JP2002220408A - Photopolymerizable composition and color filter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photopolymerizable composition with high sensitivity which dose not cause the problems of discoloration by heat treatment and therefore which can form a color filter having high transmittance and excellent image characteristic at high precision and to provide a color filter having excellent characteristics in which the image formation is performed by using the composition. SOLUTION: The composition contains a compound having an ethylenically unsaturated double bond and a photopolymerization initiator. The initiator contains (a) a compound represented by the formula (I) [Ra and Rb are each independently a 1-20C chain or cyclic alkyl group or alkenyl group which may be substituted, or they form a ring to condensate with a ring B by binding with a ring B-constituting carbon directly or through -O-, -S- or -NH-, or they may form a ring by binding through -O-, -S- or -NH-; the ring B is a benzene ring which may have a substituted group other than a ring A and -NRaRb; the ring A is a nitrogen-containing aromatic ring which may have a substituted group other than the ring B; n is 1, 2 or 3], (b) a hexaarylbiimidazole compound and (c) a thioxanthone compound.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photopolymerizable composition suitable for producing an optical color filter used for a liquid crystal display device, a solid-state image pickup device, a camera, and the like, and a production process using the photopolymerizable composition. Related color filters. Specifically, a photopolymerizable composition capable of forming a color filter having high sensitivity and no discoloration due to heat treatment, and thus having a high transmittance and excellent image characteristics, and a production process using the photopolymerizable composition. Related color filters.

[0002]

2. Description of the Related Art A color filter used for a liquid crystal display device or a solid-state imaging device is formed on a transparent substrate such as glass by a dyeing method, a printing method, an electrodeposition method, or a pigment dispersion method. Are formed.

Among these various production methods, in recent years, in the production of a color filter for a liquid crystal display device, a production method using a photosensitive resin in which a pigment is dispersed (pigment dispersion) is preferred because of high productivity and excellent fine processing. Law) is the mainstream. In the pigment dispersion method, for example, a composition in which a pigment is dispersed in a photosensitive resin is applied on a transparent substrate such as glass, and the formed coating film is exposed to radiation through a photomask,
The unexposed portion is removed by a developing process to form a pattern.

By the way, as a color liquid crystal display device,
A transmissive color liquid crystal display device in which a light source (backlight) is provided on the back surface of the device and the display is performed by the transmitted light is generally used, and a color filter is composed of three primary colors of red (R), green (G) and blue (B). An additive color mixture type is used.

In recent years, color liquid crystal display devices have rapidly been applied to monitors in addition to conventional notebook personal computers, and color filters are required to have higher brightness and higher color purity. .

It is necessary to provide an ITO electrode on the surface of a color filter for a liquid crystal display device. In this electrode forming step, the electrode is exposed to a high temperature of about 200 ° C. or more. In addition, it is exposed to a high temperature of 200 ° C. or more during the formation of the alignment film. However, when a material having poor heat resistance is used as a material for forming the pixels of the color filter, there is a problem that the image turns yellow after such a high-temperature process, and the color purity is reduced.

That is, for example, Japanese Patent Application Laid-Open No. 8-292573 discloses hexaarylbiimidazole and an aromatic mercapto compound as a photopolymerization initiator system for a photopolymerizable composition, and thioxanthone, benzophenone, acetophenone and the like as required. It is described that a photopolymerizable composition having excellent photosensitive properties can be obtained by using a sensitizer in combination.

However, when an aromatic mercapto compound such as 2-mercaptobenzthiazole is used for forming an image on a color filter, it is yellowed by oxidation of a thiol group or the like by heating, thereby lowering the transmittance in the near ultraviolet region. , Especially blue transmittance.

[0009]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned conventional problems, and is capable of forming a color filter having high sensitivity and no image discoloration due to heat treatment, and having high transmittance and excellent image characteristics with high precision. It is an object of the present invention to provide a novel photopolymerizable composition and a high-performance color filter on which an image is formed using the photopolymerizable composition.

[0010]

According to the present invention, there is provided a photopolymerizable composition comprising a compound having an ethylenically unsaturated double bond and a photopolymerization initiator system. Is (a) a compound represented by the following general formula [I],
It is characterized by containing (b) a hexaarylbiimidazole compound and (c) a thioxanthone compound.

[0011]

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That is, the present inventors have made intensive studies to achieve the above object, and as a result, it has been known that they are used as sensitizers instead of aromatic mercapto compounds conventionally used as accelerators. High sensitivity is obtained by using the compound of the above general formula [I] as an accelerator, and an image (pixel) formed by using a composition containing the compound does not yellow even by heat treatment. It has been found that a high transmittance can be obtained, and the present invention has been achieved.

That is, in the photopolymerizable composition of the present invention, (a) a compound of the general formula [I] (hereinafter referred to as “(a)” which is generally used as a near-ultraviolet sensitizer as a photopolymerization initiator system. ) Component), (b) a hexaarylbiimidazole-based compound as a radical generator (hereinafter sometimes referred to as "component (b) component"), and (c).
By using a thioxanthone-based compound as a near-ultraviolet sensitizer (hereinafter sometimes referred to as “component (c)”), high sensitivity can be achieved without impairing heat resistance.

In the present invention, the component (a) is replaced with the component (b)
When used in combination with the component and the component (c), the function as an accelerator due to the alkylamino group of the component (a) is effectively exhibited. In addition, instead of an accelerator which is easily oxidized by heat, such as 2-mercaptobenzthiazole, the component (a) which is relatively stable to heat is used as an accelerator, thereby preventing yellowing due to heating of an image and achieving high transmittance. Rate can be realized.

The "photopolymerization initiator system" in the present invention
The term means a compound or a group of compounds that generate a radical that polymerizes an ethylenically unsaturated double bond group upon irradiation with ultraviolet light. Specifically, a radical generator that generates radicals by ultraviolet light, a sensitizer that promotes radical generation by passing energy and electrons obtained by absorbing ultraviolet light to the radical generator, and other compounds are attracted. Accelerators which have hydrogen which can be easily removed and which themselves become radicals and promote the initiation of polymerization can be cited, but may contain other components effective for the function of the photopolymerization initiator system described above.

The photopolymerizable composition of the present invention preferably further contains a binder resin and a pigment.

The color filter of the present invention has an image formed using such a photopolymerizable composition of the present invention.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.

In the present specification, when an alkyl group, an alkenyl group, an alkoxy group, or the like is in the form of a chain, it may be linear or branched (that is, both linear and branched ones are included. ).

First, each component of the photopolymerization initiator system of the photopolymerizable composition of the present invention will be described.

[Photopolymerization Initiator System] (a) Component The component (a) is a compound represented by the above general formula [I]. In the above general formula [I], the substituents ^Ra and ^Rb are the same. However, they may be different, but are preferably the same for synthesis reasons. Examples of the substituent which the alkyl group or the alkenyl group of R ^a and R ^b may have include the following.

C6 to C6 such as phenyl and naphthyl
An aryl group of 14; an alkoxy group having 1 to 10 carbon atoms such as a methoxy group, an ethoxy group or a butoxy group; An aromatic heterocyclic group which is a ring; a hydroxyl group.

When R ^a and / or R ^b are bonded to each other or independently bonded to ring B to form a ring, ring B and R ^a and R ^b have the following structure, for example. . In addition, the hydrogen atom in the following structures may be substituted by a C1-C6 alkyl group.

[0024]

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When R ^a and R ^b are in the form of a chain, they are preferably straight-chain rather than branched.

R ^a and R ^b are particularly preferably an unsubstituted alkyl group having 1 to 4 carbon atoms, or a case where R ^a and R ^b are bonded to ring B to form a julolidine ring.

As the substituent which ring B may have,
For example, the following are mentioned.

Alkyl groups having 1 to 6 carbon atoms such as methyl group, ethyl group and butyl group; alkoxy groups having 1 to 6 carbon atoms such as methoxy group, ethoxy group and butoxy group; phenoxy group; A cyano group; a nitro group; an amino group; a benzyl group; a carboxyl group; an acetyl group; an optionally substituted aryl group such as a phenyl group or a naphthyl group. Here, examples of the substituent of the aryl group include a halogen atom and an amino group.

As the nitrogen-containing aromatic ring represented by ring A,
For example, a 5-membered ring such as oxazole, thiazole, imidazole, pyridine, pyrimidine, thiadiazole, oxadiazole, triazole, s-triazine or 6-membered ring
A nitrogen-containing aromatic heterocyclic ring having a membered ring, or a ring in which one or two 5- or 6-membered aromatic hydrocarbon rings such as a benzene ring and a naphthalene ring are condensed thereto.

Examples of the substituent which ring A may have include:
For example, the following are mentioned.

An alkyl group having 1 to 10 carbon atoms which may have a substituent, such as a methyl group, an ethyl group and a butyl group;
A phenyl group, an aryl group having 6 to 14 carbon atoms which may have a substituent such as a naphthyl group; oxazole, thiazole, imidazole, pyridine, pyrimidine, thiadiazole, oxadiazole, triazole, s-triazine, etc. A 5- or 6-membered aromatic heterocyclic ring which may have a substituent; an alkoxy group having 1 to 10 carbon atoms such as a methoxy group, an ethoxy group and a butoxy group; an acyl group; a methoxycarbonyl group and an ethoxycarbonyl An alkoxycarbonyl group having 2 to 10 carbon atoms such as a group; a carboxy group; a cyano group;
10 alkenyl groups; phenoxy groups, naphthyloxy groups and other aryloxy groups having 6 to 14 carbon atoms; acryloyloxy groups; halogen atoms such as fluorine and chlorine atoms; formyl groups; methylcarbonyloxy groups and propylcarbonyloxy groups An alkylcarbonyloxy group having 2 to 10 carbon atoms; a nitro group; an alkylthio group having 1 to 10 carbon atoms such as a methylthio group, a propylthio group, and a butylthio group; a phenylsulfonyl group; here,
Examples of the substituent which the alkyl group, the aryl group, and the aromatic heterocyclic group may have include a halogen atom and an amino group.

Specific examples of the component (a) are as follows:
(P-dimethylaminophenyl) benzoxazole,
2- (p-diethylaminophenyl) benzoxazole, 2- (p-dimethylaminophenyl) benzo [4
5] benzoxazole, 2- (p-dimethylaminophenyl) benzo [6,7] benzoxazole, 2,5
-Bis- (p-dimethylaminophenyl) -1,3,4
-Oxadiazole, 2- (p-dimethylaminophenyl) benzothiazole, 2- (p-diethylaminophenyl) benzothiazole, 2- (p-dimethylaminophenyl) benzimidazole, 2,5-bis- (p-dimethyl Aminophenyl) -1,3,4-thiadiazole, 2- (p-dimethylaminophenyl) pyridine, 2
-(P-dimethylaminophenyl) quinoline, 2- (p
-Dimethylaminophenyl) pyrimidine, 2,4,6-
Tris (p-dimethylaminophenyl) -s-triazine and 2- (p-dimethylaminophenyl) -1,3,3
4-triazole and the like.

In the following, the structural formulas of main ones of the above exemplified compounds are shown.

[0034]

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[0035]

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Of these, those in which the nitrogen-containing aromatic ring is benzoxazole, benzo [4,5] benzoxazole or oxadiazole are particularly preferred.

The above compounds are described, for example, in Zh. Obsh
ch. Kim. 32 2617 (1962) and British Patent No. 746,047.

Component (b) The hexaarylbiimidazole compound of component (b) is also called a 2,4,5-triarylimidazolyl dimer, and two imidazoles are linked by one covalent bond. It is a compound having the structure of the following formula.

[0039]

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In the present invention, various isomers of the above compounds can be used.

Here, the aryl group Ar is preferably a phenyl group. The three phenyl groups of Ar may each independently have a substituent, and examples of the substituent of the phenyl group include halogen, an alkyl group such as a methyl group, an alkoxy group such as a methoxy group, and a nitro group. . In particular, a hexaphenylbiimidazole compound in which the ortho position of the phenyl group at the 2-position and the 2'-position is substituted with a halogen atom such as a fluorine atom, a chlorine atom or a bromine atom, a nitro group, and a methyl group is a compound having thermal stability and photoreaction rate This is advantageous from the aspect of the characteristics.

As a specific example of the component (b), 2,2′-
Bis (o-chlorophenyl) -4,4 ′, 5,5′-tetraphenylbiimidazole, 2,2′-bis (o-bromophenyl) -4,4 ′, 5,5′-tetraphenylbiimidazole, 2,2'-bis (o, p-dichlorophenyl) -4,4 ', 5,5'-tetraphenylbiimidazole, 2,2'-bis (o-chlorophenyl)
-4,4 ', 5,5'-tetra (m-methoxyphenyl) biimidazole, 2,2'-bis (o, o'-dichlorophenyl) -4,4', 5,5'-tetraphenylbiimidazole , 2,2'-bis (o-nitrophenyl) -4,4 ', 5,5'-tetraphenylbiimidazole, 2,2'-bis (o-methylphenyl) -4,
4 ', 5,5'-tetraphenylbiimidazole and the like.

These hexaarylbiimidazole compounds are described, for example, in Bull. Chem. Soc. Japan
n, 33, 565 (1960); org. Che
m. , 36 [16] 2262 (1971).

Component (c) The thioxanthone compound of the component (c) means thioxanthone which may have a substituent. Examples of the substituent include a linear or branched alkyl group having 1 to 10, preferably 1 to 4 carbon atoms, and a halogen atom such as a fluorine atom, a chlorine atom or an iodine atom. The position of the substituent is not particularly limited, but is preferably the 2-position and / or the 4-position.

Specifically, thioxanthone; 2-ethylthioxanthone, 2-propylthioxanthone, 2-isopropylthioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone, 2,4- Alkyl-substituted thioxanthone such as methylethylthioxanthone; 2-
And halogenated thioxanthone such as chlorothioxanthone.

Of these, 2-isopropylthioxanthone, 2,4-diethylthioxanthone, or 2
-Chlorothioxanthone.

Other Components In the photopolymerizable composition of the present invention, in order to improve the sensitivity, a self-cleaving type as described below as a photopolymerization initiator system component other than the components (a) to (c) described above, Photopolymerization initiator such as hydrogen abstraction type, sensitizer, accelerator (curing accelerator)
You may use together.

Examples of the self-cleaving photopolymerization initiator include diethoxyacetophenone, 4- (2-hydroxyethoxy) phenyl- (2-hydroxy-2-propyl) ketone, and 2-hydroxy-2-methyl-1-ketone. Phenylpropan-1-one, 1-hydroxycyclohexyl-phenylketone, benzyldimethylketal, α-acyloxime ester (1-phenyl-1,2-propanedione-2- (o-ethoxycarbonyl) oxime),
1- (4-isopropylphenyl) -2-hydroxy-
2-methylpropan-1-one, 2-methyl-2-morpholino (4-thiomethylphenyl) propan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone and the like Acetophenone compounds; benzoin ether compounds such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, and benzoin isobutyl ether; acylphosphones such as 2,4,6-trimethylbenzoyldiphenylphosphine oxide and bisphosphon oxide Oxide compounds and the like can be mentioned.

Examples of the hydrogen abstraction type photopolymerization initiator include benzophenone, 4,4'-dichlorobenzophenone, 3,3 ', 4,4'-tetra (t-butylperoxycarbonyl) benzophenone, o-benzoylbenzoic acid Methyl, hydroxybenzophenone, Michler's ketone (4,4′-dimethylaminobenzophenone), 4-phenylbenzophenone, 4-benzoyl-4′-methyl-diphenylsulfide, 4,4′-diethylaminobenzophenone, 4,4′-dichlorobenzophenone,
Benzophenone compounds such as alkylated benzophenone are exemplified.

Other photopolymerization initiators include, for example, 2
Dicarbonyl compounds such as -ethylanthraquinone, 9,10-phenanthrenequinone, bibenzyl and camphorquinone; 2,2,2-trichloro [1,4 '-(1,
1-dimethylethyl) phenyl] ethanone, 2,2-dichloro-1,4- (phenoxyphenol) ethanone,
α, α, α-tribromomethylphenylsulfone,
2,4,6-tris (trichloromethyl) -triazine, 2,4-trichloromethyl- (4′-methoxyphenyl) -6-triazine, 2,4-trichloromethyl-
(4′-methoxystyryl) -6-triazine, 2,4
-Trichloromethyl- (1 ', 3'-dioxo-5'-
Halogenated compounds which are acid generators such as indanyl) -6-triazine, Irgacure 261 manufactured by Ciba-Geigy
An iron arene complex; a titanocene compound such as Irgacure 784 manufactured by Ciba Geigy; a diphenyl sulfide compound such as Optomer SP150 and SP170 manufactured by Asahi Denka; or 2-benzoylmethylene-3-methylnaphth (1.2d) thiazoline, 1 -Phenyl-1,2-
Propanedione-2- (o-ethoxycarbonyl) oxime, 3,6-bis (2-methyl-2-morpholinopropanol) -9-butylcarbazole, 10-butyl-2-chloroacridone, 9-phenylacridine, An onium salt compound that is a photoacid generator or a photoradical generator may, for example, be mentioned.

Examples of accelerators (curing accelerators) include, for example, triethanolamine, methyldiethanolamine, triisopropanolamine, methyl 4-dimethylaminobenzoate, ethyl 4-dimethylaminobenzoate, isoamyl 4-dimethylaminobenzoate, benzoic acid (2-dimethylamino) ethyl acid, 4-dimethylaminobenzoic acid (n-
Amine compounds such as butoxy) ethyl and 2-ethylhexyl 4-dimethylaminobenzoate; 2-mercaptobenzthiazole, 2-mercaptobenzimidazole,
Aromatic thiol compounds such as 2-mercaptobenzoxazole, 2,5-dimercapto-1,3,4-thiazole, 3-mercaptotriazole, 2-mercapto-4,6-dimethylaminopyridine; N-phenylglycine and derivatives thereof Dialkyl phosphite compounds such as diethyl phosphite; disulfide compounds;

Examples of the sensitizer include benzophenone compounds such as benzophenone; anthraquinone, 2-methylanthraquinone, 2-t-butylanthraquinone,
Anthraquinone compounds such as -chloroanthraquinone; ketocoumarin compounds such as 3-acylcoumarin, 7-diethylamino-3-allylcoumarin, 7-diethylamino-3- (4-diethylaminobenzoyl) coumarin, and 3,3'-carbonylbiscoumarin. Or phthalimide, acylnaphthalene, 2- (acylbutylene) thiazoline, 2- (aroylmethylene) thiazoline and the like.

These may be used alone or in combination of two or more agents having the same function. Further, agents having different functions may be used in combination.

Among these, in order not to impair the feature of the present invention that "an image having a high light transmittance (Y value) is obtained", there is originally no absorption at a wavelength of 400 nm or more, or a small absorption. Oxidation yellowing does not occur due to an agent, accelerator, or heating (good heat resistance), that is, a wavelength of 40
Initiators and accelerators that do not increase the absorption in the region of 0 nm or more, such as initiators and accelerators that do not contain functional groups such as thiols, disulfides, peroxides, and halogen atoms, are preferred.

Examples of such a compound include self-cleaving photopolymerization initiators such as acetophenone compounds, benzoin ether compounds, and acylphosphon oxide compounds.
Benzophenone among the benzophenone-based compounds,
Alkyl benzophenone and the like. Examples of the accelerator include an amine compound and a dialkyl phosphite compound.

Particularly preferably, they are selected from the above-mentioned acetophenone-based compounds, acylsulfone oxide-based compounds and amine-based compounds.

The amount of the compound used in combination with the photopolymerization initiator system according to the present invention varies depending on the absorbance of the compound in the visible light wavelength region, but is usually (a), (b), (c).
Less than or equal to the total weight of the components, preferably (a), (b),
It is 0.5 weight times or less of the total weight of the component (c), more preferably 0.1 weight times or less of the total weight of the components (a), (b) and (c).

Next, other components contained in the photopolymerizable composition of the present invention will be described.

The photopolymerizable composition of the present invention comprises, as an essential component, a compound having at least one ethylenically unsaturated double bond (hereinafter referred to as "ethylenic compound") in addition to the above-mentioned photopolymerization initiator system. And more preferably a binder resin and a pigment.

[Ethylenic Compound] The ethylenic compound is not particularly limited, and is preferably a monomer which is usually used in a photopolymerizable composition as in the present invention and is cured by the action of a photopolymerization initiator system. As the monomer, any monomer that undergoes radical polymerization by the action of a radical generated by the photopolymerization initiator system can be used. Representative examples of such a monomer include a monomer having an ethylenic double bond, and more specifically, isobutyl acrylate, t-butyl acrylate, lauryl acrylate, cetyl acrylate, stearyl acrylate, cyclohexyl acrylate, and isobonyl. Acrylate, benzyl acrylate, 2-methoxyethyl acrylate, 3-methoxybutyl acrylate, ethyl carbitol acrylate, phenoxyethyl acrylate, tetrahydrofuryl acrylate, phenoxy polyethylene glycol acrylate, methoxypropylene glycol acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl Acrylates such as acrylate; 2-acryloyloxyethyl hydrogen phthalate DOO, 2-acryloyloxypropyl hydrogensulfate phthalate, phthalates such as 2-acryloyloxy propyl tetrahydropyran hydrogensulfate phthalate;
Methacrylates such as morpholinoethyl methacrylate; fluoroalkyl (meth) acrylates such as trifluoroethyl (meth) acrylate, tetrafluoropropyl (meth) acrylate, hexafluoropropyl (meth) acrylate and octafluoropentyl (meth) acrylate; hepta Decafluorododecyl acrylate, trimethylsiloxyethyl methacrylate,
1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, 1,9-nonanediol diacrylate, neopentyl glycol diacrylate, tetraethylene glycol diacrylate, tripropylene glycol diacrylate, propylene glycol diacrylate, etc. Diacrylates; glycerin methacrylate acrylate, hisphenol A, ethylene oxide adduct diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, trimethylolpropane ethylene oxide added triacrylate, glycerin propylene oxide added triacrylate Acrylate, trisacryloyloxyethylene phosphate, Pentaerythritol hexaacrylate, novolak epoxy acrylate modified product, modified product of acrylic acid and anhydrides of novolac epoxy, N
-Vinylpyrrolidone, N-vinylcaprolactam, acrylated isocyanurate, dipentaerythritol monohydroxypentaacrylate, urethane acrylate, unsaturated polyester acrylate and the like. Among these monomers, acrylic monomers, particularly acrylic monomers having three or more ethylenic double bonds are preferred. These monomers are used alone or in combination.

[Binder Resin] The binder resin is not particularly limited as long as it is a polymer compound having a coating film forming ability, and specific examples include the following compounds.

1) Polyolefin polymer Polyethylene, polypropylene, polyisobutylene, etc. 2) Diene polymer Polybutadiene, polyisoprene, etc. 3) Polymer having a conjugated polyene structure Polyacetylene polymer, polyphenylene polymer, etc. 4) Vinyl polymer polyvinyl chloride, polystyrene , Vinyl acetate, polyvinyl alcohol, polyacrylic acid, polyacrylic acid ester, polyacrylamide, polyacrylonitrile, polyvinyl phenol, etc. 5) polyether polyphenylene ether, polyoxirane, polyoxetane, polytetrahydrofuran, polyether ketone,
6) phenolic resin novolak resin, resol resin, etc. 7) polyester polyethylene terephthalate, polyphenolphthalein terephthalate, polycarbonate, alkyd resin, unsaturated polyester resin, etc. 8) polyamide nylon-6, nylon-66, water-soluble 9) Polypeptides Gelatin, casein, etc. 10) Epoxy resins and their modified products Novolak epoxy resins, bisphenol epoxy resins, novolak epoxy acrylates and modified resins with acid anhydrides, etc. 11) Others Polyurethanes, polyimides, melamine resins , Urea resin,
Polyimidazole, polyoxazole, polypyrrole,
Polyaniline, polysulfide, polysulfone, celluloses, etc.

Among these resins, those having a carboxyl group or a phenolic hydroxyl group in the side chain or main chain of the resin, if the composition contains such a resin, the alkali development is required in the production of a color filter. Because it is possible, it is preferable from the viewpoint of pollution prevention. In particular, a resin having a carboxyl group, such as an acrylic acid (co) polymer, a styrene / maleic anhydride resin, and an acid anhydride-modified resin of novolak epoxy acrylate is preferable because of high alkali developability. Further, acrylic resins are preferred because of their excellent developability, and various copolymers can be obtained by selecting various monomers, and therefore are more preferred from the viewpoint of performance and production control.

Examples of the acrylic resin having a carboxyl group include monomers having a carboxyl group such as (meth) acrylic acid, (anhydride) maleic acid, crotonic acid, itaconic acid, and fumaric acid, and styrene, α-methylstyrene, ) Methyl acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, vinyl acetate, acrylonitrile, (meth) acrylamide, glycidyl (meth) acrylate, allyl Glycidyl ether, glycidyl ethyl acrylate, glycidyl ether crotonic acid, (meth) acrylic chloride, benzyl (meth) acrylate, hydroxyethyl (meth) acrylate, N-methylolacrylamide, N, N-dimethylacrylamide , N- methacryloyl morpholine, N, N- dimethylaminoethyl (meth) acrylate, N, N- dimethylaminoethyl acrylamide, polymers obtained by copolymerizing comonomers such.
Among them, preferred is an acrylic resin containing at least (meth) acrylic acid or (meth) acrylic acid alkyl ether as a constituent monomer, and more preferred is an acrylic resin containing (meth) acrylic acid and styrene.

These resins can also have an ethylene double bond added to the side chain. By imparting a double bond to the resin side chain, the photocurability is enhanced, so that the resolution and adhesion can be further improved, which is preferable. Examples of the synthetic means for introducing an ethylenic double bond include, for example, Japanese Patent Publication No. 50-34443 and Japanese Patent Publication No. 50-503444.
No. 4, publication No. 4, etc., and the like. Specific examples include a method in which a compound having a glycidyl group, an epoxycyclohexyl group, and a (meth) acryloyl group in combination with a carboxyl group or a hydroxyl group, an acrylic acid chloride, or the like is used. For example, glycidyl (meth) acrylate, allyl glycidyl ether, glycidyl α-ethyl acrylate, crotonyl glycidyl ether, (iso)
Crotonic acid glycidyl ether, (3,4-epoxycyclohexyl) methyl (meth) acrylate, (meth)
By using a compound such as acrylic acid chloride or (meth) allyl chloride and reacting with a resin having a carboxyl group or a hydroxyl group, a resin having a polymer group in a side chain can be obtained. Particularly, a resin obtained by reacting an alicyclic epoxy compound such as (3,4-epoxycyclohexyl) methyl (meth) acrylate is particularly preferable.

The preferred range of the weight average molecular weight of these acrylic resins measured by GPC is from 1,000 to 100,0
00. If the weight average molecular weight is less than 1000, it is difficult to obtain a uniform coating film, and if it exceeds 100,000, the developability tends to decrease. The preferred content range of the carboxyl group is 5 to 200 in terms of acid value. If the acid value is less than 5, it becomes insoluble in an alkali developer, and if it exceeds 200, the sensitivity may be reduced.

[Pigment] Image of color filter (pixel or black matrix) using the photopolymerizable composition of the present invention.
Is formed, a pigment is further contained. The pigment to be used is not particularly limited, and any pigment that is usually used for a color filter can be used, and examples thereof include pigments having the following pigment numbers.

C. I. Red; 9, 97, 122, 123,
149, 168, 177, 180, 192, 215, 2
16, 217, 220, 223, 224, 226, 22
7, 228, 240 C.I. I. Violet pigments; 19, 23, 29, 30,
37, 40, 50 C.I. I. Blue; 15, 15: 6, 22, 60, 64, 1
5: 1, 15: 4 C.I. I. Green; 7, 36 C.I. I. Black; 7 C.I. I. Yellow; 20, 24, 86, 93, 109, 11
0, 117, 125, 137, 138, 139, 14
7, 148, 153, 154, 166, 168 C.I. I. Orange; 36, 43, 51, 55, 59, 6
1 C. I. Violet; 19, 23, 29, 30, 3
7, 40, 50 C.I. I. Tea; 23, 25, 26

As specific examples, Victoria Pure Blue (42595), Auramine O (41000), Catillon Brilliant Flavin (Basic 13), Rhodamine 6GCP (45160), Rhodamine B (4517)
0), Safranin OK 70: 100 (50240), Erioglaucine X (42080), 120 / Lionol Yellow (21090), Lionol Yellow G
RO (21090), Shimla First Yellow 8G
F (21105), Benzidine Yellow 4T-564D
(21095), Shimla Fast Red 4015
(12355), Lionol Red 7B4401 (15
850), Fast Gen Blue TGR-L (7416
0), Lionol Blue SM (26150), Lionol Blue ES (Pigment Blue 15: 6), Lionologen Red GD (Pigment Red 168), Lionol Green 2YS (Pigment Green 36), etc. The numbers in parentheses in () indicate the color index (CI)).

Among them, the discoloration (yellowing) of the obtained pixels is most conspicuous, and it is the blue pixels that cause a problem. For example, Fasten Blue TGR-L (74160), Lionol Blue SM (26150), Rio Nord Blue E
In the case of a photopolymerizable composition for blue pixels using S (Pigment Blue 15: 6) or the like, the effect of the present invention is most remarkably exhibited.

The above pigments are preferably used by dispersing them in an average particle size of 1 μm or less, preferably 0.5 μm or less.

When the photopolymerizable composition of the present invention contains a pigment, a pigment dispersant may be used if necessary.

The dispersant to be used is not particularly limited, but a polymer dispersant is preferable. For example, Disperse manufactured by BYK
perbyk2000, Disperbyk182, D
isperbyk160, Disperbyk161,
Disperbyk162, Disperbyk16
3, Disperbyk164, Disperbyk1
66; SOLSPERSE 20000, S manufactured by Zeneca
OLSPERSE24000, SOLSPERSE27
000 and SOLSPERSE 28000 (all are trade names).

The photopolymerizable composition of the present invention comprises, as essential components, an ethylenic compound and a photopolymerization initiator system comprising the components (a), (b) and (c) as essential components. The content is usually 40 to 99.9% by weight of the ethylenic compound and 0.1 to 15% by weight of the component (a) of the photopolymerization initiator system in the total weight of the ethylenic compound and the photopolymerization initiator system. ,
Component (b) is 0.5 to 30% by weight, component (c) is 0.1
-15% by weight, and the total of components (a), (b) and (c) is 0.7-60% by weight.

When a binder resin is contained, the total of the binder resin and the ethylenic compound is 40 to 9% by weight in the total weight of the binder resin, the ethylenic compound and the photopolymerization initiator system.
It is preferably about 9.9% by weight, and the weight ratio of the binder resin to the ethylenic compound is preferably 1: 9 to 9: 1.

When the total weight of the ethylenic compound and the photopolymerization initiator system is 100 parts by weight, the pigment is 15 to 2 parts by weight.
The amount of the dispersant is preferably about 5 to 200 parts by weight.

If the amount of the binder resin is less than the above range, it tends to be difficult to form a coating film. If the amount exceeds the above range, the strength of the obtained coating film may be insufficient. If the amount of the ethylenic compound that is cured by the action of the photopolymerization initiator system is less than the above range, it is difficult to obtain a good image because the cross-linking density of the image-exposed image portion is not sufficient, and If it exceeds, the tackiness of the resist film after drying tends to increase and the workability tends to be poor. When the proportion of the pigment is less than the above range, it is difficult to obtain a sufficient color density, and when the proportion exceeds the above range, the pigment dispersion stability, developability, resolution, and coating film adhesion deteriorate. If the proportion of the photopolymerization initiator system is less than the above range, sufficient sensitivity cannot be obtained, and if it exceeds the above range,
In some cases, the initiator may precipitate from the photosensitive solution.

To the photopolymerizable composition of the present invention, in addition to these essential components, a coating improver, a polymerization inhibitor, a plasticizer, a flame retardant and the like can be added. These can be used alone or in combination of several kinds. The content of these optional components may be such that the effect of the present invention is not impaired, and is usually 10% by weight or less based on the total solid content of the photopolymerization initiator system.

The photopolymerizable composition of the present invention is prepared by adding these components to an organic solvent so that the solid content concentration is 5 to 50% by weight, preferably 10 to 40% by weight. You. The organic solvent is not particularly limited as long as it can dissolve or disperse the above-mentioned components and has good handleability. Specifically, methyl cellosolve, ethyl cellosolve, butyl cellosolve, diethylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, methyl ethyl ketone,
Methyl isobutyl ketone, cyclohexanone, toluene, chloroform, dichloromethane, ethyl acetate, methyl lactate, ethyl lactate, methanol, ethanol, propanol, butanol, tetrahydrofuran, and the like are mentioned, and the boiling point is preferably in the range of 100 to 200 ° C. Preferably it is in the range of 120 to 170 ° C.

The photopolymerizable composition of the present invention is produced according to a conventional method. For example, when the ink is used for forming an image of a color filter, that is, when it contains a pigment, an ink is prepared in advance by dispersing a dispersant, a pigment and an organic solvent. The photopolymerizable composition of the present invention can be obtained by further blending a binder resin, an ethylenic compound and a photopolymerization initiator system and mixing them to form a uniform solution.

The pigment is dispersed by a paint conditioner, a sand grinder, a ball mill, a roll mill,
It is preferable to use a stone mill, a jet mill, a homogenizer or the like. Since the pigment is finely divided by such a dispersion treatment, the coating characteristics of the resist can be improved. In general, in this dispersion treatment, it is preferable to use the above-described polymer dispersant as a pigment dispersant because the dispersion stability with time is excellent.

When the pigment is dispersed by a sand grinder, glass beads or zirconia beads having a diameter of 0.1 mm to several mm are preferably used as a medium. Conditions for dispersing are usually a temperature of 0 to 100 ° C, and preferably a temperature of room temperature to 80 ° C. The dispersion time is appropriately adjusted because the proper time varies depending on the composition of the ink (pigment, solvent, dispersant), the size of the sand grinder, and the like.

A binder resin, an ethylenic compound, a photopolymerization initiator system, and an organic solvent are blended and mixed with the ink obtained by the above dispersion treatment to form a uniform solution. Since the photopolymerizable composition is often mixed with a liquid, the obtained photopolymerizable composition is desirably subjected to a filtration treatment with a filter or the like.

Next, a method for manufacturing a pixel using the photopolymerizable composition of the present invention and a color filter having the same will be described.

First, a photopolymerizable composition containing a pigment is applied on a transparent substrate provided with a black matrix using an application device such as a spinner, a wire bar, a flow coater, a die coater, a roll coater, or a spray. This coating film thickness is usually 0.5 to 5 μm. After drying the coating film,
A pixel can be formed by placing a photomask thereon, exposing and developing an image through the photomask, and then heat-curing or light-curing as necessary. If red, green, and blue pigments are used as the pigment, RGB pixels can be formed. This process is repeated for each color to form a color filter.

The transparent substrate used here is not particularly limited, but is, for example, a thermoplastic such as a polyester such as polyethylene terephthalate, a polyolefin such as polypropylene or polyethylene, a polycarbonate, a polymethyl methacrylate or a polysulfone. Examples include a sheet, a thermosetting plastic sheet such as an epoxy resin, a polyester resin, and a poly (meth) acrylic resin, and various glass plates. Particularly, a glass plate and a heat-resistant plastic are preferably used from the viewpoint of heat resistance.

Such a transparent substrate may be subjected to a corona discharge treatment, an ozone treatment, a thin film treatment of various polymers such as a silane coupling agent or a urethane polymer, etc. in order to improve physical properties such as surface adhesiveness. it can.

The thickness of the transparent substrate is 0.05 to 10
mm, particularly preferably in the range of 0.1 to 7 mm. When performing thin film treatment of various polymers, the film thickness is preferably in the range of 0.01 to 10 μm, particularly preferably 0.05 to 5 μm.

The black matrix may be formed by a thin film of a metal or a metal compound such as chromium, or may be formed by using the photopolymerizable composition of the present invention containing a (pseudo) black pigment. . The thickness of the black matrix (the thickness after drying when the photopolymerizable composition is used) is 0.1%.
２2 μm, preferably 0.3-1.5 μm, more preferably 0.5-1 μm, and the light-shielding ratio at a film thickness of 1 μm is preferably 3.0 or more. Although the size of the transparent substrate is not particularly limited, a transparent substrate having a size of several centimeters square to about several hundred centimeters square is usually used as the transparent substrate.

For drying the coating film, a hot plate, an IR oven, a convection oven, or the like can be used.
Preferred drying conditions are 40 to 150 ° C., and the drying time is 10 seconds to 60 minutes.

The light source used for exposure is, for example, a lamp light source such as a xenon lamp, a halogen lamp, a tungsten lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a metal halide lamp, a medium-pressure mercury lamp, a low-pressure mercury lamp, an argon ion laser, a YAG laser, and an excimer. A laser-light source such as a laser and a nitrogen laser. In this case, when only a specific wavelength of the irradiation light is used, an optical filter may be appropriately used.

The developing treatment is not particularly limited as long as it is a solvent capable of dissolving the unexposed resist film.
For example, organic solvents such as acetone, methylene chloride, trichlene, and cyclohexanone are not preferable because they have environmental pollution, harm to humans, and danger of fire. It is preferable to use an alkali developing solution. For example, inorganic alkali agents such as sodium carbonate, sodium hydrogen carbonate, potassium carbonate, potassium hydrogen carbonate, sodium silicate, potassium silicate, sodium hydroxide, potassium hydroxide, or diethanolamine, triethanolamine, and tetraalkylammonium hydroxide salts An aqueous solution containing an organic alkali agent, and, if necessary, a surfactant, a water-soluble organic solvent, a low-molecular compound having a hydroxyl group or a carboxylic acid group, etc. for the purpose of improving image quality, shortening the development time, etc. Is used.

Examples of the surfactant in the developer include an anionic surfactant having a sodium naphthalene sulfonate group or a sodium benzene sulfonate group, a nonionic surfactant having a polyalkyleneoxy group, or a tetraalkyl ammonium group. Examples of the cationic surfactant include water-soluble organic solvents such as ethanol, propyl alcohol, butanol, methyl cellosolve, butyl cellosolve, phenyl cellosolve, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, Propylene glycol, dipropylene glycol, trifluoropropylene glycol, tetrapropylene glycol, ethylene glycol monomethyl ether acetate, propylene glycol monomethyl And the like can be given Teruasetato. Examples of the low molecular weight compound having a hydroxyl group or a carboxy group include 1-naphthol, 2-naphthol, pyrogallol, benzoic acid, succinic acid, and glutaric acid.

The development is usually carried out at a development temperature of 10 to 50 ° C., preferably 15 to 45 ° C., by a method such as immersion development, spray development, brush development, or ultrasonic development.

The formed pixels are preferably subjected to a thermal curing treatment after image formation in order to improve film strength, solvent resistance, alkali resistance and the like. This heat curing treatment is preferably performed at 150 ° C. or more and less than 300 ° C. Heat treatment temperature is 1
If the temperature is lower than 50 ° C., the thermosetting is insufficient, so that problems such as film strength, solvent resistance and alkali resistance tend to occur. If the temperature is higher than 300 ° C., excessive volume shrinkage occurs, and there is a tendency that problems occur in the adhesion to the substrate and the accuracy.

[0096]

Next, the present invention will be described more specifically with reference to Synthesis Examples, Examples and Comparative Examples. However, the present invention is not limited to the following Examples unless it exceeds the gist thereof.

<Synthesis Example (Synthesis of Binder Resin)> Acid Value 2
00, 20 g of a styrene-acrylic acid resin having a molecular weight of 5000 (copolymerization ratio: 60% by weight: 40% by weight), 0.2 g of p-methoxyphenol, 0.2 g of dodecyltrimethylammonium chloride, and 40 g of propylene glycol monomethyl ether acetate were charged into a flask. , (3,
4-epoxycyclohexyl) methyl acrylate7.
6 g was dripped and reacted at a temperature of 100 ° C. for 30 hours.
The reaction solution was reprecipitated in water and dried to obtain a resin. The weight average molecular weight of this resin measured by GPC was 10,000.
When the neutralization titration with KOH was performed, the acid value of the resin was 80 mgKOH / g.

Example 1 and Comparative Examples 1 and 2 A blue resist having the following composition was prepared. First, a binder resin, a pigment (manufactured by Toyo Ink Co., Ltd., Lionol Blue ES), a polymer dispersant and a solvent were mixed and stirred to prepare a mill base. This was dispersed in a paint shaker at room temperature for 4 hours using zirconia beads having a particle size of 0.5 mm to prepare a blue pigment dispersion. Then add the remaining ingredients and add 10
A blue resist was prepared by filtration through a μ membrane filter.

[Composition of Blue Resist] Binder resin (obtained in the above synthesis example) 25 g Ethylene compound (dipentaerythritol hexaacrylate) 15 g Pigment (Lionol Blue ES manufactured by Toyo Ink Co., Ltd.) 20 g Photopolymerization started Component (a) Component: Compound described in Table 1 1g (b) Component: 2,2′-bis (o-chlorophenyl) -4,4 ′, 5,5′-tetraphenylbiimidazole 3g (c) Component : 2 g of diethylthioxanthone having the following structure

[0100]

Embedded image

Polymer Dispersant (Disperbyk 161 manufactured by BYK Chemie) 10 g Solvent (propylene glycol monomethyl ether acetate) 300 g

Each of the prepared blue resists was coated on a glass substrate (trade name “AN63”) so that the dry film thickness became 1.8 μm.
5 "spin-coated on Asahi Glass Co., Ltd.)
Dried for 3 minutes at ° C.

Next, the dried coating film was appropriately exposed to light (200 mj /
cm ² ), 1% by weight of potassium carbonate and 4% by weight of a nonionic surfactant (“Emulgen A-60”)
Shower development was carried out at 23 ° C. using a developing solution comprising an aqueous solution containing Kao Corporation), followed by stopping the development with pure water, followed by rinsing with a water-washing spray to form a blue image. The state of formation of the obtained image was visually observed. Further, the chromaticity of the obtained blue image is determined by a spectrophotometer as Y.
The value was measured (using SB2 light source).

Thereafter, a heat treatment was performed at 230 ° C. for 30 minutes, and the Y value of the same position was measured again.

Table 1 shows the results. Note that the higher the transmittance of the pixel, the larger the Y value.

[0106]

[Table 1]

As is clear from Table 1, the methyl p-dimethylaminobenzoate used in Comparative Example 2 has no or weak image-forming ability with respect to a high-pressure mercury lamp, whereas it was used in Example 1. 2- (p-dimethylaminophenyl)
Benzoxazole and 2-mercaptobenzthiazole used in Comparative Example 1 have good image forming ability.

However, Example 1 using 2- (p-dimethylaminophenyl) benzoxazole had the same Y value before heat treatment as Comparative Example 1 using 2-mercaptobenzthiazole, It is higher than that of Comparative Example 1 after the heat treatment, and it can be seen that 2- (p-dimethylaminophenyl) benzoxazole has a very low heat transmittance due to good heat resistance, so that the decrease in light transmittance after the heat treatment is very small.

A color filter can be manufactured by forming an image on a substrate provided with a black matrix using a resist containing blue, red and green pigments in the same manner as in Example 1.

[0110]

As described in detail above, the photopolymerizable composition of the present invention has excellent image forming ability, excellent heat resistance, and has no problem of discoloration due to heat treatment. With the color filter of the present invention formed by the above method, an image with high light transmittance (especially, blue pixel) can be formed, so that a liquid crystal display device with high brightness can be provided.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G03F 7/028 G03F 7/028 (72) Inventor Hideki Nagasaka 1000 Kamoshidacho, Aoba-ku, Yokohama-shi, Kanagawa Prefecture Mitsubishi Chemical F-term in Yokohama Research Institute, Ltd. (reference) QA03 QA08 QA12 QA13 QA22 QA24 QA42 QB12 QB22 QB24 RA01 RA02 RA03 RA05 RA06 RA07 RA08 RA09 RA10 RA11 RA12 SA05 SA06 SA15 SA16 SA22 SA25 SA26 SA27 SA34 SA54 SA63 SA64 SA65 SA78 SA83 TA03 UA01 UA02 A01A10 A11A10 A10 AA38 AA43 AA68 AA69 AB01 AB02 AB07 AB11 AB17 AB19 AB20 AB21 AB28 AB33 AB37 AB38 AB40 AB41 AC10 AC23 BA27 BA28 DB02 DB36 GA07

Claims (4)

[Claims] 1. A photopolymerizable composition comprising a compound having an ethylenically unsaturated double bond and a photopolymerization initiator system, wherein the photopolymerization initiator system is represented by (a) represented by the following general formula [I]: Compound A photopolymerizable composition comprising (b) a hexaarylbiimidazole compound and (c) a thioxanthone compound. 2. The photopolymerizable composition according to claim 1, further comprising a binder resin. 3. The photopolymerizable composition according to claim 2, further comprising a pigment. 4. A color filter having an image formed by using the photopolymerizable composition according to claim 1. Description: