GB217166A - Cellulose solutions and process for their production - Google Patents

Abstract

Cellulose solutions are prepared by treating cellulose or a cellulose conversion product with a strong organic base, for example, a quaternary ammonium base or a base in the aqueous solution of which a highly electrolytically-dissociated hydroxide may be assumed to be present, in the presence or absence of caustic alkali. Suitable bases are tetra-ethyl ammonium hydroxide, tetra-methyl ammonium hydroxide, and phenyl trimethyl ammonium hydroxide. The reaction may be carried out in aqueous solution and at a room temperature or lower, for instance, below 0 DEG C., depending on the character of the original cellulosic material and on the presence or absence of alkali, the temperature being lowered by stages until solution occurs. The initial cellulose material may be bleached or unbleached cellulose products obtained by mechanical comminution of cellulose in the presence of water; products obtained by treating cellulose with oxidizing or reducing agents with or without a preliminary treatment with alkalies, acids, salts, etc.; products obtained by heating cellulose alone or in the presence of water or glycerine; products obtained by treating cellulose with hot or cold alkalies alone or in the presence of salts, with or without subsequent treatment with dilute acid and with or without previous or subsequent or simultaneous treatment with bleaching or oxidizing agents; products separated from solutions of cellulose, cellulose hydrate or hydrocellulose in ammoniacal copper oxide &c., zinc halides, or strong mineral acids such as sulphuric, phosphoric, arsenic or hydrochloric acid, or from viscose solutions; artificial silk, artificial cotton, staple fibre, etc.; products obtained by treating cellulose or its conversion products with these solvents to a point short of dissolution; hydrocelluloses such as are obtained by treating cellulose with dilute acids at ordinary or raised temperature, or by drying in the presence of acids, or by employing strong sulphuric acid at temperatures below 0 DEG C., gaseous hydrochloric acid, or chlorine; oxycelluloses; products obtained by denitrating, saponifying, &c. cellulose esters; the alkali-soluble derivatives of Specification 177,810. The solutions are coagulated by acids, salts, alcohols, water, steam, heat, etc.; and they may be worked up into artificial silk &c., films, artificial hair, plastic masses, coatings, finishings, fillings, sizes, artificial leather, &c. In examples, the starting material is treated with an aqueous or alkaline solution of tetra-ethyl or methyl ammonium hydroxide or phenylmethylammonium hydroxide, and the mixture cooled to \sw8 DEG to \sw11 DEG C. Specification 216,475 is referred to. The Specification as open to inspection under Sect. 91 (3) (a) includes the use of guanidine. This subject-matter does not appear in the Specification as accepted.