this kind of dye is by 4-(2,4-Dinitrophenylamino)phenol?aqueous solution and sulfide. Change the purity and degree of oxidation can get different colored light blue dye, usually color GuangYan degree directly with the purity in proportion, and oxidation of the final product is red. (a) will be the 4-(2,4-Dinitrophenylamino)phenol?75 % paste which in 90 ~ 92 ℃, at least 2 hours to add sodium polysulphide, and in 106 ℃ reflux 3 hours, and?sodium chloride, and heating to 109 ~ 110 ℃, heat preservation 10 hours, diluted, 45 ℃ 70 ℃ 1 1 filtering, dry; By this method the paste things in air oxidation, get color bright dye, its method is as follows: (b) water dilution from (a) paste content, add Sodium hydroxide, air oxidation 5 hours, salting out, filtering, and add Sodium carbonate drying; (C) if the increase of Sodium hydroxide to join quantity, air oxidation 14 ~ 16 hours, can further improve the brilliance, (d) will come from (C) with Sodium hydroxide has been the filter cake in 30 ℃ air oxidation about 18 hours, and then salting out, filtering and drying; (e) from the above product in disulfide and diacetyl Sodium acetate trihydrate solution, 95 ℃ treatment 5 hours, can still generate color is red and a brilliant dye. Dye with conventional method separation and drying (FIAT 1313,3,229-230). Some vulcanization direct blue is by 4-(2,4-Dinitrophenylamino)phenol and sodium polysulphide aqueous solution in 135 ~ 140 ℃ calcination, then according to the above method and oxidation.
