ACTIVE ENERGY BEAM-CURED COMPOSITION FOR OPTICAL FILM, OPTICAL FILM, POLARIZER PROTECTIVE FILM, AND POLARIZING PLATE

摘要

[Problem] To provide: an active energy beam-curable composition for optical films that combines a low photoelastic coefficient and low retardation, good resistance to moist heat, and outstanding flexibility; an optical film obtained using said composition; a polarizer protective film; and a polarizing plate. [Solution] An energy beam-curable composition for forming optical films, containing: (A) urethane (meth)acrylate (A) having a photoelastic coefficient at 23°C when cured (hereinafter merely referred to as the "photoelastic coefficient") not exceeding 30 x 10-12Pa-1, and (B) a polymer other than the component (A) and which has a photoelastic coefficient not exceeding 5 x 10-12Pa-1. The photoelastic coefficient when cured does not exceed 10 x 10-12Pa-1, in-plane retardation at the front and at a diagonal of 40° and total retardation in the thickness direction when cured as measured at a thickness of 40mum does not exceed 5nm.