阅读说明：本技术 一种亚二硫基二乙酸及亚二硫基二乙酸二铵的制备方法 (Dithiodiglycolic acid and preparation method of dithiodiglycolic diammonium ) 是由 吴钜明 李荣昌 于 2019-11-19 设计创作，主要内容包括：本发明公开了一种亚二硫基二乙酸及亚二硫基二乙酸二铵的制备方法,包括以下步骤,步骤(1)：在夹套冷却下,在纯水中分别加入巯基乙酸,得到巯基乙酸水溶液,所述巯基乙酸与纯水的质量百分比为1：(0.5～5)；步骤(2)：在所述巯基乙酸水溶液中加入三价铁催化剂；步骤(3)：在经过步骤(2)的巯基乙酸水溶液中,一边搅拌一边缓慢滴加双氧水,进行氧化反应,得到亚二硫基二乙酸水溶液；步骤(4)：把亚二硫基二乙酸水溶液经过真空干燥后,得到亚二硫基二乙酸晶体。本发明生产工艺简单,可操作性强,收率高,纯度高,三废极少,易于实现工业化应用。(The invention discloses dithiodiglycolic acid and a preparation method of the dithiodiglycolic acid diammonium, which comprises the following steps (1): under jacket cooling, adding thioglycolic acid into pure water respectively to obtain thioglycolic acid aqueous solutions, wherein the mass percentage of the thioglycolic acid to the pure water is 1: (0.5 to 5); step (2): adding a ferric iron catalyst into the thioglycollic acid aqueous solution; and (3): slowly dripping hydrogen peroxide into the mercaptoacetic acid aqueous solution obtained in the step (2) while stirring, and carrying out oxidation reaction to obtain a dithiodiglycolic acid aqueous solution; and (4): the dithiodiglycolic acid aqueous solution is dried in vacuum to obtain dithiodiglycolic acid crystals. The method has the advantages of simple production process, strong operability, high yield, high purity, few three wastes and easy realization of industrial application.)

1. A preparation method of dithiodiglycolic acid is characterized in that: comprises the following steps of (a) carrying out,

step (1): under jacket cooling, adding thioglycolic acid into pure water respectively to obtain thioglycolic acid aqueous solutions, wherein the mass percentage of the thioglycolic acid to the pure water is 1: (0.5 to 5);

step (2): adding a ferric iron catalyst into the thioglycollic acid aqueous solution;

and (3): slowly dripping hydrogen peroxide into the mercaptoacetic acid aqueous solution obtained in the step (2) while stirring, and carrying out oxidation reaction to obtain a dithiodiglycolic acid aqueous solution;

and (4): the dithiodiglycolic acid aqueous solution is dried in vacuum to obtain dithiodiglycolic acid crystals.

2. The process for the preparation of dithiodiglycolic acid according to claim 1, characterized in that: the cooling temperature of the jacket is 0-20 ℃.

3. The process for the preparation of dithiodiglycolic acid according to claim 1, characterized in that: the ferric iron catalyst in the step (2) accounts for 0-0.0001% of the weight of the obtained dithiodiglycolic acid aqueous solution.

4. The process for the preparation of dithiodiglycolic acid according to claim 1, characterized in that: and (3) the ferric iron catalyst in the step (2) is ferric chloride or ferric sulfate.

5. The process for the preparation of dithiodiglycolic acid according to claim 1, characterized in that: the metering molar ratio of hydrogen peroxide to thioglycolic acid in the step (3) is 1: (2-2.3).

6. The process for the preparation of dithiodiglycolic acid according to claim 1, characterized in that: the oxidation reaction temperature of the step (3) is controlled to be 25-50 ℃.

7. The process for the preparation of dithiodiglycolic acid according to claim 1, characterized in that: the vacuum drying temperature is-50 ℃ to 70 ℃.

8. A preparation method of diammonium dithiodiglycolate is characterized by comprising the following steps: comprises the following steps of (a) carrying out,

step (1): under jacket cooling, adding thioglycolic acid into pure water respectively to obtain thioglycolic acid aqueous solutions, wherein the mass percentage of the thioglycolic acid to the pure water is 1: (0.5 to 5);

step (2): adding a ferric iron catalyst into the thioglycollic acid aqueous solution;

and (3): slowly dripping hydrogen peroxide into the mercaptoacetic acid aqueous solution obtained in the step (2) while stirring, and carrying out oxidation reaction to obtain a dithiodiglycolic acid aqueous solution;

and (4): adding ammonia water into the dithiodiglycolic acid aqueous solution for neutralization reaction to obtain the dithiodiglycolic acid diammonium aqueous solution;

and (5): and (3) drying the diammonium dithiodiglycolate aqueous solution in vacuum to obtain the diammonium dithiodiglycolate crystal.

9. A process for the preparation of diammonium dithiodiacetate according to claim 8, characterized in that: the metering molar ratio of the thioglycolic acid to the ammonia water in the step (4) is 1: 1.

10. A process for the preparation of diammonium dithiodiacetate according to claim 8, characterized in that: the neutralization reaction temperature in the step (4) is controlled to be 20-50 ℃.

Technical Field

The invention relates to the field of fine chemical engineering, in particular to dithiodiglycolic acid and a preparation method of diammonium dithiodiglycolate.

Background

At present, the application of dithiodiglycolic acid and ammonium salt thereof is mainly in the fields of surface treatment, cosmetics and pharmacy, in the field of surface treatment, the dithiodiglycolic acid and the ammonium salt thereof are mainly used in the formula of a black passivator for electroplating zinc, the dithiodiglycolic acid and the ammonium salt thereof have the effect of blackening, replace the salt of heavy metal silver or copper in the old process, and are environment-friendly blackening agents, and the field mainly uses diammonium dithiodiglycolate water solution with the content of 45 percent; in the field of cosmetics, dithiodiglycolic acid and ammonium salt thereof are mainly used in high-grade perm water formulas, and have the effects that in the perm process, the dithiodiglycolic acid and the ammonium salt thereof can effectively prevent hair from being excessively damaged, on one hand, fibers can be repaired, on the other hand, the reduction process of the hair during setting can be adjusted, the dithiodiglycolic acid and the ammonium salt thereof are more and more commonly used in foreign perm water formulas, and although the use proportion is still not high at home, the dithiodiglycolic acid and the ammonium salt thereof are also increased year by year, and 45% of diammonium dithiodiglycolate aqueous solution is mainly used in the field; in the pharmaceutical field, dithiodiglycolic acid solid is mainly used as a pharmaceutical intermediate or a raw material. However, the existing dithiodiglycolic acid and ammonium salt thereof have complex process flow and high production cost.

Disclosure of Invention

The invention aims to overcome the defects in the prior art and provide a preparation method of dithiodiglycolic acid, which is simple and convenient to operate and has few three wastes.

The invention also aims to provide a preparation method of the dithiodiglycolic acid diammonium.

The invention is realized by the following technical scheme:

a preparation method of dithiodiglycolic acid comprises the following steps,

step (1): under jacket cooling, adding thioglycolic acid into pure water respectively to obtain thioglycolic acid aqueous solutions, wherein the mass percentage of the thioglycolic acid to the pure water is 1: (0.5 to 5);

step (2): adding a ferric iron catalyst into the thioglycollic acid aqueous solution;

and (3): slowly dripping hydrogen peroxide into the mercaptoacetic acid aqueous solution obtained in the step (2) while stirring, and carrying out oxidation reaction to obtain a dithiodiglycolic acid aqueous solution;

and (4): the dithiodiglycolic acid aqueous solution is dried in vacuum to obtain dithiodiglycolic acid crystals.

Further, the cooling temperature of the jacket is 0-20 ℃.

Further, the ferric iron catalyst of the step (2) accounts for 0-0.0001% of the weight of the obtained dithiodiglycolic acid aqueous solution.

Further, the ferric iron catalyst in the step (2) is ferric chloride or ferric sulfate.

Further, the stoichiometric molar ratio of hydrogen peroxide to thioglycolic acid in the step (3) is 1: (2-2.3).

Further, the oxidation reaction temperature of the step (3) is controlled to be 25-50 ℃.

Further, the vacuum drying temperature is-50 ℃ to 70 ℃.

A preparation method of diammonium dithiodiacetate comprises the following steps,

step (1): under jacket cooling, adding thioglycolic acid into pure water respectively to obtain thioglycolic acid aqueous solutions, wherein the mass percentage of the thioglycolic acid to the pure water is 1: (0.5 to 5);

step (2): adding a ferric iron catalyst into the thioglycollic acid aqueous solution;

and (3): slowly dripping hydrogen peroxide into the mercaptoacetic acid aqueous solution obtained in the step (2) while stirring, and carrying out oxidation reaction to obtain a dithiodiglycolic acid aqueous solution;

and (4): adding ammonia water into the dithiodiglycolic acid aqueous solution for neutralization reaction to obtain the dithiodiglycolic acid diammonium aqueous solution;

and (5): and (3) drying the diammonium dithiodiglycolate aqueous solution in vacuum to obtain the diammonium dithiodiglycolate crystal.

Further, the stoichiometric molar ratio of the thioglycolic acid to the ammonia water in the step (4) is 1: 1.

Further, the neutralization reaction temperature of the step (4) is controlled to be 20-50 ℃.

Compared with the prior art, the method takes mercaptoacetic acid and hydrogen peroxide as raw materials, takes pure water as a solvent, synthesizes and obtains the dithiodiglycolic acid aqueous solution through factors such as concentration control, temperature control, a catalyst and the like, and obtains dithiodiglycolic acid crystals after freeze drying, wherein the yield is more than 99 percent, and the purity is more than 97 percent. And adding ammonia water into the obtained dithiodiglycolic acid aqueous solution for neutralization to obtain the dithiodiglycolic acid diammonium aqueous solution, and freeze-drying to obtain dithiodiglycolic acid diammonium crystal, wherein the production process is simple and the operability is strong.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

A preparation method of dithiodiglycolic acid comprises the following steps,

step (1): under jacket cooling, adding thioglycolic acid into pure water respectively to obtain thioglycolic acid aqueous solution, wherein the mass percentage of the thioglycolic acid to the pure water is 1: (0.5 to 5); the cooling temperature of the jacket is 0-20 ℃.

Step (2): adding a ferric iron catalyst into a mercaptoacetic acid aqueous solution; the ferric iron catalyst accounts for 0-0.0001% of the weight of the obtained dithiodiglycolic acid aqueous solution. The ferric iron catalyst is ferric chloride or ferric sulfate.

And (3): slowly dripping hydrogen peroxide into the mercaptoacetic acid aqueous solution obtained in the step (2) while stirring, and carrying out oxidation reaction to obtain a dithiodiglycolic acid aqueous solution; the stoichiometric molar ratio of hydrogen peroxide to thioglycolic acid is 1: (2-2.3). The temperature of the oxidation reaction is controlled to be 25-50 ℃.

And (4): the dithiodiglycolic acid aqueous solution is dried in vacuum to obtain dithiodiglycolic acid crystals. The vacuum drying temperature is-50 ℃ to 70 ℃.

A preparation method of diammonium dithiodiacetate comprises the following steps,

step (1): under jacket cooling, adding thioglycolic acid into pure water respectively to obtain thioglycolic acid aqueous solution, wherein the mass percentage of the thioglycolic acid to the pure water is 1: (0.5 to 5); the cooling temperature of the jacket is 0-20 ℃.

Step (2): adding a ferric iron catalyst into a mercaptoacetic acid aqueous solution; the ferric iron catalyst accounts for 0-0.0001% of the weight of the obtained dithiodiglycolic acid aqueous solution. The ferric iron catalyst is ferric chloride or ferric sulfate.

And (3): slowly dripping hydrogen peroxide into the mercaptoacetic acid aqueous solution obtained in the step (2) while stirring, and carrying out oxidation reaction to obtain a dithiodiglycolic acid aqueous solution; the stoichiometric molar ratio of hydrogen peroxide to thioglycolic acid is 1: (2-2.3). The temperature of the oxidation reaction is controlled to be 25-50 ℃.

And (4): adding ammonia water into the dithiodiglycolic acid aqueous solution for neutralization reaction to obtain the dithiodiglycolic acid diammonium aqueous solution; the molar ratio of mercaptoacetic acid to ammonia was 1: 1. The neutralization reaction temperature is controlled to be 20-50 ℃.

And (5): and (3) drying the diammonium dithiodiglycolate aqueous solution in vacuum to obtain the diammonium dithiodiglycolate crystal.

In the following examples, the mercaptoacetic acid starting material used was found to be 97% by weight, measured by the method described in GB/T29678-2013.