Raychem Limited

Steven C Zingheim

Ashok K Mehan

Tai Chun Cheng

David D Taft

Hans E Lunk

James E Bell

Mark F Wartenberg

Alan S Yeung

Carl J Weber

Bruce A Kaduk

Michael Trowbridge

Ignition cables which contain a layer of a melt-extruded conductive polymer. The conductive polymer is preferably the sole current-carrying component of the cable. The polymeric component in the conductive polymer is a fluoropolymer, preferably a vinylidene fluoride copolymer having a crystallinity index of 10 to 23% and/or a DSC heat of melting of 4.7 to 9.5 J/g. Preferably, the sole conductive filler in the conductive polymer is a carbon black.

Ignition cables

Insulated electrical cables which are suitable for use in gasoline fuel tanks comprise a stranded conductor which is blocked by a polysulfide and is covered by polyamide insulation.

Fuel resistant cables

Polymeric blends

New polymeric compositions based on polytetramethylene terephthalate (PTMT) polymers are disclosed. PTMT polymers are subject to embrittlement, especially at elevated temperatures and when a flame retardant is incorporated therein. This problem is substantially reduced by blending the PTMT polymer with a second polymer which has a flex modulus of 500 to 100,000 psi and a solubility parameter within .+-.1.5 of the PTMT polymer, for example an ethylene/vinyl acetate copolymer or a block copolymer containing polyether and polyester blocks. The compositions are particularly useful as wire insulation.

Polymeric compositions

Peroxide cross-linked polymeric compositions containing brominated flame retardants have reduced water absorption if an unsaturated co-agent is used to reduce the amount of peroxide needed to effect cross-linking. This makes it possible to replace part or all of the chlorinated flame retardants conventionally used and yet to obtain cross-linked compositions which meet the IPCEA water absorption requirements and can therefore be used for insulating electrical wire and cable.

Polymeric compositions containing brominated flame retardants

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Palo Alto, CA, United States of America

Steven C Zingheim