JP2001049139A - Method for pigment formation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve problems that a long time is required in treating a pre- pigment aggregate with an organic solvent and, when the treatment is carried out under a high temperature to shorten the time required for the treatment, particles of the pigment are hard to be controlled, as the crystal growth of the particles is accelerated. SOLUTION: The aggregate of a pre-pigment of a fused polycyclic pigment having <=0.1 μm average primary particle size is formed into the pigment by treating the pre-pigment with an organic solvent in the presence of an acetylenediol-based surfactant.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a pigmentation method,
More specifically, the present invention relates to a pigmentation method in which a pre-pigmented aggregate of a condensed polycyclic pigment is treated with an organic solvent.

[0002]

2. Description of the Related Art Condensed polycyclic pigments are sometimes formed into pigments through aggregates of fine particles in a pre-pigment state. For example, the crude copper phthalocyanine after synthesis is a giant β-type crystal particle of about 10 to 200 μm, and it is necessary to reduce this to a practical size (about 0.02 to 0.1 μm) as a pigment. . For this reason, the crude copper phthalocyanine is refined by dry grinding. However, since α-type crystals of copper phthalocyanine are generated in the pulverized product by dry pulverization, the α-type crystals are stable in a grinding step called a solvent salt milling or a treatment step with an organic solvent which is the next step. It must be crystal-transformed to β-type crystal.

[0003] In the case of pigments such as phthalocyanine green and quinacridone, aggregates of fine particles can be obtained by synthesis. Therefore, particles need to be sized by organic solvent treatment.

[0004]

When an aggregate of the pre-pigment is treated with an organic solvent, there is a problem that the treatment requires a long time. If the treatment is performed at a high temperature in order to shorten the treatment time, the crystal growth of the particles is promoted, so that there is a problem that it is difficult to control the pigment particles to a desired size.

[0005]

According to the present invention, there is provided a pigment characterized in that an aggregate of a pre-pigment having an average primary particle diameter of 0.1 μm or less is treated with an organic solvent in the presence of an acetylenic diol-based surfactant. About the method of conversion. Furthermore, the present invention relates to the above pigmentation method, wherein the pigment is a condensed polycyclic pigment. Furthermore, the present invention relates to the above pigmentation method, wherein the organic solvent forms an emulsion with water. Further, the present invention relates to the above-mentioned pigmentation method using a mixture of an organic solvent and water.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. The pre-pigment in the present invention is in a state before the pigment to be commercialized, which is firmly aggregated with an average primary particle diameter of 0.1 μm or less. Pigments include copper phthalocyanine, dioxazine, high halogenated copper phthalocyanine,
Preferred are condensed polycyclic pigments such as quinacridone. The pre-pigment may be obtained by pulverizing a crude pigment by dry pulverization or may be a finely divided coarse pigment. When the pre-pigment is adjusted by dry pulverization of a crude pigment, a known pulverizer such as an attritor, a ball mill, and a vibration mill is used.

In the pigmentation treatment of the present invention, the pre-pigment is immersed in an organic solvent alone or a mixed system in which the organic solvent is water-emulsion, for the purpose of changing the crystal state in the pre-pigment and sizing the pigment particles. It is done by doing. In some cases, a grinding aid such as salt (sodium chloride) or glass nitrate (sodium sulfate) may be added for pulverization. The organic solvent may be used as a mixed system as long as it has a high affinity for water, and may be used as an emulsion using a surfactant if the solvent has no affinity for water.

The organic solvent according to the present invention has an effect of converting the crystal form of the pigment, for example, an action of converting the α-type crystal of copper phthalocyanine to a β-type, and an action of sizing the particles, for example, sizing of phthalocyanine green after synthesis. It can be selected according to the purpose of use such as the action. For example, toluene,
Aromatic compounds such as xylene, chlorobenzene and nitrobenzene, aliphatic compounds such as mineral spirits, kerosene and ligroin, isopropanol, butanol,
Alcohol compounds such as isobutanol, ethyl cellosolve, butyl cellosolve, cyclohexanol, diethylene glycol, ester compounds such as ethyl acetate, butyl acetate, butyl cellosolve acetate, acetone,
Solvents such as ketone compounds such as methyl ethyl ketone, ether compounds such as tetrahydrofuran, dioxane, and diethylene glycol mono (or di) alkyl ether, and mixtures thereof can be used.

The acetylenic diol-based surfactant of the present invention is a surfactant having acetylenic diol as a basic skeleton, and specific compounds include, for example, 3,6-dimethyl-4-octyldiol, 2,4 , 7,9-Tetramethyl-5-decyne-4,7-diol, and their ethylene oxide or propylene oxide adducts.

An acetylenic diol-based surfactant is added as it is when dissolved in an organic solvent to be used, or is dissolved in a compatible solvent in advance when it is not dissolved, or a dispersant is separately used as a dissolution aid. And add.
The addition amount is preferably 0.1 to 20% by weight based on the organic solvent.

In general, pigments are often treated with a resin in order to impart suitability according to the intended use. In the present invention, however, pigments treated with such a resin can be used. The resin treatment may be performed at the time of dry pulverization or at the time of solvent treatment. As the resin, rosins represented by polymerized rosin, hydrogenated rosin, disproportionated rosin and the like, and rosin-modified phenol resin can be freely selected.

[0012]

EXAMPLES Hereinafter, the present invention will be specifically described with reference to comparative examples and examples.

Example 1 To a 5 L dry attritor (12 kg of 3/8 inch steel ball) was added 500 parts by weight of crude copper phthalocyanine, and the mixture was pulverized at 100 ° C. for 1 hour.
A ground material containing 40% of 0% β-form crystals was obtained. 30 parts by weight of the obtained milled crude copper phthalocyanine was azeotropically mixed with 240 parts by weight of water, 120 parts by weight of isobutanol and 0.3 part by weight of an acetylenic diol surfactant (Surfynol 104: manufactured by Air Products) for 1 hour. After gently stirring in this state, isobutanol was distilled off, filtered and dried. The content of α-type crystals of the copper phthalocyanine pigment thus obtained was 1% or less, and the crystal transitioned to β-type in a very short time. Further, as compared with the pigment obtained in Comparative Example 1, the hue, the coloring power, and the like were equivalent, and the dispersibility was excellent.

[0013]

Comparative Example 1 500 parts by weight of crude copper phthalocyanine was added to a 5 L dry attritor (12 kg of 3/8 inch steel ball), and pulverized at 100 ° C. for 1 hour to obtain α-type crystal 6.
A ground material containing 40% of 0% β-form crystals was obtained. After 30 parts by weight of the obtained milled crude copper phthalocyanine was gently stirred in an azeotropic state for 4 hours together with 240 parts by weight of water and 120 parts by weight of isobutanol, the isobutanol was distilled off, filtered and dried. The content of α-type crystals in the copper phthalocyanine pigment thus obtained was 1% or less.

[0014]

Comparative Example 2 500 parts by weight of crude copper phthalocyanine was added to a 5 L dry attritor (12 kg of 3/8 inch steel ball), and pulverized at 100 ° C. for 1 hour to obtain α-type crystal 6.
A ground material containing 40% of 0% β-form crystals was obtained. After 30 parts by weight of the obtained milled crude copper phthalocyanine was slowly stirred with 240 parts by weight of water and 120 parts by weight of isobutanol in an azeotropic state for 1 hour, the isobutanol was distilled off, filtered and dried. The content of α-type crystals in the copper phthalocyanine pigment thus obtained was 32%.

[0015]

Example 2 500 parts by weight of crude copper phthalocyanine was added to a 5 L dry attritor (12 kg of 3/8 inch steel ball), and the mixture was pulverized at 100 ° C. for 1 hour.
A ground material containing 40% of 0% β-form crystals was obtained. 500 parts by weight of the obtained milled crude copper phthalocyanine was mixed with 500 parts by weight of diethylene glycol and acetylene diol surfactant 5
The mixture was kneaded for 5 hours at 90 ° C. in a 3 L kneader together with parts by weight (Surfinol 104: manufactured by Air Products).
50 parts by weight of the kneaded product was added to 2000 L of a 1% aqueous hydrochloric acid solution, dissolved at 90 ° C. for 1 hour, then filtered, washed with water and dried. The content of α-type crystals of the copper phthalocyanine pigment thus obtained was 1% or less, and the crystal transitioned to β-type in a very short time. Further, as compared with the pigment obtained in Comparative Example 1, the hue, the coloring power, and the like were equivalent, and the dispersibility was excellent.

[0016]

Comparative Example 3 500 parts by weight of crude copper phthalocyanine was added to a 5 L dry attritor (12 kg of 3/8 inch steel ball), and the mixture was ground at 100 ° C. for 1 hour to obtain α-type crystal 6.
A ground material containing 40% of 0% β-form crystals was obtained. 500 parts by weight of the obtained milled crude copper phthalocyanine was mixed with 500 parts by weight of diethylene glycol in a 3 L kneader at 90 ° C. for 5 hours.
Time kneaded. 50 parts by weight of the kneaded product was added to 2000 L of a 1% aqueous hydrochloric acid solution and dissolved at 90 ° C. for 1 hour.
Washed and dried. The content of α-type crystals in the copper phthalocyanine pigment thus obtained was 38%.

According to the pigmentation method of the present invention, an acetylenic diol-based surfactant is contained in the organic solvent when the pigment is treated with an organic solvent. As a result, the penetration of the organic solvent into the aggregates of the pre-pigment is increased, and as a result, the action of the organic solvent on the pre-pigment increases, and the processing speed by the organic solvent increases. Therefore, in the present invention, not only the time required for the solvent treatment in the pigmentation step is shortened, but also a pigment having excellent quality can be provided.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Atsushi Endo 2-3-13 Kyobashi, Chuo-ku, Tokyo Inside Toyo Ink Manufacturing Co., Ltd. (72) Inventor Tetsuya Kaneko 2-3-1 Kyobashi, Chuo-ku, Tokyo Toyo Ink Manufacturing Co., Ltd.

Claims (4)

[Claims] 1. A pigmentation method comprising treating an aggregate of a pre-pigment having an average primary particle diameter of 0.1 μm or less with an organic solvent in the presence of an acetylenic diol-based surfactant. 2. The method according to claim 1, wherein the pigment is a condensed polycyclic pigment. 3. The method according to claim 1, wherein the aggregate of the pre-pigment is a dry pulverized product of a crude pigment. 4. The method according to claim 1, wherein a mixture of an organic solvent and water is used.