Patent GB-341930-A (GB)
Title: Manufacture of artificial threads or other products from cellulose compounds
IPC: D01F2/28
Filed: 1929-07-26
Abstract: The process of Specification 335,906, [Class 95, Paints &c.], is modified by using, instead of the halogen compounds, trithio-carbonic esters, particularly of di- or polyvalent alcohols, for treatment of the viscose before shaping, coagulating, and plasticizing it.  The trithio-carbonic esters of glycol, the a , b , a -b  or a -g  esters of glycerine, or the esters of substances containing the alkylene-oxide grouping, or of monovalent alcohols for instance the diethyl or dipropyl esters, are suitable.  The ester may be mixed with the viscose after the dissolution of the latter, and the mixture may be aged for various periods up to 100 hours calculated from the time of dissolving the xanthate.  Cellulose ethers are apparently formed.  After coating a surface with the solution, it may be subjected to a bath having both a coagulating and a plasticizing effect, such as a 40-73 per cent sulphuric acid solution, which may contain ammonium sulphate, say 10 per cent, or 5-7\ba1/2\be per cent of glucose, or the bath may consist of a 32 or 40-42 per cent solution of hydrochloric acid, or of a 60-70 per cent solution of zinc chloride solution in 4-6 per cent hydrochloric acid, or of a 60-90 per cent nitric or arsenic acid solution, or phosphoric acid of sp. gr. 1,5-1,86.  Alternatively the coated surface may first be immersed in a purely coagulating bath, for instance a solution of ammonium sulphate of 25-30 per cent strength, or of 500 parts sodium bisulphate and 76 of sulphuric acid in 587 parts of water, or of sodium sulphate, ammonium sulphate, zinc sulphate, sulphuric acid, and glucose, at ordinary temperatures or up to 50 DEG  C., before plasticizing in strong acid or the like.  Plasticizing baths may have temperatures varying from 0 DEG -45 DEG  C.  As raw materials there may be used cotton linters or sulphite cellulose, pretreated or not with dilute acid at ordinary or raised temperature, or wood pulp so treated.  Ripening of the alkali cellulose may occupy various periods, for instance from 24 to 72 hours, or may be omitted.  In examples, the preparation of the viscose by varying methods, and its treatment with various quantities of esters, are described, and concentrations of the plasticizing baths are given.  Specification 26928/10 is referred to.ALSO:Cellulose xanthates and ethers, and processes for making filaments and films from.-The process described in the parent Specification is modified by using, instead of the halogen compounds, trithiocarbonic esters, particularly of di- or polyvalent alcohols, for treatment of the viscose before shaping, coagulating, and plasticizing it.  The trithiocarbonic esters of glycol, the a , b , a -b  or a -#c esters of glycerine, or the esters of substances containing the alkylene-oxide grouping, or of monovalent alcohols, for instance the diethyl or dipropyl esters, are suitable.  The ester may be mixed with the viscose after the dissolution of the latter, and the mixture may be aged for various periods up to 100 hours calculated from the time of dissolving the xanthate.  Cellulose ethers are apparently formed.  After the shaping of the viscose, it may be subjected to a bath having both a coagulating and a plasticizing effect, such as a 40-73 per cent sulphuric acid solution, which may contain ammonium sulphate, say 10 per cent, or 5-7 1/2 per cent of glucose, or the bath may consist of a 32 or 40-42 per cent solution of hydrochloric acid, or of a 60-70 per cent solution of zinc chloride solution in 4-6 per cent hydrochloric acid, or of a 60-90 per cent nitric or arsenic acid solution, or phosphoric acid of sp. gr. 1,5-1,86. Alternatively the thread or other shaped object may first be immersed in a purely coagulating bath, for instance a solution of ammonium sulphate of 25-30 per cent strength, or of 500 parts sodium bisulphate and 76 of sulphuric acid in 587 parts of water, or of sodium sulphate, ammonium sulphate, zinc sulphate, sulphuric acid, and glucose, at ordinary temperatures or up to 50 DEG  C., before plasticizing in strong acid or the like.  Plasticizing baths may have temperatures varying from 0 DEG -45 DEG  C.  The threads may be stretched in the plasticizing bath or after leaving it, for instance by passage around three glass rods, arranged at an angle to each other, or by means of hooks or differential rollers.  The lower part of the winding bobbin may run in water so as to dilute the acid; or before being washed, the threads may be cooled to -5 DEG -15 DEG  C. so as to arrest the action of the acid.  After washing, the threads may be steamed or otherwise heated.  As raw materials there may be used cotton linters or sulphite cellulose, pretreated or not with dilute acid at ordinary or raised temperature, or wood pulp so treated.  Ripening of the alkali cellulose may occupy various periods, for instance from 24 to 72 hours, or may be omitted.  In examples the preparation of the viscose by varying methods, and its treatment with various quantities of esters, are described, and details of spinning speeds, concentrations of the plasticizing baths, and lengths of immersion are given.  The process may be employed for the manufacture of films. Cotton material may be impregnated, filled, or coated on a padding, back-filling, or spreading machine with the viscose-ester solution, to which may be added a material such as talc, china clay, mica, soot, or a dyestuff or pigment, and, with or without stretching, passed through a plasticizing and coagulating bath. Specification 26928/10, [Class 2 (ii), Cellulose &c.], is referred to. Trithiocarbonic esters.-Hydrogen sulphide is passed into caustic soda solution which is then agitated with carbon disulphide. Addition of alcohol and ether produces a liquid layer of sodium trithiocarbonate, which is separated, purified by vacuum treatment, and shaken with a , b , a -b  or a -#c chlorhydrin, bromhydrin, or iodohydrin, or epimono or epidihalogen hydrins. Reaction takes place at 40- DEG 50 DEG  C. The cyclic or non-cyclic ester obtained is washed with water or dilute acid and vacuum-dried; or ether-extraction may be utilized.ALSO:The process of the parent Specification is modified by using, instead of the halogen compounds, trithio-carbonic esters, particularly of di- or polyvalent alcohols, for treatment of the viscose before shaping, coagulating, and plasticizing it.  The trithio-carbonic esters of glycol the a , b , a -b , or a -g  esters of glycerin, or the esters of substances containing the alkylene-oxide grouping, or of monovalent alcohols for instance the diethyl or dipropyl esters, are suitable.  The ester may be mixed with the viscose after the dissolution of the latter, and the mixture may be aged for various periods up to 100 hours calculated from the time of dissolving the xanthate.  Cellulose ethers are apparently formed.  After the shaping of the viscose, it may be subjected to a bath having both a coagulating and a plasticizing effect, such as a 40-73 per cent sulphuric acid solution, which may contain ammonium sulphate, say 10 per cent or 5-7 1/2 per cent of glucose, or the bath may consist of a 32 or 40-42 per cent solution of hydrochloric acid, or of a 60-70 per cent solution of zinc chloride solution in 4-6 per cent hydrochloric acid, or of a 60-90 per cent nitric or arsenic acid solution, or phosphoric acid of sp. gr. 1,5-1,86. Alternatively the shaped object may first be immersed in a purely coagulating bath for instance a solution of ammonium sulphate of 25-30 per cent strength, or of 500 parts sodium bisulphate and 76 of sulphuric acid in 587 parts of water, or of sodium sulphate, ammonium sulphate, zinc sulphate, sulphuric acid, and glucose, at ordinary temperatures or up to 50 DEG  C., before plasticizing in strong acid or the like. Plasticizing baths may have temperatures varying from 0 DEG -45 DEG C.  As raw materials there may be used cotton linters or sulphite cellulose, pretreated or not with dilute acid at ordinary or raised temperature, or wood pulp so treated. Ripening of the alkali cellulose may occupy various periods, for instance from 24 to 72 hours, or may be omitted.  In examples, the preparation of the viscose by varying methods, and its treatment with various quantities of esters, are described, and details of concentrations of the plasticizing baths.  Cotton material may be impregnated, filled, or coated on a padding, back-filling, or spreading machine with the viscose-ester solution, to which may be added a material such as talc, china clay, mica, soot, or a dyestuff or pigment, and, with or without stretching, passed through a plasticizing and coagulating bath.  Specification 26928/10, [Class 70, Indiarubber &c.], is referred to.