Patent ID: 6262209
Filing Date: 2001-07-17
Classification: C08F

Abstract:
A suspension method for preparing a modified PTFE comprising:polymerizing, in a suspension, a momomer composition comprising:perfluoroalkylvinylether comonomers in which the alkyl has from 1 to 5 carbon atoms, and/or perfluorodioxole comonomers; a part of the comonomer composition, from 15% to 90% by weight of the total amount, is available at the beginning of the reaction and the remaining part of the comonomer composition is distributed during the polymerization reaction to obtain a constant rate of comonomer incorporation in a forming polymer chain; said suspension further comprising:a perfluorinated surfactant and a buffering salt,a persulfate with a reducing agent as an initiator in a ratio to generate radicals from a redox reaction and wherein additional radicals are generated by a thermal decomposition of the persulfate; andconducting the polymerization reaction at a pressure from 15 to 30 bar.