Method for preparing N,N-diaminopropylcyclohexylamine based on cyclohexylamine

Abstract

The present invention belongs to the technical field of polymer synthesis, and particularly relates to a method for preparing N,N-diaminopropylcyclohexylamine based on cyclohexylamine, which comprises the following steps: (1) Mix cyclohexylamine with water, first add part of acrylonitrile for reaction; then add a catalyst and add the remaining acrylonitrile again for continuous reaction; filter, adsorb, and rotary evaporate the obtained solution to obtain N,N-dicyanoethylcyclohexylamine; (2) Mix N,N-dicyanoethylcyclohexylamine, cobalt-based powder catalyst, ammonia water, EDTA and a solvent, and carry out a hydrogenation reaction after introducing hydrogen to obtain N,N-diaminopropylcyclohexylamine. The reaction conditions of the present invention are relatively mild, the process is simple, the cost is low, the catalyst is stable, the conversion rate of N,N-dicyanoethylcyclohexylamine is ≥99.9%, the selectivity of N,N-diaminopropylcyclohexylamine is ≥96%, the total amount of monopropylaminocyclohexylamine is ≤3%, and the amount of condensation macromolecular by-products is ≤0.2%.

Description

Technical Field

[0001] The present invention belongs to the technical field of polymer synthesis, and particularly relates to a method for preparing N,N-diaminopropylcyclohexylamine based on cyclohexylamine. Background Art

[0002] As a multi-amino functional group compound, N,N-diaminopropylcyclohexylamine exhibits significant application potential in the field of epoxy resin curing agents due to its unique molecular structure. Epoxy resins, as a class of high-performance thermosetting materials, are widely used in fields such as electronic packaging, aerospace, coatings, and composite materials. However, their final performance highly depends on the choice of curing agents. Traditional amine curing agents such as aliphatic amines and aromatic amines can provide good cross-linking effects, but still face problems such as high toxicity, strong volatility, insufficient heat resistance, or poor toughness. Therefore, the development of new, efficient, environmentally friendly, and multifunctional curing agents has become a research hotspot, and the research on the synthesis of N,N-diaminopropylcyclohexylamine is of particular importance.

[0003] Chinese Patent CN115677509A discloses a method for preparing N,N-diaminopropylcyclohexylamine. The steps include: 1) mixing N,N-dicyanoethylcyclohexylamine and solvent A to prepare a solution; 2) mixing Raney catalyst, solvent B, and water, then adding an alkaline buffer solution and a salt solution, and then introducing hydrogen to adjust the system to the reaction pressure, heating to the reaction temperature, and then adding the solution prepared in step 1) under a hydrogen atmosphere to carry out a hydrogenation reaction to obtain N,N-diaminopropylcyclohexylamine. The pressure during the reaction process is relatively high, which also increases the requirements for the reaction equipment environment. However, increasing the reaction pressure cannot improve the selectivity of the catalyst for the reaction product and cannot effectively improve the yield of N,N-diaminopropylcyclohexylamine.

[0004] Chinese Patent CN118307416A discloses a method for one-step synthesis of special amine compounds. Under the action of a catalyst, special amine compounds for curing agents are produced in one step from acrylonitrile, amine compounds, and hydrogen. The special amine compounds include at least one of N-(3-aminopropyl)cyclohexylamine, N,N'-bis(3-aminopropyl)cyclohexylamine, N-(2-aminoethyl)-1,6-hexanediamine, N,N'-bis(2-aminoethyl)-1,6-hexanediamine, N-(3-aminopropyl)-2-methylcyclohexylamine, and N-(3-aminopropyl)-4-methylcyclohexylamine. The yield of the target product of this method reaches 95%, and there are relatively many mono-aminopropylcyclohexylamines synthesized during the reaction process, and the selectivity for the synthesis of special amine compounds for curing agents is relatively low.

[0005] Chinese Patent CN114907216A discloses a hydrogenation method of dicyanoethyl tertiary amine. The method is as follows: using a free amine adsorbent, a hydrogenation catalyst, and an organic solvent as the bottom layer, introducing H2, and using the pretreated dicyanoethyl tertiary amine as the raw material for hydrogenation reaction; switching to the unpretreated dicyanoethyl tertiary amine as the raw material to continue the hydrogenation reaction; distilling and purifying the reaction mother liquor to obtain the target product. The reaction process is uncontrollable, the product yield is low, multiple reactions and purifications are required, the production cost is higher, and the efficiency is lower.

[0006] Currently, the reaction conditions for synthesizing N,N-diaminopropylcyclohexylamine are relatively harsh, so the cost will increase during large-scale production, and it will also affect the yield and purity of the product. Summary of the Invention

[0007] According to the deficiencies in the above prior art, the technical problem to be solved by the present invention is: to provide a method for preparing N,N-diaminopropylcyclohexylamine based on cyclohexylamine. During the reaction, a cobalt-based powder catalyst is added for catalysis, and ammonia water and EDTA are added as additives, which can not only maintain the activity and selectivity of the catalyst but also synthesize N,N-diaminopropylcyclohexylamine with a high yield under relatively mild conditions.

[0008] The technical solution adopted by the present invention to solve its technical problems is:

[0009] The method for preparing N,N-diaminopropylcyclohexylamine based on cyclohexylamine according to the present invention includes the following steps:

[0010] (1) Mix cyclohexylamine with water, first add part of acrylonitrile for reaction; then add the catalyst and add the remaining acrylonitrile again to continue the reaction; filter, adsorb, and rotary evaporate the obtained solution to obtain N,N-dicyanoethylcyclohexylamine;

[0011] (2) Mix N,N-dicyanoethylcyclohexylamine, cobalt-based powder catalyst, ammonia water, EDTA, and a solvent, introduce hydrogen, and carry out a hydrogenation reaction to obtain N,N-diaminopropylcyclohexylamine.

[0012] Among them:

[0013] The preparation process of the cobalt-based powder catalyst is as follows:

[0014] A1. Mix cobalt nitrate hexahydrate, sodium silicate nonahydrate, and urea, then add deionized water and mix evenly, and then carry out precipitation to obtain a suspension containing precipitation;

[0015] A2. Filter and wash the precipitation in the suspension until it is neutral to obtain a precipitate. Then disperse the precipitate into a dispersant to form a dispersion. The dispersion is spray granulated to obtain a cobalt-based powder catalyst precursor. The cobalt-based powder catalyst precursor is calcined and then subjected to a reduction reaction to obtain a cobalt-based powder catalyst.

[0016] In the step A1, the mass ratio of cobalt nitrate hexahydrate, sodium silicate nonahydrate and urea is 1:(0.5 - 0.8):(0.8 - 1.2), the mass ratio of deionized water to cobalt nitrate hexahydrate is 10 - 30:1, the precipitation temperature is 70 - 90°C, and the precipitation time is 15 - 36 h.

[0017] In the step A2, the dispersant is deionized water, the spray granulation pressure is 0.2 - 0.3 MPa, the spray granulation temperature is 120 - 180°C, the calcination temperature is 450 - 600°C, the calcination time is 3 - 4 h, the reduction reaction is carried out in a hydrogen atmosphere, the reduction reaction temperature is 400 - 500°C, and the reduction reaction time is 3 - 4 h.

[0018] In the step (1), the mass ratio of cyclohexylamine to water is 11 - 22:1, the catalyst is AlCl3, and the mass ratio of the catalyst to cyclohexylamine is 0.03 - 0.06:1.

[0019] In the step (1), the mass ratio of part of acrylonitrile to cyclohexylamine is 0.5 - 1:1, the mass ratio of the remaining acrylonitrile to cyclohexylamine is 0.6 - 1:1, and the mass ratio of part of acrylonitrile to the remaining acrylonitrile is 1:1.05 - 1.15.

[0020] In the step (1), the reaction temperature is 40 - 60°C, the reaction time is 2 - 3 h, the continued reaction temperature is 80 - 100°C, and the continued reaction time is 10 - 30 h.

[0021] In the step (1), the adsorption is carried out by mixing and stirring with clay, the mass ratio of clay to cyclohexylamine is 1:40 - 60, the stirring adsorption temperature is 80 - 100°C; the rotary evaporation temperature is 80 - 100°C.

[0022] In the step (2), the mass ratio of the cobalt-based powder catalyst to N,N-dicyanoethylcyclohexylamine is 0.08 - 0.12:1, the solvent is one of methanol, ethanol, isopropanol or 1,4-epoxyhexane; the mass ratio of N,N-dicyanoethylcyclohexylamine, ammonia water, EDTA and the solvent is 1:(0.1 - 0.125):(0.09 - 0.11):(4 - 5).

[0023] In the step (2), the hydrogenation reaction temperature is 80 - 90°C, the hydrogenation reaction pressure is 0.4 - 0.6 MPa, and the hydrogenation reaction time is 6 - 8 h.

[0024] The present invention reacts cyclohexylamine with a part of acrylonitrile; then a catalyst is added and the reaction continues with another part of acrylonitrile, which can improve the reaction efficiency of cyclohexylamine and acrylonitrile and the yield of N,N-dicyanoethylcyclohexylamine; the obtained N,N-dicyanoethylcyclohexylamine, cobalt-based powder catalyst, ammonia water, EDTA and solvent are mixed for a hydrogenation reaction to prepare N,N-diaminopropylcyclohexylamine. By adding acrylonitrile in stages for reaction, the present invention can effectively improve the reaction efficiency and reduce the occurrence of side reactions. The solvent can disperse N,N-dicyanoethylcyclohexylamine and the catalyst, enabling ammonia water and EDTA to fully play their roles. On this basis, a hydrogenation reaction can make the cobalt-based powder catalyst adsorbed with ammonia molecules and -COO - be fully mixed with N,N-dicyanoethylcyclohexylamine, promoting the conversion of N,N-dicyanoethylcyclohexylamine.

[0025] The beneficial effects of the present invention are as follows:

[0026] (1) The present invention uses a cobalt-based powder catalyst as the main catalyst and introduces ammonia water and EDTA as additives. On the one hand, EDTA is adsorbed on the surface of the active metal state Co of the cobalt-based catalyst through physical adsorption or weak chemical adsorption. The strongly electronegative group -COO in EDTA - attracts the electrons on the surface of Co through the "inductive effect", resulting in a local decrease in the surface electron density. The ammonia molecules in ammonia water form a weak adsorption with the surface of the active metal state Co through lone pairs of electrons and feedback electrons to the surface of Co as an electron donor, partially offsetting the electron-withdrawing effect of EDTA. EDTA and ammonia water form a "pull-push" balance on the surface electron density of the active metal state Co through adsorption, optimizing the surface electron distribution and optimizing the regulation of the polarization and cleavage of the C≡N bond of N,N-dicyanoethylcyclohexylamine on the surface of Co. This balance enables the surface of the active metal state Co in the cobalt-based powder catalyst to have both high catalytic activity and anti-deactivation ability, so that the reaction can be carried out at a lower temperature and pressure, and the cobalt-based powder catalyst has higher stability; on the other hand, ammonia water can activate hydrogen species to generate NH 2- , NH 2- preferably attacks the carbon atom rather than the nitrogen atom in the cyano group, which can promote the formation of N,N-diaminopropylcyclohexylamine with -CH-NH2 from N,N-dicyanoethylcyclohexylamine. The obtained N,N-diaminopropylcyclohexylamine will not continue to hydrogenate to generate other impurities, and the addition of EDTA can make the cyano group mainly adsorbed in an end-on manner, avoiding the cyclization reaction caused by the stretching and breaking of the C-N bond, and converting the cyano group in the direction of the amino group, thereby inhibiting the formation of the by-product monopropylaminocyclohexylamine due to the shedding of the propylamino group.

[0027] (2) The reaction conditions of the present invention are relatively mild, the process is simple, the cost is low, the catalyst is stable, the conversion rate of N,N-dicyanoethylcyclohexylamine is ≥99.9%, the selectivity of N,N-diaminopropylcyclohexylamine is ≥96%, the total amount of monoaminopropylcyclohexylamine is ≤3%, and the amount of condensation macromolecular by-products is ≤0.2%. Specific Embodiments

[0028] The present invention will be further described below in conjunction with embodiments.

[0029] Example 1

[0030] The preparation process of the cobalt-based powder catalyst is as follows:

[0031] A1. Mix 9.9 g of cobalt nitrate hexahydrate, 6.07 g of sodium silicate nonahydrate and 10 g of urea, then add 300 ml of deionized water and mix evenly. Precipitate for 24 h at 90 °C to obtain a suspension containing precipitate.

[0032] A2. Filter and wash the precipitate in the suspension until neutral to obtain a precipitate. Then add the precipitate to deionized water to make a dispersion. The dispersion is spray granulated at a pressure of 0.2 MPa and a temperature of 150 °C to obtain a precursor of the cobalt-based powder catalyst. The precursor of the cobalt-based powder catalyst is calcined at 600 °C for 4 h, and finally reduced at 400 °C for 4 h in a hydrogen atmosphere using a rotary tube furnace to obtain the cobalt-based powder catalyst.

[0033] The method for preparing N,N-diaminopropylcyclohexylamine based on cyclohexylamine includes the following steps:

[0034] (1) Mix 19.8 g of cyclohexylamine with 1.8 g of water, dropwise add 11.66 g of acrylonitrile at 50 °C, react for 2 h, raise the temperature to 90 °C, add 1 g of AlCl3, and then dropwise add 12.72 g of acrylonitrile and continue to react for 10 h; filter the obtained solution, mix it with 0.5 g of clay and stir and adsorb at 90 °C, then filter the clay, and perform rotary evaporation on the obtained solution at 90 °C to obtain N,N-dicyanoethylcyclohexylamine.

[0035] (2) Add 2 g of N,N-dicyanoethylcyclohexylamine, 0.24 g of the cobalt-based powder catalyst, 0.2 g of ammonia water, 0.2 g of EDTA and 10 g of methanol to the reactor, then introduce hydrogen to 0.5 MPa, heat to 80 °C, and perform a hydrogenation reaction for 8 h to obtain N,N-diaminopropylcyclohexylamine.

[0036] The obtained N,N-diaminopropylcyclohexylamine was subjected to gas chromatography test: The experimental equipment was an Agilent gas chromatograph, the chromatographic column was HP-5, the inlet temperature was 280 °C, the FID detector temperature was 240 °C, the column flow rate was 1 ml / min, the hydrogen flow rate was 30 ml / min, the air flow rate was 400 ml / min, and the programmed temperature rise mode was: hold at 80 °C for 2 min, then rise to 240 °C at a rate of 20 °C / min and hold for 15 min. The gas chromatography test results of 10 cycles of the reaction are shown in Table 1. It can be seen from Table 1 that after 10 cycles of the reaction, the conversion rate of N,N-dicyanoethylcyclohexylamine and the selectivity of N,N-diaminopropylcyclohexylamine both remained at a relatively high level, and only a small amount of condensed macromolecules were formed, indicating that the cobalt-based powder catalyst had high stability and selectivity under the synergistic effect of EDTA and ammonia water.

[0037]

[0038] Example 2

[0039] The preparation process of the cobalt-based powder catalyst is as follows:

[0040] A1. Mix 9.9 g of cobalt nitrate hexahydrate, 5.01 g of sodium silicate nonahydrate and 11.5 g of urea, then add 100 ml of deionized water and mix evenly. Precipitate at 80 °C for 15 h to obtain a suspension containing precipitate;

[0041] A2. Filter and wash the precipitate in the suspension until it is neutral to obtain a precipitate. Subsequently, add the precipitate to deionized water to make a dispersion. The dispersion is spray granulated at a pressure of 0.3 MPa and a temperature of 180 °C to obtain a cobalt-based powder catalyst precursor. The cobalt-based powder catalyst precursor is calcined at 450 °C for 3 h, and finally reduced at 450 °C for 3 h in a hydrogen atmosphere using a rotary tube furnace to obtain a cobalt-based powder catalyst.

[0042] A method for preparing N,N-diaminopropylcyclohexylamine based on cyclohexylamine, comprising the following steps:

[0043] (1) Mix 19.8 g of cyclohexylamine with 0.9 g of water, dropwise add 14.66 g of acrylonitrile at 60 °C, react for 3 h, raise the temperature to 100 °C, then add 0.6 g of AlCl3, and dropwise add 16.72 g of acrylonitrile again and continue to react for 30 h; Filter the obtained solution, mix it with 0.3 g of clay and stir and adsorb at 80 °C, then filter the clay, and perform rotary evaporation on the obtained solution at 80 °C to obtain N,N-dicyanoethylcyclohexylamine;

[0044] (2) Mix 2 g of N,N-dicyanoethylcyclohexylamine, 0.16 g of cobalt-based powder catalyst, 0.25 g of ammonia water, 0.22 g of EDTA, and 8 g of ethanol, add them to a reactor, then introduce hydrogen to 0.4 MPa, heat to 90 °C, and carry out a hydrogenation reaction for 6 h to obtain N,N-diaminopropylcyclohexylamine.

[0045] Collect the obtained N,N-diaminopropylcyclohexylamine for gas chromatography test: The experimental equipment is an Agilent gas chromatograph, the chromatographic column is HP-5, the inlet temperature is 280 °C, the FID detector temperature is 240 °C, the column flow rate is 1 ml / min, the hydrogen flow rate is 30 ml / min, the air flow rate is 400 ml / min, and the programmed temperature rise method is: maintain at 80 °C for 2 min, then rise to 240 °C at a rate of 20 °C / min, and maintain for 15 min. The gas chromatography test results of 10 cycles of the reaction are shown in Table 2.

[0046]

[0047] Example 3

[0048] The preparation process of the cobalt-based powder catalyst is as follows:

[0049] A1. Mix 9.9 g of cobalt nitrate hexahydrate, 8.3 g of sodium silicate nonahydrate, and 8.46 g of urea, then add 200 ml of deionized water and mix evenly. Precipitate at 70 °C for 36 h to obtain a suspension containing precipitates.

[0050] A2. Filter and wash the precipitate in the suspension until neutral to obtain a precipitate. Subsequently, add the precipitate to deionized water to prepare a dispersion. The dispersion is spray granulated at a pressure of 0.25 MPa and a temperature of 120 °C to obtain a cobalt-based powder catalyst precursor. The cobalt-based powder catalyst precursor is calcined at 550 °C for 3 h, and finally reduced in a hydrogen atmosphere in a rotary tube furnace at 500 °C for 4 h to obtain a cobalt-based powder catalyst.

[0051] A method for preparing N,N-diaminopropylcyclohexylamine based on cyclohexylamine, comprising the following steps:

[0052] (1) Mix 19.8 g of cyclohexylamine with 1.2 g of water, dropwise add 18.66 g of acrylonitrile at 40 °C, react for 2 h, raise the temperature to 80 °C, then add 1.18 g of AlCl3, and dropwise add 19.72 g of acrylonitrile again and continue to react for 20 h; filter the obtained solution, mix it with 0.4 g of clay, stir and adsorb at 100 °C, then filter the clay, and carry out rotary evaporation of the obtained solution at 100 °C to obtain N,N-dicyanoethylcyclohexylamine.

[0053] (2) 2 g of N,N-dicyanoethylcyclohexylamine, 0.18 g of cobalt-based powder catalyst, 0.22 g of ammonia water, 0.185 g of EDTA, and 8 g of isopropanol were mixed and added to a reactor. Then, hydrogen gas was introduced to 0.6 MPa and heated to 85 °C for a hydrogenation reaction for 6 h to obtain N,N-diaminopropylcyclohexylamine.

[0054] The obtained N,N-diaminopropylcyclohexylamine was collected for gas chromatography test: The experimental equipment was an Agilent gas chromatograph, the chromatographic column was HP-5, the inlet temperature was 280 °C, the FID detector temperature was 240 °C, the column flow rate was 1 ml / min, the hydrogen flow rate was 30 ml / min, the air flow rate was 400 ml / min, and the programmed temperature rise mode was: maintained at 80 °C for 2 min, then heated to 240 °C at a rate of 20 °C / min and maintained for 15 min. The gas chromatography test results of 10 cycles of the reaction are shown in Table 3.

[0055]

[0056] Comparative Example 1

[0057] In step A1, cobalt nitrate hexahydrate was replaced with nickel nitrate hexahydrate to prepare a nickel-based powder catalyst. The cobalt-based powder catalyst in step (2) was replaced with a nickel-based powder catalyst, and the remaining operations were the same as in Example 1. The hydrogenated product was collected for gas chromatography test. The gas chromatography test results of 10 cycles of the reaction are shown in Table 4. The selectivity of monaminopropylcyclohexylamine in the product prepared using the nickel-based powder catalyst was relatively high, the selectivity for N,N-diaminopropylcyclohexylamine was relatively low, and the content of by-products increased, indicating that the nickel-based powder catalyst had poor selectivity for N,N-diaminopropylcyclohexylamine in the system.

[0058]

[0059] Comparative Example 2

[0060] In step (2), ammonia water was not added, and the remaining operations were the same as in Example 1. The hydrogenated product was collected for gas chromatography test. The gas chromatography test results of 10 cycles of the reaction are shown in Table 5. Compared with Example 1, the conversion rate of N,N-dicyanoethylcyclohexylamine in Comparative Example 2 was lower, indicating that the cobalt-based powder catalyst had poor stability without the synergistic effect of ammonia water and EDTA. The selectivity of N,N-diaminopropylcyclohexylamine in Comparative Example 2 was lower than that in Example 1, indicating that ammonia water played a crucial role in the system.

[0061]

[0062] Comparative Example 3

[0063] In step (2), EDTA was not added, and the remaining operations were the same as in Example 1. The product after hydrogenation was collected for gas chromatography testing. The gas chromatography test results after 10 cycles of reaction are shown in Table 6. Compared with Example 1, the conversion rate of N,N-dicyanoethylcyclohexylamine in Comparative Example 3 was lower and gradually decreased. The selectivity of N,N-diaminopropylcyclohexylamine in Comparative Example 3 was lower than that in Example 1, indicating that EDTA plays a crucial role in the system.

[0064]

[0065] Comparative Example 4

[0066] In step (2), EDTA was replaced with citric acid, and the remaining operations were the same as in Example 1. The product after hydrogenation was collected for gas chromatography testing. The gas chromatography test results after 10 cycles of reaction are shown in Table 7. Compared with Example 1, the conversion rate of N,N-dicyanoethylcyclohexylamine in Comparative Example 4 was lower, indicating that the cobalt-based powder catalyst had poor stability without the synergistic effect of EDTA and ammonia water. The selectivity of N,N-diaminopropylcyclohexylamine in Comparative Example 4 was lower than that in Example 1, indicating that the role of EDTA in the system cannot be replaced by citric acid.

[0067]

[0068] Comparative Example 5

[0069] In step (2), ammonia water was replaced with an aqueous NaOH solution, and the remaining operations were the same as in Example 1. The product after hydrogenation was collected for gas chromatography testing. The gas chromatography test results after 10 cycles of reaction are shown in Table 8. Compared with Example 1, the conversion rate of N,N-dicyanoethylcyclohexylamine in Comparative Example 5 was lower, indicating that the molecule in ammonia water that can play a synergistic role with EDTA and the cobalt-based powder catalyst is ammonia molecule rather than hydroxide ion. The cobalt-based powder catalyst had poor stability without the synergistic effect of ammonia molecule and EDTA. The selectivity of N,N-diaminopropylcyclohexylamine in Comparative Example 5 was lower than that in Example 1, indicating that the role of ammonia water in the system cannot be replaced by NaOH.

[0070]

Claims

1. A method for preparing N,N-bisaminopropylcyclohexylamine based on cyclohexylamine, characterized in that: The following steps are involved: (1) Cyclohexylamine is mixed with water, and part of acrylonitrile is first added to react; a catalyst is then added and the remaining acrylonitrile is added again to continue the reaction; the obtained solution is filtered, adsorbed, and rotary evaporated to obtain N,N-biscyanoethylcyclohexylamine, and the catalyst is AlCl3; (2) N,N-biscyanoethylcyclohexylamine, a cobalt-based powder catalyst, ammonia water, EDTA and a solvent are mixed, and hydrogen is introduced to carry out a hydrogenation reaction to obtain N,N-bisaminopropylcyclohexylamine; The preparation process of cobalt-based powder catalyst is as follows: A1. Mix cobalt nitrate hexahydrate, sodium silicate nonahydrate and urea, add deionized water and mix evenly, and then precipitate to obtain a suspension containing a precipitate; A2. Filter the precipitate in the suspension and wash it to neutrality to obtain a precipitate, then disperse the precipitate in a dispersant to prepare a dispersion, spray granulate the dispersion to obtain a cobalt-based powder catalyst precursor, calcine the cobalt-based powder catalyst precursor, and then perform a reduction reaction to obtain a cobalt-based powder catalyst.

2. The method for preparing N,N-bisaminopropylcyclohexylamine based on cyclohexylamine according to claim 1, characterized in that: In step A1, the mass ratio of cobalt nitrate hexahydrate, sodium silicate nonahydrate and urea is 1:(0.5-0.8):(0.8-1.2), the mass ratio of deionized water to cobalt nitrate hexahydrate is 10-30:1, the precipitation temperature is 70-90° C., and the precipitation time is 15-36 hours.

3. The method for preparing N,N-bisaminopropylcyclohexylamine based on cyclohexylamine according to claim 1, characterized in that: In step A2, the dispersant is deionized water, the spray granulation pressure is 0.2-0.3 MPa, the spray granulation temperature is 120-180°C, the calcination temperature is 450-600°C, the calcination time is 3-4h, the reduction reaction is carried out under a hydrogen atmosphere, the reduction reaction temperature is 400-500°C, and the reduction reaction time is 3-4h.

4. The method for preparing N,N-bisaminopropylcyclohexylamine based on cyclohexylamine according to claim 1, characterized in that: In step (1), the mass ratio of cyclohexylamine to water is 11-22:1, and the mass ratio of catalyst to cyclohexylamine is 0.03-0.06:

1.

5. The method for preparing N,N-bisaminopropylcyclohexylamine based on cyclohexylamine according to claim 1, characterized in that: In step (1), the mass ratio of part of acrylonitrile to cyclohexylamine is 0.5-1:1, the mass ratio of remaining acrylonitrile to cyclohexylamine is 0.6-1:1, and the mass ratio of part of acrylonitrile to remaining acrylonitrile is 1:1.05-1.

15.

6. The method for preparing N,N-bisaminopropylcyclohexylamine based on cyclohexylamine according to claim 1, characterized in that: In step (1), the reaction temperature is 40-60°C, the reaction time is 2-3h, the continued reaction temperature is 80-100°C, and the continued reaction time is 10-30h.

7. The method for preparing N,N-bisaminopropylcyclohexylamine based on cyclohexylamine according to claim 1, characterized in that: In step (1), the adsorption is carried out by mixing and stirring with kaolin, the mass ratio of kaolin to cyclohexylamine is 1:40-60, the stirring adsorption temperature is 80-100°C, and the rotary evaporation temperature is 80-100°C.

8. The method for preparing N,N-bisaminopropylcyclohexylamine based on cyclohexylamine according to claim 1, characterized in that: In step (2), the mass ratio of the cobalt-based powder catalyst to N,N-bis-cyanoethylcyclohexylamine is 0.08-0.12:1, and the solvent is one of methanol, ethanol, isopropanol or 1,4-epoxyhexacyclohexylamine; the mass ratio of N,N-bis-cyanoethylcyclohexylamine, ammonia water, EDTA and solvent is 1:(0.1-0.125):(0.09-0.11):(4-5).

9. The method for preparing N,N-bisaminopropylcyclohexylamine based on cyclohexylamine according to claim 1, characterized in that: In step (2), the hydrogenation reaction temperature is 80-90°C, the hydrogenation reaction pressure is 0.4-0.6MPa, and the hydrogenation reaction time is 6-8h.

Images