JPH11199640A - Hardenable resin composition and polarizing plate using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hardenable resin composition having excellent flexibility and strength, and a polarizing plate using the composition. SOLUTION: This hardenable resin composition is obtained by blending a polymerization initiator (II) into a product (I) derived by reacting (d) a compound having an active hydrogen capable of reacting with an isocyanate group and a polymerizable unsaturated group in a molecule and (e) a diamine compound with an isocyanate group in a urethane-based compound containing at least two isocyanate groups in a molecule obtained by reacting (a) a compound having at least two isocyanate groups in a molecule with (b) a compound having at least two pieces of active hydrogen capable of reacting with an isocyanate group in a molecule for introducing an unsaturated bonding into the component (c) with the component (d) and introducing a crosslinking structure into the component (c) by using the component (e). The polarizing plate is obtained by using the composition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a curable resin composition and a polarizing plate using the same, and more particularly, to a curable resin composition having excellent flexibility and strength and durability using the same. And a polarizing plate having excellent display quality.

[0002]

2. Description of the Related Art In recent years, curable resin compositions have been widely used for the formation of coating films such as paints and for applications such as adhesives. For example, coatings for decorative boards, varnishes for paper, paints for woodworking, etc. , Hard coats, adhesives, resist materials and other applications. Recently, desktop electronic calculators, electronic watches,
A polarizing plate used in a liquid crystal display device such as a word processor, an instrument of a car or a machine is also provided with a layer of the curable resin composition. In particular, since instruments are often used under severe conditions, a polarizing plate having a high degree of polarization having excellent durability such as heat resistance is required. There is also a demand for improvement in the peripheral cracks during cutting, etc.), and various proposals have been made to laminate a resin layer such as a urethane resin or a curable resin on the surface of the polarizing film with the aim of improving such durability. It is being done.

For example, JP-A-53-82433 discloses a polarizing plate provided with a urethane resin layer and a pressure-sensitive adhesive layer, and JP-A-56-80001 discloses a specific urethane. A polarizing plate in which a urethane resin layer is formed by irradiating an active energy ray after applying the prepolymer is described, and the present applicant also applied a specific urethane prepolymer to a polarizing film having a specific moisture content to form a urethane resin. A polarizing plate having a layer formed has been proposed (JP-A-7-92).
324).

[0004]

However, any of the above-mentioned curable resin composition (urethane resin) layers is excellent in that a tough urethane resin layer is formed in the sense of improving the durability of the polarizing plate. However, there are problems such as insufficient heat resistance, moisture resistance, etc., poor curing time and poor productivity, and insufficient flexibility required in the polarizing plate manufacturing process. However, there is still room for improvement in display quality, which is particularly important as a polarizing plate. In the present invention, under such a background, a curable resin composition having excellent flexibility and strength is provided, and further, heat resistance, durability such as moisture resistance, and a polarizing plate excellent in display quality are provided by using the same. The purpose is to provide.

[0005]

The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, have found that
Compound (a) having two or more isocyanate groups and compound (b) having two or more active hydrogens capable of reacting with an isocyanate group in the molecule are reacted, and the compound contains two or more isocyanate groups in the molecule. The isocyanate group of the urethane compound (c) is reacted with a compound (d) having both active hydrogen and a polymerizable unsaturated group capable of reacting with the isocyanate group in the molecule and a diamine compound (e),
(D) introduces an unsaturated bond into (c),
The curable resin composition obtained by blending the polymerization initiator (II) with the product (I) obtained by introducing a crosslinked structure into (c) by (e) has excellent flexibility and strength. The inventors have found that a polarizing plate using the same is excellent in durability and display quality, and have completed the present invention.

According to the present invention, the product (I) contains 2
The compound (a) having two or more isocyanate groups and the compound (b) having two or more active hydrogens capable of reacting with the isocyanate group in the molecule are converted from the active hydrogen of the compound (a) to the active hydrogen of the compound (b). The isocyanate group-containing urethane compound (c) obtained by reacting at a molar ratio exceeding 1 with respect to the compound (d) having both active hydrogen and a polymerizable unsaturated group capable of reacting with an isocyanate group in the molecule. And the diamine compound (e) is preferably a compound obtained by reacting the active hydrogen of (d) and the amino group of (e) with the isocyanate group of (c) at a molar ratio of less than 1 each. In the present invention, it is particularly preferable to form the coating layer by curing by irradiation with active energy rays.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described specifically. As the compound (a) having two or more isocyanate groups in the molecule used in the present invention, ethylene diisocyanate, 1,4-butane diisocyanate, 1,6
Aliphatic diisocyanates such as hexane diisocyanate; alicyclic diisocyanates such as dicyclohexylmethane diisocyanate, cyclohexane diisocyanate and methylcyclohexane diisocyanate;
And aromatic diisocyanates such as 2,6-tolylene diisocyanate, methylene diphenyl diisocyanate, diphenylmethane-4,4 diisocyanate, and m-xylylene diisocyanate; and aromatic triisocyanates such as triphenylmethane triisocyanate. .

The compound (b) having two or more active hydrogens capable of reacting with an isocyanate group in the molecule includes mono-di- or tri-ethylene- or -propylene-glycol, 1,4-butanediol, , 2-bis-
Diols such as (4-hydroxylhexyl) propane, or triol-based polyols such as glycerin, hexanetriol, trimethylolpropane, trimethylolethane, and trimethylolbenzene; adipic acid, succinic acid, phthalic acid, terephthalic acid, and acrylic acid , Polyester polyols which are condensation products of a polycarboxylic acid such as a copolymer of maleic acid with the above polyol; glyceride esters of castor oil or other hydroxylated fatty acids; polyalkylene glycols such as polyethylene glycol and polypropylene glycol. be able to.

The urethane compound (c) containing two or more isocyanate groups in the molecule can be obtained by reacting the compound (a) with the compound (b). It is necessary that the molar ratio of the isocyanate group of (a) to the active hydrogen of the compound (b) be more than 1. The molar ratio of the isocyanate group of the compound (a) to the active hydrogen of the compound (b) is preferably 1.5 / 1 or more, particularly preferably 2/1 or more. Compound (a) isocyanate group is compound (b)
If the molar ratio is less than 1 with respect to the active hydrogen, the urethane compound having a terminal isocyanate cannot be obtained, and the target product cannot be obtained in the next reaction.

Finally, the content of the free isocyanate group in the urethane compound (c) is at least 3% by weight,
Further, it is preferable to control the amount to 7 to 30% by weight. When the content of the free isocyanate group is less than 3% by weight, the compound (d) and the diamine compound (e) having both active hydrogen and a polymerizable unsaturated group capable of reacting with the isocyanate group in a molecule capable of reacting with the free isocyanate group Is undesirably reduced, and the curability is lowered and the flexibility of the final cured product is lowered. The reaction may be carried out using a ketone solvent such as acetone or methyl ethyl ketone or a solvent such as an ester solvent such as ethyl acetate or methyl acetate and stirring at 20 to 150 ° C. for 1 to 12 hours.

In the present invention, the urethane compound (c) containing two or more isocyanate groups in the molecule is then used.
The compound (d) and the diamine compound (e) having both active hydrogen and a polymerizable unsaturated group capable of reacting with the isocyanate group in the molecule are reacted with the isocyanate group of the above to obtain the product (I). In the reaction, it is necessary to introduce an unsaturated bond into (c) by (d) and to introduce a crosslinked structure into (c) by (e).

As the compound (d) having both active hydrogen and a polymerizable unsaturated group capable of reacting with an isocyanate group in the molecule, for example, a compound having a (meth) acryloyl group and a hydroxyl group, specifically, 2-hydroxy Examples include ethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, and 4-hydroxybutyl (meth) acrylate. These can be used alone or in combination of two or more.

As the diamine compound (e), for example,
Aliphatic and alicyclic diamines such as isophoronediamine and 1,6-hexanediamine, m-phenylenediamine, p-phenylenediamine, 4,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl ether, 4,4'- Diaminophenylmethane, 1,3-bis (3-aminophenoxy) benzene, 1,4-bis (3
-Aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 2,2'-bis [4- (4
-Aminophenyl) oxyphenyl] propane, bis [4- (4-aminophenyl) oxyphenyl] sulfone, bis [4- (3-aminophenyl) oxyphenyl] sulfone, polytetramethylene oxide-di-p-
Aminobenzoate, trimethylene-bis (4-aminobenzoate), 2,2 ', 3,3'-tetrachloro-
Aromatic diamines such as 4,4'-diaminodiphenylmethane, 4,4'-diamino-3,3'-diethyl-5,5'-dimethyldiphenylmethane and 3,3'-dichloro-4,4'-diaminodiphenylmethane; Amino-modified silicone at both ends (for example, a compound represented by the following formula 1) and the like. These can be used alone or in combination of two or more.

The reaction order is not particularly limited. For example, the compound (d) is first reacted with the urethane compound (c), then the compound (e) is reacted, or conversely, the compound (e) ) Is reacted first with the urethane compound (c) and then with the compound (d), or a mixture of the compound (d) and the compound (e) is added to and reacted with the urethane compound (c). Etc. are arbitrarily selected.

The reaction may be carried out using a solvent such as a ketone solvent such as methyl ethyl ketone or acetone, or an ester solvent such as ethyl acetate or methyl acetate at 20 to 150 ° C. for 1 to 12 hours. Regarding the reaction molar ratio, it is necessary that the active hydrogen of the compound (d) and the amino group of the compound (e) are each less than 1 with respect to the isocyanate group of the urethane compound (c).

In the reaction molar ratio, compound (d) is 1
Above, the sensitivity is increased but the flexibility is reduced. When the compound (e) is 1 or more, the crosslinking density is reduced and the flexibility is improved, but the sensitivity is lowered and gelation is caused. Does not work. The reaction molar ratio is such that the active hydrogen of the compound (d) and the amino group of the compound (e) are each 0.1 to 10% of the isocyanate group of the urethane compound (c).
It is preferably 0.8, more preferably 0.2 to 0.6.
The molar ratio between the active hydrogen of the compound (d) and the amino group of the compound (e) is not particularly limited, and can be arbitrarily adjusted as long as the above range is satisfied.

When the molar ratio of the active hydrogen of the compound (d) to the amino group of the compound (e) to the isocyanate group of the urethane compound (c) exceeds 1, the free isocyanate groups do not remain finally. On the other hand, if the molar ratio does not exceed 1, free isocyanate groups will remain in the finally obtained product (I), and the active energy ray described later will be used. In addition to curing by irradiation with light, curing by an active hydrogen-containing compound such as a polyol or an amine or moisture can be used in combination.

Particularly, in the present invention, the content of the isocyanate group finally remaining in the product (I) is desirably 10% by weight or less, preferably 1 to 7% by weight. If the content of the isocyanate group exceeds 10% by weight, the pot life becomes too short, the workability becomes poor, and foaming is caused during moisture curing, which is not preferable.

When the above curing by moisture or the like is used in combination, a catalyst can be used for the purpose of accelerating the curing.
Such catalysts include triethylamine, triethylenediamine, N, N, N ', N', N "-pentamethyldiethyltriamine, N, N-dimethylcyclohexylamine, N-methyldicyclohexylamine, N, N,
N ', N'-tetramethylpropylenediamine, N,
Amine catalysts such as N, N ', N'-tetramethylhexamethylenediamine, N-ethylmorpholine, N, N-dimethylmethanolamine, 1,8-diazabicyclo [5,4,0] undecene-7 and Its salt, 1,5-
Diazabicyclo [4,3,0] -5-nonene and a salt thereof, or a metal catalyst such as stannactoate or dibutyltin dilaurate is used.
About 0.01 to 10 parts by weight based on 100 parts by weight of the resin component.

The product (I) thus obtained is mixed with a polymerization initiator (II) to form a curable resin composition. Examples of the polymerization initiator (II) include a thermal polymerization initiator and a photopolymerization initiator, and examples thereof include cobalt octenoate, cobalt naphthenate, manganese octenoate, manganese naphthenate, methyl ethyl ketone peroxide, cyclohexanone peroxide, and cumene hydroperoxide. Oxide, benzoyl peroxide, dicumyl peroxide, t-butyl perbenzoate, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin-n-butyl ether, benzoin phenyl ether, anthraquinone, naphthoquinone, hivaloin ethyl ether, Benzyl ketal,
1,1-dichloroacetophenone, pt-butyldichloroacetophenone, 2-chlorothioxanthone, 2,
2-diethoxyacetophenone, Michler's ketone, 2,
2-dichloro-4-phenoxyacetophenone, 2,2
-Dimethoxy-2-phenylacetophenone, benzophenone, 2-methylthioxanthone, phenylglyoxylate, α-hydroxyisobutylphenone, dibenzosparone, benzophenone-amines (N-methyldiethanol, triethylamine, etc.), benzyldiphenyldisulfide, tetramethylthiuram Monosulfite, azobisisobutyronitrile, dibenzyl, diacetyl, acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2-methyl- [4- (methylthio) phenyl] -2-morphonino-1-propanone,
1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-onemethylbenzoyl formate and the like.

The amount of the polymerization initiator (II) is not particularly limited, but is 0.1 to 15 parts by weight, preferably 0.5 to 10 parts by weight based on 100 parts by weight of the resin component of the product (I). It is preferred that

If necessary, an ethylenically unsaturated monomer may be further added. Such ethylenically unsaturated monomers include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, t-butyl (meth) acrylate, 2-ethylhexyl (meth) Acrylate, n-nonyl (meth) acrylate, cyclohexyl (meth) acrylate, benzyl (meth) acrylate, dicyclopentenyl (meth) acrylate,
2-dicyclopentenoxyethyl (meth) acrylate, methoxyethyl (meth) acrylate, ethoxyethyl (meth) acrylate, butoxyethyl (meth) acrylate, methoxyethoxyethyl (meth) acrylate, ethoxyethoxyethyl (meth) acrylate,
Tetrahydrofurfuryl (meth) acrylate, carbitol acrylate, benzyl acrylate, allyl acrylate, phenoxyethyl acrylate, styrene, vinyltoluene, chlorostyrene, α-methylstyrene, acrylonitrile, vinyl acetate, N-vinylpyrrolidone, acryloxyethyl phosphate , 2-vinylpyridine, 2-ethylhexyl acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl acrylate, ethyl carbitol acrylate, polypropylene glycol diacrylate, polyethylene glycol (# 200, # 400, # 600) diacrylate , 2-hydroxy-3-phenoxypropyl acrylate, 2-acryloyloxyethyl succinic acid, 1,6-hexa Diacrylate, trimethylolpropane triacrylate, EO (ethylene oxide) modified trimethylolpropane triacrylate, methyl triglycol, acryloyl morpholine, 1,9-nonanediol diacrylate, 2-n-
Butyl-2-ethyl-1,3-propanediol diacrylate and the like, among which 1,9-nonanediol diacrylate, 2-n-butyl-2-ethyl-1,3
-Propanediol diacrylate, EO-modified trimethylolpropane triacrylate are preferred. The amount is not particularly limited, but the resin content of the product (I) is 1%.
0.1 to 100 parts by weight, preferably 1 to 100 parts by weight
It is preferably from 50 to 50 parts by weight.

The curable resin composition may contain an organic solvent if necessary. Examples of the organic solvent include ketone solvents such as acetone, methyl ethyl ketone and cyclohexanone, methyl acetate, ethyl acetate and butyl acetate. ,
Ethyl lactate, methoxyethyl acetate, propylene glycol monomethyl ether acetate, ester solvents such as ethylene glycol diacetate, diethyl ether,
Ethylene glycol dimethyl ether, ether solvents such as dioxane, toluene, aromatic solvents such as xylene,
Aliphatic solvents such as pentane and hexane, methylene chloride,
Examples thereof include halogen solvents such as chlorobenzene and chloroform, and alcohol solvents such as isopropyl alcohol and butanol. Furthermore, when used as a paint,
Pigments, fillers, leveling agents, defoamers, thermoplastic resins and the like may be added as additives.

Thus, the curable resin composition of the present invention can be prepared by a known method such as a curtain coater, a roll coater, a flow rotor, spraying, dipping, or the like, by using vinyl chloride, polyethylene terephthalate, polymethacrylate, polycarbonate, nylon (polyamide) or the like. It is applied to base materials such as plastic, wood, metal plate, metal oxide film, glass, ceramics, paper, and concrete, and is cured by irradiation with active energy rays. Examples of the active energy rays include far ultraviolet rays, ultraviolet rays, near ultraviolet rays, ultraviolet rays, X-rays, electromagnetic waves such as γ rays, electron beams, proton rays,
Neutron beams can be used. Above all, a curing method by ultraviolet irradiation is advantageous from the viewpoint of film formation (curing) speed, availability of a radiation irradiation device, and price. Ultraviolet rays as used in the present invention is mainly composed of light in the wavelength range of 150 to 450 nm, and is irradiated using a chemical lamp, a high-pressure mercury lamp, a metal halide lamp, a xenon lamp, or the like.

Since the curable resin composition of the present invention is excellent in flexibility and coating strength, it can be used for various applications such as various coating materials, potting materials, adhesives and the like. Among them, it is particularly preferable to apply the present invention to a polarizing plate using the curable resin composition as a protective layer of a polarizing film.

Hereinafter, the use of the curable resin composition of the present invention for a polarizing plate will be described in detail. The polarizing film used in the present invention is not particularly limited, but is preferably a uniaxially stretched film of a polyvinyl alcohol-based film, and the polyvinyl alcohol is usually produced by saponifying polyvinyl acetate obtained by polymerizing vinyl acetate. It is not necessarily limited to this, and a component which can be copolymerized with vinyl acetate, such as a small amount of unsaturated carboxylic acids (including salts, esters, amides, nitriles, etc.), olefins, vinyl ethers, unsaturated sulfonates, etc. May be contained. Average saponification degree in polyvinyl alcohol is 85 to 10
0 mol%, preferably 98-100 mol%, is practical. Further, any average degree of polymerization of the polyvinyl alcohol of the present invention can be used.

As a method for producing the polarizing film, a stock solution obtained by dissolving polyvinyl alcohol in water or an organic solvent is cast into a film, and the film is stretched and immersed in a solution of iodine or a dichroic dye for dyeing. Alternatively, a method of performing stretching and dyeing at the same time, or dyeing with iodine or a dichroic dye and stretching, followed by treatment with a boron compound may be used.
In addition, there is a method of stretching in a solution of a boron compound after dyeing, and the like can be appropriately selected and used.

As the solvent used for preparing the stock solution, for example, not only water but also dimethyl sulfoxide (D
MSO), polyhydric alcohols such as N-methylpyrrolidone, glycerin, ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, trimethylolpropane,
Amines such as ethylenediamine and diethylenetriamine and mixtures thereof are used.

In the above organic solvent, a small amount, for example, 5 to 30
Water may be contained by weight. The practical concentration of polyvinyl alcohol in the stock solution is 5 to 20% by weight. The undiluted solution of the polyvinyl alcohol film obtained using the solvent is formed by any method such as a casting method and an extrusion method, and the film is formed by a dry / wet film forming method, that is, the solution is formed into a die slit. From the air, or into an inert atmosphere such as nitrogen, helium, or argon, and then into a coagulation bath to form an unstretched film. Alternatively, the film-forming solution discharged from the spinneret may be introduced into a coagulation bath after the solvent is partially dried on a roller or a belt conveyor or the like.

The solvent used for the coagulation bath is miscible with the above-mentioned polyvinyl alcohol solvent, and examples thereof include alcohols such as methanol, ethanol, propanol and butanol, acetone, benzene and toluene. As a method for obtaining a polyvinyl alcohol-based film, a so-called gel film forming method in which a solution of polyvinyl alcohol is introduced into a coagulation bath to form a film, or the like, can also be performed.

The thickness of the raw film is 30 to 10
0 μm is preferable, and more preferably 40 to 90 μm, and 30 μm
If it is less than 100 μm, stretching is difficult. The unstretched polyvinyl alcohol film obtained as described above is then stretched, dyed, and treated with a boron compound. Stretching, dyeing, and boron compound treatment may be performed separately or simultaneously, but in the present invention, it is desirable to carry out uniaxial stretching during at least one of the dyeing step and the boron compound treatment step.

The stretching is preferably performed 3 to 10 times, preferably 3.5 to 6 times in the uniaxial direction. At this time, slight stretching (extending to the extent of preventing shrinkage in the width direction or more) may be performed in the direction perpendicular to the above. It is desirable to select the temperature condition during stretching from 40 to 170 ° C. Further, the stretching ratio may be finally set in the above range, and the stretching operation may be performed not only in one stage but also in any range of the manufacturing process.

The dyeing of the film is performed by contacting the film with a liquid containing iodine or a dichroic dye. Usually, an aqueous solution of iodine-potassium iodide is used, the concentration of iodine is 0.1 to 2 g / l, the concentration of potassium iodide is 10 to 50 g / l, and the weight ratio of iodine / potassium iodide is 20 to 100. Is appropriate. Staining time is 30-500
Seconds are practical. The temperature of the treatment bath is preferably 5 to 50C. A small amount of an organic solvent compatible with water other than the water solvent may be contained. Arbitrary means such as immersion, coating, spraying and the like can be applied as the contact means.

The dyed film is then treated with a boron compound. Boric acid and borax are practical as boron compounds. The boron compound is used in the form of an aqueous solution or a mixed solution of water and an organic solvent at a concentration of about 0.5 to 2 mol / l, and it is practically desirable that a small amount of potassium iodide coexist in the liquid. The treatment method is preferably an immersion method, but of course, a coating method and a spraying method can also be performed. The temperature during processing is 50 ~
The temperature is preferably about 70 ° C., and the treatment time is preferably about 5 to 20 minutes. If necessary, a stretching operation may be performed during the treatment.

Next, the curable resin composition is applied to at least one side of the obtained polarizing film, and irradiated with the above-mentioned active energy rays to form a coating layer (protective layer). In applying the curable resin composition of the present invention to the surface of the polarizing film as described above, a solvent that does not inhibit the polarizing property of the polarizing film, for example, ethyl acetate, butyl acetate, cellosolve acetate, methyl glycol acetate,
Ethylene glycol acetate, methoxybutyl acetate, methyl ethyl ketone, methyl isobutyl ketone,
Dilute to the desired viscosity with cyclohexanone, methylene chloride, toluene, xylene, mineral spirit, cresol, xylenol, furfural, naphtha, etc.
A curable resin composition coating solution is prepared and applied to at least one side of a polarizing film.

In the present invention, before curing by irradiation with active energy rays, the solvent in the coating solution may be volatilized and dried for the purpose of forming a film having no surface tackiness. The drying varies depending on the type of the solvent contained in the coating solution, but is generally 40 to 100 ° C, preferably 50 to 70 ° C. Drying temperature is 40
If the temperature is lower than 0 ° C., sufficient drying is not performed within a short time.
If the temperature is 0 ° C. or higher, the polarizing film is undesirably deformed by heat.

Thus, after curing by irradiation with active energy rays, the polarizing plate of the present invention can be obtained.
The thickness of the finally formed coating layer (protective layer) is 1 to 1
00 μm is preferable, and further preferably 3 to 80 μm,
Particularly, 5 to 60 μm is preferable. The coating layer of the curable resin composition may be formed on one side of the polarizing film, or may be formed on both sides. Compared to a conventional polarizing plate with a cellulose triacetate-based protective film, it is thinner and has higher durability,
A polarizing plate having a polarizing property and excellent in display quality can be obtained.

The polarizing plate of the present invention may be put to practical use with a transparent pressure-sensitive adhesive layer formed on one surface of the polarizing plate, if necessary, by a generally known method. As the pressure-sensitive adhesive layer, acrylates such as butyl acrylate, ethyl acrylate, methyl acrylate, 2-ethylhexyl acrylate and the like and α-monoolefin carboxylic acids such as acrylic acid, maleic acid, itaconic acid, methacrylic acid, Especially those mainly composed of copolymers with crotonic acid (including those to which vinyl monomers such as acrylonitrile, vinyl acetate and styrene are added) do not hinder the polarizing properties of the polarizing film, and Although it is preferable, the present invention is not limited thereto, and any transparent adhesive can be used. For example, a polyvinyl ether-based or rubber-based adhesive may be used.

Further, it is also possible to provide various functional layers on one surface of the polarizing plate (the surface on which the above-mentioned adhesive is not provided). Examples of the functional layers include an anti-glare layer, a hard coat layer, an anti-reflection layer, Examples include a half reflection layer, a reflection layer, a luminous layer, a diffusion layer, an electroluminescence layer, and the like, and it is also possible to use a combination of two or more types. For example, an anti-glare layer and an anti-reflection layer, a luminous layer and a reflection layer, A combination of a light storage layer and a half reflection layer, a light storage layer and a light diffusion layer, a light storage layer and an electroluminescence layer, a half reflection layer and an electroluminescence layer, and the like can be given. However, it is not limited to these.

By providing the above-mentioned various functional layers on the polarizing plate of the present invention, or by providing various kinds of functional layers in the polarizing plate in combination, an optical laminate having more excellent various functions can be obtained. is there.

The polarizing plate of the present invention has excellent durability and polarization characteristics and a very excellent display quality since it has a coating layer made of the above curable resin composition. . In addition, various functional layers can be laminated, and the functions of the various functional layers can be fully exhibited, such as electronic desktop calculators, electronic watches, word processors, liquid crystal display devices such as instruments for automobiles and machinery, sunglasses, and sun protection. It is used for eye glasses, stereo glasses, reflection reduction layers for display elements (CRT, LCD, etc.), medical equipment, building materials, toys, etc., and is particularly useful for liquid crystal display devices such as automobiles and instruments of machinery.

[0042]

The present invention will be specifically described below with reference to examples. In the examples, “parts” and “%” are based on weight unless otherwise specified. Example 1 2,4-tolylene diisocyanate (80%) and 2,6
-A 75% ethyl acetate solution of a urethane prepolymer consisting of a mixture of tolylene diisocyanate (20%) and trimethylolpropane ("Coronate L" manufactured by Nippon Polyurethane Co., Ltd .: isocyanate group / active hydrogen (molar ratio) =
3, free isocyanate group content 13%)
0.3 parts of dibutyltin dilaurate, 30 parts of 2-hydroxyethyl acrylate (active hydrogen in 2-hydroxyethyl acrylate / isocyanate group (molar ratio) in urethane prepolymer = 0.25) and 200 parts of methyl ethyl ketone were added, and nitrogen was added. The mixture was stirred at 60 ° C for 2 hours. To this, 2,2'-bis [4- (4-aminophenyl) oxyphenyl] propane ("BAP" manufactured by Wakayama Seika Kogyo Co., Ltd.)
P ") 60 parts (active hydrogen in 2,2'-bis [4- (4-aminophenyl) oxyphenyl] propane / isocyanate group in urethane prepolymer (molar ratio) = 0.
3) was added, and 15 parts of 2,2-dimethoxy-2-phenylacetophenone ("Irgacure 651" manufactured by Ciba Geigy) and 200 parts of methyl ethyl ketone were further added as a photopolymerization initiator, followed by stirring at 60 ° C. for 2 hours under nitrogen. Thus, a viscous curable resin composition solution was obtained.

A polyethylene terephthalate film (thickness: 38 μm) obtained by subjecting the obtained curable resin composition to release treatment.
It was applied on the top using an applicator, dried at 70 ° C. for 3 minutes in a hot air open, and then irradiated with 800 mj of ultraviolet light (using a cold mirror) under air. Further, at 60 ° C
Immersed in warm water for 30 minutes to obtain a cured film (thickness of 3 after drying).
0 μm). The cured film was measured for strength, Young's modulus, elongation at break, and flexibility as described below.

(Strength, Young's Modulus, Elongation at Break) The cured film was taken out of a polyethylene terephthalate film into a strip (15 mm × 150 mm), and was heated at 20 ° C. and 65%
A tensile test (tensile tester: “Autograph AG-100 Model” manufactured by Shimadzu Corporation) was performed under RH conditions, and the strength at break (kg / cm ² ) and the Young's modulus at 1% elongation (kg / cm) ² ) The elongation at break (%) was measured. The (flexible) cured film is taken out from the polyethylene terephthalate film in a strip shape (15 mm × 150 mm),
The occurrence of cracks when the cured film was bent with a finger from the center was observed and evaluated according to the following criteria.・ ・ ・: No crack was generated. X: Cracks occurred.

The above curable resin composition solution was applied to both sides of the following polarizing film (F-1), dried at 70 ° C. for 3 minutes, and then irradiated with 800 mj of ultraviolet light (using a cold mirror) under air. Then, add this to warm water of 60 ° C for 30 minutes.
After immersion for 5 minutes and drying, a polarizing plate (the thickness of the coating layer (protective layer) was 30 μm on one side) was obtained.

[Production of Polarizing Film (F-1)] The average degree of polymerization was 1700, the degree of saponification was 99.5 mol%, and the thickness was 80 μm.
0.2 g of iodine
/ L, 30 ° C in an aqueous solution consisting of 60 g / l potassium iodide
And then dipped in an aqueous solution (55 ° C.) having a composition of boric acid 60 g / l and potassium iodide 30 g / l, and simultaneously subjected to boric acid treatment for 5 minutes while being uniaxially stretched 4 times. Thereafter, the film was dried at 30 ° C. for 24 hours to obtain a polarizing film (single transmittance: 42.7%, polarization degree: 99.8%).
I got

The following evaluation was performed on the obtained polarizing plate. (Polarization characteristics) The single transmittance (%) and the degree of polarization (%) of the polarizing plate were measured using a high-speed multi-wavelength birefringence measuring apparatus (“R
ETS2000 "). The degree of polarization (%) was calculated by the following equation. _{[(H a -H b) /} (H a + H b)] 1/2 × 100 (%) where transmittance when H _a is a superposition of the two polarizing plates so that the absorption axis overlap ( %), And _Hb is the transmittance (%) when two polarizing plates are overlapped so that the absorption axes are orthogonal to each other.

(Durability) The obtained polarizing plate was 150 mm ×
A 200 mm size punched out so that the light absorption axis is in the 45 degree direction is bonded on a 150 mm × 200 mm size optical glass plate (1.2 mm thick) via a pressure-sensitive adhesive (acrylic adhesive). 2
The two laminate samples were superimposed via liquid paraffin such that their light absorption axes were orthogonal to each other, and the transmittance (%) of light (460 nm) in the vertical direction was measured. The measurement points were the center and the end of the laminate sample, and the end of the laminate sample was evaluated at the center of the long side of the laminate sample at two points 5 mm from the end and averaged. Further, after each of the two laminate samples was allowed to stand at 70 ° C. for 500 hours, the light transmittance was measured in the same manner as described above.

(Display quality) The obtained polarizing plate was 150 mm
A piece punched out to a size of 200 mm with a light absorption axis in the direction of 45 degrees is pasted on a 150 mm x 200 mm size optical glass plate (1.2 mm thick) via a pressure-sensitive adhesive (acrylic adhesive). Two laminated sample samples were prepared and bonded to both sides of a liquid crystal display device (10.4 inch size, TFT type, pixel number VGA) via liquid paraffin so that their light absorption axes were orthogonal to each other. And a liquid crystal display device was produced. The visibility of the liquid crystal display device when the liquid crystal display device was viewed from up, down, left, and right directions was evaluated by 10 monitors. Further, the laminate sample 2
After leaving each of the sheets at 70 ° C. for 500 hours, the above and the visibility were evaluated. The case where 7 or more people judged that the visibility was good was evaluated as ○, and the case where less than 7 people were evaluated as ×.

Example 2 In Example 1, 50 parts of 2-hydroxyethyl acrylate (active hydrogen in 2-hydroxyethyl acrylate / isocyanate group in urethane prepolymer (molar ratio) = 0.43), 2,2 80 parts of '-bis [4- (4-aminophenyl) oxyphenyl] propane ("BAPP" manufactured by Wakayama Seika Kogyo Co., Ltd.) (2,2'-bis [4-
(4-aminophenyl) oxyphenyl] active hydrogen in propane / isocyanate group (molar ratio in urethane prepolymer = 0.40) was replaced with a viscous curable resin composition solution. Obtained. The obtained curable resin composition was evaluated in the same manner as in Example 1. Further, in the same manner as in Example 1, the same evaluation was performed using the curable resin composition for the polarizing film (F-1).

Example 3 In Example 1, 2-hydroxyethyl acrylate was replaced with 4-hydroxybutyl acrylate, and 2,2'-bis [4- (4-aminophenyl) oxyphenyl] propane (manufactured by Wakayama Seika Kogyo Co., Ltd.) “BAPP”) with bis [4-
(4-Aminophenyl) oxyphenyl] sulfone ("BAPS" manufactured by Wakayama Seika Kogyo Co., Ltd.) was carried out in the same manner to obtain a viscous curable resin composition solution. The obtained curable resin composition was evaluated in the same manner as in Example 1. Further, in the same manner as in Example 1, the same evaluation was performed using the curable resin composition for the polarizing film (F-1).

Comparative Example 1 The procedure of Example 1 was repeated, except that 2,2'-bis [4- (4-aminophenyl) oxyphenyl] propane ("BAPP" manufactured by Wakayama Seika Kogyo Co., Ltd.) was not added. ,
A viscous curable resin composition solution was obtained. The obtained curable resin composition was evaluated in the same manner as in Example 1. Further, in the same manner as in Example 1, the same evaluation was performed using the curable resin composition for the polarizing film (F-1).

Comparative Example 2 The procedure of Example 1 was repeated except that no 2-hydroxyethyl acrylate was added. However, the composition was not photosensitive and a curable resin composition could not be obtained. Example,
Table 1 shows the results of the comparative example.

[0054]

Table 1 Example 1 Example 2 Example 3 Comparative Example 1 Strength (kg / cm ² ) 800 750 700 800 Young's modulus (kg / cm ² ) 29000 27000 25000 29000 Elongation at break (%) 6 6 7 2 Flexibility ○ ○ ○ × Polarization characteristics τ (%) 41.1 41.0 41.0 40.9 V (%) 99.1 99.2 99.1 99.1 Durability Initial center (%) 1.6 1.6 1.6 1.6 Edge (%) 1.6 1.6 1.6 1.6 70 ° C 500 center ( %) 2.0 2.0 2.0 After 2.0 hours End (%) 2.2 2.3 2.2 2.2 Initial display quality ○ ○ ○ ○ 70 ℃ 500 ○ ○ ○ ○ After hours

Note) τ: Single transmittance (%) V: Degree of polarization (%)

[0056]

The curable resin composition of the present invention comprises a compound (a) having two or more isocyanate groups in the molecule and a compound (b) having two or more active hydrogens capable of reacting with the isocyanate group in the molecule. A) a compound having an isocyanate group of a urethane-based compound (c) containing two or more isocyanate groups in the molecule, and having both active hydrogen and a polymerizable unsaturated group capable of reacting with the isocyanate group in the molecule. (D) and the diamine compound (e) are reacted,
(D) introduces an unsaturated bond into (c),
The product (I) obtained by introducing a crosslinked structure into (c) by (e), specifically, a compound (a) having two or more isocyanate groups in a molecule, an isocyanate group in a molecule, In a molecule obtained by reacting the compound (b) having two or more active hydrogens capable of reacting so that the molar ratio of the isocyanate group of (a) to the active hydrogen of (b) is more than 1 A compound (d) having both active hydrogen capable of reacting with an isocyanate group and a polymerizable unsaturated group in a molecule and a diamine compound (e) are added to a urethane compound (c) containing two or more isocyanate groups, A) a polymerization initiator (II) is blended with a product (I) obtained by reacting the active hydrogen of (d) and the amino group of (e) in a molar ratio of less than 1 with respect to the isocyanate group of (a). For,
Since it contains the polymerization initiator (II), it has excellent flexibility and coating film strength, and can be used for various applications such as various coating materials, potting materials, adhesives and the like.

In particular, the present invention is useful for a polarizing plate, and the curable resin composition is applied to at least one side of a polarizing film to form a coating layer, thereby obtaining polarizing characteristics, durability, and the like. A polarizing plate having excellent flexibility and excellent display quality can be obtained. In addition, various functional layers can be laminated, and the functions of the various functional layers can be fully exhibited, such as electronic desktop calculators, electronic watches, word processors, liquid crystal display devices such as instruments for automobiles and machinery, sunglasses, and sun protection. It is used for eye glasses, stereo glasses, reflection reduction layers for display elements (CRT, LCD, etc.), medical equipment, building materials, toys, etc., and is particularly useful for liquid crystal display devices such as automobiles and instruments of machinery.

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[Procedure amendment]

[Submission date] December 18, 1998

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0013

[Correction method] Change

[Correction contents]

As the diamine compound (e), for example,
Aliphatic and alicyclic diamines such as isophoronediamine and 1,6-hexanediamine, m-phenylenediamine, p-phenylenediamine, 4,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl ether, 4,4'- Diaminophenylmethane, 1,3-bis (3-aminophenoxy) benzene, 1,4-bis (3
-Aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 2,2'-bis [4- (4
-Aminophenyl) oxyphenyl] propane, bis [4- (4-aminophenyl) oxyphenyl] sulfone, bis [4- (3-aminophenyl) oxyphenyl] sulfone, polytetramethylene oxide-di-p-
Aminobenzoate, trimethylene-bis (4-aminobenzoate), 2,2 ', 3,3'-tetrachloro-
Aromatic diamines such as 4,4'-diaminodiphenylmethane, 4,4'-diamino-3,3'-diethyl-5,5'-dimethyldiphenylmethane and 3,3'-dichloro-4,4'-diaminodiphenylmethane; Amino-modified silicone at both ends (for example, a compound represented by the following formula 1) and the like. These can be used alone or in combination of two or more.

Embedded image

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0019

[Correction method] Change

[Correction contents]

When the above curing by moisture or the like is used in combination, a catalyst can be used for the purpose of accelerating the curing.
Such catalysts include triethylamine, triethylenediamine, N, N, N ', N', N "-pentamethyldiethyltriamine, N, N-dimethylcyclohexylamine, N-methyldicyclohexylamine, N, N,
N ', N'-tetramethylpropylenediamine, N,
Amine catalysts such as N, N ', N'-tetramethylhexamethylenediamine, N-ethylmorpholine, N, N-dimethylmethanolamine, and 1,8-diazabicycle
B [5,4,0] -7-undecene and salts thereof, 1,5
-Diazabicyclo [4,3,0] -5-nonene and salts thereof, or metal catalysts such as stannactoate and dibutyltin dilaurate are used, and the amount of addition is determined based on the amount of the product (I)
Is about 0.01 to 10 parts by weight based on 100 parts by weight of the resin component.

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0035

[Correction method] Change

[Correction contents]

Next, the curable resin composition is applied to at least one side of the obtained polarizing film, and irradiated with the above-mentioned active energy rays to form a coating layer (protective layer). In applying the curable resin composition of the present invention to the surface of the polarizing film as described above, a solvent that does not inhibit the polarizing property of the polarizing film, for example, ethyl acetate, butyl acetate, cellosolve acetate, methyl glycol acetate,
Ethylene glycol acetate, methoxybutyl acetate, methyl ethyl ketone, methyl isobutyl ketone,
Dilute to the desired viscosity with cyclohexanone, methylene chloride, toluene, xylene, mineral spirit, cresol, xylenol, furfural , naphtha, etc.
A curable resin composition coating solution is prepared and applied to at least one side of a polarizing film.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI // B05D 7/24 302 B05D 7/24 302T C08G 18/67 C08G 18/67 (72) Inventor Naotoshi Yamamoto Muroyama, Ibaraki-shi, Osaka 2-13-1, Nippon Gosei Chemical Industry Co., Ltd. Central Research Laboratory

Claims (4)

[Claims] 1. A compound obtained by reacting a compound (a) having two or more isocyanate groups in a molecule with a compound (b) having two or more active hydrogens capable of reacting with an isocyanate group in a molecule. Compounds (d) and diamine compounds (e) having both active hydrogen and polymerizable unsaturated groups capable of reacting with the isocyanate group in the molecule to the isocyanate group of the urethane compound (c) containing two or more isocyanate groups. The reaction is carried out, and an unsaturated bond is introduced into (c) by (d), and a polymerization initiator (II) is blended with a product (I) obtained by introducing a crosslinked structure into (c) by (e). A curable resin composition characterized by comprising: 2. The product (I) comprises a compound (a) having two or more isocyanate groups in the molecule and a compound (b) having two or more active hydrogens capable of reacting with the isocyanate group in the molecule. And a urethane compound (c) containing two or more isocyanate groups in a molecule obtained by reacting the isocyanate groups of (a) with the active hydrogen of (b) in a molar ratio exceeding 1 The compound (d) having both active hydrogen capable of reacting with an isocyanate group and a polymerizable unsaturated group in the molecule and the diamine compound (e) are reacted with the active hydrogen of (d) and (e) with respect to the isocyanate group of (c). )
2. The curable resin composition according to claim 1, wherein the amino groups are each obtained by reacting at a molar ratio of less than 1. 3. The curable resin composition according to claim 1, wherein the composition is cured by irradiation with active energy rays to form a coating layer. 4. A polarizing plate comprising the curable resin composition according to claim 1, applied to at least one surface of a polarizing film, and a coating layer formed.