ge of from 95:5 to 60:40, a mixture (as R7 rSiO4-r/2) of hydrolysis condensates of a compound of the formula (I-e), 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 class consisting of methacryloxy, amino, glycidoxy and 3,4-epoxycyclohexyl and has 1 to 3 carbon atoms, R8