Patent GB-528118-A (GB)
Abstract: 528,118. Dyeing textiles & c. SOC. OF CHEMICAL INDUSTRY IN BASLE. April 18, 1939, Nos. 11702, 11703 and 11704. Convention dates, April 19, 1938, May 28, 1938 and April 12, 1939. [Class 15 (ii)] In dyeing or printing textile fibres of regenerated cellulose, or such fibres containing a protein or an artificial resin, with sulphur dyes in presence of alkali, e.g. sodium carbonate or ammonia, in amount sufficient to give a weakly alkaline reaction, and in presence of a hydrosulphite or formaldehydesulphoxylate, the dyes are used in the form of water-soluble products obtained by (a) oxidation of the dye in presence of sodium sulphite (cf. Specification 2290/09, [Class 15 (ii)]), or (b) treatment of a sulphurized indophenol with sulphurous acid or a sulphite or bisulphite (cf. Specification 5168/01, [ Class 15]), or (c) treatment of the dye with an alkali sulphite or bisulphite (cf. Specification 3414/95, [Class 2]). In examples (1) combings of regenerated cellulose fibres containing protein, known under the Registered Trade Mark "Cisalpha" are treated for 1 hour with an aqueous liquor at 45‹C. containing sodium carbonate, sodium hydrosulphite, sodium sulphate and a product of the 'action of aqueous sodium sulphite on Pyrogene yellow O (cf. Specification 3414/95), whereupon the goods are washed, oxidized, e.g. with hydrogen peroxide, a per-salt or sodium bichromate and acetic acid, again washed and dried ; (2) similar combings, cardings, flocks or yarns or regenerated cellulose fibres are treated for 1 hour with an aqueous liquor at 60-70‹C. containing sodium carbonate, sodium hydrosulphite and a product obtained from Pyrogene blue R by the process of Specification 2290/09, whereupon the goods are further treated as in (1) ; (3) a mixed fabric containing staple fibres of regenerated cellulose and casein fibres is treated for 1 hour with an aqueous liquor at 45‹C. containing sodium carbonate, sodium hydrosulphite and a product of the action of aqueous sodium sulphite on Pyrogene deep black D, with addition after ¢ hour of sodium sulphate, whereupon the goods are oxidized by air, rinsed, further oxidized with sodium bichromate in acetic acid solution, rinsed, treated with an aqueous solution at 45‹C. containing sodium carbonate and the sodium salt of benzyl-Á-heptadecylbenzimidazole-disulphonic acid, again rinsed and dried ; (4) a fabric of regenerated cellulose or of such containing a protein is printed with an aqueous preparation containing potassium carbonate, British gum, sodium formaldehydesulphoxylate, urea, glycerol and a product obtained from Pyrogene green 3G by the process of Specification 2290/09, and the printed goods are steamed, oxidized, e.g. with sodium perborate in barium chloride solution, rinsed, soaped, again rinsed and dried ; (5) a mixed fabric comprising fibres of waste wool, with or without casein fibres, and fibres of regenerated cellulose or of regenerated cellulose containing protein or artificial resin is treated for 1 hour with a stock vat as in (3) at 45‹C. containing a product of the action of aqueous sodium sulphite on Pyrogene deep black D, with addition of sodium sulphate, rinsed, oxidized as in (1) with sodium bichromate and acetic acid and again rinsed, whereupon the wool is dyed by the after-chrome process with Eriochrome black T. The Specification as open to inspection under Sect. 91 comprises also the application of the dyeing process to other than regenerated cellulose materials and includes an example in which fat tanned glove leather is dyed a fast black by treating it for 1 hour in a stock vat as in (3) at 25-30‹C., rinsing, oxidizing as in (4) at 25‹C., again rinsing, treating for ¢ hour with an aqueous solution containing the sodium salt of benzyl-Á- heptadecylbenzimidazoledisulphonic acid and borax, rinsing, fat-liquoring and drying. This subject-matter does not appear in the Specification as accepted.