A process for the production of HMDA

Abstract

The application discloses a production method of HMDA, which comprises a process of pretreating a catalyst before a catalytic hydrogenation reaction of 4,4'-MDA; the catalyst pretreatment method is as follows: after the catalyst, a solvent and a heavy component-anti-anti regulator are mixed, the mixture is treated in a high-temperature hydrogen atmosphere for a period of time, and then the catalyst is filtered out after the treatment is completed, and a subsequent catalytic hydrogenation reaction is carried out; the heavy component-anti-anti regulator is cis-1,4-bis(aminomethyl)cyclohexane; preferably, the addition amount of the heavy component-anti-anti regulator is 0.1-15wt% of the mass of the catalyst. 12 The yield of MDA is more than 95%, the content of anti-anti isomer is 13-15%, and no heavy component is generated, so that the unit consumption of raw materials is greatly reduced, and the catalyst does not appear to be deactivated after being used for 60 batches.

Description

Technical Field

[0001] This invention relates to an improved production method, and more particularly to a method for producing HMDA. Background Technology

[0002] 4,4'-H 12 MDA is prepared by hydrogenation of 4,4'-MDA. It exists in three isomers: cis-cis, cis-trans, and trans-trans. The reaction process is shown in the following diagram:

[0003]

[0004] H 12 The melting point of MDA products is related to the composition of the three isomers, especially the trans-trans isomer. Lower trans-trans isomer content results in a lower melting point and better product flowability. For different isomer contents, H... 12 MDA products have different application areas. When the content of trans-trans isomers is above 50%, H 12 MDA is mainly used in the production of polyamides; when the content of trans-trans isomers is below 24%, in addition to being used as an amine epoxy curing agent, H... 12 MDA is mainly used to prepare a new generation of high-performance anti-aging polyurethane dicyclohexylmethane diisocyanate (H2O). 12 MDI), which is also the current H 12 The primary application areas for MDA products. And the lower the content of the trans-trans isomer, the better the downstream H... 12 During the MDA photochemical production process, H 12 The less MDA crystallizes, the less likely it is to precipitate, thus avoiding blockage of the reaction system. However, since the trans-trans isomer is a thermodynamically controlled product, it has the most stable structure among the three isomers. Without catalyst improvement or process optimization, a high content of the trans-trans isomer H will preferentially form. 12 MDA products.

[0005] Existing technologies address how to prepare H with low anti-anti content. 12 MDA proposed different solutions, such as:

[0006] CN103265438A discloses a method for preparing diaminodicyclohexylmethane (H) by hydrogenation of diaminodiphenylmethane (MDA). 12 The MDA method extends the catalyst lifetime by co-producing 2,4'-MDA and 4,4'-MDA, and the resulting anti-trans isomers are approximately 16-24%.

[0007] CN106631826B discloses a method for preparing diaminodicyclohexylmethane (H) by hydrogenation of diaminodiphenylmethane (MDA). 12The MDA method utilizes the acidity of phenolic compounds to reduce tar formation, improve catalyst activity, and increase production efficiency during hydrogenation, with a reaction rate of approximately 17-24%.

[0008] US5196594A discloses a continuous hydrogenation reduction process for MDA using supported ruthenium as a catalyst, although H 12 The yield of MDA can reach 93.7%, but the reaction rate is higher at high yields, exceeding 20%.

[0009] CN109851508B discloses a method for synthesizing HMDA with low trans-trans isomer content and low tar content. The method involves a two-step synthesis: partial hydrogenation is performed under catalyst I to generate diaminomonocyclohexylmonophenylmethane (i.e., hydrogenation of one benzene ring in MDA, H6MDA); the resulting product undergoes complete hydrogenation under catalyst II to generate H… 12 MDA, in which the tar yield is less than 2%, the other by-product yield is less than 1%, and the content of trans-trans isomers is 10-14%.

[0010] The existing technologies described above still have the following shortcomings that need to be addressed:

[0011] Currently, low-retrans-4,4'-diaminodiphenylmethane (H) is produced using 4,4'-diaminodiphenylmethane (MDA) as a raw material. 12 The MDA method generally produces a large amount of heavy components, and it is mostly impossible to control the content of the anti-antibody at a low level. At the same time, the catalyst life is short and it is impossible to maintain good reaction results in multiple batches. Summary of the Invention

[0012] To address the above technical problems, this invention proposes a method for producing HMDA. In this invention, H... 12 The MDA yield exceeds 95%, the trans-trans isomer content is 13-15%, and no heavy components are generated, which greatly reduces the unit consumption of raw materials. The catalyst can be reused 60 times without deactivation.

[0013] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0014] A method for producing HMDA includes a process of pretreating the catalyst before the catalytic hydrogenation reaction of 4,4'-MDA;

[0015] The catalyst pretreatment method is as follows:

[0016] The catalyst, solvent and heavy component-anti-anti modifier are mixed and treated in a high-temperature hydrogen atmosphere for a period of time. After the treatment, the catalyst is filtered out and the subsequent catalytic hydrogenation reaction is carried out. The heavy component-anti-anti modifier is cis-1,4-di(aminomethyl)cyclohexane.

[0017] Preferably, the amount of the heavy component-anti-anti modifier added is 0.1-15 wt% of the catalyst mass.

[0018] This invention uses cis-1,4-di(aminomethyl)cyclohexane as a regulator. After pretreatment, the catalyst more readily forms a cis structure during MDA hydrogenation, thereby reducing trans-trans selectivity. Furthermore, this method is beneficial for promoting H+... 12 MDA desorbs from the inside of the catalyst, thereby inhibiting the formation of heavy components.

[0019] In some preferred examples, the catalyst is a supported catalyst comprising an active metal and a support, preferably a supported catalyst Ru / SiO2;

[0020] Preferably, the active metal includes any one or more of Pd, Pt, Ir, Co, Ru, and Rh;

[0021] Preferably, the carrier comprises any one or more of activated carbon, silicon dioxide, alumina, zirconium oxide, barium sulfate, and calcium carbonate;

[0022] Preferably, the active metal content in the catalyst is 0.1-10 wt%, more preferably 4-5 wt%.

[0023] In some preferred examples, during catalyst pretreatment, the solvent is selected from any one or more of methanol, ethanol, isopropanol, n-butanol, 2-butanol, tetrahydrofuran, 2-methyltetrahydrofuran, dioxane, n-hexane, cyclohexane, and methylcyclohexane.

[0024] Preferably, the amount of solvent added is 50-80 times the mass of the catalyst.

[0025] In some preferred examples, the high-temperature hydrogen atmosphere treatment conditions during catalyst pretreatment are: treatment temperature of 80-200℃, hydrogen pressure of 1-10MPa, and treatment time of 0.5-12h.

[0026] In some preferred examples, the catalytic hydrogenation reaction includes hydrogenating 4,4'-MDA under the action of a pretreated catalyst; the reaction temperature is 100-200°C, the hydrogen pressure is 3-12 MPa, and the reaction time is 0.5-8 h.

[0027] In some preferred examples, the catalytic hydrogenation reaction is carried out in a solvent selected from one or more of methanol, ethanol, isopropanol, n-butanol, 2-butanol, tetrahydrofuran, 2-methyltetrahydrofuran, dioxane, n-hexane, cyclohexane, and methylcyclohexane, wherein the amount of solvent is such that the 4,4'-MDA mass concentration is 30-60 wt%.

[0028] In some preferred examples, the catalyst used in the catalytic hydrogenation reaction is 0.1-2 wt% of the mass of 4,4'-MDA.

[0029] The beneficial technical effects of the present invention are as follows:

[0030] (1) The catalyst is pretreated by heavy component-reverse-reverse regulator to change the catalyst pore structure and promote the formation of cis structure of MDA during hydrogenation, thereby reducing the content of reverse-reverse.

[0031] (2) Pretreatment of the catalyst using heavy component-reaction regulator has been shown to accelerate H 12 The desorption process of MDA from the inside of the catalyst accelerates the reaction while inhibiting the formation of heavy components;

[0032] (3) Since no heavy components are generated, the organic matter adsorbed by the catalyst is easily removed by the solvent, which extends the catalyst life. It can be used for 60 batches without deactivation. Moreover, it was found in the experiment that the catalyst has a high filtration efficiency after hydrogenation reaction. Detailed Implementation

[0033] The present invention will be further illustrated below with specific embodiments. These embodiments are merely illustrative and do not limit the scope of the invention.

[0034] Unless otherwise specified, the raw materials used in the following examples or comparative examples are all commercially available industrial-grade conventional raw materials. The main raw materials and testing instrument information are as follows:

[0035] 4,4'-MDA is from Wanhua Chemical and has a purity greater than 99%.

[0036] n-Butanol was purchased from Beijing Innovent Technology Co., Ltd., and was of analytical grade.

[0037] The Ru / SiO2 catalyst was purchased from Johnson Matthey.

[0038] cis-1,4-di(aminomethyl)cyclohexane was purchased from Beijing Innocare Technology Co., Ltd.

[0039] Gas chromatography was performed using an Agilent 7890B DB-5 capillary column with an FID detector at 300°C. The initial column temperature was 50°C, increased to 300°C at a rate of 10°C / min, and held for 20 min. Where t, tH 12 MDA stands for anti-antoisomer.

[0040]

Example 1

[0041] (1) Catalyst pretreatment: 1.0 g of Ru / SiO2 catalyst (Ru 1wt%), 80 g of n-butanol solvent, and 0.005 g of cis-1,4-di(aminomethyl)cyclohexane were added to a 1 L reactor. The reactor was substituted three times with N2 at 1 MPa (G), followed by three times with H2 at 1 MPa (G). The pressure was then increased to 1 MPa with H2. The temperature was raised to 100 °C, and the target pressure was controlled at 10 MPa. After 5 h, the reactor was cooled and filtered to remove the solvent.

[0042] (2) Hydrogenation reaction: Dissolve 250g of raw material MDA in 500g of n-butanol solvent, add it to a reactor containing pretreated catalyst, replace it three times with 1MPa(G) N2, and then replace it three times with 1MPa(G) H2. Then pressurize with H2 to 1MPa. Raise the temperature to the reaction temperature of 180℃, control the target pressure at 4MPa, react for 4h, cool down and filter, take samples for analysis, and the results are shown in Table 1 below.

[0043] Table 1. Analysis results of the reaction solution in Example 1

[0044] <![CDATA[H 12 MDA / %]]> <![CDATA[t,t-H 12 MDA / %]]> other / % Conversion rate / % Run1 95.88 14.12 4.12 100 Run20 95.27 14.31 4.73 100 Run60 94.59 14.82 5.41 100

[0045] Note: Other components mainly include intermediate hydrogenation component H6MDA and light components; heavy components were not detected.

[0046]

Example 2

[0047] (1) Catalyst pretreatment: 1.5 g of Ru / SiO2 catalyst (Ru 5wt%), 90 g of n-butanol solvent, and 0.03 g of cis-1,4-di(aminomethyl)cyclohexane were added to a 1 L reactor. The catalyst was replaced three times with N2 at 1 MPa (G), and then three times with H2 at 1 MPa (G). The pressure was then increased to 1 MPa with H2. The temperature was raised to 180 °C, and the target pressure was controlled at 8 MPa. After 4 h, the reactor was cooled and filtered to remove the solvent.

[0048] (2) Hydrogenation reaction: Dissolve 100g of raw material MDA in 100g of n-butanol solvent, add it to a reactor containing a pretreated catalyst, replace it three times with 1MPa(G) N2, and then replace it three times with 1MPa(G) H2. Then pressurize with H2 to 1MPa. Raise the temperature to the reaction temperature of 120℃, control the target pressure at 10MPa, react for 3h, cool down and filter, take samples for analysis, and the results are shown in Table 2 below.

[0049] Table 2. Analysis results of the reaction solution in Example 2

[0050]

[0051]

[0052] Note: Other components mainly include intermediate hydrogenation component H6MDA and light components; heavy components were not detected.

[0053]

Example 3

[0054] (1) Catalyst pretreatment: 1.5 g of Ru / SiO2 catalyst (Ru 5wt%), 90 g of n-butanol solvent, and 0.075 g of cis-1,4-di(aminomethyl)cyclohexane were added to a 1 L reactor. The catalyst was replaced three times with N2 at 1 MPa (G), and then three times with H2 at 1 MPa (G). The pressure was then increased to 1 MPa with H2. The temperature was raised to 180 °C, and the target pressure was controlled at 8 MPa. After 4 h, the reactor was cooled and filtered to remove the solvent.

[0055] (2) Hydrogenation reaction: Dissolve 100g of raw material MDA in 100g of n-butanol solvent, add it to a reactor containing a pretreated catalyst, replace it three times with 1MPa(G) N2, and then replace it three times with 1MPa(G) H2. Then pressurize with H2 to 1MPa. Raise the temperature to the reaction temperature of 150℃, control the target pressure at 3MPa, react for 2h, cool down and filter, take samples for analysis, and the results are shown in Table 3 below.

[0056] Table 3. Analysis results of the reaction solution in Example 3

[0057] <![CDATA[H 12 MDA / %]]> <![CDATA[t,t-H 12 MDA / %]]> other / % Conversion rate / % Run1 96.72 12.85 3.28 100 Run20 96.38 13.11 3.62 100 Run60 96.08 13.26 3.92 100

[0058] Note: Other components mainly include intermediate hydrogenation component H6MDA and light components; heavy components were not detected.

[0059]

Example 4

[0060] (1) Catalyst pretreatment: 1.5 g of Ru / SiO2 catalyst (Ru 5wt%), 90 g of n-butanol solvent, and 0.15 g of cis-1,4-di(aminomethyl)cyclohexane were added to a 1 L reactor. The catalyst was replaced three times with N2 at 1 MPa (G), and then three times with H2 at 1 MPa (G). The pressure was then increased to 1 MPa with H2. The temperature was raised to 120 °C, and the target pressure was controlled at 5 MPa. After 3 h, the reactor was cooled and filtered to remove the solvent.

[0061] (2) Hydrogenation reaction: Dissolve 150g of raw material MDA in 150g of n-butanol solvent, add it to a reactor containing pretreated catalyst, replace it three times with 1MPa(G) N2, and then replace it three times with 1MPa(G) H2. Then pressurize with H2 to 1MPa. Raise the temperature to the reaction temperature of 150℃, control the target pressure at 8MPa, react for 2h, cool down and filter, take samples for analysis, and the results are shown in Table 4 below.

[0062] Table 4. Analysis results of the reaction solution in Example 4

[0063] <![CDATA[H 12 MDA / %]]> <![CDATA[t,t-H 12 MDA / %]]> other / % Conversion rate / % Run1 96.23 12.91 3.77 100 Run20 95.81 13.18 4.19 100 Run60 95.36 13.27 4.64 100

[0064] Note: Other components mainly include intermediate hydrogenation component H6MDA and light components; heavy components were not detected.

[0065]

Example 5

[0066] (1) Catalyst pretreatment: 2g of Ru / SiO2 catalyst (Ru 4wt%), 100g of n-butanol solvent, and 0.24g of cis-1,4-di(aminomethyl)cyclohexane were added to a 1L reactor. The catalyst was replaced three times with N2 at 1MPa(G), and then three times with H2 at 1MPa(G). The pressure was then increased to 1MPa with H2. The temperature was raised to 200℃, and the target pressure was controlled at 6MPa. After 5h, the reactor was cooled and filtered to remove the solvent.

[0067] (2) Hydrogenation reaction: Dissolve 200g of raw material MDA in 300g of n-butanol solvent, add it to a reactor containing a pretreated catalyst, replace it three times with 1MPa(G) N2, and then replace it three times with 1MPa(G) H2. Then pressurize with H2 to 1MPa. Raise the temperature to the reaction temperature of 160℃, control the target pressure at 6MPa, react for 3h, cool down and filter, take samples for analysis, and the results are shown in Table 5 below.

[0068] Table 5. Analysis results of the reaction solution in Example 5

[0069] <![CDATA[H 12 MDA / %]]> <![CDATA[t,t-H 12 MDA / %]]> other / % Conversion rate / % Run1 96.06 13.25 3.94 100 Run20 95.58 13.37 4.42 100 Run60 95.21 13.58 4.79 100

[0070] Note: Other components mainly include intermediate hydrogenation component H6MDA and light components; heavy components were not detected.

[0071] Comparative Example 1

[0072] H was produced using a method essentially the same as that used in Example 2. 12 The only difference with MDA is that cis-1,4-di(aminomethyl)cyclohexane is not added during catalyst pretreatment in step (1). Samples were taken and analyzed after the reaction, and the results are shown in Table 6 below.

[0073] Table 6. Analysis results of the reaction solution in Example 6

[0074] <![CDATA[H 12 MDA / %]]> <![CDATA[t,t-H 12 MDA / %]]> Recombinant components / % other / % Conversion rate / % Run1 91.52 17.89 3.17 5.31 100 Run20 88.93 18.66 4.56 6.51 100 Run60 85.05 19.25 6.24 8.71 100

[0075] Note: Other components mainly include intermediate hydrogenation component H6MDA and light components.

[0076] The above description is only a preferred embodiment of the present invention. It should be noted that those skilled in the art can make several improvements and additions without departing from the method of the present invention, and these improvements and additions should also be considered within the scope of protection of the present invention.

Claims

1. A method for producing HMDA, characterized by, The process comprises pretreating the catalyst before the catalytic hydrogenation reaction of 4,4'-MDA; The catalyst pretreatment method is: The catalyst, solvent and heavy component-anti-backward adjustment agent are mixed, and then treated in a high-temperature hydrogen atmosphere for a period of time, and the catalyst is filtered out after the treatment, and then subjected to subsequent catalytic hydrogenation reaction; the heavy component-anti-backward adjustment agent is cis-1,4-bis(aminomethyl)cyclohexane.

2. The method of producing HMDA according to claim 1, characterized by, The addition amount of the heavy component-anti-backward adjustment agent is 0.1-15wt% of the mass of the catalyst.

3. The method of producing HMDA according to claim 1, characterized by, The catalyst is a supported catalyst comprising an active metal and a carrier.

4. The method of producing HMDA according to claim 3, characterized by, The catalyst is a supported catalyst Ru / SiO2.

5. The method of producing HMDA according to claim 3, wherein The active metal comprises any one or more of Pd, Pt, Ir, Co, Ru, and Rh.

6. The method of producing HMDA according to claim 3, wherein The carrier comprises any one or more of activated carbon, silicon oxide, aluminum oxide, zirconium oxide, barium sulfate, and calcium carbonate.

7. The method of producing HMDA according to claim 3, wherein The content of the active metal in the catalyst is 0.1-10wt%.

8. The method of producing HMDA according to claim 7, wherein The content of the active metal in the catalyst is 4-5wt%.

9. The method of producing HMDA according to claim 1, wherein In the catalyst pretreatment process, the solvent is selected from any one or more of methanol, ethanol, isopropanol, n-butanol, 2-butanol, tetrahydrofuran, 2-methyltetrahydrofuran, dioxane, n-hexane, cyclohexane, and methylcyclohexane.

10. The method of producing HMDA according to claim 9, wherein The addition amount of the solvent is 50-80 times of the mass of the catalyst.

11. The process for the production of HMDA according to any one of claims 1 to 10, characterized in that, In the catalyst pretreatment process, the treatment conditions of the high-temperature hydrogen atmosphere are: the treatment temperature is 80-200℃, the hydrogen pressure is 1-10MPa, and the treatment time is 0.5-12h.

12. The process for the production of HMDA according to any one of claims 1 to 10, characterized in that, The catalytic hydrogenation reaction comprises hydrogenation of 4,4'-MDA under the action of the pretreated catalyst; the reaction temperature is 100-200℃, the hydrogen pressure is 3-12MPa, and the reaction time is 0.5-8h.

13. The process for the production of HMDA according to any one of claims 1 to 10, characterized in that, The catalytic hydrogenation reaction is carried out in a solvent selected from any one or more of methanol, ethanol, isopropanol, n-butanol, 2-butanol, tetrahydrofuran, 2-methyltetrahydrofuran, dioxane, n-hexane, cyclohexane, and methylcyclohexane, and the amount of the solvent is such that the mass concentration of 4,4'-MDA is 30-60wt%.

14. The process for the production of HMDA according to any one of claims 1 to 10, characterized in that, In the catalytic hydrogenation reaction, the amount of the catalyst is 0.1-2wt% of the mass of 4,4'-MDA.

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