when the member is peeled off and the image display apparatus is reused, no increase in adhesive strength is seen, and the peeling member can be easily peeled off without adversely affecting the apparatus.

Claims (16)

100 weight part of (meth) acrylic-type polymer (A) containing 50 weight% or more of (meth) acrylate which has a C4 or more alkyl group as a monomer unit, 0.02-2 weight part of peroxides, and 0.01-1 weight part of a silane coupling agent The pressure-sensitive adhesive layer obtained by performing a peroxide crosslinking treatment on the pressure-sensitive adhesive composition for an optical member, wherein the pressure-sensitive adhesive layer for an optical member has a gel fraction of 40 to 90 parts by weight after the peroxide crosslinking treatment. The pressure-sensitive adhesive layer for an optical member according to claim 1, comprising 0.01 to 5 parts by weight of a crosslinking agent. The method of claim 1, The adhesive composition for optical members whose weight average molecular weight of the said (meth) acrylic-type polymer (A) is 1 million or more. delete delete delete delete delete delete delete delete delete delete The pressure-sensitive adhesive-attached optical member, wherein the pressure-sensitive adhesive layer according to any one of claims 1 to 3 is formed on one or both surfaces of the optical member. delete An image display apparatus using at least one adhesive-attached optical member according to claim 14.