JPH1123836A - Black matrix, color filter and liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the display quality of a liquid crystal display device from being degraded due to fluctuation in the gap between substrates in the surface of the display part of the liquid crystal display device by using black paste containing pigments having a grain size of specified times of thickness of a black matrix and forming a specified ratio or above in the whole pigments. SOLUTION: A pigment diffused resin bloc matrix in which >=1 wt.% of the total pigments incorporated in the black matrix are the pigments having the grain size of 0.8-1.2 times of the thickness of the black matrix is used. That is, by incorporating the pigments having the grain size nearly equal to the thickness of the black matrix into the pigment diffused resin black matrix, the matter that a columnar spacer is caved into the black matrix is suppressed when it is high pressure pressed, and the fluctuation in the gap between the substrates due to plastic deformation of a film is suppressed. Further, as a concrete example of pigments, carbon black, titanium black, graphite, etc., and listed. The graphite is preferred particularly for suppressing that the spacer is caved in.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a color filter having a black matrix, which is used for a flat panel display, particularly a liquid crystal display device.

[0002]

2. Description of the Related Art In order to color a liquid crystal display device, a color filter in which pixels of three colors of R (red), G (green) and B (blue) are arranged in a line or mosaic on a transparent substrate. Is used. For example, a TN (Twisted Nematic) type TFT which is currently widely used
(Thin Film Transistor) The color liquid crystal display device has a structure in which liquid crystal is sealed between a transparent glass substrate on which a color filter is formed and a transparent glass substrate on which a TFT is formed.

A color filter is composed of a resin film colored with a dye, a resin film in which a pigment is dispersed, a multiple interference film made of an inorganic substance, or the like on a transparent substrate such as glass. (Green) and B (blue) pixel film patterns are formed on a transparent substrate such as glass. Usually, a black matrix is provided in a gap between pixels. The black matrix plays a role in preventing a decrease in contrast due to light leakage and a malfunction of the TFT.

As a black matrix, a thin metal film such as chromium or nickel is generally used. However, the black matrix made of a metal thin film has a problem that the display quality of the display is deteriorated due to its high reflectance. In order to reduce the reflectivity, see, for example,
As disclosed in Japanese Patent Publication No. 130217, a black matrix comprising a multilayer film of chromium and chromium oxide has been proposed, but this type of black matrix has a problem in that the production cost and the waste treatment cost are high.

As a black matrix having a relatively low production cost and waste disposal cost and a small reflectance, for example, a black matrix made of a resin in which a black pigment is dispersed as disclosed in Japanese Patent Application Laid-Open No. 2-239204 is used. is there. It is possible to increase the film thickness more easily than a black matrix composed of a metal thin film or a metal / oxide multilayer film. For example, as shown in JP-A-7-318950, a pixel is formed on a resin black matrix. By stacking films, a columnar spacer having a large height can be formed.

When a transparent glass substrate on which a color filter is formed and a transparent glass substrate on which a TFT is bonded are bonded, a circle made of glass or the like is used for bonding between the substrates in order to keep a constant gap between the substrates. A sealing material made of an epoxy resin or the like in which columnar spacers are dispersed is used. Usually, curing of the epoxy resin is performed under high pressure at a high temperature.

[0007] The pigment-dispersed resin black matrix generally has a lower indentation hardness than a black matrix composed of a metal thin film or a metal / oxide multilayer film. For this reason, when a black matrix was present in the seal portion, plastic deformation of the film occurred, for example, when the columnar spacer was embedded by high-pressure pressing, and the gap between the substrates sometimes fluctuated in the plane of the display portion. . When the gap between the substrates fluctuates,
There is a problem that the display quality of the liquid crystal display device is deteriorated.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned drawbacks of the prior art. It is an object of the present invention to provide a substrate on which a color filter is formed and a TF.
At the time of laminating the substrates on which T and the like are formed, the gap between the substrates fluctuates in the surface of the display unit of the liquid crystal display device due to, for example, the insertion of a cylindrical spacer in the seal portion on the pigment-dispersed resin black matrix, An object of the present invention is to suppress a decrease in display quality of a liquid crystal display device.

[0009]

SUMMARY OF THE INVENTION The object of the present invention is as follows.
A pigment-dispersed resin black matrix, wherein at least 1% by weight of all pigments contained in the black matrix is a pigment having a particle diameter of 0.8 to 1.2 times the thickness of the black matrix, and This is achieved by a color filter having the black matrix and a liquid crystal display device having the color filter.

[0010]

In the present invention, it is important that at least 1% by weight of all the pigments contained in the black matrix is a pigment having a particle size of 0.8 to 1.2 times the thickness of the black matrix. It is. In other words, by including a pigment having a particle size comparable to the thickness of the black matrix in the pigment-dispersed resin black matrix, during pressurization with high pressure, the penetration of the columnar spacers into the black matrix is suppressed, and plastic deformation of the film is caused. Variations in the gap between the substrates can be suppressed.

Specific examples of the pigment having a particle diameter of 0.8 to 1.2 times the thickness of the black matrix used in the present invention include carbon black, titanium black, graphite and the like. As a pigment that functions to suppress the indentation of the spacer, a pigment having a large light-shielding property and a high hardness is desirable, and graphite is particularly preferable.
Without being limited to these, various pigments can be used.

It is desired that the particle size of the pigment functioning to suppress the incorporation of the spacer is substantially equal to the thickness of the black matrix. The particle size of the pigment used is 0.8 to 1.2 times, preferably 0.9 to 1.1 times, more preferably 0.95 to 1.0 times the thickness of the black matrix.
5 times. The comparison between the thickness of the black matrix and the particle size of the pigment contained therein can be performed by observing the cross section of the black matrix with an electron microscope. Also, the particle size of the pigment contained in the paste is measured by a particle analyzer or the like using a black matrix forming paste, and the thickness of the black matrix is measured by a stylus method or the like after the formation of the black matrix. And the particle size of the pigment contained can be compared.

A pigment having a particle size of 0.8 to 1.2 times the thickness of the black matrix contained in the black matrix does not exhibit the function of suppressing the incorporation of the spacer if the amount is too small. For this reason, 1% by weight or more, preferably 5% by weight or more, more preferably 10% by weight or more, and still more preferably 20% by weight or more of the total amount of the black matrix contained in the black matrix. A pigment having a particle size is contained in the black matrix.

The thickness of the black matrix used in the pigment-dispersed resin black matrix of the present invention is 0.8 times or more.
Specific examples of the pigment other than the pigment having a particle diameter of 1.2 times include the above-described carbon black, titanium black, and graphite. Further, in order to adjust the color tone of the black matrix, a blue pigment or a purple pigment may be partially used. Specific examples of blue pigments and purple pigments by color index (CI) number include Pigment Blue 15 (15: 3, 15:
4, 15: 6), 21, 22, 60, 64, and the like, and examples of violet pigments include Pigment Violet 19, 23, 29, 32, 33, 36, 37, 38, and the like.

0.8 times the thickness of the black matrix
It is desired that the particle diameter of the pigment other than the 1.2 times pigment be smaller than the thickness of the black matrix in order to keep the optical density of the black matrix uniform and prevent surface roughness. Desirable particle size of these pigments is 50% or less, preferably 20% or less, more preferably 10% or less of the thickness of the black matrix.

In the present invention, the resin for dispersing and retaining the pigment is not particularly limited as long as it is generally used for forming a pigment-dispersed resin black matrix, and any resin can be used. For example, various resins such as acrylic resin, alkyd resin, melamine resin, polyvinyl alcohol, polyamide, polyamide imide, and polyimide can be used. From the viewpoint of ease of pattern formation, it is preferable to use a photosensitive acrylic resin. However, use of polyimide is preferred from the viewpoint of heat resistance.

The polyimide is usually obtained by thermally or chemically imidizing a polyimide precursor.
As the polyimide precursor, polyamic acid and its esterified product are usually used. The polyamic acid mentioned here is usually represented by the following general formula (1).

[0018]

Embedded image (Here, R ₁ is a tetravalent organic group having 2 to 22 carbon atoms, R ₂ is a divalent organic group having 1 to 22 carbon atoms, and n is an integer of 1 or more.) The mechanical properties of the polyimide film are as follows. The higher the molecular weight, the better. For this reason, it is desired that the molecular weight of the polyamic acid as the polyimide precursor is also large. On the other hand, when the polyimide precursor film is subjected to pattern processing by wet etching, if the molecular weight of the polyamic acid is too large,
There is a problem that the time required for development becomes too long.
Therefore, the preferable range of n is 2 to 1000, more preferably 4 to 400, and still more preferably 6 to 100. Since the molecular weight of the polyamic acid generally varies, the preferable range of n herein is within the range of 50 mol% or more, preferably 70 mol% or more, more preferably 90 mol% of the total polyamic acid. It means that more than% is contained.

The polyamic acid can be obtained by reacting a tetracarboxylic dianhydride with a diamine.

The tetracarboxylic dianhydride is represented by the general formula (2).

[0021]

Embedded image (R1 in the formula Represents the above-mentioned tetravalent organic group having 2 to 22 carbon atoms. In the present invention, for example, aliphatic or alicyclic tetracarboxylic dianhydrides can be used, and specific examples thereof include 1,2,3,4-cyclobutanetetracarboxylic acid. Dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 1,2,3,5
-Cyclopentanetetracarboxylic dianhydride, 1,2,2
4,5-bicyclohexenetetracarboxylic dianhydride,
1,2,4,5-cyclohexanetetracarboxylic dianhydride, 1,3,3a, 4,5,9b-hexahydro-5
-(Tetrahydro-2,5-dioxo-3-furanyl)
-Naphtho [1,2-c] furan-1,3-dione and the like. When an aromatic compound is used, a polyimide precursor composition which can be converted into a polyimide having good heat resistance can be obtained.
', 4,4'-benzophenonetetracarboxylic dianhydride, pyromellitic dianhydride, 3,4,9,10-perylenetetracarboxylic dianhydride, 3,3', 4,4'-
Diphenylsulfonetetracarboxylic dianhydride, 4,4
'-Oxydiphthalic dianhydride, 3,3', 4,4'-
Biphenyltetracarboxylic dianhydride, 1,2,5,6
-Naphthalenetetracarboxylic dianhydride, 3,3 ″,
Examples thereof include 4,4 "-paraterphenyltetracarboxylic dianhydride and 3,3", 4,4 "-methterphenyltetracarboxylic dianhydride. A polyimide precursor composition that can be converted into a polyimide having good transparency in the region can be obtained,
Specific examples thereof include 4,4 '-(hexafluoroisopropylidene) diphthalic dianhydride. The present invention is not limited to these, and one or more tetracarboxylic dianhydrides are used.

The diamine is represented by the general formula (3) H ₂ N—R ₂ —NH ₂ (3) (wherein R ₂ represents the above-mentioned divalent organic group having 1 to 22 carbon atoms). It is. In the present invention, for example, an aliphatic or alicyclic diamine can be used as the diamine, and specific examples thereof include ethylenediamine, 1,1, and 2.
3-diaminocyclohexane, 1,4-diaminocyclohexane, 4,4'-diamino-3,3'-dimethyldicyclohexylmethane, 4,4'-diamino-3,3 '
-Dimethyldicyclohexyl and the like. Also,
When an aromatic compound is used, a polyimide precursor composition which can be converted into a polyimide having good heat resistance can be obtained. Specific examples thereof include 4,4′-diaminodiphenyl ether and 3,4′- Diaminodiphenyl ether, 4,4'-diaminodiphenylmethane, 3,3'-
Diaminodiphenylmethane, 4,4'-diaminodiphenylsulfone, 3,3'-diaminodiphenylsulfone, 4,4'-diaminodiphenylsulfide, m-
Phenylenediamine, p-phenylenediamine, 2,4
-Diaminotoluene, 2,5-diaminotoluene, 2,
6-diaminotoluene, benzidine, 3,3'-dimethylbenzidine, 3,3'-dimethoxybenzidine, o-
Trizine, 4,4 "-diaminoterphenyl, 1,5-
Diaminonaphthalene, 3,3'-dimethyl-4,4'-
Diaminodiphenylmethane, 4,4'-bis (4-aminophenoxy) biphenyl, 2,2-bis [4- (4-
Aminophenoxy) phenyl] propane, bis [4-
(4-aminophenoxy) phenyl] ether, bis [4- (4-aminophenoxy) phenyl] sulfone,
Bis [4- (3-aminophenoxy) phenyl] sulfone; When a fluorine-based material is used, a polyimide precursor composition which can be converted into a polyimide having good transparency in a short wavelength region can be obtained. As a specific example, 2,2-bis [4 -(4-aminophenoxy) phenyl] hexafluoropropane and the like.

The general formula (4)

Embedded image (R ₃ in the formula is a divalent organic group having 1 to 10 carbon atoms, R ₄ , R
₅ , R ₆ and R ₇ are monovalent organic groups having 1 to 10 carbon atoms, which may be the same or different;
Indicates an integer of 10. When the siloxane diamine represented by the formula (1) is used, the adhesion to the inorganic substrate can be improved. Siloxane diamine is usually 1 to 1 in all diamines.
Used in an amount of 20 mol%. If the amount of siloxane diamine is too small, the effect of improving the adhesiveness will not be exhibited, and if it is too large, the heat resistance will decrease. Specific examples of the siloxane diamine include bis-3- (aminopropyl) tetramethylsiloxane. In the present invention, one or more diamines can be used without being limited to these.

The synthesis of a polyamic acid is generally carried out by mixing and reacting a diamine and a tetracarboxylic dianhydride in a polar organic solvent. At this time, the degree of polymerization of the obtained polyamic acid can be controlled by the mixing ratio of the diamine and the tetracarboxylic dianhydride.

In addition, there are various methods for obtaining a polyamic acid, for example, by reacting tetracarboxylic acid dichloride and a diamine in a polar organic solvent, and then removing hydrochloric acid and the solvent to obtain a polyamic acid. However, the present invention is applicable to polyamic acids without depending on the synthesis method. In addition, the present invention is also applicable to derivatives such as the above-mentioned esterified products of polyamic acid.

As the substrate on which the black matrix is formed, a transparent substrate such as soda glass, non-alkali glass, borosilicate glass and quartz glass is usually used, but a plastic substrate can also be used. Further, for a reflection type liquid crystal display device, for example, a reflection plate in which a metal thin film is formed on glass may be used as a substrate.

One of the typical methods for producing the black matrix of the present invention is a method using a black paste in which a pigment is dispersed in a solution in which a matrix resin is dissolved in water or an organic solvent. There is no particular limitation on the solvent used for the black paste. Water and common organic solvents can be used. When polyimide is used as the resin component of the black matrix, the solvent used for the black paste is preferably a solvent that dissolves the polyimide precursor. Solvents for dissolving the polyimide precursor include amides such as N, N-dimethylacetamide and N, N-dimethylformamide, γ-butyrolactone, β
And polar organic solvents such as lactones such as -propyllactone and pyrrolidones such as 2-pyrrolidone and N-methyl-2-pyrrolidone. In addition, usually, the polyimide precursor alone is not dissolved, ethanol, butanol, alcohol such as ethylene glycol, methyl cellosolve, organic solvent such as cellosolves such as ethyl cellosolve is used by mixing with a solvent that dissolves the polyimide precursor. be able to.

The black paste is prepared by dispersing the pigment directly in the resin solution using a disperser, or dispersing the pigment in water or an organic solvent using a disperser to prepare a pigment dispersion.
Thereafter, it is manufactured by a method of mixing with a resin solution.
The method for dispersing the pigment is not particularly limited, and various methods such as a ball mill, a sand grinder, a three-roll mill, and a high-speed impact mill can be used.

In the black paste, the resin component and the pigment are usually in a weight ratio of 2: 8 to 9: 1, preferably 3: 7.
To 8: 2, more preferably 4: 6 to 7: 3. If the amount of the resin component is too small, the adhesion of the colored film to the substrate becomes poor, and if the amount of the pigment is too small, the light-shielding property decreases.

A surfactant can be added to the black paste for the purpose of improving the coatability of the black paste and the uniformity of the surface of the black film, or for improving the dispersibility of the pigment. The amount of the surfactant added is usually 0.001 to 10% by weight of the pigment, preferably 0.01 to 1% by weight. If the addition amount is too small, there is no effect of improving the coatability, the uniformity of the black film surface, or the dispersibility of the pigment. If it is too large, on the contrary, the coatability becomes poor or the pigment aggregates. Specific examples of the surfactant include anionic surfactants such as ammonium lauryl sulfate and polyoxyethylene alkyl ether triethanolamine sulfate;
Cationic surfactants such as stearylamine acetate and lauryltrimethylammonium chloride, amphoteric surfactants such as lauryldimethylamine oxide, laurylcarboxymethylhydroxyethylimidazolium betaine, polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, sorbitan mono Nonionic surfactants such as stearate are exemplified. Without being limited to these, one or two surfactants may be used.
More than one species can be used. The surfactant can be added at any point during or before or after the pigment dispersion step. However, care must be taken since the dispersibility of the pigment may change depending on the time of addition.

As a method of applying a black paste on a substrate, a method of applying the paste to a substrate by a spin coater, a bar coater, a blade coater, a roll coater, a die coater, a screen printing method, or the like, or immersing the substrate in a black paste Various methods can be used, such as a method, a method of spraying a black paste on a substrate, and a method of electrodeposition on an electrode when the resin component in the black paste is an electrolyte. When a black paste is applied to a substrate, treating the substrate surface with an adhesion aid such as a silane coupling agent can improve the adhesion between the black film and the substrate. In the case of performing electrodeposition, an electrode must be formed on a substrate.

The thickness of the black film used as the black matrix in the present invention is not particularly limited.
10 to 10 μm, preferably 0.5 to 3 μm. If the film thickness is too small, light absorption will be too small, and the light-shielding property will not be satisfied. If the film thickness is too large, there may be a problem that the step on the surface becomes large and the alignment of liquid crystal molecules is disturbed.

Next, when polyimide is used as a resin component and polyamic acid is used as a precursor thereof,
An example of a method for producing a pigment-dispersed resin black matrix is described below.

After the black paste is applied on the substrate by the method described above, a black polyimide precursor film is formed by air drying, heat drying, vacuum drying, or the like. In the case of heating and drying, use an oven, hot plate, etc.
The treatment is performed at a temperature in the range of 80 ° C, more preferably 80 to 120 ° C, for 30 seconds to 3 hours. When the temperature is too low, the solvent does not readily evaporate. Conversely, when the temperature is too high, the solubility in the developer decreases. A pattern is formed on the thus obtained polyimide precursor black film by ordinary wet etching.
First, a positive photoresist is applied on the polyimide precursor colored film to form a photoresist film. Subsequently, a mask is placed on the photoresist film, and ultraviolet light is irradiated using an exposure device. After the exposure, the photoresist coating and the polyimide precursor black film are simultaneously etched with an alkali developing solution for a positive photoresist. After the etching, the unnecessary photoresist film is removed.

Thereafter, the polyimide precursor black film is converted into a polyimide black film by heat treatment. The heat treatment is usually performed at 150 to 400 ° C., preferably at 18 ° C. in air, nitrogen atmosphere, or vacuum.
It is performed continuously or stepwise at a temperature of 0 to 350 ° C, more preferably 200 to 300 ° C, for 1 minute to 3 hours.

The color filter of the present invention can be manufactured by forming R, G and B pixel films in the openings of the pigment-dispersed black matrix of the present invention. As the pixel film, a dyeing film, a pigment dispersion film, a multiple interference film, a selective reflection film, or the like is used, and a pigment dispersion film is preferable from the viewpoint of ease of production, heat resistance, light resistance and the like.

There are no particular restrictions on the pigments that can be used in the present invention, but those that are excellent in light resistance, heat resistance and chemical resistance are preferred. Specific examples of typical pigments are indicated by color index (CI) numbers. Examples of yellow pigments include Pigment Yellow 20, 24, 83, 86, 93, 9
4, 109, 110, 117, 125, 137, 13
8, 139, 147, 148, 153, 154, 16
6, 173 and the like. Pigment oranges 13, 31, 36, 38, 40, 4 are examples of orange pigments.
2, 43, 51, 55, 59, 61, 64, 65 and the like. Examples of red pigments include Pigment Red 9, 97, 122, 123, 144, 149, 166,
168, 177, 180, 192, 215, 216, 2
24 and the like. Examples of violet pigments include Pigment Violet 19, 23, 29, 32, 33, 36,
37, 38 and the like. Examples of blue pigments include Pigment Blue 15 (15: 3, 15: 4, 15: 6, etc.), 21, 22, 60, 64, and the like. Examples of green pigments include Pigment Green 7, 10, 36,
47 and the like. In the present invention, various pigments can be used without being limited to these.

The three color pixels of R (red), G (green) and B (blue) of the color filter used in the liquid crystal display device
Since it is necessary to make the chromaticity characteristics of the RT phosphor similar, the pigments described above may be used by being combined with several colors so as to match the light transmission characteristics of the backlight and the liquid crystal display device. For example, R (red) is toned by a combination of a red pigment and a yellow pigment or an orange pigment, G (green) is toned by a combination of a green pigment and a yellow pigment or an orange pigment, and B (blue) is toned by a combination of a blue pigment and a violet pigment.

As a typical method for producing the color filter of the present invention, there is a method using a color paste in which a pigment is dispersed in a solution in which a matrix resin is dissolved in water or an organic solvent. Such a color paste is produced in the same manner as the above-mentioned black paste.
Using the prepared three color pastes of R (red), G (green), and B (blue), the same method as in the case of the pigment-dispersed resin black matrix is repeated to form a patterned pixel. A film is formed on the substrate, and the color filter of the present invention is obtained. When pattern processing of a pixel film is performed, R (red), G
By patterning and laminating part or all of the (green) and B (blue) pixel films, a color filter having columnar spacers can be obtained.

An overcoat film or a transparent conductive film is formed on the color filter thus manufactured, if necessary. Thereafter, liquid crystal is sealed between the color filter and the counter substrate, and the liquid crystal display device of the present invention is manufactured. There is no particular limitation on the liquid crystal display method, and TN, ST
N (Super Twisted Nematic), IPS
(In-plane switching), GH (guest host), FLC (ferroelectric liquid crystal), AFLC (anti-ferroelectric liquid crystal), PDLC (polymer dispersed liquid crystal), and the like.

[0041]

EXAMPLES The present invention will now be described specifically with reference to examples, but the present invention is not limited to these examples.

Example 1 500 equipped with a thermometer, a dry air inlet and a stirrer
In a 0 ml four-necked flask, 130.1 g (0.65 molar equivalent) of 4,4′-diaminodiphenyl ether,
6 ′ g of 4′-diaminodiphenyl ether (0.3
Mol equivalent), 12.4 g (0.05 mol equivalent) of bis-3- (aminopropyl) tetramethylsiloxane, 1000 g of γ-butyrolactone, and 200 g of N-methyl-2-pyrrolidone. After stirring at 1 ° C. for 1 hour, 161.1 g (0.5 mol equivalent) of 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride and 87.2 g (0.4 mol) of pyromellitic dianhydride Equivalent), 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride 26.5 g (0.09 times molar equivalent), γ-
1316.7 g of butyrolactone was charged, and the mixture was stirred at 70 ° C. for 2 hours under a dry nitrogen flow. Thereafter, 1.96 g (0.02 molar equivalent) of maleic anhydride was added and stirred for 1 hour to obtain a polyamic acid solution (polymer). Concentration 16 wt%).

25 g of a polyamic acid solution, 4.5 g of carbon black, 1.0 g of Pigment Blue 15 (phthalocyanine blue), 0.5 g of graphite having a particle size of 1.0 μm, and 45 g of N-methyl-2-pyrrolidone.
3 g, butyl cellosolve 14 g and glass beads 150 g
Together with a homogenizer at 7000 rpm for 30 minutes.
After the dispersion treatment for one minute, the glass beads were removed by filtration to obtain a black color paste. The particle size distribution of the pigment contained in the black color paste was measured using a submicron particle analyzer “N4PLUS” manufactured by Coulter, Inc.
The result was that particles having a particle size of 0.9 to 1.3 μm were present in 8% by weight of the total pigment.

A black color paste was spin-coated on an alkali-free glass substrate having a thickness of 1.1 mm.
The polyimide precursor film was heated and dried in air using an oven for 5 minutes to obtain a polyimide precursor film having a thickness of 1.5 μm. A positive photoresist was applied on the film and dried by heating at 80 ° C. for 20 minutes to obtain a 1.2 μm-thick resist film. Ultraviolet irradiation was performed through a chrome photomask using an ultraviolet exposure machine. After the exposure, the photoresist and the polyimide precursor colored film were simultaneously developed by immersion in a developer consisting of a 2.38 wt% aqueous solution of tetramethylammonium hydroxide. After the etching, the unnecessary photoresist layer was stripped with methyl cellosolve acetate. Further, the polyimide precursor black film thus obtained was heat-treated at 310 ° C. for 20 minutes in a nitrogen atmosphere,
A lattice black matrix composed of a 1.1 μm-thick polyimide black colored film of the present invention was obtained.

Next, 4,4,4 was placed in a 5000 ml four-necked flask equipped with a thermometer, a dry nitrogen inlet, and a stirrer.
'-Diaminodiphenyl ether 140.2 g (0.7
Molar equivalent), 3,3'-diaminodiphenylsulfone 6
2.1 g (0.25 mole equivalent), bis-3- (aminopropyl) tetramethylsiloxane 12.4 g (0.05
(Molar equivalent), 1000 g of γ-butyrolactone and 500 g of N-methyl-2-pyrrolidone, and the mixture was stirred at 40 ° C. for 1 hour under a dry nitrogen flow.
Benzophenonetetracarboxylic dianhydride 322.2 g
(1 molar equivalent) and 945.9 g of γ-butyrolactone were added, and the mixture was stirred at 60 ° C. for 3 hours under a dry nitrogen flow to obtain a polyamic acid solution (polymer concentration: 18 wt%).

20 g of this polyamic acid solution was taken out, and 18.6 g of γ-butyrolactone and 6.4 g of butyl cellosolve were added to obtain a solution having a polymer concentration of 8% by weight.

4 g of Pigment Red 177 (anthraquinone red), 40 g of γ-butyrolactone and 6 g of butyl cellosolve were dispersed together with 100 g of glass beads using a homogenizer at 7000 rpm for 30 minutes, and the glass beads were removed by filtration. A dispersion was obtained. A polymer concentration of 8 was added to 30 g of the pigment dispersion.
A 30% by weight solution was added and mixed to obtain a red color paste.

Further, γ was added to 20 g of the polyamic acid solution (polymer concentration 16 wt%) used for preparing the black paste.
-Butyrolactone (7.7 g) and 3-methyl-3-methoxybutanol (4 g) were added to obtain a solution having a polymer concentration of 10 wt%.

Pigment Green 7 (phthalocyanine green) (3.6 g), Pigment Yellow 83 (benzidine yellow) 0.4 g, γ-butyrolactone (32 g), and butyl cellosolve (4 g) were dispersed together with glass beads (120 g) at 7000 rpm for 30 minutes using a homogenizer. The beads were removed by filtration and a pigment concentration of 10
A pigment dispersion of wt% was obtained. 28 g of a solution having a polymer concentration of 10 wt% was added to 32 g of the pigment dispersion and mixed to obtain a green color paste.

Further, 45 g of the same polyamic acid solution (polymer concentration: 16 wt%) used in the preparation of the black and green color pastes, 2.8 g of Pigment Blue 15 (phthalocyanine blue), N-methyl-2-pyrrolidone 25. 5 g and butyl cellosolve 10 g together with 150 g of glass beads using a homogenizer at 7000 rpm
After the dispersion treatment at m for 30 minutes, the glass beads were removed by filtration to obtain a blue color paste.

A red color paste is spin-coated on a non-alkali glass substrate on which a black matrix is formed, and dried by heating in an air at 100 ° C. for 20 minutes in an oven to obtain a 1.6 μm-thick polyimide precursor. A membrane was obtained. This film is subjected to the same pattern processing as the black polyimide precursor film to form a stripe-shaped pattern, and then heat-treated at 300 ° C. for 30 minutes in a nitrogen atmosphere to form a 1.2 μm-thick polyimide red colored film. Pixels were formed. Note that, at the time of pattern processing of the red colored film, the red colored film was placed on the black matrix at the boundary with the black matrix, so that no gap was formed between the black matrix and the red colored film.

A green color paste was spin-coated on an alkali-free glass substrate and dried by heating in an air at 110 ° C. for 20 minutes in an oven to obtain a 1.5 μm-thick green polyimide precursor film. Was. This film was patterned in the same manner as the red polyimide precursor film,
Heat treatment was performed at 80 ° C. for 1 hour to form a 1.2 μm-thick polyimide green colored film pixel.

Further, a blue color paste was spin-coated on a non-alkali glass substrate, and dried by heating in an air at 130 ° C. for 20 minutes in an oven.
A blue polyimide precursor film was obtained. This film was patterned in the same manner as the red polyimide precursor film, and heat-treated at 280 ° C. for 1 hour in a nitrogen atmosphere to form a 1.2 μm-thick polyimide blue colored film pixel. Was prepared. In the pixel part of the color filter, indium tin oxide (ITO) with a thickness of 120 nm
The film was formed by sputtering. A polyimide precursor solution for forming an alignment film is printed on the ITO film using an anilox roll, and is printed at 120 ° C. for 10 minutes in a nitrogen atmosphere.
A heat treatment was performed at 50 ° C. for 20 minutes to form an alignment film having a thickness of 100 nm, and then a rubbing treatment was performed.

An epoxy resin in which a glass rod spacer having a rod diameter of 5 μm was dispersed was printed on the frame portion of the resin black matrix located outside the display screen, with an opening partly provided. After forming an ITO film and an alignment film and performing a rubbing treatment, the substrate was superposed on an alkali-free glass substrate on which spherical spacers having a diameter of 6 μm were sprayed.
After preheating at 90 ° C for 20 minutes,
A hot press was performed for 0 minutes. Thereafter, liquid crystal was injected from the opening, and the opening was sealed with an ultraviolet curable resin. The liquid crystal cell thus produced was sandwiched between polarizing plates to produce a liquid crystal display of the present invention.

When the display characteristics of the liquid crystal display device were evaluated, no display defect due to the change in the gap was found.
There were no particular problems with other display characteristics. Thereafter, the apparatus was disassembled, and the surface of the black matrix in the picture frame was observed with an electron microscope. As a result, no abnormalities such as deformation of the film due to protrusions or indentation of the glass rod spacer were found. Surface roughness meter "Surfcom" 1500
A (Tokyo Seimitsu Co., Ltd.) measured 0.1μ depth
m or more was not recognized. Also, from the cross-sectional photograph, the particle diameter in the black matrix is 0.9 μm to 1.3 μm.
The presence of graphite particles in the range of was observed. Further, the volume ratio between graphite and other pigments was determined from the cross-sectional photograph, and the weight ratio was calculated to be 8% by weight.

Comparative Example 1 A black color paste was prepared in the same manner as in Example 1 except that 0.5 g of graphite having a particle size of 0.1 μm or less was used instead of 0.5 g of graphite having a particle size of 1.0 μm. . When the particle size distribution of the pigment contained in the produced black color paste was measured with a submicron particle analyzer “N4plus” manufactured by Corouter Co., Ltd., unlike Example 1, particles having a particle size of 0.9 to 1.3 μm were obtained. Did not exist.

In the same manner as in Example 1, a resin black matrix and a color filter having a thickness of 1.1 μm were prepared, and a liquid crystal display device was prepared. When the display characteristics of the liquid crystal display device were examined, it was observed that unevenness occurred at the peripheral portion of the screen. When the device was disassembled and the surface of the black matrix in the picture frame was observed with an electron microscope, it was found that the glass rod spacers were embedded in the black matrix. The depth of the indentation was measured by a surface roughness meter “Surfcom” 1500A (manufactured by Tokyo Seimitsu Co., Ltd.) and found to be 0.3 μm. From the cross-sectional photograph, all the pigment particles were 0.1 μm or less, and no pigment particles having the same particle size as the thickness of the black matrix were observed.

Example 2 When producing a black paste, carbon black 4.5 was used.
g, Pigment Blue 15 (phthalocyanine blue)
Instead of 0.5 g and 0.5 g of graphite having a particle size of 1.0 μm, 4.2 g of carbon black, pigment blue 1
0.8 g of 5 (phthalocyanine blue) and particle size of 1.0 μm
Using 1.0 g of graphite, as in Example 1,
However, the spin coating conditions were changed so that the thickness of the black matrix was 0.9 μm, and the thicknesses of the R, G, and B pixel films were 1.5 times each. By stacking pixel films on the matrix, the height from the surface of the resin black matrix is 5μ.
A color filter on which m columnar spacers were formed was prepared.

After forming an ITO film and an alignment film and performing rubbing treatment in the same manner as in Example 1, an epoxy resin in which a glass rod spacer having a rod diameter of 5 μm is dispersed is applied to a resin black matrix located outside the display screen. The printing was performed by partially providing an opening on the frame portion. A liquid crystal display device of the present invention was manufactured in the same manner as in Example 1 except that the dispersion of the spherical spacer was omitted.

When the display characteristics of the liquid crystal display device were evaluated, no display defect due to the change in the gap was found.
There were no particular problems with other display characteristics. Thereafter, the device was disassembled, and the resin black matrix in the frame was observed with an electron microscope. 0.1 on black matrix
μm protrusions were partially observed. However, no deformation of the film due to the penetration of the glass rod spacer was observed. When measured with a surface roughness meter “Surfcom” 1500A (manufactured by Tokyo Seimitsu Co., Ltd.), a projection of 0.1 μm was observed, but no depression of 0.1 μm or more was observed.

Comparative Example 2 A resin black matrix was prepared in the same manner as in Example 2 except that 1.0 g of graphite having a particle size of 0.1 μm or less was used instead of 1.0 g of graphite having a particle size of 1.0 μm. . Then, in the same manner as in Example 2, a color filter was manufactured, and a liquid crystal display device was manufactured. When the display characteristics of the liquid crystal display device were examined, it was observed that unevenness occurred at the peripheral portion of the screen. When the apparatus was disassembled and the resin black matrix in the frame portion was observed with an electron microscope, no protrusion was observed on the black matrix, but it was observed that the glass rod spacers were embedded in the black matrix. Use the surface roughness meter "Surfcom" 1500A (Tokyo Seimitsu Co., Ltd.)
Was 0.3 μm.

[0062]

Since the resin black matrix of the present invention is configured as described above, in the liquid crystal display device using the resin black matrix of the present invention, the columnar spacer is prevented from being entangled in the black matrix in the assembling process. Therefore, it is possible to suppress a decrease in display quality due to a change in the gap.

Claims (9)

[Claims] 1. A pigment-dispersed resin black matrix formed on a substrate, wherein 1% by weight or more of all pigments contains a pigment having a particle diameter of 0.8 to 1.2 times the thickness of the black matrix. A pigment-dispersed resin black matrix produced using a paste. 2. In a pigment-dispersed resin black matrix formed on a substrate, 1% by weight or more of all pigments contained in the black matrix has a particle size of 0.8 to 1.2 times the thickness of the black matrix. A pigment-dispersed resin black matrix, which is a pigment having a diameter. 3. The black matrix having a thickness of 0.8 to 1.
3. The black matrix according to claim 1, wherein the pigment having a double particle size is graphite. 4. The black matrix according to claim 1, wherein the resin component is a polyimide resin. 5. A color filter comprising the black matrix according to claim 1. 6. The color filter according to claim 5, wherein the pixel film of the color filter is a pigment dispersion resin. 7. The color filter according to claim 6, wherein the resin component of the pigment dispersion resin is a polyimide resin. 8. The color filter according to claim 5, further comprising a columnar spacer formed by laminating a pixel film on the black matrix. 9. A liquid crystal display device comprising the color filter according to claim 5.