Patent ID: 7955685
Filing Date: 2011-06-07
Classification: C08J,C08L,Y02P,Y10T

Abstract:
1. A cellulose acylate film which is produced according to a melt casting process and which satisfies each of the following conditions (1) to (4): (1) an Re unevenness of the cellulose acylate film is from 0 to 10%, (2) an Rth unevenness of the cellulose acylate film is from 0 to 10%, (3) a thickness unevenness of the cellulose acylate film is from 0 to 2%, and (4) its humidity-dependent Re change and humidity-dependent Rth change are from 0 to 1.5%/% RH, wherein each of the Re unevenness, Rth unevenness and thickness unevenness represents the difference between the maximum value and the minimum value of 100 machine direction samples and 50 transverse direction samples divided by the mean value thereof, represented as a percentage, wherein the melt casting process comprises extruding a melt from a melt kneader through a casting die thereof onto a casting drum, and cooling and solidifying the melt to form a film, and wherein the melt is extruded out through the casting die at a temperature not lower than its Tg.