GB163018A - Improvements in and relating to the manufacture of ethers of carbohydrates having the empirical formula ncho such as cellulose, starch, dextrine and the like - Google Patents

Abstract

In the production of ethers of cellulose, its conversion products and derivatives, the cellulose &c. is, before reaction with the alkylating-, aralkylating-, or arylating-agents, treated with solid caustic alkali either in the dry state or in the presence of so little water or caustic alkali solution that at least a twentieth part of the caustic alkali remains undissolved; the products-films, celluloid, artificial filaments, and insulating-materials-prepared from the ethers eventually obtained, are distinguished by their water-resisting properties. The incorporation of the cellulose &c. with the caustic alkali may be conducted in the presence of air or inert gas, or in vacuo, and at ordinary temperatures, or with heating or cooling; and the treated cellulose may, before etherification, be freed wholly or partly from the water contained therein, and may be immediately treated with the alkylating &c. agent, or after standing. The etherification may be conducted so as first to form a lower ether, which may be converted into a higher ether by treatment with further quantities of caustic alkali and alkylating &c. agent. Specifications 6035/13 and 3370/14 are referred to. Reference has been directed to the Comptroller to Specifications 164,374, 164,375, and 164,377.ALSO:In the production of ethers of starch, dextrin, and other carbohydrates of the empirical formula (C6H10O5)n, their conversion products and derivatives, the carbohydrate is before reaction with the alkylating-, aralkylating-, or arylating-agents, treated with solid caustic alkali either in the dry state or in the presence of so little water or caustic alkali solution that at least a twentieth part of the caustic alkali remains undissolved; the products-films, celluloid, artificial filaments, and insulating-materials-prepared from the ethers eventually obtained, are distinguished by their water-resisting properties. The incorporation of the carbohydrate with the caustic alkali may be conducted in the presence of air or inert gas, or in vacuo, and at ordinary temperatures, or with heating or cooling; and the treated carbohydrate may before etherification be freed wholly or partly from the water contained therein, and may be immediately treated with the alkylating &c. agent, or after standing. The etherification may be conducted so as first to form a lower ether, which may be converted into a higher ether by treatment with further quantities of caustic alkali and alkylating &c. agent. Specification 3370/14 is referred to. Reference has been directed by the Comptroller to Specifications 164,374, 164,375, and 164,377, [all in Class 2 (ii), Cellulose &c.].