Process for the production of n,n-diethyl-1,3-propanediamine for electronic applications

Abstract

The application belongs to the field of fine chemical organic synthesis and provides a production method of diethyl-1,3-propanediamine N,N The application discloses a production method of diethyl-1,3-propanediamine, which is prepared from acrylonitrile and diethylamine and realizes addition and hydrogenation two-step reactions under the action of a bentonite-supported nickel-iron catalyst. The diethylamine is preheated by an evaporator and then introduced into a reaction kettle, so that the mass transfer and heat transfer between reactants in the reaction process are strengthened, the efficiency of Michael addition is improved, the conversion rate of acrylonitrile can reach 100%, and the yield of the intermediate 3-(diethylamino) propionitrile is 100%. By regulating the acid-base active sites of the catalyst and by the synergistic effect between the active components nickel-iron and the carrier bentonite, the stability and selectivity of the catalyst are greatly improved, and the risk caused by the introduction of other additives is avoided. The application has the advantages of simple process, low equipment investment cost and practical significance for replacing the existing production process.

Description

Technical Field

[0001] This invention belongs to the field of fine chemical organic synthesis, specifically relating to an electronic... N,N Production method of diethyl-1,3-propanediamine. Background Technology

[0002] N,N Diethyl-1,3-propanediamine is an important specialty amine with both tertiary and primary amine functional groups in its molecular structure. It is widely used in epoxy resin curing agents, polyurethane catalysts, and surfactants. Currently, its industrial production mainly employs a two-step process. First, diethylamine and acrylonitrile are reacted via a Michael addition reaction to obtain the intermediate 3-(diethylamino)propionitrile. Then, 3-(diethylamino)propionitrile reacts with hydrogen in the presence of a Raney nickel or Raney cobalt hydrogenation catalyst to obtain the target product. N,N -Diethyl-1,3-propanediamine. The first step of this process requires the addition of acid or alkali, polar solvents, increased temperature, and extended reaction time to promote the complete conversion of acrylonitrile, achieving a yield of 97-98% for 3-(diethylamino)propionitrile. This process has relatively low efficiency and poisons the catalyst used in subsequent hydrogenation reactions, affecting catalytic performance. The second step, hydrogenation, typically uses Raney nickel or Raney cobalt catalysts to reduce the cyano group. However, this reaction has low selectivity; the hydrogenation intermediate imine can be further hydrogenated to form a primary amine or react with a primary amine to deamination and form a secondary amine. The secondary amine can then be further deaminationed to form a tertiary amine. Currently, industrial production generally uses methods such as introducing ammonia or adding inorganic alkalis to suppress side reactions and improve the selectivity of the primary amine. This inevitably leads to a shortened catalyst life, generates more waste, and the primary amine selectivity is limited to a maximum of 95%, increasing the difficulty of subsequent separation and purification.

[0003] Patent CN103333073A discloses a continuous method for preparing similar products. N,N The process for dimethyl-1,3-propanediamine uses two fixed-bed reactors in series to achieve the addition and hydrogenation reactions respectively, and requires the addition of an inorganic base in alcohol or aqueous solution as an inhibitor. This method is complex to operate, has high equipment investment costs, increases waste, and the final product yield is only about 98%, with low product purity.

[0004] Patent CN113501761A discloses a continuous production N,N The method for producing diethyl-1,3-propanediamine involves a two-stage tubular fixed-bed reactor, filled with ion exchange resin and a single-atom metal catalyst, respectively, to facilitate the reaction of acrylonitrile and diethylamine to produce... N,N-Diethyl-1,3-propanediamine. This method requires two different packing materials, making the process complex. Furthermore, fixed-bed reactors suffer from poor heat transfer, complex temperature distribution, inability to use powdered catalysts, and insufficient utilization of the active inner surface of the catalyst, all of which affect the selectivity and yield of the target product and result in low economic efficiency. Summary of the Invention

[0005] To address the shortcomings of existing methods, the purpose of this invention is to provide an electronic product that features a simple process, low equipment investment cost, and high product selectivity and purity. N,N Production method of diethyl-1,3-propanediamine.

[0006] The present invention adopts the following technical solution: An electronic N,N The production method of diethyl-1,3-propanediamine employs a one-pot, two-step process to achieve the target product by Michael addition and hydrogenation reduction reactions of acrylonitrile and diethylamine under the action of a catalyst. N,N -Diethyl-1,3-propanediamine. After the reaction, trace impurities are removed by distillation using a thin-film evaporator to obtain a product with a purity of over 99.9%.

[0007] This invention utilizes a single reactor to perform a two-step reaction, synthesizing... N,N Diethyl-1,3-propanediamine. First, acrylonitrile and bentonite-supported nickel-iron catalyst are added to the reactor. Then, diethylamine is preheated and vaporized via an evaporator, and then bubbled into the reactor for an addition reaction to prepare the intermediate 3-(diethylamino)propionitrile. After the diethylamine is completely bubbled, the temperature is maintained. Once the acrylonitrile content is below 50 ppm, hydrogen gas is introduced to raise the temperature and carry out a hydrogenation reaction to prepare the target product. N,N -Diethyl-1,3-propanediamine.

[0008] This invention utilizes a bentonite-supported nickel-iron catalyst to achieve the addition reaction of acrylonitrile and diethylamine and the hydrogenation reduction reaction of the intermediate 3-(diethylamino)propionitrile. Compared to existing production processes that use a slow dropwise addition of acrylonitrile, this method preheats and vaporizes the diethylamine before blowing it into the reaction vessel, increasing the contact time between the diethylamine and acrylonitrile. Utilizing the temperature difference of the reactants, the diethylamine slowly liquefies, releasing latent heat to provide heat for the reaction, thereby improving the mass and heat transfer efficiency of the reaction. Furthermore, the active sites on the bentonite-supported nickel-iron catalyst promote the polarization of the double bonds in acrylonitrile, accelerating the reaction process and promoting the addition reaction of acrylonitrile and diethylamine. Simultaneously, it avoids the introduction of solvents and other additives, simplifying the production process and reducing the generation of waste. In the hydrogenation reduction process, the intermediate 3-(diethylamino)propionitrile reacts with hydrogen under the catalysis of a self-made bentonite-supported nickel-iron catalyst to generate the target product. By introducing metallic iron to regulate the acid-base activity sites of the catalyst, and through the synergistic effect between the active component nickel-iron and the support bentonite, the target product primary amine is generated with high selectivity. This avoids the disadvantages of adding alkaline additives in traditional processes, greatly simplifies the process flow and reduces production costs, and obtains the target product with high raw material conversion rate and yield.

[0009] In this invention, the molar ratio of acrylonitrile to diethylamine is 1:1.00-1.05. Diethylamine is preheated in an evaporator before entering the reaction vessel, with the evaporation temperature controlled at 55-75°C, preferably 55-60°C. Since the reaction of acrylonitrile and diethylamine is exothermic, the feed rate of diethylamine is interlocked with the temperature of the reaction vessel. The temperature of the reaction vessel is controlled at 60-70°C, and the feed rate of diethylamine is 50-500 kg / h, preferably 50-200 kg / h. The amount of bentonite-supported nickel-iron catalyst added is 5-30 wt% (based on the weight of acrylonitrile), preferably 5-20%.

[0010] The acrylonitrile and diethylamine mentioned are both high-purity acrylonitrile and diethylamine with a purity greater than 99%.

[0011] In this invention, the process conditions for the intermediate hydrogenation reduction process are as follows: the hydrogenation reaction temperature is 80-100℃, preferably 85-95℃; the reaction pressure is 1-4MPa, preferably 2-3MPa.

[0012] In this invention, the active components of the bentonite-supported nickel-iron catalyst are metallic nickel and iron, with the loading of the active metal being 2-20%, preferably 5-15%, and the molar ratio of metallic nickel to metallic iron being 20-50:1. The nickel salt used to prepare the active metal can be Ni(NO3)2·6H2O, NiCl2·6H2O, NiSO4·6H2O, Ni(CH3COO)2·4H2O, etc., preferably Ni(NO3)2·6H2O; the iron salt can be Fe(NO3)3·9H2O, FeCl3·6H2O, Fe2(SO4)3·9H2O, etc., preferably Fe(NO3)3·9H2O; the support can be calcium-based bentonite, sodium-based bentonite, magnesium-based bentonite, or aluminum-based bentonite, preferably sodium-based bentonite.

[0013] The preparation method of the bentonite-supported nickel-iron catalyst of the present invention is as follows: A certain amount of bentonite is dispersed in deionized water at room temperature and swelled for a certain period of time for later use. Then, a nickel salt solution and an iron salt solution of a certain concentration are prepared and added dropwise to a sodium hydroxide solution of a certain concentration in proportion. After the addition is completed, the temperature is raised to 100°C and aged for a certain period of time. The above mixture is then slowly added dropwise to the bentonite suspension. After the addition is completed, stirring is continued, and the mixture is filtered. The filter cake is washed with deionized water until neutral and dried at 100-105°C to obtain the catalyst precursor. Finally, the catalyst precursor is calcined at 400-600°C for a certain period of time in a hydrogen atmosphere at a heating rate of 5°C / min to obtain the corresponding bentonite-supported nickel-iron catalyst.

[0014] Compared with existing technologies, the advantages of this invention are as follows: using acrylonitrile and diethylamine as raw materials, a two-step reaction of addition and hydrogenation is achieved under the action of a bentonite-supported nickel-iron catalyst. Preheating and vaporizing diethylamine in an evaporator before blowing it into the reactor enhances mass and heat transfer between reactants during the reaction, improving the efficiency of Michael addition. The conversion rate of acrylonitrile can reach 100%, and the yield of the intermediate 3-(diethylamino)propionitrile is 100%. By controlling the acid-base activity sites of the catalyst and through the synergistic effect between the active component nickel-iron and the support bentonite, while avoiding the risks associated with introducing other additives, the stability and selectivity of the catalyst are greatly improved. This invention has a simple process and low equipment investment cost, making it more practically significant for replacing existing production processes. Attached Figure Description

[0015] Figure 1 This is a comparison table of the analytical results of Examples 1-6 and Comparative Examples 1-3.

[0016] Figure 2 A comparative table of changes in the conversion rate and product selectivity of raw materials after 10 applications of bentonite-supported nickel-iron catalyst. Detailed Implementation

[0017] To better understand the present invention, the following embodiments further illustrate the content of the present invention, but the content of the present invention is not limited to the following embodiments.

[0018] Example 1

[0019] 1 kg of bentonite was dispersed in 5 kg of deionized water at room temperature and stirred for 30 min. Then, 302 g of Ni(NO3)2 solution (50 wt%) and 20 g of Fe(NO3)3 solution (50 wt%) were added dropwise to the suspension and stirred for 30 min. Then, 100 g of sodium hydroxide solution (40 wt%) was slowly added dropwise to the mixture. After the addition was complete, the temperature was raised to 100 °C and aged for 2 h. After cooling to room temperature, the mixture was filtered, and the filter cake was washed with deionized water until neutral. It was then dried at 100-105 °C to obtain the catalyst precursor. Finally, the catalyst precursor was calcined at 400 °C for a certain time under a hydrogen atmosphere at a heating rate of 5 °C / min. After cooling, it was ground to 40-60 mesh to obtain a bentonite-supported nickel-iron catalyst with a loading of 5% (5% Ni). 20 Fe1 / MMT).

[0020] Example 2

[0021] 1 kg of bentonite was dispersed in 5 kg of deionized water at room temperature and stirred for 30 min. Then, 604 g of Ni(NO3)2 solution (50 wt%) and 40 g of Fe(NO3)3 solution (50 wt%) were added dropwise to the suspension and stirred for 30 min. Then, 200 g of sodium hydroxide solution (40 wt%) was slowly added dropwise to the mixture. After the addition was complete, the temperature was raised to 100 °C and aged for 2 h. After cooling to room temperature, the mixture was filtered, and the filter cake was washed with deionized water until neutral. It was then dried at 100-105 °C to obtain the catalyst precursor. Finally, the catalyst precursor was calcined at 400 °C for a certain time under a hydrogen atmosphere at a heating rate of 5 °C / min. After cooling, it was ground to 40-60 mesh to obtain a bentonite-supported nickel-iron catalyst (10% Ni). 20 Fe1 / MMT).

[0022] Example 3

[0023] 1 kg of bentonite was dispersed in 5 kg of deionized water at room temperature and stirred for 30 min. Then, 906 g of Ni(NO3)2 solution (50 wt%) and 60 g of Fe(NO3)3 solution (50 wt%) were added dropwise to the suspension and stirred for 30 min. Then, 300 g of sodium hydroxide solution (40 wt%) was slowly added dropwise to the mixture. After the addition was complete, the temperature was raised to 100 °C and aged for 2 h. After cooling to room temperature, the mixture was filtered, and the filter cake was washed with deionized water until neutral. It was then dried at 100-105 °C to obtain the catalyst precursor. Finally, the catalyst precursor was calcined at 400 °C for a certain time under a hydrogen atmosphere at a heating rate of 5 °C / min. After cooling, it was ground to 40-60 mesh to obtain a bentonite-supported nickel-iron catalyst (15% Ni). 20 Fe1 / MMT).

[0024] Example 4

[0025] 1 kg of bentonite was dispersed in 5 kg of deionized water at room temperature and stirred for 30 min. Then, 453.2 g of Ni(NO3)2 solution (50 wt%) and 20 g of Fe(NO3)3 solution (50 wt%) were added dropwise to the suspension and stirred for 30 min. Then, 100 g of sodium hydroxide solution (40 wt%) was slowly added dropwise to the mixture. After the addition was complete, the temperature was raised to 100 °C and aged for 2 h. After cooling to room temperature, the mixture was filtered, and the filter cake was washed with deionized water until neutral. It was then dried at 100-105 °C to obtain the catalyst precursor. Finally, the catalyst precursor was calcined at 400 °C for a certain time under a hydrogen atmosphere at a heating rate of 5 °C / min. After cooling, it was ground to 40-60 mesh to obtain a bentonite-supported nickel-iron catalyst (5% Ni). 30 Fe1 / MMT).

[0026] Example 5

[0027] 1 kg of bentonite was dispersed in 5 kg of deionized water at room temperature and stirred for 30 min. Then, 604.3 g of Ni(NO3)2 solution (50 wt%) and 20 g of Fe(NO3)3 solution (50 wt%) were added dropwise to the suspension and stirred for 30 min. Then, 100 g of sodium hydroxide solution (40 wt%) was slowly added dropwise to the mixture. After the addition was complete, the temperature was raised to 100 °C and aged for 2 h. After cooling to room temperature, the mixture was filtered, and the filter cake was washed with deionized water until neutral. It was then dried at 100-105 °C to obtain the catalyst precursor. Finally, the catalyst precursor was calcined at 400 °C for a certain time under a hydrogen atmosphere at a heating rate of 5 °C / min. After cooling, it was ground to 40-60 mesh to obtain a bentonite-supported nickel-iron catalyst (5% Ni). 40 Fe1 / MMT).

[0028] Example 6

[0029] At room temperature, 1 kg of bentonite was dispersed in 5 kg of deionized water. After stirring for 30 min, 755.4 g of Ni(NO3)2 solution (50 wt%) and 20 g of Fe(NO3)3 solution (50 wt%) were successively added dropwise to the above suspension and stirred for 30 min. Then, 100 g of sodium hydroxide solution (40 wt%) was slowly added dropwise to the above mixture. After the addition, the temperature was raised to 100 °C and aged for 2 h; after cooling to room temperature, filtration was carried out, and the filter cake was washed with deionized water until neutral, dried at 100 - 105 °C to obtain a catalyst precursor. Finally, the catalyst precursor was calcined at 500 °C in a hydrogen atmosphere at a heating rate of 5 °C / min for a certain time, cooled and ground to 40 - 60 mesh to obtain a bentonite-supported nickel-iron catalyst with a loading of 5% (5%Ni 50 Fe1 / MMT).

[0030] Preparation example: The catalysts prepared in the above examples were respectively used for the production of N,N -diethyl-1,3-propanediamine.

[0031] Start the acrylonitrile feed pump, pump 100 kg of acrylonitrile into the pilot-scale reactor, and then add 10 kg of the above catalyst into the reactor through the feeding hole. Replace with nitrogen and hydrogen three times respectively. Sample to control the oxygen content in the reactor to be less than 0.4%. If unqualified, continue to replace until qualified. Then, 139 kg of diethylamine was put into the evaporator, heated to 55 - 60 °C for preheating and gasification, and diethylamine was introduced into the reactor at a feeding rate of 50 kg / h for addition reaction. Turn on the condensing circulating water. After the introduction of diethylamine, keep the temperature at 60 - 70 °C for 2 h. Sample for chromatographic analysis. When the intermediate content is above 99.99% and the acrylonitrile content is at 50 ppm, hydrogen is introduced, the pressure in the reactor is controlled at 2 - 3 MPa, and the hydrogenation temperature is controlled between 85 - 95 °C for reaction. After the pressure in the reactor basically no longer changes, sample for analysis. When the content of 3-(diethylamino)propionitrile in the intermediate is less than 0.05%, it is qualified. If unqualified, continue to keep the temperature until qualified. After qualification, filter the materials in the reactor and transfer them to the thin-film evaporator for rectification to obtain high-purity N,N -diethyl-1,3-propanediamine. The corresponding analysis results are shown in Figure 1 .

[0032] Comparative Examples 1 - 3 Using the catalyst preparation methods of Examples 1-6, three Ni(NO3)2 solutions with different addition ratios were added dropwise to the above suspension as active components and stirred for 30 min. Then, a stoichiometric amount of sodium hydroxide solution (40 wt%) was slowly added dropwise to the above mixture. After the addition was complete, the temperature was raised to 100 °C and aged for 2 h. After cooling to room temperature, the mixture was filtered, and the filter cake was washed with deionized water until neutral. It was then dried at 100-105 °C to obtain the catalyst precursor. Finally, the catalyst precursor was calcined at 400 °C for a certain time under a hydrogen atmosphere at a heating rate of 5 °C / min. After cooling, it was ground to 40-60 mesh to obtain bentonite-supported nickel catalysts (Ni / MMT) with loadings of 5%, 15%, and 20%, respectively.

[0033] Examples 7-16 According to the preparation example, the catalyst prepared according to the method in Example 4 was reused ten times. After each reuse, 1 wt% of catalyst was added to compensate for catalyst loss caused by the production process. The analytical results after each reuse are shown in [the table below]. Figure 2 .

[0034] from Figure 1 As shown in Example 1 and Comparative Examples 1-3, catalysts with only a single active component are less effective than catalysts with two active components in both addition and hydrogenation reactions. The addition of active metal Fe significantly improves the catalyst activity, indicating that by introducing metallic iron to regulate the acid-base active sites of the catalyst, and through the synergistic effect between the active component nickel-iron and the support bentonite, the target product primary amine can be generated with high selectivity. Furthermore, when the molar ratio of active metals nickel to iron increases to 30, the conversion rate of acrylonitrile and intermediates reaches 99.9%, and the product selectivity is 99.9%. However, when the Fe content on the catalyst is further increased, the nickel sites on the catalyst are replaced by metallic iron, and the catalyst activity decreases slightly. Therefore, a molar ratio of nickel to iron supported on the catalyst of 30:1 is preferred.

[0035] Figure 2 The results showed that after six consecutive applications of the bentonite-supported nickel-iron catalyst, the conversion rate of the raw materials and the selectivity of the products did not change significantly. After continued application, the conversion rates of the raw materials acrylonitrile and intermediates did not change significantly, but with the increase of the number of applications, the selectivity of the target product decreased slightly. After ten consecutive applications, it decreased to 98.5%, but still had good activity, indicating that the catalyst described in this invention has good stability and lifespan.

Claims

1. A method for producing N,N-diethyl-1,3-propanediamine for electronic applications, characterized in that, Includes the following steps: Step 1: Start the acrylonitrile feed pump to pump acrylonitrile into the reactor. Add the catalyst into the reactor through the feed hole. Replace the catalyst with nitrogen and hydrogen at least 3 times each until the oxygen content of the sampled gas in the reactor is controlled to be below 0.4%. Step 2: Diethylamine is fed into an evaporator and preheated to 55-60℃ for vaporization. Diethylamine is then fed into a reactor at a feed rate of 50 kg / h for addition reaction. Cooling circulating water is circulated into the reactor jacket. After the reaction is completed, the reactor is kept at 60-70℃ for 2 hours until the reaction solution is sampled and chromatographically analyzed to show that the intermediate content is above 99.99% and the acrylonitrile content is below 50 ppm. Step 3: Introduce hydrogen gas into the reactor, maintaining the reactor pressure at 2-3 MPa and the hydrogenation temperature at 85-95℃. Continue this process until the pressure inside the reactor no longer changes, then maintain the temperature until the content of intermediate 3-(diethylamino)propionitrile is less than 0.05% in a sample analysis. Step 4: After filtering the material in the reactor, send it to a thin-film evaporator for distillation to obtain high-purity N,N-diethyl-1,3-propanediamine.

2. The method for producing N,N-diethyl-1,3-propanediamine for electronic use according to claim 1, characterized in that, The molar ratio of acrylonitrile to diethylamine is 1:1.00-1.

05. The diethylamine is preheated in an evaporator before entering the reaction vessel. The evaporation temperature is preferably 55-60℃, and the temperature of the reaction vessel is controlled at 60-70℃. The feed rate of diethylamine is 50-200 kg / h.

3. The method for producing N,N-diethyl-1,3-propanediamine for electronic use according to claim 1, characterized in that, The catalyst is added in an amount of 5-20 wt% (based on the weight of acrylonitrile).

4. The method for producing N,N-diethyl-1,3-propanediamine for electronic use according to claim 1, characterized in that, The acrylonitrile and diethylamine mentioned are both high-purity acrylonitrile and diethylamine with a purity greater than 99%.

5. The method for producing N,N-diethyl-1,3-propanediamine for electronic use according to claim 1, characterized in that, The hydrogenation reaction pressure is 2-3 MPa.

6. The method for producing N,N-diethyl-1,3-propanediamine for electronic use according to claim 1, characterized in that, The catalyst is a bentonite-supported nickel-iron catalyst, and its active components are metallic nickel and iron.

7. The method for producing N,N-diethyl-1,3-propanediamine for electronic use according to claim 6, characterized in that, The preparation method of the bentonite-supported nickel-iron catalyst is as follows: Bentonite is dispersed in deionized water at room temperature and swelled for later use. Nickel salt solution and iron salt solution are prepared and added dropwise to sodium hydroxide solution in proportion. After the addition is completed, the temperature is raised to 100℃ for aging. The above mixture is slowly added dropwise to the bentonite suspension. After the addition is completed, stirring is continued, and the mixture is filtered. The filter cake is washed with deionized water until neutral and dried at 100-105℃ to obtain the catalyst precursor. The catalyst precursor is calcined at 400-600℃ in a hydrogen atmosphere at a heating rate of 5℃ / min. After cooling, it is ground to 40-60 mesh to obtain a bentonite-supported nickel-iron catalyst with a loading of 5% (5%Ni30Fe1 / MMT).

8. The method for producing N,N-diethyl-1,3-propanediamine for electronic use according to claim 7, characterized in that, The loading of the active component is 5-15%, and the molar ratio of metallic nickel to metallic iron is 20-50:

1. The nickel salt used to prepare the active metal is one of Ni(NO3)2·6H2O, NiCl2·6H2O, NiSO4·6H2O, and Ni(CH3COO)2·4H2O, and the iron salt is one of Fe(NO3)3·9H2O, FeCl3·6H2O, and Fe2(SO4)3·9H2O, etc. The carrier is one of calcium-based bentonite, sodium-based bentonite, magnesium-based bentonite, or aluminum-based bentonite.

9. A method for producing N,N-diethyl-1,3-propanediamine for electronic use according to claim 7, characterized in that, The preferred nickel salt is Ni(NO3)2·6H2O, the preferred iron salt is Fe(NO3)3·9H2O, and the preferred carrier is sodium-based bentonite.

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