| abstract |
An object of the present invention is to provide a cellulose ester film, an optical film, a polarizing plate, a liquid crystal display device, and a method for producing a cellulose ester film that have a small retardation value even when stretched and hardly leak light. In a cellulose ester film containing a cellulose ester satisfying the following formulas (1) and (2) and a polymer obtained by polymerizing an ethylenically unsaturated monomer, at least one of the monomers has a nitrogen atom. An in-plane retardation Ro and a retardation Rt in the thickness direction of the film are in the following ranges. Formula (1) 2.70 ≦ X + Y ≦ 2.95 Formula (2) 0.5 ≦ Y ≦ 2.3 Ro ≦ 10nm −20 nm ≦ Rt ≦ 20 nm In the formula, X represents the degree of substitution of the acetyl group, and Y represents the degree of substitution of the propionyl group or butyryl group. [Selection figure] None |