AT38490B - Process for the preparation of vat dyes of the anthracene series. - Google Patents

Description

  

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  Process for the preparation of vat dyes of the anthracene series.
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 The sulfur is heated to a higher temperature and the dyes obtained in this way may be subjected to an after-treatment with hypochlorites.



   It has now been found that orange to orange-yellow vat
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 Color has turned into a pure orange due to the mixture. Then nitration is carried out, the filter residue is washed out well with water and dried. The new dye forms an orange colored powder, which is in conc. Sulfuric acid with dirty claret, in
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 Colorings are washable, lightfast and chlorinefast.



   If the swelling is carried out at a lower temperature in the above example, a more yellowish dye results.



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10 Tl. Methylchloranthraquinone (F. P. 2150) are together with 40 TI. Sulfur heated to 2i ') <0-280' for 3 4 hours. The excess sulfur is removed from the cooled and finely powdered melt by extraction with carbon disulfide or sodium sulfur. The dye obtained in this way can either be used directly for dyeing or it can be subjected to further purification by post-treatment with sodium hypochlorite. For the latter purpose, the raw dye is mixed with water to form a thin paste, then sodium hypochlorite solution is added and the mixture is stirred for about an hour at a normal or elevated temperature (water bath).

   It is then filtered, washed with water and dried. The dye forms a brown-yellow powder,

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 which is in conc. Sulfuric acid dissolves with violet-blue color, in oleum à 24010 with pure green color. When treating with caustic soda and hydrosulfite, a brown clip is created
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