GB231800A - Manufacture of new cellulose compounds - Google Patents

Abstract

Cellulose derivatives are prepared by treating a cellulose xanthic acid or a cellulose xanthate (viscose) with a monohalogen fatty acid or with a salt, ester or other derivative of such acid; the products are either soluble in water, soluble in aqueous solutions of ammonia and of aliphatic and aromatic bases, or in aqueous solutions of caustic alkalies, and from these solutions they may be separated as threads or films that are transparent, shining and pliable; the solubility depends very largely on the relative proportions of the halogen fatty acid to the cellulose derivative employed. The parent material (viscose, &c.) may be prepared from cellulose or from a conversion product such as cellulose hydrate, hydrocellulose, oxycellulose or any other derivative containing a reactive hydroxyl group. Suitable monohalogen fatty acids are:-monochloracetic acid, a-bromopropionic acid, and a-bromobutyric acid. The reaction may be carried out in neutral, acid or alkaline solution, and the cellulose xanthate may be a salt of an alkali metal or of another metal such as zinc; the cellulose xanthate may be first isolated, or the reaction mixture containing the xanthate may be treated either in its original alkaline condition or after neutralization or acidification, for example, with acetic acid; the reaction may be conducted with or without the extraneous supply of heat. The products are isolated by precipitation with a dehydrating-agent such as alcohol or acetone, or with an acid, an acid salt or an ammonium salt, &c.