JPH1046126A - Adhesive composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pressure-sensitive adhesive composition which is excellent in tackiness and cohesion, and particularly excellent in adhesion to an adherend having a surface having fine irregularities. An acrylic (co) polymer (A) containing 15% by weight or less of a polymer component having a weight average molecular weight of 100,000 or less and 10% by weight or more of a polymer component having a weight average molecular weight of 1,000,000 or more and an epoxy group And a silane compound (B) having a functional group that reacts with

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, JP-A-64-66283 and JP-A-1-178567 disclose a weight-average molecular weight of 1;
When the content of the polymer component of 100,000 or less is 15% by weight or less,
An acrylic pressure-sensitive adhesive using an acrylic polymer having a content of a polymer component having a weight-average molecular weight of 1,000,000 or more and 10% by weight or more is disclosed.

[0004]

However, although such acrylic pressure-sensitive adhesives have excellent adhesiveness at high temperatures and high humidity, their adhesiveness to adherends having minute irregularities on the surface is still insufficient. Where there is room for improvement, 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. However, there is a possibility that the adhesiveness may be reduced.
It has been found that it is difficult to improve the adhesion to an adherend having severe surface irregularities.

[0005]

The inventor of the present invention has conducted intensive studies to solve the above-mentioned problems.
As described in JP-A-66283 and JP-A-1-178567, the content of a polymer component having a weight average molecular weight of 100,000 or less is 15% by weight or less, and the content of a polymer component having a weight average molecular weight of 1,000,000 or more is 10%. A pressure-sensitive adhesive composition obtained by blending a silane compound (B) having a functional group that reacts with an epoxy group with an acrylic (co) polymer (A) in an amount of at least% by weight, The present invention was also found to have good adhesion to adherends having

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 is obtained by copolymerizing a polar monomer component with an acrylic acid alkyl ester as a main component. , N-butyl acrylate, isobutyl acrylate, 2-acrylate
Ethylhexyl, lauryl acrylate, benzyl acrylate, alkyl acrylates having about 2 to 12 carbon atoms of alkyl groups such as cyclohexyl acrylate, n-butyl methacrylate, isobutyl methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate, Alkyl groups such as benzyl methacrylate, cyclohexyl methacrylate and the like having 4 to 12 carbon atoms, such as methacrylic acid alkyl esters, and the like. Further, methyl acrylate and methyl methacrylate, ethyl methacrylate, ethyl methacrylate and the like Examples thereof include alkyl methacrylate having 1 to 3 carbon atoms, vinyl acetate, acrylonitrile, methacrylonitrile, and styrene. Further, a monomer generally used for the synthesis of an acrylic resin, such as an alkyl acrylate or an alkyl methacrylate in which an alkyl group is substituted with an aromatic ring group, a heterocyclic group, a halogen atom, etc. It can also be used for the synthesis of a system resin.

As the polar monomer, those which function as a cross-linking point or the like are used, and the kind thereof is not particularly limited. Generally, for example, acrylic acid, methacrylic acid, crotonic acid, maleic acid, itacone Carboxyl group-containing monomers such as acids, hydroxyl group-containing monomers such as 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, and 2-hydroxyvinyl ether;
N, N-dimethylaminoethyl acrylate, Nt-
Anomi group-containing monomers such as butylaminoethyl acrylate, amide group-containing monomers such as acrylamide and methacrylamide, methylol group-containing monomers such as N-methylolacrylamide and N-methylolmethacrylamide, glycidyl acrylate, glycidyl methacrylate Epoxy group-containing monomers such as The copolymerization ratio of the polar monomer component is generally 0.5 to 20 parts by weight per 100 parts by weight of the acrylic acid-based alkyl ester component.

In the production of the acrylic (co) polymer (A), a method well known to those skilled in the art, such as radical copolymerization of the above-mentioned acrylic acid alkyl ester and a polar monomer component in an organic solvent, can be used. Can be manufactured.

Examples of the organic solvent used in the radical copolymerization include aromatic hydrocarbons such as toluene and xylene, esters such as ethyl acetate and butyl acetate, and aliphatic alcohols such as n-propyl alcohol and iso-propyl alcohol. And ketones such as methyl ethyl ketone, acetone, methyl isobutyl ketone and cyclohexanone. As the polymerization catalyst used for radical copolymerization, azobisisobutyronitrile, benzoyl peroxide, di-t-
Butyl peroxide, cumene hydroperoxide and the like are mentioned as specific examples. Further, the polymerization conditions are carried out under conditions well known to those skilled in the art. In the present invention, the content of the polymer component having a weight average molecular weight of 100,000 or less in the acrylic (co) polymer (A) as described above is set to 15% by weight or less, and the content of the polymer component having a weight average molecular weight of 1,000,000 or more is further contained. When the content of the polymer component having a weight average molecular weight of 100,000 or less exceeds 15% by weight, the cohesive strength of the pressure-sensitive adhesive is reduced, and the polymer having a weight average molecular weight of 1,000,000 or more is required. If the content of the component is less than 10% by weight, the adhesive (adhesive) power of the adhesive becomes insufficient,
The object of the present invention cannot be achieved.

As a method for reducing the content of the polymer component having a weight average molecular weight of 100,000 or less to 15% by weight or less,
For example, a method of extracting and removing a low molecular weight polymer having a weight average molecular weight of 100,000 or less by purifying an acrylic (co) polymer obtained by a polymerization treatment with an organic solvent or polymerization conditions (for example, polymerization temperature and time, It can be carried out by a method of controlling the type and amount of the initiator, the method of charging the monomer (such as batch or division), the type and amount of the polymerization inhibitor, and the like, and further, a polymer component having a weight average molecular weight of 1,000,000 or more. As a method for controlling the content of 10% by weight or more, for example, the method of controlling the above polymerization conditions can be performed, but the method is not limited thereto. The weight average molecular weight of the entire acrylic (co) polymer (A) is:
Although it is not particularly limited, it is preferably from 100 to 500,000, more preferably from 500 to 3,000,000. If it is less than 100,000, the cohesive force of the pressure-sensitive adhesive decreases. Shortage is not preferred.

The silane compound (B) having a functional group which reacts 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.

[0013]

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Examples of the amino group-containing silane compound include N-β (aminoethyl) γ-aminopropylmethyldimethoxysilane, N-β (aminoethyl) γ-aminopropyltrimethoxysilane, and 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 that 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, it is also useful to further compound a compound (C) having at least two epoxy groups from the viewpoint of improving the adhesion to the base material. Glycidyl 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-dibromo / neopentyl glycol diglycidyl ether, diglycidyl adipate, diglycidyl o-phthalate, dibromoneopentyl glyco Le diglycidyl ether, polytetramethylene glycol diglycidyl ether, resorcin diglycidyl ether, sorbitol polyglycidyl ether, polyglycerol polyglycidyl ether,
Pentaerythritol polyglycidyl ether, diglycerol polyglycidyl ether, triglycidyl tris (2-hydroxyethyl) isocyanurate, glycerol diligidyl ether, glycerol triglycidyl ether, N, N, N ', N'-tetraglycidyl m-xylene diamine , 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane and the like;
Among them, ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, and trimethylolpropane triglycidyl ether are suitably used, and particularly preferred are compounds having a hydroxyl group, such as sorbitol polyglycidyl ether and polyglycerol polyglycidyl ether. And diglycerol polyglycidyl ether, glycerol diglycidyl ether and the like. 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). Examples of the crosslinking agent (D) include isocyanate compounds, epoxy compounds, aldehyde compounds, amine compounds, metal salts, and metal salts. 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 epoxy compounds include bisphenol A / epichlorohydrin type epoxy resins, 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 compound 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 metal salts, 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 compounds 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 silane compounds) (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), a polyol compound (however, a polyfunctional epoxy compound), a melamine compound, or 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 a polyether polyol, a polyester polyol, a hydroxyl group-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.).

[0027]

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

[0028]

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).

[0030]

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 acrylic (co) polymer (A), the silane compound having a functional group which reacts with an epoxy group (B), and the 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) A polymer (A), a silane compound (B), an epoxy group compound (C), a crosslinking agent (D), an amine compound (E), and a crosslinking assistant (F) are arbitrarily mixed in advance and plurally mixed. 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 strength, and also has an excellent effect of adhesiveness 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.

Then, 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.

[0044]

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 97 parts of ethyl acrylate and 3 parts of acrylic acid were copolymerized in ethyl acetate in the presence of 0.3 parts of benzoyl peroxide,
A polymerization solution having a solid content of 35% was obtained. Next, the polymerization liquid 1000
After adding 3000 parts of heptane and removing the supernatant, the operation of dissolving by adding 650 parts of toluene and removing the supernatant by adding 3000 parts of heptane was repeated 5 times to remove the low molecular weight polymer. To the mixture was added 650 parts of toluene to obtain an acrylic copolymer solution (solid content: 20%) (I).

Next, the operation of adding 420 parts of butane to 500 parts of the obtained acrylic copolymer solution (I) and separating the supernatant was repeated 5 times, and 250 parts of toluene was added to the obtained precipitate, Further, an acrylic copolymer (II) from which a low molecular weight polymer was removed was obtained. To 100 parts of the obtained acrylic copolymer (II), 1.0 part of an isocyanate-based compound Coronate L (manufactured by Nippon Polyurethane Industries, Ltd.) and 3-triethoxysilylpropylsuccinic anhydride (C) (trade name: GF- 20, Wacker-Chemie Gmb
H) (1.0 part) and 2 parts of ethyl acetate were added and mixed well to obtain a pressure-sensitive adhesive composition.

The weight average molecular weight of the acrylic copolymer in the acrylic copolymer solution (I) was 530,000, and the content of the polymer component having a weight average molecular weight of 100,000 or less was about 10%.
The content of the polymer component having a weight average molecular weight of 1,000,000 or more is about 20%, and the weight average molecular weight of the acrylic copolymer (II) is 760,000, and the content of the polymer component having a weight average molecular weight of 100,000 or less is included. The amount is about 5% and the weight average molecular weight is 1
The content of more than one million polymer components was about 35%. 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 (coating thickness after drying 25).
μm), and reciprocated three times with a manual roller according to JIS Z 0237 to obtain a glass plate (surface roughness; Ra = 0.1 μm).
m or less, 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 023 by an apparatus according to B7721
Adhesive strength (kg / 25m
m) was measured. Pulling speed is 200mm / min
Met.

(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-irregular 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, the single transmittance τ (%) and the 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).

Furthermore, 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 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 is 5% or less.
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 The procedure of Example 1 was repeated except that 1.0 part of glycerol diglycidyl ether (D) was added to the pressure-sensitive adhesive composition of Example 1, to obtain a weight average molecular weight of 550,000 and a weight average molecular weight of 10
The content of polymer components having a weight-average molecular weight of 1,000,000 or more is about 15%.
Was obtained, and a pressure-sensitive adhesive composition was similarly obtained using the acrylic copolymer (II), and was evaluated in the same manner.

Example 3 The procedure of Example 1 was repeated, except that the operation of separating the supernatant was performed seven times. The content of the polymer component having a weight average molecular weight of 570,000 and a weight average molecular weight of 100,000 or less was determined. About 1
3%, the content of a polymer component having a weight average molecular weight of 1,000,000 or more is about 22% to obtain an acrylic copolymer (II),
A pressure-sensitive adhesive composition was similarly obtained using such an acrylic copolymer (II), and was similarly evaluated.

Example 4 The procedure of Example 1 was repeated except that the addition amount of heptane was changed to 5000 parts. The content of the polymer component having a weight average molecular weight of 580,000 and a weight average molecular weight of 100,000 or less was about 1
8%, the content of a polymer component having a weight average molecular weight of 1,000,000 or more is about 21% to obtain an acrylic copolymer (II),
A pressure-sensitive adhesive composition was similarly obtained using such an acrylic copolymer (II), and was similarly evaluated.

Example 5 The procedure of Example 2 was repeated except that 1.0 part of polyoxyethylene stearylamine (F) was further added.
A pressure-sensitive adhesive composition having a degree of crosslinking based on the gel fraction of 85% and a weight-average molecular weight of the uncrosslinked polymer of 110,000 was obtained and similarly evaluated.

Example 6 The procedure of Example 2 was repeated, except that 1.0 part of triethylenediamine (E) and 1.0 part of polyoxyethylene stearylamine (F) were further added. A pressure-sensitive adhesive composition having a degree of crosslinking of 83% and a weight-average molecular weight of the uncrosslinked polymer of 100,000 was obtained and evaluated in the same manner.

Comparative Example 1 In Example 1, 3-triethoxysilylpropylsuccinic anhydride (C) (trade name: GF-20, Wacker)
r-Chemie GmbH) was not added, and the cross-linking degree based on the gel fraction was 80%.
Thus, a pressure-sensitive adhesive composition having a weight-average molecular weight of 100,000 of an uncrosslinked polymer was obtained and evaluated in the same manner.

Comparative Example 2 Acrylic copolymer solution (I) of Example 1 [Polymer having a weight-average molecular weight of 530,000, a content of a polymer component having a weight-average molecular weight of 100,000 or less about 20%, and a weight-average molecular weight of 1,000,000 or more] Component Amount of about 20%] Acrylic Copolymer 10
In 0 parts, 1.0 part of an isocyanate-based compound Coronate L (manufactured by Nippon Polyurethane Co., Ltd.) and 3-triethoxysilylpropylsuccinic anhydride (C) (trade names: GF-20, W
1.0 part of Acker-Chemie GmbH) and 10 parts of toluene were added and mixed well to obtain a pressure-sensitive adhesive composition, which was evaluated in the same manner as in Example 1.

Comparative Example 3 The procedure of Example 1 was repeated, except that the operation of separating the supernatant was performed once, and the content of the polymer component having a weight average molecular weight of 700,000 and a weight average molecular weight of 100,000 or less was determined. About 1
An acrylic copolymer (II) having a polymer component having a weight-average molecular weight of 1,000,000 or more at about 0% was obtained at 0%, and the pressure-sensitive adhesive composition was similarly prepared using such an acrylic copolymer (II). A product was obtained and evaluated similarly. Tables 1 to 4 collectively show the evaluation results of the examples and comparative examples.

[0066]

[Table 1] Adhesive physical properties General adhesive strength Cohesive strength Adhesive strength on micro uneven surface (kg / 25 mm) Example 1 1.8 ◎ 〃 ２．０ 22.0 ◎ 〃 ３ 3 1.9 ◎ ◎ 〃 4 1.9 ◎ ◎ 〃 5 1.9 ◎ ◎ 〃 6 1.7 ○ ◎ Comparative Example 1 0.5 × × 〃 20.6 △ △ ３ 30.5 × ×

[0067]

[Table 2] (Size of peeling)Polarizer Phase difference plate Elliptically polarizing plate  Cycle shock cycle shock cycle shockAfter test After test After test After test After test After test Example 1 ○ ○ ○ ○ ○ ○ 〃 2 ◎ ◎ ◎ ◎ ◎ ◎ 〃 3 ○ ○ ○ ○ ○ ○ 〃 4 ○ ○ ○ ○ ○ ○ 〃 5 ◎ ◎ ◎ ◎ ◎ ◎６ 6 ○ ○ ○ ○ ○ ○ Comparative Example 1 × × × × × × 〃2 △ △ × × △ △〃 3 × × × × × × 
 

[0068]

Table 3 (Change in optical properties) Cycle Cycle Shock Before test After test Before test Before test After test Example 1 Polarizer τ 42 41 42 42 V 99.0 99.0 99.0 99.0 Retardation plate RD 400 394 400 390 〃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 400 394 400 392４００4 Polarizing plate τ 42 42 42 41 V 99.0 99.0 99.0 98.0 Retardation plate RD 400 394 400 397 ５5 Polarizing plate τ 42 40 42 41 V 99.0 99.0 99.0 99.0 Retardation plate RD 400 395 400 394 ６6 Polarizer 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)

[0069]

(Changes in optical properties) Cycle Cycle Shock Before test After test Before test Before test After test Comparative Example 1 Polarizer τ 42 41 42 42 V 99.0 99.0 99.0 99.0 Retardation plate RD 400 390 400 390 〃2 polarizing plate τ 42 40 42 41 V 99.0 99.0 99.0 98.0 Retardation plate RD 400 392 400 394 ３3 polarizing plate τ 42 42 42 41V 99.0 99.0 99. 0 98.0 retardation plate RD 400 390 400 392 Note) τ: Single transmittance (%), V: Polarization degree (%), RD: Retardation value (nm)

[0070]

The pressure-sensitive adhesive composition of the present invention contains 15% by weight or less of a polymer component having a weight average molecular weight of 100,000 or less,
Excellent adhesiveness and cohesion because it contains an acrylic (co) polymer containing 10% by weight or more of a polymer component having a weight average molecular weight of 1,000,000 or more and a silane compound having a functional group that reacts with an epoxy group. Excellent adhesiveness to the adherend on the surface with fine irregularities, especially when used for bonding an optical film to a substrate, without causing foaming or peeling of the adhesive and its optical properties even when used for a long time Also does not decrease. 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 method according to claim 1, wherein the content of the polymer component having a weight average molecular weight of 100,000 or less is 15% by weight or less, and the weight average molecular weight is 100% or less.
An acrylic (co) polymer (A) having a content of 10,000 or more polymer components and 10% by weight or more mixed with a silane compound (B) having a functional group that reacts with an epoxy group. Adhesive composition. 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.