Method for preparing 4-methyl nitrobenzene-2-sulfonic acid self-polycondensation dye liquid color paste

A technology of nitrotoluene and self-polycondensation, applied in the field of dye chemistry, can solve the problems of large color change of colorant, large amount of organic base, large and expensive raw materials, etc., and achieves the effects of low production cost, less generation of three wastes, and easy operation.

Inactive Publication Date: 2010-08-18
TIANJIN UNIV
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  • Summary
  • Abstract
  • Description
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  • Application Information

AI Technical Summary

Problems solved by technology

The most direct method is to acidify the color paste dye with sulfuric acid or hydrochloric acid, but there are two problems: 1) the hue of the color paste changes greatly during the acidification process, and 2) alkali metal ions such as Na + The presence of the presence of lead to high viscosity colorant gel formation and difficult to filter
The disadvantage of these methods is that either the process is more complicated, or a large amount of expensive raw materials are involved
There are also patents that directly use organic bases instead of alkali metal hydroxides to catalyze the self-condensation of 4-nitrotoluene-2-sulfonic acid. Although it is easy to obtain color paste solutions that are easy to control and have good stability, the amount of organic bases is very large. Large, its production cost is higher

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0012] Add 300g (>80%) 4-nitro-2-sulfonic acid toluene, 250mL triethanolamine and 350mL diethylene glycol methyl ether into the three-necked flask, start stirring and slowly heat up, the material gradually dissolves and becomes light yellow, transparent and clear solution; when the temperature reaches 55°C, start to add 150mL of 33% sodium hydroxide aqueous solution dropwise, and control the temperature of the system not to exceed 60°C. At this time, the color of the solution gradually deepens from yellow to red; then keep stirring the solution at 60°C For 1 hour, the solution was a light sauce red turbid liquid, that is, the alkali coarse toning phase polycondensation reaction solution; then, under the condition of controlling the solution temperature at 60°C, add 50mL of 20% sodium hydroxide aqueous solution to the system, and control the reaction for 30 Minutes to obtain a deep sauce red alkali fine-toned phase polycondensation reaction solution; then add 100ml of water to t...

Embodiment 2

[0014] The experimental procedure is the same as in Example 1. Just changing 150mL mass concentration of 33% sodium hydroxide aqueous solution into 160mL mass concentration of 35% sodium hydroxide aqueous solution, the dyestuff (concentrate) obtained is orange, λmax=382nm.

Embodiment 3

[0016] The experimental procedure is the same as in Example 1. Just change 50mL mass concentration of 20% sodium hydroxide aqueous solution into 40mL mass concentration of 20% sodium hydroxide aqueous solution, and the dyestuff (concentrate) obtained is yellow-green, λmax=377nm.

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PUM

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Abstract

The invention discloses a method for preparing 4-methyl nitrobenzene-2-sulfonic acid self-polycondensation dye liquid color paste, comprising the following steps of: dissolving 4-methyl nitrobenzene-2-sulfonic acid group methylbenzene into mixed solution of triethanolamine and diethylene glycol monomethylet, dropwise adding sodium hydroxide water solution into the mixed solution with high concentration to react and obtain an alkali coarse toning phase polycondensation reaction liquid; dropwise adding sodium hydroxide water solution into the mixed solution with low concentration to the alkali crude toning phase polycondensation reaction liquid to obtain an alkali fine toning phase polycondensation reaction liquid; adding water into the alkali fine toning phase polycondensation reaction liquid to react and obtain an alkalinity-reducing polycondensation reaction liquid; and adding ethylene glycol methyl ether into the alkalinity-reducing polycondensation reaction liquid for diluting, regulating pH by using NaHSO4 and regulating pH by using tetramethylammonium hydroxide water solution, recycling ethylene glycol methyl ether through condensing a filtering liquid after filtering to obtain the 4-methyl nitrobenzene-2-sulfonic acid self-polycondensation dye liquid color paste. The invention has the advantages of less three-waste generation, low production cost, simple process and easy control.

Description

technical field [0001] The invention relates to a preparation method of 4-nitrotoluene-2-sulfonic acid self-condensation dye liquid color paste, belonging to the technical field of dye chemistry. Background technique [0002] 4-nitrotoluene-2-sulfonic acid self-condensation dyes can be divided into dyes from yellow to red according to the degree of polycondensation, among which the most widely used direct yellow 11 dye is a strong yellow dye, especially suitable for fiber, leather Waiting for dyeing. As described in U.S. Patent No. 4,310,331, etc., its production process is mainly: 4-nitrotoluene-2-sulfonic acid is catalyzed by alkali metal hydroxide, especially sodium hydroxide, under the catalysis of 50-90 ° C for half an hour to After several hours, neutralize the excess alkali with sulfuric acid or hydrochloric acid, and finally obtain the wet cake of Direct Yellow 11 by pressure filtration. The product can be directly marketed in the form of wet cake or dried powder, ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C09B57/00C09B67/44
Inventor 周雪琴刘东志李巍
Owner TIANJIN UNIV
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