PHASE DIFFERENCE FILM, METHOD FOR PRODUCING SAME, POLARIZING PLATE, AND LIQUID CRYSTAL DISPLAY DEVICE
申请人:Akasaka Kazuki
公开号:US20140142223A1
公开(公告)日:2014-05-22
The problem of the present invention is to provide a phase difference film, by utilizing a cellulose ester having an acyl group substitution degree of less than 2.0 and improved compatibility, having high phase difference property despite its small film thickness and imparting high contrast and optical transmittance to a liquid crystal display device. A polarizing plate and a liquid crystal display device provided with the phase difference film are also provided. The phase difference film of the invention contains a cellulose ester which is obtained by substituting an acyl group having at least two carbon atoms for a hydroxy group in a glucose unit composing a cellulose, the film satisfies specific expressions when DS
2
, DS
3
and DS
6
are degrees of substitution of the acyl groups for the hydroxy groups at a 2C, 3C and 6C positions, respectively, of the glucose unit.