GB189922886A - Improvements in the Manufacture of Colouring Matters. - Google Patents

Abstract

22,886. Lake, H. H., [Chemical Works formerly Sandoz]. Nov. 16. Dyes, artificial; alphylsulphamidonaphthol sulphonic acids.-Relates to new azo dyes which dye wool and silk in an acid bath bright bluish-red to violet . shades, and consist in combining 1 : 8 - alphylsulphamidonaphthol disulphonic acids with the diazo derivatives of an aromatic compound, such as aniline, o- or p-toluidine, m- or p-xylidine, mono- or di-chloraniline or their homologues, pamidoacetanilide, m - or p - nitraniline, or their homologues, o-anisidine, p-phenetidine, m-amido-pcresol ether, aniline sulphonic acids or their homologues, amidobenzoic acids, amidoazobenzene, amidoazotoluene or their sulphonic acids, alpha- or ,3- naphthylamine or mono- or di-sulphonic acids thereof. The bluest products are those derived from p-phenylenediamine and its homologues and obtained from diazotized p-amidoacetanilide or p-nitraniline. The diazo compounds combine only in alkaline solution, except in the case of diazotized nitro- or dichloro-benzenes which combine in acid or alkaline solution. The alphylsulphamidonaphthol disulphonic acids employed are produced by heating 1 : 8-amidonaphthol-3 : 6-, -2 : 4-, or -4: 6-disulphonic acid with an alphylsulphochloride, such as benzene-, o- or p-toluene-, or xylene - sulphochloride, in presence of powdered chalk at about 80‹ C. until a sample ceases to yield a diazo compound. The dialkylsulphamidonaphthol disulphonic acid thus produced is boiled with caustic soda in order to split off the alphylsulpho radicle combined with the hydroxylic oxygen. The alkaline mixture is then neutralized, the lime is precipitated by soda, and the solution is filtered off and used for the production of the azo dyes as above described. The amido group is neutralized by the presence of the alphyl-sulpho radicle, and the products have consequently the properties of naphtholsulphonic acids.