JP2001220520A - Pigment for color filter and its production method, and colored resin composition and color filter prepared by using same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pigment for color filters which is excellent in resistances to heat and light, has a high lightness, and gives a color filter having a good resistance to NMP; a production method therefore; and a coloring composition for filters and a color filter both prepared by using the pigment. SOLUTION: The production method for the pigment comprises kneading a mixture containing (A) a diketopyrrolopyrrole pigment, (B) a colorant derivative, (C) a water-soluble inorganic salt, and (D) a water-soluble organic solvent which does not substantially dissolve salt (C) and removing salt (C) and solvent (D) from the kneaded mixture. The coloring composition is prepared by dispersing the pigment in a clear resin. The color filter has pixels formed by using the coloring composition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pigment used for a color filter used in a color liquid crystal display device and a solid-state image sensor, a method for producing the same, a coloring composition using the pigment, and a color using the coloring composition. Regarding filters.

[0002]

2. Description of the Related Art A color filter is one in which two or more types of fine bands (stripe) of different hues are arranged in parallel or intersecting on the surface of a transparent substrate such as glass or the like, and fine pixels are arranged in a constant vertical and horizontal direction. It consists of those arranged in. The pixels are as fine as several tens to several hundreds of microns, and are arranged in a predetermined arrangement for each hue. A color filter is used in a color liquid crystal display device, and a transparent electrode for driving a liquid crystal is generally formed on the color filter by vapor deposition or sputtering. Is formed. In order to sufficiently obtain the performance of these transparent electrodes and alignment films, it is necessary to perform the formation step at a high temperature of generally 200 ° C. or higher, preferably 230 ° C. or higher.

[0003] For this reason, at present, as a method for producing a color filter, a method called a pigment dispersion method using a pigment having excellent light resistance and heat resistance as a coloring agent is mainly used, and the following two methods are mainly used. Manufactures color filters. In the first method, a dispersion of a pigment in a photosensitive transparent resin solution is applied to a transparent substrate such as glass, the solvent is removed by drying, pattern exposure of one filter color is performed, and then an unexposed portion is exposed. Is removed in the developing step to form a first color pattern, and if necessary, a treatment such as heating is applied. Then, the same operation is sequentially repeated for all the filter colors to produce a color filter.

In the second method, a dispersion of a pigment in a transparent resin solution is applied to a transparent substrate such as glass, the solvent is removed by drying, and a resist such as a positive resist is applied to the coating film. Then, a pattern exposure of one filter color is performed and developed to form a resist pattern. Using this as an etching resist, the pigment-dispersed coating film without the resist pattern is removed with an etchant, and the resist coating film is peeled off. After the first color pattern is formed, and if necessary, processing such as heating is applied, the same operation is sequentially repeated for all filter colors, whereby a color filter can be manufactured. The development of the resist and the etching of the pigment-dispersed coating film can be performed simultaneously.

[0005] In the above-mentioned method, dianthraquinone pigments, perylene-based pigments, diketopyrrolopyrrole-based pigments and the like have hitherto been used for the production of red filters. In particular,
Diketopyrrolopyrrole pigments have high lightness, light resistance,
Because of their excellent heat resistance, they are increasingly used as pigments for color filters. However, there is a strong demand for pigments having higher lightness. For this purpose, it is necessary to further refine the primary particle diameter of the diketopyrrolopyrrole-based pigment to improve transparency.

On the other hand, as a method for reducing the primary particle diameter of a pigment, Japanese Patent Application Laid-Open No. Hei 7-13016 discloses a method in which a pigment is prepared by solidifying a pigment at room temperature with a water-insoluble synthetic resin, a water-soluble inorganic salt such as salt, and the like. After mechanically kneading with a kneader or the like together with a water-soluble organic solvent that at least partially dissolves the synthetic resin (hereinafter, kneading a mixture containing a pigment, a water-soluble inorganic salt and a water-soluble organic solvent is referred to as salt milling. There is a method of removing inorganic salts and organic solvents by washing with water. In this method, since the primary particles of the pigment are pulverized and the crystal growth occur in parallel, a pigment having a small particle size distribution and a small average particle size is obtained, but a small surface area is obtained. This method is suitable for applications that require a pigment having a large diameter to be dispersed at a high concentration.

However, diketopyrrolopyrrole pigments are
> NH and C = O as a control,
There is a property that crystal growth is easy due to hydrogen bonding, and when salt milling treatment is performed with diketopyrrolopyrrole pigment alone,
There is a problem that crystal growth proceeds more than pulverization of primary particles and conversely, the particle diameter becomes large, and it has been regarded as a pigment unsuitable for salt milling. On the color filter, an alignment film is formed via a transparent electrode. Polyimide is generally used for the alignment film material, and a soluble material such as N-methylpyrrolidone (hereinafter referred to as NMP) is used. A solution obtained by dissolving a polyamic acid, which is a precursor of polyimide, in a basic solvent having a very high viscosity is applied to form an alignment film. However, a red filter using a conventional diketopyrrolopyrrole pigment has a drawback that the resistance to NMP is insufficient.

[0008]

DISCLOSURE OF THE INVENTION The present invention relates to a pigment for a color filter which provides a red filter having excellent heat resistance and light resistance, high brightness and good resistance to NMP, a method for producing the same, and a color using the same. It is intended to provide a coloring composition for filters and a color filter.

[0009]

Means for Solving the Problems The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, have found that diketopyrrolopyrrole-based pigments can be used for salt milling by using a dye derivative. It has been found that the crystal growth of the pyrrole pigment is suppressed, a primary particle having a fine and transparent pigment is obtained, and that the red filter formed using the pigment has good resistance to NMP. Was. It is not clear why the red filter formed using the diketopyrrolopyrrole pigment obtained by salt milling in the presence of the dye derivative has good resistance to NMP, but the shape of the primary particles of the obtained pigment is not clear. This is thought to be due to the small grain size of the rice and the small surface area for the small primary particle diameter as described above.

That is, the present invention provides a diketopyrrolopyrrole pigment (A), a dye derivative (B), a water-soluble inorganic salt (C), and a water-soluble organic salt which does not substantially dissolve the water-soluble inorganic salt (C). A pigment for a color filter, which is obtained by kneading a mixture containing a solvent (D) and then removing a water-soluble inorganic salt (C) and a water-soluble organic solvent (D). The present invention also provides the color filter pigment, wherein the dye derivative (B) is a quinacridone derivative and / or a diketopyrrolopyrrole derivative. The present invention is also a method for producing the color filter pigment. Further, the present invention is a coloring composition for a color filter, wherein the pigment for a color filter is dispersed in a transparent resin. Further, the present invention is a color filter comprising a pixel formed using the coloring composition for a color filter.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The pigment for a color filter of the present invention is specifically a diketopyrrolopyrrole pigment (A),
A mixture containing the dye derivative (B), the water-soluble inorganic salt (C), and the water-soluble organic solvent (D) that does not substantially dissolve the water-soluble inorganic salt (C) is mechanically kneaded with a kneader or the like, and then mixed with water. Into a slurry by stirring with a high-speed mixer or the like, and then the slurry is filtered and washed with water to remove the water-soluble inorganic salt (C) and the water-soluble organic solvent (D).

The diketopyrrolopyrrole (hereinafter, referred to as DPP) pigment (A) is a red pigment having a structure represented by the following general formula.
An orange pigment with excellent light and heat resistance. Specific examples of the DPP-based pigment represented by the following general formula are represented by color index numbers. I. Pigment
Red 254, 255, 264 and C.I. I. Pig
Ment Orange 71.

[0013]

Embedded image

The dye derivative (B) is a compound in which a substituent is introduced into the molecule of an organic dye, and has a DP at the time of salt milling.
It functions to suppress the crystal growth of the P-based pigment.
The structure of the organic dye serving as the parent of the dye derivative is DP
P, quinacridone, anthraquinone, perylene, perinone, isoindoline, quinophthalone,
There are metal complex systems and the like. The organic dye may be a pale yellow aromatic polycyclic compound such as a naphthalene-based or anthraquinone-based compound which is not generally called a dye. Among them, a dye derivative having a DPP-based or quinacridone-based dye as a parent skeleton is particularly preferred because of its high effect of suppressing the crystal growth of the DPP-based pigment. Further, as the dye derivative, a derivative having a yellow, orange, or red hue that has little effect on the hue of the DPP-based pigment is preferably used.

The substituents to be introduced into the organic dye include a hydroxyl group, a carboxyl group, a sulfonic group, a carbamoyl group,
Examples thereof include a sulfonamide group and a basic substituent represented by the following general formula.

Embedded image X: a direct _{bond, -CH 2 NHCOCH 2 -, -} SO 2 N
H -, - CONHOCH ₂ NH-, or - (CH _2)
q represents NH-. R ₁ and R ₂ each independently represent a saturated or unsaturated alkyl group which may be substituted, or nitrogen as R ₁ and R ₂ ;
Represents an optionally substituted heterocycle containing an oxygen or sulfur atom.

[0016]

Embedded imageZ: direct bond, -SO_Two-, -CO-, -CH_TwoNHC
OCH_Two-,-(CH _Two)_q-, -SO_TwoNH-, -C
ONH-, -CH_TwoNHCOCH_TwoNH- or-
(CH_Two)_qRepresents NH-. Here, q is an integer of 1 to 10.
Represents a number. R_Three, R_Four, R_Five, R₆: Each independently a hydrogen atom,
An optionally substituted saturated or unsaturated alkyl group, or
Or an aryl group. R₇: Saturated or unsaturated alkyl which may be substituted
Represents a group or an aryl group.

DPP pigment (A), dye derivative (B),
The amount of the dye derivative (B) used when kneading (salt milling) the mixture of the water-soluble inorganic salt (C) and the water-soluble organic solvent (D) is not particularly limited, but is based on the amount of the DPP pigment. 0.5-20% by weight, especially 2-15% by weight, is preferred. In addition, since the dye derivative (B) also has an effect as a dispersant, it is preferable to select a dye derivative having good dispersibility in a transparent resin varnish. Alternatively, it may be combined with a dispersant other than the dye derivative. Examples of dispersants other than dye derivatives include condensates of ricinoleic acid and 12-hydroxystearic acid, basic polymer compounds, copolymers containing acid groups, fatty acid esters, aliphatic polyamine / polyester graft polymers, polyethylene / A so-called resin-type dispersant such as a polypropylene addition polymer can be used. These dispersants are used at the time of salt milling treatment or at the time of dispersing the salt milled pigment in a transparent resin varnish.

The water-soluble inorganic salt (C) functions as a crushing aid, and the DPP pigment is crushed by utilizing the hardness of the inorganic salt during salt milling, and the primary particles of the DPP pigment are finely divided. Be transformed into The inorganic salt (C) is not particularly limited as long as it can be dissolved in water, and sodium chloride, barium chloride, potassium chloride, sodium sulfate and the like can be used, but sodium chloride (salt) is used from the viewpoint of price. Is preferred. The amount of the inorganic salt (C) used for salt milling depends on the processing efficiency and production efficiency.
It is preferably 1 to 20 times by weight, especially 3 to 10 times by weight of the P-based pigment. This is because the higher the ratio of the inorganic salt to the DPP-based pigment, the higher the refining efficiency, but the smaller the processing amount of the pigment at one time.

The water-soluble organic solvent (D) functions to wet the DPP pigment (A), the dye derivative (B) and the water-soluble inorganic salt (C), and dissolves (mixes) in water.
There is no particular limitation as long as the inorganic salt (C) used does not substantially dissolve. However, since the temperature rises during salt milling and the solvent tends to evaporate, a high boiling solvent having a boiling point of 120 ° C. or higher is preferred from the viewpoint of safety. Examples of the water-soluble organic solvent (D) include 2-methoxyethanol, 2-butoxyethanol, 2- (isopentyloxy) ethanol, 2- (hexyloxy) ethanol, diethylene glycol, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, Triethylene glycol, triethylene glycol monomethyl ether, liquid polyethylene glycol, 1-methoxy-2-propanol, 1-ethoxy-
Examples thereof include 2-propanol, dipropylene glycol, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, and liquid polypropylene glycol.

During salt milling, the refined DP
A resin can be used in combination to prevent strong aggregation when drying the P-based pigment and to facilitate dispersion in the transparent resin. By using a resin at the time of salt milling, a soft powder pigment can be obtained. As the resin used for the salt milling, those that are solid at room temperature, water-insoluble, and at least partially soluble in the organic solvent are preferable, and are natural resins, modified natural resins, synthetic resins, and synthetic resins modified with natural resins. Resin or the like is used. Rosin is typical as a natural resin, and rosin derivatives, cellulose derivatives, rubber derivatives, protein derivatives and oligomers thereof are used as modified natural resins. Examples of the synthetic resin include an epoxy resin, an acrylic resin, a maleic acid resin, a butyral resin, a polyester resin, a melamine resin, a phenol resin, a polyurethane resin, and a amide resin. Examples of the synthetic resin modified with a natural resin include a rosin-modified maleic resin and a rosin-modified phenol resin. The amount of the resin used is preferably in the range of 5 to 100% by weight based on the DPP pigment.

At the time of salt milling, in addition to the above resin,
Additives such as a pigment dispersing aid and a plasticizer or inorganic pigments such as calcium carbonate, barium sulfate and silica which are generally used as extenders may be used in combination. Further, the treatment may be performed by mixing with another pigment to adjust the hue.

By dispersing the pigment of the present invention in a transparent resin, a coloring composition used for producing a color filter can be obtained. The pigment and the transparent resin are mixed at a solid content weight ratio of 1: 4 to 10: 1. For the dispersion of the pigment in the transparent resin, three-roll mill, two-roll mill,
Various dispersing means such as a sand mill and a kneader can be used.
Further, in order to improve the dispersion, various dispersing aids such as surfactants and dye derivatives can be appropriately added. Since the dispersing agent is excellent in dispersing the pigment and has a large effect of preventing re-aggregation of the pigment after dispersion, when a coloring composition obtained by dispersing the pigment in a transparent resin using a dispersing agent is used. Thus, a color filter having excellent transparency can be obtained.

The transparent resin has a visible light range of 400 to 700.
The resin has a transmittance of 80% or more, preferably 95% or more in the entire wavelength region of nm. Examples of the transparent resin include a thermosetting resin, a thermoplastic resin, a photosensitive resin, and a monomer or an oligomer that cures by irradiation to form a coating film similar to the resin. These resins may be used alone or in combination of two or more. Can be used. When the coloring composition is cured by irradiation with ultraviolet rays, a photoinitiator or the like is used.
However, a high-temperature heating process is performed in a later step in the production of the color filter, and therefore, it is necessary to use a resin having high resistance even in the heating process.
In addition, since a treatment with various solvents and chemicals is also performed in a later step, the formed image is required to have solvent resistance and chemical resistance.

Examples of the thermosetting resin and the thermoplastic resin include butyral resin, styrene-maleic acid copolymer, chlorinated polyethylene, chlorinated polypropylene, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, and polyvinyl acetate. , Polyurethane resin, phenol resin, polyester resin, acrylic resin, alkyd resin, styrene resin, polyamide resin, rubber resin, cyclized rubber, epoxy resin, celluloses, polybutadiene, polyimide resin, benzoguanamine resin, melamine resin, urea Resins.

As the photosensitive resin, a (meth) acrylic compound, a silicone resin and a linear polymer having a reactive substituent such as a hydroxyl group, a carboxyl group or an amino group can be added via an isocyanate group, an aldehyde group or an epoxy group. A resin into which a photocrosslinkable group such as an acid is introduced is used. Further, a linear polymer containing an acid anhydride such as a styrene-maleic anhydride copolymer or an α-olefin-maleic anhydride copolymer is converted to a (meth) acryl compound having a hydroxyl group such as a hydroxyalkyl (meth) acrylate. A half-esterified polymer is also used.

Monomers and oligomers which cure by irradiation to form a coating film similar to a resin include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, and cyclohexyl (meth) acrylate.
Acrylate, polyethylene glycol di (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, tricyclodecanyl (meth) acrylate, hexagon of caprolactone adduct of dipentaerythritol hexa (meth) acrylate Various acrylates and methacrylates such as (meth) acrylate, acrylic acid, methacrylic acid, (meth) acrylamide, N-
Hydroxymethyl (meth) acrylamide, styrene,
Examples include vinyl acetate, acrylonitrile, melamine (meth) acrylate, and epoxy (meth) acrylate prepolymer.

Examples of the photoinitiator include 4-phenoxydichloroacetophenone, 4-t-butyl-dichloroacetophenone, diethoxyacetophenone, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropane-1one, -Hydroxycyclohexyl phenyl ketone, 2-benzyl-2-dimethylamino-1- (4-
Acetophenone-based photoinitiators such as morpholinophenyl) -butan-1-one; benzoin-based, benzophenone-based photoinitiators such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, and benzyl dimethyl ketal; benzophenone; benzoyl Benzoic acid, methyl benzoylbenzoate,
4-phenylbenzophenone, hydroxybenzophenone, acrylated benzophenone, 4-benzoyl-4 '
Benzophenone-based photoinitiators such as -methyldiphenyl sulfide; thioxanthone-based photoinitiators such as thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, isopropylthioxanthone, and 2,4-diisopropylthioxanthone; 4,6-trichloro-s
-Triazine, 2-phenyl-4,6-bis (trichloromethyl) -s-triazine, 2- (p-methoxyphenyl) -4,6-bis (trichloromethyl) -s-triazine, 2- (p-tolyl ) -4,6-Bis (trichloromethyl) -s-triazine, 2-pipenyl--4,6
-Bis (trichloromethyl) -s-triazine, 2,4
--- bis (trichloromethyl) -6-styryl s-triazine, 2- (naphth-1-yl) -4,6-bis (trichloromethyl) -s-triazine, 2- (4-methoxy-naphth-1- Yl) -4,6-bis (trichloromethyl) -s-triazine, 2,4-trichloromethyl-
Compounds such as triazine photoinitiators such as (piperonyl) -6-triazine and 2,4-trichloromethyl (4′-methoxystyryl) -6-triazine and carbazole photoinitiators and imidazole photoinitiators are used. .

The above photoinitiators may be used alone or as a mixture of two or more. As sensitizers, α-acyloxime ester, acylphosphine oxide, methylphenylglyoxylate, benzyl, 9,10-phenanthane are used. Lenquinone, camphorquinone, ethylanthraquinone,
4,4′-diethylisophthalophenone, 3,3 ′,
4,4'-tetra (t-butylperoxycarbonyl)
Compounds such as benzophenone and 4,4′-diethylaminobenzophenone can be used in combination.

In the coloring composition for a color filter, a coloring agent is sufficiently dispersed and a dry film thickness of 0.2 to
A solvent can be used for coating so as to have a thickness of 5 μm. As the solvent, for example, cyclohexanone, ethyl cellosolve acetate, butyl cellosolve acetate, 1-methoxy-2-propyl acetate, diethylene glycol dimethyl ether, ethylbenzene, ethylene glycol diethyl ether, xylene, ethyl cellosolve, methyl-n amyl ketone, propylene glycol monomethyl ether toluene, methyl ethyl ketone , Ethyl acetate, methanol, ethanol, isopropyl alcohol, butanol, isobutyl ketone, petroleum solvents and the like, and these may be used alone or as a mixture.

The coloring composition for a color filter of the present invention comprises:
It can be a gravure offset printing ink, a waterless offset printing ink, a silk screen printing ink, a solvent developing type or an alkali developing type coloring resist agent. These printing inks, colored resist agents and the like are coarse particles of 5 μm or more, preferably 1 μm, by means of centrifugation, sintering filter, membrane filter, etc.
The above coarse particles are more preferably produced by removing coarse particles of 0.5 μm or more and mixed dust.

The printing ink can form patterned pixels of each color only by repeating printing and drying.
As a method for manufacturing a color filter, it is low in cost and excellent in mass productivity. Further, fine patterns having high dimensional accuracy and smoothness can be printed by the development of printing technology. When manufacturing color filters by printing, it is important to control the fluidity of the ink on the printing press.
The viscosity of the ink can be adjusted with a dispersant or extender.

The solvent-developing or alkali-developing colored resist is applied onto a transparent substrate such as a glass plate by a coating method such as spin coating, slit coating, or roll coating. Next, UV exposure is performed through a photomask, and the unexposed portion is washed away with a solvent or an alkali developing solution to form a desired pattern, and then the same operation is repeated for other colors to form a color filter having pixels of each color. To manufacture. This manufacturing method is called a photolithography method, and a color filter with higher accuracy than the printing method can be manufactured.

As the alkali developer, an aqueous solution of sodium carbonate, caustic soda or the like is used, and an organic base such as dimethylbenzylamine or triethanolamine can also be used. Further, an antifoaming agent or a surfactant can be added. In order to increase the UV exposure sensitivity, the above-mentioned colored resist agent is applied and dried, and then a water-soluble or alkali-water-soluble resin such as polyvinyl alcohol or a water-soluble acrylic resin is applied and dried to form a film for preventing polymerization inhibition by oxygen. After that, ultraviolet exposure can be performed.

As a method for producing a color filter using a pigment, there are other methods such as an electrodeposition method and a transfer method, and the coloring composition of the present invention can be used in any method. The electrodeposition method is a method of producing a color filter by using a transparent conductive film formed on a transparent substrate and forming a colorant on the transparent conductive film by electrophoresis of colloid particles. The transfer method is a method in which a color filter layer is previously formed on the surface of a peelable transfer base sheet, and the color filter layer is transferred to a desired transparent substrate.

Hereinafter, the present invention will be described based on examples, but the present invention is not limited thereto. In Examples and Comparative Examples, “parts” indicates “parts by weight” and “%” indicates “% by weight”. The primary particle diameter of the pigment was measured by observation with a transmission electron microscope, and the specific surface area was measured by a BET method. Prior to the examples, Table 1 shows the dye derivatives used in the examples.

[0036]

[Table 1]

(Synthesis of Acrylic Resin) A reaction vessel is charged with 800 parts of cyclohexanone, heated to 100 ° C. while injecting nitrogen gas into the vessel, and a mixture of the following monomer and thermal polymerization initiator is added at the same temperature for 1 hour. The polymerization reaction was performed by dropping. 60.0 parts of styrene 60.0 parts of methacrylic acid 65.0 parts of methyl methacrylate 65.0 parts of butyl methacrylate 10.0 parts of azobisisobutyronitrile 10.0 parts After dropping, the mixture was further reacted at 100 ° C. for 3 hours, and then reacted with azobis. A solution prepared by dissolving 2.0 parts of isobutyronitrile in 50 parts of cyclohexanone was added, and the reaction was further continued at 100 ° C. for 1 hour to synthesize a resin solution. After cooling to room temperature,
About 2 g of the resin solution was sampled, dried by heating at 180 ° C. for 20 minutes to measure the nonvolatile content, and cyclohexanone was added to the previously synthesized resin solution so that the nonvolatile content was 20% to prepare an acrylic resin solution. .

Example 1 DPP pigment ("Irazine DPP REDB" manufactured by Ciba Specialty Chemicals)
O ", C.I. I. Pigment RED 254) 152
Parts, dye derivative (a) 8 parts, sodium chloride 1600
Parts and 190 parts of diethylene glycol were charged into a stainless steel 1 gallon kneader (manufactured by Inoue Seisakusho), and
Kneaded at 10 ° C for 10 hours. Next, this mixture was poured into 3 liters of warm water, stirred for about 1 hour with a high speed mixer while heating to about 80 ° C. to form a slurry, filtered and washed repeatedly to remove sodium chloride and the solvent. C. for one day and night at 15 ° C., and 156.8 parts of a color filter pigment (primary particle size: 30 to 40 nm, specific surface area: 80 m ²⁾
/ g).

Example 2 A DPP pigment was used as a DPP pigment “Irazine DPP Scarlet EK” manufactured by Ciba Specialty Chemicals (CI Pigment RED25).
In 5), the same operation as in Example 1 was carried out except that the dye derivative (a) was replaced with the dye derivative (b), and 158.7 parts of a color filter pigment (primary particle diameter 40 to 50 nm, specific surface area 68 m) was used. ² / g).

Example 3 The procedure of Example 1 was repeated, except that the dye derivative (a) was replaced with the dye derivative (c), to obtain 156.0 parts of a pigment for a color filter (primary particle diameter 30%).
-40 nm and a specific surface area of 80 m ² / g). Example 4 The same operation as in Example 1 was carried out except that the amount of the DPP pigment was changed from 152 parts to 144 parts and 8 parts of the dye derivative (a) was changed to 16 parts of the dye derivative (d).
6 parts of pigment for color filter (primary particle size 20-30n
m and a specific surface area of 85 m ² / g).

Example 5 156.0 was carried out in the same manner as in Example 1, except that the dye derivative (a) was replaced with the dye derivative (d), and the temperature during kneading was changed from 60 ° C. to 90 ° C.
Part of pigment for color filter (primary particle size 30-50 nm,
A specific surface area of 71 m ² / g) was obtained. Example 6 The same operation as in Example 1 was carried out except that the dye derivative (a) was replaced with the dye derivative (d), and 156.5 parts of a color filter pigment (primary particle diameter 30 to 40 nm, specific surface area) 79 m ² / g).

Example 7 Example 1 was repeated except that the amount of the DPP pigment was changed from 152 parts to 155.2 parts, and that 8 parts of the dye derivative (a) was changed to 4.8 parts of the dye derivative (d). The same operation was performed to obtain 156.4 parts of a color filter pigment (primary particle size: 30 to 50 nm, specific surface area: 72 m ² / g). Example 8 DPP pigment "Irgazine DPP RED"
190 parts of “BO”, 10 parts of dye derivative (d), 2000 parts of sodium chloride, and 240 parts of diethylene glycol were charged into a 1-gallon kneader made of stainless steel.
Kneaded for 0 hours. Purification and drying were carried out in the same manner as in Example 1 to obtain 194.2 parts of a color filter pigment (primary particle size: 30 to 50 nm, specific surface area: 72 m ² / g).

Example 9 The same operation as in Example 1 was carried out except that the dye derivative (a) was replaced with the dye derivative (e), and 154.8 parts of a color filter pigment (primary particle size 30
-40 nm and a specific surface area of 79 m ² / g). Example 10 A DPP pigment was used as a DPP pigment “Chromophtal DPP Orange TR” manufactured by Ciba Specialty Chemicals (CI Pigment ORANGE71).
In the same manner as in Example 1, except that the dye derivative (a) was replaced with the dye derivative (e), 156.0 parts of a color filter pigment (primary particle diameter 40 to 50 nm, specific surface area 7
3 m ² / g).

Example 11 The same operation as in Example 1 was carried out except that the dye derivative (a) was replaced with the dye derivative (f), and 156.5 parts of a color filter pigment (primary particle size 3
0-40 nm and a specific surface area of 82 m ² / g). [Example 12] A DPP pigment manufactured by Ciba Specialty Chemicals, Inc. "Irazine DPP Rubin T
R "(CI Pigment RED 264), the same operation as in Example 1 was carried out except that the dye derivative (a) was replaced with the dye derivative (f), to thereby obtain 156.5 parts of a color filter pigment (primary particles). Diameter 40-50 nm, specific surface area 73 m ² /
g) was obtained.

Example 13 The same operation as in Example 1 was carried out except that the dye derivative (a) was replaced with the dye derivative (g), and 156.5 parts of a color filter pigment (primary particle size 3
0-40 nm and a specific surface area of 77 m ² / g). [Example 14] The same operation as in Example 1 was carried out, except that the dye derivative (a) was replaced with the dye derivative (h), to perform 156.0.
Part of pigment for color filter (primary particle diameter 30-40 nm,
A specific surface area of 80 m ² / g) was obtained.

Example 15 A DPP pigment was used as a DPP pigment “Irazine DPP Scarlet EK” manufactured by Ciba Specialty Chemicals (CI Pigment RED2).
55), the same operation as in Example 1 was carried out except that the dye derivative (a) was replaced with the dye derivative (i), and 157.2 parts of a color filter pigment (primary particle diameter 40 to 50 nm, specific surface area 70 m) was used. ² / g).

Example 16 A DPP pigment was used as a DPP pigment “Irazine DPP” manufactured by Ciba Specialty Chemicals.
Rubin TR "(CI Pigment RED26)
In 4), the same operation as in Example 1 was carried out except that the dye derivative (a) was replaced with the dye derivative (j), and 156.4 parts of a color filter pigment (primary particle diameter 30 to 40 nm, specific surface area 81 m) was used. ² / g).

Example 17 DPP pigment "Chromophtal DP" manufactured by Ciba Specialty Chemicals was used.
P Orange TR "(CI Pigment ORA
NGE71) with the dye derivative (a)
156. The same operation as in Example 1 was performed, except that
6 parts of pigment for color filter (primary particle size 30-40n
m and a specific surface area of 81 m ² / g).

[Example 18] Except that 8 parts of a maleic acid resin ("Marquid No. 32" manufactured by Arakawa Chemical Industries, Ltd.) was added when kneading the DPP pigment, the dye derivative (a), sodium chloride and diethylene glycol. The same operation as in Example 1 was performed to obtain 159.1 parts of a pigment for a color filter (primary particle diameter: 30 to 40 nm, specific surface area: 87 m ² / g).

Comparative Example 1 149.0 parts of a treated pigment (primary particle diameter: 30 to 40 nm, specific surface area: 81 m ² / g) were obtained in the same manner as in Example 1 except that the dye derivative (a) was omitted. I got [Comparative Example 2] 149.0 parts of a treated pigment (primary particle diameter: 100 to 200 nm, specific surface area: 45 m ² / g) was obtained in the same manner as in Example 2, except that the dye derivative (b) was omitted. .

Comparative Example 3 A dye derivative (f) was prepared using a maleic acid resin ("Marquid No. 3" manufactured by Arakawa Chemical Industries, Ltd.).
2 ") 157.0 parts of the treated pigment (primary particle size of 40 to 60 n) was prepared in the same manner as in Example 12, except that 8 parts were used.
m, specific surface area: 78 m ² / g). [Comparative Example 4] The same operation as in Example 10 was carried out except that the dye derivative (e) was replaced with 8 parts of an epoxy resin (“Epicoat 1004” manufactured by Yuka Shell Epoxy Co., Ltd.), and 158.2 parts of the treated pigment ( Primary particle diameter 60 to 70 nm, specific surface area 78 m ²
/ g).

[Comparative Example 5] Untreated DPP pigment ("Irgafor RED" manufactured by Ciba Specialty Chemicals)
B-CF ", C.I. I. Pigment RED254,
The primary particle diameter of 40 to 60 nm, a specific surface area of 85m ² / g) [Comparative Example 6] Untreated DPP pigment (Ciba Specialty Chemicals Co., Ltd. "Irgazin DPPRED BO"
C. I. Pigment RED 254, primary particle size 2
00 to 600 nm, specific surface area 25 m ² / g)

[Comparative Example 7] Untreated DPP pigment ("Irazine DPP Scarlet EK" manufactured by Ciba Specialty Chemicals Co., Ltd., CI Pigment RED25)
5, primary particle diameter 200 to 400 nm, specific surface area 30 m ² / g) [Comparative Example 8] Untreated DPP pigment (“Irazine DPP Rubin TR” manufactured by Ciba Specialty Chemicals, C.I.
I. Pigment RED 264, primary particle diameter 40 to
100 nm, a specific surface area of 70m ² / g) [Comparative Example 9] Untreated DPP pigment (Ciba Specialty Chemicals Co., Ltd. "Kuromofutaru DPP Orange T
R ", C.I. I. Pigment ORANGE71, primary particle diameter 40 to 200 nm, specific surface area 78 m ² / g)

Mixtures of the following compositions containing the pigments obtained in the examples and comparative examples were uniformly stirred and mixed, and then filtered through a 1 μm filter to prepare an alkali-developable photosensitive coloring composition. Pigment 4.5 parts Above acrylic resin solution 24.0 parts Trimethylolpropane triacrylate 5.4 parts (“NK ester ATMPT” manufactured by Shin-Nakamura Chemical Co.) Photoinitiator (“Irgacure 907” manufactured by Ciba Geigy) 0.3 Part Sensitizer (“EAB-F” manufactured by Hodogaya Chemical Co., Ltd.) 0.2 part Cyclohexanone 65.1 parts

Using the obtained photosensitive coloring composition, a coloring material layer was formed on a transparent substrate by the following method, and the spectral transmittance, chromaticity, surface state, and NMP resistance of the coloring material layer were evaluated. .
Table 2 shows the results. 100mm x 100mm, 1.1m
On a glass substrate having a thickness of m, the obtained photosensitive coloring composition was coated with a spin coater at 500 rpm, 1000 rpm,
The coating was performed at a rotation speed of 1500 rpm and 2000 rpm to obtain four types of coated substrates having different color material layer thicknesses. Next, 70
After drying at 20 ° C. for 20 minutes, UV exposure was performed using an ultrahigh pressure mercury lamp at an integrated light amount of 150 mJ. After the exposure, the film was heated at 230 ° C. for 1 hour and allowed to cool, and then the chromaticity (Y, x, y) with a C light source was measured using a microspectrophotometer (“OSP-SP100” manufactured by Olympus Optical). The maximum transmittance, Y, x, and y when the minimum value of the spectral transmittance at a wavelength of 400 to 700 nm was 1% was determined from the four sets of chromaticity / spectroscopic measurement results.
Further, the surface state of the coated substrate at 1000 rpm was observed with an optical microscope (“BX60” manufactured by Olympus Optical Co., Ltd.). After the observation, the coated substrate was immersed in NMP for 30 minutes and dried, and then the chromaticity of the coated substrate was measured with a microspectrophotometer, and the color difference ΔE before and after immersion was determined to evaluate the NMP resistance of the coated substrate.

[0056]

[Table 2]

The coloring material layer formed using the photosensitive coloring composition obtained by dispersing the DPP pigments of Examples 1 to 17 in the transparent resin, which had been subjected to the salt milling treatment using the dye derivative, had fine pigments. Since the dispersion state is good, the maximum transmittance is high when the minimum transmittance is the same in each case. That is, it has excellent characteristics as a color filter that blocks unnecessary light and transmits more necessary light.
For example, while the maximum transmittance of the color material layer formed using the DPP pigment “Irgazine DPP RED BO” (Comparative Example 6) which is not subjected to the salt milling treatment is 87%, in Examples 1, 3 to 9, The maximum transmittance of the color material layer is 95 to 99
% Has improved dramatically.

This is the same as C.I. I. Pigment R
It is higher than the case where the finer type B-CF (Comparative Example 5) is used in ED254. In Comparative Example 1 in which the DPP pigment “Irgazine DPP RED BO” was subjected to the salt milling treatment without the dye derivative, the maximum transmittance was 79%, which was more opaque than the case where no treatment was performed. Since the primary particle diameter is larger in Comparative Example 1, it can be seen that when salt milling is performed without a dye derivative, a crystallized DPP-based pigment grows. Regarding the heat resistance, in the comparative example, protrusions of about 5 to 10 μm were observed on the surface of the coating film when heated at 230 ° C., but were not observed on the surface of the coating films of Examples 1 to 17. Further, in the NMP resistance, ΔE of the comparative example is 3 to 4, whereas in each of the examples, the color change is small, ie, around ΔE = 1, indicating that the NMP resistance is high.

[0059]

According to the present invention, fine diketopyrrolopyrrole pigments can be obtained by suppressing crystal growth. In addition, by using the pigment of the present invention, a color filter having excellent pixels having high transparency and NMP resistance can be obtained.

Continuation of the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) // G02F 1/1335 505 G02F 1/1335 505 G03F 7/004 505 G03F 7/004 505 (72) Inventor Yuji Hirasawa Tokyo 2-13-13 Kyobashi, Chuo-ku, Tokyo Toyo Ink Manufacturing Co., Ltd.

Claims (5)

[Claims] 1. A diketopyrrolopyrrole pigment (A), a dye derivative (B), a water-soluble inorganic salt (C), and a water-soluble organic solvent (D) which does not substantially dissolve the water-soluble inorganic salt (C). A color filter pigment obtained by kneading a mixture containing the following, and then removing the water-soluble inorganic salt (C) and the water-soluble organic solvent (D). 2. The pigment for a color filter according to claim 1, wherein the pigment derivative (B) is a quinacridone derivative and / or a diketopyrrolopyrrole derivative. 3. A method for producing a pigment for a color filter according to claim 1. 4. A coloring composition for a color filter, wherein the pigment for a color filter according to claim 1 or 2 is dispersed in a transparent resin. 5. A color filter comprising a pixel formed using the coloring composition for a color filter according to claim 3.