Composite microparticle of fluorine containing resins

Abstract

A composite microparticle of fluorine containing resin which is obtained by emulsion polymerization, having a core portion of a perfluoro resin which contains 80 to 100% by weight of TFE and 0 to 15% by weight of other copolymerizable fluorine containing olefin in a monomer composition, is crystalline and has a melting point of not lower than 250 C.; and a shell portion of vinylidene fluoride resin which contains 30 to 100 mole % of vinylidene fluoride and 0 to 70 mole % of other copolymerizable fluorine containing olefin (excluding hexafluoroisobutene), is crystalline and has a melting point of not lower than 70.degree. C.; the composite particle having a multilayer or gradient structure and an averaged particle size of 0.05 to 1.0 .mu.m, which is excellent in blending property with other resins or elastomers, and dispersibility in coating materials.

Dependencies are inferred from the claim text.