DE84893C - - Google Patents

Description

IMPERIAL

PATENT OFFICE.

Since then, the azo dyes of the benzidine series have only been represented technically in this way that tetrazodiphenyl, tetrazodiphenol ether and so on are based on phenols, amines or Amidophenols respectively. their sulfo and carboxylic acids act.

The present invention consists in developing a new and thorough one peculiar process for the representation of the azo dyes mentioned by oxidation each two molecules of the corresponding simple azo dyes, which differ from aniline and the like. derive. The reaction proceeds according to the following equation:

HX-N = N-Y

+ HX-N = N-Y

+ 0 = ι X-JV = JV- Y

and is a very common by X both the rest of the aniline itself as well as those of the o-toluidine, ö-anisidine, etc. (that is of bases having a free para position) and Y both α- such as .beta.-naphthol and Naphtylaminsulfosäuren, salicylic acid and the like can mean.

So far, manganese dioxide has been found to be particularly suitable as an oxidizing agent, which is stirred into the solution of the dye in question in concentrated sulfuric acid will.

Depending on the nature of the dye used, the reaction already takes place in the cold, or it must be supported by the supply of heat (e.g. heating on a water bath). The progression of this can be recognized by the change in color of the concentrated sulfuric acid solution, in that the color of the corresponding disazo dye (e.g. blue) gradually appears in place of the color resulting from the monoazo dye (e.g. yellow-red). The operation is ended as soon as successive samples no further approximation of this color to that of the corresponding XN = NY

Solution of the disazo dye shown elsewhere give more. One too long or too Vigorous action of the oxidizing agent is to be avoided, otherwise the formed one is easy Disazo dye is further changed.

In addition to the above-mentioned oxidizing agent, there are also others, e.g. B. ammonium supersulfate or lead peroxide analog.

The reaction mixtures obtained in the manner described above are worked up z. B. in the way that you pour them on ice, the crude benzidine dye usually deposited and the same from starting material that has remained roughly unchanged due to the different solubility or saltability (possibly the relevant salts) separates.

Examples:

i. Representation of a red noun dye made from aniline azo naphthoic acid.
3.59 parts of aniline-azo-naphthoic acid are finely divided into 30 parts of sulfuric acid at 66 ° C., and, after complete

Solution has occurred, with 2.0 parts of brownstone of 50 pCt. Salary staggered. By good Care is taken to ensure that the temperature does not exceed 20 to 25 °. To About 2 hours the solution color is initially red in a blue-violet respectively. Faded blue ; then it is poured onto ice and worked up.

The one obtained in this way is correct in its properties The dye corresponds to the congo presented in the usual way.

2. Blue substantive dye from o-anisidinazo - β - naphthol disulfonic acid R.

4.8 parts of o-anisidine-azo, S-naphtholedisulfonic acid R are dissolved in 45.0 parts of sulfuric acid of 66 ° C., with 2 parts finely divided Brownstone of 50 pct. Content added and about 2 hours with stirring to 50 to 60 ° warmed up. After the solution has turned pure blue, it is poured onto ice and worked up.

The representation of the other dyes of the benzidine series is analogous, the temperature to be maintained, the duration of the operation, and the amount of oxidizing agent at hand test of the progress of the reaction described above. One receives further z. B .:

from AniUn-azo-ctj-naphtol-ctg-sulfonic acid one Dye from the properties of azoorseillin,

from o-toluidine-azo-a _L -naphtol-a ,, - sulfonic acid a dye with the properties of azo blue,

from o-anisidine-azOva j-naphtol-a ₂ -sulfonic acid

a dye from the properties of benzazurine,

from aniline-azo-ßj-naphtol-ßj ß ₃ -disulfonic acid a dye with the properties of the dye benzidine 4- (2 mol.) ßj-naphtholßo ßg-disulfonic acid,

from o-toluidine-azo-naphthionic acid a dye with the properties of benzopurpurin,

from aniline-azo-salicylic acid a dye with the properties of chrysamine,
■ from o-toluidine-azo-βj-naphthylamine-βj-sulfonic acid a dye with the properties of the dye tolidine -f- (2 mol.) _{Ss r} naphthylamine - β ₃ - sulfonic acid, etc.

Claims (3)

P ate nt claims: ι. Process for the preparation of azo dyes of the benzidine series, consisting of that every 2 moles of the simple amines of the benzene series with a free para position derived azo dyes chained by oxidation. 2. The execution of the method protected by claim 1 using Brownstone with concentrated sulfuric acid. 3. In the process protected by claims 1 and 2, the use of those azo dyes which are derived on the one hand from aniline, o-toluidine and o-anisidine, and on the other hand from Ci ₁ -naphthol-α, - or a ₃ -monosulfonic acid, -ß ₂ a ₄ - or a. ₂ a _i - disulfonic acid, ßj-naphthol-ßg-sulfonic acid, -ß ₂ ß _ä -disulfonic acid, α ₁ - naphthylamine - α ₂ - sulfonic acid, ßj-naphthylamine-ßg-sulfonic acid, Ot ₁ a ₄ -dioxynaphthalene-ß ₂ ß ₃ -disulfonic acid and salicylic acid. derive.