Thermally conductive electrical tape

Claim 2

A thermally conductive tape capable of insulating heated conductor surfaces carrying high current densities, said tape being a strip formed of a composition comprising a blend comprised of ethylene propylene elastomer and an elastomer based principally on isobutylene, sufficient semi-reinforcing or non-reinforcing, non-black filler having a thermal conductivity of at least 1.1 × 10 -3 cal·cm/cm 2 ·°C·sec to endow the tape with a thermal resistivity of no more than 350° C·cm per watt, a modulus at 50% elongation of less than about 350 psi, and an ultimate elongation greater than about 700%, about 10-50 parts per 100 parts by weight elastomer of thermoplastic resin selected from polyethylene and polypropylene or mixtures thereof, about 5-75 parts per 100 parts by weight elastomer of compatible tackifier for said elastomer, and about 10-50 parts per 100 parts by weight elastomer of compatible plasticizers and softeners for said elastomers.

Claim 3

The thermally conductive tape of claim 1 in which said strip further includes, firmly united to one major surface thereof, a layer at least 0.25 mil in thickness of a pressure-sensitive adhesive composition.

Claim 4

The thermally conductive tape of claim 2 wherein said pressure-sensitive adhesive is an acrylate copolymer adhesive or a rubber-based adhesive.

Claim 5

The thermally conductive tape of claim 1 wherein said semi-reinforcing or non-reinforcing filler is selected from the group consisting of iron oxide, zinc oxide, hydrated alumina, ground crystalline silica, natural amorphous silica, aluminum silicate, anhydrous aluminum silicate, ground mica and pulverized glass.

Claim 6

The thermally conductive tape of claim 1 wherein said non-reinforcing or semi-reinforcing filler has an average particle size of at least 0.2 microns and an average surface area as measured by nitrogen adsorption of not more than 15 m 2 per gram.

Claim 7

The thermally conductive tape of claim 1 wherein said composition also includes sufficient electrically conductive filler to make said tape electrically conductive.

Claim 8

The tape of claim 6 wherein said electrically conductive filler is conductive carbon black.

Claim 9

A thermally conductive tape capable of insulating heated conductor surfaces carrying high current densities, said tape being a strip formed of a composition comprising: a. about 100 parts of a blend comprised of 15 to 100 parts by weight ethylene propylene elastomer, with the balance being an elastomer based principally on isobutylene; b. sufficient semi-reinforcing or non-reinforcing, non-black filler having a thermal conductivity of at least 1.1 × 10 -3 cal·cm/cm 2 ·°C·sec to endow said tape with a thermal resistivity of no more than 350° C·cm per watt; c. about 10-50 parts (per 100 parts elastomer) by weight of thermoplastic resin selected from polyethylene and polypropylene or mixtures thereof; d. about 5-75 parts (per 100 parts elastomer) by weight of compatible tackifier for said elastomer; e. about 10-50 parts (per 100 parts elastomer) by weight of compatible plasticizers and softeners for said elastomer; f. up to about 15 parts (per 100 parts elastomer) curing agent for said elastomer; and g. up to 20 parts (per 100 parts elastomer) carbon black filler.

Claim 10

A thermally conductive tape capable of insulating heated conductor surfaces carrying high current densities, said tape being a strip formed of a composition comprising: a. about 100 parts of a blend comprised of 15 to 100 parts by weight ethylene propylene elastomer, with the balance being an elastomer based principally on isobutylene; b. sufficient semi-reinforcing or non-reinforcing, non-black filler having a thermal conductivity of at least 1.1 × 10 -3 cal·cm/cm 2 ·°C·sec to endow said tape with a thermal resistivity of no more than 350° C·cm per watt; c. about 10-50 parts (per 100 parts elastomer) by weight of thermoplastic resin selected from polyethylene and polypropylene or mixtures thereof; d. about 5-75 parts (per 100 parts elastomer) by weight of compatible tackifier for said elastomer; e. about 10-50 parts (per 100 parts elastomer) by weight of compatible plasticizers and softeners for said elastomer; f. up to about 15 parts (per 100 parts elastomer) curing agent for said elastomer; and g. up to 20 parts (per 100 parts elastomer) carbon black filler.