The object of the present invention is to provide an
optical film excellent in transparency,
heat resistance and processability. An
optical film containing a
polymer having at least a repeating unit represented by following general formula (I):wherein in the general formula (I), R1 and R3 each independently denote a
hydrogen atom, a straight-chain or branched
alkyl group with a
carbon number of 1 to 4, or a substituted or unsubstituted
phenyl group; R2, A and B each independently denote a
hydrogen atom, 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 (however, R2 is not a
hydrogen atom); R4 denotes a
hydrogen atom, 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, a substituted or unsubstituted naphthyl group, or a substituted or unsubstituted heterocyclic group; R5 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.