Ethylene-acrylate copolymer and preparation method therefor

Abstract

The present application relates to an ethylene-acrylate copolymer, a preparation method therefor, and a catalyst system. The present invention belongs to the field of olefin polymerization and relates to an ethylene-acrylate copolymer and a preparation method therefor. The ethylene-acrylate copolymer comprises 85-99.2 mol% of structural units derived from ethylene and 0.8-15 mol% of structural units derived from acrylate. The ethylene-acrylate copolymer of the present invention exhibits shear thinning at low shear rates and shear thickening at high shear rates.

Description

Ethylene-acrylate copolymer and its preparation method Technical Field

[0001] This invention belongs to the field of olefin polymerization, specifically relating to an ethylene-acrylate copolymer, a method for preparing the ethylene-acrylate copolymer, and a catalyst system. Background Technology

[0002] Ethylene-acrylate copolymers possess excellent thermal stability, compatibility, filling capacity, adhesion, good tensile properties, and outstanding low-temperature resistance, making them widely used in food packaging, polymer modification, automotive, electronics, aerospace, and aviation fields. Industrially, high-pressure free radical polymerization can be used to prepare ethylene-acrylate copolymers, but this polymerization method involves harsh reaction conditions, high equipment investment, high energy consumption, and the resulting polymer's molecular chain structure is uncontrollable. Research has shown that coordination polymerization can also achieve copolymerization of ethylene and polar acrylate monomers, with mild polymerization conditions and controllable molecular chain structure. In 2002, Drent's research team successfully developed a palladium phosphonate catalyst, in which the strong electron donor phosphine group and the weak electron donor sulfonate group can significantly inhibit β-H elimination, thereby obtaining a linear copolymer with a high acrylate insertion rate (Chem Commun(Camb),2002(7):744-5). Mecking et al. investigated the effects of different sterically hindered substituents on phosphorus atoms on the microstructure of copolymers and analyzed the effects of substituents on the stereoselectivity of acrylate insertion in terms of spatial size and symmetry (Journal of the American Chemical Society, 2013, 135(3): 1026-1036).

[0003] As is well known, palladium phosphononsulfonate catalysts are insoluble in common polymerization solvents such as toluene, exhibiting good solubility only in chlorine-containing solvents such as dichloromethane. Therefore, existing technologies typically use dichloromethane as the catalyst solvent, which poses a challenge to the corrosion prevention of the equipment and increases investment and operating costs. If unsuitable solvents such as toluene are used as the catalyst feed medium, only a slurry feed method can be employed, thus affecting the catalyst particle size, dispersion state, and concentration gradient, which in turn impact the polymerization activity and the structure of the polymerization product. Therefore, how to solve the problem of homogeneous catalyst solution feeding is an unavoidable issue in the industrialization process.

[0004] Despite extensive research and reports on copolymers of ethylene and acrylates, further structural improvements are needed to yield copolymers with superior properties. Similarly, while numerous studies and reports have been conducted on the structures of palladium phosphononsulfonate catalysts, improvements to the catalyst systems and polymerization processes are still required. Summary of the Invention

[0005] One object of the present invention is to provide an ethylene-acrylate copolymer, as well as a method for preparing said copolymer and a catalyst system. The ethylene-acrylate copolymer exhibits shear-thickening properties.

[0006] A first aspect of the present invention provides an ethylene-acrylate copolymer comprising 85 to 99.2 mol% of ethylene-derived structural units and 0.8 to 15 mol% of acrylate-derived structural units, wherein the acrylate is an alkyl acrylate, and the alkyl group in the alkyl acrylate has x carbon atoms, where x is an integer from 1 to 8, wherein the number of short branches per thousand carbon atoms [SCB / 1000C] in the ethylene-acrylate copolymer, as measured by GPC, is greater than {1000a / (200+x×a)+10}, where a is the molar content of the acrylate-derived structural units in the copolymer.

[0007] In this invention, the acrylate may be at least one of methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, tert-butyl acrylate, n-pentyl acrylate, isopentyl acrylate, and 2-ethylhexyl acrylate.

[0008] In some embodiments of the present invention, the molecular weight distribution index (PDI) of the ethylene-acrylate copolymer is ≤2.5.

[0009] In some embodiments of the present invention, the ethylene-acrylate copolymer exhibits a linear relationship between LogIV and LogM in GPC testing, where IV is the intrinsic viscosity and M is the molecular weight; preferably, the coefficient of determination of the trend line between LogIV and LogM is greater than or equal to 0.94, more preferably greater than or equal to 0.95.

[0010] In some embodiments of this invention, the melt of the ethylene-acrylate copolymer is subjected to a low shear rate of 0.1 s at 190°C. -1 Up to high shear rate 100s -1 The process initially exhibits shear thinning followed by shear thickening (i.e., shear thinning at low shear rates and shear thickening at high shear rates). In some embodiments of this invention, the transition point between shear thinning and shear thickening is between 1 and 100 s. -1 Between 10-100 seconds is preferred. -1 Between. In some embodiments of the present invention, the ethylene-acrylate copolymer is subjected to a temperature of 190°C for 0.1 to 100 seconds. -1 The minimum viscosity at the shear rate is 0.1 s⁻¹. -1 The viscosity value is 3%-30% of the value, and in 100s -1The viscosity value is 3 to 250 times the minimum value.

[0011] In some embodiments of the present invention, the weight-average molecular weight of the ethylene-acrylate copolymer is 5,000 to 100,000 g / mol, preferably 8,000 to 50,000 g / mol.

[0012] In some embodiments of the present invention, the ratio R of the molar amount of acrylate inserted into the copolymer backbone to the total molar amount of acrylate in the ethylene-acrylate copolymer is 0.84-1.

[0013] A second aspect of the present invention provides a method for preparing the above-mentioned ethylene-acrylate copolymer, the method comprising:

[0014] The catalyst is mixed with an organoaluminum compound to form a homogeneous mixture; and the homogeneous mixture is added to a polymerization reactor to copolymerize acrylate and ethylene in the presence of an inert solvent to obtain the ethylene-acrylate copolymer.

[0015] The catalyst is at least one of the compounds shown in formula (I):

[0016] in,

[0017] R 11 Represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 30 carbon atoms optionally containing a heteroatom, or an aryl group having 6 to 30 carbon atoms optionally containing a heteroatom; preferably R 11 The heteroatom is a hydrogen atom, an alkyl group having 1 to 6 carbon atoms optionally containing a heteroatom, or an aryl group having 6 to 13 carbon atoms optionally containing a heteroatom; wherein the heteroatom is selected from halogens (e.g., fluorine, chlorine, and bromine), O, N, and S; more preferably R 11 Selected from hydrogen atom, methyl, ethyl, trifluoromethyl, acyl, acetoxy, phenyl, tolyl, xylyl, phenanthrene, and pentafluorophenyl; more preferably R 11 Selected from hydrogen atoms, methyl and phenyl;

[0018] L represents a ligand coordinated to Pd; preferably, the ligand is selected from pyridine, amine, piperidine, ether, sulfone, sulfoxide and phosphine ligands; more preferably, the ligand is selected from dimethyl sulfoxide, pyridine, tetramethylethylenediamine, triphenylphosphine and 2,6-dimethylpyridine, and even more preferably dimethyl sulfoxide;

[0019] R 12 and R 13 Each independently represents a hydrocarbon group having 1 to 30 carbon atoms, optionally containing a heteroatom, preferably R. 12 and R 13Each independently represents an aryl group having 3 to 30 carbon atoms, optionally containing a heteroatom, more preferably R 12 and R 13 Each independently represents an aryl group having 6 to 30 carbon atoms, optionally containing a heteroatom selected from O, N, and S; more preferably, R 12 and R 13 Each of the following is independently phenyl, 2-methylphenyl, 2,6-dimethylphenyl, 2-ethylphenyl, 2,6-diethylphenyl, 2-isopropylphenyl, 2,6-di(isopropyl)phenyl, 2-cyclohexylphenyl, 2,6-di(cyclohexyl)phenyl, 2-methoxyphenyl, 2,6-dimethoxyphenyl, 2-phenoxyphenyl, and 2,6-diphenoxyphenyl; and

[0020] R 14 To R 17 Each can independently represent a hydrogen atom, a halogen atom, a hydrocarbon group with 1 to 30 carbon atoms that optionally contains a heteroatom, or OR 28 CO2R 28 CO2M', C(O)N(R) 29 2. C(O)R 28 SR 28 SO2R 28 SOR 28 OSO2R 28 、P(O)(OR 28 ) 2-f (R 29 ) f CN, NHR 28 、N(R 28 2. Si(OR) 29 ) 3-e (R 9 ) e OSi(OR) 29 ) 3-e (R 29 ) e , NO2, SO3M', PO3M'2, P(O)(OR 28 )2M' or containing an epoxy group, wherein R 28 R represents a hydrocarbon group having 1 to 20 carbon atoms. 29 The symbol represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, M' represents an alkali metal, alkaline earth metal, ammonium, quaternary ammonium or phosphonium, e represents an integer from 0 to 3, and f represents an integer from 0 to 2; wherein the heteroatom is selected from O, N and S.

[0021] In some embodiments of the present invention, the catalyst is preferably at least one of the compounds represented by formula (II);

[0022] In equation (II), R 1 R 2 and R 3 Each may be the same or different, and each is independently hydrogen, C1-C 30 Alkyl groups, C1-C groups with heteroatoms 30 Alkyl, C1-C 30 Alkoxy or C6-C 30 Aryloxy groups, wherein the groups are optionally selected from halogen atoms (e.g., fluorine, chlorine, and bromine), C1-C 10 Alkyl, C1-C 10 Alkoxy, C6-C 10 Aryl and C6-C 10 The aryloxy group is substituted; and L is a ligand. The heteroatom can be selected from O, N, and S. In this invention, the ligand can be any ligand known in the art capable of coordinating to Pd. In some embodiments, the ligand L is preferably selected from pyridine, amine, piperidine, ether, sulfone, sulfoxide, and phosphine ligands; preferably, the ligand L is selected from dimethyl sulfoxide, pyridine, tetramethylethylenediamine, triphenylphosphine, and 2,6-dimethylpyridine, more preferably dimethyl sulfoxide.

[0023] In some embodiments of the present invention, preferably, the catalyst is at least one selected from 2-(bis(2-methoxyphenyl)phosphino)benzenesulfonic acid (dimethyl sulfoxide) (methyl)palladium, 2-(bis(2-phenoxyphenyl)phosphino)benzenesulfonic acid (dimethyl sulfoxide) (methyl)palladium, and 2-(bis(2-methoxyphenyl)phosphino)-4-methylbenzenesulfonic acid (dimethyl sulfoxide) (methyl)palladium.

[0024] In some embodiments of the present invention, the method may further include: providing an acrylate; and adding the acrylate and the homogeneous mixture to a polymerization reactor to copolymerize the acrylate and ethylene in the presence of an inert solvent to obtain the ethylene-acrylate copolymer. Preferably, the homogeneous mixture is added to the polymerization reactor after the acrylate is added, or the acrylate and the homogeneous mixture are added to the polymerization reactor simultaneously.

[0025] In some embodiments of the present invention, the method further includes providing a copolymerization regulator and adding the copolymerization regulator to a polymerization reactor. In some embodiments, providing the copolymerization regulator includes mixing an acrylate with the copolymerization regulator to form a homogeneous mixture; and adding the homogeneous mixture of the acrylate and the copolymerization regulator to the polymerization reactor. In some embodiments of the present invention, the copolymerization regulator is at least one of the compounds shown in formula (III) and formula (IV):

[0026] In equation (III), R 4 Selected from hydrogen atoms, C1-C 20 Hydrocarbon group, C1-C 20 Alkoxy or C6-C 20 Aryloxy groups, which are straight-chain, branched, or cyclic, and optionally selected from halogen atoms, C1-C... 10 Alkyl, C1-C 10 Alkoxy, C1-C6 carbonyl, C6-C 10 Aryl or C6-C 10 Substituents of aryloxy groups; in formula (IV), R 5 Selected from hydrogen atoms, C1-C 20 Hydrocarbon group, C1-C 20 Alkoxy or C6-C 20 Aryloxy groups, which are straight-chain, branched, or cyclic, and optionally selected from halogen atoms, C1-C... 10 Alkyl, C1-C 10 Alkoxy, C1-C6 carbonyl, C6-C 10 Aryl and C6-C 10 Substitution of aryloxy groups.

[0027] In some embodiments, preferably, the copolymerization regulator is at least one of 2,6-di-tert-butyl-4-methylphenol, 2,6-di-tert-butylphenol, 2,4,6-tri-tert-butylphenol, and 2,6-di-tert-butyl-α-(3,5-di-tert-butyl-4-oxo-2,5-cyclohexadiene-1-yl)-p-tolyloxy radical.

[0028] In some embodiments, preferably, providing the copolymerization regulator includes mixing the acrylate with the copolymerization regulator to form a homogeneous mixture; and adding the homogeneous mixture of the acrylate and the copolymerization regulator into the polymerization reactor.

[0029] In some embodiments, preferably, the molar ratio of acrylate to copolymerization regulator is 50:1 to 500:1, more preferably 100:1 to 350:1, and even more preferably 150:1 to 300:1; and / or in the polymerization reaction system, the molar ratio of the catalyst to copolymerization regulator, based on Pd atoms, is 1:1 to 1:200, preferably 1:3 to 1:100, more preferably 1:4 to 1:50, and even more preferably 1:5 to 1:30.

[0030] In some embodiments, preferably, the catalyst, based on Pd, is present in the polymerization reaction system at an amount of 10–1000 μmol / L, more preferably 30–500 μmol / L, and even more preferably 100–300 μmol / L.

[0031] In some embodiments of this invention, the organoaluminum compound is of the general formula AlR. 6 R 7 R 8 Organoaluminum compounds, in which R 6 R 7 and R 8 They are the same or different from each other, and each is independently classified as C1 to C2. 20 The hydrocarbon group, preferably R 6 R 7 and R 8 They are the same or different from each other, and each is independently classified as C1 to C2. 20 The alkyl group; more preferably, the organoaluminum compound is selected from one or more of trimethylaluminum, triethylaluminum, tri-n-propylaluminum, tri-n-butylaluminum, triisobutylaluminum, tripentylaluminum, tri-n-hexylaluminum, tri-n-octylaluminum, tri-n-decylaluminum, tri(dodecyl)aluminum, tri(tetradecyl)aluminum, tri(hexadecyl)aluminum, tri(octadecyl)aluminum and tri(eicosyl)aluminum.

[0032] In this invention, the molar ratio of palladium (Pd) in the catalyst to aluminum (Al) in the organoaluminum compound can be from 1:5 to 1:5000, for example, from 1:10 to 1:2000, for example, from 1:20 to 1:1000, or from 1:20 to 1:500. In some embodiments, the molar ratio of palladium (Pd) in the catalyst to aluminum (Al) in the organoaluminum compound can be 1:10, 1:20, 1:30, 1:40, 1:50, 1:60, 1:70, 1:80, 1:90, 1:100, 1:200, 1:300, 1:400, 1:500, 1:600, 1:700, 1:800, 1:900, 1:1000, 1:2000, 1:3000, 1:4000, 1:5000, or any combination thereof.

[0033] In some embodiments of this invention, the inert solvent is selected from the group consisting of aliphatic hydrocarbon solvents, alicyclic hydrocarbon solvents, aromatic hydrocarbon solvents, and combinations thereof; preferably selected from C6-C. 12 Alkanes, C5-C 10 Alicyclic hydrocarbons, C6-C 10 The group consisting of monocyclic aromatic hydrocarbons and combinations thereof; the C6-C 12 The alkane is preferably at least one selected from n-hexane, isohexane, n-heptane, isoheptane, n-octane, and isooctane; the C5-C 10 The alicyclic hydrocarbon is preferably at least one selected from cyclopentane, cyclohexane, cycloheptane, and cyclooctane; and the C6-C 10The monocyclic aromatic hydrocarbon is preferably toluene and / or xylene; more preferably, the inert solvent is at least one selected from n-hexane, isohexane, cyclohexane and toluene.

[0034] In some embodiments of the present invention, the polymerization temperature is between 60 and 150°C and the polymerization pressure is between 0.1 and 10 MPa. In some embodiments of the present invention, the concentration of acrylate in the polymerization reaction system is 0.1 to 5 mol / L, preferably 0.2 to 2 mol / L, more preferably 0.25 to 2 mol / L.

[0035] In some embodiments of this invention, chlorinated solvents such as dichloromethane are not used.

[0036] Another aspect of the present invention provides a catalyst system comprising a catalyst having formula (I) and an organoaluminum compound that are directly and uniformly mixed together (i.e., to obtain a homogeneous solution).

[0037] in,

[0038] R 11 Represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 30 carbon atoms optionally containing a heteroatom, or an aryl group having 6 to 30 carbon atoms optionally containing a heteroatom; preferably R 11 The heteroatom is a hydrogen atom, an alkyl group having 1 to 6 carbon atoms optionally containing a heteroatom, or an aryl group having 6 to 13 carbon atoms optionally containing a heteroatom; wherein the heteroatom is selected from halogens (e.g., fluorine, chlorine, and bromine), O, N, and S; more preferably R 11 Selected from hydrogen atom, methyl, ethyl, trifluoromethyl, acyl, acetoxy, phenyl, tolyl, xylyl, phenanthrene, and pentafluorophenyl; more preferably R 11 Selected from hydrogen atoms, methyl and phenyl;

[0039] L represents a ligand coordinated to Pd; preferably, the ligand is selected from pyridine, amine, piperidine, ether, sulfone, sulfoxide and phosphine ligands; more preferably, the ligand is selected from dimethyl sulfoxide, pyridine, tetramethylethylenediamine, triphenylphosphine and 2,6-dimethylpyridine, and even more preferably dimethyl sulfoxide;

[0040] R 12 and R 13 Each independently represents a hydrocarbon group having 1 to 30 carbon atoms, optionally containing a heteroatom, preferably R. 12 and R 13 Each independently represents an aryl group having 3 to 30 carbon atoms, optionally containing a heteroatom, more preferably R 12 and R 13Each independently represents an aryl group having 6 to 30 carbon atoms, optionally containing a heteroatom selected from O, N, and S; more preferably, R 12 and R 13 Each of the following is independently phenyl, 2-methylphenyl, 2,6-dimethylphenyl, 2-ethylphenyl, 2,6-diethylphenyl, 2-isopropylphenyl, 2,6-di(isopropyl)phenyl, 2-cyclohexylphenyl, 2,6-di(cyclohexyl)phenyl, 2-methoxyphenyl, 2,6-dimethoxyphenyl, 2-phenoxyphenyl, and 2,6-diphenoxyphenyl; and

[0041] R 14 To R 17 Each can independently represent a hydrogen atom, a halogen atom, a hydrocarbon group with 1 to 30 carbon atoms that optionally contains a heteroatom, or OR 28 CO2R 28 CO2M', C(O)N(R) 29 2. C(O)R 28 SR 28 SO2R 28 SOR 28 OSO2R 28 、P(O)(OR 28 ) 2-f (R 29 ) f CN, NHR 28 、N(R 28 2. Si(OR) 29 ) 3-e (R 29 ) e OSi(OR) 29 ) 3-e (R 29 ) e , NO2, SO3M', PO3M'2, P(O)(OR 28 )2M' or containing an epoxy group, wherein R 28 R represents a hydrocarbon group having 1 to 20 carbon atoms. 29 M' represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, M' represents an alkali metal, alkaline earth metal, ammonium, quaternary ammonium or phosphonium, e represents an integer from 0 to 3, and f represents an integer from 0 to 2.

[0042] In some embodiments of the present invention, the catalyst in the catalyst system is at least one of the compounds represented by formula (II);

[0043] In equation (II), R 1 R 2 and R 3Each may be the same or different, and each is independently hydrogen, C1-C 30 Alkyl groups, C1-C groups with heteroatoms 30 Alkyl, C1-C 30 Alkoxy or C6-C 30 Aryloxy group, wherein the group is optionally selected from halogen atoms, C1-C 10 Alkyl, C1-C 10 Alkoxy, C6-C 10 Aryl and C6-C 10 Substituent substitution of aryloxy groups, wherein the heteroatom may be selected from O, N, and S; and

[0044] L is a ligand; preferably, the ligand L is selected from pyridine, amine, piperidine, ether, sulfone, sulfoxide and phosphine ligands; preferably, the ligand L is selected from dimethyl sulfoxide, pyridine, tetramethylethylenediamine, triphenylphosphine and 2,6-dimethylpyridine, more preferably dimethyl sulfoxide;

[0045] Preferably, the catalyst is at least one selected from 2-(bis(2-methoxyphenyl)phosphino)benzenesulfonic acid (dimethyl sulfoxide) (methyl)palladium, 2-(bis(2-phenoxyphenyl)phosphino)benzenesulfonic acid (dimethyl sulfoxide) (methyl)palladium, and 2-(bis(2-methoxyphenyl)phosphino)-4-methylbenzenesulfonic acid (dimethyl sulfoxide) (methyl)palladium.

[0046] In some embodiments of the present invention, the organoaluminum compound in the catalyst system is of the general formula AlR. 6 R 7 R 8 Organoaluminum compounds, in which R 6 R 7 and R 8 They are the same or different from each other, and each is independently classified as C1 to C2. 20 The hydrocarbon group, preferably R 6 R 7 and R 8 They are the same or different from each other, and each is independently classified as C1 to C2. 20 The alkyl group; more preferably, the organoaluminum compound is selected from one or more of trimethylaluminum, triethylaluminum, tri-n-propylaluminum, tri-n-butylaluminum, triisobutylaluminum, tripentylaluminum, tri-n-hexylaluminum, tri-n-octylaluminum, tri-n-decylaluminum, tri(dodecyl)aluminum, tri(tetradecyl)aluminum, tri(hexadecyl)aluminum, tri(octadecyl)aluminum, and tri(eicosyl)aluminum. In some embodiments, R 6 R 7 and R 8 They are the same or different from each other, and each is independently classified as C1 to C2. 10Alkyl groups, for example, each of which is independently a C1 to C8 alkyl group or each of which is independently a C1 to C6 alkyl group.

[0047] In this invention, the molar ratio of palladium (Pd) in the catalyst to aluminum (Al) in the organoaluminum compound can be from 1:5 to 1:5000, for example, from 1:10 to 1:2000, for example, from 1:20 to 1:1000, or from 1:20 to 1:500. In some embodiments, the molar ratio of palladium (Pd) in the catalyst to aluminum (Al) in the organoaluminum compound can be 1:10, 1:20, 1:30, 1:40, 1:50, 1:60, 1:70, 1:80, 1:90, 1:100, 1:200, 1:300, 1:400, 1:500, 1:600, 1:700, 1:800, 1:900, 1:1000, 1:2000, 1:3000, 1:4000, 1:5000, or any combination thereof.

[0048] The catalyst system described in this invention can be used to catalyze the copolymerization of ethylene with polar monomers such as acrylate monomers. In some embodiments, the catalyst system is used in the method for preparing ethylene-acrylate copolymers according to this application.

[0049] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0050] Exemplary embodiments of the present invention will be described in more detail with reference to the accompanying drawings.

[0051] Figure 1 shows the rheological curve of the ethylene-acrylate copolymer of Example 3 of the present invention at 190°C.

[0052] Figure 2 shows the rheological curve of the ethylene-acrylate copolymer of Example 5 of the present invention at 190°C.

[0053] Figure 3 shows the rheological curve of the ethylene-acrylate copolymer of Example 6 of the present invention at 190°C.

[0054] Figure 4 shows the rheological curve of the polymer of Comparative Example 2 at 190℃.

[0055] Figure 5 shows the rheological curve of the polymer in Comparative Example 3 at 190℃.

[0056] Figure 6 shows the rheological curve of the polymer in Comparative Example 4 at 190℃.

[0057] Figure 7 shows the LogIV-LogM curves of the ethylene-acrylate copolymer of Example 6 and the polymer of Comparative Example 3. Detailed Implementation

[0058] The following provides a detailed description of specific embodiments of the present invention. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of the invention.

[0059] This invention provides an ethylene-acrylate copolymer comprising 85–99.2 mol% ethylene-derived structural units and 0.8–15 mol% acrylate-derived structural units, wherein the acrylate is an alkyl acrylate, the alkyl group of the alkyl acrylate having x carbon atoms, where x is an integer from 1 to 8, and wherein the number of short branches (thousandths of carbon branches) in 1000 carbons (C) of the ethylene-acrylate copolymer as measured by GPC [SCB / 1000C] > {1000a / (200+x×a)+10}, where a is the molar content of acrylate-derived structural units in the copolymer.

[0060] In this invention, the total number of ethylene-derived structural units and acrylate-derived structural units in the ethylene-acrylate copolymer is 100 mol%.

[0061] In this invention, x is an integer from 1 to 8. For example, x can be a range consisting of 1, 2, 3, 4, 5, 6, 7, 8, or any two of the above. For example, x can be an integer from 1 to 6, or x can be an integer from 1 to 4.

[0062] In some embodiments, preferably, the acrylate is at least one selected from methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, tert-butyl acrylate, n-pentyl acrylate, isopentyl acrylate, and 2-ethylhexyl acrylate. In some embodiments, the acrylate is at least one selected from methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, and tert-butyl acrylate.

[0063] In this invention, the ethylene-acrylate copolymer preferably comprises 88–99.1 mol% of ethylene-derived structural units and 0.9–12 mol% of acrylate-derived structural units. For example, the ethylene-acrylate copolymer may comprise 0.9 mol%, 1 mol%, 2 mol%, 3 mol%, 4 mol%, 5 mol%, 6 mol%, 7 mol%, 8 mol%, 9 mol%, 10 mol%, 11 mol%, or 12 mol% of acrylate-derived structural units.

[0064] When the ethylene-acrylate copolymer contains more than one acrylate-derived structural unit, in the formula {1000a / (200+x×a)+10}, 'a' represents the sum of the molar contents of all acrylate-derived structural units, and 'x' represents the sum of the x values ​​of each acrylate in molar proportions. For example, when there are two acrylate-derived structural units and the molar ratio of the first acrylate to the second acrylate is 1:2, then x in the formula {1000a / (200+x×a)+10} = x1×1 / 3 + x2×2 / 3. For example, when there are three acrylate-derived structural units and the molar ratio of the first acrylate, the second acrylate, and the third acrylate is 1:2:3, then x in the formula {1000a / (200+x×a)+10} = x1×1 / 6 + x2×2 / 6 + x3×3 / 6. Where x1, x2, and x3 are the number of carbon atoms in the alkyl groups of the first acrylate, second acrylate, and third acrylate molecules, respectively.

[0065] In some embodiments of this invention, the molecular weight distribution index (PDI) of the ethylene-acrylate copolymer is preferably ≤2.5. In this invention, the molecular weight distribution index (PDI) of the ethylene-acrylate copolymer is greater than or equal to 1.2, for example, greater than or equal to 1.4 or greater than or equal to 1.6.

[0066] In this invention, preferably, the molecular weight distribution index (PDI) of the ethylene-acrylate copolymer is ≤2.45, for example, PDI ≤2.42 or PDI ≤2.4.

[0067] In this invention, the comonomer content of the ethylene-acrylate copolymer can be calculated using 1H NMR spectroscopy. For example, when the comonomer is methyl acrylate (MA), the signals at chemical shifts of 3.59 ppm and 3.66 ppm are the signals of the MA unit in the polymer chain and the MA unit at the chain end, respectively. The MA content in the polymer and the proportion of MA inserted into the copolymer backbone are calculated by comparing the peak areas. Specifically, in the 1H NMR spectroscopy, the peak area at 3.59 ppm is taken as A1, corresponding to the methoxy group of methyl acrylate in the polymer chain; the peak area at 3.66 ppm is taken as A2, corresponding to the methoxy group of methyl acrylate at the chain end of the polymer chain; and the peak area at 1.25 ppm is taken as A3, corresponding to the methylene group from the ethylene monomer in the middle of the polymer chain. The formula for calculating the MA content in the polymer is:

[0068] The ratio R, which is the molar amount of MA inserted into the copolymer backbone to the total molar amount of MA in the copolymer (the sum of acrylates located in and at the ends of the polymer chain), is calculated as follows: R = A1 / (A1 + A2).

[0069] In some preferred embodiments of this invention, LogIV and LogM exhibit a linear relationship in GPC testing, where IV is the intrinsic viscosity and M is the molecular weight. In some embodiments, preferably, the coefficient of determination of the trend line between LogIV and LogM is greater than or equal to 0.94, more preferably greater than or equal to 0.95. In this invention, the coefficient of determination of the trend line between LogIV and LogM is less than 1. In this invention, the coefficient of determination is calculated by linearly fitting the discrete points of LogIV-LogM. As those skilled in the art know, the closer the coefficient of determination is to 1, the more reliable the linear fit, i.e., the more linear the discrete points of LogIV-LogM are, and the fewer long branches in the polymer structure.

[0070] In this invention, the number of short branches per thousand carbon atoms (i.e., [SCB / 1000C]) is calculated by combining GPC with infrared spectroscopy and a standard curve; the intrinsic viscosity is calculated by discharging volume to obtain the LogIV-LogM curve; see Journal of Applied Polymer Science, 2015, Vol 132, No.28, 42222.

[0071] In this invention, "long branched chain" and "short branched chain" have meanings generally known in the field of polyolefins.

[0072] In this invention, at 190°C, the melt of the ethylene-acrylate copolymer is subjected to a low shear rate of 0.1 s. -1 Up to high shear rate 100s -1 It first exhibits shear thinning and then shear thickening (i.e., it exhibits shear thinning at low shear rates and shear thickening at high shear rates).

[0073] In some embodiments of the present invention, preferably, the transition point between shear thinning and shear thickening (i.e., the minimum viscosity) is between 1 and 100 s. -1 Between 10-100 seconds is preferred. -1 Between, for example, in 10-50 seconds -1 Between 15 and 45 seconds -1 between.

[0074] In some preferred embodiments of the present invention, the ethylene-acrylate copolymer is subjected to oxidation at 190°C for 1–100 seconds. -1 The minimum viscosity at the shear rate is no greater than 0.1 s⁻¹. -1The viscosity value is 30% of the value below, and in 100s -1 The viscosity value is at least three times the minimum value. For example, at 190°C, the ethylene-acrylate copolymer exhibits a viscosity value of at least 1 to 100 s. -1 The minimum viscosity at the shear rate is 0.1 s⁻¹. -1 The viscosity value is 3-30%, for example 4-30% or 5-30%. In some embodiments, the ethylene-acrylate copolymer has a viscosity of 1-100 s. -1 The minimum viscosity at the shear rate is 0.1 s⁻¹. -1 The viscosity is 5-10% of the specified value. In some embodiments, the ethylene-acrylate copolymer has a viscosity of 1-100 s. -1 The minimum viscosity at the shear rate is 0.1 s⁻¹. -1 The viscosity value is 25-30% of the specified value. At 190°C, the ethylene-acrylate copolymer exhibits a viscosity of 100s. -1 The viscosity value is between 1 and 100 s. -1 The viscosity at the minimum shear rate is 3 to 250 times, for example, 4 to 250 times, or 5 to 250 times. In some embodiments, the ethylene-acrylate copolymer is subjected to a viscosity of 100 s at 190°C. -1 The viscosity value is between 1 and 100 s. -1 The viscosity at the minimum shear rate is 5 to 20 times that of the minimum. In some embodiments, the ethylene-acrylate copolymer is subjected to a viscosity of 100 s at 190°C. -1 The viscosity value is between 1 and 100 s. -1 The viscosity at the shear rate is 150 to 250 times the minimum value.

[0075] In this invention, a rotational rheometer is used to test and obtain the curve of shear rate versus viscosity; where shear thinning refers to the decrease in viscosity of the ethylene-acrylate copolymer melt as the shear rate increases, while shear thickening refers to the increase in viscosity of the ethylene-acrylate copolymer melt as the shear rate increases.

[0076] More specifically, in this invention, the shear rate versus viscosity curve can be obtained as follows: a copolymer disc sample with a diameter of 2 cm and a thickness of 2 mm is prepared by pressing it in a mold at 180°C; the disc sample is placed in a test container, heated to a desired temperature, for example, 190°C, and the sample is completely melted; a disc rotor is pressed to a position 1 mm from the bottom of the container, and the test begins; at the desired temperature, for example, 190°C, the frequency is scanned from low frequency to high frequency in a frequency range of, for example, 0.1 to 100 Hz to obtain the shear rate versus viscosity curve. For example, a HAAKE MARS 60 rotational rheometer can be used for the test.

[0077] In this invention, the weight-average molecular weight of the ethylene-acrylate copolymer can be 5000–100000 g / mol, preferably 8000–50000 g / mol, for example, 5000 g / mol, 6000 g / mol, 7000 g / mol, 8000 g / mol, 9000 g / mol, 10000 g / mol, 11000 g / mol, 12000 g / mol, 13000 g / mol, 15000 g / mol, 20000 g / mol, 22000 g / mol, 24000 g / mol, 25000 g / mol, 260 g / mol, etc. 00 g / mol, 27000 g / mol, 28000 g / mol, 29000 g / mol, 30000 g / mol, 32000 g / mol, 35000 g / mol, 37000 g / mol, 40000 g / mol, 43000 g / mol, 45000 g / mol, 48000 g / mol, 50000 g / mol, 55000 g / mol, 60000 g / mol, 65000 g / mol, 70000 g / mol, 80000 g / mol, 90000 g / mol, or a range consisting of any two of the above values.

[0078] In this invention, the weight-average molecular weight and molecular weight distribution index were determined by GPC method. The sample was dissolved in 1,2,4-trichlorobenzene at a concentration of 1.0 mg / ml, the test temperature was 150°C, and the flow rate of 1,2,4-trichlorobenzene was 1.0 ml / min. Polystyrene was used as an internal standard.

[0079] In some preferred embodiments of the present invention, the ratio R of the molar amount of acrylate inserted into the copolymer backbone to the total molar amount of acrylate in the ethylene-acrylate copolymer (the sum of acrylates located in and at the ends of the polymer chain) is 0.84-1. In some preferred embodiments, the ratio R of the molar amount of acrylate inserted into the copolymer backbone to the total molar amount of acrylate in the ethylene-acrylate copolymer can be 0.84, 0.85, 0.86, 0.87, 0.88, 0.89, 0.90, 0.91, 0.92, 0.93, 0.94, 0.95, 0.96, 0.97, 0.98, 0.99, 1, or any combination thereof. In this invention, "acrylate inserted into the copolymer backbone" means that the two carbons of the double bond in the acrylate monomer are located in the copolymer backbone after polymerization, while acrylate located at the copolymer end position means that the acrylate monomer is located at the chain end position of the copolymer after polymerization, including the chain end of the backbone and the chain end of the side chain.

[0080] In this invention, the melting point of the ethylene-acrylate copolymer can be 75-120°C. In some embodiments, the melting point of the ethylene-acrylate copolymer of this invention can be 75°C to 115°C.

[0081] The melting point was determined by differential scanning calorimetry (DSC). Specifically, the general procedure for determining the melting point by DSC is as follows: 10 mg of sample is placed in a crucible and measured on a differential scanning calorimeter; under a nitrogen atmosphere, the temperature is increased from -70 °C to 200 °C at a rate of 10 °C / min, held for 1 min, then decreased to -70 °C at a rate of 10 °C / min, held for 3 min, and then increased to 200 °C at a rate of 10 °C / min. The second temperature scan data is recorded; the peak of the melting peak at the second temperature increase is taken as the melting point of the polymer.

[0082] In this invention, the density of the ethylene-acrylate copolymer can be 0.94-0.965 g / cm³. 3 Density was measured at room temperature (approximately 25°C) according to ASTM-D792 method.

[0083] The number of short branches per thousand carbon atoms [SCB / 1000C] of the ethylene-acrylate copolymer of the present invention, as measured by GPC, can be 10-100, for example, 12-95, or 15-90.

[0084] The present invention also provides a method for preparing the ethylene-acrylate copolymer of the present invention, wherein the method comprises:

[0085] The catalyst is mixed with an organoaluminum compound to form a homogeneous mixture; and the homogeneous mixture is added to a polymerization reactor to copolymerize acrylate and ethylene in the presence of an inert solvent to obtain the ethylene-acrylate copolymer.

[0086] In this invention, the catalyst in the preparation method is a palladium phosphononsulfonate catalyst. In some embodiments, preferably, the catalyst is at least one of the compounds shown in formula (I):

[0087] in,

[0088] R 11 The symbol represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 30 carbon atoms optionally containing a heteroatom, or an aryl group having 6 to 30 carbon atoms optionally containing a heteroatom, wherein the heteroatom is selected from O, N, and S; preferably R. 11 The heteroatom is a hydrogen atom, an alkyl group having 1 to 6 carbon atoms optionally containing a heteroatom, or an aryl group having 6 to 13 carbon atoms optionally containing a heteroatom; wherein the heteroatom is selected from halogens (e.g., fluorine, chlorine, and bromine), O, N, and S; more preferably R 11Selected from hydrogen atom, methyl, ethyl, trifluoromethyl, acyl, acetoxy, phenyl, tolyl, xylyl, phenanthrene, and pentafluorophenyl; more preferably R 11 Selected from hydrogen atoms, methyl and phenyl;

[0089] L represents a ligand coordinated to Pd; preferably, the ligand is selected from pyridine, amine, piperidine, ether, sulfone, sulfoxide and phosphine ligands; more preferably, the ligand is selected from dimethyl sulfoxide, pyridine, tetramethylethylenediamine, triphenylphosphine and 2,6-dimethylpyridine, and even more preferably dimethyl sulfoxide;

[0090] R 12 and R 13 Each independently represents a hydrocarbon group having 1 to 30 carbon atoms, optionally containing a heteroatom, preferably R. 12 and R 13 Each independently represents an aryl group having 3 to 30 carbon atoms, optionally containing a heteroatom, more preferably R 12 and R 13 Each independently represents an aryl group having 6 to 30 carbon atoms, optionally containing a heteroatom selected from O, N, and S; more preferably, R 12 and R 13 Each of the following is independently phenyl, 2-methylphenyl, 2,6-dimethylphenyl, 2-ethylphenyl, 2,6-diethylphenyl, 2-isopropylphenyl, 2,6-di(isopropyl)phenyl, 2-cyclohexylphenyl, 2,6-di(cyclohexyl)phenyl, 2-methoxyphenyl, 2,6-dimethoxyphenyl, 2-phenoxyphenyl, and 2,6-diphenoxyphenyl; and

[0091] R 14 To R 17 Each can independently represent a hydrogen atom, a halogen atom, a hydrocarbon group with 1 to 30 carbon atoms that optionally contains a heteroatom, or OR 28 CO2R 28 CO2M', C(O)N(R) 29 2. C(O)R 28 SR 28 SO2R 28 SOR 28 OSO2R 28 、P(O)(OR 28 ) 2-f (R 29 ) f CN, NHR 28 、N(R 28 2. Si(OR) 29 ) 3-e (R 29 ) eOSi(OR) 29 ) 3-e (R 29 ) e , NO2, SO3M', PO3M'2, P(O)(OR 28 )2M' or containing an epoxy group, wherein R 28 R represents a hydrocarbon group having 1 to 20 carbon atoms. 29 M' represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, M' represents an alkali metal, alkaline earth metal, ammonium, quaternary ammonium or phosphonium, e represents an integer from 0 to 3, and f represents an integer from 0 to 2.

[0092] In this invention, more preferably, the catalyst is selected from at least one of the compounds shown in formula (II);

[0093] In equation (II), R 1 R 2 and R 3 Each may be the same or different, and each is independently hydrogen, C1-C 30 Alkyl groups, C1-C groups with heteroatoms 30 Alkyl, C1-C 30 Alkoxy or C6-C 30 Aryloxy group, wherein the group is optionally selected from halogen atoms, C1-C 10 Alkyl, C1-C 10 Alkoxy, C6-C 10 Aryl and C6-C 10 The aryl group is substituted; and L is a ligand. In this invention, as those skilled in the art will understand, R on the benzene ring in formula (II) 1 R 2 or R 3 The group indicates that one or more R groups may exist. 1 R 2 or R 3 Groups, for example, can be present in one, two, three, or four R groups respectively. 1 R 2 or R 3 Group. In this invention, the C1-C 30 Alkyl groups, C1-C groups with heteroatoms 30 Alkyl or C1-C 30 The alkoxy group can be straight-chain, branched, or cyclic. The heteroatom is selected from O, N, and S.

[0094] In some implementations, in formula (II), R 1 R 2 and R 3 Each may be the same or different, and each is independently hydrogen, C1-C20 Alkyl groups, C1-C groups with heteroatoms 20 Alkyl, C1-C 20 Alkoxy or C6-C 20 Aryloxy group, wherein the group is optionally selected from halogen atoms, C1-C 10 Alkyl, C1-C 10 Alkoxy, C6-C 10 Aryl and C6-C 10 Substituents of the aryloxy group. In this invention, the C1-C 20 Alkyl groups, C1-C groups with heteroatoms 20 Alkyl or C1-C 20 The alkoxy group can be straight-chain, branched, or cyclic. In some embodiments, in formula (II), R... 1 R 2 and R 3 Each may be the same or different, and each is independently hydrogen, C1-C 10 Alkyl groups, C1-C groups with heteroatoms 10 Alkyl, C1-C 10 Alkoxy or C6-C 10 Aryloxy groups, wherein these groups are optionally substituted with substituents selected from halogen atoms, C1-C6 alkyl, C1-C6 alkoxy, C6-C8 aryl, and C6-C8 aryloxy groups. In this invention, the C1-C... 10 Alkyl groups, C1-C groups with heteroatoms 10 Alkyl or C1-C 10 The alkoxy group can be straight-chain, branched, or cyclic. In some embodiments, in formula (II), R... 1 R 2 and R 3 Each group may be the same or different, and each independently comprises hydrogen, C1-C6 alkyl, C1-C6 alkyl with heteroatoms, C1-C6 alkoxy, or C6-C8 aryloxy, wherein these groups are optionally substituted with substituents selected from halogen atoms, C1-C6 alkyl, C1-C6 alkoxy, C6-C8 aryl, and C6-C8 aryloxy. In this invention, the C1-C6 alkyl, C1-C6 alkyl with heteroatoms, or C1-C6 alkoxy may be straight-chain, branched, or cyclic. In some embodiments, in formula (II), R 1 R 2 and R 3Each group may be the same or different, and each is independently hydrogen, C1-C4 alkyl, C1-C4 alkyl with heteroatoms, C1-C4 alkoxy, or C6 aryloxy, wherein these groups are optionally substituted with substituents selected from halogen atoms, C1-C4 alkyl, C1-C4 alkoxy, C6 aryl, and C6 aryloxy. The heteroatoms are selected from O, N, and S. In some embodiments, in formula (II), R... 1 R 2 and R 3 Each may be the same or different, and each can be independently hydrogen, methyl, ethyl, propyl, butyl, phenyl, methoxy, ethoxy, propoxy, butoxy, or phenoxy.

[0095] In this invention, C1-C having heteroatoms 30 Alkyl groups, C1-C groups with heteroatoms 20 Alkyl groups and C1-C groups with heteroatoms 10 The heteroatoms in the alkyl group can be selected from O, N, S, or combinations thereof.

[0096] In this invention, the ligand L can be selected from pyridine, amine, piperidine, ether, sulfone, sulfoxide, and phosphine ligands. In some embodiments, preferably, the ligand is selected from dimethyl sulfoxide, pyridine, tetramethylethylenediamine, triphenylphosphine, and 2,6-dimethylpyridine, more preferably dimethyl sulfoxide.

[0097] According to some embodiments of the present invention, the catalyst may be at least one of 2-(bis(2-methoxyphenyl)phosphino)benzenesulfonic acid (dimethyl sulfoxide) (methyl)palladium, 2-(bis(2-phenoxyphenyl)phosphino)benzenesulfonic acid (dimethyl sulfoxide) (methyl)palladium and 2-(bis(2-methoxyphenyl)phosphino)-4-methylbenzenesulfonic acid (dimethyl sulfoxide) (methyl)palladium.

[0098] In the method for preparing the ethylene-acrylate copolymer of the present invention, the amount of catalyst is not particularly limited, as long as it can catalyze the polymerization reaction. In some embodiments, preferably, the amount of catalyst, based on Pd, in the polymerization reaction system can be 10-1000 μmol / L, more preferably 30-500 μmol / L, and more preferably 100-300 μmol / L.

[0099] In some embodiments, preferably, the organoaluminum compound is of the general formula AlR 6 R 7 R 8 Organoaluminum compounds, in which R 6 R 7 and R 8 They are the same or different from each other, and each is independently classified as C1 to C2. 20 The hydrocarbon group, preferably R 6R 7 and R 8 They are the same or different from each other, and each is independently classified as C1 to C2. 20 Alkyl groups, for example, can each be independently C1 to C2. 10 The alkyl, C1-C8, or C1-C6 alkyl compounds are selected from one or more of trimethylaluminum, triethylaluminum, tri-n-propylaluminum, tri-n-butylaluminum, triisobutylaluminum, tripentylaluminum, tri-n-hexylaluminum, tri-n-octylaluminum, tri-n-decylaluminum, tri(dodecyl)aluminum, tri(tetradecyl)aluminum, tri(hexadecyl)aluminum, tri(octadecyl)aluminum, and tri(eicosyl)aluminum.

[0100] In this invention, the molar ratio of palladium (Pd) in the catalyst to aluminum (Al) in the organoaluminum compound can be from 1:5 to 1:5000, for example, from 1:10 to 1:2000, for example, from 1:20 to 1:1000, or from 1:20 to 1:500. In some embodiments, the molar ratio of palladium (Pd) in the catalyst to aluminum (Al) in the organoaluminum compound can be 1:10, 1:20, 1:30, 1:40, 1:50, 1:60, 1:70, 1:80, 1:90, 1:100, 1:200, 1:300, 1:400, 1:500, 1:600, 1:700, 1:800, 1:900, 1:1000, 1:2000, 1:3000, 1:4000, 1:5000, or any combination thereof.

[0101] In this invention, the method may further include: providing an acrylate; and adding the acrylate and the homogeneous mixture to a polymerization reactor to copolymerize the acrylate and ethylene in the presence of an inert solvent to obtain the ethylene-acrylate copolymer. While there is no particular limitation on the order in which the acrylate and the homogeneous mixture are added to the polymerization reactor, it is preferable that the acrylate is added to the polymerization reactor first, followed by the homogeneous mixture, or that the acrylate and the homogeneous mixture are added to the polymerization reactor simultaneously.

[0102] In some embodiments of the present invention, the method further includes providing a copolymerization regulator and adding the copolymerization regulator to a polymerization reactor. Preferably, in some embodiments of the present invention, providing the copolymerization regulator includes mixing an acrylate with the copolymerization regulator to form a homogeneous mixture; and adding the homogeneous mixture of the acrylate and the copolymerization regulator to the polymerization reactor.

[0103] In some embodiments, preferably, the copolymerization regulator is selected from at least one of the compounds shown in formula (III) and formula (IV):

[0104] In equation (III), R 4 Selected from hydrogen atoms, C1-C 20 Hydrocarbon group, C1-C 20 Alkoxy or C6-C 20 Aryloxy groups, which are straight-chain, branched, or cyclic, and optionally selected from halogen atoms, C1-C... 10 Alkyl, C1-C 10 Alkoxy, C1-C6 carbonyl, C6-C 10 Aryl or C6-C 10 Substituents of aryloxy groups;

[0105] In equation (IV), R 5 Selected from hydrogen atoms, C1-C 20 Hydrocarbon group, C1-C 20 Alkoxy or C6-C 20 Aryloxy groups, which are straight-chain, branched, or cyclic, and optionally selected from halogen atoms, C1-C... 10 Alkyl, C1-C 10 Alkoxy, C1-C6 carbonyl, C6-C 10 Aryl and C6-C 10 Substitution of aryloxy groups.

[0106] In some implementations, preferably, in formula (III), R 4 Selected from hydrogen atoms, C1-C 10 Hydrocarbon groups (e.g., C1-C) 10 Alkyl), C1-C 10 Alkoxy or C6-C 10 Aryloxy groups, which are straight-chain, branched, or cyclic, and optionally substituted with substituents selected from halogen atoms, C1-C6 alkyl, C1-C7 alkoxy, C1-C3 carbonyl, C6-C8 aryl, or C6-C8 aryloxy groups; and in formula (IV), R 5 Selected from hydrogen atoms, C1-C 10 Hydrocarbon groups (e.g., C1-C) 10 Alkyl), C1-C 10 Alkoxy or C6-C 10 Aryloxy groups, which are straight-chain, branched, or cyclic, and optionally substituted with substituents selected from halogen atoms, C1-C6 alkyl, C1-C7 alkoxy, C1-C3 carbonyl, C6-C8 aryl, or C6-C8 aryloxy groups.

[0107] According to some embodiments of the present invention, preferably, the copolymerization regulator is at least one of 2,6-di-tert-butyl-4-methylphenol, 2,6-di-tert-butylphenol, 2,4,6-tri-tert-butylphenol, and 2,6-di-tert-butyl-α-(3,5-di-tert-butyl-4-oxo-2,5-cyclohexadiene-1,4-tri-tolyloxy radical (galvanoxy radical).

[0108] According to the present invention, a homogeneous solution can be formed by mixing the catalyst with an organoaluminum compound. This allows for the feeding of a homogeneous catalyst solution without the use of chlorinated solvents such as dichloromethane during the polymerization process. In a preferred embodiment, the preparation method of the present invention does not use chlorinated solvents such as dichloromethane.

[0109] The inert solvent used in the preparation method of this invention can be any inert solvent commonly used in the field of olefin polymerization, such as aliphatic hydrocarbon solvents, alicyclic hydrocarbon solvents, and / or aromatic hydrocarbon solvents. In some embodiments, preferably, the inert solvent is C6-C. 12 Alkanes, C5-C 10 Alicyclic hydrocarbons and / or C6-C 10 Monocyclic aromatic hydrocarbons; wherein the C6-C 12 The alkane is preferably at least one selected from n-hexane, isohexane, n-heptane, isoheptane, n-octane, and isooctane; the C5-C 10 The alicyclic hydrocarbon is preferably at least one selected from cyclopentane, cyclohexane, cycloheptane, and cyclooctane; and the C6-C 10 The monocyclic aromatic hydrocarbon is preferably toluene and / or xylene. More preferably, the inert solvent is at least one selected from n-hexane, isohexane, cyclohexane, and toluene, with toluene being the most preferred.

[0110] According to the present invention, the addition of the copolymerization regulator can improve the polymerization reaction activity. The inventors have discovered that pre-mixing the acrylate with the copolymerization regulator to obtain a mixed solution, and then mixing it with other components of the polymerization reaction system, can further improve the reaction activity. Specifically, the pre-mixing time is preferably 1 to 30 minutes, more preferably 2 to 15 minutes, and even more preferably 3 to 10 minutes.

[0111] The preparation method of the present invention can improve the insertion rate of comonomers in the main chain. Therefore, a high comonomer content in the copolymer can be achieved without excessively high comonomer addition. Specifically, in the polymerization reaction system, the concentration of the acrylate can be less than 5 mol / L, preferably less than 2 mol / L, and more preferably less than 1 mol / L. Preferably, in the polymerization reaction system, the concentration of the acrylate can be 0.1 mol / L or more, preferably 0.2 mol / L or more. For example, in the polymerization reaction system, the concentration of the acrylate can be 0.1 to 5 mol / L, preferably 0.2 to 2 mol / L or 0.2 to 1 mol / L, more preferably 0.25 to 2 mol / L or 0.25 to 1 mol / L. In the present invention, the concentration of the acrylate is the concentration of the acrylate in the polymerization reaction system at the beginning of copolymerization.

[0112] According to the present invention, preferably, the molar ratio of the acrylate to the copolymerization regulator in the catalyst system is 50:1 to 500:1, more preferably 100:1 to 350:1, and more preferably 150:1 to 300:1.

[0113] According to the present invention, preferably, in the polymerization reaction system, the molar ratio of the catalyst to the copolymerization regulator, based on Pd atoms, is 1:1 to 1:200, more preferably 1:3 to 1:100, more preferably 1:4 to 1:50, and even more preferably 1:5 to 1:30.

[0114] The copolymerization described in this invention can be a continuous, semi-continuous, or batch operation. In some embodiments, continuous operation refers to continuous feeding and discharging within the reactor. In some embodiments, semi-continuous operation refers to adding all materials except ethylene at once, with ethylene continuously introduced and discharged all at once after the reaction. In some embodiments, batch operation refers to adding all materials at once and discharging all at once after the reaction.

[0115] In this invention, the copolymerization can be carried out under relatively mild process conditions. Specifically, the copolymerization temperature can be 20–150°C, preferably 40–120°C, more preferably 60–100°C; and the copolymerization pressure can be below 10 MPa, preferably 0.01–5 MPa, more preferably 0.1–2 MPa.

[0116] After polymerization, the copolymer can be separated from the solvent. This separation can be achieved using various methods commonly used in olefin polymerization, such as evaporation. This step typically also removes unreacted monomers simultaneously.

[0117] The method for preparing the copolymer further includes drying the copolymer after separating the solvent and unreacted monomers. In some embodiments, drying can be achieved by heating under vacuum.

[0118] The polymerization activity of the preparation method of this invention can be 9 × 10⁻⁶. 4 g mol -1 h -1 Up to 60×10 4 gmol -1 h -1 For example, it could be 9×10 4 g mol -1 h -1 Up to 50×10 4 g mol -1 h -1 .

[0119] The inventors of this application unexpectedly discovered that the ethylene-acrylate copolymer of the present invention exhibits the characteristic of shear thinning at low shear rates and shear thickening at high shear rates. This unique rheological property facilitates the coating, curing, or shaping of the copolymer, for example, in applications such as hot melt adhesives and tackifiers.

[0120] The ethylene-acrylate copolymer of the present invention, due to its shear-thickening properties, can be used in some embodiments for impact-resistant applications, such as shock absorption. In some embodiments, the ethylene-acrylate copolymer of the present invention can be used, for example, in shock absorbers. In some embodiments, the ethylene-acrylate copolymer of the present invention, due to its shear-thickening properties, can be used in protective equipment, such as in bulletproof or stab-resistant materials.

[0121] In one aspect, this application provides the use of the ethylene-acrylate copolymer of the present invention as a shear-thickening material.

[0122] The present invention also provides a (homogeneous) catalyst system comprising a catalyst having formula (I) and an organoaluminum compound directly and uniformly mixed together;

[0123] in,

[0124] R 11 Represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 30 carbon atoms optionally containing a heteroatom, or an aryl group having 6 to 30 carbon atoms optionally containing a heteroatom; preferably R 11 The heteroatom is a hydrogen atom, an alkyl group having 1 to 6 carbon atoms optionally containing a heteroatom, or an aryl group having 6 to 13 carbon atoms optionally containing a heteroatom; wherein the heteroatom is selected from halogens (e.g., fluorine, chlorine, and bromine), O, N, and S; more preferably R 11Selected from hydrogen atom, methyl, ethyl, trifluoromethyl, acyl, acetoxy, phenyl, tolyl, xylyl, phenanthrene, and pentafluorophenyl; more preferably R 11 Selected from hydrogen atoms, methyl and phenyl;

[0125] L represents a ligand coordinated to Pd; preferably, the ligand is selected from pyridine, amine, piperidine, ether, sulfone, sulfoxide and phosphine ligands; more preferably, the ligand is selected from dimethyl sulfoxide, pyridine, tetramethylethylenediamine, triphenylphosphine and 2,6-dimethylpyridine, and even more preferably dimethyl sulfoxide;

[0126] R 12 and R 13 Each independently represents a hydrocarbon group having 1 to 30 carbon atoms, optionally containing a heteroatom, preferably R. 12 and R 13 Each independently represents an aryl group having 3 to 30 carbon atoms, optionally containing a heteroatom, more preferably R 12 and R 13 Each independently represents an aryl group having 6 to 30 carbon atoms, optionally containing a heteroatom selected from O, N, and S; more preferably, R 12 and R 13 Each of the following is independently phenyl, 2-methylphenyl, 2,6-dimethylphenyl, 2-ethylphenyl, 2,6-diethylphenyl, 2-isopropylphenyl, 2,6-di(isopropyl)phenyl, 2-cyclohexylphenyl, 2,6-di(cyclohexyl)phenyl, 2-methoxyphenyl, 2,6-dimethoxyphenyl, 2-phenoxyphenyl, and 2,6-diphenoxyphenyl; and

[0127] R 14 To R 17 Each can independently represent a hydrogen atom, a halogen atom, a hydrocarbon group with 1 to 30 carbon atoms that optionally contains a heteroatom, or OR 28 CO2R 28 CO2M', C(O)N(R) 29 2. C(O)R 28 SR 28 SO2R 28 SOR 28 OSO2R 28 、P(O)(OR 28 ) 2-f (R 29 ) f CN, NHR 28 、N(R 28 2. Si(OR) 29 ) 3-e (R 29 ) eOSi(OR) 29 ) 3-e (R 29 ) e , NO2, SO3M', PO3M'2, P(O)(OR 28 )2M' or containing an epoxy group, wherein R 28 R represents a hydrocarbon group having 1 to 20 carbon atoms. 29 M' represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, M' represents an alkali metal, alkaline earth metal, ammonium, quaternary ammonium or phosphonium, e represents an integer from 0 to 3, and f represents an integer from 0 to 2.

[0128] In some embodiments of the present invention, the catalyst in the catalyst system is at least one of the compounds represented by formula (II);

[0129] In equation (II), R 1 R 2 and R 3 Each may be the same or different, and each is independently hydrogen, C1-C 30 Alkyl groups, C1-C groups with heteroatoms 30 Alkyl, C1-C 30 Alkoxy or C6-C 30 Aryloxy group, wherein the group is optionally selected from halogen atoms, C1-C 10 Alkyl, C1-C 10 Alkoxy, C6-C 10 Aryl and C6-C 10 Substitution of aryloxy groups; and

[0130] L is a ligand; preferably, the ligand L is selected from pyridine, amine, piperidine, ether, sulfone, sulfoxide and phosphine ligands; preferably, the ligand L is selected from dimethyl sulfoxide, pyridine, tetramethylethylenediamine, triphenylphosphine and 2,6-dimethylpyridine, more preferably dimethyl sulfoxide;

[0131] Preferably, the catalyst is at least one selected from 2-(bis(2-methoxyphenyl)phosphino)benzenesulfonic acid (dimethyl sulfoxide) (methyl)palladium, 2-(bis(2-phenoxyphenyl)phosphino)benzenesulfonic acid (dimethyl sulfoxide) (methyl)palladium, and 2-(bis(2-methoxyphenyl)phosphino)-4-methylbenzenesulfonic acid (dimethyl sulfoxide) (methyl)palladium.

[0132] In some embodiments of the present invention, the organoaluminum compound in the catalyst system is of the general formula AlR. 6 R 7 R 8 Organoaluminum compounds, in which R 6 R 7and R 8 They are the same or different from each other, and each is independently classified as C1 to C2. 20 The hydrocarbon group, preferably R 6 R 7 and R 8 They are the same or different from each other, and each is independently classified as C1 to C2. 20 The alkyl group; more preferably, the organoaluminum compound is selected from one or more of trimethylaluminum, triethylaluminum, tri-n-propylaluminum, tri-n-butylaluminum, triisobutylaluminum, tripentylaluminum, tri-n-hexylaluminum, tri-n-octylaluminum, tri-n-decylaluminum, tri(dodecyl)aluminum, tri(tetradecyl)aluminum, tri(hexadecyl)aluminum, tri(octadecyl)aluminum and tri(eicosyl)aluminum.

[0133] In this invention, the molar ratio of palladium (Pd) in the catalyst to aluminum (Al) in the organoaluminum compound can be from 1:5 to 1:5000, for example, from 1:10 to 1:2000, for example, from 1:20 to 1:1000, or from 1:20 to 1:500. In some embodiments, the molar ratio of palladium (Pd) in the catalyst to aluminum (Al) in the organoaluminum compound can be 1:10, 1:20, 1:30, 1:40, 1:50, 1:60, 1:70, 1:80, 1:90, 1:100, 1:200, 1:300, 1:400, 1:500, 1:600, 1:700, 1:800, 1:900, 1:1000, 1:2000, 1:3000, 1:4000, 1:5000, or any combination thereof.

[0134] In this invention, the catalyst system is obtained by directly mixing the catalyst with the organoaluminum compound. The mixture of the catalyst and the organoaluminum compound yields a homogeneous mixture. For ease of addition, the homogeneous mixture of the catalyst and the organoaluminum compound can be added to a certain amount of inert solvent to obtain a solution. The inert solvent can be any inert solvent commonly used in the field of olefin polymerization, such as those described above. Although palladium phosphonate catalysts are insoluble in commonly used polymerization solvents such as toluene, the homogeneous mixture obtained by mixing the palladium phosphonate catalyst with the organoaluminum compound is soluble in commonly used polymerization solvents such as toluene.

[0135] The catalyst system of the present invention can be used to catalyze the copolymerization of ethylene with polar monomers such as acrylate monomers. For example, the catalyst system of the present invention can be used in the method of the present invention for preparing ethylene-acrylate copolymers.

[0136] In this invention, all pressures are gauge pressures unless otherwise stated.

[0137] Example

[0138] The present invention will be further described below with reference to the embodiments, but the scope of the present invention is not limited to these embodiments.

[0139] The evaluation and testing methods involved in the following embodiments are as follows:

[0140] 1. The content of acrylate comonomers and the ratio R of the molar amount of acrylate inserted into the copolymer backbone to the total molar amount of acrylate in the copolymer were determined by proton nuclear magnetic resonance spectroscopy; the specific method is as specified above.

[0141] 2. GPC Testing: At PolymerCharts The tests were performed using a high-temperature gel permeation chromatography (HPC) system, specifically an Agilent Technologies 8860GC System high-performance gel permeation column. The sample was dissolved in 1,2,4-trichlorobenzene at a concentration of 1.0 mg / mL. The test temperature was 150 °C, and the flow rate of 1,2,4-trichlorobenzene was 1.0 mL / min. A standard curve was established using the molecular weight of polystyrene as an internal reference, and the molecular weight of the sample was calculated based on the elution time. An infrared detector was used. This is used to determine the methyl content in a sample and calculate the methyl content per thousand carbon atoms, i.e., the number of short branches as described in this invention. The infrared detector is positioned after the GPC column and is operated by... Software control, by The calculation software GPC-ONE automatically generates data. A viscosity detector is placed after the GPC column, with a capillary inner diameter of 0.25 mm, to determine the hydrodynamic structure and the distribution / number of long branches. The workstation obtains the LogIV-LogM curve.

[0142] 3. Rheological Testing: Testing was conducted using a HAAKE MARS 60 rotational rheometer (USA). Before testing, a circular sample with a diameter of 2 cm and a thickness of 2 mm was prepared. The sample was placed in the test container, heated to 190°C, and allowed to melt completely. Then, the disc rotor was pressed to a position 1 mm from the bottom of the container, and the test began. The shear rate versus viscosity curves were obtained by scanning at 190°C at frequencies ranging from 0.1 to 100 Hz, from low to high frequencies.

[0143] 4. Density: Measured at room temperature according to ASTM-D792 method.

[0144] 5. Melting point: Determined by differential scanning calorimetry (DSC). The DSC test procedure is as follows: Place 10 mg of sample in a crucible and measure on a METTLER TOLEDO DSC 1 differential scanning calorimeter; under a nitrogen atmosphere, heat from -70 °C to 200 °C at a rate of 10 °C / min, hold for 1 min, then cool to -70 °C at a rate of 10 °C / min, hold for 3 min, and then heat to 200 °C at a rate of 10 °C / min, recording the second temperature scan data; the peak of the melting peak at the second temperature rise is taken as the melting point of the polymer.

[0145] Example 1

[0146] The polymerization reaction was carried out in a 1.8L high-pressure reactor equipped with a mechanical stirrer and jacket, and connected to ethylene, solvent lines, and catalyst / comonomer inlets. The reaction temperature was controlled by the oil bath temperature in the jacket. 1000 mL of toluene was added to the reactor through the solvent line, and a mixture of 22.5 mL of methyl acrylate (MA) and 0.5 g of 2,6-di-tert-butyl-4-methylphenol was added through the inlet. Stirring was initiated, and the temperature was raised to 80°C. In a glove box, 60 mg of 2-(bis(2-methoxyphenyl)phosphinesulfonic acid (dimethyl sulfoxide)(methyl)palladium) was mixed with 2 mL of triisobutylaluminum and dissolved in 10 mL of toluene, then injected into the reactor through a sealed transfer container. The catalyst was prepared according to “Organometallics 1989,8,12,2907–2917”, “Chem.Commun.,2002,964-965” and “J.Am.Chem.Soc.2009,131,2,422–423”.

[0147] The reactor temperature was set to 80°C, ethylene was continuously fed into the reactor, and the reactor pressure was set to 10 bar. After half an hour, the addition of ethylene was stopped, and dilute hydrochloric acid was injected to acidify the ethanol to terminate the reaction. After depressurization, the reaction solution was poured into a flask, the solvent and unreacted monomers were evaporated to remove them, and the flask was placed in a vacuum oven and dried at 70°C for 24 hours to obtain the copolymer.

[0148] Example 2

[0149] Repeat the polymerization procedure of Example 1, except that 45 ml of methyl acrylate is added.

[0150] Example 3

[0151] Repeat the polymerization procedure of Example 1, except that 67.5 ml of methyl acrylate is added.

[0152] Example 4

[0153] Repeat the polymerization procedure of Example 1, except that 22.5 ml of n-butyl acrylate (BA) is added.

[0154] Example 5

[0155] Repeat the polymerization procedure of Example 1, except that 45 ml of n-butyl acrylate is added.

[0156] Example 6

[0157] Repeat the polymerization procedure of Example 1, except that 67.5 ml of n-butyl acrylate is added.

[0158] Example 7

[0159] The polymerization procedure of Example 1 was used, except that 2-(bis(2-methoxyphenyl)phosphino)benzenesulfonic acid (dimethyl sulfoxide) (methyl)palladium was mixed with triisobutylaluminum and then dissolved in 10 mL of dichloromethane.

[0160] Comparative Example 1

[0161] The polymerization procedure of Example 2 was used, except that triisobutylaluminum was not added and 60 mg of 2-(bis(2-methoxyphenyl)phosphine)benzenesulfonic acid (dimethyl sulfoxide)(methyl)palladium was dissolved in 10 mL of dichloromethane.

[0162] Comparative Example 2

[0163] The polymerization procedure of Example 6 was used, except that triisobutylaluminum was not added and 60 mg of 2-(bis(2-methoxyphenyl)phosphine)benzenesulfonic acid (dimethyl sulfoxide)(methyl)palladium was dissolved in 10 mL of dichloromethane.

[0164] Comparative Example 3

[0165] The copolymer used in this comparative example is a copolymer of ethylene and n-butyl acrylate, purchased from ExxonMobil under the trade name EnBA 33331.

[0166] Comparative Example 4

[0167] The copolymer used in this comparative example is a copolymer of ethylene and n-butyl acrylate, purchased from ExxonMobil under the trade name EnBA 33901.

[0168] Data for the copolymers in the examples and comparative examples are shown in Table 1.

[0169] The rheological test data of the copolymers obtained in Examples 3, 5 and 6 are shown in Table 2.

[0170] Table 2

[0171] Figures 1-6 show the rheological curves of the ethylene-acrylate copolymers of Example 3, Example 5, Example 6, Comparative Example 2, Comparative Example 3, and Comparative Example 4 at 190°C. It can be seen that the copolymers of the present invention exhibit rheological characteristics of significant shear thinning at low shear rates and strong shear thickening at high shear rates.

[0172] Figure 7 shows the LogIV-LogM curves of the ethylene-acrylate copolymer of Example 6 and the copolymer of Comparative Example 3. It can be seen that the LogIV-LogM curve of the copolymer of the present invention is basically linear, while the LogIV-LogM curve of the copolymer of Comparative Example 3 is significantly non-linear in the larger molecular weight region. This indicates that the copolymer of the present invention essentially does not contain long-branched structures, while the copolymer of Comparative Example 3 contains more long-branched chains than the copolymer of the present invention.

[0173] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

[0174] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

Claims

An ethylene-acrylate copolymer characterized in that, The copolymer comprises 85–99.2 mol% ethylene-derived structural units and 0.8–15 mol% acrylate-derived structural units, wherein the acrylate is an alkyl acrylate, and the alkyl group in the alkyl acrylate has x carbon atoms, where x is an integer from 1 to 8; wherein the number of short branches per thousand carbon atoms in the ethylene-acrylate copolymer as measured by GPC [SCB / 1000C] > {1000a / (200+x×a)+10}, where a is the molar content of the acrylate-derived structural units in the copolymer. According to claim 1, the ethylene-acrylate copolymer, wherein the acrylate is at least one selected from methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, tert-butyl acrylate, n-pentyl acrylate, isopentyl acrylate, and 2-ethylhexyl acrylate. The ethylene-acrylate copolymer according to any one of claims 1-2, wherein the molecular weight distribution index (PDI) of the copolymer is ≤2.

5. The ethylene-acrylate copolymer according to any one of claims 1-3, wherein in the GPC test, LogIV and LogM are linearly related, where IV is the intrinsic viscosity and M is the molecular weight; preferably, the coefficient of determination of the trend line of LogIV and LogM is greater than or equal to 0.94, more preferably greater than or equal to 0.

95. The ethylene-acrylate copolymer according to any one of claims 1-4, wherein the melt of the ethylene-acrylate copolymer is released from 190°C in 0.1 s. -1 The shear rate up to 100 s -1 The shear rate initially exhibits shear thinning and then shear thickening, with the transition point between shear thinning and shear thickening occurring between 1 and 100 s. -1 Between 10-100 seconds is preferred. -1 between. The ethylene-acrylate copolymer according to any one of claims 1-5, wherein, said ethylene-acrylate copolymer has a minimum value of viscosity at a shear rate of 0.1 to 100 s -1 at 190°C, and a viscosity value at 100 s -1 is 3 to 250 times the minimum value. -1 ​ The ethylene-acrylate copolymer according to any one of claims 1-6, wherein, The copolymer has a weight-average molecular weight of 5,000 to 100,000 g / mol, preferably 8,000 to 50,000 g / mol. The ethylene-acrylate copolymer according to any one of claims 1-7, wherein, The ratio R of the molar amount of acrylate inserted into the copolymer backbone to the total molar amount of acrylate in the copolymer is 0.84-1. Process for the preparation of an ethylene-acrylate copolymer according to any one of claims 1-8, characterized in that, The method includes: mixing a catalyst with an organoaluminum compound to form a homogeneous mixture; and adding the homogeneous mixture into a polymerization reactor to copolymerize acrylate and ethylene in the presence of an inert solvent to obtain the ethylene-acrylate copolymer. wherein the catalyst is at least one of the compounds of formula (I): in, R 11 represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 30 carbon atoms optionally containing a heteroatom, or an aryl group having 6 to 30 carbon atoms optionally containing a heteroatom; preferably R 11 is a hydrogen atom, an alkyl group having 1 to 6 carbon atoms optionally containing a heteroatom, or an aryl group having 6 to 13 carbon atoms optionally containing a heteroatom; wherein the heteroatom is selected from halogen (e.g. fluorine, chlorine and bromine), O, N and S; more preferably R 11 is selected from a hydrogen atom, a methyl group, an ethyl group, a trifluoromethyl group, an acyl group, an acetoxy group, a phenyl group, a tolyl group, a xylyl group, a phenanthryl group and a pentafluorophenyl group; further more preferably R 11 is selected from a hydrogen atom, a methyl group and a phenyl group; L represents a ligand coordinated to Pd; preferably, the ligand is selected from pyridine, amine, piperidine, ether, sulfone, sulfoxide and phosphine ligands; more preferably, the ligand is selected from dimethyl sulfoxide, pyridine, tetramethylethylenediamine, triphenylphosphine and 2,6-dimethylpyridine, and even more preferably dimethyl sulfoxide; R 12 and R 13 each independently represent a hydrocarbon group having 1 to 30 carbon atoms, optionally containing heteroatoms, preferably R 12 and R 13 each independently represent an aryl group having 3 to 30 carbon atoms, optionally containing heteroatoms, more preferably R 12 and R 13 each independently represent an aryl group having 6 to 30 carbon atoms, optionally containing heteroatoms, wherein the heteroatoms are selected from O, N and S; further preferably, R 12 and R 13 each independently are phenyl, 2-methylphenyl, 2,6-dimethylphenyl, 2-ethylphenyl, 2,6-diethylphenyl, 2-isopropylphenyl, 2,6-di(isopropyl)phenyl, 2-cyclohexylphenyl, 2,6-di(cyclohexyl)phenyl, 2-methoxyphenyl, 2,6-dimethoxyphenyl, 2-phenoxyphenyl and 2,6-diphenoxyphenyl; and R 14 To R 17 Each can independently represent a hydrogen atom, a halogen atom, a hydrocarbon group with 1 to 30 carbon atoms that optionally contains a heteroatom, or OR 28 CO2R 28 CO2M', C(O)N(R) 29 2. C(O)R 28 SR 28 SO2R 28 SOR 28 OSO2R 28 、P(O)(OR 28 ) 2-f (R 29 ) f CN, NHR 28 、N(R 28 2. Si(OR) 29 ) 3-e (R 29 ) e OSi(OR) 29 ) 3-e (R 29 ) e , NO2, SO3M', PO3M'2, P(O)(OR 28 )2M' or containing an epoxy group, wherein R 28 R represents a hydrocarbon group having 1 to 20 carbon atoms. 29 M' represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, M' represents an alkali metal, alkaline earth metal, ammonium, quaternary ammonium or phosphorus, e represents an integer from 0 to 3, and f represents an integer from 0 to 2. The method of preparation according to claim 9, wherein, The catalyst is at least one of the compounds of formula (II); In formula (II), R 1 , R 2 and R 3 , each the same or different, are each independently hydrogen, C1-C 30 alkyl, C1-C 30 alkyl having a heteroatom, C1-C 30 alkoxy or C6-C 30 aryloxy, wherein said groups are optionally substituted with substituents selected from the group consisting of halogen atoms, C1-C 10 alkyl, C1-C 10 alkoxy, C6-C 10 aryl and C6-C 10 aryloxy, wherein said heteroatom is selected from the group consisting of O, N and S; and L is a ligand; preferably, the ligand L is selected from pyridine, amine, piperidine, ether, sulfone, sulfoxide and phosphine ligands; preferably, the ligand L is selected from dimethyl sulfoxide, pyridine, tetramethylethylenediamine, triphenylphosphine and 2,6-dimethylpyridine, more preferably dimethyl sulfoxide; More preferably, the catalyst is at least one selected from 2-(bis(2-methoxyphenyl)phosphino)benzenesulfonic acid (dimethyl sulfoxide) (methyl)palladium, 2-(bis(2-phenoxyphenyl)phosphino)benzenesulfonic acid (dimethyl sulfoxide) (methyl)palladium and 2-(bis(2-methoxyphenyl)phosphino)-4-methylbenzenesulfonic acid (dimethyl sulfoxide) (methyl)palladium. The method of manufacturing according to claim 9 or 10, wherein the method can further comprise: Provides acrylates; and adding the acrylic ester and the homogeneous mixture into a polymerization reactor to make the acrylic ester and ethylene copolymerize in the presence of the inert solvent to obtain the ethylene-acrylic ester copolymer; preferably, the acrylic ester is added into the polymerization reactor and then the homogeneous mixture is added into the polymerization reactor, or the acrylic ester and the homogeneous mixture are simultaneously added into the polymerization reactor. The production method according to any one of claims 9 to 11, wherein The method also includes providing a copolymerization regulator and adding the copolymerization regulator to the polymerization reactor; wherein the copolymerization regulator is at least one of a compound represented by formula (III) and a compound represented by formula (IV): In equation (III), R 4 Selected from hydrogen atoms, C1-C 20 Hydrocarbon group, C1-C 20 Alkoxy or C6-C 20 Aryloxy groups, which are straight-chain, branched, or cyclic, and optionally selected from halogen atoms, C1-C... 10 Alkyl, C1-C 10 Alkoxy, C1-C6 carbonyl, C6-C 10 Aryl or C6-C 10 Substituents of aryloxy groups; in formula (IV), R 5 Selected from hydrogen atoms, C1-C 20 Hydrocarbon group, C1-C 20 Alkoxy or C6-C 20 Aryloxy groups, which are straight-chain, branched, or cyclic, and optionally selected from halogen atoms, C1-C... 10 Alkyl, C1-C 10 Alkoxy, C1-C6 carbonyl, C6-C 10 Aryl and C6-C 10 Substituent substitution of aryloxy groups; preferably, the copolymerization regulator is at least one of 2,6-di-tert-butyl-4-methylphenol, 2,6-di-tert-butylphenol, 2,4,6-tri-tert-butylphenol and 2,6-di-tert-butyl-α-(3,5-di-tert-butyl-4-oxo-2,5-cyclohexadienyl)-p-tolyloxy free radical; Preferably, the providing the copolymerization regulator comprises mixing the acrylic ester with the copolymerization regulator to form a homogeneous mixture; and adding the homogeneous mixture of the acrylic ester and the copolymerization regulator into the polymerization reactor. The preparation method according to claim 12, wherein the molar ratio of the acrylic ester to the copolymerization regulator is 50:1-500:1, preferably 100:1-350:1, more preferably 150:1-300:1; and / or the molar ratio of the catalyst to the copolymerization regulator in the polymerization system is 1:1-1:200, preferably 1:3-1:100, more preferably 1:4-1:50, further preferably 1:5-1:30, in terms of Pd atoms. The production method according to any one of claims 9 to 13, wherein The amount of the catalyst in the polymerization system is 10-1000 μmol / L, preferably 30-500 μmol / L, more preferably 100-300 μmol / L, in terms of Pd; and / or The molar ratio of palladium (Pd) in the catalyst to aluminum (Al) in the organic aluminum compound is 1:5 to 1:5000. The method of manufacturing according to any one of claims 9-14, wherein, The organoaluminum compound is an organoaluminum compound of the general formula AlR 6 R 7 R 8 wherein R 6 , R 7 and R 8 are the same as or different from each other and are each independently a C1-C 20 hydrocarbyl group, preferably R 6 , R 7 and R 8 are the same as or different from each other and are each independently a C1-C 20 alkyl group; more preferably, the organoaluminum compound is selected from one or more of trimethylaluminum, triethylaluminum, tri-n-propylaluminum, tri-n- butylaluminum, triisobutylaluminum, tripentylaluminum, tri-n-hexylaluminum, tri-n- octylaluminum, tri-n-decylaluminum, tridodecylaluminum, tritetradecylaluminum, tricetylaluminum, trioctadecylaluminum, and trieicosylaluminum. The method of manufacturing according to any one of claims 9-15, wherein, The inert solvent is selected from the group consisting of aliphatic hydrocarbon solvents, cycloaliphatic hydrocarbon solvents, aromatic hydrocarbon solvents, and combinations thereof; preferably, the inert solvent is selected from the group consisting of C6-C 12 alkanes, C5-C 10 cycloalkanes, C6-C 10 monocyclic aromatic hydrocarbons, and combinations thereof; more preferably, the C6-C 12 alkanes are at least one of n-hexane, isohexane, n-heptane, isohexane, n-octane, and isooctane; the C5-C 10 cycloalkanes are at least one of cyclopentane, cyclohexane, cycloheptane, and cyclooctane; and the C6-C 10 monocyclic aromatic hydrocarbons are toluene and / or xylene; further more preferably, the inert solvent is at least one of n-hexane, isohexane, cyclohexane, and toluene. The method of manufacturing according to any one of claims 9-16, wherein, The polymerization temperature is between 60-150 ℃ and the polymerization pressure is between 0.1-10 MPa; and / or The concentration of the acrylic ester in the polymerization system is 0.1-5 mol / L, preferably 0.2-2 mol / L, more preferably 0.25-2 mol / L; and / or The chlorine-containing solvent is not used. A catalyst system comprising a catalyst having formula (I) and an organoaluminum compound directly and uniformly mixed together; The chlorine-containing solvent is not used. R 11 represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 30 carbon atoms optionally containing a heteroatom, or an aryl group having 6 to 30 carbon atoms optionally containing a heteroatom; preferably R 11 is a hydrogen atom, an alkyl group having 1 to 6 carbon atoms optionally containing a heteroatom, or an aryl group having 6 to 13 carbon atoms optionally containing a heteroatom; wherein the heteroatom is selected from halogen (e.g. fluorine, chlorine and bromine), O, N and S; more preferably R 11 is selected from a hydrogen atom, a methyl group, an ethyl group, a trifluoromethyl group, an acyl group, an acetoxy group, a phenyl group, a tolyl group, a xylyl group, a phenanthryl group and a pentafluorophenyl group; further more preferably R 11 is selected from a hydrogen atom, a methyl group and a phenyl group; L represents a ligand coordinated to Pd; preferably, the ligand is selected from pyridine, amine, piperidine, ether, sulfone, sulfoxide and phosphine ligands; more preferably the ligand is selected from dimethyl sulfoxide, pyridine, tetramethylethylenediamine, triphenylphosphine and 2,6-dimethylpyridine, further more preferably dimethyl sulfoxide; R 12 and R 13 each independently represent a hydrocarbon group having 1 to 30 carbon atoms, optionally containing heteroatoms, preferably R 12 and R 13 each independently represent an aryl group having 3 to 30 carbon atoms, optionally containing heteroatoms, more preferably R 12 and R 13 each independently represent an aryl group having 6 to 30 carbon atoms, optionally containing heteroatoms, wherein the heteroatoms are selected from O, N and S; further preferably, R 12 and R 13 each independently are phenyl, 2-methylphenyl, 2,6-dimethylphenyl, 2-ethylphenyl, 2,6-diethylphenyl, 2-isopropylphenyl, 2,6-di(isopropyl)phenyl, 2-cyclohexylphenyl, 2,6-di(cyclohexyl)phenyl, 2-methoxyphenyl, 2,6-dimethoxyphenyl, 2-phenoxyphenyl and 2,6-diphenoxyphenyl; and R 14 to R 17 each independently represent a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 30 carbon atoms optionally containing a heteroatom, OR 28 , CO2R 28 , CO2M', C(O)N(R 29 )2, C(O)R 28 , SR 28 , SO2R 28 , SOR 28 , OSO2R 28 , P(O)(OR 28 ) 2-f (R 29 ) f , CN, NHR 28 , N(R 28 )2, Si(OR 29 ) 3-e (R 29 ) e , OSi(OR 29 ) 3-e (R 29 ) e , NO2, SO3M', PO3M'2, P(O)(OR 28 )2M' or an epoxy group-containing group, wherein R 28 represents a hydrocarbon group having 1 to 20 carbon atoms, R 29 represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, M' represents an alkali metal, an alkaline earth metal, an ammonium, a quaternary ammonium or a phosphonium, e represents an integer of 0 to 3, and f represents an integer of 0 to 2; Preferably, wherein the catalyst is at least one of the compounds shown in formula (II); In formula (II), R 1 , R 2 and R 3 , each the same or different, are each independently hydrogen, C1-C 30 alkyl, C1-C 30 alkyl having a heteroatom, C1-C 30 alkoxy, or C6-C 30 aryloxy, wherein said groups are optionally substituted with substituents selected from the group consisting of halogen atoms, C1-C 10 alkyl, C1-C 10 alkoxy, C6-C 10 aryl, and C6-C 10 aryloxy, wherein said heteroatom is selected from the group consisting of O, N, and S; and L represents a ligand coordinated to Pd; preferably, the ligand is selected from pyridine, amine, piperidine, ether, sulfone, sulfoxide and phosphine ligands; more preferably the ligand is selected from dimethyl sulfoxide, pyridine, tetramethylethylene diamine, triphenylphosphine and 2,6-dimethylpyridine. More preferably, the catalyst is at least one of 2-(bis(2-methoxyphenyl)phosphino)benzenesulfonic acid(dimethyl sulfoxide)(methyl)palladium, 2-(bis(2-phenoxyphenyl)phosphino)benzenesulfonic acid(dimethyl sulfoxide)(methy)palladium and 2-(bis(2-methoxyphenyl)phosphino)-4-methylbenzenesulfonic acid(dimethyl sulfoxide)(methyl)palladium. The catalyst system according to claim 18, wherein, The organoaluminum compound is an organoaluminum compound of the general formula AlR 6 R 7 R 8 wherein R 6 , R 7 and R 8 are the same as or different from each other and are each independently a Ci to C 20 hydrocarbyl group, preferably R 6 , R 7 and R 8 are the same as or different from each other and are each independently a Ci to C 20 alkyl group; more preferably, the organoaluminum compound is selected from one or more of trimethylaluminum, triethylaluminum, tri-n-propylaluminum, tri-n- butylaluminum, triisobutylaluminum, tripentylaluminum, tri-n-hexylaluminum, tri-n- octylaluminum, tri-n-decylaluminum, tridodecylaluminum, tritetradecylaluminum, tricetylaluminum, trioctadecylaluminum, and trieicosylaluminum; and / or The molar ratio of palladium (Pd) in the catalyst to aluminum (Al) is 1:5 to 1:5000. The catalyst system according to claim 18 for catalyzing the copolymerization of ethylene with a polar monomer, preferably the polar monomer comprises an acrylate monomer, more preferably the catalyst system is used in the production process according to any one of claims 9-17.

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