Patent ID: 7696295

Claim:
A condensation product obtained by condensing a silane diol compound (A) of the general formula (1): R 1 2 Si(OR 2 ) 2 (1) wherein R 1 represents a group having at least one aromatic group and having 6 to 20 carbon atoms, and R 2 represents hydrogen H or heavy hydrogen D, with a modified silane compound (B) of the general formula (2): R 3 Si(OR 4 ) 3 (2) wherein R 3 represents an organic group having at least one C═C double bond; and R 4 represents a C n H 2n+1 group wherein n is 1 or 2, wherein the molar ratio of (A):(B) is 1.1 to 1.4:1.