DD151003A3 - METHOD FOR PRODUCING UNIFORM 1: 2 CHROMIUM COMPLEXAZOFINS - Google Patents

Abstract

The invention relates to a process for the preparation of uniform 1: 2 chromium gem complex azo dyes based on a dye of the composition 1-amino-2-hydroxy-6-nitronaphthalenesulfonic acid (-4) -> 2-hydroxynaphthalene and at least one of the dyes 1-amino-2 -hydroxy-4-nitrobenzene -> 2-hydroxynaphthalene or 1-amino-2-hydroxy-5-nitrobenzene -> 2-hydroxynaphthalene. They are obtained by acting on the present in waeszigem medium mixture of metal-free monoazo a Monosalicylatochromverbindung at pH 1 to 2 and temperatures between 90 and 100 degrees C, then adjusts a pH between 7 and 9, abruptly to 70 to 80 Cools degree C and isolated the formed uniform 1: 2-chromium mixture complex azo dye in a conventional manner.

Description

2 11387

1978 Y / P C 09 Β / 211 387

A process for the preparation of uniform 1 ^ -chrommischkomplexazofarbstoffe

Field of application of the invention

The invention relates to the preparation of uniform 1 ^ -Chrommischkomplexazofarbstoffe the general Fonnel

(I) -Cr- (II),

where I is the residue of the dye 1-amino-2-hydroxy-β-nitronaphthalenesulfonic acid (-4) - = s * 2-hydroxynaphthalene and II is the radical of a dye i-amino-2-hydroxy-

4-nitrobenzene -5 »-2-hydroxynaphthalene or one

Dye 1 ~ amino-2-hydroxy-5-nitrobenzene ^ -2-

Hydroxynaphthalene or a mixture of the two means.

  - 2 - · 2 1 138 7 1978

, WP C 09 B / 211 387

Characteristic of the known technical solutions

Dyes of the abovementioned formula or processes for their preparation are known from DB-PS 1,291,037 and DD-PS 104,003. A disadvantage of this production process is that it causes difficulties or requires special, only with increased technical effort durchfuhrbarer methods to obtain the unsymmetrical, containing a sulfonic acid dye complex in a uniform, insoluble fractions largely avoiding composition.

Aim of the invention .

The aim of the invention is a process for the preparation of unsymmetrical 1 ^ -Chromkomplexazofarbstoffe from a mixture of metal-free dyes of the above type in an aqueous medium, which leads to uniform complex dyes optimal and consistent solubility.

Explanation of the essence of the invention

It has been found that from a present in the molar ratio of about 1: 1 mixture of the dye 1-amino - ^ - hydroxy-δ-nitronaphthalenesulfonic acid

(«4) S-2-hydroxynaphthalene and at least one of

Dyes 1-amino-2-hydroxy-4-nitrobenzene a * 2-

Hydroxynaphthalene, or 1-amino-2-hydroxy-5-nitrobenzene

, 3 »-2-hydroxynaphthalene uniform 1: 2 chromium

Mixed complex dyes can be obtained in a simple manner, if on the dye mixture in an aqueous medium, a chromating agent in the acidic range (pH 1 to 2) at temperatures between 70 and 100 ⁰ C.

- 3 - 211387 ₁₉₇₈

WP C 09 B / 211

then, while maintaining this temperature range by adding an acid-binding agent to a pH value between 7 and 9 sets, the whole thing abruptly, z. B. by the addition of ice, cooled to about 80 C and the resulting 1: 2 chromium complex amine isolated in a conventional manner.

As a chromium medium which is stable in an acid medium, a monosalicylate-chromium compound is used, as is known, for example, from DD-PS 104 003.

The "process has the advantage that it is possible to obtain uniform 1: 2 mixed complex dyes of good solubility and good filterability in one operation without intermediate isolation of the 1: 1 chromium complex of the sulfonic acid group-containing dye initially formed in the acidic medium , To use the two sulfonic acid group-free dyes and by varying the proportions of these dyes, the nuances of 1 ^ -Chrommischkomplexazofarbstoffe can be influenced in the desired manner.

Ausführun ^ EWhen games Example 1

A suspension of 21.95 parts by mole of the dye 1-amino-2-hydroxy-6-nitronaphthalene obtained in a known manner.

- 4

  · - 4 - 2113 8 7 1978

WP C 09 B / 211 387

sulfonic acid (-4)> 2-hydroxynaphthalene and 15.45 Ma.-

Parts of the dye i-amino ^ -hydroxy ^ -nitrobenzene -

2-hydroxynaphthalene in 500 parts by volume of water is made by addition of 20 parts by volume of hydrochloric acid 20 ^ο Βέ clear congo (pH 1 to 2) and heated to 80 ⁰ C. This suspension is allowed to flow into a heated to 85 ⁰ C solution of 16.5 Ma. Parts of a basic chromium sulfate with a Οίν, Ο - content of 25 % and 6.9 parts Ma salicylic acid. It is heated to 95 ⁰ C and stirred for 2 hours at this temperature. Thereafter, by adding about 30 parts by volume of sodium hydroxide solution 35 ^Ο Βέ within 20 minutes to pH 7.5. The chromation to the 1: 2 Misehkomplex is terminated immediately. By addition of ice is cooled to 80 ⁰ C, adjusted to pH 7 with hydrochloric acid, salted out, filtered and dried. The dyestuff obtained dyes wool and synthetic polyamide fibers from neutral or weakly acidic bath greenish-gray with very good fastness to light and moisture.

Example 2

If, instead of the dye mixture used in Example 1, a mixture of 21.95 parts by weight of the dye 1-amino-2-hydroxy-6-nitronaphthalenesulfonic acid (-4)?

2-hydroxynaphthalene, 8.65 parts by weight of the dye

1-amino-2-hydroxy-5-nitrobenzene> 2-hydroxynaphthalene

and 6.8 parts by weight of the dye 1-amino-2-hydroxy-4-nitro-

benzene - ^ 2-hydroxynaphthalene used, otherwise

but worked according to Example 1, one obtains a wool and synthetic polyamide fibers reddish black dye.

Claims (1)

- 5 - 2 11387 1978 WP C 09 B / 211 invention claim A process for the preparation of uniform 1: 2-chromium mixed azo dyes, by the action of a chromium-III salt in the presence of at most one mole of salicylic acid, "based on one mole of chromium salt, of a mixture of the 1: 1 in an aqueous medium in a molecular ratio of about 1: 1 Dye 1-amino-2-hydroxy-6-nitronaphtha- linsulfonic acid (-4) i> 2 ~ hydroxynaphthalene and the Dye 1 ~ amino-2-hydroxy-4-nitrobenzene ^ .2-hydroxy naphthalene and / or the dye 1-amino-2-hydroxy-5- nitrobenzene> -2 ~ hydroxynaphthalene at temperatures between 70 and 100 ⁰ C, characterized in that the required amount of the chromium-III salt at a pH of 1 to 2 and at temperatures between 90 and 100 C up to 2 hours to act on the dye mixture, then in same temperature range, the pH by addition of an acid-binding agent to a value between 7 and 9, abruptly cooled to 70 to 80 ⁰ C.'und the isolated 1: 2 ~ chrominischkomplexazofarbstoff isolated in a conventional manner.