R6 are a alkyl group having 1 to 4 carbon atoms, or ???Si(OR7)3 group on the terminal thereof in which R7 is a alkyl group having 1 to 4 carbon atoms.The active silyl group of the base material for adhesion may be the hydrolytic group-containing silyl group having the hydrolysable functional group represented by ???Si(R8a(R9)3-a group in which R8 is selected from hydrogen atom; a halogen atom; an