TWI710605B - Green pigment dispersion for color filter and color filter - Google Patents

Abstract

In view of the problems of the prior art, the subject of the present invention is to provide color characteristics Green pigment dispersion for color filters with excellent performance. In the green pigment dispersion for color filters containing a pigment, a pigment dispersant, and a solvent, the green pigment dispersion for color filters contains C.I. Pigment Green 59 as a pigment.

Description

Green pigment dispersion for color filter and color filter

The present invention relates to a green pigment dispersion and a green coloring composition used in the production of optical color filters mainly used for transmission type or reflection type color liquid crystal displays.

The color filter is composed of two or more fine bands (bands) of different hues arranged in parallel on the surface of a transparent substrate such as glass, or fine pixels are arranged in a fixed arrangement in vertical and horizontal directions. The pixel size is a fine shape from a few ten to a few 100 μm, and each hue is neatly arranged in a prescribed order. Therefore, various methods have been proposed for the manufacturing method of the color filter.

Since color filters require high transparency, in the past, they were manufactured using the so-called dyeing method by the following method: repeating the following steps three times, adding weight to an aqueous solution of dyeable natural polymers such as gelatin and casein A sensitizer such as chromic acid is sensitized, and a pixel pattern is formed by photolithography, and then the pixel pattern is dyed in a desired color to obtain a colored pattern, forming a three-color transparent colored fine pattern.

In recent years, with the increase in the size of color liquid crystal display panels and the diversification of uses, there has been a demand for improved reliability such as heat resistance and light resistance.

In response to this demand, as a color material for forming color filters, organic pigments with excellent light resistance and heat resistance are used instead of dyes with excellent color characteristics but limited heat resistance or light resistance.

When manufacturing a color filter using a radiation-sensitive coloring resin composition dispersed with organic pigments, a radiation-sensitive coloring resin composition dispersed with organic pigments is coated on a transparent substrate or a substrate on which a light-shielding layer with a desired pattern is formed in advance. After drying, the dried coating film is exposed to a desired pattern and developed to obtain pixels of various colors.

However, in the case of using a radiation-sensitive colored resin composition in which organic pigments are dispersed, for example, in a color filter in which the three primary colors of blue, green, and red light are arranged on a transparent substrate, generally speaking, With a single pigment, it is difficult to obtain the spectral spectra of each as a color filter, so it is necessary to use two or more pigments for preparation.

Regarding green color filters, as described in Patent Documents 1 to 3, etc., CI Pigment Yellow 139, 17, 128, 150, 155, 185, etc. are usually added to green pigments such as CI Pigment Green 7, 36, and 58 Yellow pigment to adjust the spectrum and brightness.

However, increasing the transmittance, that is, the brightness, and improving the color purity, and so on, increase the requirements for the color characteristics of the color filter, and only the combination of these types of pigments has a limit to the improvement of the color characteristics as a color filter.

As a green pigment with excellent color characteristics, C.I. Pigment Green 59, but due to The preparation of the pigment dispersion liquid is technically difficult, so it has not been put into practical use so far.

[Prior Art Literature]

[Patent Literature]

Patent Document 1: Japanese Patent Application Laid-Open No. 10-237325

Patent Document 2: Japanese Patent Application Laid-Open No. 11-14825

Patent Document 3: Japanese Patent Application Publication No. 2014-2314

In view of the problems of the prior art, the problem of the present invention is to provide a green pigment dispersion for color filters having excellent color characteristics.

In order to solve such problems, the inventors have conducted various studies on green pigments, combinations with yellow pigments as needed, and pigment dispersants that finely disperse them. As a result, they have found that by combining green main pigments, The yellow pigment of the toning pigment, and the specific substance of the pigment dispersant that finely disperses the pigment, can solve the above-mentioned problems, thereby completing the present invention.

That is, the present invention (1) relates to a green pigment dispersion for color filters, characterized in that the green pigment dispersion for color filters containing a pigment, a pigment dispersant, and a solvent contains CI Pigment Green 59 As a pigment.

In addition, the present invention (2) relates to the green pigment dispersion for a color filter according to the aforementioned (1), wherein the pigment dispersant contains a tertiary amine group and/ Or a quaternary ammonium group and an acrylic polymer with a block structure with an amine value of 3 mgKOH/g or more.

In addition, the present invention (3) relates to the green pigment dispersion for a color filter according to the aforementioned (1) or (2), wherein the aforementioned pigment contains C.I. Pigment Yellow 185.

In addition, the present invention (4) relates to the green pigment dispersion for a color filter according to any one of the aforementioned (1) to (3), wherein the mass ratio of the aforementioned green pigment to the aforementioned yellow pigment is 95 /5~40/60.

In addition, the present invention (5) relates to the green pigment dispersion for a color filter according to any one of (1) to (4), wherein the pigment is a pigment that has been micronized.

In addition, the present invention (6) relates to the green pigment dispersion for a color filter according to any one of the aforementioned (1) to (5), which further contains a sulfonate of C.I. Pigment Yellow 185.

In addition, the present invention (7) relates to a color filter having a coating layer formed of the green pigment dispersion for a color filter described in the aforementioned (1) to (6).

In addition, in the present invention, the amine value represents the mass (mg) of potassium hydroxide equivalent to the amount of hydrochloric acid required to neutralize the solid content of 1 g of resin, and is based on the method described in the Japanese Industrial Standard JIS K 7237. The measured value.

In the present invention, a green pigment is used as the pigment, and a yellow pigment is preferably used in combination.

As the aforementioned green pigment, C.I. Pigment Green 59 (Pigment Index Name) is used as an essential component. By using C.I. Pigment Green 59, the resulting layer composed of the green coloring composition of the color filter is thin, has high brightness, and can develop colors with excellent balance. As the green pigment and/or yellow pigment of the present invention, other green pigments may be used in combination within a range that does not substantially reduce the light transmittance of C.I. Pigment Green 59.

And when the thickness of the coating film obtained from the green coloring composition for color filters of the present invention is 2.55 μm, x is 0.200 to 0.240, preferably 0.210 to 0.230, more preferably 0.215 to 0.228; y is 0.650 to 0.705, preferably It is 0.660 to 0.690, more preferably 0.665 to 0.675; Y is 37.0 to 48.0, preferably 38.0 to 48.0.

As the yellow pigment, C.I. Pigment Yellow 185 (pigment index name) or the like is used. Among them, C.I. Pigment Yellow 185 is preferable for achieving the purpose of the present invention. As other yellow pigments, other yellow pigments may be used in combination within a range that does not substantially reduce the light transmittance of C.I. Pigment Yellow 185.

In the present invention, the mixing ratio of the green pigment and the yellow pigment is preferably based on a weight ratio, and the green pigment/yellow pigment is 95/5 to 40/60.

In order to obtain high brightness or high contrast, the pigment of the present invention preferably uses a micronized pigment. By performing the atomization treatment, the primary particle size of the pigment can be made finer and uniform.

As the above-mentioned microparticulation treatment, for example, it is preferable to carry out the microparticulation treatment by salt milling as follows, which contains untreated coloring pigments, water-soluble inorganic salts (sodium chloride, Barium, potassium chloride, etc., preferably sodium chloride, and the average particle diameter of the water-soluble inorganic salt used is preferably 50 μm or less), and a water-soluble dispersion medium (alkoxy The mixture of base alcohols, glycols, ethers, etc.) uses a kneader, roller mill, ball mill, vertical ball mill, sand mill, and the planetary mixer described in JP 2006-192385A. After kneading with mixing equipment such as TRI-MIX (trade name) manufactured by Inoue Manufacturing Co., Ltd., and MIRACLE KCK manufactured by Asada Iron Works Co., Ltd. as a continuous single-shaft mixer, the water-soluble inorganic salt and the water-soluble dispersion are removed medium.

In the present invention, the sulfonate of C.I. Pigment Yellow 185 is preferably used in combination. Specifically, the method of using the sulfonate of CI Pigment Yellow 185 in the micronization treatment of the yellow pigment, or the method of using the sulfonate of CI Pigment Yellow 185 in the step of dispersing the yellow pigment that has been micronized alone, etc. .

The usage amount of the sulfonate of C.I. Pigment Yellow 185 is 0.5 to 30 parts by mass, preferably 3 to 15 parts by mass relative to 100 parts by mass of the yellow pigment.

As the pigment dispersant used in the green pigment dispersion for the color filter used in the present invention, as an essential component, a tertiary amine group and/or quaternary ammonium group and an amine value of 3 mgKOH/g or more are used as essential components. Acrylic polymer with segmented structure.

As such a pigment dispersant, DISPERBYK-2001, DISPERBYK-2000, BYK-LPN6919, BYK-LPN21116, BYK-LPN22102 (all manufactured by BYK-Chemie), etc. can be exemplified, and these can be used alone or in combination.

In the pigment composition of the present invention, the amount of the aforementioned pigment dispersant is relative to It is preferable that it is 1-100 mass parts with respect to 100 mass parts of pigments, and it is more preferable that it is 1-60 mass parts. When the content of the aforementioned pigment dispersant is less than 1 part by mass, the pigment dispersing effect may be reduced. On the other hand, when the content exceeds 100 parts by mass, the developability may be reduced.

In addition to the aforementioned pigment dispersant, a surfactant may be used in combination as necessary. Examples of such surfactants include ionic surfactants and nonionic surfactants, and examples of ionic surfactants include cationic surfactants, anionic surfactants, and amphoteric surfactants. Examples of cationic surfactants include aliphatic amines, quaternary ammonium salts, and alkylpyridinium salts. As anionic surfactants, fatty acid salts, sulfate esters, sulfonates, phosphoric esters, etc. can be exemplified. As an amphoteric active agent, amino acid salt etc. can be illustrated. Examples of nonionic surfactants include polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, polyoxyethylene alkyl esters, sorbitan alkyl esters, and polyoxyethylene sorbitol. Anhydride alkyl esters, etc.

As the solvent used in the green pigment dispersion for color filters used in the present invention, a solvent capable of dissolving the pigment dispersant and stably dispersing the pigment is preferable.

As specific examples of such solvents, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, etc. (poly ) Alkylene glycol monoalkyl ethers; ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, etc. (poly) Alkylene glycol monoalkyl ether acetate; diethylene glycol diethyl ether, diethylene glycol methyl ethyl ether, tetrahydrofuran and other ethers; methyl ethyl ketone, Ketones such as methyl isobutyl ketone, cyclohexanone, 2-heptanone, and 3-heptanone; alkyl lactates such as methyl 2-hydroxypropionate and ethyl 2-hydroxypropionate; 2- Ethyl hydroxy-2-methylpropionate, 3-methyl-3-methoxybutyl propionate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, 3-ethyl Methyl oxypropionate, ethyl 3-ethoxypropionate, ethyl ethoxy acetate, hydroxyacetate, ethyl acetate, n-butyl acetate, isobutyl acetate, n-butyl propionate, ethyl Esters such as methyl acetate, n-pentyl formate and ethyl pyruvate; aromatic hydrocarbons such as toluene and xylene; N-methylpyrrolidone, N,N-dimethylformamide, N,N -Dimethylacetamide and other amides. These solvents can be used alone or in combination of two or more kinds. In addition, the usage amount of these solvents is preferably used in a ratio of 60 to 80% by weight with respect to the total amount of the pigment dispersion.

The green pigment composition for color filters of the present invention is mixed with green pigments, yellow pigments, pigment dispersants, solvents, etc., using ultrasonic dispersion machines, bead mills, three-roll mills, ball mills, sand mills, homogenizers, etc. It is obtained by performing kneading and dispersion treatment with a kneader or the like.

In the aforementioned dispersion treatment, the total amount of the pigment dispersant and/or solvent may be used together with the pigment during the dispersion treatment, or a part of the pigment dispersant may be added after the dispersion treatment.

Generally, the green pigment dispersion for color filters of the present invention, a binder resin, a photopolymerizable compound having one or more photopolymerizable unsaturated bonds in the molecule, a photopolymerization initiator, a solvent as needed, and others The additive mixture of as a pigment dispersion resist composition is used for the formation of color filters. Various compounding agents, preparation methods, etc. at that time are not particularly limited to the past and can be used.

[Example]

Hereinafter, the present invention will be explained more specifically with examples, but the present invention is not limited to these examples. In addition, as long as there is no special description, "parts" and "%" in this embodiment represent "parts by weight" and "% by weight".

<Pigment>

D1155 (C.I. Pigment Yellow 185, trade name Paliotol Yellow D1155, made by BASF)

6268EC (C.I. Pigment Yellow 150, trade name CHROMOFINE YELLOW 6268EC, manufactured by Dainichi Seika Co., Ltd.)

L0960HD (C.I. Pigment Yellow 138, trade name Paliotol Yellow L0960HD, manufactured by BASF)

Green S (C.I. Pigment Green 7, trade name FASTOGEN Green S, manufactured by DIC)

A110 (C.I. Pigment Green 58, trade name FASTOGEN Green A110, manufactured by DIC)

C100 (C.I. Pigment Green 59, trade name FASTOGEN Green C100, manufactured by DIC)

<Pigment Dispersant>

BYK-LPN21116 (Acrylic polymer having a tertiary amine group and a quaternary ammonium group, and a block structure with an amine value of about 29 mgKOH/g, 40% solid content, manufactured by BYK-Chemie)

<Binder Resin>

BnMA/MAA copolymer (benzyl methyl acrylate/methacrylic acid copolymer, theoretical acid value 120mgKOH/g, mass average molecular weight 25,000)

<Solvent>

PGMEA (Propylene Glycol Monomethyl Ether Acetate)

<Photopolymerizable compound>

DPHA (Dipentaerythritol hexaacrylate)

<Photoinitiator>

Ir369 (2-benzyl-(dimethylamino)-1-(4-morpholinophenyl)-1-butanone, trade name Yanjiagu 369, manufactured by BASF)

(D1155 Sulfonate)

Add 30 ml of concentrated sulfuric acid into a 100 ml Erlenmeyer flask, add 10 g of D1155 while stirring with a magnetic stirrer, and stir at room temperature for 30 minutes. A 1L beaker was filled with a mixture of 50 g of water and 50 g of ice, the above reactants were poured into the ice water, and stirred with a magnetic stirrer for 30 minutes. Filter it under reduced pressure. After washing with water, the obtained solid was dried to obtain 12 g of D1155 sulfonate.

(Micronized D1155)

Put 100 parts by mass of D1155, 1000 parts by mass of sodium chloride with a particle size of 20 μm, and 240 parts by mass of diethylene glycol into the kettle of a kneader (trade name: KHD-2, manufactured by Inoue), and knead at 75°C for 10 Hours for salt milling. Next, 1,300 parts by mass of the obtained kneaded product was poured into 3 liters of warm water, and stirred for 1 hour while being heated to 70°C to become a slurry. After repeating filtration and washing with water to remove sodium chloride and diethylene glycol, it was dried at 40°C to obtain 95 parts by mass of micronized D1155.

(Micronized D1155 (containing sulfonate))

Put 100 parts by mass of D1155, 1000 parts by mass of sodium chloride with a particle diameter of 20 μm, 7 parts by mass of D1155 sulfonate, and 240 parts by mass of diethylene glycol into the kettle of a kneader (trade name: KHD-2, manufactured by Inoue), Knead at 75°C for 10 hours for salt milling. Next, 1,300 parts by mass of the obtained kneaded product was poured into 3 liters of warm water, and stirred for 1 hour while being heated to 70°C to become a slurry. After repeating filtration and washing with water to remove sodium chloride and diethylene glycol, it was dried at 40°C to obtain 98 parts by mass of micronized D1155 (containing sulfonate).

<Pigment dispersion composition for color filter>

Mix the above-mentioned micronized pigments or various non-micronized pigments, pigment dispersants, D1155 sulfonate, binder resin (BnMA/MAA copolymer), and organic solvent (PGMEA) into the composition of Table 1, and use 0.2mmΦ oxidation The zirconium beads were kneaded in a paint conditioner for 6 hours to obtain pigment dispersion compositions 1 to 8 for color filters.

<Pigment Dispersed Resist Composition for Color Filter>

Next, the pigment dispersion compositions 1 to 8 for color filters, BnMA/MAA copolymer, DPHA, Ir369, and PGMEA into the composition of Table 2 were uniformly mixed with a high-speed mixer, and filtered with a membrane filter with a pore size of 3 μm to obtain Pigment dispersion resist compositions 1 to 8 for color filters.

<The green pigment dispersion resist compositions for color filters of Examples 1 to 2 and Comparative Examples 1 to 10>

The composition selected from the green pigment dispersion resist compositions 1 to 8 for color filters was uniformly mixed to form the pigment ratio in Table 3 to obtain the color filters of Examples 1 to 2 and Comparative Examples 1 to 10 The green pigment dispersion resist composition.

(Evaluation)

<Evaluation of the color characteristics of the green pigment dispersion resist composition for color filters>

The green pigment dispersion resist compositions for color filters of Examples 1 to 2 and Comparative Examples 1 to 10 were coated on a glass substrate with a spin coater. Next, after pre-baking at 100°C for 3 minutes, it was exposed with a high pressure mercury lamp, and then post-baked at 230°C for 30 minutes. Next, the color characteristics (x, y, Y) of each resist of Examples 1 to 2 and Comparative Examples 1 to 10 were measured with a spectrophotometer (manufactured by Shimadzu Corporation, UV-2500PC, C light source 2° field of view). In Examples 1 to 2 and Comparative Examples 1 to 10, the film thickness and lightness Y at chromaticity x=0.224 and y=0.669 were obtained.

According to Examples 1 to 2 according to the examples of the present invention, it is understood that the green pigment resist composition Y for color filters has a high value and a small film thickness, and therefore has appropriate optical properties as a color filter .

On the other hand, according to Comparative Examples 1 to 10 in which CI Pigment Green 59 is not used but other pigments are used, even if the values of x and y are the same as those in the examples, the value of Y is low, and therefore cannot be suitably used as a color filter .

As can be seen from Table 3, the green pigment dispersion for a color filter in which C.I. Pigment Green 59 was used as the green pigment had very high brightness even if the film thickness was small.

Claims (6)

A green pigment dispersion for color filters, which contains CI Pigment Green 59 as a pigment in a green pigment dispersion for color filters that includes a pigment, a pigment dispersant, and a solvent, wherein the color filter uses green The pigment dispersion further contains a sulfonate of CI Pigment Yellow 185. The green pigment dispersion for a color filter as described in item 1 of the scope of patent application, wherein the pigment dispersant contains a tertiary amine group and/or a quaternary ammonium group, and an amine value of 3 mgKOH/g or more. Acrylic polymer with segmented structure. The green pigment dispersion for a color filter according to item 1 or item 2 of the scope of patent application, wherein the pigment comprises C.I. Pigment Yellow 185. The green pigment dispersion for color filters as described in item 1 or item 2 of the scope of patent application, wherein the mass ratio of the green pigment to the yellow pigment is 95/5~40/60. The green pigment dispersion for a color filter according to item 1 or item 2 of the scope of patent application, wherein the pigment is a pigment that has been micronized. A color filter having a coating layer formed of the green pigment dispersion for a color filter according to any one of items 1 to 5 of the scope of patent application.