JP4426515B2 - Ink-jet ink for color filter, method for producing color filter, and method for producing liquid crystal display device - Google Patents

Description

  The present invention relates to an inkjet ink for a color filter used for forming a colored cured layer having a predetermined pattern such as a pixel portion (colored layer), a method for producing a color filter using the inkjet ink, and the color filter. The present invention relates to a method for manufacturing a liquid crystal display device.

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.
In general, a color liquid crystal display device has a structure in which a color filter and an electrode substrate such as a TFT substrate are opposed to each other to provide a gap of about 1 to 10 μm, a liquid crystal compound is filled in the gap and the periphery is sealed with a sealing material. Have taken. The color filter has a black matrix layer formed in a predetermined pattern on a transparent substrate to shield the boundary between pixels, and a plurality of colors (usually red (R), green) to form each pixel. A pixel portion in which (G) and three primary colors of blue (B) are arranged in a predetermined order, a protective film, and a transparent electrode film are stacked in this order from the side close to the transparent substrate. An alignment film is provided on the inner surface side of the color filter and the electrode substrate facing the color filter. Further, a spacer is provided in the gap portion in order to maintain a constant and uniform cell gap between the color filter and the electrode substrate. As the spacer, pearls having a constant particle diameter are dispersed, or columnar spacers having a height corresponding to the cell gap are arranged on the inner surface side of the color filter in an area overlapping with the position where the black matrix layer is formed. Form. 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.

  As a conventional method for forming pixels of a color filter or the like with a predetermined pattern shape, there 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, this process is repeated three times to form R, G, and B color filter layers. 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 for 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.
In the case where a pixel is formed by spraying colored ink on a substrate by an inkjet method, an end portion of the pixel may rise. In this way, when the thick film portion is larger than the average film thickness in the pixel, the pixel of the thick film portion becomes darker or cracks are likely to occur, so that ITO film formation failure occurs and causes disconnection, etc. The problem of poor display occurs. Furthermore, there arises a problem that the gap of the liquid crystal layer cannot be accurately taken.

In Patent Document 2, as means for solving the problem that the thick film portion formed at the edge of the coating surface is not formed in the slit coat method when forming the pixel of the color filter, the coloring pigment, the acrylic monomer, the acrylic type In the polymerizable composition for a color filter mainly composed of a resin, a photopolymerization initiator, a diluent solvent, and a surfactant, the surfactant has a phenyl group and a molecular weight of 3 × 10 ³ to 4 × 10 ³ . Disclosed is a polymerizable composition for a color filter using a silicon-based surfactant. However, when a silicon-based surfactant is used for the pixel, there is a problem in recoatability such that the volume resistance value increases and a problem occurs in the electrical characteristics, or the overcoat layer formed thereon is easily repelled. There is.
Japanese Patent Laid-Open No. 9-21910 JP 2004-29261 A

The present invention has been accomplished in view of the above-described actual circumstances, and a first object thereof is a color filter capable of forming a hardened layer that is unlikely to have a thick film portion at the pixel end and that has good electrical characteristics and recoatability. It is to provide an inkjet ink.
A second object of the present invention is to provide a color filter manufacturing method capable of obtaining a color filter in which a thick film portion is unlikely to be formed at an end portion of a pixel and a display defect problem is unlikely to occur.
The third object of the present invention is to provide a method of manufacturing a liquid crystal display device using a method of manufacturing a color filter that achieves the above object.

As a result of intensive studies in order to solve the above problems, the present inventors have found that an inkjet ink for a color filter using an epoxy compound, a specific polyvalent carboxylic acid derivative and a specific vinyl ether surfactant is a pixel end portion. As a result, the inventors have obtained the knowledge that it is possible to obtain a color filter in which a thick film portion is hardly formed and a display defect problem is hardly generated, and the present invention has been completed.
That is, the present invention includes the following [1] to [6].

[1] (A) an epoxy compound having two or more epoxy groups in one molecule, the vinyl groups of (B) a carboxyl group of a carboxylic acid having the structure of Formula (1) (b1), a vinyl ether compound (b2) An ink-jet ink for a color filter, which comprises a latent polyvalent carboxylic acid derivative obtained by reacting with a surfactant, (C) a vinyl ether surfactant, (D) a pigment, and (E) a solvent.

(The six-membered ring in the formula is an aromatic or alicyclic hydrocarbon. M1 is an integer of 0 to 4, t1 is an integer of 0 to 1, and n is an integer of 1 to 4. When n is 1, R ¹ is a hydrogen atom or a hydrocarbon group having 2 to 8 carbon atoms, and when n is 2 to 4, R ¹ is a hydrocarbon group having 2 to 8 carbon atoms. R ² is an alkyl group having 1 to 5 carbon atoms.)

[2] The inkjet ink for a color filter according to the above [1], wherein the content of the vinyl ether surfactant (C) is 0.05 to 1.25% by weight based on the entire solid content.

[3] The solvent (E) contains, as a main solvent, a solvent component having a boiling point of 180 to 260 ° C. and a vapor pressure of 0.5 mmHg or less at room temperature in a proportion of 80% by weight or more based on the total amount of the solvent. The inkjet ink for a color filter according to the above [1] or [2].

[4] A step of selectively depositing the color filter inkjet ink according to any one of [1] to [3] on a predetermined region on a substrate by an inkjet method to form an ink layer; And a step of curing the layer to form a colored cured layer.

[5] The method further includes a step of selectively changing the wettability of a predetermined area of the substrate surface to form an ink layer forming area having a higher ink affinity than the surrounding area, and the ink layer forming area includes the above [ [1] The method for producing a color filter according to [4], wherein the ink layer is formed by selectively attaching the inkjet ink for a color filter according to any one of [3] by an inkjet method.

[6] A step of manufacturing a color filter using the method for manufacturing a color filter according to [4] or [5], and a step of assembling the manufactured color filter and the liquid crystal driving side substrate to face each other. And manufacturing method of liquid crystal display device.

The inkjet ink for a color filter of the present invention can form a hardened layer that is unlikely to have a thick film portion at the pixel end and that has good electrical characteristics and recoatability. Furthermore, since the epoxy compound (A) and the polyvalent carboxylic acid derivative (B) are used as the essential components of the binder, the reaction point of the carboxyl group can coexist with the epoxy group at a high concentration in the ink. When an ink layer is formed using ink and heated, a high crosslink density is obtained, and the straightness in the ejection direction from the ink jet head and the stability of the ejection amount are excellent, and in the ink state, it is long from immediately after preparation. It keeps a good viscosity over a period of time and has excellent storage stability. Furthermore, since the vinyl ether surfactant (C) having good miscibility with the polyvalent carboxylic acid derivative (B) is used, it is possible to reduce the swell of the pixel end.
In addition, according to the method for manufacturing a color filter of the present invention, it is possible to obtain a color filter in which a thick film portion hardly occurs at the pixel end portion and display defects are reduced. In addition, since the manufacturing method uses an inkjet method, cost reduction and yield improvement can be realized. Furthermore, a colored hardened layer having a high crosslinking density and excellent heat resistance can be obtained.
In addition, according to the method for manufacturing a liquid crystal display device of the present invention, since a process for obtaining a color filter with reduced display defects is used, a high-quality liquid crystal display device can be obtained.

The present invention is described in detail below.
1. Ink-jet ink for color filter The ink-jet ink for color filter of the present invention comprises (A) an epoxy compound having two or more epoxy groups in one molecule, and (B) a carboxylic acid (b1) having a structure of the following formula (1). It contains a polyvalent carboxylic acid derivative made latent by the vinyl ether compound (b2), (C) a vinyl ether surfactant, (D) a pigment, and (E) a solvent.

（式中の６員環は芳香族又は脂環式の炭化水素である。ｍ１は０〜４の整数であり、ｔ１は０〜１の整数であり、ｎは１〜４の整数である。また、ｎが１の場合にはＲ¹は水素原子又は炭素数２〜８の炭化水素基であり、ｎが２〜４の場合にはＲ¹は炭素数２〜８の炭化水素基である。Ｒ²は、炭素数１〜５のアルキル基である。）
本発明によれば、ビニルエーテル系界面活性剤を用いることにより、膜表面全体に当該界面活性剤が拡散し、画素部全体において表面張力が適切なレベルまで下がり、更に表面からの溶剤の蒸発が均一化され、粘度の高低差が抑えられるため、乾燥過程における溶質の流れがなくなる又は緩和され、その結果、画素端部の盛り上がりが低減されると推定される。また、本発明によれば、ビニルエーテル系界面活性剤を用いることにより、電気特性や、画素上に形成されるオーバーコート層におけるリコート性に問題が生じないという利点を有する。

(The six-membered ring in the formula is an aromatic or alicyclic hydrocarbon. M1 is an integer of 0 to 4, t1 is an integer of 0 to 1, and n is an integer of 1 to 4. When n is 1, R ¹ is a hydrogen atom or a hydrocarbon group having 2 to 8 carbon atoms, and when n is 2 to 4, R ¹ is a hydrocarbon group having 2 to 8 carbon atoms. R ² is an alkyl group having 1 to 5 carbon atoms.)
According to the present invention, by using a vinyl ether surfactant, the surfactant is diffused over the entire film surface, the surface tension is lowered to an appropriate level in the entire pixel portion, and the evaporation of the solvent from the surface is uniform. Therefore, it is presumed that the solute flow in the drying process is eliminated or alleviated, and as a result, the rise of the pixel end is reduced. In addition, according to the present invention, by using a vinyl ether surfactant, there is an advantage that there is no problem in electrical characteristics and recoatability in an overcoat layer formed on a pixel.

Hereinafter, components used in the inkjet ink for a color filter of the present invention will be described.
<Binder system>
In the present invention, a binder system having an epoxy compound (A) having two or more epoxy groups in one molecule and a polyvalent carboxylic acid derivative (B) as essential components is used. This binder system has excellent storage stability despite the coexistence of the reactive group of the carboxyl group with the epoxy group at a high concentration, so that it is difficult to increase viscosity during ejection from the inkjet type ejection head, and is stable. Therefore, it is difficult to cause flight bending in the discharge direction and clogging of the discharge head.

<(A) Epoxy compound having two or more epoxy groups in one molecule>
(A) An epoxy compound having two or more epoxy groups in one molecule (hereinafter referred to as component (A) or epoxy compound (A)) has two or more epoxy groups, preferably 2 to 50, more preferably Is an epoxy compound (including an epoxy resin) having 2 to 20 in one molecule. The epoxy group should just be a structure which has an oxirane ring structure, for example, can show a glycidyl group, an oxyethylene group, an epoxycyclohexyl group, etc.
As the epoxy compound (A), an epoxy group-containing polymer (A1) polymerized using at least a monomer containing a carbon-carbon unsaturated bond and an epoxy group, an epoxy group-containing compound (A2) having two or more epoxy groups ).

  The epoxy group-containing polymer (A1) used in the present invention is a polymer using at least a monomer containing a carbon-carbon unsaturated bond and an epoxy group (hereinafter sometimes referred to as an epoxy group-containing monomer). It can be obtained by polymerizing the containing monomer alone or by copolymerizing an epoxy group-containing monomer and another monomer. The molecular form may be linear or may have a branched structure, and may be any form such as a random copolymer, a block copolymer, or a graft copolymer.

The epoxy group-containing polymer (A1) used in the present invention can be polymerized by an ordinary polymerization method. That is, the polymerization method is not particularly limited, and a polymerization method such as radical polymerization or ionic polymerization can be employed. More specifically, in the presence of a polymerization initiator, a bulk polymerization method, a solution polymerization method, a suspension polymerization method, A polymerization method such as an emulsion polymerization method can be employed. Depending on the polymerization method, a large amount of monomer may remain, but when this monomer affects the physical properties of the cured layer, the monomer may be removed by a vacuum distillation method, a reprecipitation purification method, or the like.
Preferred examples of the epoxy group-containing polymer (A1) used in the present invention include those having structural units represented by the following formulas (2) to (4) as epoxy group-containing structural units.

(In the formula, R ³ is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, R ⁴ is a hydrogen atom or an alkyl group having 1 to 2 carbon atoms, and p1 = 1 to 8 is an integer.)

(In the formula, R ⁵ is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, R ⁶ is a —CH ₂ O— group or —CH ₂ — group, and R ⁷ is a hydrogen atom or an alkyl group having 1 to 2 carbon atoms. Yes, and q1 is an integer of 0 to 7.)

(R ⁸ in the formula is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and r1 = 1 to 8 is an integer.)

  The epoxy group-containing polymer (A1) used in the present invention may further have a structure represented by the following formulas (5) to (7) as its structural unit.

(In the formula, R ⁹ is a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, R ¹⁰ is an alkyl group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 12 carbon atoms in the main ring, and aromatic. An aromatic hydrocarbon group, an aryl group, an aryloxy group, or an aromatic polyalkylene glycol residue.)

(In the formula, R ¹¹ is a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, and R ¹² is a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, an alkoxy group, a siloxyalkyl group, or an aromatic hydrocarbon group. is there.)

(In the formula, R ¹³ is an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group, or an aromatic hydrocarbon group.)
The structural units represented by the formulas (2) to (4) are derived from monomers represented by the following formulas (8) to (10), respectively.

(In the formula, R ¹⁴ is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, R ¹⁵ is a hydrogen atom or an alkyl group having 1 to 2 carbon atoms, and p2 = 1 to 8 is an integer.)
In the formula (8), R ¹⁴ and R ¹⁵ are each independently preferably a hydrogen atom or a methyl group, and p2 is preferably an integer of 1 to 3. Specific examples of the monomer represented by the formula (8) include glycidyl (meth) acrylate and β-methylglycidyl (meth) acrylate. Among them, glycidyl methacrylate (hereinafter, GMA) is available. It is preferable from the aspect of property. In the present invention, (meth) acrylate means that either acrylate or methacrylate may be used.

(In the formula, R ¹⁶ is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, R ¹⁷ is a —CH ₂ O— group or —CH ₂ — group, and R ¹⁸ is a hydrogen atom or an alkyl group having 1 to 2 carbon atoms. Yes, and q2 is an integer from 0 to 7.)
In the formula (9), R ¹⁶ and R ¹⁸ are each independently preferably a hydrogen atom or a methyl group, R ¹⁷ is preferably a —CH ₂ O— group, and q 2 is preferably 1. It is an integer of ~ 3. As the monomer represented by the formula (9), o-vinyl benzyl glycidyl ether, m-vinyl benzyl glycidyl ether, and p-vinyl benzyl glycidyl ether are preferable from the viewpoint of availability.

(In the formula, R ¹⁹ is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and r2 = 1 to 8 is an integer.)
In Formula (10), R ¹⁹ is preferably a hydrogen atom or a methyl group. As the monomer represented by the formula (10), 3,4-epoxycyclohexylmethyl methacrylate is preferable from the viewpoint of cured layer properties such as hardness.
The structural units represented by the formulas (5) to (7) are derived from monomers represented by the following formulas (11) to (13).

(In the formula, R ²⁰ is a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, R ²¹ is an alkyl group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 12 carbon atoms in the main ring, and aromatic. An aromatic hydrocarbon group, an aryl group, an aryloxy group, or an aromatic polyalkylene glycol residue.)
In the formula (11), when R ²¹ is represented by an alicyclic hydrocarbon group having 3 to 12 carbon atoms constituting the main ring, the alicyclic hydrocarbon group has an additional structure, for example, an intracyclic double group. It may contain a bond, a side chain of a hydrocarbon group, a side chain of a spiro ring, an intra-ring bridged hydrocarbon group, or the like.

In the formula (11), R ²⁰ is preferably hydrogen or a methyl group, and R ¹⁹ is preferably a cyclohexyl group or a dicyclopentenyl group. Specifically, as a monomer represented by Formula (11), cyclohexyl methacrylate and dicyclopentenyl methacrylate are preferable from the viewpoint of cured layer properties such as hardness and heat resistance.

(In the formula, R ²² is a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, and R ²³ is a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, an alkoxy group, a siloxyalkyl group, or an aromatic hydrocarbon group. is there.)
In the formula (12), R ²² is preferably hydrogen or a methyl group, and R ²³ is preferably a phenyl group. Specifically, as the monomer represented by the formula (12), styrene is preferable from the viewpoint of copolymerization with other monomers and availability.

(In the formula, R ²⁴ represents an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group, or an aromatic hydrocarbon group.)
In the formula (13), R ²⁴ is preferably a cyclohexyl group or a phenyl group. Specifically, as the monomer represented by the formula (13), N-cyclohexylmaleimide and N-phenylmaleimide are preferable from the viewpoint of cured layer properties such as hardness and heat resistance.

  The epoxy group-containing polymer (A1) in the resin composition of the present invention is an epoxy group-containing structure represented by the above formulas (2) to (4) as long as the epoxy equivalent is 140 to 1000 g / mol. It is preferable that at least one of the units is 10 to 100% by weight, more preferably 20 to 100% by weight, and particularly preferably 40 to 70% by weight in the epoxy group-containing polymer (A1). If the epoxy group-containing constitutional unit is less than 10% by weight, the cured layer may be poor in toughness.

  The weight average molecular weight of the epoxy group-containing polymer (A1) is preferably in the range of 2,000 to 20,000, and in the range of 3,000 to 15,000, when expressed in terms of polystyrene equivalent weight average molecular weight. It is more preferable. When the molecular weight of the epoxy group-containing polymer (A1) is less than 2,000, physical properties such as strength and solvent resistance required for the cured layer as details of the color filter are likely to be insufficient, while the molecular weight is 20, If it exceeds 000, the viscosity tends to increase, and the stability of the ejection amount when ejected from the ejection head and the straightness in the ejection direction may be deteriorated, and the storage stability may be deteriorated.

  As a synthesis example of the epoxy group-containing polymer (A1), a solvent containing no hydroxyl group was charged into a four-necked flask equipped with a thermometer, a reflux condenser, a stirrer, and a dropping funnel, and the temperature was raised to 115 ° C. while stirring. To do. The reason for using a solvent that does not contain a hydroxyl group is to avoid reaction and ring opening of the epoxy group during the synthesis reaction. Subsequently, the mixture (dropping component) of a monomer and a polymerization initiator is dropped at a constant rate from a dropping funnel over 2 hours. After completion of dropping, the mixture is maintained at 115 ° C. for 2 hours, then heated to 125 ° C., and the reaction is terminated when the temperature is maintained for 2 hours, whereby an epoxy group-containing polymer (A1) is obtained.

  The epoxy group-containing compound (A2) used in the present invention has two or more epoxy groups in the molecule. Specifically, 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 novolak type epoxy resin, orthocresol novolak type epoxy resin, trishydroxyphenylmethane type epoxy resin, trifunctional type epoxy resin, tetraphenylolethane type epoxy resin, dicyclopentadiene phenol type epoxy resin, Hydrogenated bisphenol A type epoxy resin, bisphenol A nucleated polyol type epoxy resin, polypropylene glycol type epoxy resin, glycidyl ester Epoxy resins, glycidyl amine type epoxy resin, glyoxal type epoxy resins, alicyclic epoxy resins, and heterocyclic epoxy resins.

Among these polyfunctional epoxy resins, bisphenol A type novolac epoxy resins such as trade name Epicoat 828 (made by Japan Epoxy Resin Co., Ltd.), trade name Epicoat 157S70 (made by Japan Epoxy Resin Co., Ltd.), and trade names A cresol novolac type epoxy resin such as YDCN-701 (manufactured by Toto Kasei Co., Ltd.) is particularly preferred.
The epoxy group-containing compound (A2) used in the present invention can be used alone or in combination of two or more.

<(B) Multivalent carboxylic acid derivative>
The polyvalent carboxylic acid derivative (B) in the inkjet ink for a color filter of the present invention is a vinyl ether compound (b2) in which the carboxyl group of the carboxylic acid (b1) having the structure of the following formula (1) is represented by the following formula (14). ) (Compound containing vinyl group and ether group) latent (hereinafter sometimes referred to as blocking).

（式中の６員環は芳香族又は脂環式の炭化水素である。ｍ１は０〜４の整数であり、ｔ１は０〜１の整数であり、ｎは１〜４の整数である。また、ｎが１の場合にはＲ¹は水素原子又は炭素数２〜８の炭化水素基であり、ｎが２〜４の場合にはＲ¹は炭素数２〜８の炭化水素基である。Ｒ²は、炭素数１〜５のアルキル基である。）

(The six-membered ring in the formula is an aromatic or alicyclic hydrocarbon. M1 is an integer of 0 to 4, t1 is an integer of 0 to 1, and n is an integer of 1 to 4. When n is 1, R ¹ is a hydrogen atom or a hydrocarbon group having 2 to 8 carbon atoms, and when n is 2 to 4, R ¹ is a hydrocarbon group having 2 to 8 carbon atoms. R ² is an alkyl group having 1 to 5 carbon atoms.)

（式中のＲ^２５は炭素数１〜１０の炭化水素基である。）

(R ²⁵ in the formula is a hydrocarbon group having 1 to 10 carbon atoms.)

Of the carboxylic acid (c1) represented by the formula (1), examples of the compound in which R ¹ is other than a hydrogen atom include a half ester obtained by a reaction between an alcohol compound and an acid anhydride.
Examples of alcohol compounds used in this reaction include monovalent alcohol compounds such as ethanol, propanol, hexanol, octanol, and isopropyl alcohol; ethylene glycol, propylene glycol, butanediol, hexanediol, neopentyl glycol, cyclohexanediol, and the like. Preferred examples include trivalent alcohol compounds such as glycerin, pentanetriol, hexanetriol, cyclohexanetriol, and trimethylolpropane; and tetravalent alcohol compounds such as pentaerythritol, more preferably hexanol. , Isopropyl alcohol, 1,2-propylene glycol, 1,3-propylene glycol, 1,6-hexanediol, glycerin, trimethylo Trimethylolpropane, pentaerythritol.

  In addition, examples of the acid anhydride used in this reaction include compounds represented by the following formula (15). Specifically, phthalic anhydride, 1,2-cyclohexanedicarboxylic acid anhydride, 1,2 Preferred examples include 1,4-benzenetricarboxylic anhydride (hereinafter sometimes referred to as trimellitic anhydride), 1,2,4-cyclohexanetricarboxylic anhydride, and methylhexahydrophthalic anhydride. In the above half ester body, a cured layer having a high crosslink density and high adhesion is obtained, so that a polyhydric alcohol having 3 to 6 carbon atoms and a trihydric anhydride or methylhexahydroanhydride is obtained. What is obtained by a combination with phthalic acid is preferably exemplified as (b1). Among them, methylhexahydrophthalic anhydride is preferably selected from the viewpoints of transparency and storage stability.

（式中の６員環は芳香族又は脂環式の炭化水素である。ｍ１は０〜２の整数であり、ｔ１は、０〜１の整数である。Ｒ²は、炭素数１〜５のアルキル基である。）

(6-membered ring in formula is an integer of .m1 is 0-2 aromatic or alicyclic hydrocarbons, t1 is an integer of 0 to 1 .R ² is C1-5 The alkyl group of

Among the carboxylic acids (b1) represented by the formula (1), the compound in which R ¹ is a hydrogen atom includes the formula (16) or the formula (17), and these polycarboxylic acids obtained by blocking these carboxylic acids. Since the acid derivative (B) has a high dissolving power, it is preferably used in combination with (A1) or (A2) having low compatibility.

（式中のｍ２は０〜２の整数である。）

(In the formula, m2 is an integer of 0 to 2.)

（式中のｍ３は０〜２の整数であり、ｔ２は０〜１の整数である。Ｒ²は、炭素数１〜５のアルキル基である。）
上記式（１６）または（１７）で表されるカルボン酸（ｂ１）としては、フタル酸等の芳香族ジカルボン酸；シクロヘキサンジカルボン酸等の脂環式ジカルボン酸；１，２，４−ベンゼントリカルボン酸（以下、トリメリット酸）等の芳香族トリカルボン酸；１，２，４−シクロヘキサントリカルボン酸（以下、ＣＨＴＡ）などの脂環式トリカルボン酸；ベンゼンテトラカルボン酸（ピロメリット酸）等の芳香族テトラカルボン酸；シクロヘキサンテトラカルボン酸などの脂環式テトラカルボン酸が挙げられる。中でもトリメリット酸、ＣＨＴＡ、ピロメリット酸が架橋密度、および密着性の高い硬化層が得られることから、（ｂ１）として好ましい。
本発明のカラーフィルター用インクジェットインクにおいて（ｂ１）として用いることができるカルボン酸は１種単独で、または２種以上を組み合わせて用いることができる。

(An integer of m3 is 0 to 2 in the formula, t2 is an integer of 0 to 1 .R ² is an alkyl group having 1 to 5 carbon atoms.)
Examples of the carboxylic acid (b1) represented by the above formula (16) or (17) include aromatic dicarboxylic acids such as phthalic acid; alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid; 1,2,4-benzenetricarboxylic acid Aromatic tricarboxylic acids such as (hereinafter referred to as trimellitic acid); Alicyclic tricarboxylic acids such as 1,2,4-cyclohexanetricarboxylic acid (hereinafter referred to as CHTA); Aromatic tetracarboxylic acids such as benzenetetracarboxylic acid (pyromellitic acid) Carboxylic acid; alicyclic tetracarboxylic acid such as cyclohexanetetracarboxylic acid. Among these, trimellitic acid, CHTA, and pyromellitic acid are preferable as (b1) because a cured layer having a high crosslinking density and high adhesion can be obtained.
The carboxylic acid that can be used as (b1) in the inkjet ink for a color filter of the present invention can be used alone or in combination of two or more.

  On the other hand, examples of the vinyl ether compound (b2) represented by the formula (14) that is a raw material of the polyvalent carboxylic acid derivative (B) in the inkjet ink for a color filter of the present invention include isopropyl vinyl ether, n-propyl vinyl ether, n Examples thereof include alkyl vinyl ethers such as butyl vinyl ether, isobutyl vinyl ether, t-butyl vinyl ether, 2-ethylhexyl vinyl ether, and cyclohexyl vinyl ether. Examples of the vinyl ether compound (b2) that can be suitably used in the inkjet ink for a color filter of the present invention include isopropyl vinyl ether and n-propyl vinyl ether, which can be used alone or in combination of two or more. .

  The polyvalent carboxylic acid derivative (B) used in the present invention can be obtained by reacting the carboxylic acid (b1) with the vinyl ether compound (b2) at a temperature ranging from room temperature to 150 ° C. . Since the blocking reaction is an equilibrium reaction, the reaction is promoted and the yield can be improved by using a little more vinyl ether compound (b2) than carboxylic acid (b1). Specifically, the molar equivalent ratio of the vinyl group of the vinyl ether compound (b2) to the carboxyl group of the carboxylic acid (b1) is desirably 1/1 to 2/1. When this molar equivalent ratio exceeds 2/1, the reaction temperature cannot be increased, and the reaction rate may be extremely low.

<Binder mix ratio>
The blending ratio of the epoxy group-containing polymer (A1), the epoxy group-containing compound (A2), and the polyvalent carboxylic acid derivative (B) is 10 to 80 parts by weight of the epoxy group-containing polymer (A1) by weight ratio. It is preferable to mix 10 to 60 parts by weight of the epoxy group-containing compound (A2) and 10 to 60 parts by weight of the polyvalent carboxylic acid derivative (B), and 20 to 60 parts of the epoxy group-containing polymer (A1). More preferably, 20 to 50 parts by weight of the epoxy group-containing compound (A2) and 20 to 50 parts by weight of the polyvalent carboxylic acid derivative (B) are blended, and the epoxy group-containing polymer (A1). 30 to 40 parts by weight, 25 to 35 parts by weight of the epoxy group-containing compound (A2), and 35 to 45 parts by weight of the polyvalent carboxylic acid derivative (B) are more preferable.

  The ratio of the total amount of the epoxy group-containing polymer (A1) and the epoxy group-containing compound (A2) and the amount of the polyvalent carboxylic acid derivative (B) is preferably in the following range. Molar concentration of carboxyl group generated after elimination (delatentization, deblocking) of vinyl ether compound of polyvalent carboxylic acid derivative (B), and epoxy of epoxy group-containing polymer (A1) and epoxy group-containing compound (A2) It is preferable to set the amount so that the ratio (carboxyl group / epoxy group) to the molar concentration of the group is 0.2 / 1.0 to 1.6 / 1.0, and the more preferable molar concentration ratio is 0.00. 5 / 1.0 to 1.2 / 1.0. If the molar concentration ratio between the carboxyl group and the epoxy group is less than 0.2 / 1.0, a large amount of the epoxy group remains after curing, so that the crosslinking density is lowered and the effect of the present invention may not be obtained. There is. On the other hand, if the molar concentration ratio between the carboxyl group and the epoxy group exceeds 1.6 / 1.0, the carboxyl group becomes excessive, and the physical properties of the resin are often lowered. In addition, as an additional component not included in (A1), (A2), and (B) which is an essential component in the inkjet ink for a color filter of the present invention, a functional group capable of reacting with a carboxyl group and a carboxyl group including an epoxy group When adding a compound containing carboxylic acid, the ratio of the molar concentration of the carboxyl group in the composition to the molar concentration of the functional group capable of reacting with the carboxyl group containing an epoxy group should be in the above range. Is preferred.

  Moreover, in order to provide sufficient adhesion, strength, and hardness to the cured layer, the epoxy group-containing polymer (A1) and the epoxy group-containing compound (A2) occupying the total solid content of the ink including pigments and other components. ) And the polycarboxylic acid derivative (B) in a total ratio of 50 wt% to 98.95 wt% is preferable. Here, the solid content of the ink for specifying the blending ratio includes all components except the solvent, and liquid polyfunctional epoxy resin and the like are also included in the solid content.

<(C) Vinyl ether surfactant>
The inkjet ink for a color filter of the present invention contains a vinyl ether surfactant (C) as an essential component. Here, the vinyl ether surfactant (C) is a surfactant made of a polymer obtained using a vinyl ether monomer. By using this, the surfactant diffuses over the entire film surface, and the surface tension is lowered to an appropriate level due to good miscibility with the polyvalent carboxylic acid derivative (B) in the entire pixel portion. Furthermore, since the evaporation of the solvent from the surface is made uniform and the difference in viscosity is suppressed, the flow of the solute in the drying process is eliminated or alleviated, and as a result, the swell of the pixel end is reduced. The effect was obtained.
The vinyl ether monomer used in the vinyl ether surfactant (C) is preferably an alkyl vinyl ether represented by the formula (18).

(R ²⁶ in the formula is 1 to 8 linear or branched hydrocarbons.)

R ²⁶ in the formula (18) is a linear or branched hydrocarbon having 1 to 8 carbon atoms. Preferably, it is a linear or branched hydrocarbon having 3 to 4 carbon atoms, more preferably 4 carbon atoms. If the number of carbon atoms exceeds 8, the solubility of the polymer in a solvent or the like may decrease. Examples of the alkyl vinyl ether include methyl vinyl ether, ethyl vinyl ether, n-propyl vinyl ether, isopropyl vinyl ether, n-butyl vinyl ether, isobutyl vinyl ether, t-butyl vinyl ether, pentyl vinyl ether, hexyl vinyl ether, 2-ethylhexyl vinyl ether, among others. A vinyl ether surfactant using isobutyl vinyl ether as the vinyl ether monomer is preferred from the viewpoint of making it difficult to form a thick film portion at the end.

  In the vinyl ether surfactant (C), the vinyl ether monomer and other monomers may be used for copolymerization. As copolymerizable monomers, nitrogen-containing vinyl ethers such as diethylaminoethyl vinyl ether, dimethylaminoethyl vinyl ether and morpholine ethyl vinyl ether; vinyl esters such as vinyl acetate; allyl ethers such as allyl phenyl ether; allyl esters such as allyl acetate , Maleimides such as N-phenylmaleimide and N-cyclohexylmaleimide; fumaric acid diesters such as diisopropyl fumarate and dicyclohexyl fumarate; maleic anhydride; itaconic anhydride and the like. As the polymerization method, a polymerization method such as radical polymerization or ionic polymerization can be employed. The alkyl vinyl ether represented by the formula (18) is preferably contained in an amount of 70 to 100% by weight, more preferably 80 to 100% by weight, based on the whole monomer to be polymerized. When the amount is less than 70 parts by weight, an appropriate effect does not appear, and the end portion may be thick.

  The vinyl ether surfactant (C) preferably has a weight average molecular weight of 1,000 to 10,000, more preferably 1,500 to 5,000, from the viewpoint of the effect of making it difficult to form a thick film portion at the end. . In addition, the weight average molecular weight in this invention is calculated | required by polystyrene conversion in GPC measurement.

Further, the SP value of the vinyl ether surfactant (C) is preferably 8 to 9, and more preferably 8 to 8.5 from the viewpoint of the effect of making it difficult to form a thick film portion at the end. In the case of the inkjet ink for a color filter according to the present invention, since the carboxyl group is latent, it is excellent in solubility with the above vinyl ether surfactant, and further the vinyl ether surfactant is bound by deblocking when heated. It becomes easy to collect in the vicinity of the surface without being compatible with each other, the surfactant is diffused over the entire surface of the coating film, the surface tension of the entire coating film surface is set to an appropriate level, and the drying from the coating film surface is made uniform. It is estimated that it becomes easy.
Here, the SP value is an index indicating the compatibility and incompatibility between substances. If the difference in SP value between the two substances to be mixed is small, the compatibility and solubility are large, and the solubility becomes easy. On the other hand, if the difference is large, the compatibility and solubility are small, and it becomes hardly soluble to insoluble.

  There are several methods for measuring and calculating the SP value. In the present invention, "Specific Interactions and the Miscibility of" written by Michael M. Coleman, John F. Graf, Paul C. Painter (Pennsylvania State Univ.) The calculation method described in Polymer Blends "(1991), Technomic Publishing Co. is used. However, since -COOH group and -OH group are not described, the values described in Polymer Engineering and Science, 14 (2), 147 (1974) written by R. F. Fedors are used. For example, in the case of polyvinyl isobutyl ether, the SP value is 8.35, and in the case of polyvinyl isopropyl ether, the SP value is 8.31.

The content of the vinyl ether surfactant (C) is 0.05 to 1.25% by weight based on the entire solid content, and further 0.10 to 1.00% by weight based on the entire solid content. It is preferable from the viewpoint of making it difficult to form a thick film portion at the end. If the amount is less than 0.05% by weight, an appropriate effect may not appear, and the end may become a thick film. On the other hand, if the amount exceeds 1.25% by weight, the end of the coating becomes too low and the pixel end There is a possibility that white spots may occur in the portion, and there is a possibility that the volume resistance and recoatability are inferior. The content of the vinyl ether surfactant (C) is expressed as the solid content of the vinyl ether surfactant.

<(D) Pigment>
The pigment (D) as a colorant is selected from organic colorants and inorganic colorants according to the color required by the pixel (pixel part) R, G, B, etc. and the black matrix layer. can do. 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 organic pigments include compounds classified as Pigments in the Color Index (CI; published by The Society of Dyers and Colorists), specifically those with a Color Index (CI) number. Can be mentioned.

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 oxide (III)), cadmium red, ultramarine blue, Examples include bitumen, chromium oxide green, cobalt green, amber, titanium black, synthetic iron black, and carbon black. In this invention, a pigment can be used individually or in mixture of 2 or more types.
When forming the pattern of the black matrix layer on the substrate of the color filter using the inkjet ink of the present invention, a black pigment having a high light shielding property is blended in the inkjet ink. As the black pigment having a high light shielding property, for example, an inorganic colorant such as carbon black or iron trioxide, or an organic colorant such as cyanine black can be used.

  When forming a pixel, the pigment (D) is usually blended in a proportion of 1 to 60% by weight, preferably 15 to 40% by weight, based on the total solid content of the inkjet ink. When the pigment (D) is less than 1% by weight, the light transmission density when the inkjet ink is applied to a predetermined film thickness (usually 0.1 to 2.0 μm) may not be sufficient. Further, when the pigment (D) exceeds 60% by weight, it is a coating film such as adhesion to the substrate when the ink-jet ink is applied on the substrate and cured, surface roughness of the cured film, coating film hardness, etc. There is a risk that the characteristics of the above will be insufficient.

<(E) Solvent>
In order to prepare the ink for a color filter of the present invention so that the ink can be discharged from a high-concentration liquid or immediately from the head, a solvent (E) is blended.
The inkjet ink of the present invention has a boiling point of 180 ° C. to 260 ° C., particularly 210 ° C. to 260 ° C., and a vapor pressure at room temperature (especially in the range of 18 ° C. to 25 ° C.) of 0.5 mmHg or less, particularly 0.1 mmHg or less. It is preferable to use a solvent component as a main solvent and to mix such a main solvent in a proportion of 80% by weight or more based on the total amount of the solvent. The surface tension of the main solvent is preferably 29 mN / m or more.

A solvent component having a boiling point of 180 ° C. to 260 ° C. and a vapor pressure at room temperature of 0.5 mmHg or less has an appropriate drying property and evaporation property. For this reason, if a single solvent or mixed solvent containing such a solvent component in a high blending ratio is used, the inkjet ink does not dry rapidly at the nozzle tip of the discharge head, causing a sudden increase in viscosity or clogging of the ink. Does not adversely affect the straightness and stability of discharge. At the same time, since the drying proceeds at an appropriate speed after spraying on the surface to be ejected, the ink becomes familiar with the surface to be coated and the surface of the coating film becomes horizontal and smooth, followed by natural drying or a general heating process. The ink can be dried quickly and completely. Compared to the case of using a wetting agent or a solvent having a very high boiling point, there is less possibility that the solvent remains in the coating film after the drying step.

If necessary, the solvent (E) may contain a small amount of a solvent component other than the main solvent. However, even in that case, it is preferable to use the main solvent having the above boiling point and vapor pressure at a ratio of 80% by weight or more based on the total amount of the solvent. When the ratio of the main solvent is less than 80% by weight of the total amount of the solvent, there are cases where it is not possible to reliably obtain the drying property and the evaporation property suitable for the ink jet method.
It is desirable to use the main solvent at a blending ratio as high as possible, specifically 80 wt% or more, and desirably 100 wt% as much as possible.
By forming a wettability variable layer on the surface of the substrate and exposing it, an ink-philic region is formed on a portion of the substrate where the ink layer is to be formed, and the inkjet ink of the present invention is selectively applied to the ink-philic region by the inkjet method. When using the standard solution shown in JIS K 6768: 1999 “Plastic-Film and Sheet-Wetting Tension Test Method” as the main solvent, the contact angle ( θ) was measured, and the contact angle with respect to the surface of the test piece having a critical surface tension of 30 mN / m determined from the graph of the Zisman plot was 25 ° or more, preferably 30 ° or more, and was obtained by the same measurement method. You may select and use what the contact angle with respect to the surface of the test piece whose critical surface tension is 70 mN / m is 10 degrees or less.

When an ink is prepared using a solvent that exhibits the above behavior with respect to wettability, the ink exhibits a large repellent property with respect to the surface of the wettability variable layer before changing the wettability of the wettability variable layer described later. After changing the wettability of the wettability variable layer to increase the hydrophilicity, the wettability variable layer shows a great affinity for the surface of the wettability variable layer. Therefore, the difference between the wettability of the ink with respect to the ink-philic region formed by selectively exposing a part of the surface of the wettability variable layer and the wettability of the ink repellent region with respect to the surrounding region can be increased. As a result, the ink sprayed onto the ink-philic area by the ink jet method spreads evenly to every corner of the ink-philic area. As a result, a fine and precise ink layer pattern can be formed by the inkjet method.
Here, the test piece having the above characteristics with respect to the critical surface tension may be formed of any material. Examples of test pieces having a critical surface tension of 30 mN / m include, for example, polymethyl methacrylate, polyvinyl chloride, polyvinylidene chloride, polyethylene terephthalate having a smooth surface, and the polymer or surface modifier applied on a smooth glass surface. The above test can be actually performed from among those, and the corresponding one can be selected. Moreover, as a test piece which shows critical surface tension 70mN / m, the said test is actually performed from what apply | coated nylon, the glass surface which hydrophilized, etc., and the applicable thing can be selected.

In addition, since the inkjet ink for color filter of the present invention contains the pigment (D), the main solvent that occupies most of the solvent is one that does not contain a hydroxyl group from the viewpoint of the dispersibility and dispersion stability of the pigment. Is preferably used.

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, succinate Examples thereof include dimethyl acid and diethyl succinate. These solvents are preferable not only because they satisfy the requirements of a boiling point of 180 ° C. to 260 ° C. and a vapor pressure at room temperature of 0.5 mmHg or less, but also have no hydroxyl group in the molecule. Further, these solvents are mixed with a highly dispersible solvent conventionally used for preparing pigment dispersions such as 3-methoxybutyl acetate and propylene glycol monomethyl ether acetate (PGMEA), or left as it is without mixing. A pigment dispersion can be prepared by using as a dispersion solvent.
The above-mentioned solvent exemplified as a preferable solvent is a standard solution shown in the wetting tension test method specified in JIS K 6768: 1999, and a contact angle (θ) after 30 seconds is measured by bringing a droplet into contact with each other. The contact angle with respect to the surface of the test piece having a critical surface tension of 30 mN / m determined by the Manplot graph is 25 ° or more, and the surface of the test piece having a critical surface tension of 70 mN / m determined by the same measurement method. The requirement that the contact angle is 10 ° or less is also satisfied. Therefore, these solvents are mainly used when a wettability variable layer is provided on the surface of a substrate for exposure, and ink jet ink is selectively attached using a difference in wettability between an exposed portion and an unexposed portion. It can be suitably used as a solvent.

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, it is preferable to prepare an inkjet ink using a solvent having low miscibility with water in order to substantially exclude water from the acid-epoxy crosslinking reaction system. 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 main solvents mentioned as specific examples, diethylene glycol monobutyl ether acetate does not have a hydroxyl group, and the solubility in 100 parts by weight of water at a liquid temperature of 20 ° C. is low at 6.5 parts by weight. It is particularly preferable since it exhibits the property.

The solvent is usually used at a ratio 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 solvent is less than 40% by weight, the viscosity of the ink-jet ink is high and it becomes difficult to discharge from the ink-jet head. When the solvent exceeds 95% by weight, the ink film deposited on the wettability changing portion before the ink deposit amount (ink deposition amount) with respect to the predetermined wettability changing portion (ink layer forming portion) is not sufficient. Breaks down, protrudes to the surrounding unexposed areas, and further spreads to the adjacent wettability change site (ink layer formation site). In other words, the amount of ink that can be deposited without protruding from the wettability change site (ink layer forming site) to which the ink is to be deposited becomes insufficient, the film thickness after drying is too thin, The light transmission density cannot be obtained.

<Catalyst>
In order to improve the hardness and heat resistance of the cured layer, a catalyst capable of accelerating the thermosetting reaction between acid and epoxy may be added to the inkjet ink for color filter of the present invention. As such a catalyst, a thermal latent catalyst that exhibits activity during heat curing can be used.

The heat-latent catalyst exhibits catalytic activity when heated, accelerates the curing reaction and gives good properties to the cured product, and is added as necessary. The thermal latent catalyst is preferably one that exhibits acid catalytic activity at a temperature of 60 ° C. or higher. As such, a compound obtained by neutralizing a protonic acid with a Lewis base, a compound obtained by neutralizing a Lewis acid with a Lewis base, Lewis Examples thereof include a mixture of an acid and a trialkyl phosphate, sulfonic acid esters, onium compounds, and the like, and various compounds described in JP-A-4-218561 can be used. Specifically, (i) compounds obtained by neutralizing halogenocarboxylic acids, sulfonic acids, phosphoric acid mono- and diesters with various amines such as ammonia, monomethylamine, triethylamine, pyridine, ethanolamine, or trialkylphosphine (B) compounds obtained by neutralizing Lewis acids such as BF ₃ , FeCl ₃ , SnCl ₄ , AlCl ₃ , ZnCl ₂ with the aforementioned Lewis base, (c) methanesulfonic acid, ethanesulfonic acid, benzenesulfonic acid, etc. Examples include primary alcohols, ester compounds with secondary alcohols, (d) primary alcohols, secondary monoalcohol phosphate monoester compounds, and phosphate diester compounds. Examples of the onium compound include an ammonium compound [R ₃ NR ′] ⁺ X ⁻ , a sulfonium compound [R ₃ SR ′] ⁺ X ⁻ , and an oxonium compound [R ₃ OR ′] ⁺ X ⁻ . Here, R and R ′ are groups such as alkyl, alkenyl, aryl and alkoxy.

The thermal latent catalyst is preferably a halogen-free acidic catalyst from the viewpoint of liquid crystal contamination. Specific examples of the halogen-free acidic catalyst include Nofure LC-1, Nofure LC-2, and Nofure LC-10 (all trade names, manufactured by NOF Corporation).
The heat-latent catalyst is usually 0.01 to 10 parts per 100 parts by weight in total of the epoxy group-containing polymer (A1), the epoxy group-containing compound (A2), and the polyvalent carboxylic acid derivative (B). It is blended at a ratio of about 0 part by weight.

<Pigment dispersant>
The pigment dispersant is blended in the curable resin composition as necessary in order to disperse the pigment satisfactorily. Examples of the pigment dispersant that can be used include cationic, anionic, nonionic, and amphoteric 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 10 to 50% by weight with respect to the entire solid content, and more preferably 15 to 40% by weight with respect to the entire solid content.

<Leveling agent>
As described above, (C) used in the present invention also has an action as a leveling agent. However, a leveling agent is added to the inkjet ink for a color filter of the present invention as long as the effect of the present invention is not impaired. Also good. Examples of the leveling agent include polyoxyalkylene surfactants, fatty acid ester surfactants, special acrylic polymers, and the like.

<Other ingredients>
Furthermore, the ink for 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) Ultraviolet absorber: For example, 2- (3-t-butyl-5-methyl-2-hydroxyphenyl) -5-chlorobenzotriazole, alkoxybenzophenone and the like.
d) Anti-aggregation agent: for example, sodium polyacrylate.

<Ink production method>
The inkjet ink for a color filter of the present invention may be produced by introducing each component into a single solvent or a solvent that is a mixed solvent and mixing them, and dissolving or dispersing the solid components.
However, when the pigment is directly put into the whole solvent together with other components such as a binder system 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 color dispersion, together with the components other than the pigment, is put into a solvent that is almost composed of the main solvent or composed of only the main solvent, and is sufficiently stirred and mixed by a dissolver or the like, whereby the color filter of the present invention. Ink jet ink.

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 the main 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.

<Physical properties of cured layer>
The cured layer formed using the inkjet ink for a color filter of the present invention has transparency, hardness, heat resistance (such as film loss or degree of discoloration caused by heating) and other characteristics required for the details of the color filter. Are better. For example, a cured layer having the following hardness, heat resistance and the like can be formed on a transparent substrate using the inkjet ink for a color filter of the present invention.
a) Hardness: JIS K 5600-5-4: 1999 “Paint General Test Method—Part 5: Mechanical Properties of Coating Film—Section 4: Scratch Hardness (Pencil Method)” indicates a pencil hardness of 2H or more.
b) Heat resistance: The decrease in the thickness of the cured layer after leaving the color filter at 250 ° C. for 1 hour can be 10% or less, and the color difference before and after being left can be 1 or less.
c) Solvent resistance (chemical resistance): film thickness of the cured layer after the color filter provided with the cured layer was immersed in a solvent of either isopropyl alcohol, N-methylpyrrolidone or γ-butyrolactone at a liquid temperature of 40 ° C. for 1 hour. The film thickness reduction calculated by measuring can be 10% or less even when immersed in any solvent.
d) Heat-resistant pure water: JIS K5600-5-6: 1999 “Paint General Test Method—Part 5: Mechanical Properties of Coating Film—No. after immersing color filter provided with hardened layer in pure water at 80 ° C. for 1 hour The result of “Section 6: Adhesiveness (cross-cut method)” can be 6 points or more.
It is presumed that the cured layer produced in the present invention exhibits excellent hardness, solvent resistance and warm pure water resistance, which contributes to the fact that the crosslinked density of the cured layer is often very high.

<Application>
The inkjet ink for a color filter of the present invention is particularly suitably used for forming a film having a predetermined pattern such as a pixel or a black matrix in a color filter. As the color filter, any of a color filter used for an image output device such as a liquid crystal display device or a color filter used for an image input device such as a solid-state imaging device can be suitably used.

2. Method for producing color filter The method for producing a color filter of the present invention comprises a step of forming an ink layer by selectively adhering the inkjet ink for a color filter of the present invention to a predetermined region on a substrate by an inkjet method, And a step of forming a colored cured layer by curing the ink layer.
Pixels can be obtained by blending a desired pigment such as R, G, B, or black into the color filter inkjet ink of the present invention, selectively adhering to a predetermined region on the transparent substrate of the color filter by an inkjet method, and curing. A colored hardened layer such as a portion or a light shielding layer can be formed.

An example of a method for producing a color filter including the above steps will be described below. First, a transparent substrate 1 for a color filter is prepared as shown in FIG. The transparent substrate is not particularly limited as long as it is conventionally used for a color filter. For example, quartz glass, Pyrex (registered trademark) glass, synthetic quartz plate and the like are not transparent. A transparent material having flexibility such as a rigid material, a transparent resin film, an optical resin plate, or the like can be used. Among these, 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.

Next, as illustrated in FIG. 1B, the light-shielding portion 2 is formed in a region serving as a boundary between the pixel portions on the one surface side of the transparent substrate 1. The light shielding part 2 can be formed by forming a metal thin film of chromium or the like having a thickness of about 1000 to 2000 mm by a sputtering method, a vacuum vapor deposition method or the like, and patterning this thin film. As this patterning method, a normal patterning method such as sputtering can be used.

Further, the light shielding part 2 may be a layer in which light shielding particles such as carbon fine particles, metal oxides, inorganic pigments, and organic pigments are contained in a resin binder. As the resin binder to be used, polyimide resin, acrylic resin, epoxy resin, polyacrylamide, polyvinyl alcohol, gelatin, casein, cellulose, or a mixture of one or more kinds, photosensitive resin, or O / A W emulsion type resin composition, for example, an emulsion of a reactive silicone can be used. The thickness of such a resin light-shielding portion can be set within a range of 0.5 to 10 μm. As a method for patterning such a resin light-shielding portion, a generally used method such as a photolithography method or a printing method can be used.

Next, as shown in FIG. 1C, an ink-repellent convex portion is formed on the light shielding portion pattern as necessary. The composition of such an ink repellency convex part is not particularly limited as long as it is a resin composition having ink repellency. Moreover, it does not need to be transparent in particular and may be colored. For example, a material that is used for the light-shielding portion and does not include a black material can be used. Specifically, a composition in which one or more water-soluble resins such as polyacrylamide, polyvinyl alcohol, gelatin, casein, and cellulose are mixed, or an O / W emulsion type resin composition such as reactive silicone is used. Examples of emulsions can be given. In the present invention, a photocurable resin is preferably used for reasons such as easy handling and curing. In addition, since the ink-repellent convex portion is more preferable as the ink repellency is stronger, the surface may be treated with an ink-repellent treatment agent such as a silicone compound or a fluorine-containing compound.

The patterning of the ink-repellent convex portions can be performed by printing using a coating liquid of an ink-repellent resin composition or photolithography using a photocurable coating liquid. As described above, the height of the ink-repellent convex portion is provided in order to prevent the ink from being mixed when colored by the ink jet method, and thus it is preferably high to some extent. In consideration of the overall flatness of the case, the thickness is preferably close to the thickness of the pixel portion. Specifically, although it varies depending on the amount of ink deposited, it is usually preferably in the range of 0.1 to 2.5 μm.
In addition, in the formation of the ink-repellent convex portions, surface treatment such as plasma treatment may be used to impart ink repellency. Examples of the surface treatment include reduced-pressure plasma treatment and atmospheric pressure plasma treatment in which a gas containing fluorine or a fluorine compound is used as an introduction gas and plasma irradiation is performed in a reduced-pressure atmosphere or an atmospheric pressure atmosphere. When plasma treatment is performed in a gas containing a fluorine compound and oxygen, a phenomenon occurs in which the fluorine compound enters the surface of the organic material in parallel with the above reaction. In particular, when there are more fluorine compounds than oxygen, for example, in a gas atmosphere with an excessive amount of fluorine compounds such that the content of fluorine compounds with respect to the total amount of fluorine compounds and oxygen is set to 60% or more. Then, since the fluorine compound mixing phenomenon becomes more prominent than the oxidation reaction with oxygen, the organic material surface is depolarized by the mixing phenomenon and ink repellency is imparted.

Next, the ink-jet ink of the present invention for each color is prepared as the pixel portion forming ink for each color. Then, as shown in FIG. 1 (D), on the surface of the transparent substrate 1, the pixel portion forming regions 4R, 4G, and 4B for the respective colors defined by the pattern of the light shielding layer 2 are formed. Ink is sprayed by an ink jet method to form an ink layer. In this ink spraying step, the pixel portion forming ink is unlikely to increase in viscosity at the tip portion of the head 5 and can continue to maintain good ejection properties. Accordingly, the ink of the corresponding color can be accurately and uniformly deposited in the predetermined pixel portion formation region, so that a pixel portion having no color unevenness or color loss can be formed with an accurate pattern. In addition, since the pixel portion forming ink of each color can be simultaneously sprayed onto the substrate using a plurality of heads, the working efficiency can be improved as compared with the case where the pixel portion is formed for each color.
Next, as shown in FIG. 1E, the ink layers 6R, 6G, and 6B of the respective colors are dried, pre-baked as necessary, and then cured by heating. In particular, as a drying condition for preventing the end portion of the ink layer from rising after drying, it is preferable to put a reduced-pressure drying step before a normal pre-baking step. For example, after vacuum drying at 10 Torr for 120 seconds, pre-baking for 10 minutes on a hot plate at 80 ° C. can be mentioned. Alternatively, the drying condition for preventing the end portion of the ink layer from rising after drying is preferably a time longer than about 10 minutes under a temperature condition lower than a normal pre-baking condition (about 80 ° C.). For example, it may include a drying process at 40 to 60 ° C. for 30 to 60 minutes. When the ink layer is heated, the crosslinking element of the curable resin contained in the inkjet ink causes a crosslinking reaction, and the ink layer is cured.

Since the pixel of the color filter obtained by the method for producing a color filter of the present invention is formed using the above-described inkjet ink of the present invention, an epoxy compound, a polyvalent carboxylic acid derivative, and a vinyl ether surfactant / or a chemistry thereof It is characteristic to include a variant. Here, the epoxy compound, the polyvalent carboxylic acid derivative, and the vinyl ether surfactant are the same as those described in the ink-jet ink of the present invention, and thus description thereof is omitted here. The chemical compounds of epoxy compounds, polyvalent carboxylic acid derivatives, and vinyl ether surfactants are epoxy compounds, polyvalent carboxylic acid derivatives, and vinyl ether surfactants when forming color filters or using heat or light. The agent has changed due to a chemical reaction.

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 portion is usually about 0.5 to 2.5 μm in consideration of optical characteristics and the like. In the color filter of the present invention, it is preferable that the maximum value of the film thickness of the pixel, particularly the maximum value of the film thickness of the end portion of the pixel is 3.5 μm or less, particularly preferably 3 μm or less. In the color filter of the present invention, the difference between the maximum value of the film thickness of the pixel, particularly the maximum value of the film thickness at the end of the pixel and the average film thickness is 1 μm or less, particularly preferably 0.7 μm or less. Preferably there is. In such a case, there is no problem such that the pixels in the thick film portion become dark or cracks are likely to occur, and display defects are reduced. Further, there is no problem that the gap of the liquid crystal layer cannot be accurately obtained. The film thickness refers to the height from the reference surface (surface having an average height) of the substrate. Moreover, the average film thickness of a pixel can be calculated by dividing the coating film volume in the pixel by the pixel area. Furthermore, the maximum value of the film thickness at the end portion means the value of the film thickness at the highest film thickness in the end bulge portion.

Next, as shown in FIG. 1F, a protective layer 8 is formed on the side of the transparent substrate on which the pixel portions 7R, 7G, and 7B are formed. The protective layer is provided to flatten the color filter and to prevent components contained in the pixel portion and the like from eluting into the liquid crystal layer of the liquid crystal display device. The thickness of the protective layer can be set in consideration of the light transmittance of the material used, the surface state of the color filter, etc., and can be set in the range of 0.1 to 2.0 μm, for example. The protective layer can be formed using, for example, a known transparent photosensitive resin, two-component curable transparent resin, or the like having a light transmittance required as a transparent protective layer.
Thus, the color filter 101 is manufactured using the inkjet ink for color filters of the present invention. In this example, the pixel portion is formed using the ink of the present invention. However, according to the ink jet system using the color filter ink jet ink of the present invention, the light shielding portion 2 and the like are formed in a desired pattern in addition to the pixel portion. Can be formed.

When the light-shielding part 2 is to be formed, an ink-jet ink for a color filter according to the present invention, which is prepared by blending a light-shielding colorant such as a black pigment, is prepared. Then, the ink layer is selectively adhered to a predetermined region of the surface of the transparent substrate 1 by an ink jet method to form an ink layer in a predetermined pattern, the ink layer is cured by a method such as ionizing radiation irradiation, and baked as necessary. Thus, a light shielding part can be formed.

In the above example, as shown in FIG. 1 (B), the light shielding portion 2 is formed in a region serving as a boundary between the pixel portions on the one surface side of the transparent substrate 1, and the light shielding portion 2 is further formed thereon as shown in FIG. 1 (C). As shown, the ink-repellent convex portion 3 is formed. However, the light-shielding portion 2 having a relatively high height and also serving as a partition, having the functions of the light-shielding portion 2 and the ink-repellent convex portion 3. May be provided on the substrate. In this case, the light-shielding part 2 preferably has ink repellency. For example, a water-repellent light-shielding part mixed with a water-repellent material, a water-repellent light-shielding part coated with a water-repellent material on the surface, or plasma treatment. Examples include a light-shielding portion to which water is imparted. As the means for imparting water repellency, the same means as described in the water repellency convex portion can be used.
The color filter manufacturing method of the present invention further includes a step of selectively changing the wettability in a predetermined area of the substrate surface to form an ink layer forming area having a greater ink affinity than the surrounding area. The ink layer is preferably formed by selectively adhering the above-described ink for color filter of the present invention to the ink layer forming region by an ink jet method. When ink is attached to an ink layer forming region having high ink affinity, wetting and spreading properties of the ink are improved, color loss and film thickness unevenness can be more effectively prevented, and a pixel free from brightness and color unevenness is obtained. Because you can.

The process of selectively changing the wettability in a predetermined area of the substrate surface to form an ink layer forming area having a higher ink affinity than the surrounding area is not particularly limited, and may be a plasma process or the like as described above. Surface treatment may be used. For example, when plasma treatment is performed in a gas containing a fluorine-based compound and oxygen, unreacted groups are generated on the surface of the inorganic material by plasma discharge, and the unreacted groups are oxidized by oxygen, and carbonyl groups, hydroxyl groups, etc. Polar groups are generated and ink affinity is imparted. On the other hand, in the organic material, a phenomenon occurs in which the fluorine-based compound enters the surface of the organic material in parallel with the above reaction. In particular, when the amount of fluorine compound is larger than oxygen, for example, in a gas atmosphere with an excessive amount of fluorine compound such that the content of fluorine compound relative to the total amount of fluorine compound and oxygen is set to 60% or more. Since the fluorine compound mixing phenomenon is more prominent than the oxidation reaction with oxygen, the organic material surface is depolarized by the mixing phenomenon and ink repellency is imparted. Therefore, after the light shielding part 2 and the convex part are formed on the glass substrate with an organic material, if the plasma treatment is performed under the condition that the fluorine-based compound is excessive as described above, the glass substrate corresponding to the ink layer forming region is surrounded. In comparison with the above, the ink affinity is increased, the light shielding portion 2 and the convex portion become ink repellency, and the convex portion becomes the ink repellency convex portion 3. The ink layer formation region thus obtained is easy to wet and spread ink, preventing color loss and film thickness unevenness, and preventing ink outflow from the convex portion corresponding to the boundary with other ink formation regions. The Further, in this case, when the light shielding part 2 is formed of an inorganic material and the convex part is formed thereon with an organic material, the glass substrate and the light shielding part 2 have high ink affinity, and the convex part has ink repellency. Become.

On the other hand, another method for selectively forming the ink layer forming area having a higher ink affinity than the surrounding area by selectively changing the wettability in a predetermined area of the substrate surface is as follows. The wettability variable layer that changes the wettability in the direction in which the ink affinity increases by the action of the photocatalyst is formed, and the wettability in a predetermined region on the surface of the wettability variable layer is selectively changed by exposure, There is a method of forming an ink layer forming region having a greater ink affinity than the surroundings.
When such a wettability variable layer is provided on a substrate, the standard solution shown in JIS K 6768: 1999 “Plastic-film and sheet-wetting tension test method” is used as a main solvent, and droplets are contacted. The contact angle (θ) after 30 seconds was measured, and the contact angle with respect to the surface of the test piece having a critical surface tension of 30 mN / m determined from the Zisman plot graph was 25 ° or more, and the same measurement method It is preferable to use an ink prepared using an ink having a contact angle of 10 ° or less with respect to the surface of a test piece having a critical surface tension of 70 mN / m.

In the method for producing a color filter of the present invention, an example of an aspect in which the wettability variable layer as described above is provided on a substrate will be described below. First, as shown in FIG. 2A, the light-shielding portion 2 is formed in a region serving as a boundary between the pixel portions on the one surface side of the transparent substrate 1 of the color filter. The pixel portion formation regions 4R, 4G, and 4B for each color are defined by the light shielding portion pattern. As the transparent substrate 1, the same one as described in the example described with reference to FIG. 1 can be used, and the same light shielding portion 2 as that described in the example described with reference to FIG. 1 is provided. be able to.
Next, as shown in FIG. 2B, a photocatalyst containing layer 9 as a wettability variable layer is formed on at least a partial region of the surface of the transparent substrate 1, particularly in this example, a region including a pixel portion forming region. A solid pattern (solid pattern) is formed.
Next, as shown in FIG. 2C, the photocatalyst-containing layer 9 is exposed to light 12 through a photomask 10 to be exposed to increase the ink affinity of the pixel portion formation regions 4R, 4G, and 4B. .

When the wettability of the pixel portion forming region of the wettability variable layer such as the photocatalyst containing layer 9 is selectively changed to increase the ink affinity, the ink of the present invention easily adheres to the pixel portion forming region. It spreads evenly, and on the other hand, it is strongly repelled and eliminated in the surrounding area of the pixel portion forming area, so that it adheres selectively and uniformly to the pixel portion forming area, and as a result, color unevenness and color omission are generated with an accurate pattern. No pixel portion can be formed.
The wettability variable layer used in this method is a standard solution shown in the wetting tension test method defined in JIS K 6768: 1999, and a contact angle (θ) after 30 seconds is measured after contacting a droplet, The critical surface tension obtained from the graph of the Zisman plot shows 20 to 50 mN / m before changing the wettability, and 40 to 120 mN / m after changing the wettability, preferably 70 to It is preferable that it is 110 mN / m.

When a wettability variable layer that can change the critical surface tension in this way is used, the ink has a very small contact in the pattern formation region such as the pixel portion formation region where the wettability is changed to increase the ink affinity. On the other hand, a very large contact angle is shown around the pattern formation region, and the difference in wettability can be made very large.
When exposure is performed using the photomask 10, the width of the exposed portion 11 is made wider than the width of the pixel portion forming region 4 while securing an unexposed portion at the boundary between adjacent pixel portion forming regions. It is preferable to make it. By doing in this way, every corner of the pixel portion formation region 4 is sufficiently exposed and the ink affinity increases, so that inconveniences such as color loss of the pixel portion hardly occur. The photocatalyst-containing layer 9 may be exposed in a predetermined pattern by other methods such as photolithography by scanning with a laser beam without using a photomask. Further, when exposure is performed from the back side of the transparent substrate (the side opposite to the side where the photocatalyst-containing layer 9 is provided), the light-shielding portion 2 functions as a photomask, so that no photomask is required.

The light applied to the photocatalyst-containing layer 9 may be visible light or invisible light as long as it can activate the photocatalyst, but usually light including ultraviolet light is used. Examples of such a light source including ultraviolet light include a mercury lamp, a metal halide lamp, and a xenon lamp. The wavelength of light used for this exposure can be set within a range of 400 nm or less, preferably 380 nm or less, and the amount of light irradiation during exposure increases the hydrophilicity of the exposed part by the action of a photocatalyst. It can be set as the irradiation amount required to make it.
Examples of the wettability variable layer capable of changing the wettability in the direction of increasing the ink affinity include a) a photocatalyst such as the illustrated photocatalyst-containing layer 9 and the wettability variable layer itself by the action of the photocatalyst. B) The photocatalyst-containing layer is provided on the lower side (transparent substrate side) of the wettability variable layer, and the hydrophilicity of the wettability variable layer is increased by the action of the photocatalyst present in the photocatalyst-containing layer. C) a degradable wettability variable layer comprising a photocatalyst and a binder that is decomposed by the action of the photocatalyst, wherein an exposed portion of the degradable wettability variable layer is decomposed and removed, and has a hydrophilic surface, for example, Photocatalyst present in a photocatalyst-containing layer provided with a photocatalyst-containing layer underneath a decomposable wettability variable layer comprising a binder that is exposed by the action of the photocatalyst or d) Exposed portion of the degradable wettability-variable layer by the action decomposition, base having been removed hydrophilicity can be exemplified, for example, those photocatalyst-containing layer or the like is exposed.

In the present invention, “a wettability variable layer capable of changing the wettability in the direction of increasing the ink affinity” refers to the wettability of the wettability variable layer forming surface in the laminate in which the wettability variable layer is provided on the substrate. As long as the ink affinity of the wettability variable layer itself increases as shown in the above examples a) and b). This includes the case where the wettability variable layer is decomposed and the ink-philic base is exposed as in d).
In addition, a) a photocatalyst containing layer such as the photocatalyst containing layer 9 shown in the figure and the hydrophilicity of the wettability variable layer itself is increased by the action of the photocatalyst; and b) the lower side of the wettability variable layer (transparent substrate side) ) Having a photocatalyst-containing layer, and the hydrophilicity of the wettability variable layer is increased by the action of the photocatalyst present in the photocatalyst-containing layer, described in paragraphs 149 to 174 of JP-A-2001-350012 A thing can be used suitably.

Next, an ink for forming a pixel portion of each color, which is an inkjet ink for a color filter of the present invention and is formed by blending one or more pigments, is prepared. Then, the pixel portion forming ink of the corresponding color is selectively attached to the pixel portion forming regions 4R, 4G, and 4B having increased ink affinity in the step of FIG. Ink layers 6R, 6G, and 6B as shown in D) are formed.
Next, as shown in FIG. 2 (E), the ink layers 6R, 6G, and 6B of the respective colors are dried and pre-baked as necessary, and then cured by heating, and further baked as necessary. The pixel portions 7R, 7G, and 7B for each color are formed. In particular, the drying condition for preventing the end portion of the ink layer from rising after drying is preferably performed in the same manner as described with reference to FIG. When the ink layer is heated, the crosslinking element of the curable resin contained in the composition causes a crosslinking reaction, and the ink layer is cured.

Next, as shown in FIG. 2F, the protective layer 8 is formed on the side of the transparent substrate where the pixel portions 7R, 7G, and 7B are formed. The curing step and the protective layer forming step as shown in FIGS. 2E and 2F can be performed in the same manner as described with reference to FIG.
In another example, the color filter 102 is manufactured in this way. In this example, the pixel portion is formed using the pixel portion forming ink which is the inkjet ink for the color filter of the present invention. However, the inkjet ink for the color filter of the present invention is used by utilizing the difference in wettability of the substrate surface. By selectively attaching only to the ink-philic region, a colored hardened layer other than the pixel portion such as the light-shielding portion 2 can be formed in a desired pattern.

3. Manufacturing method of liquid crystal display device The manufacturing method of the liquid crystal display device of the present invention comprises a step of manufacturing a color filter using the method of manufacturing a color filter of the present invention, and the manufactured color filter and the liquid crystal driving side substrate face each other. And assembling.
According to the method for manufacturing a liquid crystal display device of the present invention, the method includes the step of using the method for manufacturing a color filter of the present invention, wherein a color filter having higher performance is obtained using the inkjet ink for a color filter of the present invention. Therefore, a high-quality liquid crystal display device can be obtained.
When the color filter manufactured as described above and the liquid crystal drive side substrate (TFT array substrate) are opposed to each other and the inner periphery of both substrates is joined by a sealing material, both substrates maintain a cell gap of a predetermined distance. Pasted in state. An active matrix type color liquid crystal display device belonging to the liquid crystal display device manufactured by the manufacturing method of the present invention is obtained by filling the gap between the substrates with liquid crystal and sealing it.

As other manufacturing methods and configurations in the liquid crystal display device, methods and configurations that are usually used can be used, and thus description thereof is omitted here.
The liquid crystal display device obtained by the production method of the present invention is not particularly limited as long as it has the above-described color filter, and includes known liquid crystal display devices. Specifically, IPS (In-Plane Switching) type, STN (Super Twisted Nematic) type, TN (Twisted Nematic) type, ferroelectric type, antiferroelectric type, MVA mode type and the like can be mentioned.

(Production Examples 1 and 2: Synthesis of epoxy group-containing polymer (A1))
In a four-necked flask equipped with a thermometer, reflux condenser, stirrer, and dropping funnel, the solvent diethylene glycol monobutyl ether acetate (also called butyl carbitol acetate, hereinafter referred to as BCA) does not contain a hydroxyl group according to the blending ratio shown in Table 1. 44 parts by weight, and heated with stirring to 115 ° C. Next, 56.0 parts by weight of a mixture (dropping component) of the above-mentioned solvent BCA containing no monomer, a polymerization initiator, and a hydroxyl group having the composition described in Table 1 at a temperature of 115 ° C. was added from a dropping funnel over 2 hours. It was dripped quickly. After completion of dropping, the mixture is kept at 115 ° C. for 2.5 hours, then heated to 125 ° C. and kept for 2 hours to terminate the reaction, whereby the epoxy group-containing polymer (A1) having the characteristics shown in Table 1 was gotten.

* 1) Abbreviations in the table are as follows.
GMA: Glycidyl methacrylate CHMA: Cyclohexyl methacrylate MMA: Methyl methacrylate Perhexyl I: tert-hexyl peroxyisopropyl monocarbonate (trade name, manufactured by NOF Corporation)
* 2) Property: Appears visually.
* 3) Calculated from the heating residue when dried with hot air at 140 ° C. for 60 minutes.
* 4) Epoxy equivalent: An epoxy group was subjected to a ring-opening reaction with an excess of 0.2N · dioxane hydrochloride solution, and then back-titration of unreacted hydrochloric acid with 0.1N · KOH ethanol solution to calculate an epoxy equivalent. .
* 5) Measured at 20 ° C. using an E-type viscometer.
* 6) Weight average molecular weight: A value in terms of polystyrene measured by gel permeation chromatography (GPC).

(Production Examples 3 and 4: Synthesis of polyvalent carboxylic acid derivative (B))
A four-necked flask equipped with a thermometer, a reflux condenser, and a stirrer was charged according to the blending ratio shown in Table 2, heated with stirring and heated to 70 ° C. Next, stirring was continued while maintaining the temperature, and when the acid value of the mixture became 3.0 mgKOH / g or less, the reaction was terminated, and a polyvalent carboxylic acid derivative (B) having the characteristics shown in Table 2 was obtained.

* 1) Acid value of the solution: Calculated by titration with a 0.1 N · KOH ethanol solution. The acid value of the solution is determined according to the method for measuring the acid value of JIS K 0070: 1992 “Testing method for acid value, saponification value, ester value, iodine value, hydroxyl value and unsaponified product of chemical products”. A certain amount of resin was dissolved in a THF) solution, and titration was performed with a KOH / ethanol solution using phenolphthalein as an indicator for measurement.
* 2) Blocking rate: Calculated by converting to solid content from the acid value of the solution.
* 3) Block acid solid content: Ratio of polycarboxylic acid derivative produced by reaction of the charged carboxylic acid with an equivalent amount of vinyl ether compound * 4) Acid equivalent of solution: Blocking agent in water / methanol solution After dissociation, the acid value was measured. The acid value was measured according to the hydrolysis acid value measurement of JIS K 0070: 1992 “Testing method for acid value, saponification value, ester value, iodine value, hydroxyl value and unsaponified product of chemical products”.

(Production Examples 5 to 6: Synthesis of vinyl ether surfactant (C))
A four-necked flask equipped with a stirrer, a reflux condenser, a thermometer, and a nitrogen introduction tube was introduced with a sufficient amount of nitrogen to make a nitrogen atmosphere. Then Molecular 100 parts by weight of toluene dried by sheave and BF ₃ - etherate (BF ₃ -etherate) was added 0.10 parts by weight. And 100 weight part of vinyl ether compounds of the composition described in Table 3 were dripped over 2.5 hours in the state which heated up the contents to 30 degreeC, and was maintained at the same temperature. After completion of dropping, the reaction was further carried out at 50 ° C. for 1 hour. After completion of the reaction, 0.5 part by weight of 25% ammonia solution and 50 ml of water distilled twice were added to the reaction mixture, and the resulting mixture was sufficiently stirred. Subsequently, the aqueous layer was separated and removed with a separatory funnel. Further, after washing twice with 100 ml each subjected to twice distillation, toluene and residual water were distilled off under reduced pressure at 80 ° C. × 20 kPa to obtain a viscosity having the characteristics shown in Table 3. A liquid vinyl ether surfactant (C) was obtained.

* 1) Property: Appears visually.
* 2) Weight average molecular weight: A value in terms of polystyrene by gel permeation chromatography (GPC).

(Example 1: Preparation of inkjet ink (blue) for color filter)
(1) Preparation of Pigment Dispersion Each pigment, pigment dispersant, and solvent are mixed in the following ratio, 500 parts by weight of 0.3 mm zirconia beads are added, and a paint shaker (manufactured by Asada Tekko Co., Ltd.) is used. For 4 hours to prepare PB15: 6 (CI Pigment Blue 15: 6) pigment dispersion and PV23 (CI Pigment Violet 23) pigment dispersion.
[Composition of pigment dispersion]
-Each pigment: 10 parts by weight-Pigment dispersant (Disperbyk161 (manufactured by Big Chemie Japan Co., Ltd.) (solid content 30% by weight in solvent BCA)): 10 parts by weight-Pigment dispersion aid (N-phenylmaleimide / benzyl) Methacrylate copolymer (solid content 30% by weight in solvent BCA)): 10 parts by weight BCA (diethylene glycol monobutyl ether acetate): 70 parts by weight

(2) Preparation of binder composition / Binder composition A Teflon (registered trademark) -covered rotor was placed in a sample bottle and placed on a magnetic stirrer. In this sample bottle, the epoxy group-containing polymer (A1) described in the above production example, the epoxy group-containing compound (A2), the polyvalent carboxylic acid derivative (B) described in the above production example, and a thermal latent catalyst according to the following ratios: The mixture was sufficiently dissolved by stirring at room temperature, a diluent solvent was added for viscosity adjustment, and dissolved by stirring. Then, this was filtered to obtain a binder composition. The acid / epoxy equivalent ratio of the binder composition was 0.9.
[Binder composition ratio]
-Epoxy group-containing polymer (A1) of Production Example 1 (solid content 37.6 wt%): 66.7 parts by weight-Polycarboxylic acid derivative (B) of Production Example 3 (solid content 35.2 wt%) : 49.7 parts by weight-Epoxy group-containing compound (A2) (trade name Epicoat 157S70, manufactured by Japan Epoxy Resin Co., Ltd.) (solid content 27.2% by weight): 54.4 parts by weight-thermal latent catalyst (product) Name LC-1, manufactured by NOF Corporation): 3.6 parts by weight BCA: 75.6 parts by weight The above-prepared PB15: 6 pigment dispersion, PV23 pigment dispersion, and binder composition at the blending ratios shown in Table 4 After thoroughly mixing the product, a surfactant was added at a blending ratio shown in Table 4 to obtain an inkjet ink for a color filter of Example 1.

(Examples 2 to 6: Preparation of blue inkjet ink for color filter)
After preparing and mixing a pigment dispersion and a binder composition in the same manner as in Example 1, a surfactant was added. Table 4 shows the blending ratio.
(Comparative Example 1: Preparation of blue inkjet ink for color filter)
In the same manner as in Example 1, a pigment dispersion and a binder composition were prepared and mixed. No surfactant was added. Table 5 shows the blending ratio.
(Comparative Examples 2 to 4: Preparation of blue inkjet ink for color filter)
After preparing and mixing a pigment dispersion and a binder composition in the same manner as in Example 1, each surfactant was added. Table 5 shows the blending ratio.

[Evaluation methods]
1. The film thickness of the coating film edge part It adhered to the coating-film formation part on a board | substrate correctly and uniformly by the inkjet system using each said inkjet ink.
Then, it dried under reduced pressure at 10 Torr for 120 seconds, and also pre-baked for 10 minutes on an 80 degreeC hotplate. Then, in a clean oven, post-baking is performed by heating at 200 ° C. for 30 minutes, and further post-baking is performed by heating at 230 ° C. for 30 minutes. The average film thickness after drying and curing is 1.8 μm on the substrate. A coating film was formed.
The film thickness at the edge of the coating film was measured by a light interference type three-dimensional non-contact surface shape measuring apparatus (US Micromap, product name Micromap 557N). The maximum value of the film thickness at the edge was shown.

2. Volume resistance value Using the above inkjet inks, spin-coated on a 10 mm square chromium-deposited glass substrate with a thickness of 0.7 mm, heated on a hot plate at 80 ° C. for 10 minutes, and then heated in a 200 ° C. oven for 30 minutes. The film was further heated in a 230 ° C. oven for 30 minutes to form an average film thickness after curing of 1.8 μm.
In accordance with JIS K 6911, volume resistance value was measured at an applied voltage of 10 V using Hiresta-GP (MCP-HT450) manufactured by Dia Instruments Co., Ltd.

3. Recoat (overcoat)
The overcoat film composition (The Inktec Co., Ltd., product name IT-MP3260) was applied on the coating film of each inkjet ink for which the volume resistance value was measured, and the coating was applied on a hot plate at 90 ° C for 3 minutes. After heating, light was irradiated for 3 seconds at an illuminance of 35.5 mW / cm ^{2 in} terms of 365 nm using an ultrahigh pressure mercury lamp as a light source. Thereafter, development was performed, and the film was heated in a 230 ° C. oven for 30 minutes, so that the film thickness after curing was 1.8 μm. As a result, the presence or absence of repellency (a portion where the overcoat film was repelled and the film thickness was non-uniform) was visually confirmed. The case where there was no repelling was indicated by ○, and the case where there was repelling was indicated by ×.
The evaluation results are shown in Table 4 for Examples 1 to 6 and Table 5 for Comparative Examples 1 to 4 together with the amounts of each component.

Abbreviations in Table 4 and Table 5 are as follows.
* 1) LHP-90: Vinyl ether surfactant (trade name LHP-90 (containing polyvinyl isobutyl ether, SP value 8.38, solid content 50% by weight), Enomoto Kasei Co., Ltd.)
* 2) BYK-307: Silicone surfactant (trade name: BYK-307 (solid content: 100% by weight), Big Chemie Japan Co., Ltd.)
* 3) BYK-320: Silicone surfactant (trade name; BYK-320 (solid content 52% by weight), Big Chemie Japan Co., Ltd.)
* 4) Surfynol 61: Acetylene glycol surfactant (trade name; Surfynol 61 (solid content: 100% by weight), Nissin Chemical Industry Co., Ltd.)
* 5) For the pigment dispersion and binder component, only the solid content is described. All solvents contained in these components were counted in the solvent column.
* 6) The stated amount of surfactant includes the solvent.

From the results of Examples 1 to 6, it can be seen that the inkjet ink for a color filter of the present invention is excellent in reducing the end film thickness, and further excellent in recoatability and volume resistance.
In contrast, in Comparative Example 1 in which no surfactant was used and in Comparative Examples 3 and 4 in which a surfactant different from the surfactant used in the present invention was used, the end film thickness exceeded the desired range. Further, Comparative Example 2 using a surfactant different from the surfactant used in the present invention resulted in inferior volume resistance and recoatability.

(Example 7: Preparation of ink-jet ink for color filter (red))
(1) Preparation of pigment dispersion Each pigment, pigment dispersant, and organic solvent are mixed at the following ratio, and 500 parts by weight of zirconia beads having a diameter of 0.3 mm are added, and a paint shaker (manufactured by Asada Steel Corporation) is used. After dispersion for 4 hours, PR254 (CI Pigment Red 254) pigment dispersion and PR177 (CI Pigment Red 177) pigment dispersion were prepared.
[Composition of pigment dispersion]
-Each pigment: 10 parts by weight-Pigment dispersant (Disperbyk161 (produced by Big Chemie Japan) (solid content 30% by weight)): 10 parts by weight-Pigment dispersion aid (N-phenylmaleimide / benzyl methacrylate copolymer (solid content) 30 wt%)): 10 parts by weight BCA (diethylene glycol monobutyl ether acetate): 70 parts by weight

(2) Preparation of ink The above-prepared PR254 pigment dispersion, PR177 pigment dispersion, and the same binder composition as in Example 1 and BCA were sufficiently mixed at the mixing ratio shown in Table 6. Thereafter, a vinyl ether surfactant (LHP-90) was added at a blending ratio shown in Table 6 to obtain a red inkjet ink for a color filter of Example 6.
(Comparative Example 5: Preparation of inkjet ink for color filter (red))
The pigment dispersion prepared in Example 7 and the binder composition prepared in Comparative Example 1 were mixed. No surfactant was added. Table 6 shows the blending ratio.
The evaluation results are shown in Table 6 together with the amount of each component.

When the inkjet ink of Example 7 was used, the end film thickness was within the desired range, whereas when the inkjet ink of Comparative Example 5 was used, the end film thickness exceeded the desired range. .

(Example 8: Preparation of inkjet ink (green) for color filter)
(1) Preparation of pigment dispersion Each pigment, pigment dispersant, and organic solvent are mixed at the following ratio, and 500 parts by weight of zirconia beads having a diameter of 0.3 mm are added, and a paint shaker (manufactured by Asada Steel Corporation) is used. PG36 (CI Pigment Green 36) pigment dispersion, PG7 (CI Pigment Green 7) pigment dispersion, PY138 (CI Pigment Yellow 138) pigment dispersion and PY150 (C I. Pigment Yellow 150) A pigment dispersion was prepared.
[Composition of pigment dispersion]
-Each pigment: 10 parts by weight-Pigment dispersant (Disperbyk161 (manufactured by Big Chemie Japan) (solid content 30% by weight in solvent BCA)): 10 parts by weight-Pigment dispersion aid (N-phenylmaleimide / benzyl methacrylate copolymer) Combined (solid content 30% by weight): 10 parts by weight BCA (diethylene glycol monobutyl ether acetate): 70 parts by weight

(2) Preparation of ink The PG36 pigment dispersion, the PG7 pigment dispersion, the PY138 pigment dispersion and the PY150 pigment dispersion prepared as described above at the blending ratio shown in Table 7, and the same binder composition and BCA as in Example 1 were used. Mix thoroughly. A vinyl ether surfactant (LHP-90) was added at a blending ratio shown in Table 7 to obtain an inkjet ink for a color filter (green) of Example 7.
(Comparative Example 6: Preparation of green inkjet ink for color filter)
The pigment dispersion prepared in Example 8 and the binder composition prepared in Comparative Example 1 were mixed. No surfactant was added. Table 7 shows the blending ratio.
The evaluation results are shown in Table 7 together with the amount of each component.

  When the inkjet ink of Example 8 was used, the edge film thickness was within the desired range, whereas when the inkjet ink of Comparative Example 6 was used, the edge film thickness exceeded the desired range. .

(Example 9: Production of color filter)
A black matrix pattern having a line width of 20 μm and a film thickness of 1.2 μm is formed on a glass substrate (manufactured by Asahi Glass Co., Ltd.) having a thickness of 0.7 mm by a photolithographic method using a curable resin composition for black matrix. Formed.

  The blue inkjet ink of Example 1 was accurately and uniformly attached to the blue pixel forming portion partitioned by the black matrix of the substrate by the inkjet method. Next, the color filter inkjet ink (green) of Example 8 was adhered to the green pixel forming portion of the same substrate accurately and uniformly by the inkjet method. Next, the color filter inkjet ink (red) of Example 7 was adhered to the red pixel forming portion of the same substrate accurately and uniformly by the inkjet method.

  Then, it dried under reduced pressure at 10 Torr for 120 seconds, and also pre-baked for 10 minutes on an 80 degreeC hotplate. Then, in a clean oven, post-baking is performed by heating at 200 ° C. for 30 minutes, and further post-baking is performed by heating at 230 ° C. for 30 minutes, and the average film thickness after drying and curing is 1.8 μm on the substrate. An RGB three-color pixel pattern was formed. As shown in Table 8, it has been clarified that the film thickness at the edge of the pixel is reduced as compared with the conventional case.

The substrate on which the RGB pixel pattern was formed was immersed in IPA for 5 minutes, then dried by IPA vapor, washed, and then ITO (indium oxide) at a substrate setting temperature of 200 ° C. under a vacuum of 6 × 10 ⁻³ Torr. A tin) electrode was deposited to a thickness of 120 nm. The substrate on which this ITO film was formed was further immersed in IPA for 5 minutes, steam-washed with IPA, spin-coated with polyimide, and baked at 180 ° C. for 60 minutes to form an alignment film. Got.

(Comparative Example 7: Production of color filter)
Color filter inkjet ink (blue) as color filter inkjet ink (blue), color filter inkjet ink (green) as color filter inkjet ink (green), color filter inkjet ink as color filter inkjet The RGB three-color pixel having an average film thickness after drying and curing of 1.8 μm on the substrate in the same manner as in Example 9, except that the color filter inkjet ink (red) of Comparative Example 5 was used as the ink (red). A pattern was formed and a color filter was produced in the same manner.

  The film thickness of the pixel end portion of Comparative Example 7 using the ink not containing the vinyl ether surfactant was increased as shown in Table 8, respectively.

It is explanatory drawing of the method of manufacturing a color filter using the inkjet ink of this invention. It is a figure explaining another method of manufacturing a color filter using the ink-jet ink of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Transparent substrate 2 Light-shielding part 3 Ink-repellent convex part 4 Pixel part formation area 5 Inkjet head 6 Ink layer 7 Pixel part 8 Protective film 9 Photocatalyst containing layer 10 Photomask 11 Exposure part 12 Light beam 101, 102 Color filter

Claims (6)

(A) an epoxy compound having two or more epoxy groups in one molecule;
(B) A latent polyvalent carboxylic acid derivative obtained by reacting the carboxyl group of the carboxylic acid (b1) having the structure of the following formula (1) with the vinyl group of the vinyl ether compound (b2),
(C) a vinyl ether surfactant,
(D) An ink-jet ink for a color filter containing a pigment and (E) a solvent.

(The six-membered ring in the formula is an aromatic or alicyclic hydrocarbon. M1 is an integer of 0 to 4, t1 is an integer of 0 to 1, and n is an integer of 1 to 4. When n is 1, R ¹ is a hydrogen atom or a hydrocarbon group having 2 to 8 carbon atoms, and when n is 2 to 4, R ¹ is a hydrocarbon group having 2 to 8 carbon atoms. R ² is an alkyl group having 1 to 5 carbon atoms.)   The inkjet ink for color filters according to claim 1, wherein the content of the vinyl ether surfactant (C) is 0.05 to 1.25% by weight based on the entire solid content.   The solvent (E) contains a solvent component having a boiling point of 180 to 260 ° C. and a vapor pressure of 0.5 mmHg or less as a main solvent at a ratio of 80% by weight or more based on the total amount of the solvent. The inkjet ink for color filters according to claim 1 or 2.   A step of selectively depositing the color filter inkjet ink according to any one of claims 1 to 3 on a substrate by an inkjet method to form an ink layer, and curing the ink layer. Forming a colored hardened layer, and a method for producing a color filter.   The method further comprises a step of selectively changing the wettability of a predetermined area of the substrate surface to form an ink layer forming area having a greater ink affinity than the surrounding area, wherein the ink layer forming area includes: The method for producing a color filter according to claim 4, wherein the ink layer is formed by selectively attaching the ink-jet ink for a color filter according to any one of the methods by an ink-jet method.   A method for manufacturing a liquid crystal display device, comprising: a step of manufacturing a color filter using the method for manufacturing a color filter according to claim 4 or 5; and a step of assembling the manufactured color filter and a liquid crystal driving side substrate to face each other. .

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