The glass transition temperature of the raw rubber is -74 to -69 ° C, the temperature at which softening is gradually changed to a viscous flow is 130 ° C, the temperature at which decomposition starts is 200 ° C, and the temperature at which decomposition is intense is 270 ° C. The specific heat capacity (25 ° C) is 1. 88kJ / (kg • K); the thermal conductivity is 0. 134kW / (m • K); the volume expansion coefficient is (Tg or more, vulcanized rubber) 1.5~1.8; the heat of combustion is 44 .7kJ/kg.