Patent ID: 8344134
Filing Date: 2013-01-01
Classification: C08B,C08J,C08K,C08L,G02B

Abstract:
1. An optical film comprising a cellulose acetate propionate composition comprising (1) at least one acetyl group wherein the ratio of the degree of substitution of non-acetyl ester groups (DS NAC ) to degree of substitution of hydroxyl groups (DS OH ) is 15 to 200 and the non-acetyl ester degree of substitution is from 1.1 to 1.75, and, (2) a plasticizer; wherein the film has (i) an R e ranging from −5 to +5 nm and an R th ranging from −10 to +100 nm or (ii) an R e ranging from −100 to +5 nm and an R th ranging from 0 to +100 nm.