1.
    发明专利
    未知

    公开(公告)号:CH623065A5

    公开(公告)日:1981-05-15

    申请号:CH659176

    申请日:1976-05-25

    Applicant: HOECHST AG

    Abstract: Polymers on the basis of tetrafluoroethylene are produced in the presence of a redox system as catalyst consisting of a usual peroxidic compound as oxidizing component and a water-soluble nitrogen compound liberating in situ a diimine under the polymerization conditions. The polymers obtained can be processed, inter alia, into thick walled articles on a ram extruder or into large sintered block free from crack formation.

    3.
    发明专利
    未知

    公开(公告)号:DE2523570A1

    公开(公告)日:1976-12-02

    申请号:DE2523570

    申请日:1975-05-28

    Applicant: HOECHST AG

    Abstract: Polymers on the basis of tetrafluoroethylene are produced in the presence of a redox system as catalyst consisting of a usual peroxidic compound as oxidizing component and a water-soluble nitrogen compound liberating in situ a diimine under the polymerization conditions. The polymers obtained can be processed, inter alia, into thick walled articles on a ram extruder or into large sintered block free from crack formation.

    6.
    发明专利
    未知

    公开(公告)号:DE1795078A1

    公开(公告)日:1972-08-03

    申请号:DE1795078

    申请日:1968-08-07

    Applicant: HOECHST AG

    Abstract: 1,253,598. Aqueous tetrafluoroethylene polymer dispersions. FARBW'ERKE HOECHST A.G. 1 Aug., 1969 [7 Aug., 1968], No. 38710/69. Heading C3P. An aqueous polymer dispersion having a solids content of from 15 to 40% by weight based on the dispersion, wherein the particles have a core consisting of a copolymer of from 90 to 99% by weight of tetrafluoroethylene, based on the copolymer, and at least one comonomer of the formula R 1 R 2 C = CR 3 R 4 , in which at least one of the radicals R 1 , R 2 and R 3 represents a chlorine, bromine, iodine or hydrogen atom and each of the remaining radicals, which may be the same or different, represents a halogen atom or a perhalogenoalkyl or a perhalogenoalkoxy group having from 1 to 10 carbon atoms, two of the groups possibly being linked by a perhalogenated carbon bridge having from 1 to 10 carbon atoms, and an outer shell consisting of polytetrafluoroethylene, which particles have an average diameter in the range of from 0-2 to 0-5 microns, and an average core diameter of from 0-01 to 0-2 microns and wherein the copolymer of the core has a transition point of the crystalline phase in the range of from 290‹ to 322‹ C. may be prepared by (a) copolymerizing in aqueous or non-aqueous dispersion in the presence of an initiator and an emulsifier the tetrafluoroethylene and comonomer to. give a dispersion having a solids content of from 5 to 15% by weight, based on this dispersion; and (b) homopolymerizing tetrafluoroethylene in aqueous dispersion in the presence of some or all of the copolymer dispersion obtained in step (a) and of an initiator and an emulsifier. In the examples tetrafluoroethylene is copolymerized with CF 2 = CFCI, CF 2 = CFBr, CF 2 = CFI, CF 2 = CFH, CFCI = CFCI, CF 2 Cl-CF=CF 2 , CF 3 -CCl=CCl-CF 3 and CCl 2 = CCl 2 in the presence of water, perfluoroammonium octanate, sodium bisulphite, hydrocarbon oil and ammonium persulphate and then tetrafluoroethylene homopolymerized in the presence of these seed dispersions and the same polymerization ingredients. The dispersions may be coagulated by rapid stirring.

    9.
    发明专利
    未知

    公开(公告)号:DE2523569A1

    公开(公告)日:1976-12-02

    申请号:DE2523569

    申请日:1975-05-28

    Applicant: HOECHST AG

    Abstract: Polymers of tetrafluoroethylene are produced by suspension polymerization in the presence of small amounts of definite perfluorinated ethers. The products obtained have improved processing properties.

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