Method for preparing acid black 172

Abstract

The invention relates to a method for preparing acid black 172. The method comprises the following steps that: (1) 6-nitro-1 and 2-diazoxynaphthalene-4-sulfonic acid are put into a dissolution tank, added with water for dissolution, added with a sodium hydroxide solution and stirred. (2) 2-naphthol is put into the dissolution tank, added with water for dissolution, added with the sodium hydroxide solution, stirred, heated, added with a dispersant and aliphatic diol or ether and stirred again; (3) a prepared 2-naphthol solution is rapidly put into and coupled with a solution with 6-nitro-1 and2-diazoxynaphthalene-4-sulfonic acid so as to obtain coupled liquid; and (4) the coupled liquid is added with formic acid, ammonium bicarbonate or sodium bicarbonate and basic chromium sulfate, heated to be between 100 and 102 DEG C, thermally insulated and stirred so as to obtain an acid black 172 serous finished product. The method for preparing acid black 172 has the advantages of simple production process, scientific reasonable control on reaction conditions, short production cycle of produces, high yield, good quality, friction resistance, obviously raised fastness of resisting rinse and sunshine, obviously reduced side reaction and impurities, low production cost, high production efficiency and better environment-friendly property.

Description

Technical field [0001] The invention belongs to the field of metal complex azo dyes, in particular to a preparation method of acid black 172. Background technique [0002] Acid Black 172 is an acid dye named according to the international dye number. Its trade name is Neutral Black S-RL. It has higher dye fastness to wool and polyamide fibers, and the price is lower. It is widely used, and the demand in the market is increasing year by year. It is estimated that the demand in the world this year will reach 30,000 tons. The main reactions in the production of Acid Black 172 are as follows: [0003] 1.6-Nitro-1,2-diazooxynaphthalene-4-sulfonic acid dissolution: [0004] [0005] 2.2-Naphthol dissolution: [0006] [0007] 3. Coupling reaction: [0008] [0009] 4. Chromization reaction: [0010] [0011] The production method of the above reaction is mainly to put 6-nitro-1,2-diazooxynaphthalene-4-sulfonic acid into a dissolution tank, dissolve it with 30% liquid caustic soda, and put t...

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Problems solved by technology

Although the above-mentioned production method can obtain acid black 172, there are still the following problems: (1). The production process is complicated: after the product reaction is complete, steps such as salting out are also needed; (2). The product production cycle is long: mainly by the coupling of the reaction Time is determined by the chromization time. Generally, the coupling reaction needs 8 hours, and the chromation reaction needs 12 hours to reach the reaction end point, and the concentration of the general reaction solution is very low, only 8-10%; (3). The product yield is low, and the by-product There are many reactions and impurities; (4). The product has low abrasion resistance, washing resistance, and light fastness; (5). The production cost is high and the production efficiency is low; (6). The waste liquid discharge is large, and the environment The pollution is serious and the cost of treatment is high; the main reason is that a large amount of salty dye wastewater is produced in the salting out step, and the separated dye filter cake needs to be dried, crushed and other processes

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