GB190120551A - Improvements in the Manufacture of Azo Colouring Matters and Intermediate Products relating thereto - Google Patents

Abstract

20,551. Johnson, J. Y., [Badische Anilin & Soda Fabrik]. Oct. 14. 1 : 2 : 4-Trichlor-3-nitrobenzene-5-sulphonic acid is produced by sulphonating 1 : 2 : 4-trichlorbenzene, for example, by treatment with fuming sulphuric acid containing 23 per cent. of SO3, at a temperature not exceeding 50‹ C., and then nitrating the product by adding nitration acid. The mixture is poured upon ice, and the sodium salt of the new product is precipitated by common salt. 1 : 2 : 4-Trichlor-3-amidobenzene-5-sulphonic acid results when the foregoing nitro-compound is reduced by means of iron and acetic acid. It is obtained in crystalline form, by precipitating iron and acidifying the filtrate with hydrochloric acid. Dyes, artificial.-Compounds which are believed to be diazophenol derivatives are produced by acting upon the diazo compounds of the foregoing trichloraniline sulphonic acid, and upon o-nitraniline-p-sulphonic acid and 2 : 4-dinitraniline, with a compound which will bind hydrochloric acid, such as sodium acetate, sodium or potassium carbonate or bicarbonate, sodium oxalate, magnesia and the like, in suitable proportions. The process may be varied by diazotizing the parent substance with sodium nitrite and an organic acid, such as oxalic or acetic acid, whereupon diazotization and transformation into the diazophenol derivative are simultaneously effected. Another modification consists in converting the diazo derivatives of the amido compounds into the corresponding nitrosamine derivatives, as described in Specifications No. 20,605, A.D. 1893, and No. 3397, A.D. 1894, and then acidifying these products with an organic acid. The diazophenol derivatives above mentioned combine with the usual orange, red, brown, and violet ato dye-stuff components to form dyes which, when treated on the fibre with chromates, copper salts, or the like, change their shades and become faster against washing, light, and other influences. Such dyes are produced by the combination of the diazophenol derivatives with #-naphthol, resorcin, m-hydroxydiphenylamine, 1 : 8-amidonaphthol-4- sulphonic acid, 1 : 5- and 2 : 5-amidonaphthol-7- sulphonic acid, 2 : 8-amidonaphthol-6-sulphonic acid, 2-naphthol-3 : 6-disulphonic acid (R), mphenylenediamine, m-toluylenediamine, 1-naphthol- 4 - sulphonic acid, naphthionic acid, alpha - and #-naphtholcarboxylic acid, 2 : 7-dihydroxynaphthalene, and phenyl - methylpyrazolone, and particulars with regard to their properties are given in the Specification.