Catalysts for copolymerization of ethylene and methyl methacrylate and their uses.

Abstract

The present application provides a catalyst for copolymerization of ethylene and methyl methacrylate and use thereof, the catalyst comprising a main catalyst obtained by blending a compound of formula (I) and a compound of formula (II), the molar ratio of the compound of formula (I) to the compound of formula (II) being (1:49) to (49:1). The catalyst has excellent catalytic activity and is capable of copolymerizing ethylene and methyl methacrylate in a weight average molecular weight of 1×10 5 It is possible to obtain copolymers with a high molecular weight of more than g / mol.

Description

[Technical Field]

[0001] This application relates to the field of olefin polymerization, and in particular to catalysts and their uses for the copolymerization of ethylene and methyl methacrylate. [Background technology]

[0002] Functional polyethylene obtained by copolymerization of ethylene with polar methacrylic acid monomers has better compatibility, adhesion, dyeability, and printability than conventional polyethylene. However, coordination copolymerization of ethylene with methyl methacrylate poses a technical challenge. This is mainly due to the fact that methyl methacrylate has greater steric hindrance than other polar acrylate monomers, resulting in lower copolymerization activity during interaction with the active center, resulting in low copolymer molecular weights, and the difficulty in adjusting and controlling the insertion rate of methyl methacrylate into the copolymer. Conventional ethylene and methyl methacrylate copolymerization techniques mainly use late transition metal catalysts under conditions where the molar ratio of the cocatalyst aluminoxane to the main catalyst is ≦1000:1 to achieve copolymerization of ethylene and methyl methacrylate. However, the molecular weight of the resulting copolymer is low, typically 1×10 4 Only g / mol.

[0003] Therefore, how to synthesize a high molecular weight copolymer of ethylene and methacrylic acid ester has become an urgent problem to be solved in the art. Summary of the Invention [Problem to be solved by the invention]

[0004] The present application provides a catalyst for copolymerization of ethylene and methyl methacrylate, which is prepared by blending a compound of formula (I) having an α-diimide late transition metal complex structure with a compound of formula (II) having a bis(salicylaldiminato) late transition metal complex in a molar ratio within a specific range. The catalyst is used to catalyze the copolymerization reaction of methyl methacrylate and ethylene, and is a copolymer having a molecular weight of 1×10 5It is possible to obtain copolymers of ethylene and methyl methacrylate with a molecular weight of more than g / mol.

[0005] The present invention further provides a method for copolymerizing ethylene and methyl methacrylate, which method can produce copolymers of ethylene and methyl methacrylate with a molecular weight of 1×10 5 It is possible to obtain a copolymer with a high molecular weight of 1000 g / mol or more, and by this method, it is possible to complete the copolymerization of ethylene and methyl methacrylate in a short time under low reaction temperature and reaction pressure, The reaction conditions are It has the advantage of being gentle and efficient.

[0006] The present invention further provides a copolymer of ethylene and methyl methacrylate, which has the advantages of having a high molecular weight and a controllable insertion rate of methyl methacrylate. [Means for solving the problem]

[0007] The present application provides a catalyst for copolymerization of ethylene and methyl methacrylate, the catalyst comprising a main catalyst obtained by blending a compound of formula (I) and a compound of formula (II), Formula (I) Compounds of has the following structure: Represented , [ka] In the formula, R1 and R2 are each independently selected from substituted aryl, and the substituent is selected from at least one of C1-C6 alkyl and C1-C6 alkoxy; R3 and R4 are each independently selected from hydrogen and C1 to C4 alkyl; M is selected from Ni or Pd; X1 and X2 each independently represent a halogen, a C1-C4 alkyl, an aryl, a C2-C4 ether, or a C1-C4 nitrile. At least one of the following Selected from Formula (II) Compounds of has the following structure: Represented , [ka] In the formula, R5 and R6 each independently represent hydrogen, methyl, ethyl, dimethylamino, diethylamino, amino, hydroxy, or C1-C4 alkoxy. At least one of the following Selected from R7 and R8 are each independently selected from at least one of hydrogen, C1-C4 alkyl, C1-C4 dialkylamino, amino, hydroxy, and C1-C4 alkoxy; Formula (I) Compounds of and formula (II) Compounds of The molar ratio is (1:49) to (49:1).

[0008] According to the above-mentioned catalyst, the molar ratio of the compound of formula (I) to the compound of formula (II) is (1:10) to (10:1).

[0009] According to the aforementioned catalyst, the catalyst further comprises a promoter selected from aluminoxanes.

[0010] According to the above-mentioned catalyst, the co-catalyst is selected from at least one of methylaluminoxane, trialkylaluminum, and alkylaluminum halide.

[0011] According to the above-mentioned catalyst, the molar ratio of the metal element in the main catalyst to the aluminum element in the co-catalyst is 1:(50-1000).

[0012] According to the above-mentioned catalyst, the molar ratio of the metal element in the main catalyst to the aluminum element in the co-catalyst is 1:(100-500).

[0013] The present application further provides a method for copolymerizing ethylene and methyl methacrylate, which uses the above-mentioned catalyst to carry out the copolymerization reaction.

[0014] According to the copolymerization method described above, the copolymerization method comprises carrying out a copolymerization reaction of ethylene and methyl methacrylate under the catalysis of the catalyst, The copolymerization reaction pressure is ≦10 MPa and the temperature is ≦100°C.

[0015] According to the copolymerization method described above, the solvent for the copolymerization reaction is selected from at least one of toluene, n-hexane, dichloromethane, and dichloroethane.

[0016] The present application further provides a copolymer of ethylene and methyl methacrylate, the copolymer being prepared using the copolymerization method described above, wherein the weight average molecular weight of the copolymer is ≥ 1 × 10 5 g / mol. [Effects of the Invention]

[0017] The catalyst of the present invention for use in copolymerizing ethylene and methyl methacrylate is a blend of a compound of formula (I) having an α-diimide late transition metal complex structure and a compound of formula (II) having a bis(salicylaldiminato) late transition metal complex. To promote the copolymerization of ethylene and methyl methacrylate, the two compounds can exert a synergistic effect when used in a specific molar ratio, resulting in the production of a high molecular weight copolymer of ethylene and methyl methacrylate.

[0018] The copolymerization method of ethylene and methyl methacrylate according to the present invention provides a copolymer having a weight average molecular weight of 1×10 5 It is possible to obtain a copolymer of ethylene and methyl methacrylate with a copolymerization ratio of 0.1 g / mol or more. Furthermore, this method allows the copolymerization of ethylene and methyl methacrylate to be completed in a short time under low reaction temperature and pressure, and has the advantages of mild reaction conditions and high efficiency, making it favorable for industrial application.

[0019] The copolymer of ethylene and methyl methacrylate according to the present invention has a weight average molecular weight of 1×10 5 g / mol or more, it has the advantage that the insertion rate of methyl methacrylate can be controlled by preparation. DETAILED DESCRIPTION OF THE INVENTION

[0020] The present application will be described in more detail below with reference to specific examples. It should be understood that the following examples are intended to exemplify and explain the present application, and should not be construed as limiting the scope of protection of the present application. Any technology realized based on the above content of the present application should be included in the scope of protection of the present application.

[0021] In a first aspect, the present application provides a catalyst for copolymerization of ethylene and methyl methacrylate, the catalyst comprising a main catalyst obtained by combining a compound of formula (I) and a compound of formula (II): Formula (I) Compounds of has the following structure: Represented , [ka] In the formula, R1 and R2 are each independently selected from substituted aryl, and the substituent is selected from at least one of C1-C6 alkyl and C1-C6 alkoxy; R3 and R4 are each independently selected from hydrogen and C1 to C4 alkyl; M is selected from Ni or Pd; X1 and X2 each independently represent a halogen, a C1-C4 alkyl, an aryl, a C2-C4 ether, or a C1-C4 nitrile. At least one of the following Selected from Formula (II) Represented has the following structure: Represented , [ka] In the formula, R5 and R6 each independently represent hydrogen, methyl, ethyl, dimethylamino, diethylamino, amino, hydroxy, or C1-C4 alkoxy. At least one of the following Selected from R7 and R8 are each independently selected from at least one of hydrogen, C1-C4 alkyl, C1-C4 dialkylamino, amino, hydroxy, and C1-C4 alkoxy; The molar ratio of the compound of formula (I) to the compound of formula (II) is (1:49) to (49:1).

[0022] Substituted aryl refers to an aryl having a substituent bonded thereto. Specific examples of aryl include phenyl, naphthyl, and biphenyl. The present application does not limit the substitution position of the substituent on the aryl, and may be, for example, the ortho or para position of the diimide structure. C1-C6 alkyl refers to branched or linear alkyl having 1 to 6 carbon atoms, such as methyl, ethyl, propyl, isopropyl, or tert-butyl. C1-C6 alkoxy refers to branched or linear alkoxy having 1 to 6 carbon atoms, such as methoxy, ethoxy, or isopropoxy. Similarly, C1-C4 alkyl refers to linear or branched alkyl having 1 to 4 carbon atoms, and C1-C4 alkoxy refers to linear or branched alkoxy having 1 to 4 carbon atoms. C1-C4 dialkylamino refers to a substituent in which amino is substituted with two C1-C4 linear or straight-chain alkyls, and may be, for example, dimethylamino, diethylamino, dipropylamino, etc. Halogen is any of fluorine, chlorine, bromine, and iodine.

[0023] As a result of intensive research by the inventors, it has been found that the compound of formula (I) and the compound of formula (II) are blended in a molar ratio within the range of (1:49) to (49:1) to form a main catalyst, which catalyzes the copolymerization of ethylene and methyl methacrylate, and the molecular weight of ethylene and methyl methacrylate is 1×10 5Copolymers of over g / mol can be obtained. This is because the compound of formula (I) is an α-diimide late transition metal complex, and the compound of formula (II) is a bis(salicylaldiminato) late transition metal complex. The structures of these two compounds are well-matched, resulting in a synergistic effect. Furthermore, the reactivity ratio of ethylene and methyl methacrylate can be ensured within an appropriate range, maximizing the benefits of the two structurally different compounds. Furthermore, both compounds of formula (I) and formula (II) contain electron-donating groups, which reduce the likelihood of attack by the ester group on the methyl methacrylate on the metal center, while increasing the likelihood that the C=C double bond on the methyl methacrylate will insert into the vacant orbital of the metal center. This shortens the time for the double bond to coordinate to the active center, presumably enabling the production of high-molecular-weight copolymers of ethylene and methyl methacrylate.

[0024] Furthermore, when the molar ratio of the compound of formula (I) to the compound of formula (II) is (1:10) to (10:1), the catalytic activity of the catalyst, the weight average molecular weight of the copolymer, and the insertion rate of methyl methacrylate are all at a more balanced level.

[0025] The catalyst of the present invention further includes a co-catalyst. Specifically, the co-catalyst is selected from aluminoxanes. The aluminoxane can alkylate the main catalyst, capture halogen or alkyl in the main catalyst to form a cationic active center, and simultaneously act as a non-coordinating balance ion, all of which are advantageous for improving the molecular weight of the copolymer.

[0026] Furthermore, the co-catalyst is selected from at least one of methylaluminoxane (MAO), alkylaluminum, and alkylaluminum halide. The co-catalyst has a wide supply source, low cost, and at the same time, the obtained ethylene and methyl methacrylate can be easily reacted with each other. Copolymer of The primary catalyst can be assisted for further increase in molecular weight of the copolymer.

[0027] In one specific embodiment, when the molar ratio of the metal element in the main catalyst to the aluminum element in the co-catalyst is 1:(50-1000), the catalyst has excellent activity for copolymerization of ethylene and methyl methacrylate.

[0028] Furthermore, when the molar ratio of the metal element in the main catalyst to the aluminum element in the co-catalyst is 1:(100-500), it is more advantageous in improving the activity of copolymerization by the catalyst.

[0029] In a second aspect, the present application provides a method for copolymerizing ethylene and methyl methacrylate, the method using, as a copolymerization catalyst, the catalyst for copolymerizing ethylene and methyl methacrylate provided by the first aspect of the present application.

[0030] The above copolymerization method has excellent copolymerization activity, and the molecular weight of ethylene and methyl methacrylate is 1 × 10 5 The copolymerization reaction can be carried out under low polymerization temperature and low polymerization pressure, which is mild and advantageous for industrial application.

[0031] In the above copolymerization method, the insertion rate of methyl methacrylate in the copolymer can be controlled by controlling factors such as copolymerization pressure, molar ratio of raw materials to catalyst, copolymerization temperature, copolymerization time, etc. In a specific production process, the insertion rate of methyl methacrylate in the copolymer can be adjusted and controlled to meet the requirements for the ester content of different products.

[0032] In one specific embodiment, the copolymerization method described above comprises copolymerizing ethylene and methyl methacrylate under the catalysis of a catalyst, wherein the copolymerization pressure is ≦10 MPa and the temperature is ≦100° C. The copolymerization reaction of the present application can be carried out mildly within the pressure and temperature ranges, and the severity of the copolymerization reaction is reduced.

[0033] Furthermore, the copolymerization reaction can be carried out in a solvent system, specifically, the solvent can be at least one selected from toluene, n-hexane, dichloromethane, and dichloroethane. Among them, toluene, dichloromethane, and dichloroethane are polar solvents, which are advantageous for the incorporation of methyl methacrylate and improve the activity of polar copolymerization. The copolymerization reaction can also be carried out using n-hexane, which is an industrially commonly used solvent and has the advantages of easy availability and low toxicity.

[0034] In a third aspect, the present application provides a copolymer of ethylene and methyl methacrylate, the copolymer being prepared using the copolymerization method provided by the second aspect of the present application.

[0035] The copolymers of the present invention are prepared by the copolymerization method according to the second aspect of the present invention, and therefore have high molecular weights, which can meet the requirements of conventional resin processing equipment and the preparation of industrial plastics. At the same time, the insertion ratios of methyl and methyl acrylate can be adjusted, making them suitable for a wide range of applications.

[0036] The catalyst for copolymerization of ethylene and methyl methacrylate provided by the present application will be described in more detail below with reference to specific examples.

[0037] In the following examples, unless otherwise specified, the raw materials used may be commercially available or may be prepared by conventional methods, and any experimental methods for which specific conditions are not specified are based on conventional methods and conditions known in the art. [Example]

[0038] Example 1 1. The main catalyst used in the copolymerization of ethylene and methyl methacrylate in this example was obtained by blending Compound 1 and Compound 2 in a molar ratio of 1:49, and the main catalyst obtained by blending was designated as Main Catalyst A. [ka]

[0039] 2. The method for preparing the ethylene-methyl methacrylate copolymer according to this embodiment includes the following steps: 1) Into a clean and dry 150 mL autoclave, 50 mL of toluene and 40 μmol of main catalyst A were added under an ethylene atmosphere, and ethylene was bubbled in until the pressure reached 0.05 MPa. The reactor was placed in an oil bath at 60°C (copolymerization temperature) with magnetic stirring, and 50 mmol of methyl methacrylate and 7.85 mL of MAO (concentration: 1.53 mol / L) were added under stirring to adjust the Al / Ni molar ratio to 300:1. Ethylene was then bubbled in until the pressure reached 4 MPa (copolymerization pressure). After 1 hour of reaction, the bubble of ethylene was stopped. 2) The pressure is reduced, and the mixture is treated with a 5% volumetric concentration of hydrochloric acid in ethanol, followed by washing, filtration, and drying to obtain a copolymer of ethylene and methyl methacrylate.

[0040] Example 2 1. The main catalyst used in the copolymerization of ethylene and methyl methacrylate in this example was almost identical to that in Example 1, except that the molar ratio of compound 1 to compound 2 was 49:1, and the main catalyst obtained by blending them was designated as main catalyst B.

[0041] 2. The preparation method of the ethylene-methyl methacrylate copolymer in this example was almost the same as that in Example 1, except that the main catalyst A was replaced with the main catalyst B.

[0042] Example 3 1. The main catalyst used in the copolymerization of ethylene and methyl methacrylate in this example was almost identical to that in Example 1, except that the molar ratio of compound 1 to compound 2 was 1:1, and the main catalyst obtained by blending them was designated as main catalyst C.

[0043] 2. The preparation method of the ethylene-methyl methacrylate copolymer in this example was almost the same as that in Example 1, except that the main catalyst A was replaced with the main catalyst C.

[0044] Example 4 1. The main catalyst used in the copolymerization of ethylene and methyl methacrylate in this example was almost identical to that in Example 1, except that the molar ratio of compound 1 to compound 2 was 3:1, and the main catalyst obtained by blending them was designated as main catalyst D.

[0045] 2. The preparation method of the ethylene-methyl methacrylate copolymer in this example was almost the same as that in Example 1, except that the main catalyst A was replaced with the main catalyst D.

[0046] Example 5 1. The main catalyst used in the copolymerization of ethylene and methyl methacrylate in this example was the same as that in Example 3.

[0047] 2. The preparation method of the ethylene and methyl methacrylate copolymer in this example was almost the same as that in Example 3, except that 13 mL (1.53 mol / L) of MAO was added to set the Al / Ni molar ratio to 500:1.

[0048] Example 6 1. The main catalyst used in the copolymerization of ethylene and methyl methacrylate in this example was almost identical to that in Example 1, except that the molar ratio of compound 1 to compound 2 was 10:1, and the main catalyst obtained by blending these compounds was designated as main catalyst E.

[0049] 2. The preparation method of the ethylene-methyl methacrylate copolymer in this example was almost the same as that in Example 1, except that the main catalyst A was replaced with the main catalyst E.

[0050] Example 7 1. The main catalyst used in the copolymerization of ethylene and methyl methacrylate in this example was the same as in Example 1, except that the molar ratio of compound 1 to compound 2 was 1:10, and the main catalyst obtained by blending them was designated as main catalyst F. Almost It matched.

[0051] 2. In the method for preparing ethylene-methyl methacrylate copolymer according to this embodiment, MAO is replaced with sesquiethylaluminum. Replace main catalyst C with main catalyst F Other than that, the results were almost identical to those in Example 3.

[0052] Example 8 1. The main catalyst used in the copolymerization of ethylene and methyl methacrylate in this embodiment is Example 3 It was determined to be consistent with the above.

[0053] 2. The preparation method of the ethylene-methyl methacrylate copolymer in this example was almost the same as that in Example 7, except that toluene was replaced with dichloromethane and the copolymerization reaction pressure was changed from 4 MPa to 5 MPa.

[0054] Example 9 1. The main catalyst used in the copolymerization of ethylene and methyl methacrylate in this example was the same as that in Example 8.

[0055] 2. The preparation method of the ethylene-methyl methacrylate copolymer in this example was almost the same as that in Example 8, except that dichloromethane was replaced with dichloroethane and the copolymerization reaction time was changed from 1 hour to 2 hours.

[0056] Example 10 1. The main catalyst used in the copolymerization of ethylene and methyl methacrylate in this example was the same as that in Example 9.

[0057] 2. The method for preparing the ethylene-methyl methacrylate copolymer according to this embodiment is as follows: Dichloroethane is replaced with a mixed solution of dichloroethane and toluene, Dichloroethane The volume ratio of toluene to ethanol was 1:1. Example 9 It almost matched.

[0058] Example 11 1. The main catalyst used in the copolymerization of ethylene and methyl methacrylate in this example was obtained by blending Compound 3 and Compound 4 in a molar ratio of 49:1, and the main catalyst obtained by blending was designated as Main Catalyst G. [ka]

[0059] 2. The method for preparing the ethylene-methyl methacrylate copolymer according to this embodiment includes the following steps: 1) 50 mL of toluene and 40 μmol of main catalyst G were added to a clean, dry 150 mL autoclave under an ethylene atmosphere. Ethylene was then bubbled in until a pressure of 0.05 MPa was reached, and the reactor was placed in a 40°C oil bath with magnetic stirring. 50 mmol of methyl methacrylate and 7.85 mL of MAO (concentration: 1.53 mol / L) were added with stirring to achieve an Al / Ni molar ratio of 300:1. Ethylene was then bubbled in until a pressure of 3 MPa was reached, and the reaction continued for 1 hour, after which the bubble was stopped. 2) The mixture is reduced in pressure, treated with a 5% by volume solution of hydrochloric acid in ethanol, washed, filtered and dried to obtain 284 g of a copolymer of ethylene and methyl methacrylate.

[0060] Example 12 1. The main catalyst used in the copolymerization of ethylene and methyl methacrylate in this example was almost identical to that in Example 11, except that the molar ratio of compound 3 to compound 4 was 1:49, and the main catalyst obtained by blending them was designated as main catalyst H.

[0061] 2. The preparation method of the ethylene-methyl methacrylate copolymer in this example was almost the same as that in Example 11, except that the main catalyst G was replaced with the main catalyst H.

[0062] Example 13 1. The main catalyst used in the copolymerization of ethylene and methyl methacrylate in this example was substantially identical to that in Example 11, except that the molar ratio of compound 3 to compound 4 was 1:1, and the main catalyst obtained by blending them was designated as main catalyst I.

[0063] 2. The method for preparing ethylene-methyl methacrylate copolymer in this embodiment is the same as above, except that the main catalyst G is replaced with the main catalyst I. Example 11 It almost matched.

[0064] Example 14 1. The main catalyst used in the copolymerization of ethylene and methyl methacrylate in this example was almost identical to that in Example 11, except that the molar ratio of compound 3 to compound 4 was 30:1, and the main catalyst obtained by blending these compounds was designated as main catalyst J.

[0065] 2. The method for preparing ethylene-methyl methacrylate copolymer in this embodiment is the same as above, except that main catalyst G is replaced with main catalyst J. Example 11 It almost matched.

[0066] Example 15 1. The main catalyst used in the copolymerization of ethylene and methyl methacrylate in this example was a mixture of Compound 3 and Compound 4 in a molar ratio of 10:1. The main catalyst obtained by blending the two compounds was designated as Main Catalyst K. Example 11 It almost matched.

[0067] 2. The method for preparing ethylene-methyl methacrylate copolymer in this embodiment was the same as above, except that the main catalyst G was replaced with the main catalyst K, MAO was replaced with sesquiethylaluminum, the copolymerization reaction pressure was 2 MPa, and the copolymerization reaction time was 2 hours. Example 11 It almost matched.

[0068] Example 16 1. The main catalyst used in the copolymerization of ethylene and methyl methacrylate in this example was almost identical to that in Example 11, except that the molar ratio of compound 3 to compound 4 was 1:10, and the main catalyst obtained by blending them was designated as main catalyst L.

[0069] 2. The method for preparing the ethylene-methyl methacrylate copolymer in this embodiment is 7.85mL The results were almost identical to those of Example 13, except that the conditions of 13 mL of sesquiethylaluminum (concentration 1.53 mol / L) and an Al / Ni molar ratio of 300:1 were changed to 13 mL of sesquiethylaluminum (1.53 mol / L) and an Al / Ni molar ratio of 500:1, and the copolymerization reaction pressure was changed to 2 MPa and the copolymerization reaction time to 2 hours.

[0070] Example 17 1. The main catalyst used in the copolymerization of ethylene and methyl methacrylate in this example was almost identical to that in Example 16, except that the molar ratio of compound 3 to compound 4 was 2:1, and the main catalyst obtained by blending these compounds was designated as main catalyst M.

[0071] 2. The preparation method of the ethylene-methyl methacrylate copolymer in this example was almost the same as that in Example 16, except that toluene was replaced with n-hexane, the copolymerization temperature was 60°C, and the copolymerization pressure was 3 MPa.

[0072] Example 18 1. The main catalyst used in the copolymerization of ethylene and methyl methacrylate in this example was the same as that in Example 13.

[0073] 2. The preparation method of ethylene-methyl methacrylate copolymer in this example was almost the same as that in Example 13, except that toluene was replaced with a mixed solution of n-hexane and dichloroethane, the volume ratio of n-hexane to dichloroethane was 1:1, MAO was replaced with sesquiethylaluminum, and the copolymerization reaction pressure was 5 MPa.

[0074] Example 19 1. The main catalyst used in the copolymerization of ethylene and methyl methacrylate in this example was the same as that in Example 13.

[0075] 2. The method for preparing the ethylene-methyl methacrylate copolymer of this embodiment is as follows: toluene is replaced with a mixed solution of n-hexane and dichloroethane, the volume ratio of n-hexane to dichloroethane is 1:2, MAO is replaced with sesquiethylaluminum, the copolymerization reaction pressure is 10 MPa, and the copolymerization temperature is 60°C. The amount of methyl methacrylate added was 60 mmol. Other than that, the results were almost identical to those in Example 13.

[0076] Example 20 1. The main catalyst used in the copolymerization of ethylene and methyl methacrylate in this example was the same as that in Example 13.

[0077] 2. In the method for preparing the ethylene-methyl methacrylate copolymer of this embodiment, toluene is replaced with dichloromethane, MAO is replaced with sesquiethylaluminum, the copolymerization reaction pressure is 5 MPa, and the copolymerization temperature is 80°C. The amount of methyl methacrylate added was 30 mmol. Other than that, the results were almost identical to those in Example 13.

[0078] Example 21 1. The main catalyst used in the copolymerization of ethylene and methyl methacrylate in this example was obtained by blending Compound 5 and Compound 6 in a molar ratio of 49:1, and the main catalyst obtained by blending was designated as Main Catalyst N. [ka]

[0079] 2. The method for preparing the ethylene-methyl methacrylate copolymer according to this embodiment includes: 1) 50 mL of toluene and 40 μmol of the main catalyst N were added to a clean, dry 150 mL autoclave under an ethylene atmosphere. Ethylene was then bubbled in until the pressure reached 0.05 MPa. The reactor was placed in a 60°C oil bath with magnetic stirring, and 50 mmol of methyl methacrylate and 7.5 mL of sesquiethylaluminum (1.53 mol / L) were added with stirring to an Al / Ni molar ratio of 300:1. Ethylene was then bubbled in until the pressure reached 5 MPa. After 2 hours of reaction, the bubble of ethylene was stopped. 2) Under reduced pressure, the mixture is treated with a 5% volumetric concentration of hydrochloric acid in ethanol, washed, filtered, and dried to obtain a copolymer of ethylene and methyl methacrylate.

[0080] Example 22 1. The main catalyst used in the copolymerization of ethylene and methyl methacrylate in this example was almost identical to that in Example 21, except that the molar ratio of compound 5 to compound 6 was 1:49, and the main catalyst obtained by blending them was designated as main catalyst O.

[0081] 2. The preparation method of the ethylene-methyl methacrylate copolymer in this example was almost the same as that in Example 21, except that the main catalyst N was replaced with the main catalyst O.

[0082] Example 23 1. The main catalyst used in the copolymerization of ethylene and methyl methacrylate in this example was almost identical to that in Example 21, except that the molar ratio of compound 5 to compound 6 was 1:1, and the main catalyst obtained by blending them was designated as main catalyst P.

[0083] 2. The preparation method of the ethylene-methyl methacrylate copolymer in this example was almost the same as that in Example 21, except that the main catalyst N was replaced with the main catalyst P.

[0084] Example 24 1. The main catalyst used in the copolymerization of ethylene and methyl methacrylate in this example was almost identical to that in Example 21, except that the molar ratio of compound 5 to compound 6 was 10:1, and the main catalyst obtained by blending them was designated as main catalyst Q.

[0085] 2. The preparation method of the ethylene-methyl methacrylate copolymer in this example was almost the same as that in Example 21, except that the main catalyst N was replaced with the main catalyst Q.

[0086] Example 25 1. The main catalyst used in the copolymerization of ethylene and methyl methacrylate in this example was almost identical to that in Example 21, except that the molar ratio of compound 5 to compound 6 was 1:10, and the main catalyst obtained by blending them was designated as main catalyst R.

[0087] 2. The preparation method of the ethylene-methyl methacrylate copolymer in this example was almost the same as that in Example 21, except that the main catalyst N was replaced with the main catalyst R.

[0088] Example 26 1. The main catalyst used in the copolymerization of ethylene and methyl methacrylate in this example was almost identical to that in Example 21, except that the molar ratio of compound 5 to compound 6 was 1:5, and the main catalyst obtained by blending them was designated as main catalyst S.

[0089] 2. The preparation method of ethylene-methyl methacrylate copolymer in this example was almost the same as that in Example 21, except that main catalyst N was replaced with main catalyst S, sesquiethylaluminum was replaced with MAO, the copolymerization reaction temperature was 40°C, and the amount of methyl methacrylate added was 60 mmol.

[0090] Example 27 1. The main catalyst used in the copolymerization of ethylene and methyl methacrylate in this example was the same as that in Example 26.

[0091] 2. The method for preparing the ethylene-methyl methacrylate copolymer in this example was to replace toluene with dichloroethane and add 13 mL (1.53 mL) of MAO. mol / L ) and the Al / Ni molar ratio was 500:1, the results were almost identical to those of Example 26.

[0092] Example 28 1. The main catalyst used in the copolymerization of ethylene and methyl methacrylate in this example was almost identical to that in Example 27, except that the molar ratio of compound 5 to compound 6 was 2:1, and the main catalyst obtained by blending them was designated as main catalyst T.

[0093] 2. The method for preparing the ethylene-methyl methacrylate copolymer according to this embodiment is as follows: Main catalyst S was replaced with main catalyst T, dichloroethane was replaced with toluene, the copolymerization reaction pressure was 3 MPa, and the copolymerization reaction temperature was 80°C. Example 27 It almost matched.

[0094] Example 29 1. The main catalyst used in the copolymerization of ethylene and methyl methacrylate in this example was the same as that in Example 28.

[0095] 2. The preparation method of the ethylene-methyl methacrylate copolymer in this example was almost the same as that in Example 28, except that toluene was replaced with a mixed solution of dichloromethane and n-hexane, the volume ratio of dichloromethane to n-hexane was 1:3, and the copolymerization reaction time was 4 hours.

[0096] Example 30 1. The main catalyst used in the copolymerization of ethylene and methyl methacrylate in this example was the same as that in Example 23.

[0097] 2. In the method for preparing the ethylene-methyl methacrylate copolymer of this embodiment, toluene was replaced with dichloroethane, and the conditions of 7.5 mL (1.53 mol / L) of sesquiethylaluminum and Al / Ni molar ratio = 300:1 were changed to 13 mL (1.53 mol / L) of MAO and Al / Ni molar ratio = 500:1, and the copolymerization reaction time was 6 hours. Methyl methacrylate The results were almost identical to those in Example 23, except that the amount of was 30 mmol.

[0098] Example 31 1. The main catalyst used in the copolymerization of ethylene and methyl methacrylate in this embodiment is a mixture of Compound 7 and Compound 8 in a molar ratio of 1:1. 1:1 The main catalyst obtained by blending is designated as main catalyst U. [ka]

[0099] 2. The method for preparing ethylene-methyl methacrylate copolymer in this example was to add 50 mL of toluene and 40 μmol of the main catalyst U to a clean, dry 150 mL autoclave under an ethylene atmosphere. Ethylene was then vented to a pressure of 0.05 MPa. The reactor was placed in an oil bath at 60°C (copolymerization temperature) with magnetic stirring, and 50 mmol of methyl methacrylate and 13 mL of MAO (concentration 1.53 mol / L) were added under stirring to achieve an Al / Ni molar ratio of 500:1. Ethylene was then vented to a pressure of 4 MPa (copolymerization pressure). After 1 hour of reaction, the ethylene venting was stopped, the pressure was reduced, and the mixture was treated with a 5% volumetric concentration of hydrochloric acid in ethanol, followed by washing, filtration, and drying to obtain ethylene-methyl methacrylate copolymer.

[0100] Example 32 1. The main catalyst used in the copolymerization of ethylene and methyl methacrylate in this example was obtained by blending Compound 9 and Compound 10 in a molar ratio of 49:1, and the main catalyst obtained by blending was designated as Main Catalyst V. [ka]

[0101] 2. The method for preparing ethylene-methyl methacrylate copolymer in this example involves adding 50 mL of toluene and 40 μmol of main catalyst V to a clean, dry 150 mL autoclave under an ethylene atmosphere. Ethylene is then bubbled in to the autoclave to a pressure of 0.05 MPa. The reactor is placed in a 40°C oil bath with magnetic stirring, and 50 mmol of methyl methacrylate and 7.85 mL of MAO (concentration: 1.53 mol / L) are added with stirring to achieve an Al / Ni molar ratio of 300:1. Ethylene is then bubbled in to the autoclave to a pressure of 3 MPa. After reacting for 1 hour, the ethylene bubble is stopped, the pressure is reduced, and the autoclave is treated with a 5% vol. concentration of hydrochloric acid in ethanol, followed by washing, filtration, and drying to obtain 284 g of ethylene-methyl methacrylate copolymer.

[0102] Example 33 1. The main catalyst used in the copolymerization of ethylene and methyl methacrylate in this example was obtained by blending Compound 11 and Compound 12 in a molar ratio of 49:1, and this blended main catalyst was designated as Main Catalyst W. [ka]

[0103] 2. In this example, the ethylene-methyl methacrylate copolymer was prepared by adding 50 mL of toluene and 40 μmol of the main catalyst W to a clean, dry 150 mL autoclave under an ethylene atmosphere. Ethylene was then introduced to the autoclave to a pressure of 0.05 MPa. The reactor was then placed in a 60°C oil bath with magnetic stirring. 50 mmol of methyl methacrylate and 7.85 mL (1.53 mol / L) of sesquiethylaluminum were added under stirring to achieve an Al / Ni molar ratio of 300:1. Ethylene was then introduced to the autoclave to a pressure of 5 MPa. After two hours of reaction, the ethylene introduction was stopped, the pressure was reduced, and the autoclave was treated with a 5% volumetric concentration of hydrochloric acid in ethanol, followed by washing, filtration, and drying to obtain the ethylene-methyl methacrylate copolymer.

[0104] Example 34 1. The main catalyst used in the copolymerization of ethylene and methyl methacrylate in this example was the same as that in Example 3.

[0105] 2. The method for preparing ethylene-methyl methacrylate copolymer in this embodiment includes: adding 50 mL of toluene and 40 μmol of main catalyst C to a clean and dry 150 mL autoclave under ethylene atmosphere; then, ethylene is bubbled in until the pressure reaches 0.05 MPa; the reactor is placed in a 60°C oil bath with magnetic stirring; 50 mmol of methyl methacrylate and 19.63 mL (1.53 mol / L) of MAO are added under stirring to achieve an Al / Ni molar ratio of 750:1; ethylene is bubbled in until the pressure reaches 4 MPa; after reacting for 1 hour, the bubble of ethylene is stopped; the mixture is depressurized, treated with a 5% volumetric concentration of hydrochloric acid in ethanol, washed, filtered, and dried to obtain ethylene-methyl methacrylate copolymer.

[0106] Example 35 1. The main catalyst used in the copolymerization of ethylene and methyl methacrylate in this example is the same as that in Example 3.

[0107] 2. The method for preparing ethylene-methyl methacrylate copolymer in this embodiment includes: adding 50 mL of toluene and 40 μmol of main catalyst C to a clean and dry 150 mL autoclave under an ethylene atmosphere; then, ethylene is bubbled in until the pressure reaches 0.05 MPa; the reactor is placed in a 60°C oil bath with magnetic stirring; 50 mmol (1.53 mol / L) of methyl methacrylate is added under stirring to achieve an Al / Ni molar ratio of 2000:1; ethylene is bubbled in until the pressure reaches 4 MPa; after reacting for 1 hour, the bubble of ethylene is stopped; and the mixture is depressurized, treated with a 5% volumetric concentration of hydrochloric acid in ethanol, washed, filtered, and dried to obtain ethylene-methyl methacrylate copolymer.

[0108] Comparative Example 1 1. The main catalyst used in the copolymerization of ethylene and methyl methacrylate in this comparative example is Compound 5, Main catalyst Y I wrote it as 1.

[0109] 2. The method for preparing the ethylene and methacrylic acid ester copolymer according to this embodiment includes the following: 1) In a clean, dry 150 mL autoclave, add 50 mL of toluene, Catalyst Y 140 μmol of methyl methacrylate was added under an ethylene atmosphere, and ethylene was aerated until the pressure reached 0.05 MPa. The reactor was placed in a 60°C oil bath with magnetic stirring, and 30 mmol of methyl methacrylate and 7.5 mL of MAO (1.53 mol / L) were added under stirring to adjust the Al / Ni molar ratio to 300: 1. Ethylene was further aerated until the pressure reached 5 MPa, and the aeration of ethylene was stopped after 1 hour of reaction. 2) Under reduced pressure, the mixture is treated with a 5% volumetric concentration of hydrochloric acid in ethanol, washed, filtered, and dried to obtain a copolymer of ethylene and methyl methacrylate.

[0110] Comparative Example 2 1. The main catalyst used in the copolymerization of ethylene and methyl methacrylate in this comparative example is Compound 6, Main catalyst Y I wrote it as 2.

[0111] 2. The method for preparing the ethylene and methacrylic acid ester copolymer according to this embodiment includes the following: 1) In a clean, dry 150 mL autoclave, add 50 mL of toluene, Catalyst Y 240 μmol of methyl methacrylate was added under an ethylene atmosphere, and ethylene was aerated until the pressure reached 0.05 MPa. The reactor was placed in an oil bath at 60°C with magnetic stirring, and 30 mmol of methyl methacrylate and 7.5 mL of MAO (1.53 mol / L) were added under stirring to adjust the Al / Ni molar ratio to 300: 1. Ethylene was further aerated until the pressure reached 5 MPa, and the aeration of ethylene was stopped after 1 hour of reaction. 2) Under reduced pressure, the mixture is treated with a 5% volumetric concentration of hydrochloric acid in ethanol, washed, filtered, and dried to obtain a copolymer of ethylene and methyl methacrylate.

[0112] Comparative Example 3 1. This comparative exampleCompound 13 is used as a main catalyst for the copolymerization of ethylene and methyl methacrylate according to the present invention, Main catalyst Y I wrote 3. [ka]

[0113] 2. This comparative example The method for preparing the ethylene and methyl methacrylate copolymer according to the present invention includes: 1) In a clean, dry 150 mL autoclave, add 50 mL of toluene, Main catalyst Y 340 μmol of ethylene was added in an ethylene atmosphere. Then, ethylene was introduced to a pressure of 0.05 MPa, and the reactor was placed in a 60°C oil bath with magnetic stirring. 50 mmol of methyl methacrylate and 7.85 mL (1.53 mol / L) of MAO were added under stirring to adjust the Al / Ni molar ratio to 300:1. Ethylene was then introduced to a pressure of 5 MPa, and the reaction was continued for 1 hour, after which the introduction of ethylene was stopped. 2) Under reduced pressure, the mixture is treated with a 5% volumetric concentration of hydrochloric acid in ethanol, washed, filtered, and dried to obtain a copolymer of ethylene and methyl methacrylate.

[0114] Comparative Example 4 1. This comparative example As the main catalyst for the copolymerization of ethylene and methyl methacrylate according to the above, compound 14 Use Main catalyst Y I wrote 4. [ka]

[0115] 2. This comparative example The method for preparing the ethylene and methyl methacrylate copolymer according to the present invention includes: 1) In a clean and dry 150 mL autoclave, 50 mL of toluene and 440 μmol of main catalyst Y were added under an ethylene atmosphere. Ethylene was then introduced to the autoclave until a pressure of 0.05 MPa was reached. The reactor was placed in a 60°C oil bath with magnetic stirring. 50 mmol of methyl methacrylate and 7.85 mL (1.53 mol / L) of MAO were added under stirring to achieve an Al / Ni molar ratio of 300:1. Ethylene was then introduced to the autoclave until a pressure of 5 MPa was reached. After 1 hour of reaction, the introduction of ethylene was stopped. 2) Under reduced pressure, the mixture is treated with a 5% volumetric concentration of hydrochloric acid in ethanol, washed, filtered, and dried to obtain a copolymer of ethylene and methyl methacrylate.

[0116] Comparative Example 5 1. This comparative example Compound 15 is used as a main catalyst for the copolymerization of ethylene and methyl methacrylate according to the present invention, Main catalyst Y I wrote 5. [ka]

[0117] 2. This comparative example The method for preparing the ethylene and methyl methacrylate copolymer according to the present invention includes: 1) In a clean, dry 150 mL autoclave, add 50 mL of toluene, Main catalyst Y 540 μmol of methyl methacrylate was added in an ethylene atmosphere, and ethylene was aerated until the pressure reached 0.05 MPa. The reactor was placed in an oil bath at 45°C and magnetically stirred. 47 mmol of methyl methacrylate and 3.9 mL of MAO (1.53 mol / L) were added under stirring to adjust the Al / Ni molar ratio to 150: 1. Ethylene was further aerated until the pressure reached 3 MPa, and the aeration of ethylene was stopped after 2 hours of reaction. 2) Under reduced pressure, the mixture is treated with a 5% volumetric concentration of hydrochloric acid in ethanol, washed, filtered, and dried to obtain a copolymer of ethylene and methyl methacrylate.

[0118] For ease of comparison, the copolymerization reaction conditions for the above examples and comparative examples are listed in Table 1.

[0119] Test Example The catalytic activity was calculated for the catalysts used in the copolymerization of ethylene and methyl methacrylate in Examples 1 to 35 and Comparative Examples 1 to 5. The calculation formula is as follows. Catalytic activity = copolymer mass (grams) / (main catalyst loading (moles) x reaction time (hours))

[0120] The ethylene and methyl methacrylate copolymers according to Examples 1 to 35 and Comparative Examples 1 to 5 were subjected to the following parameter tests.

[0121] The molecular weight was measured using a Waters 2414 gel permeation chromatography (GPC) system. A standard polystyrene sample was used as the calibration curve, tetrahydrofuran was used as the mobile phase, the column temperature was 40°C, the sample concentration was 1 mg / mL, the loading volume was 50 μL, the elution time was 40 min, and the flow rate was 1 mL min -1 It was decided.

[0122] The method for measuring and calculating the insertion rate of methyl methacrylate is as follows: 13 For CNMR, analysis was performed using a Bruker 400MHz nuclear magnetic resonance spectrometer. 13 Based on the peak areas of -CH2 (chemical shift 1.27) and -OCH3 (chemical shift 3.56) in the CNMR spectrum, the molar insertion rate of methyl methacrylate in the ethylene-methyl methacrylate copolymer was calculated using the following two equations.

number

[0123] In the above two equations, N M is the number of moles of methyl methacrylate in the copolymer, N E is the number of moles of ethylene in the copolymer, A is the peak area of ​​-OCH3 (chemical shift 3.56) in methyl methacrylate, and B is In ethyleneThe peak area of ​​-CH2 (chemical shift 1.27) is taken as the molar insertion ratio of methyl methacrylate in the copolymer.

[0124] The test results for the above parameters are shown in Table 2.

[0125] [Table 1] TIFF0007766794000016.tif237166TIFF0007766794000017.tif66168

[0126] [Table 2] TIFF0007766794000019.tif119159

[0127] From the data in Table 2, it is clear that the catalyst according to the present invention, when used in the copolymerization of ethylene and methyl methacrylate, can give a copolymer of ethylene and methyl methacrylate with a higher molecular weight.

[0128] The above embodiments are for illustrating the technical solutions of the present application, but are not intended to limit the same. The present application will be described in detail with reference to the above embodiments. However, those skilled in the art may still modify the technical solutions described in the above embodiments or make equivalent substitutions for some or all of the technical features thereof, and it should be understood that such modifications or substitutions will not deviate from the essence of the corresponding technical solutions and the scope of the technical solutions of the embodiments of the present application.

[0129] This application claims priority to a Chinese patent application bearing application number 202111675304.4 and entitled "Catalyst for copolymerization of ethylene and methyl methacrylate and use thereof," filed with the China Patent Office on December 31, 2021, the entire contents of which are incorporated herein by reference.

Claims

1. A catalyst for copolymerization of ethylene and methyl methacrylate, comprising a main catalyst obtained by blending a compound of formula (I) and a compound of formula (II), The formula (I) has the following structure: 【Chemistry 1】 In the formula, R １ , R ２ are each independently selected from substituted aryl, the substituent being selected from at least one of C1-C6 alkyl and C1-C6 alkoxy; R ３ , R ４ are each independently selected from hydrogen and C1-C4 alkyl; M is selected from Ni or Pd; X １ and X ２ are each independently selected from at least one of halogen, C1 to C4 alkyl, aryl, C2 to C4 ether, and C1 to C4 nitrile; The formula (II) is the following structure: 【Chemistry 2】 In the formula, R ５ , R ６ are each independently selected from at least one of hydrogen, methyl, ethyl, dimethylamino, diethylamino, amino, hydroxy, and C1 to C4 alkoxy; R ７ , R ８ are each independently selected from at least one of hydrogen, C1 to C4 alkyl, C1 to C4 dialkylamino, amino, hydroxy, and C1 to C4 alkoxy; A catalyst, wherein the molar ratio of the compound of formula (I) to the compound of formula (II) is (1:49) to (49:1).

2. 2. The catalyst according to claim 1, wherein the molar ratio of the compound of formula (I) to the compound of formula (II) is from 1:10 to 10:

1.

3. The catalyst described in claim 1, further comprising a promoter selected from at least one of methylaluminoxane, trialkylaluminum, and alkylaluminum halide.

4. 4. The catalyst according to claim 3, wherein the molar ratio of the metal element in the main catalyst to the aluminum element in the co-catalyst is 1:(50-1000).

5. 5. The catalyst according to claim 4, wherein the molar ratio of the metal element in the main catalyst to the aluminum element in the co-catalyst is 1:(100-500).

6. A method for copolymerizing ethylene and methyl methacrylate, which uses the catalyst according to any one of claims 1 to 5.

7. The copolymerization method includes copolymerizing ethylene and methyl methacrylate under catalysis by the catalyst, 7. The copolymerization method according to claim 6, wherein the copolymerization reaction pressure is ≦10 MPa and the temperature is ≦100°C.

8. 8. The copolymerization method according to claim 7, wherein the solvent for the copolymerization reaction is selected from at least one of toluene, n-hexane, dichloromethane, and dichloroethane.

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