DE588607C - Process for the production of azo dyes - Google Patents

Description

GERMAN EMPIRE

REICH PATENT OFFICE

PATENT WRITING

CLASS 22 a GROUP

It was found to be valuable acetate silk dyes are obtained when using dialkylaminoazobenzene methosulfonic acids or their alkyl and halogen substitution products are nitrated with as much nitric acid as is required for the introduction of a nitro group into the dye molecule.

The new dyes are in their constitution and in their coloring properties different from those dyes obtained from a diazotized nitroaniline sulfonic acid and an aniline derivative alkylated in the amino group or from a diazotized one Nitraniline and an N-alkylated sulfonated aniline derivative based on the French Patent 584215 known method can be obtained.

According to the method known from patent specification 445 827, the Diazoverbin-

ao formation from p-chloroanilinesulfonic acid with diphenylamine coupled and then nitrated the dye obtained. In the dye B tables von Schultz, VII. edition, under No. 180 and 182, also in the Bulletin de la Societe Chimique de Paris, 1905, page 973 to 993, dyes are described that by nitrating the azo dye from diazotized Sulphanilic acid and diphenylamine or the nitroso compound of this azo dye getting produced. These dyes are not very suitable for dyeing acetate silk.

Those obtainable by the claimed process using a dialkylaniline The dyes produced are excellent for dyeing acetate silk.

The procedure is illustrated by the following examples:

example 1

33.3 g of the azo dye from diazotized i-aminobenzene-3-sulfonic acid and diethylaminobenzene (= V10 mol.) Are dissolved in 330 g of concentrated sulfuric acid at about 10 ° C. with stirring. Now allowed under cooling 70 g of mixed acid of 11 ° / ₀ (= y, y g HNO ₃₎ were added dropwise slowly and the temperature to rise to 17 ⁰ C. When all the mixed acid has been added dropwise, the mixture is stirred for some time at this temperature. The whole thing is then poured onto ice with thorough stirring, the precipitate is filtered off with suction, pressed, mixed with hot water and so much soda is added until no more carbon dioxide evolution occurs (small excess). Then it is allowed to cool, salted out, filtered off with suction, pressed and dried.

The dye thus obtained gives a red-orange of good fastness properties on acetate silk.

Example 2

34.7. g of the azo dyes from diazotized i-aminobenzene-3-sulfonic acid and i-diethylamino-3-methylbenzene (= Vio Mol.) Are concentrated with ten times the amount Sulfuric acid dissolved at about 10 ° C. 70 g of mixed acid are left with cooling

ii ° / o langeam add dropwise. The temperature should not rise ^{above 17 to 18 0 C.} After all the mixed acid has been added, the mixture is stirred for some time at this temperature and then the reaction product is poured onto a lot of ice. The precipitated dye is filtered off with suction and worked up as in Example 1 and dried.

The dye provides a real yellowish red on cellulose ester fabric.

Example 3

38.1 g of the azo dyes from diazotized

i-aminobenzene-3-sulfonic acid and i-diethylamino-3-chlorobenzene (= Vio Mol.) As indicated in Examples 1 and 2, the Subjected to nitration and worked up.

A dye is obtained which dyes acetate silk in true red-orange tones.

Example 4

37.7 g of dee azo dyes from diazotized i-aminobenzene-3-sulfonic acid and i-diethylamino-3-ethoxybenzene (= ^χ / ιο mol.) Are dissolved in sulfuric acid as above. 70 g of mixed acid at ii ° / _{0 are} added dropwise to the solution with cooling. The further treatment takes place as described in the above examples.

The hue of the dye thus obtained on acetate silk is orange.

Example

34.7 g of the azo dyes from diazotized i-aminobenzene-3-sulfonic acid and N-methylbutylaminobenzene are nitrated and worked up analogously to the above examples with n% mixed acid.

The new dye, dyed on cellulose ester fiber, delivers lively, real orange tones.

Example 6

33 »3 g of the azo dyes from diazotized

i-aminobenzene-2-sulfonic acid and diethylaminobenzene (= ¹ J ₁₀ mol.) are dissolved in iof the amount of concentrated sulfuric acid. 70 g of mixed acid at 11 ° / _{0 are} added dropwise to the solution with cooling and thorough stirring. The temperature here eoll 17 ⁰ C does not exceed. After stirring for some time, the reaction product is poured onto a lot of ice and, as mentioned above, worked up.

The dye stains Celluloeeeeterfaeer in ruby red tones.

Example 7

31.9 g of dee azo dyes aue diazotized i-aminobenzene-2-sulfonic acid and 1-dimethylamino-3-diethylbenzene are, as indicated in Example 6, nitrided and worked up.

The dye thus obtained dyes cellulose ester fibers in copper-red shades.

Example 8

37.4 g (= i / ₁₀ mol.) Of azo dyes obtained from diazotised 2, 5-dichloro-i-aminobenzene and ι -Dimethylaminobenzol-3-sulphonic acid are dissolved at about 10 ⁰ C in the iofachen amount of concentrated sulfuric acid. Now, are slowly added dropwise with good stirring 70 g of mixed acid ii ° / _Q and makes sure that the temperature does not exceed 17 ⁰ C. The mixture is stirred for some time at about 15 ⁰ C, which Reaktionsgemiech on ice afterwards gegoesen, filtered off with suction, taken up in hot water and treated with sodium carbonate, the carbon dioxide has ceased to develop. After cooling, the dye is salted out, filtered off with suction, pressed and dried.

The dye dyes the cellulose ester fiber in blue-red tones.

Claims (1)

Claim: A process for the preparation of azo dyestuffs, characterized in that Dialkylaminoazobenzolmonosulfonsäuren or their substitution products nitrated with nitric acid so much as to _go for the introduction of a nitro group is required in the dye molecule.