Alpha-olefin polymers, and methods for their preparation and use - Patents.com

Abstract

The present invention relates to the technical field of olefin polymerization and discloses an α-olefin polymer, as well as a method for preparing and using the same. The α-olefin polymer is formed by CH═CHR polymerization of at least one α-olefin monomer, in which the carbon atoms located in the main chain account for 58-87% of the total carbon atoms, where R is a linear or branched alkyl having two or more carbon atoms. The α-olefin polymer has a weight average molecular weight of 10,000-250,000 and a molecular weight distribution (PDI) of less than 3. The α-olefin polymer of the present invention has excellent thickening efficiency as a viscosity index improver for lubricating oils.

Description

Detailed Description of the Invention

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of Chinese Patent Application No. 202211308644.8 filed on October 25, 2022, Chinese Patent Application No. 202211308376.X filed on October 25, 2022, and Chinese Patent Application No. 202211309110.7 filed on October 25, 2022, the contents of which are incorporated herein by reference.

[0002] [Technical Field] The present invention relates to the technical field of olefin polymerization, and in particular to α-olefin polymers, and methods for their preparation and use.

[0003] [Background technology] In actual use, additives such as detergents, dispersants, viscosity index improvers, antioxidants, etc., are required to be added to lubricating oils to improve various properties of the oil products, among which viscosity index improvers are very important additives.

[0004] The viscosity of lubricating oils varies greatly with temperature, increasing at low temperatures and decreasing as temperatures increase, resulting in poor lubrication. Adding viscosity index improvers can effectively improve the lubricating efficiency at high temperatures, thereby improving the viscosity-temperature characteristics of lubricating oils. Among these, olefin copolymer viscosity index improvers (OCPs) are the most widely used viscosity index improvers, due to their superior thickening ability and shear stability, as well as their moderate price.

[0005] Olefin copolymer viscosity index improvers typically use ethylene as the main constituent monomer, but they face the challenge of achieving high thickening ability, solubility, and low-temperature system stability. To ensure solubility in base oils and maintain system stability at low temperatures, α-olefins such as propylene are typically copolymerized with ethylene to increase the branch content of the polyolefin. However, as the copolymerization ratio of α-olefins increases, i.e., as the branch content increases, solubility and low-temperature stability improve significantly, but thickening ability decreases significantly. To ensure sufficient thickening efficiency, the branch content must not be too high. For example, when preparing viscosity index improvers using ethylene-propylene copolymerization, the propylene unit content in the polymer is usually 50% or less. Therefore, conventional preparation methods strictly limit the amount of α-olefins used as copolymerization monomers. Furthermore, when α-olefins (especially long-chain α-olefins) are used as the main polymerization monomer, the branch content is generally too high, resulting in a decrease in viscosity and, as a result, very poor thickening efficiency.

[0006] Summary of the Invention [Problem to be solved by the invention] The present invention aims to provide an α-olefin polymer, a preparation method thereof, and use thereof, in order to solve the problems existing in the prior art that the amount of α-olefin used is strictly limited when preparing an olefin copolymer-based viscosity index improver, and that the thickening efficiency of olefin polymers prepared using α-olefin as the main polymerization monomer is relatively poor. The α-olefin polymers of the present invention are all obtained by polymerizing one kind of α-olefin or two or more kinds of α-olefin, and the α-olefin polymers have excellent thickening efficiency as viscosity index improvers for lubricating oils.

[0007] [Means for solving the problem] In order to achieve the above object, the first aspect of the present invention is Provided is an α-olefin polymer formed by CH═CHR polymerization of at least one α-olefin monomer, wherein carbon atoms located in the main chain of the α-olefin polymer account for 58 to 87% of all carbon atoms, wherein R is a linear or branched alkyl having two or more carbon atoms, the α-olefin polymer has a weight average molecular weight of 10,000 to 250,000, preferably 25,000 to 150,000, and more preferably 30,000 to 120,000, and the molecular weight distribution (PDI) of the α-olefin polymer is less than 3, preferably 2 or less.

[0008] A second aspect of the present invention provides a method for preparing the aforementioned α-olefin polymer, the method comprising the step of polymerizing an α-olefin monomer having 4 or more carbon atoms in the presence of a main catalyst, a cocatalyst, an optional chain shuttling agent, and an optional solvent, wherein the main catalyst is a late transition metal catalyst having a diimine ligand.

[0009] A third aspect of the present invention provides the use of the above-described α-olefin polymer as a viscosity index improver.

[0010] A fourth aspect of the present invention provides a lubricating oil comprising a base oil and the above-described α-olefin polymer.

[0011] [Effects of the Invention] According to the technical solution of the present invention, the α-olefin polymer has a relatively high thickening efficiency, which overcomes the technical problem traditionally existing in the prior art that the α-olefin polymer has a relatively poor property as a viscosity index improver due to the excessive carbon branching contained in the α-olefin polymer.

[0012] Furthermore, by using an α-olefin polymer as a viscosity index improver, the present invention increases the variety of viscosity index improvers available for selection, and the polyα-olefin viscosity index improver of the present invention is extremely valuable from both a practical standpoint and a technical research perspective.

[0013] [Mode for Carrying Out the Invention] Specific examples of the present invention will be described in detail below. It should be understood that the specific embodiments described herein are for the purpose of explaining and interpreting the present invention, and are not intended to limit the present invention.

[0014] The α-olefin polymer according to the present invention is formed by CH═CHR polymerization of at least one α-olefin monomer, where R is a linear or branched alkyl having two or more carbon atoms. In the α-olefin polymer, the carbon atoms located in the main chain account for 58 to 87%, preferably 60 to 85%, and more preferably 63 to 82% of the total carbon atoms.

[0015] The α-olefin polymer comprises first units -(CH2)-, second units -CH(CH3)-, and third units -CH(R)-, and the amount of the first units present is 77% or more and the amount of the third units present is 18% or less, based on the total main chain carbon atoms in the α-olefin polymer. In a preferred case, the amount of the first units present is 80 to 95%, the amount of the second units present is 1 to 10%, and the amount of the third units present is 2 to 12%, based on the total main chain carbon atoms in the α-olefin polymer. In the present invention, the third units are units obtained by α-olefin monomers without undergoing "chain transfer."

[0016] In the present invention, the weight average molecular weight of the α-olefin polymer is 10,000 to 250,000, preferably 25,000 to 150,000, and more preferably 30,000 to 120,000.

[0017] In the present invention, the molecular weight distribution (PDI) of the α-olefin polymer is less than 3, preferably 2 or less, and more preferably 1.01 to 2.

[0018] In the present invention, the weight average molecular weight M of the α-olefin polymer w, and molecular weight distribution PDI are measured by gel permeation chromatography-infrared detector (GPC-IR).

[0019] In some embodiments, the α-olefin polymer is obtained by a single homopolymerization of an α-olefin monomer, and has a weight average molecular weight of 20,000 to 250,000 (preferably 30,000 to 150,000) and a molecular weight distribution (PDI) of less than 3 (preferably 2 or less).

[0020] In a more preferred embodiment, the α-olefin polymer is a diblock polymer AB or a triblock polymer ABA, where the branching degree of the A block is greater than that of the B block. The α-olefin polymer according to this preferred embodiment has better thickening efficiency. In the present invention, the branching degree refers to the number of branches contained per 1,000 carbon atoms, and the branching degree is measured by gel permeation chromatography-infrared detector (GPC-IR).

[0021] When the α-olefin polymer is a diblock polymer or triblock polymer, in some embodiments, the α-olefin polymer is obtained by homopolymerizing one type of α-olefin monomer successively in at least two stages. In the at least two consecutive homopolymerization stages, a diblock polymer or triblock polymer having two or more blocks with different degrees of branching is formed by controlling the reaction temperature and / or the concentration of the α-olefin monomer in each reaction stage. In this embodiment, the α-olefin polymer has a weight average molecular weight of 22,000 to 180,000 (preferably 32,000 to 160,000) and a molecular weight distribution (PDI) of less than 3 (preferably 2 or less).

[0022] When the α-olefin polymer is a diblock polymer, in some other embodiments, the α-olefin polymer is obtained by sequentially homopolymerizing two types of α-olefin monomers in two stages, where one type of α-olefin monomer is used in each stage. In this embodiment, the α-olefin polymer has a weight average molecular weight of 10,000 to 250,000 (preferably 25,000 to 150,000) and a molecular weight distribution (PDI) of less than 3 (preferably 2 or less).

[0023] In the present invention, when the α-olefin polymer is a diblock polymer AB or a triblock polymer ABA, the degree of polymerization reaction in the reaction step is preferably controlled so that the A block is amorphous (i.e., non-crystalline) and the B block has some degree of crystallinity. In this case, the B block in the block polymer has a melting point, but the A block does not. More preferably, the melting point of the block polymer is -50°C to 80°C.

[0024] In the present invention, the α-olefin monomer is a linear or branched α-olefin having 4 to 20 carbon atoms (preferably 4 to 12, specifically, for example, 4, 5, 6, 7, 8, 9, 10, 11, or 12). In a preferred embodiment, the α-olefin monomer is at least one selected from 1-butene, 2-methyl-1-butene, 3,3-dimethyl-1-butene, 1-pentene, 1-pentene having one or more methyl, ethyl, or propyl substitutions, 1-hexene, 1-hexene having one or more methyl, ethyl, or propyl substitutions, 1-heptene, 1-heptene having one or more methyl, ethyl, or propyl substitutions, 1-octene having one or more methyl, ethyl, or propyl substitutions, 1-nonene, 1-decene, and 1-dodecene. More preferably, the α-olefin monomer is at least one selected from 1-butene, 2-methyl-1-butene, 3,3-dimethyl-1-butene, 1-pentene, 1-pentene having one or more methyl, ethyl, or propyl substitutions, 1-hexene, 1-hexene having one or more methyl, ethyl, or propyl substitutions, 1-heptene, and 1-heptene having one or more methyl, ethyl, or propyl substitutions, i.e., preferably an α-olefin monomer having less than 8 carbon atoms.

[0025] The method for preparing an α-olefin polymer according to the present invention comprises polymerizing an α-olefin monomer having 4 or more carbon atoms in the presence of a main catalyst, a cocatalyst, an optional chain shuttling agent, and an optional solvent, wherein the main catalyst is a late transition metal catalyst having a diimine ligand.

[0026] According to the method for preparing α-olefin polymers described in the present invention, the branching degree of the α-olefin polymers can be significantly reduced by using a late transition metal catalyst with a diimine ligand, so that the prepared α-olefin polymers exhibit relatively good thickening efficiency when used as viscosity index improvers for lubricating oils. The thickening efficiency is significantly improved compared to conventional α-olefin polymers, breaking through the conventional limitations on the proportion of α-olefins when used as viscosity index improvers.

[0027] In the method according to the present invention, the polymerization reaction process may include only one reaction stage or may include at least two reaction stages.

[0028] In some embodiments, the polymerization reaction process includes only one reaction stage, and the polymerization reaction process uses only one α-olefin monomer.

[0029] In some other embodiments, the polymerization reaction process includes at least two reaction stages, and the same α-olefin monomer is used in each reaction stage. In this embodiment, by controlling the reaction temperature and / or the concentration of the α-olefin monomer in each reaction stage, a diblock polymer AB or a triblock polymer ABA is formed, where the branching degree of the A block is greater than the branching degree of the B block.

[0030] In the above embodiment, controlling the reaction temperature of each reaction stage includes making the absolute value of the difference in polymerization reaction temperature between two adjacent reaction stages 10°C or more, preferably 20°C or more.

[0031] In the above embodiment, controlling the concentration of the α-olefin monomer in each reaction stage comprises having a ratio of the concentrations of the α-olefin monomer in two adjacent reaction stages greater than three.

[0032] In some other embodiments, the polymerization reaction process includes at least two reaction stages, and the α-olefin monomers used in each reaction stage are different, i.e., by controlling the type of α-olefin monomer in each reaction stage, a diblock polymer AB or a triblock polymer ABA is formed, where the branching degree of the A block is greater than the branching degree of the B block. In this embodiment, preferably, in two adjacent reaction stages, the carbon number of the α-olefin monomer added in the latter reaction stage is smaller than the carbon number of the α-olefin monomer added in the former reaction stage.

[0033] In the method according to the present invention, the reaction temperature of the polymerization reaction may be from -40°C to 100°C, preferably from 0°C to 70°C.

[0034] In the method according to the present invention, the reaction time of the polymerization reaction may be 5 minutes to 48 hours, preferably 10 minutes to 24 hours.

[0035] In the method according to the present invention, the concentration of the α-olefin monomer may be 0.05 mol / L or more. The range of the concentration of the α-olefin monomer varies depending on the type of the α-olefin monomer. For example, the concentration of an α-olefin monomer having 6 carbon atoms may be 8.15 mol / L or less, and the concentration of an α-olefin monomer having 14 carbon atoms may be 3.9 mol / L or less.

[0036] In some embodiments, the polymerization reaction process includes two reaction stages, and a diblock polymer is formed by controlling the reaction temperature of each reaction stage. Specifically, the reaction temperature of one reaction stage is −20° C. to 30° C., preferably 0° C. to 30° C., and the corresponding reaction time is 5 min to 48 h, preferably 10 min to 18 h. The reaction temperature of the other reaction stage is 0° C. to 80° C., preferably 25° C. to 55° C., and the corresponding reaction time is 5 min to 24 h, preferably 5 min to 4 h, more preferably 5 min to 2 h.

[0037] In some other embodiments, the polymerization reaction process includes at least two reaction stages, and a diblock polymer is formed by controlling the concentration of α-olefin monomer in each reaction stage. Specifically, the ratio of the α-olefin monomer concentrations in two adjacent reaction stages is greater than 3, preferably greater than 8, and the concentration of the α-olefin monomer in the reaction stage with the lower monomer concentration is 0.1 to 2 mol / L, preferably 0.2 to 1 mol / L. More preferably, the reaction time of the reaction stage with the lower monomer concentration is 30 min to 18 h, and the reaction time of the reaction stage with the higher monomer concentration is 3 min to 40 min.

[0038] In the present invention, the main catalyst may be selected from common late transition metal catalysts. In a relatively preferred embodiment, the main catalyst is a metal complex represented by formula (I):

[0039] [ka]

[0040] In formula (I), M is a Group VIII metal. Preferably, M is selected from nickel and palladium.

[0041] In formula (I), R1 and R4 may be the same or different and are each independently selected from C1 to C30 hydrocarbyl or heterohydrocarbyl, and R1 and R4 may optionally form a ring together, wherein the C1 to C30 hydrocarbyl may be selected from substituted or unsubstituted C1 to C30 alkyl, substituted or unsubstituted C2 to C30 alkenyl, substituted or unsubstituted C2 to C30 alkynyl, substituted or unsubstituted C6 to C30 aryl, substituted or unsubstituted C7 to C30 aralkyl, and substituted or unsubstituted C7 to C30 alkylaryl, and the C1 to C30 heterohydrocarbyl may be selected from substituted or unsubstituted C1 to C30 alkoxy, substituted or unsubstituted C2 to C30 alkenyloxy, and substituted or unsubstituted C2 to C30 alkynyloxy.

[0042] Preferably, R1 and R4 are each independently selected from substituted or unsubstituted C1 to C20 alkyl and substituted or unsubstituted C6 to C20 aryl. More preferably, R1 and R4 are each independently selected from substituted or unsubstituted C1 to C10 alkyl and substituted or unsubstituted C6 to C15 aryl.

[0043] In a most preferred embodiment, R1 and R4 are each a group represented by formula II:

[0044] [ka]

[0045] In formula (II), R 1 -R 5 may be the same or different and are each independently selected from hydrogen, halogen, hydroxy, and substituted or unsubstituted C1 to C30 hydrocarbyl or heterohydrocarbyl, and R 1 ~R 5may optionally form a ring together. Here, the C1-C30 hydrocarbyl may be selected from substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C2-C30 alkenyl, substituted or unsubstituted C2-C30 alkynyl, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C7-C30 aralkyl, and substituted or unsubstituted C7-C30 alkylaryl, and the C1-C30 heterohydrocarbyl may be selected from substituted or unsubstituted C1-C30 alkoxy, substituted or unsubstituted C2-C30 alkenyloxy, and substituted or unsubstituted C2-C30 alkynyloxy.

[0046] If preferred, R 1 , and R 3 are each independently selected from substituted or unsubstituted C3 to C10 alkyl or heterohydrocarbyl, where the C3 to C10 alkyl may be n-propyl, isopropyl, n-butyl, isobutyl, pentyl, heptyl, octyl, etc., and the C3 to C10 heterohydrocarbyl may be selected from substituted or unsubstituted C3 to C10 alkoxy, substituted or unsubstituted C3 to C10 alkenyloxy, and substituted or unsubstituted C3 to C10 alkynyloxy.

[0047] In formula (I), R2 and R3 may be the same or different and are each independently selected from hydrogen, halogen (particularly chlorine atom), and C1-C20 hydrocarbyl or heterohydrocarbyl, and R2 and R3 may optionally form a ring together, wherein the C1-C20 hydrocarbyl may be selected from substituted or unsubstituted C1-C20 alkyl, substituted or unsubstituted C2-C20 alkenyl, substituted or unsubstituted C2-C20 alkynyl, substituted or unsubstituted C6-C20 aryl, substituted or unsubstituted C7-C20 aralkyl, and substituted or unsubstituted C7-C20 alkylaryl, and the C1-C20 heterohydrocarbyl may be selected from substituted or unsubstituted C1-C20 alkoxy, substituted or unsubstituted C2-C20 alkenyloxy, and substituted or unsubstituted C2-C20 alkynyloxy.

[0048] In a preferred case, R2 and R3 are each independently selected from substituted or unsubstituted C6 to C20 aryl, substituted or unsubstituted C7 to C20 aralkyl, and substituted or unsubstituted C7 to C20 alkylaryl, or R2 and R3 together form a ring to form alkylene.

[0049] In formula (I), -L nindicates that n L groups are linked to the metal M. The n Ls may be the same or different and may each be selected from halogen, C1-C10 hydrocarbyl, and C1-C10 hydrocarbyloxy, where n is an integer satisfying the M valence state. Here, the C1-C10 hydrocarbyl may be selected from substituted or unsubstituted C1-C10 alkyl, substituted or unsubstituted C2-C10 alkenyl, substituted or unsubstituted C2-C10 alkynyl, substituted or unsubstituted C6-C10 aryl, substituted or unsubstituted C7-C10 aralkyl, and substituted or unsubstituted C7-C10 alkylaryl, and the C1-C10 hydrocarbyloxy may be selected from substituted or unsubstituted C1-C10 alkoxy, substituted or unsubstituted C2-C10 alkenyloxy, and substituted or unsubstituted C2-C10 alkynyloxy. The halogen here may be selected from fluorine, chlorine, bromine and iodine, but is most preferably bromine.

[0050] In the present invention, the alkyl may be a straight chain alkyl, a branched alkyl, or a cycloalkyl, and the alkoxy may be a straight chain alkoxy, a branched alkoxy, or a cycloalkoxy.

[0051] In the present invention, the term "substituted" in "substituted or unsubstituted" means including a substituent, and the substituent here may be selected from, for example, halogen, hydroxy, C1-C6 alkyl, halogenated C1-C6 alkyl, C1-C6 alkoxy, and halogenated C1-C6 alkoxy.

[0052] In the present invention, alkyl (e.g., C1-16 alkyl, C1-C20 alkyl, or C1-C30 alkyl) may be selected from, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, n-pentyl, isopentyl, n-hexyl, isohexyl, and 3,3-dimethylbutyl.

[0053] In the present invention, alkoxy (e.g., C1-C10 alkoxy, C1-C20 alkoxy, C1-C30 alkoxy) may be selected from, for example, methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, n-pentyloxy, isopentyloxy, n-hexyloxy, isohexyloxy, and 3,3-dimethylbutoxy.

[0054] In the present invention, aryl (eg, C6-C10 aryl, C6-C20 aryl, C6-C30 aryl) may be selected from, for example, phenyl, 4-methylphenyl, 4-ethylphenyl, dimethylphenyl, and vinylphenyl.

[0055] In the present invention, the halogen is selected from fluorine, chlorine, bromine, and iodine.

[0056] The above-mentioned late transition metal catalysts are commercially available or can be prepared according to conventional methods in the art. Specific preparation methods can be found in patent applications CN111116787A, CN112745362A, CN114478868A, and references such as Polymers 2018, 10, 2073-4360, Macromolecules 2014, 47, 3325-3331, Angew. Chem., Int. Ed. 2004, 43, 1821-1825, and J. Am. Chem. Soc. 2014, 136, 7213-7216. The relevant contents of the above-mentioned references are incorporated herein by reference, but will not be described in detail here.

[0057] In the present invention, the co-catalyst may be selected from a wide range. In a preferred embodiment of the present invention, the co-catalyst is at least one selected from organoaluminum compounds and organoboron compounds.

[0058] In the present invention, the organoaluminum compound may be one or more selected from alkylaluminumoxanes, alkylaluminums, and alkylaluminum halides. Specific examples of the organoaluminum compound include at least one selected from trimethylaluminum, triethylaluminum, triisobutylaluminum, tri-n-hexylaluminum, trioctylaluminum, diethylaluminum hydride, diisobutylaluminum hydride, diethylaluminum chloride, diisobutylaluminum chloride, ethylaluminum sesquichloride, ethylaluminum dichloride, methylaluminoxane (MAO), and modified methylaluminoxane (MMAO), but are not limited thereto. In a relatively preferred embodiment, the organoaluminum compound is at least one selected from MAO, MMAO, diethylaluminum chloride, ethylaluminum dichloride, and ethylaluminum sesquichloride.

[0059] In the present invention, the organic boron compound may be at least one selected from aromatic hydrocarbyl boron compounds and borate salts. Specific examples of the organic boron compound may include, but are not limited to, at least one selected from tris(pentafluorophenyl)borane, N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate, and trityl tetrakis(pentafluorophenyl)borate.

[0060] In the present invention, the chain transfer agent may be a dialkyl zinc. Specific examples of the dialkyl zinc include, but are not limited to, at least one selected from diethyl zinc, di(n-propyl) zinc, and di(n-octyl) zinc. When a chain transfer agent such as dialkyl zinc (particularly diethyl zinc) is added in the reaction process, the thickening efficiency of the prepared α-olefin polymer can be further improved.

[0061] In some preferred embodiments, when the polymerization reaction process includes two reaction stages and the reaction temperatures and / or α-olefin monomer concentrations of the two reaction stages are different, the polymerization reaction time of each reaction stage may be appropriately adjusted depending on the catalyst system used. For example, when the cocatalyst is methylaluminoxane (MAO), modified methylaluminoxane (MMAO), ethylaluminum sesquichloride, arylborane, etc., the reaction time in the low-concentration or low-temperature reaction stage is preferably 5 min to 2 h, more preferably 10 min to 1 h, and the reaction time in the high-concentration or high-temperature reaction stage is preferably 3 min to 1 h, more preferably 5 min to 30 min. When the co-catalyst is trimethylaluminum, triethylaluminum, triisobutylaluminum, tri-n-hexylaluminum, trioctylaluminum, diethylaluminum hydride, diisobutylaluminum hydride, diethylaluminum chloride, diisobutylaluminum chloride, ethylaluminum dichloride, or the like, the reaction time in the low-concentration or low-temperature reaction step is preferably 10 min to 48 h, more preferably 30 min to 18 h, and in the high-concentration or high-temperature reaction step, the reaction time is preferably 10 min to 24 h, more preferably 20 min to 2 h.

[0062] In the present invention, when the co-catalyst is an organoaluminum compound, the molar ratio of aluminum in the co-catalyst to M in the main catalyst is (10 to 10 7 ):1 (e.g., 10:1, 20:1, 50:1, 100:1, 200:1, 300:1, 500:1, 700:1, 800:1, 1000:1, 2000:1, 3000:1, 5000:1, 10000:1, 1000000:1, 10000000:1, and any value therebetween), but is preferably (10-100000):1, and more preferably (100-10000):1.

[0063] In the present invention, when the co-catalyst is an organoboron compound and an organoaluminum compound, the molar ratio of boron in the co-catalyst to M in the main catalyst may be (0.1 to 1000):1, (for example, 0.1:1, 0.2:1, 0.5:1, 1:1, 2:1, 3:1, 5:1, 8:1, 10:1, 20:1, 50:1, 100:1, 200:1, 300:1, 500:1, 700:1, 800:1, 1000:1, and any value therebetween, preferably (0.1 to 500):1. The molar ratio of organoaluminum to M in the main catalyst may be (10 to 10 5 ):1, for example, 10:1, 20:1, 50:1, 100:1, 200:1, 300:1, 400:1, 500:1, 600:1, 700:1, 800:1, 1000:1, 2000:1, 3000:1, 5000:1, 10000:1, 100000:1, and any value therebetween), but is preferably (10-5000):1, and more preferably (10-1000):1.

[0064] In the present invention, the molar amount of the α-olefin monomer used relative to 1 mole of the main catalyst can be selected from a wide range, and in a relatively preferred embodiment, the molar amount of the α-olefin monomer used relative to 1 mole of the main catalyst may be 100 to 30,000 moles, specifically, for example, 100, 500, 1,000, 5,000, 10,000, 20,000, or 30,000 moles.

[0065] In the present invention, the polymerization reaction may be carried out in an inert solvent, or bulk polymerization may be carried out in an olefin without using an inert solvent. When a solvent is used, the solvent is preferably at least one selected from unsubstituted or halogen-substituted aromatic hydrocarbons (e.g., toluene, xylene, chlorobenzene) and unsubstituted or halogen-substituted C5 to C20 saturated hydrocarbons (e.g., n-butane, isobutane, n-pentane, n-hexane, cyclohexane, n-heptane, octane, decane, heptane dichloromethane, 1,2-dichloroethane, and 1,1,2,2-tetrachloroethane). More preferably, the solvent contains an unsubstituted or halogen-substituted aromatic hydrocarbon, and most preferably contains at least one of toluene, xylene, and chlorobenzene.

[0066] In the present invention, an additional solvent may or may not be added (i.e., the amount of solvent used is 0). When no additional solvent is added, the added α-olefin monomer itself can function as a solvent. In the present invention, the volumetric amount of the solvent used per volumetric amount of α-olefin monomer can be selected from a wide range, but in a more preferred embodiment, the volumetric amount of the solvent used per volumetric amount of α-olefin monomer is 0 to 200 volumes, preferably 0 to 100 volumes, and more preferably 0.5 to 50 volumes.

[0067] In the present invention, the carbon number of the α-olefin monomer may be 4 to 20, preferably 4 to 12. The α-olefin monomer may be a linear or branched α-olefin. In a preferred case, the α-olefin monomer may be at least one selected from 1-butene, 2-methyl-1-butene, 3,3-dimethyl-1-butene, 1-pentene, 1-pentene having one or more methyl, ethyl, or propyl substitutions, 1-hexene, 1-hexene having one or more methyl, ethyl, or propyl substitutions, 1-heptene, 1-heptene having one or more methyl, ethyl, or propyl substitutions, 1-octene having one or more methyl, ethyl, or propyl substitutions, 1-nonene, 1-decene, and 1-dodecene. More preferably, the α-olefin monomer is at least one selected from 1-butene, 2-methyl-1-butene, 3,3-dimethyl-1-butene, 1-pentene, 1-pentene having one or more methyl, ethyl, propyl substitutions, 1-hexene, 1-hexene having one or more methyl, ethyl, propyl substitutions, 1-heptene, and 1-heptene having one or more methyl, ethyl, propyl substitutions, i.e., an α-olefin monomer preferably having less than 8 carbon atoms.

[0068] In the method for preparing an α-olefin polymer according to the present invention, the polymer solution obtained by the polymerization reaction may be post-treated. The post-treatment method can be carried out by conventional means in the art. In some embodiments, the post-treatment method comprises adding an ethanolic hydrochloric acid solution to the polymer solution to deactivate the active centers.

[0069] The present invention also provides the use of the α-olefin polymer as a viscosity index improver, particularly as a viscosity index improver for lubricating oils. When the α-olefin polymer is used as a viscosity index improver, the α-olefin polymer of the present invention has a significantly higher thickening efficiency than conventional olefin polymers. Specifically, when measured according to the method described in Appendix A of SH / T 0622-2007, the thickening efficiency of the α-olefin polymer of the present invention is 2 to 15 mm. 2 / s, preferably 3 to 10 mm 2 / s.

[0070] The present invention provides a lubricating oil containing a base oil and the α-olefin polymer, wherein the α-olefin polymer functions as a viscosity index improver.

[0071] The content of the α-olefin polymer in the lubricating oil can be determined according to the content of viscosity index improvers in conventional lubricating oils. In a preferred case, the content of the α-olefin polymer is 0.01 to 20 wt.%, preferably 0.5 to 10 wt.%, based on the total weight of the lubricating oil.

[0072] The method for applying the α-olefin polymer to a lubricating oil may be a conventional method in the art. Generally, the α-olefin polymer is mixed with a base oil of the lubricating oil at a certain ratio. The mixing temperature and heating time can be adjusted depending on the specific mixing conditions, but the mixture is usually stirred at 110 to 130°C for 3 to 4 hours.

[0073] In the present invention, the base oil may be any conventional lubricating base oil in the art, and typically may be one or more of Class I, II, III, IV and V base oils according to the American Petroleum Institute API classification.

[0074] The α-olefin polymers according to the present invention, as well as their preparation methods and uses, are further illustrated below with examples.The examples are carried out on the premise of the technical solutions of the present invention, and provide detailed implementation methods and specific operation processes, but the protection scope of the present invention is not limited to the following examples.

[0075] The experimental methods in the following examples are conventional in the art unless otherwise specified. Unless otherwise specified, all experimental materials used in the following examples are commercially available.

[0076] In the following examples and comparative examples, the weight average molecular weight M of the olefin polymer w and molecular weight distribution PDI is measured by gel permeation chromatography-infrared detector (GPC-IR).

[0077] The degree of branching of the olefin polymer is determined by gel permeation chromatography-infrared detection (GPC-IR).

[0078] The abundance (molar percentage content) of each unit and the main chain carbon ratio are detected and calculated based on the NMR carbon spectrum.

[0079] The melting point of the olefin polymer is measured by differential scanning calorimetry (DSC).

[0080] The thickening efficiency of olefin polymers used as viscosity index improvers for lubricating oils is determined according to the method in Appendix A of SH / T 0622-2007, where the concentration of the polymer is 1% and the kinematic viscosity of the base oil used is 5.8912 mm at 100°C. 2 / s, 29.6238 mm at 40°C 2 / s.

[0081] When the olefin polymer is used as a viscosity index improver for lubricating oil, the viscosity index is calculated in accordance with GB / T1995-1998.

[0082] Preparation Example 1 The process for preparing the complex of formula A is as follows:

[0083] Using paratoluenesulfonic acid as a catalyst, 0.87 g of acenaphthenequinone and 1.9 mL of 2,6-diisopropylaniline were refluxed in 100 mL of toluene for 24 hours, cooled to room temperature, the solvent was removed in vacuo, and the product was separated by column chromatography to obtain the ligand L. A obtained.

[0084] A dichloromethane solution containing 0.23 g of (DME)NiBr2 was used as the ligand L A The mixture was slowly added dropwise to a dichloromethane solution containing 0.50 g of methyl methyl acrylate, stirred at room temperature for 6 hours, and then precipitated with anhydrous ethyl ether. After filtration, the filter cake was washed with anhydrous ethyl ether and dried under vacuum to obtain the complex represented by formula A.

[0085] [ka]

[0086] Preparation Example 2 The process for preparing the complex of formula B is as follows:

[0087] Using paratoluenesulfonic acid as a catalyst, 1.14 g of 9,10-dihydro-9,10-ethyleneanthracene-11,12-dione and 1.9 mL of 2,6-diisopropylaniline were refluxed in 100 mL of toluene for 24 hours, cooled to room temperature, the solvent was removed under vacuum, and the product was separated by column chromatography to obtain the ligand L. B obtained.

[0088] A dichloromethane solution containing 0.23 g of (DME)NiBr2 was used as the ligand L B The mixture was slowly added dropwise to a dichloromethane solution containing 0.45 g of methyl methylpropional, stirred at room temperature for 6 hours, and then precipitated with anhydrous ethyl ether. After filtration, the filter cake was washed with anhydrous ethyl ether and dried under vacuum to obtain the complex represented by formula B.

[0089] [ka]

[0090] Preparation Example 3 The process for preparing the complex of formula C is as follows:

[0091] An ethanol solution containing 0.23 g of (DME)NiBr2 was added as ligand L A The mixture was slowly added dropwise to a dichloromethane solution containing 0.50 g of methyl methyl acrylate, stirred at room temperature for 6 hours, and then precipitated with anhydrous ethyl ether. After filtration, the filter cake was washed with anhydrous ethyl ether and dried under vacuum to obtain the complex represented by formula C.

[0092] [ka]

[0093] Preparation Example 4 The process for preparing the complex of formula D is as follows:

[0094] 3.0 g of compound D (represented by the formula below), 4 mL of 2,6-diisopropylaniline, and paratoluenesulfonic acid as a catalyst were refluxed in 100 mL of toluene for 24 hours, filtered to remove the solvent, the residue was dissolved in dichloromethane, passed through a basic alumina column, and rinsed with petroleum ether / ethyl acetate (20:1). The second fraction was the product, and the solvent was removed to obtain ligand L. D obtained.

[0095] A dichloromethane solution containing 0.50 g of (DME)NiBr2 was used as the ligand L D The mixture was stirred at room temperature for 6 hours to separate out and precipitate, which was then filtered, washed with ethyl ether, and dried to obtain a complex represented by formula D.

[0096] [ka]

[0097] Example 1 A 250 mL reaction flask was heated to 100°C for 2 hours, evacuated while still hot, and purged with nitrogen three times. 7 mg of the complex of formula A was added, followed by 30 mL of toluene using a syringe and thorough stirring to dissolve. 10 mL of 1-hexene was then added, followed by 1.8 mL of a 1.53 mol / L toluene solution of methylaluminoxane, and then 2 mL of a 1.0 mol / L hexane solution of diethylzinc. The reaction temperature was maintained at 30°C and the polymerization reaction was carried out for 60 minutes. After that, the reaction was quenched using a 10% by volume ethanol solution of hydrochloric acid, precipitated with ethanol, washed, vacuum dried, and the polymer product was obtained.

[0098] Example 2 A 250 mL reaction flask was heated to 100°C for 2 hours, evacuated while still hot, and purged with nitrogen three times. 7 mg of the complex represented by formula A was added, followed by 20 mL of toluene using a syringe and thorough stirring to dissolve. 20 mL of 1-hexene was then added, followed by 3 mL of a 0.4 mol / L hexane solution of ethylaluminum sesquichloride, and then 0.5 mL of a 1.0 mol / L hexane solution of diethylzinc. The reaction temperature was maintained at 30°C and the polymerization reaction was carried out for 20 minutes. After that, the reaction was quenched using a 10% vol. solution of hydrochloric acid in ethanol, precipitated with ethanol, washed, vacuum dried, and the polymer product was obtained.

[0099] Example 3 A 250 mL reaction flask was heated to 100°C for 2 hours, evacuated while still hot, and purged with nitrogen three times. 7 mg of the complex represented by formula A was added, followed by 20 mL of toluene using a syringe and thorough stirring to dissolve. 7 mL of 1-hexene was then added, followed by 3 mL of a 0.4 mol / L hexane solution of ethyl aluminum sesquichloride. The reaction temperature was maintained at 30°C and the polymerization reaction was carried out for 10 minutes. After that, the reaction was quenched using a 10% by volume ethanol solution of hydrochloric acid, precipitated with ethanol, washed, and vacuum dried to obtain the polymer product.

[0100] Example 4 A 250 mL reaction flask was heated to 100°C for 2 hours, evacuated while still hot, and purged with nitrogen three times. 7 mg of the complex represented by formula A was added, followed by 30 mL of dichloromethane added via syringe and thoroughly stirred to dissolve. 20 mL of 1-hexene was then added, followed by 2 mL of a 0.4 mol / L hexane solution of ethylaluminum sesquichloride and 25 mg of tris(pentafluorophenyl)borane. 0.2 mL of a 1.0 mol / L hexane solution of diethylzinc was then added. The reaction temperature was maintained at 30°C and the polymerization reaction was carried out for 10 minutes. After that, the reaction was quenched using a 10% vol. solution of hydrochloric acid in ethanol, precipitated with ethanol, washed, vacuum dried, and the polymer product was obtained.

[0101] Example 5 Material A consisted of 24 mg of the complex represented by formula B and 39 mL of chlorobenzene; material B consisted of 30 mL of 1-hexene, 6 mL of a 1.53 mol / L methylaluminoxane toluene solution, and 3 mL of chlorobenzene; and material C consisted of 0.8 mL of a 1.0 mol / L diethylzinc hexane solution, 30 mL of 1-hexene, and 47.2 mL of chlorobenzene. Materials A and B were each injected into two pipelines thoroughly purged with nitrogen at a flow rate of 0.25 mL / min and mixed in a T-type mixer placed in an oil bath at 0 °C. The mixed materials were immediately mixed with material C in T-type mixer 2 placed in an oil bath at 0 °C, where material C was injected into the pipeline at a flow rate of 0.5 mL / min. The mixed solution of materials A, B, and C was then poured into a 28.7 m long pipeline placed in an oil bath at 0 °C. The reactants at the outlet of the pipeline were dropped into a 10% by volume solution of hydrochloric acid in ethanol, precipitated with ethanol, washed, and vacuum dried to obtain the polymer product. All of the pipelines used were polytetrafluoroethylene (PTFE) pipelines with an inner diameter of 2 mm.

[0102] Example 6 A 250 mL reaction flask was heated to 100°C for 2 hours, evacuated while still hot, and purged with nitrogen three times. 7 mg of the complex of formula A was added, followed by 15 mL of toluene and 5 mL of hexane via syringe. The mixture was thoroughly stirred to dissolve, and 11 mL of 1-pentene was added. Next, 3 mL of a 0.4 mol / L hexane solution of ethylaluminum sesquichloride was added, followed by 0.5 mL of a 1.0 mol / L hexane solution of diethylzinc. The reaction temperature was maintained at 20°C and the polymerization reaction was carried out for 30 minutes. After that, the reaction was quenched using a 10% vol. solution of hydrochloric acid in ethanol, precipitated with ethanol, washed, and dried in vacuo to obtain the polymer product.

[0103] Example 7 A 250 mL reaction flask was heated to 100°C for 2 hours, evacuated while still hot, and purged with nitrogen three times. 7 mg of the complex of formula A was added, followed by 20 mL of toluene via syringe and thorough stirring to dissolve. 13.5 mL of 1-hexene was then added, followed by 3 mL of a 0.4 mol / L hexane solution of ethylaluminum sesquichloride, and then 0.25 mL of a 1.0 mol / L hexane solution of diethylzinc. The reaction temperature was maintained at 50°C and the polymerization reaction was carried out for 20 minutes. After that, the reaction was quenched using a 10% (volume) solution of hydrochloric acid in ethanol, precipitated with ethanol, washed, and dried in vacuo to obtain the polymer product.

[0104] Example 8 A 250 mL reaction flask was heated to 100°C for 2 hours, evacuated while still hot, and purged with nitrogen three times. 7 mg of the complex of formula A was added, followed by 10 mL of toluene via syringe and thorough stirring to dissolve. 30 mL of 1-octene was then added, followed by 5 mL of a 0.4 mol / L hexane solution of ethylaluminum sesquichloride, and then 0.5 mL of a 1.0 mol / L hexane solution of diethylzinc. The reaction temperature was maintained at 50°C and the polymerization reaction was carried out for 10 minutes. After that, the reaction was quenched using a 10% vol. solution of hydrochloric acid in ethanol, precipitated with ethanol, washed, and vacuum dried to obtain the polymer product.

[0105] Example 9 A 250 mL reaction flask was heated to 100°C for 2 hours, evacuated while still hot, and purged with nitrogen three times. 7 mg of the complex of formula A was added, followed by 30 mL of toluene via syringe and thorough stirring to dissolve. 14 mL of 1-decene was then added, followed by 2 mL of a 1.53 mol / L methylaluminoxane toluene solution, and then 0.2 mL of a 1.0 mol / L diethylzinc hexane solution. The reaction temperature was maintained at 55°C and the polymerization reaction was carried out for 10 minutes. After that, the reaction was quenched using a 10% by volume solution of hydrochloric acid in ethanol, precipitated with ethanol, washed, and dried in vacuo to obtain the polymer product.

[0106] Example 10 Material A consisted of 22.5 mL of 1-octene and 7.5 mL of a 0.4 mol / L ethylaluminum sesquichloride hexane solution. Material B consisted of 50 mg of the complex represented by formula C, 22.5 mL of toluene, and 7.5 mL of 1-octene. Material C consisted of 0.5 mL of a 1.0 mol / L diethylzinc hexane solution, 26.5 mL of 1-octene, and 32 mL of toluene. Materials A and B were injected into two pipelines thoroughly purged with nitrogen at a flow rate of 0.666 mL / min and mixed in T-type mixer 1 placed in an oil bath at 30°C. After mixing, materials A and B were immediately mixed with material C in T-type mixer 2 placed in an oil bath at 30°C. Material C was then injected into the pipelines at a flow rate of 1.333 mL / min. Next, the mixed solution of materials A, B, and C was poured into pipeline T1, a 30-m-long pipe placed in a 30°C oil bath, and then injected into pipeline T2, a 20-m-long pipe placed in a 55°C oil bath. The reactants at the outlet of T2 were added dropwise to a 10% by volume hydrochloric acid ethanol solution, washed by precipitation with ethanol, and vacuum dried to obtain the polymer product. All pipelines used were PTFE pipelines with an inner diameter of 1 mm. The polymer had a branching degree of 72 and was a diblock polymer with a melting point of 55.4°C.

[0107] Example 11 Material A consisted of 7 mg of the complex represented by formula A and 15 mL of toluene; Material B consisted of 6.3 mL of 1-decene, 3 mL of 0.4 mol / L ethylaluminum sesquichloride hexane solution, and 5.7 mL of toluene; and Material C consisted of 20 mL of 1-decene. Materials A and B were injected into two pipelines thoroughly purged with nitrogen at a flow rate of 0.268 mL / min and mixed in a T-type mixer 1 placed in an oil bath at 15°C. The mixed solution of materials A and B was then introduced into pipeline T1, a 20.5 m long pipeline placed in an oil bath at 15°C. Next, material C was mixed with the mixed solution in a T-type mixer 2 placed in an oil bath at 15°C, where it was injected into the pipeline at a flow rate of 0.358 mL / min. The mixed solution of materials A, B, and C was then introduced into pipeline T2, a 5.7 m long pipeline placed in an oil bath at 15°C. The reactant at the outlet of T2 was dropped into a 10% by volume solution of hydrochloric acid in ethanol, precipitated with ethanol, washed, and vacuum dried to obtain the polymer product. All the pipelines used were PTFE pipelines with an inner diameter of 1 mm. The branching degree of the polymer was 61, and the polymer was a diblock polymer.

[0108] Example 12 Material A consisted of 9 mg of the complex represented by formula D and 30 mL of toluene; Material B consisted of 12.6 mL of 1-decene, 6 mL of a 0.4 mol / L hexane solution of ethylaluminum sesquichloride, and 11.4 mL of toluene; and Material C consisted of 40 mL of 1-hexene. Materials A and B were injected into two pipelines thoroughly purged with nitrogen at a flow rate of 0.287 mL / min and mixed in T-type mixer 1 placed in an oil bath at 15°C. The mixed solution of materials A and B was then placed in pipeline T1, a 21.9 m long pipe fitted with an SK-type spiral mixing core, placed in an oil bath at 15°C. Material C was then mixed with the mixture in T-type mixer 2, which was also placed in an oil bath at 15°C. Material C was then injected into the pipeline at a flow rate of 0.383 mL / min. Next, the mixed solution of materials A, B, and C was poured into pipeline T2, a 6.1-m-long pipe filled with an SK-type spiral mixing core, placed in an oil bath at 15°C. The reactants at the outlet of T2 were added dropwise to a 10% by volume solution of hydrochloric acid in ethanol, washed by precipitation with ethanol, and vacuum-dried to obtain the polymer product. All pipelines used were stainless steel pipelines with an inner diameter of 1 mm. The polymer had a branching degree of 71 and was a diblock polymer with a melting point of 45.3°C.

[0109] Example 13 A 250 mL reaction flask was heated to 100°C for 2 hours, evacuated while still hot, and purged with nitrogen three times. 7 mg of the complex represented by Formula A was added, followed by 20 mL of toluene via syringe and thorough stirring to dissolve. 7.5 mL of 1-hexene was then added, followed by 3 mL of a 0.4 mol / L hexane solution of ethylaluminum sesquichloride, and then 0.3 mL of a 1.0 mol / L hexane solution of diethylzinc. The reaction temperature was maintained at 30°C and the polymerization reaction was allowed to proceed for 30 minutes. After that, a small amount of the sample was withdrawn via syringe and precipitated in ethanol. The resulting polymer sample was characterized for its branching degree of 110. The reaction flask was then transferred to a 55°C environment and the reaction was continued for 20 minutes. The reaction was quenched using a 10% (volume) hydrochloric acid ethanol solution, precipitated with ethanol, washed, and vacuum dried to obtain the polymer product. The branching degree was 95, and the polymer was a diblock polymer with a melting point of -22°C.

[0110] Example 14 A 250 mL reaction flask was heated to 100°C for 2 hours, evacuated while still hot, and purged with nitrogen three times. 7 mg of the complex represented by Formula A was added, followed by 15 mL of toluene via syringe and thorough stirring to dissolve. 6 mL of 1-hexene was then added, followed by 3 mL of a 1.53 mol / L methylaluminoxane toluene solution, and then 0.3 mL of a 1 mol / L diethylzinc hexane solution. The reaction temperature was maintained at 35°C and the polymerization reaction was continued for 20 minutes. After that, a small amount of the sample was withdrawn via syringe and precipitated in ethanol. The resulting polymer sample was characterized as having a branching degree of 111. 40 mL of toluene was then added, and the reaction was continued for 60 minutes. The reaction was quenched using a 10% (volume) hydrochloric acid ethanol solution, precipitated with ethanol, washed, and vacuum dried to obtain the polymer product. The branching degree was 86, and the polymer was a diblock polymer.

[0111] Example 15 A 250 mL reaction flask was heated to 100°C for 2 hours, evacuated while still hot, and purged with nitrogen three times. 7 mg of the complex represented by Formula A was added, followed by 10 mL of toluene via syringe and thorough stirring to dissolve. 10 mL of 1-octene was then added, followed by 1 mL of a 2 mol / L hexane solution of diethylaluminum chloride. The reaction temperature was maintained at 25°C and the polymerization reaction was allowed to proceed for 10 minutes. A small amount of the sample was withdrawn via syringe and precipitated in ethanol. The resulting polymer sample was characterized for its degree of branching of 74. The reaction flask was then transferred to a 50°C environment and the reaction continued for 10 minutes. The reaction was quenched using a 10% (volume) hydrochloric acid ethanol solution, precipitated with ethanol, washed, and vacuum dried to obtain the polymer product. The degree of branching was 64, and the polymer was a diblock polymer with a melting point of 54.4°C.

[0112] Example 16 A 250 mL reaction flask was heated to 100°C for 2 hours, evacuated while still hot, and purged with nitrogen three times. 7 mg of the complex represented by Formula A was added, followed by 15 mL of toluene via syringe and thorough stirring to dissolve. 6 mL of 1-hexene was then added, followed by 3 mL of a 1.53 mol / L toluene solution of methylaluminoxane, followed by 0.3 mL of a 1 mol / L hexane solution of diethylzinc. The reaction temperature was maintained at 35°C and the polymerization reaction was continued for 15 minutes. 40 mL of toluene was then added, and the reaction was continued for 60 minutes. Next, 18 mL of 1-hexene was added, and the reaction was continued for 15 minutes. The reaction was quenched using a 10% (volume) hydrochloric acid ethanol solution, precipitated with ethanol, washed, and vacuum dried to obtain the polymer product. The polymer was a triblock polymer.

[0113] Comparative Example 1 A 100 mL reaction flask was heated to dryness at 100°C for 2 hours, evacuated while still hot, and purged with nitrogen three times. 10 mg of the metallocene catalyst PhC(Cp)(Flu)ZrCl (purchased from APAC Pharmaceutical) was added, followed by the addition of 15 mL of 1-hexene and 2 mL of a 1.53 mol / L toluene solution of methylaluminoxane via syringe. The reaction was allowed to proceed at 25°C for 1 hour. The reaction was quenched using a 10% by volume ethanol solution of hydrochloric acid, precipitated, washed with ethanol, and vacuum dried to obtain the polymer product.

[0114] Comparative Example 2 A 100 mL reaction flask was heated to dryness at 100°C for 2 hours, evacuated while still hot, and purged with nitrogen three times. 10 mg of the metallocene catalyst PhC(Cp)(Flu)ZrCl was added, followed by 15 mL of 1-hexene and 2 mL of a 1.53 mol / L toluene solution of methylaluminoxane via syringe. The reaction was allowed to proceed at 25°C for 2 hours. The reaction was quenched using a 10% by volume ethanol solution of hydrochloric acid, precipitated, washed with ethanol, and vacuum dried to obtain the polymer product.

[0115] Comparative Example 3 A 100 mL reaction flask was heated to 100°C for 2 hours, evacuated while still hot, and purged with nitrogen three times. 10 mg of the metallocene catalyst PhC(Cp)(Flu)ZrCl was added, followed by 15 mL of 1-hexene and 2 mL of a 1.53 mol / L methylaluminoxane toluene solution via syringe. The reaction was continued at 25°C for 1 hour, the temperature was raised to 55°C, and the reaction was continued for 1 hour. The reaction was quenched using a 10% by volume solution of hydrochloric acid in ethanol, precipitated with ethanol, washed, and vacuum dried to obtain the polymer product.

[0116] Comparative Example 4 A 100 mL reaction flask was heated to 100°C for 2 hours, evacuated while still hot, and purged with nitrogen three times. 10 mg of the metallocene catalyst PhC(Cp)(Flu)ZrCl was added, followed by 15 mL of 1-hexene and 2 mL of a 1.53 mol / L toluene solution of methylaluminoxane. The mixture was then reacted at 25°C for 1 hour. 5 mL of 1-decene was added and the reaction was continued for 1 hour. The reaction was quenched using a 10% (volume) solution of hydrochloric acid in ethanol, precipitated with ethanol, washed, and vacuum-dried to obtain the polymer product.

[0117] Comparative Example 5 A 250 mL reaction flask was heated to 100°C for 2 hours, evacuated while still hot, and purged with nitrogen three times. 7 mg of the complex of formula A was added, followed by 30 mL of toluene via syringe and thorough stirring to dissolve. 10 mL of 1-hexene was then added, followed by 2.8 mL of a 1.53 mol / L toluene solution of methylaluminoxane. The reaction temperature was maintained at -10°C and the polymerization reaction was carried out for 40 minutes. After that, the reaction was quenched using a 10% by volume ethanol solution of hydrochloric acid, precipitated with ethanol, washed, and vacuum dried to obtain the polymer product.

[0118] Application Examples 1 to 16 and Application Comparative Examples 1 to 5 The olefin polymers prepared in the above examples and comparative examples were added to lubricating base oil 150SN, stirred at 120°C for about 2 hours to completely dissolve, and then the thickening efficiency was measured. The results are shown in Table 1 below.

[0119] [Table 1]

[0120] The results in Table 1 show that the α-olefin polymer of the present invention has excellent viscosity-increasing efficiency as a viscosity index improver for lubricating oil.

[0121] Although the preferred embodiments of the present invention have been described in detail above, the present invention is not limited thereto. Within the scope of the technical concept of the present invention, multiple simple modifications can be made to the technical solutions of the present invention, including combining each technical feature in any other suitable manner, and these simple modifications and combinations should also be considered as the disclosure content of the present invention, and all fall within the protection scope of the present invention.

Claims

1. CH of at least one α-olefin monomer ２ = an α-olefin polymer formed by CHR polymerization, In the α-olefin polymer, the carbon atoms located in the main chain account for 58 to 87% of all carbon atoms, and R is a linear or branched alkyl having two or more carbon atoms; the weight average molecular weight of the α-olefin polymer is 10,000 to 250,000, preferably 25,000 to 150,000, and more preferably 30,000 to 120,000; The molecular weight distribution (PDI) of the α-olefin polymer is less than 3, preferably 2 or less; The α-olefin polymer is a diblock polymer AB or a triblock polymer ABA, and the degree of branching of the A block is greater than the degree of branching of the B block.

2. The α-olefin polymer comprises a first unit —(CH ２ ) - and the second unit -CH(CH ３ 2. The α-olefin polymer of claim 1, comprising: first units -CH(R)- and third units -CH(R)-, wherein the first units are present in an amount of 77% or more and the third units are present in an amount of 18% or less, based on the total main chain carbon atoms in the α-olefin polymer.

3. 3. The α-olefin polymer according to claim 1, wherein the carbon atoms located in the main chain account for 63 to 82% of the total carbon atoms.

4. The α-olefin polymer according to claim 3, wherein, based on the total main chain carbon atoms in the α-olefin polymer, the amount of the first units present is 80 to 95%, the amount of the second units present is 1 to 10%, and the amount of the third units present is 2 to 12%.

5. the α-olefin monomer is a linear or branched α-olefin having 4 to 20 carbon atoms; The α-olefin polymer according to any one of claims 1 to 4, wherein the α-olefin monomer is at least one selected from 1-butene, 2-methyl-1-butene, 3,3-dimethyl-1-butene, 1-pentene, 1-pentene having one or more methyl, ethyl, and propyl substitutions, 1-hexene, 1-hexene having one or more methyl, ethyl, and propyl substitutions, 1-heptene, 1-heptene having one or more methyl, ethyl, and propyl substitutions, 1-octene having one or more methyl, ethyl, and propyl substitutions, 1-nonene, 1-decene, and 1-dodecene.

6. 10. A method for preparing the α-olefin polymer of claim 1, comprising: The method includes a step of polymerizing an α-olefin monomer having 4 or more carbon atoms in the presence of a main catalyst, a cocatalyst, an optional chain shuttling agent, and an optional solvent, wherein the main catalyst is a late transition metal catalyst having a diimine ligand; The polymerization process includes at least two reaction stages, A method for forming a diblock polymer A-B or a triblock polymer A-B-A by controlling the reaction temperature and / or the concentration of α-olefin monomer in each reaction step, or forming a diblock polymer A-B or a triblock polymer A-B-A by controlling the type of α-olefin monomer in each reaction step.

7. 7. The method according to claim 6, wherein controlling the reaction temperature of each reaction stage comprises making the absolute value of the difference in polymerization reaction temperature between two adjacent reaction stages 10° C. or more, preferably 20° C. or more.

8. 7. The method of claim 6, wherein controlling the concentration of α-olefin monomer in each reaction stage comprises having a ratio of the concentrations of α-olefin monomer in two adjacent reaction stages greater than 3.

9. The method according to claim 6, wherein the type of α-olefin monomer in each reaction step is controlled such that the carbon number of the α-olefin monomer added in the latter reaction step of two adjacent reaction steps is smaller than the carbon number of the α-olefin monomer added in the former reaction step.

10. The method according to any one of claims 6 to 9, wherein the reaction temperature of the polymerization reaction is -40°C to 100°C, preferably 0°C to 70°C, and the concentration of the α-olefin monomer is 0.05 mol / L or more.

11. 11. The method according to any one of claims 6 to 10, wherein the main catalyst is a metal complex of formula (I): 【Chemical 1】 (wherein M is a Group VIII metal, and R １ , and R ４ are the same or different and are each independently selected from C1 to C30 hydrocarbyl, or heterohydrocarbyl, and R １ , and R ４ may optionally form a ring with each other, and R ２ , and R ３ are the same or different and are each independently selected from hydrogen, halogen, and C1 to C20 hydrocarbyl or heterohydrocarbyl, and R ２ , and R ３ optionally form a ring together, n L's are the same or different and are each selected from halogen, C1-C10 hydrocarbyl, and C1-C10 hydrocarbyloxy, and n is an integer that satisfies the M valence state; Preferably, M is selected from nickel and palladium; Preferably, R １ , and R ４ are each independently selected from substituted or unsubstituted C1 to C20 alkyl and substituted or unsubstituted C6 to C20 aryl, more preferably R １ , and R ４ are each a group represented by formula II. 【Chemistry 2】 (In formula (II), R １ ~R ５ are the same or different and are each independently selected from hydrogen, halogen, hydroxy, and substituted or unsubstituted C1 to C30 hydrocarbyl or heterohydrocarbyl, and R １ ~R ５ are optionally joined together to form a ring, and more preferably, in formula (II), R １ , and R ３ are each independently selected from substituted or unsubstituted C3 to C10 alkyl or heterohydrocarbyl.

12. the co-catalyst is at least one selected from an organoaluminum compound and an organoboron compound; Preferably, the organoaluminum compound is one or more selected from alkylaluminoxanes, alkylaluminums, and alkylaluminum halides; The method according to any one of claims 6 to 11, wherein the organoboron compound is at least one selected from aromatic hydrocarbyl boron compounds and borate salts.

13. the chain shuttling agent is a dialkyl zinc; The method according to claim 6, wherein the dialkyl zinc is at least one selected from diethyl zinc, di(n-propyl) zinc, and di(n-octyl) zinc.

14. When the co-catalyst is an organoaluminum compound, the molar ratio of aluminum in the co-catalyst to M in the main catalyst is (10 to 10 ７ ):1, preferably (10-100000):1, more preferably (100-10000):1, When the co-catalyst is an organic boron compound and an organic aluminum compound, the molar ratio of boron in the co-catalyst to M in the main catalyst is (0.1 to 1000):1, preferably (0.1 to 500):1, and the molar ratio of organoaluminum to M in the main catalyst is (10 to 10 ５ ):1, preferably (10-5000):1, more preferably (10-1000):1; Preferably, the molar amount of the α-olefin monomer used relative to 1 mole of the main catalyst is 100 to 30,000 moles, The method according to any one of claims 6 to 13, characterized in that the volumetric amount of the solvent used is preferably 0 to 200 volumes, preferably 0 to 100 volumes, more preferably 0.5 to 50 volumes, relative to 1 volume of the α-olefin monomer.

15. The method according to any one of claims 6 to 14, wherein the solvent is at least one selected from unsubstituted or halogen-substituted aromatic hydrocarbons and unsubstituted or halogen-substituted C5 to C20 saturated hydrocarbons, preferably an unsubstituted or halogen-substituted aromatic hydrocarbon, and more preferably at least one of toluene, xylene, and chlorobenzene.

16. the α-olefin monomer has 4 to 20 carbon atoms, preferably 4 to 12 carbon atoms; Preferably, the α-olefin monomer is a linear or branched α-olefin; More preferably, the α-olefin monomer is at least one selected from 1-butene, 2-methyl-1-butene, 3,3-dimethyl-1-butene, 1-pentene, 1-pentene having one or more methyl, ethyl, propyl substitutions, 1-hexene, 1-hexene having one or more methyl, ethyl, propyl substitutions, 1-heptene, 1-heptene having one or more methyl, ethyl, propyl substitutions, 1-octene having one or more methyl, ethyl, propyl substitutions, 1-nonene, 1-decene, and 1-dodecene.

17. Use of the α-olefin polymer according to any one of claims 1 to 5 as a viscosity index improver.

18. A lubricating oil, The lubricating oil comprises a base oil and the α-olefin polymer according to any one of claims 1 to 5, Preferably, the content of the α-olefin polymer is 0.01 to 20 wt. %, preferably 0.5 to 10 wt. %, based on the total weight of the lubricating oil.

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