Polyolefin elastomer and method for producing the same

Abstract

The present invention provides a kind of polyolefin elastomer and its generation method, belong to the field of olefin polymerization technology. The generation method of the polyolefin elastomer, including a part of ethylene and α-olefin comonomer is passed into a reaction unit; another part of the α-olefin comonomer is mixed with a primary catalyst and a co-catalyst and passed into the reaction unit, so that the α-olefin comonomer and ethylene undergo polymerization reaction under catalysis to obtain a reaction solution; the reaction solution is sequentially flashed and granulated to obtain a polyolefin elastomer; wherein the primary catalyst includes a metallocene catalyst, and the co-catalyst includes an aluminum catalyst and a boron catalyst. The generation method, without adding an inert solvent in the reaction unit, simplifies the production process, reduces production costs, ensures the efficiency and stability of the polymerization reaction, and improves the production quality of the product.

Description

Technical Field

[0001] The present invention relates to the technical field of olefin polymerization, in particular to a polyolefin elastomer and a production method thereof. Background Art

[0002] Olefin polymers refer to polyolefin elastomers (POE) formed by the copolymerization of ethylene and α-olefins, such as ethylene-octene copolymers, ethylene-hexene copolymers, and ethylene-butene copolymers. POE molecular chains contain higher comonomer content and lower density. The polymer chains are all saturated with no polar groups, giving polyolefin elastomers excellent aging resistance, corrosion resistance, thermal stability, and resistance to water vapor permeation. Therefore, they can replace a range of general-purpose polymers such as EPM, EPDM, EVA, SBC, and EMA, and are widely used in automotive parts, wire and cable, machine tools, household goods, toys, recreational and sporting goods, shoe soles, seals, hot-melt adhesives, and other fields.

[0003] The emergence of POE products is inseparable from the development of homogeneous metal catalysts. Currently, domestic research on POE focuses primarily on product classification, performance, and blending or cross-linking applications. While domestic scientists have conducted extensive research on POE catalysts and achieved some progress, there is still no technology for the industrial application of POE catalysts, nor is there a method for large-scale continuous production of POE polyelastomers using catalysts.

[0004] Therefore, it is necessary to design a polyolefin elastomer and a production method thereof to solve the above problems. Summary of the Invention

[0005] In view of the above shortcomings of the prior art, the present invention provides a polyolefin elastomer and a method for producing the same. The method utilizes a separate feed step to improve the reaction efficiency and finished product quality of large-scale polymerization of polyolefin elastomers, thereby filling the relevant gaps in the prior art regarding the industrial production of POE catalysts.

[0006] To achieve the above-mentioned and other related purposes, the present invention provides a method for producing a polyolefin elastomer, the method comprising:

[0007] A portion of the α-olefin comonomer and ethylene are introduced into a reaction unit;

[0008] The other part of the α-olefin comonomer, the main catalyst, and the co-catalyst are mixed and introduced into the reaction device to cause the α-olefin comonomer to undergo polymerization reaction with the ethylene under the catalytic action to obtain a reaction liquid; wherein the main catalyst comprises a metallocene catalyst, and the co-catalyst comprises an aluminum co-catalyst and a boron co-catalyst;

[0009] The reaction liquid is flash evaporated and granulated in sequence to obtain a polyolefin elastomer.

[0010] In one example of the present invention, the mixing of another portion of the α-olefin comonomer, the main catalyst, and the co-catalyst into the reaction device comprises:

[0011] Mixing another portion of the α-olefin comonomer with the aluminum-promoting catalyst to obtain a first material; wherein the mixing time of the α-olefin comonomer and the aluminum-promoting catalyst is 2 to 4 minutes; mixing the first material with the main catalyst to obtain a second material; wherein the mixing time of the first material and the main catalyst is less than or equal to 80 seconds; mixing the second material with the boron-promoting catalyst to obtain a third material; wherein the mixing time of the second material and the boron-promoting catalyst is less than or equal to 40 seconds; and passing the third material into the reaction device.

[0012] In one example of the present invention, the metallocene catalyst includes diphenylsilyl (cyclopentadienyl) (9-fluorenyl) zirconium dichloride, and the structural formula of the metallocene catalyst is as follows:

[0013]

[0014] In one example of the present invention, the aluminum promoter is selected from at least one of methylaluminoxane, ethylaluminoxane and modified methylaluminoxane; the boron promoter is selected from at least one of perfluorophenylboron, triphenylcarbon tetrakis(pentafluorophenyl)borate and N,N-dimethylanilinium tetrakis(pentafluorophenyl)boron compound.

[0015] In one example of the present invention, the polymerization reaction pressure is 3 to 10 MPa, and the polymerization reaction time is 5 to 30 minutes.

[0016] In one example of the present invention, the polymerization reaction temperature is greater than or equal to 250° C.; in the flash evaporation step, the reaction liquid uses the residual heat of the polymerization reaction to complete component evaporation and separation.

[0017] In one example of the present invention, the α-olefin comonomer is a linear or branched α-olefin having 3 to 20 carbon atoms.

[0018] In one example of the present invention, the α-olefin comonomer is selected from at least one of propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, decene, 1-dodecene, and 1-hexadecene.

[0019] In one example of the present invention, the mass ratio of the portion of the α-olefin comonomer to the total mass of the α-olefin comonomer is 70% to 80%; the feed molar ratio of the portion of the α-olefin comonomer to the ethylene is (0.5 to 5):1; the feed concentration of the main catalyst is 0.001 to 0.1 μmol / mL, and the feed molar ratio of the main catalyst, the aluminum-assisted catalyst, and the boron-assisted catalyst is 1:(100 to 800):(0.5 to 2).

[0020] The present invention also provides a polyolefin elastomer, which is prepared by using the production method described in any of the above examples.

[0021] The present invention provides a polyolefin elastomer and a production method thereof. The production method of the polyolefin elastomer comprises the following steps: firstly, introducing a portion of ethylene and α-olefin comonomers into a reaction device for mixing, so that the ethylene and α-olefin comonomers are fully mixed before a polymerization reaction, thereby improving the efficiency of a subsequent reaction; and then, mixing another portion of the α-olefin comonomers with a main catalyst and a co-catalyst before introducing the other portion into the reaction device, thereby removing impurities in the α-olefin comonomers while allowing metal active sites provided by the main catalyst and the co-catalyst introduced into the reaction device to be surrounded by the α-olefin comonomers in advance, thereby reducing the influence of impurities on catalytic active centers, further accelerating the polymerization reaction of the ethylene and α-olefin comonomers around the metal active sites, and improving the catalyst activity in the polymerization reaction, so that the production method can synthesize polyolefin elastomers on a large scale with high efficiency and high quality.

[0022] In summary, the method for producing a polyolefin elastomer does not require the addition of an inert solvent to the reaction apparatus, thereby simplifying the production process and reducing production costs while ensuring the efficiency and stability of the polymerization reaction and improving the production quality of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other embodiments can be obtained based on these drawings without paying any creative work.

[0024] Figure 1 1 is a schematic flow chart of a method for producing a polyolefin elastomer according to one embodiment of the present invention;

[0025] Figure 2 FIG. 1 is a flow chart of step S2 in one embodiment of the present invention. DETAILED DESCRIPTION

[0026] The following describes the embodiments of the present invention through specific examples. Those skilled in the art will readily understand the other advantages and benefits of the present invention from the disclosure herein. The present invention may also be implemented or applied through various other specific embodiments, and the details in this specification may be modified or altered based on different viewpoints and applications without departing from the spirit of the present invention.

[0027] It should be noted that, unless there is a conflict, the features in the following examples and embodiments may be combined with each other. It should also be understood that the terms used in the examples of the present invention are intended to describe specific embodiments and are not intended to limit the scope of protection of the present invention. The test methods in the following examples, where specific conditions are not specified, are generally performed under conventional conditions or according to the conditions recommended by the respective manufacturers.

[0028] The invention provides a method for producing a polyolefin elastomer. The method does not require the introduction of an inert solvent into a reaction device, and realizes large-scale continuous production of the polyolefin elastomer by separately feeding a polymerization raw material and a catalyst into the reaction device.

[0029] See Figure 1 The method for producing the polyolefin elastomer comprises the following steps:

[0030] S1, introducing a portion of α-olefin comonomer and ethylene into a reaction unit;

[0031] S2, mixing another portion of the α-olefin comonomer, the main catalyst, and the co-catalyst and introducing them into the reaction device, so that the α-olefin comonomer and the ethylene undergo polymerization reaction under the catalytic action to obtain a reaction solution;

[0032] S3, flash evaporating and granulating the reaction solution in sequence to obtain a polyolefin elastomer;

[0033] Wherein, the main catalyst includes a metallocene catalyst, and the co-catalyst includes an aluminum co-catalyst and a boron co-catalyst.

[0034] The production method comprises the following steps: firstly introducing a portion of α-olefin comonomer and ethylene into a reaction device for mixing, so that the ethylene and α-olefin comonomer are uniformly mixed in advance in the reaction device, thereby improving the reaction efficiency after the catalyst is introduced; and then sequentially mixing the other portion of the α-olefin comonomer with a main catalyst and a co-catalyst before introducing the other portion into the reaction device, thereby removing impurities in the α-olefin comonomer while allowing the metal active sites provided by the main catalyst and the co-catalyst introduced into the reaction device to be surrounded by the α-olefin comonomer in advance, thereby reducing the influence of impurities on the catalytic active centers, further accelerating the polymerization reaction of ethylene and α-olefin comonomer around the metal active sites in the reaction device, improving the catalyst activity and reaction efficiency in the polymerization reaction, maintaining the reaction stability, and realizing the continuous polymerization reaction of ethylene and α-olefin comonomer in the continuous feeding process, thereby completing high-efficiency and high-quality large-scale production of polyolefin elastomers.

[0035] Step S1 includes introducing ethylene and a portion of an α-olefin comonomer into a reaction apparatus for mixing, so that the ethylene and the portion of the α-olefin comonomer are uniformly mixed in the reaction apparatus before the polymerization reaction, so that after the catalyst is introduced into the reaction apparatus, a polymerization reaction can quickly occur around the active center of the catalyst, thereby improving the reaction efficiency of the polymerization reaction; and the uniformly mixed ethylene and the portion of the α-olefin comonomer ensure that chain length reactions alternate at the metal active sites, thereby improving the utilization rate of the reaction raw materials. In step S1, the ethylene and the portion of the α-olefin comonomer can be pre-mixed before being introduced into the reaction apparatus, or the ethylene and the portion of the α-olefin comonomer can be introduced into the reaction apparatus and then uniformly mixed.

[0036] In some embodiments, in step S1, the α-olefin comonomer introduced is a linear or branched α-olefin with 3 to 20 carbon atoms. Further, the α-olefin comonomer is selected from one or more of propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, decene, 1-dodecene, and 1-hexadecene, that is, the α-olefin comonomer can be any one of the monomer types listed above, for example, 1-octene, or 1-butene, or decene, etc.; the α-olefin comonomer can also be a combination of two or more of the monomer types listed above in any proportion, such as a combination of propylene and 1-butene, or a combination of 1-pentene, 1-hexene and 1-octene, or a combination of decene, 1-dodecene and 1-hexadecene, etc., which are not listed one by one here. Of course, the α-olefin comonomer includes but is not limited to the monomer types listed above, and monomers that meet the conditions not listed above can also be selected.

[0037] In some embodiments, in step S1, the mass fraction of the introduced α-olefin comonomer relative to the total α-olefin comonomer is 70% to 80%. For example, the mass fraction of the introduced α-olefin comonomer may be 70%, 71%, 72%, 73%, 74%, 75%, 76%, 77%, 78%, 79%, or 80%. Alternatively, the mass fraction of the introduced α-olefin comonomer may be 72% to 74%.

[0038] In some embodiments, in step S1, the feed molar ratio of the portion of the α-olefin comonomer to ethylene is (0.5-5):1. For example, the feed molar ratio of the portion of the α-olefin comonomer to ethylene can be 0.5:1, 0.8:1, 1:1, 1.5:1, 2:1, 2.5:1, 3:1, 3.5:1, 4:1, 4.5:1, or 5:1. Alternatively, the feed molar ratio of the portion of the α-olefin comonomer to ethylene is (0.8-3.5):1.

[0039] In some embodiments, step S1 further includes a pretreatment step of the reaction apparatus before introducing ethylene and α-olefin comonomers. The pretreatment step renders the reaction chamber of the reaction apparatus free of water and oxygen to prevent moisture or oxygen from adversely affecting the subsequent polymerization reaction. The pretreatment step includes introducing high-purity nitrogen into the reaction chamber of the reaction apparatus at a temperature of 140° C. to 150° C., and replacing the gas in the reaction chamber with the high-purity nitrogen three to five times to ensure that the reaction chamber is free of water and oxygen.

[0040] In addition, in some embodiments, after the pretreatment step makes the reaction device free of water and oxygen, the reaction device (reactor and pipeline) needs to be preheated to the required temperature, the speed of the stirring device in the reactor is adjusted to a set speed, for example, 800 to 1000 r / min, and then the feed valve on the top of the reactor body is opened to introduce ethylene and part of the α-olefin comonomer into the reactor, and the pressure in the reactor is controlled within a reasonable range.

[0041] It should be noted that the reaction apparatus in step S1 can be any apparatus that meets the conditions for polyolefin production. For example, the reaction apparatus can be a reactor, which typically includes a reactor body, a stirring mechanism, and a heating mechanism. The reactor body is provided with a reaction chamber, the top of the reactor body is provided with multiple feeding tanks connected to the reaction chamber, and the bottom of the reactor body is provided with a discharge port. The stirring mechanism is installed in the reactor body. During the reaction process, the stirring mechanism continuously stirs the materials in the reaction chamber, thereby ensuring a more complete and efficient reaction. The heating mechanism can provide heat to the reaction chamber. The heating mechanism can provide heat to the reaction chamber in various forms, such as a heating jacket wrapped around the outside of the reactor body.

[0042] In some embodiments, in step S2, another portion of the α-olefin comonomer is first uniformly mixed with the aluminum-promoting catalyst, and then preliminarily mixed with the primary catalyst and the boron-promoting catalyst before being introduced into the reaction apparatus. This feeding step can remove impurities from the α-olefin comonomer while allowing the metal active sites provided by the primary catalyst and the co-catalyst introduced into the reaction apparatus to be surrounded by the α-olefin comonomer in advance, thereby reducing the impact of impurities on the catalytically active centers and further accelerating the polymerization reaction of ethylene and α-olefin comonomer around the metal active sites in the reaction apparatus, thereby improving the catalyst activity and reaction efficiency of the polymerization reaction.

[0043] like Figure 2 As shown, in some embodiments, step S2 includes the following steps:

[0044] S21, mixing another portion of the α-olefin comonomer with the aluminum-promoting catalyst to obtain a first material; wherein the mixing time of the α-olefin comonomer and the aluminum-promoting catalyst is 2 to 4 minutes, for example, 2 minutes, 3 minutes or 4 minutes;

[0045] Because the aluminum co-catalyst does not react with the α-olefin comonomer but can react with the primary catalyst, it removes the metal-halide bond through an alkylation reaction, thereby activating the metal cations of the primary catalyst to form catalytically active centers. Therefore, in step S21, the remaining portion of the α-olefin comonomer is thoroughly and evenly mixed with the aluminum co-catalyst. This removes impurities in the α-olefin comonomer while allowing the α-olefin comonomer to uniformly surround the aluminum co-catalyst before the reaction. During the subsequent polymerization reaction, the α-olefin comonomer can evenly surround the primary catalyst active centers bound to the aluminum co-catalyst, thereby improving the polymerization reaction efficiency.

[0046] S22. Mix the first material with the main catalyst to obtain a second material; wherein the mixing time of the first material and the main catalyst is less than or equal to 80 seconds; for example, the mixing time of the first material and the main catalyst can be 1 second, 3 seconds, 5 seconds, 8 seconds, 10 seconds, 15 seconds, 20 seconds, 25 seconds, 30 seconds, 40 seconds, 50 seconds, 60 seconds, 70 seconds or 80 seconds.

[0047] S23, mixing the second material with the boron-promoting catalyst to obtain a third material; wherein the mixing time of the second material and the boron-promoting catalyst is less than or equal to 40 seconds; for example, the mixing time of the second material and the boron-promoting catalyst can be 1 second, 3 seconds, 5 seconds, 8 seconds, 10 seconds, 15 seconds, 20 seconds, 25 seconds, 30 seconds, 35 seconds or 40 seconds.

[0048] In step S22, the first material is mixed with the main catalyst for a short time to activate the main catalyst and the aluminum-assisted catalyst, while avoiding the reaction between the α-olefin comonomer and the main catalyst; in step S23, the second material is mixed with the boron-assisted catalyst for a short time, also to avoid the reaction between the α-olefin comonomer and the main catalyst before entering the reaction device.

[0049] S24, introducing the third material into the reaction device to cause a polymerization reaction between the α-olefin comonomer and ethylene under the catalytic action to obtain a reaction liquid.

[0050] In addition, in step S1 and step S2, the above-mentioned α-olefin comonomer, ethylene, main catalyst and co-catalyst are stored in the feed tank of the reactor respectively. It should be noted that the main catalyst and co-catalyst both need to be made into solutions and stored in the feed tank, so as to control the feed concentration and rate of the main catalyst and co-catalyst during the reaction. For example, the main catalyst and toluene are made into a solution and stored in a feed tank; the co-catalyst triisobutylaluminum and hexane are made into a solution and stored in another feed tank, and ethylene and α-olefin comonomer are stored in another feed tank. Preferably, the above-mentioned α-olefin comonomer and ethylene need to be dehydrated and deoxygenated before use.

[0051] In some embodiments, in step S2, the mass fraction of the other portion of the α-olefin comonomer relative to the total α-olefin comonomer is 20% to 30%. For example, the mass fraction of the other portion of the α-olefin comonomer may be 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, or 30%. Alternatively, the mass fraction of the other portion of the α-olefin comonomer may be 26% to 28%.

[0052] In some embodiments, in step S1 and step S2, the feed concentration of the α-olefin comonomer is 3.8 to 4.2 mol / L. For example, the feed concentration of the α-olefin comonomer can be 3.8 mol / L, 3.9 mol / L, 4.0 mol / L, 4.1 mol / L or 4.2 mol / L.

[0053] In some embodiments, in step S2, the feed concentration of the main catalyst is 0.001 to 0.1 μmol / mL. For example, the feed concentration of the main catalyst can be 0.001 μmol / mL, 0.005 μmol / mL, 0.01 μmol / mL, 0.02 μmol / mL, 0.03 μmol / mL, 0.04 μmol / mL, 0.05 μmol / mL, 0.06 μmol / mL, 0.07 μmol / mL, 0.08 μmol / mL, 0.09 μmol / mL or 0.1 μmol / mL.

[0054] In some embodiments, in step S2, the feed molar ratio of the main catalyst to the auxiliary aluminum catalyst is 1:(100~800), for example, the feed molar ratio of the main catalyst to the auxiliary aluminum catalyst can be 1:100, 1:150, 1:200, 1:250, 1:300, 1:350, 1:400, 1:450, 1:500, 1:550, 1:600, 1:650, 1:700, 1:750 or 1:800.

[0055] In some embodiments, in step S2, the feed molar ratio of the main catalyst to the boron-promoting catalyst is 1:(0.5~2), for example, the feed molar ratio of the main catalyst to the boron-promoting catalyst can be 1:0.5, 1:0.8, 1:1, 1:1.3, 1:1.5, 1:1.7 or 1:2.

[0056] In some embodiments, in step S2, in the reaction apparatus, the polymerization pressure of the α-olefin comonomer and ethylene is 3 to 10 MPa. For example, the polymerization pressure may be 3 MPa, 4 MPa, 5 MPa, 6 MPa, 7 MPa, 8 MPa, 9 MPa, or 10 MPa. Alternatively, the polymerization pressure of the α-olefin comonomer and ethylene is 4 to 8 MPa.

[0057] In some embodiments, in step S2, in the reaction apparatus, the polymerization reaction time of the α-olefin comonomer and ethylene is 5 to 30 minutes. For example, the polymerization reaction time can be 5 minutes, 8 minutes, 10 minutes, 12 minutes, 15 minutes, 17 minutes, 20 minutes, 23 minutes, 25 minutes, 27 minutes or 30 minutes.

[0058] In step S3, after obtaining the reaction liquid, the reaction liquid is flash evaporated and granulated in the presence of an antioxidant to obtain a polyolefin elastomer. The flash evaporated reaction liquid is used to devolatilize and separate the components, and a flash evaporator well known to those skilled in the art can be used. Granulation is preferably performed using a twin-screw extrusion granulation technique well known to those skilled in the art to obtain the polyolefin elastomer.

[0059] In step S3, the antioxidant is preferably a phenolic antioxidant, more preferably antioxidant 1135 and / or antioxidant 1076. The present invention does not particularly limit the source of the antioxidant, and commercially available products known to those skilled in the art may be used. The present invention employs the aforementioned deactivating antioxidant, which is an active proton antioxidant that can fully react with the reaction solution, facilitating flash devolatilization to obtain a crude product.

[0060] In step S3, the flow rate of the antioxidant is preferably 1 to 100 mmol / h, for example, 5 to 50 mmol / h.

[0061] In some embodiments, the metallocene catalyst comprises diphenylsilyl(cyclopentadienyl)(9-fluorenyl)zirconium dichloride, and the structural formula of the metallocene catalyst is shown below:

[0062]

[0063] In some embodiments, the aluminum co-catalyst is selected from at least one of methylaluminoxane, ethylaluminoxane and modified methylaluminoxane. That is, the aluminum co-catalyst can be any one of the above-mentioned types of compounds, such as methylaluminoxane, ethylaluminoxane or modified methylaluminoxane; the aluminum co-catalyst can also be any two or more combinations of the above-mentioned types of compounds, such as a combination of methylaluminoxane and ethylaluminoxane, or a combination of methylaluminoxane and modified methylaluminoxane, or a combination of ethylaluminoxane and modified methylaluminoxane, or a combination of methylaluminoxane, ethylaluminoxane and modified methylaluminoxane, etc., which are not listed here one by one. In addition, when the aluminum co-catalyst is a combination of two or more materials, there is no restriction on the proportion of each material in the combination. In other embodiments, the aluminum co-catalyst can also be a type of material not listed above. In one example, optionally, the aluminum co-catalyst is methylaluminoxane and / or modified methylaluminoxane.

[0064] In some embodiments, the boron promoter catalyst is selected from at least one of perfluorophenylboron, triphenylcarbon tetrakis(pentafluorophenyl)borate, and N,N-dimethylaniline tetrakis(pentafluorophenyl)boron compounds. That is, the boron promoter catalyst can be any one of the aforementioned compound types, such as perfluorophenylboron, triphenylcarbon tetrakis(pentafluorophenyl)borate, or N,N-dimethylaniline tetrakis(pentafluorophenyl)boron compounds; the boron promoter catalyst can also be any two or more combinations of the aforementioned compound types, such as a combination of perfluorophenylboron and triphenylcarbon tetrakis(pentafluorophenyl)borate, or a combination of triphenylcarbon tetrakis(pentafluorophenyl)borate and N,N-dimethylaniline tetrakis(pentafluorophenyl)boron compounds, or a combination of perfluorophenylboron and N,N-dimethylaniline tetrakis(pentafluorophenyl)boron compounds, or a combination of perfluorophenylboron, triphenylcarbon tetrakis(pentafluorophenyl)borate, and N,N-dimethylaniline tetrakis(pentafluorophenyl)boron compounds, and the like, which are not listed here one by one. In addition, when the boron-promoting catalyst is a combination of two or more materials, there is no restriction on the ratio of each material in the combination. In other embodiments, the boron-promoting catalyst can also be a material type not listed above.

[0065] In certain embodiments, under the catalytic action of the above-mentioned metallocene catalyst and the combination of aluminum-promoting catalyst and boron-promoting catalyst, the reaction temperature of the polymerization reaction occurring in step S2 is significantly improved, and the polymerization reaction temperature can be increased to more than 250 ° C. Alternatively, the polymerization reaction temperature can be higher than 255 ° C. For example, under the catalyst combination of diphenylsilyl (cyclopentadiene) (9-fluorenyl) zirconium dichloride, methylaluminoxane and triphenyl carbon tetrakis (pentafluorophenyl) borate, the polymerization reaction temperature is 255 ° C to 260 ° C. The high polymerization reaction temperature in the present embodiment can provide enough heat so that the prepared reaction solution can utilize the waste heat of the polymerization reaction to complete the component evaporation separation in the flash step without the need for the outside world to provide additional separation heat, thereby achieving the effect of energy saving and emission reduction.

[0066] The present invention also provides a polyolefin elastomer, which is prepared using the production method described in any of the above embodiments. The production method of the polyolefin elastomer uses a single-active-center catalytic system to catalyze the copolymerization reaction of ethylene and α-olefins, and the catalytic activity of the production process reaches 200,000 g / gcat. The produced polyolefin elastomer is tested by high-temperature gel permeation chromatography, and the obtained copolymer weight-average molecular weight Mg is 55,000 to 250,000 g / mol, the molecular weight distribution index PDI is 2 to 4, the melt index of the polyolefin elastomer is 0.5 to 20 g / 10 min, and the density of the polyolefin elastomer is 0.865 to 0.895 g / cm 3 , and the glass transition temperature (Tg) is low, reaching below -65°C.

[0067] The technical solutions of the present invention are described in detail below through several specific examples and comparative examples. Unless otherwise specified, the raw materials and reagents used in the following examples are commercially available or can be prepared by conventional methods in the art.

[0068] Example 1

[0069] This embodiment provides a method for producing a polyolefin elastomer. In this embodiment, the main catalyst is diphenylsilyl (cyclopentadiene) (9-fluorenyl) zirconium dichloride, the aluminum co-catalyst is methylaluminoxane, the boron co-catalyst is triphenyl carbon tetrakis (pentafluorophenyl) borate, and the α-olefin comonomer is 1-octene. Before preparation, a 500mL reactor is replaced three times with vacuum high-purity nitrogen at 200°C; a solution of the main catalyst and toluene is stored in a feed tank, a solution of methylaluminoxane and hexane is stored in another feed tank, a solution of triphenyl carbon tetrakis (pentafluorophenyl) borate and hexane is stored in yet another feed tank, and 1-octene and ethylene are stored in separate feed tanks.

[0070] The reactor and pipeline are preheated to the required temperature, ethylene and part of the α-olefin comonomer are first mixed and then transported to the reactor at a set flow rate; then another part of the α-olefin comonomer is mixed with the aluminum-promoting catalyst for 2 minutes to obtain a first material, the first material is mixed with the main catalyst for 10 seconds to obtain a second material, the second material is mixed with the boron-promoting catalyst for 20 seconds to obtain a third material, and then the third material is continuously introduced into the reactor at a set flow rate to allow the ethylene and α-olefin comonomer to polymerize under the catalytic action to obtain a reaction liquid; the stirring speed of the reactor is The reactor was set at 800 r / min. Once the reactor was fully filled, the material overflowed from the reactor overflow port. The liquid level in the reactor was controlled by a pneumatic valve to achieve continuous discharge. The mass fraction of the partial 1-octene relative to the total 1-octene was 72%, the 1-octene feed concentration was 3.8 mol / L, the 1-octene to ethylene molar ratio was 1.2:1, the primary catalyst feed concentration was 0.002 μmol / mL, the primary catalyst to aluminum-co-catalyst feed molar ratio was 1:200, and the primary catalyst to boron-co-catalyst feed molar ratio was 1:0.8. During the stable reaction, the reactor pressure was set at 4 MPa, the polymerization reaction time was 15 minutes, and the polymerization temperature was 255°C. Finally, after the polymerization is completed, the reaction liquid is fully reacted with the antioxidant 1076 (flow rate of 10.0 mmol / h) in a flash kettle, and then flash devolatilization and twin-screw extrusion granulation are carried out to obtain a polyolefin elastomer. In the flash step, the residual heat of the polymerization reaction is used to complete the evaporation and separation of the components without the need for additional separation heat from the outside.

[0071] Example 2

[0072] This embodiment provides a production method similar to that of Example 1. This embodiment differs from Example 1 in that another portion of the α-olefin comonomer is mixed with the aluminum-promoting catalyst for 4 minutes; the 1-octene feed concentration is 4.2 mol / L, the 1-octene to ethylene molar ratio is 1.35:1, and the feed molar ratio of the primary catalyst to the aluminum-promoting catalyst is 1:150; during the stable reaction, the pressure in the reactor is set to 6 MPa, the reaction time is 10 minutes, and the polymerization temperature can be further increased to 258°C. Similarly, the flash evaporation step of the reaction solution still utilizes the residual heat of the polymerization reaction to complete the component evaporation separation, without the need for additional external separation heat.

[0073] Example 3

[0074] This embodiment provides a production method similar to that of Example 1. The difference between this embodiment and Example 1 is that the main catalyst uses diphenyl carbon bridge group-cyclopentadienyl-(2-dimethylamino-fluorenyl) zirconium dichloride, the auxiliary aluminum catalyst uses triisobutylaluminum, and the auxiliary boron catalyst uses N,N-dimethylaniline tetrakis(pentafluorophenyl)boron compound; during the preparation process, another portion of the α-olefin comonomer is mixed with the auxiliary aluminum catalyst for 4 minutes, the 1-octene feed concentration is 4.2 mol / L, the molar ratio of 1-octene to ethylene is 1.3:1, the main catalyst feed concentration is 0.003 μmol / mL, the feed molar ratio of the main catalyst to the auxiliary aluminum catalyst is 1:500, and the feed molar ratio of the main catalyst to the auxiliary boron catalyst is 1:0.8. During the stable reaction, the pressure in the reactor is set to 6 MPa, the reaction time of the material in the reactor is 15 minutes, and the polymerization reaction temperature is only 150°C; the flash evaporation temperature of the reaction liquid needs to be above 210°C, so the steam needs to provide an additional heat of 40,000 KJ / 24h during the flash evaporation step of the reaction liquid.

[0075] Example 4

[0076] This example provides a production method similar to that of Example 3. This example differs from Example 3 in that, during the preparation process, the molar ratio of 1-octene to ethylene is 1.5:1, and the molar ratio of the primary catalyst to the boron-assisted catalyst is 1:1.5. During the stable reaction, the reactor pressure is set at 6 MPa, and the polymerization temperature is only 170°C. The flash evaporation temperature of the reaction liquid must be above 210°C, so the flash evaporation step requires steam to provide an additional heat of 26,000 kJ / 24h.

[0077] The polyolefin elastomers prepared in Examples 1 to 4 were subjected to performance tests. The test results are shown in Table 1.

[0078] Table 1: Performance parameters of the polyolefin elastomers prepared in Examples 1 to 4

[0079]

[0080] The test results in Examples 1 to 4 show that the polyolefin elastomer prepared on a large scale by the continuous production method provided by the present invention has good product quality. The weight average molecular weight Mw of the polyolefin elastomers prepared in Examples 1 to 4 is 100,000 to 250,000 g / mol, the melt index of the polyolefin elastomer is 0.5 to 20 g / 10 min, and the density of the polyolefin elastomer is 0.865 to 0.895 g / cm 3 , and the glass transition temperature (Tg) is low, reaching below -65°C; in particular, the molecular weight distribution index PDI is maintained at 2 to 3. It can be seen that the polyolefin elastomer prepared under efficient reaction has a high molecular weight and its chain length uniformity is significantly improved.

[0081] Comparing the test results of Examples 1 to 2 and Examples 3 to 4, it can be seen that Examples 1 and 2 use diphenylsilyl (cyclopentadiene) (9-fluorenyl) zirconium dichloride as a catalyst combination with other aluminum-promoting catalysts, which can effectively improve the catalyst activity in the polymerization reaction and increase the polymerization reaction temperature during the reaction to provide heat for subsequent flash evaporation without the need for external steam heating, thereby achieving energy saving and emission reduction effects.

[0082] In summary, the method for producing a polyolefin elastomer does not require the addition of an inert solvent to the reaction apparatus, thereby simplifying the production process and reducing production costs while ensuring the efficiency and stability of the polymerization reaction and improving the production quality of the product.

[0083] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Anyone skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by one of ordinary skill in the art without departing from the spirit and technical principles disclosed herein are intended to be covered by the claims of the present invention.

Claims

1. A method for producing a polyolefin elastomer, characterized in that: include: A portion of the α-olefin comonomer and ethylene are introduced into a reaction unit; The other part of the α-olefin comonomer, the main catalyst, and the co-catalyst are mixed and introduced into the reaction device to cause the α-olefin comonomer to undergo a polymerization reaction with the ethylene under the action of a catalyst to obtain a reaction solution. During the polymerization reaction, the pressure of the polymerization reaction is controlled to be 3 to 10 MPa, and the polymerization reaction temperature is greater than or equal to 250° C.; wherein the main catalyst comprises diphenylsilyl (cyclopentadiene) (9-fluorenyl) zirconium dichloride, and the co-catalyst comprises an aluminum co-catalyst and a boron co-catalyst; The reaction liquid is flash-evaporated and granulated in sequence to obtain a polyolefin elastomer; in the flash-evaporation step, the reaction liquid uses the residual heat of the polymerization reaction to complete component evaporation and separation; Wherein, the structural formula of the diphenylsilyl (cyclopentadiene) (9-fluorenyl) zirconium dichloride is as follows: The mixing of another portion of the α-olefin comonomer, the main catalyst, and the co-catalyst into the reaction device comprises: mixing another portion of the α-olefin comonomer with the aluminum-promoted catalyst to obtain a first material; mixing the first material with the main catalyst to obtain a second material; mixing the second material with the boron-promoting catalyst to obtain a third material; The third material is introduced into the reaction device.

2. The generation method according to claim 1, characterized in that The mixing time of the α-olefin comonomer and the aluminum-promoting catalyst is 2 to 4 minutes; the mixing time of the first material and the main catalyst is less than or equal to 80 seconds; and the mixing time of the second material and the boron-promoting catalyst is less than or equal to 40 seconds.

3. The generation method according to claim 1, characterized in that The aluminum-promoting catalyst is selected from at least one of methylaluminoxane, ethylaluminoxane and modified methylaluminoxane; the boron-promoting catalyst is selected from at least one of perfluorophenylboron, triphenylcarbon tetrakis(pentafluorophenyl)borate and N,N-dimethylanilinium tetrakis(pentafluorophenyl)boron compound.

4. The generation method according to claim 1, characterized in that The polymerization reaction time is 5 to 30 minutes.

5. The generation method according to claim 1, characterized in that The α-olefin comonomer is a linear or branched α-olefin with 3 to 20 carbon atoms.

6. The generation method according to claim 5, characterized in that The α-olefin comonomer is selected from at least one of propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, decene, 1-dodecene, and 1-hexadecene.

7. The generation method according to claim 1, characterized in that The mass ratio of the portion of the α-olefin comonomer to the total mass of the α-olefin comonomer is 70% to 80%; the feed molar ratio of the portion of the α-olefin comonomer to the ethylene is (0.5 to 5):1; the feed concentration of the main catalyst is 0.001 to 0.1 μmol / mL, and the feed molar ratio of the main catalyst, the aluminum-assisted catalyst, and the boron-assisted catalyst is 1:(100 to 800):(0.5 to 2).

8. A polyolefin elastomer, characterized in that The product is prepared by the production method according to any one of claims 1 to 7.

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