Patent GB-538711-A (GB)
Title: Improvements in treating materials with alkaline reagents and reagents therefor
IPC: D06M13/388
Filed: 1939-10-30
Abstract: 538,711. Treating textiles with liquids; dyeing and bleaching processes ; cellulose derivatives ; resinous condensation products; hydrocarbon substitution derivatives. TOOTAL BROADHURST LEE CO., Ltd., HALL, A. J., and WOOD, F. C. Oct. 30, 1939, Nos. 8245/41, 8246/41, 8247/41, 8248/41 and 8249/41, (all divided out of 538,396), and 8250/41, (divided out of 11275/40). [Classes 2 (ii), 2 (iii) and 15 (ii)] [Also in Group III] A reagent for use in processes where alkali is required comprises an alkaline substance, an organic liquid which has at least three carbon atoms in the molecule and which is a solvent for the alkaline substance, and an organic non-solvent or poor solvent for the alkaline substance which is miscible with the solution of the alkaline substance in the organic solvent. The reagent may contain a little water, but not more than 2 per cent. The reagent may be used for reducing the acyl content of cellulose esters such as cellulose acetates or propionates, or for the hydrolysis of other cellulose derivatives, e.g. cellulose fibres which have been esterified with p-toluene sulphonic chloride. It may also be used for the production of polyvinyl alcohol from polyvinyl acetate, or for the saponification of glyceryl esters, e.g. mutton fat and other fatty or greasy substances. Ethyl acetate may be converted into ethyl aceto-acetate. The reagent may also be used for cleaning greasy metal and other materials and for dry cleaning textiles. Carbon dioxide may be removed from gases by bubbling through the reagent. Cotton, regenerated cellulose or silk fibres may be treated to effect superficial swelling and to render them superficially reactive for further treatments. Reference is made also to the use of the reagent for the hydrolysis of amides, urethanes, or proteins and for effecting changes in which the alkali acts as a swelling, condensing, coagulating, dispersing, dehydrating, polymerizing or depolymerizing agent, and to the use of the reagent for absorbing or removing acids or acid vapours from any system. The materials treated may be in the form of moulded articles, sheets, tubes, fibres, yarns and fabrics. They may contain a non-reactive as well as a reactive part. The alkali may be caustic soda or potash, or an organic base such as a quaternary ammonium or a sulphonium or iodonium base, or it may be a tertiary amine oxide, hydrazine, sodium or potassium ethylate or butylate, sodamide, a sodium derivative of acetoacetic ester, acetone or methyl ethyl ketone, or sodium or potassium oxide or peroxide. The solvent may be an aliphatic alcohol containing 3-8 carbon atoms, e.g. n-butyl alcohol, or oleyl, stearyl, ricinoleyl, benzyl, or phenyl ethyl alcohol, or cyclohexanol, an amino alcohol, an ether of ethylene glycol, acetone, ethylacetoacetate, aniline, ethyl acetate or amyl acetate. The non-solvent may be a petroleum distillate such as white spirit, hexane or petrol, or a chlorinated hydrocarbon, toluene, tetrahydronaphthalene or pyridine. Specification 538,396 is referred to for further examples of the constituents of the alkali composition. In an example, n-butyl alcohol is shaken with caustic soda till a solutionemulsion is obtained. This is poured off from the solid caustic soda and is then mixed with more butyl alcohol. The clear solution obtained is diluted with white spirit. The solution gives a fine dispersion containing caustic soda when warmed but the caustic soda re-dissolves on cooling. In another example, cellulose acetate satin fabric is steeped in a solution of caustic soda, n-butyl alcohol and white spirit. The resulting fabric dyes evenly with Chlorazol Sky Blue FF and other cotton dyes. Cellulose acetate woven fabric is printed to give a spot pattern with a paste of British gum, starch, and tartaric acid. It is then treated with the reagent and then dyed to produce a white spot pattern on a coloured ground. Cottonviscose rayon fabric is immersed in a solution of butyl alcohol, white spirit and caustic soda, and then squeezed, immersed in chlormethoxy sulphonic chloride dissolved in white spirit, and dried. It contains combined formaldehyde. Damp cotton fabric is immersed in a solution of caustic soda, butyl alcohol and white spirit, mangled and immersed in a solution of sulphuryl chloride and white spirit. The fabric is stiffened. Similar fabric is treated with the reagent and then immersed in a solution of carbon bisulphide in white spirit. The fabric is mangled, acidified and washed. It is stiffened and it dyes readily with Chlorazol Sky Blue FF. The Provisional Specifications describe also the treatment of wool with the reagent to reduce the tendency of wool to felt or shrink, and the use of the reagent in the etherification or esterification of cellulose is referred to.