Use of dinuclear ruthenium metal center complexes in the preparation of saturated nitrile-based polymers

Abstract

The application provides application of a binuclear ruthenium metal center complex in preparation of saturated nitrile-based polymers. The method comprises the following steps: contacting a nitrile-based polymer with hydrogen in the presence of a catalyst to perform a hydrogenation reaction, and preparing a hydrogenated nitrile-based polymer. The single large steric alkoxyl monochloride anion ruthenium carbene complex is used as a hydrogenation catalyst in the solution hydrogenation process of the nitrile-based polymer, and the hydrogenated nitrile-based polymer with high hydrogenation degree and low gel can be stably and efficiently produced. The catalyst has the following structure:

Description

Technical Field

[0001] This invention relates to the application of binuclear ruthenium metal center complexes in the preparation of saturated nitrile polymers, and belongs to the field of nitrile polymerization technology. Background Technology

[0002] Hydrogenated nitrile butadiene rubber (HNBR) is a high-performance specialty rubber produced by selectively hydrogenating the carbon-carbon double bonds in nitrile butadiene rubber (NBR). While retaining the excellent oil resistance, abrasion resistance, and low-temperature resistance of nitrile butadiene rubber, HNBR further improves heat resistance, ozone resistance, chemical resistance, and dynamic mechanical properties. Therefore, it is widely used in high-end technology fields such as automobiles, oil fields, and aerospace.

[0003] Currently, a relatively mature industrial method for preparing hydrogenated nitrile butadiene rubber (NBR) is solution hydrogenation. This method typically involves hydrogenating the NBR solution in the presence of a catalyst under specific temperature and hydrogen pressure conditions, followed by post-processing to obtain a series of hydrogenated NBRs with different degrees of hydrogenation and Mooney viscosities. In existing technologies, the catalysts are mainly palladium, rhodium, and ruthenium-based catalysts. For example, CN107722145B and WO2025047952A1 disclose heterogeneous catalysts formed by supporting palladium nanoparticles on various supports (such as Pd / C and Pd / Al2O3). Although these catalysts exhibit good selectivity and high hydrogenation degree, their catalytic hydrogenation efficiency is low, and palladium is expensive. Rhodium-based catalysts (such as CN104140479A and DE3463512D1) exhibit extremely high selectivity for the hydrogenation of C=C double bonds in NBR molecular chains and do not reduce nitrile groups on the molecular chains, thus avoiding problems such as cross-linking gelation and Mooney viscosity runaway. However, rhodium is expensive, and catalyst recovery technology is usually used in industrial production. Ruthenium-based catalysts have a similar general structural formula to rhodium. For example, US5208296A and US4795788A use some simple ruthenium complexes for hydrogenation reactions. Although their price is much lower than rhodium, their selectivity is poor, and they are prone to cross-linking of the product, resulting in gelation.

[0004] Ruthenium-based olefin metathesis catalysts, primarily based on Grubbs and Hoveyda-Grubbs catalysts, such as CN101024703B, CN111655740B, and CN102603928A, have also been successfully applied to the hydrogenation of nitrile rubber. These catalysts not only promote the breaking of the C=C double bond in nitrile rubber, thus achieving degradation, but also exhibit hydrogenation performance under high temperature and high pressure hydrogen conditions, making them suitable for preparing low Mooney hydrogenated nitrile rubber. However, their metathesis activity is usually high and difficult to control, requiring the use of palladium or rhodium catalysts for subsequent hydrogenation reactions, increasing the complexity of the system.

[0005] In summary, the technology for obtaining hydrogenated nitrile butadiene rubber (NBR) with different hydrogenation degrees by adjusting the type of catalyst, especially for highly saturated (environmentally resistant) NBR, still has significant room for improvement in related catalytic technologies. Furthermore, the hydrogenation process becomes more complex and difficult when NBR is functionalized with carboxyl, ester, or other groups. Besides the carbon-carbon double bond, the introduced carboxyl and ester groups may also be hydrogenated to alcohol hydroxyl groups or directly decarboxylated to form carbon-hydrogen bonds. For example, EP0360356A2 discloses a hydrogenation method for a carboxylated butadiene-styrene block polymer, using LiOH for pre-alkalization of the polymer and triethylaluminum-activated nickel 2-ethylhexanoate as a catalyst for hydrogenation, but the hydrogenation rate is only 5%. Bhowmick et al. (Bhattacharjee S., Bhowmick A., Avasthi B. Hydrogenation of liquid carboxylated nitrile rubber. Macromolecular Chemistry and Physics., 1992, 193, 659-667.) used palladium catalyst, palladium acetate, and Wilkinson catalyst to hydrogenate liquid carboxylated nitrile rubber (carboxyl content 0.05-0.07 mol / 100 g, acrylonitrile content 10-15%). The palladium catalyst only achieved 30% hydrogenation, while palladium acetate, which had 96% hydrogenation in NBR hydrogenation, did not show any hydrogenation results. The Wilkinson catalyst achieved 15% hydrogenation and 38% decarboxylation side reaction. Han, Y., Mao, L., Meng, H., et al. Novel self-crosslinking film from hydrogenated carboxylated nitrile rubber latex. J.Appl. Polym. Sci., 2014, 131, 39865. used hydrazine hydrate and hydrogen peroxide to hydrogenate carboxylated nitrile rubber, but this method generates a large amount of gas and uses a large amount of peroxide.

[0006] Therefore, developing a catalyst that can be applied to hydrogenated nitrile rubber using a small amount of catalyst to solve the problems of low catalytic activity and achieve high hydrogenation degree has become an urgent technical problem to be solved in this field. Summary of the Invention

[0007] To address the aforementioned problems, the present invention aims to provide the application of binuclear ruthenium metal-centered complexes in the preparation of saturated nitrile polymers. The catalyst of the present invention is used in the solution hydrogenation process of nitrile polymers to obtain hydrogenated nitrile polymers with high hydrogenation degrees and low gelation.

[0008] To achieve the above objectives, in a first aspect, the present invention provides a method for preparing a hydrogenated nitrile polymer, wherein the preparation method includes the following steps: In the presence of a catalyst, a nitrile polymer is contacted with hydrogen to carry out a hydrogenation reaction, thereby obtaining a hydrogenated nitrile polymer. The catalyst has the structure shown in Formula I: Formula I; Among them, R, R 1 R 2 R 3 Whether they are the same or different, they are each independently selected from hydrogen, C1-C 18 Straight-chain alkyl, C3-C 18 Branched alkyl groups, C1-C 18 Substituted alkyl groups, halogens, C6-C 18 Substituted aryl, C6-C 18 Unsubstituted aryl, C7-C 18 Aryl or C7-C 18 alkylaryl groups; Optional, R 1 R 2 R 3 Any two of them can form a ternary to twelfth element ring structure; R 31 R 32 R 33 R 34 Whether they are the same or different, they are each independently selected from hydrogen, C1-C 18 Straight-chain alkyl, C3-C 18 Branched alkyl groups, C1-C 18 The substituted alkyl group, halogen, substituted or unsubstituted ester group, substituted or unsubstituted nitro group, or substituted or unsubstituted cyano group; optionally, R 31 R 32 R 33 R 34 Any two of them can form a ternary to octet ring structure; L is a nitrogen-containing heterocyclic carbene ligand; X is an anionic ligand; M is a transition metal.

[0009] According to a specific embodiment of the present invention, preferably, R, R 1 R 2 R 3 Whether they are the same or different, they are each independently selected from hydrogen, C1-C 15 Straight-chain alkyl, C3-C 15 Branched alkyl groups, C1-C 15 Substituted alkyl groups, halogens, C6-C14 Substituted aryl, C6-C 14 Unsubstituted aryl, C7-C 15 Aryl or C7-C 15 alkylaryl groups.

[0010] According to a specific embodiment of the present invention, preferably, R, R 1 R 2 R 3 Whether they are the same or different, they are each independently selected from hydrogen, C1-C 10 Straight-chain alkyl, C3-C 10 Branched alkyl groups, C1-C 10 Substituted alkyl groups, F, Cl, Br, I, C6-C 10 Substituted aryl, C6-C 10 Unsubstituted aryl, C7-C 10 Aryl or C7-C 10 alkylaryl groups.

[0011] According to a specific embodiment of the present invention, preferably, R, R 1 R 2 R 3 Whether the groups are the same or different, they are each independently selected from hydrogen, C1-C8 straight-chain alkyl groups, C3-C8 branched-chain alkyl groups, C6-C 10 Unsubstituted aryl, C7-C 10 Aryl or C7-C 10 alkylaryl groups.

[0012] According to a specific embodiment of the present invention, preferably, R, R 1 R 2 R 3 They may be the same or different, and are each independently selected from hydrogen, C1-C6 straight-chain alkyl or C3-C6 branched alkyl.

[0013] According to a specific embodiment of the present invention, R 1 R 2 R 3 Any two of them can form a ternary, quaternary, pentagonal, hexavalent, septagonal, octagonal, decagonal, eleventh, or twelfth cyclic structure. A "cyclic structure" refers to two groups connected by chemical bonds and optionally aromatized; the "cyclic structure" can be optionally saturated or unsaturated.

[0014] According to a specific embodiment of the present invention, C6-C 18 The C6-C in the substituted aryl group 18This refers to the number of carbon atoms in the substituted aryl group, excluding the number of carbon atoms in the substituent.

[0015] According to a specific embodiment of the present invention, C1-C 18 C1-C of the substituted alkyl group 18 This refers to the number of carbon atoms in alkyl groups, excluding the number of carbon atoms in substituents.

[0016] According to a specific embodiment of the present invention, preferably, the substituent groups in the substituted alkyl and substituted aryl groups are each independently selected from one or more combinations of halogen, alkoxy, carboxyl, and aldehyde groups.

[0017] According to a specific embodiment of the present invention, preferably, when the substituent is aryl or alkylaryl, the aryl group is a 6-membered to 14-membered aryl group, more preferably, the aryl group is a 6-membered to 10-membered aryl group; further preferably, it is phenyl; for example, the aryl group can be a 6-membered, 10-membered or 14-membered aryl group.

[0018] According to a specific embodiment of the present invention, preferably, the nitrogen-heterocyclic carbene ligand has the structure shown in formula IIb or formula IIc: Formula IIb; Formula IIc; Among them, R 7 R 8 R 19 R 20 Whether they are the same or different, they are each independently selected from hydrogen, halogens, and C1-C. 18 Straight-chain alkyl, C3-C 18 Branched alkyl groups, C1-C 18 alkoxy groups, C6-C 18 Substituted aryl, C6-C 18 Unsubstituted aryl, C6-C 18 Substituted aryloxy groups, C6-C 18 Unsubstituted aryloxy groups, C7-C 18 Aryl or C7-C 18 alkylaryl groups; R 9 R 10 R 11 R 12 R 13 R 14 R 15 R 16 R 17 R 18 R 21 R 22 R 23 R 24R 25 R 26 R 27 R 28 R 29 R 30 Whether they are the same or different, they are each independently selected from hydrogen, C1-C 18 Straight-chain alkyl, C3-C 18 Branched alkyl groups, C1-C 18 alkoxy groups, C6-C 18 Substituted aryl, C6-C 18 Unsubstituted aryl, C6-C 18 Substituted aryloxy groups, C6-C 18 Unsubstituted aryloxy groups, C7-C 18 Aryl or C7-C 18 alkylaryl groups.

[0019] The nitrogen-containing heterocyclic carbene ligand introduced into the catalyst of this invention is a very strong σ-electron donor, which significantly enhances the electron density of the metal center, thereby improving both catalyst stability and its ability to activate hydrogen during catalytic cycling. Simultaneously, combined with the slow initiation characteristic of the catalyst, it provides a certain degree of sustained release within the system, ensuring the sustained activity of the active catalytic center. Furthermore, the presence of the electron-rich anion ligand makes it easier for the metal center to undergo oxidative reaction with hydrogen, generating an active catalytic structure and thus achieving the hydrogenation reaction of nitrile polymers. This is expected to further improve the hydrogenation efficiency of nitrile polymers and reduce the amount of catalyst required.

[0020] According to a specific embodiment of the present invention, preferably, R 7 R 8 R 19 R 20 Whether they are the same or different, they are each independently selected from hydrogen, F, Cl, Br, I, and Cl-C. 10 Straight-chain alkyl, C3-C 10 Branched alkyl groups, C1-C 10 alkoxy groups, C6-C 10 Substituted aryl, C6-C 10 Unsubstituted aryl, C6-C 10 Substituted aryloxy groups, C6-C 10 Unsubstituted aryloxy groups, C7-C 10 Aryl or C7-C 10 alkylaryl groups; R 9 R 10 R 11 R 12 R 13 R 14 R 15 R16 R 17 R 18 R 21 R 22 R 23 R 24 R 25 R 26 R 27 R 28 R 29 R 30 Whether they are the same or different, they are each independently selected from hydrogen, C1-C 10 Straight-chain alkyl, C3-C 10 Branched alkyl groups, C1-C 10 alkoxy groups, C6-C 10 Substituted aryl, C6-C 10 Unsubstituted aryl, C6-C 10 Substituted aryloxy groups, C6-C 10 Unsubstituted aryloxy groups, C7-C 10 Aryl or C7-C 10 alkylaryl groups.

[0021] According to a specific embodiment of the present invention, preferably, R 7 R 8 R 19 R 20 They may be the same or different, and each is independently selected from hydrogen, C1-C8 straight-chain alkyl or C3-C8 branched alkyl; R 9 R 10 R 11 R 12 R 13 R 14 R 15 R 16 R 17 R 18 R 21 R 22 R 23 R 24 R 25 R 26 R 27 R 28 R 29 R 30 They may be the same or different, and are each independently selected from hydrogen, C1-C8 straight-chain alkyl or C3-C8 branched alkyl.

[0022] According to a specific embodiment of the present invention, preferably, R 31 R 32 R 33 R34 All are H.

[0023] According to a specific embodiment of the present invention, preferably, M is selected from ruthenium or osmium; more preferably, it is ruthenium.

[0024] The catalyst used in the hydrogenated nitrile polymer prepared in this invention contains ruthenium, which is cheaper than rhodium but has different activity. To address the diffusion and stability challenges posed by high-viscosity polymer solutions, the catalyst of this invention can deeply penetrate the interior of high-viscosity solutions and maintain stable catalytic cycling at high temperatures, while possessing sufficient electron density to activate and crack hydrogen.

[0025] According to a specific embodiment of the present invention, preferably, the anionic ligand is selected from one or more combinations of halogen, carboxylate, sulfonate, alkoxy, aryloxy, alkyl mercapto, and aryl mercapto; more preferably, the anionic ligand is a halogen; even more preferably, the anionic ligand is selected from one of F, Cl, Br, and I.

[0026] According to a specific embodiment of the present invention, preferably, the catalyst has one of the following structures: Formula Ia; Formula Ib; Formula Ic; FormulaId; Formula Ie; Formula If.

[0027] The catalyst modulation of anionic ligands in this invention is the core means of precisely controlling the catalytic hydrogenation performance of complexes by altering the electronic and steric environment of the metal center. Specifically, the sterically hindered alkoxy anionic ligand increases the electron density of the metal center, promoting the oxidative addition of hydrogen and thus improving catalyst activity. Furthermore, the large steric hindrance physically shields the active metal center, preventing deactivation through coordination with carboxyl, ester, amide, or cyano groups, significantly enhancing catalyst stability. Simultaneously, by controlling substrate access, it dominates regio and stereoselectivity, achieving highly selective hydrogenation. Combining "large steric hindrance" with "electron-richness" enhances both activity and stability while achieving excellent chemoselectivity, which is crucial for realizing highly active and selective hydrogenation catalysts in the hydrogenation of nitrile polymers.

[0028] According to a specific embodiment of the present invention, preferably, the catalyst is prepared by method one or method two: Method 1: The catalyst is obtained by reacting a dichloro anion carbene complex with an alkoxy metal salt and an alkyl alcohol, wherein the molar ratio of the dichloro anion carbene complex, the alkoxy metal salt, and the alkyl alcohol is 1:(1-10):(1-20), preferably 1:(1-1.2):(1-2). The dichloro anion carbene complex has the structure shown in Formula III or Formula IV: Formula III, In Equation III, M, R, R 7 To R 18 Same as M, R, R mentioned above 7 To R 18 ; Formula IV, In equation IV, M, R, R 19 To R 30 Same as M, R, R mentioned above 19 To R 30 ; The alkoxy metal salt has the structure shown in Formula V: Formula V, In formula V, M and R 1 To R 3 Same as M and R mentioned above 1 To R 3 M1 is Li, Na, K, Ru, or Cs; The alkyl moiety of the alkyl alcohol is the same as that of the alkoxy metal salt, and the alkyl alcohol has the structure shown in Formula VI: Formula VI, In equation VI, R 1 To R 3 Same as R above 1 To R 3 ; Method 2: Alkyl alcohols The alkoxy metal salt complex reacts with the dichloro anion carbene complex to obtain the catalyst; the alkyl alcohol The molar ratio of the alkoxy metal salt complex to the dichloro anion carbene complex is (1-10):1, preferably (1-1.2):1; The alkyl alcohol The alkoxy metal salt complex has the structure shown in Formula VII: Equation VII, In equation VII, R 1 To R 3 Same as R above1 To R 3 M1 is either Na or K.

[0029] According to a specific embodiment of the present invention, preferably, in method one, the reaction temperature is -80 ℃ to 180 ℃, more preferably 0 ℃ to 40 ℃.

[0030] According to a specific embodiment of the present invention, preferably, in method one, the reaction time is 10 minutes to 48 hours, more preferably 30 minutes to 2 hours.

[0031] According to a specific embodiment of the present invention, preferably, in method one, the reaction solvent includes one or more of the following: n-pentane, n-hexane, cyclopentane, cyclohexane, acetonitrile, benzene, toluene, chlorobenzene, bromobenzene, fluorobenzene, trifluorotoluene, hexafluorobenzene, dichloromethane, dichloroethane, trichloromethane, carbon tetrachloride, 1,1,2,2-tetrachloroethane, acetone, diethyl ether, tetrahydrofuran, ethylene glycol dimethyl ether, tert-butyl methyl ether, 1,4-dioxane, methanol, ethanol, N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, hexamethylphosphoramide, and dimethyl sulfoxide; more preferably, it includes one or more of the following: benzene, toluene, and tetrahydrofuran.

[0032] According to a specific embodiment of the present invention, preferably, in method one, the feeding method is to first mix the alkoxy metal salt and the alkyl alcohol with the reaction solvent, and then add the dichloro anion carbene complex (which can be added in batches or directly); or, first mix the dichloro anion carbene complex and the alkyl alcohol with the reaction solvent, and then add the alkoxy metal salt; or, directly mix the dichloro anion carbene complex, the alkoxy metal salt, the alkyl alcohol with the reaction solvent.

[0033] In Method 1 described above, after the reaction is complete, the target product can be obtained by filtration and solvent removal. According to a specific embodiment of the present invention, preferably, Method 1 further includes product purification operations, such as recrystallization and washing. More preferably, after the reaction is complete, excess alkoxy metal salts and chloride salts generated in the reaction are removed by filtration, followed by vacuum removal of the solvent, and finally, the resulting solid residue is washed with a low-grade solvent (such as n-hexane) to obtain a pure product.

[0034] According to a specific embodiment of the present invention, preferably, in method two, the alkyl alcohol... The alkoxy metal salt complex is prepared by reacting the alkyl alcohol with the alkoxy metal salt having the same alkyl structure moiety, wherein the molar ratio of the alkyl alcohol to the alkoxy metal salt is (1-20):1, preferably (1-2):1.

[0035] According to a specific embodiment of the present invention, preferably, in method two, the reaction temperature is -80°C to 180°C, more preferably 0°C to 40°C.

[0036] According to a specific embodiment of the present invention, preferably, in method two, the reaction time is 10 minutes to 48 hours, more preferably 30 minutes to 2 hours.

[0037] According to a specific embodiment of the present invention, preferably, in method two, the reaction solvent includes one or more of the following: n-pentane, n-hexane, cyclopentane, cyclohexane, acetonitrile, benzene, toluene, chlorobenzene, bromobenzene, fluorobenzene, trifluorotoluene, hexafluorobenzene, dichloromethane, dichloroethane, trichloromethane, carbon tetrachloride, 1,1,2,2-tetrachloroethane, acetone, diethyl ether, tetrahydrofuran, ethylene glycol dimethyl ether, tert-butyl methyl ether, 1,4-dioxane, methanol, ethanol, N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, hexamethylphosphoramide, and dimethyl sulfoxide; more preferably, it includes one or more of the following: benzene, toluene, and tetrahydrofuran.

[0038] In Method 2 above, after the reaction is complete, the target product can be obtained by filtration and solvent removal. According to a specific embodiment of the present invention, preferably, Method 2 further includes product purification operations, such as recrystallization and washing. More preferably, after the reaction is complete, excess alkoxy metal salts and chloride salts generated in the reaction are removed by filtration, followed by vacuum removal of the solvent, and finally, the resulting solid residue is washed with a low-grade solvent (such as n-hexane) to obtain a pure product.

[0039] According to a specific embodiment of the present invention, preferably, in method two, the alkyl alcohol is prepared. When reacting with alkoxy metal salt complexes, the reaction temperature is -80 °C to 180 °C, more preferably 0 °C to 40 °C.

[0040] According to a specific embodiment of the present invention, preferably, in method two, the alkyl alcohol is prepared. When the reaction is an alkoxy metal salt complex, the reaction time is 30 minutes to 48 hours, more preferably 1 hour to 10 hours.

[0041] According to a specific embodiment of the present invention, preferably, in method two, the alkyl alcohol is prepared. When reacting with alkoxy metal salt complexes, the reaction solvent includes one or more of the following: n-pentane, n-hexane, cyclopentane, cyclohexane, acetonitrile, benzene, toluene, chlorobenzene, bromobenzene, fluorobenzene, trifluorotoluene, hexafluorobenzene, dichloromethane, dichloroethane, trichloromethane, carbon tetrachloride, 1,1,2,2-tetrachloroethane, acetone, diethyl ether, tetrahydrofuran, ethylene glycol dimethyl ether, tert-butyl methyl ether, 1,4-dioxane, alcohols, N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, hexamethylphosphoramide, and dimethyl sulfoxide. More preferably, it includes one or more of the following: benzene, toluene, tetrahydrofuran, and alcohols. Alkyl alcohols can also be used directly as the reaction solvent.

[0042] Alkyl alcohols Alkoxy metal salt complexes typically have low solubility, making the preparation of the alkyl alcohol difficult. In the case of alkoxy metal salt complexes, according to a specific embodiment of the present invention, preferably, a product purification operation is further included, in which most of the reaction solvent is removed using a vacuum, wherein the alkyl alcohol... A large amount of alkoxy metal salt complex precipitated, which was then filtered and washed with an appropriate amount of solvent to obtain an alkyl alcohol. Solid pure alkoxy metal salt complex.

[0043] According to a specific embodiment of the present invention, preferably, the nitrile polymer comprises a copolymer or trimer of the following repeating units: (a) Conjugated diene; (b) α,β-unsaturated nitrile monomers; (c) Comonomer, said comonomer comprising one or more of α,β-unsaturated monocarboxylic acids, α,β-unsaturated monocarboxylic acid esters and α,β-unsaturated monocarboxylic acid amides.

[0044] According to a specific embodiment of the present invention, preferably, the conjugated diene comprises at least one conjugated diene having 4-6 carbon atoms.

[0045] According to a specific embodiment of the present invention, preferably, the conjugated diene is selected from one or more combinations of 1,3-butadiene, isoprene and 2,3-dimethylbutadiene; more preferably, it is 1,3-butadiene.

[0046] According to a specific embodiment of the present invention, preferably, the α,β-unsaturated nitrile monomer comprises at least one α,β-unsaturated nitrile monomer having 3-5 carbon atoms.

[0047] According to a specific embodiment of the present invention, preferably, the α,β-unsaturated nitrile monomer is selected from one or more combinations of acrylonitrile, methacrylonitrile and ethyl acrylonitrile; more preferably, it is acrylonitrile.

[0048] According to a specific embodiment of the present invention, preferably, the comonomer includes one or more of acrylic acid, methacrylic acid, acrylate, and methacrylate.

[0049] According to a specific embodiment of the present invention, preferably, the nitrile polymer possesses one or more of the following properties: (1) Acrylonitrile content is 18%-50%; (2) Mooney viscosity [ML(1+4)100 ℃] is 40-80; (3) The weight-average molecular weight is 200,000-500,000 g / mol.

[0050] The nitrile polymers of the present invention can be prepared in a conventional manner as needed.

[0051] According to a specific embodiment of the present invention, preferably, the mass ratio of the catalyst to the nitrile polymer is 1-500 ppm; more preferably, the mass ratio of the catalyst to the nitrile polymer is 50-250 ppm.

[0052] According to a specific embodiment of the present invention, preferably, the pressure of the introduced hydrogen gas is 2-15 MPa; more preferably, the pressure of the introduced hydrogen gas is 6-10 MPa. The maintained hydrogen gas pressure typically fluctuates by no more than ±0.5 MPa.

[0053] According to a specific embodiment of the present invention, preferably, the preparation method specifically includes: mixing a nitrile polymer with a catalyst, introducing hydrogen gas to carry out a hydrogenation reaction, and then performing post-treatment to obtain a hydrogenated nitrile polymer.

[0054] According to a specific embodiment of the present invention, preferably, the temperature at which the nitrile polymer is mixed with the catalyst is 60-200 °C; more preferably, the temperature at which the nitrile polymer is mixed with the catalyst is 90-160 °C; and even more preferably, the temperature at which the nitrile polymer is mixed with the catalyst is 90-130 °C.

[0055] According to a specific embodiment of the present invention, preferably, the hydrogenation reaction takes 30 minutes to 24 hours; more preferably, the hydrogenation reaction takes 5 hours to 8 hours.

[0056] According to a specific embodiment of the present invention, preferably, the nitrile polymer is first mixed with organic solvent A to form a gel.

[0057] According to a specific embodiment of the present invention, preferably, the concentration of the adhesive solution is 1%-25%, more preferably 5%-10%.

[0058] According to a specific embodiment of the present invention, preferably, the organic solvent A includes, but is not limited to, one or more combinations of n-pentane, n-hexane, cyclopentane, cyclohexane, acetonitrile, benzene, toluene, chlorobenzene, bromobenzene, fluorobenzene, trifluorotoluene, hexafluorobenzene, dichloromethane, dichloroethane, chloroform, carbon tetrachloride, 1,1,2,2-tetrachloroethane, acetone, diethyl ether, tetrahydrofuran, ethylene glycol dimethyl ether, tert-butyl methyl ether, 1,4-dioxane, methanol, ethanol, isopropanol, N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, hexamethylphosphoramide, and dimethyl sulfoxide; more preferably, chlorobenzene.

[0059] According to a specific embodiment of the present invention, preferably, the catalyst is first mixed with organic solvent B in a protective gas to form a catalyst solution.

[0060] According to a specific embodiment of the present invention, preferably, the organic solvent B includes, but is not limited to, one or more combinations of n-pentane, n-hexane, cyclopentane, cyclohexane, acetonitrile, benzene, toluene, chlorobenzene, bromobenzene, fluorobenzene, trifluorotoluene, hexafluorobenzene, dichloromethane, dichloroethane, chloroform, carbon tetrachloride, 1,1,2,2-tetrachloroethane, acetone, diethyl ether, tetrahydrofuran, ethylene glycol dimethyl ether, tert-butyl methyl ether, 1,4-dioxane, methanol, ethanol, isopropanol, N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, hexamethylphosphoramide, and dimethyl sulfoxide; more preferably, chlorobenzene.

[0061] According to a specific embodiment of the present invention, preferably, the protective gas is nitrogen or argon.

[0062] According to a specific embodiment of the present invention, preferably, the post-processing step can be carried out using conventional methods in the art, including distillation condensation, solvent evaporation, wet flocculation, etc., usually flocculation in alcohol solvents, or removal of organic solvents under negative pressure and a certain temperature, and drying the rubber to the extent required by subsequent rubber processing methods.

[0063] Secondly, the present invention also provides a hydrogenated nitrile polymer prepared according to the above-described preparation method.

[0064] According to a specific embodiment of the present invention, preferably, the hydrogenated nitrile polymer possesses one or more of the following properties: (1) The degree of hydrogenation is 50%-100%; (2) Acrylonitrile content is 18%-50%; (3) The gel content is less than 5%; (4) The weight-average molecular weight is 200,000-500,000 g / mol; (5) The molecular weight distribution is 2.5-5.0.

[0065] According to a specific embodiment of the present invention, preferably, the degree of hydrogenation of the hydrogenated nitrile polymer is 80%-100%; more preferably, the degree of hydrogenation of the hydrogenated nitrile polymer is 90%-100%; and even more preferably, the degree of hydrogenation of the hydrogenated nitrile polymer is 98%-100%.

[0066] The acrylonitrile content of the hydrogenated nitrile polymer of the present invention is usually determined by the acrylonitrile content of the raw material nitrile polymer, and the hydrogenation process does not affect it.

[0067] According to a specific embodiment of the present invention, preferably, the gel content of the hydrogenated nitrile polymer is 2% or less. More preferably, the gel content of the hydrogenated nitrile polymer is 1% or less.

[0068] Compared with the prior art, the present invention has the following beneficial effects: This invention employs a sterically hindered alkoxy monochloro anion ruthenium carbene complex as a hydrogenation catalyst, applied to the solution hydrogenation process of nitrile polymers, which can stably and efficiently produce highly saturated (high degree of hydrogenation) and low-gelling hydrogenated nitrile polymers.

[0069] The catalyst of this invention exhibits excellent catalytic activity and efficiency, requiring a significantly lower amount of catalyst compared to conventional catalysts to achieve the same or even higher degrees of hydrogenation. Its extremely high catalytic efficiency allows for high hydrogenation rates with low dosage even when dealing with the hydrogenation of nitrile polymers with functional groups such as carboxyl, ester, and amide groups.

[0070] The catalyst of this invention exhibits extremely high chemoselectivity for carbon-carbon double bonds (C=C). Its electronic and spatial structure can recognize and activate C=C without affecting more polar groups such as cyano, carboxyl, and ester groups. Therefore, side reactions are greatly suppressed, ensuring low gel content and linearly soluble products.

[0071] The catalyst of this invention exhibits high stability to air and moisture. This makes the storage, handling, and reaction processes of the catalyst more robust, reducing the risk of production failure due to catalyst deactivation.

[0072] The catalyst of this invention is easily activated by hydrogen while retaining a certain olefin metathesis capability. It can still work effectively in high-viscosity systems with limited mass transfer; and it can achieve uniform and thorough hydrogenation in high-solids-content solutions. Attached Figure Description

[0073] Figure 1 The reaction formula for preparing hydrogenated nitrile butadiene rubber by hydrogenation of modified nitrile butadiene rubber. Detailed Implementation

[0074] In order to provide a clearer understanding of the technical features, objectives and beneficial effects of the present invention, the technical solution of the present invention will now be described in detail below, but it should not be construed as limiting the scope of implementation of the present invention.

[0075] Preparation Example 1

[0076] This preparation example provides a method for preparing an Ia catalyst, specifically including the following steps: A 4 mL dry vial was transferred to a glove box under nitrogen atmosphere. Dichloro-substituted ruthenium carbene complex (CAS: 301224-40-8, 0.08 mmol, 1 equivalent), benzene (0.5 mL), and tert-butanol (0.12 mmol, 1.5 equivalent) were added sequentially. Finally, potassium tert-butoxide solid (0.086 mmol, 1.08 equivalent) was added. Immediately after the addition of potassium tert-butoxide, the reaction flask was sealed with a lid lined with PTFE and the vial was rapidly shaken until the solid was substantially dissolved. The mixture was stirred at 600 rpm at room temperature for 1 hour. The reaction yielded a benzene solution with a product purity of approximately 95%.

[0077] Structure of Ia catalyst product: ; 1 H NMR (400 MHz, Benzene- d 6) δ 16.32 (s, 1H), 7.20 (dd, J = 7.4, 1.5Hz, 1H), 7.14 – 7.05 (m, 1H), 6.97 (s, 2H), 6.94 (s, 2H), 6.72 (t, J = 7.4Hz, 1H), 6.39 (d, J = 8.2 Hz, 1H), 4.36 (hept, J = 6.0 Hz, 1H), 3.48 – 3.38(m, 4H), 2.56 (s, 12H), 2.26 (s, 6H), 1.42 (d, J = 6.2 Hz, 3H), 1.37 (d, J =5.9 Hz, 3H), 0.82 (s, 9H). Preparation Example 2 This preparation example provides a method for preparing an Ib catalyst, specifically including the following steps: The only difference from Preparation Example 1 is that another ruthenium carbene complex (CAS: 660400-33-9) was used instead of the dichloro-substituted ruthenium carbene complex (CAS: 301224-40-8) in Preparation Example 1 as the reaction raw material.

[0078] Ib catalyst.

[0079] Preparation Example 3

[0080] This preparation example provides a method for preparing an Ic catalyst, specifically including the following steps: The only difference from Preparation Example 1 is that potassium adamantaneol is used instead of potassium tert-butoxide.

[0081] Ic catalyst.

[0082] Example 1

[0083] This embodiment provides a method for preparing hydrogenated carboxylated butadiene-acrylonitrile rubber, specifically including the following steps: In a 1 L dissolving vessel, 30 g of carboxylated acrylonitrile rubber (brand name Nandi 1072, acrylonitrile content of 25.0%, Mooney viscosity ML(1+4) 100 ℃ 48, molecular weight Mw 235715, molecular weight distribution index 2.8) and 570 g of anhydrous chlorobenzene were stirred until completely dissolved to form a homogeneous adhesive solution with a concentration of approximately 5%. The Ia catalyst was then stirred with 10 mL of anhydrous chlorobenzene in an inert gas atmosphere at room temperature until dissolved to obtain a pre-prepared chlorobenzene solution of the Ia catalyst.

[0084] The above-mentioned adhesive solution was introduced into a 1 L high-pressure reactor and purged with nitrogen. The temperature was then raised to 100 °C. A chlorobenzene solution of the Ia catalyst from Preparation Example 1, which was prepared in advance, was added. The mass ratio of the Ia catalyst to the nitrile polymer was 100 ppm. Hydrogen gas was then introduced to a pressure of 9.5 MPa, and the reaction was carried out for 6 h to obtain a hydrogenated carboxylated acrylonitrile rubber solution. This solution was then subjected to methanol flocculation and drying to obtain the hydrogenated carboxylated acrylonitrile rubber product, with a yield >98%. Figure 1 The general reaction formula for preparing hydrogenated nitrile butadiene rubber by hydrogenating modified nitrile butadiene rubber containing three types of functional side groups: carboxyl, ester, and amide is given in Example 1, which uses carboxyl nitrile butadiene rubber with X being -COOH as raw material.

[0085] Example 2

[0086] This embodiment provides a method for preparing hydrogenated carboxylated butadiene-acrylonitrile rubber, specifically including the following steps: In a 1 L dissolving vessel, 30 g of carboxylated acrylonitrile rubber (brand name Nandi 1072, acrylonitrile content of 25.0%, Mooney viscosity ML(1+4) 100 ℃ 48, molecular weight Mw 235715, molecular weight distribution index 2.8) and 570 g of anhydrous chlorobenzene were stirred until completely dissolved to form a homogeneous adhesive solution with a concentration of approximately 5%. The Ia catalyst was then stirred with 10 mL of anhydrous chlorobenzene in an inert gas atmosphere at room temperature until dissolved to obtain a pre-prepared chlorobenzene solution of the Ia catalyst.

[0087] The above-mentioned adhesive solution was introduced into a 1 L high-pressure reactor and purged with nitrogen. The temperature was then raised to 110 °C. A chlorobenzene solution of the Ia catalyst from Preparation Example 1, which was prepared in advance, was added. The mass ratio of the Ia catalyst to the nitrile polymer was 100 ppm. Hydrogen gas was then introduced to a pressure of 9.5 MPa, and after 6 h of reaction, a hydrogenated carboxylated nitrile rubber solution was obtained. Then, the solution was flocculated with methanol and dried to obtain the hydrogenated carboxylated nitrile rubber product with a yield >98%.

[0088] Example 3

[0089] This embodiment provides a method for preparing hydrogenated carboxylated butadiene-acrylonitrile rubber, specifically including the following steps: In a 1 L dissolving vessel, 30 g of carboxylated acrylonitrile rubber (brand name Nandi 1072, acrylonitrile content of 25.0%, Mooney viscosity ML(1+4) 100 ℃ 48, molecular weight Mw 235715, molecular weight distribution index 2.8) and 570 g of anhydrous chlorobenzene were stirred until completely dissolved to form a homogeneous adhesive solution with a concentration of approximately 5%. The Ia catalyst was then stirred with 10 mL of anhydrous chlorobenzene in an inert gas atmosphere at room temperature until dissolved to obtain a pre-prepared chlorobenzene solution of the Ia catalyst.

[0090] The above-mentioned adhesive solution was introduced into a 1 L high-pressure reactor and purged with nitrogen. The temperature was then raised to 120 °C. A chlorobenzene solution of the Ia catalyst from Preparation Example 1, which was prepared in advance, was added. The mass ratio of the Ia catalyst to the nitrile polymer was 100 ppm. Hydrogen gas was then introduced to a pressure of 9.5 MPa, and after 6 h of reaction, a hydrogenated carboxylated nitrile rubber solution was obtained. Then, the solution was flocculated with methanol and dried to obtain the hydrogenated carboxylated nitrile rubber product with a yield >98%.

[0091] Example 4

[0092] This embodiment provides a method for preparing hydrogenated carboxylated butadiene-acrylonitrile rubber, specifically including the following steps: In a 1 L dissolving vessel, 30 g of carboxylated nitrile rubber (brand name Nandi 1072, acrylonitrile content of 25.0%, Mooney viscosity ML(1+4) 100 ℃ of 48, molecular weight Mw of 235715, and molecular weight distribution index of 2.8) and 570 g of anhydrous chlorobenzene were stirred until completely dissolved to form a homogeneous adhesive solution with a concentration of approximately 5%. Ib catalyst and 10 mL of anhydrous chlorobenzene were stirred until dissolved in an inert gas atmosphere at room temperature to obtain a pre-prepared chlorobenzene solution of Ib catalyst.

[0093] The above-mentioned adhesive solution was introduced into a 1 L high-pressure reactor and purged with nitrogen. The temperature was then raised to 120 °C. A chlorobenzene solution of the Ib catalyst from Preparation Example 2, which was prepared in advance, was added. The mass ratio of the Ib catalyst to the nitrile polymer was 100 ppm. Hydrogen gas was then introduced to a pressure of 9.5 MPa, and after 6 h of reaction, a hydrogenated carboxylated nitrile rubber solution was obtained. Then, the solution was flocculated with methanol and dried to obtain the hydrogenated carboxylated nitrile rubber product with a yield >98%.

[0094] Example 5

[0095] This embodiment provides a method for preparing hydrogenated carboxylated butadiene-acrylonitrile rubber, specifically including the following steps: In a 1 L dissolving vessel, 30 g of carboxylated acrylonitrile rubber (brand name Nandi 1072, acrylonitrile content of 25.0%, Mooney viscosity ML(1+4) 100 ℃ of 48, molecular weight Mw of 235715, and molecular weight distribution index of 2.8) and 570 g of anhydrous chlorobenzene were stirred until completely dissolved to form a homogeneous adhesive solution with a concentration of approximately 5%. The Ic catalyst was then stirred with 10 mL of anhydrous chlorobenzene in an inert gas atmosphere at room temperature until dissolved to obtain a pre-prepared chlorobenzene solution of the Ic catalyst.

[0096] The above-mentioned adhesive solution was introduced into a 1 L high-pressure reactor and purged with nitrogen. The temperature was then raised to 120 °C. A chlorobenzene solution of the Ic catalyst from Preparation Example 2, which was prepared in advance, was added. The mass ratio of the Ic catalyst to the nitrile polymer was 100 ppm. Hydrogen gas was then introduced to a pressure of 9.5 MPa, and after 6 h of reaction, a hydrogenated carboxylated nitrile rubber solution was obtained. Then, the solution was flocculated with methanol and dried to obtain the hydrogenated carboxylated nitrile rubber product with a yield >98%.

[0097] Comparative Example 1

[0098] This comparative example provides a method for preparing hydrogenated carboxylated acrylonitrile butadiene rubber, specifically including the following steps: In a 1 L dissolving vessel, 30 g of carboxylated acrylonitrile rubber (brand name Nandi 1072, acrylonitrile content of 25.0%, Mooney viscosity ML(1+4) 100 ℃ 48, molecular weight Mw 235715, molecular weight distribution index 2.8) and 570 g of anhydrous chlorobenzene were stirred until completely dissolved to form a homogeneous adhesive solution with a concentration of approximately 5%. Hoveyda-Grubbs II catalyst and 10 mL of anhydrous chlorobenzene were stirred until dissolved under an inert gas atmosphere at room temperature to obtain a pre-prepared chlorobenzene solution of Hoveyda-Grubbs II catalyst.

[0099] After introducing the above adhesive solution into a 1 L high-pressure reactor and purging with nitrogen, the temperature was raised to 120 °C. A chlorobenzene solution of Hoveyda-Grubbs II catalyst (HG2, CAS No.: 301224-40-8, structure shown below) was added, with the mass ratio of the catalyst to the nitrile polymer being 100 ppm. Hoveyda-Grubbs II catalyst (HG2); Hydrogen gas was then introduced to a pressure of 9.5 MPa, and after 6 h of reaction, a hydrogenated carboxylated nitrile rubber solution was obtained. Then, the solution was flocculated with methanol and dried to obtain the hydrogenated carboxylated nitrile rubber product with a yield >98%.

[0100] Comparative Example 2

[0101] This comparative example provides a method for preparing hydrogenated carboxylated acrylonitrile butadiene rubber, specifically including the following steps: In a 1 L dissolving vessel, 30 g of carboxylated acrylonitrile rubber (brand name Nandi 1072, acrylonitrile content of 25.0%, Mooney viscosity ML(1+4) 100 ℃ 48, molecular weight Mw 235715, molecular weight distribution index 2.8) and 570 g of anhydrous chlorobenzene were stirred until completely dissolved to form a homogeneous adhesive solution with a concentration of approximately 5%. Wilkinson catalyst and 10 mL of anhydrous chlorobenzene were stirred until dissolved in an inert gas atmosphere at room temperature to obtain a pre-prepared chlorobenzene solution of Wilkinson catalyst.

[0102] After introducing the above adhesive solution into a 1 L high-pressure reactor and purging with nitrogen, the temperature was raised to 100 °C. A chlorobenzene solution of a pre-prepared Wilkinson catalyst (CAS No.: 14694-95-2, structure shown below) was added, with the mass ratio of the catalyst to the nitrile polymer being 100 ppm. Wilkinson catalyst; Hydrogen gas was then introduced to a pressure of 9.5 MPa, and after 6 h of reaction, a hydrogenated carboxylated nitrile rubber solution was obtained. Then, the solution was flocculated with methanol and dried to obtain the hydrogenated carboxylated nitrile rubber product with a yield >98%.

[0103] Comparative Example 3

[0104] This comparative example provides a method for preparing hydrogenated carboxylated acrylonitrile butadiene rubber, specifically including the following steps: In a 1 L dissolving vessel, 30 g of carboxylated nitrile rubber (brand name Nandi 1072, acrylonitrile content of 25.0%, Mooney viscosity ML(1+4) 100 ℃ 48, molecular weight Mw 235715, molecular weight distribution index 2.8) and 570 g of anhydrous chlorobenzene were stirred until completely dissolved to form a homogeneous adhesive solution with a concentration of approximately 5%. Ru metal catalyst and 10 mL of anhydrous chlorobenzene were stirred until dissolved in an inert gas atmosphere at room temperature to obtain a pre-prepared chlorobenzene solution of Ru metal catalyst.

[0105] After introducing the above adhesive solution into a 1 L high-pressure reactor and purging with nitrogen, the temperature was raised to 100 °C. A chlorobenzene solution of a pre-prepared Ru metal catalyst (CAS No.: 15529-49-4, structure shown below) was added, with the mass ratio of the catalyst to the nitrile polymer being 100 ppm. Ru metal catalyst; Hydrogen gas was then introduced to a pressure of 9.5 MPa, and the reaction was carried out for 6 hours to obtain a hydrogenated carboxylated acrylonitrile rubber solution. This solution was then subjected to methanol flocculation and drying to obtain the hydrogenated carboxylated acrylonitrile rubber product, with a yield >98%. Evaluation and analysis methods: (1) Degree of hydrogenation: The degree of hydrogenation was determined by NMR. The NMR data of the rubber solution before and after the hydrogenation reaction were recorded on a Pulsar-60 nuclear magnetic resonance analyzer from Oxford Instruments. The degree of hydrogenation was obtained by integrating the proton spectrum. The proton characteristic peaks of 1,4-C=C- and 1,2-C=C-, 4.8-5.2 ppm, peak area denoted as A1; the proton characteristic peaks of saturated hydrocarbons, 0-1.5 ppm, peak area denoted as A2; the proton characteristic peaks of cyano-linked protons, 1.5-2.5 ppm, peak area denoted as A3. The formula for calculating the degree of hydrogenation is as follows: Degree of hydrogenation HD (%) = 1 - Degree of unsaturation (U), Degree of unsaturation (U) = (A1÷2) / [(A1×2+A2+A3)×0.825÷8], where 0.825 is a coefficient determined by the base rubber, assuming that the number of hydrogen atoms in the butadiene monomer component accounts for the total number of hydrogen atoms under fully saturated conditions.

[0106] (2) Gel content: Acetone was used as a solvent to fully dissolve the hydrogenated nitrile rubber sample. After filtration and drying, the gel was obtained and the gel content value was obtained by weighing.

[0107] (3) Molecular weight (Mw) and molecular weight distribution index (PDI): These were determined using a Waters 2414 gel permeation chromatography (GPC) system. A polystyrene standard was used as the calibration curve. The mobile phase was THF, the column temperature was 40 ℃, the sample concentration was 1 mg / mL, the injection volume was 50 µL, the elution time was 40 min, and the flow rate was 1 mL·min. -1 .

[0108] Table 1 shows the characterization results of the hydrogenated nitrile butadiene rubber in the examples and comparative examples.

[0109] Table 1

[0110] As can be seen from Table 1, the ruthenium-based catalyst of the present invention is used for the hydrogenation of carboxylated acrylonitrile rubber to obtain hydrogenated carboxylated acrylonitrile rubber.

[0111] Using the Ia catalyst of the present invention at a dosage of 100 ppm, the degree of hydrogenation was 87.1% at a reaction temperature of 100 °C, 92.0% at 110 °C, and 99.1% at 120 °C. This may be because hydrogen has a higher solubility in solution under high pressure and low temperature, thus promoting the hydrogenation reaction. Replacing the Ia catalyst with Ib and Ic catalysts at 120 °C yielded similar results, with hydrogenation degrees of 98.2% and 98.5%, respectively. The gel content of the hydrogenated nitrile rubber in the embodiments of the present invention is less than 1%, falling within the range of low gel content. The above experimental results are superior to those of Comparative Examples 1-3, which used HG2, Wilkins catalyst, and tris(triphenylphosphine)ruthenium dichloride as hydrogenation catalysts.

Claims

1. A method for preparing a hydrogenated nitrile polymer, characterized in that, The preparation method includes the following steps: In the presence of a catalyst, a nitrile polymer is contacted with hydrogen to carry out a hydrogenation reaction, thereby obtaining a hydrogenated nitrile polymer. The catalyst has the structure shown in Formula I: Equation I; Among them, R, R 1 R 2 R 3 Whether they are the same or different, they are each independently selected from hydrogen, C1-C 18 Straight-chain alkyl, C3-C 18 Branched alkyl groups, C1-C 18 Substituted alkyl groups, halogens, C6-C 18 Substituted aryl, C6-C 18 Unsubstituted aryl, C7-C 18 Aryl or C7-C 18 alkylaryl groups; Optional, R 1 R 2 R 3 Any two of them can form a ternary to twelfth element ring structure; R 31 R 32 R 33 R 34 Whether they are the same or different, they are each independently selected from hydrogen, C1-C 18 Straight-chain alkyl, C3-C 18 Branched alkyl groups, C1-C 18 The substituted alkyl group, halogen, substituted or unsubstituted ester group, substituted or unsubstituted nitro group, or substituted or unsubstituted cyano group; optionally, R 31 R 32 R 33 R 34 Any two of them can form a ternary to octet ring structure; L is a nitrogen-containing heterocyclic carbene ligand; X is an anionic ligand; M is a transition metal.

2. The preparation method according to claim 1, characterized in that, R, R 1 R 2 R 3 Whether they are the same or different, they are each independently selected from hydrogen, C1-C 15 Straight-chain alkyl, C3-C 15 Branched alkyl groups, C1-C 15 Substituted alkyl groups, halogens, C6-C 14 Substituted aryl, C6-C 14 Unsubstituted aryl, C7-C 15 Aryl or C7-C 15 alkylaryl groups.

3. The preparation method according to claim 1, characterized in that, R, R 1 R 2 R 3 Whether they are the same or different, they are each independently selected from hydrogen, C1-C 10 Straight-chain alkyl, C3-C 10 Branched alkyl groups, C1-C 10 Substituted alkyl groups, F, Cl, Br, I, C6-C 10 Substituted aryl, C6-C 10 Unsubstituted aryl, C7-C 10 Aryl or C7-C 10 alkylaryl groups.

4. The preparation method according to claim 1, characterized in that, R, R 1 R 2 R 3 Whether the groups are the same or different, they are each independently selected from hydrogen, C1-C8 straight-chain alkyl groups, C3-C8 branched-chain alkyl groups, C6-C 10 Unsubstituted aryl, C7-C 10 Aryl or C7-C 10 alkylaryl groups.

5. The preparation method according to claim 1, characterized in that, The nitrogen-heterocyclic carbene ligand has the structure shown in formula IIb or IIc: Formula IIb; Formula IIc; Among them, R 7 R 8 R 19 R 20 Whether they are the same or different, they are each independently selected from hydrogen, halogens, and C1-C. 18 Straight-chain alkyl, C3-C 18 Branched alkyl groups, C1-C 18 alkoxy groups, C6-C 18 Substituted aryl, C6-C 18 Unsubstituted aryl, C6-C 18 Substituted aryloxy groups, C6-C 18 Unsubstituted aryloxy groups, C7-C 18 Aryl or C7-C 18 alkylaryl groups; R 9 R 10 R 11 R 12 R 13 R 14 R 15 R 16 R 17 R 18 R 21 R 22 R 23 R 24 R 25 R 26 R 27 R 28 R 29 R 30 Whether they are the same or different, they are each independently selected from hydrogen, C1-C 18 Straight-chain alkyl, C3-C 18 Branched alkyl groups, C1-C 18 alkoxy groups, C6-C 18 Substituted aryl, C6-C 18 Unsubstituted aryl, C6-C 18 Substituted aryloxy groups, C6-C 18 Unsubstituted aryloxy groups, C7-C 18 Aryl or C7-C 18 alkylaryl groups.

6. The preparation method according to claim 5, characterized in that, R 7 R 8 R 19 R 20 Whether they are the same or different, they are each independently selected from hydrogen, F, Cl, Br, I, and Cl-C. 10 Straight-chain alkyl, C3-C 10 Branched alkyl groups, C1-C 10 alkoxy groups, C6-C 10 Substituted aryl, C6-C 10 Unsubstituted aryl, C6-C 10 Substituted aryloxy groups, C6-C 10 Unsubstituted aryloxy groups, C7-C 10 Aryl or C7-C 10 alkylaryl groups; R 9 R 10 R 11 R 12 R 13 R 14 R 15 R 16 R 17 R 18 R 21 R 22 R 23 R 24 R 25 R 26 R 27 R 28 R 29 R 30 Whether they are the same or different, they are each independently selected from hydrogen, C1-C 10 Straight-chain alkyl, C3-C 10 Branched alkyl groups, C1-C 10 alkoxy groups, C6-C 10 Substituted aryl, C6-C 10 Unsubstituted aryl, C6-C 10 Substituted aryloxy groups, C6-C 10 Unsubstituted aryloxy groups, C7-C 10 Aryl or C7-C 10 alkylaryl groups.

7. The preparation method according to claim 1, characterized in that, R 31 R 32 R 33 R 34 All are H.

8. The preparation method according to claim 1, characterized in that, M is selected from ruthenium or osmium.

9. The preparation method according to claim 1, characterized in that, The anionic ligand is selected from one or more combinations of halogen, carboxylate, sulfonate, alkoxy, aryloxy, alkyl mercapto, and aryl mercapto.

10. The preparation method according to claim 1, characterized in that, The catalyst has one of the following structures: It is; Formula Ib; Formula Ic; Expression Id; Formula Ie; If expression.

11. The preparation method according to claim 10, characterized in that, The catalyst is prepared by method one or method two of the following: Method 1: The catalyst is obtained by reacting a dichloro anion carbene complex with an alkoxy metal salt and an alkyl alcohol, wherein the molar ratio of the dichloro anion carbene complex, the alkoxy metal salt, and the alkyl alcohol is 1:(1-10):(1-20). The dichloro anion carbene complex has the structure shown in Formula III or Formula IV: Formula III, In Equation III, M, R, R 7 To R 18 Same as described in claim 1; Formula IV, In equation IV, M, R, R 19 To R 30 Same as described in claim 1; The alkoxy metal salt has the structure shown in Formula V: Formula V, In formula V, R 1 To R 3 As described in claim 1, M1 is Li, Na, K, Ru, or Cs; The alkyl moiety of the alkyl alcohol is the same as that of the alkoxy metal salt, and the alkyl alcohol has the structure shown in Formula VI: Formula VI, In equation VI, R 1 To R 3 Same as described in claim 1; Method 2: Alkyl alcohols The alkoxy metal salt complex reacts with the dichloro anion carbene complex to obtain the catalyst; the alkyl alcohol The molar ratio of the alkoxy metal salt complex to the dichloro anion carbene complex is (1-10):1; The alkyl alcohol The alkoxy metal salt complex has the structure shown in Formula VII: Equation VII, In equation VII, R 1 To R 3 As described in claim 1, M1 is Na or K.

12. The preparation method according to claim 11, characterized in that, Method 1 satisfies one or more of the following conditions: (1) The reaction temperature is from -80 ℃ to 180 ℃; (2) The reaction time is 10 min-48 h; (3) The reaction solvent includes one or more of the following: n-pentane, n-hexane, cyclopentane, cyclohexane, acetonitrile, benzene, toluene, chlorobenzene, bromobenzene, fluorobenzene, trifluorotoluene, hexafluorobenzene, dichloromethane, dichloroethane, chloroform, carbon tetrachloride, 1,1,2,2-tetrachloroethane, acetone, diethyl ether, tetrahydrofuran, ethylene glycol dimethyl ether, tert-butyl methyl ether, 1,4-dioxane, methanol, ethanol, N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, hexamethylphosphoramide, and dimethyl sulfoxide; (4) The feeding method is to first mix the alkoxy metal salt and the alkyl alcohol with the reaction solvent, and then add the dichloro anion carbene complex; or, first mix the dichloro anion carbene complex and the alkyl alcohol with the reaction solvent, and then add the alkoxy metal salt; or, directly mix the dichloro anion carbene complex, the alkoxy metal salt, the alkyl alcohol with the reaction solvent.

13. The preparation method according to claim 11, characterized in that, Method 2 satisfies one or more of the following conditions: (1) The alkyl alcohol The alkoxy metal salt complex is prepared by reacting the alkyl alcohol with the alkoxy metal salt having the same alkyl structure moiety, wherein the molar ratio of the alkyl alcohol to the alkoxy metal salt is (1-20):1; (2) The reaction temperature is from -80 ℃ to 180 ℃; (3) The reaction time is 10 min-48 h; (4) The reaction solvent includes one or more of the following: n-pentane, n-hexane, cyclopentane, cyclohexane, acetonitrile, benzene, toluene, chlorobenzene, bromobenzene, fluorobenzene, trifluorotoluene, hexafluorobenzene, dichloromethane, dichloroethane, chloroform, carbon tetrachloride, 1,1,2,2-tetrachloroethane, acetone, diethyl ether, tetrahydrofuran, ethylene glycol dimethyl ether, tert-butyl methyl ether, 1,4-dioxane, methanol, ethanol, N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, hexamethylphosphoramide, and dimethyl sulfoxide.

14. The preparation method according to claim 13, characterized in that, Preparation of the alkyl alcohol For alkoxy metal salt complexes, one or a combination of two of the following conditions must be met: (1) The reaction temperature is from -80 ℃ to 180 ℃; (2) The reaction time is 10 min-48 h; (3) The reaction solvent includes one or more of the following: n-pentane, n-hexane, cyclopentane, cyclohexane, acetonitrile, benzene, toluene, chlorobenzene, bromobenzene, fluorobenzene, trifluorotoluene, hexafluorobenzene, dichloromethane, dichloroethane, chloroform, carbon tetrachloride, 1,1,2,2-tetrachloroethane, acetone, diethyl ether, tetrahydrofuran, ethylene glycol dimethyl ether, tert-butyl methyl ether, 1,4-dioxane, methanol, ethanol, N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, hexamethylphosphoramide, and dimethyl sulfoxide.

15. The preparation method according to claim 1, characterized in that, The nitrile polymer comprises copolymers or trimers of the following repeating units: (a) Conjugated diene; (b) α,β-unsaturated nitrile monomers; (c) Comonomer, said comonomer comprising one or more of α,β-unsaturated monocarboxylic acids, α,β-unsaturated monocarboxylic acid esters and α,β-unsaturated monocarboxylic acid amides.

16. The preparation method according to claim 15, characterized in that, The conjugated diene includes at least one conjugated diene having 4-6 carbon atoms.

17. The preparation method according to claim 15, characterized in that, The conjugated diene is selected from one or more combinations of 1,3-butadiene, isoprene, and 2,3-dimethylbutadiene.

18. The preparation method according to claim 15, characterized in that, The α,β-unsaturated nitrile monomer includes at least one α,β-unsaturated nitrile monomer having 3-5 carbon atoms.

19. The preparation method according to claim 15, characterized in that, The α,β-unsaturated nitrile monomer is selected from one or more combinations of acrylonitrile, methacrylonitrile, and ethyl acrylonitrile.

20. The preparation method according to claim 15, characterized in that, The comonomer includes one or more of acrylic acid, methacrylic acid, acrylate, and methacrylate.

21. The preparation method according to claim 1, characterized in that, The nitrile polymer possesses one or more of the following properties: (1) Acrylonitrile content is 18%-50%; (2) Mooney viscosity [ML(1+4)100 ℃] is 40-80; (3) The weight-average molecular weight is 200,000-500,000 g / mol.

22. The preparation method according to claim 1, characterized in that, The mass ratio of the catalyst to the nitrile polymer is 1-500 ppm.

23. The preparation method according to claim 1, characterized in that, The pressure of the hydrogen gas introduced is 2-15 MPa.

24. A hydrogenated nitrile polymer prepared by the preparation method according to any one of claims 1-23.

25. The hydrogenated nitrile polymer according to claim 24, characterized in that, The hydrogenated nitrile polymer possesses one or more of the following properties: (1) The degree of hydrogenation is 50%-100%; (2) Acrylonitrile content is 18%-50%; (3) The gel content is less than 5%; (4) The weight-average molecular weight is 200,000-500,000 g / mol; (5) The molecular weight distribution is 2.5-5.0.

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