CH228844A - Process for the preparation of a tetrakisazo dye. - Google Patents

Description

  

  Process for the preparation of a tetrakisazo dye. It has been found that a new Tetrakis # azofa # rbs: toff is obtained when the diamino compound, which is obtainable by saponifying the disazo dye itself, is obtainable by combining 1-diazo-4-acetylaminobenzal with 1 -Amino-3-methylbenzene,

          Further diazotization of the monoazo dye thus obtained and combining in an alkaline medium of mild 2-amino-8-oxynaphthalene-6-sulfonic acid, tetrazotized and combined with 2 moles of 1-amino-3-oxybenzene.



  The new dye forms a dark, bronzing powder, Idas dissolves in water with a violet color, in concentrated sulfuric acid with a blue color. The dye dyes cotton in violet-black tones, which can be developed after treatment with formaldehyde or with 4-nitro, diazo-benzene.

    The brown-black shades obtained with 4-nitrodiazobenzene are washable and, iso-neutral as well as alkaline, extremely etchable. <I> Example: </I> 15.0 parts of 1-aminoi-4-acetylaminobenzo # l 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 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 31 # onoazofarbs @ toff is filtered off,

       then make a good paste with 100 parts of water, dilute with another 500 parts of water. Then, a solution of 6.9 parts of sodium nitrite and 28 parts of 30 hydrochloric acid are added.

   The diazotization mixture is stirred well at 15 to 20 for 2 to 21/2 hours and then added to a solution which is obtained by dissolving 23.9 parts of 2-amino-8-oxynaphthalene, -6-sulfonic acid with the addition of 30 parts of sodium carbonate causes wound.

    After several hours of stirring, the sparingly soluble disazo dye is filtered off. The filtered dye will:

      stirred again with 1000 parts of water, heated to the boil and then mixed with 140 parts of 30% sodium hydroxide solution and kept at the boil for 1 to 11/2 hours with stirring. It is then neutralized with hydrochloric acid, cooled to 15,

   a solution of 13.8 parts of sodium nitrite and 55 parts of hydrochloric acid of <B> 30% </B> is added to the diaminodisiazo dye solution and at. 15 during 11 /;

       stirred for up to 2 hours. The suspension obtained in this way is stirred into a solution which contains 21.8 parts of 1-amino-3-oxybenzene and 60 parts of sodium carbonate in 300 parts of water.

   The mixture is stirred for a few hours at room temperature, carefully neutralized most of the alkali carbonate with hydrochloric acid and filtered.

 

Claims (1)

PATENT CLAIM: Process for the production of a tetrakisazo dye, @di characterized in that the diamino compound that is obtainable is obtained by saponifying the disuzo dye, which is itself obtainable by combining 1-diazo-4-acetylaminobenzene with 1-amino-3-methylbenzene, Further diazotization of the monoazo dye obtained in this way and. Combine in an alkaline medium with 2-amino-8-oxynaphthalene-6-sulfonic acid, tetra-doped and combined with 2 moles of 1-amino-3-oxybenzene. The new dye forms a dark, bronzing powder that turns into purple, dissolves in concentrated sulfuric acid with a blue color. The dye dyes cotton in violet-black tones, which can be further developed by treatment with formaldehyde or with 4-nitrodia.zobenzo, 1. The brown-black shades obtained with 4-nitrodiazobenzene are washable and, both neutral and alkaline, have excellent etching properties.