| 摘要 |
1,223,581. Tetrafluoroethylene polymer compositions. ALLIED CHEMICAL CORP. 8 July, 1968 [10 July, 1967], No. 32519/68. Heading C3P. An extrudable composition comprises a granular P.T.F.E. powder wherein the P.T.F.E. polymer is a homopolymer of polytetrafluoroethylene, a copolymer of tetrafluoroethylene with up to 10% by weight (based on the weight of copolymer) of hexafluoropropylene or chlorotrifluoroethylene, a mixture of homopolymer and one or more of such copolymers, or a mixture of such copolymers, uniformly admixed with one or more of the following perhalogenated ethanes: pentachloromonofluoroethane, 1,2 - difluorotetrachloroethane, 1,1 - difluorotetrachloroethane, 1,1,2 - trichlorotrifluoroethane, 1,1,1- trichlorotrifluoroethane, the perhalogenated ethane being present in an amount sufficient to lubricate the composition when it is extruded. Granular P.T.F.E. powders are rough, spongelike P.T.F.E. particles of super-colloidal dimensions having a total surface area of from 1 to 4 square metres per gram. |
