Electrically conductive polyetherester elastomers

Claim 1

An electrically conductive composition, capable of forming self-supporting films, consisting essentially of a uniform mixture of: (A) 100 parts of a copolyetherester having a melting point of at least about 90° C. and containing 45-85 weight percent of long-chain ester units represented by the following formula (1) ##STR3## and 15-55 weight percent of short-chain ester units represented by the following formula (2) ##STR4## wherein R is a divalent radical remaining after removal of carboxyl groups from an aromatic or aliphatic dicarboxylic acid having a molecular weight of less than 300; G is a divalent radical remaining after the removal of terminal hydroxyl groups from a poly(alkylene oxide) glycol HO-G-OH having a number average molecular weight of about 600-3500 and a carbon/oxygen atomic ratio of at least 2.5; and D is a divalent radical remaining after removal of hydroxyl groups from a diol HO-D-OH having a molecular weight of less than about 250; and (B) 60-110 parts of a conductive filler selected from the group consisting of carbon black and a mixture of carbon black and graphite, the proportion of carbon black in such a mixture being no less than about 20 weight percent; the resistivity of said electrically conductive composition being less than about 2 ohm.cm, its tensile strength at break at least about 10 MPa, and its extension at break at least 20%.