Organic pigment fine-particle, and method of producing the same
A method of producing a fine particle of an organic pigment, containing the steps of: flowing a solution of an organic pigment dissolved in an alkaline or acidic aqueous medium, through a channel which provides a laminar flow; and changing a pH of the solution in the course of the laminar flow.
1. A method of producing a fine particle of an organic pigment, comprising the steps of:
flowing a solution of an organic pigment dissolved in an alkaline or acidic aqueous medium, through a channel which provides a laminar flow; and
changing a hydrogen ion exponent (pH) of the solution in the course of the laminar flow.
2. The method according to claim 1 , wherein the solution of the organic pigment is alkaline.
3. The method according to claim 1 , wherein the solution of the organic pigment is a homogeneous solution in which the organic pigment is dissolved in a homogeneous mixed solvent of water and an organic solvent.
4. The method according to claim 1 , wherein an equivalent diameter of the channel is 10 mm or less.
5. The method according to claim 1 , wherein the solution of the organic pigment contains at least one dispersing agent.
6. The method according to claim 5 , wherein at least one of the dispersing agents is a polymer dispersing agent.
7. The method according to claim 1 , wherein the fine particle of the organic pigment is obtained as a dispersion thereof.
8. The pfedueing method according to claim 1 , wherein an equivalent diameter of the channel is 1 mm or less.
9. The method according to claim 1 , wherein the channel of the laminar flow is a micro-reaction site.
10. The method according to claim 5 , wherein the at least one dispersing agent comprises at least one anionic dispersing agent.
11. The method according to claim 5 , wherein the at least one dispersing agent comprises at least one polymer dispersing agent and at least one anionic dispersing agent.