To obtain a cellulose acetate having a low degree of polymn., a specified average degree of acetylation, a specified viscosity-average degree of polymn., a low crystallinity and an excellent moldability by adding a specified weight range of a sulfuric acid catalyst to cellulose.
A cellulose acetate(CA) of the formula, which has an average degree of acetylation of at least 58.0%, a viscosity-average degree of polymn.(DP) of 200 to 290 and a conc. solution viscosity () determined from the DP by the falling-ball viscosity determination method of the formula, is produced. CA is capable of forming moldings having improved properties, particularly film strength, and an increased flexibility, and it generates a low heat of crystallization and has a low crystallinity and an excellent moldabiity. Since CA has a high solubility in a solvent and a high moldability, while it has a high average degree of polymn. and a high average degree of substitution, moldings having a high moisture resistance and a high dimensional accuracy can be obtained from a CA solution of a low solution viscosity.
OGAWA HIROSHI
KIYOSE ATSUNOBU