COMPOSITION FOR OPTICAL FILM HAVING EXCELLENT TRANSPARENCY, STRENGTH AND HEAT RESISTANCE AND OPTICAL FILM COMPRISING THE SAME

摘要

PURPOSE: A resin composition is provided to have excellent optical properties like optical permeability, haze, etc, and to have excellent toughness and heat resistance, thereby being hardly damaged in high temperatures and high humidity. CONSTITUTION: A copolymer comprises 5-30 parts by weight of a cyclohexylmethacrylate unit, 40-70 parts by weight of a methyl methacrylate unit, 10-30 parts by weight of a styrene unit, 3-15 parts by weight of a maleic anhydride unit. The glass transition temperature of the copolymer is 120-200 °C, the average molecular weight is 30,000-130,000. A resin compostion for an optical film comprises the copolymer. An optical film comprises the resin compostion. The light transmission of the optical film is 90% or more, the thickness is 60 micron, the phase difference of planer direction in the wavelength of 589 nm is 80-200 nm, and the phase difference of thickness direction is 80-300 nm.