"er weight, and B is a polymer block of a conjugated diene having an average molecular weight between about 15,000 and 1,000,000 said oil being uniformly distributed throughout said polymer in an amount sufficient to provide between about to percent by weight oil and 5 to 20 percent by weight of blockcopolymer, said combination having a modulus of elasticity of 1 to 10 psi for 200 percent elongatio" . . . .