DE1136036B - Process for the production of azo dyes - Google Patents

Description

It has been found that valuable monoazo dyes are obtained if diazotized 2-aminodiphenylsulphone-3'-sulphonic acid esters are used the general formula

Method of manufacture
of azo dyes

-SO ₂

NH ₂

SO ₉ -OR

wherein R is a radical of the benzene, naphthalene or diphenyl series and in each of the aromatic Rings can contain further substituents with 2-amino- or 2-monoalkylaminonaphthalenesulfonic acids coupling in the 1-position united.

The aryl radicals of the diazo components to be used can contain other common azo dyes Contain radicals, for example halogen atoms, alkoxy, acylamino, nitro, alkyl, isoalkyl, alkylsulfonyl and substituted sulfonamide groups; preferred diazo components are those which do not contain sulfonic acid groups wear. The diazo components are obtained by reacting optionally substituted ones 2-Nitrodiphenylsulfon-3'-sulfochlorid with the desired phenols, naphthols or hydroxydiphenyl derivatives in the presence of alkalis and reduction of the 2-nitrodiphenylsulphone-3'-sulphonic acid aryl ester obtained in this way.

The 2-aminonaphthalenesulfonic acids which can be used as azo components can also be further substituted be. You can have ring-bonded substituents, such as halogen atoms or alkoxy groups, or, in particular in the 8-position, have a hydroxyl group. The 2-position amino group can be monosubstituted by an alkyl group. examples for Azo components which can be used according to the invention are: 2-aminonaphthaHn-5-, 6- and 7-sulfonic acid, 2-aminonaphthalene - 6,8 - disulfonic acid, 2 - amino - 8 - hydroxynaphthalene-6-sulfonic acid, 2-methylamino-8-hydroxynaphthalene-6-sulfonic acid.

The coupling of the starting components is carried out according to a method known per se in Congo acidic bis neutral medium.

The monoazo dyes are eminently suitable for dyeing animal fibers such as wool and Silk, as well as wool-like synthetic fibers such as polyamide fibers. Mostly orange-colored ones are obtained to blue-tinged red tones of high levelness. The very good lightfastness should be emphasized and the largely good wash, fulling and sea water fastness properties of the wool dyeings obtained.

Compared to that from German Patent 941 988, Example 3, using the diazo

Applicant:

Paint factories Bayer Aktiengesellschaft,
Leverkusen-Bayerwerk

Dr. AKons Dorlars

and Dr. Ludwig Nüßler, Leverkusen,

have been named as inventors

component on page 3, lines 43 to 45, known monoazo dye is the one obtainable according to the process Azo dye of the formula

SOoH

Superior to wool dyeing in seawater and perspiration fastness.

example 1

38.9 g of 2-aminodiphenylsulfon-3'-suh ° onsäurephenylester are diazotized in the usual way with 6.9 g of sodium nitrite. The diazo solution is allowed at 1O ⁰ C with stirring in an acetic acid solution of the sodium salt of 23.9 g of 2-amino-8-hydroxynaphthalene-6-suKonsäure in 250 ml of water flow, being maintained by the addition of sodium acetate a weakly acidic reaction. After Bendigung the clutch is heated to 50 to 60 ⁰ C, neutralized with sodium carbonate, sucks the precipitated dye and dried. A dark red powder is obtained, the wool from a weakly acidic bath in pure, level,

209 639/358

dyes bluish-tinged red shades that are characterized by very good lightfastness.

If, instead of 38.9 g of 2-aminodiphenylsulfone-3'-sulfonic acid phenyl ester, 40.3 g of 2-aminodiphenylsulfone-3'-sulfonic acid (2 "-methylphenyl) ester is used, this gives a dye with similar properties.

Example 2

42.3 g of 2-aminodiphenylsulfone-3'-sulfonic acid (4 "-chlorophenyl) ester are diazotized with 6.9 g of sodium nitrite and with an acetic acid solution of the sodium salt of 23.9 g of 2-amino-8-hydroxynaphthalene-6 sulfonic acid combined in 300 ml of water at 10 ° C with stirring. Once the coupling has ended is heated to 50 ⁰ C, neutralized with sodium carbonate and filtered off with suction, the deposited dye. It provides, after drying, a black red powder is neutral, the wool from to slightly acidic liquor in blue-tinged red shades of good wet and light fastness properties.

44.5 g of 2-aminodiphenylsulphone-3'-sulphonic acid (4 "-tert.-butylphenyl) ester are used as the diazo component and if you proceed according to the procedure given, you get a similar dye, whose wool dyeings have good wet and light fastness properties.

Example 3

44.5 g of 2 - aminodiphenylsulfone - 3 '- sulfonic acid (4 "-tert.-butylphenyl) ester are diazotized with 6.9 g of sodium nitrite. The diazo compound is added to a solution of 24.5 g of des at 15 ° C. with stirring Sodium salt of 2-aminonaphthalene-6-sulfonic acid in 250 ml of water, which is obtained by adding acetic acid was set weakly acidic. During the coupling, one keeps a by adding sodium acetate weakly acidic reaction. As soon as the diazo compound can no longer be detected, the temperature increases to 50 ° C warmed and neutralized with soda solution. The precipitated dye, an orange-brown powder after drying, dyes wool from a weakly acidic bath in orange tones of high levelness and lightfastness.

A similar dye is obtained by using the 2-aminonaphthalene-6-sulfonic acid used replaces the same amount of 2-aminonaphthalene-7-sulfonic acid.

Example 4

43.9 g of 2-aminodiphenylsulfone-3'-sulfonic acid (| S-naphthyl) ester are diazotized with 6.9 g of sodium nitrite and gives the diazo compound obtained at 10 ° C with stirring in an acetic acid solution of the sodium salt of 23.9 g of 2-amino-8-hydroxynaphthalene-6-sulfonic acid. A weakly acidic reaction is achieved by adding sodium acetate solution. To When the coupling is completed, the mixture is neutralized with sodium carbonate, heated to 50 ° C. and the suction filtered obtained dye from. It represents a black-red powder, the wool from weakly acidic The dye bath dyes in clear, bluish-tinged red shades of good lightfastness.

If 40.3 g of 2 - amino - 4 '- methyldiphenylsulfone - 3' - sulfonic acid phenyl ester are used as the diazo component, a similar lightfast dye is obtained by the above procedure.

Example 5

The from 43.7 g of 2-amino-4'-chlorodiphenylsulfone-3'-sulfonic acid (4 "-methylphenyl) ester and 6.9 g of sodium nitrite produced diazo compound are combined at 10 ° C with stirring with an acetic acid solution of the sodium salt of 25.3 g of 2-methylamino-8-hydroxynaphthalene-6-sulfonic acid in 300 ml of water. The resulting dye is salted out, filtered off and dried. It represents a dark powder, wool dyes in blue-tinged red tones, which are characterized by good fastness properties.

Example 6

42.3 g of 2-aminodiphenyl sulfonic acid (4 "-chlorophenyl) ester are diazotized with 6.9 g of sodium nitrite. The diazo solution is left under at 10.degree Stir in a solution of 34.8 g of the sodium salt of 2-aminonaphthalene-6,8-disulfonic acid in 300 ml Pour in water. It is blunted with sodium acetate until the reaction is weakly acidic. After completion After the coupling, the resulting dye is salted out by adding potassium chloride. After this When drying, the product is an orange-brown powder, the wool from an acid bath in orange, lightfast Tones colors.

Claims (1)

PATENT CLAIM: Process for the preparation of azo dyes, characterized in that the diazo compound of an amine of the general formula NH ₂ SO ₂ -OR in which R denotes a radical from the benzene, naphthalene or diphenyl series and in which the aryl radicals and R may contain further substituents, optionally with a coupling in the 1-position further substituted 2-amino- or 2-monoalkylammonaphthalenesulfonic acid united. Documents considered: German Patent No. 941 988. When the application was announced, a coloring table with an explanation was displayed. © 209 639/358 8.62