Patent ID: 9297944
Filing Date: 2016-03-29
CPC Classification: B32B,G02B

Claim Text:
1. An optical film prepared by biaxial stretching of a composition, the composition comprising: 40 wt % to 94 wt % of an acrylic resin; 5 wt % to 40 wt % of a styrene-acrylonitrile copolymer having a weight-average molecular weight less than 1,000,000; and 1 wt % to 20 wt % of an ultra-high molecular weight styrene-acrylonitrile copolymer having a weight-average molecular weight ranging from 1,000,000 to 9,000,000, wherein a thickness of the optical film is in a range of 20 μm to 150 μm; and wherein the optical film has an optical transmittance of 90% or more and a haze value of 2.5% or less; wherein an in-plane retardation value of the optical film is in the range of 50 nm to 200 nm; wherein a thickness retardation value of the optical film is in the range of 50 nm to 400 nm; wherein a value of R wherein the in-plane retardation value (R in Equations 1 and 2, n n n d is a thickness of the film, and the measured reference wave-length of the in-plane retardation value and the thickness retardation value is 550 nm.