GB189812679A - Manufacture of Naphthacetoldisulphonic Acids and of New Colouring Matters Derived therefrom. - Google Patents

Abstract

12,679. Imray, O., [Society of Chemical Industry in Basle]. June 6. Acetylamidonaphthol disulphonic acids, or 'naphthacetol disulphonic acids,' are produced by gently boiling 1 : 8 : 3 : 6-, 1 :8 : 4 : 6-, 1 : 8 : 2 : 4-, and 1 : 5 : 3 : 7-amidonaphthol disulphonic acids with acetic anhydride and glacial acetic acid, or other acetylizing agents, upon an oil bath until a sample gives no colour with nitrous acid. Any diacetyl amido derivative is converted into the monacetyl derivative by distilling off the acetic acid and heating the mixture with dilute sodiumcarbonate solution, or with a dilute acid, or water. The free naphthacetol disulphonic acids are very soluble and are only precipitated by acids from concentrated solutions of their salts. With diazo compounds they yield the same prodncts in acid and alkaline solutions, and they are not attacked by nitrous acid. Dyes, artificial.-Monazo dyes which yield on wool blue-red to violet tints are produced by combining the foregoing naphthacetol disulphonic acids with diazobenzene, or its sulphonic acid, or similar diazo compounds. Non-diazotizable intermediate products are formed by combining the tetrazo compound of benzidine, tolidine, or dianisidine, with one molecular proportion of one of the foregoing naphthacetol disulphonic acids in alkaline or acetic-acid solution, and disazo dyes are produced by combining these intermediate products with a molecular proportion of alpha- or #-naphthol, 2 : 6- or 2 : 7-dioxynaphthalene, 1:4-, 1:5-, or 2 : 6- naphthol sulphonic acid, naphthol carboxylic acid, 1 : 8 : 3 : 6-, 1 : 8 : 4 : 6-, 1 : 8 : 2 : 4-, or 1 : 5 : 3 : 7- amidonaphthol disulphonic acid, 2 : 8 : 6 amidonaphthol sulphonic acid, alpha-naphthylamine, pxylidine, or p-cresidine. The disazo dyes yield on unmordanted cotton violet to blue tints of a brilliant and pure shade. The naphthacetol disulphonic acids may also be combined with the known intermediate products for producing disazo dyes, but the process described above is preferred. The disazo dyes which contain a diazotizable amido group may be diazotized upon the fibre, and then be developed with #-naphthol or m-phenylenediamine, whereby violet to blue, and not black, shades are obtained.