Preparation method of 4,4'-methylene-bis-(3-chloro-2,6-diethylaniline)

Abstract

The invention discloses a preparation method of 4,4'-methylene-bis-(3-chloro-2,6-diethylaniline). The preparation method comprises the following steps: (1) in a nitrogen protective atmosphere, carrying out reaction on raw materials 2,6-diethylaniline and hydrochloric acid to generate 2,6-diethylaniline hydrochloride, and dropwisely adding formalin to carry out condensation reaction; after the reaction finishes, neutralizing with liquid caustic soda, and carrying out water separation to obtain 4,4'-methylene-bis-(2,6-diethylaniline); (2) dissolving the product in the step (1) in a solvent, and introducing chlorine to carry out chlorination reaction; after the reaction finishes, neutralizing with liquid caustic soda, and carrying out water separation to obtain a 4,4'-methylene-bis-(3-chloro-2,6-diethylaniline) crude product; and (3) dissolving the product in the step (2) in a solvent, decolorizing with activated carbon, cooling to crystallize, filtering, and drying to obtain the final product. The method has the advantages of simple technique, accessible raw materials, low price and high product purity and yield, and can easily implement industrial production.

Description

technical field

[0001] The invention belongs to the field of polymer material synthesis, and relates to a preparation method of polyurethane chain extender 4,4'-methylene-bis-(3-chloro-2,6-diethylaniline) [M-CDEA]. Background technique

[0002] The research and development of polyurethane (referred to as PU) materials has a history of more than 60 years. With the continuous expansion of the application of PU materials, the number of its products has leapt to the top of the world's six major synthetic materials, and the global output is about 10 million tons. .

[0003] Due to its excellent performance, PU materials are widely used in various fields of the national economy and in all aspects of people's basic necessities of life. Such as: various non-metallic materials in the aerospace industry, space suits, various thermal insulation materials, conveyor belts for mines, bunker materials for aircraft tanks, artificial blood vessels, artificial kidneys and other medical and h...

Examples

preparation example Construction

[0023] The present invention is a preparation method of 4,4'-methylene-bis-(3-chloro-2,6-diethylaniline), comprising the following steps:

[0024] (1) Add water and hydrochloric acid into the glass reaction bottle, and at the same time pass through nitrogen protection, then add the raw material 2,6-diethylaniline dropwise, stir evenly after the addition, and control the reaction temperature to make the raw material 2,6-diethylaniline Ethylaniline reacts with hydrochloric acid in water to generate 2,6-diethylaniline hydrochloride, then add formaldehyde solution dropwise, the concentration of hydrochloric acid is 26%-36%, the concentration of formaldehyde solution is 28%-37%, after adding Condensation reaction after heat preservation, the dropwise addition temperature and heat preservation temperature of formaldehyde solution are both 50°C-100°C, and the heat preservation time is 2-6 hours. After the reaction is completed, it is neutralized with liquid alkali, and 4,4'- The mola...

Embodiment 1

[0029] Add 600ml of water and 85ml of hydrochloric acid (36%) into a glass reaction bottle, protect it with nitrogen, add 149g of 2,6-diethylaniline dropwise, stir for 30 minutes after the addition, heat up to 50-55°C, and then add 41g of 37 % formaldehyde solution, heat up to 90-95°C and react for 2 hours after the addition, cool down to 30°C after the reaction, neutralize with 30% liquid caustic soda to PH=7, filter to obtain 4,4'-methylene-bis- (2,6-Diethylaniline).

[0030] Add the obtained 4,4'-methylene-bis-(2,6-diethylaniline) into the reaction flask, add 350g of acetic acid, stir and heat to 50-55°C, slowly pass in chlorine gas, when 4,4 When the content of ′-methylene-bis-(3-chloro-2,6-diethylaniline) is ≧95%, stop the chlorine flow, cool down to 30°C after the reaction, add 200ml of water, and use 30% liquid caustic soda and to PH = 7, filtered to obtain 4,4'-methylene-bis(3-chloro-2,6-diethylaniline) crude product.

[0031] The obtained 4,4'-methylene-bis(3-chloro...

Embodiment 2

[0033]Add 600ml of water and 288ml of hydrochloric acid (26%) into a glass reaction bottle, pass nitrogen gas protection, add 149g of 2,6-diethylaniline dropwise, stir for 30 minutes after the addition, heat up to 90-95°C, and then add dropwise 85g of 28% formaldehyde aqueous solution, after the addition, the temperature was raised to 100°C for 6 hours of reaction. After the reaction, cool down to 30°C, neutralize with 30% liquid caustic soda to pH=7, and filter to obtain 4,4'-methylene-bis-(2,6-diethylaniline).

[0034] Add the obtained 4,4'-methylene-bis-(2,6-diethylaniline) into the reaction flask, add 525g of dichloroethane, stir and heat to 60-70°C, slowly introduce chlorine gas, when When the content of 4,4′-methylene-bis-(3-chloro-2,6-diethylaniline) is ≧95%, stop the chlorine flow. After the reaction, cool down to 30°C, add 200ml of water, and use 30% Neutralize with liquid caustic soda to PH=7, filter to obtain 4,4'-methylene-bis(3-chloro-2,6-diethylaniline) crude pr...

technical field

[0001] The invention belongs to the field of polymer material synthesis, and relates to a preparation method of polyurethane chain extender 4,4'-methylene-bis-(3-chloro-2,6-diethylaniline) [M-CDEA]. Background technique

[0002] The research and development of polyurethane (referred to as PU) materials has a history of more than 60 years. With the continuous expansion of the application of PU materials, the number of its products has leapt to the top of the world's six major synthetic materials, and the global output is about 10 million tons. .

[0003] Due to its excellent performance, PU materials are widely used in various fields of the national economy and in all aspects of people's basic necessities of life. Such as: various non-metallic materials in the aerospace industry, space suits, various thermal insulation materials, conveyor belts for mines, bunker materials for aircraft tanks, artificial blood vessels, artificial kidneys and other medical and h...

Examples

preparation example Construction

[0023] The present invention is a preparation method of 4,4'-methylene-bis-(3-chloro-2,6-diethylaniline), comprising the following steps:

[0024] (1) Add water and hydrochloric acid into the glass reaction bottle, and at the same time pass through nitrogen protection, then add the raw material 2,6-diethylaniline dropwise, stir evenly after the addition, and control the reaction temperature to make the raw material 2,6-diethylaniline Ethylaniline reacts with hydrochloric acid in water to generate 2,6-diethylaniline hydrochloride, then add formaldehyde solution dropwise, the concentration of hydrochloric acid is 26%-36%, the concentration of formaldehyde solution is 28%-37%, after adding Condensation reaction after heat preservation, the dropwise addition temperature and heat preservation temperature of formaldehyde solution are both 50°C-100°C, and the heat preservation time is 2-6 hours. After the reaction is completed, it is neutralized with liquid alkali, and 4,4'- The mola...

Embodiment 1

[0029] Add 600ml of water and 85ml of hydrochloric acid (36%) into a glass reaction bottle, protect it with nitrogen, add 149g of 2,6-diethylaniline dropwise, stir for 30 minutes after the addition, heat up to 50-55°C, and then add 41g of 37 % formaldehyde solution, heat up to 90-95°C and react for 2 hours after the addition, cool down to 30°C after the reaction, neutralize with 30% liquid caustic soda to PH=7, filter to obtain 4,4'-methylene-bis- (2,6-Diethylaniline).

[0030] Add the obtained 4,4'-methylene-bis-(2,6-diethylaniline) into the reaction flask, add 350g of acetic acid, stir and heat to 50-55°C, slowly pass in chlorine gas, when 4,4 When the content of ′-methylene-bis-(3-chloro-2,6-diethylaniline) is ≧95%, stop the chlorine flow, cool down to 30°C after the reaction, add 200ml of water, and use 30% liquid caustic soda and to PH = 7, filtered to obtain 4,4'-methylene-bis(3-chloro-2,6-diethylaniline) crude product.

[0031] The obtained 4,4'-methylene-bis(3-chloro...

Embodiment 2

[0033]Add 600ml of water and 288ml of hydrochloric acid (26%) into a glass reaction bottle, pass nitrogen gas protection, add 149g of 2,6-diethylaniline dropwise, stir for 30 minutes after the addition, heat up to 90-95°C, and then add dropwise 85g of 28% formaldehyde aqueous solution, after the addition, the temperature was raised to 100°C for 6 hours of reaction. After the reaction, cool down to 30°C, neutralize with 30% liquid caustic soda to pH=7, and filter to obtain 4,4'-methylene-bis-(2,6-diethylaniline).

[0034] Add the obtained 4,4'-methylene-bis-(2,6-diethylaniline) into the reaction flask, add 525g of dichloroethane, stir and heat to 60-70°C, slowly introduce chlorine gas, when When the content of 4,4′-methylene-bis-(3-chloro-2,6-diethylaniline) is ≧95%, stop the chlorine flow. After the reaction, cool down to 30°C, add 200ml of water, and use 30% Neutralize with liquid caustic soda to PH=7, filter to obtain 4,4'-methylene-bis(3-chloro-2,6-diethylaniline) crude pr...

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