Patent ID: 8937696
Filing Date: 2015-01-20
Classification: B29C,B29K,B32B,C09K,G02B

Abstract:
1. A cellulose acylate film comprising: a cellulose acylate and a sugar ester compound, wherein the sugar ester comprises from 1 to 12 pyranose structures or furanose structures in which at least one hydroxyl group is esterified, wherein the film has an in-plane retardation at a wavelength of 550 nm satisfying the following formula (1): wherein RE (550) means the in-plane retardation of the film at a wavelength of 550 nm, wherein the film has a thickness-direction retardation at a wavelength of 550 nm satisfying the following formula (2): wherein Rth (550) means the thickness-direction retardation of the film at a wavelength of 550 nm, the film has a dimensional change before and after 24 hours at 60° C. and at a relative humidity of 90% satisfying the following formula (3) in the film conveying direction and in the direction perpendicular thereto, wherein L0 means the length (unit: mm) of the film before aged for 24 hours at 60° C. and at a relative humidity of 90%; and L′ means the length (unit: mm) of the film after aged for 24 hours at 60° C. and at a relative humidity of 90% and further after conditioned for 2 hours, wherein the film has an internal haze of at most 0.1%, wherein the cellulose acylate film is free from a compound having a negative birefringence, wherein the degree of acyl substitution of the cellulose acylate is from 2.0 to 2.6, and wherein all the acyl groups in the cellulose acylate are acetyl groups.