Patent GB-357595-A (GB)
Title: Improvements in the manufacture of artificial threads or other products from cellulose compounds
IPC: C08B13/02
Filed: 1930-03-15
Abstract: The process of the parent Specification is modified by using xanthates of such oxyalkyl derivatives of cellulose as are produced by means of cyclic ethers of di- or polyhydric alcohols in presence or absence of alkali or catalyst.  Compounds of cellulose with alkylene oxides, glycide, or butadiene dioxide are particularly suitable.  The cellulose compounds may be xanthated according to any known process of xanthating cellulose, and in particular by the processes described in Specification 335,994, [Class 2 (ii), Cellulose &c.].  The xanthated products may be mixed with other colloids such as cellulose xanthate.  They may be mixed with viscose, or cellulose xanthate may be dissolved in their solutions, or carbon bisulphide may be caused to react on a mixture of the cellulose ether and unchanged cellulose or alkali cellulose.  They may be mixed with other alkali soluble cellulose derivatives, or with alkali soluble cellulose hydrates, or proteins, or gelatine.  Softening agents such as glycerine, glycol, sugar, soap, Turkey-red oil, drying or non-drying oil, or agents such as ethylene chlorhydrin, mono- or di-chlorhydrin, or other halogen derivative of a di- or polyhydric alcohol may be added to solutions of the xanthates.  In the manufacture of the cellulose ethers, the alkali cellulose may be allowed to mature before etherifying.  A catalyst such as a copper, nickel, silver, or iron salt may be present in the etherifying mixture.  In examples, ethylene oxide is kneaded with alkali cellulose and the product is xanthated.  The solution of the xanthate is aged and filtered and then spun into coagulating and plasticizing baths in the manner described in the parent Specification.  In other examples, ethylene oxide is added directly to finely divided wood pulp or cotton linters in a rotating autoclave, dimethyl aniline p being present if desired.  The product may be acidified and washed prior to xanthation or may be xanthated directly.  Propylene oxide, or glycide may be used instead of ethylene oxide.  If the starting material is a cellulose of high viscosity, the resultant spinning solution may contain only 3 per cent of precipitable cellulose.  The artificial threads on leaving the strong acid plasticizing bath may be subjected to a low temperature before washing, for example they may be collected on hollow spools containing a freezing mixture, ice, or solid carbon dioxide. After washing, the threads may be heated or steamed before or after the drying process.  Desulphurizing may be carried out in the usual manner, or by treatment with stronger sodium sulphide solution.  In another example, cotton fabric is impregnated or coated with a solution of a xanthate of an oxyalkyl cellulose of the type specified, to which solution is added talc, china clay, zinc white, dyestuff, mica, or lampblack.  The material which may first be dried, is passed, if desired under tension, through one of the coagulating and plasticizing liquids mentioned in the parent Specification.  The fabric is then washed and dried. Specifications 335,906, [Class 140, Waterproof &c. fabrics], and 341,899 are also referred to.