Production method for fine organic pigment

Abstract

The present invention provides a process for producing a fine organic pigment having a very small primary particle size, and a fine organic pigment produced by the process; a process for producing a dispersion using the fine organic pigment, and a dispersion produced by the process; and a process for producing an ink using the dispersion. The present invention relates to [1] a process for producing a fine organic pigment, including step 1 of kneading a mixture prepared by blending a raw material organic pigment, a water-soluble inorganic salt, a water-soluble organic solvent and water with each other, the water being blended in an amount of not less than 0.6 part by mass and not more than 4.0 parts by mass on the basis of 100 parts by mass of the water-soluble inorganic salt; [2] a fine organic pigment produced by the process described in the above [1]; [3] a dispersion produced using the fine organic pigment described in the above [2]; [4] a process for producing a paste of a fine organic pigment, including step 2 of cleaning the kneaded mixture obtained in the step 1; [5] a process for producing a dispersion, including step 3 of subjecting the paste of the fine organic pigment produced by the process described in the above [4], an organic solvent and water to dispersing treatment; and [6] a process for producing an ink, including step 4 of mixing the dispersion produced by the process described in the above [5], with at least one material selected from the group consisting of water and an organic solvent.

Dependencies are inferred from the claim text.