JP2002285028A - Coating treatment pigment and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coating treatment pigment which is easily dispersed and shows an excellent stability in viscosity and dispersion of a pigment dispersed body and its manufacturing method. SOLUTION: The coating treatment pigment is obtained by forming a coating layer of a cross-linked resin including a coloring matter derivative on a surface of a pigment particle by means of kneading a composition consisting of a pigment, the coloring matter derivative, a thermoplastic resin with a cross-linking group, and a solvent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a coated pigment and a method for producing the same. More particularly, the present invention relates to a coated pigment characterized by forming a coating layer of a crosslinked resin containing a dye derivative on the surface of pigment particles, and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, when a pigment is subjected to a surface treatment with a resin, the surface treatment is performed by adsorption, precipitation and reaction. Compared with untreated pigments, surface-treated pigments are superior in viscosity of dispersions, inks and paints and their dispersion stability,
The fine dispersion is sought and demanding physical properties as product applications inks and coatings have become indispensable.
Above all, surface-crosslinked pigments have high solvent resistance, and there has been a demand for easily dispersed surface-treated pigments that can be developed for various uses. However, the finer the pigment, the more unstable the quality of the surface-treated pigment, or the thickening or agglomeration of the pigment dispersion due to the gradual dissolution of the coating resin used for the surface treatment and loss of the equilibrium of adsorption equilibrium. the cause was problems such as deteriorating the product characteristics. This surface free energy increases with the miniaturization of the primary particles of the pigment, which is a factor that makes it difficult to disintegrate aggregates to primary particles. Normally, even when a resin-based dispersant is used, it is not easy to disperse the primary particles. Furthermore, it is extremely difficult to simultaneously perform resin crosslinking on the surface of the pigment if the dispersion is performed in an insufficiently dispersed state, resulting in formation of aggregates.

[0003]

An object of the present invention is to provide a coated pigment which is easy to disperse, is excellent in the viscosity of a pigment dispersion and has excellent dispersion stability, and a method for producing the same.

[0004]

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 a pigment which forms a coating layer of a cross-linked resin on the surface of pigment particles and a method for producing the same are provided. The present invention has been completed. That is, the present invention utilizes a function in which a pigment derivative having high pigment affinity on the surface of pigment particles adsorbs the pigment skeleton in a disperser that can be strongly kneaded, and the other functional group of the pigment derivative is a resin. Due to the interaction with the functional group, the pigment derivative mediates on the pigment surface and the resin adsorbed layer is formed on the pigment surface to disperse to the primary particle level. An object of the present invention is to provide a pigment having a resin coating layer which is chemically crosslinked on the surface of a fine pigment by a reaction between functional groups of the resins in a resin adsorption layer on the surface of the pigment. It is intended to provide. Another object of the present invention is to thus coated treated pigment obtained offset inks, inkjet inks, intends to use by, for example, the colorant plastics and paints.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below in more detail.

[0006] Examples of the dye derivative in the present invention is represented by the formula (1).

Formula (1) P-Fn (wherein P is a dye residue, F is a substituent shown below, and n is 1
Shows an integer of ~ 4. )

The basic substituent F has at least one substituent selected from the group represented by the following formulas (1), (2), (3) and (4).

Equation (1)

Embedded image _{X: -SO 2 -, - CO} -, - CH 2 NHCOCH 2 -,
—CH ₂ — or a direct bond. n represents an integer of 1 to 10. R _1, R _2: each independently, an optionally substituted alkyl group, an optionally substituted alkenyl group, an optionally substituted phenyl group or further together with R ₁ and R _2, Represents an optionally substituted heterocycle containing a nitrogen, oxygen or sulfur atom. The alkyl group and the alkenyl group preferably have 1 to 10 carbon atoms.

[0010] The formula (2)

Embedded image R _1, R _2: each independently, an optionally substituted alkyl group, an optionally substituted alkenyl group, an optionally substituted phenyl group or further together with R ₁ and R _2, Represents an optionally substituted heterocycle containing a nitrogen, oxygen or sulfur atom. The alkyl group and the alkenyl group preferably have 1 to 10 carbon atoms.

[0011] The formula (3)

Embedded image _{X: -SO 2 -, - CO} -, - CH 2 NHCOCH 2 -,
—CH ₂ — or a direct bond. R _{3 represents} an alkyl group which may be substituted, an alkenyl group which may be substituted or a phenyl group which may be substituted. The alkyl group and the alkenyl group preferably have 1 to 10 carbon atoms. R ₄ , R ₅ , R ₆ , and R ₇ each independently represent a hydrogen atom, an optionally substituted alkyl group, an optionally substituted alkenyl group, or an optionally substituted phenyl group. The alkyl group and the alkenyl group preferably have 1 to 5 carbon atoms.

Equation (4)

Embedded image _{X: -SO 2 -, - CO} -, - CH 2 NHCOCH 2 -,
—CH ₂ — or a direct bond. _{Y: -NR 8 -Z-NR 9} - or a direct bond. R ₈ and R ₉ each independently represent a hydrogen atom, an optionally substituted alkyl group, an optionally substituted alkenyl group or an optionally substituted phenyl group. The alkyl group and the alkenyl group preferably have 1 to 5 carbon atoms. Z represents an alkylene group which may be substituted, an alkenylene group which may be substituted, or a phenylene group which may be substituted. The alkyl group and the alkenyl group preferably have 1 to 8 carbon atoms. P: represents a substituent represented by the formula (5) or a substituent represented by the formula (6). Q: represents a hydroxyl group, an alkoxyl group, a substituent represented by the formula (5) or a substituent represented by the formula (6).

[0013] (5)

Embedded image n represents an integer of 1 to 10. R _1, R _2: each independently, an optionally substituted alkyl group, an optionally substituted alkenyl group, an optionally substituted phenyl group or further together with R ₁ and R _2, Represents an optionally substituted heterocycle containing a nitrogen, oxygen or sulfur atom. The alkyl group and the alkenyl group preferably have 1 to 10 carbon atoms.

Equation (6)

Embedded image R _{3 represents} an alkyl group which may be substituted, an alkenyl group which may be substituted or a phenyl group which may be substituted. The alkyl group and the alkenyl group preferably have 1 to 10 carbon atoms. R ₄ , R ₅ , R ₆ , and R ₇ each independently represent a hydrogen atom, an optionally substituted alkyl group, an optionally substituted alkenyl group, or an optionally substituted phenyl group. The alkyl group and the alkenyl group preferably have 1 to 5 carbon atoms.

The substituent F having an acidic group and a neutral group has at least one substituent selected from the group represented by the following formulas (7), (8) and (9).

Equation (7)

Embedded image M: represents a hydrogen atom, a calcium atom, a barium atom, a strontium atom, a manganese atom, or an aluminum atom. l: the valence of M

Equation (8)

Embedded image R ₁₀ , R ₁₁ , R ₁₂ , R ₁₃ : hydrogen atom or carbon number 1 to 3
Represents an alkyl group of 0 (except when all are hydrogen atoms).

Equation (9)

Embedded image A: a hydrogen atom, a halogen atom, an -NO _2, -NH ₂ or SO ₃ H. k: represents an integer of 1 to 4.

Examples of the substituent such as an alkyl group which may be substituted in R _{1 to} R ₇ and Z include a halogen atom, —O
_{H, -NO 2, -NH 2,} -COOH, -CN, -SO
Examples include ₃ H, -SH, an acetyl group, a benzyl group, and a phenyl group.

[0020] Examples of the dye residue represented by P, for example diketopyrrolopyrrole pigments, azo, disazo, azo dyes such as polyazo, phthalocyanine dye, diaminodianthraquinone anthraquinone, anthrapyrimidine, flavanthrone,
Anthraquinone dyes such as anthantrone, indanthrone, pyranthrone and biolanthrone, quinacridone dyes, dioxazine dyes, perinone dyes, perylene dyes, thioindigo dyes, isoindoline dyes, isoindolinone dyes, quinophthalone dyes, There are a slen dye, a metal complex dye, an anthraquinone residue and a triazine residue.

Examples of the triazine residue include an alkyl group such as a methyl group and an ethyl group, an amino group or a dimethylamino group, an alkylamino group such as a diethylamino group and a dibutylamino group, a nitro group, a hydroxyl group, a methoxy group, and an ethoxy group. , A alkoxy group such as butoxy group or a halogen or methyl group such as chlorine, a methoxy group,
Phenyl or methyl, ethyl, methoxy, ethoxy, amino, dimethylamino, diethylamino, nitro, nitro, hydroxyl, etc., which may be substituted by amino, dimethylamino, hydroxyl, etc. 1,3,5-triazine which may have a substituent such as a phenylamino group.

The pigments constituting the present invention include diketopyrrolopyrrole pigments, azo pigments such as azo, disazo and polyazo, copper phthalocyanine, halogenated copper phthalocyanine,
Phthalocyanine-based pigments such as metal-free phthalocyanine, anthraquinone-based pigments such as aminoanthraquinone, diaminodianthraquinone, anthrapyrimidine, flavanthrone, anthantrone, indanthrone, pyranthrone and biolanthrone, quinacridone-based pigments, dioxazine-based pigments, perinone-based pigments, perylene Pigments, thioindigo pigments, isoindoline pigments, isoindolinone pigments, quinophthalone pigments, sulene pigments, metal complex pigments and other organic pigments, or titanium oxide, zinc white, zinc sulfide, lead white, carbonic acid Calcium, precipitated barium sulfate, white carbon, alumina white, kaolin clay,
Talc, bentonite, black iron oxide, cadmium red, red iron, molybdenum red, molybdate orange, chrome vermillion, graphite, cadmium yellow,
Yellow iron oxide, titanium yellow, chromium oxide, viridian, titanium cobalt green, cobalt green, cobalt chrome green, victoria green, ultramarine, navy blue, cobalt blue, cerulean blue, cobalt silica blue, cobalt zinc silica blue, manganese violet, cobalt violet Such as inorganic pigments, or
Carbon black such as acetylene black, channel black and furnace black.

As for the combination of the pigment derivative of the general formula [1] and the pigment of the present invention, it is preferable to use a compound having a similar hue or structure, since the change in hue is small.

The coating pigment of the present invention may be of any composition and means as long as it can form a coating layer of a crosslinked resin.
Preferably, 30 parts by weight and 4 to 50 parts by weight of the crosslinked resin. If the amount of the dye derivative is 1 part by weight or less or 30 parts by weight or more, it becomes difficult to coat the resin. Crosslinked resin is low, the effect of the coating is less than 4 parts by weight, 5
0 parts by weight or more becomes difficult to coat crosslinked.

The thickness of the coating layer of the coated pigment of the present invention is a value obtained by calculating the amount of resin coated on the pigment from the specific surface area of the charged pigment. There is no limitation on the thickness of the coating layer, but 0.5
It is preferably from 5 to 5 nm. 0.5nm or less in less effect of the coating process, it is difficult to more than 5nm coats crosslinking.

The coated pigment of the present invention is produced by kneading a composition comprising a pigment, a dye derivative, a thermoplastic resin having a crosslinkable group, and a solvent. The composition ratio of the composition is pigment 10
3 to 20 parts by weight of a dye derivative, resin 2
A range of 0 to 60 parts by weight and a solvent of 4 to 200 parts by weight are preferred.

The pigment, dye derivatives, and kneading the premixed so that the resin becomes uniform by dispersing machine performs. The amount of the solvent is desirably adjusted in accordance with the properties of the above composition.

The solvent is one or more solvents selected from aromatic hydrocarbons, aliphatic hydrocarbons, esters, ketones, alcohols, etc., for example, toluene, xylene, hexane, cyclohexane , Cyclohexanone, ethyl acetate, acetone, methanol, ethanol, propanol, isopropanol, diacetone alcohol, tetrahydrofuran (THF), dioxane, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethyl cellosolve acetate, methoxypropyl acetate, and the like.

As a dispersing machine, a kneader, a roll mill,
A dispersing machine such as a ball mill, a Banbury mixer, a roller mill, and a mill mill is used alone or in combination. However, kneading with a two-roll mill is preferable because mixing and kneading can be performed alone.

In the case of the two-roll mill, as the first step, wetting of the resin to the pigment and adsorption of the resin are advanced. This process is referred to as a chipping step. About 80% of solvent volatilization or 20%
It is dispersion of about times.

The second step is a coating step in which heating and kneading are continued on the kneaded material adsorbed by the resin due to chipping, and the pigment is coated.
If kneading is not possible on a mechanical basis, add an appropriate amount of solvent to help kneading of chips. At this time, crosslinking of the resin occurs, and the resin is partially cut. The reaction is excessive mechanical pressure and triturated news a mechanochemical reaction in which the result of the heating, the crosslinking reaction also only a pigment and a resin hardly occurs. The kneading in the presence pigment and a dye derivative and the resin and the dye derivative and a resin solid resin adsorption is sufficient pigment surface, resin crosslinking is estimated to result from additional heating and pressurizing 圧混 kneading. The heating temperature is preferably in the range of 80 ° C. to 120 ° C., at 80 ° C. below the temperature in some cases covering layer of crosslinked resin is not sufficiently formed.

In order to effectively produce the coated pigment of the present invention, the resin to be used preferably contains a functional group which can be crosslinked by a mechanochemical reaction. The crosslinkable group is not limited as long as it is crosslinkable, but is preferably a carboxyl group, a hydroxyl group or an alkoxyl group.

The type of the resin to be coated in the present invention is not limited as long as the pigment, the dye derivative and the resin are cross-linked by heating and kneading. Petroleum resin Examples of the resin, maleic acid resin, phenol resin, nitrocellulose, cellulose acetate butyrate, cyclized rubber, chlorinated rubber, alkyd resins, acrylic resins, polyester resins, amino resins, epoxy resins, vinyl resins, butyral such as resin and the like. Particularly, a thermoplastic resin is preferable, and examples thereof include an acrylic resin, a polyester resin, and a urethane resin.

The amount of coating is determined by solvent extraction of the resin.
It is measured from the amount of uncoated resin. Select the solvent the resin is fully dissolved, was added to 10 to 100 times of the solvent-treated pigment, eluting the resin by ultrasonic dispersion or the like. It is the simplest, most accurate and preferable to measure the coating amount because the resin solution separated by centrifugation or the like is collected and the total elution amount is calculated by measuring the weight and the like.

It is desirable that the resin not used for coating the pigment be washed with a solvent of the ink or paint to be used and then removed by filtration or the like. However, if the surplus resin does not affect the physical properties, the resin is washed. No need to do. Further, after the treated pigment is washed, it is possible to dry it when there is no agglomeration, but it is not necessary to dry it as long as it is the same solvent as the ink used.

The coated pigment can be used in the same manner as a usual pigment. The dispersing machine used when dispersing the pigment in a vehicle or the like is a sand mill, a dyno mill, a homogenizer, an attritor, a ball mill, a paint shaker, a fluidizer, a high-speed mixer, an ultrasonic dispersing machine, and the like. Beads, stainless beads or the like may or may not be used. The dispersion time is 5 minutes to 24 hours, preferably 30 minutes to 8 hours.

Since the dispersion using the coated pigment of the present invention has low viscosity and excellent dispersion stability, it can be used for inks and paints containing this dispersion as a colorant.

[0038]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on embodiments.
In the examples, parts and% indicate parts by weight and% by weight. Pigments and resins used in Examples and Comparative Examples are shown below.
Specific coating pigments and their production methods are shown below.

[0039] [Material] pigment: copper phthalocyanine blue (manufactured by Toyo Ink Mfg Rio Nord Blue FG7351)

Dye derivative: Dye derivative

Embedded image Dye derivative

Embedded image Dye derivative

Embedded image

[0041] Resin: temperature controlling regulator resin solution A separable four-necked flask,
After attaching a cooling pipe and a stirrer, charging 100 parts of ethanol, heating to 70 ° C., and replacing the inside of the reaction vessel with nitrogen,
From a dropping tube, 20 parts of methacrylic acid, 20 parts of 2-hydroxyethyl methacrylate, and 60 parts of n-butyl methacrylate
And 2,2'-azobisisobutyronitrile were added, and the reaction was continued for 5 hours to obtain an acrylic resin solution having a solid content of 50% and a weight average molecular weight of 40,000 (GPC: in terms of polystyrene).

A resin solution, a temperature control regulator in a separable four-necked flask,
Condenser, attach a stirrer, was charged with 100 parts of ethanol, after which the temperature was raised reaction vessel was purged with nitrogen to 70 ° C.,
Dimethylaminoethyl methacrylate 30 from dropping tube
Parts, 2-hydroxyethyl methacrylate 18 parts, n- butyl 52 parts of methacrylic acid, 2,2'-azobisisobutyronitrile 2 parts were added, the reaction was continued for 5 hours, 50% solids, weight average molecular weight An acrylic resin solution of 10,000 (GPC: in terms of polystyrene) was obtained.

Resin solution: 116 parts of trimethylolpropane, 16 parts of isophthalic acid
2.4 parts were charged to the flask 0.1 parts of dibutyltin oxide, the reaction was continued at gradually 200 ° C. The temperature was raised from 160 ° C. while distilling off water from the system, so that one or less acid value 2 did. After the acid value became 2 or less, the temperature was raised to 160 ° C, 122.9 parts of trimellitic anhydride was added, and the reaction was carried out at 160 ° C for 4 hours while distilling off water from the system. Was dissolved in ethyl acetate, acid value was obtained 217, NV50% of the polyester resin.

Resin solution While introducing nitrogen gas in a reactor equipped with a thermometer, a stirrer, a reflux condenser and a nitrogen gas inlet tube, Mw = 200
Poly (3-methyl-1,5-pentane adipate)
59.7 parts of diol, 15.2 parts of polyethylene glycol having Mw = 2000, 35.9 parts of 2,2-dimethylolpropionic acid, isophorone diisocyanate 13
5.7 parts of the mixture were subjected to a boiling point reaction in 200 parts of methyl ethyl ketone for 6 hours to obtain a terminal isocyanate prepolymer. After cooling to 40 ° C., 1000 parts of acetone was added to obtain an organic solvent solution of the terminal isocyanate prepolymer. Next, a mixture of 53.5 parts of isophoronediamine and 400 parts of acetone was added to an organic solvent solution of the obtained terminal isocyanate prepolymer 546.
5 parts were gradually added at room temperature and reacted at 50 ° C. for 3 hours,
An NV30% polyurethane resin solution was obtained.

[0045]

Example 1 90 parts of a copper phthalocyanine blue pigment, 10 parts of a dye derivative and 100 parts of a resin solution (resin solid content 50 parts)
Parts, 50 parts of ethanol) were uniformly stirred to obtain a mixture. The two rolls were heated to 60 ° C., the mixture was added, and the mixture was kneaded for 10 minutes and dispersed 20 times. The kneaded product was taken out, cooled to room temperature, coarsely pulverized, and 50 parts of ethanol was added to the prepared chip. The two rolls were heated to 80 ° C. and kneaded 30 times. From the middle, the heated kneaded material turned into a rubber state. The kneaded material was formed into a sheet, cooled to room temperature, and coarsely pulverized to obtain a coated product. When the coating amount was measured, it was 15 g / 100 g
(Pigment), the coating thickness was 2.1 nm.

EXAMPLE 2 90 parts of copper phthalocyanine blue pigment, 10 parts of a phthalocyanine derivative, 64 parts of the resin solution (resin solid content 32 parts, ethanol 32 parts) and uniformly stirring 50 parts of ethanol, the mixture was warmed to 60 ° C. The mixture was dispersed on two rolls 20 times after being ground for 10 minutes. Further added 50 parts of a solvent, heated and kneaded with two rolls to 80 ° C. to give a 30 times performs coating treatment products. During the dispersion, the heated kneaded material changed from a rubbery state to a crushed material, and began to fall on the tray under the two rolls. When the coating amount was measured, it was 20 g / 100 g
(Pigment), the coating thickness was 2.9 nm.

EXAMPLE 3 98 parts of copper phthalocyanine blue pigment, 2 parts of dye derivative, a resin solution 64 parts (resin solids 32 parts,
A coating treatment product was obtained in the same manner as in Example 2 with the composition of ethanol (32 parts) and 50 parts of ethanol. During the dispersion, the heated kneaded material changed from a rubbery state to a crushed material, and began to fall on the tray under the two rolls. When the coating amount was measured, it was 5 g / 100 g (pigment), and the coating thickness was 0.7 n.
m.

EXAMPLE 4 70 parts of copper phthalocyanine blue pigment, 30 parts of the dye derivative and the resin solution 125 parts (resin solids 50
Parts, 50 parts of ethanol) in the same manner as in Example 1 to obtain a coarsely pulverized product. When the coating amount was measured, it was 3
3 g / 100 g (pigment), it was coated thickness 4.7 nm.

Example 5 90 parts of copper phthalocyanine blue pigment, 10 parts of a pigment derivative and 26 parts of a resin solution (resin solid content: 13 parts)
Parts, 13 parts of ethanol) and 50 parts of ethanol in the same manner as in Example 2 to obtain a coarsely pulverized product. The coating amount was measured 13 g / 100 g (pigment), was coated thickness 1.4 nm.

Example 6 70 parts of a copper phthalocyanine blue pigment, 20 parts of a dye derivative and 20 parts of a resin solution (resin solid content of 10 parts)
Parts, 10 parts of ethanol) and 50 parts of ethanol in the same manner as in Example 1 to obtain a coarsely pulverized product. The coating amount was measured 20 g / 100 g (pigment), was coated thickness 2.0 nm.

Example 7 90 parts of a copper phthalocyanine blue pigment, 10 parts of a dye derivative and 100 parts of a resin solution (resin solid content 50 parts)
Parts, 50 parts of ethyl acetate) in the same manner as in Example 1 to obtain a coarsely pulverized product. The coated amount was measured 6
g / 100 g (pigment), and the coating thickness was 0.9 nm.

Example 8 90 parts of copper phthalocyanine blue pigment, 10 parts of a dye derivative and 167 parts of a resin solution (resin solid content 50 parts)
Parts, 117 parts of acetone) in the same manner as in Example 1 to obtain a coarsely pulverized product. Place to measure the coverage of 7
g / 100 g (pigment), and the coating thickness was 1.0 nm.

Comparative Example 1 Example 1 described in JP-A-1-144475
Was prepared. To 140 parts of copper phthalocyanine blue pigment,
Copper phthalocyanine monosulfonic acid laurylamine salt 10
Parts, 380 parts of nitrocellulose (NCH1 / 4), 65 parts of dibutyl phthalate, 10 parts of ethanol, 1 part of ethyl acetate
After adding 0 parts and premixing (mixing) until the mixture becomes uniform, the mixture is ground for 10 minutes in two rolls heated to 60 ° C.
It was rolled into a film and crushed to obtain a color chip. When the coating amount was measured, it was 0 g / 100 g (pigment),
Since the coating thickness was 0 nm, no further evaluation was performed.

[Comparative Example 2] 100 parts of copper phthalocyanine blue pigment, 125 parts of the resin solution (resin solid content: 50 parts, ethanol 50
Part) was prepared in the same manner as in Example 1 to obtain a coarsely pulverized product. The coating amount was measured 1 g / 100 g (pigment), was coated thickness 0.1 nm.

[Measurement of amount of coating resin and thickness of coating layer]
The residual solvent amount of the coarsely pulverized material is measured in advance by weight loss by heating, and the resin content A of the coarsely pulverized material is grasped. Take a certain amount of coarse pulverization, add a certain amount of solvent that can sufficiently dissolve the resin (approximately 20 to 100 times the amount of coarsely pulverized material), dissolve the coagulation sufficiently by ultrasonic dispersion, and dissolve in the solvent by centrifugation etc. The resin thus obtained is collected, and the amount B of the uncoated resin is measured. The coating resin amount C is calculated by C = AB. Coating layer thickness d
Is the specific surface area S of the pigment, the specific gravity H of the resin, and the coating amount C, d
= C × H / S. Alternatively or collected precipitated pigment, sufficiently dried, it is also possible to directly measure the amount of the resin coated C by measuring the weight loss due to thermal decomposition of the resin by thermal analysis.

The pigments obtained in Examples 1 to 8 and Comparative Examples 1 to 3 were evaluated for easy dispersibility by the following method. Table 1 shows the results
Shown in

[0048]

[Table 1]

[Evaluation of easy dispersibility] 0.1 g of the pigment of Example or Comparative Example was collected in a screw tube, and 10 g of a solvent was collected.
In addition, dispersed ultrasound 10 min, viewed state before standing for one hour. ：: There is little sediment, and the glass wall surface is transparent. Δ: There is a sediment, and the glass wall surface is opaque. X: There are many sediments.

[0050] Examples 1 to 8 obtained in the dispersion preparation and evaluation of] the pigment of Comparative Examples 1 to 3, pigment content: 20 wt%
Was added thereto, and the mixture was dispersed with a paint shaker for 2 hours to obtain a pigment dispersion. Further, as Comparative Example 3, a pigment dispersion of an untreated pigment was prepared.

Comparative Example 3 9 parts of copper phthalocyanine blue pigment, 1 part of a phthalocyanine derivative, 10 parts of a resin solution (5 parts of resin solids, 5 parts of ethanol), and 30 parts of ethanol were uniformly stirred, and dispersed for 2 hours by a paint shaker. A pigment dispersion was obtained. When the coating amount was measured, it was 0 g / 100 g.
(Pigment), the coating thickness was 0 nm.

The obtained pigment dispersion was evaluated by the following method. Table 1 shows the results. [Initial viscosity] It was measured at 25 ° C using a B-type viscometer. [Stability] The dispersion was placed in a screw-bottle bottle, left at 40 ° C. for 5 days, and the change in viscosity was evaluated. ：: Change in viscosity is 60% or less. △: change in viscosity is less than 100%. ×: change in viscosity is more than 100%.

EFFECTS OF THE INVENTION By using the coated pigment of the present invention, a pigment dispersion which is easy to disperse, has low viscosity and excellent stability,
Inks and paints can be provided. This coating treatment pigments of the present invention, due to a pigment coated with a resin which is different from crosslinked mere resin treated pigment.

 ──────────────────────────────────────────────────の Continued on the front page F term (reference) 4J037 AA02 AA10 AA11 AA12 AA14 AA16 AA17 AA19 AA22 AA24 AA25 AA27 AA28 AA29 CC02 CC06 CC12 CC15 CC16 CC22 CC23 CC24 CC26 EE03 EE28 EE47 FF15 FF23

Claims (8)

[Claims] 1. A coating treated pigment which is characterized by comprising forming a coating layer of crosslinked resin containing a dye derivative on the surface of the pigment particles. 2. The coated pigment according to claim 1, wherein the pigment derivative is a pigment derivative having a basic group. 3. A dye derivative 1 based on 100 parts by weight of the pigment.
The coated pigment according to claim 1 or 2, comprising from 30 to 30 parts by weight and 4 to 50 parts by weight of a crosslinked resin. 4. The coated pigment according to claim 1, wherein the thickness of the coating layer is 0.5 to 5.0 nm. 5. The method for producing a coated pigment according to claim 1, wherein a composition comprising a pigment, a dye derivative, a thermoplastic resin having a crosslinkable group and a solvent is kneaded. 6. The method according to claim 5, wherein the kneading is kneading with a two-roll mill. 7. The method according to claim 5, wherein the crosslinkable group is a carboxyl group, a hydroxyl group or an alkoxyl group. 8. The method according to claim 5, wherein the thermoplastic resin is an acrylic resin, a polyester resin or a urethane resin.