Patent ID: 8911837

Claim:
A retardation film comprising a thermoplastic polymer having at least a side chain component (A) oriented in a direction substantially orthogonal to a slow axis, wherein an absorption edge wavelength (λ cut-off ) of the side chain component (A) is 330 nm or more, an in-plane retardation value (Re[450]) at a wavelength of 450 nm is smaller than an in-plane retardation value (Re[650]) at a wavelength of 650 nm, and the difference (ΔRe 650-550 =Re[650]−Re[550]) between the in-plane retardation value (Re[650]) at a wavelength of 650 nm and an in-plane retardation value (Re[550]) at a wavelength of 550 nm is 10 nm or more, wherein the side chain component (A) is a substituent represented by the following general formula (b): wherein R 8 to R 15 each independently represent a hydrogen atom, a halogen atom, a straight or branched halogenated alkyl group having 1 to 4 carbon atoms, a straight or branched alkoxy group having 1 to 4 carbon atoms, a straight or branched thioalkoxy group having 1 to 4 carbon atoms, a straight or branched alkoxycarbonyl group, a substituted or non-substituted aryl group, a substituted or non-substituted vinyl group, a substituted or non-substituted ethynyl group, an acyloxy group, an amino group, an azide group, a nitro group, a cyano group, a hydroxyl group, or a thiol group, but in the formula (b), at least one substituent of R 8 to R 15 is not a hydrogen atom.