METHOD OF ACETONE-SOLUBLE CELLULOSE ACETATE PRODUCING Russian patent published in 1996 - IPC

FIELD: chemical technology. SUBSTANCE: cellulose is activated with acetic acid followed by acetylation at modulus 4-7 with mixture of acetic anhydride with acetic acid in the presence of catalyst - adduct of 1 mole sulfuric acid with 1.2-1.4 mole N,N'-dimethylacetamide taken at amount corresponding to 20-30% sulfuric acid of cellulose mass. Prepared cellulose acetate solution is treated with an aqueous acetic acid at partial neutralization of sulfuric acid. The end product is precipitated, washed and dried. Treatment of cellulose acetate solution can be carried out for two stages: firstly, with aqueous acetic acid containing 4-5% water at 70-85 C for 1-2 hr and then - with aqueous acetic acid containing 14-15% water at 65-70 C for 1-2 hr. Product can be used for acetate fibers, film, plastics production. EFFECT: improved method of producing.