GB346806A - Improvements in the manufacture of organic substitution derivatives of cellulose - Google Patents

Abstract

Halogen-containing ethers of cellulose are produced by reacting on cellulose with an aliphatic etherifying agent containing a halogen atom or atoms in addition to the etherifying atoms or group. Suitable reagents specified are epichlorhydrin, ethylene chlorobromide, 2,2-dichlor-1-bromethane, 1-chlor-2-iodoethane, 2-chlor-1-brompropane, 3-chlor-1-brompropane. When using reagents containing an alkylene oxide group, the etherification is effected in the absence of alkali, but when halogen is used as the etherifying atom bases, preferably inorganic, such as 40-50 per cent caustic alkali should be present. Caustic alkali may be used in at least sufficient quantity to form a concentrated solution with any water present. As starting materials for the process, the following may be employed, cotton, regenerated artificial fibres, or wood pulps, preferably chemical wood pulps, these materials being preferably subjected to pretreatment with organic acids, caustic alkali, mineral acids, or a combination of any of the above. In examples (1) cotton linters or purified wood pulp are treated with caustic soda and ethylene chlorobromide in two or more stages, the product washed with alcohol and dried; (2) wood pulp which has been pretreated by any of the processes referred to above, is washed with alcohol, and caused to react with epichlorhydrin. The products may be treated with ammonia or with organic amines so as to obtain amino ethers which have an affinity for acid dyestuffs. Specifications 187,639, 249,173, 263,938, [all in Class 2 (ii), Cellulose &c.], 344,480, and 344,529 are referred to.