"R7 r???Si(OR8)4-r???(I-e) wherein R7 is an alkyl group having 1 to 4 carbon atoms, a vinyl group or an alkyl group which is substituted with one or more groups selected from the group consisting of methacryloxy, amino, glycidoxy and 3,4-epoxycyclohexyl and has 1 to 3 carbon atoms, R8 is an alkyl group having 1 to 4 carbon atoms, and r is an integer of 0 to 2, the mixture having an acrylic resin: h" . . . .