JP2006017980A - Method for manufacturing color filter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a color filter for preventing color mixing in adjacent colored portions and forming a colored portion with no void or color irregularity in the region. <P>SOLUTION: The method includes steps of: (1) forming a black matrix 2 having an aperture on a transparent substrate 1; (2) forming a colored portion by depositing color ink 3 by an ink jet system on the aperture of the black matrix; and (3) simultaneously curing and flattening the color portion 5 by heat press process. The black matrix is formed by using a photosensitive resin composition containing a black light shielding material and shows water repellency and oil repellency. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a color filter for a display device such as an electrolytic emission display device, a fluorescent display device, a plasma display, and a liquid crystal display device, and more particularly to a method for manufacturing a color filter using an inkjet method.

  In recent years, a method for manufacturing a color filter using an ink jet method has been studied mainly for the purpose of cost reduction.

  As a method for producing a color filter using an inkjet method, for example, a method of forming a black matrix on a glass substrate and applying an ink to an opening of the black matrix using an inkjet recording apparatus to form a colored portion. Proposed. Furthermore, in this method, the ink is satisfactorily wet with the ink as a constituent material of the black matrix so that the ink is satisfactorily filled in the predetermined opening and the mixed color is not generated between the adjacent colored portions. Easy things are being considered.

  For example, as a method for preventing color mixing between colored portions, there is a method of forming a large ink-repellent silicone rubber pattern having the same size as the black matrix on the black matrix to prevent color mixing in the ink jet method or printing method ( Patent Document 1).

  However, the above-described method multiplies the partition walls, and it is necessary to perform the photolithography process a plurality of times. Therefore, there is a problem that the process is complicated, the cost is increased, and the yield is lowered.

  As another method, there has been proposed a method in which a black matrix is formed using a material having a contact angle of 20 ° or more with respect to ink, and ink is applied to the opening (see Patent Document 2). The above-described method is a method in which a water repellent such as a fluorine compound or a silicon compound is included in the black matrix in order to impart ink repellency to the black matrix.

  However, if the black matrix contains a fluorine compound or silicon compound, which is a water repellent, as in the above method, the black matrix material is not treated during post-baking (main curing), which is the final step of the black matrix formation process. The water repellent agent evaporates and adheres thinly to the glass substrate surface exposed at the black matrix opening.

  Even when no water repellent is used, the low-molecular organic substance in the black matrix material evaporates and adheres to the glass substrate surface in the same manner. In either case, the glass substrate surface exhibits ink repellency, and when ink is applied to the openings of the black matrix, the wettability between the glass substrate surface and the ink deteriorates, and the ink is uniformly distributed in the openings. There is a risk that white spots and color unevenness occur.

In addition, by giving ink repellency to the black matrix, the ink is repelled on the side wall surface of the black matrix, so the colored part formed in the part surrounded by the partition wall has a shape in which the ink surface is raised to a convex shape. As a result, variations in density occur in the colored portion due to the difference in film thickness.
JP 4-123005 A JP 7-35917 A

  An object of the present invention is to prevent color mixing between adjacent colored portions when applying ink to a region surrounded by a partition wall when a color filter is manufactured inexpensively by a simple process using an ink jet method. In addition, it is an object of the present invention to provide a method for manufacturing a color filter capable of forming a colored portion free from white spots and color unevenness in a region.

The present invention relates to a method for producing a color filter for a display device,
1) forming a black matrix having an opening on a transparent substrate;
2) forming a colored portion by applying colored ink to the opening of the black matrix by an ink jet method;
3) A step of simultaneously curing and flattening the colored portion by hot pressing.
A color filter manufacturing method characterized by comprising:

Further, the present invention provides a method for producing a color filter for a display device,
1) forming a black matrix having an opening on a transparent substrate;
2) forming a colored portion by applying colored ink to the opening of the black matrix by an ink jet method;
3) forming a protective layer on the entire surface of the transparent substrate on which the colored portion is formed;
4) A step of simultaneously curing and flattening the protective layer and the colored portion, and smoothing the surface of the protective layer by a heat press treatment through a film having a smooth surface,
A color filter manufacturing method characterized by comprising:

  Further, the present invention provides the method for producing a color filter according to the above invention, wherein the black matrix is a black matrix formed using a photosensitive resin composition containing a black light shielding material, and exhibits water and oil repellency. It is a manufacturing method of the color filter characterized.

  According to the present invention, it is possible to flatten the colored portion from the conventional shape by hot pressing, and it is possible to provide a color filter with extremely small color unevenness. Moreover, the color filter with the smooth surface of a protective layer can be provided by the hot press process through the film which forms a protective layer and has a smooth surface.

The present invention is described in detail below.
FIG. 1 is a process diagram for explaining an embodiment of a method for producing a color filter according to the present invention. FIG. 1A shows a state where a black matrix 2 is formed on a transparent substrate 1. First, a black matrix 2 as a partition is selectively formed on the transparent substrate 1. Thereby, the recessed part which provides the below-mentioned coloring ink in the opening part of the black matrix 2 is formed.

  Here, a glass substrate is generally used as the transparent substrate 1, but glass that satisfies the characteristics required for the final use, such as a liquid crystal display device, for example, transparency and mechanical strength, and can withstand subsequent processes is used. For example, a plastic substrate such as PET, PES, and PEN can be used.

Further, since the black matrix 2 in the present invention is also used as a partition wall for preventing color mixing of colored inks, the thickness is preferably 0.5 μm or more. Therefore, a resin (including a photopolymerizable monomer and a photopolymerization initiator), black It is desirable to use a black photosensitive resin composition mainly composed of a light-shielding material, a dispersant, a solvent, and the like, and pattern it by photolithography. Further, the method for forming the black matrix 2 is not limited to the photolithography method, and for example, it can be formed by a thermal transfer method or a printing method.

  Examples of the black light shielding material of the black matrix 2 include black pigments, black dyes, and inorganic materials, and organic pigments, carbon black, aniline black, graphite, titanium oxide, iron black, and the like are used in combination.

  Moreover, as a solvent of the black photosensitive resin composition which forms the black matrix 2, from points, such as the applicability | paintability and dispersion stability, it selects and uses suitably, Toluene, xylene, ethyl cellosolve, Examples include ethyl cellosolve acetate, diclime, and cyclohexanone.

  Moreover, it is desirable to add ink repellency to the black matrix 2 serving as a partition wall to impart ink repellency. This is to prevent the colored ink from overflowing beyond the partition walls of the black matrix 2 and to prevent color mixing between adjacent colored portions. Specific examples of the ink repellent component to be added include those having organosilicone in the main chain or side chain, silicone resin or silicone rubber containing a siloxane component, and in addition to vinylidene fluoride, vinyl fluoride, trifluoride. Examples thereof include, but are not limited to, fluorine-containing resins such as ethylene fluoride and copolymers thereof.

  Next, as shown in FIG. 1B, the colored ink 3 is applied to the opening by an inkjet method. As the printing apparatus 4 using an inkjet method, a bubble jet (registered trademark) type using an electrothermal transducer as an energy generating element, a piezo jet type using a piezoelectric element, or the like can be used.

  The material of the colored ink 3 in the present invention is mainly composed of a pigment, a resin, and a solvent. As the pigment, a dye or a pigment is used. As the resin, casein, gelatin, polyvinyl alcohol, carboxymethyl acetal, polyimide resin, acrylic resin, epoxy resin, melanin resin and the like are used, and are appropriately selected in relation to the pigment. When heat resistance and light resistance are required, an acrylic resin is preferable.

  The solvent type used for the colored ink is preferably one having a surface tension range of 35 mN / m or less and a boiling point of 130 ° C. or higher in consideration of suitability for inkjet printing. When the surface tension is 35 mN / m or more, the dot shape stability at the time of ink jet discharge 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.

In addition, a dispersant may be used to improve the dispersion of the dye in the resin. For example, a nonionic surfactant as a dispersant, for example, polyoxyethylene alkyl ether, and an ionic surfactant, for example, In addition, sodium alkylbenzene sulfonate, poly fatty acid salt, fatty acid salt alkyl phosphate, tetraalkyl ammonium salt, and the like, and organic pigment derivatives, polyesters, and the like. A dispersing agent may be used independently and may mix and use two or more types. As the solvent, in addition to solubility, stability over time, drying property, and the like are required, and the solvent is appropriately selected in relation to the dye and the resin.

  Further, the color filter formed according to the present invention can be cured by energy such as heat, light, and electron beam for the purpose of improving the durability after the colored portion is formed.

  As shown in FIG. 1C, the vertical cross-sectional shape of the colored portion 5 formed in the opening portion of the black matrix 2 using the colored ink 3 has a convex shape. In general, when a color filter is manufactured by an ink jet method using a partition wall imparted with ink repellency, this “poor flatness” is regarded as a major improvement problem. This is because although the color mixing between the colored portions can be prevented by the ink repellency of the partition walls, the vertical cross-sectional shape of the colored portion becomes a convex shape with a raised central portion due to the effect of the ink repellency. . In other words, the formed colored portion has a non-uniform film thickness in which the film thickness at the peripheral edge is thin and the center is thick. As a result, color unevenness occurs in the colored portion.

  Therefore, in the present invention, as shown in FIG. 1 (d), after the colored portion is formed, the colored portion in an undried state is hot-pressed by using a hot press device, and then cured and flattened. What is necessary is just to perform the heat processing by a hot press apparatus at 100-300 degreeC for about 10 to 240 minutes.

  By the flattening by the upper platen 6a and the lower platen 6b of the hot press apparatus, the colored portion becomes flat from the convex shape, and a color filter without color unevenness can be manufactured (FIG. 1 (e)).

  Further, as shown in FIG. 1 (f), a protective layer 7 may be formed to protect the surface of the color filter from a solvent or the like, if necessary. As the protective layer, a thermosetting type, photocuring type, light / heat combination type resin film, etc., or an inorganic film formed by vapor deposition, sputtering, etc. can be used, and it has transparency as a color filter. Any material that can withstand the subsequent ITO formation process, alignment film formation process, and the like can be used.

  Moreover, as shown in FIG. 2, it is also possible to perform planarization by a hot press apparatus after providing the protective layer 7. In this case, since the protective layer has a strong tendency to follow the minute unevenness of the colored portion, it is desirable to heat press the surface of the protective layer through a film having a smooth surface. By sticking and pressing a film having a smooth surface so that air bubbles do not enter and then solidifying the protective layer, it is possible to remove the film while the surface of the protective layer is smooth.

Examples of the present invention will be specifically described below.
(Formation of black matrix)
Resist material containing carbon black on alkali-free glass (Corning “# 1737”) (Nippon Steel Chemical Co., Ltd .; negative resist ink for black matrix “V-259 BK739P”) is a photosensitive silicon compound. A 10% addition of (dimethylpolysilane) was spin-coated to a film thickness of 1.5 μm and prebaked. Thereafter, exposure, development, and post-baking were performed to form a black matrix.
(Preparation of colored ink)
20 parts of methacrylic acid, 10 parts of methyl methacrylate, 55 parts of butyl methacrylate and 15 parts of hydroxyethyl methacrylate are dissolved in 300 g of butyl lactate, and 0.75 part of azobisisobutylnitrile is added in a nitrogen atmosphere, and the reaction is carried out at 70 ° C. for 5 hours. As a result, an acrylic copolymer resin was obtained. 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 5 to 8% and the viscosity was 15 CPS to obtain R, G and B colored inks.
(Production of color filter)
An appropriate amount of the colored ink is applied to the opening of the black matrix by an ink jet printing apparatus, and dried at 180 ° C. for 30 minutes. Formed. The colored portion could be formed without color mixing due to the ink repellency imparted to the black matrix, but the longitudinal cross-sectional shape of the colored portion was convex and the difference in film thickness was 0.5 μm.

  Thereafter, heat treatment was performed at 230 ° C. for 10 minutes while pressing the colored portion in an undried state using a flat plate heat press apparatus to perform planarization, and the entire colored portion was cured.

  When the color filter produced as described above was observed with an optical microscope and SEM, no color mixing was observed between adjacent colored portions. Further, when the cross-sectional shape of the colored portion was measured, the maximum film thickness difference was 0.2 μm, and a color filter with little color unevenness having a color difference of 3 or less could be produced.

  In the same manner as in Example 1, each colored portion was formed, followed by heat treatment at 230 ° C. for 30 minutes to completely cure the colored ink to form a colored portion. Thereafter, a UV curable resin was applied as a protective layer on the color filter so as to have a film thickness of 2 μm.

  The color filter provided with the protective layer was subjected to a heat treatment at 90 ° C. for 10 minutes while being pressed through a fluorine film using a flat plate hot press. When the fluorine-based film was removed after UV exposure from the pressure-bonded surface of the fluorine-based film, a protective layer having a smooth surface could be produced.

  When the color filter produced as described above was observed with an optical microscope and SEM, no color mixing was observed between adjacent colored portions. Further, when the flatness of the color filter surface was measured, the maximum film thickness difference was 0.1 μm. In addition, as with the protective layer, the colored portion was flattened, and a color filter with a color difference of 3 or less and less color unevenness could be produced.

  A black matrix was formed in the same manner as in Example 1, and a colored ink was applied to the black matrix opening by an ink jet printing apparatus to form a colored portion. Subsequent flattening by a hot press apparatus was not performed.

  When the color filter produced as described above was observed with an optical microscope and SEM, no color mixing was observed between adjacent colored portions. However, the cross-sectional shape of the colored portion was convex and had large color unevenness, and the color difference was measured to be 10 or more.

In the same manner as in Example 2, colored ink was applied by an inkjet printing apparatus to form a colored portion. After the colored portion was cured by heat treatment, a UV curable resin was applied so that the film thickness was 2 μm. After pre-baking at 90 ° C. for 10 minutes, an ultraviolet exposure treatment was performed to completely cure. Subsequent hot pressing was not performed.

  When the color filter produced as described above was observed with an optical microscope and SEM, no color mixing was observed between adjacent colored portions. However, the color unevenness of the colored portion was large, and the color difference was measured and found to be 10 or more.

It is process drawing explaining one Example of the manufacturing method of the color filter by this invention. It is process drawing which planarizes after providing a protective layer.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Transparent substrate 2 ... Black matrix 3 ... Colored ink 4 ... Printing device 5 using the inkjet system ... Colored part 6a ... Upper platen 6b of press device ... Press device Lower platen 7 ... Protective layer

Claims (3)

In the manufacturing method of the color filter for display device,
1) forming a black matrix having an opening on a transparent substrate;
2) forming a colored portion by applying colored ink to the opening of the black matrix by an ink jet method;
3) A step of simultaneously curing and flattening the colored portion by hot pressing.
A method for producing a color filter, comprising: In the manufacturing method of the color filter for display device,
1) forming a black matrix having an opening on a transparent substrate;
2) forming a colored portion by applying colored ink to the opening of the black matrix by an ink jet method;
3) forming a protective layer on the entire surface of the transparent substrate on which the colored portion is formed;
4) A step of simultaneously curing and flattening the protective layer and the colored portion, and smoothing the surface of the protective layer by a heat press treatment through a film having a smooth surface,
A method for producing a color filter, comprising:   3. The method for producing a color filter according to claim 1, wherein the black matrix is a black matrix formed using a photosensitive resin composition containing a black light shielding material, and exhibits water and oil repellency. .

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