A catalyst, polyalphaolefin (PAO) and method for preparing the same

Abstract

The application discloses a catalyst, poly-alpha-olefin PAO and a preparation method thereof, relates to the technical field of poly-alpha-olefin PAO, and aims to solve the problem of small molecular weight of the poly-alpha-olefin PAO. The poly-alpha-olefin PAO has a viscosity-average molecular weight in the range of 6.5 million g / mol to 20 million g / mol. And / or, the poly-alpha-olefin PAO has an activity in the range of 800 g PAO / g Cat to 2500 g PAO / g Cat; and can be applied to pipeline drag reduction of oil products.

Description

Technical Field

[0001] This application relates to the field of polyalphaolefin (PAO) technology, and more particularly to a catalyst, polyalphaolefin (PAO) and its preparation method. Background Technology

[0002] High molecular weight polyalphaolefin (PAO) is a major component of oil drag reducers. PAO with a viscosity-average molecular weight exceeding 5 million g / mol can significantly reduce frictional resistance and improve the pipeline's elastic transport capacity during oil pipeline transportation. PAO drag reducers are generally composed of homopolymers or copolymers of olefins such as 1-hexene, 1-octene, 1-decene, and 1-dodecene.

[0003] Coal-derived hydrocarbon mixtures are high in α-olefins (containing over 45% C5 and above), diverse in type, and almost entirely free of aromatics. These coal-derived mixed hydrocarbons are byproducts of the Fischer-Tropsch reaction in coal-to-oil production, and are produced in large quantities. They can provide abundant raw materials for PAO drag reducer production while simultaneously increasing the added value of coal-to-oil products.

[0004] However, PAO prepared from coal-to-hydrocarbon mixtures has a relatively small molecular weight, making it difficult to meet the requirements for drag reduction in oil pipelines. Summary of the Invention

[0005] The purpose of this application is to provide a catalyst, poly-α-olefin (PAO), and a method for preparing the same.

[0006] To achieve the above objectives, this application adopts the following technical solution: In a first aspect, this application provides a polyalphaolefin (PAO). The viscosity-average molecular weight of the PAO ranges from 6.5 million g / mol to 20 million g / mol. And / or, the activity range of the PAO is from 800 gPAO / gCat to 2500 gPAO / gCat.

[0007] The polyalphaolefin (PAO) provided in this application has a high viscosity index and relatively stable performance, making it suitable for reducing drag in oil pipelines and ensuring economical and efficient oil transportation.

[0008] In some embodiments, the viscosity-average molecular weight of the poly-α-olefin (PAO) ranges from 6.5 million g / mol to 15.5 million g / mol, or from 12 million g / mol to 15.1 million g / mol.

[0009] In some embodiments, the activity range of the poly-α-olefin PAO is 840gPAO / gCat to 2200gPAO / gCat, or 1500gPAO / gCat to 2200gPAO / gCat.

[0010] Secondly, this application provides a method for preparing poly-α-olefin (PAO). The method for preparing PAO includes: mixing a coal-to-hydrocarbon mixture containing α-olefins with a main catalyst and a co-catalyst to carry out a polymerization reaction to obtain the PAO. The main catalyst includes a MgCl2-supported TiCl4-type Ziegler-Natta catalyst, wherein the MgCl2-supported TiCl4-type Ziegler-Natta catalyst contains an internal electron donor with the following structure: ; R1 and R2 are each independently selected from substituted or unsubstituted alkyl, substituted or unsubstituted cycloalkyl, or substituted or unsubstituted aryl groups; the term "substituted or unsubstituted" means unsubstituted or substituted by one or more groups selected from those that do not participate in and interfere with the polymerization reaction.

[0011] In some embodiments, R1 and R2 are each independently selected from substituted or unsubstituted C2-C. 10 Alkyl, substituted or unsubstituted C3-C 10 cycloalkyl, or substituted or unsubstituted C6-C 10 Aryl.

[0012] In some embodiments, the term "substituted or unsubstituted" means unsubstituted or substituted with one or more groups selected from alkyl and aryl groups.

[0013] In some embodiments, the term "substituted or unsubstituted" means unsubstituted or selected from C1-C6 alkyl and C6-C6 alkyl groups. 10 One or more groups in the aryl group are substituted.

[0014] In some embodiments, the internal electron donor is selected from any one of diisopropyl 2,3-diisopropyl-2-cyanosuccinate, diisobutyl 2,3-diisopropyl-2-cyanosuccinate, isopropylphenyl 2,3-diisopropyl-2-cyanosuccinate, dibutyl 2,3-diisopropyl-2-cyanosuccinate, cyclohexyl isopropyl 2,3-diisopropyl-2-cyanosuccinate, and cyclopentyl isobutyl 2,3-diisopropyl-2-cyanosuccinate.

[0015] In some embodiments, the MgCl2-supported TiCl4-type Ziegler-Natta catalyst and the internal electron donor are in solid form.

[0016] In some embodiments, the reactants of the reaction further include a molecular weight regulator.

[0017] Preferably, the molecular weight regulator is hydrogen.

[0018] In some embodiments, the viscosity-average molecular weight of the poly-α-olefin (PAO) ranges from 6.5 million g / mol to 20 million g / mol, 6.5 million g / mol to 15.5 million g / mol, or 12 million g / mol to 15.1 million g / mol.

[0019] The activity range of the poly-α-olefin PAO is 800gPAO / gCat~2500gPAO / gCat, 840gPAO / gCat~2200gPAO / gCat, or 1500gPAO / gCat~2200gPAO / gCat.

[0020] In some embodiments, the cocatalyst has the structure (R3). m Al alkylaluminum or with the structure (R3) n AlX (3-n) Alkyl aluminum halide; wherein R3 is a C1-C8 alkyl or C3-C8 cycloalkyl; X is a halogen; m is 3; n is an integer from 1 to 3.

[0021] In some embodiments, the co-catalyst is one or more of trimethylaluminum, triethylaluminum, diethylaluminum chloride, ethylaluminum dichloride, triisobutylaluminum, tri-n-hexylaluminum, and tri-n-octylaluminum.

[0022] In some embodiments, the co-catalyst is at least one of triethylaluminum, triisobutylaluminum, tri-n-hexylaluminum, or tri-n-octylaluminum.

[0023] In some embodiments, the reactants of the reaction optionally include an external electron donor.

[0024] In some embodiments, the reactants of the reaction further include: silane-based external electron donors.

[0025] In some embodiments, the reactants of the reaction further include those with the structural formula (R4). t Si(OR5) 4-t The silane-based external electron donor; wherein R4 and R5 are each independently selected from substituted or unsubstituted saturated or unsaturated groups; the substituted or unsubstituted means substituted or unsubstituted by one or more substituents selected from heteroatoms or C1-C4 alkyl groups; the value of t is an integer from 0 to 4.

[0026] Preferably, R4 is selected from C1-C 10 Alkyl, C2-C 10 alkenyl, C3-C 10 cycloalkyl, C3-C 10Cycloalkenyl, C6-C 10 Any of the aryl groups.

[0027] Preferably, R4 is selected from substituted or unsubstituted C1-C. 10 Alkyl or C6-C 10 Aryl.

[0028] Preferably, R5 is selected from substituted or unsubstituted methyl, ethyl, n-propyl or isopropyl.

[0029] Preferably, t is 1 or 2.

[0030] In some embodiments, the titanium content in the main catalyst is 1 wt% to 4.5 wt%.

[0031] In some embodiments, the titanium content in the main catalyst is 2.0 wt% to 3.5 wt%.

[0032] In some embodiments, the molar ratio of Al in the co-catalyst to Ti in the main catalyst ranges from 50 to 1000.

[0033] In some embodiments, the molar ratio of Al in the co-catalyst to Ti in the main catalyst ranges from 100 to 500.

[0034] In some embodiments, the molar ratio of Si in the external electron donor to Ti in the main catalyst ranges from 0 to 30.

[0035] In some embodiments, the temperature range of the polymerization reaction is -40°C to 50°C.

[0036] In some embodiments, the temperature range of the polymerization reaction is -30°C to 0°C.

[0037] In some embodiments, the polymerization reaction time ranges from 0.5 hours to 50 hours.

[0038] In some embodiments, the polymerization reaction takes place over a period of 6 to 30 hours.

[0039] In some embodiments, the coal-to-hydrocarbon mixture contains C7-C. 15 Olefins and optional C7-C 15 Alkanes; based on the molar amount of the coal-derived hydrocarbon mixture, C7-C 15 The molar content of α-olefins is 60 mol% to 97 mol%.

[0040] In some embodiments, the coal-to-hydrocarbon mixture consists of C7-C 15 Olefin composition.

[0041] In some embodiments, the pure product of the coal-to-hydrocarbon mixture has an ultraviolet absorbance of less than 0.5 / cm in the 250nm~300nm wavelength range and a moisture content of less than 10ppm.

[0042] In some embodiments, the preparation method of the polyα-olefin PAO further includes: at a temperature of 100℃ to 200℃, 10 -5 ~10 3 Vacuum distillation is performed under a vacuum of Pa to remove unreacted hydrocarbon compounds.

[0043] Thirdly, this application provides a catalyst. The catalyst comprises: a MgCl2-supported TiCl4-type Ziegler-Natta catalyst. The MgCl2-supported TiCl4-type Ziegler-Natta catalyst contains an internal electron donor with the following structure: ; R1 and R2 are each independently selected from substituted or unsubstituted alkyl, substituted or unsubstituted cycloalkyl, or substituted or unsubstituted aryl groups; the term "substituted or unsubstituted" means unsubstituted or substituted by one or more groups selected from those that do not participate in and interfere with the polymerization reaction.

[0044] In some embodiments, the internal electron donor is selected from any one of diisopropyl 2,3-diisopropyl-2-cyanosuccinate, diisobutyl 2,3-diisopropyl-2-cyanosuccinate, isopropylphenyl 2,3-diisopropyl-2-cyanosuccinate, dibutyl 2,3-diisopropyl-2-cyanosuccinate, cyclohexyl isopropyl 2,3-diisopropyl-2-cyanosuccinate, and cyclopentyl isobutyl 2,3-diisopropyl-2-cyanosuccinate.

[0045] In some embodiments, the MgCl2-supported TiCl4-type Ziegler-Natta catalyst and the internal electron donor are in solid form.

[0046] In some embodiments, the content of internal electron donors in the MgCl2-supported TiCl4 type Ziegler-Natta catalyst is 0.5 wt% to 10.0 wt%.

[0047] Fourthly, this application provides a polyα-olefin (PAO). The PAO is prepared by the method described in any one of the above embodiments; or, the PAO is prepared via an olefin polymerization reaction using the catalyst described in the above embodiments. Attached Figure Description

[0048] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0049] Figure 1 A flowchart of a method for preparing poly-α-olefin (PAO) is provided for embodiments of this application. Detailed Implementation

[0050] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0051] In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0052] In embodiments of this application, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, article, or apparatus that includes that element.

[0053] In the embodiments of this application, the terms "exemplary" or "for example" are used to indicate that something is an example, illustration, or description. Any embodiment or design that is described as "exemplary" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or design. Specifically, the use of the terms "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.

[0054] An embodiment of this application provides a polyalphaolefin (PAO) with a viscosity-average molecular weight ranging from 6.5 million g / mol to 20 million g / mol.

[0055] In some embodiments, the viscosity-average molecular weight of polyalphaolefin (PAO) ranges from 6.5 million g / mol to 15.5 million g / mol.

[0056] In some embodiments, the viscosity-average molecular weight of polyalphaolefin (PAO) ranges from 12 million g / mol to 15.1 million g / mol.

[0057] For example, the viscosity-average molecular weight of polyalphaolefin (PAO) can be 6.5 million g / mol, 6.54 million g / mol, 7 million g / mol, 7.12 million g / mol, 7.5 million g / mol, 8 million g / mol, 8.66 million g / mol, 9 million g / mol, 9.5 million g / mol, 10 million g / mol, 10.5 million g / mol, 11 million g / mol, 11.5 million g / mol, 12 million g / mol, 12.5 million g / mol, 12.94 million g / mol, 13.5 million g / mol, 14 million g / mol, 14.5 million g / mol, 15.5 million g / mol, or 15.1 million g / mol, etc., and there is no limitation here.

[0058] Here, the viscosity-average molecular weight of polyalphaolefin (PAO) is measured using the Ubbelohde viscosity method.

[0059] In this application, the viscosity-average molecular weight test method for polyalphaolefin (PAO) includes: dissolving approximately 5 mg to 10 mg of PAO sample completely in 100 mL of cyclohexane or toluene, testing the pure solvent first at 30°C, and then placing the sample in the solvent to test the viscosity-average molecular weight.

[0060] Based on the relationship between the viscosity of poly(α-olefin) (PAO) solutions and the relative molecular weight of the polymer, the viscosity-average relative molecular mass of polymers can be determined using the Mark-Houwink formula: Where k and α are Mark-Houwink constants, and in toluene k = 4.14 × 10⁻⁶. -4 mL / g, α=0.625, [η] is the intrinsic viscosity; the intrinsic viscosity can be obtained according to the following formulas (1) to (3):

[0061]

[0062]

[0063] Where, η sp η0 represents the specific viscosity; η0 is the solvent viscosity, η is the polymer solution viscosity, and η is the specific viscosity. r ρ is the relative viscosity; A is the instrument constant; ρ is the polymer density; t and t0 represent the outflow time of the solution and the pure solvent, respectively.

[0064] In some embodiments, the activity range of polyalphaolefin (PAO) is 800 g PAO / g Cat to 2500 g PAO / g Cat.

[0065] In some embodiments, the activity range of polyalphaolefin (PAO) is 840 g PAO / g Cat to 2200 g PAO / g Cat.

[0066] In some embodiments, the activity range of polyalphaolefin (PAO) is 1900 gPAO / gCat to 2200 gPAO / gCat.

[0067] For example, the activity of polyalphaolefin (PAO) can be 800 gPAO / gCat, 846 gPAO / gCat, 900 gPAO / gCat, 1000 gPAO / gCat, 1100 gPAO / gCat, 1200 gPAO / gCat, 1300 gPAO / gCat, 1400 gPAO / gCat, 1500 gPAO / gCat, 1600 gPAO / gCat, 1700 gPAO / gCat, 1745 gPAO / gCat, 1784 gPAO / gCat, 1923 gPAO / gCat, 2015 gPAO / gCat, 2149 gPAO / gCat, or 2200 gPAO / gCat, etc., and there is no limitation here.

[0068] Understandably, the aforementioned polyalphaolefin (PAO) has a high viscosity index and relatively stable properties, making it suitable for reducing drag in oil pipelines and ensuring the economical and efficient transportation of oil products.

[0069] Embodiments of this application provide a method for preparing polyα-olefin (PAO). For example... Figure 1 As shown, the preparation method of poly-α-olefin PAO includes: S1.

[0070] S1: A coal-to-hydrocarbon mixture containing α-olefins is mixed with a main catalyst and a co-catalyst to carry out a polymerization reaction to obtain polyα-olefin (PAO).

[0071] The main catalysts include: MgCl2-supported TiCl4 type Ziegler-Natta catalyst.

[0072] MgCl2-supported TiCl4-type Ziegler-Natta catalysts contain internal electron donors with the following structure: ; R1 and R2 are each independently selected from substituted or unsubstituted alkyl, substituted or unsubstituted cycloalkyl, or substituted or unsubstituted aryl groups; the term "substituted or unsubstituted" means unsubstituted or substituted by one or more groups selected from those that do not participate in and interfere with the polymerization reaction.

[0073] Understandably, coal-derived hydrocarbons are rich in α-olefins (such as ethylene, propylene, and butene), and the raw materials for coal-derived hydrocarbons are widely available, which helps reduce production costs and improve the economics of the preparation process. In the domestic oil pipeline transportation sector, where cost reduction and efficiency improvement have become the mainstream trend, the polyα-olefin (PAO) prepared by the above method can significantly reduce raw material costs and the cost of PAO drag-reducing agents, better meeting current pipeline transportation needs.

[0074] The main catalyst is a MgCl2-supported TiCl4 Ziegler-Natta catalyst, which is a coordination polymerization catalyst with many active centers. It can promote the efficient polymerization of olefins and form high molecular chains. It can precisely control the chain growth process of α-olefin polymerization in coal-to-hydrocarbons. The co-catalyst can effectively activate the main catalyst. The two work together to realize the preparation of poly-α-olefin PAO with high controllability and stable performance of poly-α-olefin PAO products.

[0075] Meanwhile, the main catalyst contains an internal electron donor with a specific structure. This internal electron donor can selectively poison or passivate random active centers, while stabilizing and increasing isotactic active centers. The electron-donating ability of the internal electron donor mainly depends on the coordination of its polar groups with acidic sites on the MgCl2 support surface or with Ti active centers. Among them, the cyano group (-CN) has a strong electron-donating group, with a lone pair of electrons on its nitrogen atom and a highly polarizable triple bond structure. Introducing the cyano group can change the electron cloud distribution of the entire internal electron donor molecule, making its binding with the MgCl2 support stronger; and by introducing ester groups, the dispersion state of the internal electron donor on the surface of the main catalyst support can be optimized, thereby obtaining a more uniform distribution of active centers. Furthermore, through screening R1 and R2, the microenvironment of the catalytic center can be controlled, so that the polyalphaolefin (PAO) polymerized from the mixture has a more regular structure (or a specific degree of branching), resulting in better lubrication performance, a higher viscosity index, and more stable performance, making it suitable for oil pipeline drag reduction.

[0076] Furthermore, the introduction of molecular weight regulators allows for the flexible production of polyalphaolefin (PAO) of different viscosity grades (different molecular weights) by adjusting the amount of regulator used, while maintaining the catalyst system unchanged, to meet the needs of different application scenarios (such as gear oil, aviation lubricating oil, and lubricating grease base oil).

[0077] In some embodiments, R1 and R2 are each independently selected from substituted or unsubstituted C2-C. 10 Alkyl, substituted or unsubstituted C3-C 10 cycloalkyl, or substituted or unsubstituted C6-C 10 Aryl.

[0078] In yet another embodiment, the term "substituted or unsubstituted" means unsubstituted or substituted with one or more groups selected from alkyl and aryl groups.

[0079] In yet other embodiments, the term "substituted or unsubstituted" refers to unsubstituted or substituted compounds selected from C1-C6 alkyl and C6-C6 alkyl groups. 10 One or more groups in the aryl group are substituted.

[0080] In some embodiments, the MgCl2-supported TiCl4 type Ziegler-Natta catalyst and the internal electron donor are in solid form.

[0081] In some embodiments, the reactants of the reaction also include a molecular weight regulator.

[0082] Preferably, the molecular weight regulator is hydrogen.

[0083] Understandably, hydrogen can be used to form saturated chain ends during polymerization, which significantly improves the oxidative stability and thermal stability of polyalphaolefin (PAO) products, meeting the needs of high-end lubrication.

[0084] In some embodiments, the internal electron donor is selected from any one of diisopropyl 2,3-diisopropyl-2-cyanosuccinate, diisobutyl 2,3-diisopropyl-2-cyanosuccinate, isopropylphenyl 2,3-diisopropyl-2-cyanosuccinate, dibutyl 2,3-diisopropyl-2-cyanosuccinate, cyclohexyl isopropyl 2,3-diisopropyl-2-cyanosuccinate, and cyclopentyl isobutyl 2,3-diisopropyl-2-cyanosuccinate.

[0085] Understandably, the aforementioned solid components of the specific internal electron donor more effectively activate the Ti centers, enabling rapid chain growth to be initiated in the early stages of polymerization. Furthermore, while maintaining the stability of the active centers, it increases the compatibility of the main catalyst system with coal-to-hydrocarbons, thereby improving copolymerization efficiency. This further results in polyalphaolefin (PAO) products having better lubrication properties, higher viscosity index, and more stable performance.

[0086] In some embodiments, the cocatalyst has the structure (R3). m Al alkylaluminum or with the structure (R3) n AlX (3-n) Alkyl aluminum halide; wherein R3 is a C1-C8 alkyl or C3-C8 cycloalkyl; X is a halogen; m is 3; n is an integer from 1 to 3.

[0087] For example, the value of n can be 1, 2, or 3, etc.

[0088] In some embodiments, the co-catalyst is one or more of trimethylaluminum, triethylaluminum, diethylaluminum chloride, ethylaluminum dichloride, triisobutylaluminum, tri-n-hexylaluminum, and tri-n-octylaluminum.

[0089] In some embodiments, the co-catalyst is at least one of triethylaluminum, triisobutylaluminum, tri-n-hexylaluminum, or tri-n-octylaluminum.

[0090] For example, the co-catalyst can be trimethylaluminum, triethylaluminum, diethylaluminum chloride, ethylaluminum dichloride, triisobutylaluminum, tri-n-hexylaluminum, or tri-n-octylaluminum, and there is no limitation herein.

[0091] Understandably, co-catalysts such as alkylaluminum or alkylaluminum halide can alkylate and reduce the main catalyst, ensuring that the co-catalyst can effectively activate the main catalyst. Meanwhile, R3 is selected from C1-C8 alkyl groups, allowing for selection based on the characteristics of different alkyl groups to achieve the dual purpose of ensuring activation efficiency while inhibiting chain transfer; and, when the co-catalyst is selected from alkylaluminum halide, the halogenated group helps stabilize the active center and promotes the coordination of olefin monomers.

[0092] Furthermore, there is an interaction between the main catalyst and the co-catalyst. By selecting a suitable alkyl group, the main catalyst can be flexibly activated, forming a favorable microenvironment around the active center, which is beneficial for realizing poly-α-olefin PAO.

[0093] In some embodiments, the reactants of the reaction optionally include an external electron donor.

[0094] In some embodiments, the reactants of the reaction further include: silane-based external electron donors.

[0095] In some embodiments, the reactants of the reaction further include those with the structural formula (R4). t Si(OR5) 4-t The silane-based external electron donor; wherein R4 and R5 are each independently selected from substituted or unsubstituted saturated or unsaturated groups; substituted or unsubstituted means substituted or unsubstituted by one or more substituents selected from heteroatoms or C1-C4 alkyl groups; the value of t is an integer from 0 to 4.

[0096] For example, the heteroatom can be a halogen, S, N, or O.

[0097] Preferably, R4 is selected from C1-C 10 Alkyl, C2-C 10 alkenyl, C3-C 10 cycloalkyl, C3-C 10 Cycloalkenyl, C6-C 10 Any of the aryl groups.

[0098] Preferably, R4 is selected from substituted or unsubstituted C1-C. 10 Alkyl or C6-C 10 Aryl.

[0099] Preferably, R5 is selected from substituted or unsubstituted methyl, ethyl, n-propyl or isopropyl.

[0100] For example, the value of t can be 0, 1, 2, 3 or 4.

[0101] Preferably, t is 1 or 2.

[0102] Understandably, external electron donors further optimize and supplement the binary system of main catalyst and co-catalyst. Silane-based external electron donors can selectively coordinate with co-catalysts or main catalysts. This is because the solid components of the internal electron donors in the main catalyst have already modified some active centers during the catalyst preparation stage. However, during polymerization, some active centers may undergo structural changes or be exposed due to the effect of alkyl aluminum. The additional silane external electron donors can further modify the non-selective active centers that the solid components of the internal electron donors in the main catalyst fail to cover or that are newly generated during polymerization. They can also undergo reversible complexation reactions with alkyl aluminum to adjust the concentration of free alkyl aluminum in the system, thereby mitigating non-selective chain transfer reactions that may be caused by excessive alkyl aluminum.

[0103] Furthermore, R4 is selected from substituted or unsubstituted C1-C. 10 Alkyl or C6-C 10 Aryl, R5 is preferably a small molecule alkyl such as methyl or ethyl, and t is preferably 1 or 2, which can finely balance the polymerization activity and molecular weight, and optimize the polymerization effect for the specific composition of coal-to-olefins.

[0104] In some embodiments, the titanium content of the main catalyst is 1 wt% to 4.5 wt%.

[0105] In some embodiments, the titanium content of the main catalyst is 2.0 wt% to 3.5 wt%.

[0106] For example, the titanium content of the main catalyst can be 1.0wt%, 2.0wt%, 2.6wt%, 2.9wt%, 3.1wt%, 3.2wt%, 3.4wt%, 4wt%, or 4.5wt%, etc., and there is no limitation here.

[0107] Understandably, in MgCl2-supported TiCl4-type Ziegler-Natta catalysts, titanium (Ti) is the active center for the polymerization reaction. Controlling the titanium content to 1wt%–4.5wt% ensures a sufficiently high density of titanium atoms per unit mass of catalyst, providing ample active sites for the polymerization reaction. This results in a higher active center density during the preparation of poly-α-olefins (PAO), enabling the simultaneous initiation of more olefin molecular chains under the same conditions, thus improving the catalyst's polymerization activity (i.e., the amount of polymer produced per unit mass of catalyst) and achieving a higher product yield within a given time. Furthermore, a high titanium content (e.g., greater than 4.5wt%) may lead to overcrowding of active centers, triggering chain transfer; conversely, a low titanium content (e.g., less than 1wt%) may result in insufficient activity, failing to support the continued growth of polymer chains.

[0108] In this application, the method for determining the titanium content in the main catalyst includes steps (1) and (2).

[0109] (1) The titanium compound in the supported catalyst reacts with hydrogen peroxide to form a yellow complex, which exhibits maximum absorbance at a wavelength of 410 nm. At this wavelength, within a certain concentration range, the absorbance-concentration curve conforms to the Lambert-Beer law. A standard curve for titanium is plotted according to this law, and a linear equation is obtained through linear fitting: In this equation A Absorbance B The value represents the Ti element content, expressed in μg / mL.

[0110] (2) In an argon atmosphere, weigh 0.1000~0.2000g of catalyst into a conical flask, add 20mL of sulfuric acid (30%) to dissolve it, heat to ensure complete reaction, filter into a 50mL volumetric flask, and dilute to volume with sulfuric acid (10%), mixing thoroughly. Pipette 5mL of the above solution into a 25mL volumetric flask, dilute to volume with sulfuric acid (10%), and mix thoroughly. Using the blank solution as a reference solution, determine the absorbance using spectrophotometry (wavelength 410nm) on a 722S spectrophotometer. A Finally, the Ti element content (Y) in the catalyst is calculated using the following equation: .

[0111] In some embodiments, the molar ratio of Al in the co-catalyst to Ti in the main catalyst ranges from 50 to 1000.

[0112] In some embodiments, the molar ratio of Al in the co-catalyst to Ti in the main catalyst ranges from 100 to 500.

[0113] For example, the molar ratio of Al in the co-catalyst to Ti in the main catalyst can be 50, 200, 400, 500, 600, 700, 800, 900 or 1000, etc., and there is no limitation here.

[0114] Understandably, the above setup ensures that there are enough alkylaluminum molecules to activate each titanium active center, while avoiding the negative effects of excessive alkylaluminum or halogenated alkylaluminum.

[0115] In some embodiments, the molar ratio of Si in the external electron donor to Ti in the main catalyst ranges from 0 to 30.

[0116] For example, the molar ratio of Si in the external electron donor to Ti in the main catalyst can be 0, 5, 10, 15, 20, 25 or 30, etc., and there is no limitation here.

[0117] Understandably, the above setup can suppress non-selective centers that lead to chain transfer, enabling the molecular weight to reach ultra-high molecular weight levels while ensuring the activity of reactive centers. In summary, by setting the above two key molar ratios, the optimal ratio range for synergistic effect among the main catalyst (Ti), co-catalyst (Al), and external electron donor (Si) was formed, jointly constructing a highly efficient and durable chain growth environment, and ultimately successfully preparing poly-α-olefin PAO.

[0118] In some embodiments, the temperature range of the polymerization reaction is -40°C to 50°C.

[0119] In some embodiments, the temperature range of the polymerization reaction is -30°C to 0°C.

[0120] In some embodiments, the polymerization reaction occurs at a temperature range of -20°C.

[0121] For example, the reaction temperature can be -40℃, -30℃, -20℃, -10℃, 0℃, 10℃, 20℃, 30℃, 40℃ or 50℃, etc., and there is no limitation here.

[0122] In some embodiments, the polymerization reaction time ranges from 0.5 hours to 50 hours.

[0123] In some embodiments, the polymerization reaction time ranges from 6 hours to 30 hours.

[0124] In some embodiments, the polymerization reaction takes place over a period of 24 hours.

[0125] For example, the polymerization reaction time can be 0.5 hours, 6 hours, 10 hours, 15 hours, 20 hours, 24 hours, 30 hours, 35 hours, 40 hours, 45 hours or 50 hours, etc., and there is no limitation here.

[0126] Understandably, the above setup ensures the fluidity of the reaction system, allowing the polymer chains to grow continuously, thus ensuring the operability and basic activity of the reaction system; and provides sufficient time for the chain growth reaction of the polymerization reaction, enabling the molecular weight to reach ultra-high molecular weight through continuous accumulation.

[0127] In some embodiments, coal-to-hydrocarbon mixtures contain C7-C. 15 Olefins and optional C7-C 15 Alkanes; in molar amounts of coal-derived hydrocarbon mixtures, C7-C 15 The molar content of α-olefins is 60 mol% to 97 mol%.

[0128] In some embodiments, coal-to-hydrocarbon mixtures consist of C7-C 15 Olefin composition.

[0129] For example, the mass content of α-olefins can be 60 mol%, 70 mol%, 80 mol%, 90 mol%, or 97 mol%, and there is no limitation here.

[0130] Understandably, the raw material is a mixture of hydrocarbons from C7 to C15, that is, olefins with medium chain length are selected as polymerization monomers. After polymerization, the side chain length of α-olefins in this carbon number range is moderate, which can give the final PAO good low-temperature fluidity and provide a high viscosity index. It is an ideal raw material range for preparing high-performance lubricating oil base oil.

[0131] In Ziegler-Natta catalytic polymerization, only α-olefins (olefins with double bonds at the ends) can effectively insert into the active center for directional polymerization. The above-mentioned α-olefin content is beneficial for preparing poly-α-olefin PAO using coal-derived mixtures.

[0132] In some embodiments, the pure product of the coal-to-hydrocarbon mixture has an ultraviolet absorbance of less than 0.5 / cm in the 250nm~300nm wavelength range and a moisture content of less than 10ppm.

[0133] For example, the ultraviolet absorbance of a pure coal-derived hydrocarbon mixture in the 250nm~300nm wavelength range can be 0.5 / cm, 0.4 / cm, 0.3 / cm, 0.2 / cm or 0.1 / cm, etc., and there is no limitation here.

[0134] For example, the moisture content of a pure coal-to-hydrocarbon mixture in the 250nm~300nm wavelength range can be 10ppm, 8ppm, 6ppm, 4ppm, 2ppm or 1ppm, etc., and there is no limit here.

[0135] Setting the pure product of coal-derived hydrocarbon mixtures to have an ultraviolet absorbance of less than 0.5 / cm in the 250nm~300nm wavelength range and a moisture content of less than 10ppm ensures that the active centers can maintain their activity for a long time, which is beneficial to the continuous chain growth of PAO during the preparation of poly-α-olefin PAO.

[0136] In some embodiments, the preparation method of polyα-olefin (PAO) further includes: at a temperature of 100°C to 200°C, 10 -5 ~10 3 Vacuum distillation is performed under a vacuum of Pa to remove unreacted hydrocarbon compounds.

[0137] For example, the temperature can be 100℃, 120℃, 140℃, 160℃, 180℃ or 200℃, etc., and there is no limitation here.

[0138] For example, the vacuum level can be 10. -5 Pa, 10 -3 Pa, 10 -1 Pa, 1 Pa, 10 1 Pa or 10 3 Pa, etc., are not limited here.

[0139] Understandably, by controlling the temperature within the range of 100℃ to 200℃, thermal degradation or chain breakage of the synthesized polyalphaolefin (PAO) can be avoided during subsequent heat treatment; and by utilizing 10 -5 With a wide vacuum range of Pa to 10³ Pa, the boiling point of unreacted olefins and alkanes is significantly reduced, allowing them to be effectively vaporized and removed under mild conditions of 100℃ to 200℃. This achieves efficient separation, completely removes unreacted low-molecular-weight hydrocarbons, and greatly improves the purity, flash point, and viscosity index of PAO products, enabling them to meet the performance requirements of high-end lubricating oil base oils.

[0140] Embodiments of this application provide a catalyst comprising: a MgCl2-supported TiCl4-type Ziegler-Natta catalyst; the MgCl2-supported TiCl4-type Ziegler-Natta catalyst contains an internal electron donor with the following structure: ; R1 and R2 are each independently selected from substituted or unsubstituted alkyl, substituted or unsubstituted cycloalkyl, or substituted or unsubstituted aryl groups; the term "substituted or unsubstituted" means unsubstituted or substituted by one or more groups selected from those that do not participate in and interfere with the polymerization reaction.

[0141] In some embodiments, the preparation method of the above-mentioned MgCl2 supported TiCl4 type Ziegler-Natta catalyst includes: steps (1) to (2).

[0142] (1) Heat magnesium chloride and organic alcohol to react to form magnesium chloride alcohol; dissolve tetrabutyl titanate and internal electron donor in solvent to form a mixture, and add the mixture to magnesium chloride alcohol to react and obtain a mixed solution containing magnesium chloride.

[0143] (2) Add a mixed solution containing magnesium chloride to titanium tetrachloride, and then heat the reaction to obtain a MgCl2-supported TiCl4 type Ziegler-Natta catalyst.

[0144] In some embodiments, the internal electron donor is selected from any one of diisopropyl 2,3-diisopropyl-2-cyanosuccinate, diisobutyl 2,3-diisopropyl-2-cyanosuccinate, isopropylphenyl 2,3-diisopropyl-2-cyanosuccinate, diethyl 2,3-diisopropyl-2-cyanosuccinate, cyclohexyl isopropyl 2,3-diisopropyl-2-cyanosuccinate, and cyclopentyl isobutyl 2,3-diisopropyl-2-cyanosuccinate.

[0145] In some embodiments, the MgCl2-supported TiCl4 type Ziegler-Natta catalyst and the internal electron donor are in solid form.

[0146] In some embodiments, the content of internal electron donors in the MgCl2-supported TiCl4 type Ziegler-Natta catalyst is 0.5 wt% to 10.0 wt%.

[0147] For example, the content of the internal electron donor in the MgCl2-supported TiCl4 type Ziegler-Natta catalyst can be 0.5wt%, 2.0wt%, 4.0wt%, 6.0wt%, 8.0wt%, or 10.0wt%, etc., and there is no limitation here.

[0148] It is understood that the beneficial effects of the catalysts provided in the above embodiments of this application can be referred to the beneficial effects of the preparation method of poly-α-olefin PAO described above, and will not be repeated here.

[0149] Fourthly, embodiments of this application provide a polyalphaolefin (PAO). The PAO is prepared by any of the methods described in the above embodiments; or, the PAO is prepared via an olefin polymerization reaction using the catalyst described in the above embodiments.

[0150] It is understood that the beneficial effects of the poly-α-olefin PAO provided in the above embodiments of this application can be referred to the beneficial effects of the preparation method of poly-α-olefin PAO described above, and will not be repeated here.

[0151] Experimental Example The technical solution of this application will be further illustrated below through specific embodiments and comparative examples.

[0152] Example 1 Example 1 provides a method for preparing poly-α-olefin (PAO), comprising: (1) Catalyst preparation: 4.94 g of anhydrous magnesium chloride, 18.9 g of isooctanol and 30 mL of n-decane were added to a dry three-necked flask purged with nitrogen. The mixture was stirred and heated to 130 °C, and the reaction was continued at this temperature for 2 h. At the same time, 1.5 mL of tetrabutyl titanate and 2 mL of diisobutyl 2,3-diisopropyl-2-cyanosuccinate were used as internal electron donors to prepare a 5 mL toluene solution, which was stirred at room temperature for half an hour. Then, the toluene solution was added to the magnesium chloride alcohol solution, and the reaction was continued at 130 °C for 1 h to obtain a mixed solution containing magnesium chloride. The mixed solution was cooled and slowly added dropwise to 200 mL of titanium tetrachloride at -20 °C, with mechanical stirring during the dropwise addition. After the dropwise addition was complete, the temperature was slowly raised to 110 °C, and about 1.2 mL of the internal electron donor compound was added. The reaction was continued for 2 h, the liquid phase was filtered off, and an equal amount of titanium tetrachloride was added to continue the reaction for 2 h. After the reaction was complete, the catalyst was thoroughly washed with hexane (50 mL × 5), dried under vacuum, sealed under a nitrogen atmosphere, and stored in a desiccator. The catalyst contained 3.4% titanium.

[0153] (2) Preparation of poly-α-olefin PAO: The 250 mL reaction flask equipped with a magnetic dome was replaced with nitrogen gas several times and placed in a -20 °C cold bath. Under nitrogen protection, 60 mL of mixed α-olefin C8-12 (α-olefin content of 91 mol%) and 2 mL of triethylaluminum hexane solution co-catalyst (concentration 1 mmol / mL) and 2 mL of cyclohexylmethyldimethoxysilane hexane solution (concentration 1 mmol / mL) were added sequentially. The mixture was stirred and matured thoroughly. Then, about 20 mg of the above main catalyst was added and stirred continuously at 300 rpm for 24 hours at this temperature. The reaction product was terminated with ethanol and dried under vacuum at 120 °C to remove unreacted monomers, resulting in solid PAO product. The polymer activity was obtained by formula (polymer mass / catalyst mass) and the activity was 1784.0 g PAO / g Cat. The viscosity-average molecular weight of PAO was 13.5 million g / mol.

[0154] Example 2 Example 2 provides a method for preparing poly-α-olefin (PAO), comprising: (1) Catalyst preparation: The preparation method is the same as in Example 1, except that the internal electron donor is 2,3-diisopropyl-2-cyanosuccinate diisopropyl ester; the catalyst has a titanium content of 2.6%.

[0155] (2) Preparation of poly-α-olefin PAO: The 250 mL reaction flask equipped with a magnetic dome was replaced with nitrogen gas several times and placed in a -20 °C cold bath. Under nitrogen protection, 60 mL of mixed α-olefin C9-11 and 3 mL of triisobutylaluminum hexane solution co-catalyst (concentration 1 mmol / mL) and 2 mL of cyclopentylmethyldimethoxysilane hexane solution (concentration 1 mmol / mL) were added sequentially. The mixture was stirred and matured thoroughly. Then, about 20 mg of the above main catalyst was added and stirred continuously at 300 rpm. The reaction was continued at this temperature for 24 hours. The reaction product was terminated with ethanol and dried under vacuum at 120 °C to remove unreacted monomers, resulting in solid PAO product. The polymer activity was obtained by formula (polymer mass / catalyst mass) and the activity was 2015 g PAO / g Cat. The viscosity-average molecular weight of PAO was 15.1 million g / mol.

[0156] Example 3 Example 3 provides a method for preparing poly-α-olefin (PAO), comprising: (1) Catalyst preparation: The preparation method is the same as in Example 1. The internal electron donor is 2,3-diisopropyl-2-cyanosuccinic acid phenyl isopropyl ester; the catalyst has a titanium content of 3.1%.

[0157] (2) Preparation of poly-α-olefin PAO: The 250 mL reaction flask equipped with a magnetic dome was replaced with nitrogen gas several times and placed in a -20 °C cold bath. Under nitrogen protection, 60 mL of mixed α-olefin C8-12 (α-olefin content of 89 mol%) and 3 mL of tri-n-octyl aluminum hexane solution co-catalyst (concentration 1 mmol / mL) and 2 mL of cyclopentylmethyl dimethoxysilane hexane solution (concentration 1 mmol / mL) were added sequentially. The mixture was stirred and matured thoroughly. Then, about 20 mg of the above main catalyst was added and stirred continuously at 300 rpm for 24 hours at this temperature. The reaction product was terminated with ethanol and dried under vacuum at 120 °C to remove unreacted monomers, resulting in solid PAO product. The polymer activity was obtained by formula (polymer mass / catalyst mass) and the activity was 2015 g PAO / g Cat. The viscosity-average molecular weight of PAO was 15.1 million g / mol.

[0158] Example 4 Example 4 provides a method for preparing poly-α-olefin (PAO), comprising: (1) Catalyst preparation: Same as in Example 1.

[0159] (2) Preparation of poly-α-olefin PAO: The 250 mL reaction flask equipped with a magnetic dome was replaced with nitrogen gas several times and placed in a -10℃ cold bath. Under nitrogen protection, 60 mL of 1-decene (α-olefin content of 95 mol%) and 2 mL of triisobutylaluminum hexane solution co-catalyst (concentration of 1 mmol / mL) and 2 mL of cyclopentylmethyldimethoxysilane hexane solution (concentration of 1 mmol / mL) were added in sequence. The mixture was stirred and matured thoroughly. Then, about 20 mg of the above main catalyst was added and stirred continuously at 300 rpm. The reaction was continued at this temperature for 24 hours. The reaction product was terminated with ethanol and dried under vacuum at 120℃ to remove unreacted monomers, resulting in solid PAO product. The polymer activity was obtained by formula (polymer mass / catalyst mass) and the activity was 1923 g PAO / g Cat. The viscosity-average molecular weight of PAO was 8.66 million g / mol.

[0160] Example 5 Example 5 provides a method for preparing poly-α-olefin (PAO), comprising: (1) Catalyst preparation: Same as in Example 3.

[0161] (2) Preparation of poly-α-olefin PAO: The 250 mL reaction flask equipped with a magnetic dome was replaced with nitrogen gas several times and placed in a 0 °C cold bath. Under nitrogen protection, 60 mL of 1-octene (α-olefin content of 96 mol%) and 2 mL of triisobutylaluminum hexane solution co-catalyst (concentration of 1 mmol / mL) and 1 mL of cyclopentylmethyldimethoxysilane hexane solution (concentration of 1 mmol / mL) were added sequentially. The mixture was stirred and matured thoroughly. Then, about 20 mg of the above main catalyst was added and stirred continuously at 300 rpm. The reaction was continued at this temperature for 24 hours. The reaction product was terminated with ethanol and dried under vacuum at 120 °C to remove unreacted monomers, resulting in solid PAO product. The polymer activity was obtained by formula (polymer mass / catalyst mass) and the activity was 2149 g PAO / g Cat. The viscosity-average molecular weight of PAO was 6.54 million g / mol.

[0162] Example 6 Example 6 provides a method for preparing poly-α-olefin (PAO), comprising: (1) Catalyst preparation: The preparation method is the same as in Example 1, except that the internal electron donor is diethyl 2,3-diisopropyl-2-cyanosuccinate and the catalyst has a titanium content of 2.9%.

[0163] (2) Preparation of poly-α-olefin PAO: The 250 mL reaction flask equipped with a magnetic dome was replaced with nitrogen gas several times and placed in a -30 °C cold bath. Under nitrogen protection, 60 mL of mixed α-olefin C8-12 (α-olefin content of 85 mol%) and 4 mL of tri-n-octyl aluminum hexane solution co-catalyst (concentration 1 mmol / mL) and 1 mL of cyclopentylmethyl dimethoxysilane hexane solution (concentration 1 mmol / mL) were added sequentially. The mixture was stirred and matured thoroughly. Then, about 20 mg of the above main catalyst was added and stirred continuously at 300 rpm for 24 hours at this temperature. The reaction product was terminated with ethanol and dried under vacuum at 120 °C to remove unreacted monomers, resulting in solid PAO product. The polymer activity was obtained by formula (polymer mass / catalyst mass) and the activity was 846 g PAO / g Cat. The viscosity-average molecular weight of PAO was 12.94 million g / mol.

[0164] Example 7 Example 7 provides a method for preparing poly-α-olefin (PAO), comprising: (1) Catalyst preparation: The preparation method is the same as in Example 1, except that the internal electron donor is dibutyl 2,3-diisopropyl-2-cyanosuccinate; the catalyst has a titanium content of 3.2%.

[0165] (2) Preparation of poly-α-olefin PAO: The 250 mL reaction flask equipped with a magnetic dome was replaced with nitrogen gas several times and placed in a 0 °C cold bath. Under nitrogen protection, 60 mL of mixed α-olefin C8-14 (α-olefin content of 90 mol%) and 3 mL of triisobutylaluminum hexane solution co-catalyst (concentration 1 mmol / mL) and 2 mL of cyclopentylmethyldimethoxysilane hexane solution (concentration 1 mmol / mL) were added in sequence. The mixture was stirred and matured thoroughly. Then, about 20 mg of the above main catalyst was added and stirred continuously at 300 rpm for 24 hours at this temperature. The reaction product was terminated with ethanol and dried under vacuum at 120 °C to remove unreacted monomers, resulting in solid PAO product. The polymer activity was obtained by formula (polymer mass / catalyst mass) and the activity was 1745 g PAO / g Cat. The viscosity-average molecular weight of PAO was 7.12 million g / mol.

[0166] Example 8 Example 8 provides a method for preparing poly-α-olefin (PAO), comprising: (1) Catalyst preparation: Same as in Example 1.

[0167] (2) Preparation of poly-α-olefin PAO: The 250 mL reaction flask equipped with a magnetic dome was replaced with nitrogen gas several times and placed in a -20 °C cold bath. Under nitrogen gas, 60 mL of mixed α-olefin C8-14 (α-olefin content of 90 mol%) and 3 mL of triisobutylaluminum hexane solution co-catalyst (concentration of 1 mmol / mL) and 2 mL of cyclopentylmethyldimethoxysilane hexane solution (concentration of 1 mmol / mL) were added in sequence. The mixture was stirred and matured thoroughly. Then, about 20 mg of the above main catalyst was added and 5 mmol of hydrogen gas was added. The mixture was stirred continuously at 300 rpm for 24 hours at this temperature. The reaction product was terminated with ethanol and dried under vacuum at 120 °C to remove unreacted monomers, resulting in solid PAO product. The polymer activity was obtained by formula (polymer mass / catalyst mass) and the activity was 2209 g PAO / g Cat. The viscosity-average molecular weight of PAO was 6.72 million g / mol.

[0168] Comparative Example 1 (1) Catalyst preparation: The preparation method is the same as in Example 1, except that the internal electron donor is 9,9-dimethoxyfluorene and the catalyst has a titanium content of 3.5%.

[0169] (2) Preparation of poly-α-olefin PAO: The 250 mL reaction flask equipped with a magnetic dome was replaced with nitrogen gas several times and placed in a 0 °C cold bath. Under nitrogen protection, 60 mL of mixed α-olefin C8-14 (α-olefin content of 90 mol%) and 3 mL of triisobutylaluminum hexane solution co-catalyst (concentration 1 mmol / mL) and 2 mL of cyclopentylmethyldimethoxysilane hexane solution (concentration 1 mmol / mL) were added in sequence. The mixture was stirred and matured thoroughly. Then, about 20 mg of the above main catalyst was added and stirred continuously at 300 rpm. The reaction was continued at this temperature for 24 hours. The reaction product was terminated with ethanol and dried under vacuum at 120 °C to remove unreacted monomers, resulting in solid PAO product. The polymer activity was obtained by formula (polymer mass / catalyst mass) and the activity was 2000 g PAO / g Cat. The viscosity-average molecular weight of PAO was 4.66 million g / mol.

[0170] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A poly-α-olefin (PAO), characterized in that, The viscosity-average molecular weight of the poly-α-olefin PAO ranges from 6.5 million g / mol to 20 million g / mol. And / or, the activity range of the poly-α-olefin PAO is 800gPAO / gCat to 2500gPAO / gCat.

2. The poly-α-olefin PAO according to claim 1, characterized in that, The viscosity-average molecular weight of the poly-α-olefin PAO is in the range of 6.5 million g / mol to 15.5 million g / mol, or 12 million g / mol to 15.1 million g / mol. And / or, the activity range of the poly-α-olefin PAO is 840gPAO / gCat to 2200gPAO / gCat, or 1500gPAO / gCat to 2200gPAO / gCat.

3. A method for preparing poly-α-olefin (PAO), characterized in that, include: A coal-to-hydrocarbon mixture containing α-olefins is mixed with a main catalyst and a co-catalyst to carry out a polymerization reaction to obtain the polyα-olefin PAO; The main catalyst includes a MgCl2-supported TiCl4-type Ziegler-Natta catalyst, wherein the MgCl2-supported TiCl4-type Ziegler-Natta catalyst contains an internal electron donor with the following structure: ； R1 and R2 are each independently selected from substituted or unsubstituted alkyl, substituted or unsubstituted cycloalkyl, or substituted or unsubstituted aryl groups; the term "substituted or unsubstituted" means unsubstituted or substituted by one or more groups selected from those that do not participate in and interfere with the polymerization reaction.

4. The method for preparing poly-α-olefin (PAO) according to claim 3, characterized in that, R1 and R2 are each independently selected from substituted or unsubstituted C2-C. 10 Alkyl, substituted or unsubstituted C3-C 10 cycloalkyl, or substituted or unsubstituted C6-C 10 Aryl; And / or, the term "substituted or unsubstituted" means unsubstituted or substituted with one or more groups selected from alkyl and aryl groups; Alternatively, the term "substituted or unsubstituted" refers to unsubstituted or substituted compounds selected from C1-C6 alkyl and C6-C6 alkyl groups. 10 One or more groups in the aryl group are substituted; Alternatively, the internal electron donor is selected from any one of diisopropyl 2,3-diisopropyl-2-cyanosuccinate, diisobutyl 2,3-diisopropyl-2-cyanosuccinate, isopropylphenyl 2,3-diisopropyl-2-cyanosuccinate, diethyl 2,3-diisopropyl-2-cyanosuccinate, cyclohexyl isopropyl 2,3-diisopropyl-2-cyanosuccinate, and cyclopentyl isobutyl 2,3-diisopropyl-2-cyanosuccinate. And / or, the reactants of the reaction further include a molecular weight regulator; preferably, the molecular weight regulator is hydrogen. And / or, the viscosity-average molecular weight range of the poly-α-olefin PAO is 6.5 million g / mol to 20 million g / mol, 6.5 million g / mol to 15.5 million g / mol, or 12 million g / mol to 15.1 million g / mol; The activity range of the PAO is 800gPAO / gCat~2500gPAO / gCat, 840gPAO / gCat~2200gPAO / gCat, or 1500gPAO / gCat~2200gPAO / gCat; And / or, the co-catalyst has the structure (R3). m Al alkylaluminum or with the structure (R3) n AlX (3-n) Alkyl aluminum halide; wherein R3 is a C1-C8 alkyl or C3-C8 cycloalkyl; X is a halogen; m is 3; n is an integer from 1 to 3; Alternatively, the co-catalyst may be one or more of trimethylaluminum, triethylaluminum, diethylaluminum chloride, ethylaluminum dichloride, triisobutylaluminum, tri-n-hexylaluminum, and tri-n-octylaluminum; Alternatively, the co-catalyst may be at least one of triethylaluminum, triisobutylaluminum, tri-n-hexylaluminum, or tri-n-octylaluminum.

5. The method for preparing poly-α-olefin (PAO) according to claim 3, characterized in that, The reactants in the reaction may optionally include an external electron donor; Alternatively, the reactants of the reaction may also include: silane-based external electron donors; Alternatively, the reactants of the reaction may also include those with the structural formula (R4). t Si(OR5) 4-t Silane-based external electron donors; wherein R4 and R5 are each independently selected from substituted or unsubstituted saturated or unsaturated groups; the substituted or unsubstituted refers to being substituted or unsubstituted by one or more substituents selected from heteroatoms or C1-C4 alkyl groups; the value of t is an integer ranging from 0 to 4; Preferably, R4 is selected from C1-C 10 Alkyl, C2-C 10 alkenyl, C3-C 10 cycloalkyl, C3-C 10 Cycloalkenyl, C6-C 10 Any of the aryl groups; Preferably, R4 is selected from substituted or unsubstituted C1-C. 10 Alkyl or C6-C 10 Aryl; Preferably, R5 is selected from substituted or unsubstituted methyl, ethyl, n-propyl, or isopropyl. Preferably, t is 1 or 2.

6. The method for preparing poly-α-olefin (PAO) according to claim 3, characterized in that, The titanium content in the main catalyst is 1 wt% to 4.5 wt%; or, the titanium content in the main catalyst is 2.0 wt% to 3.5 wt%. And / or, the molar ratio of Al in the co-catalyst to Ti in the main catalyst is in the range of 50 to 1000; or, the molar ratio of Al in the co-catalyst to Ti in the main catalyst is in the range of 100 to 500; And / or, the molar ratio of Si in the external electron donor to Ti in the main catalyst is in the range of 0 to 30.

7. The method for preparing poly-α-olefin (PAO) according to claim 3, characterized in that, The polymerization reaction temperature range is -40℃ to 50℃; or, the polymerization reaction temperature range is -30℃ to 0℃. And / or, the polymerization reaction time ranges from 0.5 hours to 50 hours; or, the polymerization reaction time ranges from 6 hours to 30 hours; And / or, the coal-to-hydrocarbon mixture contains C7-C 15 Olefins and optional C7-C 15 Alkanes; based on the molar amount of the coal-derived hydrocarbon mixture, C7-C 15 The molar content of α-olefins is 60 mol% to 97 mol%; or, the coal-to-hydrocarbon mixture is composed of C7-C... 15 Olefin composition; And / or, the pure product of the coal-to-hydrocarbon mixture has an ultraviolet absorbance of less than 0.5 / cm in the 250nm~300nm wavelength range and a moisture content of less than 10ppm; And / or, the method for preparing the poly-α-olefin PAO further includes: at a temperature of 100℃~200℃, 10 -5 ~10 3 Vacuum distillation is performed under a vacuum of Pa to remove unreacted hydrocarbon compounds.

8. A catalyst, characterized in that, The MgCl2-supported TiCl4-type Ziegler-Natta catalyst contains an internal electron donor with the following structure: ； R1 and R2 are each independently selected from substituted or unsubstituted alkyl, substituted or unsubstituted cycloalkyl, or substituted or unsubstituted aryl groups; the term "substituted or unsubstituted" means unsubstituted or substituted by one or more groups selected from those that do not participate in and interfere with the polymerization reaction.

9. The catalyst according to claim 8, characterized in that, The internal electron donor is selected from any one of 2,3-diisopropyl-2-cyanosuccinate, diisobutyl-2,3-diisopropyl-2-cyanosuccinate, isopropylphenyl-2,3-diisopropyl-2-cyanosuccinate, dibutyl-2,3-diisopropyl-2-cyanosuccinate, cyclohexylisopropyl-2,3-diisopropyl-2-cyanosuccinate, and cyclopentylisobutyl-2,3-diisopropyl-2-cyanosuccinate. And / or, the MgCl2-supported TiCl4-type Ziegler-Natta catalyst and the internal electron donor are in solid form; And / or, the content of internal electron donors in the MgCl2-supported TiCl4 type Ziegler-Natta catalyst is 0.5wt%~10.0wt%.

10. A poly-α-olefin (PAO), characterized in that, The poly-α-olefin PAO is prepared by the method of any one of claims 2 to 7; or, the poly-α-olefin PAO is prepared by olefin polymerization using the catalyst described in claim 8 or 9.

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