Patent GB-341843-A (GB)
Title: Manufacture of artificial threads and other products from cellulose
IPC: D01F2/28
Filed: 1929-07-20
Abstract: Artificial materials as defined in the parent Specification are obtained by treating viscose, or a derivative such as a cellulose xanthic acid, with a halogenated fatty acid or a salt or ester thereof and then giving solutions of the product the appropriate shape or form and treating with agents which coagulate the solutions and have a plasticizing effect on the artificial materials produced. Alternatively the solutions may be treated with coagulating agents and then with plasticizing agents.  The process is carried out in a similar manner to that of the parent Specification.  It is preferred to use strong mineral acid such as sulphuric acid of not less than 35 per cent strength and preferably not less than 50 per cent strength as the plasticizing agent.  Equivalent proportions of other strong mineral acids such as hydrochloric acid may be used.  The products have high tenacity in dry and wet condition and good extensibility. The halogen fatty acid may be mono-, di-, or tri-chloro-, bromo-, or iodo-acetic acid, or a-chloro-, or bromo-propionic, butyric, or succinic acid, or b -chloro-lactic acid.  The halogen fatty acid may be neutralized with sodium bicarbonate before being added to the viscose solution.  In some cases it is preferable to employ as starting material for making the viscose such wood pulp or cotton linters as lead to the production of solutions of high viscosity. The solutions may be coagulated in ammonium sulphate solution, or sodium sulphate, ammonium sulphate, zinc sulphate, glucose, and dilute sulphuric acid, prior to treatment with strong sulphuric acid. Specification 231,800, [Class 2 (ii), Cellulose &c.], is referred to.ALSO:Cellulose xanthates, ethers, processes for making filaments and films from; plastic compositions containing cellulose esters and ethers; adhesives; sizes and finishes; ink; paper, treating with special materials; liquids, processes and materials for treating fabrics, yarns, &c. with; coating processes; single coatings.-Artificial threads and other materials as defined in the parent Specification are obtained by treating viscose, or a derivative such as a cellulose xanthic acid, with halogenated fatty acids or their salts or esters, and then giving solutions of the product the appropriate shape or form and treating with agents which have a coagulating and plasticizing effect. Alternatively the solutions may be treated with coagulating agents and then with plasticizing agents.  The process is carried out in a similar manner to that of the parent Specification.  It is preferred to use strong mineral acid such as sulphuric acid of not less than 35 per cent strength and preferably of not less than 50 per cent strength as the plasticizing agent.  The products have high tenacity in dry and wet condition and good extensibility. The halogen fatty acid used may be mono-, di-, or tri-chloro, bromo, or iodo-acetic acid, or a -chloro- or bromo-propionic, butyric, or succinic acid, or b -chloro-lactic acid.  In an example, wood pulp or cotton linters are treated with caustic soda lye, and the alkali-cellulose is comminuted and mixed with carbon disulphide.  The cellulose xanthate is dissolved in dilute caustic soda to form a solution containing 6,5 per cent cellulose and 8 per cent caustic soda.  Alternatively, the proportion of cellulose or caustic soda may be decreased.  To the viscose, a solution of monochloracetic acid neutralized with sodium bicarbonate is added and the mixture is allowed to stand for some time at room temperature.  The solution is filtered and then pressed through a platinum nozzle into strong sulphuric acid.  The artificial silk threads then pass over stretching rollers, rods or hooks to a bobbin dipping into water.  They are then washed, purified, dried and finished in known manner.  Examples of the spinning speeds, lengths of immersion in the plasticizing bath and subsequent air path of the threads are given.  The temperature of the plasticizing bath may be above or below room temperature and may even be below 0 DEG  C.  In some cases it is advantageous to employ such parent materials as produce solutions of high viscosity.  The solutions may be coagulated in ammonium sulphate solution, or sodium sulphate, ammonium sulphate, zinc sulphate, glucose and dilute sulphuric acid, prior to treatment with strong sulphuric acid.  Instead of strong sulphuric acid, equivalent proportions of other strong mineral acids such as hydrochloric acid may be used. Films may be made by passing the solutions through slots into a plasticizing bath and then washing and drying in the known manner. Cotton fabric may be impregnated or coated on a padding, spreading, or back-filling machine with a solution of viscose and halogen fatty acid containing a filler or pigment such as talc, China clay, mica, or soot.  It is then passed, if desired in stretched condition, through a plasticizing bath, washed and dried.  Specification 231,800, [Class 2 (ii), Cellulose &c.], is referred to.ALSO:Artificial materials as defined in the parent Specification are obtained by treating viscose, or a derivative such as a cellulose xanthic acid with a halogenated fatty acid or a salt or ester thereof and then giving solutions of the product the appropriate shape or form and treating with agents which coagulate the solutions and have a plasticizing effect on the artificial materials produced.  Alternatively the solutions may be treated with coagulating agents and then with plasticizing agents. The process is carried out in a similar manner to that of the parent Specification.  It is preferred to use strong mineral acid such as sulphuric acid of not less than 35 per cent strength and preferably not less than 50 per cent strength as the plasticizing agent. Equivalent proportions of other strong mineral acids such as hydrochloric acid may be used.  The products have high tenacity in dry and wet condition and good extensibility.  The halogen fatty acid may be mono-, di-, or tri-chloro-, bromo-, or iodo-acetic acid, or a -chloro-, or bromo-propionic, butyric, or succinic acid, or b -chloro-lactic acid.  The halogen fatty acid may be neutralized with sodium bicarbonate before being added to the viscose solution.  In some cases it is preferable to employ as starting material for making the viscose, such wood pulp or cotton linters as leads to the production of solutions of high viscosity. The solutions may be coagulated in ammonium sulphate solution, or sodium sulphate, ammonium sulphate, zinc sulphate, glucose, and dilute sulphuric acid, prior to treatment with strong sulphuric p  acid.  Specification 231,800, [Class 2 (ii), Cellulose &c.], is referred to.