JP2000241621A - Photo-curing composition for color filter, color filter, and liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve high optical density without increasing film thickness, allow manufacturing of a color filter good in pattern shape, and improve high sensitivity, developing ability, and resolution, by containing silica-coated carbon black. SOLUTION: This composition contains a compound having at least one of binder resin and ethylene unsaturated double-bond, photopolymerization initiator, and solvent, as well as the silica-coated carbon black. In this case, the carbon black is silica-coated in a gas phase, is silica-coated in a liquid phase, or is treated with vapor plasma and then silica-coated. Silica amount in this silica-coated carbon black is usually 0.5-50 wt.% as SiO2, preferably about 1-40 wt.%.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photocurable composition for a color filter used in the production of an optical color filter used for a color television, a liquid crystal display device, a solid-state imaging device, a camera, and the like, and the composition. The present invention relates to a color filter having a black matrix formed by using the color filter and a liquid crystal display device using the color filter.

More specifically, the present invention relates to a photocurable composition for a color filter having high sensitivity and excellent developability, a color filter having high accuracy and excellent contrast, and a liquid crystal display having excellent visibility.

[0003]

2. Description of the Related Art In a liquid crystal display device, a color filter is mounted on one substrate holding liquid crystal for displaying a color image. The color filter is usually glass,
A black matrix is formed on the surface of a transparent substrate such as a plastic sheet. Subsequently, a number of color patterns such as stripes or mosaics having a width of 5 to 200 μm of three or more different hues such as red, green and blue are formed. It is formed with an accuracy of μm.

[0004] Typical production methods of a color filter include a dyeing method, a printing method, a pigment dispersion method, an electrodeposition method, an ink jet method and the like. Among these, in particular, the pigment dispersion method of forming a color filter pixel by applying a photocurable composition containing a color material on a transparent substrate, repeating image exposure, development, and curing as necessary is a color filter. It is widely used because it has high accuracy such as pixel position and film thickness, has excellent durability such as light resistance and heat resistance, and has few defects such as pinholes.

Usually, a grid or stripe is formed between red, green, and blue (hereinafter sometimes referred to as RGB) color patterns to improve contrast and to shield a transistor such as a TFT (thin film transistor) for driving liquid crystal from light. It is common to arrange a light-shielding black matrix such as a shape. As a black matrix, a method using a metal film such as chromium, a method using a photocurable resin in which a light-shielding color material is dispersed, and the like are known.

A metal film such as chromium has a high light-shielding ratio, and a black matrix using the same can easily achieve a high optical density (about 0.15 μm in film thickness and an optical density (OD) of 4 or more). High resolution can be achieved by using a type photoresist. However, since it is a metal film, the reflectance of visible light is high, and the contrast of a displayed image is likely to be reduced due to the reflection of external light, and the image quality is likely to be reduced due to the reflection of a bright surrounding object. Further, since a metal such as chromium is vapor-deposited on the transparent substrate and the chromium layer is etched through a photolithography process, the manufacturing process is complicated and the cost is high. Further, there is a problem that an environmental problem is caused by a waste liquid of the etching process. For this reason, a black matrix (resin black matrix) formed using a photocurable resin in which a light-shielding color material is dispersed has attracted attention.

In a resin black matrix, the image quality characteristics are improved because the visible light reflectance of the surface is as low as several percent, but the light shielding ratio is low, so that the light shielding property (optical density) is equivalent to that of a black matrix made of a metal film such as chromium. In order to exhibit (3), it is necessary to increase the content of the light-shielding color material or increase the film thickness. In the method of increasing the film thickness,
When the RGB color pixels are formed after the black matrix is formed, the portions of the pixels provided on the black matrix are raised in a protruding manner, so that the flatness is impaired and the alignment of the liquid crystal is disturbed. However, there is a problem that the disconnection of the ITO film easily occurs. For this reason, in order to achieve a light-shielding rate equivalent to that of a metal film such as chromium, it is necessary to form a black matrix by increasing the content of the light-shielding color material.

In recent years, a color filter having better color contrast has been desired, and a black matrix has been required to have a high light blocking ratio (optical density (OD) of 3 or more). In order to achieve an optical density of 3 or more in the resin black matrix, the content of the light-shielding color material is 30 to 60% (0.5 to
(At a film thickness of about 3 μm), which results in a high density. However, at such a high density, light at the time of exposure is blocked, sensitivity and developability are reduced, and the accuracy of a color filter obtained by photolithography is reduced. There is a problem to do.

For the purpose of improving the reduction in sensitivity due to the increase in the concentration of the color material, various photopolymerization initiator systems have been studied in the production of color filters by a pigment dispersion method using a photopolymerizable composition. Examples thereof include a triazine-based compound or a combination of a triazine-based compound and an imidazole-based compound (JP-A-6-201913), and a combination of a Michler's ketone and an imidazole-based compound (JP-A-5-173320). Or, “Fine Chemical”, March 1, 1991, Vol.
0, No. 4, p. The dialkyl acetophenone-based, benzyl dialkyl ketal-based, benzoin-based, benzoin alkyl ether-based, and thiomosantone derivatives described in Nos. 16 to 26 are used for color filters (JP-A-4-190362, JP-A-5-3030).
No. 12, JP-A-6-35188, etc.). on the other hand,
In order to increase the sensitivity of the photocurable composition, an aromatic mercapto compound such as 2-mercaptobenzthiazole, 2-mercaptobenzoxazole, or 2-mercaptobenzimidazole has been added to the imidazole-based compound (Japanese Patent Application Laid-Open No. No. 59-56403).

[0010] By using these initiator systems, quite satisfactory sensitivity has been obtained in the photopolymerizable composition for a black matrix. However, it is desired to further increase the sensitivity and improve the developability and resolution. ing.

[0011]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned conventional problems and makes it possible to achieve a high optical density without increasing the film thickness and to manufacture a color filter having an excellent pattern shape. Highly sensitive photocurable composition for color filter with excellent developability and resolution, high-precision color filter obtained by using this photocurable composition for color filter, and liquid crystal with excellent image quality characteristics It is an object to provide a display device.

[0012]

The photocurable composition for a color filter according to claim 1 of the present invention is characterized in that it contains carbon black coated with silica. The photocurable composition for a color filter according to claim 2 of the present invention,
The photocurable composition for a color filter according to claim 1, wherein, in addition to the silica-coated carbon black, a binder resin, a compound having at least one ethylenically unsaturated double bond, a photopolymerization initiator system, and a solvent. It is characterized by containing.

The photocurable composition for a color filter according to claim 3 of the present invention is the photocurable composition for a color filter according to claim 1 or 2, wherein carbon black is coated with silica in a gas phase. There is a feature. The photocurable composition for a color filter according to claim 4 of the present invention is the photocurable composition for a color filter according to claim 1 or 2, wherein carbon black is coated with silica in a liquid phase. Features.

The photocurable composition for a color filter according to claim 5 of the present invention is the photocurable composition for a color filter according to any one of claims 1 to 4, wherein carbon black is subjected to a steam plasma treatment. Later, it is characterized by being coated with silica. The photocurable composition for a color filter according to the sixth aspect of the present invention is the second aspect.
In the photocurable composition for a color filter according to any one of items 1 to 5, the photopolymerization initiator system contains at least one compound selected from a biimidazole compound, a titanocene compound, a triazine compound, and an oxadiazole compound. It is characterized by doing.

The photocurable composition for a color filter according to claim 7 of the present invention is the photocurable composition for a color filter according to claim 6, wherein the photocurable composition for a color filter is a biimidazole compound, a titanocene compound, a triazine compound and an oxadiazole compound. Other than at least one compound selected from
At least one selected from amino group-containing sensitizing dyes, thiol compounds, N-phenylglycine and derivatives thereof
A compound of the type described above.

The color filter according to claim 8 of the present invention comprises:
It has a black matrix formed using the photocurable composition for a color filter according to any one of claims 1 to 7. A liquid crystal display according to a ninth aspect of the present invention uses the color filter according to the seventh aspect.

Hereinafter, the present invention will be described in detail. (Silica-coated carbon black) The photocurable composition for a color filter of the present invention contains silica-coated carbon black in order to exhibit excellent image-forming properties and high light-shielding properties. The amount of silica in the silica coating-coated carbon black is usually 0.5 to 50% by weight as SiO ₂ , preferably 1 to 50% by weight.
It is about 40% by weight. The method of coating the carbon black with silica can be performed in a gas phase or a liquid phase, but may be performed by any method.

For example, in a gas phase method, carbon black is placed in a closed container, and the closed container is evacuated. A silica source such as tetramethoxysilane or tetraethoxysilane is introduced therein, the silane source is adsorbed on the carbon black surface, and the carbon black reacts with the silica source. After the completion of the reaction, the excess silica source is removed under reduced pressure, and subsequently an alkali such as ammonia is introduced into the closed vessel to convert methoxy and ethoxy groups to hydroxy groups. Through this series of operations, a silica monomolecular film is coated on the carbon black surface. This operation may be repeated as necessary to control the amount of silica coated on the carbon black.

As a method of coating in the liquid phase,
Carbon black is used as an aqueous dispersion, and an alkali such as potassium hydroxide or ammonia is added to the aqueous carbon black dispersion, and a silica source is added thereto. As the silica source at this time, a silicic acid solution or the like obtained by dealkalizing a water glass aqueous solution with a cation exchange resin or the like is preferably used. As another method, a sol-gel reaction of a silica source such as tetramethoxysilane or tetraethoxysilane may be used. In the method utilizing the sol-gel reaction, a carbon black aqueous dispersion is made acidic with hydrochloric acid or the like, or made alkaline with ammonia or the like, and reacted by adding a silica source such as tetramethoxysilane or tetraethoxysilane.

As the carbon black to be coated with silica, carbon black which has not been subjected to any pretreatment may be used. Alternatively, carbon black having a hydroxyl group introduced to the surface by performing a steam plasma treatment may be used. As the water vapor plasma treatment, for example, there is a method in which carbon black is placed in a closed container, and after degassing, hydroxyl groups are introduced into the carbon black surface by performing plasma irradiation while introducing water vapor.

Instead of the steam plasma treatment, the surface of the carbon black may be oxidized to promote the introduction of silica onto the carbon black. Examples of the oxidation treatment include a high-temperature baking method by heating at 100 to 300 ° C. in an air atmosphere, an acid treatment method of contacting with an acid such as nitric acid or perchloric acid, or hydrogen peroxide at a temperature of 100 to 250 ° C.
There is an ozone oxidation method of heating at a temperature of 100 to 300 ° C. in an ozone atmosphere.

The silica coating (liquid phase, gas phase) and various pretreatments (steam plasma treatment, oxidation treatment, etc.) may be performed in any combination. To carbon black that has been subjected to steam plasma treatment,
Silica coating in the gas phase, b. Silica coating in gas phase without pre-treatment, c. Preferably, carbon black coated with silica in the liquid phase without any pretreatment is used. Or c. Is more preferable.

In the present invention, there is no particular limitation on the carbon black to be coated with silica, and furnace black, acetylene black or the like having a specific surface area of 25 to 500 g / m ² is usually used. Specifically, for example, the following carbon blacks can be mentioned. Mitsubishi Chemical Corporation: MA7, MA8, MA11, MA10
0, MA220, MA230, # 52, # 50, # 4
7, # 45, # 2700, # 2650, # 2200, #
1000, # 990, # 900, etc. Degussa: Printex95, Printex 9
0, Printex85, Printex75, Pri
ntex55, Printex45, Printex4
0, Printex30, Printex3, Prin
texA, PrintexG, SpecialBlac
k550, SpecialBlack350, Spec
ialBlack250, SpecialBlack1
00 etc. manufactured by Cabot Corporation: Monarch 460, Monarc
h430, Monarch280, Monarch12
0, Monarch 800, Monarch 4630,
REGAL99, REGAL99R, REGAL41
5, REGAL415R, REGAL250, REGAL
L250R, REGAL330, BLACK PEAR
LS480, PEARLS130, etc., manufactured by Colombian Carbon: RAVE11, RAV
EN15, RAVE30, RAVE35, RAVE
N40, RAVEN410, RAVEN420, RAV
EN450, RAVEN500, RAVE780, R
AVEN850, RAVE890H, RAVE10
00, RAVEN1020, RAVEN1040, etc. The above carbon black may be used in combination with other black inorganic or organic pigments. Since other black pigments have a lower light-shielding property than carbon black, the mixing ratio is naturally limited, and is preferably 50% by weight or less based on the total amount of the black coloring material. Examples of other black pigments include titanium black, aniline black, iron oxide black pigment, and red, green,
A mixture of three blue organic pigments can be used as a black pigment. (Photocurable composition) In the photocurable composition for a color filter of the present invention, there is no particular limitation other than carbon black, and an image is formed by photocuring by exposure through a mask and removal of an uncured portion by development. Any composition that can be formed may be used, but particularly preferred is a photocuring composition containing, in addition to carbon black, a binder resin, a compound having at least one ethylenically unsaturated double bond, a photopolymerization initiator system, and a solvent. The composition is an acidic composition. Hereinafter, each component of the photocurable composition containing such a component will be described in detail. (Binder Resin) The photocurable composition for a color filter of the present invention contains a binder resin as a material having a function as a binder for improving compatibility, film-forming properties, developability and adhesion. Although there is no particular limitation on the type of the binder resin, in the present invention, in order to form a high-sensitivity and high-definition image of the black matrix which is a light shielding material, and to improve the film strength of the formed black matrix, a binder is particularly preferable. As the resin, an organic polymer substance having an ethylenically unsaturated double bond in a side chain is preferable.
Among them, a copolymer having an ethylenically unsaturated double bond, a carboxyl group and a hydroxyl group is preferably used,
In particular, a styrene-based copolymer or an acrylic-based copolymer having an ethylenically unsaturated double bond, a carboxyl group, and a hydroxyl group is preferable.

Such a copolymer can be obtained by (1) copolymerizing a monomer having the above functional group, or (2) adding a polymer having a functional functional group to a polymer such as a styrene copolymer or an acrylic copolymer. It can be obtained by a method such as introduction of a group, but the method (2) is generally preferred from the viewpoint of ease of synthesis. Specific examples of the organic polymer having at least one ethylenically unsaturated double bond in the side chain include styrene, α-methyl-
Styrene monomers such as styrene and vinyltoluene; carboxylic acids containing unsaturated groups such as acrylic acid, methacrylic acid, cinnamic acid, maleic acid, fumaric acid, maleic anhydride, itaconic acid; methyl (meth) acrylate, ethyl (meth)
Acrylate, propyl (meth) acrylate, allyl (meth) acrylate, butyl (meth) acrylate,
2-ethylhexyl (meth) acrylate, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, benzyl (meth) acrylate, etc.
Esters of (meth) acrylic acid such as hydroxyphenyl (meth) acrylate and methoxyphenyl (meth) acrylate benzyl (meth) acrylate; acrylonitrile; vinyl acetate, vinyl versatate, vinyl propionate, vinyl cinnamate, vinyl pivalate, etc. It can be obtained by introducing an ethylenic double bond into the side chain of a copolymer such as vinyl acid.

The ethylenically unsaturated double bond in the side chain can be introduced by an organic bond such as an ester bond, an amide bond, an ether bond, an imide bond, and a urethane bond. As an example of the introduction reaction, a part or all of the carboxylic acid group and / or the hydroxyl group of the organic polymer copolymer is converted into glycidyl (meth) acrylate, allyl glycidyl ether, and an alicyclic epoxy group having the following structure. It can also be introduced by reacting with an unsaturated compound having an aliphatic epoxy group such as an unsaturated compound. In this specification, “(meth) acryl” indicates “acryl or methacryl”. The same applies to “(meth) acrylate”.

[0026]

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[0027]

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[0028]

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[In each formula, R ₁ represents a hydrogen atom or a methyl group. R ₂ represents a divalent saturated aliphatic hydrocarbon group having 1 to 6 carbon atoms. R ₃ represents a divalent hydrocarbon group having 1 to 10 carbon atoms. l shows the integer of 0-10. And the like. In the above, as the divalent aliphatic saturated hydrocarbon group having 1 to 6 carbon atoms represented by R ₂ , a linear or branched alkylene group such as methylene, ethylene,
Examples include propylene, tetramethylene, ethylethylene, pentamethylene, and hexamethylene groups.
Examples of the divalent hydrocarbon group having 1 to 10 carbon atoms represented by R ₃ include methylene, ethylene, propylene, tetramethylene, ethylethylene, pentamethylene, hexamethylene, polymethylene, phenylene,

[0030]

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And the like. In the present invention, particularly preferred organic polymer substances include styrene, α-methylstyrene,
10 to 98 mol% of a copolymer monomer having a phenyl group such as benzyl (meth) acrylate, hydroxyphenyl (meth) acrylate, methoxyphenyl (meth) acrylate, hydroxyphenyl (meth) acrylamide, and hydroxyphenyl (meth) acrylsulfonamide. , Preferably 20-80 mol%, more preferably 3
The copolymer containing (meth) acrylic acid at a ratio of 2 to 90% by weight, preferably 10 to 70% by weight, and 2 to 5% by
A reactant to which 0 mol%, preferably 5 to 40 mol% of an epoxy group-containing unsaturated compound is added is desirable.

The molecular weight of such an organic polymer substance is 1,000 to 1,000, in terms of weight average molecular weight (Mw).
000, preferably 2,000 to 300,000, more preferably 3,000 to 100,000.
If the Mw of the organic polymer substance is significantly lower than this range, the film thickness of the image area tends to be reduced during development. Conversely, if the Mw of the organic polymer substance is extremely high, the poor removability of the non-image area during development occurs. Tend to occur.

The photocurable composition for a color filter of the present invention may further contain another organic or inorganic polymer.
These organic and inorganic polymers include polyethylene glycol, polypropylene glycol, polytetraethylene glycol, epichlorohydrin and bisphenol A.
Polyamides such as polyethers and copolymerized polyethers, polyvinyl alkyl ethers, soluble nylons and the like, polyurethanes, polyethylene terephthalate / isophthalate, polyethylene adipate, polytetraethylene adipate, polyesters such as polyethylene fumarate,
Acetyl cellulose, polyvinyl formal, polyvinyl butyral and the like can be mentioned. (Compound having at least one ethylenically unsaturated heavy bond) A compound having at least one ethylenically unsaturated heavy bond (hereinafter referred to as "ethylenic compound") is a radical generated from a photopolymerization initiator system described later. Is a compound in which a polymerization reaction is induced by The ethylenic compound may be a monomer or an oligomer having an ethylenically unsaturated double bond in a side chain or a main chain. In addition,
The meaning of the monomer in the present invention is a concept corresponding to a so-called polymer substance, and therefore includes not only a monomer in a narrow sense but also a dimer, a trimer, and an oligomer.

Examples of the ethylenic compound include unsaturated carboxylic acids, esters of aliphatic (poly) hydroxy compounds with unsaturated carboxylic acids, esters of aromatic polyhydroxy compounds with unsaturated carboxylic acids, and unsaturated carboxylic acids. Of poly (carboxylic acid) and aliphatic polyhydroxy compound and ester obtained from aliphatic polyhydroxy compound, ethylene oxide of aromatic polyhydroxy compound, esterification reaction of propylene oxide adduct with unsaturated carboxylic acid, addition of ethylene oxide and propylene oxide of aliphatic polyhydroxy compound Reaction between a product and an unsaturated carboxylic acid, an ester of a caprolactone-modified polyhydric alcohol and an unsaturated carboxylic acid, a reaction product of a polyhydric alcohol and a polyhydric isocyanate and an unsaturated carboxylic acid, a styryl terminal compound, and a phosphorus-containing compound. Acid unsaturated compound, polyepoxy Adducts of an unsaturated carboxylic acid.

Of these, esters of the aliphatic polyhydroxy compound and the unsaturated carboxylic acid include, specifically, ethylene glycol diacrylate, triethylene glycol diacrylate, neopentyl glycol diacrylate, hexanediol diacrylate, Acrylic acid such as methylolpropane triacrylate, trimethylolethane triacrylate, pentaerythritol diacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, glycerol acrylate, etc. Ester, a method in which the acrylate of these exemplified compounds is replaced with methacrylate. Acrylic acid esters, as well as itaconic acid esters instead itaconate, maleic acid esters, and the like was replaced with crotonic acid ester or maleate was replaced crotonate.

Examples of the ester of the aromatic polyhydroxy compound and the unsaturated carboxylic acid include hydroquinone diacrylate, hydroquinone dimethacrylate, resorcin diacrylate, resorcin dimethacrylate, and pyrogallol triacrylate. The ester obtained by the esterification reaction of the unsaturated carboxylic acid with the polycarboxylic acid and the polyhydric hydroxy compound is not necessarily a single substance, but typical examples include condensation of acrylic acid, phthalic acid and ethylene glycol. Product, acrylic acid, maleic acid and diethylene glycol condensate,
Examples include condensates of methacrylic acid, terephthalic acid and pentaerythritol, condensates of acrylic acid, adipic acid, butanediol and glycerin.

Other examples of the ethylenic compound used in the present invention include acrylamides such as ethylene bisacrylamide; allyl esters such as diallyl phthalate; and vinyl group-containing compounds such as divinyl phthalate. Examples of the oligomer having an ethylenically unsaturated bond in the main chain include, for example, a polyester obtained by a polycondensation reaction of an unsaturated divalent carboxylic acid and a dihydroxy compound, and a polymerization of an unsaturated divalent carboxylic acid and a diamine. There is a polyamide obtained by a condensation reaction.

The oligomer having an ethylenically unsaturated bond in the side chain includes a divalent carboxylic acid having an unsaturated bond in the side chain, for example, itaconic acid, propylidene succinic acid,
There is a condensation polymer of ethylidene malonic acid or the like with a dihydroxy or diamine compound. Further, a polymer having a functional group having a reactive activity such as a hydroxy group or a methyl halide group in a side chain, for example, polyvinyl alcohol, poly (2-hydroxyethyl methacrylate), polyepichlorohydrin, etc., and acrylic acid, methacrylic acid, crotonic acid A polymer obtained by a polymer reaction with an unsaturated carboxylic acid such as described above can also be suitably used. (Photopolymerization initiator system) The photopolymerization initiator system used in the present invention is not particularly limited as long as it is a compound capable of polymerizing an ethylenically unsaturated double bond by actinic rays, but a biimidazole compound, a titanocene compound, a triazine compound And at least one compound selected from amino group-containing sensitizing dyes, thiol compounds, N-phenylglycine and derivatives thereof. Is more preferable from the viewpoint of the above performance.

Specific examples of the biimidazole compound include:
2,2'-bis (o-chlorophenyl) -4,4 ',
5,5'-tetraphenylbiimidazole, 2,2'-
Bis (o-chlorophenyl) -4,4 ', 5,5'-tetra (p-carbethoxyphenyl) biimidazole,
2,2'-bis (o-chlorophenyl) -4,4 ',
5,5'-tetra (p-bromophenyl) biimidazole, 2,2'-bis (o-chlorophenyl) -4,
4 ', 5,5'-tetra (o, p-dichlorophenyl)
Biimidazole, 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 can be mentioned.

The titanocene compound is disclosed in
152396, JP-A-61-151197, JP-A-63-10602, JP-A-63-41
484, JP-A-2-291, JP-A-3-1
JP-A-2403, JP-A-3-20293, JP-A-3-27393, JP-A-3-52050,
JP-A-4-221958, JP-A-4-21975
No. 6, JP-A-3-27393 and the like can be used.
Cyclopentadienyl-Ti-di-chloride, di-cyclopentadienyl-Ti-bis-phenyl, di-cyclopentadienyl-Ti-bis-2,3,4,5,6-
Pentafluorophenyl-1-yl, dicyclopentadienyl-Ti-bis-2,3,5,6-tetrafluorophenyl-1-yl, di-cyclopentadienyl-Ti-bis-2,4,6 -Trifluorophenyl-1-yl, di-
Cyclopentadienyl-Ti-bis-2,6-di-fluorophenyl-1-yl, di-cyclopentadienyl-T
i-bis-2,4-di-fluorophenyl-1-yl, di-methylcyclopentadienyl-Ti-bis-2,3,
4,5,6-pentafluorophenyl-1-yl, di-methylcyclopentadienyl-Ti-bis-2,3,5
6-tetrafluorophenyl-1-yl, di-methylcyclopentadienyl-Ti-bis-2,6-difluorophenyl-1-yl, di-cyclopentadienyl-Ti-bis-2,6-difluoro- 3- (pyr-1-yl) -phenyl-1-yl and the like can be mentioned.

As an example of the triazine compound, a triazine compound having a halomethyl group is preferably used. Examples thereof include 6-phenyl-2,4-bis (trichloromethyl) -s-triazine, 6- (p-methoxyphenyl) -2,4-bis (trichloromethyl) -s-triazine.
Triazine, 6- [p- (N, N-bis (ethoxycarbonylmethyl) amino) phenyl) -2,4-bis (trichloromethyl) -s-triazine, 6- (p-styrylphenyl) -2,4- Bis (trichloromethyl) -s
-Triazine, 6-p-chlorophenyl-2,4-bis (trichloromethyl) -s-triazine, 6- (p-methylthiophenyl) -2,4-bis (trichloromethyl) -s-triazine and the like.

As an example of the oxadiazole compound, an oxadiazole compound having a halomethyl group is preferably used. Examples thereof include 2-phenyl-5-trichloromethyl-1,3,4-oxadiazole,
(P-methylphenyl) -5-trichloromethyl-1,
3,4-oxadiazole, 2- (p-methoxyphenyl) -5-trichloromethyl-1,3,4-oxadiazole, 2-styryl-5-trichloromethyl-1,
3,4-oxadiazole, 2- (p-methoxystyryl) -5-trichloromethyl-1,3,4-oxadiazole, 2- (p-butoxystyryl) -5-trichloromethyl-1,3 4-oxadiazole and the like.

Examples of the amino group-containing sensitizing dye include dialkylaminophenyl groups described in JP-A-6-19240 and JP-A-6-19249.
Specifically, as the compound having a dialkylaminophenyl group, a compound represented by the following structural formula,

[0044]

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[0045]

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Compounds such as ethyl p-diethylaminobenzoate and Michler's ketone, and dialkylaminophenylcarbaldehydes such as p-diethylaminobenzcarbaldehyde and 7-julolidylcarbaldehyde are exemplified. Of these, compounds having a dialkylaminophenyl group are more sensitive and preferred. As the thiol compound, examples of the aliphatic polyfunctional thiol compound used in the present invention include hexanedithiol, decanedithiol, 1,4-dimethylmercaptobenzene, butanediol bisthiopropionate, and butanediol bisthioglycolate. , Ethylene glycol bisthioglycolate, trimethylolpropane tristhioglycolate, butanediol bisthiopropionate, trimethylolpropane tristhiopropionate, trimethylolpropane tristhioglycolate, pentaerythritol tetrakisthiopropionate, penta Erythritol tetrakisthioglycolate, trishydroxyethyltristhiopropionate, 2-mercapto-benzothiazole, 2-mercapto-benzoxazole, 2 -Mercapto-benzodizole, and the like.

Examples of N-phenylglycine and its derivatives include N-phenylglycine, an alkyl group, an alkoxyl group, an amino group, a nitro group, a cyano group or a halogen-substituted N-phenylglycine, and a carboxylic acid of N-phenylglycine. And the like. The content of each component of the photocurable composition for a color filter of the present invention is such that the blending amount of the binder resin is 5 with respect to the total solid content excluding the solvent.
The content of the compound having at least one ethylenically unsaturated double bond is preferably 5 to 4% by weight.
The amount is preferably 0% by weight, and the amount of the photopolymerization initiator is preferably 0.1 to 20% by weight, particularly 0.5 to 15% by weight, particularly preferably 1 to 10% by weight. Further, the content ratio of each compound in the photopolymerization initiator system is such that at least one compound selected from a biimidazole compound, a titanocene compound, a triazine compound and an oxadiazole compound is the total amount of the solid content excluding the solvent. At 0.01
It is preferably about 5% by weight. Further, when an amino group-containing sensitizing dye is contained, the content is preferably in the range of 0.01 to 5% by weight, and at least one compound selected from thiol compounds, N-phenylglycine and derivatives thereof is 0.01 to 5% by weight. It is preferably in the range of 5% by weight, especially in the range of 0.1 to 4% by weight.

The compounding amount of the silica-coated carbon black as the light-shielding material is such that a light-shielding ratio at a film thickness of 1 μm is 3.0, and further a photo-curable composition is required to form a black matrix having a high light-shielding ratio of 3.5 or more. It is preferably in the range of 20 to 90% by weight, especially 30 to 80% by weight, based on the total solid content in the product. When blending the silica-coated carbon black into the composition, various dispersants and dispersing agents can be used as long as the object of the present invention is not impaired.

In the present invention, the solvent dissolves and disperses the above-mentioned components, and specifically, methyl cellosolve, ethyl cellosolve, butyl cellosolve, diethylene glycol monomethyl ether, propylene glycol monomethyl ether acetate (hereinafter referred to as “PGMA”).
c ". ), Methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, toluene, chloroform, dichloromethane, ethyl acetate, methyl lactate, ethyl lactate, methanol, ethanol, propanol, butanol, tetrahydrofuran and the like.

The photocurable composition of the present invention has a solid content of 5 to 50% by weight, preferably 1%, by using these solvents.
The solution is prepared so as to be in the range of 0 to 40% by weight. next,
The method for producing the photocurable composition for a color filter of the present invention will be described. In the present invention, first, a dispersion of silica-coated carbon black is produced. In order to promote the dispersion of the silica-coated carbon black and stabilize the dispersion, the binder resin may be dispersed together with the binder resin, or various dispersants and dispersing aids may be used as long as the purpose is not impaired. As a method of dispersing, a paint conditioner, a sand grinder, a ball mill, a roll mill, a stone mill, a jet mill, a homogenizer and the like can be used. When dispersing using a paint conditioner or a sand grinder, the dispersion is performed using glass beads or zirconia beads having a diameter of 0.1 to several millimeters. The conditions for dispersion are
Usually, the temperature is between 0 ° C and 100 ° C, preferably between room temperature and 60 ° C. The dispersion time varies depending on the carbon black, dispersant, dispersant, binder resin and the like used, but is from 10 minutes to 50 hours, preferably from 20 minutes to 20 hours.

Subsequently, a binder resin, a compound having at least one ethylenically unsaturated double bond, a photopolymerization initiator and a solvent are added to the silica-coated carbon black dispersion, and various additives ( (A leveling agent, a light stabilizer and the like) to produce a photocurable composition.
Next, the photocurable composition obtained above is applied on a transparent substrate using a coating device such as a spinner, a wire bar, a flow coater, a die coater, a roll coater, or a spray and dried. A photomask is placed, a resin black matrix image is formed by image exposure, development, and, if necessary, heat curing or light curing through the photomask, and the same operation is repeated for each of the three colors RGB to form a film on the transparent substrate. A color filter image having a thickness of 0.5 to 3 μm is formed. The thickness of the black matrix after drying is 0.1 to 5 μm, preferably 0.3 to 5 μm.
The optical density is preferably in the range of 0.5 to 2.5 μm, more preferably 0.5 to 1.5 μm, and the optical density at a film thickness of 1 μm is preferably 3.0 or more.

The transparent substrate used here is a transparent substrate for a color filter, and the material is not particularly limited. For example, polyester such as polyethylene terephthalate, polypropylene, polyolefin such as polyethylene, polycarbonate, polymethyl Examples include thermoplastic resin sheets of methacrylate and polysulfone, thermosetting plastic sheets such as epoxy resin, polyester resin, and 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.

When forming a resin black matrix or a pixel of each color of RGB on such a transparent substrate, a corona discharge treatment, an ozone treatment, a silane cup treatment, etc. are previously applied to the substrate surface in order to improve the physical properties such as surface adhesiveness. It is preferable to perform a thin film treatment of various polymers such as a ring agent and a urethane polymer. The thickness of the transparent substrate is 0.05 to 10 mm,
In particular, it is preferably in the range of 0.1 to 2 mm. When a thin film treatment of various polymers is performed, the film thickness is preferably in the range of 0.01 to 10 μm, particularly preferably 0.05 to 5 μm.

Although the size of the transparent substrate is not particularly limited, a transparent substrate of about several to several tens cm × several to several tens cm is usually used as the transparent substrate. Light sources used for exposure include, for example, lamp light sources such as xenon lamps, halogen lamps, tungsten lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, metal halide lamps, medium-pressure mercury lamps, low-pressure mercury lamps, argon ion lasers, and YAG lasers.
A laser light source such as a laser, an excimer laser, and a nitrogen laser is exemplified. In this case, when only a specific wavelength of the irradiation light is used, an optical filter may be appropriately used.

In the development processing, it is preferable to use an alkali developer. For example, it contains 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 diethanolamine, triethanolamine and tetraalkylammonium hydroxide salt. If necessary, an aqueous solution containing a surfactant, a water-soluble organic solvent, a low molecular compound having a hydroxyl group or a carboxylic acid group, or the like is used for the purpose of improving image quality, shortening the development time, and the like.

Examples of the surfactant in the developer include an anionic surfactant having a sodium naphthalenesulfonate group, a sodium benzenesulfonate group, a nonionic surfactant having a polyalkyleneoxy group, and a cation having a tetraalkylammonium group. Examples of the water-soluble organic solvent include ethanol, propion alcohol, butanol, methyl cellosolve, butyl cellosolve, phenyl cellosolve, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, and propylene. Glycol, dipropylene glycol, tripropylene glycol, tetrapropylene glycol, ethylene glycol monomethyl ether acetate, propylene glycol monomethyl And ether acetate.

Examples of the low molecular weight compound having a hydroxyl group or a carboxy group include 1-naphthol, 2-naphthol,
Examples include pyrogallol, benzoic acid, succinic acid, and glutaric acid. Development processing is usually 15 to 40 ° C,
The development is preferably performed at a development temperature of 20 to 30 ° C. by a method such as immersion development, spray development, brush development, or ultrasonic development.

After the development treatment, a curing treatment can be performed for the purpose of stabilizing various physical properties. The curing treatment includes a treatment by heating, a treatment by ultraviolet rays, and the like.

[0059]

The present invention will be described in more detail with reference to the following examples and comparative examples, but the present invention is not limited to the following examples unless it exceeds the gist of the present invention. Production Example 1 (Production of steam plasma-treated carbon black) Carbon black (MA100, manufactured by Mitsubishi Chemical Corporation)
10 g was put into a glass flask, and attached to a rotary stirring, vacuum degassing apparatus. The flask was evacuated while rotating and stirring (vacuum degree: 0.1 torr or less). After the deaeration is completed, while passing steam, the steam introduction amount is 40 scc.
m), plasma irradiation was performed at 30 W for 1 hour at room temperature.
After the plasma irradiation, air was introduced into the flask to atmospheric pressure, and the steam plasma-treated carbon black was taken out. Production Example 2 (Production of Silica-Coated Carbon Black) Gas Phase Method 10 g of carbon black to be coated with silica (MA100 manufactured by Mitsubishi Chemical Co., Ltd. or obtained by subjecting the same to steam plasma treatment according to Production Example 1) was placed in a glass autoclave. The autoclave was degassed. In a separate container, tetraethoxysilane was prepared by freezing and degassing with liquid nitrogen to remove air. The two containers were connected by a gas line, and the container containing carbon black was filled with tetraethoxysilane. The autoclave was heated to 60 ° C. to react tetraethoxysilane with carbon black for 3 hours. After the reaction, the glass autoclave was degassed to remove excess tetraethoxysilane. Subsequently, ammonia gas was introduced into the autoclave,
C. for 3 hours to convert unreacted ethoxy groups of the tetraethoxysilane reacted on the carbon black into hydroxy groups. Excess ammonia gas was degassed to terminate the reaction. The above reaction of tetraethoxysilane,
The conversion of ethoxy groups to hydroxy groups by ammonia was repeated three times, and finally air was introduced to take out silica-coated carbon black. Liquid phase method 10 g of carbon black coated with silica (MA100 manufactured by Mitsubishi Chemical Co., Ltd. or obtained by subjecting it to steam plasma treatment according to Production Example 1) was added to 200 m of pure water.
The resulting mixture was charged into a glass container containing 1 with stirring to prepare an aqueous dispersion of carbon black. 1 g of concentrated hydrochloric acid was added to the aqueous carbon black dispersion to make it acidic. Further, 1.0 g of tetraethoxysilane is added and reacted at 60 ° C. for 3 hours. After the completion of the reaction, the dispersion was subjected to solid-liquid separation by pressure filtration,
A silica coated carbon black was obtained. Production Example 3 (Production of Carbon Black Dispersion) 2.0 g of the silica-coated carbon black obtained in Production Example 2 and a dispersant (BYK-18 manufactured by BYK-Chemie)
2) 0.88 g and 6.64 g of propylene glycol monomethyl ether acetate are mixed, and the mixture is placed in a paint shaker containing 3.5 times by weight of zirconia beads having a diameter of 0.5 mm and dispersed for 5 hours. A dispersion was produced. The substances and abbreviations used to describe the present invention are shown below.

Binder resin (P-1)

[0061]

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Ethylene compound (M-1)

[0063]

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Photopolymerization initiator

[0065]

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[0066]

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Reference Examples 1 to 3 "Production of red, green, and blue pigment-dispersed inks" Red pigment: Lionogen Red GD2.6 manufactured by Toyo Ink Co., Ltd.
2.6 g of dispersant BYK-161 manufactured by Big Chemie
And 9.5 g of propylene glycol monomethyl ether acetate, and the mixture was placed in a paint shaker containing 0.5 times the weight of zirconia beads having a diameter of 3.5 mm, and dispersed for 10 hours to produce a red pigment dispersion. (Reference Example 1).

Similarly, a green pigment dispersion was prepared using Lionol Green 2YS (manufactured by Toyo Ink) as a green pigment (Reference Example 2), and Lionol Blue ES (manufactured by Toyo Ink) was used as a blue pigment. A blue pigment dispersion was produced (Reference Example 3). Hereinafter, "gas-phase method silica coating water vapor plasma treated carbon black" refers to Production Example 1
Represents carbon black obtained by subjecting the carbon black subjected to the water vapor plasma treatment to silica coating by the gas phase method of Production Example 2.

The “liquid-phase method silica-coated steam plasma-treated carbon black” refers to carbon black obtained by subjecting the steam plasma treatment of Production Example 1 to silica coating by the liquid-phase method of Production Example 2. The “vapor-phase method silica-coated carbon black” refers to carbon black that has not been subjected to the steam plasma treatment and is coated with silica by the vapor-phase method of Production Example 2.

Similarly, the “liquid-phase method silica-coated steam plasma-treated carbon black” refers to carbon black not subjected to the steam plasma treatment.
Represents carbon black coated with silica by the liquid phase method. "... carbon black dispersion" means a carbon black dispersion prepared according to Production Method 3 using any of the above silica-coated carbon blacks. Example 1 A binder resin (P-1), dipentaerythritol hexaacrylate (M-1) as an ethylenic compound, and photopolymerization initiation were added to the fumed silica-coated water vapor plasma-treated carbon black dispersion obtained in Production Example 3. 2,2'-bis (o-chlorophenyl) -4,
4 ', 5,5'-tetraphenylbiimidazole (R-
1) 4,4'-bis (diethylamino) benzophenone (Y-1) and pentaerythritol tetrakisthiopropionate (T-1) are blended in the ratio shown in Table 1,
Propylene glycol monomethyl ether acetate was added as a solvent to prepare a coating solution such that the solid content concentration became 25%.

The prepared coating solution containing carbon black was applied to a glass substrate by a spin coater so as to have a dry film thickness of 0.9 μm, and dried at a drying temperature of 70 ° C. for 3 minutes. Next, a width of 30 μm, a length of 300 μm, and a width of 1 μm.
Using a negative photomask for a black matrix which is repeated at a pitch of 00 μm, and exposing at an appropriate exposure dose (100 mj / cm 2) with a 3 Kw ultra-high pressure mercury lamp, 0.01
Using a developer consisting of an aqueous solution containing 5% by weight of potassium hydroxide and 0.05% of a nonionic surfactant (Emulgen A-60 manufactured by Kao), shower-developed at 23 ° C, and stopped with pure water. Then, it was rinsed with a water spray to form a black matrix. Thereafter, the sample was heat-treated at 200 ° C. for 10 minutes to be thermally cured. The obtained black matrix had a sharp edge shape, the line width stability during development (development latitude) was 25 seconds or more, and no surface roughness due to the developer was observed. When coating, exposure and development were carried out in the same manner using a photomask having a line / space from 1 μm to 50 μm, a fine line with an image quality of 6 μm or less could be reproduced. Comparative Example 1 The gas-phase-processed silica-coated steam plasma-treated carbon black dispersion of Example 1 was replaced with carbon black without silica coating (Mitsubishi Chemical Corporation, M
Example 1 except that the dispersion was changed to A100).
As a result, the image quality was 15 μm.
The development latitude was 10 seconds. Examples 2 to 4 The gas-phase-process silica-coated steam plasma-treated carbon black dispersion of Example 1 was replaced with a liquid-phase silica-coated steam-plasma-treated carbon black dispersion, a gas-phase silica-coated carbon black dispersion, and a liquid-phase silica. The procedure was performed in the same manner as in Example 1 except that the coating carbon black dispersion was changed. Example 5 2,2'-bis (o-chlorophenyl)-of Example 1
4,4 ', 5,5'-Tetraphenylbiimidazole (R-1) is converted to dicyclopentadienyl-Ti-bis-
2,3,5,6-tetrafluorophenyl-1-yl (R
-2: The same operation as in Example 1 was performed, except that the product was changed to "CGI-784" manufactured by Ciba-Geigy. Example 6 The same operation as in Example 1 was performed except that 4,4'-bis (diethylamino) benzophenone (Y-1) in Example 1 was changed to 4,4'-bis (dimethylamino) benzophenone (Y-2). Was. Example 7 The pentaerythritol tetrakisthiopropionate (T-1) of Example 1 was replaced with N-phenylglycine (T-
The procedure was changed to 2) and performed in the same manner as in Example 1. Table 1 below shows the proportions and evaluation results of each component of the compositions of Examples and Comparative Examples. In addition, the weight% in the table indicates the ratio to the total solid content. The exposure amount and image quality suitable for transmission density have the following meanings or evaluation methods. [Transmission Density] The transmission density (ABS) of the sample was measured using a Macbeth densitometer TR-927. The thickness of the photocurable layer of the sample was measured by α-step manufactured by Tencor Instruments, Inc., and the results are shown in parentheses. The value of the transmission density corresponds to the optical density. [Appropriate exposure amount] After applying a color material-containing photocurable coating solution on a glass substrate and drying, a Ugra test chart is placed on a sample, and 3 Kw ultra-high pressure is applied while changing various exposure amounts from above the chart. Exposure amount when the narrowest positive and negative line widths of the fine line image in the obtained Ugura test chart image become the same, after exposure with a mercury lamp and development processing. [Image quality] In the same manner as in [Appropriate exposure], a photocurable coating solution containing a color material is applied to a glass substrate, dried, and then exposed using a Ugura test chart at an appropriate exposure, followed by standard development. A developing process was performed using the liquid to form a colored image. The fine line image in the colored image was observed with a microscope of 400 times, and the line width (resolution), linearity, and surface state of the thinnest fine line reproduced were evaluated. The finer the line, the better the image quality.

[0072]

[Table 1]

Example 8 A black matrix was formed on a glass substrate in the same manner as in Example 1 above, and a dry film was formed on the glass substrate using the red pigment dispersion obtained in Reference Example 1 above. It is applied by a spin coater so that the thickness becomes 1.3 μm,
Let dry. Next, at 100 μm in width and 300 μm in height, 30
Exposure is performed using a colored pixel negative mask that is repeated at a pitch of μm, and is developed using a developing solution composed of an aqueous solution containing 0.2% by weight of potassium hydroxide and 0.5% by weight of a nonionic surfactant, and is then added to pure water. The development was stopped by rinsing with a water-washing spray to form colored pixels. Then, the sample was
A heat treatment was performed at 00 ° C. for 10 minutes to thermally cure. The obtained colored pixel had a sharp edge shape and an appropriate tapered shape. No surface film roughness was observed during development, and no decrease in film thickness was observed. Sequentially, green,
Two color blue pixels were formed to produce a color filter.
The obtained color filter was of high quality with high definition and no color bleeding. Example 9 When a liquid crystal display device was assembled using the color filters obtained in Example 8, an image having excellent contrast could be displayed.

[0074]

According to the present invention, the sensitivity of the photocurable composition for a color filter containing a black color material can be greatly improved, and the resolution and developability are excellent, and high accuracy and high light shielding are achieved. A high-density black matrix, and a high-definition color filter with high color density can be provided. In addition, the photocurable composition of the present invention has excellent storage stability.

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Claims (9)

[Claims] 1. A photocurable composition for a color filter, comprising carbon black coated with silica. 2. The photocurable composition for a color filter according to claim 1, wherein, in addition to the silica-coated carbon black, a binder resin, a compound having at least one ethylenically unsaturated double bond, and photopolymerization initiation. A photocurable composition for a color filter, comprising an agent system and a solvent. 3. The carbon black according to claim 1, wherein the carbon black is coated with silica in a gas phase.
Or the photocurable composition for a color filter according to 2. 4. The method according to claim 1, wherein the carbon black is coated with silica in a liquid phase.
Or the photocurable composition for a color filter according to 2. 5. The photocurable composition for a color filter according to claim 1, wherein the carbon black is subjected to a steam plasma treatment and then coated with silica. 6. The photopolymerization initiator system according to claim 2, wherein the photopolymerization initiator system contains at least one compound selected from a biimidazole compound, a titanocene compound, a triazine compound and an oxadiazole compound. The photocurable composition for a color filter according to any one of the above. 7. The photopolymerization initiator system, in addition to at least one compound selected from a biimidazole compound, a titanocene compound, a triazine compound and an oxadiazole compound, an amino group-containing sensitizing dye, a thiol compound,
The photocurable composition for a color filter according to claim 6, comprising at least one compound selected from N-phenylglycine and a derivative thereof. 8. A color filter having a black matrix formed on a transparent substrate using the photocurable composition for a color filter according to claim 1. 9. A liquid crystal display device using the color filter according to claim 8.