Retardation film, and optical compensation layer, optical compensation polarizing plate, liquid crystal display device and organic EL display device each using said retardation film

摘要

The present invention achieves a phase difference film that is excellent in wavelength dispersion property, in-plane retardation, and film thickness, by using a polymeric material (i) which is composed of at least one type of cellulose derivative having a specific alkoxyl group substitution degree D₁ and a specific 2-naphthoyl group substitution degree D₂ and (ii) which has a specific total 2-naphthoyl group substitution degree D₃.