TW201739845A - Green pigment dispersion for color filter and color filter - Google Patents

Abstract

Provided is a green pigment dispersion for color filters, ensuring excellent color properties. More specifically, provided is a green pigment dispersion for color filters. To this end, the green pigment dispersion for color filters contains a pigment, a pigment dispersion agent, and a solvent, and a C.I. pigment green 59 is used as the pigment.

Description

Green pigment dispersion for color filters

The present invention relates to a green pigment dispersion and a green coloring composition which are mainly used in the production of an optical color filter for a transmissive or reflective type color liquid crystal display.

The color filter is configured by arranging two or more fine bands (strips) of different hue in parallel on the surface of a transparent substrate such as glass, or arranging fine pixels in a vertical and horizontal arrangement. The pixel size is a fine shape of several 10 to several hundred μm, and each hue is neatly arranged in a predetermined order. Therefore, various methods have been proposed for the method of manufacturing a color filter.

Since the color filter requires high transparency, it has been conventionally manufactured by a so-called dyeing method: the following steps are repeated three times, and a heavy weight is added to an aqueous solution of a dyeable natural polymer such as gelatin or casein. A sensitizer such as chromic acid is photo-sensitized, a pixel pattern is formed by photolithography, and then the pixel pattern is dyed to a desired color to obtain a color pattern, thereby forming a three-color transparent colored fine pattern.

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

In order to meet this demand, an organic pigment excellent in light resistance and heat resistance is used as a color material for forming a color filter, and a dye having excellent color properties but limited heat resistance and light resistance is used.

When a color filter is produced using a radiation sensitive colored resin composition in which an organic pigment is dispersed, a radiation sensitive colored resin composition in which an organic pigment is dispersed is applied onto a transparent substrate or a substrate on which a light shielding layer to be patterned is formed in advance. After drying, the dried coating film is exposed to a desired pattern and developed to obtain pixels of respective colors.

However, in the case of using a radiation sensitive colored resin composition in which an organic pigment is dispersed, for example, in a color filter in which three primary colors of blue, green, and red light are arranged on a transparent substrate, in general, It is difficult to obtain a spectral spectrum of each color filter as a single pigment, and therefore it is necessary to prepare using two or more kinds of pigments.

In the green color filter, as described in Patent Documents 1 to 3, 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, etc., raises the demand for the color characteristics of the color filter, and only the combination of these types of pigments has limitations in improving the color characteristics of the color filter.

The green pigment excellent in color characteristics is C.I. Pigment Green 59. However, since the production of the pigment dispersion liquid is technically difficult, it has not been put to practical use. [Prior Art Literature]

[Patent Document 1] Japanese Laid-Open Patent Publication No. Hei. No. Hei. No. Hei. No. Hei.

[Problems to be Solved by the Invention] In view of the problems of the prior art, an object of the present invention is to provide a green pigment dispersion for a color filter excellent in color characteristics.

[Means for Solving the Problem] In order to solve such a problem, the present inventors have conducted various studies on a green pigment, a combination of a yellow pigment as needed, and a pigment dispersant which finely disperses them. The present invention has been accomplished by solving the above problems by a green main pigment, a yellow pigment as a coloring pigment, and a specific substance as a pigment dispersing agent for finely dispersing a pigment.

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

Further, the invention (2) is the green pigment dispersion for a color filter according to the above (1), wherein the pigment dispersant comprises a tertiary amino group and/or a quaternary ammonium group, and has 3 mgKOH/ An acrylic polymer having a block type structure of an amine value of g or more.

Further, the invention (3) is the green pigment dispersion for a color filter according to the above item (1) or (2), wherein the pigment comprises C.I. Pigment Yellow 185.

The green pigment dispersion for a color filter according to any one of the preceding claims, wherein the mass ratio of the green pigment to the yellow pigment is 95. /5 to 40/60.

The green pigment dispersion for a color filter according to any one of the above aspects, wherein the pigment is a microparticulated pigment.

The green pigment dispersion for a color filter according to any one of the above aspects, wherein the sulfonate of C.I. Pigment Yellow 185 is further contained.

Further, the invention (7) relates to a color filter comprising the coating layer formed of the green pigment dispersion for a color filter according to the above (1) to (6).

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

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

As the green pigment, C.I. Pigment Green 59 (pigment index name) was used as an essential component. By using C.I. Pigment Green 59, the obtained green coloring composition of the color filter has a thin layer, high brightness, and excellent color 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 lower the light transmittance of C.I. Pigment Green 59. Further, when the thickness of the coating film obtained by the green coloring composition for a color filter 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; and y is 0.650 to 0.705. 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 preferably used for the purpose of the present invention, and other yellow pigments may be used in combination as long as the light transmittance of C.I. Pigment Yellow 185 is not substantially lowered.

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

In order to obtain high definition or high contrast, the pigment of the present invention preferably uses a micronized pigment. By performing the microparticulation treatment, the primary particle diameter of the pigment can be made finer and more uniform. As the above-mentioned microparticulation treatment, for example, it is preferable to carry out a micronization treatment by salt milling, and to include an untreated coloring pigment and a water-soluble inorganic salt (sodium chloride, cesium chloride, potassium chloride, etc., preferably sodium chloride, Further, the average particle diameter of the water-soluble inorganic salt to be used is preferably 50 μm or less, and a water-soluble dispersion medium (alkoxy alcohol, glycol, ether, etc.) which does not substantially dissolve the water-soluble inorganic salt. TRI-MIX (trade name) manufactured by Inoue Seisakusho Co., Ltd., which is a planetary mixer described in JP-A-2006-192385, is used as a mixture, as a mixture, a kneader, a roll mill, a ball mill, a vertical ball mill, a sand mill, and a sand mill. After mixing with a kneading apparatus such as MIRACLE KCK manufactured by Asada Iron Works Co., Ltd. in a continuous uniaxial kneader, the water-soluble inorganic salt and the water-soluble dispersion medium are removed.

In the present invention, a sulfonate of C.I. Pigment Yellow 185 is preferably used in combination. Specifically, a method of using a sulfonate of CI Pigment Yellow 185 in combination with a microparticulation treatment of a yellow pigment, or a method of dispersing a sulfonate of CI Pigment Yellow 185 in the step of dispersing a single microparticulated yellow pigment may be mentioned. . C.I. The amount of the sulfonate of the pigment yellow 185 is from 0.5 to 30 parts by mass, preferably from 3 to 15 parts by mass, per 100 parts by mass of the yellow pigment.

As a pigment dispersant used for the green pigment dispersion for a color filter used in the present invention, as the essential component, an intercalation having a tertiary amino group and/or a quaternary ammonium group and having an amine value of 3 mgKOH/g or more is used. An acrylic polymer having a segment structure. As such a pigment dispersing agent, DISPERBYK-2001, DISPERBYK-2000, BYK-LPN6919, BYK-LPN21116, BYK-LPN22102 (all manufactured by BYK-Chemie Co., Ltd.) and the like can be exemplified, and they can be used singly or in combination.

In the pigment composition of the present invention, the amount of the pigment dispersant used is preferably from 1 to 100 parts by mass, more preferably from 1 to 60 parts by mass, per 100 parts by mass of the pigment. When the content of the pigment dispersant is less than 1 part by mass, the pigment dispersion effect may be lowered. On the other hand, when it exceeds 100 parts by mass, the developability may be lowered.

Further, in addition to the aforementioned pigment dispersant, a surfactant may be used in combination as needed. Examples of such a surfactant include an ionic surfactant and a nonionic surfactant. Examples of the ionic surfactant include a cationic surfactant, an anionic surfactant, and an amphoteric surfactant. The cationic surfactant may, for example, be an aliphatic amine, a quaternary ammonium salt or an alkylpyridinium salt. The anionic surfactant may, for example, be a fatty acid salt, a sulfate, a sulfonate or a phosphate. As the amphoteric active agent, an amino acid salt or the like can be exemplified. Examples of the nonionic surfactant include polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, polyoxyethylene alkyl esters, sorbitan alkyl esters, and polyoxyethylene sorbitol. Anhydride alkyl esters and the like.

The solvent used for the green pigment dispersion for color filters used in the present invention is preferably a solvent capable of dissolving the pigment dispersant and stably dispersing the pigment. Specific examples of such a solvent include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, and the like. Alkylene glycol monoalkyl ethers; ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate (poly) Alkyl glycol monoalkyl ether acetate; ethers such as diethylene glycol diethyl ether, diethylene glycol methyl ethyl ether, tetrahydrofuran; methyl ethyl ketone, methyl isobutyl ketone, ring a ketone such as ketone, 2-heptanone or 3-heptanone; an alkyl lactate such as methyl 2-hydroxypropionate or ethyl 2-hydroxypropionate; 2-hydroxy-2-methylpropionic acid Ethyl ester, 3-methyl-3-methoxybutyl propionate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, methyl 3-ethoxypropionate, 3 - Ethyl ethoxypropionate, Ethyl ethoxyacetate, hydroxyacetate, ethyl acetate, n-butyl acetate, isobutyl acetate, n-butyl propionate, methyl acetate, n-methyl formate Esters of esters, ethyl pyruvate, etc.; toluene, dimethyl Like aromatic hydrocarbons; N-methylpyrrolidone, N, N- dimethylformamide, N, N- dimethylacetamide and the like Amides. These solvents may be used singly or in combination of two or more. Further, the amount of these solvents used is preferably used in a proportion of 60 to 80% by weight based on the total amount of the pigment dispersion.

The green pigment composition for a color filter of the present invention is obtained by mixing a green pigment, a yellow pigment, a pigment dispersant, a solvent, etc., using an ultrasonic disperser, a bead mill, a three-roll mill, a ball mill, a sand mill, a homogenizer, A kneading machine or the like is obtained by kneading and dispersing a treatment.

In the dispersion treatment described above, the pigment dispersant and/or the solvent may be used together with the pigment in the dispersion treatment, or a part of the pigment dispersant may be added after the dispersion treatment.

In general, the green color pigment dispersion of the color filter of the present invention and a binder resin, a photopolymerizable compound having one or more photopolymerizable unsaturated bonds in the molecule, a photopolymerization initiator, a solvent as needed, and the like The additive mixture is used as a pigment dispersion resist composition for the formation of a color filter. The various compounding agents, preparation methods, and the like at that time are not particularly limited to the conventional ones and can be used. [Examples]

Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited to the examples. Further, "parts" and "%" in the present embodiment mean "parts by weight" and "% by weight" unless otherwise specified. <Pigment> D1155 (CI Pigment Yellow 185, trade name: Paliotol Yellow D1155, manufactured by BASF Corporation) 6268EC (CI Pigment Yellow 150, trade name CHROMOFINE YELLOW 6268EC, manufactured by Daisei Seiki Co., Ltd.) L0960HD (CI Pigment Yellow 138, trade name Paliotol Yellow L0960HD, manufactured by BASF Corporation) Green S (CI Pigment Green 7, trade name FASTOGEN Green S, manufactured by DIC Corporation) A110 (CI Pigment Green 58, product name FASTOGEN Green A110, manufactured by DIC Corporation) C100 (CI Pigment Green 59, trade name FASTOGEN Green C100, manufactured by DIC Corporation <Pigment Dispersant> BYK-LPN21116 (acrylic polymer having a tertiary structure and a quaternary ammonium group and having a block structure of about 29 mgKOH/g amine value, solid content 40) %, BYK-Chemie Co., Ltd.) <Binder resin> BnMA/MAA copolymer (methyl methacrylate/methacrylic acid copolymer, theoretical acid value: 120 mgKOH/g, mass average molecular weight: 25,000) <solvent> PGMEA ( Propylene glycol monomethyl ether acetate) <Photopolymerizable compound> DPHA (dipentaerythritol hexaacrylate) <Photopolymerization initiator> Ir369(2-benzyl-(dimethylamino)-1-(4- Morpholino phenyl) -1-butanone, under the trade name Irgacure 369, BASF Corporation)

(D1155 sulfonate) 30 ml of concentrated sulfuric acid was placed in a 100 ml Erlenmeyer flask, and 10 g of D1155 was placed while stirring with a magnetic stirrer, and the mixture was stirred at room temperature for 30 minutes. A 1 L beaker was charged with a mixture of 50 g of water and 50 g of ice, and the above reaction was poured into the ice water and stirred with a magnetic stirrer for 30 minutes. This was filtered and washed with water under reduced pressure, and the obtained solid was dried to obtain 12 g of D1155 sulfonate. (Micronized D1155) 100 parts by mass of D1155, 1000 parts by mass of sodium chloride having a particle diameter of 20 μm, and 240 parts by mass of diethylene glycol were placed in a kettle of a kneading machine (trade name: KHD-2, manufactured by Inoue Co., Ltd.). The mixture was kneaded at ° C for 10 hours for salt milling. Next, 1300 parts by mass of the obtained kneaded product was placed in 3 liters of warm water, and the mixture was stirred for 1 hour while being heated to 70 ° C to obtain a slurry. After repeatedly filtering and washing with water to remove sodium chloride and diethylene glycol, the mixture was dried at 40 ° C to obtain 95 parts by mass of micronized D1155. (Micronized D1155 (containing a sulfonate)) 100 parts by mass of D1155, 1000 parts by mass of sodium chloride having a particle diameter of 20 μm, and 7 parts by mass of D1155 sulfonate were placed in a kettle of a kneader (trade name: KHD-2, manufactured by Inoue Co., Ltd.). The compound and 240 parts by mass of diethylene glycol were kneaded at 75 ° C for 10 hours for salt milling. Next, 1300 parts by mass of the obtained kneaded product was placed in 3 liters of warm water, and the mixture was stirred for 1 hour while being heated to 70 ° C to obtain a slurry. After repeatedly filtering and washing with water to remove sodium chloride and diethylene glycol, the mixture was dried at 40 ° C to obtain 98 parts by mass of micronized D1155 (containing a sulfonate).

<Pigment Dispersion Composition for Color Filter> The above-mentioned finely divided pigment or non-micronized pigment, pigment dispersant, D1155 sulfonate, binder resin (BnMA/MAA copolymer), and organic solvent (PGMEA) are tabulated. The composition of 1 was mixed, and the zirconia beads of 0.2 mmφ were kneaded by a paint conditioner for 6 hours to obtain pigment dispersion compositions 1 to 8 for color filters.

Table 1

<Pigment-dispersed resist composition for color filter> Next, the pigment dispersion compositions 1 to 8 for color filters and BnMA/MAA copolymer, DPHA, Ir369, and PGMEA were made into the composition of Table 2 using a high-speed mixer. After mixing, the mixture was filtered through a membrane filter having a pore size of 3 μm to obtain pigment-dispersed resist compositions 1 to 8 for color filters.

Table 2

<Green pigment-dispersed resist composition for color filters of Examples 1 and 2 and Comparative Examples 1 to 10> Composition selected from green pigment-dispersed resist compositions 1 to 8 for color filters The pigment ratio in Table 3 was uniformly mixed, and the green pigment-dispersed resist compositions for color filters of Examples 1 and 2 and Comparative Examples 1 to 10 were obtained.

table 3

(Evaluation) <Evaluation of Color Characteristics of Green Pigment Dispersion Resist Composition for Color Filters> Color filters for Examples 1 and 2 and Comparative Examples 1 to 10 were used for green pigment dispersion resist compositions A spin coater is applied to the glass substrate. Next, after prebaking 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 the respective resists of Examples 1 and 2 and Comparative Examples 1 to 10 were measured by 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 the lightness Y at chromaticity x = 0.224 and y = 0.669 were obtained.

According to the first to second embodiments according to the examples of the present invention, it is understood that since the green pigment resist composition Y for a color filter has a high value and a small film thickness, it has appropriate optical properties as a color filter. . On the other hand, in Comparative Examples 1 to 10 in which other pigments were used without using CI Pigment Green 59, even if the values of x and y were the same as in the examples, since the value of Y was low, it could not be suitably used as a color filter. .

As is clear from Table 3, the green pigment dispersion for a color filter using C.I. Pigment Green 59 as a green pigment has a very small film thickness and a very high brightness.

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Claims (7)

A green pigment dispersion for a color filter comprising C.I. Pigment Green 59 as a pigment in a green pigment dispersion for a color filter comprising a pigment, a pigment dispersant and a solvent. The green pigment dispersion for a color filter according to claim 1, wherein the pigment dispersant comprises an intercalation having a tertiary amino group and/or a quaternary ammonium group and having an amine value of 3 mgKOH/g or more. An acrylic polymer having a segment structure. The green pigment dispersion for a color filter according to claim 1 or 2, wherein the pigment comprises C.I. Pigment Yellow 185. The green pigment dispersion for a color filter according to any one of claims 1 to 3, wherein a mass ratio of the green pigment to the yellow pigment is 95/5 to 40/60. The green pigment dispersion for a color filter according to any one of claims 1 to 4, wherein the pigment is a microparticulated pigment. The green pigment dispersion for color filters according to any one of claims 1 to 5, further comprising a sulfonate of C.I. Pigment Yellow 185. A color filter comprising a coating layer formed of a green pigment dispersion for a color filter according to any one of claims 1 to 6.