JP2007093840A - Transparent substrate with black matrix, color filter and manufacturing method of them - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an effective control method for obtaining excellent flatness of pixel and desirable ink repellency in black matrix surface in order to prevent color irregularity, void and color mixing due to ink overflow from occurring in a manufacturing method of a color filter. <P>SOLUTION: The manufacturing method of a transparent substrate with black matrix comprises a process of manufacturing the black matrix containing an ink-repellent agent on the transparent substrate, wherein, upon heat curing of the black matrix, the heat curing is performed, so that the black matrix-formation surface side of the transparent substrate is heated and the black matrix-nonformation surface side of the transparent substrate is cooled. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The present invention relates to a color filter used for a color display device and the like, and more particularly to a method for manufacturing a transparent substrate with a black matrix of a color filter.

As a method for manufacturing a color filter used in a color display device such as a color liquid crystal display, an inkjet method has been proposed.

Examples of a method for manufacturing a color filter using an inkjet method include methods described in Patent Document 1, Patent Document 2, Patent Document 3, and the like.

In Patent Document 1, in order to prevent spreading of colored ink outside a desired colored region on a glass substrate, a pattern is formed by previously containing a fluorine-based water / oil repellent in a light shielding pattern (black matrix). In addition, it is described that colored ink is fixed only in a colored region. Patent Documents 2 and 3 describe that a black matrix containing a fluorine-containing compound and / or a silicon-containing compound is used as a partition wall for bleeding in ink in a coloring process and preventing color mixing. .
In this specification, the term black matrix is used to mean a light shielding pattern. That is, the term black matrix is not limited to the lattice shape, but includes the stripe shape and the meander shape.

However, in these methods, the pattern cross-sectional shape tends to be a convex shape or a concave shape due to the difference in surface energy between the black matrix surface and the colored ink surface, and pixel smoothing is very difficult. In particular, in the case of a color filter, when the spectral characteristics change depending on the pixel film thickness, and the pixel film thickness becomes non-uniform, there is a problem that color unevenness and color loss (white loss) occur and display quality deteriorates. .

In addition, in order to reduce the surface energy of the black matrix surface and make the pixel thickness uniform, even if the amount of the ink repellent agent in the black matrix is reduced, the ink repellency at the top of the black matrix is not sufficiently maintained. There is a problem that color mixing occurs due to overflow of ink.
JP-A-6-347637 JP-A-7-35915 JP 7-35917 A

The present invention has been made in view of these problems. In the method for manufacturing a color filter, the present invention is excellent in pixel smoothness, and prevents color unevenness, color loss (missing white), and color mixing due to ink overflow. Another object of the present invention is to provide an effective control method for obtaining desired ink repellency on the black matrix surface.

The invention described in claim 1
In a method for producing a black matrix containing an ink repellent agent on a transparent substrate,
A transparent with black matrix, wherein the black matrix forming surface side of the transparent substrate is heated and the black matrix non-forming surface side of the transparent substrate is cooled when the black matrix is thermally cured. A method for manufacturing a substrate.

The invention described in claim 2
2. The method for producing a transparent substrate with a black matrix according to claim 1, wherein a heating temperature on the black matrix forming surface side is 150 ° C. or higher and 230 ° C. or lower.

The invention according to claim 3
2. The method for producing a transparent substrate with a black matrix according to claim 1, wherein the cooling temperature on the black matrix non-forming surface side is −20 ° C. or more and 40 ° C. or less.

The invention according to claim 4
A transparent substrate with a black matrix produced by the method for producing a transparent substrate with a black matrix according to claim 1.

The invention described in claim 5
5. The transparent substrate with a black matrix according to claim 4, wherein the ink repellency at the top of the black matrix is greater than the ink repellency at the bottom of the black matrix.

The invention described in claim 6
6. The transparent substrate with a black matrix according to claim 4, wherein the contact angle of the colored ink having a surface tension of 40 mN / m or less with respect to the top of the black matrix is 30 ° or more and 60 ° or less. .

The invention described in claim 7
A method for producing a color filter, wherein a colored pattern is formed by ejecting colored ink to an opening of a black matrix of a transparent substrate with a black matrix according to any one of claims 4 to 6 by an inkjet method. .

The invention according to claim 8 provides:
A color filter, wherein a colored pattern is provided in an opening of a black matrix of the transparent substrate with a black matrix according to any one of claims 4 to 6.

The transparent substrate with a black matrix and the color filter using the same according to the present invention have both a light shielding function and an ink repellency function with a single black matrix. Furthermore, when the production method of the present invention is used, the ink repellency at the top of the black matrix can be made larger than the ink repellency of the portion other than the top of the black matrix. Therefore, there are no problems such as color mixing due to overflow of ink, white spots and color unevenness when a colored pattern is provided between black matrix patterns, providing excellent color filter characteristics and excellent color characteristics. it can.

Embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited thereto. FIG. 1 shows an embodiment of a color filter manufacturing method according to the present invention. In the color filter of FIG. 1, a black matrix 2 is formed on a transparent substrate 1. The ink repellency of the upper top portion 23 of the black matrix 2 is larger than the ink repellency of the lower portion 24 of the black matrix 2. Furthermore, after discharging the red (R), green (G), and blue (B) colored inks 7 to the openings between the black matrices 2 by the ink jet method, the solvent is first evaporated and then the ink is cured, A colored pattern 7 (7R, 7G, 7B) is formed.

  As the transparent substrate 1 of the present invention, a glass substrate, a quartz substrate, a plastic substrate, or the like can be used.

As the material of the black matrix 2 in the present invention, a black resin composition mainly composed of a black light shielding material, a photoinitiator, a dispersant, a resin, a solvent, and an ink repellent agent is used.
Examples of the black light shielding material of the black matrix 2 in the present invention include black pigments, black dyes, inorganic materials, etc., and organic pigments, carbon black, aniline black, graphite, titanium oxide, iron black and the like are used in combination. Is.

Casein, gelatin, polyvinyl alcohol, carboxymethyl acetal, polyimide resin, acrylic resin, epoxy resin, melanin resin, and the like are appropriately selected as the resin of the black matrix 2 material in the present invention. An acrylic resin is preferred when heat resistance and light resistance are required. In addition, since a photolithography method is employed, a photosensitive resin is used.

Examples of the dispersant for the material of the black matrix 2 in the present invention include nonionic surfactants such as polyoxyethylene alkyl ether, and ionic surfactants such as sodium alkylbenzene sulfonate and poly fatty acid salts. In addition, fatty acid salt alkyl phosphates, tetraalkylammonium salts, and the like, organic pigment derivatives, polyesters, and the like. One type of dispersant may be used alone, or two or more types of dispersants may be mixed and used.

The solvent for the material of the black matrix 2 in the present invention is appropriately selected and used from the viewpoints of the coating property and dispersion stability of the black resin composition, and includes toluene, xylene, ethyl cellosolve, ethyl cellosolve acetate. , Diclime, cyclohexanone and the like.

The ink repellent agent in the present invention is preferably a material containing silicon or / and fluorine atoms having a low affinity with the resin contained in the black matrix 2 material. Specific examples of the ink repellent agent include those having an organic silicone in the main chain or side chain, and a silicone resin or silicone rubber containing a siloxane component, in addition to vinylidene fluoride, vinyl fluoride, ethylene trifluoride. And fluororesins such as these copolymers, but are not limited thereto.

The black matrix 2 is formed by photolithography. As a specific process, first, the material of the black matrix 2 is applied on the transparent substrate 1 with a uniform film thickness, and is heated (prebaked) at a predetermined temperature (FIGS. 1A to 1B). A pattern is exposed with respect to this coating film through the light shielding mask 3 (FIG.1 (c)). Next, when developed, a pattern of the black matrix 2 is formed, and finally, the black matrix 2 is formed by thermosetting (post-baking).

When the colored ink is injected between the black matrixes 2, in order to reduce the color mixture in the adjacent colored pattern 7 and to reduce the white spots and color unevenness of the colored pattern 7, the above-described thermosetting (post-bake) is performed. In the process, the black matrix formation surface side is heated while cooling the black matrix non-formation surface side of the transparent substrate 1.

That is, when the black matrix forming surface side is heated, an ink repellent agent having a low affinity with components other than the ink repellent agent contained in the black matrix 2 causes phase separation, and the ink repellent agent is unevenly distributed on the top portion 23 of the black matrix. . On the other hand, since the ink repellent agent hardly causes phase separation from components other than the ink repellent agent contained in the black matrix 2 in the lower portion 24 of the low temperature black matrix, the ink repellency is lowered. Therefore, the mixed color of the adjacent colored pattern 7 when the colored ink is injected between the black matrixes 2 is prevented by the high ink repellency of the black matrix top 23, and the low ink repellency of the lower part 24 of the black matrix is further reduced. Depending on the property, it is possible to prevent white spots and color unevenness of the colored pattern 7.

As a heating method on the black matrix forming surface side, a hot plate, an oven, an IR heater or the like shown in 4 is appropriately selected and used. However, the black matrix is effectively applied with a temperature gradient in the thickness direction of the black matrix 2. When making the surface temperature of the formation surface uniform, it is particularly preferable to use a hot plate. Either a contact type or a non-contact type may be used as the heating method, but it is preferable to perform contact type heating when performing high-temperature heating.

The heating temperature on the black matrix forming surface side is preferably 150 ° C. or higher and 230 ° C. or lower. When the heating temperature is less than 150 ° C., the black matrix 2 is not thermally cured, and when the heating temperature is higher than 230 ° C., the black matrix 2 is decomposed, so that the black matrix 2 cannot be molded.

As a cooling method for the black matrix non-formation surface side of the transparent substrate, a cool plate, a Peltier or the like shown in 5 is appropriately selected and used. In particular, when performing low-temperature cooling at 0 ° C. or lower, Peltier is used. As the cooling method, either a contact type or a non-contact type may be used.

The cooling temperature on the black matrix non-forming surface side of the transparent substrate is preferably set to −20 ° C. or more and 40 ° C. or less. When the cooling temperature is higher than 40 ° C., there is no temperature difference from the top of the black matrix 2, so that ink repellency does not occur only at the top of the black matrix 23. When the cooling temperature is lower than −20 ° C., the lower part of the black matrix 2 is not thermally cured, which is not preferable because the black matrix 2 cannot be formed.

When the contact angle of the colored ink having a surface tension of 40 mN / m or less is A with respect to the upper top portion 23 of the black matrix 2, it is preferable that 30 ° ≦ A ≦ 60 °. In the case of A <30 °, color mixture to the adjacent colored pattern 7 is likely to occur, which causes a decrease in yield. When A> 60 °, the colored pattern 7 has a convex shape, and white spots or color unevenness of the colored pattern 7 occurs. The contact angle of the colored ink can be adjusted by adding the ink repellent agent to the black matrix.

The material of the colored ink of the present invention includes a color pigment, a resin, a dispersant, a solvent, and the like.
Specific examples of the pigment used as the colorant include Pigment Red 9, 19, 38, 43, 97, 122, 123, 144, 149, 166, 168, 177, 179, 180, 192, 215, 216, 208, 216, 217, 220, 223, 224, 226, 227, 228, 240, Pigment Blue 15, 15: 6, 16, 22, 29, 60, 64, Pigment Green 7, 36, Pigment Red 20, 24, 86, 81, 83, 93, 108, 109, 110, 117, 125, 137, 138, 139, 147, 148, 153, 154, 166, 168, 185, Pigment Orange 36, Pigment Violet 23, and the like. Not a thing Yes. Further, these may be used in combination of two or more in order to obtain the desired hue.

As the solvent species used for the colored ink, those having an appropriate surface tension range of 40 mN / m or less in an ink jet system and a boiling point of 130 ° C. or more are preferable. When the surface tension is 40 mN / m or more, the dot shape stability at the time of ink jet ejection is significantly adversely affected. When the boiling point is 130 ° C. or less, the drying property in the vicinity of the nozzle is remarkably increased. This is not preferable because it causes clogging and other defects. Specifically, 2-methoxyethanol, 2-ethoxyethanol, 2-butoxyethanol, 2-ethoxyethyl acetate, 2-butoxyethyl acetate, 2-methoxyethyl acetate, 2-ethoxyethyl ether, 2- (2-ethoxy Ethoxy) ethanol, 2- (2-butoxyethoxy) ethanol, 2- (2-ethoxyethoxy) ethyl acetate, 2- (2-butoxyethoxy) ethyl acetate, 2-phenoxyethanol, diethylene glycol dimethyl ether, etc. The solvent is not limited to these, and any solvent that satisfies the above requirements can be used. Moreover, you may mix and use 2 or more types of solvents as needed.

Casein, gelatin, polyvinyl alcohol, carboxymethyl acetal, polyimide resin, acrylic resin, epoxy resin, melanin resin, and the like are used as the resin of the colored ink of the present invention, and are appropriately selected in relation to the pigment. An acrylic resin is preferred when heat resistance and light resistance are required.

In order to improve the dispersion of the dye in the resin, a dispersant may be used. As the dispersant, as the nonionic surfactant, for example, polyoxyethylene alkyl ether, etc., and as the ionic surfactant Examples thereof include sodium alkylbenzene sulfonate, poly fatty acid salt, fatty acid salt alkyl phosphate, tetraalkyl ammonium salt, and other organic pigment derivatives and polyester. One type of dispersant may be used alone, or two or more types of dispersants may be mixed and used. The solvent is required to have stability over time, drying property, etc. in addition to solubility, and is appropriately selected in relation to the dye and the resin.

An ink jet method is used to form the colored pattern 7. As the ink jet device to be used, there are a piezo conversion method and a heat conversion method depending on the ink discharge method, and the piezo conversion method is particularly preferable. A device in which the ink particleization frequency is about 5 to 100 kHz, the nozzle diameter is about 5 to 80 μm, three heads are arranged, and 60 to 500 nozzles are incorporated in one head is suitable.

After ink discharge, the solvent was evaporated. Next, the resin in the ink is cured to form a color filter.

In the present invention, if a black matrix is used as a simple partition and a light emitting material for an EL display is used instead of the colored ink, the EL display can be manufactured.

Examples of the present invention will be specifically described below.
First, the black matrix 2 was created.
(Preparation of ink repellent black matrix)
10 parts by weight of an acrylic precursor, 7.5 parts by weight of carbon black, 130 parts by weight of NMP, 5 parts by weight of a dispersant (copper phthalocyanine derivative), 5 parts by weight of an initiator and 0.5 parts by weight of an ink repellent (polyalkylsiloxane) While cooling with a bead mill disperser, the mixture was dispersed for 3 hours to prepare a black matrix composition.

The black matrix composition was applied onto alkali-free glass (Corning, product number 1737) by spin coating, and then prebaked at 90 ° C. for 2 minutes on a hot plate. Next, after exposure and development, a 200 ° C. hot plate is brought into contact with the black matrix forming surface, and a 20 ° C. cool plate is brought into contact with the black matrix non-forming surface of the transparent substrate for 15 minutes. To form a black matrix. The film thickness of the black matrix was 2.0 μm.

The contact angle of the top of the black matrix with the colored ink (surface tension 30 mN / m) was measured and found to be 48 °, confirming that the top of the black matrix had ink repellency with respect to the colored ink. did. Further, when the surface tension of the black matrix opening with respect to the colored ink on the glass surface was measured, it was confirmed that the colored ink was wet and was ink-philic to the colored ink.

(Preparation of colored ink)
20 parts by weight (60 g) of methacrylic acid, 10 parts by weight (30 g) of methyl methacrylate, 55 parts by weight of butyl methacrylate (165 g) and 15 parts by weight of hydroxyethyl methacrylate (45 g) are dissolved in 300 g of butyl lactate, and azobis under nitrogen atmosphere. An acrylic copolymer resin was obtained by adding 0.75 parts by weight (2.25 g) of isobutylnitrile and reacting at 70 ° C. for 5 hours. The obtained acrylic copolymer resin was diluted with propylene glycol monomethyl ether acetate so that the resin concentration would be 10% to obtain a diluted solution of the acrylic copolymer resin. 19.0 g of pigment and 0.9 g of dispersant were added to 80.1 g of this diluted solution, and kneaded with three rolls to obtain red, green and blue colored varnishes. Each colored varnish was adjusted with propylene glycol monomethyl ether acetate so that the pigment concentration was 12 to 15% and the viscosity was 15 cps to obtain R, G and B colored inks.

(Production of color filter)
Each of the R, G, and B colored inks is used for the opening of the black matrix, and each of red (R), green (G), and blue (B) is printed by an inkjet printing apparatus equipped with a 12 pl and 180 dpi head. A colored pattern 7 (7R, 7G, 7B) was formed.

After the colored ink was discharged, the solvent was first evaporated by heating at 150 ° C. for 1 minute on a hot plate. Next, the colored pattern 7 (7R, 7G, 7B) was formed by heating the ink at 230 ° C. for 1 hour to cure the ink.

The color filter thus obtained was a good color filter with good smoothness and little color unevenness.

<Comparative Example 1>
A black matrix was prepared in the same manner as in Example 1 except that the cooling temperature of the transparent substrate was set to 80 ° C. The ink repellency occurred not only at the top of the black matrix but also at the bottom of the black matrix. When a color filter was produced in the same manner as in Example 1, the color ink was repelled at the black matrix opening, resulting in a color filter with many color loss (white spots).

<Comparative example 2>
A black matrix was prepared by the same method as in Example 1 except that the cooling temperature of the transparent substrate was set to −50 ° C. As a result, the black matrix could not be molded due to insufficient thermosetting at the bottom of the black matrix.

<Comparative Example 3>
A black matrix was produced by the same method as in Example 1 except that the heating temperature on the black matrix forming surface side was set to 130 ° C., but the black matrix was not sufficiently cured and the black matrix could not be molded.

<Comparative example 4>
A black matrix was produced by the same method as in Example 1 except that the heating temperature on the black matrix forming surface side was set to 270 ° C. As a result, the black matrix melted and the black matrix could not be molded.

It is explanatory drawing which shows the manufacturing method of the color filter of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Transparent substrate 2 ... Black matrix 3 ... Shading mask 4 ... Heating material 5 ... Cooling material 6 ... Inkjet apparatus 7 ... Coloring pattern 7R ... Coloring pattern (red )
7G ... Coloring pattern (green)
7B Coloring pattern (blue)
21 ... Black matrix material coating 22 applied on transparent substrate 22 ... Black matrix material pattern 23 ... Black matrix top 24 ... Black matrix bottom

Claims (8)

In a method for producing a black matrix containing an ink repellent agent on a transparent substrate,
A transparent with black matrix, wherein the black matrix forming surface side of the transparent substrate is heated and the black matrix non-forming surface side of the transparent substrate is cooled when the black matrix is thermally cured. A method for manufacturing a substrate. The method for producing a transparent substrate with a black matrix according to claim 1, wherein the heating temperature on the black matrix forming surface side is 150 ° C or higher and 230 ° C or lower. The method for producing a transparent substrate with a black matrix according to claim 1, wherein the cooling temperature on the non-black matrix forming surface side is -20 ° C or higher and 40 ° C or lower. A transparent substrate with a black matrix produced by the method for producing a transparent substrate with a black matrix according to claim 1. The transparent substrate with a black matrix according to claim 4, wherein the ink repellency at the top of the black matrix is greater than the ink repellency at the bottom of the black matrix. 6. The transparent substrate with a black matrix according to claim 4, wherein the contact angle of the colored ink having a surface tension of 40 mN / m or less with respect to the top of the black matrix is 30 ° or more and 60 ° or less. A method for producing a color filter, wherein a colored pattern is formed by ejecting colored ink to an opening of a black matrix of a transparent substrate with a black matrix according to any one of claims 4 to 6 by an inkjet method.   A color filter, wherein a colored pattern is provided in an opening portion of a black matrix of the transparent substrate with a black matrix according to any one of claims 4 to 6.