CELLULOSE DERIVATIVE, METHOD FOR PRODUCING SAME, OPTICAL FILM, CIRCULAR POLARIZING PLATE, AND ORGANIC ELECTROLUMINESCENT DISPLAY DEVICE

摘要

The problem addressed by the present invention is to provide: a cellulose derivative that achieves superior wavelength dispersion and λ/4 phase difference and that has low phase difference unevenness; a method for producing same; an optical film; a circular polarizing plate; and an organic EL display device. The cellulose derivative has a glucose skeleton represented by general formula (1), and is characterized by the average degree of substitution and the total average degree of substitution of hydrogen atoms in hydroxyl groups at position 2, 3, and 6 of the glucose skeleton satisfying all the conditions stipulated by the belowmentioned relational expressions (1-1) to (1-4). Relational expression (1-1): the total average degree of substitution (DSa) of an aliphatic group is 1.40 ≤ DSa ≤ 2.80. Relational expression (1-2): the total average degree of substitution (DSb) of an aromatic group is 0.00 < DSb ≤ 1.50. Relational expression (1-3): DSb (position 6) < DSb (position 2) + DSb (position 3). Relational expression (1-4): 1.50 < DSa + DSb ≤ 2.90.