Patent GB-348283-A (GB)
Title: Manufacture of new dyestuffs
IPC: C09B56/04
Filed: 1930-03-14
Abstract: Stilbene dyes; azo dyes and soluble metal compounds thereof.-The condensation in various proportions of compounds containing one or more amino groups, e.g. aminoazo dyestuffs, with 4 : 41-dinitrostilbene-2 : 21-disulphonic acid, 4 : 41-dinitrodibenzyl- 2 : 21-disulphonic acid, or a conversion product of p-nitrotoluenesulphonic acid is effected under pressure; the products give dyeings of deeper tone and of increased fastness to alkalies and to light as compared with the products obtainable without the use of pressure, and may be further treated with oxidizing agents or with agents yielding metals, or with both; alternatively metal compounds of aminoazo dyestuffs may be condensed under pressure with the above nitrosulphonic acids.  The following examples are specified.  (1) A caustic soda solution containing a mixture of the saponified dyestuff from diazotized aniline-3-sulphonic acid and aniline-O -methanesulphonic acid with 4 : 41-dinitrostilbene-2 : 21-disulphonic acid is heated in an autoclave for 6 hours at 115-120 DEG  C.; the product dyes cotton orange tints fast to light and alkali; other diazo components, such as aniline-2-sulphonic acid, aniline-4-sulphonic acid, 2-toluidine-4-sulphonic acid, 2-chloraniline-5-sulphonic acid, 4-chloraniline-3-sulphonic acid, 1 : 5- or 1 : 6-aminonaphthalene-sulphonic acid, or 2-aminonaphthalene-3 : 6-disulphonic acid, and other coupling components, such as 2-toluidine-O -methanesulphonic acid, p-xylidine-1-methyl-3-amino-4-alkoxybenzenes, and 1-naphthylamine, may be used, the dyeings ranging from orange to brown-red.  (2) A product similarly obtained by condensation at 125-130 DEG  C. with the use of twice the quantity of aminoazo dyestuff used in (1) dyes cotton yellow-orange tints very fast to light and alkali; if the condensation is effected at 150 DEG  C. the dyeings are red-orange; the condensation with non-sulphonated aminoazo compounds, such as aminoazobenzene, aminoazotoluene, phenylazo-a -naphthylamine, or 4-chloro-41-amino-51-methoxy-21-methylazobenzene is advantageously effected in presence of alcohol.  (3) A caustic soda solution containing a mixture of the saponified dyestuff from diazotized aniline-3-sulphonic acid and aniline-O -methanesulphonic acid with the dyestuff from diazotized aniline-3-sulphonic acid and cresidine, and with 4 : 41-dinitrostilbene-2 : 21-disulphonic acid, is heated in an autoclave for 8 hours at 120-125 DEG  C.  (4) A caustic soda solution containing a mixture of the dyestuff 4-chloro-2-aminophenol --> (alkaline) 2: 5 : 7-aminonaphtholsulphonic acid with 4 : 41-dinitrodibenzyl-2 : 21-disulphonic acid is heated under pressure for 6 hours at 120-125 DEG  C.; the product dyes cotton red-brown tints which become fast grey on after-coppering; a similar product is obtained by condensing under pressure the copper compound of the dyestuff 4 - chloro - 2 - aminophenol - 6 - sulphonic acid --> (alkaline) 2 : 5 : 7-aminonaphtholsulphonic acid with 4 : 41-dinitrostilbene-2 : 21-disulphonic acid.  (5) A caustic soda solution containing a mixture of the dyestuff 4-aminoacetanilide --> salicylic acid (two different proportions specified) and 4 : 41-dinitrostilbene-2 : 21-disulphonic acid is heated in an autoclave for 4 hours at 115-120 DEG  C.; the products dye cotton orange tints which become red-brown on after-coppering.  An example of the dyeing process is also given.  Specification 19807/07, [Class 2, Acids and salts, Organic &c.], is referred to.