ompound 1: KBE-103 available from Shin-Etsu Chemical Co., Ltd. (phenyltriethoxysilane)Silane Compound 2: KBM-103 available from Shin-Etsu Chemical Co., Ltd. (phenyltrimethoxysilane)Silane Compound 3: KBM-3063 available from Shin-Etsu Chemical Co., Ltd. (hexyltrimethoxysilane)Further, in the above-mentioned chemicals, chemicals obtained from resources other than petroleum are the natural rubber, ep