Process for the manufacture of halogen-containing resin particles of larger bulk density comprising mixing particles of the resin with inorganic salts, treated in a mixture in a gaseous phase and separating the inorganic salt from the product

A process for the manufacture of spherical particles, having a heavier bulk specific gravity, of halogen-containing ethylene resin prepared from at least one monomer selected from vinylidene fluoride, vinyl fluoride, chlorotrifluoroethylene, trifluoroethylene, tetrafluoroethylene, vinylchloride, vinylidene chloride and vinyl bromide, said process comprising in combination of;

• a step of mixing 100 wt. parts of particles of the said resin with 20-500 wt. parts of one or more of the heat-resisting inorganic salts having particle sizes of 0.01-50 , which are in the form of stable particles at a temperature higher than the melting point of said halogen-containing ethylene resin;
• a step for heat-treating said mixture in a gaseous phase at a temperature higher than melting point of the said resin;
• and a further step for separating said inorganic salt or salts from the heat-treated intermediate products.