Fluororubber, a process for its production and its use, as well as a process for producing fluororubber moldings and/or coatings
AssigneeBayer Aktiengesellschaft
InventorsRalf Kruger, Jurgen Ackermann, Dieter Wrobel, Helmut Steinberger
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Abstract
The present invention relates to a new fluororubber, a process for its production and its use, as well as a process for producing fluororubber mouldings and/or coatings.
Claims10
Fluororubber comprising a polymer of a) vinylidene fluoride and optionally further fluorine-containing and/or non-fluorine-containing monomers, and b) at least one compound from the group consisting of diiodomethane, 1,2-diiodo-1,1-difluoroethane, 1-iodo-2-bromo-1,1-difluoroethane, 1-bromo-2-iodo-1,1-difluoroethane and 1,2-dibromo-1,1-difluoroethane, in which at least 80% of the terminal groups in the polymer have the formula --CH.sub.2 --X where X=Br and/or I, wherein the fluororubber polymer contains iodine and/or bromine in amounts of 1-5 wt.% by weight of polymer and has a complex viscosity at 100.degree. C. and .omega.=6.3 s.sup.-1 of 0.01-30 kPa.s, as well as a temperature index, calculated as quotient of the viscosities at 40.degree. and 100.degree. C., of 3-250.
Process for producing a fluororubber, wherein a) vinylidene fluoride and optionally further fluorine-containing and/or non-fluorine-containing monomers are polymerised by a free radical mechanism at temperatures of 0.degree. C. to 70.degree. C. in the presence of b) at least one compound selected from the group consisting of diiodomethane, 1,2-diiodo-1,1-difluoroethane, 1-iodo-2-bromo-1,1-difluoroethane, 1-bromo-2-iodo-1,1-difluoroethane, 1,2-dibromo-1,1-difluoroethane or mixtures thereof, and in the presence of an initiator, further auxiliaries or both.
Process for producing fluororubber mouldings and/or coatings, characterised in that fluororubbers having a viscosity temperature index at 40.degree./100.degree. C. of 3 to 250 are injection moulded at temperatures of 40 to 250.degree. C. under pressure in moulds heated to 100.degree. to 250.degree. C. and are crosslinked therein.
Dependencies are inferred from the claim text.