JP2015057464A - Adhesive composition, adhesive composition for polarizing plate, adhesive for polarizing plate, and polarizing plate using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an adhesive composition which is an adhesive excellent in adhesion strength, which is suitable for bonding various protective films for a polarizing plate with a polarizer, in particular, bonding a protective film other than TAC (triacetyl cellulose) with a polarizer, and which is excellent in production efficiency and resistance to color fading.SOLUTION: The adhesive composition comprises a metal or semimetal compound (A) that can form a chelate, and a photopolymerizable compound (B) having a functional group that can form a chelate with the metal or the semimetal, or comprises a chelate compound (A-B) formed by the metal or semimetal compound (A) that can form a chelate and the photopolymerizable compound (B) having a functional group that can form a chelate with the metal or the semimetal.

Description

  The present invention relates to an adhesive composition, an adhesive composition for a polarizing plate, an adhesive for a polarizing plate, and a polarizing plate using the same, and specifically constitutes a polarizing plate used for a liquid crystal display device or the like. The present invention relates to an adhesive composition used for an active energy ray-curable acrylic adhesive suitable for bonding a polarizer and a protective film.

  Liquid crystal display devices are widely used as image display devices for liquid crystal televisions, computer displays, mobile phones, digital cameras, and the like. Such a liquid crystal display device has a configuration in which polarizing plates are laminated on both sides of a glass substrate in which liquid crystal is encapsulated, and various optical functional films such as a retardation plate are laminated thereon as necessary.

  Conventionally, a polarizing plate has been used as a structure in which a protective film is bonded to at least one surface, preferably both surfaces, of a polarizer made of a polyvinyl alcohol film. Here, as a polarizer, a dichroic substance such as iodine is formed in a PVA film formed by using a polyvinyl alcohol resin having a high saponification degree (hereinafter, polyvinyl alcohol is abbreviated as “PVA”). A uniaxially stretched PVA-based film in which the material is dispersed and adsorbed and preferably further crosslinked with a crosslinking agent such as boric acid is widely used. Since such a polarizer is a uniaxially stretched PVA-based film, it easily contracts under high humidity. Therefore, a protective film is bonded to the polarizer for the purpose of supplementing moisture resistance and strength.

  As such a protective film, thermoplastic resins such as cellulose resin, polycarbonate resin, cyclic polyolefin resin, (meth) acrylic resin, and polyester resin are transparent, mechanical strength, thermal stability, moisture barrier property, isotropic property, etc. In particular, a protective film made of a triacetyl cellulose (TAC) resin has been widely used.

  These protective films are bonded to the polarizer by an adhesive, and as such an adhesive, from the viewpoint of adhesiveness to a polarizer having a hydrophilic surface, it is the same as the PVA resin aqueous solution, particularly the polarizer. A PVA resin aqueous solution mainly composed of a high saponification degree PVA resin is preferably used.

  By the way, in recent years, thinning of a polarizing plate has been demanded, and instead of a TAC film that has been most commonly used as a protective film, an acrylic film or a cyclic polyolefin resin film is used. However, these protective films instead of the TAC film cannot be firmly bonded to the polarizer using a conventional PVA adhesive. Therefore, various adhesives suitable for laminating protective films such as acrylic films and cyclic polyolefin resin films have been developed as alternatives to PVA adhesives.

  In addition, since the PVA adhesive is used as a solution or dispersion using water, it is necessary to dry the water when the adhesive is cured, and it takes a long time to dry the water. Accordingly, there has been a demand for improvement in that the drying efficiency is poor and the production efficiency of the polarizing plate is lowered.

  For example, Patent Document 1 proposes an adhesive composed of a composition containing an epoxy resin that does not contain an aromatic ring as a main component and a photocationic polymerization initiator. Such an adhesive is cationic polymerization by irradiation with active energy rays. Even if a resin film with low moisture permeability is used as the protective film, the protective film is applied to one or both sides of the polarizer with sufficient adhesive strength without causing problems such as poor appearance. It is described that a combined polarizing plate can be provided.

  Moreover, in patent document 2, the active energy ray hardening-type adhesive composition containing 3 types of radically polymerizable compounds from which SP value differs as a hardening component is excellent in adhesiveness of a polarizer and a protective film, and durability, It has been proposed as an adhesive with excellent water resistance.

  Furthermore, in Patent Document 3, 4-butylhydroxy acrylate: 20 to 90% by weight, ω-carboxy-polycaprolactone acrylate: 1 to 70% by weight, other radical polymerizable compound: 0 to 15% by weight, photopolymerization initiator : 0.01-20% by weight, Silane coupling agent: 0-10% by weight, radically polymerizable adhesive for forming a polarizing plate such that the glass transition temperature after curing is -80 to 0 ° C A composition has been proposed, and by using the adhesive composition, a PVA polarizer and a hard-to-adhere protective film typified by an acrylic film or a cycloolefin film are used as constituent layers, and the adhesive strength It is said that it is a polarizing plate which can form the small polarizing plate piece which is large and is excellent in durability, and is excellent in the punching workability.

  Patent Document 4 discloses an ultraviolet curable composition containing a (meth) acrylamide compound having no hydroxyl group, a (meth) acrylic acid alkyl ester compound having a hydroxyl group, boric acid and a photopolymerization initiator. It has been proposed that by using the adhesive composition, an ultraviolet curable composition having excellent adhesive strength can be obtained not only for various protective films but also for acrylic resin films.

JP 2004-245925 A JP 2012-144690 A JP 2010-282161 A JP2013-194082A

  However, the adhesive of Patent Document 1 uses a cationic polymerizable UV curable adhesive instead of a water-based adhesive. However, the cationic polymerizable UV curable adhesive has a dark reaction after UV irradiation. Therefore, when a long cured product is formed into a take-up roll, there is a problem that curling tends to occur during storage. In addition, the cationic polymerizable ultraviolet curable adhesive has a problem that it is easily affected by humidity during curing and the cured state tends to vary.

  In the radical polymerizable ultraviolet curable adhesive of Patent Document 2 described above, the adhesive layer is relatively hard, resulting in a decrease in adhesive strength over time, which is not satisfactory in terms of punching resistance and durability. There wasn't.

  In the radical polymerizable adhesive composition of the above-mentioned Patent Document 3, since the shrinkage is accompanied by curing shrinkage when the (meth) acrylic acid monomer is cured, the stability of the initial adhesion is lowered and the adhesive force is not sufficient.

  The ultraviolet curable composition of Patent Document 4 shows an adhesive force to the acrylic resin film, but the adhesive force to the polarizer is not sufficient and the color loss resistance is weak.

  Therefore, although the active energy ray-curable adhesive does not require a drying step and the production efficiency is higher than the PVA adhesive used as an aqueous solution, it can sufficiently bond various protective films for polarizing plates and polarizers. Was difficult and further improvement was required.

  In recent years, there has also been a problem that color loss (discoloration) occurs when a polarizing plate is left under high temperature and high humidity for a long time. For example, it is a more severe evaluation, but it is immersed in warm water. Therefore, there is a demand for a polarizing plate that does not lose color or has reduced color loss even in such a state. As a method for obtaining such a polarizing plate excellent in color fading resistance, in the situation where improvement of an adhesive for laminating a polarizer and a protective film is also required, the adhesion described in Patent Documents 1 to 4 above. In the case of the agent, such color loss resistance cannot be obtained.

  Therefore, in the present invention, under such a background, the adhesive is excellent in adhesive force, and is suitable for bonding various protective films for polarizing plates and polarizers, in particular, protective films other than TAC and polarizers. An object of the present invention is to provide an adhesive composition that is excellent in production efficiency and excellent in resistance to color loss, particularly an adhesive composition for polarizing plates.

  However, the present inventors have made extensive studies in view of such circumstances, and as a result, in an adhesive composition for an active energy ray-curable polarizing plate, a metal or semi-metal chelate compound is present when it becomes an adhesive. As a result, it was found that the polarizer and the protective film were excellent in adhesion, and further, the color fading resistance of the polarizing plate was excellent, and the present invention was completed.

  That is, the gist of the present invention is an adhesive comprising a chelate-forming metal or metalloid compound (A) and a photopolymerizable compound (B) containing a functional group capable of chelating with the metal or metalloid. The present invention relates to a composition, and is formed from a chelatable metal or metalloid compound (A) and a photopolymerizable compound (B) containing a functional group capable of chelating with the metal or metalloid. The present invention relates to an adhesive composition containing a chelate compound (AB).

  Furthermore, the present invention provides an adhesive composition for a polarizing plate using the adhesive composition, an adhesive for a polarizing plate obtained by curing the adhesive composition, and a polarizer and a protective film through the adhesive for the polarizing plate. The present invention also provides a polarizing plate in which is attached.

  Here, in the present invention, it is important that a metal or metalloid chelate compound is present. This is because the hydroxyl group on the PVA surface forming the polarizer and the chelate-forming functional group in the adhesive are included. It is presumed that the color loss resistance of the polarizing plate is improved in order to form a chemical bond, increase the adhesive strength between the polarizer and the protective film, and prevent the diffusion of iodine in the polarizer.

  The adhesive composition of the present invention, especially the adhesive composition for polarizing plates, has high production efficiency of polarizing plates, and various protective films for polarizing plates and polarizers, particularly acrylic films and cyclic polyolefin resin films. Protective films other than TAC and polarizers can be sufficiently bonded, and color loss is suppressed even when the polarizing plate is immersed in high temperature and high humidity or warm water. Excellent polarizing plates can be obtained.

The present invention will be described in detail below, but these show examples of desirable embodiments.
In the present invention, (meth) acryl means acryl or methacryl, (meth) acryloyl means acryloyl or methacryloyl, and (meth) acrylate means acrylate or methacrylate.
The acrylic monomer is a monomer having at least one of an acryloyl group and a methacryloyl group, and the acrylic resin is a resin obtained by polymerizing a polymerization component containing at least one acrylic monomer.

(Adhesive composition)
The adhesive composition of the present invention comprises:
[I] A metal or metalloid compound (A) capable of forming a chelate and a photopolymerizable compound (B) containing a functional group capable of chelating with the metal or metalloid. Yes,
Also,
[II] A chelate compound (AB) formed from a chelate-forming metal or metalloid compound (A) and a photopolymerizable compound (B) containing a functional group capable of chelating with the metal or metalloid ).

<Metal or metalloid compound (A) capable of chelate formation>
The chelate-forming metal or metalloid compound (A) used in the present invention is not particularly limited as long as it can form a chelate with the photopolymerizable compound (B) described later. For example, a metal or metalloid alcoholate , A hydrolyzate of the alcoholate, a condensate of the alcoholate, a chelate compound of the alcoholate, a partial alcoholate of the chelate compound, and a metal or metalloid acylate. In particular, metal or metalloid alcoholates and chelate compounds of the alcoholates are preferable. Particularly, metal or metalloid alcoholates represented by the following general formula (1), and chelate compounds of the alcoholates Is preferably used.
In addition, as a metal or metalloid compound (A) which can form a chelate, only 1 type may be used from the said compound, and arbitrary 2 or more types may be used together.

(Wherein M represents a metal or metalloid atom, R ¹ represents a monovalent organic group having 1 to 10 carbon atoms which may be the same or different, and R ² represents hydrogen which may be the same or different; A C1-5 alkyl group or a C1-6 acyl group or phenyl group, m and n each represent an integer of 0 or more, and m + n represents a valence of M.)

  In the general formula (1), examples of the metal or metalloid atom represented by M include transition metal, group 2, group 12, group 13, and group 14 metal or metalloid elements. Boron, silicon, aluminum, zirconium, titanium, magnesium, chromium, cobalt, copper, iron, nickel, vanadyl, zinc, indium, calcium, manganese, tin are preferred, and boron, silicon, aluminum, titanium, chromium, copper, Iron, nickel, zinc and indium are preferred. In general, divalent to tetravalent metals or metalloids are used, and boron, silicon, aluminum, titanium and zirconium are particularly preferably used. Further, it is most preferable that the alcoholate or acylate is in a liquid state and boron or silicon is used from the viewpoint of convenience of handling. Moreover, even if it is a solid state, it should just be easily soluble in a photopolymerizable compound (C).

In the general formula (1), as the monovalent organic group having 1 to 10 carbon atoms represented by R ¹ , when the general formula (1) is a metal or semimetal alcoholate, for example, methyl Group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, sec-butyl group, t-butyl group, n-hexyl group, n-heptyl group, n-octyl group, Alkyl groups such as 2-ethylhexyl group; acyl groups such as acetyl group, propionyl group, butyryl group, valeryl group, benzoyl group, trioyl group; vinyl group, allyl group, cyclohexyl group, phenyl group, glycidyl group, (meth) acrylic group In addition to oxy groups, ureido groups, amide groups, fluoroacetamide groups, isocyanate groups, etc., substituted derivatives of these groups can be mentioned. Examples of the substituent in the substituted derivative include a halogen atom, a substituted or unsubstituted amino group, a hydroxyl group, a mercapto group, an isocyanate group, a glycidoxy group, a 3,4-epoxycyclohexyl group, a (meth) acryloxy group, and a ureido group. And ammonium base. However, the carbon number of R ¹ composed of these substituted derivatives is 10 or less including the carbon atom in the substituent.

In addition, as R ¹ when the general formula (1) is a metal or metalloid acylate, for example, an acetoxyl group, a propionyloxyl group, a butyryloxyl group, a valeryloxyl group, a benzoyloxyl group, a trioyloxyl group, and the like Of the acyloxyl group.
In the above general formula (1), when two or more R ^{1 s} are present, they may be the same or different from each other, but are preferably the same.

In the general formula (1), examples of the alkyl group having 1 to 5 carbon atoms represented by R ² include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, sec- A butyl group, a t-butyl group, an n-pentyl group, and the like can be exemplified. Examples of the acyl group having 1 to 6 carbon atoms include an acetyl group, a propionyl group, a butyryl group, a valeryl group, and a caproyl group. Can do. Moreover, what is represented by R ² may be hydrogen.
In the general formula (1), when a plurality of R ² are present, they may be the same or different from each other, but the same is preferable.

The hydrolyzate of a metal or metalloid alcoholate in the present invention is a product obtained by hydrolyzing an OR ² group contained in the metal or metalloid alcoholate, but is an OR contained in a metal or metalloid alcoholate. All of ² need not be hydrolyzed. For example, only one of them may be hydrolyzed, two or more may be hydrolyzed, or a mixture thereof.

  The condensate of metal or metalloid alcoholate in the present invention is a product in which the hydrolyzate of metal or metalloid alcoholate is condensed to have a MOM structure. It is not necessary that all the hydroxyl groups of the hydrolyzate are condensed, and it is a concept that includes a mixture of a small part of the hydroxyl groups, a mixture of those having different degrees of condensation, and the like.

  The metal or metalloid alcoholate chelate compound in the present invention is a compound having a structure in which at least one of metal or metalloid alcoholate ligands is chelate-bonded. Such metal or metalloid alcoholate chelate compounds include metal or metalloid alcoholates and β-diketones, β-ketoesters, hydroxycarboxylic acids, hydroxycarboxylates, hydroxycarboxylic acid esters, ketoalcohols and aminoalcohols. It is preferably obtained by reaction with at least one selected compound.

  Among these compounds, β-diketones or β-ketoesters are preferably used, and specific examples thereof include acetylacetone, methyl acetoacetate, ethyl acetoacetate, acetoacetate-n-propyl, acetoacetate-i- Propyl, acetoacetate-n-butyl, acetoacetate-sec-butyl, acetoacetate-t-butyl, 2,4-hexane-dione, 2,4-heptane-dione, 3,5-heptane-dione, 2,4 -Octane-dione, 2,4-nonane-dione, 5-methyl-hexane-dione and the like can be mentioned. Of these, acetylacetone and ethyl acetoacetate are particularly preferably used.

The hydrolyzate of the chelate compound in the present invention is not necessarily required to hydrolyze all the OR ² groups contained in the chelate compound, like the hydrolyzate of the metal or metalloid alcoholate described above. Only one may be hydrolyzed, two or more may be hydrolyzed, or a mixture thereof.

  The metal or metalloid acylate in the present invention is one in which at least one of the ligands of the metal or metalloid alcoholate is an acyloxyl group.

Among these chelate-forming metal or metalloid compounds (A), as specific examples of metal or metalloid alcoholates and metal or metalloid alcoholate chelate compounds,
[1] Boron compounds such as boric acid, trimethyl borate, triethyl borate, tributyl borate (including normal, iso, tertiary and secondary), tripropyl borate, triisopropyl borate, trimethyl carbitol borate and the like;

[2] Aluminum hydroxide, triethoxyaluminum, diethoxy-acetylacetonate aluminum, ethoxy-bis (acetylacetonato) aluminum, tris (acetylacetonato) aluminum, tripropoxyaluminum, dipropoxy-acetylacetonatoaluminum, propoxy-bis (Acetylacetonato) aluminum, tributoxyaluminum, dibutoxy-acetylacetonatoaluminum, butoxybis (acetylacetonato) aluminum, diethoxyethylacetoacetate aluminum, ethoxybis (ethylacetoacetate) aluminum, tris (ethylacetoacetate) ) Aluminum, dipropoxy ethyl acetoacetate aluminum, propoxy bis Le acetoacetate) aluminum, dibutoxy ethylacetoacetate aluminum, aluminum compounds such as butoxy-bis (ethylacetoacetate) aluminum;

[3] Titanium hydroxide, tetraethoxy titanium, triethoxy acetylacetonato titanium, diethoxy bis (acetylacetonato) titanium, ethoxy tris (acetylacetonato) titanium, tetrakis (acetylacetonato) titanium, tetrapropoxy titanium, Tripropoxy acetylacetonato titanium, dipropoxy bis (acetylacetonato) titanium, propoxy tris (acetylacetonato) titanium, tetrabutoxy titanium, tributoxy acetylacetonato titanium, dibutoxy bis (acetylacetonato) titanium, butoxy・ Tris (acetylacetonate) titanium, triethoxy ethylacetoacetate titanium, diethoxy bis Ethyl acetoacetate) titanium, ethoxy tris (ethyl acetoacetate) titanium, tetrakis (ethyl acetoacetate) titanium, tripropoxy ethyl acetoacetate titanium, dipropoxy bis (ethyl acetoacetate) titanium, propoxy tris (ethyl acetoacetate) Titanium compounds such as titanium, tributoxy ethyl acetoacetate titanium, dibutoxy bis (ethyl acetoacetate) titanium, butoxy tris (ethyl acetoacetate) titanium;

[4] Tetrakis (methoxy) zirconium, tetrakis (ethoxy) zirconium, tetrakis (propoxy) zirconium, tetrakis (isopropoxy) zirconium, tetrakis (butoxy) zirconium, tetrakis (isobutyloxy) zirconium, tetrakis (second butyloxy) zirconium, tetrakis (Tertiary butyloxy) zirconium, tetrakis (amyloxy) zirconium, tetrakis (tertiary amyloxy) zirconium, tetrakis [2- (2-methoxy) ethoxy] zirconium, tetrakis [2- (1-methyl-2-methoxy) propoxy] zirconium , Tetrakis [2- (2-methoxy) propoxy] zirconium, tetrakis [2- (dimethylamino) ethoxy] zirconium, tetrakis [2- 2-dimethylamino-1-methyl) propoxy] zirconium, tetrakis [2- (2-dimethylamino) propoxy] zirconium, bis (2-propoxy) bis [2- (2-dimethylamino-1-methyl) propoxy] zirconium Bis (tertiary butoxy) bis [2- (2-dimethylamino-1-methyl) propoxy] zirconium, bis (tertiary butoxy) bis [2- (2-dimethylamino) propoxy] zirconium, (tertiary butoxy) Alkoxyzirconium compounds such as tris [2- (2-dimethylamino-1-methyl) propoxy] zirconium and tris (tertiary butoxy) [2- (2-dimethylamino-1-methyl) propoxy] zirconium; tetrakis (dimethylamino) ) Zirconium, tetrakis (diethylamino) zir Ni, Tetrakis (ethylmethylamino) zirconium, Tetrakis (dipropyl) zirconium, Tetrakis (dibutylamino) zirconium, Bis (dimethylamino) bis (diethylamino) zirconium, Bis (diethylamino) bis (ethylmethylamino) zirconium, (Diethylamino) tris (Ethylmethylamino) zirconium, bis (methoxy) bis (dimethylamino) zirconium, bis (methoxy) bis (diethylamino) zirconium, bis (methoxy) bis (ethylmethylamino) zirconium, bis (ethoxy) bis (dimethylamino) ) Zirconium, bis (ethoxy) bis (diethylamino) zirconium, bis (ethoxy) bis (ethylmethylamino) zirconium, bis (2-propoxy) bis ( Aminozirconium compounds such as diethylamino) zirconium, bis (tertiarybutyl) bis (diethylamino) zirconium, bis (tertiarybutyl) bis (ethylmethylamino) zirconium, (tertiarybutyl) tris (ethylmethyl) zirconium, and tetrakisacetyl Acetonate, tetrakisethyl acetoacetonate, tetrakis hexane-2,4-dionate, tetrakis-5-methylhexane-2,4-dionate, tetrakisheptane-2,4-dionate, tetrakis-2-methylheptane-3,5 -Dionate, tetrakis-5-methylheptane-2,4-dionate, tetrakis-6-methylheptane-2,4-dionate, tetrakis-2,2-dimethylheptane-3,5-dionate, tetrakis-2,6- Dimethyl Butane-3,5-dionate, tetrakis-2,2,6-trimethylheptane-3,5-dionate, tetrakis-2,2,6,6-tetramethylheptane-3,5-dionate, tetrakis-octane-2 , 4-Dionate, Tetrakis-2,2,6-trimethyloctane-3,5-Dionate, Tetrakis-2,6-dimethyloctane-3,5-Dionate, Tetrakis-2-methyl-6-ethyldecane-3,5 -Alkylated β-diketonates such as dionate, tetrakis-2,2-dimethyl-6-ethyldecane-3,5-dionate, tetrakis-1,1,1-trifluoropentane-2,4-dionate, tetrakis-1 , 1,1-trifluoro-5,5-dimethylhexane-2,4-dionate, tetrakis-1,1,1,5 Fluorine-substituted alkyl β-diketonates such as 5,5-hexafluoropentane-2,4-dionate and tetrakis-1,3-diperfluorohexylpropane-1,3-dionate, tetrakis-1,1,5,5 -Tetramethyl-1-methoxyhexane-2,4-dionate, tetrakis-2,2,6,6-tetramethyl-1-methoxyheptane-3,5-dionate, tetrakis-2,2,6,6-tetra Zirconium β-diketone compounds such as ether-substituted β-diketonates such as methyl-1- (2-methoxyethoxy) heptane-3,5-dionate;

[5] Zinc hydroxide, diethoxy zinc, ethoxy acetyl acetonate zinc, bis (acetyl acetonate) zinc, dipropoxy zinc, propoxy acetyl acetonate zinc, dibutoxy zinc, butoxy acetyl acetonate zinc, ethoxy ethyl acetoacetate Zinc compounds such as zinc, bis (ethyl acetoacetate) zinc, propoxy-ethyl acetoacetate zinc, butoxy-ethyl acetoacetate zinc, di (acetylacetonato) zinc, di (ethylacetoacetate) zinc;

[6] Tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, tetraisopropoxysilane, tetra-n-butoxysilane, tetraisobutoxysilane, tetra-sec-butoxysilane, tetra-tert-butoxysilane, etc. Silicon compounds such as tetraalkoxysilane and compounds obtained by hydrolyzing (condensing) them;
Can be mentioned.

  Among these metal or metalloid alcoholates and chelate compounds, preferred are boric acid, trimethyl borate, triethyl borate, tripropyl borate, tributyl borate, aluminum hydroxide, triethoxyaluminum, tripropoxyaluminum, tributoxy. Aluminum, dipropoxy ethyl acetoacetate aluminum, tris (ethyl acetoacetate) aluminum, tris (acetylacetonato) aluminum, titanium hydroxide, dibutoxy bis (acetylacetonato) titanium, dipropoxy bis (acetylacetonato) titanium, diethoxy・ Bis (acetylacetonato) titanium, dibutoxy ・ bis (ethylacetoacetate) titanium, dipropoxy bis (d (Ruacetoacetate) titanium, diethoxy bis (ethylacetoacetate) titanium, zinc hydroxide, di (acetylacetonato) zinc, and di (ethylacetoacetate) zinc. Particularly preferred compounds are boric acid and trimethylborate. Triethyl borate, tripropyl borate, tributyl borate, aluminum hydroxide, tripropoxyaluminum, tris (acetylacetonato) aluminum, dibutoxy bis (acetylacetonato) titanium, di (acetylacetonato) zinc and the like. Furthermore, boric acid, trimethyl borate, and triethyl borate from the viewpoint of convenience in handling in a liquid state at room temperature, solubility in the photopolymerizable compound (C), and reactivity with the hydroxyl group of the PVA resin forming the polarizer. Most preferred are trialkyl borates having an alkyl group having 1 to 5 carbon atoms such as tripropyl borate and tributyl borate, particularly tributyl borate.

  Specific examples of metal or metalloid acylates include dihydroxy titanium dibutyrate, di-i-propoxy titanium diacetate, di-i-propoxy titanium dipropionate, and di-i-propoxy titanium dimaloniate. And di-i-propoxy-titanium dibenzoylate, di-n-butoxy-zirconium diacetate, di-i-propylaluminum monomalonate and the like. Particularly preferred compounds are dihydroxy-titanium dibutyrate, di- -Titanium compounds such as i-propoxy-titanium diacetate.

<Photopolymerizable compound (B) containing a functional group capable of chelating with the metal or metalloid>
Further, the photopolymerizable compound (B) containing a functional group capable of chelating with the metal or metalloid used in the present invention may be a compound having the functional group and an ethylenically unsaturated group.

  Examples of the functional group capable of forming a chelate with the above metal or metalloid include a functional group having a β-diketone structure and a β-diketone structure such as acetoacetyl group and malonic acid ester. An acetoacetyl group is preferred from the viewpoint of convenience and reactivity with a hydroxyl group.

  In the present invention, when the photopolymerizable compound (B) containing a functional group capable of chelating with a metal or a metalloid is an acetoacetyl group-containing ethylenically unsaturated compound (b1), for example, it is produced by the following method. can do.

(I) A diketene is reacted with the functional group-containing ethylenically unsaturated compound (i). Examples of the functional group include a hydroxyl group, an amide group, a urethane group, an amino group, and a carboxyl group, and those suitable as the functional group-containing ethylenically unsaturated compound (i) include an alkylene group having 1 to 10 carbon atoms. Aliphatic acetoacetyl group-containing alkyl (meth) acrylate compounds having 2-hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, 2-hydroxy-3 -(Meth) acrylates having a C1-C5 hydroxyalkyl group such as chloropropyl (meth) acrylate.

(II) The functional group-containing ethylenically unsaturated compound (i) is transesterified with acetoacetate.

In the case of (I) above, the reaction of diketene is non-catalytic, as well as the presence of tertiary amines, acids (sulfuric acid, etc.), basic salts (sodium acetate, etc.), organometallic compounds (dibutyltin laurate, etc.) Can be done below.
The reaction of (II) acetoacetate is preferably performed in the presence of a transesterification catalyst such as calcium acetate, zinc acetate, lead oxide or the like.
Among the above functional group-containing ethylenically unsaturated compounds (i), a (meth) acrylate having a hydroxyalkyl group is preferable from the viewpoints of versatility and convenience, production stability, and storage stability.

<Photopolymerizable compound (C)>
In the present invention, it is preferable from the viewpoint of coating property, curability, adhesiveness and the like that it further contains a photopolymerizable compound (C) (however, excluding the photopolymerizable compound (B)). .
As the photopolymerizable compound (C) used in the present invention, the photopolymerizable compound (B) is excluded, and an ethylenically unsaturated compound (c1) having one ethylenically unsaturated group and an ethylenically unsaturated compound are used. It is preferably at least one selected from the group of ethylenically unsaturated compounds (c2) having two or more saturated groups.

  Examples of the ethylenically unsaturated compound having one ethylenically unsaturated group (hereinafter sometimes abbreviated as “monofunctional monomer”) (c1) include styrene, vinyltoluene, chlorostyrene, and α-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, glycerol mono (meth) acrylate, glycidyl ( Acrylate), lauryl (meth) acrylate, cyclohexyl (meth) acrylate, isobornyl (meth) acrylate, tricyclodecanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, Dicyclopentanyl (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 (n = 2) (meth) acrylate, noni Half of phthalic acid derivatives such as ruphenol propylene oxide modified (n = 2.5) (meth) acrylate, 2- (meth) acryloyloxyethyl acid phosphate, 2- (meth) acryloyloxy-2-hydroxypropyl phthalate ) Acrylate, furfuryl (meth) acrylate, carbitol (meth) acrylate, benzyl (meth) acrylate, butoxyethyl (meth) acrylate, allyl (meth) acrylate, acryloylmorpholine, dimethylacrylamide, 2-hydroxyethylacrylamide, N-methylol (Meth) acrylamide, N-vinylpyrrolidone, 2-vinylpyridine, polyoxyethylene secondary alkyl ether acrylate, and the like.

  In addition, a Michael adduct of acrylic acid or 2-acryloyloxyethyldicarboxylic acid monoester can also be used in combination. As the Michael adduct of acrylic acid, acrylic acid dimer, methacrylic acid dimer, acrylic acid trimer, methacrylic acid A trimer, an acrylic acid tetramer, a methacrylic acid tetramer, etc. are mentioned. The 2-acryloyloxyethyl dicarboxylic acid monoester is a carboxylic acid having a specific substituent, for example, 2-acryloyloxyethyl succinic acid monoester, 2-methacryloyloxyethyl succinic acid monoester, 2-acryloyloxy Examples thereof include ethyl phthalic acid monoester, 2-methacryloyloxyethyl phthalic acid monoester, 2-acryloyloxyethyl hexahydrophthalic acid monoester, 2-methacryloyloxyethyl hexahydrophthalic acid monoester, and the like. Furthermore, other oligoester acrylates can also be mentioned.

  The ethylenically unsaturated compound having two or more ethylenically unsaturated groups (hereinafter sometimes abbreviated as “polyfunctional monomer”) (c2) includes a bifunctional monomer and a trifunctional or higher functional monomer. It is done.

  Examples of the bifunctional monomer include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, and 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, cyclohexanedimethanol di (meth) acrylate, Xylated cyclohexanedimethanol di (meth) acrylate, dimethylol dicyclopentane di (meth) acrylate, tricyclodecane dimethanol di (meth) acrylate, 1,6-hexanediol 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, phthalic acid diglycidyl ester di (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 include trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, and dipentaerythritol hexa (meth). ) Acrylate, tri (meth) acryloyloxyethoxytrimethylolpropane, glycerin polyglycidyl ether poly (meth) acrylate, isocyanuric acid ethylene oxide modified triacrylate, caprolactone modified dipentaerythritol penta (meth) acrylate, caprolactone modified dipentaerythritol hexa ( (Meth) acrylate, caprolactone-modified pentaerythritol tri (meth) acrylate, caprolact Modified pentaerythritol tetra (meth) acrylate, ethylene oxide modified dipentaerythritol penta (meth) acrylate, ethylene oxide modified dipentaerythritol hexa (meth) acrylate, ethylene oxide modified pentaerythritol tri (meth) acrylate, ethylene oxide modified pentaerythritol tetra (Meth) acrylate, ethoxylated glycerin triacrylate and the like can be mentioned.
The photopolymerizable compound (C) may be used alone or in combination of two or more.

  Thus, in the present invention, [I] a chelate-forming metal or metalloid compound (A) and a photopolymerizable compound (B) containing a functional group capable of chelating with the metal or metalloid, preferably other An adhesive composition comprising a photopolymerizable compound (C) (excluding the photopolymerizable compound (B)), and [II] a chelate-forming metal or metalloid compound (A); , A chelate compound (AB) formed from a photopolymerizable compound (B) containing a functional group capable of chelating with the metal or metalloid, preferably other photopolymerizable compound (C) ( However, an adhesive composition containing a photopolymerizable compound (B) is used.

  With regard to the blending ratio of (A) and (B), (A) / (B) is preferably 1/99 to 50/50 by weight, particularly 5/95 to 40/60, more preferably 10 / 90 to 30/70 is preferable. If the value of (A) / (B) is too small, there is a tendency that the adhesive force between the polarizer and the protective film is lowered and the color loss resistance is lowered, and if too large, the durability during the hot water resistance test is lowered. There is a tendency to invite.

  In the case of [I] above, (A) to (C) can be appropriately blended to form an adhesive composition. About each content rate of (A)-(C), (A) is 0.1-30 weight% with respect to the sum total of (A)-(C), (B) is 0.9-40 weight%. , (C) is preferably 30 to 99% by weight, in particular (A) is 0.5 to 20% by weight, (B) is 1.5 to 30% by weight, and (C) is 50 to 98% by weight. %, (A) is preferably 1 to 15% by weight, (B) is preferably 5 to 20% by weight, and (C) is preferably 65 to 94% by weight. If the content of (A) is too small, the adhesive strength between the polarizer and the protective film tends to decrease and the color loss resistance tends to decrease. If the content is too large, the durability decreases during the hot water resistance test, and the polarization There exists a tendency for the adhesive force of a child and a protective film to fall. When there is too little content of this (B), there exists a tendency for the adhesive force of a polarizer and a protective film to fall, and when too large, there exists a tendency for the durability at the time of a hot water resistance test to fall. When there is too little content of this (C), there exists a tendency for the durability at the time of a hot water test to fall, and when too much, there exists a tendency for the adhesive force of a polarizer and a protective film to fall.

  In the present invention, the adhesive composition containing (A) and (B), preferably (C), is applied to a substrate such as a polarizer, and is usually 50 to 200 ° C., particularly preferably 60 to 150. A chelate compound (AB) can be formed by drying at 0 degreeC. Moreover, after making it the adhesive composition containing (A) and (B), preferably further (C), (A) and (B) are usually reacted at 50 to 120 ° C., particularly preferably at 60 to 90 ° C. To form a chelate compound (AB).

  In the case of [II], a chelate compound (AB) formed from (A) and (B), and preferably (C), is contained. ), (B), a chelate compound (AB) formed from (A) and (B), and preferably (C).

The content of the chelate compound (AB) is preferably 0.5 to 50% by weight, particularly 1 to 40% by weight, and more preferably 5 to 30% by weight.
If the content is too small, the adhesive force between the polarizer and the protective film tends to decrease and the color loss resistance tends to decrease. If the content is too large, the durability decreases during the hot water resistance test, and the polarizer and the protective film. There is a tendency for the adhesive strength of the steel to decrease.

  In forming such a chelate compound (AB), it is usually mixed at 20 to 120 ° C., particularly 30 to 80 ° C.

  In the present invention, the presence of the above-described metal or metalloid chelate compound exhibits an effect of excellent color fading resistance of the polarizing plate.

  In the adhesive composition of the present invention, a polymerization initiator, a silane coupling agent, an antistatic agent, other acrylic adhesives, other adhesives, urethane resins, rosins, as long as the effects of the present invention are not impaired. Rosin ester, hydrogenated rosin ester, phenol resin, aromatic modified terpene resin, aliphatic petroleum resin, alicyclic petroleum resin, styrene resin, xylene resin and other tackifiers, polyol and other plasticizers, coloring Conventionally known additives such as additives, fillers, anti-aging agents, ultraviolet absorbers, functional dyes, and compounds that cause coloration or discoloration upon irradiation with ultraviolet rays or radiation can be incorporated. The blending amount is preferably 30% by weight or less, particularly preferably 20% by weight or less, based on the total composition.

  In addition to the above additives, a small amount of impurities contained in the raw materials for producing the constituent components of the adhesive composition may be contained.

<Polymerization initiator (D)>
In this invention, it is preferable to contain said polymerization initiator (D) and to harden an adhesive composition further.
As the polymerization initiator (D), for example, various polymerization initiators such as a photopolymerization initiator (d1) and a thermal polymerization initiator (d2) can be used. It is preferable to use d1) in that it can be cured by irradiation with active energy rays such as ultraviolet rays for a very short time.

  When the photopolymerization initiator (d1) is used, the adhesive composition is cured by irradiation with active energy rays, and when the thermal polymerization initiator (d2) is used, the adhesive composition is cured by heating. However, it is also preferable to use both in combination as necessary.

  Examples of the photopolymerization initiator (d1) include diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzyldimethyl ketal, 4- (2-hydroxyethoxy) phenyl- (2 -Hydroxy-2-propyl) ketone, 1-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 (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 (d2) include methyl ethyl ketone peroxide, cyclohexanone peroxide, methylcyclohexanone 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, these thermal polymerization initiators (d2) may be used alone or in combination of two or more.

  About content of the said polymerization initiator (D), with respect to 100 weight part of the sum total of said (A) and (B) (when (C) is contained, the sum of (A)-(C)), It is preferable that it is 0.5-20 weight part, Especially preferably, it is 0.8-15 weight part, More preferably, it is 1-10 weight part. When the content of the polymerization initiator (D) is too small, the curability tends to be poor and the physical properties tend to become unstable. When the content is too large, the low molecular weight component increases and the crosslinking density decreases, resulting in water resistance and heat resistance. There is a tendency to decrease.

  Thus, the adhesive composition of the present invention is obtained. The adhesive composition of the present invention preferably functions as an adhesive by being cured by irradiation with active energy rays, and is preferably used as an adhesive for a polarizing plate for bonding a polarizer and a protective film. It is something that can be done.

  The adhesive composition of the present invention may contain a solvent or may be used as a solventless composition, but it is better to use it as a solventless composition in terms of excellent adhesive performance. preferable.

(Polarizer)
There is no restriction | limiting in particular as said polarizer, A well-known thing can be used.
For example, (i) A dichroic material such as iodine or a dichroic dye is adsorbed on a vinyl alcohol resin film such as a PVA film, a partially formalized PVA film, or an ethylene-vinyl alcohol resin film. Stretched (for example, see JP-A-2001-296427, JP-A-7-333426), (ii) a birefringent material having liquid crystallinity together with a dichroic material in the above (i) is a vinyl alcohol resin What is contained in the film (for example, see JP-A-2007-72203), (iii) A uniaxially stretched thermoplastic norbornene resin film containing a dichroic material (for example, JP-A-2001-356213) (Iv) PVA resin or ethylene-vinyl alcohol resin is dehydrated or deaceticated. Introducing a polyene structure continue, polyene-based film obtained by stretching them (e.g., see JP Patent 2007-17845.), And the like.
Among these, a uniaxially stretched film in which iodine is adsorbed on a PVA-based film is preferable because of excellent polarization characteristics.

  The thickness of such a polarizer is usually 0.1 to 100 μm, particularly 0.5 to 80 μm, more preferably 1 to 60 μm.

(Protective film)
The protective film can make up for deficiency in durability under high humidity, which is a problem of polarizers, by bonding to at least one surface, preferably both surfaces, of the polarizer.
Furthermore, the properties required for the protective film used in the present invention include transparency, mechanical strength, thermal stability, moisture barrier properties, optical isotropy, and the like.

As a material for such a protective film, a cellulose ester resin, a cyclic olefin resin, and a (meth) acrylic resin are preferably used from the viewpoints of optical properties and durability.
Other materials include polyester resins such as polyethylene terephthalate and polyethylene naphthalate, polystyrene resins such as polystyrene and acrylonitrile / styrene copolymers, polyolefin resins such as polyethylene and polypropylene, polyarylate resins, and polycarbonate resins. , Vinyl chloride resins, amide resins such as nylon and aromatic polyamide, (fluorine-containing) polyimide resins, polyether ether ketone resins, polyphenylene sulfide resins, vinylidene chloride resins, polyvinyl acetal resins such as polyvinyl butyral And polyoxymethylene resins and epoxy resins. These may be used alone or in combination of two or more.

  Typical examples of the cellulose ester resin used in the cellulose ester resin film include triacetyl cellulose and diacetyl cellulose, but other lower fatty acid esters of cellulose, cellulose acetate propionate, cellulose acetate butyrate, and the like. The mixed fatty acid ester can be used.

  Examples of the cyclic olefin resin used in the cyclic olefin resin film include norbornene resins. Such norbornene resins include, for example, ring-opening (co) polymers of norbornene monomers, addition-polymerized norbornene monomers, addition-copolymerized norbornene monomers and olefin monomers such as ethylene and α-olefins. Resin etc. are included.

  Specific examples of norbornene-based monomers include dimers such as norbornene and norbornadiene; tricyclics such as dicyclopentadiene and dihydroxypentadiene; heptacyclics such as tetracyclopentadiene; these methyl, ethyl, propyl and butyl Substituents such as alkyl, alkenyl such as vinyl, alkylidene such as ethylidene, aryl such as phenyl, tolyl, and naphthyl; and ester groups, ether groups, cyano groups, halogens, alkoxycarbonyl groups, pyridyl groups, hydroxyl groups, carvone Examples include substituents having groups containing elements other than carbon and hydrogen, such as acid groups, amino groups, hydroxyl-free groups, silyl groups, epoxy groups, acryloyl groups, and methacryloyl groups.

  Examples of commercially available cyclic olefin-based resin films include “ARTON” manufactured by JSR, “ZEONOR”, “ZEONEX” manufactured by Nippon Zeon, “OPTOREZ” manufactured by Hitachi Chemical, and “APEL” manufactured by Mitsui Chemicals. it can.

  Examples of the (meth) acrylic resin used in the (meth) acrylic resin film include poly (meth) acrylic acid esters such as polymethyl methacrylate, methyl methacrylate- (meth) acrylic acid copolymer, and methyl methacrylate. -(Meth) acrylic acid ester copolymer, methyl methacrylate-acrylic acid ester- (meth) acrylic acid copolymer, (meth) acrylic acid methyl-styrene copolymer, polymer having alicyclic hydrocarbon group [For example, methyl methacrylate-cyclohexyl methacrylate copolymer, methyl methacrylate- (meth) acrylate norbornyl copolymer, etc.], (meth) having a high glass transition temperature obtained by intramolecular crosslinking or intramolecular cyclization reaction Acrylic resins, rubber-acrylic graft type core-shell polymers, and the like can be mentioned.

  Examples of such commercially available (meth) acrylic resin films include “Acrypet VRL20A”, “Acrypet IRD-70” manufactured by Mitsubishi Rayon Co., Ltd., “MUX-60” manufactured by UMGABS, and the like.

  In addition, the protective film is subjected to surface hydrophilization treatment such as saponification treatment with an alkali solution for a film made of a cellulose ester resin or corona discharge treatment or plasma treatment for a film made of a cyclic olefin resin, as necessary. It may be what you did.

In addition, in order to improve the affinity with the adhesive on the surface of the protective film, it is possible to perform various surface treatments other than hydrophilization, and (meth) acrylic acid ester latex or styrene latex on the surface of the protective film, Examples thereof include an easy-adhesion layer and an anchor coat layer containing polyethyleneimine, polyurethane / polyester copolymer, etc., and a surface treatment method using a coupling agent such as a silane coupling agent and a titanium coupling agent. In addition, it is also possible to use together the above-mentioned various surface treatment methods.
Moreover, what coated the antistatic agent on the surface of the protective film or contained it in the film is also preferably used.

  Although the thickness of such a protective film is not particularly limited, a film thicker than the polarizer is usually used, and has a function of imparting strength as a base material of the polarizer, and is usually 10 to 100 μm, preferably 20 to 80 μm. is there.

  Further, such a protective film can be provided with a hard coat layer on the surface where the polarizer is not laminated, or can be subjected to various treatments such as anti-sticking, anti-reflection and anti-glare. Furthermore, various optical functional films such as a phase difference plate and a viewing angle widening film can be laminated.

(Polarizer)
The polarizing plate of the present invention is formed by laminating the above polarizer and a protective film via an adhesive for polarizing plates. Specifically, the protective film is bonded to at least one surface, preferably both surfaces, of the polarizer using the polarizing plate adhesive of the present invention, and the liquid adhesive composition is usually polarized. After applying uniformly to a child or a protective film, or both, both are bonded together, pressure-bonded, and irradiated with active energy rays to form a polarizing plate.

  When coating such an adhesive composition on a polarizer or a protective film, for example, reverse coater, gravure coater (direct, reverse or offset), bar reverse coater, roll coater, die coater, bar coater, rod coater, etc. Or can be applied by dipping.

  For such bonding and pressure bonding, for example, a roll laminator or the like can be used, and the pressure is selected from the range of 0.1 to 10 MPa.

  For such active energy ray irradiation, rays such as far ultraviolet rays, ultraviolet rays, near ultraviolet rays, infrared rays, electromagnetic waves such as X rays and γ rays, 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 without using the said photoinitiator (d1).

A high pressure mercury lamp, an electrodeless lamp, an ultrahigh pressure mercury lamp carbon arc lamp, a xenon lamp, a metal halide lamp, a chemical lamp, a black light, an LED, or the like is used as a light source when performing such ultraviolet irradiation.
Such ultraviolet irradiation is performed under conditions of ^{2 to} 3000 mJ / cm ² , preferably 10 to 2000 mJ / cm ² .

Particularly if the high-pressure mercury lamp, for example, 5~3000mJ / cm ^2, preferably at the conditions of 50~2000mJ / cm ^2.
Moreover, in the case of the said electrodeless lamp, it is 2-2000 mJ / cm < ² >, for example, Preferably it carries out on the conditions of 10-1000 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.

  The irradiation direction of such active energy rays (electron beam, ultraviolet ray, etc.) can be irradiated from any appropriate direction, but it is preferable to irradiate from the transparent protective film side in terms of preventing the polarizer from deteriorating.

  The thickness of the adhesive layer in the polarizing plate of the present invention obtained as described above is usually 0.01 to 10 μm, preferably 0.01 to 5 μm, particularly preferably 0.01 to 2 μm, more preferably 0.01 to 1 μm. It is. If the thickness is too thin, the cohesive force of the adhesive force itself cannot be obtained and the adhesive strength tends not to be obtained. If the thickness is too thick, the workability of the polarizing plate tends to be reduced due to cracks during punching.

  The adhesive composition of the present invention is an adhesive having excellent adhesive strength at the initial stage and over time, and can be used for various applications. In particular, various protective films for polarizing plates and polarizers, particularly those other than TAC. The protective film and the polarizer can be suitably used for bonding, and there is no need for a drying step, so that the production efficiency of the polarizing plate is excellent, and the color fading resistance of the polarizing plate is also excellent.

  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.

The following components were prepared.
[Metal or metalloid compound (A) capable of chelating]
・ (A-1) Tributyl borate (“Tri-n-butyl borate” manufactured by Kanto Chemical Co., Inc.)
-(A-2) Titanium tetraisopropylate ("Origatix TA-10" manufactured by Matsumoto Fine Chemical Co., Ltd.)
-(A-3) Titanium tetra-n-butyrate ("Origatix TA-25" manufactured by Matsumoto Fine Chemical Co., Ltd.)
(A-4) Aluminum triacetylacetonate (“Nasemu Arnium” manufactured by Nippon Chemical Industry Co., Ltd.)
・ (A-5) Boric acid (manufactured by Wako Pure Chemical Industries, Ltd.)

[Photopolymerizable compound (B) containing functional group capable of chelating with metal or metalloid]
(B-1) 2-acetoacetoxyethyl methacrylate (“AAEM” manufactured by Nippon Synthetic Chemical Industry Co., Ltd.)

[Photopolymerizable compound (C)]
・ (C-1) Acryloylmorpholine ("ACMO" manufactured by Kojin Co., Ltd.)
(C-2) Dimethylacrylamide (“DMAA” manufactured by Kojin Co., Ltd.)
(C-3) ethylene glycol diacrylate (“FA-222A” manufactured by Hitachi Chemical Co., Ltd.)

[Polymerization initiator (D)]
(D-1) 1-hydroxycyclohexyl phenyl ketone (“Irgacure 184” manufactured by BASF)
(D-2) 2,4,6-trimethylbenzoyl-diphenylphosphine oxide (“Lucirin TPO” manufactured by BASF)

[Example 1]
<Preparation of adhesive composition>
In a preparation flask, 5 parts (solid content) of tributyl borate (A-1), 15 parts of 2-acetoacetoxyethyl methacrylate (B-1), 50 parts of dimethylacrylamide (C-2), ethylene glycol diacrylate (C- 3) 30 parts, 1.5 parts of Irgacure 184 (D-1) and 1.5 parts of lucillin TPO (D-2) were charged simultaneously and mixed to obtain an adhesive composition.

[Examples 2-8, Comparative Examples 1-2]
An adhesive composition was prepared in the same manner as in Example 1 except that the blending components prepared above were blended in the proportions shown in Table 1 below.

<Preparation of polarizing plate test piece>
First, a 60 μm PVA film was stretched 1.5 times while immersed in a water bath with a water temperature of 30 ° C. Next, it is stretched 1.3 times while being immersed for 240 seconds in a dyeing tank (30 ° C.) consisting of 0.2 g / L of iodine and 15 g / L of potassium iodide, and further 50 g / L of boric acid and 30 g of potassium iodide. / L was immersed in a boric acid treatment tank (50 ° C.) and boric acid treatment was performed for 5 minutes while simultaneously uniaxially stretching 3.08 times. Thereafter, it was dried to produce a polarizer having a total draw ratio of 6 times.
Next, the adhesive composition obtained above on an acrylic film (trade name “Acryprene” manufactured by Mitsubishi Rayon Co., Ltd.) having a size of 200 mm × 50 mm and a thickness of 75 μm is formed with a bar coater (No. 10) so that the film thickness becomes 5 μm. After two coated acrylic films with an adhesive composition layer were produced, they were superposed on both sides of the above polarizer having a size of 150 mm × 30 mm, and bonded together at a nip pressure of 2 MPa using a roll machine to obtain a laminated film. .
Next, from both sides on the acrylic film side of the laminated film, UV irradiation is performed with an ultraviolet irradiation device equipped with a high-pressure mercury lamp at a peak illuminance of 130 mW / cm ² and an integrated exposure amount of 900 mJ / cm ² (365 nm) to adhere. The agent composition was cured, Examples 1 to 7 were dried at 80 ° C. for 3 minutes, and Examples 8 and Comparative Examples 1 and 2 were not dried, and the obtained laminated film was used as a polarizing plate test piece.

  Performance evaluation was performed as follows using the polarizing plate test piece obtained above.

[Adhesiveness]
The polarizing plate test piece was cut into 120 mm × 25 mm, and the degree of adhesion between the acrylic film and the polarizer when the stress in the 90 ° direction was applied to the two acrylic films was evaluated according to the following criteria.
(Evaluation criteria)
◎… Strongly adhered ○… Adhered ×… Not adhered

[Color loss resistance]
The polarizing plate test piece was cut into 5 cm × 5 cm and immersed in warm water at 60 ° C., and the color tone of the polarizing plate test piece after 48 hours was observed and evaluated according to the following criteria.
○: Situation before the test and no change in color tone △… Slight color loss (fading) ×… Color loss completely (fading)

[water resistant]
The polarizing plate test piece was cut into 5 cm × 5 cm, immersed in warm water at 60 ° C., the adhesion of the polarizing plate test piece after 48 hours was observed, and evaluated according to the following criteria.
○: No peeling from the end of the test piece Δ: Peeling in the range of less than 5 mm from the end of the test piece ×: Peeling in the range of 5 mm or more from the end of the test piece

  Examples 1-8 adhesives comprising a chelate-forming metal or metalloid compound (A) and a photopolymerizable compound (B) containing a functional group capable of chelating with the metal or metalloid The composition was able to sufficiently bond the polarizer and the protective film, and had an excellent effect in terms of color loss resistance and water resistance. In contrast, Comparative Example 1 that does not contain a chelate-forming metal or metalloid compound (A) or a comparison that does not contain a photopolymerizable compound (B) containing a functional group capable of chelating with a metal or metalloid The adhesive composition of Example 2 was inferior not only in adhesion but also in color fading resistance and water resistance, and could not be put to practical use as an adhesive composition. This shows that the adhesive composition of the present invention is very excellent.

  The adhesive composition for polarizing plate comprising the adhesive composition of the present invention and such an adhesive composition is excellent in adhesion between the polarizer and the protective film, and also has excellent production efficiency without requiring a drying step. Furthermore, it has excellent anti-color loss properties of the polarizing plate, and is particularly useful not only for the TAC film but also for bonding a protective film such as an acrylic film or a cyclic polyolefin resin film and a polarizer. It is a thing. Moreover, the pressure-sensitive adhesive composition of the present invention can be used for, for example, laminating various optical films or sheets, and laminating electronic parts, precision equipment, packaging materials, display materials, and the like in addition to the polarizing plate adhesive application. It can also be used.

Claims (12)

  An adhesive composition comprising a chelate-forming metal or metalloid compound (A) and a photopolymerizable compound (B) containing a functional group capable of chelating with the metal or metalloid.   Containing a chelate compound (A-B) formed from a chelate-forming metal or metalloid compound (A) and a photopolymerizable compound (B) containing a functional group capable of chelating with the metal or metalloid An adhesive composition characterized by comprising:   The chelate-forming metal or metalloid compound (A) is at least one selected from the group consisting of boron compounds, aluminum compounds, titanium compounds, zirconium compounds, zinc compounds, and silicon compounds. The adhesive composition according to 1 or 2.   The photopolymerizable compound (B) containing a functional group capable of chelating with a metal or metalloid is an acetoacetyl group-containing ethylenically unsaturated compound (b1). The adhesive composition according to item.   The acetoacetyl group-containing ethylenically unsaturated compound (b1) is an aliphatic acetoacetyl group-containing alkyl (meth) acrylate compound having an alkylene group having 1 to 10 carbon atoms. Adhesive composition.   The adhesive composition according to any one of claims 1 to 5, further comprising a photopolymerizable compound (C) (excluding the photopolymerizable compound (B)).   The photopolymerizable compound (C) is selected from the group consisting of an ethylenically unsaturated compound (c1) having one ethylenically unsaturated group and an ethylenically unsaturated compound (c2) having two or more ethylenically unsaturated groups. The adhesive composition according to claim 6, wherein the adhesive composition is at least one.   Furthermore, a polymerization initiator (D) is contained, The adhesive composition as described in any one of Claims 1-7 characterized by the above-mentioned.   An adhesive composition for polarizing plates, comprising the adhesive composition according to any one of claims 1 to 8.   A polarizing plate adhesive obtained by curing the polarizing plate adhesive composition according to claim 9.   A polarizing plate adhesive comprising the polarizing plate adhesive composition according to claim 9 cured by irradiation with active energy rays.   A polarizer and a protective film are bonded together via the polarizing plate adhesive according to claim 10 or 11.