Patent ID: 8900793

Claim:
A polymer having a repeating unit shown by the following general formula (1), wherein R 1 represents any of a hydrogen atom, a fluorine atom, a methyl group, and a trifluoromethyl group, each R 2 , R 3 , and R 4 independently represents any of a substituted or an unsubstituted linear, branched, or cyclic alkyl, alkenyl, and oxoalkyl group having 1 to 10 carbon atoms; or any of a substituted or an unsubstituted aryl, aralkyl, and aryl oxoalkyl group having 6 to 18 carbon atoms; or any two or more of R 2 , R 3 , and R 4 may be bonded with each other to form a ring together with a sulfur atom in the formula, X 1 represents O or CH 2 , A 1 represents a linear, a branched, or a cyclic divalent hydrocarbon group having 1 to 10 carbon atoms, B 1 represents an alkylene group having 1 to 10 carbon atoms or an arylene group having 6 to 18 carbon atoms wherein these groups may optionally contain a hetero atom except for a fluorine atom, and k 1 represents an integer of 0 or 1.