A nickel complex and a method of preparation, catalyst composition and use, a process for the copolymerization of ethylene with alpha-olefins and for the homopolymerization of ethylene

Abstract

The application relates to the field of polyolefin catalysis, and discloses a nickel complex, a preparation method, a catalyst composition, application, an ethylene and alpha-olefin copolymerization method and an ethylene homopolymerization method. The nickel complex has the structure shown in formula (I). The nickel complex provided by the application has excellent water oxygen stability, the preparation method of the nickel complex is simple to operate, and the cost of the nickel complex in the preparation, purification, storage and use processes is significantly reduced. When the nickel complex is applied to the copolymerization reaction of ethylene and alpha-olefin and the homopolymerization reaction of ethylene, the nickel complex has excellent catalytic activity and good thermal stability, and has a good industrial application prospect. Formula (I).

Description

Technical Field

[0001] This invention relates to the field of polyolefin catalysis, specifically to a nickel complex and its preparation method, a catalyst composition and its application, and methods for copolymerizing ethylene with α-olefins and homopolymerizing ethylene. Background Technology

[0002] Polyolefin materials are among the most widely used and highest-volume polymer materials in the world, and are essential basic materials related to national economy and people's livelihood. Generally speaking, polyolefin materials refer to resin materials produced by copolymerization or homopolymerization of ethylene, propylene and some α-olefins (1-butene, 1-hexene, 1-octene, etc.), among which polyethylene and polypropylene are dominant.

[0003] Introducing a certain proportion of α-olefins as comonomers during ethylene polymerization can effectively reduce the polymer's density and crystallinity, and improve its processing properties. The resulting material is called polyolefin elastomer (POE). POE materials exhibit excellent macroscopic properties due to their unique microstructure: they possess the high elasticity of rubber at room temperature and good plasticity at high temperatures. Therefore, POE materials are widely used in many fields such as packaging, photovoltaic films, automotive parts, and wires and cables, possessing significant commercial value.

[0004] The core of polyolefin (POE) material production lies in catalysts, among which transition metal catalysts are key. By adjusting the electronic properties of the metal center and the steric hindrance of the ligands in transition metal catalysts, it is possible not only to increase polyolefin yield and reduce costs, but also to precisely control the microstructure and product performance of the polymer.

[0005] In the industrial production of POE, metallocene catalysts are currently the most widely used catalysts for olefin polymerization. However, metallocene catalysts are highly sensitive to water and oxygen, and are easily and rapidly deactivated upon contact with water and oxygen, even accompanied by exothermic and spontaneous combustion risks, posing a significant safety hazard in production. Therefore, in actual production and operation, it is essential to strictly isolate the water and oxygen environment, which significantly increases costs in preparation, purification, storage, and use. To address this bottleneck, developing novel transition metal catalysts that combine reliable performance, water and oxygen stability, convenient preparation, and low cost has become an urgent need for the development of the POE industry.

[0006] Compared to metallocene catalysts, post-transition metal catalysts, especially nickel catalysts with α-diimine ligand complexes, possess advantages such as high polymerization activity, weak oxygen affinity, good stability, and simple preparation. They are a class of catalysts suitable for the copolymerization of ethylene with α-olefins and the homopolymerization of ethylene. In 1995, Brookhart's group at the University of North Carolina at Chapel Hill, funded by DuPont, first reported a class of α-diimine nickel-based catalysts (structure shown in formula (II)). This class of catalysts can efficiently catalyze the polymerization of ethylene to high molecular weight polyethylene at room temperature (J. Am. Chem. Soc. 1995, 117, 6414-6415.). This landmark advancement spurred widespread research interest in post-transition metal catalysts in the field of olefin polymerization. However, these post-transition metal catalysts generally have poor thermal stability: as the reaction temperature increases, their catalytic activity and the molecular weight of the polyethylene product decrease sharply, and they are usually completely deactivated at around 60°C (Organometallics. 2017,36, 1196-1203.). This limitation severely restricts their industrial application, but it also continues to stimulate the research interest of academia and industry in their improvement and optimization.

[0007] Equation (II),

[0008] Taking the representative acenaphthoquinone skeleton α-diimine nickel catalyst (chemical structure shown in formula (II)) as an example, current strategies to improve the thermal stability of the catalyst focus on introducing alkyl or aryl groups with large steric hindrance at the R and R" sites. This type of structural modification can effectively restrict the rotation of the CN bond (as shown by the arrow in formula (II)), thereby preventing a series of side reactions that cause catalyst deactivation. However, the synthesis of such sterically hindered ligands involves many steps, low yield, and high cost, which is not conducive to industrialization and commercialization (Poly. Chem. 2019, 10, 2354-2369).

[0009] In contrast, non-acenaphthoquinone framework α-diimine nickel catalyst systems exhibit unique potential. Through flexible framework design, precise control over the electronic environment and spatial structure of the metal center can be achieved without relying on ultra-large sterically hindered substituents, potentially simplifying ligand synthesis routes and reducing production costs while maintaining high thermal stability. However, these systems still face some challenges, such as the catalytic activity and copolymerization ability of some novel frameworks not yet matching those of traditional acenaphthoquinone systems, and the structure-activity relationship between their structure and performance needs further clarification.

[0010] Therefore, developing novel non-acenaphthoquinone framework α-diimine nickel catalyst systems that possess excellent thermal stability, are easy to synthesize, and have controllable costs has become an urgent need to promote the development of the polyolefin industry. Summary of the Invention

[0011] The purpose of this invention is to overcome the problems of insufficient thermal stability and poor olefin polymerization performance of nickel α-diimine catalysts with acenaphthoquinone skeleton in the prior art.

[0012] To achieve the above objectives, a first aspect of the present invention provides a nickel complex having the structure shown in formula (I):

[0013] Formula (I);

[0014] In equation (I),

[0015] R 1 R 2 R 3 R 4 R 5 R 6 R 7 R 8 R 9 R 10 Each is independently selected from H, unsubstituted, or derived from R. 11 C with substituent group 1-6 Alkyl, C 2-6 alkenyl, C 6-10 Aryl, halogen, hydroxyl, C 1-6 Alkoxy and -NR 12 R 13 At least one of them; R 11 Selected from halogens, unsubstituted or derived from C 1-6 At least one of the alkyl groups substituted with at least one of the phenyl groups; R 12 and R 13 Each is independently selected from hydrogen and C. 1-6 At least one of alkyl groups; each X is independently selected from halogens.

[0016] In some embodiments, in the nickel complex, in formula (I),

[0017] R 1 R 2 R 3 R 4 R 5 R 6 R 7 R 8 R 9 R 10 Each is independently selected from H, unsubstituted, or derived from R. 11 C with substituent group 1-4 Alkyl, C 6-8 Aryl, fluorine, chlorine, hydroxyl, C 1-4 At least one of the alkoxy groups; R 11Selected from halogens, unsubstituted or derived from C 1-4 At least one of the alkyl groups substituted with at least one of the phenyl groups; each X is independently bromine and / or chlorine.

[0018] In some embodiments, in the nickel complex, in formula (I),

[0019] R 1 R 3 R 5 R 6 R 8 R 10 Each is independently selected from H, unsubstituted, or derived from R. 11 Substituted methyl group, unsubstituted methyl group, or methyl group composed of R 11 Ethyl groups substituted with groups, unsubstituted ethyl groups, or ethyl groups derived from R 11 Substituted n-propyl group, unsubstituted or derived from R 11 At least one of the following groups: isopropyl, methoxy, ethoxy, propoxy, and isopropoxy; R 11 Selected from phenyl, phenyl groups substituted with at least one group selected from methyl, ethyl, n-propyl, propoxy, and at least one fluorine group; R 2 R 4 R 7 R 9 All are H; all X are bromine.

[0020] According to one specific embodiment, in the nickel complex, the nickel complex represented by formula (I) is any one of the following:

[0021]

[0022]

[0023] .

[0024] A second aspect of the present invention provides a method for preparing the nickel complex described in the first aspect, the method comprising:

[0025] (1) Compound C-1 is subjected to a first condensation reaction with an aniline compound to obtain intermediate product I or intermediate product II; wherein the aniline compound is compound C-2 and / or compound C-3;

[0026] Optionally, the method further includes: subjecting the intermediate product I to the aniline compound in a second condensation reaction to obtain intermediate product II;

[0027] (2) The intermediate product II is subjected to a coordination reaction with a nickel catalyst precursor to obtain the nickel complex shown in formula (I);

[0028]

[0029] R in compound C-2, compound C-3, intermediate I, and intermediate II 1 R 2 R 3 R 4 R 5 R 6 R 7 R 8 R 9 and R 10 The definition corresponds to the definition described in the first aspect above.

[0030] In some embodiments, in step (1) of the preparation method, the first condensation reaction and the second condensation reaction are carried out under the action of an additive, wherein the additive is selected from at least one of formic acid, p-toluenesulfonic acid, zinc chloride and acetic acid.

[0031] In some embodiments, in step (2) of the preparation method, the coordination reaction is carried out in an inert gas atmosphere.

[0032] According to one specific embodiment, in step (2) of the preparation method, the nickel catalyst precursor is nickel dimethyl ether dichloride and / or nickel dimethyl ether dibromide.

[0033] In some embodiments, in step (2) of the preparation method, the molar ratio of the intermediate product II to the nickel catalyst precursor is 1-2:1.

[0034] In some embodiments, in step (2) of the preparation method, the conditions for the coordination reaction include: a temperature of 15-35°C and a time of 2-24 h.

[0035] A third aspect of the present invention provides a catalyst composition comprising a main catalyst and a co-catalyst.

[0036] The main catalyst is the nickel complex described in the first aspect above.

[0037] In some embodiments, the co-catalyst in the catalyst composition is selected from at least one of aluminoxane, alkylaluminum chloride, and nonhalogenated alkylaluminum.

[0038] In some embodiments, the aluminoxane in the catalyst composition is methylaluminoxane and / or modified methylaluminoxane.

[0039] According to one specific embodiment, in the catalyst composition, the alkylaluminum chloride is selected from at least one of diethylaluminum chloride, sesquichlorodiethylaluminum, and diethylaluminum chloride.

[0040] According to one specific embodiment, in the catalyst composition, the non-halogenated alkylaluminum is selected from at least one of trimethylaluminum, triethylaluminum, triisobutylaluminum, and tributylaluminum.

[0041] In some embodiments, the molar ratio of the co-catalyst (calculated as aluminum) to the main catalyst (calculated as nickel) in the catalyst composition is 50-5000:1.

[0042] A fourth aspect of the invention provides the use of the catalyst composition described in the third aspect in olefin polymerization.

[0043] A fifth aspect of the present invention provides a method for copolymerizing ethylene with α-olefins, the method being carried out using the components of the catalyst composition described in the third aspect above, comprising:

[0044] S1: In the presence of organic solvent A, main catalyst and co-catalyst, ethylene and α-olefin are copolymerized to obtain material A;

[0045] S2: The material A is subjected to a first quenching reaction with quenching agent A.

[0046] In some embodiments, in step S1 of the method, the conditions for the copolymerization reaction include: a temperature of 0-100°C, a time of 0.1-6 h, and a pressure of 1-40 atm.

[0047] According to one specific embodiment, in step S1 of the method, the molar ratio of the co-catalyst (calculated as aluminum) to the main catalyst (calculated as nickel) is 200-2000:1.

[0048] In some embodiments, in step S2 of the method, the quenching agent A is an acidic solution and / or C. 1-3 Alcohols.

[0049] In some embodiments, in step S1 of the method, the conditions for the copolymerization reaction include a temperature of 25-60°C.

[0050] According to one specific embodiment, in step S1 of the method, the molar ratio of the co-catalyst (calculated as aluminum) to the main catalyst (calculated as nickel) is 600-1200:1.

[0051] A sixth aspect of the present invention provides a method for homopolymerization of ethylene, the method comprising using the components of the catalyst composition described in the third aspect above, comprising:

[0052] (I) In the presence of organic solvent B, main catalyst and co-catalyst, ethylene is subjected to homopolymerization to obtain material B;

[0053] (II) The material B is subjected to a second quenching reaction with the quenching agent B.

[0054] In some embodiments, in step (I) of the method, the conditions for the homopolymerization reaction include: a temperature of 0-140°C, a time of 0.1-6 h, and a pressure of 1-40 atm.

[0055] According to one specific embodiment, in step (I) of the method, the molar ratio of the co-catalyst, calculated as aluminum, to the main catalyst, calculated as nickel, is 50-2000:1.

[0056] In some embodiments, in step (II) of the method, the quenching agent B is an acidic solution and / or C. 1-3 Alcohols.

[0057] In some embodiments, in step (I) of the method, the conditions for the homopolymerization reaction include a temperature of 10-100°C.

[0058] According to one specific embodiment, in step (I) of the method, the molar ratio of the co-catalyst, calculated as aluminum, to the main catalyst, calculated as nickel, is 200-500:1.

[0059] Compared with the prior art, the present invention has at least the following beneficial effects:

[0060] The nickel complex provided by this invention has excellent water and oxygen stability and can be stored at room temperature in an air environment. Moreover, the preparation method of the nickel complex is simple and significantly reduces the cost in the preparation, purification, storage and use process.

[0061] The nickel complex provided by this invention exhibits excellent catalytic activity and good thermal stability when applied to the copolymerization of ethylene and α-olefins and the homopolymerization of ethylene, and has promising prospects for industrial application. Detailed Implementation

[0062] The endpoints and any values ​​of the ranges disclosed herein 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 the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0063] As previously stated, a first aspect of the present invention provides a nickel complex having the structure shown in formula (I):

[0064] Formula (I);

[0065] In equation (I),

[0066] R 1 R 2 R 3 R 4 R 5 R 6 R 7 R 8 R 9 R 10 Each is independently selected from H, unsubstituted, or derived from R. 11 C with substituent group 1-6 Alkyl, C 2-6 alkenyl, C 6-10 Aryl, halogen, hydroxyl, C 1-6 Alkoxy and -NR 12 R 13 At least one of them; R 11 Selected from halogens, unsubstituted or derived from C 1-6 At least one of the alkyl groups substituted with at least one of the phenyl groups; R 12 and R 13 Each is independently selected from hydrogen and C. 1-6 At least one of alkyl groups; each X is independently selected from halogens.

[0067] In some embodiments, in the nickel complex, in formula (I),

[0068] R 1 R 2 R 3 R 4 R 5 R 6 R 7 R 8 R 9 R 10 Each is independently selected from H, unsubstituted, or derived from R. 11 C with substituent group 1-4 Alkyl, C 6-8 Aryl, fluorine, chlorine, hydroxyl, C 1-4 At least one of the alkoxy groups; R 11 Selected from halogens, unsubstituted or derived from C 1-4 At least one of the alkyl groups substituted with at least one of the phenyl groups; each X is independently bromine and / or chlorine.

[0069] In some embodiments, in the nickel complex, in formula (I),

[0070] R 1 R 3 R 5 R 6 R 8 R 10 Each is independently selected from H, unsubstituted, or derived from R. 11 Substituted methyl group, unsubstituted methyl group, or methyl group composed of R 11 Ethyl groups substituted with groups, unsubstituted ethyl groups, or ethyl groups derived from R 11 Substituted n-propyl group, unsubstituted or derived from R 11 At least one of the following groups: isopropyl, methoxy, ethoxy, propoxy, and isopropoxy; R 11 Selected from phenyl, phenyl groups substituted with at least one group selected from methyl, ethyl, n-propyl, propoxy, and at least one fluorine group; R 2 R 4 R 7 R 9 All are H; all X are bromine.

[0071] According to one specific embodiment, in the nickel complex, the nickel complex represented by formula (I) is any one of the following:

[0072]

[0073]

[0074] .

[0075] As previously described, a second aspect of the present invention provides a method for preparing the nickel complex described in the first aspect, the method comprising:

[0076] (1) Compound C-1 is subjected to a first condensation reaction with an aniline compound to obtain intermediate product I or intermediate product II; wherein the aniline compound is compound C-2 and / or compound C-3;

[0077] Optionally, the method further includes: subjecting the intermediate product I to the aniline compound in a second condensation reaction to obtain intermediate product II;

[0078] (2) The intermediate product II is subjected to a coordination reaction with a nickel catalyst precursor to obtain the nickel complex shown in formula (I);

[0079]

[0080] R in compound C-2, compound C-3, intermediate I, and intermediate II 1 R2 R 3 R 4 R 5 R 6 R 7 R 8 R 9 and R 10 The definition corresponds to the definition described in the first aspect above.

[0081] In some embodiments, in step (1) of the preparation method, the first condensation reaction and the second condensation reaction are carried out under the action of an additive, wherein the additive is selected from at least one of formic acid, p-toluenesulfonic acid, zinc chloride and acetic acid.

[0082] In some embodiments, in step (1) of the preparation method, the molar ratio of compound C-1 to the aniline compound is 1:1-3.

[0083] In some embodiments, in step (1) of the preparation method, the conditions for the first condensation reaction and the second condensation reaction include: a temperature of 10-200°C and a time of 2-24 h.

[0084] In some embodiments, in step (1) of the preparation method, the first condensation reaction and the second condensation reaction are carried out in the presence of organic solvent I, which is selected from at least one of methanol, ethanol, acetic acid, toluene, and acetonitrile. According to one specific embodiment, organic solvent I is selected from at least one of methanol, acetic acid, and toluene.

[0085] According to a specific embodiment, in step (1) of the preparation method, the method further includes: subjecting the material I obtained from the first condensation reaction and the second condensation reaction to a first purification.

[0086] In some embodiments, the first purification operation includes: concentrating, washing, and drying the material I, or filtering, washing, separating, and drying the material I. The washing agent is selected from at least one of methanol, ethanol, acetic acid, diethyl ether, and potassium oxalate.

[0087] The present invention does not have any special requirements for the specific operations of concentration, washing, drying, filtration and separation. Those skilled in the art can perform these operations according to conventional technical means in the field. The present invention will not elaborate further here, and those skilled in the art should not understand this as a limitation of the present invention.

[0088] In some embodiments, in step (2) of the preparation method, the coordination reaction is carried out in an inert gas atmosphere.

[0089] According to one specific embodiment, the inert gas is selected from at least one of nitrogen, helium, and argon.

[0090] In some embodiments, in step (2) of the preparation method, the coordination reaction is carried out in the presence of organic solvent II, which is selected from at least one of dichloromethane, trichloromethane, tetrahydrofuran, 1,4-dioxane, and toluene. According to one specific embodiment, the organic solvent II is dichloromethane.

[0091] According to one specific embodiment, in step (2) of the preparation method, the nickel catalyst precursor is nickel dimethyl ether dichloride and / or nickel dimethyl ether dibromide. According to one specific embodiment, in step (2) of the preparation method, the nickel catalyst precursor is nickel dimethyl ether dibromide.

[0092] In some embodiments, in step (2) of the preparation method, the molar ratio of the intermediate product II to the nickel catalyst precursor is 1-2:1.

[0093] In some embodiments, in step (2) of the preparation method, the conditions for the coordination reaction include: a temperature of 15-35°C and a time of 2-24 h.

[0094] According to one specific embodiment, in step (2) of the preparation method, the conditions for the coordination reaction include: a temperature of 20-30°C and a time of 10-14 h. For example, the conditions for the coordination reaction include: a temperature of 25°C and a time of 12 h.

[0095] According to one specific embodiment, in step (2) of the preparation method, the method further includes: subjecting the material II obtained from the coordination reaction to a second purification.

[0096] In some embodiments, the second purification operation includes: concentrating the material II to obtain a solid product, washing the solid product with a detergent, and / or recrystallizing the solid product in a mixed solution of organic solvent III and alkane.

[0097] According to one specific embodiment, the detergent is selected from at least one of anhydrous diethyl ether, petroleum ether, and acetone; the organic solvent III is selected from at least one of dichloromethane, trichloromethane, and tetrahydrofuran; and the alkane is hexane and / or pentane. Exemplarily, the detergent is anhydrous diethyl ether, and the organic solvent III is dichloromethane.

[0098] The present invention does not have any special requirements for the specific operations of concentration, washing and recrystallization. Those skilled in the art can perform these operations according to conventional technical means in the field. The present invention will not elaborate further here, and those skilled in the art should not understand this as a limitation of the present invention.

[0099] According to one specific embodiment, the method further includes the operation of preparing compound C-1, comprising:

[0100] The phenanthrene was diacylated to give compound C-1.

[0101] In some embodiments, the diacylation reaction is carried out in the presence of a Lewis acid catalyst, an acylation reagent, and a solvent.

[0102] In some embodiments, the molar ratio of the phenanthrene to the Lewis acid catalyst is 1:1-3.

[0103] According to one specific embodiment, the Lewis acid catalyst is selected from at least one of aluminum tribromide, aluminum trichloride, and ferric trichloride.

[0104] In some embodiments, the molar ratio of the phenanthrene to the acylation reagent is 1:1-2.

[0105] In some embodiments, the acylation agent is selected from at least one of oxaloyl bromide, acetyl chloride, and benzoyl chloride.

[0106] According to one specific embodiment, the solvent is selected from at least one of carbon disulfide, dichloromethane, and nitrobenzene.

[0107] In some embodiments, the diacylation reaction is first carried out at a temperature of -50°C to -20°C for 2-4 hours, and then at a temperature of 20-30°C for 1-3 hours.

[0108] In some embodiments, the diacylation reaction is carried out in an inert gas atmosphere.

[0109] According to one specific embodiment, the inert gas is selected from at least one of nitrogen, helium, and argon.

[0110] In some embodiments, the diacylation reaction further includes post-processing the liquid obtained from the diacylation reaction. The present invention does not require specific operations for the post-processing, but it may include, for example, removing the inert gas protection from the liquid, then mixing it with a terminator to terminate the reaction, and then separating, washing, and concentrating the reaction solution after the termination reaction to obtain compound C-1. Exemplarily, the terminator is ice water, the separation solution is dichloromethane, the washing agent is deionized water and saturated brine, and the concentration is performed using silica gel column chromatography.

[0111] The present invention does not have any special requirements for the specific operations of separation, washing and concentration. Those skilled in the art can perform these operations according to conventional technical means in the field. The present invention will not elaborate further here, and those skilled in the art should not understand this as a limitation of the present invention.

[0112] As previously described, a third aspect of the present invention provides a catalyst composition comprising a main catalyst and a co-catalyst.

[0113] The main catalyst is the nickel complex described in the first aspect above.

[0114] In some embodiments, the co-catalyst in the catalyst composition is selected from at least one of aluminoxane, alkylaluminum chloride, and nonhalogenated alkylaluminum.

[0115] In some embodiments, the aluminoxane in the catalyst composition is methylaluminoxane and / or modified methylaluminoxane. According to one specific embodiment, the aluminoxane in the catalyst composition is methylaluminoxane.

[0116] According to one specific embodiment, in the catalyst composition, the alkylaluminum chloride is selected from at least one of diethylaluminum chloride, sesquichlorodiethylaluminum, and ethylaluminum dichloride. According to another specific embodiment, in the catalyst composition, the alkylaluminum chloride is diethylaluminum chloride.

[0117] According to one specific embodiment, in the catalyst composition, the non-halogenated alkylaluminum is selected from at least one of trimethylaluminum, triethylaluminum, triisobutylaluminum, and tributylaluminum.

[0118] In some embodiments, the molar ratio of the co-catalyst (calculated as aluminum) to the main catalyst (calculated as nickel) in the catalyst composition is 50-5000:1.

[0119] As previously stated, a fourth aspect of the present invention provides the use of the catalyst composition described in the third aspect in olefin polymerization.

[0120] As previously described, a fifth aspect of the present invention provides a method for copolymerizing ethylene with α-olefins, the method comprising using the components of the catalyst composition described in the third aspect above, including:

[0121] S1: In the presence of organic solvent A, main catalyst and co-catalyst, ethylene and α-olefin are copolymerized to obtain material A;

[0122] S2: The material A is subjected to a first quenching reaction with quenching agent A.

[0123] In some embodiments, in step S1 of the method, the α-olefin is selected from at least one of 1-butene, 1-hexene, and 1-octene.

[0124] In some embodiments, in step S1 of the method, the molar ratio of the α-olefin to the main catalyst is 2500-3000:1.

[0125] In some embodiments, in step S1 of the method, the organic solvent A is selected from at least one of toluene, xylene, chlorobenzene, benzene, hexane, pentane, heptane, and dichloromethane.

[0126] In some embodiments, in step S1 of the method, the conditions for the copolymerization reaction include: a temperature of 0-100°C, a time of 0.1-6 h, and a pressure of 1-40 atm.

[0127] In some embodiments, in step S1 of the method, the conditions for the copolymerization reaction include: a temperature of 25-60°C, a time of 0.2-2 h, and a pressure of 5-15 atm.

[0128] According to one specific embodiment, in step S1 of the method, the molar ratio of the co-catalyst (calculated as aluminum) to the main catalyst (calculated as nickel) is 200-2000:1.

[0129] According to one specific embodiment, in step S1 of the method, the molar ratio of the co-catalyst (calculated as aluminum) to the main catalyst (calculated as nickel) is 600-1200:1.

[0130] In step S1 of the method, the present invention does not have special requirements for the specific operation of the copolymerization reaction. For example, it may include: adding organic solvent A and main catalyst to a dry reaction vessel under an ethylene atmosphere, and introducing ethylene until the ethylene pressure reaches a predetermined value, adding co-catalyst and α-olefin; and stopping the introduction of ethylene gas and depressurizing after the copolymerization reaction is completed.

[0131] In some embodiments, in step S2 of the method, the quenching agent A is an acidic solution and / or C. 1-3 Alcohols.

[0132] In some embodiments, in step S2 of the method, the quenching agent A is a hydrochloric acid-ethanol solution. According to one specific embodiment, the quenching agent A is a 2-8 wt% hydrochloric acid-ethanol solution.

[0133] According to one specific embodiment, in step S2 of the method, the method further includes: filtering, washing and drying the mixture I obtained from the first quenching reaction.

[0134] The present invention does not impose any special requirements on the specific operations of filtration, washing, and drying. Those skilled in the art can perform these operations according to conventional technical means in the field. The present invention will not elaborate further here, and those skilled in the art should not understand this as a limitation of the present invention.

[0135] As previously described, a sixth aspect of the present invention provides a method for homopolymerization of ethylene, the method comprising using the components of the catalyst composition described in the third aspect above, including:

[0136] (I) In the presence of organic solvent B, main catalyst and co-catalyst, ethylene is subjected to homopolymerization to obtain material B;

[0137] (II) The material B is subjected to a second quenching reaction with the quenching agent B.

[0138] In some embodiments, in step (I) of the method, the organic solvent B is selected from at least one of toluene, xylene, chlorobenzene, benzene, hexane, pentane, heptane, and dichloromethane.

[0139] In some embodiments, in step (I) of the method, the conditions for the homopolymerization reaction include: a temperature of 0-140°C, a time of 0.1-6 h, and a pressure of 1-40 atm.

[0140] In some embodiments, in step (I) of the method, the conditions for the homopolymerization reaction include: a temperature of 10-100°C, a time of 0.2-2 h, and a pressure of 5-10 atm.

[0141] According to one specific embodiment, in step (I) of the method, the molar ratio of the co-catalyst, calculated as aluminum, to the main catalyst, calculated as nickel, is 50-2000:1.

[0142] According to one specific embodiment, in step (I) of the method, the molar ratio of the co-catalyst, calculated as aluminum, to the main catalyst, calculated as nickel, is 200-500:1.

[0143] In step (I) of the method, the present invention does not have any particular requirements for the specific operation of the homopolymerization reaction. For example, it may include: adding organic solvent B and main catalyst to a dry reaction vessel under an ethylene atmosphere, and introducing ethylene until the ethylene pressure reaches a predetermined value, and adding a co-catalyst; after the homopolymerization reaction is completed, stopping the introduction of ethylene gas and depressurizing.

[0144] In some embodiments, in step (II) of the method, the quenching agent B is an acidic solution and / or C. 1-3 Alcohols.

[0145] In some embodiments, in step (II) of the method, the quencher B is a hydrochloric acid-ethanol solution. According to one specific embodiment, the quencher B is a 2-8 wt% hydrochloric acid-ethanol solution.

[0146] According to one specific embodiment, in step (II) of the method, the method further includes: filtering, washing and drying the mixture II obtained from the second quenching reaction.

[0147] The present invention does not impose any special requirements on the specific operations of filtration, washing, and drying. Those skilled in the art can perform these operations according to conventional technical means in the field. The present invention will not elaborate further here, and those skilled in the art should not understand this as a limitation of the present invention.

[0148] The present invention will be described in detail below through embodiments. Unless otherwise specified, the analytical and testing methods described in the following embodiments and comparative examples are conventional methods.

[0149] Molecular formula: determined based on the chemical structure of the chemical substance;

[0150] Elemental analysis: Results obtained using organic elemental analyzer methods;

[0151] Catalytic activity: expressed as "g polymer·mol Ni -1 ·h -1 ", which is the amount of polymer that can be produced per mole of nickel catalyst per unit time. This data was obtained through ethylene polymerization experiments."

[0152] Glass transition temperature (T) g ): Obtained by differential scanning calorimetry (DSC).

[0153] Melting point (T) m ): Obtained by differential scanning calorimetry (DSC);

[0154] Weight-average molecular weight (M w ): Result obtained by temperature gel permeation chromatography (GPC) analyzer;

[0155] Molecular weight distribution index (PDI): obtained by temperature gel permeation chromatography (GPC) analyzer;

[0156] Hydrogen nuclear magnetic resonance spectrum: obtained by Bruker 400 MHz nuclear magnetic resonance spectrometer.

[0157] Unless otherwise specified, the reagents and materials used in the following examples and comparative examples are commercially available.

[0158] Fibre: Purchased from Adamas Reagents Ltd., brand name 86163B;

[0159] 2,6-Diisopropylaniline: purchased from Adamas Reagents Ltd., grade 40849F;

[0160] Ethylene glycol dimethyl ether nickel bromide: purchased from Sigma-Aldridge, grade 406341;

[0161] 2,6-Bis(diphenylmethyl)-4-methylaniline: purchased from Adamas Reagent Co., Ltd., grade 3938378C;

[0162] Methylaluminoxane: purchased from Sigma-Aldridge, grade 404594;

[0163] Diethylaluminum chloride: purchased from Adamas Reagents Ltd., grade 91609J.

[0164] Unless otherwise specified, room temperature in the following examples and comparative examples refers to 25±1℃.

[0165] Preparation Example 1

[0166] The preparation method of nickel complex N-1 is as follows:

[0167] (a) Synthesis of compound C-1:

[0168] (1) Under a nitrogen atmosphere, 10 mL of carbon disulfide and 5.6 mmol of aluminum tribromide were added to a 50 mL Schlenk flask with a stir bar. The mixture was cooled to -40 °C, and then 2.81 mmol of phenanthrene (1.0 equivalent), 2.81 mol of oxaloyl bromide (1.0 equivalent) and 4 mL of carbon disulfide were added. The mixture was stirred at -40 °C for 3 h, and then the cold bath was removed. The mixture was stirred at room temperature for 2 h to obtain the reaction solution.

[0169] (2) After the reaction is complete, remove the nitrogen protection and slowly add 30 mL of ice water to the above reaction solution to quench the reaction. After the quenching reaction is complete, add 30 mL of dichloromethane to the reaction solution and separate the organic phase using a separatory funnel. Wash the organic phase three times with deionized water, each time with a volume of 20 mL, and wash the organic phase once with saturated saline solution, with a volume of 20 mL, to obtain the solid product.

[0170] (3) The solid product was concentrated and the crude product was purified by silica gel column chromatography (eluent: petroleum ether: ethyl acetate = 6:1) to obtain 508 mg of compound C-1 (acetylphenol anthracene-4,5-dione, molecular weight 232.1, structure shown below), with a yield of 78%.

[0171]

[0172] 400 MHz 1H NMR spectrum data for compound C-1: 1 H-NMR (400M, CDCl3): δ8.87 (d, J = 8.3Hz, 1H), 8.72 (d, J = 8.2 Hz, 1H), 8.40 (s, 1H), 8.20-8.17 (m, 2H), 7.98 (dd,J = 8.3 Hz, 7.2 Hz, 1H), 7.94 (ddd, J = 8.3 Hz, 7.2 Hz, 1.3 Hz, 1H), 7.84 (ddd, J = 8.3 Hz, 7.2 Hz, 1.2 Hz, 1H).

[0173] (II) Synthesis of intermediate product II-1:

[0174] To a mixture of 19 mL methanol and 1 mL formic acid, 1.0 mmol of compound C-1 (1.0 equivalent) and 2.2 mmol of 2,6-diisopropylaniline (2.2 equivalent) were added. The resulting mixture was stirred at room temperature for 12 h, then concentrated to obtain a crude solid product. Finally, the crude product was washed with cold methanol, and the resulting solid was dried to give 490 mg of intermediate II-1 ((4E,5E)-N4,N5-bis(2,6-diisopropylphenyl)acetylphenanthrene-4,5-diimide, molecular weight 550.8, structure shown below), in 89% yield.

[0175]

[0176] (III) Synthesis of nickel complex N-1:

[0177] In a glove box under nitrogen atmosphere, 1.1 mmol of intermediate II-1 (1.1 equivalent), 1.0 mmol of ethylene glycol dimethyl ether nickel bromide (1.0 equivalent), and 5 mL of dry dichloromethane were added to a 4 mL sample vial equipped with a stir bar. The mixture was stirred at room temperature for 12 h, and then concentrated to obtain a dark red solid crude product. Finally, the product was washed with anhydrous diethyl ether (20 mL of diethyl ether was used for each wash, for a total of three washes). The dark red solid was collected and dried to obtain 546 mg of nickel complex N-1 (structure shown below), with a yield of 71%.

[0178]

[0179] The elemental analysis data of nickel complex N-1 showed no significant changes after being exposed to air for two weeks.

[0180] Preparation Example 2

[0181] The preparation method of nickel complex N-2 is as follows:

[0182] (a) Synthesis of compound C-1:

[0183] Compound C-1 was synthesized using the same procedure as step (a) of Preparation Example 1;

[0184] (II) Synthesis of intermediate product I-2:

[0185] 0.1 mmol of p-toluenesulfonic acid (0.1 equivalent) was added to 5 mL of a dry toluene solution containing 1 mmol of compound C-1 (1.0 equivalent) and 1.1 mmol of 2,6-diisopropylaniline (1.1 equivalent). The reaction mixture was heated under reflux at 160 °C for 12 h, and then concentrated to obtain a solid crude product. Finally, the crude product was washed with cold ethanol to give 336 mg of intermediate I-2 ((E)-4-(2,6-diisopropylphenylamino)acetylphenanthrene-5(4H)-one, molecular weight 392.2, structure shown below), in 86% yield.

[0186]

[0187] (III) Synthesis of intermediate product II-2:

[0188] Intermediate II-2 was synthesized using a similar process to that used in step (ii) of Preparation Example 2, except that in step (iii), intermediate I-2 was used instead of compound C-1 from step (ii), and 2,6-bis(diphenylmethyl)-4-methylaniline was used instead of 2,6-diisopropylaniline. 414 mg of intermediate II-2 ((4E,5E)-N5-(2,6-bis(diphenylmethyl)-4-methylphenyl)-N4-(2,6-diisopropylphenyl)acetylphenanthrene-4,5-diimide, molecular weight 814.4, structure shown below) was obtained in a yield of 51%.

[0189]

[0190] (iv) Synthesis of nickel complex N-2:

[0191] Nickel complex N-2 was synthesized using a similar process to that used in step (iii) of Preparation Example 1. The difference was that in step (iv) of Preparation Example 2, intermediate II-2 was used instead of intermediate II-1 in step (iii) of Preparation Example 1, and the amounts of intermediate II-2, nickel dimethyl ether bromide (EDGB), and dichloromethane were 0.33 mmol, 0.30 mmol, and 2 mL, respectively. 262 mg of nickel complex N-2 (structure shown below) was obtained, with a yield of 85%.

[0192]

[0193] The nickel complex N-2 showed no significant changes in elemental analysis data after being exposed to air for two weeks.

[0194] Preparation Example 3

[0195] The preparation method of nickel complex N-3 is as follows:

[0196] (a) Synthesis of compound C-1:

[0197] Compound C-1 was synthesized using the same procedure as step (a) of Preparation Example 1;

[0198] (II) Synthesis of intermediate product II-3:

[0199] To a 10 mL acetic acid solution containing 1.0 mmol of compound C-1 (1.0 equivalent) and 2.5 mmol of 2,6-bis(diphenylmethyl)-4-methylaniline (2.5 equivalent), 1.2 mmol of anhydrous zinc chloride (1.2 equivalent) was added. The reaction mixture was heated under reflux at 160 °C for 20 h. After the reaction was complete, the reaction mixture was cooled to room temperature, filtered, and the red solid precipitate was collected. The solid was then washed three times with acetic acid and diethyl ether. The resulting red solid was dissolved in dichloromethane, and the organic phase was washed with a saturated potassium oxalate aqueous solution. Finally, the organic phase was separated, collected, and dried to give 472 mg of intermediate II-3 ((4E,5E)-N4,N5-bis(2,6-bis(diphenylmethyl)-4-methylphenyl)acetylphenanthrene-4,5-diimide, molecular weight 1076.2, structure shown below), in a yield of 44%.

[0200]

[0201] (III) Synthesis of nickel complex N-3:

[0202] In a glove box under nitrogen atmosphere, 0.55 mmol of intermediate II-3 (1.1 equivalent), 0.50 mmol of ethylene glycol dimethyl ether nickel bromide (1.0 equivalent), and 10 mL of dry dichloromethane were added to a 25 mL sample vial equipped with a stir bar. The mixture was stirred at room temperature for 12 h, and then concentrated to obtain a dark red solid crude product. Finally, the product was washed with anhydrous diethyl ether (20 mL of diethyl ether was used for each wash, for a total of three washes). The dark red solid was collected and dried to obtain 555 mg of nickel complex N-3 (structure shown below), with a yield of 86%.

[0203]

[0204] The elemental analysis data of the nickel complex N-3 showed no significant changes after being exposed to air for two weeks.

[0205] The molecular formulas and elemental analyses of the nickel complexes obtained in Preparation Examples 1 to 3 are shown in Table 1.

[0206] Table 1

[0207]

[0208] Example A1

[0209] The applications of nickel complexes and co-catalysts in the copolymerization of ethylene and α-olefins are as follows, and the specific types and amounts of components are shown in Table 2.

[0210] (1) Replace 1 L of clean and dry stainless steel reactor with ethylene three times, add 400 mL of dry toluene, α-olefin and 20 μmol of main catalyst in sequence, add 30 wt% methylaluminoxane solution (solvent is toluene) into the reactor with a dry syringe, and introduce ethylene, keep the pressure at 1 atm, and then stir the reaction mixture at temperature T1 for 30 min to obtain the reaction solution;

[0211] (2) Add 5wt% hydrochloric acid-ethanol solution to the above reaction solution to terminate the reaction. After washing and filtering with ethanol, the obtained material is placed in a vacuum oven at 60°C for 24 h to dry to constant weight, and a polymer is obtained. The polymer is a white solid with a certain elasticity.

[0212] The polymer prepared in Example A1 had a molecular weight distribution index (PDI) of 2.23 and a glass transition temperature (Tg). g The temperature is -58℃, and the melting point (T) is... m The temperature was 5.3℃.

[0213] Examples A2 to A7

[0214] The amount of the main catalyst was kept constant, and the process was carried out in a similar manner to that in Example A1. The difference was that the types and amounts of each component were different, as listed in Table 2. A polymer was prepared, which was a white solid with a certain degree of elasticity.

[0215] Comparative Examples A1 to Comparative Examples A2

[0216] The amount of the main catalyst was kept constant, and the process was similar to that in Example A1. The difference was that the main catalyst used in the comparative example was a nickel α-diimine catalyst with a acenaphthoquinone framework, the structural formula of which is shown below:

[0217] .

[0218] In addition, the types and amounts of each component are different, as detailed in Table 2. The resulting polymer is a white solid with a certain degree of elasticity.

[0219] Table 2

[0220]

[0221] Catalytic activity and weight-average molecular weight (M) of the polymers prepared in Examples A1 to A7 and Comparative Examples A1 to A2 w The results are shown in Table 3.

[0222] Table 3

[0223]

[0224] Example B1

[0225] The application of nickel complexes and co-catalysts in the homopolymerization of ethylene is as follows, and the specific types and amounts of components are shown in Table 4.

[0226] (1) Replace the 1 L clean and dry stainless steel reactor with ethylene three times, keeping the ethylene pressure at 1 atm. Add 200 mL of dry toluene and diethylaluminum chloride (n-hexane solution, concentration 1 mol / L) in sequence. Dissolve 10 μmol of the main catalyst in 1 mL of dry dichloromethane to obtain a catalyst solution. Inject the catalyst solution into the reactor using a dry syringe and introduce ethylene, keeping the pressure at 7 atm. Then stir the reaction mixture at temperature T2 for 30 min to obtain the reaction solution.

[0227] (2) Add 5wt% hydrochloric acid-methanol solution to the above reaction solution to terminate the reaction. After washing and filtering with ethanol, the resulting material is placed in a vacuum oven at 60°C for 24 h to dry to constant weight, and the polymer is obtained.

[0228] Examples B2 to B6

[0229] The amount of the main catalyst was kept constant, and the process was carried out in a manner similar to that in Example B1. The difference was that the types and amounts of each component were different, as detailed in Table 4, and the polymer was prepared.

[0230] Comparative Examples B1 to B2

[0231] The amount of the main catalyst was kept constant, and the process was carried out in a manner similar to that in Example B1. The difference was that the types and amounts of each component were different, as detailed in Table 4, and the polymer was prepared.

[0232] Table 4

[0233]

[0234] Catalytic activity and weight-average molecular weight (M) of the polymers prepared in Examples B1 to B6 and Comparative Examples B1 to B2 w The results of the polymer molecular weight distribution index (PDI) are shown in Table 5.

[0235] Table 5

[0236]

[0237] The results above demonstrate that the nickel complex prepared using the method described in this invention exhibits excellent catalytic activity and good thermal stability. Specifically, the nickel complex provided by this invention demonstrates high catalytic activity (0.75 × 10⁻⁶) in both the copolymerization of ethylene with α-olefins and the homopolymerization of ethylene. 6 -3.04×10 6 Furthermore, it maintained stable catalytic activity at 80℃; while the comparative acenaphthene-based α-diimine nickel catalyst showed catalytic activity <0.4×10⁻⁶ when applied to the copolymerization of ethylene and α-olefins and the homopolymerization of ethylene. 6 Furthermore, the catalytic activity decreases significantly when the reaction temperature is above 60℃.

[0238] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A nickel complex, characterized in that, The nickel complex has the structure shown in formula (I): Equation (I); In equation (I), R 1 R 3 R 5 R 6 R 8 R 10 Each is independently selected from H, unsubstituted, or derived from R. 11 Substituted methyl group, unsubstituted methyl group, or methyl group composed of R 11 Ethyl groups substituted with groups, unsubstituted ethyl groups, or ethyl groups derived from R 11 Substituted n-propyl group, unsubstituted or derived from R 11 At least one of the following groups: isopropyl, methoxy, ethoxy, propoxy, and isopropoxy; R 11 Selected from phenyl, phenyl groups substituted with at least one group selected from methyl, ethyl, n-propyl, propoxy, and at least one fluorine group; R 2 R 4 R 7 R 9 All are H; Each X is bromine.

2. The nickel complex according to claim 1, characterized in that, The nickel complex shown in formula (I) is any one of the following: 。 3. A method for preparing the nickel complex of claim 1, characterized in that, The method includes: (1) Compound C-1 and compound C-3 undergo a first condensation reaction to obtain intermediate product I; (2) The intermediate product I is subjected to a second condensation reaction with compound C-2 to obtain intermediate product II; (3) The intermediate product II is subjected to a coordination reaction with the nickel catalyst precursor to obtain the nickel complex shown in formula (I); R in compound C-2, compound C-3, intermediate I, and intermediate II 1 R 2 R 3 R 4 R 5 R 6 R 7 R 8 R 9 and R 10 The definition corresponds to the definition in claim 1.

4. A method for preparing the nickel complex of claim 1, characterized in that, The method includes: (1) Compound C-1 was subjected to a third condensation reaction with compounds C-2 and C-3 to obtain intermediate product II; (2) The intermediate product II is subjected to a coordination reaction with a nickel catalyst precursor to obtain the nickel complex shown in formula (I); R in compounds C-2, C-3, and intermediate II 1 R 2 R 3 R 4 R 5 R 6 R 7 R 8 R 9 and R 10 The definition corresponds to the definition in claim 1.

5. The method according to claim 3, characterized in that, The first condensation reaction and the second condensation reaction are carried out in the presence of an additive selected from at least one of formic acid, p-toluenesulfonic acid, zinc chloride, and acetic acid.

6. The method according to claim 4, characterized in that, The third condensation reaction is carried out in the presence of an additive selected from at least one of formic acid, p-toluenesulfonic acid, zinc chloride, and acetic acid.

7. The method according to claim 3 or 4, characterized in that, The coordination reaction is carried out in an inert gas atmosphere.

8. The method according to claim 3 or 4, characterized in that, The nickel catalyst precursor is nickel dichloroethylene glycol dimethyl ether or nickel dibromide ethylene glycol dimethyl ether. The molar ratio of intermediate product II to the nickel catalyst precursor is 1-2:

1.

9. The method according to claim 3 or 4, characterized in that, The conditions for the coordination reaction include: a temperature of 15-35℃ and a time of 2-24 h.

10. A catalyst composition, characterized in that, The catalyst composition contains a main catalyst and a co-catalyst. The main catalyst is the nickel complex described in claim 1 or 2.

11. The catalyst composition according to claim 10, characterized in that, The cocatalyst is selected from at least one of aluminoxane, alkylaluminum chloride, and nonhalogenated alkylaluminum.

12. The catalyst composition according to claim 11, characterized in that, The aluminumoxane is methylaluminoxane; The alkylaluminum chloride is selected from at least one of diethylaluminum chloride, sesqui-diethylaluminum chloride, and diethylaluminum chloride. The non-halogenated alkyl aluminum is selected from at least one of trimethylaluminum, triethylaluminum, and tributylaluminum.

13. The catalyst composition according to any one of claims 10-12, characterized in that, The molar ratio of the co-catalyst (calculated as aluminum) to the main catalyst (calculated as nickel) is 50-5000:

1.

14. The use of the catalyst composition according to claims 10-13 in olefin polymerization.

15. A method for copolymerizing ethylene with α-olefins, characterized in that, This method is carried out using the components of the catalyst composition according to any one of claims 10-13, comprising: S1: In the presence of organic solvent A, main catalyst and co-catalyst, ethylene and α-olefin are copolymerized to obtain material A; S2: The material A is subjected to a first quenching reaction with quenching agent A.

16. The method according to claim 15, characterized in that, In step S1, the conditions for the copolymerization reaction include: a temperature of 0-100°C, a time of 0.1-6 h, and a pressure of 1-40 atm; In step S1, the molar ratio of the co-catalyst (calculated as aluminum) to the main catalyst (calculated as nickel) is 200-2000:

1. In step S2, the quenching agent A is an acidic solution and / or C. 1-3 Alcohols.

17. The method according to claim 16, characterized in that, In step S1, the conditions for the copolymerization reaction include: a temperature of 25-60°C; In step S1, the molar ratio of the co-catalyst (calculated as aluminum) to the main catalyst (calculated as nickel) is 600-1200:

1.

18. A method for homopolymerization of ethylene, characterized in that, This method is performed using any of the components in the composition according to any one of claims 10-13, comprising: (I) In the presence of organic solvent B, main catalyst and co-catalyst, ethylene is subjected to homopolymerization to obtain material B; (II) The material B is subjected to a second quenching reaction with the quenching agent B.

19. The method according to claim 18, characterized in that, In step (I), the conditions for the homopolymerization reaction include: a temperature of 0-140°C, a time of 0.1-6 h, and a pressure of 1-40 atm; In step (I), the molar ratio of the co-catalyst (calculated as aluminum) to the main catalyst (calculated as nickel) is 50-2000:1; In step (II), the quenching agent B is an acidic solution and / or C. 1-3 Alcohols.

20. The method according to claim 19, characterized in that, In step (I), the conditions for the homopolymerization reaction include: a temperature of 10-100°C; In step (I), the molar ratio of the co-catalyst (calculated as aluminum) to the main catalyst (calculated as nickel) is 200-500:1.

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