PROCESS FOR PRODUCING FLUOROPOLYMER PARTICLES

摘要

To provide a process for producing fluoropolymer particles, whereby formation of fine particles is suppressed. A process for producing fluoropolymer particles, which comprises (i) a step of preparing a solution or dispersion of a fluoropolymer (A) having the fluoropolymer (A) dissolved or dispersed in a solvent (B), wherein the solvent (B) contains a good solvent (B2) whereby the degree of swelling of the fluoropolymer (A) exceeds 50%, and the degree of swelling of the fluoropolymer (A) by the solvent (B) is from 50 to 1,200%; and (ii) a step of mixing the solution or dispersion of a fluoropolymer (A) with a solvent (C) to flocculate the fluoropolymer (A) thereby to form particles of the fluoropolymer (A), wherein the solvent (C) contains a poor solvent (C1) whereby the degree of swelling of the fluoropolymer (A) is at most 50%, the degree of swelling of the fluoropolymer (A) by a mixed solvent (BC) of the solvents (B) and (C) is from 0 to 100%, the ratio (W C /W B ) of the mass (W C ) of the solvent (C) to the mass (W B ) of the solvent (B) is from 1 to 5, and the ratio (S BC /S B ) of the degree of swelling (S BC ) of the fluoropolymer (A) by the mixed solvent (BC) to the degree of swelling (S B ) of the fluoropolymer (A) by the solvent (B) is at most 0.5.