Method for producing organic pigment microparticles

A method of producing organic pigment microparticles, comprising the following steps:

• 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 microparticles of the organic pigment 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 the 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
• after Step 1, Step 2 is completed at a predetermined time until the organic pigment microparticles grow and/or aggregate.

A method of producing organic pigment microparticles, comprising the following steps:

• 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 microparticles of the organic pigment 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 the 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 inorganic oxide coating;
• wherein Step 1 and Step 2 are performed out continuously in the thin film fluid.