Abstract: Novel silicon-containing organic fluoropolymers which are appliable to materials over a wide range and which have excellent antifouling property. The silicon-containing organic fluoropolymer of the invention is represented by the general formula and has a number average molecular weight of from 5×102 to 1×105: wherein Rf represents perfluoroalkyl; Z represents fluoro or trifluoromethyl; a, b, c, d and e each independently represent 0 or an integer of 1 or above, provided that a+b+c+d+e is not less than 1 and the order of the repeating units parenthesized by subscripts a, b, c, d and e occurring in the formula is not limited to that shown; Y represents hydrogen or alkyl containing 1 to 4 carbon atoms; X represents hydrogen, bromo or iodo; R1 represents hydroxy or a hydrolyzable substituent group; R2 represents hydrogen or a monovalent hydrocarbon group; 1 represents 0, 1 or 2; m represents 1, 2 or 3; and n represents an integer of 2 or above.

Abstract: A fluorine-containing copolymer comprising monomeric units of:(a) tetrafluoroethylene,(b) 8 to 15% by weight of hexafluoropropene on the basis of the weight of the copolymer, and(c) 0.2 to 2% by weight of a fluoroalkyl vinyl ether of the formula:CF.sub.2 .dbd.CF--O--(CF.sub.2).sub.n --CF.sub.2 Xwherein X is hydrogen or fluorine, and n is an integer of 3 to 9, on the basis of the weight of the copolymer, which has good moldability and improved stress crack resistance and flex resistance when formed as an article such as a film.

Abstract: A fluorine-containing copolymer comprising monomeric units of(a) tetrafluoroethylene,(b) 8 to 15% by weight of hexafluoropropene on the basis of the weight of the copolymer, and(c) 0.2 to 2% by weight of a fluoroalkyl vinyl ether of the formula:CF.sub.2 .dbd.CF--O--(CF.sub.2).sub.n --CF.sub.2 X (I)wherein X is hydrogen or fluorine, and n is an integer of 3 to 9 on the basis of the weight of the copolymer, which has improved stress crack resistance, and flex resistance as well as good moldability.

Abstract: A process for preparing a tetrafluoroethylene/fluoro(alkyl vinyl ether) copolymer comprising polymerizing tetrafluoroethylene and fluoro(alkyl vinyl ether) in an aqueous suspension system which comprises a mixed medium of water and a fluorohydrocarbon or a chlorofluorohydrocarbon in a volume ratio of from 1:1 to 10:1 at a temperature of from 0.degree. to 25.degree. C. in the presence of a polymerization initiator of the formula:[Cl(CF.sub.2).sub.n --COO].sub.2 (I)wherein n is an integer of 1 to 10, the copolymer obtained by the process having a small number of unstable terminal groups and excellent flex life.