CH274848A - Process for the preparation of a monoazo dye. - Google Patents

Description

  

  Process for the preparation of a monoazo dye. It has been found that new, valuable monoazo dyes are obtained if diazotized I-halogen-2-amino-1-oxybenzenesulfonic acids are combined with 4-alkyl-1-oxybenzenes whose alkyl groups have 3 to 6 carbon atoms.



  The halogen-2-amino-1-oxybenzene-sulfGn acids can, for. B. bromine or, in particular, chloro-amino-oxybenzene-sulfonic acids. As ChlorA2-amino-1-oxybenzenesulfonic acid, for. B. 6-chloro-2-amino-l-oxybenzene-4-sulfonic acid, 4-chloro-2-amino-l-oxybenzene-5-sulfonic acid, 3,6-diehlor-2-amino-l- oxybenzene-4-sulphonic acid or 4-chloro-2-amino = 1-oxybenzene-6-sulphonic acid can be used.



  The alkyl radicals of the 4-alkyl-1-oxybenzenes used as starting materials contain 3 to 6 carbon atoms; these can be straight or branched. The term alkyl radical here also includes cycloalkyl radicals. Particularly valuable dyes are obtained with 4-amyl-l-oxybenzenes. For example, the following 4-alkyl-1-oxybenzenes can be considered
EMI0001.0029
      The diazotization of the halogen-2-amino-l-oxy-

      Benzene sulfonic acids can be carried out in a customary manner known per se, e.g. B. by adding the required amount of sodium nitrite to a freshly prepared, weakly hydrochloric acid suspension of the I-halogen-2-amino-1-oxybenzenesulfonic acid.



  The coupling of the, diazotized halogen-2-amino-l @: oxybenzene-sulfonic acids can be carried out in alkali, for example alkali carbonate to alliali hydroxydalkalisehem medium, optionally with the addition of neutral or basic solvents such as. B. Alko hol or pyridine, or other agents promoting the coupling.



  The new monoazo dyes obtainable in the manner indicated above correspond to the general formula
EMI0002.0015
    in which R is an aromatic radical of the benzene series in that the -ON group is in o-position to the azo group and X is an alliyl group with 3 to 6 carbon atoms.



  These new products can be used for dyeing and printing various materials, but mainly those of animal origin such as wool, silk and leather. Particularly valuable products are obtained when the dyes obtainable by the present process are treated with metal donors. This treatment can be carried out in a manner known per se in substance, in the dye bath or on the fiber. Thus, the metallization in substance, z.

   B. with chromium-releasing agents in neutral or alkaline Me medium, in the presence or absence of suitable additives such. B. aromatic o-oxycarboxylic acids, neutral salts or bases, organic solvents or other additives promoting complex formation can take place openly or under pressure. The metallization in the dye bath or on the fiber can also be carried out in a known manner, for. B. with the addition of neutral chromates and ammonium salts are made.



  According to the above process, one obtains, inter alia, dyes which dye wool in very genuine, in particular lightfast, shades using the usual chromating processes.



  The subject of the present patent is. a process for the preparation of a monoazo dye. The process is characterized in that diazotized 4-chloro-2-amino-1-oxybenzene-6-sulfonic acid is combined with 4-tertiaryamyl-1-oxybenzene.



  The new dye dissolves in hot dilute sodium carbonate solution with brown red and in conc. Sulfuric acid with a yellow-red color and dyes wool from an acid bath in yellow-brown tones, which, when chromium-plating, turn into a violet-brown with excellent fastness properties.

   The dye is also ideal for dyeing using the single-bath chrome plating process. Example: 22.4 parts of 4-chloro-2-amino-1-oxybenzene-6-stilfonic acid are suspended in 60 parts of water and, after addition of 5 parts of 30% hydrochloric acid, with external cooling, with 25 parts by volume of 4N sodium nitrite solution at 10 to 150 diazotized. The diazo solution is neutralized with sodium carbonate and added to a solution cooled to 120 or

   Sus pension of 17.5 parts of 4-tertiary amyl-l-oxybenzene of the formula
EMI0002.0065
    in 100 parts of water, 1.2 parts of 30% sodium hydroxide solution and 9 parts of anhydrous sodium carbonate.

   After stirring for 10 hours at 12 to 150, the coupling mixture is replaced with 15 parts by volume of 2N-ratriumhy droxydlösung and stirring is continued at the same temperature until the diazo reaction disappears. The separated dye is then filtered off, washed with dilute sodium chloride solution and dried.

 

Claims (1)

Claim: Process for the preparation of a monoazo dye, characterized in that diazotized 4-chloro-2-amino-1-oxybenzene-6-su1-fonic acid is used with 4-tertiaryamyl-1-oxybenzene united. The new dye dissolves in hot dilute sodium carbonate solution with brown red and in conc. Sulfuric acid with a yellow-red color and dyes wool from an acid bath in yellow-brown tones, which, after being chromated, change into a violet-brown with excellent fastness properties. The dye is also particularly suitable for dyeing using the single-bath chrome plating process.