GB491488A - Improvements in and relating to cellulose derivatives and shaped structures made therefrom - Google Patents

Abstract

Cellulose ethers which are soluble in caustic soda solution but insoluble or scarcely soluble in water, are improved as regards their solubility and their filtering and spinning capacities, by exposing the isolated and dried ethers to a temperature exceeding 40 DEG C., e.g. to a temperature between 40 and 250 DEG C. The treatment of cellulose ethers which are soluble in caustic soda solution only on refrigerating the mixture, e.g. as described in Specification 212,864, [Class 2 (ii)], is included. Suitable cellulose ethers are those containing not more than one ether group per one or even ten or more cellulose units, e.g. such alkyl ethers prepared as described in Specifications 177,810, 200,816, 200,834, 203,346, 203,347, [all in Class 2 (ii)], and 374,964, hydroxy-alkyl ethers as described in Specifications 231,807 and 231,808, [both in Class 2 (ii)], and hydroxyparaffin monocarboxylic derivatives as described in Specifications 231,809, 231,810, and 231,811, [all in Class 2 (ii)]. The action of the heating on the cellulose ether may be accelerated or intensified by the addition of a thorium salt, a cerium salt, an alcohol, or an inorganic or organic nitrogen base. The products may be further improved by treating them with an acid or acid salt, e.g. hydrochloric or sulphuric acid of 0,5 to 3 per cent strength at room temperature. The cellulose ethers may be worked up into products such as filaments, films, plates, adhesives, finishes, coatings and the like, by contacting the shaped solution of the cellulose ether with an agent having a coagulating and/or a plasticizing action on the shaped material, e.g. a bath containing from 25 to 70 per cent of sulphuric acid. The cellulose ethers may be worked up into xanthates, examples of such processes being described in Specifications 335,993, 335,994, [both in Class 2 (ii)], 357,167, 357,527, 357,595, 459,122, 459,123, 459,124, 462,283, 462,456, 462,712, and 462,713. According to the Provisional Specification the invention may also be applied to the treatment of cellulose esters which are at least partially soluble in caustic soda solution, these including cellulose mono-esters of dicarboxylic acids, and alkali-soluble cellulose nitrate. Specifications 281,352, 312,197, 323,731, 323,732, [all in Class 2 (ii)], 341,899, 356,776, 408,950, 457,031, 470,746, 472,888, 472,933, and 474,223 also are referred to.