Patent ID: 7495049

Claim:
A composition of melt processible fluoropolymer and inorganic fine particles of average particle size 1 μm or less, said inorganic fine particles being dispersed in said fluoropolymer, said composition being obtained by melt-mixing said melt processible fluoropolymer and aggregated said inorganic fine particles, said aggregated inorganic fine particles being obtained by (a) drying a mixed solution of inorganic fine particles and an inorganic salt to obtain a solid material, (b) removing the inorganic salt from this solid material using a solvent, and (c) drying said solid material to obtain said aggregated inorganic fine particles, both said drying steps being done below the temperature at which surface fusion between the inorganic fine particles occurs, whereby said aggregates are the result of the mutual cohesive force of the inorganic fine particles.