JP2009102572A - Thermosetting inkjet ink for color filter and color filter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide thermosetting inkjet ink for a color filter, the adhesion and surface hardness of which after thermosetted are made excellent and to provide the color filter using the thermosetting inkjet ink. <P>SOLUTION: The thermosetting inkjet ink for the color filter comprises a pigment, a pigment dispersing agent, a solvent, a thermal polymerization initiator, an epoxy resin (except for a silane-modified epoxy resin having an alkoxy group), and the silane-modified epoxy resin having the alkoxy group. <P>COPYRIGHT: (C)2009,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.
In such a color filter of a liquid crystal display, usually, there are three primary color patterns of red (R), green (G), and blue (B), and electrodes corresponding to the R, G, and B pixels, respectively. By turning on and off the liquid crystal, the liquid crystal operates as a shutter, and light passes through each of the R, G, and B pixels, and color display is performed.
As a conventional method for producing a color filter, for example, a staining method can be mentioned. In this dyeing method, first, a water-soluble polymer material, which is a dyeing material, is formed on a glass substrate, patterned into a desired shape by a photolithography process, and then the obtained pattern is immersed in a dyeing bath. To get a colored pattern. By repeating this three times, R, G, and B pixels are formed. Another method is a pigment dispersion method. In this method, a photosensitive resin layer in which a pigment is dispersed is first formed on a substrate, and this is patterned to obtain a monochromatic pattern. Further, by repeating this process three times, R, G, and B pixels are formed. Still other methods include an electrodeposition method, a method in which a pigment is dispersed in a thermosetting resin, R, G, and B are printed three times, and then the resin is thermoset.

However, in any method, in order to color three colors of R, G, and B, it is necessary to repeat the same process three times, which causes a problem of high cost, and the yield decreases because the same process is repeated. There is a problem of doing.
As a method of manufacturing a color filter that solves these problems, Patent Document 1 describes that a pixel portion is formed by spraying a colored ink containing a thermosetting resin onto a substrate by an inkjet method and heating. Has been.

Japanese Patent Laid-Open No. 9-21910

  In order to improve the color reproducibility and contrast of the recent color filters, the color filter inkjet ink is required to have a high concentration of pigment contained in the inkjet ink and to improve dispersibility. In addition, as the concentration of the pigment increases, the dispersibility of the pigment tends to decrease. For this reason, it is necessary to increase the amount of the pigment dispersant together with the amount of the pigment contained in the inkjet ink. However, increasing the amount of pigment and pigment dispersant contained in the ink-jet ink for the color filter results in a relative decrease in components that contribute to the film properties of the cured film such as a binder, resulting in a decrease in the curability of the ink. However, there exists a problem that the adhesiveness and surface hardness of a cured film fall.

  In view of the above circumstances, an object of the present invention is to provide a thermosetting inkjet ink for a color filter excellent in adhesion after heat curing and surface hardness, and a color filter using the inkjet ink. is there.

As a result of intensive studies, the present inventors have found that the above problems can be solved by including a silane-modified epoxy resin having a specific structure as a thermosetting inkjet ink for a color filter. It came to complete.
That is, the thermosetting inkjet ink for a color filter according to the present invention includes a pigment, a pigment dispersant, a solvent, a thermal polymerization initiator, an epoxy resin (excluding a silane-modified epoxy resin having an alkoxy group), and a silane having an alkoxy group. It contains a modified epoxy resin.

  According to the present invention, a pixel excellent in adhesion and surface hardness can be formed by incorporating a silane-modified epoxy resin having a specific structure in the thermosetting inkjet ink for a color filter.

  In the thermosetting inkjet ink for color filters according to the present invention, the epoxy resin (excluding the silane-modified epoxy resin having an alkoxy group) has two or more epoxy groups in one molecule. This is preferable from the viewpoint of improving film properties such as solvent resistance and adhesion of the formed pixel.

  In the thermosetting inkjet ink for a color filter according to the present invention, the silane-modified epoxy resin having an alkoxy group is obtained by a dealcoholization reaction between an epoxy resin having a hydroxyl group and a hydrolyzable alkoxysilane. Is preferable from the viewpoint of forming a pixel having excellent heat resistance.

  In the thermosetting inkjet ink for color filters according to the present invention, it is preferable that the thermal polymerization initiator is an acid anhydride from the viewpoint of a long pot life and a small calorific value.

  In the thermosetting inkjet ink for a color filter according to the present invention, the pigment is C.I. I. Pigment red 254, C.I. I. Pigment red 177, and C.I. I. It is preferable that at least one pigment selected from the group consisting of CI Pigment Yellow 150 is included from the viewpoint of high coloring power.

  In the thermosetting inkjet ink for color filters according to the present invention, the blending weight ratio (P / V) of the pigment (P) and the solid content (V) other than the pigment is 0.5 to 1.2. Is preferred. If the P / V ratio is too low, in order to obtain sufficient coloring power, it is necessary to increase the amount of ink droplets that adhere to the pixel formation region, which causes problems such as ink breaking from the pixel formation region. There is a case. On the other hand, if the P / V ratio is too high, there may be a problem that the ejection performance such as clogging or flight bending occurs in the ejection head or the film surface becomes rough.

  The color filter which concerns on this invention has a pixel which consists of a hardened | cured material of the thermosetting inkjet ink for color filters which concerns on this invention, It is characterized by the above-mentioned. ADVANTAGE OF THE INVENTION According to this invention, it can be set as the high quality color filter provided with the pixel excellent in adhesiveness and surface hardness.

The thermosetting inkjet ink for a color filter of the present invention can form a pixel having excellent adhesion and surface hardness by containing a silane-modified epoxy resin having a specific structure.
Moreover, according to this invention, the high quality color filter provided with the pixel excellent in the said adhesiveness and surface hardness can be provided.

  Hereinafter, the thermosetting inkjet ink for color filters and the color filter of the present invention will be described in order.

I. Thermosetting inkjet ink for color filter The thermosetting inkjet ink for color filter according to the present invention includes a pigment, a pigment dispersant, a solvent, a thermal polymerization initiator, an epoxy resin (excluding a silane-modified epoxy resin having an alkoxy group), And a silane-modified epoxy resin having an alkoxy group.
In the silane-modified epoxy resin having an alkoxy group of the present invention, a part or all of the hydroxyl groups of the epoxy resin are modified with a hydrolyzable alkoxysilane, and the silane-modified epoxy resin having an alkoxy group is a color filter. By adding to the thermosetting inkjet ink for use, the thermosetting property of the inkjet ink is improved and the thermosetting reaction is promoted, so that a pixel having excellent adhesion and surface hardness can be formed.
Further, in the present invention, since a thermosetting resin is used, there is an advantage that a special incidental equipment such as light irradiation is not required and productivity is high.

  Hereinafter, components used in the thermosetting inkjet ink for color filter of the present invention will be described.

<Pigment>
The thermosetting inkjet ink for a color filter according to the present invention contains a pigment. The pigment used here is C.I. I. Pigment red 254, C.I. I. Pigment red 177, and C.I. I. In view of high coloring power, at least one pigment selected from the group consisting of CI Pigment Yellow 150 is preferable. However, it is not limited to these.
In addition, C.I. I. Pigment red 254, C.I. I. Pigment red 177, and C.I. I. By combining Pigment Yellow 150, even when pixels are formed by the ink jet method, pixels having high luminance and high contrast can be obtained while realizing a specific color.

  As other pigments, any one of organic colorants and inorganic colorants can be selected and used according to the color required by the pixel (pixel portion) R, G, B, etc. or the black matrix layer. . As the organic colorant, for example, dyes, organic pigments, natural pigments, and the like can be used. Moreover, as an inorganic coloring agent, an inorganic pigment, an extender pigment, etc. can be used, for example. Among these, organic pigments are preferably used because they have high color developability and high heat resistance. Examples of the organic pigment include compounds classified as pigments in the color index (CI; issued by The Society of Dyers and Colorists), specifically, the following color index (C.I. ) Can be listed.

  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 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. 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. 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 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 224, C.I. I. Pigment red 226, C.I. I. Pigment red 242, C.I. I. Pigment red 243, C.I. I. Pigment red 245, C.I. I. Pigment red 255, C.I. I. Pigment red 264, C.I. I. Pigment red 265;

Specific examples of the inorganic pigment or extender pigment include titanium oxide, barium sulfate, calcium carbonate, zinc white, lead sulfate, yellow lead, zinc yellow, red rose (red iron (III) oxide), cadmium red, amber, etc. Can be mentioned.
In the present invention, the pigments can be used alone or in admixture of two or more.
Moreover, in the inkjet ink which concerns on this invention, a pigment is mix | blended normally in the ratio of 1-60 weight% with respect to the solid content whole quantity of an inkjet ink, Preferably it is 15-40 weight%.

In the ink-jet ink according to the present invention, the mixing weight ratio (P / V) of the pigment (P) and the solid content (V) other than the pigment is 0.5 to 1.2. This is preferable from the viewpoint of preventing breakage of the ink and the balance of the obtained film properties. Here, the “solid content” indicates components other than the solvent in the ink. If the P / V ratio is too low, in order to obtain sufficient coloring power, it is necessary to increase the amount of ink droplets that adhere to the pixel formation region, which causes problems such as ink breaking from the pixel formation region. There is a case. On the other hand, if the P / V ratio is too high, there may be a problem that the ejection performance such as clogging or flight bending occurs in the ejection head or the film surface becomes rough.
In the present invention, C.I. I. C. has higher coloring power than CI Pigment Yellow 139 I. When Pigment Yellow 150 is used, sufficient coloring power can be exhibited even if the amount of the entire pigment in the pixel is reduced. Therefore, in the inkjet ink, it is possible to reduce the blending weight ratio of the pigment (P) and the solid content (V) other than the pigment (hereinafter simply referred to as P / V ratio). By making the P / V ratio relatively small, the ink jet ink ejection performance is improved, surface roughness is less likely to occur, and film properties such as durability such as heat resistance are improved. It is preferable that it is .5-0.75. On the other hand, by making the P / V ratio relatively high, the P / V ratio is 0.75 to 1 in terms of realizing the same coloring power as a pixel with a smaller amount of ink, that is, a thinner film thickness than in the past. .2 is preferable.

<Pigment dispersant>
A pigment dispersant is blended in the thermosetting inkjet ink for color filter of the present invention in order to disperse the pigment satisfactorily. Examples of the pigment dispersant that can be used include cationic, anionic, nonionic, amphoteric, and silicone surfactants. Among the surfactants, polymer surfactants (polymer dispersants) as exemplified below are preferable. Further, a dispersion auxiliary resin such as a special acrylic polymer may be further used.
That is, 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 Polymeric surfactants such as polyethylene glycol diesters such as polyethylene glycol dilaurate and polyethylene glycol distearate; sorbitan fatty acid esters; fatty acid-modified polyesters; tertiary amine-modified polyurethanes are preferably used.
The content of the pigment dispersant is preferably 5 to 50% by weight based on the entire solid content, and more preferably 10 to 30% by weight based on the entire solid content.

<Epoxy resin (excluding silane-modified epoxy resin having an alkoxy group)>
The epoxy resin (excluding the silane-modified epoxy resin having an alkoxy group) used in the present invention has an epoxy group in one molecule from the viewpoint of film physical properties such as solvent resistance and adhesion of a pixel formed by inkjet ink. It is preferable to have two or more. As an epoxy group, what is necessary is just a group which has an epoxide structure, for example, a glycidyl group, an oxyethylene group, an epoxycyclohexyl group etc. can be shown.

Epoxy resins (excluding silane-modified epoxy resins having an alkoxy group) have a polystyrene-equivalent weight average molecular weight of 3000 to 20000 from the viewpoint of increasing the crosslink density of the cured film and improving the ink jetting performance by reducing the viscosity. It is preferable that it is 4000-15000.
If the molecular weight of the epoxy resin (excluding the silane-modified epoxy resin having an alkoxy group) is too small, the physical properties such as strength and solvent resistance required for the cured layer as the details of the color filter are likely to be insufficient. If the molecular weight is more than 20000, the viscosity is likely to increase, and the stability of the ejection amount and the straightness of the ejection direction when ejecting from the ejection head by the ink jet method may be degraded, and the stability of long-term storage will be degraded. Because there is a fear.

  The epoxy resin (excluding the silane-modified epoxy resin having an alkoxy group) is not particularly limited as long as it contains two or more epoxy groups in one molecule. For example, bisphenol A type epoxy resin, bisphenol F type epoxy Resin, brominated bisphenol A type epoxy resin, bisphenol S type epoxy resin, diphenyl ether type epoxy resin, hydroquinone type epoxy resin, naphthalene type epoxy resin, biphenyl type epoxy resin, fluorene type epoxy resin, phenol novolac type epoxy resin, orthocresol novolak Type epoxy resin, trishydroxyphenylmethane type epoxy resin, trifunctional type epoxy resin, tetraphenylolethane type epoxy resin, dicyclopentadienephenol type epoxy resin, hydrogenated bisphenol Nord A type epoxy resin, bisphenol A nucleated polyol type epoxy resin, polypropylene glycol type epoxy resin, glycidyl ester type epoxy resin, glycidyl amine type epoxy resin, glioxal type epoxy resin, alicyclic epoxy resin, heterocyclic type epoxy resin, etc. Can be used.

  More specifically, bisphenol A type epoxy resins such as trade name Epicoat 828 (made by Japan Epoxy Resin), trade name Epicoat 807 (made by Japan Epoxy Resin), trade name YDF-175S (made by Toto Kasei), etc. Bisphenol F type epoxy resin, brominated bisphenol A type epoxy resin such as trade name YDB-715 (manufactured by Toto Kasei Co., Ltd.), bisphenol S type epoxy resin such as trade name EPICLON EXA1514 (manufactured by Dainippon Ink and Chemicals), trade name Biphenyl such as hydroquinone type epoxy resin such as YDC-1312 (manufactured by Tohto Kasei Co., Ltd.), naphthalene type epoxy resin such as brand name EPICLON EXA4032 (manufactured by Dainippon Ink & Chemicals, Inc.), and brand name Epicoat YX4000H (manufactured by Japan Epoxy Resin Co., Ltd.) Type D Poxy resin, bisphenol A type novolak epoxy resin such as trade name Epicoat 157S70 (made by Japan Epoxy Resin), phenol such as trade name Epicoat 154 (made by Japan Epoxy Resin), trade name YDPN-638 (made by Toto Kasei) Novolak type epoxy resin, cresol novolac type epoxy resin such as trade name YDCN-701 (manufactured by Toto Kasei Co., Ltd.), dicyclopentadiene phenol type epoxy resin such as trade name EPICLON HP-7200 (manufactured by Dainippon Ink and Chemicals, Inc.), product Trishydroxyphenylmethane type epoxy resin such as name Epicoat 1032H60 (manufactured by Japan Epoxy Resin), trifunctional type epoxy resin such as trade name VG3101M80 (made by Mitsui Chemicals), brand name Epicoat 1031S (Japan) Hydrogenation such as tetraphenylolethane type epoxy resin such as Poxyresin), tetrafunctional type epoxy resin such as trade name Denacol EX-411 (manufactured by Nagase Kasei Kogyo Co., Ltd.) Bisphenol A type epoxy resin, glycidyl ester type epoxy resin such as trade name Epicoat 190P (manufactured by Japan Epoxy Resin Co., Ltd.), glycidyl amine type epoxy resin such as trade name YH-434 (manufactured by Tohto Kasei Co., Ltd.), trade name YDG-414 ( Glyoxal type epoxy resins such as Toto Kasei Co., Ltd., alicyclic epoxy resins such as trade name EHPE3150 (manufactured by Daicel Chemical Industries, Ltd.), and alicyclic polyfunctional products such as brand name Epolide GT-401 (manufactured by Daicel Chemical Industries, Ltd.) Complexes such as epoxy compounds and triglycidyl isocyanate (TGIC) A ring type epoxy resin etc. can be illustrated. Further, if necessary, a trade name Neotote E (manufactured by Toto Kasei Co., Ltd.) can be mixed as an epoxy reactive diluent.

Among these epoxy resins (excluding silane-modified epoxy resins having an alkoxy group), alicyclic epoxy resins such as trade name EHPE3150 (manufactured by Daicel Chemical Industries), and Epicoat 157S70 (manufactured by Japan Epoxy Resin) Bisphenol A type novolac epoxy resins are particularly preferred.
Moreover, these epoxy resins (except the silane modified epoxy resin which has an alkoxy group) may be used individually by 1 type, and may be used in combination of 2 or more type.

  The content of the epoxy resin (excluding the silane-modified epoxy resin having an alkoxy group) is preferably 1 to 50 parts by weight, more preferably 3 to 30 parts by weight with respect to 100 parts by weight of the total solid content. It is. This is because if the content of the epoxy resin (excluding the silane-modified epoxy resin having an alkoxy group) is too small, sufficient thermosetting may not be obtained. Moreover, when there is too much content of an epoxy resin (except the silane modified epoxy resin which has an alkoxy group), it will cause a curing defect.

<Silane-modified epoxy resin having an alkoxy group>
The thermosetting inkjet ink for a color filter of the present invention contains a silane-modified epoxy resin having an alkoxy group in order to improve adhesion and surface hardness after curing.
The silane-modified epoxy resin having an alkoxy group is obtained by subjecting an epoxy resin having a hydroxyl group and a hydrolyzable alkoxysilane to a dealcoholization reaction, for example, by a method described in JP-A-2001-59011.

  The epoxy resin used as a raw material for the silane-modified epoxy resin having an alkoxy group is not particularly limited as long as it has a hydroxyl group capable of condensation reaction. For example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type Epoxy resin, 4,4'-biphenol, tetramethyl bisphenol A type epoxy resin, dimethyl bisphenol A type epoxy resin, tetramethyl bisphenol F type epoxy resin, dimethyl bisphenol F type epoxy resin, tetramethyl bisphenol S type epoxy resin, dimethyl bisphenol S type epoxy resin etc. are mentioned. As these epoxy resins, for example, Japan Epoxy Resin Co., Ltd., Epicoat 828, Epicoat 807 and the like are commercially available.

  Examples of the hydrolyzable alkoxysilane used as a raw material for the silane-modified epoxy resin having an alkoxy group include tetraalkoxysilanes such as tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetraisopropoxysilane, and tetrabutoxysilane, Methyltrimethoxysilane, methyltriethoxysilane, methyltripropoxysilane, methyltriisopropoxysilane, methyltributoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, Alkyltrialkoxysilanes such as isopropyltrimethoxysilane and isopropyltriethoxysilane; aryltrialkoxysilanes such as phenyltrimethoxysilane; Trialkoxysilanes having a functional group trimethoxysilane, dialkoxysilane such as dimethyldimethoxysilane, and the like.

  The silane-modified epoxy resin having an alkoxy group is, for example, from Arakawa Chemical Industry Co., Ltd., Composelane series (condensation reaction product of bisphenol A type epoxy resin and methoxysilane (trade name: Composelane HBEP125), bisphenol A type. It can be obtained as a condensation reaction product of epoxy resin and methoxysilane having a methyl group (trade name: Composelane E103B)).

  The content of the silane-modified epoxy resin having an alkoxy group is preferably 1 to 20 parts by weight, more preferably 2 to 13 parts by weight with respect to 100 parts by weight of the total solid content. If the content of the silane-modified epoxy resin having an alkoxy group is too small, sufficient thermosetting may not be obtained, and if the content of the silane-modified epoxy resin having an alkoxy group is too large, curing is poor. May occur.

  Further, the weight ratio of the silane-modified epoxy resin having an alkoxy group in the thermosetting inkjet ink for color filters and the epoxy resin (excluding the silane-modified epoxy resin having an alkoxy group) (silane-modified epoxy resin having an alkoxy group) The epoxy resin (excluding the silane-modified epoxy resin having an alkoxy group) is preferably 0.1 to 1.2, more preferably 0.3 to 1.0, and particularly preferably 0.4 to 0.00. 8. By satisfying the above range, it is possible to obtain a thermosetting inkjet ink for a color filter capable of forming pixels having excellent adhesion and surface hardness.

<Thermal polymerization initiator>
The thermal polymerization initiator used in the present invention is not particularly limited, but an acid anhydride is preferable from the viewpoint of a long pot life and a small calorific value. Examples of the acid anhydride include polyvalent carboxylic acid anhydrides, and specifically include phthalic anhydride, itaconic anhydride, succinic anhydride, citraconic anhydride, dodecenyl succinic anhydride, tricarballylic anhydride, maleic anhydride. Aliphatic polycarboxylic dianhydrides such as acids, hexahydrophthalic anhydride, dimethyltetrahydrophthalic anhydride, hymic anhydride, nadic anhydride, and other aliphatic or alicyclic dicarboxylic dianhydrides; pyromellitic anhydride , Aromatic polycarboxylic acid anhydrides such as trimellitic anhydride and benzophenone tetracarboxylic anhydride; and ester group-containing acid anhydrides such as ethylene glycol bistrimellilate and glyceryl tristrimellate An epoxy resin curing agent made of carboxylic acid anhydride can also be suitably used. .

  Said thermal polymerization initiator can be used individually by 1 type or in mixture of 2 or more types. The amount of the thermal polymerization initiator used in the present invention is usually 1 to 100 parts by weight of an epoxy compound (epoxy resin (excluding a silane-modified epoxy resin having an alkoxy group) and a silane-modified epoxy resin having an alkoxy group). It is the range of 100 weight part, Preferably it is 5-50 weight part. If the blending amount of the thermal polymerization initiator is less than 1 part by weight, curing may be insufficient and a tough coating film may not be formed. Moreover, when the compounding quantity of a thermal-polymerization initiator exceeds 100 weight part, there exists a possibility that the adhesiveness with respect to the board | substrate of a coating film may be inferior.

<Solvent>
The thermosetting inkjet ink for a color filter of the present invention is mixed with a solvent in order to prepare the ink so that the ink can be discharged from a high concentration liquid or immediately from the head.
In order to prepare the thermosetting inkjet ink for a color filter of the present invention into a high-concentration ink for storage or an ink that can be applied immediately, the solvent is particularly limited as long as it is a solvent that suitably dissolves and disperses solid components. Not.

  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 Glycol oligomer ether esters such as diethylene glycol monobutyl ether acetate; aliphatic or aromatic esters such as ethyl acetate and propyl benzoate; dicarboxylic acid diesters such as diethyl carbonate; and methyl 3-methoxypropionate Alkoxycarboxylates; ketocarboxylates such as ethyl acetoacetate; Alcohols or phenols such as diol, isopropanol and phenol; aliphatic or aromatic ethers such as diethyl ether and anisole; alkoxy alcohols such as 2-ethoxyethanol and 1-methoxy-2-propanol; diethylene glycol; Examples include glycol oligomers such as tripropylene glycol; alkoxy alcohol esters such as 2-ethoxyethyl acetate; ketones such as acetone and methyl isobutyl ketone.

Moreover, since the thermosetting inkjet ink for color filters according to the present invention contains a pigment, it is preferable to use a solvent that does not contain a hydroxyl group from the viewpoint of the dispersibility and dispersion stability of the pigment.
Preferred solvents include 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 Examples thereof include dimethyl and diethyl succinate. These solvents are mixed with or without being mixed with a highly dispersible solvent conventionally used for preparing pigment dispersions such as 3-methoxybutyl acetate and propylene glycol monomethyl ether acetate (PGMEA). It can be used as a solvent to prepare a pigment dispersion.

Further, when water is mixed in the solvent, the hydroxyl group of the water molecule is present in the solvent, so that the same problem as in the case of using the solvent having a hydroxyl group may be caused. Therefore, in order to substantially exclude moisture from the acid-epoxy crosslinking reaction system, it is preferable to prepare an inkjet ink using an organic solvent having low miscibility with water. From this viewpoint, the solubility of the solvent for preparing the ink-jet ink in water is preferably 20 parts by weight or less with respect to 100 parts by weight of water having a liquid temperature of 20 ° C.
Among the solvents mentioned as specific examples, diethylene glycol monobutyl ether acetate does not have a hydroxyl group, and its solubility in 100 parts by weight of water at a liquid temperature of 20 ° C. is low at 6.5 parts by weight. Is particularly preferable.

  The solvent is usually used in an amount of 40 to 95% by weight with respect to the total amount of the ink-jet ink containing the solvent to prepare the ink-jet ink. When the amount of the solvent is too small, the viscosity of the inkjet ink is high, and in the case of the inkjet ink, it becomes difficult to discharge from the inkjet head. Also, if there is too much solvent, the ink will break from the predetermined ink layer formation site, the amount of ink that can be deposited on the ink layer formation site will be insufficient, the film thickness after drying will be too thin, Accordingly, a sufficient transmission density cannot be obtained.

<Other ingredients>
Furthermore, the thermosetting inkjet ink for color filters of this invention can mix | blend 1 type (s) or 2 or more types of other additives as needed. The following can be illustrated as such an additive.
a) Filler: For example, glass, alumina and the like.
b) Adhesion promoter: for example, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (2-methoxyethoxy) silane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane.
c) Leveling agents: For example, vinyl polymers such as polyoxyalkylene surfactants, fatty acid ester surfactants, special acrylic polymers, vinyl ether polymers, and the like.
d) Anti-aggregation agent: for example, sodium polyacrylate.

<Ink production method>
The thermosetting inkjet ink for a color filter of the present invention may be produced by adding and mixing each component into a solvent and dissolving or dispersing the solid component.
However, if the pigment is directly put into the whole solvent together with other components such as a resin and mixed with stirring, the pigment is often not sufficiently dispersed in the solvent. Therefore, usually, a solvent having good dispersibility and dispersion stability of the pigment is prepared, and the pigment is added thereto together with the dispersant, and sufficiently stirred with a dissolver or the like to prepare a pigment dispersion. Then, the obtained pigment dispersion is put into a solvent together with components other than the pigment, and sufficiently stirred and mixed with a dissolver or the like, whereby the ink-jet ink according to the present invention can be obtained.

  As the remaining solvent into which the pigment dispersion is charged, an inkjet ink having a composition obtained by subtracting the amount of the solvent used for preparing the pigment dispersion from the final composition of the entire solvent is diluted to the final concentration. May be completed. Alternatively, a high-concentration inkjet ink may be prepared by introducing the pigment dispersion into a relatively small amount of solvent. The high-concentration ink-jet ink can be stored as it is and diluted to the final concentration just before use and used in the ink-jet method.

II. Next, the color filter of the present invention will be described. The color filter of the present invention is characterized by having pixels made of a cured product of the thermosetting inkjet ink for color filter described above.

In the present invention, a pixel having excellent adhesion and surface hardness can be obtained by curing the above-described thermosetting inkjet ink for color filter. Therefore, according to the present invention, it is possible to obtain a high-quality color filter including pixels having excellent adhesion and surface hardness.
Hereinafter, the color filter of the present invention will be described separately for each configuration.
First, the structure of the color filter will be described here.

Examples of the color filter include a color filter used for an image output device such as a liquid crystal display device, a color filter used for an image input device such as a solid-state imaging device, and the like. As an example, a typical example of a color filter structure used in a liquid crystal display device will be described with reference to FIG.
In general, as shown in FIG. 1A, a color liquid crystal display device (101) is provided with a gap portion 3 of about 1 to 10 μm with a color filter 1 and an electrode substrate 2 such as a TFT substrate facing each other. 3 is filled with a liquid crystal compound L, and the periphery thereof is sealed with a sealing material 4. The color filter 1 includes a black matrix layer 6 formed in a predetermined pattern on the transparent substrate 5 to shield the boundary between pixels, and a plurality of colors (usually red (R (R)) to form each pixel. ), Green (G), blue (B) three primary colors) arranged in a predetermined order, a protective film 8, and a transparent electrode film 9 are stacked in this order from the side close to the transparent substrate. I'm taking it. An 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. Furthermore, a spacer is provided in the gap 3 in order to maintain a constant and uniform cell gap between the color filter 1 and the electrode substrate 2. As the spacer, pearls 11 having a constant particle diameter are dispersed, or columnar spacers 12 having a height corresponding to the cell gap as shown in FIG. It forms in the area | region which overlaps with the position in which the layer 6 is formed. 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. 2 is a longitudinal sectional view showing an example (color filter 103) of the color filter according to 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. An alignment film 10 is formed on the innermost surface of the color filter 103, in this case 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. 2) 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. In the color filter 102, columnar spacers are formed in a sea-island shape on the protective film 8 via the transparent electrode film 9, but the protective film 8 and the columnar spacer 12 are integrally formed and covered thereover. A transparent electrode film 9 may be formed. In the case where the color filter does not include a black matrix layer, columnar spacers can be formed in regions where pixels are not formed.

1. Substrate The transparent substrate 5 is not particularly limited as long as it is conventionally used for a color filter, but there is no flexibility such as quartz glass, Pyrex (registered trademark) glass, synthetic quartz plate and the like. A transparent flexible material having flexibility such as a transparent rigid material, a transparent resin film, or an optical resin plate can be used. Among them, Corning 7059 glass is a material having a small coefficient of thermal expansion, excellent dimensional stability and workability in high-temperature heat treatment, and is an alkali-free glass containing no alkali component in the active matrix. Suitable for color filters for color liquid crystal display devices. In the present invention, a transparent substrate is usually used, but a reflective substrate or a white colored substrate can also be used. Moreover, you may use the board | substrate which surface-treated for the purpose of alkali elution prevention, gas-barrier provision, and other purposes as needed.

2. Pixel A pixel is usually formed of three colors of red (R), green (G), and blue (B). The coloring pattern shape in the pixel can be a known arrangement such as a stripe type, a mosaic type, a triangle type, or a four-pixel arrangement type, and the coloring area can be arbitrarily set.
The thickness of the pixel is usually about 0.5 to 2.5 μm. Alternatively, the thickness of each color pixel may be changed so that the red pixel 7R is the thinnest, and the green pixel 7G and the blue pixel 7B become thicker in this order, and the optimal thickness may be set for each color.

3. Black Matrix Layer The black matrix layer 6 is provided so as to surround 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 may be a metal thin film such as chromium by sputtering, vacuum deposition, or the like. Alternatively, the black matrix layer 6 may be a resin layer in which light shielding particles such as carbon fine particles, metal oxides, inorganic pigments, and organic pigments are contained in a resin binder. In the case of a resin layer containing light-shielding particles, there are a method of patterning by development using a photosensitive resist and a method of patterning using an inkjet ink containing light-shielding particles. The black matrix layer 6 may be formed using the inkjet ink according to the present invention containing light-shielding particles.
The thickness of the black matrix layer is about 1000 to 2000 mm in the case of a metal thin film, and about 0.5 to 2.5 μm in the case of a light shielding resin layer.

4). Protective Film The protective film 8 is provided to flatten the surface of the color filter and prevent the components contained in the pixels 7 from eluting into the liquid crystal layer. The protective film 8 covers the black matrix layer 6 and the pixels 7 by a known negative photocurable transparent resin composition or thermosetting transparent resin composition by a method such as spin coater, roll coater, spray, printing, etc. And can be formed by curing with light or heat.
The thickness of the protective film 8 can be set in consideration of the light transmittance of the material used, the surface state of the color filter, and the like, and can be set, for example, in the range of 0.1 to 2.0 μm.

5). Others The color filter of the present invention may be one in which, for example, a transparent electrode layer, an alignment film, a columnar spacer, or the like is formed in addition to the black matrix layer, pixels, protective film, and substrate. Since the transparent electrode layer, the alignment film, and the columnar spacer can be the same as those used in a general color filter, description thereof is omitted here.

  The present invention is not limited to the above embodiment. The above-described embodiment is an exemplification, and the present invention has substantially the same configuration as the technical idea described in the claims of the present invention, and any device that exhibits the same function and effect is the present invention. It is included in the technical scope of the invention.

  Hereinafter, the present invention will be described more specifically with reference to examples.

<Example 1>
(1) Preparation of pigment dispersion A pigment, a pigment dispersant, and a solvent are mixed at the following ratio, 200 parts by weight of zirconia beads having a diameter of 0.5 mm are added, and 3 hours using a paint shaker (manufactured by Asada Tekko) Dispersed to prepare a pigment dispersion.

[Composition of pigment dispersion]
Pigment (CI Pigment 254) (BT-CF: trade name, manufactured by Ciba Specialty Chemicals): 10 parts by weight Pigment dispersant (Disperbyk 161: trade name, manufactured by Big Chemie Japan, solid content in solvent) 30% by weight): 10.5 parts by weight • BDGAC (diethylene glycol monobutyl ether acetate): 74.5 parts by weight

(2) Preparation of thermosetting inkjet ink for color filter Epoxy resin (excluding silane-modified epoxy resin having alkoxy group) (EHPE3150: trade name, manufactured by Daicel Chemical Industries, Ltd.) 100 parts by weight and silane-modified having alkoxy group Epoxy resin (Composeran E103A: trade name, manufactured by Arakawa Chemical Industries, Inc., containing 50.4% dipropylene glycol dimethyl ether solvent): 90 parts by weight, thermal polymerization initiator (acid anhydride) (Ricacid MTA-15: product 104.5 parts by weight of BDGAC was added to a mixed solution with 5.2 parts by weight of a product (name, Shin Nippon Rika Co., Ltd.) to prepare a resin composition having a solid content of 50% by mass.
Next, the pigment dispersion and the resin composition are sufficiently mixed, the blending weight ratio (P / V) of the pigment (P) and the solid content (V) other than the pigment is 0.6, and the mixture BDGAC was added so that the solid content was 19% by mass to prepare a thermosetting inkjet ink for color filters. Similarly, a thermosetting inkjet ink for a color filter was prepared so that the blending weight ratio (P / V) of the pigment (P) and the solid content (V) other than the pigment was 0.8.

<Example 2>
Example 1 except that 83 parts by weight (Licacid HNA-100: trade name, manufactured by Shin Nippon Rika Co., Ltd.) and 156 parts by weight of Composelan E103A were used as the thermal polymerization initiator (acid anhydride) in Example 1. In the same manner, a thermosetting inkjet ink for a color filter was prepared.

<Example 3>
In Example 2, a thermosetting inkjet ink for a color filter was prepared in the same manner as in Example 2 except that 5.2 parts by weight of HNA-100 (thermal polymerization initiator) and 90 parts by weight of Composelan E103A were used. did.

<Comparative Example 1>
In Example 1, a thermosetting inkjet ink for a color filter was prepared in the same manner as in Example 1 except that the silane-modified epoxy resin having an alkoxy group (Composeran E103A) was not used.

<Comparative example 2>
In Example 2, a thermosetting inkjet ink for a color filter was prepared in the same manner as in Example 2 except that the silane-modified epoxy resin having an alkoxy group (Composeran E103A) was not used.

<Comparative Example 3>
In Example 3, a thermosetting inkjet ink for a color filter was prepared in the same manner as in Example 3 except that the silane-modified epoxy resin having an alkoxy group (Composeran E103A) was not used.

About each obtained thermosetting inkjet ink for color filters, the resin cured film was formed as follows and surface hardness and adhesiveness were evaluated. The evaluation results are also shown in Table 1.
(Formation of coating film)
Each inkjet ink was applied onto a 0.7 mm thick glass substrate (Corning Corp., 1737) by spin coating.
Thereafter, prebaking was performed on a hot plate at 90 ° C. for 10 minutes. Then, in a clean oven, post-baking was performed by heating at 200 ° C. for 30 minutes, and further post-baking was performed by heating at 240 ° C. for 30 minutes to form a color filter layer.

〔Evaluation methods〕
(1) Surface hardness (pencil hardness)
The pencil hardness of the surface of the color filter layer was evaluated by “pencil scratch test” in accordance with 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” according to JIS K 5400-1990 8.5.3. In Table 1, the number of grids remaining without peeling off the color filter layer in 100 grids is shown.

It is typical sectional drawing about an example of a liquid crystal panel. It is typical sectional drawing about another example of a liquid crystal panel. It is a typical longitudinal cross-sectional view which shows an example 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 Orientation film 11 Pearl 12 Columnar spacer 101, 102 Color liquid crystal display device 103 Color filter

Claims (7)

  A thermosetting for a color filter comprising a pigment, a pigment dispersant, a solvent, a thermal polymerization initiator, an epoxy resin (excluding a silane-modified epoxy resin having an alkoxy group), and a silane-modified epoxy resin having an alkoxy group Ink jet ink.   The thermosetting inkjet ink for a color filter according to claim 1, wherein the epoxy resin (excluding a silane-modified epoxy resin having an alkoxy group) has two or more epoxy groups in one molecule.   The thermosetting for color filter according to claim 1, wherein the silane-modified epoxy resin having an alkoxy group is obtained by subjecting an epoxy resin having a hydroxyl group and a hydrolyzable alkoxysilane to a dealcoholization reaction. Ink jet ink.   The thermosetting inkjet ink for a color filter according to any one of claims 1 to 3, wherein the thermal polymerization initiator is an acid anhydride.   The pigment is C.I. I. Pigment red 254, C.I. I. Pigment red 177, and C.I. I. The thermosetting inkjet ink for a color filter according to any one of claims 1 to 4, comprising at least one pigment selected from the group consisting of CI Pigment Yellow 150.   6. The blending weight ratio (P / V) of the pigment (P) and the solid content (V) other than the pigment is 0.5 to 1.2. 6. 2. A thermosetting inkjet ink for a color filter.   A color filter comprising a pixel made of a cured product of the thermosetting inkjet ink for a color filter according to claim 1.

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