. . "nder the name SE30 by General Electric and that sold under the name AK 500000 by Wacker,the substituents R1 to R6 and X are a methyl group and p and n are such that the molecular weight is 250,000 g/mol, such as that sold under the name Silbione 70047 V by Rhodia,the substituents R1 to R6 are a methyl group and the substituent X is a hydroxyl group, such as that sold under the name Q2-1401 or Q2-1" . . . . . . .