Patent ID: 8647725

Claim:
A cellulose acylate film, comprising an acyl-modified compound of a reduction product of a ketone compound-formaldehyde polymer, wherein the acyl-modified compound is a compound represented by the following Formula (I): wherein, R 1 and R 2 each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms; R 3 , R 4 and R 5 each independently represent a hydrogen atom, a formyl group or an alkylcarbonyl group having 2 to 15 carbon atoms, but not all of them represent hydrogen atoms; A and B each independently represent an aryl group having 6 to 10 carbon atoms; R 6 and R 7 each independently represent a hydrogen atom, a halogen atom or an alkyl or alkoxy group having 1 to 6 carbon atoms; m and n each independently represent an integer of 0 or 1 or more, but are not 0 simultaneously; p and q are each independently 0 or an integer of 1 or 2, wherein a degree of acyl substitution of cellulose acylates in the cellulose acylate film is 2.0 to 2.97, wherein in-plane retardation (Re) and retardation in a thickness direction (Rth) of the cellulose acylate film at a measurement wavelength of 548 nm or 446 nm satisfy the relationships represented by formulae (3-c) and (4-c): 0.75 ≦Re (446)/ Re (548)<0.95 formula (3-c) 0.75 ≦Rth (446)/ Rth (548)≦0.95 formula (4-c), wherein a moisture permeability of the cellulose acylate film is 1000 to 2500 g/m 2 ·24 h under an environment of 60° C. and 95% RH.