- Diazotization method of wet nitroaniline
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The invention provides a diazotization method of wet nitroaniline, and relates to the field of dye synthesis. The diazotization method comprises following steps: step one, evenly stirring sulfuric acid (98%) and nitrosyl sulfuric acid (40%) in a diazotization reactor; and step two, adding wet nitroaniline into the diazotization reactor at a controlled temperature of -10 to 40 DEG C to obtain diazotization salts, wherein the mole ratio of sulfuric acid to nitrosyl sulfuric acid to diazotization component is 1.0-6: 1.02-1.1: 1. The quality of the provided wet dye is the same as that of a dry product, the diazotization component does not need to be dried, and the provided dye is energy saving and environmentally friendly.
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Paragraph 0024-0027
(2019/01/05)
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- Preparation method of ester group-containing azo disperse dye
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The invention discloses a preparation method of an ester group-containing azo disperse dye. The method comprises the following steps: carrying out a coupling reaction on a diazo salt and a coupling component, adding an alkali to the above obtained azo compound material system after the coupling reaction is completed in order to adjust the pH value of the system to 5-7, carrying out heating crystal transformation, and post-processing to obtain a dye filter cake. The pH value of the system is adjusted to 5-7 after the coupling reaction and before the crystal transformation, so hydrolysis of ester groups in the dye product is avoided, the yield of the dye product is improved, and the content of organic matters in wastewater is reduced, thereby the wastewater post-treatment difficulty is reduced.
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Paragraph 0050; 0051; 0052; 0053
(2016/10/10)
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