Patent GB-434736-A (GB)
Title: Improvements in or relating to the manufacture of printing pastes for textile materials
Filed: 1934-03-08
Abstract: Printing; dye mixtures.--A printing paste comprises as principal colour component a yellow or orange vat dye having only moderate printing qualities and as subsidiary colour component a yellow or orange 1 : 8-di-(acylamino)-anthraquinone exhibiting a greater vat-solubility than the principal dyestuff.  The proportion of principal to subsidiary component is preferably between 10 : 1 and 1 : 1.  Alternatively the principal and/or subsidiary components may each be a mixture of suitable vat dyestuffs of the kinds specified. The presence of the subsidiary component enhances the tinctorial strength, ageing characteristics and brightness of the print.  A table is given specifying suitable mixtures, principal components specified being 1 : 5 - di - (benzoylamino) - anthraquinone, 1 - benzoylamino - 5 - (1 : 9 - thiazoleanthrone - 2 - carbonyl) - aminoanthraquinone, 1 - benzoylamino - 5 - b  - naphthoylamino - anthraquinone, mixtures of any one of the above with pyranthrone and diphenyl - 2 (N) - 1 : 6 (N) : 5 - anthraquinone - dithiazole, and mixtures of diphenyl-2 (N) : 1 : 7 (N) : 8 - anthraquinone - dithiazole or 1 : 5 - di - (anisoylamino)-anthraquinone with pyranthrone and diphenyl - 2 (N) : 1 : 6 (N) : 5 - anthraquinone - dithiazole, and subsidiary components specified being 1 : 8 - di - (benzoylamino-and 1 : 8 - di - (anisoylamino) - anthraquinone. The following examples are specified.  (1) A solution of crude 1 : 8 - di - (benzoylamino) - anthraquinone (1 part) in 95 per cent. sulphuric acid at 5 DEG  C. is poured into ice water, filtered and washed free of acid; the filter cake is suspended in water, warmed to 80--85 DEG C., with addition of a dilute alkaline hypochlorite solution, so maintained for 2--4 hours, again filtered and washed free of alkali; it is then made into an aqueous paste with an addition of Leucanol or other wetting agent, milled to the desired degree and mixed with a similarly prepared paste of 1 : 5 - di - (benzoylamino) - anthraquinone (2 parts).  (2) 1 : 5 - Di - (benzoylamino) - anthraquinone (2 parts) in powder form and 1 : 8 - di - (benzoylamino) - anthraquinone (1 part) in powder form are together stirred into 95 per cent. sulphuric acid at 5 DEG  C. and the solution is treated as in (1).  (3) Cotton fabric is printed with an aqueous paste containing wheat starch, British gum, gum tragacanth, potassium carbonate, sodium formaldehydesulphoxylate, glycerol and the dye paste obtained in (1) or (2) and the printed fabric is dried, steamed for 2--8 minutes at 101--102 DEG  C., oxidized in dilute sodium bichromate solution or in cold running water, soaped, rinsed and dried.  Other assistants or dispersing agents, e.g. isopropylnaphthalenesulphonic acids, abietenesulphonic acids, diethylene glycol or polyhydroxyalkylamines, may be incorporated in the printing pastes.  The Specification as open to inspection under Sect. 91 comprises also the use as principal components of vat dyes which are not yellow or orange and the use as subsidiary components of any vat dyes of similar colour to, but of greater vat solubility than, the respective principal components.  The table includes a further example in which the principal component is 1 : 5 - di - (benzoylamino) - anthraquinone and the subsidiary component is a mixture of 1 : 8 - di - (benzoylamino) - anthraquinone and 1 - benzoylamino - anthraquinone.  The following are also specified as subsidiary components, viz. a - or b -acetylamino-anthraquinone, 1 : 4 - di - (benzoylamino) - anthraquinone, 1 - benzoylamino - 4 - (or 8 -) halogen - anthraquinones, 1 - benzoylamino - 4 - (or 8 -) amino - anthraquinone, 1 - benzoylamino - 4 - (or 8 -) hydroxy - anthraquinone or alkyl ethers thereof, 1 - benzoylamino - anthraquinone - 6 - carboxylic acid, hydroxybenzoylamino-anthraquinone, the imide from 1 : 9-anthrathiazole-2-carboxylic acid or from a 1-aroylamino-anthraquinone - 6 - carboxylic acid or from anthraquinone - 2 - carboxylic acid and a - or b -amino-anthraquinone, the di-imide from a 1-aroylamino - anthraquinone - 6 - carboxylic acid (2 mols.) or from anthraquinone-2-carboxylic acid (2 mols.) and 1 : 8-diamino-anthraquinone (1 mol.).  This subject-matter does not appear in the Specification as accepted.