| abstract |
Provided is an optical film that is formed from a copolycarbonate having required wavelength dispersion properties, low photoelasticity, and excellent melt mouldability. The optical film comprises a copolycarbonate formed from 25 to 90 mol% of units (A) represented by formula (A)[where R 1 and R 2 are each independently a hydrogen atom, C1-10 hydrocarbon group, or halogen atom; R 3 and R 4 are each independently a C1-10 hydrocarbon group; m and n are each independently an integer between 0 and 4; and p and q are each independently an integer of 0 or greater.] and 10 to 75 mol% of units (B) represented by formula (B) where R a is a C4-20 monocyclic or polycyclic alicyclic hydrocarbon group, and the alicyclic hydrocarbon group optionally contains hetero atoms, and optionally has a bridged structure; and q is 0 or 1.],and satisfies formula (1)R (450) <R (550) <R (650) [where R(450), R(550), and R(650) are the film in-plane phase difference values at wavelengths of 450 nm, 550 nm, and 650 nm, respectively. |