JPH1046124A - Self-adhesive composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a self-adhesive compsn. which is excellent in self- adhesiveness and cohesive power and in adhesion esp. to an adherend with minute unevenness. SOLUTION: This compsn. is prepd. by compounding an acrylic (co)polymer which has a ratio of the wt.-average mol.wt. by the light scattering method to that expressed in terms of polystyrene of 1.3 or higher in a wt.-average mol.wt. by gel permeation chromatography with an epoxy-reactive silane compd.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an acrylic pressure-sensitive adhesive composition, and more particularly, to a pressure-sensitive adhesive composition having excellent adhesion between an optical film such as a polarizing film and a glass substrate.

[0002]

2. Description of the Related Art Generally, conventionally used pressure-sensitive adhesive compositions or applied articles such as pressure-sensitive adhesive tapes and pressure-sensitive adhesive sheets can be adhered to various surfaces of an applied body at room temperature with a pressure of about a finger pressure. Acrylic pressure-sensitive adhesives are also frequently used for bonding optical films such as polarizing films, but the required performance has been improving year by year, and the balance of tackiness and cohesion has been excellent. An adhesive is required.

For example, Japanese Patent Application Laid-Open No. 1-1193384 discloses that a specific acrylic monomer is used as an adhesive having an excellent balance between adhesive force and cohesive force, as well as excellent adhesiveness to curved surfaces and excellent heat resistance. And a weight-average molecular weight determined by gel permeation chromatography (GPC), wherein the ratio of weight-average molecular weight determined by light scattering / weight-average molecular weight determined by polystyrene conversion is 1.
An acrylic pressure-sensitive adhesive containing three or more branched polymers as components is disclosed.

[0004]

However, although such acrylic pressure-sensitive adhesives have excellent adhesion to large curved surfaces, there is still room for improvement in adhesion to adherends having minute irregularities on the surface. In the remaining places, particularly when used for bonding a polarizing film as described above, the glass surface as the adherend is poor in smoothness or when the surface is provided with irregularities in design (for example, display frame,
In the case where characters, characters, patterns, etc. are provided on the glass surface by printing, etc.), the surface to be adhered has a micro-rough surface with a roughness of several μm or several tens μm. In addition, the study of the present inventors has found that it is difficult to improve the adhesiveness to an adherend having severe surface irregularities only by controlling the weight-average molecular weight ratio. .

[0005]

The inventor of the present invention has conducted intensive studies to solve the above-mentioned problems.
In the weight average molecular weight by gel permeation chromatography (GPC) as described in 193384, the ratio (I) between the weight average molecular weight (I) by light scattering method and the weight average molecular weight (II) by polystyrene conversion method.
/ (II) Acrylic (co) polymer having 1.3 or more (A)
In addition, the pressure-sensitive adhesive composition obtained by further blending a silane compound (B) having a functional group that reacts with an epoxy group has good adhesiveness to an adherend having a surface having fine irregularities as described above. The present invention has been completed and the present invention has been completed.

The pressure-sensitive adhesive composition of the present invention is characterized in that the acrylic (co) polymer (A) and the silane compound (B) having a functional group which reacts with an epoxy group as described above are the most important constituents. And a compound (C) having at least two epoxy groups, a crosslinking agent (D), an amine compound (excluding silane compounds) (E), a crosslinking assistant (F), and the like. The effect of the present invention can be more remarkably exhibited by blending, and it is particularly useful for bonding an optical film such as a polarizing film to a glass substrate.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described specifically. The acrylic (co) polymer (A) of the present invention has a weight-average molecular weight determined by gel permeation chromatography (hereinafter abbreviated as GPC) as described in JP-A-1-193384. Acrylic copolymer having a ratio (I) / (II) of 1.3 or more between the weight average molecular weight (I) according to the formula (1) and the weight average molecular weight (II) according to the polystyrene conversion method, specifically, ethyl acrylate,
Propyl acrylate, butyl acrylate, isobutyl acrylate, 2-ethylhexyl acrylate, octyl acrylate, isooctyl acrylate, isononyl acrylate, isodecyl acrylate, butyl methacrylate, 2-ethylhexyl methacrylate, isononine methacrylate, methacrylic acid An acrylic monomer such as isodecyl is used as an essential component in an amount of 50 to 100% by weight, and as other monomers, for example, acrylic acid, methacrylic acid, methyl acrylate, methyl methacrylate, 2-hydroxyethyl acrylate, methacrylic acid 2 A known monomer used for modifying an acrylic polymer for a pressure-sensitive adhesive such as hydroxyethyl, acrylamide, methacrylamide, vinyl acetate, acrylonitrile, methacrylonitrile, styrene, etc., in an amount of 50% by weight of all monomers used; Mitsuru is intended to contain.

The acrylic (co) polymer (A) used in the present invention comprises one or more acrylic monomers as described above and, if necessary, one or more modifying monomers. The ratio (I) / (I) of the weight average molecular weight by light scattering method (I) and the weight average molecular weight (II) by polystyrene conversion method in weight average molecular weight by GPC using two or more kinds.
Polymerization treatment is carried out so that I) becomes 1.3 or more, preferably 1.3 to 3.0. If the ratio is less than 1.3, sufficient adhesive strength cannot be obtained, which is not suitable.

As a method for controlling such a ratio, for example, on the premise that the above-mentioned monomer is polymerized so as to have a composition containing the acrylic monomer unit, a polymerizable unsaturated group is added to the terminal. A macromonomer having a functional group such as a hydroxyl group or a carboxyl group; Examples thereof include a method of reacting a compound having a functional group such as an isocyanate group or an epoxy group capable of reacting with the functional group, and the synthesis of a macromonomer having a polymerizable unsaturated group at the terminal. For example, a terminal carboxylated prepolymer is obtained using a carboxyl group-containing chain transfer agent such as mercaptoacetic acid or thioglycolic acid, and this is mixed with acrylic acid Jill, glycidyl methacrylate, α
-A method of reacting a functional group capable of reacting with the terminal carboxyl group of the prepolymer with a compound having a polymerizable unsaturated group, such as glycidyl ethyl acrylate, may be performed by an appropriate method, and the hydroxyl group Synthesis of a polymer containing a functional group such as or a carboxyl group, for example, a method using acrylic acid or methacrylic acid, a hydroxyl group-containing alkyl ester thereof or the like as a component monomer, or the above-described carboxyl group-containing chain transfer agent A method of obtaining a terminal carboxylated prepolymer by using a compound having a functional group capable of reacting with the above functional group such as a hydroxyl group, that is, a compound to be introduced into a polymer containing a functional group such as a hydroxyl group or a carboxyl group. Examples include, for example, hexamethylene diisocyanate, diphenylmethane diisocyanate Or toluidine diisocyanate, isophorone diisocyanate, such as those adducts the polyisocyanate compound, tris (epoxypropyl)
Japanese Patent Application Laid-Open Publication No. Hei. The examples described in JP-A-193384 can be cited, but in addition to these, the amount of the polar monomer to be copolymerized during the polymerization of the acrylic (co) polymer is adjusted, The ratio can also be controlled by, for example, a method in which the body is dropped in a time-division manner, and the polymerization method is a known polymerization method such as a melt polymerization method, an emulsion polymerization method, a bulk polymerization method, and a suspension polymerization method. A method can be adopted.

The weight average molecular weight (I) of the acrylic (co) polymer (A) obtained by the above method by GPC light scattering method is 2 × 10 ⁵ to 8 × 10 ⁶ , especially 5 × 10 ⁵ to
5 × 10 ⁶ is preferably used, and the weight average molecular weight (II) by polystyrene conversion is 1.5 × 1
0 ^{5 to} 6.2 × 10 ⁶ , especially 3.8 × 10 ^{5 to} 3.8 × 1
0 of ⁶ what it is preferably used.

The silane compound (B) having a functional group capable of reacting with an epoxy group used together with the acrylic (co) polymer (A) is not particularly limited. (Including those having an acid anhydride structure), amino group-containing silane compounds, hydroxyl group-containing silane compounds, amide group-containing silane compounds, and mercapto group-containing silane compounds. Most preferred are silane compounds having an acid anhydride structure. As such a carboxyl group-containing silane compound, for example, 3-triethoxysilylpropyl succinic anhydride (trade name: GF-20, Wa)
ccker-Chemie GmbH), 3-triethoxysilylpropylsuccinic acid represented by the following formula 2, 3-
Trimethoxysilylpropyl succinic acid (anhydride), 3-
Methyldimethoxysilylpropylsuccinic acid (anhydride),
Methyldiethoxysilylpropylsuccinic acid (anhydride),
1-carboxy-3-triethoxysilylpropyl succinic anhydride represented by the following formula 3 is exemplified.

[0012]

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The amino group-containing silane compounds include N-β (aminoethyl) γ-aminopropylmethyldimethoxysilane, N-β (aminoethyl) γ-aminopropyltrimethoxysilane, N-β (aminoethyl )
Examples of hydroxyl group-containing silane compounds such as γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, and the like include γ-hydroxypropyl Amide group-containing silane compounds such as trimethoxysilane include γ-amidopropyltrimethoxysilane, and mercapto group-containing silane compounds include γ-mercaptopropyltrimethoxysilane.

The content of the silane compound (B) having a functional group which reacts with the epoxy group is 0.0 to 100 parts by weight of the acrylic (co) polymer (A).
001 to 10 parts by weight, preferably 0.0005 to 7 parts by weight, more preferably 0.001 to 5 parts by weight. If the content is less than 0.0001 part by weight, it is difficult to obtain the effect of the addition, and if it exceeds 10 parts by weight, the cohesive strength decreases, which is not preferable. Further, in the present invention, if necessary, other silane compounds such as epoxy silane and acrylic silane can be used in combination with the silane compound (B) having a functional group that reacts with the epoxy group.

In the present invention, a compound (C) having at least two epoxy groups may be further compounded.
This compound (C) is useful in improving the adhesion to a substrate, and
As, ethylene glycol diglycidyl ether,
Polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, trimethylolpropane triglycidyl ether, 2 , 2-Dibromoneopentyl glycol diglycidyl ether, adipic acid diglycidyl ester, o-phthalic acid diglycidyl ester, dibromoneopentyl glycol diglycidyl ether, polytetramethylene glycol diglycidyl ether, resorcin diglycidyl ether, sorbitol polyglycidyl Ether, polyglycerol polyglycidyl ether, pentaerythri Polyglycidyl ether, diglycerol polyglycidyl ether, triglycidyl tris (2-hydroxyethyl) isocyanurate, glycerol diliglycidyl ether, glycerol triglycidyl ether, N, N, N ', N'-tetraglycidyl m-xylene diamine , 1,3-bis (N, N-
Diglycidylaminomethyl) cyclohexane and the like, among which ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, and trimethylolpropane triglycidyl ether are preferably used, and particularly preferable are compounds having a hydroxyl group, For example, sorbitol polyglycidyl ether, polyglycerol polyglycidyl ether, diglycerol polyglycidyl ether, glycerol diliglydyl ether and the like are employed. Among them, glycerol diglycidyl ether is mentioned as the most preferred.

The content of the compound (C) having at least two epoxy groups is 0.0001 with respect to 100 parts by weight of the acrylic (co) polymer (A).
It is desired that the amount be 10 to 10 parts by weight, preferably 0.001 to 10 parts by weight, more preferably 0.001 to 5 parts by weight. If the content is less than 0.0001 part by weight, the effect of the addition cannot be obtained, and if it exceeds 10 parts by weight, the cohesive strength decreases, which is not preferable.

In the present invention, it is also useful to further add a crosslinking agent (D), and the crosslinking agent (D) may be an isocyanate compound, an epoxy compound, an aldehyde compound, an amine compound, a metal salt, a metal salt, or the like. Alkoxides, metal chelates, ammonium salts, hydrazine compounds and the like are exemplified. Among the crosslinking agents (D), as the isocyanate compound, tolylene diisocyanate, hydrogenated tolylene diisocyanate, tolylene diisocyanate adduct of trimethylolpropane, xylylene diisocyanate adduct of trimethylolpropane, triphenylmethane triisocyanate, methylene bis ( 4-phenylmethane) triisocyanate, isophorone diisocyanate, and the like, and ketoxime-blocked products, phenol-blocked products, and isocyanurates thereof.

Examples of the epoxy compound include bisphenol A / epichlorohydrin type epoxy resin, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, glycerin di or triglycidyl ether, 1,6-hexanediol diglycidyl ether, and trimethylolpropane. Triglycidyl ether, diglycidylaniline, diglycidylamine,
N, N, N ', N'-tetraglycidyl m-xylenediamine, 1,3-bis (N, N'-diglycidylaminomethyl) cyclohexane and the like.

Examples of the aldehyde compounds include glyoxal, malondialdehyde, succindialdehyde, maledialdehyde, glutardialdehyde, formaldehyde, acetaldehyde, benzaldehyde and the like. As the amine compound, hexamethylenediamine, triethyldiamine, polyethyleneimine, hexamethylenetetramine, diethylenetriamine, triethyltetramine, isophoronediamine, amino resin,
Melamine resins and the like can be mentioned.

As the metal salt, aluminum, iron, copper,
Salts of polyvalent metals such as zinc, tin, titanium, nickel, antimony, magnesium, vanadium, chromium, zirconium, chlorides, bromides, nitrates, sulfates, acetates and the like, for example, cupric chloride, aluminum chloride, chloride Examples include ferrous iron, stannic chloride, zinc chloride, nickel chloride, magnesium chloride, aluminum sulfate, copper acetate, and chromium acetate. Examples of the metal alkoxide include tetraethyl titanate, tetraethyl zirconate, and aluminum isopropionate.

Examples of the metal chelate compound include acetylacetone and acetoacetate coordination compounds of polyvalent metals such as aluminum, iron, copper, zinc, tin, titanium, nickel, antimony, magnesium, vanadium, chromium, and zirconium. . As ammonium salts,
Examples thereof include ammonium chloride, ammonium sulfate, ammonium acetate, and ammonium propionate. Examples of the hydrazine compound include hydrazine, hydrazine hydrate, and inorganic salts such as base salts, sulfates and phosphates thereof, and organic acid salts such as formic acid and oxalic acid.

In the present invention, among the above crosslinking agents (D), isocyanate compounds are preferable, and among them, tolylene diisocyanate adduct of trimethylolpropane is most effective. The content of the crosslinking agent (D) is 0.01 to 10 parts by weight, preferably 0.1 to 7 parts by weight, based on 100 parts by weight of the acrylic (co) polymer (A).
Parts by weight, more preferably 0.3 to 5 parts by weight. If the content is less than 0.01 part by weight, curing will not be sufficiently performed and the composition will be poor under high temperature conditions. On the other hand, if the content exceeds 10 parts by weight, the curing will be accelerated too much and the adhesive strength will be undesirably reduced.

In the present invention, it is preferable to further contain an amine compound (excluding a silane compound) (E) in addition to the above, so that the effects of the present invention can be remarkably exhibited. The amine compound (E) is not particularly limited,
For example, triethylenediamine, N, N, N ', N'-
Tetramethyltrimethylenediamine, methyliminobispropylamine, aminoethylpiperazine, N, N,
N ', N'-tetramethylethylenediamine, hexamethylenetetramine, 2,4,6-tris (dimethylaminomethyl) phenol, 2-methylimidazole, pyridine, 1-cyanoethyl-2-methylimidazole,
1,8-diazabicyclo-7-undecene, benzyldimethylamine, triethanolamine, benzyltrimethylammonium chloride, tributylamine, boron trifluoride-dimethylamine complex and the like, among which triethylenediamine, N, N, N ' , N'-Tetramethyltrimethylenediamine, N, N, N ', N'-tetramethylethylenediamine, 2-methylimidazole are particularly preferred. The content of the amine compound (E) is 0.0001 to 10 parts by weight, preferably 0.01 part by weight, based on 100 parts by weight of the acrylic (co) polymer (A).
It is desired that the amount be from 0.01 to 10 parts by weight, more preferably from 0.001 to 5 parts by weight.

In the present invention, in addition to the above (A) to (E), one or more of a polyol compound (however, a polyfunctional epoxy compound), a melamine compound, and divinylbenzene may be used as a crosslinking aid (F). It is preferable to contain more than one species. The content is 0.001 to 50 parts by weight, preferably 0.01 to 3 parts by weight in the case of a polyol compound, based on 100 parts by weight of the acrylic (co) polymer (A).
0 parts by weight, 0.001 to 10 in the case of a melamine compound
Parts by weight, preferably 0.001 to 0.5 parts by weight, and in the case of divinylbenzene, 0.0001 to 10 parts by weight, preferably 0.001 to 10 parts by weight. Can demonstrate.

The polyol compound is not particularly limited, and may be polyether polyol, polyester polyol, hydroxyl-containing polybutadiene polyol,
Acrylic polyols, castor oil derivatives, nitrogen-free polyols such as tall oil derivatives, and the like, among which preferably, trimethylolpropane, 1,4-butanediol, polytetramethylene ether glycol,
Examples thereof include ethylene glycol, propylene glycol, and 3-methylpentane-1,3,5-triol, and preferably include nitrogen-containing polyol compounds represented by the following chemical formulas (4) and (6). Specifically, chemical formula 4 includes triethanolamine, methyldiethanolamine, polyoxyethylene stearylamine, polyoxyethylene laurylamine, preferably methyldiethanolamine and polyoxyethylene stearylamine. Chemical formula 6 includes N, N, N ′. , N'-tetrakis (2-hydroxypropyl) ethylenediamine,
ADEKA QUADROL (Asahi Denka Kogyo Co., Ltd.).

[0026]

Embedded image Here, R and R 'are alkyl groups, R ₁ is hydrogen, an alkyl group, an acyl group, a phenyl group or any of the following formulas 5, and m, n, k, and l are integers of 0 or more (provided that , M and n, and k and l do not both become 0 at the same time.)

Embedded image

[0027]

Embedded image Here, R and R 'are alkyl groups, X is an alkylene group or a phenylene group, and a, b, m, n, k, l, x and y are integers of 0 or more (provided that a, b, m and n, k and l, x and y
Do not become 0 at the same time. ), P is an integer of 1 or more.

The melamine compound is not particularly limited, but is preferably a compound represented by the following formula (7). Specifically, R ₂ is hydrogen (9% by weight), —CH ₂ OH (31% by weight), Super Beckamine J-820-60 (Dainippon Ink and Chemicals) consisting of —CH ₂ OBu (60% by weight).

[0029]

Embedded image Here, R ₂ is hydrogen or —CH ₂ —O—R ₂ ′ (however,
R ₂ ′ is hydrogen or an alkyl group), R ₃ is R ₂ or a bond formed by condensation, and r is an integer of 1 or more.

When divinylbenzene is used, it is preferable that the obtained pressure-sensitive adhesive composition is applied to a substrate, bonded to a film or the like, and then irradiated with an electron beam as necessary.
For electron beam irradiation, 0.1 Mrad to 10 Mrad
It is preferable to irradiate the irradiation amount. In the present invention, when the amine compound (E) and the crosslinking aid (F) are used in combination, they exhibit the best adhesive physical properties.

In the present invention, the above-mentioned acrylic (co) polymer (A), a silane compound having a functional group which reacts with an epoxy group (B), and a compound having at least two epoxy groups (C), a cross-linking agent (D), an amine compound (E), a cross-linking aid (F), and the like may be contained, and there is no particular limitation on the compounding method. (Co) polymer (A), silane compound (B), epoxy group compound (C), crosslinking agent (D), amine compound (E), crosslinking assistant (F) The remaining components may be mixed later, and the silane-based compound (B) having a functional group that reacts with the epoxy group may be used at the time of producing the acrylic (co) polymer (A), Coexist during polymerization of components or react with epoxy group The silane compound (B) having a functional group and the compound (C) having at least two epoxy groups are reacted at 10 to 50 ° C. for 1 to 50 hours (using a reaction catalyst if necessary), Acrylic resin is added, and this is post-reacted with an acrylic resin, or further copolymerized with other acrylic monomers using a monomer obtained by reacting an adduct of the silane compound with a functional group-containing acrylic monomer. Or you may be.

Thus, the pressure-sensitive adhesive composition of the present invention is excellent in tackiness and cohesive force, and also has an excellent effect of adhesion to a rough surface having fine irregularities, which is a feature of the present invention. It is. Regarding the use of such a pressure-sensitive adhesive composition, a solution dissolved in an organic solvent such as toluene, ethyl acetate, methyl ethyl ketone, or acetone is applied to a substrate or a film such as a release film, and then 30 to 170 ° C., preferably 4 to 170 ° C.
It is dried and cured at a drying temperature of 0 to 150 ° C. to obtain its adhesive properties.

The pressure-sensitive adhesive composition comprises a pressure-sensitive adhesive tape,
It is effectively used for various adhesive applications such as adhesive sheets, and is further bonded to various substrates. The base material is not particularly limited, but a metal plate of any material including a stainless steel plate, an aluminum plate, a steel plate, a copper plate, etc., a synthetic resin decorative plate such as a polyethylene plate, a polypropylene plate, a melamine plate, a phenol plate, a plywood, a veneer In addition to a so-called plate-shaped material such as a glass plate, it can be bonded to the surface of a rod-shaped material, pottery or various molded products. After lamination, electron beam irradiation may be performed as described above, if necessary.

Further, the pressure-sensitive adhesive composition of the present invention exhibits a very excellent effect in bonding a substrate, particularly a glass substrate, to an optical film. That is, by using the pressure-sensitive adhesive composition, the adhesiveness to the glass substrate having fine irregularities as described above is excellent, and appearance defects such as foaming and peeling of the pressure-sensitive adhesive layer do not occur. An excellent optical laminate can be obtained.

The optical film used in the present invention is not particularly limited as long as it has optical characteristics.
It is preferable to use a polarizing film, a retardation film, an elliptically polarizing film, and the like. By using the pressure-sensitive adhesive composition of the present invention for bonding these optical films to a glass substrate, an optical film having excellent heat resistance, wet heat resistance, and optical properties. An optical laminate of a film / glass substrate is obtained. In the present invention, an optical film such as a polarizing film, a retardation film, and an elliptically polarizing film is provided with a protective layer. However, unless otherwise specified, the optical film is referred to as an optical film regardless of the presence or absence of the protective layer.

Hereinafter, the optical laminate will be described in detail. In the present invention, for example, a polyvinyl alcohol-based polarizing film as a base material, a polarizing plate provided with a protective layer as necessary, or a polyvinyl alcohol-based or polycarbonate-based retardation film as a base material, which is necessary. The pressure-sensitive adhesive layer and the release film are added to a retardation plate provided with a protective layer, or an elliptically polarizing plate obtained by combining a polarizing film and a retardation film. As a method of adding a pressure-sensitive adhesive layer and a release film, a pressure-sensitive adhesive layer is provided on a release film, and a method of bonding an optical film thereon, or conversely, a pressure-sensitive adhesive layer is provided on an optical film, A method of attaching a release film thereon is usually employed.

The optical film having the pressure-sensitive adhesive layer obtained in this manner is appropriately cut at the time of use, the release film is peeled off, and the optical film is bonded to glass or another base material as a mating base material. Used for anti-glare or as sunglasses. The optical film having the pressure-sensitive adhesive layer is used for a reflective or transflective liquid crystal display panel by further providing a reflector and / or a translucent layer. This reflector is usually made of aluminum, silver or other foil,
A board is used. Further, as the translucent layer, the reflectance and the transmittance are selected so that the translucent layer can be used for both the reflection type and the transmission type, and the material is appropriately selected.

Examples of the retardation film include, but are not limited to, polyvinyl alcohol, polycarbonate, polyester, polyarylate, polyimide, polyolefin, polystyrene, polysulfone, polyethersulfone, polyvinylidene fluoride / polymethyl methacrylate, and liquid crystal polymer. , Triacetylcellulose-based resin, cyclic polyolefin, saponified ethylene-vinyl acetate copolymer, polyvinyl chloride and the like are used, but polycarbonate and polyvinyl alcohol-based resin films are mainly used. Polyvinyl alcohol-based resins are usually produced by saponifying polyvinyl acetate obtained by polymerizing vinyl acetate. A small amount of unsaturated carboxylic acids (including salts, esters, amides, nitriles, etc.), olefins, vinyl ethers, It may contain a component copolymerizable with vinyl acetate, such as a saturated sulfonate. Also, polyvinyl alcohol was reacted with aldehydes in the presence of an acid,
For example, a so-called polyvinyl acetal resin such as a polybutyral resin and a polyvinyl formal resin and a polyvinyl alcohol derivative may be used. Average polymerization degree is 500 ~
10,000, the degree of saponification is 80-100 mol%,
It is desirable that the film is uniaxially stretched to about 1.01 to 4 times.

On the other hand, the polarizing film has an average degree of polymerization of 15
The above-mentioned polyvinyl alcohol-based resin having a saponification degree of 85 to 100 mol% as a raw film,
An aqueous solution of iodine-potassium iodide or a uniaxially stretched film dyed with a dichroic dye (a stretch ratio of about 2 to 10 times, preferably about 3 to 7 times) is used.

Examples of the protective layer include conventionally known cellulose acetate films, acrylic films, polyester resin films, polyolefin resin films, polycarbonate films, polyetheretherketone films, and polysulfone films. However, a cellulose acetate film such as a cellulose triacetate film is preferably used. Furthermore, if necessary, an ultraviolet absorber such as a salicylic acid ester compound, a benzophenol compound, a benzotriazole compound, a cyanoacrylate compound, or a nickel complex compound may be added to the resin film.

The optical laminate of the present invention has various layer constitutions without any particular limitation. For example, protective layer / polarizing film / protective layer / pressure-sensitive adhesive layer of the present invention / glass (or release film), functional layer / protective layer / polarizing film / protective layer / pressure-sensitive adhesive layer of the present invention / glass (or release film) Mold film), retardation film / pressure-sensitive adhesive layer of the present invention / glass (or release film), protective layer / retardation film / protective layer / pressure-sensitive adhesive layer of the present invention / glass (or release film),
(Protective layer /) Polarized film (/ Protective layer) / Acrylic adhesive layer / (Protective layer /) Retardation film (/ Protective layer) / Adhesive layer of the present invention / Glass (or release film), functional layer / Protective layer / polarizing film (/ protective layer) / acrylic pressure-sensitive adhesive layer / (protective layer /) retardation film (/ protective layer) / pressure-sensitive adhesive layer of the present invention / glass (or release film), masking layer / Polarizing film (/ protective layer) / acrylic pressure-sensitive adhesive layer / (protective layer /) retardation film (/ protective layer) / pressure-sensitive adhesive layer of the present invention / glass (or release film), (protective layer /)
Retardation film (/ protective layer) / acrylic pressure-sensitive adhesive layer /
(Protective layer /) Polarizing film (/ Protective layer) / Adhesive layer of the present invention / Glass (or release film), Masking layer / Retardation film (/ Protective layer) / Acrylic adhesive layer / (Protective layer / ) Polarizing film (/ protective layer) / pressure-sensitive adhesive layer of the present invention / glass (or release film), (glass or release film /) pressure-sensitive adhesive layer of the present invention / (protective layer /) retardation film (/ protection Layer) / acrylic pressure-sensitive adhesive layer / (protective layer /) polarized film (/ protective layer) / pressure-sensitive adhesive layer of the present invention / glass (or release film).

The functional layer includes a hard coat layer, an antireflection layer, an antiglare layer, and the like. Further, as the masking layer, a polyethylene film having a thickness of about 10 to 100 μ, a synthetic resin film such as a polyethylene terephthalate film is used, and as the release film, a release silicone, wax, paraffin,
A release paper provided with a release layer made of a synthetic resin such as chromium chloride stearate or a thermoplastic resin or a thermosetting resin, or a synthetic resin based material such as a polyester film, a polypropylene film, or a polyethylene terephthalate film is used. . Furthermore, regarding the lamination of the protective layer and the polarizing film or the retardation film, natural or synthetic rubber, acrylic resin, butyral resin, epoxy resin, polyester resin, polyamide resin, polyvinyl alcohol resin and the like as main components Using an adhesive or a pressure-sensitive adhesive to be applied, the adhesive can be bonded by an air drying method, a chemical curing method, a thermosetting method, a hot melting method, or the like.

[0043]

The present invention will be specifically described below with reference to examples. In the following, “parts” and “%” are based on weight unless otherwise specified. Example 1 [Preparation of acrylic copolymer (A)] Acrylic acid 2 was placed in a reaction vessel equipped with a cooling pipe, a nitrogen introduction pipe, a thermometer, and a stirrer.
-60 parts of ethylhexyl, 40 parts of butyl acrylate,
Add 1 part of 4,4'-azobiscyanovaleric acid and 1 part of thioglycolic acid, and place in a solvent system consisting of 75 parts of methyl ethyl ketone and 75 parts of toluene at 70 ° C. under nitrogen purging.
For 8 hours, and the resulting reaction product was purified by precipitation with a mixed solvent of methanol / water to obtain a terminal carboxylated prepolymer. Next, 100 parts of the obtained terminal carboxylated prepolymer, 4 parts of glycidyl methacrylate, 0.5 part of tributylamine and 0.5 part of hydroquinone are placed in the same reaction vessel as above, and a solvent system comprising 150 parts of xylene is also used. Was reacted at 140 ° C. for 6 hours, and the obtained reaction product was purified by precipitation with a mixed solvent of methanol / water, and then dried under reduced pressure to obtain a macromonomer having a polymerizable unsaturated group at a terminal.

Then, 10 parts of the macromonomer, 51 parts of 2-ethylhexyl acrylate, 34 parts of butyl acrylate, 5 parts of acrylic acid and 0.5 part of 2,2'-azobisisobutyronitrile were added in the same manner as described above. Put it in the reaction vessel,
The reaction was carried out at 60 ° C. for 8 hours in a solvent system comprising 150 parts of ethyl acetate to obtain an acrylic copolymer (A). The weight average molecular weight (I) of the acrylic copolymer (A) by GPC light scattering method is about 1.2 million, the weight average molecular weight (II) by polystyrene conversion method is about 900,000,
(I) / (II) was 1.36. The measurement of the weight average molecular weight (I) by the light scattering method of GPC and the weight average molecular weight (II) by the polystyrene conversion method were performed by using a GPC device equipped with a light scattering photometer and a differential refractometer as a detector.
A sample concentration of 1 mg / ml, a sample introduction amount of 500 μl, a column temperature of 38 ° C., and a flow rate of 1 ml / min were carried out using tetrahydrofuran as an eluent, and a monodisperse polystyrene having a weight average molecular weight of 42,000 was used as a standard sample. .

The acrylic copolymer (A) obtained above
In a toluene solution (solid content: 20%) of 100 parts of the solid content of the copolymer solution, 3-triethoxysilylpropylsuccinic anhydride (B) (trade names: GF-20, Wa)
1.0 part of ckerer-Chemie GmbH), 1.0 part of glycerol diglycidyl ether (C), coronate L of an isocyanate compound as a crosslinking agent (D)
1.0 part (manufactured by Nippon Polyurethane Co., Ltd.) was added and mixed well to obtain an adhesive composition. With respect to the obtained pressure-sensitive adhesive composition, general adhesive strength, cohesive strength, and adhesive strength on a fine uneven surface were evaluated. The methods for evaluating the general adhesive force, the cohesive force, and the adhesive force on the fine uneven surface are as described below.

(General Adhesive Strength) After dissolving the above-mentioned pressure-sensitive adhesive composition in toluene, it is coated on a polyethylene terephthalate film and dried at 100 ° C. for 2 minutes (coated thickness 25 after drying).
μm), and reciprocated three times with a manual roller according to JIS Z 0237 to form a glass plate (surface roughness Ra = 0.1 μm).
Hereinafter, it was crimped to a size (width: 25 mm, length: 180 mm). The sample was autoclaved (50 ° C, 15
5 kg / cm ² ), and heat-treated at 60 ° C. for 12 hours.
After leaving for 1 hour under the condition of 20 ° C and 65% RH, JIS
JIS Z 02 using a device according to B 7721
Adhesive strength (kg / 25
mm). Pulling speed is 200mm / mi
n.

(Cohesive force) A polyethylene terephthalate film (size:
A glass plate (surface unevenness: 25 mm in width and 150 mm in length)
Same as above, size: width 40mm, length 80mm)
Crimping was performed three times with a manual roller according to Z0237. The sample was autoclaved (50 ° C, 15
5 kg / cm ² ), left for 1 hour under the conditions of 20 ° C. and 65% RH, and then applied a 1 kg load to the end,
According to SZ0237, the size (mm) of the shift after 48 hours at 70 ° C. was measured and evaluated according to the following criteria. ◎: less than 0 to 0.5 (mm) ○: 0.5 to less than 5.0 (mm) △: less than 5.0 to 10.0 (mm) ×: 10.0 (Mm) or more

(Adhesive force of micro-uneven surface) Surface roughness is Ra
A PET film coated with the above-mentioned pressure-sensitive adhesive composition is adhered to a glass plate having a thickness of 1.0 μm according to JIS Z 0237, and the peeling force immediately after the sticking (a) and the peeling force after 3 hours at 90 ° C. (B) was measured, and its rate of change (b) / (a) was determined and evaluated according to the following criteria. ◎ ・ ・ ・ (b) / (a) ≧ 1.4 ○ ・ ・ ・ 1.4> (b) / (a) ≧ 1.2 Δ ・ ・ ・ 1.2> (b) / (a) ≧ 1.1 ×... 1.1> (b) / (a)

Further, the obtained pressure-sensitive adhesive composition was prepared to have a thickness of 1.1 m.
m on a glass plate having a thickness of 25 μm after drying using an applicator, and dried at 100 ° C. for 2 minutes to obtain an adhesive plate. On the other hand, a polyvinyl alcohol polarizing film having a thickness of 30 μm (average degree of polymerization) 1700, an average saponification degree of 99 mol%, stretched 4 times) on both sides of a 80 μm-thick cellulose triacetate film-laminated polarizing plate (the stretching axis direction of the polyvinyl alcohol polarizing film is inclined 45 ° to 15 °).
(Cut to 0 mm × 200 mm), and the adhesive plate was laminated on one surface thereof, and pressed with a roller to produce a glass laminated polarizing plate. The polarizing plate was subjected to a cycle test and a shock test as described below, and the size (mm) of peeling after the test was measured and evaluated according to the following criteria.

(Cycle test) A polarizing plate was heated at 40 ° C. and 95%
After standing for 60 minutes under RH conditions, 105 minutes after 30 minutes
It was left for 60 minutes under the condition of ° C. 30 minutes later, 4
Exposure to 0 ° C. and 95% RH was performed, and the same operation was performed for a total of 1 hour.
Performed 0 times. (Shock test) After the polarizing plate was allowed to stand at 0 ° C. for 30 minutes, it was immediately allowed to stand at 100 ° C. for 30 minutes.
Then, it was again exposed to the condition of 0 ° C.
Performed 0 times.

The evaluation criteria are as follows.・ ・ ・: Peeling less than 0 to 2 (mm) ○: Peeling less than 2 to 5 (mm) △: Peeling less than 5 to 10 (mm) ×: Peeling of 10 (mm) or more The optical property change after the cycle test and after the shock test was evaluated.

As for the optical characteristics of the polarizing plate, a single transmittance τ (%) and a degree of polarization V (%) were measured. Here, the degree of polarization in the present invention is represented by [(H ₁₁ −H ₁ ) / (H ₁₁ + H ₁ )] ^1/2 × 100 (%), where H ₁₁ is the superposition of two polarizing film samples. during, transmittance orientation direction was measured using a spectrophotometer in a state superimposed to have the same direction of the polarizing film (%), H ₁ at the time of superposition of two samples, the polarizing film It is a transmittance (%) measured in a state where the alignment directions are superposed so as to be orthogonal to each other.

Similarly, a retardation film (average degree of polymerization: 170
0, an average saponification degree of 97 mol%, a 1.1-fold stretched polyvinyl alcohol film, and a film thickness of 50 μm), a retardation plate (polyvinyl alcohol film) having an 80 μm-thick cellulose triacetate film laminated on both sides of the retardation film. Tilt the stretching axis direction of the film by 45 degrees, 150mm x 200
mm), the adhesive plate was laminated on one surface thereof, and pressed with a roller to produce a glass laminated retardation plate. A cycle test and a shock test were performed on the retardation plate in the same manner as described above, and the magnitude of the peeling after the test (m
m) and changes in optical properties were evaluated.

The retardation value (RD) of the optical characteristics of the retardation plate was measured. The retardation value (RD) of the retardation film refers to the main stretching direction (M
D) and the refractive index (II _MD -II _TD ) in the direction perpendicular thereto (TD direction) and the thickness (d) of the retardation film, and are defined by a polarizing microscope (Nikon with a Babinet type compensator). (POH-1 type) was measured by a compensation method (the light source was white light).

Further, an elliptically polarizing plate having a constitution of cellulose triacetate film / polarizing film / cellulose triacetate film / adhesive layer / cellulose triacetate film / retardation film / cellulose triacetate film / adhesive layer is also used. A cycle test and a shock test were performed to evaluate the size (mm) of peeling.

The change in the optical characteristics of the polarizing plate is evaluated by the difference between the single transmittance τ (%) and the degree of polarization V (%) before and after the test, and it is desired that the absolute value be 5% or less in absolute value.
The retardation plate is evaluated based on the difference between the RD values before and after the test, and is desirably 30 nm or less in absolute value.

Example 2 [Preparation of acrylic copolymer (A)] In the preparation of acrylic copolymer (A) in Example 1, 15 parts of a macromonomer, 48 parts of 2-ethylhexyl acrylate, The procedure was the same except that butyl acid was changed to 32 parts.
C has a weight average molecular weight (I) of about 150
10,000, weight average molecular weight by polystyrene conversion method (II)
Was about 900,000 and (I) / (II) was 1.67, giving an acrylic copolymer (A). 100 parts of the acrylic copolymer (A) obtained above was treated with 3-triethoxysilylpropylsuccinic anhydride (B) (trade name: GF-20, Wack)
In the presence of 1.0 part of er-Chemie GmbH), 0.1 part of benzoyl peroxide as a polymerization initiator was added and polymerized in toluene to obtain a copolymer solution. Ethylene glycol diglycidyl ether (C) was added to the copolymer solution based on 100 parts of the solid content of the copolymer solution.
1.0 part and 1.0 part of an isocyanate-based compound Coronate L (manufactured by Nippon Polyurethane Co., Ltd.) as a crosslinking agent (D) were added and mixed well to obtain a pressure-sensitive adhesive composition, which was evaluated in the same manner as in Example 1. Was done.

Example 3 Preparation of Acrylic Copolymer (A) 80 parts of butyl acrylate, 14 parts of butyl methacrylate, and ethyl acetate were placed in a reaction vessel equipped with a cooling pipe, a nitrogen introducing pipe, a thermometer, and a stirrer. After refluxing 200 parts and 0.1 part of azoisobutyronitrile for 3 hours, at 70 ° C., 0.5 part of azoisobutyronitrile was added.
, A mixture of 5 parts of acrylic acid, 1 part of hydroxyethyl methacrylate and 200 parts of toluene were added dropwise over 4 hours, and the weight average molecular weight (I) by GPC light scattering method was about 1,000,000. As a result, an acrylic copolymer (A) having a weight average molecular weight (II) of about 710,000 and (I) / (II) of 1.4 was obtained. Evaluation was carried out in the same manner as in Example 1 using the acrylic copolymer (A) obtained above.

Example 4 Preparation of Acrylic Copolymer (A) 30 parts of butyl acrylate, 20 parts of butyl methacrylate, and 2 parts of toluene were placed in a reaction vessel equipped with a cooling pipe, a nitrogen introducing pipe, a thermometer, and a stirrer.
After refluxing 00 parts and 1.0 part of azoisobutyronitrile for 3 hours, at 70 ° C., a mixture of 20 parts of butyl acrylate, 5 parts of acrylic acid, 10 parts of hydroxyethyl methacrylate and 200 parts of ethyl acetate was reduced to 1/5. The weight average molecular weight (I) was determined by GPC light scattering method.
However, an acrylic copolymer (A) having a weight-average molecular weight (II) of about 530,000 and a polystyrene conversion method of (I) / (II) of 1.5 was obtained. Using the acrylic copolymer (A) obtained above, a pressure-sensitive adhesive composition was obtained in the same manner as in Example 2, and the pressure-sensitive adhesive composition was evaluated in the same manner as in Example 1.

Example 5 An adhesive composition was obtained in the same manner as in Example 1 except that glycerol diglycidyl ether (C) was not added. Was evaluated.

Example 6 The procedure of Example 3 was repeated, except that 1.0 part of polyoxyethylene stearylamine (F) was further added. The resulting pressure-sensitive adhesive composition was evaluated in the same manner as in Example 1. Was.

Example 7 The same procedure as in Example 1 was repeated except that 1,8-diazabicyclo-7-
The same procedure was performed except that 1.0 part of undecene (E) and 1.0 part of polyoxyethylene stearylamine (F) were added, and the obtained pressure-sensitive adhesive composition was evaluated in the same manner as in Example 1.

Comparative Example 1 [Preparation of Acrylic Copolymer (A)] In Example 1, the addition amount of 2,2′-azobisisobutyronitrile was 1/50, and the weight was measured by GPC light scattering method. An acrylic copolymer (A) having an average molecular weight (I) of about 700,000, a weight average molecular weight (II) in terms of polystyrene of about 580,000, and (I) / (II) of 1.2 is obtained. Was. Using the acrylic copolymer (A) obtained above, a pressure-sensitive adhesive composition was obtained in the same manner as in Example 1, and the pressure-sensitive adhesive composition was evaluated in the same manner as in Example 1. Comparative Example 2 A pressure-sensitive adhesive composition was obtained in the same manner as in Example 1 except that 3-triethoxysilylpropylsuccinic anhydride (B) was not added. Evaluation was performed in the same manner as in Example 1. Tables 1 to 3 collectively show the evaluation results of the examples and the comparative examples. Regarding the change in the optical properties of Comparative Examples 1 and 2, the optical properties could not be measured because the peeling after the test was large, so the measured values before the test were not described.

[0064]

[Table 1] Adhesive Properties General Adhesive Force Cohesive Force Adhesive Force on Micro-Uneven Surface (kg / 25mm) Example 1 2.0 ◎ 〃 21.9 〃 3 1.8 〃 ◎ ４ 4 1.8 ◎ ◎ ５ 5 1.5 ○ ○ 〃 6 1.9 ◎ ◎ 〃 7 1.9 ◎ ◎ Comparative Example 1 0.5 × × 〃 20.5 × ×

[0065]

[Table 2] (Size of peeling) Polarizer retarder elliptically polarizer cycle Shock cycle Shock cycle After shock test After test After test After test After test Example 1 ◎ ◎ ◎ ◎ ◎ ◎ ◎ ◎ 2 ◎ ○ ◎ ○ ◎ ○ 〃 3 ◎ ◎ ◎ ◎ ◎ ◎ 〃 4 ◎ ◎ ◎ ◎ ◎ ◎ 〃 5 ○ ○ ○ ○ ○ ○ 〃 6 ◎ ○ ◎ ○ ◎ ○ 〃 7 ○ ○ ○ ○ ○ ○ Comparative Example 1 × × × × × × × 〃 2 × × × × × ×

[0066]

Table 3 (Change in optical properties) Cycle Cycle Shock Before test After test Before test Before test After test Example 1 Polarizing plate τ 42 41 42 42 V 99.0 99.0 99.0 99.0 Retardation plate RD 400 395 400 390 〃2 polarizing plate τ 42 40 42 41 V 99.0 99.0 99.0 98.0 Retardation plate RD 400 395 400 394 ３3 polarizing plate τ 42 41 42 42V 99.0 99.0 99. 0 98.0 Retardation plate RD 400 393 400 390 4 Polarizing plate τ 42 42 42 41 V 99.0 99.0 99.0 98.0 Retardation plate RD 400 393 400 391 〃5 Polarizing plate τ 42 40 42 41 V 99.0 99.0 99.0 99.0 Retardation plate RD 400 392 400 390 〃6 Polarizer τ 42 41 42 42 V 99.0 99.0 99. 0 98.0 Retardation plate RD 400 392 400 391〃7 Polarizing plate τ 42 41 42 42 V 99.0 99.0 99.0 98.0 Retardation plate RD 400 392 400 390 Note) τ: Single transmittance ( %), V: degree of polarization (%), RD: retardation value (nm) Incidentally, both the polarizing plates and the retardation plates of Comparative Examples 1 and 2 were remarkably peeled and had a problem in appearance, and the optical characteristics were measured. Without.

[0067]

The pressure-sensitive adhesive composition of the present invention is an acrylic (co) polymer (A) having a specific weight average molecular weight.
And a silane-based compound (B) having a functional group that reacts with an epoxy group.
And has excellent adhesion to the adherend on the surface with minute irregularities,
In particular, when used for adhesion between an optical film and a substrate, an effect that the optical characteristics are not deteriorated even when used for a long time without foaming or peeling of the pressure-sensitive adhesive is exhibited. Utilizing such characteristics, it is used for a liquid crystal display, and is particularly useful for a vehicle, various industrial instruments, display of household electric appliances, and the like.

Claims (12)

[Claims] 1. The ratio (I) / () of the weight average molecular weight (G) by gel permeation chromatography (GPC) between the weight average molecular weight (I) by light scattering method and the weight average molecular weight (II) by polystyrene conversion method. II) is 1.3
A pressure-sensitive adhesive composition comprising the above acrylic (co) polymer (A) and a silane compound (B) having a functional group that reacts with an epoxy group. 2. The pressure-sensitive adhesive composition according to claim 1, wherein the functional group that reacts with the epoxy group is any one of a carboxyl group, an amino group, a hydroxyl group, and an amide group. 3. The content of the silane compound (B) having a functional group that reacts with an epoxy group is 0.0001 to 10 parts by weight based on 100 parts by weight of the acrylic (co) polymer (A). The pressure-sensitive adhesive composition according to claim 1 or 2, wherein 4. The pressure-sensitive adhesive composition according to claim 1, further comprising a compound (C) having at least two epoxy groups. 5. The pressure-sensitive adhesive composition according to claim 4, wherein the compound (C) having at least two epoxy groups is a compound also having a hydroxyl group. 6. The content of the compound (C) having at least two epoxy groups is 0.0001 to 10 parts by weight based on 100 parts by weight of the acrylic (co) polymer (A). The pressure-sensitive adhesive composition according to claim 4 or 5, wherein 7. A cross-linking agent (D) further comprising an acrylic (co)
The pressure-sensitive adhesive composition according to any one of claims 1 to 6, wherein the pressure-sensitive adhesive composition is blended in an amount of 0.01 to 10 parts by weight based on 100 parts by weight of the polymer (A). 8. The pressure-sensitive adhesive composition according to claim 1, further comprising an amine compound (excluding a silane compound) (E). 9. An amine compound (E) comprising triethylenediamine, N, N, N ', N'-tetramethyltrimethylenediamine, methyliminobispropylamine, aminoethylpiperazine, N, N, N', N ' -Tetramethylethylenediamine, hexamethylenetetramine, 2,
4,6-tris (dimethylaminomethyl) phenol,
2-methylimidazole, pyridine, 1-cyanoethyl-2-methylimidazole, 1,8-diazabicyclo-
The pressure-sensitive adhesive composition according to claim 8, wherein the pressure-sensitive adhesive composition is at least one selected from 7-undecene, benzyldimethylamine, triethanolamine, benzyltrimethylammonium chloride, tributylamine, and boron trifluoride-dimethylamine complex. . 10. The composition according to claim 1, further comprising at least one compound selected from the group consisting of a polyol compound (excluding a polyfunctional epoxy compound), a melamine compound, and divinylbenzene as the crosslinking assistant (F). 1-9
The pressure-sensitive adhesive composition according to any one of the above. 11. The pressure-sensitive adhesive composition according to claim 1, which is used for bonding a substrate and an optical film. 12. The pressure-sensitive adhesive composition according to claim 11, wherein the optical film is any one of a polarizing film, a retardation film, and an elliptically polarizing film.