Patent ID: 8236208
Filing Date: 2012-08-07
Classification: C08K,C08L,C09K,G02B

Abstract:
1. A method of manufacturing an optical cellulose ester film comprising the steps of: (a) mixing a cellulose ester (A); at least one ester based plasticizer (B) of ester based plasticizers composed of polyhydric alcohol and univalent carboxylic acid and ester based plasticizers composed of polyvalent carboxylic acid and monohydric alcohol; at least one stabilizer (C) selected from a group consisting of a phenol based stabilizer, a hindered amine based stabilizer and a phosphorous based stabilizer; and a hydrogen bonding solvent (D), wherein the mixing includes: (i) mixing the cellulose ester (A), the ester based plasticizer (B), and the stabilizer (C) so as to form a mixture; (ii) drying the mixture, and (iii) mixing the dried mixture and the hydrogen bonding solvent (D) so as to prepare a composition, (b) heating and melting the composition, and (c) melt-casting the melted composition so as to form an optical cellulose ester film, wherein the composition contains the hydrogen bonding solvent (D) in an amount of 0.1-5 parts by weight with respect to 100 parts by weight of the cellulose ester; and the optical cellulose ester film contains the hydrogen bonding solvent (D) in an amount of 0.005-2.0 parts by weight with respect to 100 parts by weight of the cellulose ester.