Patent ID: 7807239

Claim:
An optical film containing a polymer having at least a repeating unit represented by following general formula (I): wherein in the general formula (I), R 1 , A and B denote a hydrogen atom; R 3 denotes a hydrogen atom or a straight-chain or branched alkyl group with a carbon number of 1 to 4; R 2 denotes a halogen atom, a straight-chain or branched alkyl group with a carbon number of 1 to 4, a straight-chain or branched alkyl halide group with a carbon number of 1 to 4, a straight-chain or branched alkoxy group with a carbon number of 1 to 4, an alkoxycarbonyl group, an acyloxy group, an amino group, an azide group, a nitro group, a cyano group or a hydroxyl group ; R 4 denotes a straight-chain or branched alkyl group with a carbon number of 1 to 4, a substituted or unsubstituted cycloalkyl group with a carbon number of 5 to 10, a substituted or unsubstituted phenyl group, or a substituted or unsubstituted naphthyl group; R 5 denotes a hydrogen atom, a straight-chain or branched alkyl group with a carbon number of 1 to 4, a benzyl group, a silyl group, a phosphoric acid group, an acyl group, a benzoyl group or a sulfonyl group; l, m and n denote an integer of 2 or more.