CATALYST FOR THE COPOLYMERIZATION OF ETHYLENE AND METHYLMETHACRYLATE AND ITS USE

Abstract

The present application provides a catalyst for the copolymerization of ethylene and methyl methacrylate, as well as an application thereof. The catalyst comprises a main catalyst, which is obtained by compounding a compound of formula (I) and a compound of formula (II); the molar ratio of compound of formula (I) to compound of formula (II) is (1:49) to (49:1). The catalyst has excellent catalytic activity, and a high molecular weight copolymer of ethylene and methyl methacrylate can be obtained, with a weight-average molecular weight of not less than 1 x 10⁵ g / mol.

Description

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims priority to Chinese Patent Application No. 202111675304.4, filed with the China National Intellectual Property Administration on December 31, 2021, entitled “CATALYST FOR COPOLYMERIZATION OF ETHYLENE AND METHYL METHACRYLATE AND APPLICATION THEREOF,” the disclosure of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0002] The application belongs to the field of olefin polymerization and relates to a catalyst for the copolymerization of ethylene and methyl methacrylate and its application. BACKGROUND

[0003] Compared with conventional polyethylene, functional polyethylene obtained by copolymerizing ethylene and polar methacrylic acid monomer exhibits better compatibility, adhesion, dyeability, and printability. However, the coordination copolymerization of ethylene and methyl methacrylate poses a technical challenge, mainly due to the high steric hindrance of methyl methacrylate compared to other polar acrylate monomers. This results in poor copolymerization activity upon interaction with an active site and a low molecular weight of the copolymer, making it difficult to control the incorporation rate of methyl methacrylate into the copolymer.The existing copolymerization technology of ethylene and methyl methacrylate mainly uses a post-transition metal catalyst, which can achieve the copolymerization of ethylene and methacrylic acid under the condition of a molar ratio of alumina as a cocatalyst to the main catalyst of ≤ 1000:1. However, the molecular weight of the resulting copolymer is low, typically only 1×10. 4 g / mol.

[0004] Therefore, the synthesis of a high molecular weight copolymer of ethylene and methyl methacrylate is an urgent problem in the state of the art. SUMMARY

[0005] The present application provides a catalyst for the copolymerization of ethylene and methyl methacrylate, which is used by compounding a compound of formula (I) having an α-diimine late-transition metal complex structure and a compound of formula (II) having a bissalicylaldiminato late-transition metal complex in a specific molar ratio range. The catalyst is used to catalyze a copolymerization reaction of methyl methacrylate and ethylene, and a copolymer of ethylene and methyl methacrylate having a molecular weight of not less than 1×10 5 g / mol can be obtained.

[0006] The present application also provides a process for the copolymerization of ethylene and methyl methacrylate, by which a copolymer of ethylene and methyl methacrylate having a high molecular weight of not less than 1×10 5g / mol can be obtained. Furthermore, the process can perform copolymerization of ethylene and methyl methacrylate at a relatively low reaction temperature and relatively low reaction pressure in a relatively short time, which has the advantages of mildness and high efficiency.

[0007] The present application also provides a copolymer of ethylene and methyl methacrylate which has the advantages of a high molecular weight and an adjustable incorporation rate of methyl methacrylate.

[0008] The present application provides a catalyst for the copolymerization of ethylene and methyl methacrylate. The catalyst comprises a main catalyst obtained by compounding a compound of formula (I) and a compound of formula (II); a structure of formula (I):wherein R1 and R2 are each independently selected from substituted aryl, wherein one 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-C4 alkyl; M is selected from Ni or Pd; X1 and X2 are each independently selected from halogen, C1-C4 alkyl, aryl, C2-C4 ether and C1-C4 nitrile; a structure of formula (II): wherein R5 and R6 are each independently selected from hydrogen, methyl, ethyl, dimethylamino, diethylamino, amino, hydroxyl and C1-C4 alkoxy; R7 and R8 are each independently selected from at least one of hydrogen, C1-C4 alkyl, C1-C4 dialkylamino, amino, hydroxyl and C1-C4 alkoxy; a molar ratio of formula (I) to formula (II) is from (1:49) to (49:1).

[0009] For the above catalyst, the molar ratio of the compound of formula (I) to the compound of formula (II) is (1:10) to (10:1).

[0010] In the above-mentioned catalyst, the catalyst further contains a cocatalyst selected from aluminoxane.

[0011] In the above catalyst, the cocatalyst is selected from at least one of methylaluminoxane, trialkylaluminum and alkylaluminum halide.

[0012] In the above-mentioned catalyst, the molar ratio between the metal element in the main catalyst and the aluminum element in the co-catalyst is 1: (50-1000).

[0013] In the above-mentioned catalyst, the molar ratio between the metal element in the main catalyst and the aluminum element in the co-catalyst is 1: (100-500).

[0014] The present application also provides a process for the copolymerization of ethylene and methyl methacrylate, in which the above-mentioned catalyst is used to carry out a copolymerization reaction.

[0015] In the above-mentioned copolymerization method, the copolymerization method includes: carrying out the copolymerization reaction of ethylene and methyl methacrylate under catalysis of the catalyst; a pressure of the copolymerization reaction is ≤ 10 MPa and the temperature of the copolymerization reaction is ≤ 100 °C

[0016] For the above-mentioned copolymerization reaction, a solvent for the copolymerization reaction is selected from at least one of toluene, n-hexane, dichloromethane and dichloroethane.

[0017] The present application also provides a copolymer of ethylene and methyl methacrylate, which is prepared by the above-mentioned copolymerization reaction and has a weight-average molecular weight of ≥1×10 5 g / mol.

[0018] In the catalyst used for the copolymerization of ethylene and methyl methacrylate of the present application, by compounding the compound of formula (I) having an α-diimine late transition metal complex structure with the compound of formula (II) having a bissalicylaldiminato late transition metal complex, the two compounds can synergize with each other to promote the copolymerization of ethylene and methyl methacrylate within a certain molar ratio range, thereby obtaining a high molecular weight copolymer of ethylene and methyl methacrylate.

[0019] By the process for copolymerizing ethylene and methyl methacrylate of the present invention, the copolymer of ethylene and methyl methacrylate having a weight-average molecular weight of not less than 1×10 5 g / mol can be obtained. Furthermore, by using this method, the copolymerization of ethylene and methyl methacrylate can be completed in a relatively short time at a relatively low reaction temperature and pressure, which offers the advantages of mild reaction conditions and high efficiency, making it advantageous for industrial applications.

[0020] The copolymer of ethylene and methyl methacrylate of the present application has the advantages of a weight-average molecular weight of not less than 1×10 5 g / mol and an adjustable incorporation rate of methyl methacrylate. DESCRIPTION OF EMBODIMENTS

[0021] The present application is described in more detail below with reference to specific embodiments. It is understood that the following examples serve only to describe and explain the present application by way of example and are not to be understood as limiting the scope of the present application. All technologies implemented based on the above-mentioned contents of the present application fall within the scope of the present application.

[0022] A first aspect of the present application provides a catalyst for the copolymerization of ethylene and methyl methacrylate, which contains a main catalyst, and the main catalyst is obtained by compounding a compound of formula (I) and a compound of formula (II); a structure of formula (I):wherein R1 and R2 are each independently selected from substituted aryl, wherein one 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-C4 alkyl; M is selected from Ni or Pd; X1 and X2 are each independently selected from halogen, C1-C4 alkyl, aryl, C2-C4 ether and C1-C4 nitrile; a structure of formula (II) is: wherein R5 and R6 are each independently selected from hydrogen, methyl, ethyl, dimethylamino, diethylamino, amino, hydroxyl and C1-C4 alkoxy; R7 and R8 are each independently selected from at least one of hydrogen, C1-C4 alkyl, C1-C4 dialkylamino, amino, hydroxyl and C1-C4 alkoxy; a molar ratio of the compound of formula (I) to the compound of formula (II) is from (1:49) to (49:1).

[0023] Substituted aryl refers to an aryl bonded to a substituent. The aryl may, in particular, be phenyl, naphthyl, biphenyl, and the like. In the present application, the substitution position of the substituent on the aryl is not limited. For example, it may be located at an ortho position of a diimine structure or at a para position of the diimine structure. C1-C6 alkyl refers to a branched alkyl group or a linear alkyl group having 1 to 6 carbon atoms, for example, methyl, ethyl, propyl, isopropyl, tert-butyl, etc.; C1-C6 alkoxy group refers to a branched alkoxy group or a linear alkoxy group having 1 to 6 carbon atoms, for example, methoxy, ethoxy, isopropoxy, etc.Likewise, a C1-C4 alkyl group refers to a linear alkyl group or a branched alkyl group having 1 to 4 carbon atoms, and a C1-C4 alkoxy group refers to a linear alkoxy group or a branched alkoxy group having 1 to 4 carbon atoms. The C1-C4 dialkylamino group refers to a substituent in which one amino group is substituted by two C1-C4 linear or linear alkyl groups, e.g., dimethylamino, diethylamino, dipropylamino, and the like. Halogen is one of the elements fluorine, chlorine, bromine, and iodine.

[0024] The inventors' research has revealed that the compound of formula (I) and the compound of formula (II) are compounded in a molar ratio of (1:49) to (49:1) to form a main catalyst capable of catalyzing the copolymerization of ethylene and methyl methacrylate to produce a copolymer of ethylene and methyl methacrylate having a molecular weight of not less than 1×10 5g / mol. This may be because the compound of formula (I) is an α-diimine late-transition metal complex and the compound of formula (II) is a bissalicylaldiminato late-transition metal complex, and the structures of the two can be matched and coordinated, thereby ensuring that the reactivity ratio of ethylene and methyl methacrylate is within a suitable range and maximizing the advantages of two compounds with different structures.In addition, both the compound of formula (I) and the compound of formula (II) are linked with an electron-donating group, which can mitigate the possibility of a metal center being attacked by an ester group of methyl methacrylate, and at the same time increase the possibility of inserting the C=C double bond of methyl methacrylate into the empty orbit of the metal center and shortening the coordination time between the double bond and an active center, thereby obtaining a high molecular weight copolymer of ethylene and methacrylic acid.

[0025] Furthermore, when the molar ratio of the compound of formula (I) to the compound of formula (II) is (1:10)-(10:1), the catalytic activity of the catalyst, the weight-average molecular weight of the copolymer and the incorporation rate of methyl methacrylate are more balanced.

[0026] It is understood that the catalyst of the present applications also contains a cocatalyst. In particular, the cocatalyst of the present application is selected from aluminoxane, which can alkylate the main catalyst and also remove the halogen or alkyl in the main catalyst to form a cationic active site, while simultaneously acting as a non-coordinating equilibrium ion, both of which are beneficial for increasing the molecular weight of the copolymer.

[0027] Furthermore, the cocatalyst is selected from at least one of methylaluminoxane (MAO), alkylaluminum, and alkylaluminum halide. The cocatalyst can be obtained from a wide range of sources, is cost-effective, and can assist the main catalyst in further increasing the molecular weight of the recovered ethylene and methyl methacrylate.

[0028] In a specific implementation where the molar ratio between the metal element in the main catalyst and the aluminum element in the cocatalyst is 1: (50-1000), the catalyst shows excellent copolymerization activity between ethylene and methyl methacrylate.

[0029] In addition, if the molar ratio between the metal element in the main catalyst and the aluminum element in the cocatalyst is 1: (100-500), it is advantageous for improving the copolymerization activity of the catalyst.

[0030] A second aspect of the present application provides a process for the copolymerization of ethylene and methyl methacrylate, in which the catalyst for the copolymerization of ethylene and methyl methacrylate provided in the first aspect of the present application is used as the copolymerization catalyst.

[0031] The above copolymerization method has excellent copolymerization activity and can produce a copolymer of ethylene and methyl methacrylate having a molecular weight of not less than 1×10 5 g / mol. Furthermore, this process allows the copolymerization reaction to be carried out at a relatively low polymerization temperature and low polymerization pressure, meaning the reaction conditions are relatively mild, which is favorable for industrial application.

[0032] The above-mentioned copolymerization process can also control the incorporation rate of methyl methacrylate into the copolymer by controlling factors such as copolymerization pressure, molar ratio of raw material to catalyst, copolymerization temperature, and copolymerization time. In the specific production process, the incorporation rate of methyl methacrylate into the copolymer can be regulated according to the ester content requirements of different products.

[0033] In a specific implementation, the above-mentioned copolymerization method includes: conducting a copolymerization reaction of ethylene and methyl methacrylate under catalysis of a catalyst, wherein a pressure of the copolymerization reaction is ≤10 MPa and a temperature of the copolymerization reaction is ≤100°C. The copolymerization reaction of the present application can be smoothly carried out in this pressure and temperature range, which reduces the intensity of the copolymerization reaction.

[0034] Furthermore, the above copolymerization reaction can be carried out in a solvent system. Specifically, the solvent can be selected from at least one of the following: toluene, n-hexane, dichloromethane, and dichloroethane. Among them, toluene, dichloromethane, and dichloroethane are polar solvents, which have a positive effect on the incorporation of methacrylic acid and the improvement of polar copolymerization activity. The above-mentioned copolymerization reaction can also be carried out using n-hexane, which is a widely used solvent in the industry and has the advantages of easy availability and low toxicity.

[0035] A third aspect of the present application provides a copolymer of ethylene and methyl methacrylate prepared by the copolymerization process according to the second aspect of the present application.

[0036] The copolymer of this application is produced by the copolymerization method provided by the second aspect of the present application, so that it has a relatively high molecular weight that can meet the application requirements of existing resin processing equipment and commercial plastics, and has an adjustable incorporation rate of methyl and methyl acrylate and a wide range of applications.

[0037] The catalyst for the copolymerization of ethylene and methyl methacrylate provided in the present application is described in more detail below with reference to specific embodiments.

[0038] It should be noted that in the following working examples, unless otherwise stated, all raw materials used are commercially available or can be prepared by conventional methods, and that the experimental procedures without specifying conditions are conventional procedures and conventional conditions well known in the art. Example 1

[0039] 1. The main catalyst of the catalyst used for the copolymerization of ethylene and methyl methacrylate in the present embodiment is obtained by compounding Compound 1 and Compound 2 in a molar ratio of 1:49, and the main catalyst obtained by such mixing is referred to as Main Catalyst A.

[0040] 2. The process for producing the copolymer of ethylene and methyl methacrylate in the present embodiment includes the following steps: 1) In a clean and dry 150-mL autoclave, add 50 mL of toluene and 40 μmol of the main catalyst A under an ethylene atmosphere; then, feed ethylene until the pressure reaches 0.05 MPa, and place the reaction autoclave in an oil bath at 60°C (copolymerization temperature) and perform electromagnetic stirring; add 50 mmol of methyl methacrylate and 7.85 mL of MAO (concentration: 1.53 mol / L) with stirring, with the molar ratio of Al / Ni = 300:1; continue feeding ethylene until the pressure reaches 4 MPa (copolymerization pressure), and conduct the reaction for 1 h, then stop feeding ethylene. 2) Depressurization; using a hydrochloric acid-ethanol solution with a volume concentration of 5% for processing; then washing, filtering, and drying to obtain a copolymer of ethylene and methyl methacrylate. Example 2

[0041] 1. The main catalyst of the catalyst used for the copolymerization of ethylene and methyl methacrylate in the present embodiment is substantially the same as in embodiment 1, except that the molar ratio of Compound 1 to Compound 2 is 49:1 and the main catalyst obtained by compounding is referred to as Main Catalyst B.

[0042] 2. The process for producing the copolymer of ethylene and methyl methacrylate in the present embodiment is substantially the same as in embodiment 1, except that the main catalyst A is replaced by the main catalyst B. Example 3

[0043] 1. The main catalyst of the catalyst used for the copolymerization of ethylene and methyl methacrylate in the present embodiment is substantially the same as in embodiment 1, except that the molar ratio of Compound 1 to Compound 2 is 1:1 and the main catalyst obtained by compounding is referred to as Main Catalyst C.

[0044] 2. The process for producing the copolymer of ethylene and methyl methacrylate in the present embodiment is substantially the same as in embodiment 1, except that the main catalyst A is replaced by the main catalyst C. Example 4

[0045] 1. The main catalyst of the catalyst used for the copolymerization of ethylene and methyl methacrylate in the present embodiment is substantially the same as in embodiment 1, except that the molar ratio of Compound 1 to Compound 2 is 3:1 and the main catalyst obtained by compounding is referred to as Main Catalyst D.

[0046] 2. The process for producing the copolymer of ethylene and methyl methacrylate in the present embodiment is substantially the same as in embodiment 1, except that the main catalyst A is replaced by the main catalyst D. Example 5

[0047] 1. The main catalyst of the catalyst used for the copolymerization of ethylene and methyl methacrylate in the present embodiment is the same as that used in embodiment 3.

[0048] 2. The method for preparing the copolymer of ethylene and methyl methacrylate in the present embodiment is substantially the same as in embodiment 3, except that 13 ml of MAO (1.53 mol / l) is added and the molar ratio of Al / Ni is 500:1. Example 6

[0049] 1. The main catalyst of the catalyst used for the copolymerization of ethylene and methyl methacrylate in the present embodiment is substantially the same as in embodiment 1, except that the molar ratio of Compound 1 to Compound 2 is 10:1 and the main catalyst obtained by compounding is referred to as Main Catalyst E.

[0050] 2. The process for producing the copolymer of ethylene and methyl methacrylate in the present embodiment is substantially the same as in embodiment 1, except that the main catalyst A is replaced by the main catalyst E. Example 7

[0051] 1. The main catalyst of the catalyst used for the copolymerization of ethylene and methyl methacrylate in the present embodiment is the same as in embodiment 1, except that the molar ratio of Compound 1 to Compound 2 is 1:10 and the main catalyst obtained by compounding is referred to as Main Catalyst F.

[0052] 2. The process for producing the copolymer of ethylene and methyl methacrylate in the present embodiment is substantially the same as in embodiment 3, except that MAO is replaced by aluminum sesquiethyl. Example 8

[0053] 1. The main catalyst of the catalyst used for the copolymerization of ethylene and methyl methacrylate in the present embodiment is the same as that in embodiment 7.

[0054] 2. The method for producing the copolymer of ethylene and methyl methacrylate of the present embodiment is substantially the same as that of Embodiment 7, except that toluene is replaced with dichloromethane and the reaction pressure for copolymerization is changed from 4 MPa to 5 MPa. Example 9

[0055] 1. The main catalyst of the catalyst used for the copolymerization of ethylene and methyl methacrylate in the present embodiment is the same as that in embodiment 8.

[0056] 2. The method for producing the copolymer of ethylene and methyl methacrylate in the present embodiment is substantially the same as in embodiment 8, except that dichloromethane is replaced with dichloroethane and the reaction time for copolymerization is changed from 1 h to 2 h. Example 10

[0057] 1. The main catalyst of the catalyst used for the copolymerization of ethylene and methyl methacrylate in the present embodiment is the same as that in embodiment 9.

[0058] 2. The method for producing the copolymer of ethylene and methyl methacrylate in the present embodiment is substantially the same as in embodiment 8, except that n-hexane is replaced by a mixed solution of dichloroethane and toluene, wherein a volume ratio of n-hexane to toluene in the mixed solution is 1:1. Example 11

[0059] 1. The main catalyst of the catalyst used for the copolymerization of ethylene and methyl methacrylate in the present embodiment is obtained by mixing Compound 3 and Compound 4 in a molar ratio of 49:1, and the main catalyst obtained by such compounding is referred to as Main Catalyst G.

[0060] 2. The process for producing the copolymer of ethylene and methyl methacrylate in the present embodiment includes the following steps: 1) In a clean and dry 150-mL autoclave, add 50 mL of toluene and 40 μmol of the main catalyst G under an ethylene atmosphere; then, feed ethylene until the pressure reaches 0.05 MPa, and place the reaction autoclave in an oil bath at 40°C and perform electromagnetic stirring; add 50 mmol of methyl methacrylate and 7.85 mL of MAO (concentration: 1.53 mol / L) with stirring, with the molar ratio Al / Ni = 300:1; continue feeding ethylene until the pressure reaches 3 MPa, and conduct the reaction for 1 h, then stop the feed of ethylene. 2) Depressurization; using a hydrochloric acid-ethanol solution with a volume concentration of 5% for processing; then washing, filtering, and drying to obtain 284 g of the copolymer of ethylene and methyl methacrylate. Example 12

[0061] 1. The main catalyst of the catalyst used for the copolymerization of ethylene and methyl methacrylate in the present embodiment is substantially the same as in embodiment 11, except that the molar ratio of Compound 3 to Compound 4 is 1:49 and the main catalyst obtained by compounding is referred to as Main Catalyst H.

[0062] 2. The process for producing the copolymer of ethylene and methyl methacrylate in the present embodiment is substantially the same as in embodiment 11, except that the main catalyst G is replaced by the main catalyst H. Example 13

[0063] 1. The main catalyst of the catalyst used for the copolymerization of ethylene and methyl methacrylate in the present embodiment is substantially the same as in embodiment 11, except that the molar ratio of Compound 3 to Compound 4 is 1:1 and the main catalyst obtained by compounding is referred to as Main Catalyst I.

[0064] 2. The process for producing the copolymer of ethylene and methyl methacrylate in the present embodiment is substantially the same as in embodiment 12, except that the main catalyst G is replaced by the main catalyst I. Example 14

[0065] 1. The main catalyst of the catalyst used for the copolymerization of ethylene and methyl methacrylate in the present embodiment is substantially the same as in embodiment 11, except that the molar ratio of Compound 3 to Compound 4 is 30:1 and the main catalyst obtained by compounding is referred to as Main Catalyst J.

[0066] 2. The process for producing the copolymer of ethylene and methyl methacrylate in the present embodiment is substantially the same as in embodiment 12, except that the main catalyst G is replaced by the main catalyst J. Example 15

[0067] 1. The main catalyst used in the present embodiment as a catalyst for the copolymerization of ethylene and methyl methacrylate in the present embodiment is substantially the same as in Embodiment 12, except that the molar ratio of Compound 3 to Compound 4 is 10:1 and the main catalyst obtained by compounding is referred to as Main Catalyst K.

[0068] 2. The process for producing the copolymer of ethylene and methyl methacrylate in the present embodiment is substantially the same as in embodiment 12, except that the main catalyst G is replaced by the main catalyst K, MAO is replaced by aluminum sesquiethyl, the reaction pressure for the copolymerization is 2 MPa, and the reaction time for the copolymerization is 2 h. Example 16

[0069] 1. The main catalyst of the catalyst used for the copolymerization of ethylene and methyl methacrylate in the present embodiment is substantially the same as in embodiment 11, except that the molar ratio of Compound 3 to Compound 4 is 1:10 and the main catalyst obtained by compounding is referred to as Main Catalyst L.

[0070] 2. The preparation method of the copolymer of ethylene and methyl methacrylate in the present embodiment is essentially the same as in Embodiment 13, except that 7.5 ml of MAO (concentration: 1.53 mol / L) and an Al / Ni molar ratio of 300:1 are replaced by 13 ml of aluminum sesquiethyl (1.53 mol / L) and an Al / Ni molar ratio of 500:1, the reaction pressure for the copolymerization is 2 MPa, and the reaction time for the copolymerization is 2 h. Example 17

[0071] 1. The main catalyst of the catalyst used for the copolymerization of ethylene and methyl methacrylate in the present embodiment is substantially the same as in embodiment 16, except that the molar ratio of Compound 3 to Compound 4 is 2:1 and the main catalyst obtained by compounding is referred to as Main Catalyst M.

[0072] 2. The method for producing the copolymer of ethylene and methyl methacrylate in the present embodiment is substantially the same as in embodiment 16, except that toluene is replaced by n-hexane, the copolymerization temperature is 60 °C, and the copolymerization pressure is 3 MPa. Example 18

[0073] 1. The main catalyst of the catalyst used for the copolymerization of ethylene and methyl methacrylate in the present embodiment is the same as that in embodiment 13.

[0074] 2. The method for producing the copolymer of ethylene and methyl methacrylate in this embodiment is substantially the same as in embodiment 13, except that toluene is replaced with a mixed solution of n-hexane and dichloroethane, a volume ratio of n-hexane to dichloroethane being 1:1, MAO is replaced with aluminum sesquiethyl, and the reaction pressure for copolymerization is 5 MPa. Example 19

[0075] 1. The main catalyst of the catalyst used for the copolymerization of ethylene and methyl methacrylate in the present embodiment is the same as that in embodiment 13.

[0076] 2. The method for producing the copolymer of ethylene and methyl methacrylate in this embodiment is substantially the same as in embodiment 13, except that toluene is replaced with a mixed solution of n-hexane and dichloroethane, wherein a volume ratio of n-hexane to dichloroethane is 1:2, MAO is replaced with aluminum sesquiethyl, the reaction pressure for copolymerization is 10 MPa, and the copolymerization temperature is 60 °C. Example 20

[0077] 1. The main catalyst of the catalyst used for the copolymerization of ethylene and methyl methacrylate in the present embodiment is the same as that in embodiment 13.

[0078] 2. The method for producing the copolymer of ethylene and methyl methacrylate in this embodiment is substantially the same as in embodiment 13, except that toluene is replaced with dichloromethane, MAO is replaced with aluminum sesquiethyl, the reaction pressure for copolymerization is 5 MPa, and the copolymerization temperature is 80 °C. Example 21

[0079] 1. The main catalyst of the catalyst used for the copolymerization of ethylene and methyl methacrylate in the present embodiment is obtained by mixing Compound 5 and Compound 6 in a molar ratio of 49:1, and the main catalyst obtained by such compounding is referred to as Main Catalyst N.

[0080] 2. The process for producing the copolymer of ethylene and methyl methacrylate in the present embodiment includes the following steps: 1) In a clean and dry 150-mL autoclave, add 50 mL of toluene and 40 μmol of the main catalyst N under an ethylene atmosphere; then feed ethylene until the pressure reaches 0.05 MPa, and place the reaction autoclave in an oil bath at 60 °C and perform electromagnetic stirring; add 50 mmol of methyl methacrylate and 7.5 mL of aluminum sesquiethyl (1.53 mol / L) with stirring, where the Al / Ni molar ratio is 300:1; continue feeding ethylene until the pressure reaches 5 MPa, and carry out the reaction for 2 h, then stop feeding ethylene. 2) Depressurization; using a hydrochloric acid-ethanol solution with a volume concentration of 5% for processing; then washing, filtering, and drying to obtain the copolymer of ethylene and methyl methacrylate. Example 22

[0081] 1. The main catalyst of the catalyst used for the copolymerization of ethylene and methyl methacrylate in the present embodiment is substantially the same as in embodiment 21, except that the molar ratio of Compound 5 to Compound 6 is 1:49 and the main catalyst obtained by compounding is referred to as Main Catalyst O.

[0082] 2. The process for producing the copolymer of ethylene and methyl methacrylate in the present embodiment is substantially the same as in embodiment 21, except that the main catalyst N is replaced by the main catalyst O. Example 23

[0083] 1. The main catalyst of the catalyst used for the copolymerization of ethylene and methyl methacrylate in the present embodiment is substantially the same as in embodiment 21, except that the molar ratio of Compound 5 to Compound 6 is 1:1 and the main catalyst obtained by compounding is referred to as Main Catalyst P.

[0084] 2. The process for producing the copolymer of ethylene and methyl methacrylate in the present embodiment is substantially the same as in embodiment 21, except that the main catalyst N is replaced by the main catalyst P. Example 24

[0085] 1. The main catalyst of the catalyst used for the copolymerization of ethylene and methyl methacrylate in the present embodiment is substantially the same as in embodiment 21, except that the molar ratio of Compound 5 to Compound 6 is 10:1 and the main catalyst obtained by compounding is referred to as Main Catalyst Q.

[0086] 2. The process for producing the copolymer of ethylene and methyl methacrylate in the present embodiment is substantially the same as in embodiment 21, except that the main catalyst N is replaced by the main catalyst Q. Example 25

[0087] 1. The main catalyst of the catalyst used for the copolymerization of ethylene and methyl methacrylate in the present embodiment is substantially the same as in embodiment 21, except that the molar ratio of Compound 5 to Compound 6 is 1:10 and the main catalyst obtained by compounding is referred to as Main Catalyst R.

[0088] 2. The process for producing the copolymer of ethylene and methyl methacrylate in the present embodiment is substantially the same as in embodiment 21, except that the main catalyst N is replaced by the main catalyst R. Example 26

[0089] 1. The main catalyst of the catalyst used for the copolymerization of ethylene and methyl methacrylate in the present embodiment is substantially the same as in embodiment 21, except that the molar ratio of Compound 5 to Compound 6 is 1:5 and the main catalyst obtained by compounding is referred to as Main Catalyst S.

[0090] 2. The method for producing the copolymer of ethylene and methyl methacrylate in the present embodiment is substantially the same as in embodiment 21, except that the main catalyst N is replaced by the main catalyst S, the aluminum sesquiethyl is replaced by MAO, the reaction temperature of the copolymerization is 40 °C, and the amount of methyl methacrylate added is 60 mmol. Example 27

[0091] 1. The main catalyst of the catalyst used for the copolymerization of ethylene and methyl methacrylate in the present embodiment is the same as that in embodiment 26.

[0092] 2. The method for preparing the copolymer of ethylene and methyl methacrylate in this embodiment is essentially the same as in embodiment 26, except that toluene is replaced with dichloroethane, the amount of MAO added is 13 ml (1.53 M), and the Al / Ni molar ratio is 500:1. Example 28

[0093] 1. The main catalyst of the catalyst used for the copolymerization of ethylene and methyl methacrylate in the present embodiment is substantially the same as in embodiment 27, except that the molar ratio of Compound 5 to Compound 6 is 2:1 and the main catalyst obtained by compounding is referred to as Main Catalyst T.

[0094] 2. The method for producing the copolymer of ethylene and methyl methacrylate in the present embodiment is substantially the same as in embodiment 21, except that the main catalyst N is replaced by the main catalyst T, dichloroethane is replaced by toluene, the reaction pressure for the copolymerization is 3 MPa, and the reaction temperature for the copolymerization is 80 °C. Example 29

[0095] 1. The main catalyst of the catalyst used for the copolymerization of ethylene and methyl methacrylate in the present embodiment is the same as that in embodiment 28.

[0096] 2. The preparation method of the copolymer of ethylene and methyl methacrylate in the present embodiment is substantially the same as in Embodiment 28, except that toluene is replaced with a mixed solution of dichloromethane and n-hexane, wherein a volume ratio of dichloromethane to n-hexane is 1:3, and the reaction time of copolymerization is 4 h. Example 30

[0097] 1. The main catalyst of the catalyst used for the copolymerization of ethylene and methyl methacrylate in the present embodiment is the same as that in embodiment 23.

[0098] 2. The preparation method of the copolymer of ethylene and methyl methacrylate in the present embodiment is substantially the same as in Embodiment 23, the difference being that toluene is replaced with dichloroethane, 7.5 ml (1.53 mol / L) of aluminum sesquiethyl and an Al / Ni molar ratio of 300:1 is replaced with 13 ml of MAO (1.53 mol / L) and an Al / Ni molar ratio of 500:1, the reaction time of the copolymerization is 6 h, and the amount of methacrylic acid added is 30 mmol. Example 31

[0099] 1. The main catalyst of the catalyst used for the copolymerization of ethylene and methyl methacrylate in the present embodiment is obtained by compounding Compound 7 and Compound 8 in a molar ratio of 1:49, and the main catalyst obtained by such mixing is referred to as Main Catalyst U.

[0100] 2. The method for producing the copolymer of ethylene and methyl methacrylate of the present embodiment includes the following steps: In a clean and dry 150-ml autoclave, adding 50 ml of toluene and 40 μmol of the main catalyst U under an ethylene atmosphere; then feeding ethylene until the pressure is 0.05 MPa, and placing the reaction autoclave in an oil bath at 60°C (copolymerization temperature) and performing electromagnetic stirring; and adding 50 mmol of methyl methacrylate and 13 ml of MAO (concentration of 1.53 mol / L) with stirring, wherein the Al / Ni molar ratio is 500:1; continuing to feed ethylene until the pressure reaches 4 MPa (copolymerization pressure) and conducting the reaction for 1 h, then stopping the feed of ethylene; depressurizing; Using a hydrochloric acid-ethanol solution with a volume concentration of 5% for processing;then washing, filtering and drying to obtain the copolymer of ethylene and methyl methacrylate.; Example 32

[0101] 1. The main catalyst of the catalyst used for the copolymerization of ethylene and methyl methacrylate in the present embodiment is obtained by compounding Compound 9 and Compound 10 in a molar ratio of 49:1, and the main catalyst obtained by such compounding is referred to as Main Catalyst V.

[0102] 2. The method for producing the ethylene-methyl methacrylate copolymer of the present embodiment includes the following steps: In a clean and dry 150-ml autoclave, adding 50 ml of toluene and 40 μmol of the main catalyst V under an ethylene atmosphere; then feeding ethylene until the pressure is 0.05 MPa, and placing the reaction autoclave in an oil bath at 40°C and performing electromagnetic stirring; adding 50 mmol of methyl methacrylate and 7.85 ml of MAO (concentration of 1.53 mol / L) with stirring, wherein the Al / Ni molar ratio is 300:1; continuing to feed ethylene until the pressure reaches 3 MPa and conducting the reaction for 1 h, then stopping the feed of ethylene thereafter; depressurizing; Using a hydrochloric acid-ethanol solution with a volume concentration of 5% for processing; then washing, filtering, and drying to obtain 284 g of the copolymer of ethylene and methyl methacrylate. Example 33

[0103] 1. The main catalyst of the catalyst used for the copolymerization of ethylene and methyl methacrylate in the present embodiment is obtained by compounding Compound 11 and Compound 12 in a molar ratio of 49:1, and the main catalyst obtained by such compounding is referred to as Main Catalyst W.

[0104] 2. The method for producing the ethylene-methyl methacrylate copolymer of the present embodiment includes the following steps: In a clean and dry 150-ml autoclave, adding 50 ml of toluene and 40 μmol of the main catalyst W under an ethylene atmosphere; then feeding ethylene until the pressure is 0.05 MPa, and placing the reaction autoclave in an oil bath at 60°C and performing electromagnetic stirring; adding 50 mmol of methyl methacrylate and 7.85 ml of aluminum sesquiethyl (1.53 mol / L) with stirring, wherein the Al / Ni molar ratio is 300:1; continuing to feed ethylene until the pressure reaches 5 MPa and conducting the reaction for 2 h, then stopping the feed of ethylene; releasing the pressure; Using a hydrochloric acid-ethanol solution with a volume concentration of 5% for processing; then washing, filtering, and drying to obtain the copolymer of ethylene and methyl methacrylate. Example 34

[0105] 1. The main catalyst of the catalyst used in this embodiment for the copolymerization of ethylene and methyl methacrylate is the same as in embodiment 3.

[0106] 2. The method for producing the ethylene-methyl methacrylate copolymer of the present embodiment includes the following steps: In a clean and dry 150-ml autoclave, add 50 ml of toluene and 40 μmol of the main catalyst C under an ethylene atmosphere; then supply ethylene until the pressure is 0.05 MPa, and place the reaction autoclave in an oil bath at 60°C and perform electromagnetic stirring; add 50 mmol of methyl methacrylate and 19.63 ml of MAO (1.53 mol / L) with stirring, where the Al / Ni molar ratio is 750:1; continue supplying ethylene until the pressure reaches 4 MPa and conduct the reaction for 1 h, then stop supplying ethylene; release the pressure; use a hydrochloric acid-ethanol solution with a volume concentration of 5% for processing; then washing, filtering and drying to obtain the copolymer of ethylene and methyl methacrylate. Example 35

[0107] 1. The main catalyst of the catalyst used in this embodiment for the copolymerization of ethylene and methyl methacrylate is the same as in embodiment 3.

[0108] 2. The method for producing the ethylene-methyl methacrylate copolymer of the present embodiment includes the following steps: In a clean and dry 150-ml autoclave, adding 50 ml of toluene and 40 μmol of the main catalyst C under an ethylene atmosphere; then feeding ethylene until the pressure is 0.05 MPa, and placing the reaction autoclave in an oil bath at 60°C and performing electromagnetic stirring; adding 50 mmol of methyl methacrylate and 52.33 ml of sesquiethylaluminum (1.53 mol / L) with stirring, wherein the Al / Ni molar ratio is 2000:1; continuing to feed ethylene until the pressure reaches 4 MPa and conducting the reaction for 1 h, then stopping the feed of ethylene; releasing the pressure; Using a hydrochloric acid-ethanol solution with a volume concentration of 5% for processing; then washing, filtering, and drying to obtain the copolymer of ethylene and methyl methacrylate. Comparison example 1

[0109] 1. The main catalyst of the catalyst used in the present Comparative Example for the copolymerization of ethylene and methyl methacrylate is Compound 5, which is referred to as Main Catalyst X1.

[0110] 2. The process for producing the copolymer of ethylene and methyl methacrylate in the present embodiment includes the following steps: 1) In a clean and dry 150 mL autoclave, add 50 mL of toluene and 140 μmol of catalyst X1 under an ethylene atmosphere; then, feed ethylene until the pressure reaches 0.05 MPa, and place the reaction autoclave in an oil bath at 60 °C and perform electromagnetic stirring; add 30 mmol of methyl methacrylate and 7.5 mL of MAO (1.53 mol / L) with stirring, with the Al / Ni molar ratio being 300:1; continue feeding ethylene until the pressure reaches 5 MPa, and carry out the reaction for 1 h, then stop feeding ethylene. 2) Depressurization; using a hydrochloric acid-ethanol solution with a volume concentration of 5% for processing; then washing, filtering, and drying to obtain the copolymer of ethylene and methyl methacrylate. Comparison example 2

[0111] 1. The main catalyst used in the present comparative example for the copolymerization of ethylene and methyl methacrylate is compound 6, which is referred to as main catalyst X2.

[0112] 2. The process for producing the copolymer of ethylene and methyl methacrylate in the present embodiment includes the following steps: 1) In a clean and dry 150 mL autoclave, add 50 mL of toluene and 240 μmol of catalyst X2 under an ethylene atmosphere; then feed ethylene until the pressure reaches 0.05 MPa, and place the reaction autoclave in an oil bath at 60 °C and perform electromagnetic stirring; add 30 mmol of methyl methacrylate and 7.5 mL of MAO (1.53 mol / L) with stirring, where the Al / Ni molar ratio is 300:1; continue feeding ethylene until the pressure reaches 5 MPa, and carry out the reaction for 1 h, then stop feeding ethylene. 2) Depressurization; using a hydrochloric acid-ethanol solution with a volume concentration of 5% for processing; then washing, filtering, and drying to obtain the copolymer of ethylene and methyl methacrylate. Comparison example 3

[0113] 1. The main catalyst used in the present embodiment for the copolymerization of ethylene and methyl methacrylate is compound 13, which is referred to as main catalyst X3.

[0114] 2. The process for producing the copolymer of ethylene and methyl methacrylate in the present embodiment includes the following steps: 1) In a clean and dry 150 mL autoclave, add 50 mL of toluene and 40 μmol of the main catalyst X3 under an ethylene atmosphere; then feed ethylene until the pressure reaches 0.05 MPa, and place the reaction autoclave in an oil bath at 60 °C and perform electromagnetic stirring; add 50 mmol of methyl methacrylate and 7.85 mL of MAO (1.53 mol / L) with stirring, where the Al / Ni molar ratio is 300:1; continue feeding ethylene until the pressure reaches 5 MPa, and carry out the reaction for 1 h, then stop feeding ethylene. 2) Depressurization; using a hydrochloric acid-ethanol solution with a volume concentration of 5% for processing; then washing, filtering, and drying to obtain the copolymer of ethylene and methyl methacrylate. Comparison example 4

[0115] 1. The main catalyst of the catalyst used in the present embodiment for the copolymerization of ethylene and methyl methacrylate is compound 15, which is referred to as main catalyst X4.

[0116] 2. The process for producing the copolymer of ethylene and methyl methacrylate in the present embodiment includes the following steps: 1) In a clean and dry 150 mL autoclave, add 50 mL of toluene and 40 μmol of the main catalyst Y4 under an ethylene atmosphere; then feed ethylene until the pressure is 0.05 MPa, and place the reaction autoclave in an oil bath at 60°C and perform electromagnetic stirring; add 50 mmol of methyl methacrylate and 7.85 mL of MAO (1.53 mol / L) with stirring, where the Al / Ni molar ratio is 300:1; continue feeding ethylene until the pressure reaches 5 MPa, and carry out the reaction for 1 h, then stop feeding ethylene. 2) Depressurization; using a hydrochloric acid-ethanol solution with a volume concentration of 5% for processing; then washing, filtering, and drying to obtain the copolymer of ethylene and methyl methacrylate. Comparison example 5

[0117] 1. The main catalyst of the catalyst used in the present embodiment for the copolymerization of ethylene and methyl methacrylate is compound 15, which is referred to as main catalyst X5.

[0118] 2. The process for producing the copolymer of ethylene and methyl methacrylate in the present embodiment includes the following steps: 1) In a clean and dry 150 mL autoclave, add 50 mL of toluene and 40 μmol of the main catalyst X5 under an ethylene atmosphere; then feed ethylene until the pressure reaches 0.05 MPa, and place the reaction autoclave in an oil bath at 45°C and perform electromagnetic stirring; add 47 mmol of methyl methacrylate and 3.9 mL of MAO (1.53 mol / L) with stirring, where the Al / Ni molar ratio is 150:1; continue feeding ethylene until the pressure reaches 3 MPa, and carry out the reaction for 2 h, then stop feeding ethylene. 2) Depressurization; using a hydrochloric acid-ethanol solution with a volume concentration of 5% for processing; then washing, filtering, and drying to obtain the copolymer of ethylene and methyl methacrylate.

[0119] To simplify the comparison, the reaction conditions for the copolymerization of the above working examples and the comparative examples are listed in Table 1. Test examples

[0120] The calculation of the catalytic activity is carried out for the catalysts used for the copolymerization of ethylene and methyl methacrylate in Working Examples 1-35 and Comparative Examples 1-5, the calculation formula being: Catalytic activity = copolymer mass (g) / (amount of added main catalyst (mol) × reaction time (h)).

[0121] The copolymers of ethylene and methyl methacrylate of Working Examples 1-35 and Comparative Examples 1-5 are tested for the following parameters.

[0122] Method for determining molecular weight: Gel permeation chromatography (GPC, 2414) manufactured by American Waters Company is used for the determination, in which a polystyrene standard sample is used for a calibration curve, a mobile phase is tetrahydrofuran, a column temperature is 40 °C, the sample concentration is 1 mg / ml, an injection volume is 50 µl, the elution time is 40 min, and the flow rate is 1 ml min. -1 amounts.

[0123] Method for measuring and calculating the methyl methacrylate insertion rate: Analyzing the 13 C NMR of the copolymer using an American Bruker 400MHz nuclear magnetic resonance apparatus; corresponding to a peak area of ​​-CH2 (chemical shift 1.27) and a peak area of ​​-OCH3 (chemical shift 3.56) in the 13C NMR spectrum, calculating a molar incorporation rate of methyl methacrylate in the copolymer of ethylene and methyl methacrylate according to the following two formulas: 3NMA=4NEB E=11+NM / NE

[0124] In the two formulas above, N M a number of moles of methyl methacrylate in the copolymer, N E is a mole number of ethylene in the copolymer, A is a peak area of ​​-OCH3 (chemical shift 3.56) in methyl methacrylate, and B is a peak area of ​​-CH2 (chemical shift 1.27), and E is the mole incorporation rate of methyl methacrylate in the copolymer.

[0125] The test results for the above parameters are shown in Table 2. Table 1 Main catalyst Methyl methacrylate amount / m mol Cocatalyst solvent Molar ratio Al / M Copolymerization pressure IMPa Copolymerization temperature / °C (I) (II) Molar ratio of (I) to (II) Example 1 1 2 1:49 50 MAO toluene 300:1 4 60 Example 2 1 2 49:1 50 MAO toluene 300:1 4 60 Example 3 1 2 1:1 50 MAO toluene 300:1 4 60 Example 4 1 2 3:1 50 MAO toluene 300:1 4 60 Example 5 1 2 1:1 50 MAO toluene 500:1 4 60 Example 6 1 2 10:1 50 MAO toluene 300:1 4 60 Example 7 1 2 1:10 50 Aluminum sesquiethyl toluene 300:1 4 60 Example 8 1 2 1:1 50 Aluminum sesquiethyl Dichloromethane 300:1 5 60 Example 9 1 2 1:1 50 Aluminum sesquiethyl Dichloroethane 300:1 5 60 Example 10 1 2 1:1 50 Aluminum sesquiethyl Dichloroethane and toluene (volume ratio: 1:1) 300:1 5 60 Example 11 3 4 49:1 50 MAO toluene 300:1 3 40 Example 12 3 4 1:49 50 MAO toluene 300:1 3 40 Example 13 3 4 1:1 50 MAO toluene 300:1 3 40 Example 14 3 4 30:1 50 MAO toluene 300:1 3 40 Example 15 3 4 10:1 50 Aluminum sesquiethyl toluene 300:1 2 40 Example 16 3 4 1:10 50 Aluminum sesquiethyl toluene 500:1 2 40 Example 17 3 4 2:1 50 Aluminum sesquiethyl n-hexane 500:1 3 60 Example 18 3 4 1:1 50 Aluminum sesquiethyl n-Hexane and dichloroethane (volume ratio 1:1) 300:1 5 40 Example 19 3 4 1:1 60 Aluminum sesquiethyl n-Hexane and dichloroethane (volume ratio 1:2) 300:1 10 60 Example 20 3 4 1:1 30 Aluminum sesquiethyl Dichloromethane 300:1 5 80 Example 21 5 6 49:1 50 Aluminum sesquiethyl toluene 300:1 5 60 Example 22 5 6 1:49 50 Aluminum sesquiethyl toluene 300:1 5 60 Example 23 5 6 1:1 50 Aluminum sesquiethyl toluene 300:1 5 60 Example 24 5 6 10:1 50 Aluminum sesquiethyl toluene 300:1 5 60 Example 25 5 6 1:10 50 Aluminum sesquiethyl toluene 300:1 5 60 Example 26 5 6 1:5 60 MAO toluene 300:1 5 40 Example 27 5 6 1:5 60 MAO Dichloroethane 500:1 5 40 Example 28 5 6 2:1 60 MAO toluene 500:1 3 80 Example 29 5 6 2:1 60 MAO Dichloromethane and n-hexane (volume ratio 1:3) 500:1 3 80 Example 30 5 6 1:1 30 MAO Dichloroethane 500:1 5 60 Example 31 7 8 1:1 50 MAO toluene 500:1 4 60 Example 32 9 10 49:1 50 MAO toluene 300:1 3 40 Example 33 11 12 49:1 50 Aluminum sesquiethyl toluene 300:1 5 60 Example 34 1 2 1:1 50 MAO toluene 750:1 4 60 Example 35 1 2 1:1 50 MAO toluene 2000:1 4 60 Comparison example 1 5 - - 30 MAO toluene 300:1 5 60 Comparison example 2 - 6 - 30 MAO toluene 300:1 5 60 Comparison example 3 13 - - 50 MAO toluene 300:1 5 60 Comparison example 4 - 14 - 50 MAO toluene 300:1 5 60 Comparison example 5 - 15 - 47 MAO toluene 150:1 3 45

[0126] Note: M stands for the metal element in the main catalyst. Table 2 Copolymer mass / g Catalytic activity / (g polymer / mol Mh) Weight average molecular weight of the copolymer / (g / mol) Methyl methacrylate incorporation rate / mol% Example 1 8,4 2,1×10 5 1,05×10 5 15,8 Example 2 20,4 5.8×10 5 2,85×10 5 3,9 Example 3 19,2 4.8×10 5 1,93×10 5 11,6 Example 4 20 5.0×10 5 2,43×10 5 15,5 Example 5 72 1,8×10 6 2,07×10 5 10,2 Example 6 21,2 5,3×10 5 2,2×10 5 0,5 Example 7 4,8 1,2×10 5 1,55×10 5 6,2 Example 8 12,8 3,2×10 5 1,61×10 5 16,2 Example 9 42,4 5,3×10 5 2,84×10 5 9 Example 10 22,4 2,8×10 5 3,1×10 5 9,1 Example 11 284 7,1×10 6 6,41×10 5 3,2 Example 12 30 3,5×10 5 3,27×10 5 17,6 Example 13 30 7,5×10 5 5,11×10 5 15,5 Example 14 26 6,5×10 5 5,59×10 5 5,6 Example 15 68 8,5×10 5 6,93×10 5 4,7 Example 16 296 3,7×10 6 4,56×10 5 17,2 Example 17 48,8 6,1×10 5 4,26×10 5 14,5 Example 18 6,8 1,7×10 5 4,56×10 5 10,2 Example 19 14,8 3,7×10 5 4,87×10 5 12,4 Example 20 5,2 1,3×10 5 4,49×10 5 10,7 Example 21 92 1,1×10 6 2,18×10 5 3,7 Example 22 8 1,0×10 5 1,05×10 5 13,7 Example 23 26,4 3,3×10 5 1,28×10 5 13,5 Example 24 92 1,1×10 6 1,99×10 5 2,4 Example 25 71,2 8,9×10 5 1,99×10 5 12,4 Example 26 9,2 1,15×10 5 1,18×10 5 10,1 Example 27 8,8 1,1×10 5 1,05×10 5 12,1 Example 28 58,4 7,3×10 5 1,16×10 5 6,7 Example 29 116,8 2,3×10 5 1,26×10 5 5,7 Example 30 136,8 5,7×10 5 1,02×10 5 11,6 Example 31 368 9,2×10 6 3,15×10 5 11,7 Example 32 324 8,1×10 6 2,41×10 5 2,7 Example 33 376 4,7×10 6 2,02×10 5 4,1 Example 34 17,2 4,3×10 5 1,59×10 5 10,2 Example 35 16,4 4,1×10 5 1,03×10 5 9,6 Comparison example 1 250 6,25×10 6 5,1×10 4 1,6 Comparison example 2 4 1×10 5 1,0×10 4 15,8 Comparison example 3 0,48 1,2×10 4 1,02×10 4 3,1 Comparison example 4 0,21 5,1×10 3 7,0×10 3 52 Comparison example 5 - 3,34×10 4 6.41×10 4 (Numerical mean) 70,1

[0127] From the data in Table 2, it can be seen that when the catalyst of the present application is used for the copolymerization of ethylene and methyl methacrylate, a copolymer of ethylene and methyl methacrylate with a higher molecular weight can be obtained.

[0128] The above embodiments are only illustrative of the technical solutions of the present application and are not intended to limit them. Although the present application has been described in detail with reference to the above embodiments, it will be apparent to those skilled in the art that: the technical solutions described in the above embodiments may still be modified, or some or all of their technical features may be substituted; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] CH 202111675304.4

[0001]

Claims

[1] A catalyst for the copolymerization of ethylene and methyl methacrylate, the catalyst comprising a main catalyst, and the main catalyst is obtained by compounding a compound of formula (I) and a compound of formula (II); a structure of formula (I) is: wherein R1 and R2 are each independently selected from substituted aryl, wherein one 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-C4 alkyl; M is selected from Ni or Pd; X1 and X2 are each independently selected from halogen, C1-C4 alkyl, aryl, C2-C4 ether and C1-C4 nitrile; a structure of formula (II) is: wherein R5 and R6 are each independently selected from hydrogen, methyl, ethyl, dimethylamino, diethylamino, amino, hydroxyl and C1-C4 alkoxy; R7 and R8 are each independently selected from at least one of hydrogen, C1-C4 alkyl, C1-C4 dialkylamino, amino, hydroxyl and C1-C4 alkoxy; a molar ratio of the compound of formula (I) to the compound of formula (II) is from (1:49) to (49:1). [2] A catalyst according to claim 1, wherein the molar ratio of the compound of formula (I) to the compound of formula (II) is (1:10) to (10:1). [3] A catalyst according to claim 1 or 2, wherein the catalyst further comprises a cocatalyst selected from aluminoxane. [4] The catalyst according to claim 3, wherein the cocatalyst is selected from at least one of methylaluminoxane, trialkylaluminum and alkylaluminum halide. [5] The catalyst according to claim 3 or 4, wherein a molar ratio between the metal element in the main catalyst to the aluminum element in the co-catalyst is 1: (50-1000). [6] A catalyst according to claim 5, wherein the molar ratio between the metal element in the main catalyst and the aluminum element in the cocatalyst is 1: (100-500). [7] A process for the copolymerization of ethylene and methyl methacrylate, which process uses the catalyst according to any one of claims 1 to 6. [8] The copolymerization process according to claim 7, wherein the copolymerization process comprises: conducting a copolymerization reaction of ethylene and methyl methacrylate under catalysis of the catalyst; wherein a pressure of the copolymerization reaction is ≤ 10 MPa and a temperature of the copolymerization reaction is ≤ 100 °C. [9] The copolymerization process according to claim 8, wherein a solvent for the copolymerization reaction is selected from at least one of toluene, n-hexane, dichloromethane and dichloroethane. [10] A copolymer of ethylene and methyl methacrylate, wherein the copolymer is prepared by the copolymerization process according to any one of claims 7 to 9 and has a weight-average molecular weight of ≥1×10 5 g / mol.