Patent ID: 6844133

Claim:
A polymer comprising recurring units of the following general formula (1) and recurring units of the following general formulas (2) and/or the following general formula (3), the polymer having a weight average molecular weight of 1000 to 500,000, wherein R 1 is hydrogen or methyl, R 2 is hydrogen or a straight, branched, or cyclic alkyl group having 1 to 8 carbon atoms, R 3 is CO 2 R 4 , R 4 is a straight, branched, or cyclic alkyl group having 1 to 15 carbon atoms in which at least one oxygen atom may intervene in any carbon-to-carbon bond, R 5 and R 7 each are hydrogen or methyl, and R 6 , R 8 , and R 9 each are a straight, branched, or cyclic alkyl group having 1 to 15 carbon atoms.