Patent ID: 9690138
Date: 2017-06-27
CPC Classifications: C09K,G02B,G02F

Claim:
1. A retardation film comprising: 1) an acrylic film comprising a resin blend of an acrylic resin and a copolymer resin containing an aromatic vinyl-based unit, wherein the copolymer resin containing an aromatic vinyl-based unit is a styrene-maleic anhydride copolymer (SMA), a styrene-acrylonitrile copolymer (SAN), or an α-methyl styrene-acrylonitrile copolymer (AMSAN), and the content of the aromatic vinyl-based unit is in a range of 10 to 25 wt % of the entire composition of the resin blend, 2) a coating layer of a negative C-type material, wherein the C-type layer comprises a cellulose derivative having a weight average molecular weight of 100,000 to 300,000, and 3) a primer layer including a copolymer containing an aromatic vinyl-based unit and a maleic acid-based unit, provided between, and in contact with, the acrylic film and the coating layer of the negative C-type material, wherein the copolymer has a weight average molecular weight of 50,000 to 1,000,000, wherein a retardation value R where n wherein 3) the primer layer has a thickness of 0.1 to 5 μm.