Long optical film, circularly polarizing plate and organic electroluminescence display device comprising the long optical film

摘要

One aspect of the present invention includes a cellulose derivative and silica-based fine particles, the angle formed by the long direction and the slow axis is 40 to 50 °, and the in-plane retardation Ro550 at a wavelength of 550 nm is 120 nm or more. It is a long optical film which is 160 nm or less and satisfies the following formulas (1) to (3). 1.8 ≦ Y ≦ 2.6 (1) 0.3 ≦ XES ≦ 1.5 (2) 0.3 ≦ XET ≦ 2.3 (3) (where XES Is the ester average degree of substitution of the cellulose derivative, XYTH is the ether average degree of substitution of the cellulose derivative, and Y is the total degree of substitution of the cellulose derivative)