GB336621A - Improvements in the treatment or production of cellulose derivative materials - Google Patents

Abstract

336,621. Dreyfus, H. July 9, 1929. Yarns &c., treating with liquids, gases, and vapours.-For mordanting and weighting of materials made of or containing cellulose acetate or other organic esters of cellulose or of cellulose ethers, the mordanting or weighting metal radicle or a precipitant therefor is incorporated in the spinning solution; and the formed filaments are subjected to a treatment either in the course of their production or continuously with their production or subsequently thereto such as will fix the metal on the materials Metals that may be so introduced are aluminium, chromium, iron, tin, zinc, tungsten and bismuth If to the spinning solution there is added a precipitant such as tannic acid then it is preferred to apply the metal to the finished materials or to the materials continuously with their productions under such conditions that swelling of the cellulose derivative takes place, for example, by emploving the methods of Specification 258,874, 259 899. 281,084, 284,798 and 285,941. With the preferred method, namely, that in which the metal radicle is incorporated with the spinning solution, the following are examples of salts that may be used :-stannic chloride and thiocyanate, ferric chloride and thiocyanate, aluminium and chromium thiocyanates, and zinc chloride; and as precipitant there may be used sodium phosphate solution or water containing alkali such as ammonia or soda ash, although in the case of the mordant metals water by itself may be employed. The precipitant may be applied to the finished threads, yarns, fabrics, &c., or the threads may be treated therewith as they leave the spinning cells, or the precipitant may be incorporated in the coagulation bath or in a subsequent treatment bath. The acetylation solutions as obtained by the processes of Specifications 308,322, 308,323, 309,201; 312,095, 312,096, and 312,098, [all in Class 2 (ii), Cellulose &c.], may be used for spinning since these already contain the metal radicle, the mineral acid being, if desired, first neutralized by sodium acetate and the excess of anhydride being destroyed by the addition of dilute acetic acid. Such solutions are conveniently spun into dilute acetic acid, and the metal fixed by carrying the filaments into a soda ash bath or by subsequent treatment with such a bath. Mordant or other dyestuffs may be added to the coagulation or fixing baths. Specifications 323,501 and 323,785 are referred to.