Method for treating ethylene gas, polyolefin elastomer and preparation method thereof

Abstract

The present invention provides a method for treating ethylene gas, a polyolefin elastomer and a preparation method thereof, belonging to the technical field of polymerization process. The method for treating ethylene gas includes: sequentially passing commercially available ethylene gas through a primary purification tank, a secondary purification tank and a tertiary purification tank to obtain activated ethylene gas; wherein, the primary purification tank is filled with a triglyceride solution of Cu(Qc) 2 or a triglyceride solution of Zn(benzimidazole) 2 or pure triglyceride, where Qc represents quinoline-5-carboxylate; the secondary purification tank is filled with anhydrous ether; the tertiary purification tank is filled with an organic solvent containing trace water, and the organic solvent is selected from isobutane, n-pentane, isopentane, n-hexane, methylcyclopentane, n-heptane, methylcyclohexane, isooctane, and at least one of toluene and a mixture of isomeric saturated alkanes of C 4 -C 8 .

Description

Technical Field

[0001] The present invention belongs to the technical field of polymerization process engineering, and particularly relates to a method for treating ethylene gas, a polyolefin elastomer and a preparation method thereof, and more specifically relates to a method for treating ethylene gas, a preparation method for solution polymerization of a polyolefin elastomer, and a polyolefin elastomer. Background Art

[0002] At present, when carrying out homopolymerization reaction or copolymerization reaction with ethylene gas, generally, it is directly introduced into a reaction kettle for solution polymerization reaction to prepare a homopolymer of ethylene or a copolymer containing ethylene. However, because there are some impurity gases in the ethylene gas, such as ethane, it is likely to cause a decrease in the activity of the solution polymerization reaction. Therefore, there is still room for further improvement in the activity of the solution polymerization reaction. Summary of the Invention

[0003] In view of the above technical problems, the present invention provides a method for treating ethylene gas, a polyolefin elastomer and a preparation method thereof, in order to at least partially solve the above technical problems. For this purpose, the technical solutions provided by the present invention are as follows.

[0004] As the first aspect of the present invention, there is provided a method for treating ethylene gas, comprising: passing commercially available ethylene gas successively through a primary purification tank, a secondary purification tank and a tertiary purification tank to obtain activated ethylene gas; wherein, the primary purification tank is filled with a triglyceride solution of Cu(Qc) 2 or a triglyceride solution of Zn(benzimidazole) 2 or pure triglyceride, where Qc represents quinoline-5-carboxylate; the secondary purification tank is filled with anhydrous ether; the tertiary purification tank is filled with an organic solvent containing trace water, and the organic solvent is selected from at least one of isobutane, n-pentane, isopentane, n-hexane, methylcyclopentane, n-heptane, methylcyclohexane, isooctane, and a mixture of toluene and C 4 -C 8 isomeric saturated alkane mixture.

[0005] As the second aspect of the present invention, there is provided a preparation method for a polyolefin elastomer, comprising: using the activated ethylene gas obtained by the above method for treating ethylene gas as a reaction raw material for solution polymerization.

[0006] As the third aspect of the present invention, there is provided a polyolefin elastomer prepared by the above preparation method for a polyolefin elastomer, wherein the polyolefin elastomer is a homopolymer of activated ethylene gas, or a copolymer of activated ethylene gas and an α-olefin of C 3 -C 12 .

[0007] In an embodiment of the present invention, commercially available ethylene gas is introduced into a primary purification tank. Since triglyceride has a higher adsorption selectivity for impurity gases (such as ethane) in ethylene gas, it can dissolve or adsorb them into the triglyceride while not adsorbing ethylene, thus achieving the primary purification of ethylene gas. Subsequently, the ethylene gas treated in the primary purification tank is introduced into a secondary purification tank. Since part of the triglyceride will be carried away during the transportation of the ethylene gas to the secondary purification tank, at this time, part of the triglyceride contained in the ethylene gas can be removed by using anhydrous ether in the secondary purification tank, realizing the secondary purification of the ethylene gas purified at the primary stage. Finally, the ethylene gas treated in the secondary purification tank is transported into a tertiary purification tank, and the ethylene gas treated in the secondary purification tank is purified and activated by using an organic solvent containing trace water in the tertiary purification tank to obtain activated ethylene gas, improving the purity and activity of the ethylene gas.

[0008] Further, using the activated ethylene gas as a raw material for preparing polyolefin elastomers by solution polymerization reaction can improve the activity of the solution polymerization reaction, thereby obtaining polyolefin elastomers with excellent properties, such as homopolymers of the activated ethylene gas, or copolymers of the activated ethylene gas and C 3 -C 12 α-olefins, which helps to further reduce the cost of polyolefin elastomers and enables industrial production. Detailed implementation mode

[0009] The embodiments of the present invention will be described below, but it should be understood that these descriptions are only exemplary and do not intend to limit the scope of the present invention. In the following detailed description, for the sake of explanation, many specific details are set forth to provide a comprehensive understanding of the embodiments of the present invention. However, obviously, one or more embodiments can also be implemented without these specific details. In addition, in the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessarily confusing the concepts of the present invention.

[0010] Currently, commercially available ethylene gas is generally directly used for solution polymerization reaction to prepare polyolefin elastomers, such as homopolymers of ethylene or copolymers containing ethylene. However, impurity gases (such as ethane) contained in the ethylene gas will reduce the activity of the ethylene polymerization reaction, and thus polyolefin elastomers with higher performance cannot be obtained. In response to this, the present invention proposes a method for treating ethylene gas, and uses the activated ethylene gas as a raw material for solution polymerization reaction. The activated ethylene gas makes the polymerization reaction have higher activity, and thus polyolefin elastomers with higher performance can be prepared.

[0011] Specifically, as the first aspect of the present invention, a method for treating ethylene gas is provided, including: passing commercially available ethylene gas successively through a primary purification tank, a secondary purification tank, and a tertiary purification tank to obtain activated ethylene gas; wherein, the primary purification tank is loaded with a triglyceride solution of Cu(Qc) 2 or a triglyceride solution of Zn(benzimidazole) 2 or pure triglyceride, where Qc represents quinoline-5-carboxylate; the secondary purification tank is loaded with anhydrous ether; the tertiary purification tank is loaded with an organic solvent containing trace water, and the organic solvent is selected from isobutane, n-pentane, isopentane, n-hexane, methylcyclopentane, n-heptane, methylcyclohexane, isooctane, and at least one of toluene and a mixture of isomeric saturated alkanes of C 4 -C 8 .

[0012] In an embodiment of the present invention, commercially available ethylene gas is introduced into the primary purification tank. By utilizing the higher adsorption selectivity of the triglyceride in the primary purification tank for impurity gases (such as ethane) in ethylene gas, the impurity gases can be dissolved or adsorbed into the triglyceride while ethylene is not adsorbed, thereby achieving the primary purification of ethylene gas. Subsequently, the ethylene gas treated by the primary purification tank is introduced into the secondary purification tank. During this process, the ethylene gas purified at the primary stage will carry away some triglyceride. By using the anhydrous ether in the secondary purification tank, part of the triglyceride contained in the ethylene gas purified at the primary stage can be removed, thereby achieving the secondary purification of the ethylene gas purified at the primary stage. Finally, the ethylene gas purified at the secondary stage treated by the secondary purification tank is transported into the tertiary purification tank. By using the organic solvent containing trace water in the tertiary purification tank, a small amount of anhydrous ether in the ethylene gas purified at the secondary stage can be removed to achieve the purification and activation of ethylene gas to obtain activated ethylene gas. The present invention improves the purity and activity of ethylene gas through a specific purification and activation sequence and the purification and activation reagents used.

[0013] For example: The ethylene gas in a commercially available ethylene cylinder is successively introduced into a primary purification tank (abbreviated as "purification tank 1"), a secondary purification tank (abbreviated as "purification tank 2"), and a tertiary purification tank (abbreviated as "purification tank 3") for purification and activation to obtain activated ethylene gas.

[0014] According to an embodiment of the present invention, in the primary purification tank, the concentration of Cu(Qc) 2 or Zn(benzimidazole) 2 is 1 μmol / L - 100 μmol / L. Within this concentration range, it helps to improve the selective adsorption of impurity gases in ethylene gas and improve the activation efficiency and purity of ethylene gas.

[0015] According to an embodiment of the present invention, Cu(Qc) 2 is formed from copper hydroxide (Cu(OH)2 ), and quinoline-5-carboxylic acid (HQc) were obtained by ball milling in the presence of N,N-dimethylformamide and ethanol. For example: Cu(OH) 2 and HQc were added to a steel tank containing N,N-dimethylformamide (DMF) and ethanol (EtOH), and ball milled at 25 Hz for 15 minutes, then dissolved in triglyceride and stirred evenly to obtain a triglyceride solution of Cu(Qc) 2 .

[0016] According to an embodiment of the present invention, Zn(benzimidazole) 2 was obtained by dissolving benzimidazole and zinc in acetic acid in proportion, followed by refluxing and rotary evaporation, where the molar ratio of benzimidazole to zinc was 2:1. For example: benzimidazole and zinc were dissolved in an acetic acid solution at a molar ratio of 2:1 and refluxed at 65 °C for 4 h. Subsequently, the solvent was rotary evaporated, and the remaining liquid was transferred to a beaker. After cooling to room temperature, the beaker was sealed. After standing for several days, it was dissolved in triglyceride to obtain a triglyceride solution of Zn(benzimidazole) 2 .

[0017] As a second aspect of the present invention, a method for preparing a polyolefin elastomer is provided. The preparation method uses the activated ethylene gas obtained by the treatment method of ethylene gas in the above embodiment as the reaction raw material for solution polymerization.

[0018] In an embodiment of the present invention, by activating ethylene gas, the purity and activity of the ethylene raw material are improved, enabling the solution polymerization reaction to have higher activity, and thus enabling the preparation of ethylene homopolymers with higher performance, such as ethylene-based polyolefin elastomers (EPOE), or copolymers of ethylene and α-olefins (such as C 3 -C 12 α-olefins).

[0019] According to an embodiment of the present invention, the preparation method of solution polymerization of polyolefin elastomers includes: introducing a main catalyst, a cocatalyst, and activated ethylene gas into a reaction kettle containing a polymerization solvent to carry out a solution polymerization reaction to obtain a polyolefin elastomer, which is a homopolymer of the activated ethylene gas; wherein, the polymerization solvent is the same as the organic solvent loaded in the tertiary purification tank, and the molar ratio of trace water in the polymerization solvent to the cocatalyst is 1:2 - 1:6. In other words, the polymerization solvent is an organic solvent containing trace water, selected from isobutane, n-pentane, isopentane, n-hexane, methylcyclopentane, n-heptane, methylcyclohexane, isooctane, and toluene and C 4 -C 8At least one of the isomeric saturated alkane mixtures. The content of trace water in the organic solvent in the tertiary purification tank is 5 wt% or less of the organic solvent, preferably 0.5 - 5 wt%. In the tertiary purification tank, ethylene gas will carry away the water and enter the reaction kettle, where it reacts with the cocatalyst in the solution polymerization reaction to generate an active substance, improving the polymerization reaction activity of the activated ethylene gas.

[0020] In an embodiment of the present invention, in the presence of a main catalyst and a cocatalyst, a solution polymerization reaction (such as a homopolymerization reaction) is carried out in a reaction kettle through activated ethylene gas, and a homopolymer of the activated ethylene gas (abbreviated as the homopolymer of ethylene), that is, ethylene vinyl olefin elastomer (EPOE), can be obtained. The preparation method of the polyolefin elastomer provided by the present invention is relatively simple, and by preparing EPOE through activated ethylene, the polymerization reaction activity is greatly improved, thereby improving the properties of EPOE, such as physical and mechanical properties, aging resistance, ultraviolet resistance, low temperature properties (-40 °C to -4 °C), flow properties, affinity, etc.

[0021] According to an embodiment of the present invention, the organic solvent loaded in the tertiary purification tank is the same as the polymerization solvent, preferably at least one of n-hexane, methylcyclopentane, n-heptane and their isomeric saturated alkane mixtures with C 4 -C 8 and more preferably n-heptane.

[0022] According to an embodiment of the present invention, the main catalyst is a diimine nickel catalyst, and the diimine nickel catalyst has the structure shown in the following formula (1):

[0023] Formula (1), where R is selected from at least one of isobutyl, phenyl, and hydrogen. More specifically, the main catalyst used in the present invention is a diimine nickel catalyst produced by Hefei Zhongke Kele New Materials Co., Ltd., and this catalyst has a large steric hindrance. The preparation method of the diimine nickel catalyst can refer to the publicly disclosed Chinese patent application documents, such as Chinese patent application documents with publication numbers CN118084719A, CN117865847A, CN117659237A, CN117645552A, CN117902999A, CN117658851A, etc.

[0024] According to an embodiment of the present invention, the cocatalyst is selected from at least one of triethylaluminum, diethylaluminum chloride, dichloroethylaluminum, sesquialteraluminum chloride, monochloroisobutylaluminum, and dichloroisobutylaluminum. The molar ratio of trace water in the polymerization solvent to the cocatalyst is 1:2 - 1:6. Among them, when the cocatalyst is diethylaluminum chloride (DEAC), the molar ratio of trace water in the polymerization solvent to diethylaluminum chloride is 1:3; when the cocatalyst is triethylaluminum, the molar ratio of trace water in the polymerization solvent to triethylaluminum is 1:2; when the cocatalyst is dichloroethylaluminum (EADC), the molar ratio of trace water in the polymerization solvent to dichloroethylaluminum is 1:6. The trace water contained in the polymerization solvent can react with the cocatalyst to generate ethylaluminoxane (EAO) to increase the activity of the polymerization reaction. For example: ; .

[0025] According to an embodiment of the present invention, in the solution polymerization reaction, the polymerization temperature of the solution polymerization reaction is 25°C - 45°C, and the polymerization pressure is 0.6 Mpa - 2.0 Mpa.

[0026] For example, the method for preparing vinyl polyolefin elastomer by solution polymerization reaction may include: introducing a polymerization solvent (such as n-heptane) into the reaction kettle, and using nitrogen to vacuum displace the air in the reaction kettle for multiple times (such as 3 times). Subsequently, the ethylene gas in the commercially available ethylene gas cylinder is directly passed through purification tank 1, purification tank 2, and purification tank 3 in sequence for purification and activation to obtain activated ethylene gas. The obtained activated ethylene gas is introduced into the reaction kettle to displace the nitrogen in the reaction kettle for multiple times. Furthermore, after introducing the cocatalyst (such as DEAC) into the reaction kettle and stirring for 25 min, the main catalyst (such as the diimine nickel catalyst shown in formula (1), where R is selected from H) is introduced into the reaction kettle and stirred for 1 min, and activated ethylene gas is introduced into the reaction kettle for solution polymerization reaction. During the polymerization reaction, the polymerization temperature is controlled at 25 - 45°C, and the polymerization pressure is controlled at 0.6 MPa - 2.0 MPa to obtain vinyl polyolefin elastomer (i.e., homopolymer of ethylene). Among them, the flow rate of the activated ethylene gas is 4 L / min - 8 L / min, preferably 6 L / min; the concentration of the main catalyst in a single reaction kettle is 2 μmol / L - 50 μmol / L; the number of moles of aluminum (Al) in the cocatalyst is 300 - 500 times the number of moles of nickel (Ni) in the main catalyst.

[0027] According to an embodiment of the present invention, another preparation method for solution polymerization of polyolefin elastomer is provided, including: in the presence of a main catalyst and a cocatalyst, introducing C 3 -C 12 α-olefin and activated ethylene gas into the reaction kettle containing the polymerization solvent for solution polymerization reaction to obtain polyolefin elastomer, and the polyolefin elastomer is C3 -C 12 Copolymer of α-olefin and activated ethylene gas.

[0028] In an embodiment of the present invention, in the presence of a main catalyst and a cocatalyst, activated ethylene gas and C 3 -C 12 α-olefin are copolymerized to obtain a polyolefin elastomer (i.e., POE). The polyolefin elastomer is a copolymer of activated ethylene gas and C 3 -C 12 α-olefin. For example, it can be a copolymer of ethylene and propylene, or a copolymer of ethylene and 1-octene. Polyolefin elastomer (POE) is a random copolymer of ethylene and α-olefin with a relatively high content of α-olefin comonomer, belonging to thermoplastic elastomer, which has elasticity without vulcanization. The polyolefin elastomer (POE) has a narrow molecular weight distribution index (PDI = 2 - 4) and a relatively high comonomer content (10% - 30%), so that the polyolefin elastomer (POE) has excellent low-temperature resistance (-24°C to -4°C), aging resistance, good mechanical properties and processing properties. It can replace part of ethylene-propylene rubber and can also be widely used as an impact modifier for polyolefin materials to prepare instrument panels, bumpers, connectors and plugs, pipes, instrument parts, sheets, gardening tools and building materials. It can also be directly made into molded products and extruded products. It is an elastomer material with excellent performance and higher added value.

[0029] According to an embodiment of the present invention, the main catalyst, cocatalyst, and polymerization solvent involved in the preparation of polyolefin elastomer (POE) from activated ethylene gas and C 3 -C 12 α-olefin are the same as those used in the above embodiment for preparing vinyl polyolefin elastomer (EPOE) from activated ethylene gas, and will not be elaborated here in detail.

[0030] According to an embodiment of the present invention, the comonomer for solution polymerization reaction with ethylene gas is preferably C 3 -C 8 α-olefin, such as any one of 1-propene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene.

[0031] For example, a solution polymerization preparation method of a polyolefin elastomer based on activated ethylene and 1-octene comonomer includes: introducing a polymerization solvent (such as n-heptane) into a reaction kettle, and using nitrogen to vacuum displace the air in the reaction kettle for multiple times. Subsequently, the ethylene gas in a commercially available ethylene gas cylinder is directly passed through purification tank 1, purification tank 2, and purification tank 3 in sequence for purification and activation to obtain activated ethylene gas. The activated ethylene gas is introduced into the reaction kettle to displace the nitrogen in the reaction kettle for multiple times. Furthermore, after introducing the DEAC cocatalyst into the reaction kettle and stirring for 25 min, the main catalyst (such as the diimine nickel catalyst shown in formula (1), where R is selected from H) is introduced into the reaction kettle and stirred for 1 min, and activated ethylene gas and 1-octene (comonomer) are introduced into the reaction kettle for solution polymerization reaction. During the polymerization reaction, the polymerization temperature is controlled at 25 - 45 °C, and the polymerization pressure is controlled at 0.6 MPa - 2.0 MPa, thereby obtaining a polyolefin elastomer (i.e., a copolymer of ethylene and 1-octene). The flow rate of the activated ethylene gas is 4 L / min - 8 L / min, preferably 6 L / min; the concentration of the main catalyst in a single reaction kettle is 2 μmol / L - 50 μmol / L; the molar number of aluminum (Al) in the cocatalyst is 300 - 500 times the molar number of nickel (Ni) in the main catalyst.

[0032] As the third aspect of the present invention, there is provided a polyolefin elastomer prepared by the method using the polyolefin elastomer in the above embodiment. The polyolefin elastomer is a homopolymer of activated ethylene gas or a copolymer of activated ethylene gas and an α-olefin of C 3 -C 12

[0033] The technical solution of the present invention will be further explained below in conjunction with specific embodiments. Unless otherwise specified, the reagents used in the following embodiments are all common commercially available reagents.

[0034] Example 1

[0035] Preparation of vinyl polyolefin elastomer

[0036] Raw materials: Commercially available ethylene gas is stored in an ethylene gas cylinder and is polymerization-grade ethylene (purity 99.95%); the organic solvent or polymerization solvent is n-heptane containing trace water (water content is 0.5 wt% of n-heptane); the cocatalyst is diethylaluminum chloride; the main catalyst , where R is isobutyl, named Cat-1.

[0037] Treatment of ethylene gas: The ethylene gas in a commercially available ethylene gas cylinder is directly passed through purification tank 1, purification tank 2, and purification tank 3 in sequence for purification and activation to obtain activated ethylene gas; wherein purification tank 1 is filled with Cu(Qc) 2The triglyceride solution, purification tank 2 is filled with anhydrous ether, and purification tank 3 is filled with n-heptane containing trace water.

[0038] Homopolymerization reaction of ethylene to prepare ethylene-based polyolefin elastomer (EPOE): The n-heptane containing trace water (i.e., the polymerization solvent) is introduced into the reaction kettle, and the air in the reaction kettle is replaced with nitrogen under vacuum, repeating multiple times (such as 3 times). Subsequently, the obtained activated ethylene gas is introduced into the reaction kettle to replace the nitrogen in the reaction kettle, repeating 3 times. Furthermore, the co-catalyst is introduced into the reaction kettle and stirred for 25 min, then the main catalyst is introduced into the reaction kettle and stirred for 1 min, and the activated ethylene gas is introduced into the reaction kettle for solution polymerization reaction. During the polymerization reaction, the polymerization temperature is controlled at 25 °C and the polymerization pressure is controlled at 0.6 MPa to obtain the ethylene-based polyolefin elastomer (i.e., the homopolymer of ethylene). The flow rate of the activated ethylene gas is 6 L / min; the concentration of the main catalyst in a single reaction kettle is 4 μmol / L; the molar number of aluminum (Al) in the co-catalyst is 300 times that of nickel (Ni) in the main catalyst.

[0039] Example 2

[0040] The ethylene-based polyolefin elastomer is prepared by the same method as in Example 1, and the only difference is that: in the main catalyst, R is selected from phenyl, named Cat-2.

[0041] Example 3

[0042] The ethylene-based polyolefin elastomer is prepared by the same method as in Example 1, and the only difference is that: in the main catalyst, R is selected from hydrogen, named Cat-3.

[0043] Example 4

[0044] The ethylene-based polyolefin elastomer is prepared by the same method as in Example 1, and the only difference is that: the polymerization temperature is 35 °C.

[0045] Example 5

[0046] The ethylene-based polyolefin elastomer is prepared by the same method as in Example 1, and the only difference is that: the polymerization temperature is 45 °C.

[0047] Example 6

[0048] The ethylene-based polyolefin elastomer is prepared by the same method as in Example 1, and the only difference is that: the polymerization pressure is 1.0 MPa.

[0049] Example 7

[0050] The ethylene-based polyolefin elastomer is prepared by the same method as in Example 1, and the only difference is that: the polymerization pressure is 2.0 MPa.

[0051] Comparative Example 1

[0052] The vinyl polyolefin elastomer was prepared by the same method as in Example 1, with the only difference being that the ethylene gas was not treated successively using Purification Tank 1, Purification Tank 2, and Purification Tank 3. In other words, the vinyl polyolefin elastomer was directly prepared by solution polymerization using commercially available ethylene gas.

[0053] Comparative Example 2

[0054] The vinyl polyolefin elastomer was prepared by the same method as in Example 2, with the only difference being that the ethylene gas was not treated successively using Purification Tank 1, Purification Tank 2, and Purification Tank 3. In other words, the vinyl polyolefin elastomer was directly prepared by solution polymerization using commercially available ethylene gas.

[0055] Comparative Example 3

[0056] The vinyl polyolefin elastomer was prepared by the same method as in Example 3, with the only difference being that the ethylene gas was not treated successively using Purification Tank 1, Purification Tank 2, and Purification Tank 3. In other words, the vinyl polyolefin elastomer was directly prepared by solution polymerization using commercially available ethylene gas.

[0057] Comparative Example 4

[0058] The vinyl polyolefin elastomer was prepared by the same method as in Example 4, with the only difference being that the ethylene gas was not treated successively using Purification Tank 1, Purification Tank 2, and Purification Tank 3. In other words, the vinyl polyolefin elastomer was directly prepared by solution polymerization using commercially available ethylene gas.

[0059] Comparative Example 5

[0060] The vinyl polyolefin elastomer was prepared by the same method as in Example 5, with the only difference being that the ethylene gas was not treated successively using Purification Tank 1, Purification Tank 2, and Purification Tank 3. In other words, the vinyl polyolefin elastomer was directly prepared by solution polymerization using commercially available ethylene gas.

[0061] Comparative Example 6

[0062] The vinyl polyolefin elastomer was prepared by the same method as in Example 6, with the only difference being that the ethylene gas was not treated successively using Purification Tank 1, Purification Tank 2, and Purification Tank 3. In other words, the vinyl polyolefin elastomer was directly prepared by solution polymerization using commercially available ethylene gas.

[0063] Comparative Example 7

[0064] The vinyl polyolefin elastomer was prepared by the same method as in Example 7, with the only difference being that the ethylene gas was not treated successively using purification tank 1, purification tank 2, and purification tank 3. In other words, the vinyl polyolefin elastomer was directly prepared by solution polymerization using commercially available ethylene gas.

[0065] Furthermore, the activities of preparing the vinyl polyolefin elastomer in Examples 1 - 7 and Comparative Examples 1 - 7 were tested, and the specific test results are shown in Table 1.

[0066] Table 1

[0067]

[0068] Note: The activity was obtained by weighing the product after drying and dividing the obtained mass by the mass of the catalyst used (including the main catalyst and the cocatalyst).

[0069] As shown in Table 1, by comparing Examples 1 - 3 and Comparative Examples 1 - 3, it can be found that by using the purification tank provided by the present invention to activate the ethylene gas to obtain activated ethylene gas and applying it to the ethylene solution polymerization reaction, there is a certain activation effect on different catalysts, and the activities of the polymerization reactions in the examples are all higher than those in the comparative examples. By comparing Example 1, Examples 4 - 5 and the corresponding Comparative Example 1, Comparative Examples 4 - 5, it can be found that as the polymerization temperature increases, the activation effect of the purification tank becomes more significant, manifested as a significant increase in the activity of the polymerization reaction, and the activities of the polymerization reactions in the examples are all higher than those in the comparative examples. By comparing Example 1, Examples 6 - 7 and the corresponding Comparative Example 1, Comparative Examples 6 - 7, it can be found that as the polymerization pressure increases, the activation effect of the purification tank becomes more significant, manifested as a significant increase in the activity of the polymerization reaction, and the activities of the polymerization reactions in the examples are all higher than those in the comparative examples.

[0070] Furthermore, by removing purification tank 1 and keeping other conditions the same as in Examples 1 - 7, the influence of purification tank 1 on the activity of the ethylene solution polymerization reaction was explored.

[0071] Comparative Example A1

[0072] The vinyl polyolefin elastomer was prepared by the same method as in Example 1, with the only difference being that purification tank 1 was removed and purification tanks 2 and 3 were retained.

[0073] Comparative Example A2

[0074] The vinyl polyolefin elastomer was prepared by the same method as in Example 2, with the only difference being that purification tank 1 was removed and purification tanks 2 and 3 were retained.

[0075] Comparative Example A3

[0076] The vinyl polyolefin elastomer was prepared by the same method as in Example 3, and the only difference was that: the purification tank 1 was removed, and the purification tanks 2 and 3 were retained.

[0077] Comparative Example A4

[0078] The vinyl polyolefin elastomer was prepared by the same method as in Example 4, and the only difference was that: the purification tank 1 was removed, and the purification tanks 2 and 3 were retained.

[0079] Comparative Example A5

[0080] The vinyl polyolefin elastomer was prepared by the same method as in Example 5, and the only difference was that: the purification tank 1 was removed, and the purification tanks 2 and 3 were retained.

[0081] Comparative Example A6

[0082] The vinyl polyolefin elastomer was prepared by the same method as in Example 6, and the only difference was that: the purification tank 1 was removed, and the purification tanks 2 and 3 were retained.

[0083] Comparative Example A7

[0084] The vinyl polyolefin elastomer was prepared by the same method as in Example 7, and the only difference was that: the purification tank 1 was removed, and the purification tanks 2 and 3 were retained.

[0085] The activities of the vinyl polyolefin elastomers prepared in the above Comparative Examples A1 - A7 were tested, and the specific test results are shown in Table 2.

[0086] Table 2

[0087]

[0088] As shown in Table 2, by comparing Examples 1 - 7 and Comparative Examples A1 - A7, it can be found that after removing the purification tank 1, the activation effect of the purification tanks 2 and 3 on ethylene gas decreased, which was manifested as the activities of the polymerization reactions in Examples 1 - 7 were all higher than those in Comparative Examples A1 - A7. This shows that the purification tank 1 is indispensable.

[0089] Furthermore, by removing the purification tank 2 and keeping other conditions the same as in Examples 1 - 7, the influence of the purification tank 2 on the activity of the ethylene solution polymerization reaction was explored.

[0090] Comparative Example B1

[0091] The vinyl polyolefin elastomer was prepared by the same method as in Example 1, and the only difference was that: the purification tank 2 was removed, and the purification tanks 1 and 3 were retained.

[0092] Comparative Example B2

[0093] The vinyl polyolefin elastomer was prepared by the same method as in Example 2, with the only difference being that purification tank 2 was removed, and purification tanks 1 and 3 were retained.

[0094] Comparative Example B3

[0095] The vinyl polyolefin elastomer was prepared by the same method as in Example 3, with the only difference being that purification tank 2 was removed, and purification tanks 1 and 3 were retained.

[0096] Comparative Example B4

[0097] The vinyl polyolefin elastomer was prepared by the same method as in Example 4, with the only difference being that purification tank 2 was removed, and purification tanks 1 and 3 were retained.

[0098] Comparative Example B5

[0099] The vinyl polyolefin elastomer was prepared by the same method as in Example 5, with the only difference being that purification tank 2 was removed, and purification tanks 1 and 3 were retained.

[0100] Comparative Example B6

[0101] The vinyl polyolefin elastomer was prepared by the same method as in Example 6, with the only difference being that purification tank 2 was removed, and purification tanks 1 and 3 were retained.

[0102] Comparative Example B7

[0103] The vinyl polyolefin elastomer was prepared by the same method as in Example 7, with the only difference being that purification tank 2 was removed, and purification tanks 1 and 3 were retained.

[0104] The activities of the vinyl polyolefin elastomers prepared in Comparative Examples B1 - B7 were tested, and the specific test results are shown in Table 3.

[0105] Table 3

[0106]

[0107] As shown in Table 3, by comparing Examples 1 - 7 and Comparative Examples B1 - B7, it can be found that after removing purification tank 2, the activation effect of purification tanks 1 and 3 on ethylene gas decreased, as manifested by the fact that the activities of the polymerization reactions in Examples 1 - 7 were all higher than those in Comparative Examples B1 - B7. This shows that purification tank 2 is indispensable.

[0108] Furthermore, by removing purification tank 3 and keeping other conditions the same as in Examples 1 - 7, the influence of purification tank 3 on the activity of ethylene solution polymerization reaction was explored.

[0109] Comparative Example C1

[0110] The vinyl polyolefin elastomer was prepared by the same method as in Example 1, and the only difference was that: the purification tank 3 was removed, and the purification tanks 1 and 2 were retained.

[0111] Comparative Example C2

[0112] The vinyl polyolefin elastomer was prepared by the same method as in Example 2, and the only difference was that: the purification tank 3 was removed, and the purification tanks 1 and 2 were retained.

[0113] Comparative Example C3

[0114] The vinyl polyolefin elastomer was prepared by the same method as in Example 3, and the only difference was that: the purification tank 3 was removed, and the purification tanks 1 and 2 were retained.

[0115] Comparative Example C4

[0116] The vinyl polyolefin elastomer was prepared by the same method as in Example 4, and the only difference was that: the purification tank 3 was removed, and the purification tanks 1 and 2 were retained.

[0117] Comparative Example C5

[0118] The vinyl polyolefin elastomer was prepared by the same method as in Example 5, and the only difference was that: the purification tank 3 was removed, and the purification tanks 1 and 2 were retained.

[0119] Comparative Example C6

[0120] The vinyl polyolefin elastomer was prepared by the same method as in Example 6, and the only difference was that: the purification tank 3 was removed, and the purification tanks 1 and 2 were retained.

[0121] Comparative Example C7

[0122] The vinyl polyolefin elastomer was prepared by the same method as in Example 7, and the only difference was that: the purification tank 3 was removed, and the purification tanks 1 and 2 were retained.

[0123] The activities of the vinyl polyolefin elastomers prepared in the above Comparative Examples C1 - C7 were tested, and the specific test results are shown in Table 4.

[0124] Table 4

[0125]

[0126] As shown in Table 4, by comparing Examples 1 - 7 and Comparative Examples C1 - C7, it can be found that after removing the purification tank 3, the activation effect of purification tanks 1 and 2 on ethylene gas significantly decreases, manifested as the activity of the polymerization reaction in Examples 1 - 7 being higher than that in Comparative Examples C1 - C7. This indicates that purification tank 3 is indispensable.

[0127] Furthermore, by removing purification tanks 1 and 2, with other conditions being the same as in Examples 1 - 7, the influence of purification tanks 1 and 2 on the polymerization reaction activity of ethylene solution was explored.

[0128] Comparative Example D1

[0129] The vinyl polyolefin elastomer was prepared using the same method as in Example 1, with the only difference being that purification tanks 1 and 2 were removed, and purification tank 3 was retained.

[0130] Comparative Example D2

[0131] The vinyl polyolefin elastomer was prepared using the same method as in Example 2, with the only difference being that purification tanks 1 and 2 were removed, and purification tank 3 was retained.

[0132] Comparative Example D3

[0133] The vinyl polyolefin elastomer was prepared using the same method as in Example 3, with the only difference being that purification tanks 1 and 2 were removed, and purification tank 3 was retained.

[0134] Comparative Example D4

[0135] The vinyl polyolefin elastomer was prepared using the same method as in Example 4, with the only difference being that purification tanks 1 and 2 were removed, and purification tank 3 was retained.

[0136] Comparative Example D5

[0137] The vinyl polyolefin elastomer was prepared using the same method as in Example 5, with the only difference being that purification tanks 1 and 2 were removed, and purification tank 3 was retained.

[0138] Comparative Example D6

[0139] The vinyl polyolefin elastomer was prepared using the same method as in Example 6, with the only difference being that purification tanks 1 and 2 were removed, and purification tank 3 was retained.

[0140] Comparative Example D7

[0141] The vinyl polyolefin elastomer was prepared using the same method as in Example 7, with the only difference being that purification tanks 1 and 2 were removed, and purification tank 3 was retained.

[0142] The activities of preparing vinyl polyolefin elastomers in the above Comparative Examples D1 - D7 were tested, and the specific test results are shown in Table 5.

[0143] Table 5

[0144]

[0145] As shown in Table 5, by comparing Examples 1 - 7 and Comparative Examples D1 - D7, it can be found that after removing Purification Tank 1 and Purification Tank 2, the activation effect of only using Purification Tank 3 on ethylene gas is not significant, which is manifested as the activities of the polymerization reactions in Examples 1 - 7 being higher than those in Comparative Examples D1 - D7. This shows that Purification Tank 3 cannot be used alone, that is, Purification Tank 1 and Purification Tank 2 are indispensable.

[0146] Furthermore, by removing Purification Tank 2 and Purification Tank 3, with other conditions the same as those in Examples 1 - 7, the influence of Purification Tank 2 and Purification Tank 3 on the activity of the ethylene solution polymerization reaction was explored.

[0147] Comparative Example E1

[0148] The vinyl polyolefin elastomer was prepared by the same method as in Example 1, with the only difference being: Purification Tank 2 and Purification Tank 3 were removed, and Purification Tank 1 was retained.

[0149] Comparative Example E2

[0150] The vinyl polyolefin elastomer was prepared by the same method as in Example 2, with the only difference being: Purification Tank 2 and Purification Tank 3 were removed, and Purification Tank 1 was retained.

[0151] Comparative Example E3

[0152] The vinyl polyolefin elastomer was prepared by the same method as in Example 3, with the only difference being: Purification Tank 2 and Purification Tank 3 were removed, and Purification Tank 1 was retained.

[0153] Comparative Example E4

[0154] The vinyl polyolefin elastomer was prepared by the same method as in Example 4, with the only difference being: Purification Tank 2 and Purification Tank 3 were removed, and Purification Tank 1 was retained.

[0155] Comparative Example E5

[0156] The vinyl polyolefin elastomer was prepared by the same method as in Example 5, with the only difference being: Purification Tank 2 and Purification Tank 3 were removed, and Purification Tank 1 was retained.

[0157] Comparative Example E6

[0158] The vinyl polyolefin elastomer was prepared in the same manner as in Example 6, with the only difference being that purification tanks 2 and 3 were removed, and purification tank 1 was retained.

[0159] Control Example E7

[0160] The vinyl polyolefin elastomer was prepared in the same manner as in Example 7, with the only difference being that purification tanks 2 and 3 were removed, and purification tank 1 was retained.

[0161] The activities of the vinyl polyolefin elastomers prepared in the above Control Examples E1 - E7 were tested, and the specific test results are shown in Table 6.

[0162] Table 6

[0163]

[0164] As shown in Table 6, by comparing Examples 1 - 7 and Control Examples E1 - E7, it can be found that after removing purification tanks 2 and 3, the activation effect of only using purification tank 1 on ethylene gas is not significant, which is manifested as the activities of the polymerization reactions in Examples 1 - 7 being higher than those in Control Examples E1 - E7. This shows that purification tank 1 cannot be used alone, that is, purification tanks 2 and 3 are indispensable.

[0165] Furthermore, by removing purification tanks 1 and 3, with other conditions being the same as in Examples 1 - 7, the influence of purification tanks 1 and 3 on the activity of the ethylene solution polymerization reaction was explored.

[0166] Control Example F1

[0167] The vinyl polyolefin elastomer was prepared in the same manner as in Example 1, with the only difference being that purification tanks 1 and 3 were removed, and purification tank 2 was retained.

[0168] Control Example F2

[0169] The vinyl polyolefin elastomer was prepared in the same manner as in Example 2, with the only difference being that purification tanks 1 and 3 were removed, and purification tank 2 was retained.

[0170] Control Example F3

[0171] The vinyl polyolefin elastomer was prepared in the same manner as in Example 3, with the only difference being that purification tanks 1 and 3 were removed, and purification tank 2 was retained.

[0172] Control Example F4

[0173] The vinyl polyolefin elastomer was prepared in the same manner as in Example 4, with the only difference being that purification tanks 1 and 3 were removed, and purification tank 2 was retained.

[0174] Comparative Example F5

[0175] The vinyl polyolefin elastomer was prepared by the same method as in Example 5, and the only difference was that purification tanks 1 and 3 were removed, and purification tank 2 was retained.

[0176] Comparative Example F6

[0177] The vinyl polyolefin elastomer was prepared by the same method as in Example 6, and the only difference was that purification tanks 1 and 3 were removed, and purification tank 2 was retained.

[0178] Comparative Example F7

[0179] The vinyl polyolefin elastomer was prepared by the same method as in Example 7, and the only difference was that purification tanks 1 and 3 were removed, and purification tank 2 was retained.

[0180] The activities of the vinyl polyolefin elastomers prepared in Comparative Examples F1 - F7 were tested, and the specific test results are shown in Table 7.

[0181] Table 7

[0182]

[0183] As shown in Table 7, by comparing Examples 1 - 7 and Comparative Examples F1 - F7, it can be found that after removing purification tanks 1 and 3, the activation effect of only using purification tank 2 on ethylene gas is not significant, which is manifested as the activities of the polymerization reactions in Examples 1 - 7 being higher than those in Comparative Examples F1 - F7. This shows that purification tank 2 cannot be used alone, that is, purification tanks 1 and 3 are indispensable.

[0184] Through the comparison of the above examples and comparative examples, it is shown that only when all three purification tanks are present and ethylene gas is activated in a specific order can the highest activity be obtained, thus proving the interdependent relationship among purification tanks 1, 2, and 3.

[0185] Furthermore, using the same method as in Example 1, the effect of the activated ethylene gas on the polymerization reaction of ethylene and α - olefin to form a copolymer of ethylene and α - olefin was explored.

[0186] Example 8

[0187] A copolymer of ethylene and propylene was prepared by the same method as in Example 1, and the only difference was that the mass ratio of the activated ethylene gas (abbreviated as ethylene) to propylene was 1:4, the polymerization temperature was 25°C, and the polymerization pressure was 0.5 MPa.

[0188] Comparative Example G1

[0189] The copolymer of ethylene and propylene was prepared by the same method as in Example 8, with the only difference being that the ethylene gas was not treated sequentially using purification tank 1, purification tank 2, and purification tank 3. In other words, the commercially available ethylene gas was directly used to prepare the copolymer of ethylene and propylene through solution polymerization with propylene.

[0190] Example 9

[0191] The copolymer of ethylene and propylene was prepared by the same method as in Example 8, with the only difference being that the mass ratio of the activated ethylene gas (abbreviated as ethylene) to propylene was 1:3.

[0192] Control Example G2

[0193] The copolymer of ethylene and propylene was prepared by the same method as in Example 9, with the only difference being that the ethylene gas was not treated sequentially using purification tank 1, purification tank 2, and purification tank 3. In other words, the commercially available ethylene gas was directly used to prepare the copolymer of ethylene and propylene through solution polymerization with propylene.

[0194] Furthermore, the activities of the copolymers of ethylene and propylene prepared in Examples 8 - 9 and Control Examples G1 - G2 were tested, and the specific test results are shown in Table 8.

[0195] Table 8

[0196]

[0197] As shown in Table 8, it can be seen from Examples 8 - 9 that by activating the ethylene gas using the purification tank provided by the present invention and carrying out copolymerization reaction of the obtained activated ethylene gas with propylene, a relatively high polymerization activity can be achieved.

[0198] In summary, the present invention provides a method for treating ethylene gas, by which activated ethylene gas is obtained through activation of ethylene. Applying the activated ethylene to the preparation of polyolefin elastomers through solution polymerization can significantly improve the polymerization activity of the polyolefin elastomers, and thus higher-performance vinyl polyolefin elastomers or copolymers of ethylene and α-olefins can be prepared. Compared with other methods for preparing polyolefin elastomers, the present invention activates ethylene gas through three purification tanks, with lower cost. The prepared polyolefin elastomers have excellent physical and mechanical properties, aging resistance, and ultraviolet resistance, good low-temperature properties and rheological properties, higher transparency, better dimensional stability, and good affinity with polyolefins, laying a foundation for copolymerization with α-olefins or polar monomers in the future, and can be applied in fields such as automotive parts, wire and cable, machine tools, shoemaking, seals, and hot melt adhesives, better meeting the market demand.

[0199] The specific embodiments described above further elaborate on the objective, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only for the specific embodiments of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc., made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for preparing a polyolefin elastomer, characterized in that: The preparation method uses activated ethylene gas obtained by the following ethylene gas treatment method as a reaction raw material for solution polymerization; Wherein, the method for treating ethylene gas comprises: The commercially available ethylene gas is sequentially passed through a primary purification tank, a secondary purification tank, and a tertiary purification tank to obtain activated ethylene gas; Wherein, the primary purification tank is loaded with a triglyceride solution of Cu(Qc)2, where Qc represents quinoline-5-carboxylate; The secondary purification tank is loaded with anhydrous ether; The three-stage purification tank is loaded with an organic solvent containing trace amounts of water, wherein the organic solvent is n-heptane, and the content of trace amounts of water in the organic solvent in the three-stage purification tank is 0.5-5wt% of the organic solvent; In the primary purification tank, the concentration of Cu(Qc)2 is 1 μmol / L-100 μmol / L.

2. The preparation method according to claim 1, characterized in that: The Cu(Qc)2 is obtained by ball milling copper hydroxide and quinoline-5-carboxylic acid in the presence of N,N-dimethylformamide and ethanol.

3. The preparation method according to claim 1, characterized in that: The preparation method comprises: Passing the main catalyst, the co-catalyst and the activated ethylene gas into a reaction kettle containing a polymerization solvent to carry out a solution polymerization reaction to obtain a polyolefin elastomer, wherein the polyolefin elastomer is a homopolymer of the activated ethylene gas; The polymerization solvent is the same as the organic solvent loaded in the three-stage purification tank, and the molar ratio of trace water in the polymerization solvent to the co-catalyst is 1:2-1:

6.

4. The preparation method according to claim 1, characterized in that: The preparation method comprises: In the presence of the main catalyst and the co-catalyst, C3-C 12 α-olefin and the activated ethylene gas, and carry out solution polymerization to obtain a polyolefin elastomer, wherein the polyolefin elastomer is C3-C 12 Copolymers of alpha-olefins and ethylene.

5. The preparation method according to claim 3 or 4, characterized in that: The co-catalyst is selected from at least one of triethylaluminum, diethylaluminum chloride, ethylaluminum dichloride, sesquiethylaluminum chloride, monoisobutylaluminum chloride, and diisobutylaluminum dichloride; The main catalyst is a nickel diimide catalyst, and the nickel diimide catalyst has a structure as shown in the following formula (1): Formula (1), wherein R is selected from at least one of isobutyl, phenyl and hydrogen.

6. The preparation method according to claim 4, characterized in that: The comonomer used in the solution polymerization reaction with ethylene gas is selected from C3-C8 α-olefins.

7. The preparation method according to claim 5, characterized in that: The polymerization temperature in the solution polymerization reaction is 25° C.-45° C., and the polymerization pressure is 0.6 MPa-2.0 MPa.

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