Ethylene / α-olefin copolymers and methods for preparing same

Abstract

The present invention relates to an ethylene / α-olefin copolymer and a method for preparing the same. The ethylene / α-olefin copolymer has an α-olefin content of 30 wt % or more and a density of 0.875 g / cm 3 The melting point is 90°C or higher, and the α-olefin is C3 to C 20 The ethylene-α-olefin copolymer of the present invention has a higher usable temperature range than conventional polyolefin elastomers at the same comonomer content, and is therefore suitable for use in high-temperature environments.

Description

Detailed Description of the Invention

[0001] [Technical Field] The present invention relates to the field of olefin coordination polymerization, and in particular to ethylene / α-olefin copolymers, methods for preparing ethylene / α-olefin copolymers, and ethylene / α-olefin copolymers prepared by the methods.

[0002] [Background technology] Polyolefin elastomer (POE) is an elastomer obtained by polymerizing ethylene and α-olefins in the presence of a homogeneous metal catalyst. In the narrow sense, polyolefin elastomer refers to a copolymer of ethylene and α-olefins (1-butene, 1-hexene, or 1-octene) with a mass fraction of α-olefins exceeding 20%. POE has a wide range of applications, including as a rubber, a thermoplastic elastomer, and an impact modifier and toughener for plastics. POE is used to toughen and modify various plastics, making it a strong competitor to conventional tougheners.

[0003] POE is synthesized by DuPont Dow Elastomers in the United States using the high-temperature solution Insite process. The catalyst used in this process is the CGC catalyst. Exxon primarily produces POE using the Exxpol polymerization process, which uses metallocene catalysts.

[0004] CN102464751B discloses a method for copolymerizing ethylene and α-olefins. The method is carried out by copolymerizing ethylene and α-olefins under the action of a metallocene catalyst and an alkylaluminoxane to obtain a copolymer. The molar content of branched chain units in the copolymer is 2 mol% to 18 mol%, and the weight average molecular weight is 1×10 4 ~1×10 6 and the molecular weight distribution M w / M nis 1 to 3, the melt index is 0.001 g / 10 min to 25 g / 10 min, the melting point is 115° C. to 135° C., and the comonomer content is less than 30 wt %.

[0005] CN108752526A discloses a catalyst system for preparing copolymers of ethylene and / or α-olefins with cyclic olefins, specifically a toluene solution of a metallocene compound, an organoboron compound and an alkylaluminum.

[0006] Polyolefin elastomers prepared with existing single catalyst systems have lower melting points, e.g., below 90° C., when the comonomer content exceeds 30 wt %. The lower melting point limits the use temperature range of such materials, affecting their use in higher temperature environments.

[0007] DISCLOSURE OF THE INVENTION In view of the problem that the melting point of polyolefin elastomer products is lower when the comonomer content is higher in the prior art, the present invention provides an ethylene-α-olefin copolymer and a preparation method thereof. The ethylene-α-olefin copolymer of the present invention has a relatively high melting point.

[0008] A first aspect of the present invention is an ethylene / α-olefin copolymer, the ethylene / α-olefin copolymer having an α-olefin content of 30 wt% or more and a density of 0.875 g / cm 3 and the melting point is 90°C or higher, and the α-olefin is a C3 to C 20 The present invention provides an ethylene / α-olefin copolymer, which is an α-olefin.

[0009] A second aspect of the present invention provides a method for preparing an ethylene / α-olefin copolymer, the method comprising conducting a copolymerization reaction of ethylene with an α-olefin in solution in at least one reactor in the presence of at least one catalyst to obtain an ethylene / α-olefin copolymer; maintaining a molar concentration ratio of ethylene to the α-olefin in the solution in the reactor at 0.6 to 2.2 throughout the reaction process; The catalyst is (A) a catalyst component; (B) an organoboron compound, and (C) containing an organoaluminum compound; The catalyst component is a premix of a half-sandwich metallocene catalyst precursor and an alkylaluminum compound; The half-sandwich metallocene catalyst precursor comprises a compound having the general formula Cp'LMQ2, Cp' is an optionally substituted cyclopentadiene group or a group derived therefrom, and is preferably one or more selected from the group consisting of substituted or unsubstituted cyclopentadienyl, substituted or unsubstituted indenyl, and substituted or unsubstituted fluorenyl; when Cp' contains a substituent, the substituent is selected from the group consisting of C1 to C 12 Alkyl, C1-C 12 Alkoxy, C1-C 12 Cyril, C6~C 12 Aryl, C7-C 12 Aralkyloxy, C2-C 12 Alkynyl and C8-C 12 arylalkynyl, preferably C1-C8 alkyl, more preferably C1-C6 alkyl, and even more preferably methyl, ethyl, n-propyl, isopropyl, n-butyl, and isobutyl; L is one or more of an optionally substituted phenolic ligand and a phosphanimine ligand; M is an element selected from Group IVB, preferably Zr and / or Ti, more preferably Ti; Each Q is independently selected from halogen and / or C1-C6 alkyl, preferably halogen and / or C1-C3 alkyl, more preferably chlorine and / or methyl.

[0010] A third aspect of the present invention provides an ethylene / α-olefin copolymer prepared by the above method.

[0011] Compared with the prior art, the present invention has the following features: In the present invention, a homogeneous metal catalyst precursor mixture is used together with an organoaluminum compound and an organoboron compound, and the ratios of ethylene and comonomer in the system are simultaneously controlled to catalyze the copolymerization of ethylene with α-olefins, thereby preparing an ethylene copolymer with high activity, and the copolymerization activity of ethylene with α-olefins is 10 7 g mol -1 (metal) h -1 The α-olefin content is higher than 30wt% and the density is 0.875g / cm 3 Under conditions where the comonomer content is less than 90° C., the melting point of the resulting copolymer may exceed 90° C. Compared with conventional polyolefin elastomers, the ethylene-α-olefin copolymer of the present invention has a higher use temperature at the same comonomer content and is therefore suitable for use in higher temperature environments.

[0012] Other features and advantages of the present invention are described in detail in the Detailed Description section that follows.

[0013] [Brief description of the drawing] Exemplary embodiments of the invention will now be described in more detail with reference to the accompanying drawings.

[0014] FIG. 1 is a graph of the crystallization curves of the copolymer prepared in Example 1 at different initial cooling temperatures T1.

[0015] FIG. 2 is a graph of the crystallization curves of the copolymer prepared in Example 5 at different initial cooling temperatures T1.

[0016] FIG. 3 is a graph of the crystallization curves of the copolymer prepared in Example 6 at different initial cooling temperatures T1.

[0017] 4a and 4b show the results of low field nuclear magnetic resonance relaxation experiments of the copolymers of the present invention and comparative copolymers.

[0018] 5a-5c show the results of low field nuclear magnetic resonance relaxation experiments of prior art copolymers.

[0019] 6a to 6c show the results of low-field nuclear magnetic resonance relaxation experiments of the comparative patent sample, the copolymers of Comparative Example 3 and Comparative Example 1.

[0020] 7a-7h show the DSC curves of the fractions obtained after CEF fractionation of the copolymers of the present invention.

[0021] 8a-8b show the CEF-IR characterization results of the third temperature fraction (high melting point fraction) obtained after substantially removing the soluble fraction from the above 80°C fraction obtained after CEF fractionation of the copolymer of the present invention by immersion in xylene at room temperature for 7 days, followed by immersion in xylene at 85°C for 2 days.

[0022] FIG. 9 shows the crystallization elution fraction (CEF) elution curve.

[0023] Detailed Description Hereinafter, embodiments of the present invention will be described in detail. It should be understood that the embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0024] The present invention provides an ethylene / α-olefin copolymer, the copolymer having an α-olefin content of 30 wt % or more and a density of 0.875 g / cm 3 The melting point is 90°C or higher, and the α-olefin is C3 to C 20 It is an α-olefin.

[0025] According to the present invention, in some embodiments, the ethylene / α-olefin copolymer has the following properties: an α-olefin content of 30 wt% to 55 wt% and a density of 0.850 g / cm 3 ~0.875g / cm3 The melting point is 90°C to 130°C, the crystallinity is 0.05% to 15%, preferably 0.1 to 10%, and the melt flow rate at 190°C under a load of 2.16 kg is greater than 0.1 g / 10 min, preferably 0.2 g / 10 min to 400 g / 10 min.

[0026] According to the present invention, the density of the ethylene / α-olefin copolymer is 0.850 g / cm 3 ~0.875g / cm 3 For example, 0.850 g / cm 3 , 0.851g / cm 3 , 0.852g / cm 3 , 0.853g / cm 3 , 0.854g / cm 3 , 0.855g / cm 3 , 0.856g / cm 3 , 0.857g / cm 3 , 0.858g / cm 3 , 0.859g / cm 3 , 0.860g / cm 3 , 0.861g / cm 3 , 0.862g / cm 3 , 0.863g / cm 3 , 0.864g / cm 3 , 0.865g / cm 3 , 0.866g / cm 3 , 0.867g / cm 3 , 0.868g / cm 3 , 0.869g / cm 3 , 0.870g / cm 3 , 0.871g / cm 3 , 0.872g / cm 3 , 0.873g / cm 3 , 0.874g / cm 3 , 0.875g / cm 3 , or a range formed by any two of the above values.

[0027] According to the present invention, the crystallinity of the ethylene / α-olefin copolymer is 0.05% to 15%, preferably 0.1% to 10%, and may be, for example, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, 1.5%, 2.0%, 2.5%, 3.0%, 3.5%, 4.0%, 4. 5%, 5.0%, 5.5%, 6.0%, 6.5%, 7.0%, 7.5%, 8.0%, 8.5%, 9.0%, 9.5%, 10.0%, 10.5%, 11.0%, 11.5%, 12.0%, 12.5%, 13.0%, 13.5%, 14.0%, 14.5%, 15.0%, or a range formed by any two of the above values.

[0028] In some embodiments, the ethylene / α-olefin interpolymers of the present invention have the following properties when tested using a differential scanning calorimeter (DSC): When tested by differential scanning calorimetry, the ethylene / α-olefin copolymer has a melting endotherm peak between 90°C and 130°C; and / or The copolymer was tested by differential scanning calorimetry by heating it to 180°C at a rate of 10°C / min, and the peak temperature of the resulting melting peak was determined as T m After stabilizing for 10 minutes, the copolymer was cooled to -50°C at a rate of 10°C / min, and then the copolymer was heated to T1 at a rate of 10°C / min; after stabilizing for 10 minutes, the copolymer was cooled to -50°C at a rate of 10°C / min, and a crystallization exothermic peak occurred, and the peak temperature was recorded as T2; T1, T m and T2 satisfies: (i)T m <T1≦T m At +20°C, T2 increases with a decrease in T1, (ii) T1>T m At +20°C, T1 decreases but T2 does not change.

[0029] The ethylene / α-olefin copolymer of the present invention is characterized by a high melting point and a high comonomer content, which is advantageous in ensuring a wider applicable temperature range while maintaining high elasticity. The ethylene / α-olefin copolymer of the present invention has a melting point of 90 to 130°C. In some embodiments, the melting point of the ethylene / α-olefin copolymer of the present invention can be 90°C, 95°C, 100°C, 105°C, 110°C, 115°C, 120°C, 125°C, or 130°C, or a range formed by any two of the above values. In some embodiments, the ethylene / α-olefin copolymer of the present invention preferably has a melting point of 95 to 130°C, more preferably 100 to 130°C, more preferably 105 to 130°C, for example, 110 to 130°C or 120 to 130°C. The melting point of the ethylene / α-olefin copolymer of the present invention can be measured, for example, using a DSC method, for example, as described below.

[0030] According to the present invention, the α-olefin is preferably a C3-C 10 It is an α-olefin. C3-C 10 The α-olefins include, but are not limited to, one or more of propylene, 1-butene, 1-hexene, 1-octene, and 1-decene, and preferably one or more of 1-hexene, 1-octene, and 1-decene.

[0031] According to the present invention, the ethylene / α-olefin copolymer has an α-olefin content of 30 wt% to 55 wt%. For example, the α-olefin content of the ethylene / α-olefin copolymer of the present invention can be 30 wt%, 31 wt%, 32 wt%, 33 wt%, 34 wt%, 35 wt%, 36 wt%, 37 wt%, 38 wt%, 39 wt%, 40 wt%, 41 wt%, 42 wt%, 43 wt%, 44 wt%, 45 wt%, 46 wt%, 47 wt%, 48 wt%, 49 wt%, 50 wt%, 51 wt%, 52 wt%, 53 wt%, 54 wt%, 55 wt%, or a range formed by any two of the above values.

[0032] In the present invention, the content of α-olefin in the copolymer can be measured by nuclear magnetic resonance (NMR) spectroscopy, such as high-temperature nuclear magnetic resonance carbon spectroscopy; for example, it can be measured as described below. The use of nuclear magnetic resonance (NMR) spectroscopy to measure comonomer content is known in the art.

[0033] According to the present invention, the ethylene / α-olefin interpolymer has at least two peaks on an elution curve obtained by the crystallization elution fraction (CEF) method. In some embodiments, the ethylene / α-olefin interpolymer of the present invention has two peaks, three peaks, four peaks, or five peaks on an elution curve obtained by the crystallization elution fraction (CEF) test method.

[0034] In some embodiments, the first temperature fraction, the second temperature fraction, and the third temperature fraction are obtained by crystallization elution fractionation (CEF) of the ethylene / α-olefin copolymer of the present invention, wherein the first temperature fraction is a fraction below 40°C, the second temperature fraction is a fraction between 40 and 80°C, and the third temperature fraction is a fraction above 80°C; based on the weight of the ethylene / α-olefin copolymer, the content of the first temperature fraction is 80 wt% to 98 wt%, the content of the second temperature fraction is 1 wt% to 10 wt%, and the content of the third temperature fraction is 1 wt% to 10 wt%.

[0035] In some embodiments, when obtained by crystallization elution fractionation (CEF) of the ethylene / α-olefin copolymer of the present invention, the content of the first temperature fraction is 84 wt% to 95.5 wt%, the content of the second temperature fraction is 1.5 wt% to 8 wt%, and the content of the third temperature fraction is 3 wt% to 8 wt%, based on the weight of the ethylene / α-olefin copolymer; preferably, the content of the first temperature fraction is 85 wt% to 94.5 wt%, the content of the second temperature fraction is 2 wt% to 7.5 wt%, and the content of the third temperature fraction is 3.5 wt% to 7.5 wt%, based on the weight of the ethylene / α-olefin copolymer.

[0036] In some embodiments of the present invention, the first temperature fraction has at least two peaks, for example, two or three peaks, on its DSC curve, the second temperature fraction has at least three peaks, for example, three, four or five peaks, on its DSC curve, and the third temperature fraction has at least two peaks, for example, two or three peaks, on its DSC curve. In some embodiments, for at least two peaks on the DSC curve of the first temperature fraction, the lowest melting point peak corresponds to a melting point below 45°C and the highest melting point peak corresponds to a melting point above 80°C; for at least three peaks on the DSC curve of the second temperature fraction, the lowest melting point peak corresponds to a melting point below 40°C, at least one intermediate melting point peak corresponds to a melting point between 40°C and 80°C, and the highest melting point peak corresponds to a melting point above 80°C; and for at least two peaks on the DSC curve of the third temperature fraction, the lowest melting point peak corresponds to a melting point below 40°C and the highest melting point peak corresponds to a melting point above 80°C.

[0037] In some embodiments, the third temperature fraction (i.e., the fraction above 80°C) of the ethylene / α-olefin copolymer obtained by the crystallization elution fraction (CEF) test method is immersed in xylene at room temperature for 7 days, and then at 85°C for 2 days to obtain a third temperature fraction (high melting point fraction) from which the soluble fraction has been (substantially) removed. When measured by weight after drying in a vacuum oven at 80°C for 8 hours, the third temperature fraction (high melting point fraction) comprises 2 to 8 wt% of the total weight of the ethylene / α-olefin copolymer.

[0038] In this application, room temperature means about 25°C.

[0039] According to the present invention, the ethylene / α-olefin copolymer of the present invention comprises a block copolymer of ethylene and an α-olefin and a random copolymer of ethylene and an α-olefin, and the random copolymer of ethylene and an α-olefin comprises an ethylene random copolymer elastomer and a linear low-density polyethylene. The random copolymer of ethylene and an α-olefin is the major component; preferably, the content of the random copolymer of ethylene and an α-olefin is 89 to 98 wt % based on the weight (100 wt %) of the ethylene / α-olefin copolymer, and the content of the block copolymer of ethylene and an α-olefin is 2 to 11 wt %. In some embodiments, the content of the block copolymer of ethylene and an α-olefin may be 2 to 10 wt %, 2 to 9 wt %, or 2 to 8 wt %. In the present invention, the block copolymer of ethylene and an α-olefin comprises a block mainly composed of ethylene and a block mainly composed of an α-olefin. In the present invention, the linear low-density polyethylene is a third temperature fraction (high melting point fraction) from which the soluble fraction has been (substantially) removed, and the third temperature fraction (high melting point fraction) is obtained by immersing the third temperature fraction (i.e., the fraction above 80°C) of an ethylene / α-olefin copolymer obtained by crystallization elution fraction (CEF) separation in xylene at room temperature for 7 days, and then immersing it in xylene at 85°C for 2 days.

[0040] In the present invention, the content of the ethylene and α-olefin block copolymer is calculated using the ratio of the sequence structures according to the following formula: W ブロック共重合体 =336×n OOO / [336×n OOO +84×n EEE +168×(n EEO +n EOE )+252×(n OEO +n OOE )]. In the formula, n OOO , n EEE , n EEO , n EOE , n OEO and n OOEare the mole percent contents of OOO, EEE, EEO, EOE, OEO, and OOE sequence structures in the ethylene / α-olefin copolymer, respectively, the total of OOO, EEE, EEO, EOE, OEO, and OOE sequence structures is 100%, E represents an ethylene structural unit, and O represents an α-olefin structural unit. In the present invention, the above sequence structures are determined using high-temperature nuclear magnetic resonance carbon spectroscopy.

[0041] According to the present invention, a third temperature fraction (i.e., a fraction above 80°C) of an ethylene / α-olefin copolymer obtained by the crystallization elution fractionation (CEF) method is immersed in xylene at room temperature for 7 days, and then in xylene at 85°C for 2 days to obtain a third temperature fraction (high melting point fraction) from which the soluble fraction has been (substantially) removed. The comonomer content (i.e., the amount of -CH3 contained per 1,000 carbon atoms in the molecular chain) of the third temperature fraction (high melting point fraction) from which the soluble fraction has been (substantially) removed is detected using an infrared detector during the crystallization elution fractionation (CEF) process. According to the present invention, the comonomer content of the third temperature fraction (high melting point fraction) from which the soluble fraction has been (substantially) removed can be 5 wt% to 25 wt%, preferably 5.5 wt% to 22 wt%, and more preferably 6 wt% to 20 wt%.

[0042] In the ethylene / α-olefin copolymer of the present invention, the molar content of the OOO sequence structure is 0.7% to 3.5%, preferably 0.8% to 3.2%, preferably 0.85% to 3.0%, more preferably 0.9% to 2.8%; the total of EEE, EEO, OEO, EOE, OOE, and OOO sequence structures in the ethylene / α-olefin copolymer is 100%, where E represents an ethylene structural unit and O represents an α-olefin structural unit. In the present invention, the sequence structure is determined using high-temperature nuclear magnetic resonance carbon spectroscopy.

[0043] The present invention further provides a method for preparing an ethylene / α-olefin copolymer, the method comprising conducting a copolymerization reaction of ethylene with an α-olefin in solution in at least one reactor in the presence of at least one catalyst to obtain an ethylene / α-olefin copolymer; maintaining a molar concentration ratio of ethylene to the α-olefin in the solution in the reactor at 0.6 to 2.2 throughout the reaction process; The catalyst is (A) a catalyst component; (B) an organoboron compound, and (C) containing an organoaluminum compound; The catalyst component is a premix of a half-sandwich metallocene catalyst precursor and an alkylaluminum compound; The half-sandwich metallocene catalyst precursor comprises a compound having the general formula Cp'LMQ2, Cp' is an optionally substituted cyclopentadiene group or a group derived therefrom, and is preferably one or more selected from the group consisting of substituted or unsubstituted cyclopentadienyl, substituted or unsubstituted indenyl, and substituted or unsubstituted fluorenyl; when Cp' is a substituent (i.e., a group substituted with a substituent), the substituent is C1 to C 12 Alkyl, C1-C 12 Alkoxy, C1-C 12 Cyril, C6~C 12 Aryl, C7-C 12 Aralkyloxy, C2-C 12 Alkynyl and C8-C 12 arylalkynyl, preferably C1-C8 alkyl, more preferably C1-C6 alkyl, and even more preferably methyl, ethyl, n-propyl, isopropyl, n-butyl, and isobutyl; L is one or more of an optionally substituted phenolic ligand and a phosphanimine ligand; M is an element selected from Group IVB, preferably Zr and / or Ti, more preferably Ti; Each Q is independently selected from halogen and / or C1-C6 alkyl, preferably halogen and / or C1-C3 alkyl, more preferably chlorine and / or methyl.

[0044] According to the present invention, the molar concentration ratio of ethylene to α-olefin in the solution in the reactor is preferably maintained at 0.65 to 1.6, preferably 0.8 to 1.4. For example, the molar concentration ratio of ethylene to α-olefin can be maintained at 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, any value between any two of the above values, or within a range formed by any two of the above values.

[0045] According to the present invention, the catalyst component of the present invention can be formed by contacting a half-sandwich metallocene catalyst precursor with an alkylaluminum compound in advance, which has the advantage of increasing the polymerization activity during polymerization and improving the copolymerization effect. According to the present invention, an ethylene / α-olefin copolymer having a high melting point and a high comonomer content can be produced with high productivity by controlling the ethylene / α-olefin concentration ratio.

[0046] One of the key points of the present invention is to control the ratio of ethylene to the concentration of α-olefin, and therefore there is no particular requirement for the respective concentration ranges of ethylene and α-olefin in the solution. According to the present invention, the molar concentration of ethylene in the solution in the reactor can be 0.05 to 10 mol / L, preferably 0.3 to 4 mol / L; and / or the molar concentration of α-olefin can be 0.031 to 15.4 mol / L, preferably 0.2 to 6.15 mol / L. For example, the molar concentrations of ethylene in the solution in the reactor can be 0.05 mol / L, 0.10 mol / L, 0.15 mol / L, 0.20 mol / L, 0.25 mol / L, 0.30 mol / L, 0.35 mol / L, 0.40 mol / L, 0.45 mol / L, 0.50 mol / L, 0.55 mol / L, 0.60 mol / L, 0.65 mol / L, 0.70 mol / L, 0.75 mol / L, 0.80 mol / L, 0.85 mol / L, 0.90 ...2 mol / L, 0.14 mol / L, 0.16 mol / L, 0.18 mol / L, 0.19 mol / L, 0.21 mol / L, 0.22 mol / L, 0.23 mol / L, 0.24 mol / L, 0.25 mol / L, 0.26 mol / L, 0.27 mol / L, 0.28 mol / L, 0. It can be 95 mol / L, 1.0 mol / L, 1.5 mol / L, 2.0 mol / L, 2.5 mol / L, 3.0 mol / L, 3.5 mol / L, 4.0 mol / L, 4.5 mol / L, 5.0 mol / L, 5.5 mol / L, 6.0 mol / L, 6.5 mol / L, 7.0 mol / L, 7.5 mol / L, 8.0 mol / L, 8.5 mol / L, 9.0 mol / L, 9.5 mol / L, 10 mol / L, or a range formed by any two of the above values.For example, the molar concentration of α-olefin in the solution in the reactor is 0.031 mol / L, 0.05 mol / L, 0.06 mol / L, 0.07 mol / L, 0.08 mol / L, 0.09 mol / L, 0.1 mol / L, 0.2 mol / L, 0.3 mol / L, 0.4mol / L, 0.5mol / L, 0.6mol / L, 0.7mol / L, 0.8mol / L, 0.9mol / L, 1mol / L, 1.5mol / L, 2mol / L, 2.5mol / L, 3mol / L, 3.5mol / L, 4mol / L, The concentration can be 4.5 mol / L, 5 mol / L, 5.5 mol / L, 6 mol / L, 6.5 mol / L, 7 mol / L, 7.5 mol / L, 8 mol / L, 8.5 mol / L, 9 mol / L, 9.5 mol / L, 10 mol / L, 10.5 mol / L, 11 mol / L, 11.5 mol / L, 12 mol / L, 12.5 mol / L, 13 mol / L, 13.5 mol / L, 14 mol / L, 14.5 mol / L, 15 mol / L, 15.4 mol / L, or a range formed by any two of the above values.

[0047] In the prior art, the α-olefin is generally added in one portion, making it impossible to guarantee that the molar concentration ratio of ethylene to α-olefin always remains within the range required by the present invention. Without being bound by any theory, it is believed that this makes it impossible to obtain the ethylene / α-olefin copolymers of the present invention.

[0048] Various means can be used to achieve control of the ethylene / α-olefin concentration ratio. In some embodiments, for example, ethylene is continuously fed and the α-olefin is intermittently fed. "Intermittently feeding" means that the α-olefin is added in batches, and the number of batches is determined based on the principle of ensuring the above-mentioned concentration ratio. For example, according to some embodiments, the α-olefin can be added in two, three, four, five, or more batches. In some embodiments, the α-olefin can be added in batches at equal intervals depending on the total polymerization time. For example, if the total polymerization time is 30 minutes and the α-olefin is added in three batches, the first batch is added at 0 minutes, the second batch is added at 10 minutes, and the third batch is added at 20 minutes. In some embodiments, the time intervals between batches of α-olefin addition may be the same or different. In the present invention, when the α-olefin is added in batches, the amount of α-olefin added in the first batch can generally be higher than that of subsequent batches. In some embodiments, the amount of α-olefin added in the first batch can comprise 30% to 90% of the total amount of α-olefin added, such as 30%, 40%, 50%, 60%, 70%, 80%, 90%, or a range formed by any two of the foregoing values.

[0049] Those skilled in the art can appropriately select the time interval for batch feeding of the α-olefin to achieve a desired molar concentration ratio of ethylene to the α-olefin depending on the application. In some embodiments, when the α-olefin is intermittently fed, the time interval can be 1 minute to 30 minutes, for example, 1 minute to 15 minutes. The time interval for intermittent feeding refers to the time interval from the end of the last feed to the start of the next feed. Specifically, the time interval can be 1 minute, 2 minutes, 3 minutes, 4 minutes, 5 minutes, 6 minutes, 7 minutes, 8 minutes, 9 minutes, 10 minutes, 11 minutes, 12 minutes, 13 minutes, 14 minutes, 15 minutes, 16 minutes, 17 minutes, 18 minutes, 19 minutes, 20 minutes, and any value between any two of the above values.

[0050] In some embodiments, both ethylene and α-olefin are continuously fed to achieve the desired ethylene / α-olefin concentration ratio. The feed rates of ethylene and α-olefin can be appropriately selected by those skilled in the art to maintain the progress of polymerization and achieve the desired ethylene / α-olefin concentration ratio of the present invention.

[0051] In this application, the concentration ratio of ethylene to α-olefin in the solution in the polymerization reactor at the time of sampling can be determined as follows: samples of the polymerization solution (containing the polymer) are taken out from the polymerization reactor at different times, the solution samples are tested to determine the amount (concentration) of the polymer in the solution sample and the comonomer content in the polymer, and the concentration ratio of ethylene to α-olefin in the solution in the polymerization reactor at the time of sampling is determined according to the concentration of the polymer, the structure of the polymer, and the amount of monomer / comonomer fed. The sampling frequency can be reasonably determined by those skilled in the art, as long as it can meet the requirements of this application regarding the concentration ratio of ethylene to α-olefin.

[0052] Conditions for the copolymerization reaction of ethylene and an α-olefin can be suitably selected by those skilled in the art, including, for example, the pressure in the reactor, the polymerization temperature, the polymerization time, etc. For example, those skilled in the art can select polymerization conditions generally known in the art for carrying out the copolymerization of ethylene and an α-olefin in solution to obtain a polyolefin elastomer.

[0053] In some embodiments, the copolymerization reaction conditions of the present invention may include the following conditions: the polymerization pressure may be 0.1 MPa to 10 MPa, preferably 0.2 MPa to 5 MPa; the polymerization temperature may be -30°C to 160°C, preferably 10°C to 120°C; and the polymerization time may be 1 minute to 300 minutes, preferably 10 minutes to 60 minutes. In some embodiments, the polymerization pressure may be 0.1 MPa, 0.2 MPa, 0.3 MPa, 0.4 MPa, 0.5 MPa, 0.6 MPa, 0.7 MPa, 0.8 MPa, 0.9 MPa, 1 MPa, 1.5 MPa, 2 MPa, 2.5 MPa, 3 MPa, 3.5 MPa, 4 MPa, 4.5 MPa, 5 MPa, 5.5 MPa, 6 MPa, 6.5 MPa, 7 MPa, 7.5 MPa, 8 MPa, 8.5 MPa, 9 MPa, 9.5 MPa, 10 MPa, or a range formed by any two of the above values. The polymerization temperature can be −30° C., −20° C., −10° C., 0° C., 10° C., 20° C., 30° C., 40° C., 50° C., 60° C., 70° C., 80° C., 90° C., 100° C., 110° C., 120° C., 130° C., 140° C., 150° C., 160° C., or a range formed by any two of the above values. The polymerization time can be 1 minute, 2 minutes, 3 minutes, 4 minutes, 5 minutes, 6 minutes, 7 minutes, 8 minutes, 9 minutes, 10 minutes, 20 minutes, 30 minutes, 40 minutes, 50 minutes, 60 minutes, 70 minutes, 80 minutes, 90 minutes, 100 minutes, 150 minutes, 200 minutes, 250 minutes, 300 minutes, or a range formed by any two of the above values.

[0054] According to some embodiments of the present invention, in the catalyst component of the present invention, the half-sandwich metallocene catalyst precursor is at least one selected from the compounds of formula I and formula II: [ka] In Formula I, R1, R2, and R3 are the same or different and each independently represent hydrogen, substituted or unsubstituted C1-C 20 Straight or branched alkyl, substituted or unsubstituted C6-C 20 Aryl and substituted or unsubstituted C2-C 20alkynyl; preferably, R1, R2 and R3 are the same or different and each independently selected from the group consisting of hydrogen, substituted or unsubstituted C1-C6 straight or branched alkyl, substituted or unsubstituted C6-C8 aryl, and substituted or unsubstituted C2-C8 alkynyl; for example, R1, R2 and R3 are the same or different and can be independently selected from the group consisting of hydrogen, methyl, ethyl, n-propyl, isopropyl, n-butyl, t-butyl, t-butylethynyl, trimethylsilylethynyl, 9-anthracenylalkynyl, etc.; In Formula I, R4 to R8 are the same or different and each independently represent hydrogen, substituted or unsubstituted C1 to C6 20 R4 to R8 are selected from the group consisting of straight-chain or branched alkyl, and any two adjacent groups of R4 to R8 are optionally linked to form a ring, for example, a 5-membered or 6-membered ring; preferably, R4 to R8 are the same or different and each independently selected from the group consisting of hydrogen, substituted or unsubstituted C1 to C6 straight-chain or branched alkyl, and any two adjacent groups of R4 to R8 are optionally linked to form a ring; more preferably, R4 to R8 are the same or different and each independently selected from the group consisting of hydrogen, substituted or unsubstituted C1 to C4 straight-chain or branched alkyl, and any two adjacent groups of R4 to R8 can be optionally linked to form a ring; for example, R4 to R8 are the same or different and each independently selected from hydrogen, methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, etc.; In formula I, M is an element selected from Group IVB, preferably Zr and / or Ti, more preferably Ti; each Q is independently selected from halogen and / or C1-C6 alkyl, preferably selected from halogen and / or C1-C3 alkyl, more preferably selected from chlorine and / or methyl; In Formula II, R1', R2' and R3' are the same or different and each independently represent a substituted or unsubstituted C1-C 20 Straight or branched alkyl, substituted or unsubstituted C3-C 20Cycloalkyl and substituted or unsubstituted C6-C 20 aryl; preferably, R1', R2' and R3' are the same or different and each independently selected from the group consisting of substituted or unsubstituted C1-C6 straight or branched alkyl, substituted or unsubstituted C3-C6 cycloalkyl, and substituted or unsubstituted C6-C8 aryl; for example, R1', R2' and R3' are the same or different and each independently selected from methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, phenyl, etc.; In Formula II, R4' to R8' are the same or different and each independently represent hydrogen, substituted or unsubstituted C1 to C8 20 straight-chain or branched alkyl, and any two adjacent groups of R4' to R8' are optionally linked to form a ring; preferably, R4' to R8' are the same or different and each independently selected from the group consisting of hydrogen, substituted or unsubstituted C1 to C6 straight-chain or branched alkyl, and any two adjacent groups of R4' to R8' are optionally linked to form a ring; for example, R4' to R8' are the same or different and each independently selected from hydrogen, methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, etc.; In formula II, M' is an element selected from group IVB, preferably Zr and / or Ti, more preferably Ti; and Q' is selected from halogen and / or C1-C6 alkyl, preferably halogen and / or C1-C3 alkyl, more preferably chlorine and / or methyl.

[0055] In the present invention, when R1 to R8 and R1' to R8' are substituents (i.e., groups substituted with a substituent), the substituent is selected from the group consisting of halogen, C1 to C 12 Alkyl, C1-C 12 Alkoxy, C1-C 12 Cyril, C6~C 12 Aryl, C7-C 12 Aralkyloxy, C2-C 12 Alkynyl and C8-C12 It may be one or more independently selected from the group consisting of arylalkynyl; for example, it may be one or more selected from C1-C8 alkyl, for example, it may be one or more selected from C1-C6 alkyl, for example, it may be one or more selected from methyl, ethyl, n-propyl, isopropyl, n-butyl and isobutyl.

[0056] In some preferred embodiments of the present invention, the half-sandwich metallocene catalyst precursor comprises at least one of the following precursors 1-11: R1=R2=iPr, R3=H, R4~R8=Me, M=Ti, Q=Cl(1); R1=R2=iPr, R3=H, R4~R8=H, M=Ti, Q=Cl(2); R1 = R2 = iPr, R3 = H, R5 = R6 = R7 = H, R4 and R8 form a ring, which together with the cyclopentadienyl form an indenyl (corresponding to Cp', which is indenyl), M = Ti, Q = Cl(3); R1=R2=tBu, R3=H, R4~R8=Me, M=Ti, Q=Cl(4); R1=R2=H, R3=H, R4~R8=Me, M=Ti, Q=Cl(5); R1 = R2 = trimethylsilylethynyl, R3 = tBu, R4–R8 = Me, M = Ti, Q = Cl(6); R1 = R2 = t-butylethynyl, R3 = H, R4–R8 = Me, M = Ti, Q = Cl(7); R1 = R2 = 9-anthracenylalkynyl, R3 = H, R4–R8 = Me, M = Ti, Q = Cl(8); R1'=R2'=R3'=tBu, R4'~R8'=H, M'=Ti, Q'=Cl(9); R1' = R2' = R3' = tBu, R4' to R8' = Me, M' = Ti, Q' = Cl (10); and R1'=R2'=R3'=iPr, R4'~R8'=Me, M'=Ti, Q'=Cl(11).

[0057] The half-sandwich metallocene catalyst precursor of the present invention can be prepared by methods well known in the art, for example, by the methods disclosed in CN112745365A, CN112745405A or CN112745444A.

[0058] The catalyst components in the present invention can be prepared by methods well known in the art; for example, they can be prepared according to the methods disclosed in CN112745365A, CN112745405A or CN112745444A.

[0059] The alkylaluminum compound used in the method of the present invention may be any alkylaluminum compound commonly used in the art for olefin polymerization or copolymerization. In some embodiments, the alkylaluminum compound used for premixing with the half-sandwich metallocene catalyst precursor according to the present invention may have the general formula AlR'3, where R' is the same or different, R' is a C1-C8 alkyl, and one or two alkyls are optionally substituted by chlorine; the alkylaluminum compound is preferably trimethylaluminum, triethylaluminum, tri-n-butylaluminum, triisobutylaluminum, tri-n-hexylaluminum, alkylaluminum chloride, Al(n-CH 13 )3 and Al(n-CH 17 ) 3, more preferably one or more of trimethylaluminum, triethylaluminum, triisobutylaluminum and tri-n-hexylaluminum, and most preferably triisobutylaluminum.

[0060] According to the present invention, the premix of the half-sandwich metallocene catalyst precursor and the alkylaluminum compound may further comprise a solvent. Preferably, the premix of the half-sandwich metallocene catalyst precursor and the alkylaluminum compound further comprises a solvent. In some embodiments, the solvent is a C6 to C6 alkylaluminum compound.20 Aromatic hydrocarbons and C4-C 20 It may be one or more selected from alkanes; preferably, it may be one or more selected from the group consisting of benzene, toluene, xylene, ethylbenzene, hexane, heptane, isobutane and cyclohexane.

[0061] According to the present invention, when the premix of the half-sandwich metallocene catalyst precursor and the alkylaluminum compound contains a solvent, the premix is ​​preferably a homogeneous solution.

[0062] According to the present invention, when the premix of the half-sandwich metallocene catalyst precursor and the alkylaluminum compound contains a solvent, the sum of the concentrations of the half-sandwich metallocene catalyst precursor and the alkylaluminum compound in the premix (i.e., the total concentration) may be 0.01 to 10 g / L, preferably 0.1 to 3 g / L, and more preferably 0.1 to 2 g / L.

[0063] According to the present invention, the olefin polymerization catalyst component is preferably obtained by contacting a half-sandwich metallocene catalyst precursor with an alkylaluminum compound.

[0064] In a preferred embodiment of the present invention, the olefin polymerization catalyst component can be obtained by the following method: mixing a half-sandwich metallocene catalyst precursor and an alkylaluminum compound in a solvent for 0.5 to 30 minutes, preferably 15 to 30 minutes. In some embodiments, the mixed solution obtained after mixing can be allowed to stand for 0.5 to 48 hours, preferably 0.5 to 24 hours. In one embodiment, the olefin polymerization catalyst component can be obtained by a method comprising mixing a half-sandwich metallocene catalyst precursor and an alkylaluminum compound in a solvent for 15 to 30 minutes, and then allowing the mixed solution to stand for preferably 0.5 to 24 hours.

[0065] The above mixing and standing can be carried out at, for example, 0°C to 60°C, for example, 10°C to 45°C, and preferably at room temperature.

[0066] In some embodiments, the mixing and settling is carried out in the presence of an inert gas, including, but not limited to, nitrogen and one or more of the noble gases, such as helium, neon, and argon.

[0067] In some embodiments, preparing the catalyst components can include: separately adding a half-sandwich metallocene catalyst precursor and an alkylaluminum compound to a solvent; adding a half-sandwich metallocene catalyst precursor to a vessel and then adding a solution of an alkylaluminum compound; adding a solution of an alkylaluminum compound to a vessel and then adding the half-sandwich metallocene catalyst precursor; etc.

[0068] According to the present invention, the molar ratio of the half-sandwich metallocene catalyst precursor to the alkylaluminum compound in the premix may be 1:(2-200), preferably 1:(2-100), and more preferably 1:(20-100).

[0069] The organoboron compound used in the method of the present invention can be an organoboron compound commonly used in the art for olefin polymerization or copolymerization. In some embodiments, the organoboron compound can be selected from fluoroorganoboron compounds and / or fluoroorganoborate compounds.

[0070] In some embodiments, the fluoroorganoboron compound can be selected from tris(pentafluorophenyl)boron and / or tris[3,5-bis(trifluoromethyl)phenyl]boron.

[0071] In some embodiments, the fluoroorganoborate compound is selected from fluorinated arylborates, preferably one or more selected from the group consisting of N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate, triphenyltetrakis(pentafluorophenyl)borate, trityl tetrakis(pentafluorophenyl)borate, lithium tetrakis(pentafluorophenyl)borate, N,N-dimethylanilinium tetrakis[3,5-bis(trifluoromethyl)phenyl]borate, and triphenylcarbenium tetrakis[3,5-bis(trifluoromethyl)phenyl]borate.

[0072] The organoaluminum compound used as catalyst component C in the process of the present invention can be any organoaluminum compound commonly used in the art for olefin polymerization or copolymerization. In some embodiments, the organoaluminum compound as catalyst component C can be selected from alkylaluminum compounds and / or organoaluminoxane compounds. The alkylaluminum compounds and organoaluminoxane compounds can be those commonly used in olefin polymerization or copolymerization.

[0073] In some embodiments, the alkyl aluminum compound can have the general formula AlR'3, where R' is the same or different, and R' is a C1-C8 alkyl, where one or two alkyls can be optionally substituted by chlorine. In some embodiments, the alkyl aluminum compound is preferably trimethyl aluminum, triethyl aluminum, tri-n-butyl aluminum, triisobutyl aluminum, tri-n-hexyl aluminum, alkyl aluminum chloride, Al(n-CH 13 )3 and Al(n-CH 17 ) 3, more preferably one or more of trimethylaluminum, triethylaluminum, triisobutylaluminum and tri-n-hexylaluminum, and most preferably triisobutylaluminum.

[0074] In some embodiments, the organoaluminoxane compound can have the following general structure: [ka] In the formula, R is C1 to C 12 It is selected from hydrocarbyl, preferably C1-C6 alkyl, more preferably methyl and / or isobutyl.

[0075] In the present invention, the organoaluminum compound in the catalyst (catalyst component C) and the alkylaluminum compound used in the premix may be the same compound or different compounds.

[0076] According to the present invention, the molar ratio of the catalyst component (component A) (calculated based on the half-sandwich metallocene catalyst precursor), the organoboron compound (component B), and the organoaluminum compound (component C) can be 1:(1-20):(50-3000). In some embodiments, the molar ratio of the catalyst component (calculated based on the half-sandwich metallocene catalyst precursor), the organoboron compound, and the organoaluminum compound can be 1:(2-10):(100-500) in order to further improve copolymerization performance and catalytic activity.

[0077] Without being limited by theory, the organoaluminum compound co-catalyst added during the reaction process can react with polar impurities in the polymerization reaction mixture to prevent catalyst deactivation and also act as an alkylating agent for the catalyst. The organoboron compound acts as a Lewis acid and a protonic acid to activate the catalyst.

[0078] The present invention is not particularly limited to the order of addition of the catalyst precursor, boron compound, and alkylaluminum compound in the catalyst, as long as it can catalyze the copolymerization reaction of ethylene and α-olefin. In some embodiments, according to the present invention, components A, B, and C in the catalyst can be added sequentially, simultaneously, or two of them can be added first, followed by the last one. In some embodiments, components A and C are preferably added separately to the polymerization system. Without being limited by theory, adding components A and C separately to the polymerization system has the advantage of reducing the influence of impurities.

[0079] According to the present invention, the copolymerization reaction is carried out in an inert solvent. Solvents commonly used in the art for olefin polymerization or copolymerization can be used. In some embodiments, the inert solvent is a C6-C 20 Aromatic hydrocarbons and C4-C 20 It may be one or more selected from alkanes, preferably one or more selected from benzene, toluene, hexane and heptane.

[0080] In the method of the present invention for preparing an ethylene / α-olefin copolymer, the copolymerization reaction further comprises adding a terminator to terminate the polymerization reaction, i.e., deactivate the active center, after the polymerization reaction is completed. The terminator is not particularly limited and can be various terminators that can terminate active polymer chains in the field of olefin polymerization. In some embodiments, the terminator can be, for example, one or more of water, methanol, ethanol, n-propanol, and isopropanol.

[0081] The present invention also provides an ethylene / α-olefin copolymer prepared by the above method.

[0082] The ethylene / α-olefin copolymer of the present invention has no unsaturated double bonds, is excellent in weather resistance and chemical resistance, has higher shear sensitivity, has high melt strength, is easy to process and apply, and is easy to recover and recycle. The ethylene / α-olefin copolymer of the present invention can replace some rubbers and can be used as a thermoplastic elastomer in fields such as high-performance films, toughened automotive materials, buildings, electronic and electrical appliances, daily necessities, and medical devices.

[0083] [Example] The present invention will be further described with reference to the following examples, but the scope of the present invention is not limited to these examples.

[0084] Unless otherwise specified, all operations and processes relating to the present invention are conventional operations and processes in the art.

[0085] Unless otherwise specified, all equipment used in the present invention is conventional equipment in the art.

[0086] Test methods related to the examples of the present invention are as follows.

[0087] (Melting point (T m ) and crystallinity) The melting point and crystallinity were measured by a differential scanning calorimeter (DSC 822e, METTLER TOLEDO), the heating and cooling rates were 10° C. / min, and the data were read on the second scan curve.

[0088] (Melt flow rate (melt index, MFR)) According to GB / T 3682.2-2018, the melt flow rate is measured by a melt flow rate meter CEAST6942 manufactured by Ceast, Italy, at a temperature of 190°C and a load of 2.16 kg.

[0089] (Polymer density) The density of the polymer is measured by density gradient column according to GB / T 1033.2-2010.

[0090] (α-olefin content in polymer) The α-olefin content of the polymer is measured by high-temperature nuclear magnetic resonance carbon spectroscopy, which is performed at 110°C using a Bruke 400 NMR spectrometer with 1,2,4-trichlorobenzene as the solvent.

[0091] (polymerization activity) The polymerization activity is expressed as the ratio of the mass of the polymer obtained to the molar amount of metal in the catalyst and the reaction time, ie, activity = polymer mass / (molar amount of metal in catalyst x reaction time).

[0092] (Crystallization Elution Fractionation (CEF) method) A polymer sample (20 mg) was weighed into a sample vial and loaded into the autosampler of a polymer CEF unit (a model CEF device from Polymer Char, Spain). The vial was filled with 6–7 mL of 1,2,4-trichlorobenzene (TCB) and heated to the dissolution temperature (160 °C) for 2 h at three different shaking speeds. The solution (0.5 mL) was then loaded onto a CEF column (two CEF columns purchased from Polymer Char, installed in series). After equilibration at the predetermined stabilization temperature (130 °C) for 5 min, the temperature was lowered from the stabilization temperature to 30 °C, causing the polymer solution to crystallize. After equilibration at 30 °C for 10 min, the soluble fraction was eluted at 30 °C for 10 min. The crystallized sample was then eluted with TCB at a temperature ramp from 30 °C to 130 °C. At the end of the run, the CEF column was washed at 150 °C for 5 min. Other CEF run conditions are as follows: cooling rate of 0.5°C / min, flow rate during crystallization of 0.02 mL / min, heating rate of 1.0°C / min, and flow rate during elution of 2.0 mL / min. Eluted samples are measured for outlet temperature and comonomer content by infrared detector IR5.

[0093] DSC characterization of CEF fractions Each fraction obtained by CEF fractionation is air-dried and then dried in a vacuum oven at 80°C for 8 hours, after which the solid is weighed to determine the content of each fraction.

[0094] Next, a DSC test is carried out using a DSC (DSC 822e, METTLER TOLEDO), with a heating rate of 10°C / min, and data from the first and second scan curves are recorded.

[0095] Prior to DSC testing, 0.5 g of the vacuum-dried fraction was immersed in 10 mL of xylene for 7 days at room temperature to remove low-melting-point components, and then air-dried. After vacuum drying (8 hours in a vacuum oven at 80 °C), DSC characterization was performed.

[0096] (Low field NMR test) Both time-domain 1H NMR T2 relaxation and spin diffusion experiments were performed using a Bruker Minispec MQ-20 (F series) relaxometer. The instrument's proton resonance frequency was 19.65 MHz, and the permanent magnet temperature was constantly maintained at 40°C. The 90° and 180° RF pulse times were 3.1 and 6.2 μs, respectively. The receiver dead time was 9 μs, and the dwell time was 0.64 μs. The NMR instrument was equipped with a 10 mm temperature probe, and precise adjustment of the test temperature was achieved with an accuracy of ±0.5°C using a Bruker N2VT temperature controller. To ensure temperature accuracy, the instrument temperature was calibrated using a PT100 RTD thermocouple (HH804U) before the start of the experiment. The test sample was filled into a 9 mm diameter NMR tube to a height of approximately 12 mm to ensure that the sample was positioned in the most uniform position within the instrument's RF field.

[0097] (Determination of the molar concentration ratio of ethylene to α-olefin) The molar concentration ratio of ethylene to α-olefin during the polymerization process is determined as follows: 10 mL of the solution is removed at time intervals such as 2 minutes, 5 minutes, or 10 minutes; the removed solution is poured into ethanol to obtain a polymer. The obtained polymer is then dried in a vacuum oven at 80°C for 8 hours, and the comonomer content in the copolymer is determined by high-temperature nuclear magnetic resonance carbon spectroscopy, followed by the comonomer consumption. The molar concentration of α-olefin is determined according to the concentration of the polymer in the solution, the structure of the polymer, and the amount of comonomer supplied. The amount of comonomer supplementation is then determined to ensure the desired molar concentration ratio of ethylene to α-olefin.

[0098] The structure of the half-sandwich metallocene catalyst precursor used in the examples and comparative examples is as follows: R1 = R2 = iPr, R3 = H, R4 to R8 = Me, M = Ti, Q = Cl (Precursor 1) R1=R2=iPr, R3=H, R4~R8=H, M=Ti, Q=Cl (precursor 2) R1 = R2 = iPr, R3 = H, R5 = R6 = R7 = H, R4 and R8 form a ring and further together with the cyclopentadienyl form an indenyl, M = Ti, Q = Cl (precursor 3); R1 = R2 = tBu, R3 = H, R4–R8 = Me, M = Ti, Q = Cl (precursor 4); R1 = R2 = H, R3 = H, R4–R8 = Me, M = Ti, Q = Cl (precursor 5); R1 = R2 = trimethylsilylethynyl, R3 = tBu, R4–R8 = Me, M = Ti, Q = Cl (precursor 6); R1 = R2 = t-butylethynyl, R3 = H, R4–R8 = Me, M = Ti, Q = Cl (Precursor 7) R1 = R2 = 9-anthracenylalkynyl, R3 = H, R4–R8 = Me, M = Ti, Q = Cl (precursor 8); R1′ = R2′ = R3′ = tBu, R4′–R8′ = H, M′ = Ti, Q′ = Cl (precursor 9); R1′ = R2′ = R3′ = tBu, R4′–R8′ = Me, M′ = Ti, Q′ = Cl (precursor 10); R1′ = R2′ = R3′ = iPr, R4′–R8′ = Me, M′ = Ti, Q′ = Cl (precursor 11).

[0099] In the following preparative examples, the various reagents and reactants used are commercially available. Where necessary, necessary treatments known in the art are carried out to meet the requirements of the reaction.

[0100] [Example 1] The catalyst component was prepared in a nitrogen-protected glove box at room temperature (25°C). 5 μmol of precursor 1 powder was weighed and placed in a glass bottle. 0.2 mL of a 0.5 mol / L hexane solution of triisobutylaluminum was added dropwise, followed by 4.8 mL of toluene. The mixture was stirred for approximately 30 minutes to obtain an orange-red toluene solution of catalyst component 1, which was then allowed to stand for 24 hours.

[0101] The reactor was a 500 mL autoclave equipped with a stirrer. Prior to the reaction, the reactor underwent standard dehydration and deoxygenation treatments, followed by three cycles of purifying with polymerization-grade ethylene. The autoclave was first charged with 183.75 mL of purified toluene (solvent), followed by 0.75 mL of a 1 mol / L hexane solution of triisobutylaluminum, 12.5 mL of purified 1-octene, 1 mL of a 5 mmol / L toluene solution of catalyst component 1, and 2 mL of a 5 mmol / L toluene solution of trityl tetrakis(pentafluorophenyl)borate. The reactor temperature was raised to 30 °C, and ethylene was continuously fed to maintain the reactor pressure at 0.4 MPa. After 10 minutes of reaction, an additional 7.8 mL of purified 1-octene was added, followed by a third 6.5 mL of purified 1-octene after a total reaction time of 20 minutes. The molar concentration ratio of ethylene to 1-octene in the reactor was maintained at 1.1–1.3 throughout the reaction process. After a total reaction time of 30 minutes, the ethylene supply was stopped and ethanol was added to terminate the reaction. The temperature was lowered to 20°C and the mixture was vented. The mixture was added to a three-fold volume of ethanol and filtered. The resulting polymer was dried overnight in a vacuum oven at 80°C. The polymer weighed 33.8 g. The polymerization activity was 1.35 x 10 7 g mol -1 (cat)·h -1and the density is 0.866 g / cm 3 The octene mass content was 40%, the melting point was 119.5°C, the crystallinity was 5.314%, and the melt index was 15.1 g / 10 min.

[0102] The obtained copolymer was subjected to a differential scanning calorimeter test, in which the copolymer was heated to 180°C at a rate of 10°C / min, and the peak temperature of the resulting melting peak was determined as T m After stabilization for 10 minutes, the copolymer was cooled to -50°C at a rate of 10°C / min, and then heated to T1 at a rate of 10°C / min. After stabilization for 10 minutes, the copolymer was cooled to -50°C at a rate of 10°C / min, generating a crystallization exothermic peak, which was recorded as T2. By varying the cooling start temperature T1 to different values, multiple crystallization curves were obtained, as shown in Figure 1. When the T1 temperature was T m <T1≦T m +20℃, T2 increases as T1 decreases, and T1 temperature > T m At +20°C, it can be seen that T2 did not change with the decrease in T1.

[0103] [Example 2] The polymerization was carried out according to the method of Example 1, with the following differences: 177.9 mL of hexane was used as the solvent; three batches of 1-octene were added in amounts of 15.6 mL, 7.8 mL, and 6.7 mL, respectively; the molar concentration ratio of ethylene to 1-octene in the reactor was maintained at 0.6-0.8 throughout the reaction process; the amount of a 1 mol / L hexane solution of triisobutylaluminum added was 1.5 mL; the amount of a 5 mmol / L toluene solution of trityl tetrakis(pentafluorophenyl)borate added was 5 mL; and the reactor temperature was 60 °C. 27.1 g of polymer was obtained, with a polymerization activity of 1.08 × 10 7 g mol -1 (cat)·h -1 and the density is 0.861 g / cm 3The octene mass content was 51%, the melting point was 110.5° C., the crystallinity was 0.186%, and the melt index was 382.4 g / 10 min.

[0104] [Example 3] The polymerization was carried out according to the method of Example 1, with the following differences: 176.7 mL of hexane was used as the solvent; two batches of 1-octene were added in amounts of 9.3 mL and 4.5 mL, with the second addition being carried out at 15 minutes; the molar concentration ratio of ethylene to 1-octene in the reactor was maintained at 0.8-1.0 throughout the reaction process; the total reaction time was 30 minutes; the amount of a 1 mol / L hexane solution of triisobutylaluminum added was 3 mL; the amount of a 5 mmol / L toluene solution of trityl tetrakis(pentafluorophenyl)borate added was 10 mL; and the reactor temperature was 80 °C. 19.4 g of polymer was obtained, with a polymerization activity of 7.76 × 10 6 g mol -1 (cat)·h -1 and the density is 0.862 g / cm 3 The octene mass content was 44%, the melting point was 120.4°C, the crystallinity was 7.79%, and the melt index was 7.7g / 10min.

[0105] [Example 4] The polymerization was carried out according to the method of Example 1, with the following differences: the polymerization pressure was 0.8 MPa; the amount of toluene added was 180.25 mL; three batches of 1-octene were added in amounts of 16 mL, 8.4 mL, and 7.5 mL, respectively; the molar concentration ratio of ethylene to 1-octene in the reactor was maintained between 1.9 and 2.1 throughout the reaction process; and 2 mL of a 5 mmol / L toluene solution of N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate was added instead of the toluene solution of trityl tetrakis(pentafluorophenyl)borate. 35.8 g of polymer was obtained, with a polymerization activity of 1.43 × 10 7 g mol -1 (cat)·h -1and the density is 0.872 g / cm 3 The octene mass content was 36%, the melting point was 120.0° C., the crystallinity was 6.83%, and the melt index was 0.47 g / 10 min.

[0106] [Example 5] The polymerization was carried out according to the method of Example 1, with the following differences: the solvent was 188.75 mL of hexane; the polymerization monomer was 1-hexene, which was added in three batches, with the same addition timing as in Example 1, and the addition amounts were 10 mL, 5.0 mL, and 4.5 mL, respectively; the molar concentration ratio of ethylene to 1-hexene in the reactor was maintained at 1.1 to 1.3 throughout the reaction process. 25.8 g of polymer was obtained, with a polymerization activity of 1.03 × 10 7 g mol -1 (cat)·h -1 and the density is 0.866 g / cm 3 The hexene mass content was 35%, the melting point was 122.6°C, the crystallinity was 4.30%, and the melt index was 0.77g / 10min.

[0107] The obtained copolymer was subjected to a differential scanning calorimeter test, in which the copolymer was heated to 180°C at a rate of 10°C / min, and the peak temperature of the resulting melting peak was determined as T m After stabilization for 10 minutes, the copolymer was cooled to -50°C at a rate of 10°C / min, and then heated to T1 at a rate of 10°C / min. After stabilization for 10 minutes, the copolymer was cooled to -50°C at a rate of 10°C / min, generating a crystallization exothermic peak, which was recorded as T2. By varying the cooling start temperature T1 to different values, multiple crystallization curves were obtained, as shown in Figure 2. When the T1 temperature was T m <T1≦T m +20℃, T2 increases as T1 decreases, and T1 temperature > T m At +20°C, it can be seen that T2 did not change with the decrease in T1.

[0108] [Example 6] The polymerization was carried out according to the method of Example 1, with the following differences: the solvent was 181.15 mL of heptane; the polymerization monomer was 1-decene, which was added in three batches, with the same addition timing as in Example 1, and the addition amounts were 15.1 mL, 8.7 mL, and 7.5 mL, respectively; the molar concentration ratio of ethylene to 1-decene in the reactor was maintained at 1.1 to 1.3 throughout the reaction process. 38.3 g of polymer was obtained, with a polymerization activity of 1.53 × 10 7 g mol -1 (cat)·h -1 and the density is 0.866 g / cm 3 The mass content of decene was 42%, the melting point was 124.2°C, the crystallinity was 9.49%, and the melt index was 22.9g / 10min.

[0109] The obtained copolymer was subjected to a differential scanning calorimeter test, in which the copolymer was heated to 180°C at a rate of 10°C / min, and the peak temperature of the resulting melting peak was determined as T m After stabilization for 10 minutes, the copolymer was cooled to -50°C at a rate of 10°C / min, and then heated to T1 at a rate of 10°C / min. After stabilization for 10 minutes, the copolymer was cooled to -50°C at a rate of 10°C / min, generating a crystallization exothermic peak, which was recorded as T2. By varying the cooling start temperature T1 to different values, multiple crystallization curves were obtained, as shown in Figure 3. When the T1 temperature was T m <T1≦T m +20℃, T2 increases as T1 decreases, and T1 temperature > T m At +20°C, it can be seen that T2 did not change with the decrease in T1.

[0110] [Example 7] Polymerization was carried out according to the method of Example 5, with the following differences: Catalyst precursor 3 was used; 1-hexene was added in three batches, with the same addition timing as in Example 1, and the addition amounts were 10 mL, 1.3 mL, and 1.0 mL, respectively; the molar concentration ratio of ethylene to 1-hexene in the reactor was maintained at 1.1 to 1.3 throughout the reaction process. 5.25 g of polymer was obtained, with a polymerization activity of 2.10 × 10 6 g mol -1 (cat)·h -1 and the density is 0.856 g / cm 3 The hexene mass content was 49%, the melting point was 121.2°C, the crystallinity was 0.17%, and the melt index was 114.9g / 10min.

[0111] [Example 8] The polymerization was carried out according to the method of Example 5, except that catalyst precursor 9 was used.

[0112] 38.9 g of polymer was obtained, and the polymerization activity was 1.56 × 10 7 g mol -1 (cat)·h -1 and the density is 0.860 g / cm 3 The hexene mass content was 47%, the melting point was 124.8°C, the crystallinity was 4.30%, and the melt index was 153g / 10min.

[0113] [Example 9] The polymerization was carried out according to the method of Example 1, with the following differences: Catalyst Precursor 2 was used; three batches of 1-octene were added in amounts of 12.5 mL, 1.6 mL, and 1.3 mL, respectively; the molar concentration ratio of ethylene to 1-octene in the reactor was maintained at 1.1-1.2 throughout the reaction process. 7.44 g of polymer was obtained, with a polymerization activity of 2.98 × 10 6 g mol -1 (cat)·h -1 and the density is 0.861 g / cm 3The octene mass content was 45%, the melting point was 108.4°C, the crystallinity was 0.492%, and the melt index was 212g / 10min.

[0114] [Example 10] The polymerization was carried out according to the method of Example 1, except that Catalyst Precursor 4 was used.

[0115] 35.7 g of polymer was obtained, and the polymerization activity was 1.43 × 10 7 g mol -1 (cat)·h -1 and the density is 0.864 g / cm 3 The octene mass content was 43%, the melting point was 116° C., the crystallinity was 2.38%, and the melt index was 7.54 g / 10 min.

[0116] [Example 11] The polymerization was carried out according to the method of Example 1, with the following differences: Catalyst Precursor 5 was used; three batches of 1-octene were added in amounts of 12.5 mL, 1.0 mL, and 1.0 mL, respectively; the molar concentration ratio of ethylene to 1-octene in the reactor was maintained at 1.1-1.2 throughout the reaction process. 4.47 g of polymer was obtained, with a polymerization activity of 1.79 × 10 6 g mol -1 (cat)·h -1 and the density is 0.862 g / cm 3 The octene mass content was 45%, the melting point was 90° C., the crystallinity was 1.57%, and the melt index was 93.8 g / 10 min.

[0117] [Example 12] The polymerization was carried out according to the method of Example 9, except that Catalyst Precursor 6 was used.

[0118] 6.68 g of polymer was obtained, and the polymerization activity was 2.67 × 10 6 g mol -1 (cat)·h -1and the density is 0.868 g / cm 3 The octene mass content was 39%, the melting point was 122° C., the crystallinity was 4.17%, and the melt index was 3.12 g / 10 min.

[0119] [Example 13] The polymerization was carried out according to the method of Example 9, except that Catalyst Precursor 7 was used.

[0120] 6.02 g of polymer was obtained, and the polymerization activity was 2.41 × 10 6 g mol -1 (cat)·h -1 and the density is 0.866 g / cm 3 The octene mass content was 41%, the melting point was 113° C., the crystallinity was 2.38%, and the melt index was 7.54 g / 10 min.

[0121] [Example 14] The polymerization was carried out according to the method of Example 9, except that Catalyst Precursor 8 was used.

[0122] 8.74 g of polymer was obtained, and the polymerization activity was 3.50 × 10 6 g mol -1 (cat)·h -1 and the density is 0.864 g / cm 3 The octene mass content was 43%, the melting point was 115.6°C, the crystallinity was 1.68%, and the melt index was 18.04g / 10min.

[0123] [Example 15] The polymerization was carried out according to the method of Example 1, except that catalyst precursor 10 was used.

[0124] 41.9 g of polymer was obtained, and the polymerization activity was 1.68 × 10 7 g mol -1 (cat)·h -1 and the density is 0.865 g / cm 3The octene mass content was 42%, the melting point was 106° C., the crystallinity was 3.46%, and the melt index was 6.55 g / 10 min.

[0125] [Example 16] The polymerization was carried out according to the method of Example 9, except that catalyst precursor 11 was used.

[0126] 7.76 g of polymer was obtained, and the polymerization activity was 3.1 × 10 6 g mol -1 (cat)·h -1 and the density is 0.863 g / cm 3 The octene mass content was 43%, the melting point was 95° C., the crystallinity was 0.667%, and the melt index was 43.4 g / 10 min.

[0127] [Comparative Example 1] The reactor was a 500 mL autoclave equipped with a stirrer. Prior to the reaction, conventional dehydration and deoxygenation treatments were performed, followed by three flushes with polymerization-grade ethylene. The autoclave was first charged with 183.75 mL of purified toluene, followed by 0.75 mL of a 1 mol / L hexane solution of triisobutylaluminum, 26.8 mL of purified 1-octene, 1 mL of a 5 mmol / L toluene solution of CGC-Ti catalyst component, and 2 mL of a 5 mmol / L toluene solution of trityl tetrakis(pentafluorophenyl)borate. The reactor temperature was raised to 30 °C, and ethylene was continuously fed. The reactor pressure was 0.4 MPa. After 30 minutes of reaction time, the ethylene feed was stopped, and ethanol was added to terminate the reaction. The temperature was lowered to 20 °C, the mixture was discharged, and the mixture was added to a three-fold volume of ethanol and filtered. The resulting polymer was dried overnight in a vacuum oven at 80 °C. The polymer was weighed and found to be 10.8 g. The polymerization activity was 1.28 × 10 7 g mol -1 (cat)·h -1 and the density is 0.869 g / cm 3The octene mass content was 38%, the melting point was 57° C., the crystallinity was 9.46%, and the melt index was 1.26 g / 10 min.

[0128] Comparative Example 2 The polymerization was carried out according to the method of Example 1, except for the following: 26.8 mL of purified 1-octene was added all at once, and the molar concentration ratio of ethylene to 1-octene in the reactor was less than 0.55 at the initial stage of the reaction. 28.8 g of polymer was obtained, with a polymerization activity of 1.15 × 10 7 g mol -1 (cat)·h -1 and the density is 0.850 g / cm 3 The mass content of octene was less than 60%. No clear melting point was observed, so the crystallinity could not be calculated. The melt index was 93 g / 10 min.

[0129] [Examples 17 to 18 and Comparative Example 3] A continuous solution polymerization procedure was used. Ethylene, 1-octene, the primary catalyst solution, a toluene solution of trityl tetrakis(pentafluorophenyl)borate, and a triisobutylaluminum solution were continuously introduced into a 1.8 L polymerization vessel and reacted. The ethylene and 1-octene introduction rates were adjusted so that the molar concentration ratio of ethylene to 1-octene in the reaction system was always maintained at 1.1 to 1.3. After the reaction, the solution was collected in a post-treatment vessel, and ethanol was added to the vessel. After the reaction was completed, 200 mL of the polymer solution was taken and added to 600 mL of ethanol to precipitate the product, which was then filtered. The resulting polymer was dried overnight in a vacuum oven at 80 °C, and the product was characterized. The results are shown in Table 1.

[0130] [Table 1]

[0131] (High-Temperature Nuclear Magnetic Resonance Carbon Spectroscopy) The copolymers of Examples 2, 17, and 18 and Comparative Example 3 were tested using high-temperature nuclear magnetic resonance, as were the polymers of Example 1 of Dow 8150 and CN110272515B. The structural data of the copolymers measured are shown in the table below, where E represents an ethylene structural unit and O represents an α-olefin structural unit.

[0132] [Table 2]

[0133] It can be seen that the copolymer of the present invention has a much higher content of OOO sequence structures than the copolymer of Comparative Example 3.

[0134] The content of the block copolymer was calculated using the ratio of the sequence structures according to the following formula: W ブロック共重合体 =336×n OOO / [336×n OOO +84×n EEE +168×(n EEO +n EOE )+252×(n OEO +n OOE )] In the formula, n OOO , n EEE , n EEO , n EOE , n OEO and n OOE are the mole percent contents of OOO, EEE, EEO, EOE, OEO, and OOE sequence structures, respectively.

[0135] The calculated block copolymer contents are shown in the table below.

[0136] [Table 3]

[0137] (Low-field nuclear magnetic resonance testing) The copolymers of Examples 1 and 17, as well as a blend of POE 8150 (DOW) and HDPE (LyondellBasel 4261), were measured using low-field nuclear magnetic resonance relaxation studies. The results are shown in Figures 4a and 4b. POE-5 is the copolymer of Example 1, and HMPOE is the copolymer of Example 17. The blend of POE 8150 and HDPE was obtained as follows: HDPE and POE 8150 (weight ratio 5:95) were dissolved in xylene at 140°C, mixed uniformly, and the solution was rapidly poured into acetone for precipitation. In Figure 4a, 121 indicates the test result when the sample was heated to melt and reached exactly 121°C, and 121melt indicates the test result when the sample was cooled to crystallize and reached exactly 121°C.

[0138] Relaxation experiments showed that the blended HDPE did not affect the network relaxation behavior of POE8150, while the state (melting or crystallization) of the high-melting-point component in our copolymer significantly affected the network relaxation behavior of the system. This indicates that the high-melting-point component in our copolymer contains long sequences of ethylene blocks linked to molecular blocks primarily composed of α-olefins (i.e., the high-melting-point ethylene blocks in the high-melting-point component are chemically linked to molecular blocks primarily composed of side-by-side octene, which is not present in physical blends such as POE and LLDPE). This is because at 121°C, some of the polyethylene segments are not yet melted, and these unmelted segments restrict the mobility of the polymer molecular chains.

[0139] Figures 5a-5c show the results of low-field nuclear magnetic resonance relaxation experiments on LLDPE (DOW 2045G), the commercial POE product LC670 (LG), and their mixtures. The LC670 / LLDPE mixture was obtained as follows: POE LC670 and LLDPE (weight ratio 95:5) were dissolved in xylene at 140 °C, mixed uniformly, and the solution was rapidly poured into acetone for precipitation.

[0140] The results of the relaxation experiments showed that for LLDPE / LC670 blends, LLDPE did not affect the network relaxation behavior of LC670.

[0141] 6a-6c show the results of low-field nuclear magnetic resonance relaxation experiments for the comparative sample (polymer of Example 1 of CN110272515B) and the copolymers of Comparative Examples 3 and 1 of the present invention, respectively.

[0142] (Crystallization Elution Fraction (CEF) test) For copolymers POE-1 and POE-2, three fractions were prepared using the crystallization elution fraction (CEF) test: below 40°C (<40°C), 40°C to 80°C, and above 80°C (>80°C), and DSC characterization was performed. Copolymer POE-1 was the copolymer obtained in Example 17, and copolymer POE-2 was the copolymer obtained in Example 18.

[0143] The content of the fraction below 40°C was calculated based on the test concentration and obtained directly from the instrument. The content ratios of the 40°C to 80°C fraction and the fraction above 80°C were determined by peak area ratio, and the respective contents were obtained from the instrument according to the content of the fraction below 40°C. The crystallization elution fraction (CEF) elution curve is shown in Figure 9.

[0144] The results of the crystallization elution fraction (CEF) test are shown in the table below.

[0145] [Table 4]

[0146] The fractions separated by CEF were air-dried and then dried in a vacuum oven at 80°C for 8 hours, after which the solids were weighed to determine the content of each fraction.

[0147] Before the DSC test, 0.5 g of the vacuum-dried fraction was immersed in 10 mL of xylene at room temperature for 7 days to remove low-melting-point components, and then air-dried and vacuum-dried (in a vacuum oven at 80 °C for 8 h) before being subjected to DSC characterization.

[0148] Figure 7a shows the DSC curve of the 40°C to 80°C fraction of POE-1; Figure 7b shows the DSC curve of the less than 40°C fraction of POE-1; Figure 7c shows the DSC curve of the more than 80°C fraction of POE-1; Figure 7d shows the DSC curve of the less than 40°C fraction of POE-2; Figure 7e shows the DSC curve of the 40°C to 80°C fraction of POE-2; and Figure 7f shows the DSC curve of the more than 80°C fraction of POE-2.

[0149] The fractions above 80°C of POE-1 and POE-2 were immersed in xylene at room temperature for 7 days, followed by immersion in xylene at 85°C for 2 days. After two xylene treatments, the soluble fraction was substantially removed, yielding the treated fractions (high-melting-point fractions). The high-melting-point fractions were dried in a vacuum oven at 80°C for 8 hours, and their contents were 4% and 6%, respectively, relative to the total mass of the initial sample. The DSC curves of the high-melting-point fractions are shown in Figures 7g and 7h, respectively.

[0150] In the DSC graphs of Figures 7a to 7h, the upper curve is the graph obtained by the first scan, and the lower curve is the graph obtained by the second scan performed consecutively.

[0151] (CEF-IR infrared analysis) The fractions above 80°C of POE-1 and POE-2 were characterized by CEF-IR. Copolymer POE-1 was the copolymer obtained in Example 17, and copolymer POE-2 was the copolymer obtained in Example 18. The fractions above 80°C of each of POE-1 and POE-2 were immersed in xylene at room temperature for 7 days, and then at 85°C for 2 days. The soluble fraction was substantially removed to obtain a treated fraction above 80°C (high melting point fraction). The high melting point fraction was dried in a vacuum oven at 80°C for 8 hours and then subjected to CEF-IR infrared analysis. The horizontal axis of Figure 8a is the elution temperature, the vertical axis is the infrared absorption, and the peak of the curve represents the melting point. The horizontal axis of Figure 8b is the elution temperature, and the vertical axis is the amount of -CH3 per 1,000 carbon atoms in the molecular chain, which can represent the content of comonomer units.

[0152] As can be seen from Figures 8a and 8b, the melting point and composition of the highest temperature peak obtained by CEF-IR analysis of the high melting point fraction of the present copolymer are different from those of the block copolymer Infuse 9000 (Dow Chemical) and LLDPE 2045G. The melting point of the highest temperature peak obtained by CEF-IR analysis of the high melting point fraction of the present copolymer is higher than that of the block copolymer Infuse 9000 but close to that of LLDPE 2045G. The comonomer content of the copolymer at the highest temperature peak obtained by CEF-IR analysis of the high melting point fraction of the present copolymer is lower than that of the block copolymer Infuse 9000 at the same elution temperature but higher than that of LLDPE 2045G. From the curves shown in FIG. 8b, it can be determined that the comonomer content of the high melting point fraction of the copolymer of Example 17 obtained by CEF-IR analysis is 6.4 wt%-9.6 wt%, and the comonomer content of the high melting point fraction of the copolymer of Example 18 obtained by CEF-IR analysis is 8 wt%-18.4 wt%, while the comonomer content of Infuse 9000 is 21 wt%-48 wt%, and the comonomer content of LLDPE 2045G is 2 wt%-6.4 wt%.

[0153] Although the embodiments of the present invention have been described above, the above description is illustrative and not exhaustive, and the present invention is not limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

[0154] The range endpoints and any values ​​disclosed herein are not intended to be limiting to the exact range or value, but rather, these ranges or values ​​are intended to include values ​​close to that range or value. For numerical ranges, the various range endpoints, various range endpoints and individual point values, and individual point values ​​can be combined with each other to create one or more new numerical ranges, and these new numerical ranges are to be considered to be specifically disclosed herein.

[0155] The present invention relates to an ethylene / α-olefin copolymer and a method for preparing the same. The ethylene / α-olefin copolymer has an α-olefin content of 30 wt % or more and a density of 0.875 g / cm 3 The melting point is 90°C or higher, and the α-olefin is C3 to C 20 The ethylene-α-olefin copolymer of the present invention has a higher usable temperature range than conventional polyolefin elastomers at the same comonomer content, and is therefore suitable for use in higher temperature environments. [Brief explanation of the drawings]

[0156] [Figure 1] 1 is a graph of the crystallization curve of the copolymer prepared in Example 1 at different initial cooling temperatures T1. [Figure 2] 1 is a graph of the crystallization curve of the copolymer prepared in Example 5 at different initial cooling temperatures T1. [Figure 3] 1 is a graph of the crystallization curve of the copolymer prepared in Example 6 at different initial cooling temperatures T1. [Figure 4a] 1 shows the results of low-field nuclear magnetic resonance relaxation experiments of the copolymers of the present invention and comparative copolymers. [Figure 4b] 1 shows the results of low-field nuclear magnetic resonance relaxation experiments of the copolymers of the present invention and comparative copolymers. [Figure 5a] 1 shows the results of low-field nuclear magnetic resonance relaxation experiments of prior art copolymers. [Figure 5b] 1 shows the results of low-field nuclear magnetic resonance relaxation experiments of prior art copolymers. [Figure 5c] 1 shows the results of low-field nuclear magnetic resonance relaxation experiments of prior art copolymers. [Figure 6a] The results of low-field nuclear magnetic resonance relaxation experiments of the comparative patent samples, the copolymers of Comparative Example 3 and Comparative Example 1 are shown. [Figure 6b] The results of low-field nuclear magnetic resonance relaxation experiments of the comparative patent samples, the copolymers of Comparative Example 3 and Comparative Example 1 are shown. [Figure 6c]The results of low-field nuclear magnetic resonance relaxation experiments of the comparative patent samples, the copolymers of Comparative Example 3 and Comparative Example 1 are shown. [Figure 7a] 1 shows the DSC curves of fractions obtained after CEF fractionation of the copolymer of the present invention. [Figure 7b] 1 shows the DSC curves of fractions obtained after CEF fractionation of the copolymer of the present invention. [Figure 7c] 1 shows the DSC curves of fractions obtained after CEF fractionation of the copolymer of the present invention. [Figure 7d] 1 shows the DSC curves of fractions obtained after CEF fractionation of the copolymer of the present invention. [Figure 7e] 1 shows the DSC curves of fractions obtained after CEF fractionation of the copolymer of the present invention. [Figure 7f] 1 shows the DSC curves of fractions obtained after CEF fractionation of the copolymer of the present invention. [Figure 7g] 1 shows the DSC curves of fractions obtained after CEF fractionation of the copolymer of the present invention. [Figure 7h] 1 shows the DSC curves of fractions obtained after CEF fractionation of the copolymer of the present invention. [Figure 8a] 1 shows the CEF-IR characterization results of the third temperature fraction (high melting point fraction). [Figure 8b] 1 shows the CEF-IR characterization results of the third temperature fraction (high melting point fraction). [Figure 9] The crystallization elution fraction (CEF) elution curve is shown.

Claims

1. An ethylene / α-olefin copolymer, The ethylene / α-olefin copolymer has an α-olefin content of 30 wt % or more and a density of 0.875 g / cm ３ and the melting point is 90°C or higher, and the α-olefin is C ３ ~C ２０ α-olefin, and preferably the α-olefin is C ３ ~C １０ an α-olefin, more preferably one or more selected from the group consisting of propylene, 1-butene, 1-hexene, 1-octene, and 1-decene, and even more preferably one or more selected from the group consisting of 1-hexene, 1-octene, and 1-decene; An ethylene / α-olefin copolymer characterized by:

2. The ethylene / α-olefin copolymer has an α-olefin content of 30 wt % to 55 wt % and a density of 0.850 g / cm ３ ~0.875g / cm ３ The ethylene / α-olefin copolymer according to claim 1, having a melting point of 90°C to 130°C, a crystallinity of 0.05% to 15%, preferably 0.1% to 10%, and a melt flow rate at 190°C under a load of 2.16 kg of more than 0.1 g / 10 min, preferably 0.2 g / 10 min to 400 g / 10 min.

3. The ethylene / α-olefin copolymer according to claim 1 or 2, wherein the ethylene / α-olefin copolymer has the following properties: When tested by differential scanning calorimetry, the ethylene / α-olefin interpolymer has a melting endotherm peak between 90°C and 130°C; and / or The copolymer was tested by differential scanning calorimetry by heating it to 180°C at a rate of 10°C / min, and the peak temperature of the resulting melting peak was measured as T ｍ After stabilization for 10 minutes, the copolymer was cooled to −50° C. at a rate of 10° C. / min, and then the copolymer was cooled to T １ After stabilization for 10 minutes, the copolymer was cooled to −50° C. at a rate of 10° C. / min to generate a crystallization exothermic peak, and the peak temperature was T ２ When recorded as T １ , T ｍ and T ２ satisfies the following: (i) T ｍ <T １ ≦T ｍ At +20°C, T １ With the decrease in T ２ increases, (ii) T １ >T ｍ At +20°C, T １ Even if T decreases ２ does not change.

4. The ethylene / α-olefin copolymer according to any one of claims 1 to 3, wherein the ethylene / α-olefin copolymer has at least two peaks on an elution curve obtained by a crystallization elution fraction (CEF) test method.

5. The ethylene / α-olefin copolymer of claim 4, wherein the ethylene / α-olefin copolymer has the following properties: The first temperature fraction, the second temperature fraction, and the third temperature fraction are obtained by a crystallization elution fraction (CEF) test method, and the first temperature fraction is a fraction below 40°C, the second temperature fraction is a fraction between 40°C and 80°C, and the third temperature fraction is a fraction above 80°C; and the content of the first temperature fraction is 80 wt% to 98 wt%, the content of the second temperature fraction is 1 wt% to 10 wt%, and the content of the third temperature fraction is 1 wt% to 10 wt%, based on the weight of the ethylene / α-olefin copolymer.

6. 6. The ethylene / α-olefin interpolymer according to claim 5, wherein the first temperature fraction has at least two peaks on its DSC curve, the second temperature fraction has at least three peaks on its DSC curve, and the third temperature fraction has at least two peaks on its DSC curve.

7. of at least two peaks on the DSC curve of the first temperature fraction, the lowest melting point peak corresponds to a melting point below 45°C and the highest melting point peak corresponds to a melting point above 80°C; of at least three peaks on the DSC curve of the second temperature fraction, the lowest melting point peak corresponds to a melting point below 40°C, at least one intermediate melting point peak corresponds to a melting point between 40°C and 80°C, and the highest melting point peak corresponds to a melting point above 80°C; 7. The ethylene / α-olefin copolymer according to claim 6, wherein, of at least two peaks on a DSC curve of the third temperature fraction, the peak with the lowest melting point corresponds to a melting point lower than 40°C and the peak with the highest melting point corresponds to a melting point higher than 80°C.

8. immersing the third temperature fraction in xylene at room temperature for 7 days, and then in xylene at 85°C for 2 days, thereby obtaining a third temperature fraction from which the soluble fraction has been (substantially) removed, wherein the amount of the third temperature fraction from which the soluble fraction has been (substantially) removed is 2 to 8 wt % based on the total weight of the ethylene / α-olefin copolymer; and / or The ethylene / α-olefin copolymer according to any one of claims 5 to 7, wherein the comonomer content of the third temperature fraction from which the soluble fraction has been (substantially) removed, as determined by infrared detection in a crystallization elution fraction (CEF) analysis, is 5 wt% to 25 wt%, preferably 5.5 wt% to 22 wt%, and more preferably 6 wt% to 20 wt%.

9. The ethylene / α-olefin copolymer according to any one of claims 1 to 8, wherein the ethylene / α-olefin copolymer comprises a block copolymer of ethylene and an α-olefin and a random copolymer of ethylene and an α-olefin, and the random copolymer of ethylene and an α-olefin is a major component; preferably, based on the weight of the ethylene / α-olefin copolymer, the content of the random copolymer of ethylene and an α-olefin is 89 wt % to 98 wt %, and the content of the block copolymer of ethylene and an α-olefin is 2 wt % to 11 wt %.

10. 10. The ethylene / α-olefin copolymer according to any one of claims 1 to 9, wherein the mole % content of OOO sequences in the ethylene / α-olefin copolymer is 0.7% to 3.5%, preferably 0.8% to 3.2%, preferably 0.85% to 3.0%, and more preferably 0.9% to 2.8%; and the total of EEE, EEO, OEO, EOE, OOE and OOO sequences in the ethylene / α-olefin copolymer is 100%, wherein E represents an ethylene structural unit and O represents an α-olefin structural unit.

11. carrying out a copolymerization reaction of ethylene and an α-olefin in solution in the presence of at least one catalyst in at least one reactor to obtain an ethylene / α-olefin copolymer; maintaining a molar concentration ratio of ethylene to the α-olefin in the solution in the reactor between 0.6 and 2.2 throughout the reaction process; The catalyst is (A) a catalyst component; (B) an organoboron compound, and (C) containing an organoaluminum compound; The catalyst component is a premix of a half-sandwich metallocene catalyst precursor and an alkylaluminum compound; The half-sandwich metallocene catalyst precursor has the general formula Cp'LMQ ２ and a compound having the formula: Cp' is an optionally substituted cyclopentadiene group or a group derived therefrom, and is preferably one or more selected from the group consisting of substituted or unsubstituted cyclopentadienyl, substituted or unsubstituted indenyl, and substituted or unsubstituted fluorenyl; when Cp' contains a substituent, the substituent is selected from the group consisting of C １ ~C １２ Alkyl, C １ ~C １２ Alkoxy, C １ ~C １２ Cyril, C. ６ ~C １２ Aryl, C ７ ~C １２ Aralkyloxy, C ２ ~C １２ Alkynyl and C ８ ~C １２ arylalkynyl, preferably C １ ~C ８ alkyl, more preferably C １ ~C ６ alkyl, and more preferably one or more selected from methyl, ethyl, n-propyl, isopropyl, n-butyl, and isobutyl; L is one or more of an optionally substituted phenolic ligand and a phosphanimine ligand; M is an element selected from Group IVB, preferably Zr and / or Ti, more preferably Ti; Each Q is independently halogen and / or C １ ~C ６ Alkyl, preferably halogen and / or C １ ~C ３ alkyl, more preferably selected from chlorine and / or methyl, A method for preparing ethylene / α-olefin copolymers.

12. maintaining a molar concentration ratio of ethylene to α-olefin in the solution in the reactor of 0.65 to 1.6, preferably 0.8 to 1.4; and / or The molar concentration of ethylene in the solution in the reactor may be 0.05 to 10 mol / L, preferably 0.3 to 4 mol / L; and / or the molar concentration of α-olefin may be 0.031 to 15.4 mol / L, preferably 0.2 to 6.15 mol / L; and / or The method according to claim 11, wherein the copolymerization reaction conditions include a polymerization pressure of 0.1 MPa to 10 MPa, preferably 0.2 MPa to 5 MPa; a polymerization temperature of −30° C. to 160° C., preferably 10° C. to 120° C.; and a polymerization time of 1 minute to 300 minutes, preferably 10 minutes to 60 minutes.

13. Ethylene is continuously fed and the α-olefin is intermittently fed, preferably at intervals of 1 minute to 15 minutes between the intermittent feeding of the α-olefin, or The process according to any one of claims 11 to 12, wherein both ethylene and the α-olefin are fed continuously.

14. The method of any one of claims 11 to 13, wherein the half-sandwich metallocene catalyst precursor is at least one of a compound of formula I and a compound of formula II: 【Chemical 1】 In formula I, R １ , R ２ and R ３ are the same or different and each independently represent hydrogen, substituted or unsubstituted C １ ~C ２０ Straight or branched alkyl, substituted or unsubstituted C ６ ~C ２０ Aryl and substituted or unsubstituted C ２ ~C ２０ alkynyl; R ４ ~R ８ are the same or different and each independently represent hydrogen, substituted or unsubstituted C １ ~C ２０ linear or branched alkyl; R ４ ~R ８ any two adjacent groups of are optionally linked to form a ring; In formula I, M is an element selected from Group IVB, preferably Zr and / or Ti, more preferably Ti; each Q is independently a halogen and / or C. １ ~C ６ alkyl, preferably halogen and / or C １ ~C ３ alkyl, more preferably chlorine and / or methyl; In formula II, R １ ', R ２ ' and R ３ ' are the same or different and each independently represent a substituted or unsubstituted C １ ~C ２０ Linear or branched alkyl, substituted or unsubstituted C ３ ~C ２０ Cycloalkyl, and substituted or unsubstituted C ６ ~C ２０ aryl; R ４ '~R ８ ' are the same or different and each independently represent hydrogen, substituted or unsubstituted C １ ~C ２０ linear or branched alkyl; R ４ '~R ８ any two adjacent groups in ' are optionally linked to form a ring; In Formula II, M' is an element selected from Group IVB, preferably Zr and / or Ti, more preferably Ti; each Q' is independently a halogen and / or C. １ ~C ６ alkyl, preferably halogen and / or C １ ~C ３ alkyl, more preferably chlorine and / or methyl; Preferably, in formula I, R １ , R ２ and R ３ are the same or different and each independently represent hydrogen, substituted or unsubstituted C １ ~C ６ Linear or branched alkyl, substituted or unsubstituted C ６ ~C ８ Aryl and substituted or unsubstituted C ２ ~C ８ alkynyl; R ４ ~R ８ are the same or different and each independently represent hydrogen, substituted or unsubstituted C １ ~C ６ linear or branched alkyl; R ４ ~R ８ any two adjacent groups of are optionally linked to form a ring; More preferably, in formula I: R １ =R ２ =iPr、R ３ =H、R ４ ~R ８ =Me、M=Ti、Q=Cl(1); R １ =R ２ =iPr、R ３ =H、R ４ ~R ８ =H、M=Ti、Q=Cl(2); R １ =R ２ = iPr, R ３ = H, R ５ =R ６ =R ７ = H, R ４ and R ８ forms a ring and further forms an indenyl together with the cyclopentadienyl, M=Ti, Q=Cl(3); R １ =R ２ =tBu,R ３ =H、R ４ ~R ８ =Me、M=Ti、Q=Cl(4); R １ =R ２ =H、R ３ =H、R ４ ~R ８ =Me、M=Ti、Q=Cl(5); R １ =R ２ = trimethylsilylethynyl, R ３ = tBu, R ４ ~R ８ =Me, M=Ti, Q=Cl(6); R １ =R ２ = t-butylethynyl, R ３ = H, R ４ ~R ８ =Me, M=Ti, Q=Cl(7); R １ =R ２ = 9-anthracenylalkynyl, R ３ = H, R ４ ~R ８ = Me, M = Ti, Q = Cl (8); Preferably, in formula II, R １ ', R ２ ' and R ３ ' are the same or different and each independently represent a substituted or unsubstituted C １ ~C ６ Straight or branched alkyl, substituted or unsubstituted C ３ ~C ６ Cycloalkyl, and substituted or unsubstituted C ６ ~C ８ aryl; R ４ '~R ８ ' are the same or different and each independently represent hydrogen, substituted or unsubstituted C １ ~C ６ is selected from the group consisting of straight chain or branched alkyl; R ４ '~R ８ any two adjacent groups of ' are optionally joined to form a ring; More preferably, in formula II: R １ ’=R ２ ’=R ３ ’=tBu、R ４ ’~R ８ ’=H、M’=Ti、Q’=Cl(9); R １ ’=R ２ ’=R ３ ’=tBu、R ４ ’~R ８ ’=Me、M’=Ti、Q’=Cl(10); R １ '=R ２ '=R ３ '=iPr,R ４ '~R ８ Q′=Me, M′=Ti, Q′=Cl(11).

15. The alkylaluminum compound has the general formula AlR' ３ wherein R' is the same or different, and R' is C １ ~C ８ alkyl, one or two of which are optionally substituted by chlorine; the alkylaluminum compound is preferably selected from trimethylaluminum, triethylaluminum, tri-n-butylaluminum, triisobutylaluminum, tri-n-hexylaluminum, alkylaluminum chloride, Al(n-C ６ H １３ ) ３ and Al(n-C ８ H １７ ) ３ more preferably, one or more of trimethylaluminum, triethylaluminum, triisobutylaluminum and tri-n-hexylaluminum, most preferably triisobutylaluminum; and / or The premix further comprises a solvent, the solvent comprising ６ ~C ２０ Aromatic hydrocarbons and C ４ ~C ２０ the premix is ​​preferably a homogeneous solution; and / or The catalyst component is obtained by contacting the half-sandwich metallocene catalyst precursor with the alkylaluminum compound; preferably, the half-sandwich metallocene catalyst precursor and the alkylaluminum compound are mixed in a solvent for 0.5 to 30 minutes, preferably 15 to 30 minutes, to obtain the catalyst component, and more preferably, after mixing, the mixed solution is allowed to stand for 0.5 to 48 hours, more preferably 0.5 to 24 hours to obtain the catalyst component; and / or The method according to any one of claims 11 to 14, wherein the total concentration of the half-sandwich metallocene catalyst precursor and the alkylaluminum compound in the premix is ​​0.01 to 10 g / L, preferably 0.1 to 3 g / L, more preferably 0.1 to 2 g / L; and / or the molar ratio of the half-sandwich metallocene catalyst precursor to the alkylaluminum compound is 1:(2 to 200), preferably 1:(2 to 100), more preferably 1:(20 to 100).

16. the organoboron compound is selected from a fluoroorganoboron compound and / or a fluoroorganoborate compound; preferably the fluoroorganoboron compound is selected from tris(pentafluorophenyl)boron and / or tris[3,5-bis(trifluoromethyl)phenyl]boron; preferably the fluoroorganoborate compound is selected from a fluorinated arylborate, preferably one or more of N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate, triphenyltetrakis(pentafluorophenyl)borate, trityl tetrakis(pentafluorophenyl)borate, lithium tetrakis(pentafluorophenyl)borate, N,N-dimethylanilinium tetrakis[3,5-bis(trifluoromethyl)phenyl]borate, and triphenylcarbenium tetrakis[3,5-bis(trifluoromethyl)phenyl]borate; and / or the organoaluminum compound is selected from alkylaluminum compounds and / or organoaluminoxane compounds; Preferably, the alkylaluminum compound has the general formula AlR' ３ R' may be the same or different, and C １ ~C ８ alkyl, one or two of which are optionally substituted with chlorine; the alkyl aluminum compound is preferably selected from trimethyl aluminum, triethyl aluminum, tri-n-butyl aluminum, triisobutyl aluminum, tri-n-hexyl aluminum, alkyl aluminum chloride, Al(n-C ６ H １３ ) ３ and Al(n-C ８ H １７ ) ３ more preferably, one or more of trimethylaluminum, triethylaluminum, triisobutylaluminum, and tri-n-hexylaluminum, most preferably, triisobutylaluminum; Preferably, the organoaluminoxane compound has the following general structure: 【Chemistry 2】 In the formula, R is C １ ~C １２ hydrocarbyl, preferably C １ ~C ６ alkyl, more preferably methyl and / or isobutyl; and / or The method according to any one of claims 11 to 15, wherein the molar ratio of the catalyst component calculated from the half-sandwich metallocene catalyst precursor, the organoboron compound, and the organoaluminum compound is 1:(1-20):(50-3000), preferably 1:(2-10):(100-500).

17. The copolymerization reaction is carried out in an inert solvent, and the inert solvent is C ６ ~C ２０ Aromatic hydrocarbons and C ４ ~C ２０ The method according to any one of claims 11 to 16, wherein the alkyl group is one or more selected from alkanes, preferably one or more selected from benzene, toluene, hexane and heptane.

18. The process according to any one of claims 11 to 17, used to prepare the ethylene / α-olefin copolymer according to any one of claims 1 to 10.

19. An ethylene / α-olefin copolymer prepared by the method of any one of claims 11 to 18.

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