The retardation film of the present invention contains a resin having positive refractive index anisotropy and containing at least one bonding group of a carbonate bond and an ester bond and one or more structural units selected from the group consisting of a structural unit represented by the general formula (1) and a structural unit represented by the general formula (2), in which the value of wavelength dispersion (R450/R550) as a ratio of retardation R450 at a wavelength of 450 nm to retardation R550 at a wavelength of 550 nm is more than 0.5 and less than 1.0:
(in formula (1) and formula (2), definitions of R1 to R9 are the same as in the description).
本发明的延缓膜含有一种具有正折射率各向异性的
树脂,该
树脂至少含有一个
碳酸键和一个酯键的键基,以及一个或多个结构单元,这些结构单元选自通式(1)和通式(2)结构单元组成的组、其中波长色散值(R450/R550)为波长 450 纳米时的延迟率 R450 与波长 550 纳米时的延迟率 R550 之比,大于 0.5 而小于 1.0:
(在式(1)和式(2)中,R1 至 R9 的定义与说明中的相同)。