DE487972C - Process for the production of azo dyes - Google Patents

Description

Process for the preparation of azo dyes It has been found that valuable azo dyes are formed when the diazo compounds of aminobenzoesäureh or their derivatives, such as halogen-, nitro-, alkyl-substituted aminobenzoic acids, those with more than two carbon atoms in the molecule are esterified is combined with couplable azo components and thereby the components is selected such that at least one sulfo group is present in the dye. the Dyes obtainable in this way produce dyeings on wool that are largely through excellent fastness properties, especially due to very good light and wash fastness, are excellent; partly they are also used for the production of lacquer dyes very suitable.

Compared to the corresponding azo dyes from diazotized aminobenzoic acids, which are esterified with methyl or ethyl alcohol, they have the advantage of the better ones Walk, perspiration and wash fastness.

Example z = 9.3 parts of n-butyl anthranilic acid are diazotized in concentrated hydrochloric acid with the addition of ice in the usual way and leaves the liquid in a soda-alkaline solution of 36 parts of 2-naphthol-3-6-disulfonic acid sodium flow. The dyestuff sucked off after the coupling is complete delivers on wool bright orange with excellent fastness properties. Instead of the butyl o-aminobenzoate the corresponding p-aminibenzoic acid ester can also be used.

Example 2 The solution of the diazo compound in 29.1 parts of anthranilic acid n-butyl ester sulfate is left in an aqueous solution of 25.4 parts of i- (4'-sulfophenyl) -3-methyl-5-pyrazolone and pour in 150 parts of anhydrous soda. The one after about 2 to 3 hours Stirring extracted dye stains wool in beautiful yellow and real tones, their Lightfastness is particularly noteworthy. It can also be used as a paint dye. If the z- (5'-sulfo-2'-chlorophenyl) -3-methyl-5-pyrazolone is used instead of the pyrazolone mentioned, in this way a dye is obtained which gives a more greenish yellow.

Example 3 From the solution of the diazo compound of 29.1 parts of anthranilic acid n-butyl ester sulfate and the soda-alkaline solution of 31.5 parts z-phenylamino-8-naphthol-6-sulfonic acid, obtained under the conditions given in Example 2, a dye which Wool is reddish brown and is dyed in a real way.

Example [Into the solution of the diazo compound of 13.8 parts of p-nitroaniline 36.3 parts of x, 8-aminonaphthol - 3-6. - sodium disulfonic acid are weak acidified thin paste entered. When the coupling is complete, the liquid becomes made alkaline with soda and with the diazo solution of = 9.3 parts by weight of anthranilic acid n-butyl ester offset. The dye formed is salted out at about 5o ', suctioned off when. if necessary redissolved and dried. It delivers a real black on wool.

Claims (1)

Claim: A process for the preparation of azo dyes, consisting in that the diazo compounds of aminobenzoic acids or their derivatives, which are esterified with alcohols containing more than two carbon atoms in the molecule, are combined with azo components capable of coupling and the components are selected in such a way that at least one sulfo group in the Dye is included.