M. Technique Company, Ltd.

Kazutaka Takeda

Masakazu Enomura

Daisuke Honda

The present application provides black perylene pigment microparticles having an average circularity of 0.8 or more which are amorphous; and a method of producing the black perylene pigment microparticles, which comprises a step of mixing a pigment solution in which a black perylene pigment is dissolved and a precipitation solvent for precipitating black perylene pigment microparticles from the pigment solution to form black perylene pigment microparticles, wherein at least one of the pigment solution and the precipitation solvent independently includes a salt of an alkaline earth metal and/or a particle growth inhibitor. The present invention can provide black perylene pigment microparticles having good dispersibility, high concealability and light-shielding property and controlled hue and chroma, and a method of easily producing the same, and the like.

Black perylene pigment microparticles, method of producing the same, black pigment composition comprising the same, and method of producing black perylene pigment microparticles having controlled hue and/or chroma

A method of producing organic pigment microparticles includes: Step 1 of precipitating organic pigment microparticles by mixing an organic pigment raw material liquid in which an organic pigment raw material is mixed with a solvent, and a precipitation solvent for precipitating the organic pigment microparticles from the organic pigment raw material liquid in a thin film fluid formed by introducing the organic pigment raw material liquid and the precipitation solvent in a space between at least two processing surfaces which are disposed so as to face each other, being capable of approaching to and separating from each other, at least one of which rotates relatively to the other; and Step 2 of coating at least a part of the organic pigment microparticles with an oxide coating; wherein the oxide coating is optically colorless and transparent, and Step 1 and Step 2 are performed out continuously in the thin film fluid.

Method for producing organic pigment microparticles

At least a first fluid and a second fluid are used and are not miscible with each other. At least the first fluid includes one or two items selected from an organic compound, a reactant, and a phase transfer catalyst. From among the fluids other than the first fluid, at least the second fluid includes at least one item from among the items not selected from the three items. The first fluid and second fluid contain all three items. Each of the fluids are merged in a thin-film fluid formed between processing faces that rotate relative to each other. A phase transfer catalyst reaction occurs in the thin-film fluid. Among the first fluid and the second fluid, at least the fluid containing the phase transfer catalyst is prepared so that the phase transfer catalyst is substantially homogeneously mixed before being introduced between the processing faces.

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Izumi, Japan

Kazutaka Takeda