Antistatic or semi-conductive polyurethane elastomers

摘要

A polyurethane elastomer showing desirable conductivity properties comprises at least 0.3 percent by weight of an aggregated particulate carbon black, having a particle size of less than or equal to 100 nanometers, that forms a continuous conductive pathway within the polyurethane elastomer. The polyurethane elastomer may exhibit a surface resistivity ranging from 1 x 10 to 1 x 10 ohms. It may be made by first preparing an isocyanate-terminated prepolymer containing the carbon black, the prepolymer having a volume resistivity of from 1 x 10 to 1 x 10 ohms, and then reacting the isocyanate-terminated prepolymer with an isocyanate-reactive component. The proportion of the prepolymer ensures that it forms a continuous phase in the final elastomer.