PROCESS FOR PREPARING COPOLYMERS Russian patent published in 1997 - IPC

FIELD: chemical, machine-building and other industries. SUBSTANCE: process for preparing tetrafluoroethylene (TFE)-based copolymers is carried out by aqueous emulsion copolymerization in the presence of perfuluorinated emulsifier and water-soluble radical initiator of mixture composed of 54.5-72.0 mole% TFE, 27.7-45.4 mole% perfluoromethylvinyl ether (PFVE) and 0.1-0.3 mole% modifying hexafluoropropylene monomer at elevated temperature in vacuum. The reaction mixture is replenished with mixture composed of 67-80 mole% TFE and 20-33 mole% PFVE. The resulting copolymer has improved elastic properties, homogeneous in composition, has good reproducing properties. EFFECT: more efficient preparation process. 2 tbl