| abstract |
An object of the present invention is to provide a method for producing an optical film that is excellent in transparency, thermal expansibility, curling property, and heat resistance and has high productivity, and further provides an element substrate using the optical film. Dissolving cellulose nanofibers substituted with a propionyl group and having a substitution degree of 0.1 to 1.5 and a crystallinity of 50 to 95% in a solvent that partially dissolves or swells, A method for producing an optical film containing cellulose nanofibers, wherein the dispersion is cast to form a film. [Selection figure] None |