Ethylene-propylene-alpha-olefin-diene quaternary copolymer rubber and preparation method thereof

Abstract

The invention relates to an ethylene-propylene-alpha-olefin-diene quaternary copolymer rubber, which is a random copolymer formed by copolymerization of ethylene, propylene, high-carbon alpha-olefin and diene, on the basis of the total molar weight of the quadripolymer, the molar percentage content of each monomer unit meets the following conditions: 20-80% of an ethylene unit, 2-60% of a propylene unit, 2-50% of a high-carbon alpha-olefin unit and 1-15% of a diene unit, and the sum of the molar percentage content of the ethylene unit, the propylene unit, the high-carbon alpha-olefin unit and the diene unit is 100%; the number-average molecular weight of the quadripolymer is 30 to 800 kg / mol, and the molecular weight distribution index of the quadripolymer is 1.10 to 2.90; the metallocene catalyst is introduced, so that the reactivity ratio difference of ethylene, propylene and high-carbon alpha-olefin is reduced, the polymerization chain transfer side reaction of ethylene, propylene and high-carbon alpha-olefin is inhibited, random high insertion of high-carbon alpha-olefin in ethylene propylene rubber is realized, and the high-carbon alpha-olefin / ethylene propylene rubber composite material is obtained. The high-molecular-weight narrow-distribution ethylene-propylene-diene monomer rubber is prepared by a one-pot method, so that the melt elasticity, cold resistance, moisture resistance, flow ductility and processability are improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of synthetic rubber, and in particular relates to an ethylene-propylene-alpha-olefin-diene quaternary copolymer rubber and a preparation method thereof. Background Art

[0002] Due to its excellent weathering and aging resistance, EPDM rubber (EPR) has found widespread application in automotive parts, building materials, electrical appliances, and rubber-plastic blends. While EPDM exhibits excellent mechanical and compression set properties under normal conditions, it suffers from poor low-temperature resistance, with mechanical properties significantly degrading below -40°C. Introducing a high-carbon α-olefin into EPDM increases the molecular chain spacing, increasing the free space between the chains and lowering the glass transition temperature, significantly improving the rubber's low-temperature properties, particularly its resilience, flexural strength, and crack growth resistance at low temperatures. Mitsui Chemicals of Japan has synthesized EPDM, replacing propylene with butene. This EPDM can be used at -60°C, while its high-temperature performance is comparable to that of EPDM, allowing long-term operation at 150°C. It also exhibits excellent moisture resistance. However, compared to the more widely used EPDM, this EPDM rubber has a lower molecular weight and inferior mechanical properties. Therefore, it is often blended with EPDM in the preparation of sealants, cable insulation, and resilient windshields for low-temperature applications. The casting properties of ethylene-propylene-α-olefin ternary copolymers will also be better, and they can be used as cast films and heat-sealing layers of aluminized films.

[0003] To address the current challenges with EPDM and EPDM, the preparation of ethylene-propylene-α-olefin-diene tetrapolymer rubber is of great significance for the development of rubber materials with superior overall performance. However, the vanadium and titanium Ziegler-Natta catalysts currently used in the preparation of EPDM have low catalytic activity, necessitating the use of large quantities of catalyst. Furthermore, vanadium is a toxic substance, and the polymer must undergo a complex deashing process. Furthermore, this catalytic system can produce gels during polymerization, hindering long-term operation. Compared to Ziegler-Natta catalysts, metallocene catalysts have higher activity, require lower catalyst dosages, and do not require deashing. Furthermore, metallocene catalysts can control selectivity and monomer reactivity ratios, reducing the formation of physical and chemical gels and enabling the preparation of EPDM with a controllable structure and narrow distribution. However, the preparation of ethylene-propylene-α-olefin-diene quaternary copolymer rubber has higher requirements for metallocene catalysts: 1) the difference in the reactivity ratio of the four monomers cannot be too large, and random copolymerization of the four monomers can be achieved, which can effectively regulate the composition of the copolymer; 2) the chain transfer side reaction during the polymerization of high-carbon α-olefins cannot be too large, and a polymer with a high insertion rate and high molecular weight can be obtained; 3) the copolymerization of multiple dienes can be achieved, and the residual double bonds cannot react. It is difficult for existing metallocene catalysts to meet these conditions at the same time. Therefore, the patent (application number 202210990224.6) discloses a polyethylene-propylene-butene ternary rubber and a preparation method thereof. By copolymerizing butadiene and isoprene under the action of an initiator and a 1,2-structure regulator, a high-vinyl butadiene-isoprene copolymer is prepared. The copolymer is selectively hydrogenated to prepare an ethylene-propylene-butene ternary rubber. However, this method can only produce butene copolymers, and α-olefins with longer carbon chains cannot be introduced into ethylene-propylene rubber.

[0004] In view of this, this patent proposes an ethylene-propylene-α-olefin-diene tetrapolymer rubber and a preparation method thereof, which uses a metallocene catalyst to catalyze the copolymerization of ethylene, propylene, high-carbon α-olefins with a carbon number greater than 3, and diolefins, reduces the difference in the reactivity rate of ethylene, propylene and high-carbon α-olefins, inhibits the chain transfer side reaction in the polymerization process of high-carbon α-olefins, and introduces high-carbon α-olefins randomly and with a high insertion rate into EPDM rubber to prepare a high molecular weight, narrow distribution, and composition-controlled tetrapolymer, thereby improving the melt elasticity, cold resistance, moisture resistance and processability of EPDM rubber. Summary of the Invention

[0005] In response to the defects in the performance of existing EPDM rubber, the first object of the present invention is to provide an ethylene-propylene-α-olefin-diene quaternary copolymer rubber, randomly and highly inserted into the EPDM rubber with a variety of high-carbon α-olefins, and develop a new EPDM rubber with high molecular weight and narrow distribution, so as to optimize the rubber properties through copolymerization rather than blending.

[0006] A second object of the present invention is to provide a novel method for preparing ethylene-propylene rubber, which utilizes a metallocene catalyst to catalyze the tetrapolymerization of ethylene, propylene, α-olefin, and diene. The method has the advantage of efficiently preparing a high-molecular-weight multi-component random copolymer in one pot.

[0007] To achieve the above first object, the present invention provides the following technical solutions:

[0008] An ethylene-propylene-alpha-olefin-diene quaternary copolymer rubber is disclosed. The copolymer rubber is a random copolymer formed by copolymerizing ethylene, propylene, a higher alpha-olefin and a diene. Based on the total molar weight of the quaternary copolymer, the molar percentage of each monomer unit satisfies the following conditions: ethylene unit: 20-80%, propylene unit: 2-60%, higher alpha-olefin unit: 2-50%, diene unit: 1-15%, and the sum of the molar percentages of the ethylene, propylene, higher alpha-olefin and diene is 100%. The quaternary copolymer has a number average molecular weight of 30-800 kg / mol and a molecular weight distribution index of 1.10-2.90. The higher alpha-olefin units and diene units are evenly distributed in the random ethylene-propylene rubber chain in an isolated form.

[0009] Furthermore, the high carbon α-olefin is C 4-12 Straight chain α-olefins or alkyl substituted C 4-12 Branched alpha-olefins.

[0010] Furthermore, the diene is selected from one of a bridged cyclic diene, a linear diene, a cyclic diene, and a conjugated diene.

[0011] To achieve the above first object, the present invention provides the following technical solutions:

[0012] A method for preparing an ethylene-propylene-α-olefin-diene tetrapolymer rubber comprises the following steps: catalyzing ethylene, propylene, a high-carbon α-olefin, and a diene in an organic solvent by a metallocene catalyst under an inert gas atmosphere to obtain the tetrapolymer rubber; the polymerization temperature is 20-150° C., the polymerization pressure is 0.1-8 MPa, and the polymerization time is 5-90 min.

[0013] Furthermore, the metallocene catalyst includes a main catalyst and a co-catalyst, wherein the main catalyst is a metallocene compound containing heteroatom coordination; and the co-catalyst is an organic boron auxiliary agent.

[0014] Furthermore, the molecular formula of the metallocene compound is CpML2X, wherein Cp is selected from cyclopentadienyl, substituted cyclopentadienyl, indenyl, substituted indenyl, fluorenyl or substituted fluorenyl; M is selected from metals Ti, Zr and Hf; L is selected from chlorine, C 1-6hydrocarbyl, CH2SiMe3, CH2C6H4NMe2-o, CH2Ph or CH(SiMe3)2; X is a Lewis base containing O, N, P or S heteroatom.

[0015] Further, the organic boron reagent is selected from at least one of [Ph3C][B(C6F5)4], [PhMe2NH][B(C6F5)4], [HNMe(C 18 H 37 )2][B(C6F5)4] or B(C6F5)3.

[0016] Further, the organic solvent is selected from at least one of isopentane, n-hexane, isohexane, cyclohexane, isoheptane, toluene, xylene.

[0017] The present application has the following beneficial effects:

[0018] First, the four-component copolymer rubber is prepared by one-pot high-efficiency four-component polymerization of ethylene, propylene, high-carbon α-olefin and diene using a metallocene catalyst, and the four-component copolymer rubber has more excellent low-temperature resistance.

[0019] Second, the present application uses a heteroatom-coordinated complex as a main catalyst, and the catalyst shows high catalytic activity and inhibits the chain transfer side reaction in the polymerization process of high-carbon α-olefin, so that the obtained four-component copolymer rubber has high molecular weight and narrow molecular weight distribution.

[0020] Third, the present application reduces the difference in reactivity ratio of ethylene, propylene and high-carbon α-olefin by means of ligand regulation, realizes high content and random insertion of high-carbon α-olefin in the copolymer, and prepares a four-component copolymer with controllable composition and random sequence, which can effectively destroy the crystallization of polyethylene segments even when the content of ethylene is high. BRIEF DESCRIPTION OF DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor under the premise of the drawings.

[0022] Figure 1 NMR hydrogen spectrum of ethylene, propylene, 1-butene, 5-vinyl-2-norbornene four-component copolymer prepared for the present application embodiment 1;

[0023] Figure 2 NMR hydrogen spectrum of ethylene, propylene, 1-butene, 5-vinyl-2-norbornene four-component copolymer prepared for the present application embodiment 1;

[0024] Figure 3 This is the H NMR spectrum of the ethylene, propylene, 1-octene, and ethylidene norbornene tetrapolymer prepared in Example 2 of the present invention;

[0025] Figure 4 This is the C NMR spectrum of the ethylene, propylene, 1-octene, and ethylidene norbornene tetrapolymer prepared in Example 2 of the present invention;

[0026] Figure 5 The DSC curve of the tetrapolymer of ethylene, propylene, 1-butene and 5-vinyl-2-norbornene prepared in Example 1 of the present invention;

[0027] Figure 6 This is the DSC curve of the tetrapolymer of ethylene, propylene, 1-octene and ethylidene norbornene prepared in Example 2 of the present invention;

[0028] Figure 7 This is the DSC curve of the tetrapolymer of ethylene, propylene, 4-methyl-1-pentene and isoprene prepared in Example 3 of the present invention;

[0029] Figure 8 The DSC curve of the tetrapolymer of ethylene, propylene, 1-dodecene and 1,4-hexadiene prepared in Example 4 of the present invention;

[0030] Figure 9 This is the DSC curve of the tetrapolymer of ethylene, propylene, 5-methyl-1-hexene and cyclohexadiene prepared in Example 5 of the present invention;

[0031] Figure 10 This is the DSC curve of the tetrapolymer of ethylene, propylene, 1-butene and dicyclopentadiene prepared in Example 6 of the present invention;

[0032] Figure 11 This is the DSC curve of the tetrapolymer of ethylene, propylene, 1-butene and ethylidene norbornene prepared in Example 7 of the present invention;

[0033] Figure 12 The DSC curve of the ethylene, propylene, and 5-vinyl-2-norbornene terpolymer prepared in Comparative Example 1 of the present invention;

[0034] Figure 13 This is the DSC curve of the ethylene, propylene and cyclohexadiene terpolymer prepared in Comparative Example 2 of the present invention. DETAILED DESCRIPTION

[0035] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0036] Except for the metallocene catalyst, the conditions not specified in the examples were carried out according to conventional conditions or the conditions recommended by the manufacturer. The reagents or instruments used without specifying the manufacturer were all commercially available conventional products.

[0037] The present invention provides an ethylene-propylene-alpha-olefin-diene quaternary copolymer rubber. The copolymer rubber is a random copolymer formed by copolymerizing ethylene, propylene, a higher-carbon alpha-olefin and a diene. Based on the total molar weight of the quaternary copolymer, the molar percentage of each monomer unit satisfies the following conditions: ethylene unit: 20-80%, propylene unit: 2-60%, higher-carbon alpha-olefin unit: 2-50%, and diene unit: 1-15%, and the sum of the molar percentages of the ethylene, propylene, higher-carbon alpha-olefin and diene is 100%. The number average molecular weight of the quaternary copolymer is 30-800 kg / mol, and the molecular weight distribution index is 1.10-2.90. The higher-carbon alpha-olefin unit and the diene unit are evenly distributed in the random ethylene-propylene rubber chain in an isolated form.

[0038] Furthermore, the high carbon α-olefin is C 4-12 Straight chain α-olefins or alkyl substituted C 4-12 Branched alpha-olefins.

[0039] Furthermore, the diene is selected from one of a bridged cyclic diene, a linear diene, a cyclic diene, and a conjugated diene.

[0040] The present invention also provides a method for preparing an ethylene-propylene-α-olefin-diene tetrapolymer rubber, comprising the steps of: polymerizing ethylene, propylene, high-carbon α-olefins, and dienes in an organic solvent using a metallocene catalyst under an inert gas atmosphere to obtain the tetrapolymer rubber; wherein the polymerization temperature is 20 to 150° C., the polymerization pressure is 0.1 to 8 MPa, and the polymerization time is 5 to 90 minutes.

[0041] Furthermore, the metallocene catalyst includes a main catalyst and a co-catalyst, wherein the main catalyst is a metallocene compound containing heteroatom coordination; and the co-catalyst is an organic boron auxiliary agent.

[0042] Further, the metallocene compound has a molecular formula of CpML2X, wherein Cp is selected from cyclopentadienyl, substituted cyclopentadienyl, indenyl, substituted indenyl, fluorenyl, or substituted fluorenyl; M is selected from metals Ti, Zr, and Hf; L is selected from chlorine, C 1-6 hydrocarbyl, CH2SiMe3, CH2C6H4NMe2-o, CH2Ph, or CH(SiMe3)2; and X is a Lewis base containing O, N, P, or S heteroatom.

[0043] Further, the organic boron reagent is selected from at least one of [Ph3C][B(C6F5)4], [PhMe2NH][B(C6F5)4], [HNMe(C 18 H 37 ][B(C6F5)4], or B(C6F5)3.

[0044] Further, the organic solvent is selected from at least one of isopentane, n-hexane, isohexane, cyclohexane, isoheptane, toluene, xylene.

[0045] Preparation Example 1

[0046] Preparation of the mono-metallocene titanium catalyst (C9H7)Ti(CH2C6H4NMe2-o)2Py

[0047] In anhydrous and anaerobic inert atmosphere, 2.679 g of (C9H7)TiCl3 powder was dissolved in 25 mL of tetrahydrofuran, 1.433 g of 1-trimethylsilylpyrrolidine was added under stirring at room temperature, and the reaction was stirred at 90°C for 8 h. Then, 2.820 g of LiCH2C6H4NMe2-o was added under stirring, and the reaction was continued for 1 h. The solvent was removed under vacuum, and the residual solid was extracted with toluene. After concentration, it was put into a refrigerator at -30°C overnight, and recrystallization was performed to obtain 3.598 g of the mono-metallocene titanium catalyst (C9H7)Ti(CH2C6H4NMe2-o)2Py, with a yield of 72%. 1 H NMR (400 MHz, toluene-d8, δ, ppm): 6.53-7.38 (m, 14H, C6H4, C9H7, Py), 6.17 (m, 2H, Py), 5.57 (s, 3H, C9H7), 2.19 (s, 12H, NMe2), 0.99 (s, 4H, CH2).

[0048] Preparation Example 2

[0049] Preparation of the mono-metallocene titanium catalyst (1,3-(SiMe3)2-C9H5)Ti(CH2Ph)2SPh

[0050] In an anhydrous and oxygen-free inert atmosphere, 4.120 g of (1,3-(SiMe3)2-C9H5)TiCl3 powder was weighed and dissolved in 25 mL of tetrahydrofuran. 1.000 g of LiSPh was added with stirring at room temperature, and the reaction was stirred for 1 hour. 1.960 g of LiCH2Ph ​​was then added with stirring, and the reaction continued for 1.5 hours. The solvent was removed in vacuo, and the residual solid was extracted with toluene. After concentration, the solid was placed in a -30°C refrigerator overnight and recrystallized to obtain 4.786 g of the monotitanocenes (1,3-(SiMe3)2-C9H5)Ti(CH2Ph)2SPh catalyst in an 80% yield. 1 H NMR (400MHz, toluene-d8, δ, ppm): 7.89 (d, 2H, C9H5), 7.64-6.89 (m, 18H, C9H5, CH2Ph, SPh), 0.96 (s, 4H, CH2), 0.43 (s, 12H, SiMe3).

[0051] Preparation Example 3

[0052] Monozirconocene catalyst (C5H5)Zr(n-C6H 13 Preparation of 2OPh

[0053] In an anhydrous and oxygen-free inert atmosphere, 2.598 g of (C5H5)ZrCl3 powder was weighed and dissolved in 25 mL of tetrahydrofuran. 1.000 g of LiOPh was added under stirring at room temperature and the reaction was stirred for 1 hour. 1.842 g of n-hexyllithium was added under stirring and the reaction was continued for 0.5 hour. The solvent was removed in vacuo and the residual solid was extracted with toluene. After concentration, the solid was placed in a -30°C refrigerator overnight and recrystallized to obtain 3.417 g of monocyclopentadienyl zirconocene catalyst (C5H5)Zr(n-C6H 13 )2OPh, with a yield of 82%. 1 H NMR (400MHz, toluene-d8, δ, ppm): 6.46-7.24(m,5H,Ph), 5.79(s,5H,C5H5), 0.88(t,6H,CH3), 1.10-1.24(t,16H,CH2), 0.12(t,4H,ZrCH2).

[0054] Preparation Example 4

[0055] Monohafnocene catalyst (9-SiMe3-C 13 H8) Preparation of Hf(n-C4H9)2N=PPh3

[0056] In an anhydrous and oxygen-free inert atmosphere, 5.219 g (C 13H8SiMe3)HfCl3 powder was dissolved in 25 mL of tetrahydrofuran, 3.491 g of Me3SiN=PPh3 was added with stirring at room temperature, and the reaction was stirred at 90 °C for 12 h. With stirring, 1.280 g of n-butyllithium was added, and the reaction was continued for 0.5 h. The solvent was removed in vacuo, the residual solid was extracted with toluene, and the extract was concentrated and placed in a -30 °C freezer overnight to give 5.643 g of the mono-cyclopentadienyl hafnium catalyst (9-SiMe3-C 13 H8)Hf(n-C4H9)2N=PPh3 in 70% yield. 1 H NMR (400 MHz, toluene-d8, δ, ppm): 8.05-7.02 (m, 8H, C 13 H8), 7.29 (m, 15H, PPh3), 1.76 (q, 4H, CH3CH2); 1.56 (q, 4H, CH2CH2CH2); 1.10 (t, 6H, CH2CH3), 0.67 (s, 9H, SiMe3), 0.14 (t, 4H, HfCH2).

[0057] Preparation Example 5

[0058] Preparation of mono-cyclopentadienyl zirconium catalyst (C5Me4SiMe3)ZrMe2MEP

[0059] In an anhydrous and anaerobic inert atmosphere, 3.879 g of (C5Me4SiMe3)ZrCl3 powder was dissolved in 25 mL of tetrahydrofuran, and 1.573 g of 1-(trimethylsilyl)piperidine was added with stirring at 70 °C, and the reaction was stirred for 12 h. With stirring, 0.438 g of methyllithium was added, and the reaction was continued for 1 h. The solvent was removed in vacuo, the residual solid was extracted with toluene, and the extract was concentrated and placed in a -30 °C freezer overnight to give 3.368 g of the mono-cyclopentadienyl zirconium catalyst (C5Me4SiMe3)ZrMe2MEP in 85% yield. 1 H NMR (400 MHz, toluene-d8, δ, ppm): 2.76 (m, 4H, MEP), 2.22 (s, 6H, C5Me4), 1.91 (s, 6H, C5Me4), 1.53 (m, 6H, MEP), 0.70 (s, 6H, Me2), 0.43 (s, 9H, SiMe3).

[0060] Example 1

[0061] Preparation of a tetrapolymer of ethylene, propylene, 1-butene and 5-vinyl-2-norbornene

[0062] Under the protection of inert gas nitrogen, 30 mL of anhydrous and oxygen-free cyclohexane, 6 g of 1-butene and 0.1 g of 5-vinyl-2-norbornene were added to a dry and deoxygenated polymerization reactor, ethylene and propylene gas (ethylene / propylene molar ratio of 10:1) was introduced, the temperature was raised to a polymerization temperature of 20°C and a polymerization pressure of 0.2 MPa, 5 μmol of metallocene catalyst and 5 μmol of B(C6F5)3 were added to the polymerization reactor, the polymerization reaction was stirred for 10 minutes, and 6.81 g of copolymer was obtained after removing volatile components from the polymerization solution, wherein the metallocene catalyst was prepared by the method of Preparation Example 1 of Metallocene Catalyst.

[0063] GPC measured the number average molecular weight of the copolymer to be 750 kg / mol and the molecular weight distribution to be 2.90; the H NMR spectrum of the tetrapolymer of ethylene, propylene, 1-butene and 5-vinyl-2-norbornene was as follows: Figure 1 As shown in FIG, the copolymer composition is as follows: ethylene 71.9 mol%, propylene 4.1 mol%, 1-butene 22.6 mol%, 5-vinyl-2-norbornene 1.2 mol%. The C NMR spectrum of the quaternary copolymer of ethylene, propylene, 1-butene and 5-vinyl-2-norbornene is shown in FIG. Figure 2 As shown in Figure 2, the copolymer is a random copolymer, and the 1-butene and 5-vinyl-2-norbornene units are isolated and distributed in the copolymer chain. DSC tests the thermal properties of the copolymer, such as Figure 5 The glass transition temperature of the copolymer shown is -67°C.

[0064] Example 2

[0065] Preparation of ethylene, propylene, 1-octene and ethylidene norbornene tetrapolymer

[0066] Under the protection of inert gas argon, 30 mL of anhydrous and oxygen-free toluene, 0.5 g of 1-octene and 0.5 g of ethylidene norbornene were added to a dry and deoxygenated polymerization reactor, and 2 MPa of ethylene and propylene gas mixed in a molar ratio of 1 / 1 was introduced. The temperature was raised to 80° C., 0.5 μmol of metallocene catalyst and 5 μmol of [Ph3C][B(C6F5)4] were added to the polymerization reactor, and the polymerization reaction was stirred for 30 minutes. After removing volatile components from the polymerization solution, 5.78 g of a copolymer was obtained, wherein the metallocene catalyst was prepared by the method of Preparation Example 2 of Metallocene Catalyst.

[0067] The number average molecular weight of the copolymer measured by GPC is 420 kg / mol, and the molecular weight distribution is 1.96; the H NMR spectrum of the tetrapolymer of ethylene, propylene, 1-octene and ethylidene norbornene is as follows Figure 3 As shown in FIG, the copolymer composition is as follows: ethylene 59 mol%, propylene 34 mol%, 1-octene 4 mol%, ethylidene norbornene 3 mol%. The NMR carbon spectrum of the quaternary copolymer of ethylene, propylene, 1-octene and ethylidene norbornene is shown in FIG. Figure 4 As shown, the copolymer is a random copolymer, and the 1-octene and ethylidene norbornene units are isolated and distributed in the copolymer chain. The thermal properties of the copolymer were tested by DSC, and the results are shown in Figure 6 As shown in Figure 2, the glass transition temperature of the copolymer is -50°C.

[0068] Example 3

[0069] Preparation of ethylene, propylene, 4-methyl-1-pentene and isoprene tetrapolymer

[0070] Under the protection of inert gas nitrogen, 30 mL of anhydrous and oxygen-free n-hexane, 10 g of 4-methyl-1-pentene, and 3 g of isoprene were added to a dry and deoxygenated polymerization reactor. Ethylene and propylene gases (ethylene / propylene molar ratio of 3:1) were introduced, and the temperature was raised to a polymerization temperature of 100° C. and a polymerization pressure of 5 MPa. 5 μmol of metallocene catalyst and 5 μmol of [PhMe2NH][B(C6F5)4] were added to the polymerization reactor. The polymerization reaction was stirred for 10 minutes. After removing volatile components from the polymerization solution, 5.14 g of a copolymer was obtained. The metallocene catalyst was prepared by the method of Preparation Example 3 of Metallocene Catalyst.

[0071] GPC measured the number average molecular weight of the copolymer to be 42 kg / mol, with a molecular weight distribution of 1.12. NMR measured the copolymer composition to be: 27.3 mol% ethylene, 11.9 mol% propylene, 48.3 mol% 4-methyl-1-pentene, and 12.5 mol% isoprene. DSC tested the thermal properties of the copolymer, such as Figure 7 As shown, the glass transition temperature of the copolymer is -54°C.

[0072] Example 4

[0073] Preparation of tetrapolymer of ethylene, propylene, 1-dodecene and 1,4-hexadiene

[0074] Under the protection of inert gas argon, 30 mL of anhydrous and oxygen-free isoheptane, 10 g of 1-dodecene and 2 g of 1,4-hexadiene were added to a dry and deoxygenated polymerization reactor, ethylene and propylene gas (ethylene / propylene molar ratio of 3:1) were introduced, the temperature was raised to 150 ° C, the polymerization pressure was 8 MPa, 5 μmol of metallocene catalyst and 5 μmol of [HNMe(C 18 H 37 )2][B(C6F5)4] was added into the polymerization reactor and the polymerization reaction was stirred for 90 minutes. After removing the volatile components from the polymerization liquid, 4.54 g of copolymer was obtained, wherein the metallocene catalyst was prepared by the method of Preparation Example 4 of the metallocene catalyst.

[0075] The number average molecular weight of the copolymer measured by GPC was 91 kg / mol, and the molecular weight distribution was 1.52. The composition of the copolymer measured by NMR was: 47.5 mol% ethylene, 27.9 mol% propylene, 18.1 mol% 1-dodecene, and 6.3 mol% 1,4-hexadiene. The thermal properties of the copolymer were tested by DSC. Figure 8 As shown, the glass transition temperature of the copolymer is -58°C.

[0076] Example 5

[0077] Preparation of tetrapolymer of ethylene, propylene, 5-methyl-1-hexene and cyclohexadiene

[0078] Under the protection of inert gas nitrogen, 30 mL of anhydrous and oxygen-free xylene, 10 g of 5-methyl-1-hexene and 2 g of cyclohexadiene were added to a dry and deoxygenated polymerization reactor, ethylene and propylene gas (ethylene / propylene molar ratio of 1:3) was introduced, the temperature was raised to 150 ° C, the polymerization pressure was 8 MPa, 5 μmol of metallocene catalyst and 5 μmol of [HNMe(C 18 H 37 )2][B(C6F5)4] was added into the polymerization reactor and the polymerization reaction was stirred for 40 minutes. After removing the volatile components from the polymerization liquid, 5.14 g of copolymer was obtained, wherein the metallocene catalyst was prepared by the method of Preparation Example 5 of the metallocene catalyst.

[0079] The number average molecular weight of the copolymer measured by GPC was 51 kg / mol, and the molecular weight distribution was 1.82. The composition of the copolymer measured by NMR was: 20.5 mol% ethylene, 57.9 mol% propylene, 18.6 mol% 5-methyl-1-hexene, and 3.0 mol% cyclohexadiene. The thermal properties of the copolymer were tested by DSC. Figure 9 The glass transition temperature of the copolymer shown is -43°C.

[0080] Example 6

[0081] Preparation of ethylene, propylene, 1-butene, dicyclopentadiene tetrapolymer

[0082] Under the protection of inert gas nitrogen or argon, 30 mL of anhydrous and oxygen-free isopentane, 10 g of 1-butene and 0.4 g of dicyclopentadiene were added to a dry and deoxygenated polymerization reactor, ethylene and propylene gas (ethylene / propylene molar ratio of 10:1) were introduced, the temperature was raised to 20°C and the polymerization pressure was 1.2 MPa, 5 μmol of metallocene catalyst and 5 μmol of [HNMe(C 18 H 37)2][B(C6F5)4] was added into the polymerization reactor and the polymerization reaction was stirred for 20 minutes. After removing the volatile components from the polymerization liquid, 6.13 g of copolymer was obtained, wherein the metallocene catalyst was prepared by the method of Preparation Example 3 of the metallocene catalyst.

[0083] GPC measured the number average molecular weight of the copolymer to be 31 kg / mol, with a molecular weight distribution of 2.30. NMR measured the copolymer composition to be: 49.2 mol% ethylene, 5.2 mol% propylene, 41.6 mol% 1-butene, and 4 mol% dicyclopentadiene. DSC tested the thermal properties of the copolymer, as shown in FIG. Figure 10 As shown, the glass transition temperature of the copolymer is -59°C.

[0084] Example 7

[0085] Preparation of tetrapolymer of ethylene, propylene, 1-butene and ethylidene norbornene

[0086] Under the protection of inert gas nitrogen or argon, 30 mL of anhydrous and oxygen-free n-pentane, 8 g of 1-butene and 0.6 g of ethylidene norbornene were added to a dry and deoxygenated polymerization reactor, ethylene and propylene gas (ethylene / propylene molar ratio of 4:1) was introduced, the temperature was raised to a polymerization temperature of 20°C and a polymerization pressure of 0.1 MPa, 5 μmol of metallocene catalyst and 5 μmol of B(C6F5)3 were added to the polymerization reactor, the polymerization reaction was stirred for 20 minutes, and 6.13 g of copolymer was obtained after removing volatile components from the polymerization solution, wherein the metallocene catalyst was prepared by the method of Preparation Example 3 of Metallocene Catalyst.

[0087] GPC measured the number average molecular weight of the copolymer to be 31 kg / mol, with a molecular weight distribution of 2.30. NMR measured the copolymer composition to be: 53.2 mol% ethylene, 7.1 mol% propylene, 31.6 mol% 1-butene, and 8.1 mol% ethylidene norbornene. DSC tested the thermal properties of the copolymer, as shown in FIG. Figure 11 As shown, the glass transition temperature of the copolymer is -63°C.

[0088] Comparative Example 1

[0089] Preparation of ethylene, propylene and 5-vinyl-2-norbornene terpolymer

[0090] Under the protection of inert gas nitrogen or argon, 30 mL of anhydrous and oxygen-free cyclohexane and 0.1 g of 5-vinyl-2-norbornene were added to a dry and deoxygenated polymerization reactor, ethylene and propylene gas (ethylene / propylene molar ratio of 7:3) was introduced, the temperature was raised to a polymerization temperature of 20°C and a polymerization pressure of 0.2 MPa, 5 μmol of metallocene catalyst and 5 μmol of B(C6F5)3 were added to the polymerization reactor, the polymerization reaction was stirred for 10 minutes, and 3.64 g of copolymer was obtained after removing volatile components from the polymerization solution, wherein the metallocene catalyst was prepared by the method of Preparation Example 1 of Metallocene Catalyst.

[0091] GPC measured the number average molecular weight of the copolymer to be 750 kg / mol, with a molecular weight distribution of 2.90. NMR measured the copolymer composition to be: ethylene 71.0 mol%, propylene 28.0 mol%, 5-vinyl-2-norbornene 1.0 mol%. DSC tested the thermal properties of the copolymer, such as Figure 12 As shown, the glass transition temperature of the copolymer is -51°C.

[0092] Comparative Example 2

[0093] Preparation of ethylene, propylene and cyclohexadiene terpolymer

[0094] Under the protection of inert gas nitrogen or argon, 30 mL of anhydrous and oxygen-free xylene and 2 g of cyclohexadiene were added to a dry and deoxygenated polymerization reactor, ethylene and propylene gas (ethylene / propylene molar ratio of 1:3) were introduced, the temperature was raised to 150 ° C, the polymerization pressure was 8 MPa, 5 μmol of metallocene catalyst and 5 μmol of [HNMe(C 18 H 37 )2][B(C6F5)4] was added into the polymerization reactor and the polymerization reaction was stirred for 40 minutes. After removing the volatile components from the polymerization liquid, 3.14 g of copolymer was obtained, wherein the metallocene catalyst was prepared by the method of Preparation Example 5 of the metallocene catalyst.

[0095] GPC measured the number average molecular weight of the copolymer to be 51 kg / mol, with a molecular weight distribution of 1.82. NMR measured the copolymer composition to be: 30.5 mol% ethylene, 66.6 mol% propylene, and 2.9 mol% cyclohexadiene. DSC tested the thermal properties of the copolymer, such as Figure 13 As shown, the glass transition temperature of the copolymer is -35°C.

[0096] The glass transition temperatures of the copolymers prepared in different embodiments and comparative examples are shown in Table 1:

[0097] Table 1 Glass transition temperature of copolymers prepared in different embodiments and comparative examples (°C)

[0098]

[0099] As shown in Table 1, the glass transition temperature of the tetrapolymer in Example 1 is as low as -67°C, significantly superior to the -51°C glass transition temperature of the EPDM rubber prepared in Comparative Example 1. This performance improvement stems from the high random insertion ratio of 1-butene, reaching 22.6 mol%. The insertion of 1-butene creates a relatively large internal space in the EPDM rubber, reducing the density of entanglement points, thereby enhancing the molecular chain flexibility of the EPDM rubber and significantly lowering the glass transition temperature. Combining the data from Example 5 and Comparative Example 2 also shows that the introduction of 1-butene into EPDM rubbers of different compositions can effectively lower the rubber's glass transition temperature and improve its low-temperature resistance.

[0100] At the same time, the metallocene catalyst has a significant regulatory effect on the copolymerization behavior. Example 1 uses the single titanocene catalyst of Preparation Example 1 to achieve a high insertion rate of 1-butene, a number average molecular weight of 750 kg / mol, and a molecular weight distribution of 2.90, reflecting the advantages of the metallocene catalyst in inhibiting chain transfer and improving the matching of monomer reactivity ratios.

[0101] In summary, the present invention regulates the random copolymer structure of quaternary monomers (ethylene, propylene, high-carbon α-olefins, and dienes) through metallocene catalysts, achieves a high proportion of high-carbon α-olefin insertion and precise control of molecular weight, improves low-temperature resistance by lowering the glass transition temperature, and the synergistic effect of monomer composition, catalyst type, and diene type can flexibly regulate material properties, verifying the significant advantages of quaternary copolymerization in optimizing the comprehensive properties of EPDM rubber, such as low-temperature resistance and processability.

[0102] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements 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 invention.

Claims

1. An ethylene-propylene-α-olefin-diene quaternary copolymer rubber, characterized in that: The copolymer rubber is a random copolymer formed by copolymerization of ethylene, propylene, high-carbon α-olefins and dienes; based on the total molar weight of the tetrapolymer, the molar percentage of each monomer unit meets the following conditions: ethylene unit: 20-80%, propylene unit: 2-60%, high-carbon α-olefin unit: 2-50%, diene unit: 1-15%, and the sum of the molar percentages of ethylene, propylene, high-carbon α-olefins and diene is 100%; the number average molecular weight of the tetrapolymer is 30-800 kg / mol, and the molecular weight distribution index is 1.10-2.90; the high-carbon α-olefin units and diene units are evenly distributed in the random EPDM rubber chain in an isolated form.

2. The ethylene-propylene-α-olefin-diene tetrapolymer rubber according to claim 1, characterized in that: The high carbon α-olefin is C 4-12 Straight chain α-olefins or alkyl substituted C 4-12 Branched alpha-olefins.

3. The ethylene-propylene-α-olefin-diene tetrapolymer rubber according to claim 1, characterized in that: The diene is selected from the group consisting of bridged cyclic diene, linear diene, cyclic diene and conjugated diene.

4. The method for preparing the ethylene-propylene-α-olefin-diene tetrapolymer rubber according to any one of claims 1 to 3, characterized in that: In an inert gas atmosphere, ethylene, propylene, high carbon α-olefins and dienes are polymerized in an organic solvent using a metallocene catalyst to obtain the quaternary copolymer rubber. The polymerization temperature is 20 to 150° C., the polymerization pressure is 0.1 to 8 MPa, and the polymerization time is 5 to 90 minutes.

5. The method for preparing the ethylene-propylene-α-olefin-diene quaternary copolymer rubber according to claim 4, characterized in that: The metallocene catalyst comprises a main catalyst and a co-catalyst, wherein the main catalyst is a metallocene compound containing heteroatom coordination; and the co-catalyst is an organic boron auxiliary agent.

6. The method for preparing the ethylene-propylene-α-olefin-diene quaternary copolymer rubber according to claim 5, characterized in that: The molecular formula of the metallocene compound is CpML2X, wherein Cp is selected from cyclopentadienyl, substituted cyclopentadienyl, indenyl, substituted indenyl, fluorenyl or substituted fluorenyl; M is selected from metals Ti, Zr and Hf; L is selected from chlorine, C 1-6 Hydrocarbon, CH2SiMe3, CH2C6H4NMe2-o, CH2Ph ​​or CH(SiMe3)2; X is a Lewis base containing an O, N, P or S heteroatom.

7. The method for preparing the ethylene-propylene-α-olefin-diene quaternary copolymer rubber according to claim 5, characterized in that: The organic boron reagent is selected from [Ph3C][B(C6F5)4], [PhMe2NH][B(C6F5)4], [HNMe(C 18 H 37 )2][B(C6F5)4] or at least one of B(C6F5)3.

8. The method for preparing the ethylene-propylene-α-olefin-diene quaternary copolymer rubber according to claim 4, characterized in that: The organic solvent is selected from at least one of isopentane, n-hexane, isohexane, cyclohexane, isoheptane, toluene and xylene.

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