Patent GB-367920-A (GB)
Title: Manufacture of artificial threads or other products from cellulose compounds
IPC: D01F2/28
Filed: 1930-08-25
Abstract: Artificial threads, films, and other products are obtained by reacting on cellulose, preferably in presence of alkali, with a halogenalkylamine or halogenaralkylamine, xanthating the compound produced, bringing the xanthated product if desired in the presence of cellulose xanthate into the appropriate shape or form and acting upon it with an agent which has a coagulating effect and also a plasticizing effect on the coagulated product. Alternatively, the xanthated product may be treated first with a coagulating agent and then with a plasticizing agent.  The ordinary coagulating baths known in the viscose art may be used for the coagulating step and to these baths there may be added inorganic or organic liquid, crystalline, or colloidal substances such as natural or synthetic tanning materials, proteins, proteids, and polysaccharides.  The plasticizing bath may contain strong mineral acid such as sulphuric acid, mineral acid, and alcohol, an ester of an aliphatic or aromatic alcohol, and a mineral acid, a carboxy-organo-mineral acid such as sulpho-acetic acid, a sulphonic acid of an aromatic hydrocarbon, an aromatic sulpho-acid containing nitrogen, or sulphuric acid with bisulphates, formaldehyde, or pyridine.  During spinning the materials may be stretched.  The extensibility of materials such as threads can be improved by treatment with shrinking agents. They may be desulphurized by treatment with hot and strong alkali sulphide or hydrosulphide solution.  In an example, wood pulp or cotton linters are steeped in caustic soda solution and after standing for a few hours, excess of solution is removed by pressing.  The pressed alkali-cellulose is comminuted and b -chlorpropylamine hydrochloride is kneaded with it.  After several hours the product is washed.  It is then treated with caustic soda, pressed, shredded, and mixed with carbon bisulphide.  The product is dissolved in dilute caustic soda solution, and spun into strong sulphuric acid or first into a coagulating bath, the threads being subsequently passed through sulphuric acid of plasticizing strength.  A small proportion of copper acetate may be added to the alkali cellulose before the etherification step.  If desired the process may be carried out at raised temperature.  Other examples describe modifications in the practical details of the process including the proportions and concentrations of the reacting substances and the duration of the treatments.  Alcoholic caustic soda or potash may be used instead of aqueous alkali.  Other halogen alkylamines such as chloro-ethyl-diethylamine, dibromopropylamine, or g -chloro-propyl-dimethylamine either in the form of the free base or as the hydrochloride or hydrobromide may be used.  Instead of chloro- or bromo-derivatives, the corresponding iodo-compounds may be used. Cotton material may be impregnated, filled, or coated in a padding, back-filling or spreading machine with a solution of one of the xanthated products described to which talc, china clay, zinc white, mica, or lampblack has been added.  The material is then passed through a plasticizing bath, or a coagulating bath followed by a plasticizing bath, and is then washed and dried.  Specifications 264,161, 274,521, 274,690, 281,351, 281,352, 298,548, 312,197, 317,608, 322,731, 323,732, 335,906, and 335,994, [all in Class 2 (ii), Cellulose &c.], are referred to.  The Provisional Specification also describes the addition to cellulose of the substances mentioned in Specification 368,288.