| abstract |
An object of the present invention is to provide a highly transparent polyimide film which controls the retardation Rth in the thickness direction within a desired range, and a polyamic acid and varnish for obtaining the polyimide film. In order to solve the above-mentioned problems, a polyimide film including polyimide obtained by reacting tetracarboxylic dianhydride and diamine was produced, and (a) the retardation Rth in the thickness direction was -5nm per 10μm thickness The above is 100nm or less, (b) the light transmittance at a wavelength of 400nm is 80% or more, (c) the haze is 3% or less, and (d) the glass transition temperature is 250°C or more. |