Patent ID: 8431663

Claim:
A polymer comprising a repeating unit represented by a following formula (1): wherein: each of A 1 , A 2 , A 3 , and A 4 independently represents a hydrogen atom, a halogen atom, an alkyl group, an aralkyl group, an aryl group, a silyl group, a siloxy group, an alkoxy group, an aralkyloxy group, an aryloxy group, an amino group, an amide group, an imide group, or a hydrocarbon thio group; each of A 1 , A 2 , A 3 , and A 4 is independently any of these groups at different carbons to which the each of A 1 , A 2 , A 3 , and A 4 is bonded, and A 1 , A 2 , A 3 , and A 4 may be bonded to each other; and each of m, n, and k is independently an integer in a range of 2 to 20.