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.

主权项

1: A phase difference film, comprising:
a polymeric material comprising a cellulose derivative having a polymerization unit of the formula (1): wherein each of R1, R2, and R3 independently contains an aliphatic group, an unsaturated aliphatic group, or a 2-naphthoyl group, wherein the phase difference film has an in-plane retardation Re(550) of from 130 nm to 160 nm, a reverse wavelength dispersion property Re(450)/Re(550) of from 0.80 to 0.86, and a film thickness of from 20 μm to 50 μm, in the cellulose derivative, a sum of substitution degrees D1 of alkoxyl groups each containing an aliphatic group or an unsaturated aliphatic group is from 2.00 to 2.70, in the cellulose derivative, a substitution degree D2 of 2-naphthoyl groups is from 0.30 to 1.00, in the polymeric material, a total substitution degree D3 of 2-naphthoyl groups is from 0.41 to 0.50, and the substitution degrees D1 and D2 satisfy D1+D2≦3.0.