Patent ID: 8044159

Claim:
A homopolymer having a repeating unit represented by the following formula (2): wherein X 1 , X 2 , X 3 and X 4 are independently of one another an atom belonging to group 16 of the periodic table; R 1 and R 2 are independently of each other a hydrogen atom or a hydrocarbyl group having 1 to 20 carbon atoms, and R 1 and R 2 may be linked with each other; and A 1 , A 2 , A 3 , A 4 , A 5 , A 6 , A 7 , A 8 , A 9 and A 10 are independently of one another a hydrogen atom, a halogen atom, an alkyl group, an aralkyl group, an aryl group, a substituent-having silyl group, an alkoxy group, an aralkyloxy group, an aryloxy group, a disubstituent-having amino group, or a hydrocarbylthio group.