GB797946A - Colouring cellulosic textiles - Google Patents

Abstract

Cellulosic textile materials are coloured by impregnating them, locally or otherwise, with an aqueous medium containing a monoazo or polyazo dyestuff having at least one ionic solubilizing group, such as a sulphonic acid or carboxylic acid group, and also at least one primary or secondary amino group carrying as N-substituent a 1 : 3 : 5 triazine radical containing at least one halogen atom attached to a carbon atom of the triazine ring, and then subjecting the materials to the action of an acid-binding agent in aqueous medium. Alternatively, the textile may be treated, before, during or after the application of the dyestuff, with an aqueous solution of a substance which on heating or steaming liberates an acid-binding agent, in which case heating or steaming is finally applied. As applied to printing, the acid-binding agent or a substance which, on heating or steaming, liberates an acid-binding agent, may be incorporated with the dyestuff in the printing paste, and the printed material may then be heated or steamed. Suitable acid-binding agents are caustic soda, caustic potash, sodium carbonate or bicarbonate, trisodium phosphate and sodium metasilicate, suitable substances liberating the acid-binding agent on steaming being sodium bicarbonate and sodium trichloroacetate. Electrolytes, such as sodium chloride or sulphate, may be added to the aqueous solution of the acid-binding agent. The dyebath or printing paste may contain the usual additives such as urea, sodium sulphate, sodium alginate, cellulose ethers, starch and locust bean gum. The material may be padded with the dyestuff solution and dried prior to treatment with the acid-binding agent. In continuous processes, e.g. employing the molten-metal technique, the drying step may be effected at 70-170 DEG C. If the dyestuffs contain metallisable groups, then an after-treatment with a metal compound, e.g. a copper, nickel, cobalt or chromium compound, may be effected. Examples of dyeing and printing are given. The dyestuffs may be prepared by condensing an amino-azo or amino-polyazo compound with cyanuric chloride or by coupling a diazo compound with a primary condensation product from an amino compound and cyanuric chloride or by condensing a diamine and cyanuric chloride, diazotizing the so-formed product and then coupling with an appropriate component. Long lists of suitable dyestuffs are given. Specifications 342,167, 363,897, [both in Group IV], 774,925, 785,120 and 785,222 are referred to.