JP5349019B2 - Optical member pressure-sensitive adhesive composition, optical member pressure-sensitive adhesive, and optical member with a pressure-sensitive adhesive layer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a highly durable adhesive, which has excellent adhesion between an optical laminate, especially a polarizing plate, and a glass substrate even under high-temperature and high-humidity conditions causing no foaming nor separation between an adhesive layer and the glass substrate, can suppress occurrence of a light leakage phenomenon caused by shrinkage of a polarizing film, and causes no increase in adhesion with the lapse of time to realize excellent reworkability, for an optical member, and to provide an optical member with the adhesive layer. <P>SOLUTION: The adhesive for an optical member is produced by crosslinking a resin composition [I] containing an acrylic resin component (A) with an acid value of 0.1-100 mgKOH/g and a silane coupling agent component (B). The silane coupling agent component (B) contains an epoxy group containing silane coupling agent (B1) and a mercapto group containing silane coupling agent (B2). <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to an optical film (polarizing film, retardation film, optical compensation film, brightness enhancement film, etc.) that is suitably used for an image display device such as a liquid crystal display device, an organic EL display device, and a PDP. A pressure-sensitive adhesive for an optical member for bonding an optical laminate having a film coated with a protective film such as a cellulose triacetate film and a glass substrate of a liquid crystal cell, and an optical member provided with such a pressure-sensitive adhesive layer, Regarding the polarizing plate with the pressure-sensitive adhesive layer, more specifically, the adhesive property between the optical laminate and the glass substrate is excellent even under high temperature and high humidity conditions, and foaming or peeling occurs between the pressure-sensitive adhesive layer and the glass substrate. In addition, it has excellent durability, such as preventing light leakage caused by the shrinkage of the optical film, and reworkability without causing an increase in adhesive strength over time. Excellent optical member for a pressure-sensitive adhesive, and to a such a PSA layer with the optical member.

  Conventionally, a polarizing plate in which both sides of an optical member, for example, a polyvinyl alcohol film provided with polarization properties, are coated with a cellulose film, for example, a cellulose triacetate film, 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, and this lamination to the liquid crystal cell surface is performed by contacting the cell surface with an adhesive layer provided on the polarizing plate surface, It is usually done by pressing.

The liquid crystal display panels obtained in this way are widely used as display devices for personal computers, liquid crystal televisions, car navigation systems, etc., and the use environment has become very harsh, and in such harsh environments. It is required to withstand even the use of
For example, in a severe environment such as high temperature and high humidity, a phenomenon such as foaming or peeling between the pressure-sensitive adhesive and the glass plate becomes a problem. In addition, the polarizing film shrinks in a high temperature and high humidity environment, whereas the pressure-sensitive adhesive layer cannot follow the shrinking of the polarizing film, and light leaks from the peripheral edge of the liquid crystal display panel. The so-called light leakage phenomenon becomes a problem.

In addition, when an optical member is attached, if a foreign object is caught in the bonding surface or if the bonding position is misaligned, the optical member must be removed from the liquid crystal cell and reworked. It is. When peeling such an optical member from the liquid crystal cell, it is necessary to peel the optical member without changing the gap of the liquid crystal cell so as not to break it. Therefore, it is necessary to suppress the peelability that can be easily peeled off, that is, the increase in the adhesive strength over time.
However, emphasizing the durability of the pressure-sensitive adhesive for optical members, adopting a method that simply increases the adhesive strength results in inferior peelability, and it is not easy to achieve both durability and suppression of increase in adhesive strength over time. It was.

As a method for solving such a problem, for example, a pressure-sensitive adhesive composition comprising a carboxyl group-containing acrylic copolymer, a crosslinking agent, and a silane wrap ring agent containing a mercapto group or an alicyclic epoxy group as an essential component is proposed. (For example, refer to Patent Documents 1 and 2).
JP 2003-193013 A JP 2004-224873 A

  However, in the technologies disclosed in Patent Documents 1 and 2, although a slight improvement in reworkability is observed by using a silane coupling agent, a temperature change repetition test (−40 ° C. to 80 ° C.) is used as a durability test. It was not carried out, and it could not be judged that it had a level of durability that could withstand use in a display for installation in a car with a large temperature change.

  Therefore, in the present invention, under such a background, even under conditions of high temperature and high humidity, the optical laminate, particularly the adhesive property between the polarizing plate and the glass substrate is excellent, and foaming occurs between the pressure-sensitive adhesive layer and the glass substrate. In addition, the optical member has excellent durability, such as prevention of light leakage caused by contraction of the polarizing film, and excellent rework without increasing the adhesive force with time. It is an object to provide a pressure-sensitive adhesive for use and an optical member with such a pressure-sensitive adhesive layer.

  However, as a result of intensive studies in view of such circumstances, the present inventors, as a result, in an adhesive for an optical member, when the acrylic resin that is the base polymer usually contains an acidic group such as a carboxyl group, the durability is Although improved, it is thought that the adhesive strength with time increases and the reworkability deteriorates. By adding at least two kinds of specific silane coupling agents to such an acrylic resin, both durability and reworkability are achieved. As a result, the present invention has been completed.

That is, the gist of the present invention is an adhesive composition [I] for an optical member containing an acrylic resin component (A) having an acid value of 0.1 to 100 mgKOH / g and a silane coupling agent component (B) . The silane coupling agent component contains an epoxy group-containing silane coupling agent (B1) and a mercapto group-containing silane coupling agent (B2), and the pressure-sensitive adhesive composition [I] for an optical member contains a crosslinking agent (C And / or an unsaturated group-containing compound (D) and a polymerization initiator (E), and an optical member pressure-sensitive adhesive composition and an optical member pressure-sensitive adhesive .
In this invention, the optical member with an adhesive layer formed by laminating | stacking the said adhesive for optical members on an optical member is also provided.

  The pressure-sensitive adhesive for optical members of the present invention has excellent adhesion between the optical laminate and the glass substrate even under high temperature and high humidity conditions, and foaming and peeling do not occur between the pressure-sensitive adhesive and the glass substrate. In addition, the liquid crystal display panel capable of suppressing the light leakage phenomenon caused by the contraction of the optical film can be obtained. Further, since the adhesive force with time does not increase, the optical member is bonded to the liquid crystal cell. At this time, even if foreign matter mixing, damage, adhesion mistake, or the like occurs, it has an effect on reworkability such as excellent peeling and easy re-bonding.

The present invention is described in detail below.
In the present invention, (meth) acrylic acid is acrylic acid or methacrylic acid, (meth) acryl is acrylic or methacrylic, (meth) acryloyl is acryloyl or methacryloyl, and (meth) acrylate is acrylate or Each means methacrylate.

The pressure-sensitive adhesive composition [I] for optical members in the present invention comprises an acrylic resin component (A) having an acid value of 0.1 to 100 mgKOH / g, a silane coupling agent component (B) , a crosslinking agent (C), And / or containing an unsaturated group-containing compound (D) and a polymerization initiator (E) .
Such an acrylic resin component (A) may have an acid value in the range of 0.1 to 100 mgKOH / g, and contains, for example, an acidic group such as a carboxyl group, a phosphoric acid group, or a sulfonic acid group. An acrylic resin is mentioned. Two or more kinds of these acrylic resins containing acidic groups may be used in combination.
In addition, the acid value in this invention has shown the acid value with respect to solid content of an acrylic resin component (A).
Among the acrylic resins containing an acidic group, those containing a carboxyl group are preferable in terms of easily obtaining adhesive properties.
Hereinafter, the carboxyl group-containing acrylic resin (A1) will be described.

  The carboxyl group-containing acrylic resin (A1) contains the carboxyl group-containing monomer (a1) as an essential component as a copolymerization component, preferably a (meth) acrylic acid ester monomer (a2), and, if necessary, other copolymerization. It is obtained by copolymerizing with the polymerizable monomer (a3).

  Examples of the carboxyl group-containing monomer (a1) in the present invention include (meth) acrylic acid, crotonic acid, maleic acid, maleic anhydride, itaconic acid, fumaric acid, acrylamide N-glycolic acid, cinnamic acid, (meth) Michael adduct of acrylic acid (for example, acrylic acid dimer, methacrylic acid dimer, acrylic acid trimer, methacrylic acid trimer, acrylic acid tetramer, methacrylic acid tetramer, etc.), 2- (meth) acryloyloxyethyldicarboxylic acid monoester (for example, 2-acryloyloxyethyl succinic acid monoester, 2-methacryloyloxyethyl succinic acid monoester, 2-acryloyloxyethyl phthalic acid monoester, 2-methacryloyloxyethyl phthalic acid monoester, 2-acryloyloxy ester Hexahydro phthalic acid monoester, 2-methacryloyloxyethyl hexahydrophthalic acid mono ester) and the like. Of these, (meth) acrylic acid are preferred. These may be used alone or in combination of two or more.

Examples of the (meth) acrylic acid ester monomer (a2) include (meth) acrylic acid alkyl ester and (meth) acrylic acid phenyl ester.
Examples of such (meth) acrylic acid alkyl ester include methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, iso-butyl (meth) acrylate, tert-butyl (meth) acrylate, n -Propyl (meth) acrylate, n-hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, iso-octyl (meth) acrylate, n-octyl (meth) acrylate, nonyl (meth) acrylate, lauryl (meth) acrylate Among these, the alkyl group is preferably a (meth) acrylic acid alkyl ester having 1 to 12 carbon atoms, particularly 1 to 8 carbon atoms, and more preferably 4 to 8 carbon atoms. N-Butyl (meth) acrylic acid in terms of balance of durability Rate is preferable. These may be used alone or in combination of two or more.

  Other copolymerizable monomers (a3) include, for example, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-chloro-2-hydroxypropyl (meth) acrylate, tetrahydrofurfuryl (meth) Hydroxyl-containing unsaturated monomers such as acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, diethylene glycol (meth) acrylate, polyethylene glycol (meth) acrylate, N-methylol (meth) acrylamide, glycidyl (meth) acrylate, allyl Glycidyl group-containing unsaturated monomers such as glycidyl (meth) acrylate, t-butylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate Amino group-containing monomers such as relate, 2- (acetoacetoxy) ethyl (meth) acrylate, acetoacetyl group-containing monomers such as allyl acetoacetate, 2-methoxyethyl (meth) acrylate, 3-methoxyethyl (meth) acrylate, methoxy Allyl compounds such as alkoxy (poly) alkylene glycol mono (meth) acrylates such as diethylene glycol (meth) acrylate, N- (meth) acrylamidomethyltrimethylammonium chloride, allyltrimethylammonium chloride, dimethylallyl vinyl ketone, N-vinyl Pyrrolidone, vinyl propionate, vinyl stearate, vinyl chloride, vinylidene chloride, vinyl acetate, vinyl monomers such as styrene, (meth) acrylonitrile, n-dodecyl Rukaputan and the like.

  The carboxyl group-containing acrylic resin (A1) is produced by polymerizing the monomer components. Such polymerization can be performed by a conventionally known method. For example, in an organic solvent, a polymerization monomer such as the carboxyl group-containing monomer (a1), an acrylate ester monomer (a2), another copolymerizable monomer (a3), a polymerization initiator (azobisisobutyronitrile, Azobisisovaleronitrile, benzoyl peroxide, etc.) are mixed or dropped and polymerized at reflux or usually at 50 to 90 ° C. for 2 to 20 hours.

  In the present invention, the carboxyl group-containing acrylic resin (A1) has 0.01 to 10% by weight, particularly preferably 0.1% by weight of the carboxyl group-containing monomer (a1) as a copolymerization component based on the total copolymerization component. It is preferably contained in an amount of 02 to 8% by weight, more preferably 0.05 to 1% by weight, and the (meth) acrylic acid ester monomer (a2) is 70 to 99.99% by weight, particularly 82 to 99.5% by weight. Further, it is preferably contained in 94 to 99% by weight, and 0 to 20% by weight, particularly 0.1 to 10% by weight, more preferably 0.5 to 5% by weight, of the other copolymerizable monomer (a3). It is preferable.

  Up to this point, the carboxyl group-containing acrylic resin (A1) has been described. However, the above-mentioned case is also applicable when an acrylic resin having an acidic group other than a carboxyl group (for example, a phosphoric acid group or a sulfonic acid group) is used as the acidic group. Adjust and use according to the description.

  In the acrylic resin component (A) in the present invention, the acid value needs to be 0.1 to 100 mgKOH / g, and when the upper limit is exceeded, the adhesive force of the pressure-sensitive adhesive to the glass substrate becomes too strong. Therefore, the reworkability is deteriorated, and if it is less than the lower limit value, the adhesive strength to the glass substrate is weakened, thereby adversely affecting the durability. A preferable range of the acid value is 0.2 to 50 mgKOH / g, particularly preferably 0.5 to 10 mgKOH / g, and more preferably 1 to 5 mgKOH / g.

  The weight average molecular weight of the acrylic resin constituting the acrylic resin component (A) in the present invention is usually preferably 600,000 or more from the viewpoint of the balance between durability performance and light leakage prevention performance, and particularly preferably 800,000. More preferably, it is 1 million or more, particularly preferably 1.4 million or more. If the weight average molecular weight is too low, the pressure-sensitive adhesive layer tends to be inferior in the balance between durability performance such as heat resistance and moisture heat resistance and light leakage prevention performance. The upper limit of the weight average molecular weight of the acrylic resin component (A) is usually 3 million from the viewpoint of ease of production and economy.

  Further, the dispersity (weight average molecular weight / number average molecular weight) of the acrylic resin constituting the acrylic resin component (A) in the present invention is preferably 10 or less, more preferably 7 or less, and particularly preferably. Is 5 or less, particularly preferably 3.5 or less. When the degree of dispersion is too large, the pressure-sensitive adhesive layer tends to be inferior in durability performance such as heat resistance and light leakage. The lower limit of the degree of dispersion is usually 2 from the viewpoint of productivity.

  Furthermore, the glass transition temperature of the acrylic resin constituting the acrylic resin component (A) is usually −20 ° C. or less, particularly −25 to −70 ° C., more preferably −40 to −60 ° C., and the glass transition temperature. If it is too high, tack tends to be insufficient.

In addition, said weight average molecular weight and number average molecular weight are the weight average molecular weights by standard polystyrene molecular weight conversion, and high performance liquid chromatography (Nippon Waters company make, "Waters 2695 (main body)" and "Waters 2414 (detector)"). ), Column: Shodex GPC KF-806L (exclusion limit molecular weight: 2 × 10 ⁷ , separation range: 100 to 2 × 10 ⁷ , theoretical plate number: 10,000 plates / pack, packing material: styrene-divinylbenzene copolymer weight The dispersion is obtained from the weight average molecular weight and the number average molecular weight. The glass transition temperature is calculated from the Fox equation.

  In addition, the acrylic resin component (A) in the present invention may be composed only of an acrylic resin containing an acidic group as described above, or does not contain an acrylic resin containing an acidic group and an acidic group. A mixture of acrylic resins may also be used. When an acrylic resin containing an acidic group is mixed with an acrylic resin not containing an acidic group, the acid value of the entire acrylic resin component is 0.1 to 100 mgKOH / g, particularly 0.2 to What is necessary is just to adjust so that it may be set to 50 mgKOH / g, further 0.5-10 mgKOH / g, especially 1-5 mgKOH / g.

  In addition, it is preferable that resin composition [I] in this invention has an acrylic resin component (A) as a main component, and a main component is 50 weight normally with respect to resin composition [I] whole quantity. % Or more, preferably 60% by weight or more, more preferably 70% by weight or more.

  In addition to the acrylic resin component (A), the resin composition [I] in the present invention further includes an epoxy group-containing silane coupling agent (B1) and a mercapto group-containing silane coupling agent as the silane coupling agent component (B). It contains at least two kinds of (B2) as essential components.

  In the present invention, by using the epoxy group-containing silane coupling agent (B1) and the mercapto group-containing silane coupling agent (B2) in combination, the balance between the durability performance and the rework performance is compared with the case where each is used alone. It becomes an excellent adhesive.

  Specific examples of the epoxy group-containing silane coupling agent (B1) include, for example, γ-glycidoxypropyltrialkoxysilane such as γ-glycidoxypropyltrimethoxysilane and γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, etc. γ-glycidoxypropylalkyldialkoxysilane, methyltri (glycidyl) silane, β- (3,4-epoxycyclohexyl) ethyl Examples include β- (3,4-epoxycyclohexyl) ethyltrialkoxysilane such as trimethoxysilane and β- (3,4-epoxycyclohexyl) ethyltriethoxysilane, among which γ-glycidoxypropyl is preferable. Trimethoxysilane, γ-glyce Sidoxypropyltriethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, and β- (3,4 epoxycyclohexyl) ethyltrimethoxysilane.

  Specific examples of the mercapto group-containing silane coupling agent (B2) include, for example, γ-mercaptopropyltrialkoxysilane such as γ-mercaptopropyltrimethoxysilane and γ-mercaptopropyltriethoxysilane, and γ-mercaptopropyldimethoxymethyl. Examples include γ-mercaptopropyl dialkoxyalkylsilane such as silane. Among them, γ-mercaptopropyltrimethoxysilane is preferable.

  As the silane coupling agent component (B), in addition to the epoxy group-containing silane coupling agent (B1) and mercapto group-containing silane coupling agent (B2), if necessary, an acrylic silane coupling agent, One type or two or more types selected from a hydroxyl group silane coupling agent, a carboxyl group silane coupling agent, an amino group silane coupling agent, an amide group silane coupling agent, an isocyanate group silane coupling agent, and the like. You may use together.

  In the present invention, the content of the silane coupling agent component (B) is preferably 0.01 to 2 parts by weight, particularly 0.02 with respect to 100 parts by weight of the acrylic resin component (A). It is preferable that it is -1.5 weight part, Furthermore, it is 0.03-1 weight part. When there is too little content of a silane coupling agent component (B), there exists a tendency for an addition effect not to be acquired, and when there is too much, there exists a tendency for durability to deteriorate.

  The content of the epoxy group-containing silane coupling agent (B1) is preferably 0.02 to 1 part by weight, particularly preferably 0.03, per 100 parts by weight of the acrylic resin component (A). It is -0.5 weight part, More preferably, it is 0.05-0.3 weight part. If the content is too small, the durability tends to be inferior, and if the content is too large, the addition effect of a certain level or more does not appear and tends to be uneconomical.

  On the other hand, the content of the mercapto group-containing silane coupling agent (B2) is preferably 0.01 to 0.5 parts by weight, particularly preferably 0, per 100 parts by weight of the acrylic resin component (A). 0.02 to 0.3 parts by weight, more preferably 0.03 to 0.2 parts by weight. When the content is too small, the rework performance tends to be inferior, and when the content is too large, the durability performance tends to deteriorate.

  Furthermore, the content ratio ((B1) / (B2); weight ratio) of the epoxy group-containing silane coupling agent (B1) and the mercapto group-containing silane coupling agent (B2) is (B1) / (B2) = 1 to 1. It is preferably 10, more preferably (B1) / (B2) = 1.3-5, and even more preferably (B1) / (B2) = 1.5-3. If this value is too small, the rework performance tends to be inferior, and if it is too large, the durability tends to deteriorate.

  In the present invention, a resin composition containing an epoxy group-containing silane coupling agent (B1) and a mercapto group-containing silane coupling agent (B2) as the acrylic resin component (A) and the silane coupling agent component (B). The product [I] becomes a pressure-sensitive adhesive by being crosslinked.

  As for the crosslinking method, there are (1) a method of crosslinking with a crosslinking agent and (2) a method of crosslinking with at least one of active energy rays and heat. Further, it is particularly preferable to use the methods (1) and (2) in combination from the viewpoint of increasing the cross-linking of the pressure-sensitive adhesive layer and improving the light leakage prevention property.

First, (1) a method of crosslinking with a crosslinking agent will be described.
In the case of crosslinking with a crosslinking agent, the resin composition [I] contains a crosslinking agent (C) in addition to the acrylic resin component (A) and the silane coupling agent component (B), The crosslinking agent reacts with the functional group of the acrylic resin to perform crosslinking (chemical crosslinking).

The crosslinking agent (C) may be any compound having a functional group that reacts with the functional group contained in the acrylic resin component (A). For example, 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-aziridinylpropionate, trimethylo Rupropane-tri-β-aziridinylpropionate, N, N′-diphenylmethane-4,4′-bis (1-aziridinecarboxamide), N, N′-hexamethylene-1,6-bis (1- Aziridine compounds such as aziridinecarboxamide), melamine compounds such as hexamethoxymethylmelamine, hexaethoxymethylmelamine, hexapropoxymethylmelamine, hexaptoxymethylmelamine, hexapentyloxymethylmelamine, hexahexyloxymethylmelamine, melamine resin For example, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, hydrogenated tolylene diisocyanate, 1,3-xylylene diisocyanate, 1,4-xylylene diisocyanate, hexamethylene diisocyanate, di Phenylmethane-4,4-diisocyanate, isophorone diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane, tetramethylxylylene diisocyanate, 1,5-naphthalene diisocyanate, triphenylmethane triisocyanate, and their polyisocyanate compounds and tri Adducts with polyol compounds such as methylolpropane, isocyanate compounds such as burettes and isocyanurates of these polyisocyanate compounds, glyoxal, malondialdehyde, succindialdehyde, maleindialdehyde, glutardialdehyde, formaldehyde, acetaldehyde, Aldehyde compounds such as benzaldehyde, hexamethylenediamine, triethyldiamine, polyethyleneimine, Axamethylenetetraamine, diethylenetriamine, triethyltetraamine, isophoronediamine, amino resins, amine compounds such as polyamide, aluminum, iron, copper, zinc, tin, titanium, nickel, antimony, magnesium, panadium, chromium, zirconium, etc. Examples include metal chelate compounds such as multi-metallic acetylacetone and acetoacetyl ester coordination compounds. Among them, isocyanate compounds are preferred in terms of improving adhesion to the base material and reactivity with the base polymer. Used.
Moreover, these crosslinking agents (C) may be used independently and may be used together 2 or more types.

  The content of the crosslinking agent (C) can be appropriately selected depending on the amount of the functional group contained in the acrylic resin component (A), the molecular weight of the acrylic resin component (A), and the purpose of use. The amount is preferably 0.05 to 15 parts by weight, more preferably 0.1 to 12 parts by weight, and particularly preferably 1.5 to 10 parts by weight with respect to 100 parts by weight of the component (A).

  If the amount of the crosslinking agent (C) is too small, the cohesive force tends to be insufficient, and sufficient durability tends not to be obtained. If the amount is too large, the flexibility and adhesive strength are lowered, the durability is deteriorated, and peeling occurs. Since it becomes easy, there exists a tendency for bonding with an optical film to become difficult.

Next, (2) a method of crosslinking by at least one of active energy rays and heat will be described.
In the case of crosslinking with at least one of active energy rays and heat, the resin composition [I] is an unsaturated group-containing compound in addition to the acrylic resin component (A) and the silane coupling agent component (B). (D) and a polymerization initiator (E) are contained. Such an unsaturated group-containing compound is polymerized (polymerized) by at least one of active energy rays and heat, and crosslinked with an acrylic resin (physical crosslinking).

Examples of the unsaturated group-containing compound (D) include urethane (meth) acrylate compounds and ethylenically unsaturated monomers having one or more ethylenically unsaturated groups in one molecule, such as monofunctional monomers, 2 A functional monomer, a trifunctional or higher monomer can be used.
Among these, in order to increase the crosslink density of the pressure-sensitive adhesive, it is preferable to use a polyfunctional monomer or compound. Furthermore, in order to increase the adhesion to the substrate or the adherend, a highly polar urethane (meth) acrylate It is preferable to use an ethylenically unsaturated monomer having a base compound or a polar site.

  A urethane (meth) acrylate compound is a (meth) acrylate compound having a urethane bond in the molecule, a (meth) acrylic compound containing a hydroxyl group, a polyvalent isocyanate compound, and a polyol as necessary. Can be produced by reaction. It is also effective to leave the isocyanate group consciously, make urethane acrylate having an isocyanate group and an unsaturated bond in the molecule, create a crosslinking point with the acrylic polymer, and increase the cohesive strength of the adhesive.

  The (meth) acrylic compound containing a 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. Among them, hydroxyl group-containing (meta) having three or more acryloyl groups ) 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 which 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 or trimer compounds or multimeric compounds of these polyisocyanates, burette type polyisocyanates, water-dispersed polyisocyanates (for example, “Aquanate 100” manufactured by Nippon Polyurethane Industry Co., Ltd., ("Aquanate 110", "Aquanate 200", "Aquanate 210", etc.), or the reaction products of these polyisocyanates and polyols.

  Examples of such polyols include, but are not limited to, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, polypropylene glycol, butylene glycol, polybutylene glycol, 1,6 -Hexanediol, neopentyl glycol, cyclohexanedimethanol, hydrogenated bisphenol A, polycaprolactone, trimethylolethane, trimethylolpropane, polytrimethylolpropane, pentaerythritol, polypentaerythritol, sorbitol, mannitol, glycerin, polyglycerin, poly Polyhydric alcohols such as tetramethylene glycol; polyethylene oxide, poly Polyether polyol having at least one structure of propylene oxide, ethylene oxide / propylene oxide block or random copolymerization; the polyhydric alcohol or polyether polyol and maleic anhydride, maleic acid, fumaric acid, itaconic anhydride, itacone Examples include polyester polyols that are condensates of polybasic acids such as acids, adipic acid, and isophthalic acid; caprolactone-modified polyols such as caprolactone-modified polytetramethylene polyol; polyolefin-based polyols; polybutadiene-based polyols such as hydrogenated polybutadiene polyol, and the like. .

  Furthermore, as such polyols, 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-butanediol sulfonate, and the like.

  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.

  As a manufacturing method of the said urethane (meth) acrylate type compound, it does not restrict | limit in particular, For example, a hydroxyl-containing (meth) acrylic compound and a polyvalent isocyanate compound are mixed in inert gas atmosphere, Usually, 30-80 degreeC, The method of making it react for 2 to 20 hours is mentioned. 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 1000 to 3500, and particularly preferably 1200 to 3000. If the important 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 the production tends to be difficult.

  The monofunctional monomer may be any monomer containing one ethylenically unsaturated group. For example, styrene, vinyltoluene, chlorostyrene, α-methylstyrene, methyl (meth) acrylate, ethyl (meta ) 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 ( Acrylate), 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 (meth) acrylate, nonylphenol propylene oxide modified (meth) acrylate, phthalic acid such as 2- (meth) acryloyloxy-2-hydroxypropyl phthalate Derivative 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 a Michael adduct of acrylic acid or 2-acryloyloxyethyldicarboxylic acid monoester in addition to the above. Examples of the Michael adduct of acrylic acid include acrylic acid dimer, methacrylic acid dimer, and acrylic acid. Examples include trimers, methacrylic acid trimers, acrylic acid tetramers, and methacrylic acid tetramers. Examples of 2-acryloyloxyethyl dicarboxylic acid monoester which is a carboxylic acid having a specific substituent include 2-acryloyloxyethyl succinic acid monoester, 2-methacryloyloxyethyl succinic acid monoester, and 2-acryloyloxyethyl. Examples include phthalic acid monoester, 2-methacryloyloxyethyl phthalic acid monoester, 2-acryloyloxyethyl hexahydrophthalic acid monoester, and 2-methacryloyloxyethyl hexahydrophthalic acid monoester. Furthermore, oligoester acrylate is also mentioned.

  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) Examples include acrylate, diglycidyl phthalate di (meth) acrylate, hydroxypivalic acid-modified neopentyl glycol di (meth) acrylate, isocyanuric acid ethylene oxide-modified diacrylate, and 2- (meth) acryloyloxyethyl acid phosphate diester.

  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 pen (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. Is mentioned.

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

  As content of an unsaturated group containing compound (D), 5-99 weight part is preferable with respect to 100 weight part of acrylic resin components (A), More preferably, it is 5-50 weight part, More preferably, it is 8-30. Parts by weight. When the content is too large, the compatibility with the resin is deteriorated and the coating tends to be whitened. When the content is too small, the crosslinking density of the pressure-sensitive adhesive is insufficient, and the light leakage prevention property tends to be deteriorated. .

  In the present invention, the unsaturated group content as a whole of the resin composition [I] is usually preferably 10 to 360 mmol / 100 g from the viewpoint of balancing durability and light leakage prevention performance. Especially preferably, it is 30-240 mmol / 100g, More preferably, it is 50-180 mmol / 100g. If the unsaturated group content is too small, the cohesive force is insufficient, which tends to make it difficult to balance durability and light leakage prevention performance. If the content is too large, the adhesive strength tends to be high and the durability tends to be adversely affected. is there.

  The polymerization initiator (E) is not particularly limited, and various polymerization initiators such as a photopolymerization initiator (E1) and a thermal polymerization initiator (E2) can be used. Use of the photopolymerization initiator (E1) is preferable in that it can be cured by irradiation with active energy rays such as ultraviolet rays for a very short time.

  In addition, when the photopolymerization initiator (E1) is used, the resin composition [I] is polymerized by irradiation with active energy rays, and when the thermal polymerization initiator is used, the resin composition [I] is crosslinked by heat. However, it is also preferable to use both in combination as necessary.

  The photopolymerization initiator (E1) is not particularly limited, and examples thereof include diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzyldimethyl ketal, 4- (2 -Hydroxyethoxy) phenyl- (2-hydroxy-2-propyl) ketone, 1-hydroxycyclohexylphenylketone, 2-methyl-2-morpholino (4-thiomethylphenyl) propan-1-one, 2-benzyl-2- Acetophenones such as dimethylamino-1- (4-morpholinophenyl) butanone and 2-hydroxy-2-methyl-1- [4- (1-methylvinyl) phenyl] propanone oligomer; benzoin, benzoin methyl ether, benzoin ethyl Ether, benzoin isopropyl ether, benzo Benzoins such as isobutyl ether; benzophenone, methyl o-benzoylbenzoate, 4-phenylbenzophenone, 4-benzoyl-4′-methyl-diphenyl sulfide, 3,3 ′, 4,4′-tetra (t-butylper (Oxycarbonyl) benzophenone, 2,4,6-trimethylbenzophenone, 4-benzoyl-N, N-dimethyl-N- [2- (1-oxo-2-propenyloxy) ethyl] benzenemethananium bromide, (4- Benzophenones such as benzoylbenzyl) trimethylammonium chloride; 2-isopropylthioxanthone, 4-isopropylthioxanthone, 2,4-diethylthioxanthone, 2,4-dichlorothioxanthone, 1-chloro-4-propoxythioxanthone, 2- (3-dimethyla Thioxanthones such as no-2-hydroxy) -3,4-dimethyl-9H-thioxanthone-9-one mesochloride; 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, bis (2,6-dimethoxybenzoyl) Acylphosphones such as -2,4,4-trimethyl-pentylphosphine oxide and bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide; In addition, as for these photoinitiators (D1), 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 (E2) include methyl ethyl ketone peroxide, cyclohexanone peroxide, methylcyclohexanone peroxide, methyl acetoacetate peroxide, acetyl acetate peroxide, 1,1-bis (t-hexylperoxy). −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 (4,4- -T-butylperoxycyclohexyl) propane, p-menthane hydroperoxide, diisopropylbenzene hydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide, cumene hydroperoxide, t-hexyl hydroperoxide, 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-trimethylhexanoyl peroxide Oxide, octanoyl peroxide Id, 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-tetramethyl Rubutyl peroxyneodecanoate, 1-cyclohexyl-1-methylethylperoxyneodecanoate, t-hexylperoxyneodecanoate, t-butylperoxyneodecanoate, t-hexylperoxypi Valate, t-butylperoxypivalate, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, 2,5-dimethyl-2,5-bis (2-ethylhexanoylperoxy) ) Hexanoate, 1-cyclohexyl-1-methylethylperoxy-2-ethylhexanoate, t-hexylperoxy-2-ethylhexanoate, t-butylperoxy-2-ethylhexanoate, t-hexyl Peroxyisopropyl monocarbonate, t-butyl peroxyisobutyrate, t-butyl Tilperoxymalate, t-butylperoxy-3,5,5-trimethylhexanoate, t-butylperoxylaurate, t-butylperoxyisopropylmonocarbonate, t-butylperoxy-2-ethylhexyl Monocarbonate, t-butylperoxyacetate, t-butylperoxy-m-toluylbenzoate, t-butylperoxybenzoate, 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-butyltrimethylsilyl peroxide, 3,3 ′, 4,4′-tetra (t-bu Organic peroxide initiators such as tilperoxycarbonyl) 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'-azobisiso Butyronitrile, 2,2'-azobis (2,4-dimethylvaleronitrile), 2,2'-azobis (2-methylpropionamidine) dihydrochloride, 2,2'-azobis (2-methyl-N-phenylpropiyl) Onamidine) dihydrochloride, 2,2′-azobis [N- (4-chlorophenyl) -2-methylpropionamidine] dihydride 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) propane] 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-methyl-N- (2-hydroxyethyl) propyl Lopionamide], 2,2′-azobis (2-methylpropionamide), 2,2′-azobis (2,4,4-trimethylpentane), 2,2′-azobis (2-methylpropane), dimethyl- Initiation of azo compounds such as 2,2-azobis (2-methylpropionate), 4,4'-azobis (4-cyanopentanoic acid), 2,2'-azobis [2- (hydroxymethyl) propionitrile] Agents; 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 a polymerization initiator (E), 0.01-10 weight part with respect to 100 weight part of acrylic resin components (A), Especially 0.1-7 weight part, Furthermore, 0.2- It is preferably 5 parts by weight, particularly 0.3 to 3 parts by weight. If the content is too small, the curability tends to be poor and the physical properties tend to become unstable, and if it is too much, no further effect tends to be obtained.
The content of the photopolymerization initiator (E1) is preferably 0.01 to 10 parts by weight, particularly 0.1 to 5 parts by weight, based on 100 parts by weight of the acrylic resin component (A). Furthermore, it is 0.3 to 3 parts by weight.
About content of a thermal-polymerization initiator (E2), it is preferable that it is 0.01-10 weight part with respect to 100 weight part of acrylic resin components (A), Especially 0.1-5 weight part, Furthermore, Is 0.3 to 3 parts by weight.

  In the case of using the photopolymerization initiator (E1) as the polymerization initiator (E), in the irradiation of the active energy rays, light rays such as far ultraviolet rays, ultraviolet rays, near ultraviolet rays and infrared rays, electromagnetic waves such as X rays and γ rays are used. In addition, electron beams, proton beams, neutron beams, and the like can be used, but curing by ultraviolet irradiation is advantageous from the viewpoint of curing speed, availability of an irradiation device, price, and the like. In addition, when performing electron beam irradiation, it can harden | cure even without using a photoinitiator (E1).

As a light source for such 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 a 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 . In the case of an electrodeless lamp, it is performed under the conditions of, for example, ^{2 to} 1500 mJ / cm ² , preferably 5 to 500 mJ / cm ² . The irradiation time varies depending on the type of light source, the distance between the light source and the coating surface, the coating thickness, and other conditions, but it may be usually from several seconds to several tens of seconds, and in some cases, may be a fraction of a second. In the case of 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 (E2) as a polymerization initiator (E), 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 the thermal polymerization initiator (E2) 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 above crosslinking, either photocrosslinking or thermal crosslinking may be used, but photocrosslinking and thermal crosslinking may be used in combination as necessary.

  In the present invention, the combined use of (1) cross-linking with a cross-linking agent and (2) cross-linking with at least one of active energy rays and heat increases the cross-linking density of the pressure-sensitive adhesive and increases the cohesive force. This is preferable in terms of a balance between leakage prevention and durability.

  In the resin composition [I] forming the pressure-sensitive adhesive layer in the present invention, other pressure-sensitive adhesives, urethane resins, rosins, rosin esters, hydrogenated rosin esters, phenol resins, Aromatically modified terpene resins, aliphatic petroleum resins, alicyclic petroleum resins, styrene resins, xylene resins, and other tackifiers, known additives, and coloration or discoloration caused by irradiation with ultraviolet rays or radiation Compounds can be added.

Thus, in the present invention, an adhesive for optical members obtained by crosslinking the above resin composition [I] is obtained. By providing such an adhesive on the optical member (optical laminate), the adhesive is provided. A layered optical member can be obtained.
The optical member with the pressure-sensitive adhesive layer is preferably further provided with a release sheet on the surface opposite to the optical member of the pressure-sensitive adhesive layer.

The method for producing the optical member with the pressure-sensitive adhesive layer is not particularly limited. (1) A method of further bonding a release sheet after applying and drying the resin composition [I] on the optical member. Or (2) The resin composition [I] is applied on the release sheet, dried, and then manufactured by a method of laminating the optical member. The resin composition on the release sheet of (2) The production method of applying [I] is preferable in that the possibility that the substrate is deteriorated by the diluting solvent is low.
In practical use, the release sheet is peeled off and used, and the release sheet is preferably a silicon-based release sheet.

  When the resin composition [I] is crosslinked by at least one of active energy rays and heat, (1) the resin composition [I] is applied on the optical member, dried, and then released. A method of bonding sheets and irradiating with active energy rays and / or heat treatment, (2) After applying and drying the resin composition [I] on the release sheet, an optical member is bonded, and active energy rays A method of irradiation and / or heat treatment, (3) a method of applying a resin composition [I] on an optical member, drying, further irradiating with active energy rays and / or heat treatment, and then bonding a release sheet; (4) The resin composition [I] is applied on the release sheet, dried, and further subjected to active energy ray irradiation and / or heat treatment, and then manufactured by a method of bonding an optical member.

  In the above application, it is preferably applied after diluting with a solvent, and the dilution concentration is preferably 10 to 50% by weight, particularly preferably 11 to 25% by weight. Such a 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, and ethyl acetoacetate, acetone, methyl ethyl ketone, A ketone solvent such as methyl isobutyl ketone and an aromatic solvent such as toluene and xylene can be used. Among these, ethyl acetate and methyl ethyl ketone are preferably used from the viewpoints of solubility, drying property, price, and the like.

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

In addition, the said gel fraction becomes a standard of a crosslinking degree, and is computed with the following method.
That is, an adhesive sheet (not provided with a separator) obtained as described below is wrapped in a 200 mesh SUS wire mesh, immersed in toluene at 23 ° C. for 24 hours, and the insoluble adhesive component remaining in the wire mesh The weight percentage is taken as the gel fraction. However, the weight of the substrate is subtracted.

  Moreover, although the thickness of the adhesive layer obtained is not specifically limited, 10-40 micrometers is preferable and 12-30 micrometers is especially preferable. If the thickness 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 obtained in the present invention is directly or has a release sheet, and after peeling off the release sheet, the surface of the pressure-sensitive adhesive layer is bonded to a glass substrate and used for, for example, a liquid crystal display board. It is.

  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. , An optical compensation film, a brightness enhancement film, and those in which these are laminated, and the like. Among them, a polarizing plate is particularly effective in the present invention.

  The polarizing plate used in the present invention is usually obtained by laminating a cellulose triacetate film as a protective film on both sides of a polarizing film, and the polarizing film has an average polymerization degree of 1,500 to 10,000, saponification. A uniaxially stretched film dyed with an aqueous solution of iodine-potassium iodide or a dichroic dye (2 to 10 times, preferably 3 A draw ratio of about 7 times) is used.

  Polyvinyl alcohol resins are usually produced by saponifying polyvinyl acetate obtained by polymerizing vinyl acetate, but small amounts of unsaturated carboxylic acids (including salts, esters, amides, nitriles, etc.), olefins, vinyl ethers, A component copolymerizable with vinyl acetate, such as a saturated sulfonate, may be contained. Further, polyvinyl alcohol is reacted with an aldehyde in the presence of an acid, for example, so-called polyvinyl acetal resins and polyvinyl alcohol derivatives such as polybutyral resins and polyvinyl formal resins.

EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated further more concretely, this invention is not limited to a following example, unless the summary is exceeded.
In the examples, “parts” and “%” mean weight basis unless otherwise specified.

[Preparation of acrylic resin component (A)]
[Carboxyl group-containing acrylic resin (A-1)]
In a four-necked round bottom flask equipped with a reflux condenser, a stirrer, a nitrogen gas inlet and a thermometer, 0.5 parts of acrylic acid (a1), 1 part of hydroxyethyl acrylate (a2), butyl acrylate (a2) 98.5 parts, 80 parts of ethyl acetate and 40 parts of acetone were charged. After heating and refluxing, 0.03 part of azobisisobutyronitrile was added as a polymerization initiator, and the mixture was reacted at the reflux temperature of ethyl acetate for 3 hours. The acrylic resin (A-1) solution (weight average molecular weight 1.8 million, dispersity 3, glass transition temperature -49 ° C., solid content 16%, viscosity 8500 mPa · s (25 ° C.), acid value 3. 89 mg KOH / g) was obtained.

[Epoxy group-containing silane coupling agent (B-1)]
The following were prepared as an epoxy group-containing silane coupling agent (B-1).
γ-glycidoxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., “KBM403”)

[Mercapto group-containing silane coupling agent (B-2)]
The following were prepared as mercapto group-containing silane coupling agents (B-2).
γ-mercaptopropyltrimethoxysilane (“KBM803” manufactured by Shin-Etsu Chemical Co., Ltd.)

[Crosslinking agent (C-1)]
The following were prepared as a crosslinking agent (C-1).
55% ethyl acetate solution of tolylene diisocyanate adduct of trimethylolpropane (manufactured by Nippon Polyurethane, “Coronate L-55E”)

[Production of unsaturated group-containing compound (D-1)]
In a 4-neck round bottom flask equipped with a reflux condenser, a stirrer, a nitrogen gas inlet and a thermometer, 19.2 parts of isophorone diisocyanate, 0.05 part of di-t-butylhydroxyphenol, 0.02 of dibutyltin dilaurate The reaction was continued at 70 ° C. at a temperature of 50 ° C. or less and 80.8 parts of a mixture of pentaerythritol triacrylate and pentaerythritol tetraacrylate (Kyoeisha Chemical Co., Ltd., light acrylate PE-3A, hydroxyl value 120 mg KOH / g). Then, an unsaturated group-containing compound (D-1) was obtained.

[Photopolymerization initiator (E-1)]
The following were prepared as the photopolymerization initiator (E-1).
A mixture of benzophenone and 1-hydroxycyclohexyl phenyl ketone in a mass ratio of 1: 1 (Ciba Specialty Chemicals, “Irgacure 500”)

Example 1
A resin composition [I] solution (diluted to a viscosity (1000-10000 mPa · s / 25 ° C.) with ethyl acetate) was prepared with the composition shown in Table 1. The obtained resin composition [I] solution was applied to a polyester release sheet so that the thickness after drying was 25 μm, dried at 90 ° C. for 3 minutes, and then the resin composition [I] layer side was formed. The film was transferred onto a polarizing plate (thickness: 190 μm), and irradiated with ultraviolet rays at 600 mW / cm ² and 240 mJ / cm ² from the release sheet side with an electrodeless lamp manufactured by Fusion, at 23 ° C. and 65% R.D. H. The film was aged for 14 days to obtain a polarizing plate with an adhesive layer.
About the obtained polarizing plate with an adhesive layer, rework property and durability were evaluated as follows.

  The polarizing plate was 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). A polarizing plate (inclined in the direction of the stretching axis of the polyvinyl alcohol polarizing film by 45 degrees and cut into 100 mm × 100 mm) was used.

Example 2 and Comparative Examples 1 and 2
The same operation as in Example 1 was performed with the blending composition shown in Table 1 to obtain a polarizing plate with an adhesive layer.
About the obtained polarizing plate with an adhesive layer, rework property and durability were evaluated as follows.

  Moreover, the sample for gel fraction measurement was obtained by the method similar to the above using the polyethylene terephthalate film (thickness 38 micrometers) instead of the polarizing plate, and measured as follows.

(Gel fraction)
After cutting the obtained sample to 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 to the longitudinal direction of the SUS mesh sheet. After wrapping the sample from the center, the gel fraction was measured by weight change when immersed in a sealed container containing 250 g of toluene in a 23 ° C. environment for 24 hours. The results are shown in Table 1.

[Reworkability]
(Measurement of adhesive strength)
About the polarizing plate with the adhesive layer prepared in Examples 1 and 2 and Comparative Examples 1 and 2, it was cut into a width of 25 mm, the release film was peeled off, and the adhesive layer side was made an alkali-free glass plate (manufactured by Corning). , “Corning 1737”), and the polarizing plate and the glass plate were bonded together. Then, the autoclave process (50 degreeC, 0.5 MPa, 20 minutes) was performed, and the 180 degreeC peeling test was done after 1 day and 14 days. In the peelability, it is desired that the adhesive strength is small, and the target is 10 N / 25 mm or less after 1 day and 20 N / 25 mm or less after 14 days.
(Evaluation)
○: The difference between the adhesive strength after 14 days and the adhesive strength after 1 day is less than 0 to 5 N / 25 mm. Δ The difference between the adhesive strength after 14 days and the adhesive strength after 1 day is 5 N / 25 mm or more.
Less than 10N / 25mm × ・ ・ ・ The difference between the adhesive strength after 14 days and the adhesive strength after 1 day is 10N / 25mm or more

〔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 Corp., “Corning 1737”) to obtain the polarizing plate and the glass plate. After pasting, autoclave treatment (50 ° C., 0.5 MPa, 20 minutes) was performed, and thereafter, foaming, peeling, and light leakage phenomenon in the following durability tests (1) to (3) were evaluated.
(1) Heat test 80 ° C, 500 hours endurance test (2) Moisture and heat resistance test 60 ° C, 90% RH, 500 hours endurance test (3) Temperature change repetition test After leaving at -40 ° C for 30 minutes, at 80 ° C The operation of leaving for 30 minutes is one cycle.
Endurance test for 300 cycles

〔Evaluation criteria〕
(Foam)
○ ... No foaming △ ... Slight foaming is observed × ... Many foaming is observed (peeling)
○ ・ ・ ・ No peeling or peeling less than 0.5mm, or generation of ukiato △ ・ ・ ・ Peeling less than 1mm or generation of ukiato × ・ ・ ・ Peeling of 1mm or more, or generation of ukiato (light leakage)
○ ・ ・ ・ No or almost no light leakage △ ・ ・ ・ Slight leakage occurred × ・ ・ ・ Large light leakage on 4 sides

From the above results, Examples 1 and 2 containing both an epoxy group-containing silane coupling agent and a mercapto group-containing silane coupling agent are excellent in both durability and reworkability, whereas they contain an epoxy group. In Comparative Example 1 containing only the silane coupling agent, although it is excellent in durability, it is understood that an increase in adhesive strength with time occurs and the reworkability is inferior. Further, it can be seen that Comparative Example 2 containing only the mercapto group-containing silane coupling agent is excellent in reworkability but inferior in durability.
From the above, in order to have both durability and reworkability excellent in balance, it is effective to contain both an epoxy group-containing silane coupling agent and a mercapto group-containing silane coupling agent.

  The pressure-sensitive adhesive for optical members of the present invention is excellent in reworkability without causing an increase in adhesive strength over time, and is excellent in adhesiveness between the optical laminate and the glass substrate even under high temperature and high humidity conditions. In addition, there is no foaming or peeling between the glass substrate and the light leakage phenomenon caused by the shrinkage of the optical film, so that a liquid crystal display panel with excellent durability can be obtained, which is very useful It is.

Claims (10)

It is an adhesive composition [I] for an optical member containing an acrylic resin component (A) having an acid value of 0.1 to 100 mgKOH / g and a silane coupling agent component (B) ,
The silane coupling agent component (B) contains an epoxy group-containing silane coupling agent (B1) and a mercapto group-containing silane coupling agent (B2) ,
The pressure-sensitive adhesive composition for optical members [I] contains a crosslinking agent (C) and / or an unsaturated group-containing compound (D) and a polymerization initiator (E). Composition. 2. The optical member according to claim 1, wherein the content of the epoxy group-containing silane coupling agent (B1) is 0.02 to 1 part by weight with respect to 100 parts by weight of the acrylic resin component (A). Adhesive composition . The content of the mercapto group-containing silane coupling agent (B2) is 0.01 to 0.5 parts by weight with respect to 100 parts by weight of the acrylic resin component (A). An adhesive composition for optical members. The content ratio (weight ratio) of the epoxy group-containing silane coupling agent (B1) and the mercapto group-containing silane coupling agent (B2) is (B1) / (B2) = 1 to 10. 1-3. The adhesive composition for optical members in any one of 1-3.   A pressure-sensitive adhesive for optical members, wherein the pressure-sensitive adhesive composition [I] for optical members according to claim 1 is crosslinked. The pressure-sensitive adhesive composition for optical members according to claim 5 , wherein the pressure-sensitive adhesive composition for optical members [I] contains a crosslinking agent (C) and is crosslinked by a crosslinking agent. The optical member pressure-sensitive adhesive composition [I] contains an unsaturated group-containing compound (D) and a polymerization initiator (E), and is crosslinked by at least one of active energy rays and heat. an optical member for the pressure-sensitive adhesive of claim 5 Symbol mounting. The pressure-sensitive adhesive for optical members according to any one of claims 5 to 7, wherein a gel fraction of the pressure-sensitive adhesive is 80% or more. The pressure-sensitive adhesive for optical members according to claim 5, wherein the optical member is a polarizing plate. An optical member with an adhesive layer, wherein the adhesive for an optical member according to claim 5 is laminated on an optical member.