JP2009244513A - Thermosetting inkjet ink for color filter, and color filter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide thermosetting inkjet ink for color filter having excellent adhesion and surface hardness after heat curing. <P>SOLUTION: This thermosetting inkjet ink for color filter contains pigment, pigment dispersing agent, a solvent, thermal polymerization initiator, an epoxy compound, and an oxetane resin having a silsesquioxane skeleton and/or an epoxy resin. In addition, this color filter has a pixel formed of substances obtained by curing the thermosetting inkjet ink for color filter. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a thermosetting inkjet ink for a color filter used for forming pixels having a predetermined pattern, and a color filter manufactured using the same.

In recent years, with the development of personal computers, especially portable personal computers, the demand for liquid crystal displays, especially color liquid crystal displays, has been increasing. A color filter of a liquid crystal display usually has a coloring pattern of three primary colors of red (R), green (G), and blue (B), and the liquid crystal has ON and OFF electrodes corresponding to the R, G, and B pixels, respectively. As a shutter, the light passes through the R, G, and B pixels, and color display is performed. A specific example of the manufacturing method of the color filter is a staining method. First, a water-soluble polymer material that is a dyeing material is formed on a glass substrate, and after the water-soluble polymer material is patterned into a desired shape by a photolithography process, the resulting pattern is immersed in a dyeing bath, A colored pattern is obtained. This operation is repeated three times to form R, G, and B pixels. Another specific example of the method for producing the color filter is a pigment dispersion method. First, a pigment is dispersed on a substrate to form a photosensitive resin layer, and a monochromatic pattern is obtained by patterning the photosensitive resin layer. Further, this process is repeated three times to form R, G, and B pixels. Another specific example of the method for producing a color filter is an electrodeposition method; a method in which a pigment is dispersed in a thermosetting resin and R, G and B are printed three times, and then the resin is thermoset.
However, in any method, since the three colors of R, G, and B are colored, the same process is repeated three times, resulting in high cost and low yield. Therefore, formation of a pixel portion in which a colored ink containing a thermosetting resin is sprayed on a substrate by an ink jet method and then heated is examined (for example, see Patent Document 1).

In recent years, there has been a demand for improvement in color reproducibility and contrast of color filters, and thus there is a demand for higher concentration, improved dispersibility, and refinement of pigments contained in inkjet inks for color filters. As the concentration and the size of the pigment are increased, it is necessary to increase the amount of the pigment dispersant together with the amount of the pigment contained in the inkjet ink in order to stabilize the fine dispersion of the pigment. However, when the amount of the pigment and the pigment dispersant contained in the inkjet ink for the color filter is increased, the components contributing to the film physical properties of the cured film such as the binder are relatively decreased, and as a result, the curability of the ink is reduced. The adhesiveness and surface hardness of the cured film are reduced.
Japanese Patent Laid-Open No. 9-21910

  The problem to be solved by the present invention is to provide a thermosetting inkjet ink for a color filter having excellent adhesion and surface hardness after thermosetting. Another problem to be solved by the present invention is to provide a color filter using the inkjet ink.

  In order to solve the above-mentioned problems, the inventors of the present invention diligently studied thermosetting inkjet inks for color filters. As a result, the inventor of the present invention has found that the above problem is solved by adding an oxetane resin and / or an epoxy resin having a silsesquioxane skeleton to a thermosetting inkjet ink for a color filter. The invention has been completed.

The present invention is a thermosetting inkjet ink for color filters containing a pigment, a pigment dispersant, a solvent, a thermal polymerization initiator, an epoxy compound and an oxetane resin having a silsesquioxane skeleton and / or an epoxy resin.
Addition of an oxetane resin having a silsesquioxane skeleton and / or an epoxy resin to a thermosetting inkjet ink for a color filter enables formation of a pixel having excellent adhesion and surface hardness.

In a preferred embodiment of the present invention, the epoxy compound has two or more epoxy groups in one molecule.
Addition of an epoxy compound having two or more epoxy groups in one molecule to the thermosetting ink jet ink for color filter improves film physical properties such as solvent resistance and adhesion of pixels formed by the ink jet ink.

In another preferred embodiment of the present invention, the blending mass ratio (P / V) of the pigment (P) and the solid content (V) other than the pigment is 0.3 to 1.2.
A P / V ratio that is too low can increase the amount of ink droplets that adhere to the pixel formation region in order to obtain sufficient coloring power, and can cause problems such as ink breakage from the pixel formation region. On the other hand, an excessively high P / V ratio may cause problems such as clogging at the discharge head, deterioration in discharge performance such as flight bending, and rough surface of the film.

This invention is a color filter which has a pixel which consists of a hardened | cured material of the said thermosetting inkjet ink for color filters.
The color filter of the present invention includes pixels having excellent adhesion and surface hardness.

  The thermosetting inkjet ink for a color filter of the present invention forms a pixel having excellent adhesion to glass and surface hardness by containing an oxetane resin having a silsesquioxane skeleton containing silicon atoms and / or an epoxy resin. . The color filter of the present invention includes pixels having excellent adhesion and surface hardness.

  Arbitrary pigments are selected from organic colorants and inorganic colorants according to the color required for R, G, B, etc. of the pixel (pixel portion) and the black matrix layer. Specific examples of the organic colorant are dyes, organic pigments, and natural pigments. Specific examples of the inorganic colorant are inorganic pigments and extender pigments. Organic pigments are preferably used because of their high color developability and heat resistance. Specific examples of organic pigments are assigned the following color index (CI) numbers, which are classified as pigments in the color index (CI; issued by The Society of Dyers and Colorists). It is a compound.

  C. I. Pigment yellow 1, C.I. I. Pigment yellow 3, C.I. I. Pigment yellow 12, C.I. I. Pigment yellow 13, C.I. I. Pigment yellow 14, C.I. I. Pigment yellow 15, C.I. I. Pigment yellow 16, C.I. I. Pigment yellow 17, C.I. I. Pigment yellow 20, C.I. I. Pigment yellow 24, C.I. I. Pigment yellow 31, C.I. I. Pigment yellow 55, C.I. I. Pigment yellow 60, C.I. I. Pigment yellow 61, C.I. I. Pigment yellow 65, C.I. I. Pigment yellow 71, C.I. I. Pigment yellow 73, C.I. I. Pigment yellow 74, C.I. I. Pigment yellow 81, C.I. I. Pigment yellow 83, C.I. I. Pigment yellow 93, C.I. I. Pigment yellow 95, C.I. I. Pigment yellow 97, C.I. I. Pigment yellow 98, C.I. I. Pigment yellow 100, C.I. I. Pigment yellow 101, C.I. I. Pigment yellow 104, C.I. I. Pigment yellow 106, C.I. I. Pigment yellow 108, C.I. I. Pigment yellow 109, C.I. I. Pigment yellow 110, C.I. I. Pigment yellow 113, C.I. I. Pigment yellow 114, C.I. I. Pigment yellow 116, C.I. I. Pigment yellow 117, C.I. I. Pigment yellow 119, C.I. I. Pigment yellow 120, C.I. I. Pigment yellow 126, C.I. I. Pigment yellow 127, C.I. I. Pigment yellow 128, C.I. I. Pigment yellow 129, C.I. I. Pigment yellow 138, C.I. I. Pigment yellow 139, C.I. I. Pigment yellow 150, C.I. I. Pigment yellow 151, C.I. I. Pigment yellow 152, C.I. I. Pigment yellow 153, C.I. I. Pigment yellow 154, C.I. I. Pigment yellow 155, C.I. I. Pigment yellow 156, C.I. I. Pigment yellow 166, C.I. I. Pigment yellow 168, C.I. I. Pigment yellow 175, C.I. I. Pigment yellow 180, C.I. I. Pigment yellow 185, C.I. I. Pigment yellow 213, C.I. I. Pigment yellow 214;

  C. I. Pigment orange 1, C.I. I. Pigment orange 5, C.I. I. Pigment orange 13, C.I. I. Pigment orange 14, C.I. I. Pigment orange 16, C.I. I. Pigment orange 17, C.I. I. Pigment orange 24, C.I. I. Pigment orange 34, C.I. I. Pigment orange 36, C.I. I. Pigment orange 38, C.I. I. Pigment orange 40, C.I. I. Pigment orange 43, C.I. I. Pigment orange 46, C.I. I. Pigment orange 49, C.I. I. Pigment orange 51, C.I. I. Pigment orange 61, C.I. I. Pigment orange 63, C.I. I. Pigment orange 64, C.I. I. Pigment orange 71, C.I. I. Pigment orange 73;

  C. I. Pigment violet 1, C.I. I. Pigment violet 19, C.I. I. Pigment violet 23, C.I. I. Pigment violet 29, C.I. I. Pigment violet 32, C.I. I. Pigment violet 36, C.I. I. Pigment violet 38;

  C. I. Pigment red 1, C.I. I. Pigment red 2, C.I. I. Pigment red 3, C.I. I. Pigment red 4, C.I. I. Pigment red 5, C.I. I. Pigment red 6, C.I. I. Pigment red 7, C.I. I. Pigment red 8, C.I. I. Pigment red 9, C.I. I. Pigment red 10, C.I. I. Pigment red 11, C.I. I. Pigment red 12, C.I. I. Pigment red 14, C.I. I. Pigment red 15, C.I. I. Pigment red 16, C.I. I. Pigment red 17, C.I. I. Pigment red 18, C.I. I. Pigment red 19, C.I. I. Pigment red 21, C.I. I. Pigment red 22, C.I. I. Pigment red 23, C.I. I. Pigment red 30, C.I. I. Pigment red 31, C.I. I. Pigment red 32, C.I. I. Pigment red 37, C.I. I. Pigment red 38, C.I. I. Pigment red 40, C.I. I. Pigment red 41, C.I. I. Pigment red 42, C.I. I. Pigment red 48: 1, C.I. I. Pigment red 48: 2, C.I. I. Pigment red 48: 3, C.I. I. Pigment red 48: 4, C.I. I. Pigment red 49: 1, C.I. I. Pigment red 49: 2, C.I. I. Pigment red 50: 1, C.I. I. Pigment red 52: 1, C.I. I. Pigment red 53: 1, C.I. I. Pigment red 57, C.I. I. Pigment red 57: 1, C.I. I. Pigment red 57: 2, C.I. I. Pigment red 58: 2, C.I. I. Pigment red 58: 4, C.I. I. Pigment red 60: 1, C.I. I. Pigment red 63: 1, C.I. I. Pigment red 63: 2, C.I. I. Pigment red 64: 1, C.I. I. Pigment red 81: 1, C.I. I. Pigment red 83, C.I. I. Pigment red 88, C.I. I. Pigment red 90: 1, C.I. I. Pigment red 97, C.I. I. Pigment red 101, C.I. I. Pigment red 102, C.I. I. Pigment red 104, C.I. I. Pigment red 105, C.I. I. Pigment red 106, C.I. I. Pigment red 108, C.I. I. Pigment red 112, C.I. I. Pigment red 113, C.I. I. Pigment red 114, C.I. I. Pigment red 122, C.I. I. Pigment red 123, C.I. I. Pigment red 144, C.I. I. Pigment red 146, C.I. I. Pigment red 149, C.I. I. Pigment red 150, C.I. I. Pigment red 151, C.I. I. Pigment red 166, C.I. I. Pigment red 168, C.I. I. Pigment red 170, C.I. I. Pigment red 171, C.I. I. Pigment red 172, C.I. I. Pigment red 174, C.I. I. Pigment red 175, C.I. I. Pigment red 176, C.I. I. Pigment red 177, C.I. I. Pigment red 178, C.I. I. Pigment red 179, C.I. I. Pigment red 180, C.I. I. Pigment red 185, C.I. I. Pigment red 187, C.I. I. Pigment red 188, C.I. I. Pigment red 190, C.I. I. Pigment red 193, C.I. I. Pigment red 194, C.I. I. Pigment red 202, C.I. I. Pigment red 206, C.I. I. Pigment red 207, C.I. I. Pigment red 208, C.I. I. Pigment red 209, C.I. I. Pigment red 215, C.I. I. Pigment red 216, C.I. I. Pigment red 220, C.I. I. Pigment red 222, C.I. I. Pigment red 224, C.I. I. Pigment red 226, C.I. I. Pigment red 238, C.I. I. Pigment red 242, C.I. I. Pigment red 243, C.I. I. Pigment red 245, C.I. I. Pigment red 254, C.I. I. Pigment red 255, C.I. I. Pigment red 264, C.I. I. Pigment Red 265

C. I. Pigment green 7, C.I. I. Pigment green 36; C.I. I. Pigment Green 58
C. I. Pigment blue 15, C.I. I. Pigment blue 15: 3, C.I. I. Pigment blue 15: 4, C.I. I. Pigment blue 15: 6, C.I. I. Pigment blue 60, C.I. I. Pigment Blue 80

  Specific examples of the inorganic pigment and extender pigment are titanium oxide, barium sulfate, calcium carbonate, zinc white, lead sulfate, yellow lead, zinc yellow, red bean (red iron (III) oxide), cadmium red, and amber. One or more of the above pigments are used. The blending ratio of the pigment to the thermosetting inkjet ink for color filter is usually 1 to 60% by mass, preferably 15 to 40% by mass.

  From the viewpoint of ink ejection performance, prevention of ink breakage, and balance of film properties obtained, the pigment (P) and the solid content (V) other than the pigment contained in the thermosetting inkjet ink for color filters of the present invention are preferred. The blending mass ratio (P / V) is 0.3 to 1.2. Here, the “solid content” indicates components other than the solvent in the ink. If the P / V ratio is too low, the amount of ink droplets attached to the pixel formation region in order to obtain sufficient coloring power may be increased, and problems such as ink breakage from the pixel formation region may occur. On the other hand, an excessively high P / V ratio may cause problems such as clogging at the discharge head, deterioration in discharge performance such as flight bending, and rough surface of the film.

The thermosetting inkjet ink for a color filter of the present invention contains a pigment dispersant that favorably disperses the pigment. Specific examples of the pigment dispersant are a cationic surfactant, an anionic surfactant, a nonionic surfactant, an amphoteric surfactant, and a silicone surfactant. A preferred surfactant is a polymer surfactant (polymer dispersant) described below.
Polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, and polyoxyethylene oleyl ether; polyoxyethylene alkyl phenyl ethers such as polyoxyethylene octyl phenyl ether and polyoxyethylene nonyl phenyl ether; polyethylene Polyethylene glycol diesters such as glycol dilaurate and polyethylene glycol distearate; sorbitan fatty acid esters; fatty acid-modified polyesters; tertiary amine-modified polyurethanes The content of the pigment dispersant is 5 to 50 mass based on the entire solid content. The preferable content is 10 to 30% by mass with respect to the entire solid content. A dispersion auxiliary resin such as a special acrylic polymer can be used together with the pigment dispersant.

  The thermosetting inkjet ink for a color filter of the present invention contains an epoxy compound. A preferable epoxy compound is a resin having two or more epoxy groups in one molecule from the viewpoint of film physical properties such as solvent resistance and adhesion of a pixel formed with an inkjet ink. Specific examples of the epoxy group are a glycidyl group, an oxyethylene group, and an epoxycyclohexyl group.

  From the viewpoint of improving the crosslink density of the cured film and improving the ink jet ejection performance by reducing the viscosity of the ink, the preferred weight average molecular weight of the epoxy compound is 3000 to 20000 in terms of polystyrene, and the more preferred weight average molecular weight is 4000 to 2000. 15000. When the weight average molecular weight is less than 3000, physical properties such as strength and solvent resistance required for the cured layer of the color filter tend to be insufficient. On the other hand, when the weight average molecular weight is greater than 20000, the viscosity of the ink is likely to increase, the stability of the ejection amount of the ink ejected from the ejection head by the inkjet method, and the straightness in the ejection direction are reduced, and the long-term ink Storage stability decreases.

Specific examples of compounds having two or more epoxy groups in one molecule are bisphenol A type epoxy resins such as Epicoat 828 (Japan Epoxy Resin Co., Ltd.); Epicoat 807 (Japan Epoxy Resin Co., Ltd.), YDF Bisphenol F type epoxy resin such as Y-175S (manufactured by Toto Kasei Co., Ltd.); Brominated bisphenol A type epoxy resin such as YDB-715 (manufactured by Tohto Kasei Co., Ltd.); EPICLON EXA1514 (Dainippon Ink Chemical Co., Ltd.) Bisphenol S type epoxy resin; diphenyl ether type epoxy resin; hydroquinone type epoxy resin such as YDC-1312 (manufactured by Tohto Kasei Co., Ltd.); naphthalene type such as EPICLON EXA4032 (manufactured by Dainippon Ink & Chemicals, Inc.) Epoxy resin; Epicoat YX400 Biphenyl type epoxy resins such as H (made by Japan Epoxy Resin Co., Ltd.); fluorene type epoxy resins; bisphenol A type novolac type epoxy resins such as Epicoat 157S70 (made by Japan Epoxy Resin Co., Ltd.); Epicoat 154 (Japan Epoxy Resin ( Phenol novolac type epoxy resins such as YDPN-638 (manufactured by Toto Kasei Co., Ltd.); Orthocresol novolak type epoxy resins such as YDCN-701 (manufactured by Toto Kasei Co., Ltd.); EPICLON HP-7200 (large) Dicyclopentadiene phenol type epoxy resin such as Nippon Ink Chemical Co., Ltd .; trishydroxyphenylmethane type epoxy resin such as Epicoat 1032H60 (manufactured by Japan Epoxy Resin Co., Ltd.); VG3101M80 (Mitsui Chemicals) Trifunctional epoxy resin such as Epicote 1031S (manufactured by Japan Epoxy Resin Co., Ltd.); Tetraphenylol ethane type epoxy resin such as Dencoal EX-411 (manufactured by Nagase Chemtex Co., Ltd.) Type epoxy resin; dicyclopentadiene phenol type epoxy resin; hydrogenated bisphenol A type epoxy resin such as ST-3000 (manufactured by Tohto Kasei Co., Ltd.); bisphenol A nucleated polyol type epoxy resin; polypropylene glycol type epoxy resin; Glycidal ester type epoxy resin such as YE-434 (manufactured by Tohto Kasei Co., Ltd.); Glyoxal such as YDG-414 (manufactured by Tohto Kasei Co., Ltd.); Type epoxy resin; EHPE3 Alicyclic epoxy resin such as 150 (manufactured by Daicel Chemical Industries, Ltd.); alicyclic polyfunctional epoxy compound such as Eporide GT-401 (manufactured by Daicel Chemical Industries, Ltd.); complex such as triglycidyl isocyanate (TGIC) It is a ring type epoxy resin. An epoxy reactive diluent such as Neotote E (manufactured by Toto Kasei Co., Ltd.) can be mixed as necessary.
Specific examples of particularly preferable epoxy resins are alicyclic epoxy resins such as EHPE3150 (manufactured by Daicel Chemical Industries, Ltd.) and bisphenol A type novolak epoxy resins such as Epicoat 157S70 (manufactured by Japan Epoxy Resins Co., Ltd.). One or more epoxy compounds are used.

  The preferable content of the epoxy compound is 1 to 50 parts by mass with respect to 100 parts by mass of the solid content, and the more preferable content is 3 to 30 parts by mass with respect to 100 parts by mass of the solid content. If the content of the epoxy compound is too small, sufficient ink curability cannot be obtained. On the other hand, when the content of the epoxy compound is too large, ink curing failure occurs.

The thermosetting inkjet ink for a color filter of the present invention contains an oxetane resin and / or an epoxy resin having a silsesquioxane skeleton. Silsesquioxane is a general term for polysiloxanes represented by the composition formula (RSiO _3/2 ) _n and has various structures such as a ladder type and a cage type.
Oxetane resins having a silsesquioxane skeleton are commercially available. Specific examples of commercially available oxetane resins having a silsesquioxane skeleton include OX-SQ-H manufactured by Toagosei Co., Ltd., OX-SQ manufactured by Toagosei Co., Ltd., and OX-SQ SI manufactured by Toagosei Co., Ltd. -20. A preferred oxetane resin having a silsesquioxane skeleton is OX-SQ-H manufactured by Toagosei Co., Ltd. OX-SQ-H manufactured by Toagosei Co., Ltd. is obtained by condensing an alkoxysilyl group of an oxetanylsilane compound represented by the following formula (1) (OXT-610 manufactured by Toagosei Co., Ltd.) in the presence of an alkali or an acid. Manufactured.

  Epoxy resins having a silsesquioxane skeleton are also commercially available. A specific example of a commercially available epoxy resin having a silsesquioxane skeleton is Combocelan HBSQ-502-6 manufactured by Arakawa Chemical Industries, Ltd.

  The thermosetting inkjet ink for a color filter of the present invention may contain a binder resin other than an oxetane resin and / or an epoxy resin having a silsesquioxane skeleton. The said binder resin is resin conventionally used as binder resin for color filters, such as photosensitive resin and non-photosensitive resin. Specific examples of the photosensitive resin include a photosensitive cyclized rubber resin, a photosensitive phenol resin, a photosensitive polyacrylate resin, a photosensitive polyamide resin, a photosensitive polyimide resin, an unsaturated polyester resin, and a polyester acrylate resin. Resins, polyepoxy acrylate resins, polyurethane acrylate resins, polyether acrylate resins, and polyol acrylate resins. Specific examples of the non-photosensitive resin solution include cellulose acetate resin, nitrocellulose resin, styrene (co) polymer, polyvinyl butyral resin, aminoalkyd resin, polyester resin, amino resin-modified polyester resin, polyurethane Resin, acrylic polyol urethane resin, soluble polyamide resin, soluble polyimide resin, soluble polyamideimide resin, soluble polyesterimide resin, hydroxyethyl cellulose, water-soluble salt of styrene-maleic acid ester copolymer, (meta ) Water-soluble salts of acrylate (co) polymers, water-soluble amino alkyd resins, water-soluble amino polyester resins, and water-soluble polyamide resins. One or more binder resins can be used.

The preferable content of (a) oxetane resin and / or epoxy resin having a silsesquioxane skeleton and (b) other binder resin is 5 to 80 parts by mass with respect to 100 parts by mass of the solid content, and is more preferable. Content is 15-60 mass parts with respect to 100 mass parts of solid content. If the content of (a) oxetane resin and / or epoxy resin having a silsesquioxane skeleton and (b) other binder resin is too small, sufficient thermosetting of the ink cannot be obtained. On the other hand, if the content of (a) oxetane resin and / or epoxy resin having a silsesquioxane skeleton and (b) other binder resin is too large, ink curing failure occurs.
The ratio of (a) oxetane resin and / or epoxy resin having a silsesquioxane skeleton and (b) other binder resin (a) oxetane resin and / or epoxy resin having a silsesquioxane skeleton is 10 to 10%. It is 100 mass%, Preferably it is 50-100 mass%, More preferably, it is 80-100 mass%.

  The thermosetting inkjet ink for a color filter of the present invention contains a thermal polymerization initiator. From the viewpoint of extending the pot life of the ink and reducing the amount of heat generated by the ink, a preferred thermal polymerization initiator is an acid anhydride. Specific examples of the acid anhydride include phthalic anhydride, itaconic anhydride, succinic anhydride, citraconic anhydride, dodecenyl succinic anhydride, tricarballylic anhydride, maleic anhydride, hexahydrophthalic anhydride, dimethyltetrahydrophthalic anhydride, anhydrous Aliphatic polycarboxylic dianhydrides such as hymic acid and nadic anhydride; aromatic polycarboxylic anhydrides such as pyromellitic anhydride, trimellitic anhydride and benzophenone tetracarboxylic anhydride; ethylene glycol bis trimellerate It is a commercially available epoxy resin curing agent containing an ester group-containing acid anhydride such as glycerin tristrimelinate; a carboxylic acid anhydride. One or more thermal polymerization initiators are used.

  The blending amount of the thermal polymerization initiator is usually in the range of 1 to 100 parts by mass, preferably 5 to 50 parts per 100 parts by mass in total of the oxetane resin and / or epoxy resin having an epoxy compound and a silsesquioxane skeleton. Part by mass. When the blending amount of the thermal polymerization initiator is less than 1 part by mass per 100 parts by mass in total of the oxetane resin and / or epoxy resin having an epoxy compound and a silsesquioxane skeleton, the ink is insufficiently cured and is tough. A coating film is not formed. On the other hand, when the blending amount of the thermal polymerization initiator exceeds 100 parts by mass per 100 parts by mass in total of the oxetane resin and / or epoxy resin having an epoxy compound and a silsesquioxane skeleton, the adhesion of the coating film to the substrate is low. Become.

  The thermosetting inkjet ink for a color filter of the present invention contains a solvent so that the ink is stored at a high concentration and adjusted to a concentration that can be immediately ejected from the head. The solvent is not limited to a specific compound. Specific examples of the solvent include glycol ethers such as ethylene glycol monoethyl ether and diethylene glycol diethyl ether; glycol ether esters such as ethylene glycol monomethyl ether acetate; glycol oligomer ethers such as diethylene glycol monomethyl ether; diethylene glycol monomethyl ether acetate and diethylene glycol mono Glycol oligomer ether esters such as butyl ether acetate; aliphatic or aromatic esters such as ethyl acetate and propyl benzoate; dicarboxylic acid diesters such as diethyl carbonate; alkoxycarboxylic acid esters such as methyl 3-methoxypropionate; Ketocarboxylic esters such as ethyl acetate; ethanol, isopropanol, phenol Alcohols or phenols; aliphatic or aromatic ethers such as diethyl ether and anisole; alkoxy alcohols such as 2-ethoxyethanol and 1-methoxy-2-propanol; glycol oligomers such as diethylene glycol and tripropylene glycol; Alkoxy alcohol esters such as 2-ethoxyethyl acetate; ketones such as acetone and methyl isobutyl ketone.

  From the viewpoints of pigment dispersibility and dispersion stability, preferred solvents are compounds that do not contain a hydroxyl group. Specific examples of preferred solvents are ethylene glycol monobutyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, diethyl adipate, dibutyl oxalate, dimethyl malonate, diethyl malonate, succinic acid Dimethyl and diethyl succinate. These solvents are used as dispersion solvents with or without being mixed with highly dispersible solvents conventionally used in the preparation of pigment dispersions such as 3-methoxybutyl acetate and propylene glycol monomethyl ether acetate (PGMEA). It is done.

When water is mixed in the solvent, the hydroxyl group of the water molecule is present in the solvent, and the same problem as in the case of using a solvent having a hydroxyl group may occur. Accordingly, since water is substantially excluded from the acid-epoxy crosslinking reaction system, an organic solvent having low miscibility with water is preferably used for preparing the ink-jet ink. The solubility of the solvent used for preparing the inkjet ink in water is preferably 20 parts by mass or less with respect to 100 parts by mass of water at 20 ° C.
Among the solvents mentioned as specific examples, diethylene glycol monobutyl ether acetate has no hydroxyl group, its solubility in 100 parts by mass of water at 20 ° C. is 6.5 parts by mass, and its water miscibility is Since it is low, it is particularly preferable.

  The content of the solvent is usually 40 to 95% by mass with respect to the total amount of the inkjet ink containing the solvent. If the content of the solvent is too small, the viscosity of the inkjet ink becomes high, and it becomes difficult to eject the inkjet ink from the inkjet head. On the other hand, if the content of the solvent is too large, the ink breaks from the predetermined ink layer formation site, the ink deposition amount of the ink layer formation site becomes insufficient, and as a result, the film thickness after drying is too thin, A sufficient transmission density of the color filter cannot be obtained.

  The thermosetting inkjet ink for a color filter of the present invention may contain other additives such as a filler, an adhesion promoter, a leveling agent, and an anti-aggregation agent as necessary. Specific examples of the filler are glass and alumina. Specific examples of the adhesion promoter are vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (2-methoxyethoxy) silane, and N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane. Specific examples of the leveling agent are vinyl polymers such as polyoxyalkylene surfactants, fatty acid ester surfactants, special acrylic polymers, and vinyl ether polymers. A specific example of the aggregation inhibitor is sodium polyacrylate.

  The components contained in the thermosetting inkjet ink for color filter of the present invention are charged into a solvent and mixed, and the solid component is dissolved or dispersed, whereby the thermosetting inkjet ink for color filter of the present invention can be produced. However, stirring and mixing of other components such as the pigment and resin in the solvent does not always sufficiently disperse the pigment in the solvent. Therefore, usually, the pigment and the pigment dispersant are put into a solvent having good dispersibility and dispersion stability of the pigment, and sufficiently stirred by a stirrer such as a dissolver to prepare a pigment dispersion, and then the obtained pigment The dispersion is put into a solvent together with components other than the pigment, and is sufficiently stirred and mixed by a stirrer such as a dissolver to produce the thermosetting inkjet ink for a color filter of the present invention.

  Specific examples of the color filter of the present invention are a color filter used for an image output device of a liquid crystal display device and a color filter used for an image input device of a solid-state imaging device. FIG. 1 is a schematic cross-sectional view showing one embodiment of a liquid crystal display device. The color filter 1 of the color liquid crystal display device (101) and the electrode substrate 2 such as a TFT substrate are opposed to each other, and a gap portion 3 of about 1 to 10 μm is provided. The gap 3 is filled in the liquid crystal compound L, and the periphery thereof is sealed with a sealing material 4. A black matrix layer 6 formed in a predetermined pattern to shield the boundary between pixels, and a plurality of colors (usually red (R), green (G), blue (B) to form each pixel The color filter 1 is configured by laminating a pixel 7, a protective film 8, and a transparent electrode film 9 on the transparent substrate 5 in this order from the transparent substrate 5 side. The alignment film 10 is provided on the inner surface side of the color filter 1 and the electrode substrate 2 facing the color filter 1. A spacer is provided in the gap 3 so that the cell gap between the color filter 1 and the electrode substrate 2 is maintained constant and uniform. Pearl 11 having a constant particle size is dispersed as a spacer. As shown in FIG. 2, columnar spacers 12 having a height corresponding to the cell gap can be formed in a region overlapping the position where the black matrix layer 6 is formed on the inner surface side of the color filter. A color image is obtained by controlling the light transmittance of each of the pixels colored in each color or the liquid crystal layer behind the color filter.

  FIG. 3 is a longitudinal sectional view showing one embodiment (color filter 103) of the color filter of the present invention. The color filter 103 covers the black matrix layer 6 formed in a predetermined pattern on the transparent substrate 5, pixels 7 (7R, 7G, 7B) formed in a predetermined pattern on the black matrix layer, and the pixels. The protective film 8 formed in this way is provided. A transparent electrode film 9 for driving liquid crystal is formed on the protective film 8. The alignment film 10 is formed on the innermost surface of the color filter 103, that is, on the transparent electrode.

  The columnar spacer 12 is a shape of a convex spacer, and is formed at a plurality of predetermined locations (four locations in FIG. 3) on the transparent electrode 9 in accordance with the region (non-display region) where the black matrix layer 6 is formed. ing. The columnar spacer 12 is formed on the transparent electrode 9, the pixel 7, or the protective film 8. The columnar spacer 12 is formed in a sea island shape on the protective film 8 of the color filter 102 via the transparent electrode film 9, but the protective film 8 and the columnar spacer 12 are integrally formed, and the transparent electrode film 9 is It can be formed to cover the top. When the color filter does not include a black matrix layer, columnar spacers can be formed in regions where pixels are not formed.

  A transparent substrate conventionally used for color filters is used as the transparent substrate 5. Specific examples of the transparent substrate 5 include transparent rigid materials having no flexibility such as quartz glass, Pyrex (registered trademark) glass, and synthetic quartz plates; transparent transparent films having flexibility such as transparent resin films and optical resin plates. Flexible material. Corning 1737 glass has a low coefficient of thermal expansion, high dimensional stability and high workability during high-temperature heat treatment, and is a material that does not contain alkali components. Therefore, it is suitable for color filters for color liquid crystal display devices using the active matrix method. ing. Instead of the transparent substrate constituting the color filter of the present invention, a reflective substrate or a white colored substrate can be used. Furthermore, the surfaces of these substrates can be treated as necessary for the purpose of preventing alkali elution, imparting gas barrier properties, and other purposes.

  The pixel of the color filter of the present invention is usually formed with three colors of red (R), green (G), and blue (B). The colored pattern shape of the pixels is a known arrangement such as a stripe type, a mosaic type, a triangle type, or a four-pixel arrangement type, and the colored area is arbitrarily set. The thickness of the pixel is usually about 0.5 to 2.5 μm. The thickness of each color pixel can be set so that the red pixel 7R is the thinnest, and the green pixel 7G and the blue pixel 7B become thicker in this order.

  The black matrix layer 6 of the color filter of the present invention is provided so as to surround between the pixels 7R, 7G, and 7B and the outside of the pixel formation region in order to improve the contrast of the display image. The black matrix layer 6 can be a metal thin film such as chromium formed by sputtering, vacuum deposition, or the like. The black matrix layer 6 may also be a resin layer containing light shielding particles such as carbon fine particles, metal oxides, inorganic pigments, and organic pigments in a resin binder. The resin layer containing light-shielding particles is formed by (a) a method of patterning by developing a photosensitive resist or (b) a method of patterning by inkjet ink containing light-shielding particles. The black matrix layer 6 can be formed by the inkjet ink of the present invention containing light shielding particles. The thickness of the black matrix layer 6 made of a metal thin film is about 1000 to 2000 mm, and the thickness of the black matrix layer 6 made of a light-shielding resin layer is about 0.5 to 2.5 μm.

  The protective film 8 of the color filter of the present invention is provided to flatten the surface of the color filter and to prevent the components contained in the pixels 7 from eluting into the liquid crystal layer. A known negative photocurable transparent resin composition or thermosetting transparent resin composition is applied so as to cover the black matrix layer 6 and the pixels 7 by a method such as spin coater, roll coater, spray, printing, etc. The protective film 8 is formed by being cured by light or heat. The thickness of the protective film 8 is set in the range of, for example, 0.1 to 2.0 μm in consideration of the light transmittance of the material used, the surface state of the color filter, and the like.

Specific examples of components of the color filter of the present invention other than the black matrix layer, pixels, protective film and substrate are a transparent electrode layer, an alignment film and a columnar spacer. The transparent electrode layer, alignment film, and columnar spacer are those used in general color filters.
In addition, this invention is not limited to the said embodiment. The above-described embodiment is an exemplification, and all color filters having substantially the same configuration as the technical idea described in the claims of the present invention and exhibiting the same function and effect are the technology of the present invention. To be included in the scope.

EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to these Examples.
Various physical properties were measured as follows.

(1) Surface hardness (pencil hardness)
A thermosetting inkjet ink for a color filter was applied to the substrate with a spin coater, and was heated and dried in a 90 ° C. hot plate for 10 minutes and then in a 200 ° C. oven for 5 minutes. Thereafter, the substrate on which the cured film was formed was heated in an oven at 240 ° C. for 40 minutes, and the cured film was baked. The pencil hardness of the surface of the obtained color filter layer was evaluated by a “pencil scratch test” based on JIS K 5400-1990 8.4.1.

(2) Adhesiveness Adhesiveness between the color filter layer and the substrate was evaluated by an “adhesive cross-cut tape method” based on JIS K 5400-1990 8.5.3. Table 1 shows the number of grids remaining without peeling off the color filter layer in 100 grids.

Example 1
Preparation of pigment dispersion 15 parts by weight of C.I. I. Pigment Red 254 (IRGAPHOR RED BT-CF manufactured by Ciba Specialty Chemicals Co., Ltd.), 10.5 parts by mass of a pigment dispersant (Ajinomoto Fine Techno Co., Ltd., Asper PB821), and 74.5 parts by mass of a solvent (diethylene glycol monobutyl ether) Acetate) is mixed, 250 parts by mass of zirconia beads (diameter 0.1 mm) are added to the obtained mixture, and dispersion is performed with a paint shaker (manufactured by Asada Tekko Co., Ltd.) for 5 hours to obtain a pigment dispersion. It was.

Preparation of thermosetting inkjet ink for color filter 100 parts by mass of epoxy resin having 2 or more epoxy groups in one molecule (EHPE3150 manufactured by Daicel Chemical Industries, Ltd.), 43 parts by mass of silsesquioxane skeleton Oxetane resin (OX-SQ-H manufactured by Toagosei Co., Ltd.) and 5.2 parts by mass of a thermal polymerization initiator (an acid anhydride, Rikacid MTA-15 manufactured by Shin Nippon Rika Co., Ltd.) were mixed, and 148. 2 parts by mass of diethylene glycol monobutyl ether acetate was added to obtain a resin composition having a solid content of 50% by mass. The resin composition and the pigment dispersion are mixed, and then the blending mass ratio (P / V ratio) of the pigment (P) and the solid content (V) other than the pigment is 0.78, the solid content concentration in the liquid mixture Diethylene glycol monobutyl ether acetate was added so as to be 19.7% by mass to prepare a thermosetting inkjet ink for a color filter. The results are shown in Table 1.

Example 2
A thermosetting inkjet ink for a color filter was prepared in the same manner as in Example 1 except that the P / V ratio was changed to 1.15. The results are shown in Table 1.

Example 3
A thermosetting inkjet ink for a color filter was prepared in the same manner as in Example 1 except that the P / V ratio was changed to 0.55. The results are shown in Table 1.

Example 4
15 parts by weight of C.I used in Example 1 I. In place of Pigment Red 254, 4.5 parts by mass of C.I. I. Pigment Red 254 (IRGAPHOR RED BT-CF manufactured by Ciba Specialty Chemicals), 7.5 parts by mass of C.I. I. Pigment Red 177 (Chromophthal Red A2B manufactured by Ciba Specialty Chemicals) and 3.0 parts by mass of C.I. I. A thermosetting inkjet ink for a color filter was prepared in the same manner as in Example 1 except that CI Pigment Yellow 150 (YELLOW PIGMENT E4GN manufactured by LANXESS) was used. The results are shown in Table 1.

Example 5
15 parts by weight of C.I used in Example 1 I. In place of Pigment Red 254, 10.5 parts by mass of C.I. I. Pigment Green 36 (LIONOL GREEN 2YS manufactured by Toyo Ink Manufacturing Co., Ltd.) and 4.5 parts by mass of C.I. I. A thermosetting inkjet ink for a color filter was prepared in the same manner as in Example 1 except that CI Pigment Yellow 150 (YELLOW PIGMENT E4GN manufactured by LANXESS) was used. The results are shown in Table 1.

Example 6
15 parts by weight of C.I used in Example 1 I. Instead of Pigment Red 254, 14.1 parts by mass of C.I. I. Pigment Blue 15: 6 (LIONOL BLUE ES manufactured by Toyo Ink Manufacturing Co., Ltd.) and 0.9 parts by mass of C.I. I. Except that CI Pigment Violet 23 (LIONOGEN VIOLET RL manufactured by Toyo Ink Manufacturing Co., Ltd.) was used, a thermosetting inkjet ink for a color filter was prepared in the same manner as in Example 1. The results are shown in Table 1. ing.

Example 7
Instead of the oxetane resin having a silsesquioxane skeleton used in Example 1 (OX-SQ-H manufactured by Toagosei Co., Ltd.), an epoxy resin having a silsesquioxane skeleton (Arakawa Chemical Industries, Ltd.) A thermosetting inkjet ink for a color filter was prepared in the same manner as in Example 1 except that Comboceran HBSQ-502-6) was used. The results are shown in Table 1.

Comparative Example 1
A thermosetting inkjet ink for a color filter was prepared in the same manner as in Example 1 except that an oxetane resin having a silsesquioxane skeleton was not used. The results are shown in Table 1.

  The adhesiveness and surface hardness after thermosetting of the thermosetting inkjet ink for color filters of Examples 1 to 6 are excellent. The surface hardness after thermosetting of the thermosetting inkjet ink for color filters of Comparative Example 1 that does not contain an oxetane resin having a silsesquioxane skeleton is low.

Typical sectional drawing which shows one embodiment of a liquid crystal display device Typical sectional drawing which shows one embodiment of a liquid crystal display device Schematic longitudinal cross-sectional view which shows one embodiment of the color filter of this invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Color filter, 2 ... Electrode substrate, 3 ... Gap part, 4 ... Sealing material, 5 ... Transparent substrate, 6 ... Black matrix layer, 7 (7R, 7G, 7B) ) ... Pixel, 8 ... Protective film, 9 ... Transparent electrode film, 10 ... Alignment film, 11 ... Pearl, 12 ... Columnar spacer, 101 ... Color liquid crystal display device, 102: Color liquid crystal display device, 103: Color filter

Claims (4)

  A thermosetting inkjet ink for a color filter containing a pigment, a pigment dispersant, a solvent, a thermal polymerization initiator, an epoxy compound and an oxetane resin having a silsesquioxane skeleton and / or an epoxy resin.   The thermosetting inkjet ink for color filters according to claim 1, wherein the epoxy compound has two or more epoxy groups in one molecule.   The thermosetting inkjet for color filters according to claim 1 or 2, wherein a blending mass ratio (P / V) of the pigment (P) and a solid content (V) other than the pigment is 0.3 to 1.2. ink.   The color filter which has a pixel which consists of a hardened | cured material of the thermosetting inkjet ink for color filters as described in any one of Claims 1-3.

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