Patent ID: 8114949

Claim:
A copolymer consisting essentially of: a constituent unit consisting of a monomer represented by the following formula (1): wherein R represents a hydrogen atom or a methyl group, R 1 represents a methyl group and R 2 represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, or R 1 and R 2 are combined with each other to form a ring structure; A 1 represents a single bond, alkylene, oxyalkylene, —C(O)O—, or —CH 2 CH 2 OC(O)—; A 2 represents a single bond, alkylene, oxyalkylene, —CO—, —C(O)O—, or —C(O)OCH 2 CH 2 —; and Z represents a cyclohexane ring, norbornane ring, bicyclo[2.2.2]octane ring, or tetracyclo[4.4.0.1 2,5 .1 7,10 ]dodecane ring, all of which may have a substituent; one or more constituent units derived from a monomer having a lactone structure in a molecule, and, one or more constituent units derived from a monomer containing an alicylic skeleton having a hydroxy group or a cyano group in a molecule, and one or more constituent units derived from monomers selected from the group consisting of monomers represented by the following formulae (6-1), (6-2), (6-4), (6-5), (6-14), (6-15), (6-16), (6-18), (6-57), (6-58), (6-65), (6-66), and (6-67): wherein R represents a hydrogen atom or a methyl group.