DE903618C - Process for the production of vivid pink to red coloring and printing dyes - Google Patents

Description

Process for the production of vivid pink to red coloring and printing Dyes In patent specification 525 668 is a process for the production of pink to red-staining vat dyes described, which consists in that one 2-anile the 6-halodiketodihydrothionaphthenes with 3-oxy-4-alkylthionaphthenes and their Nuclear substitution products, especially those which are in the 6-position by halogen are substituted, or vice versa 6-halo-3-oxythionaphthene with 2-anilene of q.-Alkyl-2, 3-diketodihydrothionaphthenes and their substitution products, in particular those substituted in the 6-position; condensed.

The q.-methyl-6, 6'-dihalogenthioindigos obtained in this way, among other things provide pink to red colorations and prints on the vegetable fibers that are reflected distinguished by good fastness properties, in particular good light fastness.

It has now been found that the dyes mentioned are per se known methods into the corresponding leucosulfuric acid esters or their salts get convicted. These provide dyes and prints on the vegetable fibers, the surprisingly liveliness that comes with the underlying vat dyes obtained quite significantly outperform. Because these dyeings and prints are also very good have good light fastness and very good wet fastness properties means finding these new dyes represent a major technological asset. Dyes that such great Liveliness combined with very good lightfastness and have very good wet fastness properties are up to now not in any of the different series Dye groups become known.

Example In 1,000 parts of pyridine: slowly eat zoo while cooling Parts of chlorosulphonic acid run in and then give a mixture of ioo at about 25 ' Share finely ground q.-methyl-6, 6 '- dichloro bi.sthionaphthenindigo and 100 parts Copper powder too. When the esterification is complete, about 600 parts become water given, the deposited copper-pyridine complex salt of the leuco-sulfuric acid ester Sucked off, washed with water and stirred into the ester sodium salt by stirring with sodium hydroxide solution convicted. The pyridine is now removed by distillation under reduced pressure Pressure, sucks the residual liquid from copper residues and falls out of the filtrate the leuco-sulfuric acid ester in the form of its sodium salt by adding common salt the end. This can be brought into dough or powder form in the usual way. It solves easily dissolves in: water and results in one of the usual printing methods on cotton or other fabrics, strong, very clear kosan tones with very good fastness properties. They are relative to the prints available with the underlying vat dye significantly superior to the clarity of the hue.

A very similar result can be achieved if one uses the above example Instead of copper powder, iron powder is used and the rest of the procedure is as stated there.

You can also start from the dried leuco vat dye and this in dimethylaniline with chlorosulfonic acid according to a known process in the leucosulfuric acid ester convict.

Claims (1)

PATENT CLAIM: Process for the production of vivid pink to red coloring and printing dyes, characterized in that 4.-methyl-6, 6'-dihalogenthioindigo into the corresponding leuco-sulfuric acid ester by methods known per se or their salts transferred ..