Patent ID: 7470385

Claim:
A process for producing a cellulose acylate film comprising two or more layers, comprising casting at least two cellulose acylate solutions according to a co-casting method, wherein the association molecular weight of cellulose acylate determined on the basis of the static light scattering in the solution for forming an outer layer is smaller than the association molecular weight of cellulose acylate determined on the basis of the static light scattering in the solution for forming an inner layer, wherein each cellulose acylate solution comprises a non-chlorine-containing solvent, said non-chlorine-containing solvent being a mixed solvent comprising a ketone having a solubility parameter of 19 to 21 and an ester having a solubility parameter of 19 to 21, and wherein an alcohol is added into only the inner layer immediately before casting, or the alcohol content based on the total amount of the solvents in the inner layer is 2.0 to 6.0 times as large as that in the outer layer.