yl group, R2 is a hydrogen atom, an alkyl group having 1-6 carbon atoms, a phenyl group or a phenethyl group, and a is a number of 2-200, and (2) a homopolymer or a copolymer which does not contain alkenyl groups of a hydrogen polysiloxane macromonomer having a structural unit represented by the following general formula: ##STR27## wherein R1 is an alkyl group having 1-6 carbon atoms, a phenyl gro