CH228846A - Process for the preparation of a tetrakisazo dye. - Google Patents

Description

  

      Additional patent to main patent No. 226016. Process for the production of a tetrahisazo dye. It has been found that a new tetrakis azo color is obtained when the diamino compound, which is obtainable by saponifying the isazafax material, which itself is obtainable by combining 3-diazophenyloxamic acid with 1-amino-3 -methylbenzene, further diazotization:

  of the monoazo obtained in this way - dye and combining in alkaline, chemical medium with 2-amino-8-oxynaphthalene-6-sulfone: acid, tetrazotized and combined with 2 mol of 1,3-dioxybene, ol.



  The new dye forms a dark, bronzing powder that dissolves in water with a reddish-brown color and in concentrated sulfuric acid with a green color. The dye dyes cotton in violet-brown tones,

   which can be developed after treatment with formaldehyde or with 4-Ni trodiazoben.zol. The brown tones obtained with 4-nitrodiazobenzene are washable and, both neutral and alkaline, excellently etchable. Example,:

       18.0 parts of 3-aminophenyloxamic acid are diazotized in a known manner; the diazo solution is made congoneutral by adding 20% sodium acetate solution;

         , then a solution of 10.7 parts. 1- Amino-3-methylbenzene, dissolved in 50 parts of water with the aid of 13 parts of 30% hydrochloric acid, was added. After 24 hours, the insoluble mono # azo color # s # to # ff is inherited by filtration,

       then stirred well with 600 parts of water and converted into the sodium salt by adding sodium hydroxide solution. Then a solution of. 6.9 parts of sodium nitrite and 28 parts of 30% hydrochloric acid were added.

   The diazotization mixture is stirred well at 8 to 10 for 2 to 2i / hours and then added to a solution which, by dissolving, 23; 9 parts, 2-amino-8-oxynaphthralin-6-isulphonic acid with addition of 30 parts of sodium carbonate was prepared.

   After several hours of stirring, the disazo dye is salted out and filtered off. The filtered dye is mixed with 1000 parts of water like .der,

          heated to boiling and then treated with 140 parts of 30% sodium hydroxide solution and obtained for 1 to 11/2 hours while stirring at the boil. Here on it is neutralized with hydrochloric acid, cooled to 15, the diaminodisazo dye solution with a solution of 13,

  8 parts of sodium nitrite and 55 parts of 30ö hydrochloric acid are set and stirred at: 15 for 11/2 to 2 hours.



  The suspension obtained in this way is stirred into a solution which, in 300 parts of water, contains 22.0 parts of 1,3 @ -Dioxyben @ zol, and 60 parts of Na; contains trium carbonate. The mixture is stirred for a few hours at room temperature, carefully neutralized, most of the alkali metal carbonate with hydrochloric acid and filtered.

 

Claims (1)

Claim: Process for the production of a tetraki: sazo dye, characterized in that the dia.mino compound which is obtainable by saponifying the dis.azo dye, which itself is contained, is obtained by combining 3-diazophenyloxamines .ura with 1-amino-3-methylbenzene, further diazotization of the ilonoazofa obtained in this way: s and combining in an alkaline medium with the 2-amin.o-8-oxynaphtha.lin-6-sulfonic acid, tetrazotized and combined with 2 moles of 1,3-dioxybenzene. The new dye forms a dark, bronzing powder that dissolves in water with a reddish-brown color, in concentrated sulfuric acid with a green color. The dye dyes cotton in violet-brown shades, which can be developed by treating with formaldehyde or with 4-nitrodiazobenzene. The brown tones obtained with 4-nitrodiazobenzene are washable and, both neutral and alkaline, extremely etchable.