CH228847A - Process for the preparation of a tetrakisazo dye. - Google Patents

Description

  

      Additional patent to main patent No. 226016. Process for the production of a tetrakisazo dye. It has been found that a new tetrakisazo dye can be obtained by: the diamino compound that is available;

      by saponifying the disazo dye, which itself is available by combining 3-diazo, ph enyloxamic acid with 1-amino-3-methylbenzene, further diazation:

  of the monoazo dye obtained in this way and combining in alk @ ali- shem Meldium with 2-amino-5-oxynapli th @ alin-7-sulfonic acid, tetrazotized and combined with 2 times 1,3-dioxybenzene.



  The new dye forms a dark, bronzing powder that turns red-violet in water, in; concentrated sulfuric acid with a green color. The dye dyes cotton in red-violet tones, which can be redeveloped by treatment with formaldehyde or with 4-nitro, diazobienzo1.

    The brown tones obtained with 4-nitro-diazabenzene are washable and, both neutral and alkaline, excellently etchable. Example: 18.0 parts of 3-aminophenyloxamic acid become; diazofed in a known manner;

      the diazo solution is rendered kongon # neutral by adding 20% sodium acetate solution;

            Then a solution of 10.7 parts of 1-amino-3-methylbenzene, dissolved in 50 parts of water with the aid of 13 parts of 30% strength hydrochloric acid, is added. After 24 hours, the insoluble monoazo dye is filtered off,

            .then thoroughly boiled with 600 parts of water and converted into .d "sodium salt by adding sodium hydroxide solution. Then a solution of 6.9 parts of sodium nitrite and 28 parts of 30% hydrochloric acid are added.

   The diazotization mixture is boiled well at 8 to 10 for 2 to 21 / hours and then added to a solution, the -by dissolving 23,

  9 parts of 2-amino-5-oxynaphthalin-7-suMonsäuTe with the addition of 30 parts of sodium carbonate was prepared. After several hours of stirring, the disazo dye winds out, salted and filtered off. The filtered dye is mixed with 1000 parts of water like that, heated to boiling and then with 14,

  0 parts of 30% sodium hydroxide solution are added and kept at the boil for 1 to 11/2 hours with stirring.

   It is then neutralized with hydrochloric acid, cooled to 15%, the diamino disazo dye solution is admixed with a solution of 13.8 parts of sodium nitrite and 55 parts of 30% hydrochloric acid and left to rest at 15 for 11/2 to 2 hours rt.



  The suspension obtained in this way is stirred into a solution which contains, in 300 parts of water, 22.0 parts of 1,3-dioxybenzene and 60 parts of sodium carbonate. The mixture is stirred for a few hours at room temperature, the largest part of the alkali carbonate is carefully neutralized with hydrochloric acid and filtered.

 

Claims (1)

PATENT CLAIM: Process for the production of a tetrakisazo dye, characterized in that the diamino compound, which is obtainable by saponifying the disa.zofa_rabric which is itself obtainable by combining 3-diazophenyloxamic acid with 1-amino-3-methylbenzene, Further diazotization of the lblon.oazofa dye thus obtained and combination in an alkaline medium with the 2-amino-5-oxyn.a, phthalene-7-sulfonic acid, tetrazotized and combined with 2 mol of 1,3-dioxybenzene. The new dye forms a dark, bronzing powder that dissolves in water with a red-violet color, in concentrated sulfuric acid with a green color. The dye dyes cotton in red-violet tones, which can be developed further by treatment with formaldehyde or with 4-nitrodiazobenzene. The brown tones obtained with 4-nitrodiazobenzene are washable and, both neutral and alkaline, extremely etchable.