GB331903A - Process for the manufacture of cellulose ether esters - Google Patents

Abstract

331,903. Carpmael, A., (I. G. Farbenindustrie Akt.-Ges).. March 28, 1929. Right to Patent relinquished. Cellulose ether-esters are prepared by acetylating with acetic anhydride in the present of acetic acid as solvent and a small quantity of a customary catalyst, a cellulose ether containing about 1/2 to 1 1/2 alkyl groups calculated on the molecule C6 H10 O5 and comprising a small proportion of benzyl cellulose. A cellulose ether which contains from about. 1/2 to 2 per cent of benzyl cellulose is preferably employed. Instead of benzyl cellulose a substituted benzyl derivative such as o-, m-, and particularly p-nitro- or bromo-benzyl cellulose may be used. It is stated that smaller quantities of catalyst may be employed in the acetylation than are usually required, for example, with sulphuric acid 0.1 to 3 per cent, and with zinc chloride 10 to 30 per cent calculated on the cellulose ether are sufficient. In an example, cellulose (cotton or wood pulp) is soaked in caustic soda solution and treated with ethyl and benzyl chlorides to give a monoethyl cellulose containing about 1 per cent of benzyl, which is then acetylated with acetic anhydride in the presence of acetic acid and sulphuric acid. The monoethyl-1 1/2-acetyl cellulose (containing about 1 per cent of benzyl) obtained, is soluble in acetone, acetic ether, and chlorinated hydrocarbons, and may be used in the manufacture of films and artificial threads.