Hydrogenated nitrile rubber and preparation method thereof

Abstract

The invention discloses a preparation method of hydrogenated butadiene-acrylonitrile rubber, which comprises the following steps: contacting a butadiene-acrylonitrile rubber solution with a molecular weight adjusting catalyst, and contacting a double decomposition reaction mixture with hydrogen under hydrogenation reaction conditions in the presence of a hydrogenation catalyst system to obtain a hydrogenation reaction mixture, the hydrogenation catalyst system contains a hydrogenation catalyst, a ligand and an auxiliary agent, the auxiliary agent is selected from one or two or more of compounds shown in the formula IV, and (LoM) pYq is shown in the formula IV. According to the preparation method of the hydrogenated butadiene-acrylonitrile rubber, the hydrogenation reaction activity can be obviously improved, the reaction speed can be increased, the reaction time can be shortened, and the Mooney viscosity of the product can be effectively reduced.

Description

Technical Field

[0001] The invention relates to the field of rubber preparation, and specifically discloses a method for preparing hydrogenated nitrile rubber. Background Art

[0002] Hydrogenated nitrile rubber is generally prepared by selective hydrogenation of nitrile rubber. Due to the special structure, it usually has excellent oil resistance, high temperature resistance, high pressure resistance, oxidation resistance and mechanical properties. It is a special rubber with excellent comprehensive performance and has been widely used in aerospace, oil exploration, automobile manufacturing and other fields.

[0003] Due to the high cost of nitrile rubber hydrogenation catalysts, complex hydrogenation processes, and harsh hydrogenation reaction conditions, the price of its products has remained high, which has seriously hindered the further expansion of its application areas and scope of use. In recent years, the focus of research on hydrogenated nitrile rubber has been concentrated on the following aspects: first, to find cheap metal catalysts to complete selective hydrogenation reactions to reduce catalyst costs; second, to improve the hydrogenation efficiency of existing catalytic systems through various means to achieve the purpose of reducing catalyst usage and improving production efficiency; third, to continuously improve catalyst recovery efficiency and reduce catalyst residues in products; fourth, to improve the comprehensive performance of products (including product processing performance, mechanical properties, etc.), and continuously expand the application field and use effect of hydrogenated nitrile rubber.

[0004] However, the Mooney viscosity of nitrile rubber has always increased significantly during the hydrogenation process, and the hydrogenation efficiency of the hydrogenation catalyst is low, and other problems have not been well solved.

[0005] Therefore, there is an urgent need to solve the problem that the Mooney viscosity of nitrile rubber increases significantly during the hydrogenation process and the hydrogenation efficiency of the hydrogenation catalyst is low. Summary of the invention

[0006] The purpose of the present invention is to overcome the defects of the prior art method that the Mooney viscosity of nitrile rubber increases significantly after hydrogenation and the hydrogenation reaction efficiency of the hydrogenation catalyst is low, and to provide a hydrogenated nitrile rubber and a preparation method thereof. In the preparation method of the hydrogenated nitrile rubber, the hydrogenation reaction activity of the hydrogenation catalyst is high and the Mooney viscosity of the prepared hydrogenated nitrile rubber is significantly improved.

[0007] A first aspect of the present invention provides a method for preparing hydrogenated nitrile rubber, wherein the method comprises the following steps:

[0008] (1) dissolving the nitrile rubber in an organic solvent to obtain the nitrile rubber solution;

[0009] (2) contacting the nitrile rubber solution with a molecular weight regulating catalyst under olefin metathesis reaction conditions to obtain a metathesis reaction mixture,

[0010] The molecular weight regulating catalyst is selected from at least one compound represented by formula I,

[0011]

[0012] In Formula I, G1 is hydrogen, C2-C 20 Substituted or unsubstituted alkenyl, C2-C 20 Substituted or unsubstituted alkynyl, C1-C 20 Substituted or unsubstituted alkyl, C6-C 20 Substituted or unsubstituted aryl, C1-C 20 Carboxylate group, C1-C 20 Substituted or unsubstituted alkoxy, C2-C 20 Substituted or unsubstituted alkenyloxy, C2-C 20 Substituted or unsubstituted alkynyloxy, C6-C 20 Substituted or unsubstituted aryloxy, C1-C 20 Substituted or unsubstituted alkylthio, C1-C 20 substituted or unsubstituted alkylsulfonyl, or C1-C 20 a substituted or unsubstituted alkylsulfinyl group,

[0013] E1 and E2 are each independently anionic ligands,

[0014] F1 and F2 are each independently a neutral ligand,

[0015] H is an anionic ligand,

[0016] z is an integer from 1 to 6;

[0017] (3) contacting the metathesis reaction mixture with hydrogen under hydrogenation reaction conditions in the presence of a hydrogenation catalyst system to obtain a hydrogenation reaction mixture, wherein the hydrogenation catalyst system comprises a hydrogenation catalyst, a ligand and an auxiliary agent;

[0018] The hydrogenation catalyst is selected from at least one compound represented by formula II and / or at least one compound represented by formula III,

[0019] (R m A) s RxF 1 n Formula II

[0020] In formula II, m R are the same or different and are independently selected from C1-C8 alkyl, C4-C8 cycloalkyl, C6-C 15 Aryl or C7-C 15 The aralkyl group,

[0021] A is phosphorus, arsenic, sulfur or sulfoxide,

[0022] n X 1 are the same or different, each independently hydrogen or an anion,

[0023] s is 2, 3 or 4, m is 2 or 3, n is 1, 2 or 3;

[0024] M 1 a M 2 b X 2 h L 1 j Formula III

[0025] In Formula III, M 1 Rhodium, M 2 For ruthenium,

[0026] h X 2 are the same or different and are each independently chlorine, bromine or hydrogen,

[0027] j L 1 are the same or different, and are each independently an organic phosphine, an organic cerium, a nitrogen-containing organic compound, a sulfur-containing organic compound, or an oxygen-containing organic compound,

[0028] 1≤a≤6, 1≤b≤3, 3≤h≤7, 6≤j≤21;

[0029] The auxiliary agent is selected from at least one compound represented by formula IV,

[0030] (L 2 o M) p Y q Formula IV

[0031] In Formula IV, o L 2 The same or different, independently C1-C8 alkyl, C4-C8 cycloalkyl, C6-C 15 Aryl or C7-C 15 The aralkyl group,

[0032] M is phosphorus or arsenic,

[0033] q Y are the same or different and are each independently an anion,

[0034] o is 3, 4, 5 or 6, p is 1, 2 or 3, and q is 1, 2 or 3.

[0035] The second aspect of the present invention provides a hydrogenated nitrile rubber prepared by the above preparation method.

[0036] Through the above technical scheme, the hydrogenated nitrile rubber and the preparation method thereof provided by the present invention achieve the following beneficial effects:

[0037] The preparation method of the hydrogenated nitrile rubber of the present invention can not only significantly improve the hydrogenation reaction activity of the hydrogenation catalyst, increase the reaction speed, shorten the reaction time, and improve the hydrogenation degree of the product, but also the Mooney viscosity of the product before and after the hydrogenation reaction changes little.

[0038] Other features and advantages of the present invention will be described in detail in the following detailed description. DETAILED DESCRIPTION

[0039] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0040] In the present invention, the C1-C8 alkyl group includes a C1-C8 straight-chain alkyl group and a C3-C8 branched-chain alkyl group, and specific examples thereof may include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, 2-methylbutyl, 3-methylbutyl, 2,2-dimethylpropyl, n-hexyl, 2-methylpentyl, 3-methylpentyl, 4-methylpentyl, 2,3-dimethylbutyl, 2,2-dimethylbutyl, 3,3-dimethylbutyl, 2-ethylbutyl, n-heptyl, 2-methylhexyl, 3-methylhexyl, 4-methylhexyl, 5-methylhexyl, 2,2-dimethylpentyl, 2,3-dimethylpentyl, 2,4 -dimethylpentyl, 3,3-dimethylpentyl, 3,4-dimethylpentyl, 4,4-dimethylpentyl, 2-ethylpentyl, 3-ethylpentyl, n-octyl, 2-methylheptyl, 3-methylheptyl, 4-methylheptyl, 5-methylheptyl, 6-methylheptyl, 2,2-dimethylhexyl, 2,3-dimethylhexyl, 2,4-dimethylhexyl, 2,5-dimethylhexyl, 3,3-dimethylhexyl, 3,4-dimethylhexyl, 3,5-dimethylhexyl, 4,4-dimethylhexyl, 4,5-dimethylhexyl, 5,5-dimethylhexyl, 2-ethylhexyl, 3-ethylhexyl, 4-ethylhexyl, 2-n-propylpentyl and 2-isopropylpentyl.

[0041] In the present invention, specific examples of the C4-C8 cycloalkyl group may include, but are not limited to, cyclobutyl, cyclopentyl, cyclohexyl, 4-methylcyclohexyl, 4-ethylcyclohexyl, 4-n-propylcyclohexyl and 4-n-butylcyclohexyl.

[0042] In the present invention, C6-C15 Specific examples of the aryl group may include, but are not limited to, phenyl, naphthyl, 2-methylphenyl, 2-ethylphenyl, 4-methylphenyl, and 4-ethylphenyl.

[0043] In the present invention, the term "aralkyl" can be represented by Ar x -N-, wherein x Ar are the same or different and are independently aryl, N is an alkyl, and x is an integer from 1 to 3. 15 Specific examples of the aralkyl group may include, but are not limited to, phenylmethyl, phenylethyl, phenyl-n-propyl, phenyl-n-butyl, phenyl-t-butyl, phenyl-isopropyl, phenyl-n-pentyl, and phenyl-n-butyl.

[0044] A first aspect of the present invention provides a method for preparing a hydrogenated nitrile rubber, the method comprising the following steps:

[0045] (1) dissolving the nitrile rubber in an organic solvent to obtain the nitrile rubber solution;

[0046] (2) contacting the nitrile rubber solution with a molecular weight regulating catalyst under olefin metathesis reaction conditions to obtain a metathesis reaction mixture,

[0047] The molecular weight regulating catalyst is selected from at least one compound represented by formula I,

[0048]

[0049] In Formula I, G1 is hydrogen, C2-C 20 Substituted or unsubstituted alkenyl, C2-C 20 Substituted or unsubstituted alkynyl, C1-C 20 Substituted or unsubstituted alkyl, C6-C 20 Substituted or unsubstituted aryl, C1-C 20 Carboxylate group, C1-C 20 Substituted or unsubstituted alkoxy, C2-C 20 Substituted or unsubstituted alkenyloxy, C2-C 20 Substituted or unsubstituted alkynyloxy, C6-C 20 Substituted or unsubstituted aryloxy, C1-C 20 Substituted or unsubstituted alkylthio, C1-C 20 substituted or unsubstituted alkylsulfonyl, or C1-C 20 a substituted or unsubstituted alkylsulfinyl group,

[0050] E1 and E2 are each independently anionic ligands,

[0051] F1 and F2 are each independently a neutral ligand,

[0052] H is an anionic ligand,

[0053] z is an integer from 1 to 6;

[0054] (3) contacting the metathesis reaction mixture with hydrogen under hydrogenation reaction conditions in the presence of a hydrogenation catalyst system to obtain a hydrogenation reaction mixture, wherein the hydrogenation catalyst system comprises a hydrogenation catalyst, a ligand, and an auxiliary agent;

[0055] The hydrogenation catalyst is selected from at least one compound represented by formula II and / or at least one compound represented by formula III,

[0056] (R m A) s RxF 1 n Formula II

[0057] In formula II, m R are the same or different and are independently selected from C1-C8 alkyl, C4-C8 cycloalkyl, C6-C 15 Aryl or C7-C 15 The aralkyl group,

[0058] A is phosphorus, arsenic, sulfur or sulfoxide,

[0059] n X 1 are the same or different, each independently hydrogen or an anion,

[0060] s is 2, 3 or 4, m is 2 or 3, n is 1, 2 or 3;

[0061] M 1 a M 2 b X 2 h L 1 j Formula III

[0062] In Formula III, M 1 Rhodium, M 2 For ruthenium,

[0063] h X 2 are the same or different and are each independently chlorine, bromine or hydrogen,

[0064] j L 1 are the same or different, and are each independently an organic phosphine, an organic cerium, a nitrogen-containing organic compound, a sulfur-containing organic compound, or an oxygen-containing organic compound,

[0065] 1≤a≤6, 1≤b≤3, 3≤h≤7, 6≤j≤21;

[0066] The auxiliary agent is selected from at least one compound represented by formula IV,

[0067] (L 2 o M) p Y q Formula IV

[0068] In Formula IV, o L 2 The same or different, independently C1-C8 alkyl, C4-C8 cycloalkyl, C6-C 15 Aryl or C7-C 15 The aralkyl group,

[0069] M is phosphorus or arsenic,

[0070] q Y are the same or different and are each independently an anion,

[0071] o is 3, 4, 5 or 6, p is 1, 2 or 3, and q is 1, 2 or 3.

[0072] In one embodiment of the present invention, in Formula I, G1 is preferably C6-C 20 The substituted or unsubstituted aryl group is preferably a phenyl group.

[0073] In a specific embodiment of the present invention, in Formula I, E1 and E2 can be various common anionic ligands, for example, each can be a halogen ion, preferably a chloride ion.

[0074] In one embodiment of the present invention, in Formula I, F1 and F2 can each be a common neutral ligand, and specific examples thereof can include but are not limited to: phosphine, amine, thioether, carbene, or substituted or unsubstituted imidazolidine. Preferably, F1 and F2 are phosphine, carbene, or substituted or unsubstituted imidazolidine. More preferably, F1 is a phosphine, and F2 is a substituted or unsubstituted imidazolidine.

[0075] In the present invention, the phosphine can be a compound in which the hydrogen in various phosphine molecules is partially or completely replaced by an organic group, and the organic groups are the same or different and can be selected from chain alkyl (such as C1-C 10 Alkyl) and substituted or unsubstituted cycloalkyl (such as C6-C 12 The phosphine is preferably a trialkylphosphine, more preferably a tricyclohexylphosphine.

[0076] In a specific embodiment of the present invention, H can be various common anionic ligands, for example, it can be a halogen ion, preferably an iodide ion.

[0077] According to the method of the present invention, the substituted or unsubstituted imidazolidine has a structure shown in Formula V,

[0078]

[0079] In Formula V, G2 and G3 are the same or different and are each independently C6-C 20 A substituted or unsubstituted aryl group.

[0080] In one embodiment of the present invention, in Formula V, G2 and G3 are the same or different and are each independently G4, G5, G6, G7 and G8 are the same or different, and are each independently hydrogen or a C1-C5 alkyl group.

[0081] In the present invention, the C1-C5 alkyl group includes a C1-C5 straight-chain alkyl group or a C3-C5 branched-chain alkyl group, and specific examples thereof may include but are not limited to: methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl or n-pentyl.

[0082] In one embodiment of the present invention, in Formula V, G2 and G3 are

[0083] In one embodiment of the present invention, in Formula V, G2 and G3 are

[0084] In a preferred embodiment of the present invention, in Formula I, G1 is phenyl, F1 is phosphine, F2 is substituted or unsubstituted imidazolidine, E1 and E2 are chloride ions, and H is iodide ion.

[0085] In a more preferred embodiment of the present invention, in Formula I, G1 is phenyl, F1 is phosphine, and F2 is E1 and E2 are chloride ions, and H is iodide ion.

[0086] In one embodiment of the present invention, in Formula II, m R are the same or different and are each independently C6-C 15 Preferably, in Formula II, m R's are all phenyl.

[0087] In one specific embodiment of the present invention, in Formula II, A is phosphorus.

[0088] In one embodiment of the present invention, in formula II, A is an anion. Preferably, in formula II, A is a halogen ion. Further preferably, in formula II, A is a chloride ion or a bromide ion. Particularly preferably, in formula II, A is a chloride ion.

[0089] In a preferred embodiment, the hydrogenation catalyst is (PPh3)3RhCl.

[0090] In one embodiment of the present invention, in Formula III, h X 2 are the same or different and are each independently chlorine, bromine or hydrogen. Preferably, X 2 For chlorine.

[0091] In one embodiment of the present invention, in Formula III, j L 1 are the same or different, and are each independently an organic phosphine, an organic cerium, a nitrogen-containing organic compound, a sulfur-containing organic compound, or an oxygen-containing organic compound. The organic phosphorus may be an organic monophosphine or an organic diphosphine. Preferably, in Formula III, L 1 More preferably, in Formula III, L 1 It is triphenylphosphine.

[0092] In a specific embodiment of the present invention, in formula III, a, b, h and j are each integers, wherein 1≤a≤6, 1≤b≤3, 3≤h≤7, 6≤j≤21.

[0093] In one embodiment of the present invention, in Formula III, M 1 Rhodium, M 2 For ruthenium, X 2 For chlorine, L 1 is an organic monophosphine, preferably triphenylphosphine. In this preferred embodiment, in formula III, a:b is 1-3:1, preferably, a:b is 2:1.

[0094] In a preferred embodiment of the present invention, in Formula III, M 1 Rhodium, M 2 For ruthenium, X 2 For chlorine, L 1 is triphenylphosphine, a is 2, b is 1, h is 4, and j is 9. In another preferred embodiment, in Formula III, M 1 Rhodium, M 2 For ruthenium, X 1 For chlorine, L 2 is triphenylphosphine, a is 3, b is 1, h is 5, and j is 12. In another preferred embodiment of the present invention, in formula III, M 1 Rhodium, M 2 For ruthenium, X 1 For chlorine, L 1 is triphenylphosphine, a is 1, b is 1, h is 3, and j is 6.

[0095] The hydrogenation catalyst M 1 a M 2 b X 2 h L1 j It can be prepared by a method comprising the following steps:

[0096] (1) L 1 and solvent are added into the reaction flask, and refluxed to dissolve under stirring;

[0097] (2) The M 1 Metal halides and M 2 The metal halides are mixed and dissolved in a hot solvent, and added into a reaction bottle at reflux temperature to react;

[0098] (3) Removing the solvent to obtain a crystalline or powdery hydrogenation catalyst.

[0099] In one embodiment of the present invention, in Formula IV, o L 2 The same or different, each independently C6-C 15 Preferably, in Formula IV, o L 2 All are phenyl.

[0100] In one embodiment of the present invention, in formula IV, q Y are the same or different and are independently a halogen ion. Preferably, in formula IV, q Y are the same or different and are independently a chloride ion or a bromide ion. More preferably, in formula IV, Y is a chloride ion.

[0101] In a specific embodiment of the present invention, in step (3), from the perspective of further improving the hydrogenation reaction activity of the hydrogenation catalyst and further improving the hydrogenation degree of the hydrogenation product, the auxiliary agent is preferably (PPh4)Cl and / or (PPh4)Br.

[0102] According to the method of the present invention, the auxiliary agent in step (3) can be commercially available.

[0103] According to the method of the present invention, in step (2), the consumption of the molecular weight regulating catalyst can be appropriately selected according to the quality of the acrylonitrile-butadiene rubber, so as to achieve catalytic function. Generally, the consumption of the molecular weight regulating catalyst can be 0.002% by weight to 5% by weight of the total consumption of the acrylonitrile-butadiene rubber, preferably 0.005% by weight to 1% by weight of the total consumption of the acrylonitrile-butadiene rubber, more preferably 0.006% by weight to 0.5% by weight of the total consumption of the acrylonitrile-butadiene rubber, and further preferably 0.02% by weight to 0.1% by weight of the total consumption of the acrylonitrile-butadiene rubber.

[0104] According to the method of the present invention, in step (2), from the perspective of further improving the regulating ability of the molecular weight regulating catalyst, the contact between the nitrile rubber solution and the molecular weight regulator catalyst is preferably carried out in the presence of at least one regulator, and preferably, the regulator can be an olefin.

[0105] In the present invention, there is no particular limitation on the amount of the regulator, and the regulator in the conventional amount in the art can be used, for example, the amount of the regulator is 10-20 parts by weight relative to 100 parts by weight of the nitrile rubber dry glue.

[0106] In the present invention, the olefin used as the regulator may be at least one of a monoolefin, a diolefin and a polyolefin (i.e., an olefin molecule containing three or more carbon-carbon double bonds). The olefin used as the regulator is preferably a olefin of the general formula C k H 2k The hydrocarbon represented by , wherein k can be an integer greater than 2, preferably an integer from 2 to 20.

[0107] In a specific embodiment of the present invention, the regulator is derived from the 1,2-butadiene structure in the nitrile rubber.

[0108] In a preferred embodiment of the present invention, the regulator is one or more selected from olefins, such as C2-C 20 Preferably, the regulator is one or more selected from α-olefins, so that the metathesis reaction can be carried out under milder conditions. Further preferably, the regulator is selected from C2-C 20 One or more of the α-olefins of the present invention, such as one or more of ethylene, 1-propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-dodecene, 1-hexadecene, 1-octadecene or 1-eicosene. More preferably, the regulator is C2-C 10 One or two or more of the α-olefins, for example, one or two or more of ethylene, 1-propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene or 1-decene.

[0109] According to the method of the present invention, in step (2), the nitrile rubber glue is contacted with the molecular weight regulator and an optional regulator to reduce the molecular weight of the nitrile rubber. The reduction range of the molecular weight can be selected according to the intended use of the nitrile rubber.

[0110] According to the method of the present invention, in step (2), the olefin metathesis reaction conditions can be conventionally selected. Generally, the temperature of the metathesis reaction can be 30-150°C, preferably 40-120°C, and more preferably 45-100°C. The time for contacting the nitrile rubber glue with the molecular weight regulating catalyst can be appropriately selected according to the temperature of contact, so as to obtain the expected molecular weight. Generally, the contact time of the nitrile rubber glue with the molecular weight regulating catalyst can be 0.01-4 hours, preferably 0.1-3 hours, more preferably 0.2-2 hours, and further preferably 0.5-1 hours.

[0111] According to the method of the present invention, in step (3), the amount of the hydrogenation catalyst can be selected according to the amount of the acrylonitrile-butadiene rubber. Preferably, the mass of the hydrogenation catalyst is 0.01wt%-5wt% of the mass of the acrylonitrile-butadiene rubber, to improve the degree of hydrogenation of the hydrogenated product. More preferably, the mass of the hydrogenation catalyst is 0.05wt%-1wt% of the mass of the acrylonitrile-butadiene rubber. Further preferably, the mass of the hydrogenation catalyst is 0.05wt%-0.5wt% of the mass of the acrylonitrile-butadiene rubber. Further preferably, the mass of the hydrogenation catalyst is 0.05wt%-0.2wt% of the mass of the acrylonitrile-butadiene rubber.

[0112] In step (3), the amount of the auxiliary agent can be selected according to the amount of the hydrogenation catalyst. Preferably, the mass of the auxiliary agent is 0.001wt%-200wt% of the mass of the hydrogenation catalyst, which can further improve the degree of hydrogenation of the hydrogenated product. More preferably, the mass of the auxiliary agent is 0.01wt%-160wt% of the mass of the hydrogenation catalyst. Further preferably, the mass of the auxiliary agent is 0.1wt%-150wt% of the mass of the hydrogenation catalyst. Further preferably, the mass of the auxiliary agent is 1wt%-100wt% of the mass of the hydrogenation catalyst.

[0113] According to the method of the present invention, in step (3), the ligand may be one or more of an organic phosphine, an organic cerium, a nitrogen-containing organic compound, a sulfur-containing organic compound or an oxygen-containing organic compound. The organic phosphine may be an organic monophosphine or an organic diphosphine. The ligand may be a ligand that is compatible with L in the hydrogenation catalyst. 1 The same may also be L in the hydrogenation catalyst 1 Preferably, the ligand is different from L in the hydrogenation catalyst. 1The same. In a preferred embodiment, the ligand is an organic monophosphine and / or an organic diphosphine, and specific examples thereof may include but are not limited to one or two or more of triphenylphosphine, 1,3-bis(diphenylphosphino)propane or 1,4-bis(diphenylphosphino)butane. In a more preferred embodiment, the ligand is an organic monophosphine, which can further improve the degree of hydrogenation of the hydrogenated product. In a further preferred embodiment, the ligand is triphenylphosphine.

[0114] According to the method of the present invention, in step (3), the amount of the ligand can be selected according to the amount of the hydrogenation catalyst. Preferably, the mass of the ligand is 1-20 times the mass of the hydrogenation catalyst, which can further increase the degree of hydrogenation of the hydrogenated product. More preferably, the mass of the ligand is 4-15 times the mass of the hydrogenation catalyst. Further preferably, the mass of the ligand is 6-12 times the mass of the hydrogenation catalyst.

[0115] According to the method of the present invention, in step (3), the temperature of the hydrogenation reaction can be 50-180°C, preferably 80-150°C, more preferably 80-130°C, and further preferably 80-120°C. In step (3), the hydrogen pressure can be 0.1-15MPa, preferably 4-12MPa, and more preferably 5-10MPa, and the pressure is a gauge pressure. In step (3), the duration of contact between the metathesis reaction mixture and hydrogen can be 1-20 hours, preferably 4-16 hours, more preferably 4-12 hours, and further preferably 5-8 hours.

[0116] According to the method of the present invention, the organic solvent in the hydrogenation reaction mixture can be removed by conventional methods to obtain the hydrogenated nitrile rubber. For example, the organic solvent in the hydrogenation reaction mixture can be removed by one or two or more combinations of methods such as ethanol condensation and steam distillation to obtain a hydrogenated product, and then the solvent on the hydrogenated product is removed to obtain a hydrogenated nitrile rubber. There is no particular limitation on the method for removing the solvent on the hydrogenated product, and various methods commonly used by those skilled in the art can be used. In one embodiment, the method for removing the solvent on the hydrogenated product is vacuum drying, and the temperature of the vacuum drying can be 50-100°C, preferably 55-80°C. The duration of the vacuum drying can be selected according to the temperature of the vacuum drying. Generally, the duration of the vacuum drying can be 1-10 hours, preferably 5-8 hours.

[0117] According to the method of the present invention, in step (1), the mass percentage concentration of acrylonitrile-butadiene rubber in the acrylonitrile-butadiene rubber glue (that is, the percentage value of the mass of acrylonitrile-butadiene rubber and the mass sum of acrylonitrile-butadiene rubber and organic solvent) is not particularly limited and can be a concentration commonly used in the art. Preferably, in the acrylonitrile-butadiene rubber glue, the mass percentage concentration of acrylonitrile-butadiene rubber is 2-15%. More preferably, in the acrylonitrile-butadiene rubber glue, the mass percentage concentration of acrylonitrile-butadiene rubber is 4-12%. Further preferably, in the acrylonitrile-butadiene rubber glue, the mass percentage concentration of acrylonitrile-butadiene rubber is 6-10%.

[0118] According to the method of the present invention, in step (1), the nitrile rubber may be various nitrile rubbers containing carbon-carbon double bonds (C=C) and cyano groups (CN), and may be binary nitrile rubber and / or ternary nitrile rubber. Specific examples of the nitrile rubber may include, but are not limited to, butadiene-acrylonitrile rubber, butadiene-(meth)acrylonitrile rubber, 2-methyl-1,3-butadiene-acrylonitrile rubber, 2-methyl-1,3-butadiene-(meth)acrylonitrile rubber, butadiene-acrylonitrile-acrylic rubber, butadiene-acrylonitrile-methyl acrylate rubber, butadiene-acrylonitrile-ethyl acrylate rubber, butadiene-acrylonitrile-tert-butyl acrylate rubber, butadiene-acrylonitrile-butyl acrylate rubber, butadiene-acrylonitrile-(meth)acrylic rubber, butadiene-acrylonitrile-methyl (meth)acrylate rubber, butadiene-acrylonitrile-ethyl (meth)acrylate rubber, butadiene-acrylonitrile-tert-butyl (meth)acrylate rubber, At least one of butadiene-acrylonitrile-(meth)acrylate butyl rubber, butadiene-(meth)acrylonitrile-acrylic rubber, butadiene-(meth)acrylonitrile-methyl acrylate rubber, butadiene-(meth)acrylonitrile-ethyl acrylate rubber, butadiene-(meth)acrylonitrile-t-butyl acrylate rubber, butadiene-(meth)acrylonitrile-butyl acrylate rubber, butadiene-(meth)acrylonitrile-(meth)acrylic rubber, butadiene-(meth)acrylonitrile-methyl (meth)acrylate rubber, butadiene-(meth)acrylonitrile-ethyl (meth)acrylate rubber, butadiene-(meth)acrylonitrile-t-butyl (meth)acrylate rubber and butadiene-(meth)acrylonitrile-butyl (meth)acrylate rubber.

[0119] Preferably, the acrylonitrile rubber is butadiene-acrylonitrile rubber and / or butadiene-(methyl)acrylonitrile rubber.When the acrylonitrile rubber is a mixture of butadiene-acrylonitrile rubber and butadiene-(methyl)acrylonitrile rubber, there is no requirement for the ratio of butadiene-acrylonitrile rubber and butadiene-(methyl)acrylonitrile rubber to add, and it can be any ratio.According to the method of the present invention, the cyano content in the acrylonitrile rubber can be conventionally selected.Preferably, the cyano content in the acrylonitrile rubber is 20-50 weight %.The cyano content adopts nuclear magnetic resonance spectroscopy to measure.

[0120] According to the method of the present invention, in step (1), the organic solvent may be any organic solvent capable of dissolving nitrile rubber, and the organic solvent may be at least one of aromatic hydrocarbons, halogen-substituted aromatic hydrocarbons, halogenated alkanes, ketones, oxacycloalkanes and amides. Preferably, the organic solvent is at least one of benzene, toluene, xylene, chlorobenzene, dichlorobenzene, trichlorobenzene, acetone, butanone, tetrahydrofuran, dioxane and N,N-dimethylformamide.

[0121] According to the method of the present invention, step (1) preferably includes degassing the nitrile rubber glue. The nitrile rubber glue can be degassed by filling an inert gas into a container containing the nitrile rubber glue, then degassing, and repeating the filling and degassing at least three times, thereby degassing the nitrile rubber glue.

[0122] The second aspect of the present invention provides a hydrogenated nitrile rubber prepared by the above preparation method.

[0123] The present invention is further described below with reference to the following examples, but the scope of the present invention is not limited thereby.

[0124] In the following examples and comparative examples, the degree of hydrogenation of hydrogenated nitrile rubber is determined by nuclear magnetic resonance spectroscopy, and the degree of hydrogenation is calculated by the method described in "Nuclear magnetic resonance analysis method for microstructure and hydrogenation degree calculation of hydrogenated nitrile rubber [J]. Petrochemical Industry, 2014, 43: 403-405".

[0125] In the following examples and comparative examples, the Mooney viscosity is tested by the method specified in GB / T 1232.1-2016 "Unvulcanized rubber - Determination by disc shear viscometer Part 1: Determination of Mooney viscosity".

[0126] In the following examples and comparative examples, the method for determining the gel content is as follows: weigh w1 grams of dry gel, add chlorobenzene to prepare a 1 g / 100 mL solution, dissolve for 24 hours, pour the solution into a 360-mesh filter with a constant weight (w2 grams) and filter, then dry the 360-mesh filter containing insoluble matter to a constant weight, the weight is recorded as w3 grams, and the gel content is calculated using the following formula:

[0127] Gel content (ppm) = (w3-w2) / w1×10 6 .

[0128] In the following examples and comparative examples, (PPh4)Cl, (PPh4)Br and (PPh3)3RhCl were purchased from J&K Company.

[0129] In the following examples and comparative examples, butadiene-acrylonitrile rubber was purchased from Ruiong Company with a brand number of 4050, a cyanide content of 41% by mass, and a Mooney viscosity (100° C., 1+4 min) of 55.

[0130] In the following examples and comparative examples, unless otherwise specified, pressures are gauge pressures.

[0131] Preparation Example 1

[0132] This preparation example is used to illustrate the preparation method of the molecular weight regulating catalyst.

[0133] Under nitrogen protection, 760 mg of iodine, 848 mg of the compound represented by formula V (purchased from J&K Technology Co., Ltd.) and 20 mL of dichloromethane were added to a 100 mL three-necked flask and stirred at room temperature (25°C) for 0.5 hours. The obtained mixture was separated by aluminum oxide column chromatography (developing solvent: dichloromethane), and the obtained eluent was concentrated and washed with cyclohexane to obtain 1.31 g of a yellow solid catalyst. The obtained catalyst was subjected to nuclear magnetic resonance hydrogen spectrum ( 1 H-NMR) and carbon nuclear magnetic resonance spectroscopy ( 13 C-NMR) analysis confirmed that the obtained catalyst had the structure shown in Formula VI.

[0134] 1 H-NMR (400MHz, DMSO) δ (ppm): 1.35-2.06 (m, 33H), 1.81 (s, 18H), 2.62 (m, 4H), 6.11 (d, 1H), 7.38-7.50 (m, 5H), 7.59-7.67 (m, 3H).

[0135] 13 C-NMR (100MHz, DMSO) δ (ppm): 24.8, 25.5, 26.2, 26.3, 26.4, 26.6, 31.9, 32.1, 129.1, 129.2, 129.3, 129.5, 130.7, 134.2, 134.3, 193.0.

[0136]

[0137] Wherein, in Formula V and Formula VI, Cy is cyclohexyl.

[0138] The catalyst shown in formula VI is that G1 is phenyl, E1 and E2 are chloride ions, F1 is tricyclohexylphosphine, and F2 is The compound represented by formula I when H is iodide ion and z is 5.

[0139] Preparation Example 2

[0140] This preparation example is used to illustrate the bimetallic hydrogenation catalyst M 1 a M 2 b X 2 h L 1 j (P1) preparation method, wherein M 1 Rhodium, M 2 For ruthenium, X 2 For chlorine, L 1 is triphenylphosphine, a:b is 2:1, h is 4, and j is 9.

[0141] 4.5 g of PPh3 was dissolved in a hot ethanol solution at 70°C under argon protection, the dissolved solution was added to a reaction bottle and heated to reflux; 0.5 g of RhCl3·H2O and 0.23 g of RuCl3·H2O were weighed and dissolved in an ethanol solution under argon protection, and the ethanol solution of RhCl3·H2O and RuCl3·H2O was added dropwise to the reaction bottle, the reflux reaction was maintained for 2.5 hours, and then the temperature was lowered to 25°C, the reaction mixture was filtered, and the obtained solid phase material was washed with ether to obtain a powdered hydrogenation catalyst, in which Rh:Ru=2:1 (molar ratio).

[0142] Preparation Example 3

[0143] This preparation example is used to illustrate the bimetallic hydrogenation catalyst M 1 a M 2 b X 2 h L 1 j (P2) preparation method, wherein M 1 Rhodium, M 2 For ruthenium, X 2 For chlorine, L 1 is triphenylphosphine, a:b is 3:1, h is 5, and j is 12.

[0144] 6 g of PPh3 was dissolved in a hot ethanol solution at 70°C under argon protection, the dissolved solution was added to a reaction bottle and heated to reflux; 0.75 g of RhCl3·H2O and 0.23 g of RuCl3·H2O were weighed and dissolved in an ethanol solution under argon protection, and the ethanol solution of RhCl3·H2O and RuCl3·H2O was added dropwise to the reaction bottle, the reflux reaction was maintained for 2.5 hours, and then the temperature was lowered to 25°C, the reaction mixture was filtered, and the obtained solid phase material was washed with ether to obtain a powdered hydrogenation catalyst, in which Rh:Ru=3:1 (molar ratio).

[0145] Examples 1-8

[0146] Examples 1-8 are used to illustrate the preparation method of the hydrogenated nitrile rubber of the present invention, and the specific preparation method is as follows:

[0147] (1) dissolving the nitrile rubber in an organic solvent to obtain a nitrile rubber solution, and degassing the nitrile rubber solution;

[0148] (2) adding a molecular weight regulating catalyst to the nitrile rubber solution, and reacting under olefin metathesis reaction conditions to obtain a metathesis reaction mixture, wherein the olefin metathesis reaction conditions include: a reaction temperature of A° C. and a reaction time of B hours;

[0149] (3) adding a hydrogenation catalyst, a ligand and an auxiliary agent to the metathesis reaction mixture, then charging hydrogen, and reacting with stirring, wherein the reaction conditions include: a hydrogen pressure of C MPa, a reaction temperature of D°C, and a reaction time of E hours;

[0150] (4) The hydrogenation reaction mixture was condensed with ethanol to precipitate a hydrogenation product, and the hydrogenation product was vacuum dried at 60° C. for 8 hours to obtain a hydrogenated nitrile rubber.

[0151] The specific preparation conditions are listed in Table 1. The hydrogenation degree, Mooney viscosity and gel content of the obtained hydrogenated nitrile rubber were measured, and the results are listed in Table 1.

[0152] Comparative Examples 1-4

[0153] The hydrogenated nitrile rubber was prepared by the same method as in Example 1-8, except that the experimental conditions listed in Table 1 were used. The hydrogenation degree, Mooney viscosity and gel content of the prepared hydrogenated nitrile rubber are listed in Table 1.

[0154] Table 1

[0155]

[0156]

[0157] Table 1 (continued)

[0158]

[0159] It can be seen from Table 1 that, compared with Comparative Examples 1-4, according to Examples 1-8 of the preparation method of the present invention, an olefin metathesis reaction is first carried out before the hydrogenation reaction, which can effectively reduce the Mooney viscosity of the obtained hydrogenated nitrile rubber while ensuring a high degree of hydrogenation. Specifically, in the present invention, the degree of hydrogenation of the hydrogenated nitrile rubber is greater than or equal to 81% and the Mooney viscosity is less than or equal to 96.

[0160] Specifically, by comparing Example 2 with Comparative Example 1, it can be seen that according to the method of the present invention, the olefin metathesis reaction is first carried out before the hydrogenation reaction, which can effectively reduce the Mooney viscosity of the product and also has a certain promoting effect on the improvement of the hydrogenation degree of the product.

[0161] Furthermore, by comparing Examples 2, 3, and 4 with Comparative Examples 2, 3, and 4, it can be seen that according to the method of the present invention, the addition of the auxiliary agent can obtain a higher degree of hydrogenation.

[0162] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A method for preparing hydrogenated nitrile rubber, characterized in that: The method comprises the following steps: (1) dissolving the nitrile rubber in an organic solvent to obtain a nitrile rubber solution; (2) contacting the nitrile rubber solution with a molecular weight regulating catalyst under olefin metathesis reaction conditions to obtain a metathesis reaction mixture, The molecular weight regulating catalyst is selected from at least one compound represented by formula I, In Formula I, G1 is hydrogen, C2-C 20 Substituted or unsubstituted alkenyl, C2-C 20 Substituted or unsubstituted alkynyl, C1-C 20 Substituted or unsubstituted alkyl, C6-C 20 Substituted or unsubstituted aryl, C1-C 20 Carboxylate group, C1-C 20 Substituted or unsubstituted alkoxy, C2-C 20 Substituted or unsubstituted alkenyloxy, C2-C 20 Substituted or unsubstituted alkynyloxy, C6-C 20 Substituted or unsubstituted aryloxy, C1-C 20 Substituted or unsubstituted alkylthio, C1-C 20 substituted or unsubstituted alkylsulfonyl, or C1-C 20 a substituted or unsubstituted alkylsulfinyl group, E1 and E2 are each independently anionic ligands, F1 and F2 are each independently a neutral ligand, H is an anionic ligand, z is an integer from 1 to 6; (3) contacting the metathesis reaction mixture with hydrogen under hydrogenation reaction conditions in the presence of a hydrogenation catalyst system to obtain a hydrogenation reaction mixture, wherein the hydrogenation catalyst system comprises a hydrogenation catalyst, a ligand and an auxiliary agent; The hydrogenation catalyst is selected from at least one compound represented by formula II and / or at least one compound represented by formula III, (R m A) s RxF 1 n Formula II In formula II, m R are the same or different and are independently selected from C1-C8 alkyl, C4-C8 cycloalkyl, C6-C 15 Aryl or C7-C 15 The aralkyl group, A is phosphorus, arsenic, sulfur or sulfoxide, n X 1 are the same or different, each independently hydrogen or an anion, s is 2, 3 or 4, m is 2 or 3, n is 1, 2 or 3; M 1 a M 2 b X 2 h L 1 j Formula III In Formula III, M 1 Rhodium, M 2 For ruthenium, h X 2 are the same or different and are each independently chlorine, bromine or hydrogen, j L 1 are the same or different, and are each independently an organic phosphine, an organic cerium, a nitrogen-containing organic compound, a sulfur-containing organic compound, or an oxygen-containing organic compound, 1≤a≤6, 1≤b≤3, 3≤h≤7, 6≤j≤21; The auxiliary agent is selected from at least one compound represented by formula IV, (L 2 o M) p Y q Formula IV In Formula IV, o L 2 The same or different, independently C1-C8 alkyl, C4-C8 cycloalkyl, C6-C 15 Aryl or C7-C 15 The aralkyl group, M is phosphorus or arsenic, q Y are the same or different and are each independently an anion, o is 3, 4, 5 or 6, p is 1, 2 or 3, and q is 1, 2 or 3.

2. The preparation method according to claim 1, wherein In Formula I, G1 is C6-C 20 A substituted or unsubstituted aryl group, preferably a phenyl group; In formula I, E1 and E2 are each independently a halogen ion, preferably a chloride ion; In formula I, F1 and F2 are each independently a phosphine, an amine, a thioether, a carbene, or a substituted or unsubstituted imidazolidine, preferably a phosphine, a carbene, or a substituted or unsubstituted imidazolidine; In formula I, H is a halogen ion, preferably an iodide ion.

3. The preparation method according to claim 1 or 2, wherein In formula I, G1 is phenyl; In formula I, F1 is a phosphine, preferably a trialkylphosphine; In formula I, F2 is a substituted or unsubstituted imidazolidine; In formula I, E1 and E2 are chloride ions; In formula I, H is an iodide ion.

4. The preparation method according to claim 2 or 3, wherein The substituted or unsubstituted imidazolidine has a structure shown in Formula V, In Formula V, G2 and G3 are the same or different and are each independently C6-C 20 a substituted or unsubstituted aryl group; Preferably, G2 and G3 are each independently G4, G5, G6, G7 and G8 are each independently hydrogen or C1-C5 alkyl; More preferably, G2 and G3 are 5. The preparation method according to any one of claims 1 to 4, wherein: In step (2), the amount of the molecular weight regulating catalyst is 0.002-5% by weight of the total amount of the nitrile rubber, preferably 0.005% by weight to 1% by weight of the total amount of the nitrile rubber, and more preferably 0.006% by weight to 0.5% by weight of the total amount of the nitrile rubber.

6. The preparation method according to any one of claims 1 to 5, wherein: In step (2), the contact between the molecular weight regulating catalyst and the nitrile rubber solution is carried out in the presence of at least one regulating agent; Preferably, the modifier is an olefin.

7. The preparation method according to claim 6, wherein: The olefin is a monoolefin, preferably an α-olefin, and more preferably a C2-C 20 The alpha-olefin is preferably C2-C 10 of α-olefins.

8. The preparation method according to any one of claims 1 to 7, wherein: In step (2), the olefin metathesis reaction conditions include: a temperature of 30-150°C, preferably 40-120°C.

9. The preparation method according to any one of claims 1 to 8, wherein: In step (3), the amount of the hydrogenation catalyst added is 0.01wt%-5wt% of the mass of the nitrile rubber, preferably 0.05wt%-1wt%, and more preferably 0.05wt%-0.5wt%.

10. The preparation method according to any one of claims 1 to 9, wherein: In step (3), the amount of the ligand added is 1-20 times, preferably 4-15 times, the mass of the hydrogenation catalyst.

11. The preparation method according to any one of claims 1 to 10, wherein: In step (3), the amount of the additive added is 0.001wt%-200wt% of the mass of the hydrogenation catalyst, preferably 0.01wt%-160wt%, more preferably 1wt%-100wt%.

12. The preparation method according to any one of claims 1 to 11, wherein: In step (3), the ligand is at least one of an organic phosphine, an organic cerium, a nitrogen-containing organic compound, a sulfur-containing organic compound, and an oxygen-containing organic compound; Preferably, the ligand is an organic monophosphine; More preferably, the ligand is triphenylphosphine.

13. The preparation method according to any one of claims 1 to 12, wherein: In step (3), the auxiliary agent is (PPh4)Cl and / or (PPh4)Br.

14. The preparation method according to any one of claims 1 to 13, wherein: In step (3), the hydrogenation reaction conditions include: temperature of 50-180° C., hydrogen pressure of 0.1-15 MPa, contact time of 1-20 hours, and the pressure is gauge pressure; Preferably, in step (3), the hydrogenation reaction conditions include: temperature of 80-150° C., hydrogen pressure of 4-12 MPa, contact time of 4-16 hours, and the pressure is gauge pressure.

15. The preparation method according to any one of claims 1 to 14, wherein: In step (1), the mass percentage concentration of nitrile rubber in the nitrile rubber solution is 2-15%, preferably 4-12%.

16. The method according to any one of claims 1 to 15, wherein: In step (1), the organic solvent is selected from at least one of aromatic hydrocarbons, halogen-substituted aromatic hydrocarbons, halogenated alkanes, ketones, oxacycloalkanes and amides; Preferably, in step (1), the organic solvent is selected from at least one of benzene, toluene, xylene, chlorobenzene, dichlorobenzene, trichlorobenzene, acetone, butanone, tetrahydrofuran, dioxane and N,N-dimethylformamide.

17. The preparation method according to any one of claims 1 to 16, wherein: Step (1) also includes degassing the nitrile rubber solution.

18. The preparation method according to any one of claims 1 to 17, wherein: The nitrile rubber is a binary nitrile rubber and / or a ternary nitrile rubber; Preferably, the nitrile rubber is selected from the group consisting of butadiene-acrylonitrile rubber, butadiene-(meth)acrylonitrile rubber, 2-methyl-1,3-butadiene-acrylonitrile rubber, 2-methyl-1,3-butadiene-(meth)acrylonitrile rubber, butadiene-acrylonitrile-acrylic rubber, butadiene-acrylonitrile-methyl acrylate rubber, butadiene-acrylonitrile-ethyl acrylate rubber, butadiene-acrylonitrile-tert-butyl acrylate rubber, butadiene-acrylonitrile-butyl acrylate rubber, butadiene-acrylonitrile-(meth)acrylic rubber, butadiene-acrylonitrile-methyl (meth)acrylate rubber, butadiene-acrylonitrile-ethyl (meth)acrylate rubber, butadiene-acrylonitrile-tert-butyl (meth)acrylate rubber, butadiene- At least one of acrylonitrile-(meth)acrylate butyl rubber, butadiene-(meth)acrylonitrile-acrylic rubber, butadiene-(meth)acrylonitrile-methyl acrylate rubber, butadiene-(meth)acrylonitrile-ethyl acrylate rubber, butadiene-(meth)acrylonitrile-tert-butyl acrylate rubber, butadiene-(meth)acrylonitrile-butyl acrylate rubber, butadiene-(meth)acrylonitrile-(meth)acrylic rubber, butadiene-(meth)acrylonitrile-methyl (meth)acrylate rubber, butadiene-(meth)acrylonitrile-ethyl (meth)acrylate rubber, butadiene-(meth)acrylonitrile-tert-butyl (meth)acrylate rubber and butadiene-(meth)acrylonitrile-butyl (meth)acrylate rubber; More preferably, the nitrile rubber is butadiene-acrylonitrile rubber and / or butadiene-(meth)acrylonitrile rubber.

19. A hydrogenated nitrile rubber obtained by the preparation method according to any one of claims 1 to 18.

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