Patent ID: 6489033
Filing Date: 2002-12-03
Classification: H01G,Y10T

Abstract:
An electret consisting essentially of mixture of at least one cycloolefin copolymer withat least one different polyolefin, and said cycloolefin copolymer contains from 0.1 to 100% by weight, based on the total weight of the cycloolefin polymer of polymerized units of the formulae I, II, IIâ€², III, IV, V or VI wherein R1, R2, R3, R4, R5, R6, R7 and R8 are identical or different and are a hydrogen atom or a C1-C20-hydrocarbon radical, wherein the same radicals R1 to R8 in the various formulae I to VI may have a different meaning, and where n may be from 0 to 5, and from 0 to 99 mol %, based on the total makeup of the cycloolefin copolymer, of polymerized units which derive from one or more acyclic olefins of the formula VII wherein R9, R10, R11 and R12 are identical or different and are a hydrogen atom, a linear, branched, saturated or unsaturated C1-C20-hydrocarbon radical and from 0 to 45 mol %, based on the total makeup of the cycloolefin copolymer, of polymerized units which derive from one or more monocyclic olefins of the formula VIII and n is a number from 2 to 10 and said at least one different polyolefin is selected from the group consisting of (a) homopolymers of ethylene and propylene, (b) copolymers of ethylene and propylene, (c) copolymers of ethylene with a linear or branched olefin, (d) copolymers of propylene with a linear or branched olefin and (e) terpolymers of ethylene, propylene with a linear or branched olefin.