Patent GB-536841-A (GB)
Title: A process of treating a product synthetically formed from protein material to improve or modify its dyeing affinities, resistance to water and chemicals, and other properties
IPC: C08L89/00
Filed: 1939-11-24
Abstract: 536,841. Artificial filaments, films &c. ; albumens ; dyeing processes ; ketenes : waterproofing ; purifying wool fat. ATLANTIC RESEARCH ASSOCIATES, Inc. Nov. 24, 1939, Nos. 30711 and 30712. Convention dates, Nov. 25, 1938, and Aug. 23, 1939. [Classes 2 (ii), 2 (iii)] and 15 (ii)] [Also in Groups III and VIII] Artificial filaments, films, and other shaped materials having a protein basis are subjected to the action of an acylating agent in the presence of a fatty acid which acts as a catalyst. The treatment renders the materials more resistant to water, acids and alkalies, and their dyeing properties are rendered similar to those of wool, so that mixtures of these materials with wool may be dyed uniformly. The tensile strength may be increased by the treatment. The materials may have a basis of casein derived from milk or soya beans. The artificial fibres may be obtained by extruding a solution of casein in caustic soda containing, if desired, a plasticizer or softening agent. The coagulated fibres may be treated' with acids, salts or formaldehyde, prior to the treatment with an acylating agent. Acetic anhydride, carbon suboxide, alkyl chloro-carbonates, ketene, aldo- and keto-ketenes and ketenes of lower fatty acids, such as butyl and amyl ketenes, may be used as acylating agent. The acylating agent may be used in gaseous form. When ketenes are used, condensation or polymerization reactions with the protein may take place in addition to acylation. Ketene may be obtained by passing acetone vapour through a heated copper tube. It may be used without separation of the methane which is generated with it, or it may be diluted with carbon dioxide. The artificial protein fibres may be subjected to ketene vapour at room temperature or at an elevated temperature and the process may be carried out as a batch operation or as a continuous process. Yarns or staple fibre may be passed continuously through a long chamber in which ketene vapour is passed in the same direction as or in counter-current to the yarns. The filaments or fibres may be under tension during the acylation treatment, and stretching may be effected. If desired the acylating agent may be used in solution in a solvent such as mineral spirit. The fibres are preferably dried prior to the acylation. To avoid sticking of the fibres during drying they may be subjected to a treatment with formaldehyde, or they may be washed in a bath of alcohol, acetone or other dehydrating organic liquid, containing a small amount of fat or fatty acid. After the acylation treatment, the fibres may be washed with water, dilute ammonia solution, solutions of alkaline salts or soaps or buffering salts, so as to adjust their pH value to between 5 and 8. The fibres may be treated with softening or plasticizing substances such as oils, fats, higher alcohols and their esters, glycerol, wool fat, tricresyl phosphate or phthalic esters. An aqueous emulsion containing " Lanolin " (Registered Trade Mark) and soap may be used for softening and for adjusting the pH value. Sodamide-treated anhydrous lanolin may be used. This may be prepared by mixing dry lanolin with sodamide and a little xylene to bring the mixture to the desired viscosity. The mixture may be heated to 210‹C. The amide, remaining after the treatment, and the reaction products stratify and may be removed from the lanolin by skimming. The fatty acid used in the acylation of the artificial protein materials may also be a softening agent. Fatty or softening material may be applied to the fibres prior to the treatment with ketene or other acylating agent. Soap solution may be applied to the coagulated and still acid fibres, whereby the acid is neutralized and the fatty acid is precipitated on the fibres. This fatty acid serves as the catalyst in the treatment with ketene. Sulphur may be introduced into the fibres, e.g. by treatment with sulphur compounds before or after the ketene treatment. Ammonium, zinc or hydrogen sulphide may be used. The acylating agent may be mixed with a sulphur compound or a thio-acylating agent may be used, e.g. a thioanhydride of an aliphatic acid. The sulphur compound may be thioglycollic acid. Specification 495,332 is referred to. The Specification as open to inspection under Sect. 91 describes also the production of ketene from acetone vapour which is passed along a copper tube forming an electric resistance. The tube is heated by means of a large current at low voltage. It may be connected across the secondary of a transformer, and to prevent oxidation it may have a ceramic covering. It may be in the form of a helix. The temperature may be raised to 750-760‹C. The acylation of the artificial protein materials may be carried out without a catalyst or with catalytic materials other than fatty acids, e.g. aluminium chloride, ammonium chloride, a fatty acid ester, glycerine, wool fat or a phthalic ester. This subject-matter does not appear in the Specification as accepted.