WO2005103823A1

WO2005103823A1 - Photosensitive composition for black matrix

Info

Publication number: WO2005103823A1
Application number: PCT/JP2005/008270
Authority: WO
Inventors: Satoru Ishigaki; Mina Onishi; Katsumi Murofushi; Katsutoshi Morinaka
Original assignee: Showa Denko K.K.
Priority date: 2004-04-23
Filing date: 2005-04-22
Publication date: 2005-11-03

Abstract

The invention provides a photosensitive composition for a black matrix, comprising binder resin (A) which contains a urethane acrylate compound produced by reaction between an isocyanate compound (a-1) represented by formula (1) and a polyhydroxy compound (a-2), CH2=CH-COO-R-NCO (1), (wherein R represents a hydrocarbon group having 1 to 30 carbon atoms), black-base pigment (B). The composition may further comprise ethylenic unsaturated monomer (C), photopolymerization initiator (D) and organic solvent (E). The mass contents of the components other than organic solvent (E) is 10-40 % for binder resin (A), 25-60 % for black-base pigment (B), 5-20 % for ethylenic unsaturated monomer and 2-25 % for photopolymerization initiator (D). By using the composition, a pattern having a thin film property and a high light-shielding property can be easily formed by a photolithography method, and the composition has sufficient sensitivity, resolution, developability, durability and curing speed.

Description

DESCRIPTION

PHOTOSENSITIVE COMPOSITION FOR BLACK MATRIX

CROSS-REFERENCE TO RELATED APPLICATIONS This is an application filed pursuant to 35 U.S.C. Section 111(a) with claiming the benefit of U.S. provisional application Serial No. 60/567,526 filed May 4, 2004 under the provision of 35 U.S.C. 111(b), pursuant to 35 U.S.C. Section 119(e) (1).

TECHNICAL FIELD The present invention relates to a photosensitive coloring composition for color filters which is used in production of optical color filters used in color televisions, liquid crystal display elements, solid imaging devices, cameras, etc. More particularly, the invention relates to a photosensitive composition for black matrix which is endowed with an excellent light-shielding performance as well as high sensitivity and excellent developability, and a method for enhancing photosensitivity by using the photosensitive coloring composition.

BACKGROUND ART Color filters are typically produced by forming a black matrix on the surface of a transparent substrate such as a glass sheet and a plastic sheet, followed by sequentially forming pixels of three or more different hues such as red (R) , green (G) and blue (B) in a stripe-like pattern, a mosaic pattern, etc. A black matrix is typically provided in a lattice-like, a stripe-like, or a mosaic pattern among the color patterns of R, G, and B, and works to enhance contrast by preventing intermingling of the colors or to prevent mis-operation of a TFT caused by light leakage. Thus, the black matrix must have a high light- shielding performance. Conventionally, black matrices are typically formed from metallic film such as chromium film. In manufacture of a black matrix from such metallic film, metal such as chromium is vapor-deposited on a transparent substrate through a photolithography step, and the formed chromium layer is etched, to thereby produce a thin black matrix with high light-shielding performance. However, the above method is problematic; i.e., these production steps require a long period of time, which leads to low productivity and high costs, and involve environmental problems caused by etching waste water. In addressing the aforementioned problems, there has been extensively studied a technique for forming low-cost, non- polluting black matrices (resin black matrices) by use of a photosensitive resin in which a light-shielding pigment or dye is dispersed. However, resin black matrices also have the below- described drawbacks and have not been employed in practice. In order to develop a light-shielding performance (optical density) of a resin black matrix equivalent to that of a black matrix made from metallic film such as chromium film, the amount of a light- shielding pigment or dye or the film thickness must be increased. In the case where the film thickness is increased, low flatness of a formed black matrix affects the flatness of color pixels of R, G, and B formed on the black matrix. Thus, variation in gap dimensions of a liquid crystal cell and disorder of liquid crystal alignment occur, thereby deteriorating display performance. In addition, problematic breakage of a transparent electrode (ITO film) provided on the color filter occurs. In the case where the amount of a light-shielding pigment or dye is increased (JP-A-1998-300923) , problematic deterioration occurs in terms of sensitivity, developability, resolution, adhesion, etc. of a photosensitive resin (black resist) . Thus, productivity decreases and precision and reliability required for color filters fail to be attained. In other words, employment of resin black matrices in practice is impeded by absence of a photosensitive material which can provide sensitivity, developability, resolution, and adhesion when the material is formed into a thin film of high light-shielding performance. As described above, due to the object imparting a high- sensitive photocurability to a resin composition which is seemingly contradictory, considering that a resin composition has an inherent property a light-shielding property which is a property conflicting with photoreactivity, realization of practical resin black matrices has been difficult.

DISCLOSURE OF THE INVENTION The object of the present invention is to solve the above- mentioned problems, enabling easy formation of a pattern having a thin film property and a high light-shielding property by a photolithography method and production of a resin black matrix of a color filter having sufficient sensitivity, resolution, developability, durability and curing speed with a high precision at low cost. Further, other objects of the present invention are to enhance image quality of color filter and realize non- pollutive black matrix by using resin. As a result of intensive studies, the inventors of the present invention found that a photosensitive composition for a black matrix having high sensitivity and high curing speed can be obtained by using a specific urethane acrylate compound as a binder resin, and thus achieved the present invention. Namely, the present invention relates to a photosensitive composition for a black matrix as described below in 1 to 14. 1. A photosensitive composition for a black matrix, comprising a binder resin (A) and a black-base pigment (B) , the binder resin (A) containing a urethane acrylate compound which is produced by reaction between an isocyanate compound (a-1) represented by formula (1) and a polyhydroxy compound (a-2) CH₂=CH-COO-R-NCO (1) (wherein R represents a hydrocarbon group having 1 to 30 carbon atoms) .

2. The photosensitive composition for the black matrix as described in 1, wherein the polyhydroxy compound (a-2) is at least one compound selected from the group consisting of the following (I) to (V) : (I) a polyester polyol compound; (II) a polycarbonate polyol compound; (III) a polyether polyol compound; (IV) a polyurethane polyol compound; and (V) a homopolyer or copolymer of a hydroxyalkyl (meth) acrylate .

3. The photosensitive composition for the black matrix as described in 1, wherein R in the isocyanate compound (a-1) represents an alkylene group having 1 to 6 carbon atoms .

4. The photosensitive composition for the black matrix as described in 1, wherein the isocyanate compound (a-1) is 2- acryloyloxyethyl isocyanate. 5. The photosensitive composition for the black matrix as described in 1, wherein the urethane acrylate compound has a carboxyl group.

6. The photosensitive composition for the black matrix as described in 1, wherein the black-base pigment (B) is carbon black.

7. The photosensitive composition for the black matrix as described in 1, wherein the binder resin (A) further comprises epoxy (meth) acrylate.

8. The photosensitive composition for the black matrix as described in 7, wherein the epoxy (meth) acrylate resin is a novolak-type epoxy (meth) acrylate resin having a carboxyl group.

9. The photosensitive composition for the black matrix as described in 7, wherein the epoxy (meth) acrylate resin is a cresol novolak-type epoxy (meth) acrylate resin having a carboxyl group. 10. The photosensitive composition for the black matrix as described in 1, further comprising an ethylenic unsaturated monomer (C) .

11. The photosensitive composition for the black matrix as described in 1 or 10, further comprising a photopolymerization initiator (D) .

12. The photosensitive composition for the black matrix as described in 11, further comprising an organic solvent (E) , wherein the other components are contained at the compositional ratio of binder resin (A) :10 to 40 mass %, black-base pigment (B) :25 to 60 mass %, ethylenic unsaturated monomer (C) : 5 to 20 mass % and photopolymerization initiator (D) : 2 to 25 mass %.

13. The photosensitive composition for the black matrix as described in 12, further comprising a polyfunctional thiol (F) , wherein the photopolymerization initiator (D) is contained at 2 to 20 mass % and the polyfunctional thiol (F) is contained at 2 to 20 mass %.

14. The photosensitive composition for the black matrix as described in 12, wherein the content of the organic solvent (E) is adjusted by setting the solid content (the term solid" used herein means all the components other than organic solvent (E) ) to a range of 5 to 50 mass % in preparing the solution of the composition.

DETAILED DESCRPTION OF THE INVENTION Hereinafter, the present invention will be described in detail. The photosensitive composition for black matrix according to the present invention, which is a photosensitive composition comprising at least a binder resin (A) and a black-base pigment (B) , may comprise an ethylenic unsaturated monomer (C) . Further, a polymerization initiator (D) , an organic solvent (E) for the purpose of adjusting concentration and viscosity of the composition and the like may be blended therein. The binder resin (A) to be used in the present invention is characterized by comprising a urethane acrylate compound which is a reaction product of an isocyanate compound (a-1) represented by the following general formula (1) with a polyhydroxy compound (a-

2) . CH₂=CH-COO-R-NCO (1) (In the formula, R represents a hydrocarbon group having from 1 to 30 carbon atoms.) In the present invention, if a different isocyanate compound is used in place of the isocyanate compound represented by the above-described formula (1), sensitivity and curing speed is decreased. In formula (1), R represents a hydrocarbon group having 1 to 30 carbon atoms and an alkylene group having having 1 to 6 carbon atoms is preferable. Specific examples of R having 1 to 6 carbon atoms include methylene group, ethylene group, 1, 2-propylene group, 1, 3-propylene group and 1,4-butylene group. Specific examples of isocyanate compound (a-1) represented by formula (1) include 2-acryloyloxyethyl isocyanate and 4- acryloyloxybutyl isocyanate. The polyhydroxy compound (a-2) to be used in the present invention is a compound having two or more hydroxyl groups in one molecule and is preferably one or more compounds selected from the group consisting of (I) to (V) described below. (I) Polyester polyol compound A polyester polyol compound to be used in the present invention is a compound having two or more hydroxyl groups and one or more ester bonds in one molecule and examples of such a polyester polyol compound include a polyester-type polyol to be obtained by esterification of a polyhydric alcohol with a polybasic acid and polylactone-type diols such as polycaprolactone diol and polybutylolactone diol . As any one of these compounds, a compound synthesized such that a carboxyl group remains or the like can also be used. (II) Polycarbonate polyol compound A polycarbonate polyol compound to be used in the present invention is a compound having two or more hydroxyl groups and one or more carbonate bonds in one molecule and is preferably a compound as represented by formula (2) : HO- (R^O-COOJ_n- (R²-0-COO)_m-R³-OH (2) (In the formula, R¹, R² and R³ each independently represent a linear, branched or cyclic hydrocarbon group having 2 to 30 carbon atoms which may have a hydroxyl group and/or a carboxyl group; and n each independently represent 0 or an integer of from 1 to 100, with a proviso that a sum of m and n is 1 or more . ) It is preferable that the R¹, R² and R³ each independently represent an alkylene group having 2 to 12 carbon atoms. Specific examples of such alkylene groups include ethylene group, tri ethylene group, tetramethylene group, penta ethylen group, hexamethylene group, propylene group, 2, 2-dimethyl-l, 3-propylene group, 1, 2-cyclohexylene group, 1, 3-cyclohexylene group and 1,4- cyclohexhlene group. Such polycarbonate polyols can be obtained by, for example, a reaction between a diaryl carbonate such as diphenyl carbonate and an polyol such as ethylene glycol, tetramethylene glycol, hexamethylene glycol, trimethylol ethane, trimethlylol propane, glycerin and sorbitol . (Ill) Polyether polyol A polyether polyol to be used in the present invention is a compound having two or more hydroxyl groups and one or more ether bonds in one molecule and a known compound can be used. As such polyether polyols, polyalkylene oxide, polyglycerin, phenoxy resin and cellulose or a derivative thereof can be illustrated. The polyalkylene oxide to be used as the polyether polyol in the present invention is a compound having a structure in which two or more alkylene glycols are condensed by dehydration and a known compound can be used. Such polyalkylene oxides can each be produced by a dehydration reaction of the alkylene glycol or ring-opening polymerization of an alkylene oxide. Specific examples of alkylene glycol include ethylene glycol, propylene glycol, 1, 4-butanediol, 1, 3-butanediol, 1, 5-pentanediol, neopentyl glycol, 3-methyl-l, 5-pentanediol, 1, 6-hexanediol and 1, 4-cyclohexane dimethanol. Further, examples of alkylene oxide include ethylene oxide, propylene oxide, trimethylene oxide and tetrahydrofuran. Specific examples of the polyalkylene oxide to be used as polyether polyol according to the present invention include polyethylene glycol, polypropylene glycol, polyethylene glycol/polypropylene glycol copolymer, polytetramethylene glycol and polyhexamethylene glycol. The phenoxy resin to be used as polyether polyol according to the present invention is a polyhydroxy polyether resin obtained by a polyaddition reaction of a bisphenol compound with a bisepoxy compound. Commercially available products can be used. Examples of such a product include EPOTOHTO YP-50, YP-50S (manufactured by Tohto Kasei Co., Ltd.) and UCAR, PKHC and PKHH (manufactured by Union Carbide) . As a phenoxy resin to be used in the present invention, not only the above-described commercially available products but also phenoxy resins having a desired structure which can be obtained by polyaddition reaction of various types of bisphenol compounds with bisepoxy compounds can be used. A bisphenol compound and a bisepoxy compound serving as starting materials of the phenoxy resin are known materials and accordingly, both are commercially available. Examples of commercially available bisphenol compound includes Bisphenol A, Bisphenol S, Bisphenol ^'SH, Bisphenol F and Bisphenol Z (manufactured by Mitsubishi Chemical Corporation) , hydroquinone, resorcin, biphenol, hexafluoroisopropylydene diphenol, dihydroxynaphthalene, tetramethyl biphenol and dicyclopentadiene- odified bisphenol. Further, the bisepoxy compound is a diglycidyl ether compound which derives from the bisphenol compound and epichlorohydrin. Examples of such compounds as using Bisphenol A as a starting material include EPIKOTE 828, EPIKOTE 1001 and EPIKOTE 1004 (trade names; manufactured by Yuka Shell Epoxy K.K.), EPOMIK R-140P and EPOMIK R-301 (trade names; manufactured by Mitsui Chemicals, Inc.) . Examples of cellulose derivatives usable as polyether polyol compound in the present invention include methyl cellulose, ethyl cellulose, carboxymethyl cellulose, hydroxyethyl cellulose, hydroxybutyl cellulose and hydroxypropyl cellulose. Commercially available products can be used as these cellulose derivatives. (IV) Polyurethane polyol compound A polyurethane polyol compound to be used in the present invention has two or more hydroxyl groups and one or more urethane bonds in one molecule. Such a polyurethane polyol compound can be obtained by reacting a polyisocyanate and a polyol by an arbitrary method. In the reaction, an isocyanate compound (a-1) may also be charged to prepare the binder resin (A) . As polyisocyanate, known compounds can be used. Specific examples thereof include diisocyanates such as 2,4-toluenediisocyanate, 2,6-toluene diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, diphenylmethylene diisocyanate, (o, m or p)-xylylene diisocyanate, methylene-bis (cyclohexyl isocyanate), trimethyl hexamethylene diisocyanate, cyclohexane-1, 3-dimethylene diisocyanate, cyclohexane-1, 4-dimethylene diisocyanate and 1,5- naphthalene diisocyanate. These polyisocyanates can be used singly or in combination of two or more types. Example of polyols usable in the present invention include diol compounds such as ethylene glycol, propylene glycol, 1,4- butanediol, 1, 3-butanediol, 1, 5-pentanediol, neopentyl glycol, 3- methyl-1, 5-pentanediol, 1, 6-hexanediol and 1, 4-cyclohexanediol, triol compounds such as glycerin and trimethylol propane and polyol compounds such as pentaerythritol, dipentaerithritol and diglycerin. Further, as polyol compound, a polyol compound having a carboxyl group such as dihydroxyaliphatic carboxylic acid can be used and since alkali developability can be imparted by introducing a carboxylic group into the urethane acrylate compound (A) , such a compound is preferably used. Examples Of such a polyol compound having a carboxyl group include dimethylol propionic acid and dimethlol butanoic acid. These compounds may be used singly or in combination of two or more types. Further, (I) polyester polyol compound described above, (II) polycarbonate polyol compound described above and (III) polyalkylene oxide compound described above can also be used as the polyol compound. (V) Homopolymer or copolymer of hydroxyalkyl (meth) acrylate A homopolymer or copolymer of hydroxyalkyl (meth) acrylate is a polymer obtained by ho opolymerizing or copolymerizing one or more types of hydroxyalkyl (meth) acrylates by an arbitrary method. Examples of such hydroxyalkyl (meth) acrylates used herein include 2-hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydorxybutyl (meth) acrylate, glycerin mono (meth) acrylate, glycerin di (meth) acrylate, trimethylolpropane mono (meth) acrylate, pentaerithritol mono (meth) acrylate, dipentaerithritol mono (meth) acrylate, ditrimethylolpropane mono (meth) acrylate, trimethylolpropane-alkylene oxide adduct-mono (meth) acrylate, 2- hydroxy-3-phenoxypropyl acrylate, polyethylene glycol (meth) acrylate and 6-hydroxyhexanoyloxyethyl (meth) acrylate. Among these (meth) acrylates, 2-hydroxyethyl (meth) acrylate, hydoxypropyl (meth) acrylate and hydroxybutyl (meth) acryalte are preferable and 2-hydroxyethyl (meth) acrylate is particularly preferable. These (meth) acrylates each having a hydroxyl group may be used singly or in combination of two or more types. Other constituents than hydroxyalkyl (meth) acrylates which constitute the copolymer are unsaturated compounds each having a copolymerizability with any one of these hydroxyalkyl (meth) acrylates. Specific examples thereof include alkyl (meth) acrylates such as methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, sec-butyl (meth) acrylate, tert-butyl (meth) acrylate, hexyl (meth) acrylate, octyl (meth) acrylate, isooctyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, decyl (meth) acrylate, lauryl ^' (meth) acrylate and stearyl (meth) acrylate; alicyclic (meth) acrylates such as cyclohexyl (meth) acrylate, bornyl (meth) acrylate, isobornyl (meth) acrylate, dicyclopentenyl (meth) acrylate and dicyclopentenyloxyethyl (meth) acrylate; aromatic (meth) acrylates such as benzyl (meth) acrylate, phenyl (meth) acrylate, phenyl carbitol (meth) acrylate, nonyl phenyl (meth) acrylate, nonyl phenyl carbitol (meth) acrylate and nonyl phenoxy (meth) acrylate; (meth) acrylates each having an amino group such as 2- dimethylaminoethyl (meth) acrylate, 2-diethylaminoethyl (meth) acrylate and 2-tert-butylaminoethyl (meth) acrylate; methacrylates each having a phosphorous atom such as methacryloxyethyl phosphate, bis (methacryloxy ethyl phosphate, methacryloxyethyl phenyl acid phosphate (phenyl P) ; glycidyl (meth) acrylate; allyl (meth) acrylate; and phenoxyethylacrylate . Further, an unsaturated compound having a carboxyl group or an acid anhydride group such as (meth) acrylic acid, itaconic acid, maleic anhydride, itaconic anhydride, polycaprolactone (meth) acrylate, (meth) acryloyloxyethyl phthalate and (meth) acryloyloxyethyl succinate can also be used. The term ^λλ (meth) acrylate" used herein denotes a methacrylate and/or an acrylate. Furthermore, N-vinyl compounds such as N-vinyl pyrrolidone, N-vinyl formamide and N-vinyl acetamide, and vinyl aromatic compounds such as styrene and vinyl toluene can favorably be used. [Urethane acrylate compound] A urethane acrylate compound to be used in the binder resin (A) according to the present invention has an acid value of, preferably 5 to 150 mgKOH/g and, particularly preferably 30 to 120 mgKOH/g. When the acid value is less than 5 mgKOH/g, alkali developability may sometimes be decreased, while, with thee acid value exceeding 150 mgKOH/g, alkali resistance, electric characteristics and the like of the cured film may sometimes be impaired. Further, the term "acid value" as used herein denotes an acid value of a solid content and a value measured in accordance with JIS K0070. A number average molecular weight (value expressed in terms of polystyrene as measured by gel permeation chromatography (GPC) ) of the above-described urethane acrylate compound is generally in the range of from 500 to 100,000 and, preferably from 3,000 to 50,000. When it is less than 500, film strength is remarkably decreased, while, with the number average molecular weight exceeding 100,000, the alkali developability is remarkably decreased. In combination with the urethane acrylate compound, for the purpose of further enhancing photosensitivity of the photosensitive composition according to the present invention, an epoxy (meth) acrylate resin having a carboxyl group can be used in the binder resin (A). An epoxy (meth) acrylate resin having the carboxyl group can be obtained by adding an unsaturated monocarboxylic acid to an epoxy group of an epoxy resin and, then, allowing the resin to react with a polybasic acid anhydride. Examples of epoxy resins usable herein include bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, novolak epoxy resin, (o, , p-) cresol novolak epoxy resins, phenol novolak epoxy resin, naphthol-modified novolak epoxy resin, and halogenated phenol novolak epoxy resin. Of these, carboxylic group-containing epoxy (meth) acryltae resins which are prepared by using as raw materials, novolak-type epoxy resins such as novolak epoxy resin, (o, m, p~) cresol novolak epoxy resins, phenol novolak epoxy resin, naphthol-modified novolak epoxy resin, and halogenated phenol novolak epoxy resin are preferred from the viewpoint of photosensitivity. Among them, (o, m, p-) cresol novolak epoxy resin is particularly preferred from the viewpoint of compatibility to acrylic copolymers used in the present invention. The preferable weight average molecular weight of these epoxy resin as measured through GPC is within a range of 300 to 100,000. When the molecular weight is less than 300, film strength decreases, whereas when the molecular weight exceeds 100,000, the resins tend to cause gelling during addition reaction of an unsaturated monocarboxylic acid, resulting in difficulty in production. Examples of unsaturated monocarboxylic acids used for synthesizing the epoxy (meth) acrylate resins include (meth) acrylic acid, 2- (meth) acryloyloxyethylsuccinic acid, 2- (meth) acryloyloxyethylphthalic acid, (meth) acryloyloxyethylhexahydrophthalic acid, (meth) acrylic acid dimer, itaconic acid, crotonic acid, and cinnamic acid. Of these, acrylic acid is particularly preferred from the viewpoint of high reactivity. Addition of the unsaturated monocarboxylic acid to an epoxy resin can be carried out through any known method. For example, the addition can be carried out in the presence of an esterification catalyst at 50-150 °C. Examples of employable esterification catalysts include tertiary amines such as triethylamine, trimethylamine, benzyldimethyla ine and benzyldiethylamine; and quaternary ammonium salts such as tetramethylammonium chloride, tetraethylammonium chloride, and dodecyltrimethylammonium chloride. The addition amount of unsaturated monocarboxylic acid is preferably 0.5 to 1.2 equivalents, more preferably 0.7 to 1.1 equivalents, based on 1 equivalent of epoxy groups of the epoxy resin. Examples of polybasic acid anhydrides to be added to an epoxy resin to which an unsaturated carboxylic acid has been added include maleic acid anhydride, succinic acid anhydride, itaconic acid anhydride, phthalic acid anhydride, tetrahydrophthalic acid anhydirde, hexahydrophthalic acid anhydride, pyromellitic acid anhidride, trimellitic acid anhydride, and benzophenonetetracarboxylic acid dianhydride. Addition of a polybasic acid anhydride can also be carried out through any known method, and the polybasic acid anhydride can be added continuously under conditions similar to those of addition reaction of an unsaturated monocarboxylic acid. The addition amount of the polybasic acid anhydride is preferably controlled such that the acid value of the resultant resin falls within a range of 10 to 150 mgKOH/g, more preferably 20 to 140 mgKOH/g. When the acid value is less than 10 mgKOH/g, alkali developability becomes poor, whereas when the acid value exceeds 150 mgKOH/g, the development rate excessively increases, resulting in poor practical utility. The amount of the above urethane acrylate compound in binder resin (A) in the present invention is usually 10 mass% or more, preferably 20 mass% or more, and more preferably in a range of from 30 to 90 mass%. The mass ratio of the urethane acrylate compound/the epoxy (meth) acrylate resins in the binder resin (A) in the present invention is preferably in a range of from 30/70 to 90/10 in light of the balance between film strength and photosensitivity, more preferably 40/60 to 85/15. When the ratio of the urethane acrylate is less than 30/70, film strength may decrease, whereas when the ratio of epoxy (meth) acrylate resins is less than 90/10, sufficient photosensitivity cannot be attained. [black-base pigment (B) ] The black-base pigment (B) is a material having a function to shield visible rays and the conventional black-base pigment can be used. Examples of black-base pigments include carbon black, acetylene black, lamp black, carbon nano-tube, graphite, iron black, black iron-oxide pigment, aniline black, cyanine black, and titanium black. Alternatively, three organic pigments of red, green, and blue are mixed to provide a black pigment. Of these, carbon black is preferred from the viewpoint of its light- shielding property and image characteristics. Commercially available carbon black may be employed in the present invention. Here, the term "carbon black" refers to black or grayish black powder generated by incomplete combustion or thermal decomposition of organic matters, which comprises carbon as the main component. The state of the carbon black surface at the micro level may vary depending on the production method thereof. Examples of the method employable for producing carbon black include a channel method, a furnace method, a thermal method, a lamp black method and an acetylene method. In the present invention, any carbon black regardless of the production method may be used without problems . In consideration for the dispersibility and resolution, a preferred particle diameter of the carbon black is in a range of from 5 to 200 nm. If the particle diameter is less than 5 nm, uniform dispersion is difficult to achieve and if it exceeds 200 nm, the resolution will be decreased. A more preferred particle diameter is in a range of from 10 to 100 nm. Specific examples of the carbon black are as follows.. Products of Degussa: Printex 95, Printex 90, Printex 85, Printex 75, Printex 55, Printex 45, Printex 40, Printex 30,

Printex 3, Printex A, Printex G, Special Black 550, Special Black 350, Special Black 250, Special Black 100 and Special Black 4, ; Products of Mitsubishi Chemical Co.:MA7, MA8, MA11, MA100, MA220, MA230, #52, #50, #47, #45, #2700, #2650, #2200, #1000, #990 and #900; Products of Cabot: Monarch 460, Monarch 430, Monarch 280, Monarch 120, Monarch 800, Monarch 4630, REGAL 99, REGAL 99R, REGAL 415, REGAL 415R, REGAL 250, REGAL 250R, and REGAL 330, and BLACK PEARLS 480; and

Products of Colombian Carbon Company: RAVEN 11, RAVEN 15, RAVEN 30, RAVEN 35, RAVEN 40, RAVEN 410, RAVEN 420, RAVEN 450, RAVEN 500, RAVEN 780, RAVEN 850, RAVEN 890H, RAVEN 1000, RAVEN 1020, and RAVEN 1040. The black-base pigment used in the present invention may be a black pigment alone or a mixture of a black pigment and other black-base or inorganic or organic color pigments. The aforementioned carbon black or black pigments may be used in combination with other black-base pigments or inorganic or organic color pigments. However, since light-shielding property and image characteristic of pigments other than carbon black are lower than those properties of carbon black, the blending amount of pigments other than carbon black is naturally limited, [ethylenic unsaturated monomer (C) ] The ethylenic unsaturated monomer (C) can be used in the photosensitive composition for black matrix of the present invention other than the above (A) and (B) . The ethylenic unsaturated monomer (C) is a compound which polymerizes by radicals generated from a photopolymerization initiator upon irradiation with an active light beam. Any of such compounds can be used, and it is preferable that a compound having a boiling point of 150°C or higher be used. Examples of the ethylenic unsaturated monomer (C) include compounds having one ethylenic unsaturated group in one molecule such as 4-tert-butylcyclohexyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentanyloxyethyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, isobornyl (meth) acrylate, ethoxydiethylene glycol (meth) acrylate, methoxytriethylene glycol (meth) acrylate, ethoxydipropylene glycol (meth) acrylate, phenoxyethyl (meth) acrylate, phenoxydiethylene glycol (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, N,N-dimethylaminoethyl (meth) acrylate, N,N- dimethylaminopropyl (meth) acrylamide, N- (meth) acryloylmorpholine, 2- (meth) acryloyloxyethylsuccinic acid, 2- (meth) acryloyloxyethylphthalic acid, 2- (meth) acryloyloxyethyl acid phosphate, N-vinylpyrrolidone and N-vinylcaprolactam; and compounds having at least two ethylenic unsaturated groups in one molecule such as ethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, neopenthyl glycol di (meth) acrylate, 1,6- hexanediol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolethane tri (meth) acrylate, trimethylolpropane-ethylene- oxide-modified tri (meth) acrylate, trimethylolpropane-propylene- oxide-modified tri (meth) acrylate, pentaerythritol di (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate and glycerol di (meth) acrylate. These ethylenic unsaturated monomers may be used singly or in combination of two or more species, [photopolymerization initiator (D) ] The photopolymerization initiator (D) of the present invention is a compound which generates radicals upon excitation by an active light beam and initiates polymerization of ethyleneic unsaturated bonds. The photopolymerization initiator must generate radicals under highly light-shielding conditions. Thus, compounds having high photosensitivity are employed as the initiator. Examples of such photopolymerization initiators include a hexaarylbii idazole compound (I) ; a triazine compound (II) ; an aminoacetophenone compound (III) ; a combination of a sensitizing dye and an organoborate salt compound represented by formula (1) (IV); a titanocene compound (V); and an oxadiazole compound (VI) . Among them, a hexaarylbiimidazole compound (I) ; a triazine compound (II) ; an aminoacetophenone compound (III) ; and a combination of a sensitizing dye and an organoborate salt compound represented by formula (1) (IV) are preferred. Examples of hexaarylbiimidazole compounds (I) include 2, 2 '-bis (o-chlorophenyl) -4, 4 ' , 5, 5' -tetraphenyl-1, 2 '-biimidazole, 2,2 '-bis (o-bromophenyl) -4, 4 ' , 5, 5' -tetraphenyl-1, 2 '-biimidazole, 2, 2 '-bis (o-chlorophenyl) -4, 4' , 5, 5 '-tetra (o, p-dichlorophenyl) - 1,2 '-biimidazole, 2, 2 '-bis (o, p-dichlorophenyl) -4,4' , 5, 5 '-tetra (o, p-dichlorophenyl) -1, 2 '-biimidazole, 2, 2 '-bis (o-chlorophenyl) - 4,4' , 5, 5' -tetra (m-methoxyphenyl)-l, 2 '-biimidazole and 2, 2' -bis (o- methylphenyl) -4, 4 ' , 5, 5' -tetraphenyl-1, 2 '-biimidazole. When a hexaarylbiimidazole compound (I) is employed, a sensitizer may be added in order to enhance sentitivity. Examples of the sensitizer include benzophenone compounds such as benzophenone, 2, 4, 6-trimethylbenzophenone, 4-phenylbenzophenone, 4, 4 '-bis (dimethylamino) benzophenone and 4,4'- bis (diethylamino) benzophenone; and thioxanthone compounds such as 2, 4-diethylthioxanthone, isopropylthioxanthone, 2,4- diisopropylthioxanthone and 2-chlorothioxanthone. Examples of triazine compounds (II) include 2, 4, 6-tris (trichloromethyl) -s-triazine, 2, 4, 6-tris (tribromomethyl) -s-triazine, 2-propionyl-4, 6-bis (trichloromethyl) -s-triazine, 2-benzoyl-4, 6-bis (trichloromethyl) -s-triazine, 2- (4-chlorophenyl) -4, 6-bis (trichloromethyl) -s-triazine, 2, 4-bis (4-methoxyphenyl) -6-trichloromethyl-s-triazine, 2- (4-mehtoxyphenyl) -2, 6-bis (trichloromethyl) -s-triazine, 2- (4-mehtoxystyryl) -4, 6-bis (trichloromethyl) -s-triazine, 2- (4-chlorostyryl) -4, 6-bis (trichloromethyl) -s-triazine, 2- (4-aminophenyl) -4, 6-bis (trichloromethyl) -s-triazine, 2, 4-bis (3-chlorophenyl) -6-trichloromethyl-s-triazine and 2- (4-aminostyryl) -4, 6-bis (dichloromethyl) -s-triazine. Examples of aminoacetophenone compounds include 2-methyl-l- [4- (methylthio) phenyl] -2-morpholinopropan-l-one, and 2-benzyl-2~ dimethylamino-1- (4-morpholinophenyl) -butanone-1. In the photopolymerization initiator comprising a combination of a sensitizer and an organoborate salt compound, the quaternary organoborate salt compound preferably used is represented by formula (3) : [(R⁴) (R⁵) (R⁶) (R⁷) B]-- Z⁺ (3) (In the formula, each of R⁴, R⁵, R⁶ and R⁷ represents any of an alkyl group, an aryl group, an aralkyl group, an alkenyl group, an alkynyl group, a silyl group and a heterocyclic group which may have substituents and a halogen atom; and 70 represents an arbitrary cation.) The quaternary organoborate salt compound of the present invention consists of a quaternary organoborate anion and an arbitrary cation (Z⁺) . The quaternary organoborate salt compound itself absorbs a UV beam, to thereby generate radicals. However, combination thereof with a sensitizer provides a photopolymerization initiator of higher sensitivity. In formula (3) , each of R⁴, R⁵, R⁶ and R⁷ represents an alkyl group, an aryl group, an aralkyl group, an alkenyl group, an alkynyl group, a silyl group, or a heterocyclic group, and these groups may have substituents . Examples of the substituent, which should not be construed as limiting the invention, include a methyl group, an ethyl group, an n-propyl group, an isopropyl, group, an n-butyl group, a sec-butyl group, an isobutyl group, a tert-butyl group, an n-octyl group, an n-dodecyl group, a cyclopentyl group, a cyclohexyl group, a phenyl group, a tolyl group, a xylyl group, an anisyl group, a biphenyl group, a naphthyl group, a benzyl group, a phenethyl group, a diphenylmethyl group, a methoxy group, an ethoxy group, an n- propoxy group, an isopropoxy group, an n-butoxy group, a sec- butoxy group, a tert-butoxy group, a methylenedioxy group, ethylenedioxy group, a phenoxy group, a naphthoxy group, a benzyloxy group, a methylthio group, a phenylthio group, a 2- furyl group, a 2-thienyl group, a 2-pyridyl group, and a fluoro group. Examples of the quaternary organoborate anion in formula (3) include methyltriphenylborate, n-butyltriphenylborate, n- octyltriphenylborate, n-dodecyltriphenylborate, sec- butyltriphenylborate, tert-butyltriphenylborate, benzyltriphenylborate, n-butyltri (p-anisyl)borate, n-octyltri (p- anisyl)borate, n-dodecyltri (p-anisyl)borate, n-butyltri (p- tolyl)borate, n-butyltri (o-tolyl)borate, n-butyltri (4-tert- butylphenyl)borate, n-butyltri (4-fluoro-2-methylphenyl)borate, n- butyltri (4-fluorophenyl)borate, n-butyltri (1-naphthyl)borate, ethyltri (1-naphthyl)borate, n-butyltri [1- (4- ethylnaphthyl) ]borate, methyltri [1- (4-methylnaphthyl) ]borate, triphenylsilyltriphenylborate, trimethylsilyltriphenylborate, tetra-n-butylborate, di-n-butyldiphenylborate and tetrabenzylborate. Of these, compounds of a structure in which R¹ is an alkyl group and each of R², R³, and R⁴ represents a naphthyl group are preferred in the present invention, in light of balance between stability and photoreactivity. Examples of the cation (Z⁺) in formula (3) include tetramethylammonium, tetraethylammonium, tetra-n-butylammonium, tetraoctylammonium, N-methylquinolinium, N-ethylquinolinium, N- methylprydinium, N-ethylpyridinium, tetramethylphosphonium, tetra-n-butylphosphonium, trimethylsulfonium, triphenylsulfonium, trimethylsulfoxonium, diphenyliodonium, di(4-tert- butylphenyl) iodonium, lithium cation and sodium cation. Any combination of the anion and 70 can be employed in the present invention. However, the present invention is not limited by examples of the combination. The quaternary organoborate salt compound may be used in combination of two or more species. Any compound can be used as the sensitizer which is used in combination with the quaternary organoborate compound, so long as the compound absorbs light and decomposes the quaternary organoborate salt compound. Examples of preferably used compounds include benzophenone compounds, thioxanthone compounds, quinone compounds and compounds selected from cationic dye represented by formula (4) : D-A (4) (In the formula, D represents a cation having a maximum absorption wavelength within a wavelength range of 300-500 nm and A represents an arbitrary anion.) Examples of benzophenone compounds include benzophenone, 4- methylbenzophenone, 2, 4, 6-trimethylbenzophenone, benzoylbenzoic acid, 4-phenylbenzophenone, 3, 3 '-dimethyl-4-methoxybenzophenone, 4-benzoyl-4'-methyldiphenylsulfide, 4,4'- bis (dimethylamino) benzophenone, 4,4'- bis (diethylamino) benzophenone, (2-acryloyloxyethyl) (4- benzoylbenzyl) dimethylammonium bromide, 4- (3-dimethylamino-2- hydroxypropoxy) -benzophenone methochloride monohydrate and (4- benzoylbenzyl) trimethylammonium chloride. Examples of thioxanthone compounds include thioxanthone, 2, 4-diethylthioxanthone, isopropylthioxanthone, 2,4- diisopropylthioxanthone, 2-chlorothioxanthone, l-chloro-4- propoxythioxanthone, and 2- (3-dimethylamino-2-hydroxypropoxy) - 3, 4-dimethyl-9H-thioxanthen-9-one methochloride . Examples of quinone compounds include 2-ethylanthraquinone and 9, 10-phenanthrenequinone. D in the cationic dye represented by formula (4) is a cation derived from a compound having a maximum absorption wavelength within a wavelength range of 300-500 nm. Examples of preferred D include methine, polymethine, azamethine, and diazamethine . Examples of A in formula (4) include halogen anions such as Cl^~, Br^~, and I^"; sulfonate anions such as benzenesulfonate anion, p- toluenesulfonate anion, methanesulfonate anion and 1- naphthalenesulfonate anion; borate anions such as tetraphenylborate, tetraanisylborate, n-butyltriphenylborate, tetrabenzylborate and tetrafluoroborate; various anions such as CIO4-, PF₆ ^", SbF₆ ^~, and BF₄ ^~. However, the present invention is not limited to these examples. Examples of the titanocene compound (V) which can be used in the invention include those disclosed in Japanese Patent Application Laid-Open {kokai) Nos. 59-152396 (US Patent No. 4,590,287), 61-151197 (US Patent No. 4,713,401), 63-10602 (EP 242330), 63-41484 (US Patent No. 4,857,654), 2-291 (US Patent No. 5,008,302), 3-12403 (US Patent No. 5,192,642), 3-20293 (US Patent No. 5,075,467),, 3-27393 (US Patent No. 5,068,371), 3-52050, 4- 221958 (EP 447930), and 4-21975. Specific examples include dicyclopentadienyl-Ti-dichloride, dicyclopentadienyl-Ti-diphenyl, • dicyclopentadienyl-Ti-bis (2,3,4,5, 6-pentafluorophenyl) , dicyclopentadienyl-Ti-bis (2,3,5, 6-tetrafluorophenyl) , dicyclopentadienyl-Ti-bis (2,4, 6-trifluorophenyl) , dicyclopentadienyl-Ti-bis (2, 6-difluorophenyl) , dicyclopentadienyl-Ti-bis (2, 4-difluorophenyl) , bis (methylcyclopentadienyl) -Ti-bis (2, 3,4,5, 6-pentafluorophenyl) , bis (methylcyclopentadienyl) -Ti-bis (2, 3, 5, 6-tetrafluorophenyl) , and bis (methylcyclopentadienyl) -Ti-bis (2, 6-difluorophenyl) . Examples of oxadiazole compounds (VI) include those containing a halomethyl group such as 2-phenyl-5-trichloromethyl- 1,3, 4-oxadiazole, 2- (p-methylphenyl) -5-trichloromethyl-l, 3, 4- oxadiazole, 2- (p-methoxyphenyl) -5-trichloromethyl-l, 3, 4- oxadiazole, 2-styryl-5-trichloromethyl-l, 3, 4-oxadiazole, 2- (p- methoxystyryl) -5-trichloromethyl-l, 3, 4-oxadiazole, and 2- (p- butoxystyryl) -5-trichloromethyl-l, 3, 4-oxadiazole. [organic solvent (E) ] The photosensitive composition for black matrix of the present invention is generally used in form of a solution or dispersion in the organic solvent (E) . The solvent used herein is not particularly limited, and examples include ethers such as diisopropyl ether, ethyl isobutyl ether and butyl ether; esters such as ethyl acetate, isopropyl acetate, (n, sec, tert-

) butyl acetate, amyl acetate, ethyl 3-ethoxypropionate, methyl 3- methoxypropionate, ethyl 3-methoxypropionate, propyl 3- methoxypropionate and butyl 3-methoxypropionate; ketones such as methylethyl ketone, isobutyl ketone, diisopropyl ketone, ethylamyl ketone, methylbutyl ketone, methylhexyl ketone, methylisoamyl ketone, methylisobutyl ketone and cyclohexanone; glycols such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether-, ethylene glycol diethyl ether, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monoethyl ether acetate, propylene glycol mono- t-butyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, dipropylene glycol monoethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monomethyl ether acetate, dipropylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether and tripropylene glycol methyl ether, and the mixture thereof. These organic solvent (E) is a solvent in which the aforementioned components can be dissolved or dispersed. A preferable solvent is selected from those having a boiling point of 100-200°C, more preferably 120-170°C. These solvents may be used singly or in combination. The amount of the organic solvent (E) is adjusted such that, the solid content of the photosensitive composition for black matrix of the present invention falls within 5-50 mass%, more preferably 10-30 mass%. In this case, the solid content means all the components excluding the organic solvent (E) . [polyfunctional thiol (F) ] The photosensitive composition for black matrix of the present invention may contain a polyfunctional thiol serving as a chain-transfer agent which is a part of the photopolymerization initiator system. Addition of the polyfunctional thiol suppresses oxygen-induced polymerization inhibition, and uniform photocuring reaction is attained even under highly light-shielding conditions . Polyfunctional thiols (F) is a compound having at least two thiol groups, and examples include hexandithiol, decandithiol, butanediol bisthiopropionate, butandiol bisthioglycolate, ^' ethylene glycol bisthioglycolate, ethylene glycol bisthiopropionate, trimethylolpropane tristhioglycolate, trimethylolpropane tristhiopropionate, pentaerythritol tetrakisthioglycolate, pentaerythritol tetrakisthiopropionate, trimercaptopropionic acid tris (2-hydroxyethyl) isocyanurate, 1,4- dimethylmercaptobenzene, 2, 4, 6-trimercapto-s-triazine, and 2- (N,N-dibutylamino) -4, 6-dimercapto-s-triazine. These polyfunctional thiols may be used singly or in combination of multiple species. The mass ratio of the polyfunctional thiol (F) to the total amount of (I) hexaarylbiimidazole compound serving as a photopolymerization initiator, (II) triazine compound, (III) aminoacetophenone compound, (IV) combination of a sensitizer and an organoborate salt compound, (V) titanocene compound and (VI) oxadiazole compound is preferably from 10/1 to 1/10 in the light of photosensitivity, more preferably, 5/1 to 1/5. [other photopolymerization initiators] Examples of other photopolymerization initiators which can be used in the photosensitive composition of the present invention include acetophenone compounds such as diethoxyacetophenone, 2-hydroxy-2-methyl-l-phenylpropan-l-one, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-l-one, 1- hydroxycyclohexylphenylketone and 4-tert-butyl- trichloroacetophenone;benzoin compounds such as benzyl dimethyl ketal, benzoin ethyl ether and benzoin isopropyl ether; glyoxyester compounds such as methylphenylglyoxylate; acylphosphine oxide compounds such as 2,4,6- trimethylbenzoyldiphenylphosphine oxide; and bisacylphosphine oxide compounds such as bis (2, 6-dimethoxybenzoyl) -2, 4, 4- trimethylpentylphosphine oxide, bis (2, 6-dichlorobenzoyl) - phenylphosphine oxide, bis (2, 6-dichlorobenzoyl) -2, 5- dimethylphenylphosphine oxide and bis (2,4,6- trimethylbenzoyl) phenylphosphine oxide . [hydrogen-donating compound] The photosensitive composition for black matrix of the present invention may also contain a hydrogen-donating compound, which can donate hydrogen to a photo-excited initiator and to radicals generated from the initiator. Examples of the hydrogen- donating compound include aliphatic amines such as triethanolamine and methyldiethanolamine; aromatic amine such as 2-dimethylaminoethylbenzoic acid, ethyl 4-dimethylaminobenzoate, isobutyl 4-dimethylaminobenzoate and 4,4- dimethylaminobenzophenone; thiol compounds such as 2- mercaptobenzothiazole, 2-mercaptobenzoxazole and 2- mercaptobenzoxazole . [mass contents] In the photosensitive composition for black matrix of the present invention, preferable amounts of components excluding the organic solvent (E) will next be described. The amount of the binder resin (A) is preferably 10-40 mass %, more preferably 15- 35 mass %. When the amount is 10 mass % or less, film strength decreases, whereas when the amount exceeds 40 mass%, sufficient optical density cannot be attained. The amount of the black-base pigment (B) is preferably 25-60 mass %, more preferably 30-55 mass %. When the amount is less than 25 mass %, sufficient optical density cannot be attained, whereas when the amount exceeds 60 mass %, film strength decreases. The amount of the ethylenic unsaturated monomer (C) is preferably 5-20 mass%, more preferably 8-18 mass % . When the amount is less than 5 mass%, sufficient photosensitivity cannot be attained, whereas when the amount exceeds 20 mass %, sufficient optical density cannot be attained. The amount of the photopolymerization initiator (D) is preferably 2-25 mass %, more preferably 5-20 mass %. When the amount is less than 2 mass %, sufficient photosensitivity cannot be attained, whereas the amount exceeding 25 mass % results in excessively high photosensitivity, which leads to decrease in resolution. In a case where polyfunctional thiol (F) is added, the preferable amount of the photopolymerization initiator (D) is preferably 2-20 mass %, more preferably 3-15 mass % . When the amount is less than 2 mass %, sufficient photosensitivity cannot be attained, whereas when the amount exceeds 20 mass %, the photosensitivity becomes excessively high, which leads to decrease in resolution. In this case, the preferable amount of the polyfunctional thiol (F) is preferably 2-20 mass %, more preferably 3-15 mass % . When the amount is less than 2 mass %, sufficient effect exerted by polyfunctional thiol cannot be attained, whereas when the amount is in excess of 20 mass %, the photosensitivity becomes excessively high, which leads to decrease in resolution. In addition to these essential components (A) and (B) and/or (C) , (D) , (E) , or (F) , the composition of the present invention may further contain a pigment-dispersant, an adhesion-improving agent, a leveling agent, a developability-improving agent, an anti-oxidant, a thermal polymerization inhibitor, etc.

Particularly, since the coloring composition according to the present invention requires fine dispersion of coloring materials and stable dispersion state in light of stability of product quality, a pigment-dispersant is preferably added in some cases. The pigment-dispersant is a substance having affinity with both a pigment and a binder resin. Examples of the pigment- dispersant include nonionic, cationic, or anionic surfactants and polymer dispersants. Of these, polymer dispersant is preferred for its excellent effects of temporal dispersion stability. Particularly, it is advantageous to use those having a basic functional group such as a primary, secondary, or tertiary a ino group or a nitrogen-containing heterocyclic group such as pyridine, pyrimidine, or pyrazine; or other functional groups such as amide group and a urethane group, [production method] Next, the method for producing the photosensitive composition for black matrix of the present invention will next be described. The photosensitive composition for black matrix can be produced by mixing the above components in arbitrary methods . That is, the production can be carried out by mixing the components at the same time or mixing each component sequentially. In the present invention, if dispersion treatment is carried out with mixing all the components being mixed, properties of components having high reactivity may be modified due to heat generated during the dispersion step. Therefore, it is preferable that first black-base pigment (B) is dispersed in a mixture of other components, i.e., solvent and pigment dispersant, or a mixture of the two with binder resin (A) and then the mixture is further mixed with the other components . The dispersion treatment can be carried out by use of a paint conditioner, a sand grinder, a ball mill, a three roll mill, a stone mill, a jet mill, a ho ogenizer, etc. Through dispersion treatment, the black-base pigment is formed into microparticles . Thus, light-shielding performance and coating property are improved. When a sand grinder is employed for dispersion, glass beads or zirconia beads having a size of 0.1 to several millimeters are preferably used. Dispersion is typically carried out at 0-100°C, preferably in a range of room temperature to 80°C. Since suitable duration of the dispersion treatment varies in accordance with, for example, the compositional proportions (of coloring material, solvent, dispersant and binder resin) in the coloring composition and apparatus scale of the sand grinder, the duration is appropriately modified. When a three roll mill is employed for dispersion, the temperature during treatment typically falls within a range of 0- 60 °C. When the temperature of the heat caused by the friction of rolls considerably exceeds 60°C, the inside of the rolls is cooled with circulation of water. The number of repetition of feeding ink to the three roll mill is not particularly limited, as it depends on the velocity of the rolls, pressure between the rolls, viscosity of the material, etc., and is generally 2 to 10 repetitions . The photosensitive composition for black matrix is produced by mixing the composition prepared through the above dispersion step with the other components by an arbitrary method. Since the photosensitive liquid often collects tiny dusts during production steps, the thus-obtained photosensitive composition for color filters is preferably subjected to filtration by use of a filter, etc. Taking a color filter for liquid crystal display elements which is formed by laminating, in the following order, a resin black matrix, pixels and a protective film, the production method of color filter using the photosensitive composition for black matrix of the present invention will next be described. A photosensitive composition for black matrix is applied to a transparent substrate. The solvent is dried off by means of, for example, an oven, and a black matrix pattern is formed through exposure followed by development. Subsequently, the substrate is postbaked, to thereby form a black matrix. In the present invention, no particular limitation is imposed on the material of the transparent substrate, and examples of preferred substrate materials include inorganic glass such as quartz glass, borosilicate glass, or silica-coated sodalime glass; polyesters such as polyethylene terephthalate; polyolefins such as polypropylene and polyethylene; thermoplastics such as polycarbonate, polymethylmethacrylate, and polysulfone; thermosetting plastics such as epoxy resin and polyester resin, in a form of film or sheet. These transparent substrate may be subjected to a preliminary treatment such as corona discharge treatment, ozone treatment, and thin film treatment with a variety of polymers such as a silane-coupling agent and a urethane polymer, so as to improve physical properties of the substrate such as adhesion on the surface. Coating methods are not specifically limited and carried out by a known method. Specifically, coating may be carried out by using a coating apparatus such as a dip coater, a roll coater, a wire bar, a flow coater, a die coater, a spray coater and a spin coater. Drying the solvent after coating can be carried out in optional methods . The solvent in the composition is dried off by means of a drying apparatus such as a hotplate, a IR oven, and a convection oven. Preferably, drying is carried out under a condition of drying temperature between 0-150°C and drying time of 10 seconds to 60 minutes. The solvent may be dried off in a vacuum. The exposure step is carried out by placing a photomask onto a sample and exposing the sample to an image through the photomask. Examples of light sources employed for exposure include lamp light sources such as a xenon lamp, a high-pressure mercury arc, an ultrahigh-pressure mercury arc, a metal halide lamp, an intermediate-pressure mercury lamp, and a low-pressure mercury lamp; laser light sources such as an argon ion laser, a YAG laser, an excimer laser and a nitrogen laser. An optical filter may be employed in the case where light of a specific wavelength is employed in irradiation. The photosensitive composition for black matrix of the present invention exhibits a high sensitivity even the composition has a high optical density, and can be cured with irradiation of light having an energy of 200 mJ/cm² or less. The energy of the irradiated light can be measured by use of, for example, an ultraviolet-integral actinometer UIT-150 (light- receptor UVD-S365) (product of Ushio Denki) . Development is performed through dipping, showering, puddling, or a similar method by use of a developer, to thereby develop a resist. No limitation is imposed on the species of developers so long as the developer is a solvent capable of dissolving unexposed portions of a resist film. Examples of the developers include organic solvents such as acetone, methylene chloride, trichlene and cyclohexanone, However, alkali developers are preferably employed. Examples of the alkali developers include aqueous solutions containing an inorganic alkali agent such as sodium carbonate, potassium carbonate, sodium silicate, potassium silicate, sodium hydroxide and potassium hydroxide; or an organic alkali agent such as diethanola ine, triethanolamine, and tetraalkylammonium hydroxide. The alkali developers may further contain, in accordance with need, a surfactant, a water- soluble organic solvent, a low-molecular compound having a hydroxyl group or a carboxyl group. Particularly, since many surfactants exert effects for improving developability and resolution, and also for reducing stain in the background, such surfactants are preferably incorporated. Examples of surfactants for the developers include anionic surfectants having a sodium naphthalenesulfonate moiety or a sodium benzenesulfonate moiety; non-ionic surfactants having a polyalkyleneoxy moiety; and cationic surfactants having a tetraalkylammonium moiety. No particular limitation is imposed on the development method, and development is typically carried out at 10-50 °C, preferably at 15-45 °C, through a method such as immersion development, spray development, brush development, or ultrasonic development. Postbaking is carried out at 150-300°C for 1-120 minutes by use of the similar apparatus as used for the solvent drying. Film thickness of the thus-obtained black matrix preferably falls between 0.1-2 μ, more preferably 0.1-1.5 μ, still more preferably 0.1-1 μ. Moreover, the optical density at those thickness is preferably 3 or more, in order to function as a black matrix. The black matrix pattern formed through the present step is provided with openings of approximately 20-200 μm in the black matrix. In the subsequent step, pixels are formed in these spaces. Pixels of a plurality of colors will next be formed in the openings provided in the black matrice. Typically, pixels have three colors (R, G and B) , and the photosensitive composition is colored with the aforementioned pigments, or dyes. Firstly, the photosensitive composition is applied onto a transparent substrate on which a black matrix pattern has been formed. Then, the solvent of the composition is dried off in an oven or the like, thereby forming a colored layer of the first color on the entire surface of the black matrix. Since a color filter generally has a plurality of colors, unnecessary portions of the layer are removed through a lithographic method, and thereby a desired pixel pattern of the first color is formed. The thickness of the pixel film falls within approximately 0.5-3 μm. Thus, the above procedure is repeated as many times as the number of colors of the pixels, to thereby form pixels of a plurality of colors, producing a color filter. Preferably, the same apparatus and agents which are employed for formation step of the black matrix are preferably used for the above pixel formation steps, but different apparatuses and/or agents may be used without any problems. Subsequently, a protective film is optionally stacked if necessary. The material for the protective film is not particularly limited, and examples include acrylic resin, epoxy resin, silicone resin and polyimide resin. In another method, patterned pixels are formed in advance on a transparent substrate, followed by application of a photosensitive coloring composition for black color filters thereon. Exposure is then performed from the transparent substrate side while the pixels act as a mask, to thereby form black matrix among the pixels. Such method is knows as a back exposure method. Finally, in accordance with needs, an ITO transparent electrode may be stacked, and patterning thereof may be carried out through a customary method.

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail with reference to embodiments; however, the present invention is by no means limited thereto .

Production Example 1: Synthesis of binder resin (UA-1) In a reaction vessel provided with a stirrer, a thermometer and a condenser, 625 g (0.5 mol) of polycaprolactonediol (manufactured by Daicel Chemical Industries, Ltd.; trade name: PLACCEL 212; average molecular weight: 1,250) as a polyester polyol, 142 g (1.0 mol) of 2-acryloyloxyethyl isocyanate and 1.0 g each of p-methoxyphenol and di-t-butyl-hydroxytoluene were charged. While stirring, the resultant mixture was heated to 60°C and, after such heating was stopped, was added with 0.2 g of dibutyl tin dilaurate. When a temperature inside the vessel started to decrease, the mixture was heated again and continued stirring at 80°C. Then, when it was confirmed by an infrared absorption spectrum that an absorption spectrum (2280 cm^-1) of an isocyanate group almost disappeared, the reaction was terminated, to thereby obtain a urethane acrylate compound (UA-1) in a thick liquid state. The average molecular weight of the thus-obtained urethane acrylate was 1,600.

Production Example 2: Synthesis of binder resin (UA-2) A urethane acrylate compound (UA-2) was synthesized in a same manner as in Production Example 1 except that 500 g (0.5 mol) of polycarbonate diol (manufactured by Daicel Chemical Industries, Ltd.; trade name: PLACCEL CD210PL; average molecular weight: 1,000) was used in place of polycaprolactonediol. The number average molecular weight of the thus-obtained urethane acrylate was 1,300.

Production Example 3: Synthesis of binder resin (UA-3) A urethane acrylate compound (UA-3) was synthesized in a same manner as in Production Example 1 except that 425 g (0.5 mol) of polytetramethylene glycol (manufactured by Hodogaya Chemical Co., Ltd.; trade name: PTMG-850; average molecular weight: 850) was used in place of polycaprolactonediol. The number average molecular weight of the thus-obtained urethane acrylate was 1,200.

Production Example 4: Synthesis of binder resin (UA-4) 255 g (0.3 mol) of polytetramethylene glycol (manufactured by Hodogaya Chemical Co., Ltd.; trade name: PTMG-850; molecular weight: 850), 67 g (0.5 mol) of dimethylol propionic acid, 133 g (0.6 mol) of isophorone diisocyanate, 56.8 g (0.4 mol) of 2- acryloyloxyethyl isocyanate and 0.1 g each of p-methoxyphenol and di-t-butyl-hydroxytoluene were charged. While stirring, the resultant mixture was heated to 60°C and, after such heating was stopped, 0.1 g of dibutyl tin dilaurate was added thereto. When a temperature inside a reaction vessel started to decrease, the mixture was heated again and stirring was continued at 80°C. Then, when it was confirmed by an infrared absorption spectrum that an absorption spectrum (2280 cm^-1) of an isocyanate group almost disappeared, the reaction was terminated, to thereby obtain a urethane acrylate compound (UA-4) in a thick liquid state. The number average molecular weight of the thus-obtained urethane acrylate was 22,000 and the acid value thereof was 46 mgKOH/g.

Production Example 5: Synthesis of binder resin (UA-5) A urethane acrylate compound (UA-5) was synthesized in a same manner as in Production Example 1 except that 1,000 g (1 mol) of polycarbonate diol (manufactured by Daicel Chemical Industries, Ltd.; trade name: PLACCEL CD210PL; average molecular weight: 1,000), 938 g(7 mol) of dimethylolpropionic acid, 1332 g(6mol) of isophorone diisocyanate as polyisocyanate and 568 g (4.0 mol) of 2-acryloyloxyethyl isocyanate were used. The number average molecular weight of the thus-obtained urethane acrylate was 16,000 and the acid value thereof was 120 mgKOH/g.

Production Example 6: Synthesis of binder resin (UA-6) In a four-necked flask provided with a dropping funnel, a thermometer, a condenser tube and a stirrer, 12.0 parts by mass of methacrylic acid, 14.0 parts by mass of methyl methacrylate, 43.0 parts by mass of butyl methacrylate, 6.0 parts by mass of 2- hydroxyethyl acrylate and 225.0 parts by mass of propylene glycol monomethyl ether acetate were charged and, then the inside of the four-necked flask was purged with nitrogen for one hour. Further, after the resultant mixture was heated in an oil bath to 90°C, thereto was added dropwise a mixture of 12.0 parts by mass of methacrylic acid, 14.0 parts by mass of methyl methacrylate, 43.0 parts by mass of butyl methacrylate, 6.0 parts by mass of 2- hydroxyethyl acrylate, 225.0 parts by mass of propylene glycol monomethyl ether acetate and 3.2 parts by mass of azobisisobutylonitile over one hour. After the resultant mixture was subjected to polymerization for 3 hours, thereto was added a mixture of 1.0 part by mass of azobisisobutylonitrile and 15.0 parts by mass of propylene glycol monomethyl ether acetate, and the resultant mixture was heated to 100°C, subjected to polymerization for 1.5 hours and then was cooled. To the resultant mixture, 12.0 parts by mass of 2- acryloyloxyethyl isocyanate was gradually added and stirred for 4 hours at 80°C, to thereby synthesize a copolymer (UA-6) . The acid value of the thus-obtained copolymer was 92 mgKOH/g and the mass average molecular weight of the thus-obtained copolymer in terms of polystyrene measured by GPC was 23,000.

Comparative Production Example 1: Synthesis of binder resin (UA- 7) 850 g (1 mol) of polytetramethylene glycol (manufactured by Hodogaya Chemical Co., Ltd.; trade name: PTG-850SN; molecular weight: 850), 938 g (7 mol) of dimethylol propionic acid and 1,998 g (9 mol) of isophorone diisocyanate were charged. While stirring, the resultant mixture was heated to 60°C and, after such heating was stopped, thereto was added 1.4 g of dibutyl tin dilaurate . When a temperature inside the reaction vessel started to decrease, the mixture was heated again to 80°C and stirring was continued with the temperature being maintained at 75 to 85°C. Then, when a concentration of remaining NCO came to a theoretical value, the reaction was terminated, to thereby obtain a urethane oligomer. Further, after 0.9 g each of p-methoxyphenol and di-t- butyl-hydroxytoluene was charged in the reaction vessel, 238 g (2.05 mol) of 2-hydroxyethyl acrylate was added thereto and, then, the reaction was started again. Then, when it was confirmed by an infrared absorption spectrum that an absorption spectrum (2280 cm^" ¹) of an isocyanate group almost disappeared, the reaction was terminated, to thereby obtain a urethane acrylate compound (UA-7) in a thick liquid state. The average molecular weight of the thus-obtained urethane acrylate was 16,000 and the acid value thereof was 90 mgKOH/g.

Comparative Production Example 2: Synthesis of binder resin (UA-

8) A urethane acrylate compound (UA-8) in a thick liquid state was obtained in a same manner as in Production Example 1 except that 2-methacryloyloxyethyl isocyanate was used in place of 2- acryloyloxyethyl isocyanate in a same mol number as that of 2- acryloyloxyethyl isocyanate. ^'

Production Example 7: Synthesis of epoxy acrylate resin (EP-1) 210 parts by mass of a cresol novolak type epoxy resin (trade name: EPOTOHTO YDCN-704; manufactured by Tohto Kasei Co.,

Ltd.; epoxy equivalent: 210; softening point: 90 °C) , 72 parts by mass of acrylic acid, 0.28 parts by mass of hydroquinone and

232.6 parts by mass of diethylene glycol monoethyl ether acetate were charged and, then, heated to 95 °C. After it was confirmed that the resultant mixture was uniformly dissolved, 1.4 parts by mass of triphenylphosphine was charged and, then, heated to 100°C and, thereafter, subjected to reaction for about 30 hours, to thereby obtain a reaction product having an acid value of 0.5 mgKOH/g. To the thus-obtained reaction product, 66.9 parts by mass of tetrahydrophthalic anhydride was charged and, then, heated to 90 °C and, thereafter, subjected to reaction for about 6 hours. Then, it was confirmed by an IR analysis that an absorption of the acid anhydride disappeared, to thereby obtain an epoxyacrylate resin EP-1 having an acid value of a solid content of 70 mgKOH/g and a concentration of a solid content of 60.0%.

Production Example 8: Synthesis of epoxy acrylate resin (EP-2) 210 parts by mass of a cresol novolak type epoxy resin (trade name: EPOTOHTO YDCN-704; manufactured by Tohto Kasei Co., Ltd.; epoxy equivalent: 210; softening point: 90 °C) , 72 parts by mass of acrylic acid, 0.28 parts by mass of hydroquinone, 232.6 parts by mass of diethylene glycol monoethyl ether acetate were charged and, then heated to 95 °C. After it was confirmed that the resultant mixture was uniformly dissolved, 1.4 parts by mass of triphenylphosphine was charged and, then heated to 100 °C and, thereafter, subjected to reaction for about 30 hours, to thereby obtain a reaction product having an acid value of 0.5 mgKOH/g. To thus-obtained reaction product, 44 parts by mass of succinic anhydride was charged and, then heated to 90 °C and, thereafter, subjected to reaction for about 6 hours. Then, it was confirmed by an IR analysis that an absorption of the acid anhydride s disappeared, to thereby obtain an epoxyacrylate resin EP-2 having an acid value of a solid content of 70 mgKOH/g and a concentration of a solid content of 58.5%.

Example 1 : Preparation of coloring composition 30.0 parts by mass of (UA-1) (solid content: 7.0 parts by mass) produced in Production Example 1, 5.0 parts by mass of propylene glycol monomethyl ether acetate, 3.5 parts by mass of a dispersant (trade name: FLOWLEN DOPA-33; manufactured by Kyoeisha Chemical Co., Ltd.; solid content: 30%) and 7.0 parts by mass of carbon black (trade name: Special Black 4; manufactured by Degussa AG) were mixed and the mixture was left standing overnight. Next, after stirring for one hour, the resultant mixture was 4 times passed through a three-roll mill (model: RIII-1RM-2; manufactured by Kodaira Seisakusho Co., Ltd.) . To the resultant black mixture, cyclohexanone was added to adjust the concentration, to thereby obtain a black coloring composition having a concentration of a solid content of 18.0%. After preparing a photosensitive composition for a black matrix by mixing the thus-obtained coloring composition and other components at ratios as shown in Table 1, the resultant mixture was filtered by using a filter having a pore size of 0.8 μm (for GFP, Kiriyama Filter Paper) . Then, the resultant filtrate was evaluated on photosensitivity and resist physical properties (OD value (optical density) , reflectivity and pencil hardness) in accordance with methods as described below.

Evaluation of Photosensitivity Each of the photosensitive compositions obtained in accordance with the above-described procedures was spin-coated on a glass substrate (size: 100x100 mm) and, then dried for 30 minutes at room temperature and thereafter, pre-baked for 20 minutes at 70°C. After measuring film thickness of the thus- formed resist by using a film thickness meter (trade name: SURFCOM 130A; manufactured by Tokyo Seimitsu Co., Ltd.), the resist was photocured in an exposing apparatus having a built-in ultrahigh pressure mercury lamp (trade name: MultilightML-25lA/B; manufactured by Ushio Inc.) at various exposure amounts. The exposure amount was measured by an ultraviolet integrating photometer (trade name: UIT-150 (UVD-S365 as for light receiving portion); manufactured by Ushio Inc.). Further, the resist was subjected to alkali development by using an alkali developing agent (trade name: Developer 9033, which contains a 0.1% aqueous solution of potassium carbonate; manufactured by Shipley Far East Ltd.) for a predetermined period of time at 25°C (the developing time was set to be twice the time in which the resist film before exposure to light was completely developed by the alkali development). After the alkali . development was performed, the glass substrate was washed with water and dried by air-spraying and, then, film thickness of the remaining resist was measured. The exposure amount at which the value (remaining film sensitivity) determined by the formula as described below was 95 % or more was defined as photosensitivity of the photosensitive coloring composition for the color filter. The results are shown in Table 1.

Remaining Film Sensitivity (%)=(Film thickness after alkali development) / (Film thickness before alkali development) xl00

Evaluation of Physical Properties of Resist Each of the above-prepared photosensitive compositions for the black matrix was spin-coated on a glass substrate (size: 100x100 mm) and, then, dried for 30 minutes at room temperature and, thereafter, pre-baked for 20 minutes at 70°C. After the resultant resist was photocured by using an ultrahigh pressure mercury lamp with an exposure amount twice the photosensitivity which each of the compositions has, the resist was post-baked for 30 minutes at 200°C and, then, the thus-obtained resist-coated glass substrate was subjected to evaluations as described below.

OD Value (Optical density) By measuring transmittance at 550 nm by using a standard plate having a known OD value, a calibration curve was constructed. Then, by measuring transmittance of each of the resist-coated glass substrates of Examples and Comparative

Examples at 550 nm, an OD value was determined. The results are shown in Table 1.

Reflectivity By using a spectrophotometer (trade name: UN-3100PC; manufactured by Shimadzu Corporation) , reflectivity at 550 nm of each of the resists was measured.

Pencil hardness Measurements were conducted in accordance with JIS K5400 "General Test Methods for Coating Composition, 8.4: Pencil Scratch Value". The results are shown in Table 1.

Examples 2 to 10 and Comparative Examples 1 to 2 : Evaluations were performed in the same manner as in Example 1 except by using each component at a ratio as shown in Table 1. The results are shown in Table 1. Table 1

*1: carbon black *2: trimethylolpropane triacrylate

*3 : 2,2' -bis (o-chlorophenyl) -4, 4' 5, 5' -tetraphenyl-1, 2' -biimidazole

*4 : 4,4' -bis (dimethylamino)benzophenone

*5:propyleneglycol monomethylether acetate

*6: cyclohexanone *7: trimethylolpropane tristhiopropionate INDUSTRIAL APPLICABILITY The photosensitive composition for black matrix using a specific urethane acrylate according to the present invention has an extremely high sensitivity, can rapidly be cured by a small amount of exposure and enables efficient production of black matri .

Claims

1. A photosensitive composition for a black matrix, comprising a binder resin (A) and a black-base pigment (B) , the binder resin (A) containing a urethane acrylate compound which is produced by reaction between an isocyanate compound (a-1) represented by formula (1) and a polyhydroxy compound (a-2) CH₂=CH-COO-R-NCO ( 1 )

(wherein R represents a hydrocarbon group having 1 to 30 carbon atoms) .

2. The photosensitive composition for the black matrix as claimed in claim 1, wherein the polyhydroxy compound (a-2) is at least one compound selected from the group consisting of the following (I) to (V) : (I) a polyester polyol compound; (II) a polycarbonate polyol compound; (III) a polyether polyol compound; (IV) a polyurethane polyol compound; and (V) a homopolyer or copolymer of a hydroxyalkyl (meth) acrylate .

3. The photosensitive composition for the black matrix as claimed in claim 1, wherein R in the isocyanate compound (a-1) represents an alkylene group having 1 to 6 carbon atoms.

4. The photosensitive composition for the black matrix as claimed in claim 1, wherein the isocyanate compound (a-1) is 2- acryloyloxyethyl isocyanate.

The photosensitive composition for the black matrix as claimed in claim 1, wherein the urethane acrylate compound has a carboxyl group .

6. The photosensitive composition for the black matrix as claimed in claim 1, wherein the black-base pigment (B) is carbon black.

7. The photosensitive composition for the black matrix as claimed in claim 1, wherein the binder resin (A) further comprises epoxy (meth) acrylate.

8. The photosensitive composition for the black matrix as claimed in claim 7, wherein the epoxy (meth) acrylate resin is a novolak-type epoxy (meth) acrylate resin having a carboxyl group.

9. The photosensitive composition for the black matrix as claimed in claim 7, wherein the epoxy (meth) acrylate resin is a cresol novolak-type epoxy (meth) acrylate resin having a carboxyl group .

10. The photosensitive composition for the black matrix as claimed in claim 1, further comprising an ethylenic unsaturated monomer (C) .

11. The photosensitive composition for the black matrix as claimed in claim 1 or 10, further comprising a photopolymerization initiator (D) .

12. The photosensitive composition for the black matrix as claimed in claim 11, further comprising an organic solvent (E) , wherein the other components are contained at the compositional ratio of binder resin (A) :10 to 40 mass %, black-base pigment (B) :25 to 60 mass %, ethylenic unsaturated monomer (C) : 5 to 20 mass % and photopolymerization initiator (D) : 2 to 25 mass %.

13. The photosensitive composition for the black matrix as claimed in claim 12, further comprising a polyfunctional thiol (F) , wherein the photopolymerization initiator (D) is contained at 2 to 20 mass % and the polyfunctional thiol (F) is contained at 2 to 20 mass %.

14. The photosensitive composition for the black matrix as claimed in claim 12, wherein the content of the organic solvent (E) is adjusted by setting the solid content (the term "solid" used herein means all the components other than organic solvent (E) ) to a range of 5 to 50 mass % in preparing the solution of the composition.