Patent ID: 7223451
Filing Date: 2007-05-29
Classification: B32B,C08G,C08J,C09K,G02B,Y10T

Abstract:
1. A uni- or bi-axially oriented film (A) which comprises a polymer or polymer mixture containing a recurring unit represented by the following formula (I): wherein R wherein R each of the polymer and the polymer mixture containing the recurring unit represented by the above formula (I) in an amount of more than 30 mol % and up to 60 mol % based on the total of all the recurring units of the polymer or polymer mixture and having a glass transition temperature of 165° C. or higher, (B) which has a heat shrinkage factor when it is heated at 90° C. for 500 hours under no load of 0.1% or less obtained by heat setting after stretching, and (C) which satisfies the following formula (1): wherein R(450) and R(550) are retardations within the film plane at wavelengths of 450 nm and 550 nm, respectively.