Patent GB-267162-A (GB)
Title: Manufacture of dyestuffs
IPC: C09B33/18
Filed: 1927-03-08
Abstract: 267,162. Soc. of Chemical Industry in Basle. March 8, 1926, [Convention date]. Trisazo dyes are made by coupling a diazo compound with a diazotizable second component free from hydroxyl groups, and further diazotizing the product and coupling either with resorcinol and causing the diazo compound of a dehydrothiotoluidine sulphonic acid to act on the disazo dyestuff thus obtained, or with a monazo dyestuff from resorcinol and the diazo compound of a dehydrothiotoluidine sulphonic acid. As first diazo components, aniline, sulphanilic acid, paminoacetanilide, Cleve's acid, 2-naphthylamine. 4 : 8-disulphonic acid, p-nitraniline-o-sulphonic acid, naphthylamine, dehydrothiotoluidine and their homologues and substitution products are specified; as second components free from hydroxyl groups, Cleve's acid, cresidine , anaphthylamine and their homologues and substitution'products are specified. If the final product contains nitro-groups or acidylamino-groups it is reduced or saponified. The products dye vegetable fibres bordeaux or violet to brown tints. In an example the monoazo dyestuff from sulphanilic acid and Cleve's acid is diazotized, coupled with m-aminophenol, and the product is coupled with diazotized dehydrothiotoluidine sulphonic acid; the resulting dyestuff dyes cotton blackbrown. The dyeing properties of the dyestuffs obtained by the use of various combinations of the above first and second components are tabulated. The saponified product from p-aminoacetanilide, Cleve's acid, resorcinol and dehydrothiotoluidine sulphonic acid gives violet-brown shades on cotton when diazotized and developed with #-naphthol. The Specification as open to inspection under Sect. 91 (3) (a) comprises also the use of any meta-compound of the benzene series in place of resorcinol and the use of any diazo compound in place of that of a dehydrothiotoluidine sulphonic acid, and specifies the following further examples :-(1) the monoazo dyestuff from sulphanilic acid and Cleve's acid is diazotized, coupled with resorcinol, and the disazo dyestuff thus produced is coupled with diazotized aniline: the same product may be obtained by diazotizing the monoazo dyestuff from sulphanilic acid and Cleve's acid and coupling with the monoazo dyestuff from aniline and resorcinol: it dyes cotton in red-brown, very even tints. (2) the monoazo dyestuff from sulphanilic acid and Cleve's acid is diazotized, coupled with m-aminophenol, and the product is coupled with diazotized dehydrothiotoluidine sulphonic acid; the resulting dyestuff dyes cotton black-brown, and (3) diazotized Cleve's acid is coupled with Cleve's acid, rediazotized, coupled with m-phenylenediamine, and finally coupled with diazotized dehydrothiotoluidine sulphonic acid; the product dyes cotton very equal deep brown tints. The dyeing properties of the dyestuffs obtained from the following components are also tabulated :-sulphanilic acid, Cleve's acid, resorcinol, and p-aminoacetanilide or dehydrothiotoluidine sulphonic acid; metanilic acid or p-nitraniline-o-sulphonic acid, Cleve's acid, m-phenylenediamine or m-toluylenediamine, and dehydrothiotoluidine sulphonic acid; sulphanilic acid, Cleve's acid, m-aminophenol, and sulphanilic acid. This subject-matter does not appear in the Specification as accepted.