JP5583367B2 - Optical member pressure-sensitive adhesive composition, optical member pressure-sensitive adhesive, and optical member with a pressure-sensitive adhesive layer obtained using the same - Google Patents

Description

  The present invention is an optical film (polarizing film, retardation film, optical compensation film, brightness enhancement film, etc.) suitably used for image display devices such as liquid crystal display devices, organic EL display devices, and PDPs. Optical member pressure-sensitive adhesive composition used for bonding a polarizing film with an optical laminate coated with a protective film such as a cellulose triacetate film and a glass substrate of a liquid crystal cell, an optical member pressure-sensitive adhesive, and the optical The present invention relates to an optical member with a pressure-sensitive adhesive layer in which a pressure-sensitive adhesive layer made of a pressure-sensitive adhesive for members is formed, particularly a polarizing plate with a pressure-sensitive adhesive layer. More specifically, it has excellent antistatic performance, and also has excellent adhesion between the optical laminate and the glass substrate even under high temperature and high humidity conditions, and foaming or peeling between the adhesive layer and the glass substrate is possible. In addition, the pressure-sensitive adhesive composition for optical members and the pressure-sensitive adhesive for optical members, which are excellent in durability, such as being able to prevent the light leakage phenomenon caused by the shrinkage of the optical film, and the pressure-sensitive adhesive obtained by using the same The present invention relates to an optical member with an agent layer.

  Conventionally, a polarizing film, for example, a polarizing plate coated with a cellulose film, for example, a cellulose triacetate film, on both sides of a polarizing film, for example, a polyvinyl alcohol film having a polarizing property, is a liquid crystal component that is aligned between two glass plates. Lamination is carried out on the surface of the sandwiched liquid crystal cell to form a liquid crystal display panel. This lamination to the liquid crystal cell surface is performed by bringing the pressure-sensitive adhesive layer provided on the polarizing plate surface into contact with the liquid crystal cell surface. This is usually done by pressing.

  The pressure-sensitive adhesive layer provided on the surface of the optical member such as the polarizing plate is provided with a separator for the purpose of preventing scratches or dirt, or the surface for the purpose of preventing scratches or dirt generated during processing and transporting processes. Although a protective film or the like is provided, these separators and the surface protective film are not necessary and are peeled and removed when they are bonded to a liquid crystal cell or the like. Static electricity is generated when the separator or the surface protection film is peeled off from such an optical member, and this static electricity causes dust to adhere to the optical member, causes an abnormal display due to disorder of the liquid crystal alignment, and peripheral circuit elements. There is a problem that problems such as electrostatic breakdown occur.

  In addition, when an optical member provided with the above-mentioned pressure-sensitive adhesive layer is bonded to a liquid crystal cell, if foreign matter is mixed, damaged, or an adhesion error occurs, it will be peeled off and re-bonded. As described above, static electricity is generated and a problem occurs. As a countermeasure for preventing the occurrence of defects due to the generation of static electricity, for example, in an adhesive composition used for an optical member, it has been proposed to blend an ionic liquid with a base polymer (see Patent Document 1). In addition, it has been proposed that an acrylic base polymer is blended with an antistatic agent in which a polymer having a polyalkylene structure and a hydroxyl group is mixed with an ionic substance (see Patent Document 2).

JP 2006-11365 A JP 2006-199873 A

  However, in the disclosed technique of Patent Document 1, although the effect of antistatic performance is recognized, there is a possibility that bleeding occurs over time because the ionic liquid is blended, and the base polymer itself is charged. It is a general one that does not have a preventive ability, and relies on the antistatic performance of only the ionic liquid. Further, the durability and light leakage prevention performance, which are important for the optical members to be used, particularly for polarizing plate applications, have not been considered at all.

  On the other hand, in the disclosed technology of Patent Document 2, the effect of antistatic performance is recognized as in Patent Document 1, but the antistatic agent blended in the base polymer may bleed over time. It was unbearable for practical use.

  By the way, liquid crystal display panels using polarizing plates are widely used as display devices for personal computers, liquid crystal televisions, car navigation systems, etc., and the use environment has become very harsh. It is required to be excellent in durability even in use, for example, there is no phenomenon such as foaming or peeling between the pressure-sensitive adhesive layer and the glass plate even under a severe environment such as high temperature and high humidity, In a high-temperature, high-humidity environment, the polarizing film contracts, whereas the adhesive layer cannot follow the contraction of the polarizing film, and light leaks from the peripheral edge of the liquid crystal display panel. It is required that there is no so-called light leakage phenomenon.

  The present invention has been made in view of such circumstances, and is excellent in antistatic performance, and further excellent in adhesion between an optical laminate, particularly a polarizing plate and a glass substrate, even under high temperature and high humidity conditions. In addition, the pressure-sensitive adhesive composition for optical members has excellent durability, such as no foaming or peeling between the pressure-sensitive adhesive layer and the glass substrate, and preventing light leakage caused by shrinkage of the polarizing film, and the like. An object is to provide a pressure-sensitive adhesive for optical members and an optical member with a pressure-sensitive adhesive layer obtained using the same.

  As a result of diligent investigations to solve the above-mentioned object, the present inventors have determined that, as the main component acrylic resin (A) constituting the resin composition that is a pressure-sensitive adhesive material, Alternatively, by using a resin having a betaine structure, in addition to the excellent adhesive performance of acrylic resins, it is possible to obtain a good antistatic performance, and furthermore, a bleed phenomenon is suppressed and a resin composition excellent in durability can be obtained. And reached the present invention.

That is, the present invention is a pressure-sensitive adhesive resin composition for an optical member comprising, as a main component, an acrylic resin (A) having an acid-base ion pair and / or a betaine structure in the molecule, the acrylic resin (A) a weight average molecular weight of Ri from 1000000 to 4000000 der, and the glass transition temperature of -80 to-20 ° C. der Ru optical member pressure-sensitive adhesive resin composition [I] in which the first gist.

  And this invention makes the 2nd summary the adhesive for optical members formed by bridge | crosslinking the adhesive resin composition [I] for optical members which is the said 1st summary.

  Furthermore, this invention makes the 3rd summary the optical member with an adhesive layer formed by laminating | stacking the adhesive layer which consists of an adhesive for optical members which is the said 2nd summary on an optical member.

Thus, the present invention is mainly composed of an acrylic resin (A) having an acid-base ion pair and / or a betaine structure in the molecule, and the acrylic resin (A) has a weight average molecular weight of 1,000,000 to 4,000,000. der is, and has a glass transition temperature of -80 to-20 ° C. der Ru optical member pressure-sensitive adhesive resin composition [I], comprising further optical member pressure-sensitive adhesive resin composition [I] is crosslinked It is an adhesive for optical members. For this reason, occurrence of bleed-out from the above-mentioned pressure-sensitive adhesive is suppressed, and it is excellent in the balance between pressure-sensitive adhesive properties and antistatic performance, and even under conditions of high temperature and high humidity, an optical laminate, particularly a polarizing plate and a glass substrate A liquid crystal display panel with excellent durability, such as no foaming or peeling between the pressure-sensitive adhesive layer and the glass substrate, and prevention of light leakage caused by contraction of the polarizing film Can be obtained.

  The acrylic resin (A) has an acid-base ion pair in the molecule, and the ion pair is a carboxyl group-containing acrylic resin obtained by copolymerizing a carboxyl group-containing monomer. When the group is neutralized to form an ion pair, excellent antistatic performance can be exhibited.

  The pressure-sensitive adhesive resin composition [I] for optical members contains an unsaturated group-containing compound (B) as a polymerizable component, and also contains a polymerization initiator (C), and is crosslinked by active energy rays and / or heat. As a result, even better durability and light leakage prevention properties can be obtained.

  When the unsaturated group-containing compound (B) is an oxyalkylene chain-containing urethane (meth) acrylate compound or a (meth) acrylate compound containing an acid-base ion pair and / or a betaine structure in the molecule, Further excellent antistatic ability is imparted.

  When the gel fraction of the pressure-sensitive adhesive for optical members is 80% or more, further excellent durability and light leakage prevention properties can be obtained.

  The pressure-sensitive adhesive resin composition [I] for optical members of the present invention is mainly composed of an acrylic resin (A) having an acid-base ion pair and / or a betaine structure in the molecule. And the adhesive for optical members of this invention consists of a polymer (crosslinked body) by which the polymeric component of this adhesive resin composition [I] for optical members is superposed | polymerized (crosslinked).

First, the said adhesive resin composition [I] for optical members is demonstrated.
The pressure-sensitive adhesive resin composition for optical members (hereinafter, also simply referred to as “resin composition”) [I] is mainly composed of an acrylic resin (A) having an acid-base ion pair and / or a betaine structure in the molecule. It is what.

  As means for introducing an acid-base ion pair and / or a betaine structure into the acrylic resin molecule, usually, [1] a functional group-containing monomer that can be an acid-base ion pair is copolymerized, For example, a method of changing the group to an acid-base ion pair can be used.

  The method of changing the functional group in the acrylic resin to an acid-base ion pair is a method of neutralizing a carboxyl group in a carboxyl group-containing resin obtained by copolymerizing a carboxyl group-containing monomer with a neutralizing agent, a resin Examples thereof include a method of containing an amino group therein and quaternizing the amino group.

  In addition to the method [1], there can also be mentioned [2] a method of copolymerizing an acid-base ion pair and / or a monomer (m1) having a betaine structure in the molecule.

  First, the method [1] will be specifically described.

  The acrylic resin (A) is usually copolymerized with a (meth) acrylic acid ester monomer (a1) as a main component and a functional group-containing monomer (a2) that can be an acid-base ion pair as a copolymerization component. It is obtained by neutralizing the product. If necessary, the other functional group-containing monomer (a3) and other copolymerizable monomer (a4) can be further used as a copolymerization component.

Examples of the (meth) acrylic acid ester monomer (a1) include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, tert -Butyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isononyl (meth) acrylate, cyclohexyl (meth) acrylate, isooctyl (meth) acrylate, n-octyl (meth) acrylate, lauryl (meth) ) Such as aliphatic (meth) acrylic acid alkyl esters such as acrylate and isobornyl (meth) acrylate, phenoxyethyl (meth) acrylate, and phenoxypolyalkylene glycol (meth) acrylate. Family (meth) acrylic acid esters, (meth) acryloyl morpholine, (meth) heterocycle containing such alkyl acrylate imidazole (meth) acrylate monomer and the like.
Among these, a (meth) acrylic acid alkyl ester is preferable, a (meth) acrylic acid alkyl ester having 1 to 12 carbon atoms in an alkyl group is particularly preferable, and a (meth) acrylic acid having 4 to 12 carbon atoms is more preferable. It is preferable to use an alkyl ester in order to improve the balance between the adhesive performance and the durability performance, and it is particularly preferable to use butyl acrylate as the main monomer from the viewpoint of the balance between the antistatic performance and the durability performance.
The said (meth) acrylic acid ester-type monomer (a1) can be used individually or in combination of 2 or more types.

  In addition, even when the (meth) acrylic acid alkyl ester having 4 to 12 carbon atoms is mainly used as the (meth) acrylic acid ester monomer (a1), the alkyl group has 3 or less carbon atoms. Or 13 or more (meth) acrylic acid alkyl esters can be used in combination as appropriate.

  The content of the (meth) acrylic acid ester monomer (a1) is preferably 20 to 99.9 parts by weight, more preferably 30 to 99 parts by weight, particularly preferably 100 parts by weight of all monomers. 50 to 98 parts by weight. When the content is too small, the tendency of inferior adhesive properties is observed, and when the content is too large, the antistatic performance tends to decrease.

  As the functional group-containing monomer (a2) that can be an ion pair of the acid-base, for example, an acid group-containing monomer and a base-containing monomer are preferable. An amino group-containing monomer is preferable, and a carboxyl group-containing monomer and an amino group-containing monomer are more preferable.

  Examples of the carboxyl group-containing monomer include (meth) acrylic acid, crotonic acid, maleic acid, maleic anhydride, fumaric acid, citraconic acid, glutaconic acid, itaconic acid, acrylamide N-glycolic acid, and 2-acryloyloxyethyl succinate. Michael, adducts of acid, cinnamic acid, (meth) acrylic acid (for example, acrylic acid dimer, methacrylic acid dimer, acrylic acid trimer, methacrylic acid trimer, acrylic acid tetramer, methacrylic acid tetramer, etc.) Acrylic acid and methacrylic acid are preferably used.

  Examples of the sulfonic acid group-containing monomer include sulfonic acid ester compounds of hydroxyalkyl (meth) acrylate such as 2- (meth) acryloyloxyethyl sulfuric acid and 2- (meth) acryloyloxyethylsulfonic acid.

  Examples of the phosphoric acid group-containing monomer include hydroxyalkyl phosphate compounds such as 2- (meth) acryloyloxyethyl acid phosphate.

  Examples of the amino group-containing monomer include alkylamino group-containing (meta) such as t-butylaminoethyl (meth) acrylate, ethylaminoethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, and diethylaminoethyl (meth) acrylate. ) Acrylate and the like.

  Examples of the other functional group-containing monomer (a3) include a hydroxyl group-containing monomer, an acetoacetyl group-containing monomer, an amide group-containing monomer, and an epoxy group-containing monomer. In addition, the same carboxyl group-containing monomer and amino group-containing monomer as those described above are also mentioned, and these monomers are used without changing the functional group of the monomer into an ion pair. These other functional group-containing monomers (a3) can be used alone or in combination of two or more.

  Examples of the hydroxyl group-containing monomer include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-chloro-2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6 -Hydroxyhexyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, diethylene glycol mono (meth) acrylate, polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, N-methylol (meth) Acrylamide, tripropylene glycol mono (meth) acrylate, 1,4-butylene glycol mono (meth) acrylate, glycerol mono (meth) acrylate, 2-hydroxy ester Examples include luacryloyl phosphate, caprolactone-modified 2-hydroxyethyl (meth) acrylate, allyl alcohol, etc. Among them, carbon number of 1-4 such as 2-hydroxyethyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, etc. A (meth) acrylate having a hydroxyalkyl group is preferably used.

  Examples of the acetoacetyl group-containing monomer include 2- (acetoacetoxy) ethyl (meth) acrylate, allyl acetoacetate, diacetone acrylamide, and the like.

  Examples of the amide group-containing monomer include (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, N, N-dibutyl (meth) acrylamide, N-methylol acrylamide, Examples thereof include N-methoxyethyl acrylamide, N- (n-butoxymethyl) acrylamide, dimethylaminopropyl acrylamide, t-butyl acrylamide and the like.

  Examples of the epoxy group-containing monomer include glycidyl (meth) acrylate and allyl glycidyl ether.

  Examples of the other copolymerizable monomer (a4) include acrylonitrile, methacrylonitrile, vinyl imidazole, styrene, α-methylstyrene, vinyl acetate, vinyl propionate, vinyl chloride, vinylidene chloride, alkyl vinyl ether, vinyl toluene, And monomers such as vinyl pyridine, vinyl pyrrolidone, itaconic acid dialkyl ester, fumaric acid dialkyl ester, allyl alcohol, acrylic chloride, and methyl vinyl ketone.

  When the purpose is to increase the molecular weight of the acrylic resin (A), ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, A compound having two or more ethylenically unsaturated groups such as propylene glycol di (meth) acrylate and divinylbenzene can also be used in combination.

  Such an acrylic resin (A) can be produced, for example, by radical copolymerization in an organic solvent. Examples of the organic solvent used for the radical polymerization include aromatic hydrocarbons such as toluene and xylene; aliphatic hydrocarbons such as hexane and heptane; esters such as ethyl acetate and butyl acetate; n-propyl alcohol, iso- Examples thereof include aliphatic alcohols such as propyl alcohol; ketones such as methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone. Aromatic hydrocarbons, esters, and ketones are preferable.

  In addition, as the radical polymerization initiator used for the radical copolymerization, 2,2′-azobisisobutyronitrile, 2,2′-azobis-2-methylbutyronitrile, which are ordinary radical polymerization initiators, are used. , 4,4'-azobis (4-cyanovaleric acid), 2,2'azobis (2-methylpropionic acid) and other azo compounds, benzoyl peroxide, lauroyl peroxide, di-t-butyl peroxide, cumene Examples thereof include peroxide compounds such as hydroperoxide.

As a neutralizing agent for neutralizing a carboxyl group in a carboxyl group-containing acrylic resin obtained by copolymerizing a carboxyl group-containing monomer as a functional group-containing monomer (a2) that can be an ion pair of the acid base, Ammonia, ammonium salt showing alkalinity, and primary amines such as monoethylamine and monoethanolamine; secondary amines such as diethylamine and diethanolamine; triethylamine, triethanolamine, N, N, N′-trimethylethylenediamine, N-methyldiethanolamine, N Tertiary amines such as N, diethylhydroxylamine; amino compounds having a plurality of nitrogen atoms in one molecule such as diamine and polyethyleneimine; amine compounds such as cyclic amino compounds such as pyridine; lithium hydroxide, sodium hydroxide , Hydroxylation Hydroxides of alkali metal such as potassium, and the like.
Among these, alkali metal hydroxides are preferable from the viewpoint of antistatic ability after neutralization, and potassium hydroxide is particularly preferable from the viewpoint of compatibility with the polymer.

  Further, quaternization at the time of quaternizing the amino group in the amino group-containing acrylic resin obtained by copolymerizing the amino group-containing monomer as the functional group-containing monomer (a2) that can be an ion pair of the acid-base. Examples of the agent include inorganic acids or organic acids such as hydrochloric acid, nitric acid, sulfuric acid, dimethyl sulfuric acid, and diethyl sulfuric acid, and chlorides such as methyl chloride, ethyl chloride, and benzyl chloride.

  The amount of the neutralizing agent and quaternizing agent used is preferably 0.1 to 2 in terms of an equivalent ratio with a functional group that can be an acid-base ion pair of an acrylic polymer, and particularly 0.3 to 1.2 is preferable, and 0.7 to 1 is more preferable.

  Next, [2] a method of copolymerizing an acid-base ion pair and / or a monomer (m1) having a betaine structure in the molecule will be described.

  In the method [2], the functional group-containing monomer (a2) that can be an acid-base ion pair in the method [1] is used as the monomer (m1) having an acid-base ion pair and / or a betaine structure. ), But the copolymerization is carried out in the same manner as in the above [1] (however, neutralization after the copolymerization is not necessary).

  As the monomer (m1) having an acid-base ion pair and / or a betaine structure, a monomer having a quaternary ammonium salt structure such as dimethylaminoethyl (meth) acrylate quaternized product or diethylaminoethyl (meth) acrylate quaternized product N- (3-sulfopropyl) -N-methacryloxyethyl-N, N-dimethylammonium betaine, N- (3-sulfopropyl) -N-methacrylamidopropyl-N, N-dimethylammonium betaine, etc. Among these monomers, dimethylaminoethyl (meth) acrylate quaternized compounds are preferably used because of their availability.

  In addition to the methods [1] and [2] above, [3] any one of the groups included in the group of isocyanate group, hydroxyl group, carboxyl group or anhydride, epoxy group, amide group, acetoacetyl group, or A method of reacting a compound having a plurality of functional groups and an acid-base ion pair and / or a betaine structure with an acrylic resin containing a functional group capable of reacting with the functional group can also be used.

  In the present invention, the acrylic resin (A) has an acid-base ion pair and / or a betaine structure as an essential component in the molecule, but may also have an oxyalkylene chain in the molecule. This is preferable in terms of improving the antistatic performance.

  As a means for introducing an oxyalkylene chain (structure) into the molecule of the acrylic resin (A), there is usually a method of copolymerizing an oxyalkylene structure-containing monomer.

  Examples of the monomer having an oxyalkylene structure include a compound represented by the following general formula (1) (hereinafter referred to as an oxyalkylene structure-containing unsaturated monomer). The oxyalkylene structure-containing unsaturated monomer is preferably used in terms of excellent antistatic performance.

  X in the general formula (1) is an alkylene group, and among them, an alkylene group having 1 to 10 carbon atoms is preferable, and an ethylene group, a propylene group, and a tetramethylene group are particularly preferable. Furthermore, an ethylene group is preferable. In the case where n is a polyoxyalkylene chain moiety having 2 or more, a homopolymer of the same oxyalkylene chain may be used, or different oxyalkylene chains may be copolymerized randomly or in a block form.

  Y in the general formula (1) is a (meth) acryloyl group or an alkenyl group. As the alkenyl group, those having 2 to 6 carbon atoms, for example, a vinyl group or an allyl group are usually used. Among these, Y is preferably a methacryloyl group, an acryloyl group or an allyl group, and particularly preferably a methacryloyl group or an acryloyl group.

  Z in the said General formula (1) is a hydrogen atom or an alkyl group, and a C1-C4 thing is normally used as an alkyl group. Among these, Z is preferably a hydrogen atom, a methyl group, or an ethyl group.

  In the above general formula (1), n is an integer of 1 or more indicating the number of moles of alkylene oxide added, preferably 1 to 500, and the smaller n is the balance between antistatic performance and durability. This is preferable.

Specific examples of the unsaturated monomer having an oxyalkylene structure are shown below.
[Y: (meth) acryloyl group]
For example, polyethylene glycol derivatives such as polyethylene glycol mono (meth) acrylate, polypropylene glycol derivatives such as polypropylene glycol mono (meth) acrylate, polyethylene glycol-polypropylene glycol-mono (meth) acrylate, poly (ethylene glycol-tetramethylene glycol) mono (Meth) acrylate, poly (propylene glycol-tetramethylene glycol) mono (meth) acrylate, methoxyethyl (meth) acrylate, ethoxyethyl (meth) acrylate, methyl carbitol (meth) acrylate, ethyl carbitol (meth) acrylate, etc. Can be given.

[When Y is an alkenyl group]
Examples thereof include polyethylene glycol derivatives such as polyethylene glycol monoallyl ether, polypropylene glycol derivatives such as polypropylene glycol monoallyl ether, and polyethylene glycol-polypropylene glycol-monoallyl ether.

  Among these, polyethylene glycol derivatives are preferable, and the number of moles of added ethylene oxide n is an integer of 1 or more indicating the number of moles of added alkylene oxide, preferably 1 to 500, and more preferably n is smaller. It is preferable in terms of a balance between prevention performance and durability. When the value of ethylene oxide addition mole number n is too large, the durability tends to deteriorate. Furthermore, it is preferable that Y in the said General formula (1) is a (meth) acryloyl group from the point of influence on sclerosis | hardenability.

  Moreover, as a weight average molecular weight of the oxyalkylene structure containing unsaturated compound represented by the said General formula (1), 100-20000 are preferable normally, Especially 100-4000, Furthermore, 120-300 are preferable. When the weight average molecular weight is too small, the antistatic ability tends to be inferior. When the weight average molecular weight is too large, the crystallinity becomes high and the handling tends to be difficult.

  In this way, an acrylic resin (A) having an acid-base ion pair and / or a betaine structure in the molecule is obtained. Among all the monomers constituting the acrylic resin (A), monomers that form the acid-base ion pair and / or betaine structure, that is, the functional group-containing monomer (a2) or acid that can be an acid-base ion pair Usually, the amount of the monomer (m1) having a base ion pair and / or a betaine structure is preferably 0.1 to 80 parts by weight, more preferably 0.5 to 50 parts by weight based on 100 parts by weight of the total monomers. Part by weight, particularly preferably 2 to 30 parts by weight, more preferably 8 to 20 parts by weight is preferred. If the amount of the acid-base ion pair and / or the betaine structure monomer is too small, sufficient antistatic performance tends to be difficult to obtain, and if too much, the polarity of the acrylic resin (A) as a whole is high. Therefore, the manufacturing tends to be very difficult.

Thus obtained, the weight average molecular weight of the acrylic resin (A) having an ion pair and / or betaine structure of acid-base (Mw) of the molecule, Ri 1 to 4 million der, further, 120 It is preferably 10,000 to 3,000,000. If the weight average molecular weight is too small, there is a tendency that sufficient cohesive force cannot be obtained even by irradiation with active energy rays described later, and if it is too large, a large amount of diluting solvent is required, which is preferable in terms of coating property and cost. There is no tendency.

  In addition, the said weight average molecular weight is a weight average molecular weight by standard polystyrene molecular weight conversion, and column: Shodex GPC in a high performance liquid chromatography ("Waters 2695 (main body)" and "Waters 2414 (detector)" by Japan Waters)). KF-806L (exclusion limit molecular weight: 2 × 10 7, separation range: 100 to 2 × 10 7, theoretical plate number: 10,000 plates / piece, filler material: styrene-divinylbenzene copolymer, filler particle size: 10 μm) It is measured by using three series.

  The dispersity (Mw / Mn) of the acrylic resin (A) having an acid-base ion pair and / or a betaine structure in the molecule thus obtained is usually preferably 2 to 30, In particular, it is preferably 2.5 to 8. Furthermore, it is preferable that it is 2.7-5. If the degree of dispersion is too small, it tends to be difficult to manufacture. If the degree of dispersion is too large, the balance between durability and light leakage performance tends to be poor. In addition, said Mn shows the number average molecular weight of acrylic resin (A), and the said number average molecular weight (Mn) is calculated | required by the method similar to the said weight average molecular weight.

Further, the glass transition temperature of the acrylic resin (A) having an ion pair and / or betaine structure acid bases in the molecule, - 80 ~ - was 20 ° C., tends to be insufficient tack the glass transition temperature is too high If it is too low, it tends to be inferior in heat resistance. The glass transition temperature is calculated from the Fox equation.

  The pressure-sensitive adhesive resin composition for an optical member of the present invention may consist of only an acrylic resin (A) having an acid-base ion pair and / or a betaine structure in the molecule. ) And an active energy ray-polymerizable unsaturated group-containing compound (B), a polymerization initiator (C), and a crosslinking agent (D) described later.

Below, the adhesive for optical members of this invention is demonstrated.
The pressure-sensitive adhesive for optical members of the present invention is obtained by crosslinking a resin composition [I] whose main component is an acrylic resin (A) having an acid-base ion pair and / or a betaine structure in the molecule. . In the present invention, the “main component” means that the acrylic resin (A) is usually 50% by weight or more, preferably 60% by weight or more, more preferably based on the total amount of the resin composition [I]. Means 70% by weight or more. The acrylic resin (A) having an acid-base ion pair and / or a betaine structure in the molecule is the same as described in the resin composition.

  As a method of crosslinking the resin composition [I], [α] a method of containing an unsaturated group-containing compound (B) and a polymerization initiator (C) and crosslinking with active energy rays and / or heat, [β A method of crosslinking using a crosslinking agent (D) is mentioned. And as for the degree of cross-linking, sufficient can be obtained only by the method [α], but if possible, the cross-linking of the pressure-sensitive adhesive is made more dense, and the light leakage prevention property is improved. It is particularly preferable to use the methods [α] and [β] in combination.

  First, the unsaturated group-containing compound (B) and the polymerization initiator (C), which are the methods of [α], are contained, and the resin composition [I] is treated with active energy rays and / or heat (active energy ray irradiation and A method of crosslinking by heating) will be described.

  In the case of crosslinking by active energy rays and / or heat (irradiation of active energy rays and / or heating), in addition to the acrylic resin (A), the unsaturated group-containing compound is used as the resin composition [I]. Resin composition [I] containing (B) and a polymerization initiator (C) is used. Thus, by containing an unsaturated group containing compound (B), hardening can be adjusted and it becomes possible to implement | achieve the adhesive physical property suitable for an optical member use. Moreover, the reaction at the time of active energy ray irradiation can be stabilized by containing the said polymerization initiator (C).

  In the case of the cross-linking, the unsaturated group-containing compound (B) is polymerized (polymerized) by active energy rays and / or heat to perform cross-linking (physical cross-linking) with the acrylic resin (A). When the acrylic resin (A) is an unsaturated group-containing acrylic resin, the unsaturated group-containing acrylic resin is not limited to polymerization of the unsaturated group-containing compound (B) by active energy rays and / or heat. Polymerization of the resin (A) and the unsaturated group-containing compound (B) will also be considered.

  The unsaturated group-containing compound (B) used in the present invention may be a monofunctional unsaturated group-containing compound having one unsaturated group in one molecule, or two or more in one molecule. A polyfunctional unsaturated group-containing compound having an unsaturated group may be used, but preferably an unsaturated group-containing compound having two or more unsaturated groups, more preferably an unsaturated group-containing compound having three or more unsaturated groups. A saturated group-containing compound, particularly preferably an unsaturated group-containing compound having 5 or more unsaturated groups, is preferred from the viewpoint of curability when irradiated with active energy rays.

Examples of the structure of the unsaturated group-containing compound (B) include urethane (meth) acrylate compounds, epoxy (meth) acrylate compounds, polyester (meth) acrylate compounds, and one or more ethylene in one molecule. An ethylenically unsaturated monomer containing a polymerizable unsaturated group, for example, a monofunctional monomer, a bifunctional monomer, a trifunctional or higher functional monomer, and the like can be used. Among these, it is preferable to use urethane (meth) acrylate (b1) and ethylenically unsaturated monomer (b2) from the viewpoint of excellent curing speed and ultimate physical properties.
In addition, the unsaturated group-containing compound (B) may contain an oxyalkylene chain, a hydroxyl group, or an acid-base ion pair and / or a structural portion exhibiting hydrophilicity such as a betaine structure. From the aspect, it is more preferable.

  The urethane (meth) acrylate compound (b1) is a (meth) acrylate compound having a urethane bond in the molecule, and can be produced by reacting a (meth) acrylic compound containing a hydroxyl group with a polyvalent isocyanate compound. .

  The (meth) acrylic compound containing the hydroxyl group is not particularly limited, and examples thereof include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 4- Hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 2- (meth) acryloyloxyethyl-2-hydroxypropyl phthalate, 2-hydroxy-3- (meth) acryloyloxypropyl (meth) acrylate, Caprolactone-modified 2-hydroxyethyl (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol penta (meth) acrylate, caprolactone-modified dipentaerythritol penta (meth) acrylate, capro Examples include kuton-modified pentaerythritol tri (meth) acrylate, ethylene oxide-modified dipentaerythritol penta (meth) acrylate, and ethylene oxide-modified pentaerythritol tri (meth) acrylate. ) Acrylic compounds are preferably used. Moreover, these can be used 1 type or in combination of 2 or more types.

  The polyvalent isocyanate compound is not particularly limited, and examples thereof include aromatic, aliphatic, and alicyclic polyisocyanates. Among them, tolylene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, Polyphenylmethane polyisocyanate, modified diphenylmethane diisocyanate, hydrogenated xylylene diisocyanate, xylylene diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, tetramethylxylylene diisocyanate, isophorone diisocyanate, norbornene diisocyanate, 1,3-bis (isocyanato) Methyl) cyclohexane, phenylene diisocyanate, lysine diisocyanate, lysine triisocyanate And polyisocyanates such as naphthalene diisocyanate, trimer compounds or multimeric compounds of these polyisocyanates, burette-type polyisocyanates, water-dispersed polyisocyanates (for example, “Aquanate 100”, “Aqua Nate 110 ”,“ Aquanate 200 ”,“ Aquanate 210 ”, etc.), or the reaction products of these polyisocyanates and polyols. Among them, a trimer compound or a multimeric compound of isophorone diisocyanate, tolylene diisocyanate, hexamethylene diisocyanate is preferably used.

  Examples of the polyol include, but are not limited to, alkylene glycols such as ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, polypropylene glycol, butylene glycol, and polybutylene glycol. Compounds, 1,6-hexanediol, neopentyl glycol, cyclohexanedimethanol, hydrogenated bisphenol A, polycaprolactone, trimethylolethane, trimethylolpropane, polytrimethylolpropane, pentaerythritol, polypentaerythritol, sorbitol, mannitol, Multivalent alcohols such as glycerin, polyglycerin, polytetramethylene glycol A polyether polyol having at least one structure of polyethylene oxide, polypropylene oxide, ethylene oxide / propylene oxide block or random copolymerization; the polyhydric alcohol or polyether polyol and maleic anhydride, maleic acid, fumaric acid, anhydrous Polyester polyols that are condensates with polybasic acids such as itaconic acid, itaconic acid, adipic acid, and isophthalic acid; caprolactone-modified polyols such as caprolactone-modified polytetramethylene polyol; polyolefin-based polyols; polybutadiene-based polyols such as hydrogenated polybutadiene polyols Etc. Among these, polyethylene glycol derivatives are preferably used, and polyethylene glycol and polyethylene glycol monomethyl ether are particularly preferably used.

  Furthermore, as the polyol, for example, 2,2-bis (hydroxymethyl) butyric acid, tartaric acid, 2,4-dihydroxybenzoic acid, 3,5-dihydroxybenzoic acid, 2,2-bis (hydroxymethyl) propionic acid, 2,2-bis (hydroxyethyl) propionic acid, 2,2-bis (hydroxypropyl) propionic acid, dihydroxymethylacetic acid, bis (4-hydroxyphenyl) acetic acid, 4,4-bis (4-hydroxyphenyl) pentanoic acid Also included are carboxyl group-containing polyols such as homogentisic acid, sulfonic acid group or sulfonate group-containing polyols such as sodium 1,4-butanediolsulfonate.

  When using the reaction product of polyisocyanate and polyol, for example, it may be used as a terminal isocyanate group-containing polyisocyanate obtained by reacting the polyol with the polyisocyanate. In the reaction between the polyisocyanate and the polyol, a metal catalyst such as dibutyltin dilaurate or an amine catalyst such as 1,8-diazabicyclo [5.4.0] undecene-7 is used for the purpose of promoting the reaction. Is also preferable.

  In addition, it is preferable to use an oxyalkylene chain-containing urethane (meth) acrylate compound as the urethane (meth) acrylate compound (b1) in view of excellent antistatic performance.

  The oxyalkylene chain-containing urethane (meth) acrylate compound is obtained by using an alkylene glycol compound among the polyols, and the structure of the oxyalkylene chain-containing urethane (meth) acrylate compound is as follows. One of the hydroxyl groups at both ends of the alkylene glycol compound reacts with an isocyanate group, and the other is a urethane (meth) acrylate having an oxyalkylene chain structure that remains as a hydroxyl group. Even after the treatment, the oxyalkylene chain has a high degree of freedom and is easy to transport ions, which is preferable in that it exhibits excellent antistatic performance.

  The oxyalkylene chain-containing urethane (meth) acrylate compound is obtained by using an alkylene glycol compound having only one hydroxyl group in place of the polyol alkylene glycol compound having a plurality of hydroxyl groups. It may be a thing. Examples of the alkylene glycol compounds having only one hydroxyl group include polyethylene glycol monomethyl ether, polyethylene glycol lauryl ether, polyethylene glycol cetyl ether, polyethylene glycol stearyl ether, polyethylene glycol nonyl phenyl ether, polyethylene glycol tridecyl ether, and polyethylene glycol. Examples include alkyl group-containing polyalkylene glycol derivatives such as oleyl ether, polyethylene glycol octyl phenyl ether, polyethylene glycol derivatives such as polyoxyethylene oleyl cetyl ether, and polypropylene glycol derivatives such as polypropylene glycol monomethyl ether.

  The method for producing the urethane (meth) acrylate compound is not particularly limited, and for example, a hydroxyl group-containing (meth) acrylic compound and a polyvalent isocyanate compound are mixed in an inert gas atmosphere, 30 to 80 ° C., 2 to An example is a method of reacting for 10 hours. In this reaction, it is preferable to use a urethanization catalyst such as tin octenoate, di-n-butyltin dilaurate, lead octylate, potassium octylate, potassium acetate, stannous octoate, or triethylenediamine.

  The weight average molecular weight of the urethane (meth) acrylate compound is preferably 300 to 4000, more preferably 400 to 3500, and particularly preferably 500 to 3000. That is, if the weight average molecular weight is too small, the cohesive force tends to be insufficient after curing, and if it is too large, the viscosity becomes too high and production tends to be difficult.

  Moreover, as a urethane (meth) acrylate type compound in this invention, it is also preferable to use the urethane (meth) acrylate type compound which has a quaternary ammonium salt structure in a molecule | numerator.

  As said monofunctional monomer, what is necessary is just a monomer containing one ethylenically unsaturated group, for example, styrene, vinyl toluene, chlorostyrene, (alpha) -methylstyrene, methyl (meth) acrylate, ethyl (meth) acrylate, Acrylonitrile, vinyl acetate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, phenoxyethyl (meth) acrylate, 2-phenoxy-2-hydroxypropyl (meth) Acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, 3-chloro-2-hydroxypropyl (meth) acrylate, glycerin mono (meth) acrylate, glycidyl (meth) acrylate, lauryl (meth) acrylate Lilate, cyclohexyl (meth) acrylate, isobornyl (meth) acrylate, tricyclodecanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, n-butyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate , Octyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, dodecyl (meth) acrylate, n-stearyl (meth) acrylate, benzyl (meth) acrylate, phenol ethylene oxide modified ( Of phthalic acid derivatives such as (meth) acrylate, nonylphenol propylene oxide modified (meth) acrylate, 2- (meth) acryloyloxy-2-hydroxypropyl phthalate Half ester (meth) acrylate, furfuryl (meth) acrylate, carbitol (meth) acrylate, benzyl (meth) acrylate, butoxyethyl (meth) acrylate, allyl (meth) acrylate, acryloylmorpholine, 2-hydroxyethylacrylamide, N -Methylol (meth) acrylamide, N-vinylpyrrolidone, 2-vinylpyridine, 2- (meth) acryloyloxyethyl acid phosphate monoester and the like.

  Examples of the ethylenically unsaturated monomer include, in addition to the above, a Michael adduct of acrylic acid or 2-acryloyloxyethyl dicarboxylic acid monoester, and examples of the Michael adduct of acrylic acid include acrylic acid dimer, methacrylic acid dimer, Examples include acrylic acid trimer, methacrylic acid trimer, acrylic acid tetramer, and methacrylic acid tetramer. Examples of the 2-acryloyloxyethyl dicarboxylic acid monoester that is a carboxylic acid having a specific substituent include 2-acryloyloxyethyl succinic acid monoester, 2-methacryloyloxyethyl succinic acid monoester, and 2-acryloyloxy. Examples thereof include ethylphthalic acid monoester, 2-methacryloyloxyethylphthalic acid monoester, 2-acryloyloxyethyl hexahydrophthalic acid monoester, and 2-methacryloyloxyethyl hexahydrophthalic acid monoester. Furthermore, oligoester acrylate is also mentioned. In addition, potassium acrylate and imidazolium acrylate are also preferably used.

  The bifunctional monomer may be any monomer containing two ethylenically unsaturated groups. For example, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, polyethylene Glycol di (meth) acrylate, propylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, butylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, ethylene Oxide modified bisphenol A type di (meth) acrylate, propylene oxide modified bisphenol A type di (meth) acrylate, 1,6-hexanediol di (meth) acrylate 1,6-hexanediol ethylene oxide modified di (meth) acrylate, glycerin di (meth) acrylate, pentaerythritol di (meth) acrylate, ethylene glycol diglycidyl ether di (meth) acrylate, diethylene glycol diglycidyl ether di ( (Meth) acrylate, diglycidyl phthalate di (meth) acrylate, hydroxypivalic acid-modified neopentyl glycol di (meth) acrylate, isocyanuric acid ethylene oxide-modified diacrylate, 2- (meth) acryloyloxyethyl acid phosphate diester It is done.

  The tri- or higher functional monomer may be any monomer containing three or more ethylenically unsaturated groups. For example, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) ) Acrylate, dipentaerythritol tri (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, tri (meth) acryloyloxyethoxytrimethylolpropane, Glycerin polyglycidyl ether poly (meth) acrylate, isocyanuric acid ethylene oxide modified tri (meth) acrylate, ethylene oxide modified dipentaerythritol (Meth) acrylate, ethylene oxide modified dipentaerythritol hexa (meth) acrylate, ethylene oxide modified pentaerythritol tri (meth) acrylate, ethylene oxide modified pentaerythritol tetra (meth) acrylate, succinic acid modified pentaerythritol tri (meth) acrylate Etc.

  On the other hand, the compound in which an oxyalkylene chain is contained in the ethylenically unsaturated monomer (b2) having one or more ethylenically unsaturated groups in one molecule is not particularly limited. Examples thereof include monofunctional monomers, bifunctional monomers, and trifunctional or higher monomers containing an oxyalkylene chain to be described.

  Examples of the monofunctional monomer containing the oxyalkylene chain include a monofunctional monomer containing an oxyalkylene chain represented by the following general formula (2).

  A in the general formula (2) is a (meth) acryloyl group or an alkenyl group. As the alkenyl group, those having 2 to 6 carbon atoms, for example, a vinyl group or an allyl group are usually used. Among these, a methacryloyl group, an acryloyl group, and an allyl group are preferable, and a methacryloyl group and an acryloyl group are particularly preferable.

  B in the said General formula (2) is a hydrogen atom, an alkyl group, a phenyl group, or an acyl group, As a alkyl group, C1-C20 normally, Preferably the thing of 1-10 is used. Among these, a hydrogen atom, a methyl group, and an ethyl group are preferable.

  N in the general formula (2) is an integer of 1 or more, preferably 1 to 500, particularly preferably 2 to 100, and further preferably 3 to 50. If the value of n is too small, the antistatic ability tends to be insufficient, and if it is too large, the durability tends to be insufficient.

Specific examples of the monofunctional monomer containing the oxyalkylene chain are as follows: [A: (meth) acryloyl group]
For example, polyethylene glycol derivatives such as polyethylene glycol mono (meth) acrylate, polypropylene glycol derivatives such as polypropylene glycol mono (meth) acrylate, polyethylene glycol-polypropylene glycol-mono (meth) acrylate, poly (ethylene glycol-tetramethylene glycol) mono (Meth) acrylate, poly (propylene glycol-tetramethylene glycol) mono (meth) acrylate, and the like.

[A: In the case of an alkenyl group]
Examples thereof include polyethylene glycol derivatives such as polyethylene glycol monoallyl ether, polypropylene glycol derivatives such as polypropylene glycol monoallyl ether, and polyethylene glycol-polypropylene glycol-monoallyl ether.

  Among these, polyethylene glycol derivatives are preferable, and the number of moles of added ethylene oxide n is preferably 5 to 500, particularly 5 to 100, and more preferably 6 to 30 in terms of the balance between antistatic ability and durability. If the ethylene oxide addition mole number n is too small, the antistatic ability tends to be inferior, and if it is too large, the durability tends to deteriorate. Furthermore, A is preferably a (meth) acryloyl group from the viewpoint of influence on curability.

  Moreover, as a weight average molecular weight of the monofunctional monomer containing the oxyalkylene chain shown by the said General formula (2), 100-20000 are preferable normally, Especially it is 200-10000, Furthermore, 300-1000 are preferable. When the weight average molecular weight is too small, the antistatic ability tends to be inferior. When the weight average molecular weight is too large, the crystallinity becomes high and the handling tends to be difficult.

  Examples of the bifunctional monomer containing two ethylenically unsaturated groups containing the oxyalkylene chain include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, Polyethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, butylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, Ethylene oxide modified bisphenol A di (meth) acrylate, propylene oxide modified bisphenol A di (meth) acrylate, 1,6-hexanediol ethylene Xoxide modified di (meth) acrylate, glycerin di (meth) acrylate, pentaerythritol di (meth) acrylate, ethylene glycol diglycidyl ether di (meth) acrylate, diethylene glycol diglycidyl ether di (meth) acrylate, diglycidyl phthalate diester (Meth) acrylate, hydroxypivalic acid-modified neopentyl glycol di (meth) acrylate, isocyanuric acid ethylene oxide-modified diacrylate, and the like.

  Examples of the tri- or higher functional monomer containing three or more ethylenically unsaturated groups containing an oxyalkylene chain include, for example, isocyanuric acid ethylene oxide-modified triacrylate, ethylene oxide-modified dipentaerythritol penta (meth) acrylate, ethylene Examples thereof include oxide-modified dipentaerythritol hexa (meth) acrylate, ethylene oxide-modified pentaerythritol tri (meth) acrylate, and ethylene oxide-modified pentaerythritol tetra (meth) acrylate.

  In the present invention, among the unsaturated group-containing compound (B), in order to increase the crosslinking density of the pressure-sensitive adhesive, it is preferable to use a polyfunctional, that is, an unsaturated group-containing compound having two or more unsaturated groups, In particular, an unsaturated group-containing compound having 3 or more unsaturated groups is preferred. Moreover, it is also preferable to use the urethane (meth) acrylate type compound (b1) and ethylenically unsaturated monomer (b2) containing an oxyalkylene chain at the point which shows the outstanding antistatic performance. In particular, urethane (meth) acrylate compounds containing oxyalkylene chains and containing 3 or more unsaturated groups are preferred.

  In addition, it is also preferable to use a (meth) acrylate compound containing an acid-base ion pair and / or a betaine structure in the molecule as the unsaturated group-containing compound (B) from the viewpoint of further improving the antistatic ability. .

  An example of a method for producing a (meth) acrylate compound containing an acid-base ion in the molecule is a method of reacting a polyfunctional (meth) acrylate monomer containing a carboxyl group with potassium hydroxide. However, the present invention is not limited to this.

  These urethane (meth) acrylate compounds and ethylenically unsaturated monomers constituting the unsaturated group-containing compound (B) may be used alone or in combination of two or more.

  As content of the said unsaturated group containing compound (B), 5-99 weight part is preferable with respect to 100 weight part of acrylic resin (A), More preferably, it is 5-50 weight part, More preferably, it is 8-30. Parts by weight. If the content of the unsaturated group-containing compound (B) is too large, the compatibility with the resin is deteriorated and the coating tends to be whitened. If the content is too small, the crosslinking density of the pressure-sensitive adhesive is insufficient. There is a tendency for leakage prevention properties to deteriorate.

  In order to further improve the antistatic performance of the adhesive obtained in the present invention, it is also effective to increase the antistatic performance of the unsaturated group-containing compound (B). In order to obtain the effect of improving the antistatic performance, a compound having an antistatic performance may be used as the ethylenically unsaturated monomer, and a hydrophilic component as a constituent component of the urethane (meth) acrylate compound. You may use the compound which has both the structural site | part which shows this, and the antistatic performance which has a hydroxyl group.

  As the polymerization initiator (C), for example, various polymerization initiators such as a photopolymerization initiator (C1) and a thermal polymerization initiator (C2) can be used. Use of C1) is preferable in that it can be crosslinked (cured) by irradiation with active energy rays such as ultraviolet rays for a very short time.

  When the photopolymerization initiator (C1) is used, the resin composition [I] is crosslinked by irradiation with active energy rays, and when the thermal polymerization initiator (C2) is used, the resin composition [I] is heated. It is also preferable to use both in combination, if necessary.

  Examples of the photopolymerization initiator (C1) include diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzyldimethyl ketal, 4- (2-hydroxyethoxy) phenyl- (2 -Hydroxy-2-propyl) ketone, 1-hydroxycyclohexyl phenylketone, 2-methyl-2-morpholino (4-thiomethylphenyl) propan-1-one, 2-benzyl-2-dimethylamino-1- (4- Acetophenones such as morpholinophenyl) butanone and 2-hydroxy-2-methyl-1- [4- (1-methylvinyl) phenyl] propanone oligomer; benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl Ben such as ether Ins; benzophenone, methyl o-benzoylbenzoate, 4-phenylbenzophenone, 4-benzoyl-4'-methyl-diphenyl sulfide, 3,3 ', 4,4'-tetra (t-butylperoxycarbonyl) benzophenone, 2,4,6-trimethylbenzophenone, 4-benzoyl-N, N-dimethyl-N- [2- (1-oxo-2-propenyloxy) ethyl] benzenemethananium bromide, (4-benzoylbenzyl) trimethylammonium Benzophenones such as chloride; 2-isopropylthioxanthone, 4-isopropylthioxanthone, 2,4-diethylthioxanthone, 2,4-dichlorothioxanthone, 1-chloro-4-propoxythioxanthone, 2- (3-dimethylamino-2-hydroxy -3 Thioxanthones such as 4-dimethyl-9H-thioxanthone-9-one mesochloride; 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, bis (2,6-dimethoxybenzoyl) -2,4,4-trimethyl- And acyl phosphine oxides such as pentylphosphine oxide and bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide; In addition, as for these photoinitiators (C1), only 1 type may be used independently and 2 or more types may be used together.

  These auxiliary agents include triethanolamine, triisopropanolamine, 4,4′-dimethylaminobenzophenone (Michler ketone), 4,4′-diethylaminobenzophenone, 2-dimethylaminoethylbenzoic acid, 4-dimethylaminobenzoic acid. Ethyl, 4-dimethylaminobenzoic acid (n-butoxy) ethyl, isoamyl 4-dimethylaminobenzoate, 2-ethylhexyl 4-dimethylaminobenzoate, 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone Etc. can be used in combination.

  Among these, benzyl dimethyl ketal, 1-hydroxycyclohexyl phenyl ketone, benzoyl isopropyl ether, 4- (2-hydroxyethoxy) -phenyl (2-hydroxy-2-propyl) ketone, 2-hydroxy-2-methyl-1- It is preferable to use phenylpropan-1-one.

  Examples of the thermal polymerization initiator (C2) include methyl ethyl ketone peroxide, cyclohexanone peroxide, methyl cyclohexanone peroxide, methyl acetoacetate peroxide, acetyl acetate peroxide, 1,1-bis (t-hexyl peroxide). ) -3,3,5-trimethylcyclohexane, 1,1-bis (t-hexylperoxy) -cyclohexane, 1,1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane, 1, 1-bis (t-butylperoxy) -2-methylcyclohexane, 1,1-bis (t-butylperoxy) -cyclohexane, 1,1-bis (t-butylperoxy) cyclododecane, 1,1- Bis (t-butylperoxy) butane, 2,2-bis (4 -Di-t-butylperoxycyclohexyl) propane, p-menthane hydroperoxide, diisopropylbenzene hydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide, cumene hydroperoxide, t-hexyl hydroper Oxide, t-butyl hydroperoxide, α, α′-bis (t-butylperoxy) diisopropylbenzene, dicumyl peroxide, 2,5-dimethyl-2,5-bis (t-butylperoxy) hexane, t-Butyl cumyl peroxide, di-t-butyl peroxide, 2,5-dimethyl-2,5-bis (t-butylperoxy) hexyne-3, isobutyryl peroxide, 3,5,5-trimethylhexa Noyl peroxide, octanoyl per Oxide, lauroyl peroxide, stearoyl peroxide, succinic acid peroxide, m-toluoyl benzoyl peroxide, benzoyl peroxide, di-n-propyl peroxydicarbonate, diisopropyl peroxydicarbonate, bis (4-t-butyl) (Cyclohexyl) peroxydicarbonate, di-2-ethoxyethyl peroxydicarbonate, di-2-ethoxyhexyl peroxydicarbonate, di-3-methoxybutyl peroxydicarbonate, di-s-butyl peroxydicarbonate, Di (3-methyl-3-methoxybutyl) peroxydicarbonate, α, α'-bis (neodecanoylperoxy) diisopropylbenzene, cumylperoxyneodecanoate, 1,1,3,3-te Lamethylbutyl peroxyneodecanoate, 1-cyclohexyl-1-methylethylperoxyneodecanoate, t-hexylperoxyneodecanoate, t-butylperoxyneodecanoate, t-hexylperoxy Pivalate, t-butylperoxypivalate, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, 2,5-dimethyl-2,5-bis (2-ethylhexanoylper) Oxy) hexanoate, 1-cyclohexyl-1-methylethylperoxy-2-ethylhexanoate, t-hexylperoxy-2-ethylhexanoate, t-butylperoxy-2-ethylhexanoate, t- Hexyl peroxyisopropyl monocarbonate, t-butyl peroxyisobutyrate t-butyl peroxymalate, t-butyl peroxy-3,5,5-trimethylhexanoate, t-butyl peroxylaurate, t-butyl peroxyisopropyl monocarbonate, t-butyl peroxy-2 -Ethylhexyl monocarbonate, t-butyl peroxyacetate, t-butyl peroxy-m-toluylbenzoate, t-butyl peroxybenzoate, bis (t-butylperoxy) isophthalate, 2,5-dimethyl-2,5 -Bis (m-toluylperoxy) hexane, t-hexylperoxybenzoate, 2,5-dimethyl-2,5-bis (benzoylperoxy) hexane, t-butylperoxyallyl monocarbonate, t-butyltrimethylsilylper Oxide, 3,3 ', 4,4'-tetra Organic peroxide initiators such as (t-butylperoxycarbonyl) benzophenone and 2,3-dimethyl-2,3-diphenylbutane; 2-phenylazo-4-methoxy-2,4-dimethylvaleronitrile, 1- [(1-cyano-1-methylethyl) azo] formamide, 1,1′-azobis (cyclohexane-1-carbonitrile), 2,2′-azobis (2-methylbutyronitrile), 2,2′- Azobisisobutyronitrile, 2,2'-azobis (2,4-dimethylvaleronitrile), 2,2'-azobis (2-methylpropionamidine) dihydrochloride, 2,2'-azobis (2-methyl- N-phenylpropionamidine) dihydrochloride, 2,2'-azobis [N- (4-chlorophenyl) -2-methylpropionamidine] Hydride chloride, 2,2'-azobis [N- (4-hydrophenyl) -2-methylpropionamidine] dihydrochloride, 2,2'-azobis [2-methyl-N- (phenylmethyl) propionamidine] dihydrochloride 2,2'-azobis [2-methyl-N- (2-propenyl) propionamidine] dihydrochloride, 2,2'-azobis [N- (2-hydroxyethyl) -2-methylpropionamidine] dihydrochloride, 2,2'-azobis [2- (5-methyl-2-imidazolin-2-yl) propane] dihydrochloride, 2,2'-azobis [2- (2-imidazolin-2-yl) propane] dihydrochloride, 2,2'-azobis [2- (4,5,6,7-tetrahydro-1H-1,3-diazepin-2-yl) Lopan] dihydrochloride, 2,2'-azobis [2- (3,4,5,6-tetrahydropyrimidin-2-yl) propane] dihydrochloride, 2,2'-azobis [2- (5-hydroxy-3 , 4,5,6-tetrahydropyrimidin-2-yl) propane] dihydrochloride, 2,2'-azobis [2- [1- (2-hydroxyethyl) -2-imidazolin-2-yl] propane] dihydrochloride 2,2'-azobis [2- (2-imidazolin-2-yl) propane], 2,2'-azobis [2-methyl-N- [1,1-bis (hydroxymethyl) -2-hydroxyethyl] ] Propionamide], 2,2'-azobis [2-methyl-N- [1,1-bis (hydroxymethyl) ethyl] propionamide], 2,2'-azobis [2-me Til-N- (2-hydroxyethyl) propionamide], 2,2'-azobis (2-methylpropionamide), 2,2'-azobis (2,4,4-trimethylpentane), 2,2'- Azobis (2-methylpropane), dimethyl-2,2-azobis (2-methylpropionate), 4,4'-azobis (4-cyanopentanoic acid), 2,2'-azobis [2- (hydroxymethyl ) Propionitrile] and the like; and the like. In addition, only 1 type may be used independently for these thermal polymerization initiators, and 2 or more types may be used together.

  About content of the said polymerization initiator (C), 0.01-10 weight part with respect to 100 weight part of said acrylic resin (A), Especially 0.1-7 weight part, Furthermore, 0.3 It is preferably ~ 3 parts by weight. If the content of the polymerization initiator (C) is too small, the curability tends to be poor and the physical properties tend not to be stable, and if it is too much, no further effect can be obtained.

  In the active energy ray irradiation, far ultraviolet rays, ultraviolet rays, near ultraviolet rays, infrared rays and other electromagnetic waves, X rays, γ rays and other electromagnetic waves, as well as electron beams, proton rays, neutron rays, etc. can be used. Curing by ultraviolet irradiation is advantageous from the standpoint of availability of the device and price. In addition, when performing electron beam irradiation, it can harden | cure even without using the said photoinitiator (C1).

As a light source for the ultraviolet irradiation, a high pressure mercury lamp, an electrodeless lamp, an ultrahigh pressure mercury lamp, a carbon arc lamp, a xenon lamp, a metal halide lamp, a chemical lamp, a black light, or the like is used. In the case of the high-pressure mercury lamp, for example, it is performed under conditions of 5 to 3000 mJ / cm ² , preferably 10 to 1000 mJ / cm ² . Moreover, in the case of the said electrodeless lamp, it is performed on the conditions of 2-1500 mJ / cm < ² >, for example, Preferably it is 5-500 mJ / cm < ² >. The irradiation time varies depending on the type of the light source, the distance between the light source and the coating surface, the coating thickness, and other conditions, but may be usually from several seconds to several tens of seconds, and in some cases, may be a fraction of a second. On the other hand, in the case of the electron beam irradiation, for example, an electron beam having an energy in the range of 50 to 1000 Kev is used, and the irradiation amount is preferably 2 to 50 Mrad.

  Moreover, when using a thermal-polymerization initiator (C2) as said polymerization initiator (C), a polymerization reaction is started and advanced by heating. The treatment temperature and treatment time at the time of crosslinking by heating vary depending on the type of thermal polymerization initiator (C2) to be used, and are usually calculated from the half-life of the initiator, but the treatment temperature is usually The temperature is preferably 70 ° C to 170 ° C, and the treatment time is usually preferably 0.2 to 20 minutes, and particularly preferably 0.5 to 10 minutes.

  When performing the crosslinking, either crosslinking by irradiation with active energy rays or thermal crosslinking may be used, but crosslinking by irradiation with active energy rays and thermal crosslinking may be used in combination as necessary.

Next, a method of crosslinking using the [β] crosslinking agent (D) will be described.
In the case of crosslinking using the crosslinking agent (D), as the resin composition [I], in addition to the acrylic resin (A), a resin composition [I] further containing a crosslinking agent (D) is used.

  When the crosslinking agent (D) is used, the acrylic resin (A) preferably has a functional group, and crosslinking (chemical crosslinking) is performed by reacting the functional group with the crosslinking agent.

  As said crosslinking agent (D), what is necessary is just a compound which has a functional group which reacts with the functional group contained in the said acrylic resin (A), for example, a bisphenol A * epichlorohydrin type epoxy resin, ethylene glycol diglycidyl ether , Polyethylene glycol diglycidyl ether, glycerin diglycidyl ether, glycerin triglycidyl ether, 1,6-hexanediol diglycidyl ether, trimethylolpropane triglycidyl ether, sorbitol polyglycidyl ether, polyglycerol polyglycidyl ether, pentaerythritol polyglycidyl erythritol , Epoxy compounds such as diglycerol polyglycidyl ether, tetramethylolmethane-tri-β-aziridinyl propionate, Roll propane-tri-β-aziridinyl propionate, N, N′-diphenylmethane-4,4′-bis (1-aziridinecarboxamide), N, N′-hexamethylene-1,6-bis (1 -Aziridine compounds such as -aziridinecarboxamide), melamines such as hexamethoxymethyl melamine, hexaethoxymethyl melamine, hexapropoxymethyl melamine, hexaptoxymethyl melamine, hexapentyloxymethyl melamine, hexahexyloxymethyl melamine, melamine resin Compound, for example, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, hydrogenated tolylene diisocyanate, 1,3-xylylene diisocyanate, 1,4-xylylene diisocyanate, hexamethylene diisocyanate Diphenylmethane-4,4-diisocyanate, isophorone diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane, tetramethylxylylene diisocyanate, 1,5-naphthalene diisocyanate, triphenylmethane triisocyanate, and these polyisocyanate compounds and tri Adducts with polyol compounds such as methylolpropane, isocyanate compounds such as bullets and isocyanurates of these polyisocyanate compounds, glyoxal, malondialdehyde, succindialdehyde, maleindialdehyde, glutardialdehyde, formaldehyde, acetaldehyde, Aldehyde compounds such as benzaldehyde, hexamethylene diamine, triethyl diamine, polyethylene imi , Amine compounds such as hexamethylenetetraamine, diethylenetriamine, triethyltetraamine, isophoronediamine, amino resin, polyamide, aluminum, iron, copper, zinc, tin, titanium, nickel, antimony, magnesium, panadium, chromium, zirconium, etc. Metal chelate compounds such as polymetallic acetylacetone and acetoacetyl ester coordination compounds, and the like. Among them, isocyanate compounds are preferred in terms of improving adhesion to the base material and reactivity with the base polymer. Used for. These crosslinking agents (D) may be used alone or in combination of two or more.

  The content of the crosslinking agent (D) can be appropriately selected depending on the amount of the functional group contained in the acrylic resin (A), the molecular weight of the acrylic resin (A), and the purpose of use. (A) It is preferable that it is 0.1-15 weight part with respect to 100 weight part, Furthermore, it is preferable that it is 0.2-12 weight part, especially 1.5-10 weight part. If the amount of the crosslinking agent (D) is too small, there is a tendency that the cohesive force is insufficient and sufficient durability cannot be obtained. If the amount is too large, the flexibility and adhesive strength are lowered, the durability is deteriorated, and peeling is caused. Tends to occur, and it tends to be difficult to bond to an optical film.

  Further, in the present invention, in order to further improve the antistatic performance of the pressure-sensitive adhesive obtained by crosslinking the resin composition [I], a compound having an antistatic performance was introduced into a part of the crosslinking agent. It is also preferable to use a crosslinking agent. As the compound having antistatic performance, the same compound as the compound having antistatic performance introduced into the side chain of the acrylic resin (A) by grafting reaction can be used.

  As a method for introducing a compound having antistatic performance into such a crosslinking agent, for example, when a polyisocyanate compound is used as the crosslinking agent, a compound having a hydroxyl group in its structure as a compound having antistatic performance. And a crosslinking agent in which a compound having antistatic performance is partially introduced can be produced by the reaction of the hydroxyl group and the isocyanate group.

  In addition, regarding the introduction of the compound having antistatic performance into the crosslinking agent, a compound having antistatic performance may be introduced into the crosslinking agent in advance and mixed with the acrylic resin (A), or the acrylic resin. (A) At the time of mixing with the crosslinking agent (D), a compound having antistatic performance may be added at the same time to react with the crosslinking agent (D).

  In the present invention, sufficient crosslinking can be obtained only by the above [α] active energy ray and / or heat (active energy ray irradiation and / or heating). By using in combination, the crosslink density of the pressure-sensitive adhesive is increased, the cohesive force is increased, and a further superior one in terms of prevention of light leakage and durability can be obtained.

  In the present invention, the resin composition [I], which is a pressure-sensitive adhesive forming material, is an acrylic resin (E) having no acid-base ion pair and / or betaine structure in the molecule (hereinafter simply referred to as “acrylic resin”). (E) ”is sometimes included for improving reworkability. The content of the acrylic resin (E) is preferably 1 to 100 parts by weight, more preferably 5 to 50 parts by weight, particularly preferably 10 to 100 parts by weight of the previous acrylic resin (A). -40 parts by weight, particularly preferably 20-35 parts by weight. If the content is too small, the effect of addition tends not to be obtained. If the content is too large, the proportion of the ionic component in the resin composition is relatively reduced, and the antistatic performance tends to be inferior.

  As said acrylic resin (E), the thing similar to monomer (a1)-(a4) used for the above-mentioned acrylic resin (A) is selected suitably, and such a monomer component is copolymerized (or homopolymerized). The obtained acrylic resin may be used.

  Specifically, the monomer (a1) is 0 to 100% by weight, the monomer (a2) is 0 to 10% by weight, the monomer (a3) is 0 to 50% by weight, and the monomer (a4) is 0 to 30% by weight. It is preferably an acrylic resin obtained by copolymerizing the resin composition contained therein, and the oxyalkylene structure-containing unsaturated monomer represented by the general formula (1) is preferably 0 to 100% by weight, particularly It is preferably 10 to 80% by weight, more preferably 20 to 60% by weight, from the viewpoint of improving the antistatic performance.

  Moreover, it is also preferable to contain 5-70 weight% of hydroxyl-containing monomers, such as 2-hydroxyethyl (meth) acrylate, in terms of improvement in antistatic performance, improvement in reworkability, and improvement in durability. The amount is particularly preferably 8 to 60% by weight, further preferably 11 to 50% by weight, and particularly preferably 20 to 40% by weight.

  About the weight average molecular weight of acrylic resin (E), Preferably it is 300,000-2,500,000, Most preferably, it is 600,000-2 million. If the weight average molecular weight is too small, there is a tendency that sufficient agglomeration force cannot be obtained even by at least one cross-linking treatment of active energy rays and heat described later. And the cost tends to be unfavorable.

  The degree of dispersion (weight average molecular weight / number average molecular weight) of the acrylic resin (E) is not particularly limited, but is preferably 7 or less, and particularly preferably 5.5 or less. When the degree of dispersion is too high, the pressure-sensitive adhesive layer tends to be inferior in durability performance such as heat and moisture resistance and light leakage. The lower limit of the degree of dispersion is usually 1.1 from the viewpoint of production limit.

  The glass transition temperature of the acrylic resin (E) is not generally specified, but is preferably −80 to −20 ° C., particularly preferably −70 to −30 ° C. If the glass transition temperature is too high, tack tends to be insufficient. If it is too low, it tends to be inferior in heat resistance.

  In addition, said weight average molecular weight, dispersion degree, and glass transition temperature are measured and calculated according to the above-mentioned method.

  In the present invention, it is preferable that the resin composition [I], which is a pressure-sensitive adhesive forming material, further contains a silane coupling agent (F) from the viewpoint of improving adhesion to an optical member. As content of the said silane coupling agent (F), it is normally set to 0.001-10 weight part with respect to 100 weight part of acrylic resin (A), More preferably, 0.01-1 weight part Particularly preferred is 0.03 to 0.8 parts by weight. If the content of the silane coupling agent (F) is too small, there is a tendency that the effect of addition cannot be obtained. If the content is too large, the compatibility with the acrylic resin (A) is poor and adhesive strength and cohesive force cannot be obtained. Tend.

  Examples of the silane coupling agent (F) include epoxy silane coupling agents, acrylic silane coupling agents, mercapto silane coupling agents, hydroxyl group silane coupling agents, carboxyl group silane coupling agents, amino Examples thereof include a base silane coupling agent, an amide group silane coupling agent, and an isocyanate group silane coupling agent. These may be used alone or in combination of two or more. Among these, an epoxy silane coupling agent and a mercapto silane coupling agent are preferably used. In particular, the combined use of an epoxy silane coupling agent and a mercapto silane coupling agent improves wet heat durability and adhesive strength. Is preferable in that it does not rise too much.

  Specific examples of the epoxy-based silane coupling agent include, for example, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, and γ-glycid. Examples include xylpropylmethyldimethoxysilane, methyltri (glycidyl) silane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, and the like. -Glycidoxypropyltrimethoxysilane, [gamma] -glycidoxypropyltriethoxysilane, [gamma] -glycidoxypropylmethyldiethoxysilane, [beta]-(3,4-epoxycyclohexyl) ethyltrimethoxysilane.

  Specific examples of the mercapto silane coupling agent include γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, and γ-mercaptopropyldimethoxymethylsilane.

  In the present invention, the resin composition [I] which is a pressure-sensitive adhesive forming material may further contain an antistatic agent (G) in order to further improve the antistatic performance of the pressure-sensitive adhesive obtained. preferable. Examples of the antistatic agent (G) include cationic antistatic agents of quaternary ammonium salts such as tetraalkylammonium sulfonates, aliphatic sulfonates, higher alcohol sulfates, and higher alcohol alkylene oxide adducts. Anionic antistatic agent such as sulfate ester salt, higher alcohol phosphate ester salt, higher alcohol alcohol alkylene oxide adduct phosphate ester salt, alkali metal salt of organic acid or inorganic acid such as lithium perchlorate or lithium chloride, alkali Examples include earth metal salts, higher alcohol alkylene oxide adducts, polyalkylene glycol fatty acid esters, and the like.

  As content of the said antistatic agent (G), it is normally set to 0.001-20 weight part with respect to 100 weight part of acrylic resin (A), More preferably, 0.01-7 weight part, Particularly preferred is 0.02 to 1 part by weight. If the content of the antistatic agent (G) is too small, the effect of addition tends not to be obtained, and if it is too large, the durability may deteriorate or the antistatic agent may bleed out.

In the present invention, the resin composition [I], which is a pressure-sensitive adhesive-forming material, further includes other acrylic pressure-sensitive adhesives, other pressure-sensitive adhesives, urethane resins, rosins, and rosin esters as long as the effects of the present invention are not impaired. , Hydrogenated rosin esters, phenol resins, aromatic modified terpene resins, aliphatic petroleum resins, alicyclic petroleum resins, styrene resins, xylene resins, etc., colorants, fillers, anti-aging agents Conventionally known additives such as ultraviolet absorbers, and compounds that cause coloration or discoloration upon irradiation with ultraviolet rays or radiation can be added.
In addition to the above additives, a small amount of impurities contained in the raw materials for producing the constituent components of the resin composition [I] may be contained.

Thus, in this invention, the adhesive for optical members formed by bridge | crosslinking said resin composition [I] is obtained.
In addition, as a crosslinking method of the resin composition [I] whose main component is an acrylic resin (A) having an acid-base ion pair and / or a betaine structure in the molecule, the resin composition [I] is substantially Without containing an unsaturated group, the resin composition [I] may be cross-linked by a method of irradiating active energy rays. At this time, the polymerization initiator (C), the crosslinking agent (D), the acrylic resin (E), the silane coupling agent (F), and the antistatic agent (G) are contained for the same reason as described above. Is preferable.

  And the optical member with an adhesive layer can be obtained by carrying out the lamination formation of the adhesive layer which consists of the said adhesive on an optical member (optical laminated body).

  The optical member with the pressure-sensitive adhesive layer is preferably further provided with a release sheet on the surface opposite to the surface of the optical member on which the pressure-sensitive adhesive layer is provided.

  Examples of the method for producing the optical member with the pressure-sensitive adhesive layer include [1] a method in which the resin composition [I] is applied on the optical member and dried, and then a release sheet is bonded, or [2] After applying and drying the resin composition [I] on the mold sheet, it can be produced by a method of bonding an optical member or the like. Especially, the manufacturing method which apply | coats resin composition [I] on a release sheet which is the method of said [2] is preferable at the point with a low possibility of degrading an optical member with a dilution solvent.

  Moreover, when using the optical member with an adhesive layer for practical use, the said release sheet is peeled and used. And as said release sheet, it is preferable to use a silicon-type release sheet.

  Further, when the resin composition [I] is crosslinked by at least one of active energy ray irradiation and heating, [1] the resin composition [I] is coated on the optical member, dried, and then released. A method of pasting sheets and performing treatment by at least one of active energy ray irradiation and heating, [2] On the release sheet, after applying and drying the resin composition [I], the optical members are pasted, Method of performing treatment by active energy ray irradiation and heating, [3] Applying and drying resin composition [I] on the optical member, further performing treatment by irradiation of active energy ray and heating, and then attaching a release sheet [4] The resin composition [I] is applied on the release sheet, dried, and further subjected to active energy ray irradiation and heating, and then the optical member is bonded. Kill.

  In applying the resin composition [I], the resin composition [I] is preferably diluted with a solvent, and the dilution concentration is preferably 10 to 50% by weight, particularly preferably 11 to 25%. % By weight. The solvent is not particularly limited as long as it dissolves the resin composition [I]. For example, ester solvents such as methyl acetate, ethyl acetate, methyl acetoacetate, ethyl acetoacetate, acetone, A ketone solvent such as methyl ethyl ketone and methyl isobutyl ketone, an aromatic solvent such as toluene and xylene, and an alcohol solvent such as methanol, ethanol and propyl alcohol can be used. Among these, ethyl acetate, methyl ethyl ketone, and methanol are preferably used from the viewpoints of solubility, drying properties, price, and the like.

  The application of the resin composition [I] is performed by a conventional method such as roll coating, die coating, gravure coating, comma coating, or screen printing.

  The gel fraction of the pressure-sensitive adhesive layer produced by the above method is preferably 80% or more, particularly 90% or more from the viewpoint of durability performance and light leakage prevention performance. If the gel fraction is too low, the durability and light leakage phenomenon due to insufficient cohesive force tend to be deteriorated. In general, the upper limit of the gel fraction is 100%.

  In adjusting the gel fraction of the optical member pressure-sensitive adhesive to the above range, for example, adjusting the irradiation amount and irradiation intensity of the active energy ray, adjusting the type of polymerization initiator and the combination ratio thereof, This is achieved by adjusting the blending amount of the polymerization initiator. Moreover, since the gel fraction changes by each interaction, the irradiation amount and irradiation intensity | strength of said active energy ray, the composition ratio of a polymerization initiator, and addition amount need to balance each.

  The gel fraction is a measure of the degree of crosslinking, and is calculated, for example, by the following method. That is, a pressure-sensitive adhesive sheet (not provided with a separator) in which a pressure-sensitive adhesive layer is formed on a polymer sheet (for example, polyethylene terephthalate film or the like) as a base material is wrapped with a 200-mesh SUS wire mesh, and 23 in toluene. The weight percentage of the insoluble pressure-sensitive adhesive component immersed in the wire mesh at 24 ° C. for 24 hours is defined as the gel fraction. However, the weight of the substrate is subtracted.

  Moreover, the thickness of the adhesive layer in the optical member with an adhesive layer obtained is although it does not specifically limit, 10-40 micrometers is preferable and especially 12-30 micrometers is preferable. If the thickness of the pressure-sensitive adhesive layer is too thin, the adhesive physical properties tend to be difficult to stabilize, and if it is too thick, adhesive residue tends to occur.

  The optical member with the pressure-sensitive adhesive layer of the present invention has a release sheet directly or after the release sheet is peeled off, and then the surface of the pressure-sensitive adhesive layer is bonded to a glass substrate and used for a liquid crystal display panel, for example. .

  The initial adhesive strength of the pressure-sensitive adhesive layer of the present invention is appropriately determined according to the material of the adherend. For example, when sticking on a glass substrate, it preferably has an adhesive strength of 0.2 N / 25 mm to 20 N / 25 mm, and more preferably 0.5 N / 25 mm to 10 N / 25 mm.

  The initial adhesive strength is calculated as follows. About a polarizing plate with an adhesive layer, it cut | judged to width 25mm width, peels a release film, presses the adhesive layer side to a non-alkali glass plate (Corning company make, "Corning 1737"), and a polarizing plate A glass plate is bonded. Then, after performing an autoclave process (50 degreeC, 0.5 MPa, 20 minutes), a 180 degreeC peeling test is done. In addition, in peelability, it is desired that adhesive force is small.

  The optical member in the present invention is not particularly limited, and an optical film suitably used for an image display device such as a liquid crystal display device, an organic EL display device, or a PDP, such as a polarizing plate, a retardation plate, or an elliptical polarizing plate. , Optical compensation films, brightness enhancement films, and those in which these are laminated. Among them, a polarizing plate is particularly effective in the present invention.

  The polarizing plate used in the present invention is usually a laminate of a cellulose triacetate film as a protective film on both sides of a polarizing film. The polarizing film has an average degree of polymerization of 1,500 to 10,000, A uniaxially stretched film dyed with an aqueous solution of iodine-potassium iodide or a dichroic dye using a film made of a polyvinyl alcohol resin having a degree of conversion of 85 to 100 mol% as a raw film (usually 2 to 10 times, preferably Is a stretching ratio of about 3 to 7 times.

  The polyvinyl alcohol resin is usually produced by saponifying polyvinyl acetate obtained by polymerizing vinyl acetate, but a small amount of unsaturated carboxylic acid (including salt, ester, amide, nitrile, etc.), olefins, vinyl ether And a component copolymerizable with vinyl acetate, such as an unsaturated sulfonate. Moreover, what is called polyvinyl acetal resin and polyvinyl alcohol derivatives, such as polybutyral resin and polyvinyl formal resin, which are obtained by reacting polyvinyl alcohol with an aldehyde in the presence of an acid can be mentioned.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples unless it exceeds the gist. In the examples, “parts” and “%” mean weight basis unless otherwise specified.

  First, various acrylic resins and various unsaturated group-containing compounds were prepared as follows. In addition, regarding the measurement of the weight average molecular weight of acrylic resin, dispersion degree, and glass transition temperature, it measured according to the above-mentioned method. In addition, regarding the measurement of a viscosity, it measured according to the 4.5.3 rotational viscometer method of JISK5400 (1990).

[Preparation of acrylic resin (A-1)]
A 4-neck round bottom flask equipped with a reflux condenser, stirrer, nitrogen gas inlet and thermometer was charged with 10 parts of acrylic acid, 90 parts of butyl acrylate, 100 parts of ethyl acetate, and 45 parts of acetone, and heating and refluxing started. Thereafter, 0.03 part of azobisisobutyronitrile (AIBN) was added as a polymerization initiator, reacted for 3 hours at the reflux temperature of ethyl acetate, diluted with ethyl acetate, and an acrylic resin solution [weight average molecular weight (Mw) 1.6 million, dispersity (Mw / Mn) 3.2, glass transition temperature -49 ° C., solid content 17.5%, viscosity 8200 mPa · s (25 ° C.)].
To 100 parts (solid content) of the acrylic resin obtained above, dilute with methanol to contain a 10% methanol solution of potassium hydroxide (0.95 equivalents per mole of carboxyl groups) as a neutralizing agent. The mixture was sufficiently stirred to obtain a 12% solution of acrylic resin (A-1).

[Preparation of acrylic resin (A-2)]
The acrylic resin 100 parts (solid content) obtained above is diluted with methanol to contain a 10% methanol solution of potassium hydroxide as a neutralizing agent (1.0 equivalent per 1 mol of carboxyl groups). The mixture was sufficiently stirred to obtain a 12% solution of acrylic resin (A-2).

[Preparation of acrylic resin (A-3)]
A four-necked round bottom flask equipped with a reflux condenser, stirrer, nitrogen gas inlet and thermometer was charged with 15 parts of acrylic acid, 85 parts of butyl acrylate, 100 parts of ethyl acetate, and 45 parts of acetone, and heating and refluxing started. Thereafter, 0.03 part of azobisisobutyronitrile (AIBN) was added as a polymerization initiator, reacted for 3 hours at the reflux temperature of ethyl acetate, diluted with ethyl acetate, and an acrylic resin solution [weight average molecular weight (Mw) 1.6 million, dispersity (Mw / Mn) 3.2, glass transition temperature -49 ° C., solid content 17.3%, viscosity 12200 mPa · s (25 ° C.)].
To 100 parts (solid content) of the acrylic resin obtained above, dilute with methanol to contain a 10% methanol solution of potassium hydroxide (0.95 equivalents per mole of carboxyl groups) as a neutralizing agent. The mixture was sufficiently stirred to obtain a 12% solution of acrylic resin (A-3).

[Preparation of Acrylic Resin (A′-1)]
A 4-neck round bottom flask equipped with a reflux condenser, stirrer, nitrogen gas inlet and thermometer was charged with 5 parts of acrylic acid, 95 parts of butyl acrylate and 80 parts of ethyl acetate, and 40 parts of acetone, and heating and refluxing started. Thereafter, 0.03 part of azobisisobutyronitrile was added as a polymerization initiator, reacted for 3 hours at the reflux temperature of ethyl acetate, diluted with ethyl acetate, and then an acrylic resin (A′-1) solution [weight average molecular weight. 1.8 million, dispersion degree 3.0, glass transition temperature -51 ° C., solid content 16%, viscosity 8500 mPa · s (25 ° C.)].

[Preparation of acrylic resin (A'-2)]
In a 4-neck round bottom flask equipped with a reflux condenser, a stirrer, a nitrogen gas inlet and a thermometer, 1 part of 2-hydroxyethyl acrylate (a1), 98.5 parts of butyl acrylate (a2), acrylic acid ( a3) 0.5 parts, 85 parts of ethyl acetate and 45 parts of acetone were added, and after heating to reflux, 0.03 part of azobisisobutyronitrile (AIBN) was added as a polymerization initiator, and the mixture was refluxed at ethyl acetate for 3 hours. After the reaction, it is diluted with ethyl acetate, and the acrylic resin (A′-2) solution [weight average molecular weight (Mw) 1.65 million, dispersity (Mw / Mn) 3.4, glass transition temperature −53 ° C., solid content 18%, viscosity 8000 mPa · s (25 ° C.)].

[Production of unsaturated group-containing compound (B-1)]
In a four-necked round bottom flask equipped with a reflux condenser, a stirrer, a nitrogen gas inlet and a thermometer, 19.2 g (0.086 mol) of isophorone diisocyanate, 0.05 g of di-t-butylhydroxytoluene, dibutyltin 0.02 g of dilaurate was charged, and a mixture of pentaerythritol triacrylate and pentaerythritol tetraacrylate (manufactured by Kyoeisha Chemical Co., Ltd., light acrylate PE-3A, hydroxyl value 120 mgKOH / g) at 50 ° C. or less, 80.8 g (0.27 mol) The reaction was continued at 70 ° C., and the reaction was terminated when the residual isocyanate group reached 0.3% to obtain an unsaturated group-containing compound (B-1).

[Production of unsaturated group-containing compound (B-2)]
In a four-necked flask equipped with a thermometer, a stirrer, and a water-cooled condenser, 94.1 g (0.42 mol) of isophorone diisocyanate (isocyanate group content 37.8%) and 2,6-di-t-butylhydroxytoluene 2.0 g and 0.1 g of dibutyltin dilaurate were charged, and dipentaerythritol pentaacrylate (0.51 mol) [mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (hydroxyl value 50.0 mgKOH / g) was charged dropwise in about 2 hours and reacted at 60 ° C. for 2 hours. When the residual isocyanate group reached 2.1%, polyethylene glycol (weight average molecular weight 993.1, ethylene Number of moles of oxide added 22 and hydroxyl value 113 mgKOH g) 336.2 g (0.34 mol) was added at 55 ° C. and reacted at 60 ° C. for 4 hours. When the residual isocyanate group reached 0.3%, the reaction was terminated and contained an unsaturated group. A composition containing compound (B-2) was obtained (resin concentration 100%).
The composition obtained by the above preparation contains 69.4% of an unsaturated group-containing compound (B-2), and an ethylenically unsaturated monomer (a mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate). The content was 30.6%, and the weight average molecular weight was 2500.

[Unsaturated group-containing compound (B-3)]
Methoxypolyethylene glycol-monoacrylate (manufactured by NOF Corporation, BLEMMER AME-400)

[Unsaturated group-containing compound (B-4)]
Alkali-soluble polyfunctional acrylate (acid value 95.2: Aronix M-510 (manufactured by Toagosei Co., Ltd.)) was collected, diluted with methyl ethyl ketone (MEK), and 10% methanol solution of potassium hydroxide (carboxyl group 1 as a neutralizing agent). 1.0 equivalent) with respect to a mole, and stirred well to obtain a 50% solution of the unsaturated group-containing compound (B-4).

[Photopolymerization initiator (C-1)]
A mixture of benzophenone and 1-hydroxycyclohexyl phenyl ketone at a mass ratio of 1: 1 (Ciba Specialty Chemicals, Irgacure 500)

[Acrylic resin (E-1)]
A 4-neck round bottom flask equipped with a reflux condenser, stirrer, nitrogen gas inlet and thermometer was charged with 100 parts of ethyl acetate, and 0.05 parts of azobisisobutyronitrile (AIBN) as a polymerization initiator. The mixture was heated while stirring, and at 78 ° C., a mixture of 30 parts of 2-hydroxyethyl acrylate (a1) and 70 parts of butyl acrylate (a2) was added dropwise over 2 hours. In the course of the polymerization, while sequentially adding a polymerization initiator solution in which 0.05 part of AIBN was dissolved in 10 parts of ethyl acetate, the mixture was polymerized at the ethyl acetate reflux temperature for 3.5 hours, and then diluted with an acrylic resin (E-1 ) Solution (weight average molecular weight (Mw) 850,000, dispersity (Mw / Mn) 4.5, glass transition temperature -43 ° C., solid content 35%, viscosity 7,000 mPa · s (25 ° C.)).

[Silane compound (F-1)]
γ-glycidoxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., KBM-403)

[Antistatic agent (G-1)]
1-methyl-3-octyl-imidazolium bromide

[Examples 1-9, Comparative Examples 1-2]
A resin composition to be a pressure-sensitive adhesive forming material for an optical member is prepared by blending each blended component prepared and prepared as described above in the ratio shown in Table 1 below, and this is coated with ethyl acetate. A resin composition solution was prepared by diluting to a viscosity of 1000 to 10,000 mPa · s (25 ° C.).

And after apply | coating the said resin composition solution to the polyester-type release sheet so that the thickness after drying may be set to 25 micrometers, and drying for 3 minutes at 90 degreeC, the formed resin composition layer side is made into the polarizing plate ( The film was transferred onto a 190 μm-thickness electrode, and was irradiated with a fusion-free electrodeless lamp [H bulb of LH6UV lamp (effective irradiation width 150 mm × 1 row)], peak illuminance: 600 mW / cm ² , integrated exposure: 240 mJ / cm ² Irradiation was performed at 23 ° C. × 65% R.D. H. The film was aged for 14 days to obtain a polarizing plate with an adhesive layer. The polarizing plate is laminated with a cellulose triacetate film having a thickness of 80 μm on both sides of a 30 μm-thick polyvinyl alcohol polarizing film (average polymerization degree 1700, average saponification degree 99 mol%, iodine staining, 4-fold stretching). The polarizing plate (the polyvinyl alcohol polarizing film was cut into 100 mm × 100 mm by tilting the direction of the stretching axis by 45 °) was used.

  On the other hand, by using a polyethylene terephthalate (PET) film (thickness 38 μm) in place of the polarizing plate in the same manner as described above, a gel fraction, surface resistivity, and adhesive strength measurement sample were prepared.

  Using the thus obtained polarizing plate with the pressure-sensitive adhesive layer or PET film with the pressure-sensitive adhesive layer, its physical properties [surface resistivity, gel fraction, durability (wet heat resistance test, heat cycle test), adhesive strength Were measured and evaluated according to the following methods. These results are also shown in Table 2 below.

[Surface resistivity]
The obtained PET film with the pressure-sensitive adhesive layer was cut into a size of 40 × 40 mm, and this was left to stand for 3 hours under conditions of a temperature of 23 ° C. and a relative humidity of 65%, and then the release sheet was peeled off. About the adhesive layer after 10 to 20 seconds, the surface resistivity was measured using a resistivity meter (manufactured by Mitsubishi Chemical Co., Ltd., Harrester UP). In addition, it means that antistatic performance is so high that surface resistivity is small.

[Gel fraction]
After the obtained PET film with the pressure-sensitive adhesive layer is cut into 40 × 40 mm, the release sheet is peeled off and the pressure-sensitive adhesive layer side is bonded to a 50 × 100 mm SUS mesh sheet (200 mesh), and then the SUS mesh sheet. The sample was wrapped from the center with respect to the longitudinal direction, and the sample was wrapped. Then, the gel fraction was measured by weight change when immersed in a sealed container containing 250 g of toluene.

〔durability〕
The release sheet of the obtained polarizing plate with the pressure-sensitive adhesive layer was peeled off, and the pressure-sensitive adhesive layer side was pressed against a non-alkali glass plate (Corning 1737, manufactured by Corning) to bond the polarizing plate and the glass plate. Thereafter, autoclave treatment (50 ° C., 0.5 MPa, 20 minutes) was performed, and thereafter, foaming, peeling, and light leakage phenomenon were evaluated in the following durability tests (wet heat resistance test, heat cycle test).

〔An endurance test〕
(1) Moisture and heat resistance test 60 ° C., 90% R.D. H. Endurance test for 100 hours (2) Heat cycle test Endurance test for 100 cycles with the operation of leaving at −40 ° C. for 30 minutes and then leaving at 85 ° C. for 30 minutes as one cycle (3) Heat resistance test 80 ° C. for 100 hours An endurance test

〔Evaluation criteria〕
(Foam)
◎ ... No foaming is observed. ○ ... No foaming is observed. △ ... Slight foaming is observed.
◎ ・ ・ ・ No peeling ○○ Peeling less than 0.5 mm or generation of a lift mark △ ・ ・ ・ Peeling of 0.5 mm or more and less than 10 mm or generation of a lift mark × ・ ・ ・ 10 mm or more Exfoliation or generation of a 10mm or more lift mark (light leakage)
Only the heat resistance test (3) was evaluated for light leakage.
◎ ・ ・ ・ No light leakage ○ ・ ・ ・ Almost no light leakage △ ・ ・ ・ Slight light leakage occurred × ・ ・ ・ Large light leakage occurred on 4 sides

〔Adhesive force〕
About the prepared polarizing plate with an adhesive layer, it cuts to width 25mm width, peels off a release film, presses the adhesive layer side to a non-alkali glass board (Corning company make, "Corning 1737"), and polarized light The plate and the glass plate were bonded together. Thereafter, autoclave treatment (50 ° C., 0.5 MPa, 20 minutes) was performed, and a 180 ° C. peel test was performed 24 hours later. In the peelability, it is desired that the adhesive strength is small, and the target is 10 N / 25 mm or less after one day.

  From the above results, the examples have low surface resistivity and excellent antistatic performance, and are good in any of the heat test, heat cycle test, and moist heat test (foaming, peeling, light leakage in heat test). Evaluation results are obtained, and it is clear that excellent durability is provided. Moreover, a sufficiently satisfactory value with no problem with respect to adhesive strength was obtained.

  On the other hand, the comparative example 1 was inferior to the peeling item in a heat cycle test, and the surface resistivity was high compared with the Example, and it was inferior to antistatic performance. Further, Comparative Example 2 in which the ionic liquid was simply mixed had a slightly lower surface resistivity than Comparative Example 1, but satisfactory antistatic performance was not obtained.

  The pressure-sensitive adhesive for optical members of the present invention is less likely to be charged with static electricity generated in each step, and has excellent adhesion between the optical laminate and the glass substrate even under high temperature and high humidity conditions. Since foaming and peeling do not occur between the glass substrate and the light leakage phenomenon caused by the contraction of the optical film can be suppressed, a liquid crystal display panel with excellent durability can be obtained, which is very useful. is there.

Claims (11)

An adhesive resin composition for an optical member, the main component of which is an acrylic resin (A) having an acid-base ion pair and / or a betaine structure in the molecule, wherein the acrylic resin (A) has a weight average molecular weight of 100 from 10,000 to 4,000,000 der it is, and an optical member for pressure-sensitive adhesive resin composition having a glass transition temperature, characterized in der Rukoto -80~-20 ℃ [I].   The acrylic resin (A) has an acid-base ion pair in the molecule, and the carboxyl group in the carboxyl group-containing acrylic resin obtained by copolymerizing the carboxyl group-containing monomer is the ion pair. The pressure-sensitive adhesive resin composition [I] for optical members according to claim 1, which is neutralized to form an ion pair.   A pressure-sensitive adhesive for optical members, wherein the pressure-sensitive adhesive resin composition [I] for optical members according to claim 1 or 2 is crosslinked.   The pressure-sensitive adhesive resin composition [I] for optical members contains an unsaturated group-containing compound (B) as a polymerizable component and a polymerization initiator (C), and is crosslinked by active energy rays and / or heat. The pressure-sensitive adhesive for optical members according to claim 3.   The pressure-sensitive adhesive for optical members according to claim 4, wherein the unsaturated group-containing compound (B) is an oxyalkylene chain-containing (meth) acrylate-based compound.   The pressure-sensitive adhesive for optical members according to claim 4, wherein the unsaturated group-containing compound (B) is a (meth) acrylate-based compound containing an acid-base ion pair and / or a betaine structure in the molecule.   The pressure-sensitive adhesive resin composition [I] for optical members contains a crosslinking agent (D), and is crosslinked by the crosslinking agent (D). The pressure-sensitive adhesive for optical members according to any one of claims 3 to 6. Agent.   The pressure-sensitive adhesive resin composition [I] for optical members further contains an acrylic resin (E) having no acid-base ion pair and / or betaine structure in the molecule. The adhesive for optical members as described.   The pressure-sensitive adhesive for optical members according to any one of claims 3 to 8, wherein the gel fraction of the pressure-sensitive adhesive for optical members is 80% or more.   An optical member is a polarizing plate, The adhesive for optical members as described in any one of Claims 3-9.   An optical member with a pressure-sensitive adhesive layer, wherein the pressure-sensitive adhesive layer made of the pressure-sensitive adhesive for optical members according to any one of claims 3 to 10 is laminated on the optical member.