JPH1010312A - Color filter with red picture element containing perylenetetracarboxylic acid anhydride pigment and production of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a color filter with a red pixel excellent in transparency, sharpness and heat resistance by forming a red picture element contg. a perylenetetracarboxylic acid anhydride pigment having a specified average particle size of primary particles. SOLUTION: This color filter has a red pixel contg. a perylenetetracar boxylic acid anhydride pigment having 10-50nm average size diameter of primary particles. The pigment may contain various additives and treating agents if the average particle size is 10-50nm. In the case of <10nm average particle size, particles of the pigment cannot be dispersed because of high aggregating force and heat and light resistances are deteriorated. In the case of >50nm, light transmittance is deteriorated and optical characteristics are inferior as compared with the case of a color mixture.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a perylenetetracarboxylic anhydride pigment (CI Pigment Red 2).
The present invention relates to a color filter having a red pixel containing (24) and a method for producing the pigment.

[0002]

2. Description of the Related Art In computers and televisions, liquid crystal display devices have been widely used for the purpose of reducing the thickness of displays and saving power. The liquid crystal display element
Color display can be achieved by combining with a color filter. Conventionally, as a colorant for a color filter, a dye has been mainly used, but a pigment has been used in place of the dye in view of an increase in required quality for light resistance and the like. .

[0003] Pigments used in color filters include:
In addition to being clear and transparent, it is also required to have excellent heat resistance due to the requirements in the color filter manufacturing process.

[0004] Because of such required quality, the red pixel for the color filter has C.I. I. Pigment Red 177 and C.I. I. Pigment Yellow 83, 110, 139
And the like. Further, the primary particle size of the pigment used for these varies.

[0005]

As described above, in the case of a red pixel in which two kinds of pigments are mixed, the mixing ratio of the yellow pigment mixed with the red pigment is large, and it is difficult to obtain good light transmittance and sharpness. In order to solve this problem, it has been proposed to use a solid solution of two or more kinds of pigments as described in, for example, Japanese Patent Application Laid-Open No. 5-281414.

However, the solid solution does not reach the optical characteristics such as transparency and sharpness of a single pigment, and in recent years,
Larger device screens require higher light transmission and contrast than ever before, and when used for color filters,
It was not always satisfactory.

An object of the present invention is to provide a color filter having red pixels having excellent transparency, sharpness and heat resistance.

[0008]

Means for Solving the Problems The present inventors have proposed a perylenetetracarboxylic anhydride pigment (CI.I.) having an average particle diameter in the range of 10 to 50 nm as a red pigment used for a red pixel for a color filter. Pigment Red 22
By using 4), it is possible to use yellow pigments without using them or to reduce the mixing ratio thereof extremely.
The inventors have found that the light transmittance or the sharpness are superior to those of the conventional mixed colors, and have completed the present invention.

That is, in order to solve the above-mentioned problems, the present invention is characterized by (1) having a red pixel containing a perylenetetracarboxylic anhydride pigment having an average primary particle size in the range of 10 to 50 nm. Color filter,
And (2) a method for producing a perylene tetracarboxylic acid anhydride pigment having an average primary particle size in the range of 10 to 50 nm, wherein the crude perylene tetracarboxylic acid anhydride is wet-milled in an alkaline atmosphere. I will provide a.

[0010]

DETAILED DESCRIPTION OF THE INVENTION The perylenetetracarboxylic anhydride pigment (CI Pigment Red 2) used in the present invention is used.
24) may contain various additives and treating agents as long as the average particle size is in the range of 10 to 50 nm. When the average particle diameter is smaller than 10 nm, the cohesive force between the pigments is so strong that the pigments cannot be dispersed, and the heat resistance and the light resistance deteriorate, which is not preferable. On the other hand, when the thickness is larger than 50 nm, the light transmittance is deteriorated, and the optical characteristics are inferior to the case where the colors are mixed.

The average particle size of the primary particles used in the present invention is as follows:
Based on a photograph taken by a transmission electron microscope, 50 to 100 pigment particles are sampled, the major axis and the minor axis are added, divided by 2, and averaged.

[0012] The perylenetetracarboxylic anhydride pigment used in the present invention is, for example, wet milling a crude perylenetetracarboxylic acid using a dispersing machine together with a milling medium in an alkaline atmosphere such as an alkaline solvent. It is obtained by doing.

At the time of wet grinding, various dispersants, additives, resins, solvents and the like can be added. Among these,
An alkali-soluble resin that dissolves in an alkaline atmosphere is particularly preferable from the viewpoint that reaggregation of the pigment during wet grinding can be prevented. When an alkali-soluble resin is used, after wet milling, an acid is added to change the atmosphere from an alkaline atmosphere to an acidic atmosphere to precipitate the resin, or to remove an organic amine such as barium chloride, calcium chloride, or an alkylamine. In addition, it is preferable that the surface treatment of the pigment is performed by insolubilizing the resin by using a metal salt or an amine salt.

As the alkaline solvent, there is no problem even if other additives are contained as long as a water-soluble organic solvent and various alkalis are dissolved in water.

Examples of the water-soluble organic solvent include alcohols such as methyl alcohol, ethyl alcohol, n-butyl alcohol, isobutyl alcohol, tert-butyl alcohol, n-propyl alcohol and isopropyl alcohol; dimethylformaldehyde, dimethylacetamide and the like. Amides; ketones such as acetone and methyl ethyl ketone; ethers such as tetrahydrofuran, dioxane, ethylene glycol methyl ether, ethylene glycol ethyl ether, diethylene glycol methyl ether, diethylene glycol ethyl ether, triethylene glycol monomethyl ether, and triethylene ethylene glycol monoethyl ether , Ethylene glycol, propylene glycol, butylene glycol, trie Glycol, 1, 2, 6
Polyhydric alcohols such as hexanetriol, thiodiglycol, diethylene glycol, polyethylene glycol, polypropylene glycol, and glycerin; N-methyl-pyrrolidone and 1,3-dimethyl-2-imidazolidinone; Among these water-soluble organic solvents, polyhydric alcohols and ethers are preferable. Also,
These water-soluble organic solvents can be used alone or in combination of two or more.

The amount of the water-soluble organic solvent added is water 10
The range of 0 to 100 parts by weight relative to 0 parts by weight is preferable.

As the alkali, for example, ethanolamine, diethanolamine, triethanolamine, N
-Methylethanolamine, N-dimethylethanolamine, N-ethyldiethanolamine, N-diethylethanolamine, diisopropanolamine, 2-amino-2-methylpropanol, 2-ethyl-2-amino-1,3-propanediol, Organic amines such as 2- (aminoethyl) ethanolamine, tris (hydroxymethyl) aminomethane, ammonia, triethylamine, piperidine and morpholine; and inorganic bases such as sodium hydroxide, potassium hydroxide and lithium hydroxide.
These alkalis can be used alone or in combination of two or more.

When an organic amine is used, the amount of the organic amine is preferably in the range of pH 7 to 10 in an alkaline atmosphere. p
When H is lower than 7, grinding tends not to proceed, and when pH exceeds 10, perylenetetracarboxylic acid is dissolved, viscosity during wet grinding increases, and productivity tends to deteriorate. Absent.

Examples of the alkali-soluble resin include known general resins such as natural resins such as rosin and polyvinyl-based, polyester-based, urethane-based and amide-based synthetic resins having an acidic group such as a carboxyl group or a sulfonic acid group. However, the present invention is not particularly limited thereto.

The concentration of the perylenetetracarboxylic acid in the alkali solution is preferably as high as possible if it can be dissolved. Is more preferred.

The concentration of the alkali-soluble resin in the alkali solution is preferably 40% by weight or less, more preferably in the range of 0.5 to 20% by weight, and particularly preferably in the range of 1 to 15% by weight.

Examples of the acid for forming an acidic atmosphere include inorganic acids such as hydrochloric acid and sulfuric acid, and organic acids such as acetic acid and formic acid. It is preferable to use an inorganic acid in consideration of the environment. The addition amount of these acids is sufficient as long as the resin can be precipitated on the pigment surface.

Examples of the dispersing machine used for wet grinding include a bead mill such as a dry mill, a sand mill, and a dyno mill.
Attritors, ball mills and the like can be mentioned. In particular, among these, it is preferable to use a dry mill or a dyno mill that can be manufactured continuously.

As the grinding medium, steel beads, glass beads, ceramic beads and the like can be used, and the size thereof is preferably in the range of 0.1 to 30 mm, and 0.2 to 3 mm.
The range of mm is particularly preferred.

The grinding temperature is not particularly limited, but is preferably in the range from room temperature to the boiling point of the solvent to be used, since devices such as a pressure vessel and a cooling device are not required.

The grinding time is not particularly limited, but a shorter time is preferable because no energy is required.

Since the stirring peripheral speed of the dispersing machine varies depending on the type of the dispersing machine, the type of beads, and the composition of the dispersing medium, the average particle size of the primary particles of the perylene tetracarboxylic anhydride pigment is 10
There is no particular limitation as long as the speed can be adjusted to 50 nm.

The perylenetetracarboxylic anhydride pigment obtained by the production method of the present invention can be used as a wet cake or as a dry pigment after drying and pulverization, for printing inks, paints, plastics, metal inks, printing agents, stationery,
Although it can be used as a colorant for various articles such as toner and jet ink, it can be particularly suitably used for optical elements such as color filters by utilizing its sharpness and transparency.

In order to produce an optical element using a perylenetetracarboxylic anhydride pigment, a thin film containing at least a perylenetetracarboxylic anhydride pigment is formed on a transparent substrate such as a glass plate or a transparent resin film. Just do it.

Examples of the method of forming a thin film include a wet process using a pigment dispersion, such as a spin coating method, a printing method, an electrolytic method, and an electrodeposition method, and a dry process such as vapor deposition and sputtering. Is preferred.

In the method of forming a thin film by a wet process, a resin having film-forming properties can be added to a pigment dispersion containing a perylenetetracarboxylic anhydride pigment, and a surfactant, a dispersant, an antifoaming agent, and a leveling agent can be added. Additives such as agents can also be added.

Examples of the resin having film forming properties include polyester resin, polycarbonate resin, polyvinyl butyral resin, polyvinyl carbazole resin, polystyrene resin, polyvinyl acetate resin, polyvinyl chloride resin,
Polyvinylidene chloride resin, polyvinylidene fluoride resin,
Acrylic resin, methacrylic resin, silicone resin, alkyd resin, melamine resin, melamine-alkyd resin, phenolic resin, polyamide resin, polyurethane resin, polyimide resin, epoxy resin, phenoxy resin,
Styrene-butadiene copolymer, styrene-maleic anhydride copolymer, vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinyl acetate-maleic anhydride copolymer, and the like. These resins having film forming properties can be used alone or in combination of two or more.
In addition, a resin precursor that can generate these resins by the action of heat, light, an electron beam, or the like can also be used.

Solvents that can be used for preparing the pigment dispersion include, for example, hydrocarbons such as toluene, xylene and mineral spirit; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone;
Dichloromethane, dichloroethane, trichloroethane,
Halogenated hydrocarbons such as trichloroethylene and chlorobenzene; ethers such as tetrohydrofuran, dioxane, monoglyme, diglyme and anisole; methanol, ethanol, propanol, butanol, methyl cellosolve, ethyl cellosolve, butyl cellosolve, cyclohexanol and 2-methoxy- 1-propanol,
Alcohols such as 2-butoxy-1-propanol; esters such as ethyl acetate, propyl acetate, butyl acetate, cellosolve acetate, butyl cellosolve acetate, 2-methoxy-1-propyl acetate, and 2-butoxy-1-propyl acetate; dimethyl Amides such as formamide and N-methylpyrrolidone; water; These solvents can be used alone or in combination of two or more.

To prepare a pigment dispersion, a perylenetetracarboxylic anhydride pigment and a solvent, and if necessary, a resin having film-forming properties, additives, etc., are mixed with a ball mill, bead mill, sand mill, pearl mill, paint shaker, What is necessary is just to disperse | distribute by dispersion means, such as a sand grinder, an attritor, a disperser, a homomixer, and an ultrasonic disperser.

[0035]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Production Examples, Examples and Comparative Examples. In the following example,
“Parts” means “parts by weight”.

<Production Example 1> (Production of Perylene Tetracarboxylic Anhydride Pigment) Stavelite Rosin (manufactured by Rika Hercules) 160
, 800 parts of water, 2400 parts of water, 800 parts of isopropyl alcohol and 800 parts of perylenetetracarboxylic anhydride.

Using a stirrer type bead mill (“DCP Mill SF-12” manufactured by Dry Swerke Co.), the mixture was mixed with zirconia beads having a stirrer peripheral speed of 11 m / sec and a diameter of 0.20 mm (Showa Shell Sekiyu Sekiyu KK). The dispersion was dispersed for 2 hours under the conditions of a filling rate of 83% of "Micro Haika Z200" manufactured by Fuji Chemical Co., Ltd. and a dispersion temperature of 28 ° C. to obtain a pigment dispersion having a pH of 8.5.

To this pigment dispersion, 3800 parts of water was added and stirred, and 1N hydrochloric acid was further added until the pH of the content became 4.9 to obtain a suspension in which a resin was deposited on the pigment surface. Was. After the suspension was filtered to separate a wet cake-like suspension, the wet cake was washed with water until the pH of the washing solution became nearly neutral. Thereafter, the wet cake washed with water is dried and then pulverized to obtain a perylene tetracarboxylic anhydride pigment (CI Pigment Red 22).
4) was obtained. The average primary particle size of the pigment is 25 n
m.

<Production Example 2> (Production of perylene tetracarboxylic anhydride pigment) 400 parts of perylene tetracarboxylic anhydride and 360 parts of water
0 parts, add dimethylaminoethanol and adjust pH.
9.8.

Using a stirrer type bead mill (“DCP Mill SF-12” manufactured by Dry Swerke Co.), the mixture was stirred with a zirconia bead having an outer peripheral speed of 11 m / sec and a diameter of 0.20 mm (Showa Shell Sekiyu KK) The dispersion was dispersed for 1 hour under the conditions of a filling rate of 83% and a dispersion temperature of 28 ° C. of “Micro Haika Z200” manufactured by Co., Ltd., to obtain a pigment dispersion having a pH of 9.5. However, dimethylaminoethanol was appropriately added to maintain the pH at 9.5 during dispersion.

To this pigment dispersion, 3800 parts of water was added and stirred, and 1N hydrochloric acid was further added until the pH of the content became 5.0 to obtain a suspension. After the suspension was filtered to separate a wet cake-like suspension, the wet cake was washed with water until the pH of the washing solution became nearly neutral. Thereafter, the wet cake washed with water was dried and pulverized to obtain a perylene tetracarboxylic anhydride pigment (CI Pigment Red 224). The average primary particle size of the pigment was 45 nm.

<Production Example 3> (Production of Perylene Tetracarboxylic Anhydride Pigment) 262.3 parts of "Johncryl 61J" aqueous solution (styrene acrylic resin manufactured by Johnson Polymer), water 293
7.7 parts, 400 parts of dimethylformaldehyde and 800 parts of perylenetetracarboxylic anhydride were mixed.

Using a stirrer type bead mill (“DCP Mill SF-12” manufactured by Dry Swerke Co.), the mixture was stirred at an outer peripheral speed of 11 m / sec and zirconia beads having a diameter of 0.20 mm (Showa Shell Sekiyu KK) Was dispersed for 2 hours under the conditions of a filling rate of 83% and a dispersion temperature of 28 ° C. Dimethylaminoethanol was appropriately added to maintain the pH at 9.0 during dispersion.

To this pigment dispersion, 3800 parts of water was added and stirred, and 1N hydrochloric acid was further added until the pH of the content became 4.0 to obtain a suspension in which a resin was deposited on the pigment surface. Was. After the suspension was filtered to separate a wet cake-like suspension, the wet cake was washed with water until the pH of the washing solution became nearly neutral. Thereafter, the washed wet cake is dried and then pulverized to obtain a perylenetetracarboxylic anhydride pigment (CI Pigment Red 22).
4) was obtained. The average primary particle size of the pigment is 32 n
m.

<Production Example 4> (Production of perylenetetracarboxylic anhydride pigment) 400 parts of perylenetetracarboxylic anhydride and 360 parts of water
0 parts were mixed. This mixture is stirred with a bead mill (“DCP Mill SF-12” manufactured by Dry Swerke).
Using a stirrer, peripheral speed of 11 m / sec, diameter 0.20 mm
Of zirconia beads ("Micro Haika Z200" manufactured by Showa Shell Sekiyu KK) is 83%, and the suspension dispersion temperature is 28.
The mixture was dispersed for 1 hour under the condition of ° C. to obtain a pigment dispersion.

After the pigment dispersion was filtered to separate a wet cake-like suspension by filtration, the wet cake was washed with water until the pH of the washing solution became nearly neutral. Thereafter, the wet cake washed with water was dried and then pulverized to obtain a pigment of perylenetetracarboxylic anhydride pigment (CI Pigment Red 224). The average primary particle size of the pigment was 60 nm.

<Production Example 5> (Production of solid solution pigment) I. Pigment Red 177 (30 parts) and C.I.
I. 10 parts of Pigment Yellow 83 were dissolved in 240 parts of sulfuric acid. The solution was slowly added to 600 parts of water at 15 ° C. to precipitate a pigment. The precipitated pigment was filtered, and the pigment collected by filtration until the washing liquid was about neutral was washed with water and dried to obtain a solid solution pigment.

<Example 1> (Preparation and evaluation of optical element) In a glass container, 2 parts of the perylenetetracarboxylic anhydride pigment obtained in Production Example 1 and an ultraviolet curable acrylic resin (Dainippon Ink Chemical Co., Ltd.) "Unidick S5-122")
4 parts, 94 parts of 2-butoxy-1-propanol and 0.1 part of 0.1 part.
300 parts of 4 mm zirconia beads were added, and the mixture was shaken with a paint shaker for 2 hours to prepare a coating solution.

"Irgacure 651" (a photopolymerization initiator manufactured by Ciba Geigy) was added to the coating solution thus obtained.
0.2 parts were added, and the mixture was applied on a glass plate (7059: manufactured by Corning Co., Ltd.) using a spin coater (1H-3D type: manufactured by Mikasa Co., Ltd.), dried at room temperature, and then By irradiating ultraviolet rays for 15 seconds under a mercury lamp, the ultraviolet-curable acrylic resin was cured to obtain a colored glass plate usable as an optical element. The application conditions were 200 rpm for 10 seconds, and then 2000 rpm for 30 seconds.

The transmission spectrum of the optical element thus obtained was measured by a spectrophotometer (“U-3500” manufactured by Hitachi, Ltd.).
As a result, the wavelength was 650 nm and the wavelength was 45 nm.
The transmittance at 0 nm is 85.2% and 0.5%, respectively.
Met.

<Example 2> (Preparation and evaluation of optical element) In Example 1, the perylenetetracarboxylic anhydride obtained in Production Example 2 was replaced with the perylenetetracarboxylic anhydride pigment obtained in Production Example 1. An optical element was obtained in the same manner as in Example 1, except that a pigment was used.

The wavelength of the optical element thus obtained is 650.
at 0.4 nm and 450 nm respectively.
And 1.5%.

<Example 3> (Preparation and evaluation of optical element) In Example 1, the perylenetetracarboxylic anhydride obtained in Production Example 3 was used instead of the perylenetetracarboxylic anhydride pigment obtained in Production Example 1. An optical element was obtained in the same manner as in Example 1, except that a pigment was used.

The wavelength of the optical element thus obtained is 650.
at 450 nm and 84.4%, respectively.
And 1.6%.

<Comparative Example 1>
In place of the perylene tetracarboxylic anhydride pigment obtained in the above,
An optical element was obtained in the same manner as in Example 1, except that the perylenetetracarboxylic anhydride pigment obtained in Production Example 4 was used.

The wavelength 650 of the optical element thus obtained was obtained.
The transmittance at 7 nm and 450 nm was 78.3%, respectively.
And 2.1%, and the color purity and the transparency were inferior to those of the optical elements obtained in the respective examples.

<Comparative Example 2>
Instead of 2 parts of perylene tetracarboxylic anhydride pigment obtained in the above, "Fastogen Sup
er Red) ATY-TR "(CI Pigment Red 177 manufactured by Dainippon Ink and Chemicals, Inc.), 1.5 parts of dry pigment and" Shimule Fast Yellow "
r Fast Yellow) 4181 "(CI Pigment Yellow 83, manufactured by Dainippon Ink and Chemicals, Incorporated) was used in the same manner as in Example 1 except for using 0.5 part.

The wavelength of the optical element thus obtained was 650.
The transmittance at 7 nm and 450 nm was 76.4%, respectively.
And 3.0%, and the color purity and the transparency were inferior to those of the optical elements obtained in the respective examples.

<Comparative Example 3>
An optical element was obtained in the same manner as in Example 1, except that 2 parts of the solid solution pigment obtained in Production Example 5 was used instead of 2 parts of the perylene tetracarboxylic anhydride pigment obtained in.

The wavelength of the optical element thus obtained is 650.
The transmittance at 7 nm and 450 nm is 79.4%, respectively.
And 2.1%, and the color purity and the transparency were inferior to those of the optical elements obtained in the respective examples.

[0061]

The color filter of the present invention contains a perylenetetracarboxylic anhydride pigment having an average primary particle size in the range of 10 to 50 nm in a red pixel, thereby providing transparency and color purity (clearness). ) And heat resistance are obtained.

The perylenetetracarboxylic anhydride pigment having an average primary particle size in the range of 10 to 50 nm obtained by the production method of the present invention is excellent in transparency, sharpness and heat resistance. It can be suitably used for optical elements, especially for color filters.

Claims (4)

[Claims] 1. A color filter comprising a red pixel containing a perylenetetracarboxylic anhydride pigment having an average primary particle size in the range of 10 to 50 nm. 2. Production of a perylene tetracarboxylic anhydride pigment having an average primary particle size of 10 to 50 nm, wherein the crude perylene tetracarboxylic anhydride is wet-milled in an alkaline atmosphere. Method. 3. The method according to claim 2, wherein the wet grinding is carried out in the presence of an alkali-soluble resin. 4. The average particle diameter of primary particles is 10 to 50 nm.
Perylene tetracarboxylic anhydride pigment in the range of,
The color filter according to claim 1, which is manufactured by the manufacturing method according to claim 2 or 3.