Patent ID: 9151870
Filing Date: 2015-10-06
Classification: C08J,C08L,C09K,G02B,G02F

Abstract:
1. An optical film comprising a cellulose ester (A) which satisfies formulae (1) and (2) below and a vinyl-based polymer (B), wherein; a content ratio of the cellulose ester (A) and the vinyl-based polymer (B) is within a range from 95:5 to 50:50 by mass, the cellulose ester (A) is a cellulose acetate propionate or a cellulose acetate butyrate, the cellulose ester (A) having a molecular weight of from 32,000 to 52,000, the vinyl-based polymer (B) is composed of a non-aromatic vinyl-based monomer having a solubility parameter of 17.5 (MPa the non-aromatic vinyl-based monomer of the vinyl-based polymer (B) comprises 70% by mass or more of methyl methacrylate, and a weight average molecular weight of the vinyl-based polymer (B) is within a range from 500 to 10,000: wherein X represents a degree of substitution with acetyl group, Y i represents a degree of substitution with acyl group having 3 or more carbon atoms, and n i represents a number of carbon atoms of the acyl group having 3 or more carbon atoms, and i represents an integer of 3 or larger, which equals to the number of carbon atoms n i .