Improvements in the Manufacture and Production of Sulphur Dyes for Dyeing Cotton Directly.

摘要

16,932. Johnson, J. Y., [Kalle & Co.]. July 30. Dyes, artificial; naphthylene 1 - 3 - dithiourea 6-sulphonic acid.-Relates to the manufacture of dyes containing sulphur which dye cotton olive green and brown or yellow shades by melting the dithiourea derivatives of aromatic m-diamines, such as m-phenylenediamine, m-toluylenediamine, and naphthylene 1-3-diamine 6-sulphonic acid, with sulphur and sodium sulphide. The shade varies with the temperature of the melt. The naphthylene dithiourea sulphonic acid is obtained by mixing naphthylene 1-3-diamine 6-sulphonic acid with hot water, hydrochloric acid, and ammonium thiocyanate, boiling the mixture, evaporating to dryness, and heating at 130‹ C. until quite hard. The mass is dissolved in hot water, filtered, and the thiourea derivative salted out.