GB526330A - Improved preparation of water-soluble cellulose ethers - Google Patents

Abstract

526,330. Cellulose ethers. TENNANT, W. J. (Dow Chemical Co.). March 13, 1939, No. 8070. [Class 2 (ii)] Alkali cellulose containing at least 0.9 and not substantially greater than 1.2 parts sodium hydroxide, and at least 0.9 and not substantially greater than 1.5 parts of. water per part of cellulose by weight, is etherified with an alkylating agent such as the methyl or ethyl halides and sulphates, the alkylating agent being supplied in quantity at least equivalent to the sodium hydroxide present. The reaction is continued till the sodium hydroxide is substantially neutralized but discontinued while the reaction mixture is still slightly alkaline. A uniform cold water-soluble lower alkyl ether of cellulose containing 25-33 per cent. of alkoxyl groups and soluble in water at temperatures below room temperature but insoluble in water at temperatures above 65 ‹C. is obtained. Methyl chloride, bromide, or iodide, or the corresponding ethyl halide may be used as etherifying agent. Etherification may be effected at raised temperature. The cellulose ethers obtained may be used for printing on cloth, and after dyeing the treated cloth, the cellulose ether may be removed by treatment with cold water. The cellulose ethers may also be used in the preparation of adhesive compositions and emulsions. Specifications 181,393, [Class 2 (ii)], and 427,387 are referred to.