GB516634A - Improvements in or relating to the production of solutions of low substituted cellulose ethers - Google Patents

Abstract

516,634. Cellulose ether solutions; yarns and films; textile dressings. DU PONT DE NEMOURS & CO., E. I. July 1, 1938, No. 19612. Convention date, July 1, 1937. [Class 2 (ii)] Low substituted cellulose ethers are dissolved in aqueous caustic alkali in the presence of an alkali metal salt of an amphoteric oxide or hydroxide of an element of group II of the Periodic System, e.g. sodium zincate or sodium beryllate. In a modification, the salt is added to a preformed solution of the cellulose derivative. The alkali metal salt may be prepared by dissolving the amphoteric oxide, hydroxide, or salt thereof in the caustic soda solution. and may be present in concentration lying between 0.1 per cent. (calculated on the amphoteric oxide) and the saturation limit. In an example. (1) methyl cellulose soluble in cold caustic soda is slurried in a sodium zincate solution containing 6 per cent. of sodium hydroxide and 1-2 per cent. of zinc oxide, and the slurry cooled. The solution obtained is then brought back to room temperature. In other examples (2) glycol cellulose soluble in cold caustic alkali is slurried with sodium zincate solution and cooled, (3) cellulose glycollic acid soluble in dilute caustic soda is cooled with a solution of sodium zincate, (4) methyl cellulose insoluble in aqueous caustic solution is dissolved in a solution of sodium zincate, (5) glycol cellulose insoluble in aqueous caustic soda even on chilling, is dissolved in sodium zincate solution, and (6) cellulose glycollic acid insoluble in caustic soda solution even on chilling, is dissolved in aqueous sodium zincate. The solutions may be coagulated in yarn or film form or applied as textile or paper dressings and then coagulated.