Patent ID: 9221954
Filing Date: 2015-12-29
Classification: C08J,G02B,G02F

Abstract:
1. A polyimide film, which is obtained by a process comprising: polymerizing a diamine and a dianhydride in presence of a first solvent to give a polyamic acid solution; imidizing the polyamic acid solution; adding the imidized solution to a second solvent; performing filtration and drying to give a solid polyimide resin; and dissolving the solid polyimide resin in the first solvent to prepare a polyimide solution, which is then subjected to a film forming process to obtain the polyimide film, wherein the polyimide film has a refractive index of 1.60 or less and a birefringence of 0.10 or less when measured using a prism coupler; an average transmittance of 85% or more at 380-780 nm when measured using a UV spectrophotometer for a film thickness of 25-100 μm; a yellowness index of 5.0 or less and a whiteness index of 60 or more for the film thickness of 25-100 μm; and color coordinates in which L is 90 or more, a is 5 or less and b is 5 or less, when measured using a UV spectrophotometer for the film thickness of 25-100 μm.