JP2000214581A - Photosensitive coloring composition and heat-resistant color filter using the same - Google Patents

Abstract

(57) [Problem] To provide a photosensitive coloring composition capable of producing a heat-resistant color filter having good storage stability and excellent flatness. Another object of the present invention is to provide a heat-resistant color filter that has excellent flatness and does not cause disconnection of a drive electrode or the like, and does not cause a decrease in an electric field, leakage of electric charges to an adjacent pixel, or the like. An inorganic pigment coated on a transparent inert layer is provided.
A photosensitive coloring composition comprising 3, 14, 15, and 16. Also,
A heat-resistant color filter in which a black matrix layer BK and coloring pattern layers R, G, and B are formed on a transparent substrate 1. At least a part of the black matrix layer and the coloring pattern layer is the photosensitive coloring composition. Be formed using.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color filter used for a display device such as a field emission display, a plasma discharge display panel, a fluorescent display device and a color liquid crystal display and a solid-state image pickup device, and particularly to a reflectance. The present invention relates to a heat-resistant color filter used for reduction of contrast, improvement of contrast, and control of spectral characteristics.

[0002]

2. Description of the Related Art In the above color liquid crystal display, a color filter having a spectral characteristic of a desired color is often used for displaying a color image, and an organic pigment is formed by a dyeing method, a pigment dispersion method, a printing method, or the like. Or a resin layer colored with an organic dye is used as a color filter. (M. Tani, et al: “LCD
Color Filters: Characteris
tics and Future Issues ”, S
ID 95 SEMINAR LECTURE (199
5) etc.)

Further, as a useful means for improving the display image quality of a cathode ray tube display (CRT), a low-speed electron beam fluorescent display panel, and the like, it has been proposed to use a color filter for reducing the reflectance of the displayed image and improving the contrast. . (TI
to, et al: "MicrofilterTM"
Color CRT, SID 95 Digest,
p. 25 (1995) etc.)

[0004] By the way, a plasma discharge display panel or a field emission display requires a heating process at 400 ° C or higher for melting a low-melting glass and sealing two glass substrates at the time of manufacture. If a filter is used, the constituent organic materials will burn, decompose, etc. in the high-temperature heating process, reducing the reflectance,
Color filter characteristics such as contrast improvement and spectral characteristic control cannot be exhibited.

As one method of solving this problem, there has been proposed a color filter adapted to a high-temperature manufacturing process by using a coloring material in which an inorganic pigment is dispersed in a low-melting glass. (Sakai et al .: "Ultra-low reflectivity color display discharge panel (3)" Technical Report of the Institute of Television Engineers of Japan, ED9
93, IPD113-8 (1986-11), etc.)

In this proposal, a paste consisting of a low-melting glass powder, an inorganic pigment, and a resin binder for temporarily fixing these materials to a transparent substrate is screen-printed on pixel portions on the transparent substrate and printed. The pixel pattern is fired at about 600 ° C. to burn off organic components such as a resin binder, and at the same time, melt the low-melting glass powder to coat and fix the inorganic pigment on the transparent substrate to form a colored pattern layer. The colored pattern layer composed only of the layer has durability to a high-temperature heating process.

However, in the screen printing method adopted in the above proposal, the screen plate generally expands and contracts under conditions such as the ambient temperature of the printing press, humidity, squeegee pressure and squeegee moving speed, and the pattern to be printed tends to be distorted. Also,
There is a disadvantage that it is difficult to print a fine pattern due to the limitation of the screen mesh opening.

Further, in order to satisfy the spectral characteristics of the color filter, the thickness of the low melting point glass and the pigment constituting the colored pattern layer is about 10 μm. A step is generated, and disconnection is likely to occur when a drive electrode or the like required later as a plasma discharge display panel or a field emission display is formed. Then, in addition to the problem of the resolution and the dimensional accuracy of the colored pattern layer, a problem also occurs in image quality such as a display defect.

As a method of solving these problems in the screen printing method, a pattern formation using a photolithography method and a subsequent flattening process have been proposed. In other words, after applying a photosensitive coloring composition containing acrylic resin, polyfunctional acrylic monomer, photopolymerization initiator, and coloring pigment as constituents, repeating pattern exposure and the like for the required number of times, heating and firing, and coloring on a transparent substrate This is a method of forming only a pigment on a colored pattern layer having a predetermined shape, and then providing an overcoat layer having a light transmitting property on the pigment formed as the colored pattern layer and a peripheral portion thereof to flatten the surface. (Japanese Patent Application No. 7-298200)

[0010] In the color filter produced by using this photolithography method, the pigment is formed as a black matrix layer and a colored pattern layer with a good resolution characteristic of the photolithography method. And a color filter in which the problem of dimensional accuracy has been solved.

In addition, the flattening process using the transparent overcoat layer after the formation of the black matrix layer and the colored pattern layer results in a thickness of about several μm for each of the black matrix layer and the colored pattern layer caused by the difference in coloring power of the colored pigment. The difference is flattened to provide a color filter in which the problem of disconnection of the drive electrode or the like in the screen printing method is solved.

Further, for example, even in the case of a display color filter in which an electrode is formed below the color filter, the unevenness caused by the drive electrode and the like is flattened by the overcoat layer, so that the unevenness on the color filter is reduced. The display defects caused by the display are reduced.

FIG. 2 is a diagram schematically showing a cross section of an example of a color filter produced by such a method. FIG.
In the color filter, the black matrix layer (BK) on the transparent substrate (1), the colored pattern layer (R,
G, B) and an overcoat layer (12). R, G, and B represent a red pattern layer, a green pattern layer, and a blue pattern layer of the colored pattern layers, respectively, and have different thicknesses. This is because the amount of a coloring pigment having a high coloring power is reduced, and the amount of a coloring pigment having a low coloring power is increased, thereby forming a colored pattern layer having desired coloring. The thickness difference is represented by h, and the film thickness of the overcoat layer (12) required for flattening the thickness difference is represented by H.

In FIG. 2, 3, 4, 5, and 6 denote a black pigment, a red pigment, a green pigment, and a blue pigment, respectively, and each amount is schematically shown. The number of black points of each color pigment indicates the quantitative ratio of each color pigment, and one black point indicates one unit amount. Reference numeral 8 denotes a low melting point glass. For example, in the black matrix layer (BK), since the coloring power of the black pigment (3) is high, the amount is 4 units to obtain the desired coloring.
For the red pigment (4) and the green pigment (5), the amounts are 6, 8, and 9 units corresponding to the respective coloring powers.

Therefore, the black matrix layer (B
K) and the respective colored pattern layers (R, G, B) have different film thicknesses, resulting in a film thickness difference (h). This difference in film thickness is eliminated by the flattening process using the overcoat layer (12) as described above.

However, when a dielectric material or the like whose main component is low-melting glass is used as a material for the planarization treatment, the thickness (H) of the overcoat layer (12) is about 10 μm, which is several times or more of the color pattern layer. When the thickness exceeds the range, unevenness on the color filter is reduced, but there is a problem that the brightness of the display is reduced by light absorption by the low melting point glass.

FIG. 3 shows an overcoat layer using a low melting glass on a transparent substrate (1) on which a black matrix layer (BK) and a colored pattern layer (R, G, B) shown in FIG. 2 are formed. This shows an example of a color filter in which an overcoat layer (22) is formed using a metal oxide instead of forming a color filter. When forming an overcoat layer of a metal oxide by a sol-gel method using a metal alkoxide such as silicon or titanium as a material, if the thickness of the overcoat layer is about 2 μm or more, cracks (not shown) occur, and When the film thickness (H ′) of the coat layer is about 1 μm or less, no cracking occurs, but as shown in FIG. 3, the difference in film thickness between the colored pattern layers remains almost as it is.

Even when the overcoat layer is made of two layers of a low-melting glass and a metal oxide, for example, if the overcoat layer of the low-melting glass is made thin and the overcoat layer of the metal oxide is made thick, Cracks have occurred.

On the other hand, when a plasma discharge display panel or a field emission display is manufactured by using a heat-resistant color filter having a structure in which a black matrix layer, a colored pattern layer, and an overcoat layer are formed thereon, Lighting unevenness and display bleeding between pixels occur due to a decrease in electric field and non-uniformity, leakage of electric charges to adjacent pixels,
The display quality of the display may be reduced. This is mainly due to the low resistance value of the inorganic pigment used in the black matrix layer and the colored pattern layer.

On the other hand, for example, in a photosensitive coloring composition, in a system containing an alkali-soluble resin, a polymerizable compound, a photopolymerization initiator, an inorganic pigment or the like as a main component, the inorganic pigment is finely divided into fine particles. The equilibrium state of the photosensitive coloring composition dispersed in the coloring composition as a dispersion system is destroyed with the lapse of time during storage, and the viscosity of the photosensitive coloring composition tends to increase. For this reason, there is a problem that storage stability of the photosensitive coloring composition is deteriorated and performance such as coatability is deteriorated.

[0021]

The object of the present invention is to improve the dispersibility of the inorganic pigment in the photosensitive coloring composition, to improve the storage stability, the coating suitability, and the flatness. An object of the present invention is to provide a photosensitive coloring composition that enables production of an excellent heat-resistant color filter. Another object of the present invention is to provide an overcoat layer having a small thickness, which has excellent flatness, does not cause breakage in a drive electrode or the like to be formed later, and has an electric field when used in a display. It does not cause lighting unevenness or display bleeding between pixels due to reduction, non-uniformity, leakage of charges to adjacent pixels, etc.,
An object of the present invention is to provide a heat-resistant color filter that does not deteriorate display quality of a display.

[0022]

The first invention of the present invention is a photosensitive coloring composition containing an inorganic pigment coated on a transparent inert layer.

In the photosensitive coloring composition according to the present invention, the material of the inactive layer is silicon dioxide, titanium oxide, magnesium oxide, aluminum oxide, cesium oxide or the like. ~ 1
A photosensitive coloring composition characterized in that the inorganic pigment is coated with 00% by weight of an inert layer material.

A second invention according to the present invention is a heat-resistant color filter having a black matrix layer and a colored pattern layer formed on a transparent substrate, wherein the black matrix layer and the colored pattern layer have at least a part thereof. A heat-resistant color filter formed using the photosensitive coloring composition of the first invention.

In the heat resistant color filter according to the present invention, the black matrix layer and the colored pattern layer may have an overcoat layer of a light-transmitting low-melting glass or a metal oxide obtained by firing a metal alkoxide. It is a heat-resistant color filter that is a feature.

[0026]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a photosensitive coloring composition according to the present invention and a heat-resistant color filter using the same will be described in detail based on one embodiment.

In the photosensitive coloring composition, for example, in a system containing an alkali-soluble resin, a polymerizable compound, a photopolymerization initiator, an inorganic pigment, or the like as a main component, the inorganic coloring matter is fine particles. There is a tendency that the equilibrium state as a dispersion system dispersed therein collapses with the lapse of time during storage, and the viscosity of the photosensitive coloring composition increases. For this reason, there is a problem that performance such as storability and coatability of the photosensitive coloring composition is deteriorated. In the present invention, the inorganic pigment is coated with a transparent inert layer to reduce the surface activity of the inorganic pigment, thereby preventing the dispersion of the equilibrium state of the photosensitive coloring composition as a dispersion system.

Further, in the present invention, the inorganic pigment is coated with a transparent inert layer, and the coating amount is such that the inorganic pigment is coated in accordance with the coloring power of each inorganic pigment.
For example, in the case of an inorganic pigment having a high coloring power such as a black pigment, the coating amount of the transparent inactive layer is increased, and in the case of an inorganic pigment having a low coloring power such as a green pigment, the transparent inactive layer Reduce the amount of coating. Then, the formed black matrix layer and the respective colored pattern layers have a desired coloring, and the thicknesses of the respective layers are substantially the same. Thereby, a heat-resistant color filter having good flatness can be obtained.

Further, in the present invention, the inorganic pigment is coated with a transparent inactive layer. For example, silicon dioxide is used as the material of the inactive layer. As a result, the inorganic pigment coated with the inactive layer has a high resistance value, and if a heat-resistant color filter using such a high-resistance inorganic pigment is used for a display, a reduction in electric field and unevenness may occur. This is a heat-resistant color filter that does not cause unevenness in lighting, display bleeding between pixels, or the like due to leakage of charge to adjacent pixels.

Examples of the material of the inert layer used in the present invention include silicon dioxide, titanium oxide, magnesium oxide, aluminum oxide, cesium oxide and the like. It is preferred that the inorganic pigment is coated with the material of the active layer.

The photosensitive coloring composition of the present invention is, for example, a photosensitive coloring composition containing as a main component an alkali-soluble resin, a polymerizable compound, a photopolymerization initiator, an inorganic pigment and the like.

As the inorganic pigment used in the present invention, each of red, green, blue and black inorganic pigments is appropriately used.
Red inorganic pigments include Fe ₂ O ₃ , Pb ₃ O ₄ and 2S
such as _{b 2 S · Sb 2 O 3} , Sb 2 S 3 · Sb 2 O 3 is,
Green inorganic pigments include Cr ₂ O ₃ , Cr ₂ O (O
_{H) 4, Cu (CH 3} CO 2) 2 · 3CuO (AsO 2) 2,
Such as CoO · ZnO · MgO is, as the blue inorganic _{pigments, 3NaAl · SiO 4 · Na 2} S 2, 2 (Na 2 O
・ Al ₂ O ₃ .2SiO ₂ ) ・ Na ₂ S ₂ , Fe ₄ [F
e (CN) _{6] 3nH 2 O, CoO · nAl 2} O 3, ( or n = 2~3), CoO · nSnO 2 · mMgO (n =
1.5 to 3.5, m = 2 to 6), etc., as the inorganic black _{pigment, CuO · Cr 2 O 3,} CuO · Cr 2 O 3 · M
_{nO 2, CuO · Fe 2 O} 3 · Cr 2 O 3, and the like as a coloring pigment usable.

Of these inorganic pigments, each of the color pigments except black has the spectral characteristics required as a color filter pigment,
It is desirable to have appropriate transparency and coloring power, and also to have durability such as heat resistance, and also, as a photosensitive coloring composition, a resin component or the like so that appropriate viscosity characteristics and coating suitability are exhibited. It is selected in consideration of compatibility with

FIG. 1 is a diagram schematically showing a cross section of an embodiment of a heat-resistant color filter according to the present invention. In FIG. 1, the heat-resistant color filter includes a black matrix layer (BK), a colored pattern layer (R, G, B) and an overcoat layer (2) on a transparent substrate (1). R, G, and B denote a red pattern layer, a green pattern layer, and a blue pattern layer, respectively, of the colored pattern layers, each of which has substantially the same film thickness, and a small difference in film thickness (h '). The properties are good.

In FIG. 1, 13, 14, 15, and 1
Reference numeral 6 denotes a black inorganic pigment, a red inorganic pigment, a green inorganic pigment, and a blue inorganic pigment, and the respective amounts are schematically shown.
Reference numeral 7 denotes an inactive layer. The number of black spots of each inorganic pigment indicates the quantitative ratio of each inorganic pigment, and one black spot indicates one unit amount. For example, in the black matrix layer (BK), since the coloring power of the black inorganic pigment (13) is high, the amount is 4 units in order to obtain a desired coloring. However, the blue inorganic pigment (16) and the red inorganic pigment (1) are used.
4) In the green inorganic pigment (15), the amount is 6, 8, and 9 units corresponding to each coloring power.

Then, as shown in FIG. 1, in the present invention, each of the inorganic pigments (1) is contained in a transparent inert layer (7).
3, 14, 15 and 16), and the amount of coating corresponds to the coloring power of each inorganic pigment. For example, in the case of an inorganic pigment having a high coloring power such as a black inorganic pigment (13), the coating amount of the transparent inert layer is increased, and in the case of an inorganic pigment having a low coloring power such as a green inorganic pigment (15). Reduces the coverage of the transparent inert layer (7).

In FIG. 1, the area shown by the dotted line represents the amount of the transparent inert layer (7) covering one unit amount of each inorganic pigment. Therefore, the formed black matrix layer (BK) and the respective colored pattern layers have a desired coloring, and the respective film thicknesses are substantially the same.
Thereby, a heat-resistant color filter having good flatness can be obtained.

As shown in FIG. 1, the heat-resistant color filter according to the present invention is a heat-resistant color filter having a small difference in film thickness (h ') and good flatness. By providing the overcoat layer (2), a heat-resistant color filter having excellent flatness is obtained. In this case, the thickness (H ″) of the overcoat layer (2) is sufficiently thin and excellent in flatness.

As a method of coating the inorganic pigment with a transparent inert layer, the inorganic pigment is poured into water so as not to aggregate, and then uniformly dispersed by a disperser or an emulsifier.
The solution is heated to about 60 ° C, and the metal salt hydrolyzes P
A general method is to add a metal salt solution while adding and adjusting a drug so as to be in the H range. As metal salts,
For example, inorganic salts such as sodium silicate, and organic silicates such as ethyl orthosilicate are used. Considering the thickness of the transparent inert layer on the surface of the inorganic pigment, the input amount of the silicate solution is set to 5 to 100% by weight based on 100% by weight of the inorganic pigment. Further, the added chemicals include HCl and H _2.
Acids such as SO ₄ and HNO ₃ , NaOH, KOH, Na
Bases such as ₂ CO ₃ and K ₂ CO ₃ are mentioned.

The alkali-soluble resin used in the present invention includes, for example, (meth) acrylic acid containing (meth) acrylic acid.
Acrylic resin, rosin resin or maleic acid resin is used. (Meth) acrylic resin is a copolymer of monomers of acrylic acid and methacrylic acid and their esters, or a mixture of monomers thereof, and is a copolymer of 60 mol% or less of radically polymerizable monomers such as styrene, vinyl acetate, and maleic anhydride. Copolymers are also used. However, a three-dimensionally crosslinked polymer, such as a copolymer with a polyfunctional monomer, has poor solubility and is not suitable for the present invention.

The maleic acid resin has an acid value of 40 to 40.
Although 160 compounds are used, those having an acid value of 80 or more are preferable from the viewpoint of alkali developing suitability when the photosensitive coloring composition is used. Further, for example, even an alkali-insoluble resin can be used as long as it is 10% by weight or less, preferably 5% by weight or less in the nonvolatile components of the photosensitive coloring composition.

The photopolymerizable compound used in the present invention is a compound having a free-radical addition-polymerizable or crosslinkable ethylenically unsaturated group, and may have one or more ethylenically unsaturated groups, for example, It is a monomer or oligomer having a vinyl group or an allyl group, or a polymer having an ethylenically unsaturated group at a terminal or a side chain. Examples thereof include acrylic acid and its salts, acrylic esters, acrylamides, methacrylic acid and its salts, methacrylic esters, methacrylamides, maleic anhydride, maleic esters, itaconic esters,
Styrenes, vinyl ethers, vinyl esters, N
-Vinyl heterocycles, allyl ethers, allyl esters, and derivatives thereof.

Preferred polyfunctional acrylic monomers and oligomers include (meth) acrylic acid, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, cyclohexyl (meth) acrylate, (meth) acrylamide, vinyl acetate, N-hydroxymethyl (meth) acrylamide, polyethylene glycol di (meth) acrylate, pentaerythritol tri (meth) acrylate, styrene, vinyl acetate, various acrylic vinyl esters, various methacrylic esters, acrylonitrile, dipentaerythritol hexa (meth) Acrylate, tricyclodecanyl (meth) acrylate, hexa (meth) acrylate of caprolactone adduct of dipentaerythritol hexa (meth) acrylate, Lamin (meth) acrylate, epoxy (meth) acrylate prepolymer can be mentioned.

The photopolymerization initiator used in the present invention includes 4-phenoxydichloroacetophenone, 4-t-
Butyl-dichloroacetophenone, diethoxyacetophenone, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1one, 1-hydroxycyclohexylphenyl ketone, 2-benzyl-2-dimethylamino-1- (4 Acetophenone-based photoinitiators such as -morpholinophenyl) -butan-1-one; benzoin-based, benzophenone-based photoinitiators such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether and benzyl dimethyl ketal; benzophenone; benzoyl Benzoic acid, methyl benzoylbenzoate, 4-phenylbenzophenone, hydroxybenzophenone, acrylated benzophenone,
Benzophenone-based photoinitiators such as 4-benzoyl-4′-methyldiphenylsulfide, thioxanthone,
Thioxanthone-based photoinitiators such as chlorthioxanthone, 2-methylthioxanthone, isopropylthioxanthone, and 2,4-diisopropylthioxanthone;
6-trichloro-s-triazine, 2-phenyl-4,
6-bis (trichloromethyl) -s-triazine, 2-
(P-methoxyphenyl) -4,6-bis (trichloromethyl) -s-triazine, 2- (p-tolyl) -4,
6-bis (trichloromethyl) -s-triazine, 2-
Pipenyl-4,6-bis (trichloromethyl) -s-triazine, 2,4-bis (trichloromethyl) -6
Styryl s-triazine, 2- (naphth-1-yl)-
4,6-bis (trichloromethyl) -s-triazine,
2- (4-methoxy-naphth-1-yl) -4,6-bis (trichloromethyl) -s-triazine, 2,4-trichloromethyl- (piperonyl) -6-triazine,
2,4-trichloromethyl (4'-methoxystyryl)
It is possible to use a compound such as a triazine-based photoinitiator such as -6-triazine, a carbazole-based photoinitiator, and an imidazole-based photoinitiator.

The photoinitiators may be used alone or as a mixture of two or more. As sensitizers, α-acyloxime ester, acylphosphine oxide, methylphenylglyoxylate, benzyl, 9,10-phenanthrene Quinone, camphorquinone, ethylanthraquinone,
4,4′-diethylisophthalophenone, 3,3 ′,
4,4'-tetra (t-butylperoxycarbonyl)
Compounds such as benzophenone and 4,4'-diethylaminobenzophenone can also be used.

In producing the photosensitive coloring composition, as a means for dispersing the inorganic pigment coated with the transparent inert layer into an alkali-soluble resin and a polyfunctional acrylic monomer, a three-roll mill or a two-roll mill may be used. , A sand mill, a kneader and the like can be used. Further, in order to improve the dispersion, various surfactants and a dispersing aid such as a derivative of an inorganic pigment may be appropriately added. The dispersing aid is excellent in dispersing the inorganic pigment and has a large effect of preventing the re-aggregation of the inorganic pigment after the dispersion, so that a color filter having excellent transparency can be obtained. Select and use those that do not hinder the storage stability of the product.

As a method of applying the photosensitive coloring composition on the transparent substrate, a method suitable for the viscosity of the manufactured photosensitive coloring composition may be selected. In the case of a high viscosity, screen printing or a die coating method is used. For example, in the case of low viscosity, a method having good coating flatness may be selected from methods such as spin coating, spray coating, and roll coating.

Further, in order to improve the dispersibility of the inorganic pigment in the photosensitive coloring composition and to adjust the coating thickness on the transparent substrate, the viscosity may be adjusted by adding a solvent. . Examples of the solvent include cyclohexanone, ethyl cellosolve acetate, butyl cellosolve acetate,
-Methoxy-2-propyl acetate, diethylene glycol dimethyl ether, ethylbenzene, ethylene glycol diethyl ether, xylene, ethyl cellosolve, methyl-n amyl ketone, propylene glycol monomethyl ether toluene, methyl ethyl ketone, ethyl acetate, methanol, ethanol, isopropyl alcohol, butanol, isobutyl ketone And petroleum solvents and the like, and these are used alone or as a mixture.

[0049]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail.

<Example 1> (Inactivation treatment of inorganic pigment) The following were used as the inorganic pigment. -Black pigment 15 (manufactured by Dainichi Seika Kogyo: "TM Black 3510")-Red pigment 12 (manufactured by Dainichi Seika Kogyo: "TRANS"
OXIDE RED ")-Green pigment 14 (manufactured by Dainichi Seika Kogyo Co., Ltd .:" TM Green 3320 ")-Blue pigment 13 (manufactured by Dainichi Seika Kogyo Co., Ltd .:" TM blue 3450 ")

10 parts by weight of the above black pigment was put into 150 parts by weight of pure water, and heated to 80 ° C. while performing ultrasonic dispersion and stirring. Next, after adjusting the pH to 9 by adding a 5% NaOH solution, a sodium silicate aqueous solution (pure water 73
30 parts by weight of sodium silicate in parts by weight) were added dropwise over time. At this time, in order to maintain the solution at pH 9, a 5% HCl solution was appropriately added dropwise and reacted for 1 hour. Next, a 5% HCl solution was added until the pH became 6, and the mixture was kept for another 15 minutes. The obtained precipitate was subjected to centrifugal filtration, washing with pure water, and sufficient heating and drying to produce a black inorganic pigment having a silicate formed on the surface as an inert layer.

10 parts by weight of each of the above red pigment, green pigment and blue pigment were put into 150 parts by weight of pure water,
It heated to 80 degreeC, performing ultrasonic dispersion and stirring. Next, after adjusting the pH to 9 by adding a 5% NaOH solution, 5 parts by weight of an aqueous sodium silicate solution (27 parts by weight of sodium silicate in 73 parts by weight of pure water) was added dropwise over time. At this time, in order to maintain the solution at pH 9, a 5% HCl solution was appropriately added dropwise and reacted for 1 hour. Next, a 5% HCl solution is
And kept for a further 15 minutes. The obtained precipitate is subjected to centrifugal filtration, pure water washing and sufficient heat drying,
Red, green, silicate formed on the surface as an inert layer,
A blue inorganic pigment was produced.

(Preparation of alkali-soluble acrylic resin) 55 parts by weight of butyl methacrylate, 20 parts of methyl methacrylate
Parts by weight, 15 parts by weight of 2-hydroxyethyl methacrylate, and 10 parts by weight of methyl acrylate are copolymerized using 2- (2-ethoxyethoxy) ethanol as a solvent, to give a ratio of 40 parts by weight of acrylic resin and 60 parts by weight of solvent. It was prepared as follows.

(Preparation of photosensitive coloring composition) A photosensitive coloring composition was prepared using the above-mentioned inactivated inorganic pigment in the following compounding ratio.

(Photosensitive black composition) ・ Acrylic resin 8.2% by weight ・ Polyfunctional oligoester acrylate 4.9% by weight Dipentaerythritol hexaacrylate ・ Photopolymerization initiator 1.0% by weight Trichloromethyl S-triazine ・Diluent solvent 56.4% by weight 2- (2-ethoxyethoxy) ethanol ・ Coloring pigment 29.5% by weight Black pigment (inactivated “TM Black 3510”)

(Photosensitive red composition) ・ Acrylic resin 8.2% by weight ・ Polyfunctional oligoester acrylate 4.9% by weight Dipentaerythritol hexaacrylate ・ Photopolymerization initiator 1.0% by weight Piperonyl trichloromethyl S -Triazine -Diluent 56.4% by weight 2- (2-ethoxyethoxy) ethanol -Coloring pigment 29.5% by weight Red pigment (inactivated "TRANS OXIDE RED")

(Photosensitive green composition) ・ Acrylic resin 8.2% by weight ・ Polyfunctional oligoester acrylate 4.9% by weight Dipentaerythritol hexaacrylate ・ Photopolymerization initiator 1.0% by weight Piperonyl trichloromethyl S -Triazine -Diluent 56.4% by weight 2- (2-ethoxyethoxy) ethanol -Coloring pigment 29.5% by weight Green pigment (inactivated "TM Green 3320")

(Photosensitive Blue Composition) ・ Acrylic resin 8.2% by weight ・ Polyfunctional oligoester acrylate 4.9% by weight Dipentaerythritol hexaacrylate ・ Photopolymerization initiator 1.0% by weight Piperonyl trichloromethyl S -Triazine -Diluent 56.4% by weight 2- (2-ethoxyethoxy) ethanol -Coloring pigment 29.5% by weight Blue pigment (inactivated "TM Blue 3450")

(Preparation of Heat-Resistant Color Filter) The photosensitive black composition was screen-printed on a transparent substrate using a stainless steel screen plate having a thickness of 350 μm and a plate thickness of 80 μm, and left at room temperature for 5 minutes. After the film surface was dried, it was dried at 70 ° C. for 20 minutes to form a photosensitive black composition layer. The thickness of the obtained photosensitive black composition layer is about 2.7 μm.
And the surface state was smooth.

Next, a photomask in which a light-shielding film is formed so as to form a black matrix layer of a light-shielding portion having a length of 200 mm × width of 150 μm and a line width of 10 μm is brought into close contact with the photosensitive black composition layer and an ultra-high pressure mercury lamp. The exposure amount is 400
Contact exposure was performed under the condition of mJ / cm ² . After exposure, temperature 20
Spray development was performed for 50 seconds at a blowing pressure of 1 kg / cm ² with an alkali developing solution at a temperature of 0 ° C. to remove unexposed portions of the photosensitive black composition layer. After drying the substrate after the development processing, a heat hardening treatment was performed at 230 ° C. for 1 hour. The thickness of the patterned black matrix layer after hardening was about 2.5 μm.

Subsequently, the photosensitive red composition was screen-printed on a transparent substrate on which the black matrix layer was formed using a 330-mesh, 80-μm-thick stainless steel screen plate, and left at room temperature for 5 minutes. Then, the film surface was dried, and then dried at 70 ° C. for 20 minutes to form a photosensitive red composition layer. The obtained photosensitive red composition layer had a thickness of about 3.0 μm, had a uniform thickness over the entire surface, and had a smooth surface state.

Next, a photomask having a light-shielding film in which a stripe pattern having a length of 200 mm and a width of 150 μm is repeatedly formed at a pitch of 480 μm is brought into close contact with the photosensitive red composition layer so as to match the opening of the black matrix layer. Contact exposure was performed with an ultrahigh pressure mercury lamp under the conditions of an exposure amount of 350 mJ / cm ² . After the exposure, spray development was performed for 50 seconds at an ejection pressure of 1 kg / cm ² with an alkali developing solution at a temperature of 20 ° C. to remove the unexposed portions of the photosensitive red composition layer. After the developed substrate was dried, it was heated and hardened at 230 ° C. for 1 hour. The thickness of the patterned red pattern layer after hardening was about 2.8 μm.

Subsequently, the photosensitive green composition was coated on the transparent substrate on which the patterned black matrix layer and red pattern layer were formed under the same conditions as described above.
5 μm coating, the same photomask as above was adhered to the photosensitive green composition layer, and the exposure amount was 300 m with an ultra-high pressure mercury lamp.
Contact exposure was performed under the condition of J / cm ² . After exposure, temperature 20 ℃
Was spray-developed at an ejection pressure of 1 kg / cm ² for 60 seconds to remove the unexposed portions of the photosensitive green composition layer, thereby exposing the glass substrate. After drying the developed substrate, a hardening treatment was performed at 230 ° C. for 1 hour. The thickness of the patterned green pattern layer after hardening is about 3.3μ.
m.

The same steps were repeated using the above photosensitive blue composition to form a black matrix layer, a red pattern layer, a green pattern layer, and a blue pattern layer on a transparent substrate.

Next, a baking treatment was performed. The transparent substrate on which each layer is formed is heated in an air atmosphere at a temperature rising rate of 4 ° C./min, and baked at a temperature of 430 ° C. for 60 minutes.
After further heating to 0 ° C. and baking at a temperature of 580 ° C. for 30 minutes, the substrate was cooled to room temperature at a temperature lowering rate of 4 ° C./min, so that the organic resin component of the photosensitive coloring composition layer was burned and removed. . Thus, a black matrix layer of a black pigment having a thickness of about 1.9 μm, a red pattern layer of a red pigment having a thickness of about 2.0 μm, a green pattern layer of a green pigment having a thickness of about 2.3 μm, and a film thickness of about 2. A heat-resistant color filter on which a blue pattern layer of a 3 μm blue pigment was formed was obtained. It was found that the difference in the coating amount by the silicate compound increased the film thickness.

The difference in film thickness between the black matrix layer and each colored pattern layer of the obtained heat resistant color filter was about 0.4.
μm and good flatness as a heat-resistant color filter. Also, at this time,
The optical density at 500 nm of the black matrix layer was 1.5.

Subsequently, on this heat resistant color filter,
An overcoat layer was provided. 325 mesh plate thickness 80μ
A low-melting glass paste (LF-01, manufactured by Nippon Electric Glass Co., Ltd.) was screen-printed using a stainless steel screen plate, and left at room temperature for 10 minutes to dry the film surface. After drying at 90 ° C. for 15 minutes, a low-melting glass paste layer was formed.

Then, a firing treatment was performed in the same manner as described above. 4
Heating in air atmosphere at a heating rate of ° C / min, temperature 420 ° C
Then, the substrate was further heated to 580 ° C. continuously, baked at a temperature of 580 ° C. for 30 minutes, and then cooled at room temperature at a rate of 4 ° C./min. By the firing treatment under these conditions, the low-melting glass became an overcoat layer having a light-transmitting property, and the black matrix layer and the inorganic pigment of each colored pattern layer were formed into a heat-resistant color filter coated with the low-melting glass.

At this time, the thickness of the overcoat layer is about 2
μm, and a sufficiently excellent flatness was obtained with an overcoat layer having a small film thickness. Further, the pattern shape and the formation position of this heat-resistant color filter both accurately reflect the light-shielding film pattern of the photomask, and the spectral transmittance of the heat-resistant color filter showed a desired value.

<Example 2> The heat-resistant color filter produced in Example 1, that is, the difference in film thickness between the black matrix layer and each colored pattern layer was as small as about 0.4 μm.
An overcoat layer was provided on a heat-resistant color filter having good flatness. A metal alkoxide was used instead of the low-melting glass paste as the material used.

On this heat resistant color filter, 325
A metal alkoxide (manufactured by Nippon Soda Co., Ltd .: Atron NSi) was used to fix the pigmented colored pattern layer using a stainless steel screen plate having a mesh plate thickness of 80 μm.
-500) was screen-printed and left at room temperature for 10 minutes to dry the film surface. After drying at 90 ° C. for 15 minutes, a metal alkoxide sol film was formed.

Next, as in Example 1, heating was performed in an air atmosphere at a heating rate of 4 ° C./min, and calcination was performed at a temperature of 420 ° C. for 60 minutes. After firing at the temperature for 30 minutes, the substrate was cooled at a temperature lowering rate of 4 ° C./min. By performing the baking treatment under these conditions, the condensation polymerization reaction by the dehydration reaction and the dealcoholization reaction of the metal alkoxide sol film was promoted, and a gelled metal oxide film was formed. With this gelled metal oxide film overcoat layer, a heat-resistant color filter in which a black matrix layer of a black pigment and each colored pattern layer were fixed by firing on a transparent substrate was obtained.

The pattern shape and the formation position of the obtained heat-resistant color filter both accurately reflect the light-shielding film pattern of the photomask, and the spectral transmittance of the heat-resistant color filter shows a desired value. The film thickness difference between
It was excellent at 3 μm.

<Comparative Example 1> The above-mentioned inorganic pigment which was not subjected to the deactivation treatment was used. The mixing ratio of each photosensitive coloring composition is as follows.

(Photosensitive coloring composition) ・ Acrylic resin 8.2% by weight ・ Polyfunctional oligoester acrylate 4.9% by weight Dipentaerythritol hexaacrylate ・ Photopolymerization initiator 1.0% by weight Trichloromethyl S-triazine ・Diluent solvent 56.4% by weight 2- (2-ethoxyethoxy) ethanol • Color pigment 29.5% by weight Black pigment (untreated, untreated)

(Preparation of Heat-Resistant Color Filter) A heat-resistant color filter was prepared in the same manner as in Example 1, and an overcoat layer was formed in the same manner as in Example 2. The thickness difference between the colors of the obtained heat resistant color filter was as large as about 0.8 μm.

<Comparative Results> (Increase in Viscosity of Photosensitive Colored Composition) The photosensitive red compositions of Examples 1 and 2 did not show a large change in viscosity even after storage at room temperature for one month. The photosensitive red composition of Comparative Example 1 gelled after storage at room temperature for one month, and it was difficult to form a flat and uniform coating film by screen printing.

(Production of Field Emission Display) On the heat-resistant color filters of Example 1, Example 2, and Comparative Example 1, transparent electrode patterns corresponding to the respective colored pattern layers were formed by vacuum sputtering. And an etching using a photosensitive resist to form an anode electrode on the heat-resistant color filter. Then, corresponding to each colored pattern layer, a phosphor having each spectral characteristic is formed by a screen printing method and baked, and an aluminum thin film is formed thereon by a vacuum deposition method to form an anode as a metal back layer. A substrate was prepared.

Next, an opposing cathode substrate was manufactured.
An emitter wiring layer having a thickness of about 0.2 μm is formed on a glass substrate by photolithography, and plasma CVD is performed thereon.
About 1μ of phosphorus-doped hydrogenated amorphous silicon layer
m thickness, silicon oxide is formed as an etching mask pattern layer by reactive evaporation, patterned into a circular mask shape of about 1.2 μm in diameter, and then phosphorus-doped hydrogenated amorphous by RIE (reactive ion etching). The silicon layer was etched and processed into a truncated cone shape.

Subsequently, a silicon oxide film having a thickness of about 0.7 μm was deposited as an insulating layer, and Nb as a gate electrode material was deposited thereon with a thickness of about 0.3 μm. This allows
The insulating layer and the gate electrode located around the emitter can be formed in a self-aligned manner with a certain gap without contacting the emitter.

This was immersed in a buffered hydrofluoric acid solution at room temperature for 2 minutes to lift off the etching mask pattern layer. After the insulating material layer and the gate electrode material layer laminated thereon were peeled off, the gate was removed. A cathode substrate as an electron-emitting device was obtained by patterning the Nb film of the electrode into an electrode shape by photolithography. The obtained cathode substrate had a structure in which the distance between the emitter electrode and the gate electrode was about 0.7 μm, and was a cathode substrate on which a large number of electron-emitting device arrays were formed.

The anode substrate on which the heat-resistant color filter was formed and the cathode substrate were opposed at a distance of 30 mm, and the periphery of each substrate was fused with low-melting glass, followed by evacuation to a sufficient degree of vacuum. A voltage was applied between the emitter electrode and the gate electrode with a polarity having a positive polarity on the gate electrode side while applying 800 V to emit a phosphor pattern of each color.

At this time, in the field emission display equipped with the heat-resistant color filters of the first and second embodiments, only the phosphor portion irradiated with the electron beam emits light, and emission with good spectral characteristics is performed through the heat-resistant color filter. Light was obtained,
In the field emission display equipped with the heat-resistant color filter of Comparative Example 1, a phenomenon in which light was emitted not only to the electron beam irradiating portion but also to peripheral pixels was observed. Further, in Comparative Example 1, when the applied voltage between the anode substrate and the cathode substrate was increased, crosstalk in which a potential was generated at the drive electrode adjacent to the anode substrate was observed.

Therefore, in order to compare the insulation resistance of the black matrix layer in Examples 1, 2 and Comparative Example 1, the substrate was so formed as to have the same thickness as the black pigment after firing in each example. A black pigment layer was formed on the substrate, and the resistance of the substrate was measured by a method according to a volume resistivity test of JIS standard (C2103-1991). As shown below, a large difference was observed in the insulation resistance value, and it was shown that when the resistance value was small, a problem was likely to occur in the display quality of the field emission display. Inactive layer coating Insulation resistance Example 1 Yes> 10 ³ MΩcm Example 2 Yes> 10 ³ MΩcm Comparative Example 1 None 10 ¹ MΩcm

In the plasma discharge display panel, a transparent electrode with a bus electrode is provided on the front substrate in order to display an image by plasma discharge.
This is an indispensable element for charge accumulation and voltage application, which are a series of operations for performing plasma discharge. Therefore, even when the color filter is provided below or above the transparent electrode on the front substrate, it is essential for a good image display that a series of operations for performing the plasma discharge can be performed satisfactorily. Including a portion having a low resistance value is not preferable for good plasma discharge operation and image display.

[0086]

Since the present invention is a photosensitive coloring composition containing an inorganic pigment coated on a transparent inert layer, the surface activity of the inorganic pigment is reduced, and the dispersion as a dispersion system of the photosensitive coloring composition is reduced. This will prevent the collapse of the equilibrium state, resulting in a photosensitive coloring composition having good storage stability and coating suitability. Further, in the present invention, since the coating amount of the transparent inactive layer is coated in accordance with the coloring power of each inorganic pigment, the formed black matrix layer, and each colored pattern layer has a desired coloring. And, a heat-resistant color filter having good flatness, each film thickness of which is substantially the same, and an overcoat layer of a light-transmitting low-melting glass or a metal oxide obtained by firing a metal alkoxide. By providing this, a photosensitive coloring composition from which a heat-resistant color filter having excellent flatness can be obtained is obtained.

The present invention relates to a heat-resistant color filter having a black matrix layer and a colored pattern layer formed on a transparent substrate, wherein at least a part of the black matrix layer and the colored pattern layer is the photosensitive colored layer of the invention described above. Since the color filter is formed using the composition, a heat-resistant color filter having good flatness without causing disconnection in a drive electrode or the like to be formed later is obtained. Further, a heat-resistant color filter having excellent flatness can be obtained by providing an overcoat layer of a light-transmitting low-melting glass or a metal oxide obtained by firing a metal alkoxide.

Further, since silicon dioxide, titanium oxide, magnesium oxide, aluminum oxide, cesium oxide, and the like are used as the material of the inert layer, the inorganic pigment has a low resistance value. When used in a display, a heat-resistant color filter which does not cause unevenness in lighting due to a decrease in electric field, non-uniformity, leakage of electric charges to adjacent pixels, or display blur between pixels. .

[Brief description of the drawings]

FIG. 1 is a diagram schematically showing a cross section of one embodiment of a heat-resistant color filter according to the present invention.

FIG. 2 is a diagram schematically illustrating a cross section of an example of a color filter manufactured by a conventional method.

FIG. 3 is a diagram illustrating an example of a color filter in which an overcoat layer is formed using a metal oxide.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Transparent substrate 2, 12 ... Overcoat layer 3, 13 ... Black inorganic pigment 4, 14 ... Red inorganic pigment 5, 15 ... Green inorganic pigment 6, 16 ... Blue inorganic Pigment 7 ... Inactive layer 8 ... Low melting point glass h, h '... Film thickness difference H, H', H "... Overcoat layer film thickness R ... Colored pattern (red G: colored pattern (green) B: colored pattern (blue) BK: black matrix layer

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G02F 1/1335 505 G09F 9/00 349A G09F 9/00 349 C08L 101/00 (72) Inventor Kazushige Kitazawa Tokyo Inside Letterpress Printing Co., Ltd., 1-5-1, Taito, Taito-ku, Tokyo (72) Inventor Ken Ken Itoi, Letterpress Printing Co., Ltd., 1-1-1, Taito, Taito-ku, Tokyo

Claims (4)

[Claims] 1. A photosensitive coloring composition comprising an inorganic pigment coated on a transparent inert layer. 2. The material of said inert layer is silicon dioxide, titanium oxide, magnesium oxide, aluminum oxide, cesium oxide or the like.
The photosensitive coloring composition according to claim 1, wherein the inorganic pigment is coated with the material of the inert layer in an amount of from 100 to 100% by weight. 3. A heat-resistant color filter having a black matrix layer and a colored pattern layer formed on a transparent substrate, wherein at least a part of the black matrix layer and the colored pattern layer are at least partly formed. A heat-resistant color filter formed using the photosensitive coloring composition according to any one of the preceding claims. 4. The heat-resistant material according to claim 3, further comprising an overcoat layer of a light-transmitting low-melting glass or a metal oxide obtained by firing a metal alkoxide on the black matrix layer and the colored pattern layer. Color filter.