Thermal conductive polymeric PTC compositions

摘要

A positive temperature coefficient (PTC) composition that has improved thermal conductivity and that includes a thermoplastic polymer, carbon black and graphite. The compositions offer improved thermal conductivity and/or rheology of the PTC composition as compared to compositions that do not include graphite, or that use smaller graphite particles. The compositions may also include one or more additives. The PTC compositions of the present invention offer improved thermal conductivity at most any temperature and permit PTC materials to be designed that can be tailored to operate at different temperatures based upon the thermoplastic polymer used.

主权项

1. A positive temperature coefficient composition comprising:
a) from about 30 to about 90% by weight of a semi-crystalline thermoplastic polymer having a degree of crystallinity of at least 5%; b) from about 5 to about 50% by weight carbon black; and c) from about 5 to about 50% by weight graphite having a carbon content of at least 99% and an average particle size of from 10 microns to 300 microns; wherein the positive temperature coefficient composition has an improved thermal conductivity as compared to a composition consisting of the thermoplastic polymer and the carbon black; wherein the composition has a room temperature volume resistivity at 23° C. of from 2.01 Ω·cm to 169.19 Ω·cm.