GB709150A - Improvements in colouring articles of natural or synthetic textile raw materials - Google Patents

Abstract

Threads, fibres, bands and fabrics of natural and synthetic textile materials are coloured by impregnating them with an aqueous dispersion of a water-insoluble vat dyestuff (insoluble in aliphatic esters of acetic acid) of which the particle size has been brought to less than 10 mm , and then drying the articles. Particles of this size are stated to be capable of penetrating the inter-micellar spaces of the articles and to be retained after drying. When used for printing the usual thickeners are added and the print dried, steamed and soaped at the boil. The process is applicable to wool, cotton, silk regenerated cellulose, acetate silk, polyamides, polymethanes, polyesters, polyvinyl chloride and polyacrylonitrile. In the examples (1) Indanthrene Blue is triturated with lactose, the mixture added to water and the coarser particles separated by sedimentation; cotton is impregnated with the remaining dispersion at room temperature, soaped at the boil, rinsed and dried; it is coloured blue; (2) Indanthrene Blue is converted into its leuco vat acid and the latter kneaded with dextrin and dispersed in water; viscose is dyed blue by impregnation with this dispersion at room temperature; the vat acid is reoxidized partly during kneading and partly in the dyebath; dyeing is accelerated by heating and/or by adding an inorganic salt; (3) a similar preparation is made from the vat dyestuff 2-(1-aminoanthraquinonyl-2)-(anthraquinono-2':3'-4:5-oxazole)-see Specification 298,545, [Class 2(iii)]-and used for dyeing wool, silk, acetate silk polyesters, polyamides or polyacrylonitrile in red shades; pyranthrone similarly gives orange shades.