CN114057638A

CN114057638A - Method for removing impurity primary amine in anti-aging agent TMQ

Info

Publication number: CN114057638A
Application number: CN202010782934.0A
Authority: CN
Inventors: 付春; 韦志强; 高留冕
Original assignee: China Petroleum and Chemical Corp; Sinopec Nanjing Chemical Industry Corp; Research Institute of Sinopec Nanjing Chemical Industry Co Ltd
Current assignee: China Petroleum and Chemical Corp; Sinopec Nanjing Chemical Industry Corp; Research Institute of Sinopec Nanjing Chemical Industry Co Ltd
Priority date: 2020-08-06
Filing date: 2020-08-06
Publication date: 2022-02-18

Abstract

The invention belongs to the technical field of fine chemical engineering, and provides a method for removing primary amine impurities in an anti-aging agent TMQ. The TMQ crude product containing a large amount of primary amine is generated by carrying out polycondensation reaction on aniline, a catalyst and acetone, and then the TMQ crude product is reacted with strong acid and sodium nitrite solution with certain concentration, and a TMQ finished product with low content of primary amine is obtained by neutralization, water separation and distillation, so that the generation of primary amine carcinogenic substances is reduced. By adopting the method, the primary amine content in the TMQ finished product can be reduced to below 50ppm from 6-8%.

Description

Method for removing impurity primary amine in anti-aging agent TMQ

Technical Field

The invention relates to a method for removing primary amine impurities in an anti-aging agent TMQ, belonging to the technical field of fine chemical engineering.

Background

The anti-aging agent TMQ is a di-, tri-or tetra-polymer of 2,2, 4-trimethyl-1, 2-dihydroquinoline, is also called anti-aging agent RD, is mainly used as an antioxidant for rubber and rubber products, is suitable for natural rubber, synthetic rubber and latex, has stronger inhibiting effect on the catalytic oxidation of harmful metal ions such as copper, manganese and the like, and has good compatibility with rubber, low volatility, small blooming property and high extraction resistance. The rubber is widely used by rubber processing industry at home and abroad, and is added to common tires, radial tires or other rubber products to achieve better protection efficiency.

The anti-aging agent TMQ is prepared by firstly condensing aniline and acetone under acidic conditions to generate a monomer TMDQ (2, 2, 4-trimethyl-1, 2-dihydroquinoline), polymerizing the TMDQ to generate reaction liquid of di-tri-tetramer, tetramer of TMDQ, neutralizing with liquid alkali, distilling and the like. The TMQ is synthesized by taking hydrochloric acid as a catalyst, and the main principle is as follows:

。

under the acidic condition, acetone and aniline can also generate a plurality of other side reactions, wherein primary amine is a side reaction product of the acetone and is one of the control indexes of TMQ finished products because the primary amine is proved to have carcinogenicity, and the content of the primary amine is generally required to be less than or equal to 5%.

In the prior production method of the anti-aging agent TMQ at home and abroad, primary amine is controlled mainly by adjusting process conditions and detecting finished products, a quantitative intermediate control method is not available, and the content of the primary amine in the finished products is higher (6-8 percent, weight percentage, the same below).

Disclosure of Invention

The invention aims to overcome the defects of the prior art, and the content of primary amine in a finished product is controlled by improving a post-treatment process in the production process of TMQ, so that the generation of carcinogens is reduced, and the environment-friendly production of TMQ is realized.

The invention provides a method for removing primary amine impurities in an anti-aging agent TMQ.

The method is realized by the following steps: the method for removing the primary amine impurities in the antioxidant TMQ is characterized by comprising the following steps: and (2) carrying out polycondensation reaction on aniline, a catalyst and acetone to obtain a TMQ crude product containing primary amine, reacting the TMQ crude product containing primary amine with an epoxy compound solution in the presence of a solvent, and removing the solvent through distillation to obtain the TMQ finished product with low content of primary amine.

Generally, the method comprises the steps of adding a proper amount of solvent into a TMQ finished product obtained by carrying out polycondensation reaction on aniline, a catalyst and acetone to dissolve a solid into a uniform solution, then dropwise adding an organic solvent solution containing an epoxy compound into the dissolved solution, keeping stirring for 0-60 minutes at the dropwise adding temperature of 20-40 ℃, then heating to 25-100 ℃ for reaction for 20-120 minutes, and distilling to remove the solvent after the reaction is finished to obtain the finished product.

The epoxy compound is ethylene oxide, propylene oxide or any component or proportion composition thereof.

The solvent used in the reaction is polar organic alkyl alcohol or alkyl ketone, such as methanol, ethanol, isopropanol, acetone, butanone, methyl isobutyl ketone, etc. or mixture of any components or proportion thereof.

The weight ratio of the solvent to TMQ is 1:1-10, preferably 1: 2-4.

The molar ratio of primary amine (calculated as aniline) to epoxy compound is 1:1 to 1.5, preferably 1:1.05 to 1.2.

The dropping temperature of the epoxy compound is 20 to 40 ℃, preferably 25 to 30 ℃.

The temperature of the reaction of the primary amine with the epoxy compound is from 25 to 100 ℃ and preferably from 60 to 65 ℃.

The reaction time of the primary amine with the epoxy compound is 20 to 120 minutes, preferably 50 to 60 minutes.

Effects of the invention

By adopting the method, the primary amine content in the TMQ finished product can be reduced to below 50ppm from 6-8%.

Detailed Description

It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present invention will be described in detail with reference to examples.

Example 1

Adding 100 g of TMQ (containing 6 percent of primary amine) and 200 g of methanol into a reactor, stirring until a uniform solution is formed, then dropwise adding a mixed solution of 3.5 g (with the purity of 99.5 percent) of ethylene oxide and 50 g of methanol into the reactor at 25 ℃ under stirring, wherein the dropwise adding time is 30 minutes, the adding is finished, the reaction temperature is increased to 60-65 ℃, stirring reaction is maintained for 60 minutes, after the reaction is finished, excessive unreacted ethylene oxide and solvent are removed under the condition of the vacuum degree of 0.05-0.06MPA, cooling, obtaining a finished product, and analyzing and detecting the content of the primary amine to be 8 PPM.

Example 2

The procedure is otherwise as in example 1, except that 3.0 g of ethylene oxide are added and the primary amine content is determined to be 41 ppm.

Example 3

The procedure is otherwise as in example 1, except that 4.5 g of propylene oxide are used instead of ethylene oxide and the primary amine content is determined to be 10 ppm.

Example 4

The other conditions were the same as in example 1, except that an equimolar mixture of propylene oxide and ethylene oxide was used, and the primary amine content was found to be 16 ppm.

Example 5

The other conditions were the same as in example 1 except that ethanol was used instead of methanol. And detecting to obtain the TMQ finished product with the primary amine content of 22 ppm.

Example 6

The other conditions were the same as in example 1 except that acetone was used instead of methanol. And detecting to obtain the TMQ finished product with the primary amine content of 19 ppm.

Example 7

The other conditions were the same as in example 1 except that isopropanol was used instead of methanol. And detecting to obtain the TMQ finished product with the primary amine content of 38 ppm.

Example 8

The other conditions were the same as in example 1, except that methyl isobutyl ketone was used instead of methanol. And detecting to obtain the TMQ finished product with 48ppm of primary amine content.

Example 9

The other conditions were the same as in example 1, except that the reaction temperature was 50 ℃ and that the TMQ product primary amine content was 40ppm by detection.

Example 9

The other conditions were the same as in example 1, except that the reaction temperature was 100 ℃ and that the TMQ product had a primary amine content of 48ppm as measured.

Example 10

The other conditions were the same as in example 1, except that the reaction was maintained for 30 minutes, and the TMQ product was measured to have a primary amine content of 26 ppm.

Example 11

The other conditions were the same as in example 1, except that the reaction was maintained for 100 minutes, and the TMQ product was measured to have a primary amine content of 8 ppm.

Example 12

The other conditions are the same as example 1, except that the solvent is a mixture of methanol and acetone with equal mass, and the TMQ finished product primary amine content is 12ppm after detection.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and it is obvious to those skilled in the art that the present invention may be modified and changed in various ways, such as changing the catalyst, the solvent, the feeding method, the reactor, etc. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for removing primary amine impurities in an anti-aging agent TMQ is characterized by comprising the following steps: and (2) carrying out polycondensation reaction on aniline, a catalyst and acetone to obtain a TMQ crude product containing primary amine, reacting the TMQ crude product containing primary amine with an epoxy compound solution in the presence of a solvent, and removing the solvent through distillation to obtain the TMQ finished product with low content of primary amine.

2. The method as set forth in claim 1, wherein a solvent is added to the TMQ product obtained by polycondensation of aniline, catalyst and acetone to dissolve the solid into a homogeneous solution, then an organic solvent solution containing an epoxy compound is added dropwise to the dissolved solution at a temperature of 20 to 40 ℃ while stirring for 0 to 60 minutes, then the temperature is raised to 25 to 100 ℃ to react for 20 to 120 minutes, and the solvent is distilled off after the reaction is completed to obtain the TMQ product.

3. The method of claim 1, wherein the epoxy compound is ethylene oxide, propylene oxide, or a combination thereof in any proportion or combination thereof.

4. The method according to claim 1, wherein the solvent is a polar organic alkyl alcohol or alkyl ketone selected from methanol, ethanol, isopropanol, acetone, methyl ethyl ketone, methyl isobutyl ketone, or a mixture thereof in any ratio or proportion.

5. The process according to claim 3, characterized in that the weight ratio of solvent to TMQ is from 1:1 to 10, preferably from 1:2 to 4.

6. The process according to claim 1, characterized in that the molar ratio of primary amine (calculated as aniline) to epoxy compound is from 1:1 to 1.5, preferably from 1:1.05 to 1.2.

7. The method according to claim 1, wherein the dropping temperature of the epoxy compound is 25 to 30 ℃.

8. The process according to claim 1, wherein the temperature at which the primary amine is reacted with the epoxy compound is 60 to 65 ℃.

9. The process according to claim 1, characterized in that the reaction time of the primary amine with the epoxy compound is 50 to 60 minutes.

10. The method of claim 1, wherein the TMQ product has a primary amine content of 50ppm or less.