Abstract: Cellulose acetate having a high moldability and low solution viscosity in spite of having a high average degree of polymerization is obtained. The low molecular weight components of cellulose acetate (e.g., CTA having average degree of acetylation of 59.0 to 62.5%) are eluted with a washing solvent to produce a cellulose acetate having a molecular weight distribution Mw/Mn of 1 to 1.7. As the washing solvent, those swell or partially dissolve the cellulose acetate, for example, those which dissolve 0.1 to 30% by weight of cellulose acetate can be used. This solvent includes, for example, a solvent having a solubility parameter .delta. of 7 to 12.5 (ketones, ethers, organic acid, esters, etc.).

Abstract: Cellulose acetate having a high moldability and low solution viscosity in spite of having a high average degree of polymerization is obtained. The low molecular weight components of cellulose acetate (e.g., CTA having average degree of acetylation of 59.0 to 62.5%) are eluted with a washing solvent to produce a cellulose acetate having a molecular weight distribution Mw/Mn of 1 to 1.7. As the washing solvent, those swell or partially dissolve the cellulose acetate, for example, those which dissolve 0.1 to 30% by weight of cellulose acetate can be used. This solvent includes, for example, a solvent having a solubility parameter .delta. of 7 to 12.5 (ketones, ethers, organic acid, esters, etc.).

Abstract: An object of the invention is to obtain cellulose acetate having improved physical properties, particularly film strength and improved flexibility of the molded product. Cellulose acetate having an average degree of acetylation of not less than 59%, viscosity average degree of polymerization (DP) of not less than 290. and concentrated solution viscosity (.eta.) according to falling ball viscosity method for viscosity average degree of polymerization (DP) expressed by the following formula (1):2.814.times.ln(DP)-11.753.ltoreq.ln(.eta.).ltoreq.7.28.times.ln(DP)-37.059( 1)and a process for the production thereof.

Abstract: A process for the preparation of a cellulose acetate film comprises the steps of: cooling a mixture of cellulose acetate and an organic solvent to -100.degree. to -10.degree. C.; warming the cooled mixture to 0.degree. to 50.degree. C. to dissolve the cellulose acetate in the organic solvent; casting the obtained solution on a support; and evaporating the organic solvent to form the cellulose acetate film. The cellulose acetate has an average acetic acid content in the range of 58.0 to 62.5%. The organic solvent is acetone.

Abstract: A cellulose acetate solution has cellulose acetate in a solvent. The cellulose acetate has an average acetic acid content in the range of 58.0 to 62.5%. In the first embodiment of the invention, the solvent is a mixture of acetone and another organic solvent. The organic solvent is an ether having 3 to 12 carbon atoms, a ketone having 4 to 12 carbon atom, an ester having 3 to 12 carbon atoms, or an alcohol having 1 to 6 carbon atoms. In the second embodiment, the solvent is the ether, the ketone or the ester. Processes for the preparation of the solution and a cellulose acetate film are also disclosed.