Patent ID: 9671544
Date: 2017-06-06
CPC Classifications: B29C,B29D,B29K,B29L,C08J,C09K,G02B,G02F

Claim:
1. A phase difference film, comprising: a polymeric material comprising a cellulose derivative having a polymerization unit of the formula (1): wherein each of R 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 D in the cellulose derivative, a substitution degree D in the polymeric material, a total substitution degree D the substitution degrees D