CH301651A - Process for the preparation of a metal-containing azo dye. - Google Patents

Description

  

  Process for the preparation of a metal-containing azo dye. It has been found that a new, valuable metal-containing azo dye is obtained by using the monoazo dye of the formula
EMI0001.0008
         lets cobalt donor act in such a way that a cobalt-containing azo dye is formed which contains two monoazo dye molecules bound to a cobalt atom in a complex.



  The new dye forms a water-soluble powder that dyes wool from neutral to acetic acid baths in brown-yellow tones.



  The monoazo dye used as the starting material and corresponding to the above formula can be prepared by coupling 1- (4'-tertiaryamylphenyl) -3-methyl-5-pyrazolone using methods known per se, e.g. B. using hydrochloric acid and sodium nitrite, diazotized 2-amino-1-oxybenzene-4-sulfonic acid amide.



  The 1- (4'-tertiaryamylphenyl) -3-methyl-5-pyrazolone used here can be obtained by methods known per se, e.g. B. by reducing diazotized 4-tertiaryamyl aniline and condensing the resulting 4-tertiary amylphenyl hydrazine with aeetoacetic acid amide or acetoacetic ester to give the desired pyrazolone.

      The treatment with the cobalt-releasing agents takes place according to the present process in such a way that a cobalt-containing dye is produced which contains less than one atom of cobalt in a complex bond per molecule of dye. Accordingly, the metallization is expediently carried out with such cobalt-releasing agents and by methods which, experience has shown, provide complex cobalt compounds of this composition.

   It is generally advisable to use less than one atom of cobalt on a molecule of a dye and / or to carry out the metallization in a weakly acidic to alkaline medium. Cobalt salts, such as cobalt sulfate or cobalt acetate, and optionally also freshly precipitated cobalt hydroxide, are expediently used as cobalt-releasing agents.



  <I> Example: </I> 18.8 parts of 2-4mino-1-oxybenzene-4-sulfonic acid amide are dissolved in 50 parts of water and 14 parts of 30% hydrochloric acid and, at 0 to 5, with an aqueous solution of 6 , 9 parts of sodium nitrite diazotized. The diazo suspension neutralized with sodium carbonate is at 10 to 12 in a solution of 24,

  6 parts of 1 -! @ '- Tertiäramylphenyl) - 3-methyl-5-pyrazolone, 50 parts of water and 14.0 parts of 30 1 / o N atri umhydroxydlösung poured sen. The coupling is very quick. The dye is deposited by adding sodium chloride.



  4.07 parts of the dye obtainable in this way are dissolved as moist Filtex cows in 100 parts of water and dissolved by adding 5 parts by volume of 2-xx-sodium oxy-d3 oxide solution and heating.

   The approximately 80 warm dye solution is mixed with 1.5 parts of crystallized sodium acetate and then with 30 parts of a low-70 cobalt sulfate solution with a cobalt content of 1.31 / 0. After a short time the complex formation is over,

   and the cobalt compound of the dye can be removed by adding sodium chloride and dilute acetic acid.

 

Claims (1)

PATENT CLAIM: Process for the production of an azo dye containing metal lx, characterized in that the monoazo dye of the formula EMI0002.0047 cobalt releasing agents like that. lets act that a cobalt-containing azo dye is formed, which contains two monoazo dye molecules bound to a cobalt atom in a complex. The new dye forms a water-soluble powder that dyes wool from neutral to acetic acid baths in brown-yellow shades. SUBClaims 1. Process according to claim, characterized in that an amount of a cobalt-releasing agent containing less than one atom of cobalt is applied to a mole-kill monoazo dye. \ _ '. Process according to patent claim, characterized by the fact that the metallization is carried out in an alkaline-sensitive medium. 3. The method according to claim, characterized in that the cobalt-releasing agent used is simple cobalt salts.