MODIFIED TETRAFLUOROETHYLENE/ETHYLENE COPOLYMER PRODUCTION PROCESS Russian patent published in 2000 - IPC

FIELD: polymer production. SUBSTANCE: invention relates to production of copolymers exhibiting high strength and dielectric characteristics along with chemical stability, heat (up to 200 C) and radiation resistance, which are, in particular, useful as structural materials in a variety of mechanical engineering areas and as strong electric- insulating materials in electrical industry. Copolymers of invention are prepared by aqueous-emulsion copolymerization of tetrafluoroethylene with ethylene and modifying comonomer in presence of initiator and fluorinated emulsifier, which process is carried out by feeding, into reaction zone, replacing amounts of equimolar mixture tetrafluoroethylene and ethylene at constant copolymerization rate. Process is distinguished by that above-said initiator is represented by system of beta-hydroxyethyl-tert-butyl peroxide/ascorbic acid at molar ratio (20-25): 1, copolymerization rate is maintained constant by portionwise feed of ascorbic acid after 18-20% of the total weight of replacing monomer mixture is consumed, and molar ratio of peroxide to ascorbic acid in reaction zone is maintained (7-10): 1 during polymerization process. EFFECT: simplified process and improved working characteristics of copolymers. 1 tbl, 10 ex