KR101873819B1 - Fine yellow pigments composition, pigments dispersion containing said composition and method for preparing said composition - Google Patents

Abstract

It is an object of the present invention to provide a fine yellow pigment composition which can improve the contrast ratio when used as an ink for a coating film such as a color filter.
The above problems are solved by a fine yellow pigment composition comprising a quinophthalone-based pigment, a sulfonated quinophthalone-based pigment derivative and a specific triazine-based pigment derivative. The fine yellow pigment composition is prepared by a process comprising the step of crushing and kneading a mixture containing a quinophthalone-based pigment, the sulfonated quinophthalone-based pigment derivative and the triazine-based pigment derivative at 60 degrees or less .

Description

TECHNICAL FIELD [0001] The present invention relates to a fine yellow pigment composition, a pigment dispersion containing the fine yellow pigment composition, and a method for producing the fine yellow pigment composition. BACKGROUND ART [0002]

The present invention relates to a yellow pigment composition (yellow pigment composition), and more particularly to a fine yellow pigment composition containing a finely divided yellow pigment.

In printing inks, paints, inks for inkjet printers, and inks for color filters, it is possible to exhibit high coloring power by dispersing the pigment in a fine state, (Color tone) and luster of a coated workpiece, and imparts proper characteristics such as a chromaticity of a coated film such as a color filter and a contrast ratio. In recent years, higher clarity, gloss, chromaticity, contrast ratio, and the like have been demanded in these applications.

As a countermeasure thereof, a method of making the pigment finer is employed. In general, however, pigment particles once dispersed in a mixture of water, a solvent and a resin (a coloring agent such as a paint or an ink) are mixed with the mixture (a pigment dispersion )), And there is a strong tendency to form secondary particles by aggregation as the particle diameter of the primary particles of the pigment becomes smaller. Therefore, even if the pigment is finely dispersed, the finely dispersed pigment particles are stably dispersed It is difficult. When the pigment particles are agglomerated in the pigment dispersion, various undesirable phenomena such as an increase in the viscosity of the pigment dispersion, a decrease in the gloss of the coated surface of the impregnated product, and a decrease in the performance of the coated film occur.

As the pigment for the color filter, three colors of red, green and blue are mainly used, but yellow pigments are commonly used as complementary colors. As such yellow pigments, quinophthalone-based pigments are known to have good heat resistance and weather resistance. However, when the pigments are miniaturized as described above, their performance sometimes deteriorates , The same applies to other uses besides color filters).

As a remedy for this, there has been proposed a method of employing a quinophthalone pigment having a specific crystal structure (Patent Document 1), and a method using a quinophthalone derivative sulfonic acid (Patent Document 2). Further, in Patent Document 1, it is said that the wet grinding (temperature of grinding) temperature is preferably 80 degrees or more.

However, when these techniques are used as an ink for a coating film such as a color filter, there is still room for improvement in terms of the improvement of the contrast ratio.

Patent Document 1: Japanese Patent Application Laid-Open No. 2002-105351 Patent Document 2: Japanese Patent Application Laid-Open No. 2003-167112

In view of the above problems, an object of the present invention is to provide a fine yellow pigment composition which can improve a contrast ratio when used as an ink for a coating film such as a color filter.

As a result of intensive studies, the present inventors have found that the above-mentioned problems can be solved by using quinophthalone-based pigments and specific pigment derivatives of plural species, and have reached the present invention.

That is, the gist of the present invention is as follows.

The first aspect of the present invention is a colorant composition comprising a quinophthalone-based pigment, a sulfonated quinophthalone-based pigment derivative and a triazine-based pigment derivative (triazine-based pigment derivative) represented by the following formula (1) ≪ / RTI >

[Formula 1]

(In the formula (1), A represents an aromatic amine residue (aromatic amine residue), and B represents a chlorine atom, a hydroxyl group, a sulfanilic acid residue or an orthanilic acid residue.

In the present invention, it is preferable that A, which is an aromatic amine residue of the triazine-based pigment derivative, is a group represented by the following formula (2).

[Formula 2]

[Formula 3]

(Wherein Q ¹ , Q ² , Q ³ and Q ⁴ each independently represent -H, a halogen atom, a lower alkyl group or a lower alkoxy group, X represents -H, -OH or -NH ₂ , W Represents -CH ₂ -, -O-, -SO ₂ - or formula (3), and m and n are each independently 0 or 1.)

A second aspect of the present invention relates to a pigment dispersion comprising the fine yellow pigment composition.

According to a third aspect of the present invention, there is provided a process for producing the fine yellow pigment composition, comprising the step of milling a mixture comprising a quinophthalone-based pigment, the sulfonated quinophthalone-based pigment derivative and the triazine- And a process for kneading the fine yellow pigment.

According to the fine yellow pigment composition of the present invention, when the composition is used as an ink for a coating film such as a color filter, the contrast ratio of the coating film can be improved.

According to the method for producing a fine yellow pigment composition according to the present invention, the fine yellow pigment composition can be easily produced.

The fine yellow pigment composition according to the present invention comprises a quinophthalone-based pigment, a sulfonated quinophthalone-based pigment derivative and a triazine-based pigment derivative represented by the above formula (1).

As the quinophthalone-based pigment, CI Pigment Yellow 138 (hereinafter abbreviated as PY138) is a representative color index (hereinafter abbreviated as C.I.) ). As PY138, a known one can be used, and examples thereof include Paliotol Yellow D0960 manufactured by BASF.

[Formula 4]

In the present invention, the diameter of the primary particles of the pigment is preferably in the range of 20 to 60 m from the viewpoint of securing the dispersibility of the pigment and improving the contrast ratio.

The sulfonated quinophthalone-based pigment derivative (hereinafter simply referred to as "sulfonated pigment derivative" in some cases) may be obtained by subjecting a quinophthalone-based pigment or a copper (or its) pigment derivative to sulfonation treatment Lt; / RTI > The sulfonation treatment can be carried out, for example, by the method described in Japanese Patent Application Laid-Open No. 2009-126994 and other known methods.

In the present invention, the sulfonic acid obtained by the above method or the like may be used as it is, or the salt of the above sulfonic acid may be used. Examples of the compound or atom which forms a salt with the sulfonic acid include monoalkylamine having 1 to 3 valences such as lithium, potassium, sodium, calcium, magnesium, strontium and aluminum, ethylamine and butylamine, , Dialkylamines such as diethylamine, trialkylamines such as trimethylamine and triethylamine, organic amines such as alkanolamines such as monoethanolamine, diethanolamine and triethanolamine, and ammonia.

In addition, when the salt is an alkali metal salt, the salt becomes water-soluble. By dissolving the salt in water and then merely filtering it, water-insoluble impurities can be easily separated and a sulfonated pigment derivative having high purity can be obtained.

The sulfonated quinophthalone-based pigment derivative used in the present invention includes, for example, a compound having a chemical structure represented by the following formula (5) or a salt thereof.

[Formula 5]

(In the formula (5), p represents an integer of ^{1 to} 5. X ^{1 to} X ⁸ each independently represent a hydrogen atom or a halogen atom.)

The sulfonated pigment derivative having such a structure has a planar surface due to a quinoline structure and a planar surface due to a phthalimide structure has a nonparallel state (non-parallel state). Therefore, a quinophthalone- And it is believed that the pigment has an appropriate affinity with quinophthalone-based pigment particles and inhibits aggregation of quinophthalone-based pigment particles. The sulfonated pigment derivative is also highly compatible with the triazine-based pigment derivative as described later, and it is considered that the action of the sulfonated pigment derivative on the quinophthalone-based pigment can be effectively exerted by the interaction of the two . In addition, since a sulfo group is contained in the molecule, it is considered that the dispersibility with respect to the solvent described later is excellent and effectively functions at the time of preparing the pigment dispersion.

In the present invention, it is preferable to use the sulfonated quinophthalone-based pigment derivative represented by the above formula (5). Among them, it is preferable that all of X ^{1 to} X ⁸ are chlorine atoms. As a result, the affinity with the quinophthalone-based pigment represented by the formula (4) is improved and the adsorption of the derivative to the pigment particles is promoted, thereby more effective prevention of crystal growth can be expected.

The triazine-based pigment derivative may be any one having a structure represented by the formula (1). The triazine-based pigment derivative having such an aromatic amine residue is a compound rich in π electrons. The compound approaches the surface of the quinophthalone-based pigment crystal grains and interacts with π electrons of the pigment molecule, It is considered that the crystal growth of the primary particles of the quinophthalone-based pigment can be suppressed / controlled.

In addition, since the triazine-based pigment derivative also interacts with the π electrons possessed by the molecules of the sulfonated pigment derivative, both of them have high affinity, and the effect on both of the quinophthalone-based pigments can be effectively exhibited .

In addition, since a sulfo group is contained in the molecule in the same manner as in the case of the above sulfonated pigment derivative, it is considered that it is excellent in dispersibility with respect to a solvent to be described later and effectively functions in preparing the pigment dispersion.

In the present invention, it is preferable to use a triazine-based pigment derivative represented by the above formula (1), wherein A, which is an aromatic amine residue of the triazine-based pigment derivative, is a group represented by the above formula (2). In the present invention, the lower alkyl group and the lower alkoxy group in the present invention means that the lower alkyl group has 1 to 4 carbon atoms. In the case of such a carbon number, it is considered that the affinity with the pigment is improved because the steric hindrance is low.

As specific examples of the group represented by the above-mentioned (2), from the viewpoint of suppressing the crystal growth of the quinophthalone-based pigment and decreasing the diameter of the primary particles, any one of the groups represented by the formulas (6) to (8) .

[Formula 6]

[Equation 7]

[Equation 8]

Such a triazine pigment derivative may be prepared by a known method, or a commercially available triazine pigment derivative may be used.

In the fine pigment composition of the present invention, the content of the sulfonated pigment derivative is not particularly limited, but is preferably 2 to 20 parts by weight based on 100 parts by weight of the quinophthalone-based pigment from the viewpoint of improving the contrast ratio of the coating film , More preferably 5 to 10 parts by weight. The content of the triazine-based pigment derivative is not particularly limited, but is preferably 1 to 10 parts by weight, more preferably 2 to 5 parts by weight, based on 100 parts by weight of the quinophthalone-based pigment from the viewpoint of improving the contrast ratio of the coating film More preferable.

The fine yellow pigment composition of the present invention may contain a dispersant, a resin and the like in addition to the above-mentioned pigments and pigment derivatives, if necessary.

The fine yellow pigment composition of the present invention can be obtained by subjecting a mixture containing a quinophthalone-based pigment, the sulfonated quinophthalone-based pigment derivative and the triazine-based pigment derivative to a process of grinding and kneading at 60 ° or less .

PY138 is said to have good heat resistance and weather resistance as described above. For example, in Patent Document 1, the wet grinding temperature is preferably 80 DEG C or more. However, the inventors of the present invention have found that it is possible to further improve the contrast ratio of a coating film such as a color filter by performing the grinding and milling at a relatively low temperature as described above.

It is also found that crystal growth of the pigment particles is effectively suppressed by crushing and kneading the quinophthalone-based pigment by using a plurality of specific pigment derivatives described above, and finally it is possible to further improve the contrast ratio of the coated film such as a color filter I got it.

In the present invention, the kneaded product may be ground and kneaded at a temperature as low as 60 degrees or less, but more preferably 20 degrees or more, more preferably 30 to 50 degrees, from the viewpoint of improving the contrast ratio. By carrying out the grinding and milling at such a lower temperature, the viscosity of the kneaded product is increased and the shearing force (shearing force) is more imparted to the kneaded product, thereby contributing to the miniaturization of the pigment. When the granules are milled and kneaded at a temperature lower than 20 ° C, the diameter of the primary particles of the pigment becomes excessively small, so that the viscosity of the pigment particles coalesces at the time of preparing the pigment dispersion and the contrast ratio of the coating film may be affected.

The method for producing the fine yellow pigment composition of the present invention will be described on the basis of a suitable example using a wet milling method. However, the present invention is not limited thereto, and if it can be performed at a specific temperature, May be used.

In this example, the quinophthalone-based pigment, the sulfonated pigment derivative, the triazine-based pigment derivative, the water-soluble inorganic salt, and the water-soluble organic solvent are mixed and premixed by a mixer such as a super mixer. At this time, 2 to 20 parts by weight of the sulfonated pigment derivative, 1 to 10 parts by weight of the triazine-based pigment derivative, 500 to 1500 parts by weight of the water-soluble inorganic salt, 100 to 1000 parts by weight of the water-soluble organic solvent 100 To 400 parts by weight.

As the water-soluble inorganic salt, those known as a grinding aid such as sodium chloride, (anhydrous) sodium sulfate (sodium sulfate) ((anhydrous) sodium sulfate) and the like can be suitably used. The particle diameter of the inorganic salt is not particularly limited, but from the viewpoint of fineness of the pigment, a particle size of 50 탆 or less, preferably 10 탆 or less may be used. Also, as described in Japanese Patent Application Laid-Open No. 2009-263501, even if the particles are finely divided and sized (in the aggregate of particles such as powders, the particle diameter of the contained particles is adjusted to a certain range) good.

As the water-soluble organic solvent, a known organic solvent used in salt milling can be used, and examples thereof include diethylene glycol (DEG), ethylene glycol, polyethylene glycol, propylene glycol, glycerin and the like , But is not limited thereto.

Next, the premixed mixture is supplied to a kneader, and the mixture is kneaded and kneaded while adjusting the temperature of the mixture (kneaded product) to 60 ° C or less. At this time, the temperature of the mixture is preferably controlled such that the mixture discharged from the outlet of the kneader is fed to the kneaded product during the milling and kneading in the kneading vessel in the case of a batch type kneading machine, Calibrate the calibrated thermometer and measure it.

A known kneader may be used as long as it can adjust the temperature as described above. Concretely, a batch type kneader such as a kneader or a continuous type kneader may be used. From the viewpoint of temperature control of the mixture during the pulverization and kneading, it is preferable to use a continuous kneader. Examples of the continuous kneader include a two-axis continuous kneader disclosed in Japanese Patent Application Laid-Open No. 9-263723 and a continuous kneader disclosed in Japanese Patent Application Laid-Open No. 2006-77062. In the latter, Is Miracle KCK manufactured by Asada Iron &

Further, the above-mentioned ground-chain mixture obtained by carrying out the above-mentioned crushing and kneading is washed with ion-exchanged water (ion-exchanged water) or the like to obtain a fine pigment paste. Thereafter, the fine pigment paste after washing with water as required is dried by a drier to obtain a dried block of fine pigment, which is pulverized by a known pulverizer to obtain a powder of fine pigment.

In the present invention, the fine pigment paste or powder of the fine pigment obtained as described above is referred to as a fine yellow pigment composition.

The pigment dispersion of the present invention comprises the fine yellow pigment composition.

The pigment dispersion preferably contains a solvent, a dispersant, a dispersing resin, a different pigment (including a pigment derivative), and other components in addition to the fine yellow pigment composition. Each of these components can be appropriately used in publicly known ones, and the outline thereof will be described below. On the other hand, in detail, it is possible to suitably use, for example, those described in Japanese Patent Application Laid-Open No. 2009-126994.

As the solvent, a water-soluble solvent is preferably used. By using a water-soluble solvent as the solvent, the dispersibility of the pigment can be made particularly excellent. As the water-soluble solvent, a hydrophilic solvent can be used. Specifically, for example, a liquid having a solubility of 3 g or more per 100 g of water at 25 DEG C can be used.

As the water-soluble solvent, a compound having a functional group (functional group) having high hydrophilicity such as a hydroxyl group and a compound having a polyglycol skeleton can be suitably used. For example, diethylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate (PMA) and the like.

In the present invention, a non-aqueous solvent may be used.

The dispersion agent is not particularly limited, and for example, a polymer dispersant may be used. Examples of the polymeric dispersant include basic polymer dispersants, neutral polymer dispersants, acidic polymer dispersants, and the like. Examples of such a high-molecular-weight dispersant include dispersants composed of an acrylic type and a modified acrylic copolymer, urethane type dispersants, polyaminoamide salts, polyether esters, phosphoric acid esters, and aliphatic polyvalent carboxylic acids.

The content of the dispersing agent in the pigment dispersion is not particularly limited, but is preferably 2 to 28 wt%, more preferably 9 to 25 wt%.

Examples of the dispersion resin include alginic acids, polyvinyl alcohol, hydroxypropylcellulose, carboxymethylcellulose, hydroxyethylcellulose, methylcellulose, styrene-acrylic acid resin, styrene-acrylic acid- Styrene-maleic acid half ester resin, methacrylic acid-methacrylic acid ester resin, acrylic acid-acrylic ester resin, isobutylene-maleic acid resin, rosin-modified maleic acid resin, poly Polyvinyl pyrrolidone, gum arabic starch, polyallylamine, polyvinyl amine, and polyethyleneimine. One or more of these may be used in combination.

The content of the dispersion resin in the pigment dispersion is not particularly limited, but is preferably 2 to 21 wt%, more preferably 6 to 19.5 wt%.

As the other pigments, various known pigments or pigment derivatives thereof may be used. One or more of these pigments and pigment derivatives may be used.

The content of the pigment (the yellow micropigment composition of the present invention and all other pigments (including pigment derivatives)) in the pigment dispersion is preferably 10 wt% or more, more preferably 10 to 25 wt%.

Examples of the other components include a coloring agent, a pH adjuster, an antioxidant, an ultraviolet absorber, an antiseptic, and an antifungal agent. They may be suitably added as long as they do not interfere with the effect of the present invention.

The pigment dispersion of the present invention can be prepared by a known method. A suitable example of the embodiment is briefly described below, but is not limited thereto.

In this example, inorganic beads are added in a multistage manner to a mixed liquid containing a fine yellow pigment composition, a solvent, a dispersant, and a dispersion resin to perform dispersion treatment. By adding inorganic beads in such a multistage manner, the fine pigment composition or the like can be efficiently dispersed in a fine state. On the other hand, the above-mentioned other pigments and other components may be added as necessary.

Examples of the inorganic beads include, but are not limited to, beads made of zirconia (for example, Toray ceram grinding balls (trade name), available from Toray Industries, Inc.).

The average particle diameter of the inorganic beads used in each step is not particularly limited, but it is preferable to decrease the average particle diameter sequentially. For example, when inorganic beads are added in two steps, the average particle diameter of the inorganic beads in the first step is 0.5 to 3.0 mm, and the inorganic beads are 0.03 to 0.3 mm in the second step.

The amount of the inorganic beads to be added in each step is not particularly limited, but is preferably 300 to 500 parts by weight based on 100 parts by weight of the mixed solution. In addition, the added amount in the respective ranges may be the same or different.

The dispersing device for dispersing treatment is not particularly limited, and examples thereof include a media type dispersing device such as a pearl mill, and a uniaxial or biaxial mixer such as a disper mill. The treatment time is not particularly limited, but is preferably 10 to 120 minutes. The number of revolutions of the stirring blade of the dispersing device is not particularly limited, but is preferably 1000 to 5000 rpm. On the other hand, the types and conditions of these devices may be appropriately selected in each step.

The number of monomers to which the inorganic beads are added is not particularly limited, but is preferably added in two stages. In this example, other inorganic beads are added at the subsequent stage after removing the inorganic beads added in each step. As a method of removing the inorganic beads, a known method such as filtration may be used.

The dispersed mixture liquid obtained by adding inorganic beads in a multi-step manner under the above-described conditions for dispersion treatment and removing the inorganic beads added at the final stage is the pigment dispersion of the present invention.

The pigment dispersion of the present invention can be used, for example, in various printing inks such as various paints, offset printing, gravure printing, inks (film colorants) for coating films such as color filters, and coating materials for lenses.

The pigment dispersion of the present invention can be used for forming a coating film. The coating film is formed by applying a pigment dispersion onto a substrate by a method such as bar coating, spin coating, roll coating, slit coating, brush coating, offset printing and gravure printing, And drying (desolvating) treatment to form a desired coating film.

[Example]

Hereinafter, the present invention will be described in more detail with reference to examples and comparative examples.

(Production Example 1) Preparation of triazine-based pigment derivative (A)

To 100 parts of water was added 7.3 g of cyanuric chloride and 6.8 g of sulfanilic acid (trade name: ASA Sulfanilic Acid, manufactured by Suga Chemical Industry Co., Ltd.), which was reacted with one Cl of cyanuric chloride, . Next, 10 g of 4,4'-methylene di-2,6-xylydine (trade name: KAYABOND C-200S, Japan Chemical Co., Ltd.) reacting with one Cl of the reaction product was added, . The resulting reaction product was filtered, and the residue was washed with water. The residue was allowed to stand overnight in a thermostatic bath at 80 degrees centigrade overnight to obtain 17.0 g of a triazine derivative (A) represented by the following formula (9).

[Equation 9]

(Preparation Example 2) Preparation of triazine-based pigment derivative (B)

10 g of 3,3'-dichlorobenzidine was added to 100 g of water, and 7.3 g of cyanuric chloride, which was reacted with one amino group, was added thereto, followed by reaction at 20 ° C for 1 hour. Subsequently, 13.7 g of sulfanilic acid was added and reacted at 90 DEG C for 1 hour to obtain 26.6 g of a triazine-based pigment derivative (B) having the structure of the following formula (10).

[Equation 10]

(Example 1)

500 g of Yellow 138 (trade name: Paliotol Yellow L0960HD, manufactured by BASF) as a quinophthalone-based pigment, 5000 g of anhydrous sodium sulfate (average particle size of about 5 탆, sodium sulfate anhydrous as described in JP 2009-263501 A) 50 g of a sulfonated pigment derivative represented by the following formula (11) and 25 g of a triazine-based pigment derivative (A) of Production Example 1 were uniformly dispersed in a super mixer (Super Mixer SMV-20 ) For about 2 minutes.

This mixture was supplied to a continuous kneader (Miracle KCK32 type, manufactured by Asada Iron Works). The kneading conditions were such that the extruded amount was 6.6 kg / h, the number of revolutions was 90 rpm, and the temperature of the kneaded material was adjusted to 45 °, followed by grinding and kneading. 1300 g of the granulated and kneaded mixture was dispersed in 8000 g of ion-exchanged water (ion-exchanged water) of 40 degrees and dispersed. Thereafter, the mixture was transferred to a Nutsche filter and washed with water until the sodium sulfate was removed. (Pigment water) paste.

This pigment water paste was dried at 60 degrees for 20 hours. This dried material was pulverized with a pulverizer (Small Grinder Sample Mill SK-M2, manufactured by Public Reality Co., Ltd.) to obtain about 90 g of a fine yellow pigment composition containing a quinophthalone-based pigment, a sulfonated pigment derivative and a triazine-based pigment derivative .

[Equation 11]

(P in the formula (11) is an integer of 1 to 5)

(Example 2)

About 90 g of a fine yellow pigment composition including a quinophthalone-based pigment, a sulfonated pigment derivative and a triazine-based pigment derivative was obtained in the same manner as in Example 1 except that the triazine derivative (A) was replaced with the triazine derivative (B) .

(Example 3)

About 90 g of a fine yellow pigment composition including a quinophthalone-based pigment, a sulfonated pigment derivative and a triazine-based pigment derivative was obtained in the same manner as in Example 1 except that the kneaded product was ground and kneaded while controlling the temperature to be 30 ° C .

(Example 4)

About 90 g of a fine yellow pigment composition containing a quinophthalone-based pigment, a sulfonated pigment derivative and a triazine-based pigment derivative was obtained in the same manner as in Example 1 except that the kneaded product was ground and kneaded while controlling the temperature to be 50 ° C .

(Comparative Example 1)

About 90 g of a fine yellow pigment composition including a quinophthalone-based pigment and a sulfonated pigment derivative was obtained in the same manner as in Example 1 except that no triazine derivative was added.

(Comparative Example 2)

About 90 g of a fine yellow pigment composition containing a quinophthalone-based pigment and a sulfonated pigment derivative was obtained in the same manner as in Comparative Example 1, except that the amount of the sulfonated pigment derivative was changed to 75 g.

(evaluation)

≪ Preparation of pigment dispersion and coating film &

17.36 g of Fastogen GREEN A11O (manufactured by DIC) as a green pigment, 23.55 g of a fine yellow pigment composition of Examples and Comparative Examples as a complementary color pigment, and 5.89 g of a sulfonated pigment derivative represented by the above formula (11) 24.5 g of Disperbyk LPN-6919 (manufactured by Big Chemie) as a dispersant, 27.6 g of SPCN-2000 (manufactured by Showa Highpolymer Co., Ltd.) as a dispersion resin and 71.1 g of PMA as an organic solvent were charged in a 400 ml capacity Shaft mixer), and the mixture was stirred for 10 minutes. At this time, the number of revolutions of the stirring blade provided in the stirrer was set to 2000 rpm.

Then, 640 g of inorganic beads having an average particle diameter of 0.8 mm (first inorganic beads, made of zirconia, "Toray ceram crushing ball" (trade name), manufactured by Dora Co., Ltd.) were added and stirred for 30 minutes at room temperature to obtain a first (First treatment). At this time, the number of revolutions of the stirring blade provided in the stirrer was set to 2000 rpm.

Next, the inorganic beads (first inorganic beads) were removed by filtration using a filter ("PALL HDCII Membrane Filter", manufactured by PALL), and then PMA was added so that the pigment content was 15 wt% (Manufactured by Toray Industries, Inc.), which is made of zirconia, was added in an amount of four times the weight of the entire preparation, and the mixture was further stirred for 90 minutes, (Second treatment). At this time, the number of revolutions of the stirring blade provided in the stirrer was set to 2000 rpm.

Thereafter, the inorganic beads (second inorganic beads) were removed by filtration using a filter ("PALL HDCII Membrane Filter" (trade name), manufactured by PALL) to obtain a desired pigment dispersion.

A thin film coated plate (coating film) was prepared using the spinning coater (MIKASA SPINCORTER IH-DX2) as the pigment dispersion prepared as described above. The coated film was heated at 230 DEG C for 1 hour, and the following evaluation was made.

(evaluation)

A Y value, an x value, and a contrast ratio (CR) were measured with a spectrophotometer (SPECTROPHOTOMETER CM-3700d) using the coating film prepared as described above.

On the other hand, a method of measuring the contrast is as follows. That is, the color filter was sandwiched between two polarizing plates, and the transmitted light illuminance when the polarizing planes of the respective polarizing plates were made parallel to the illuminance of the transmitted light when the polarizing planes were made parallel were measured, and the ratios were obtained. For measurement of transmitted light intensity, a luminance meter "LS-100" (manufactured by Minolta Co.) was used. The results of each measurement are shown in Table 1. On the other hand, the column of the evaluation in the table is a value in the case where the y value is 0.55, and the contrast ratio CR is the contrast ratio based on the value in Comparative Example 1. [

[Table 1]

Note 1: The derivative 1 is a sulfonated pigment derivative represented by the formula (11)

Note 2: Derivative 2 is a triazine-based pigment derivative (A) of Production Example 1,

Note 3: Derivative 3 is a triazine-based pigment derivative (B) of Production Example 2,

As shown in Table 1, when a pigment dispersion obtained by using a yellow fine pigment composition comprising a sulfonated pigment derivative and a triazine-based pigment derivative prepared by kneading and milling at a predetermined temperature is used, the pigment dispersion prepared by this pigment dispersion The coating film has an improved contrast ratio. On the other hand, when the addition amount of the sulfonated pigment derivative is increased without using the triazine pigment derivative, the contrast ratio is remarkably reduced.

Thus, the fine yellow pigment composition of the present invention is very suitable for providing a coating film such as a color filter having an improved contrast ratio.

Claims (4)

A yellow pigment composition comprising a quinophthalone pigment (quinophthalone pigment), a sulfonated quinophthalone pigment derivative, and a triazine pigment derivative (triazine pigment derivative) represented by the following formula (1) (Fine yellow pigment composition).
[Formula 1]

(In the formula (1), A represents a group represented by the following formula (2) and B represents a chlorine atom, a hydroxyl group, a sulfanilic acid residue or an orthanilic acid residue.
[Formula 2]

(Wherein Q ¹ , Q ² , Q ³ and Q ⁴ each independently represent -H, a halogen atom, an alkyl group having 1 to 4 carbon atoms or an alkoxy group having 1 to 4 carbon atoms, X is -H, -OH or -NH ₂ , W represents -CH ₂ -, m and n are each independently 0 or 1.)
A pigment dispersion (pigment dispersion) comprising the fine yellow pigment composition according to claim 1.
A process for producing a fine yellow pigment composition according to any one of claims 1 to 4, wherein the mixture containing the quinophthalone-based pigment, the sulfonated quinophthalone-based pigment derivative and the triazine- A step of grinding, a step of grinding, and a step of kneading. delete