JP4385641B2 - Manufacturing method of color filter - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a color filter substrate, a color filter, and a manufacturing method thereof used for a color display device and the like.
[0002]
[Prior art]
In recent years, an ink jet method has been proposed as a simple method for manufacturing a color filter substrate used in a color display device such as a color liquid crystal display.
[0003]
In the manufacturing method of the color filter substrate using the inkjet method, in order to prevent the ink from spreading outside the desired colored region on the glass substrate, a black matrix material previously containing a hydrofluoric acid-based water / oil repellent is used. A black matrix is provided by pattern formation by photolithography, and ink is fixed only in a colored region which is an opening of the black matrix (Patent Document 1). In addition, in order to improve the fixing property of the color material, an ink absorption layer (image receiving layer) is provided below the black matrix and the colored region (Patent Document 2).
[0004]
[Patent Document 1]
Japanese Patent Laid-Open No. 6-347637 [Patent Document 2]
Japanese Patent Laid-Open No. 11-326622
[Problems to be solved by the invention]
However, since the ink absorption layer is obtained by applying and drying a solution in which a resin (for example, polyvinyl alcohol) is dissolved in a solvent (for example, water), a coloring material such as a dye adsorbed on the ink adsorption layer is transferred. There is a risk that. In addition, when an uncured or semi-cured photo-curing resin is used as the resin for the ink adsorption layer, and the color material is applied to the ink adsorption layer and then cured, it is intended to be chemically or physically fixed. Since the black matrix is cured by ultraviolet rays or the like at the time of pattern formation by photolithography, there is a problem that it is difficult.
[0006]
[Means for Solving the Problems]
The present invention has been made to solve these problems, and provides a color filter substrate, a color filter, and a method for manufacturing the same, with the advantage of the ink-jet method being simple and with little risk of color material migration. To do.
[0007]
In order to achieve the above object in the present invention, first, in claim 1, in a method for producing a color filter in which ink is arranged on a transparent substrate by an ink jet method,
(1) A step of forming an ink absorbing layer made of an electron beam curable resin on a transparent substrate,
(2) A step of forming a black matrix made of a photocurable resin on the ink absorbing layer by a photolithography method,
(3) a step of filling the black matrix opening with colored ink by an ink jet method and coloring the ink absorbing layer;
(4) a step of curing the colored ink absorbing layer by electron beam irradiation;
Is a method for producing a color filter.
The color filter substrate according to claim 1, wherein a contact angle between the ink absorption layer and the ink is 15 ° or less.
The method for producing a color filter according to claim 1, wherein the black matrix has ink repellency.
Further, in claim 4, the black matrix having ink repellency is such that the surface layer farthest from the transparent substrate has better ink repellency than the layer in contact with the transparent substrate, and the surface layer and the ink The color filter manufacturing method according to claim 3, wherein the contact angle of the color filter is 15 ° or more.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
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 substrate, a color filter and a method for manufacturing the same according to the present invention.
[0009]
In the color filter substrate of FIG. 1, an ink absorption layer 2 is formed on a transparent substrate 1 (FIG. 1 (a)) (FIG. 1 (b)), and a black matrix 3 made of a photocurable resin is formed thereon. (FIG. 1 (c)). Next, colored inks of red (R), green (G), and blue (B) are ejected to the openings of the black matrix 3 by the inkjet method (FIG. 1 (d)) (FIG. 1 (e)), and then an electron beam is applied. By irradiation (FIG. 1 (f)), the colored layer 4 is formed to complete the color filter (FIG. 1 (g)).
[0010]
The transparent substrate 1 of the present invention is not particularly limited as long as it has mechanical properties and optical properties required by the color filter, but a glass substrate, a quartz substrate, a plastic substrate, or the like can be used.
[0011]
The ink absorbing layer 2 made of the uncured or semi-cured electron beam curable resin of the present invention is transparent, has excellent fixability of the coloring material in the received ink, can be cured with an electron beam, and is a black matrix. Performances such as substantially no complete curing by exposure at the time of formation, no discoloration or fading, and various resistances are required.
[0012]
Further, as a performance required for the ink absorbing layer, the contact angle with the colored ink is preferably 15 ° or less. If the contact angle with the colored ink is 15 ° or more, the wettability is poor, and this may cause defects such as white spots in the pixels.
[0013]
The ink absorbing layer 2 is formed by applying and drying an ink absorbing layer composition composed mainly of an electron beam curable resin and composed of a solvent and, if necessary, organic and inorganic fine particles. The electron beam curable resin is not particularly limited as long as it satisfies the above-mentioned required characteristics, but includes an aliphatic acrylate, an alicyclic acrylate, an aromatic acrylate, an OH group, an allyl group, a glycidyl group, a carboxyl group, a chromo group, a bromo group, or the like. Resin monomers or oligomers such as functional group-containing acrylates, phosphorus acrylates, and metal acrylates can be used. Alternatively, a methacrylate having the same skeleton as the acrylate can also be used. Alternatively, resin monomers or oligomers such as pyrrolidone and vinyl acetate can be used.
[0014]
It is also effective to contain fine particles (fillers) in this resin within a range that does not impair the transparency in order to increase ink absorbability. Examples of the filler include fine powder silicic acid for inorganic fine particles, and acrylic resin, styrene resin, urea formaldehyde resin, benzoguanamine resin, silicone resin, and fluorine resin for organic fine particles, and acrylic resin is preferable from the viewpoint of transparency. Further, the addition amount of the filler is preferably 1 to 10% by weight with respect to 100% by weight of the ink absorbing layer composition.
[0015]
The solvent of the ink absorbing layer composition is appropriately selected and used from the viewpoints of the coating property and dispersion stability of the composition, and includes toluene, xylene, ethyl cellosolve, ethyl cellosolve acetate, diclime, cyclohexanone, and the like. can give.
[0016]
The ink absorbing layer composition is applied by a coating method such as a spin coater, a slit coater, or a micro gravure. After the ink absorbing material is applied, the coating film is dried so as to be tack-free.
[0017]
The black matrix 3 in the present invention is formed by patterning by a photolithography method using a black photocurable resin composition mainly composed of a black light shielding material, a photoinitiator, a dispersant, a resin (including a monomer), and a solvent. It is formed.
[0018]
Examples of the black light shielding material include black pigments, black dyes, inorganic materials, and the like, and organic pigments, carbon black, aniline black, graphite, titanium oxide, iron black, and the like are used as a mixture.
[0019]
As the photoinitiator, a photopolymerizable monomer or a photopolymerization initiator is used.
[0020]
By adding the photoinitiator to the black photocurable resin composition and not to the ink absorbing layer composition, the ink absorbing layer is cured by the light source when the black matrix 3 is patterned by photolithography. do not do. Therefore, the ink absorption capacity is not impaired.
[0021]
Examples of the dispersant include non-ionic surfactants such as polyoxyethylene alkyl ether, and ionic surfactants such as sodium alkylbenzene sulfonate, poly fatty acid salt, fatty acid salt alkyl phosphate, tetra In addition to alkylammonium salts, organic pigment derivatives, polyesters, and the like can be given. One type of dispersant may be used alone, or two or more types of dispersants may be mixed and used.
[0022]
The solvent is appropriately selected and used from the viewpoint of the coating property and dispersion stability of the black photocurable resin composition, such as toluene, xylene, ethyl cellosolve, ethyl cellosolve acetate, diclime, cyclohexanone, etc. Can be given.
[0023]
Note that when an ink repellent agent is added to the black photocurable resin composition, the ink can be prevented from flowing out to adjacent pixels, and color mixing can be prevented.
[0024]
The ink repellent agent in the present invention is preferably a material containing silicon and / or fluorine atoms. 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, or ethylene trifluoride. And fluororesins such as these copolymers, but are not limited thereto.
[0025]
Further, after adding an ink repellent agent to the black photocurable resin composition, a black matrix is formed by photolithography. At the time of baking in the photolithography process, the ink repellent agent is unevenly distributed on the surface portion of the black matrix. Therefore, the ink repellency of the surface portion of the black matrix farthest from the transparent substrate is better than the ink repellency of the layer in contact with the transparent substrate. Since the difference in surface tension between the layer in contact with the transparent substrate of the black matrix and the ink is small, the flatness of the pixels is improved.
[0026]
The black matrix 3 is formed by a photolithography method. In order to prevent the ink absorbing layer from being cured when the black matrix is formed by a photolithography method, it is adjusted so as not to include a photoinitiator that reacts with light to be used.
[0027]
A method for producing a color filter using the color filter substrate produced by the above steps will be described.
[0028]
The material of the color ink 4 of the present invention is composed of 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. What There. Further, these may be used in combination of two or more in order to obtain the desired hue.
[0029]
As the solvent species used for the colored ink 4, those having an appropriate surface tension range of 35 mN / m or less in the ink jet system and a boiling point of 130 ° C. or more are preferable. 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.
[0030]
As the resin of the colored ink 4 of the present invention, 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. An acrylic resin is preferred when heat resistance and light resistance are required.
[0031]
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.
[0032]
An ink jet method is used to form the colored layer. 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.
[0033]
After the colored ink is ejected by the ink jet method, an electron beam is irradiated to cure the ink absorption layer with the electron beam, thereby completing a color filter.
[0034]
【Example】
Examples of the present invention will be specifically described below.
[0035]
<Example 1>
(Preparation of ink absorption layer)
As the ink absorbing layer composition, an acrylic polymer (Dianar BR-85, manufactured by Mitsubishi Rayon Co., Ltd.) prepared in a 10% toluene solution was used. The ink absorbing layer composition was applied onto alkali-free glass (Corning, product number 1737) using a spin coater, and then dried at 100 ° C. for 10 minutes to form a coating film having a thickness of about 2.0 μm.
[0036]
(Production of black matrix)
10 parts by weight of a polyimide precursor (manufactured by Toray Industries, Inc .: “Semicofine SP-510”), 7.5 parts by weight of carbon black, 130 parts by weight of NMP, 5 parts by weight of a dispersant (copper phthalocyanine derivative), a photopolymerization initiator 5 Part by weight and 0.5 part by weight of an ink repellent (polyalkylsiloxane) were dispersed for 3 hours while cooling with a bead mill disperser to prepare a black photocurable resin composition. This black matrix composition was formed into a coating film of about 1.0 μm on the ink absorbing layer by a spin coater. A black matrix was produced by heat curing at 100 ° C. for 20 minutes to complete a color filter substrate. The electron beam curable resin of the ink absorbing layer was semi-cured.
[0037]
(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 a dispersant were added to 80.1 g of this diluted solution, and kneaded with three rolls to obtain colored varnishes of red, green and blue. 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.
[0038]
(Production of color filter)
Each of the R, G, and B colored inks is used at the opening of the black matrix, and each of red (R), green (G), and blue (B) is printed by an inkjet printer equipped with a 12 pl and 180 dpi head. A patterned colored layer (5) was formed.
[0039]
The color filter substrate was irradiated with an electron beam of 25 Mrad to cure the ink absorption layer, thereby forming a color filter substrate.
[0040]
The color filter thus obtained is a color filter having no color mixing, excellent density balance, sharp pixel shape, sharp pixel edges, and little color material migration even after a durability test. It was.
[0041]
【The invention's effect】
According to the present invention, an ink absorption layer of a color filter substrate in which an ink absorption layer made of an electron beam curable resin is formed on a transparent substrate, and a black matrix made of a photocurable resin is further formed on the ink absorption layer. By filling with colored ink, it is possible to provide a color filter with little transition of color material, no color mixing, excellent density balance, clear pixel shape and sharp pixel edges.
[0042]
[Brief description of the drawings]
FIG. 1 is an explanatory diagram showing a cross-sectional structure of an example of a color filter substrate and a color filter manufacturing method according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Transparent substrate 2 Ink absorption layer 3 Black matrix 4 Colored ink 5 Inkjet apparatus

Claims (4)

In the method of manufacturing a color filter in which ink is arranged on a transparent substrate by an inkjet method,
(1) A step of forming an ink absorbing layer made of an electron beam curable resin on a transparent substrate,
(2) A step of forming a black matrix made of a photocurable resin on the ink absorbing layer by a photolithography method,
(3) a step of filling the black matrix opening with colored ink by an ink jet method and coloring the ink absorbing layer;
(4) a step of curing the colored ink absorbing layer by electron beam irradiation;
A method for producing a color filter, comprising: The method for producing a color filter according to claim 1, wherein a contact angle between the ink absorption layer and the ink is 15 ° or less. The method for producing a color filter according to claim 1, wherein the black matrix has ink repellency. The black matrix having ink repellency has better ink repellency of the surface layer farthest from the transparent substrate than the ink repellency of the layer in contact with the transparent substrate, and the contact angle between the surface layer and the ink is 15 ° or more. The method for producing a color filter according to claim 3, wherein:

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