Additive compositions for low loss wire and cable dielectric and products obtained thereby

Abstract

There are disclosed additive compositions for polymer base materials, which additive compositions are comprised of blowing agent (direct gas or chemical blowing agent), thermoplastic polymer carrier for the chemical blowing agent and filler, wherein the thermoplastic polymer carrier has a melting point below the decomposition temperature of the chemical blowing agent. The additive compositions improve the dielectric properties of a foamed material and find particular application as additives for coverings for metallic or non-metallic conductive wire or cable composites. The chemical blowing agent for the additive can be selected from those based on hydrazine, hydrazide, or azodicarbonamide, or those based on combinations of sodium citrate/citric acid and sodium bicarbonate. The filler for the additive can be selected from calcium carbonate, zeolites, clay and other known fillers. The polymer base material for the additive can be, e.g., polyethylene, polypropylene, polybutylene, poly (p-phenylene oxide), polystyrene and combinations thereof.

Dependencies are inferred from the claim text.