Abstract: A tetrafluoroethylene copolymer composition for injection molding having excellent resistance to chemical permeation and durability, comprised of polytetrafluoroethylene and copolymer of tetrafluoroethylene and perfluoro(alkyl vinyl ether). The composition has a melt flow rate of 12 g/10 min or greater, a flex life of 20,000 cycles or greater, and a nitrogen gas permeability of 0.8×10?10 cm3 (STP).cm/cm2.sec.cm Hg or less.

Abstract: A composition having excellent resistance to chemical permeation, comprising (A) a tetrafluoroethylene-perfluoro(alkyl vinyl ether) copolymer, (B) a melt-flowable polytetrafluoroethylene directly obtained by the polymerization of tetrafluoroethylene, and (C) a polytetrafluoroethylene with a low molecular weight obtained by the radiolysis of a non-melt flowable polytetrafluoroethylene with a high molecular weight; the weight ratio of A/(B+C) is 80/20 to 30/70; and the weight ratio of (A+B)/C is 99.99/0.01 to 90/10.

Abstract: A composition comprising tetrafluoroethylene/perfluoro(alkyl vinyl ether) copolymer and PTFE micropowder with flex life superior to compositions made exclusively of tetrafluoroethylene/perfluoro(alkyl vinyl ether) copolymer having equivalent perfluoro(alkyl vinyl ether) content and melt flow rate.

Abstract: A composition comprising tetrafluoroethylene/perfluoro(alkyl vinyl ether) copolymer and PTFE micropowder with flex life superior to compositions made exclusively of tetrafluoroethylene/perfluoro(alkyl vinyl ether)copolymer having equivalent perfluoro(alkyl vinyl ether) content and melt flow rate.

Abstract: A composition comprising tetrafluoroethylene/perfluoro(alkylvinylether) copolymer and PTFE micropowder with flex life superior to compositions made exclusively of tetrafluoroethylene/perfluoro(alkylvinylether) copolymer having equivalent perfluoro(alkylvinylether) content and melt flow rate.

Abstract: A composition of tetrafluoroethylene/perfluoro(alkyl vinyl ether) having at least 4 wt % perfluoro(alkyl vinyl ether) and a melt flow rate of no greater than 4 g/10 min, and 5 to 30 wt % low molecular weight PTFE, has improved gas impermeability and also mechanical strength.

Abstract: A composition of tetrafluoroethylene/perfluoro(alkyl vinyl ether) having at least 4 wt % perfluoro(alkyl vinyl ether) and a melt flow rate of no greater than 4 g/10 min, and 5 to 30 wt % low molecular weight PTFE, has improved gas impermeability and also mechanical strength.

Abstract: A tetrafluoroethylene/fluoroalkoxy trifluoroethylene copolymer (PFA) composition which has finer spherulite diameters compared to a conventional PFA is provided, so as to give fabricated articles having excellent surface smoothness, and which are free from problems, such as process contamination and the like, caused by leaching. This effect is obtained by incorporating into the composition prior to fabrication a polytetrafluoroethylene having a crystallization temperature of at least 305.degree. C. and a heat of crystallization of at least 50 J/g.

Abstract: A tetrafluoroethylene/fluoroalkoxy trifluoroethylene copolymer (PFA) composition which has finer spherulite diameters compared to a conventional PFA is provided, so as to give fabricated articles having excellent surface smoothness, and which are free from problems, such as process contamination and the like, caused by leaching. This effect is obtained by incorporating into the composition prior to fabrication a polytetrafluoroethylene having a crystallization temperature of at least 305.degree. C. and a heat of crystallization of at least 50 J/g.