公开(公告)号：CA1192348A

公开(公告)日：1985-08-20

申请号：CA366609

申请日：1980-12-11

Applicant: HOECHST AG

Inventor： KUHLS JUERGEN ,  HARTWIMMER ROBERT

IPC: C08J3/12 ,  C08F14/00 ,  C08F14/26 ,  C08F214/26 ,  C08F259/08 ,  C08J3/16 ,  C08L1/00 ,  C08L27/00 ,  C08L27/12 ,  C08L27/18

Abstract: of the disclosure Free-flowing sintering powders based on polymers containing at least 98.5 % by weight of tetrafluoroethylene units can be prepared from colloidal polymer dispersions obtained in a customary manner by emulsion polymerization, stirring being carried out initially, optionally with the addition of an inorganic salt, until thickening, indicated by optical inhomogeneities, is achieved, an organic liquid which wets the polymer particles and is soluble in water to the extent of not more than 15 % by weight then being added and stirring then being continued until granules are produced. The polymers preferably contain up to 1.5 % by weight of polymerized units of at least one modifying, perfluorinated monomer. The free-flowing sintering powders have a high bulk density, an excellent flow time and further advantageous properties. They can be provided with customary fillers and are suitable for ram extrusion and for press-sinter processing to give sintered blocks and subsequently veneer-cut films.

公开(公告)号：CA1164121A

公开(公告)日：1984-03-20

申请号：CA380722

申请日：1981-06-26

Applicant: HOECHST AG

Inventor： SULZBACH REINHARD A ,  HARTWIMMER ROBERT

IPC: C08F210/00 ,  C08F2/22 ,  C08F2/26 ,  C08F2/38 ,  C08F10/00 ,  C08F14/00 ,  C08F210/02 ,  C08F214/26 ,  D06M15/244 ,  C08K5/10 ,  C08K5/16 ,  C08L23/08 ,  C08L27/18

Abstract: HOE 8O/F 915 Process for the preparation of aqueous, colloidal dispersions of copolymers of the tetrafluoroethylene/ ethylene type An improved process for the preparation of aqueous, colloidal dispersions of copolymers comprising at most 60 mole % of units of tetrafluoroethylene, 60 to 40 mole % of units of ethylene and 0 to 15 mole % of units of at least one other a-olefinic monomer, which can be copolymerized with tetrafluoroethylene and ethylene, in the presence of manganese compounds as the catalyst is described. In this process, the emulsion polymerization is carried out in an aqueous phase in the presence a) of a chain transfer agent of the formula X-CH2-COOR (X = C1, Br, COOH, COOR, COCH3, CH3, C2H5 or C3H7 ; and R = C1-C4 alkyl), and b) of a compound which stabilizes the dispersion and has the formula NH4-0-?-Y (Y - COONH4, COOH, CH3, CH20H, CH2COOH or CH2C00NH4) b) can additionally contain an ammonium salt of an inorganic non-metal acid, for example ammonium chloride or fluoride Terpolymers or quaterpolymers containing, in addition to tetrafluoroethylene and ethylene, preferably hexafluoropropylene an /or a "bulky" vinyl monomer as the third and/or fourth comonomer are preferably prepared, The copolymer dispersions thus prepared have very low coagulate contents and are very stable and the copolymers have melt flow indices most appropriate to - 1a the processing operations. They can be processed to coatings and shaped articles,

公开(公告)号：CA1102491A

公开(公告)日：1981-06-02

申请号：CA285724

申请日：1977-08-30

Applicant: HOECHST AG

Inventor： HARTWIMMER ROBERT ,  KUHLS JUERGEN

IPC: C08F14/00 ,  C08F2/16 ,  C08F14/28 ,  C08F16/00 ,  C08F16/14 ,  C08F214/26

Abstract: of the disclosure The invention relates to a process for the copolymerization of tetrafluoroetbylene with fluorinated alkylvinyl ethers of the formula XCF2-(CF2)n-O-CF=CF2 wherein X is H, C1 or F, and n is 1 to ?, in the presence of hexafluoropropene, and the thermoplastic terpolymers so obtained. The copolymerization may be carried out according to the suspension process or the emulsion process in liquid phase in the presence of liquid chain transfer agents . In the presence of hexafluoropropene, the amount of fluorinated alkylvinyl ethers incorporated is considerably increased. The terpolymers in accordance with this invention are distinguished by a number of interesting properties.

公开(公告)号：CA943973A

公开(公告)日：1974-03-19

申请号：CA115067

申请日：1971-06-08

Applicant: HOECHST AG

Inventor： HARTWIMMER ROBERT ,  KUHLS JURGEN

IPC: C07C19/08 ,  C07C17/367 ,  C07C23/02

Abstract: 1338425 Cyclic perfluoro-olefins FARBWERKE HOECHST AG 22 June 1971 [24 June 1970] 29257/71 Heading C2C A pyrolysis process for the preparation of at least one cyclic perfluoro-olefin having 4-6 ring members and/or at least one perfluoroalkylsubstituted cyclo perfluoro-olefin having 4-6 ring members, both being of the formula C n F 2n-2 , in which n is 4-12, comprises thermally cracking at least one acyclic polyfluorocarbon having a molecular weight of at least 500, at 500-1000‹ C., the maximum pressure during cracking being from 50 to 300 atm. gauge, and subsequently separating the reaction products. Suitable starting materials are, for example, polytetrafluoroethylene and copolymers of tetrafluoroethylene with other fluoro-olefines. Some byproducts of formula C n F 2n +2 and C n F 2n may also be obtained.

公开(公告)号：CA677818A

公开(公告)日：1964-01-14

申请号：CA677818D

Applicant: HOECHST AG

Inventor： HARTWIMMER ROBERT ,  WIBERG EGON ,  GUMBOLDT ALBERT G M