Imine-amine complex, double-imine-amine nickel complex, preparation method, nickel-based catalyst and application thereof

Abstract

The present invention provides an imine-amine complex, a double-ligand imine-amine nickel complex, a preparation method, a nickel-based catalyst, and applications. The imine-amine ligand compound has the structure shown in Formula III below; wherein R1 is a methyl group, a phenyl group, or a tert-butyl group; and R2 is a hydrogen group, a methyl group, or a methoxy group. The nickel complex formed by the imine-amine ligand compound coordinated with nickel can be used as a primary catalyst to directly catalyze ethylene polymerization in the presence of a co-catalyst to produce a low-molecular-weight, highly branched polyethylene oil. This polyethylene oil has a narrow molecular weight distribution, a high degree of branching, stable performance, a low pour point, a high viscosity index, and excellent stability and viscosity-temperature performance, making it suitable for use in place of high-quality PAO lubricant base oils. #imgabs0#

Description

Technical Field

[0001] The invention belongs to the field of olefin polymerization, and particularly relates to an imine-amine complex, a double-imine-amine nickel complex and a preparation method thereof, a nickel-based catalyst and application thereof in the preparation of low-molecular-weight highly branched polyethylene oil. Background Art

[0002] Poly-α-olefin (PAO) is a highly branched liquid polyolefin product rich in long-chain branches (typically C8). Due to its unique, highly branched structure, PAO exhibits excellent viscosity-temperature performance and low-temperature flow properties. Furthermore, its chemical composition is free of easily oxidized impurities such as aromatics, nitrogen, and sulfur, resulting in excellent antioxidant stability. Therefore, as a high-end synthetic lubricant, PAO plays an irreplaceable role in mechanical lubrication, particularly for specialized military and aerospace equipment and lubrication in extreme weather conditions.

[0003] Currently, polyalphaolefins (PAOs) are primarily produced using long-chain alpha-olefins (typically 1-decene) as raw materials, through cationic oligomerization (with BF3 as the initiator) or coordination oligomerization (with ZN catalysts or cyclopentadiene catalysts as the catalyst) to produce highly branched polyethylene oils. However, long-chain alpha-olefins are expensive and their sources are limited; in addition, the broad distribution of the final product requires cutting, resulting in a complex production process and expensive polyalphaolefin (PAO) lubricants. Using ethylene, which is abundant and inexpensive, as a raw material, olefin coordination polymerization generally produces linear polymers, making highly branched products difficult to obtain. In 1995, Professor Brookhart first developed an alpha-diimine nickel-palladium catalyst capable of catalyzing ethylene polymerization to produce branched or highly branched polymers. This is primarily due to the common occurrence of a chain walk in nickel-palladium catalysts during ethylene polymerization, leading to the formation of branches.

[0004] Further in-depth research has shown that the degree and distribution of branching are primarily influenced by the catalyst structure, polymerization temperature, and ethylene pressure. Generally, the chain walking process of nickel-palladium catalysts is a random process, resulting in an uncontrollable branching distribution in the product, a high methyl content, and difficulty in obtaining products with high long-chain branching content. Regarding the structure of α-diimine nickel-palladium catalysts, obtaining an oily product requires a low molecular weight, which typically requires a catalyst with low axial steric hindrance (small aniline hindrance). However, catalysts with low steric hindrance have poor thermal stability and are prone to decomposition and deactivation at high temperatures. Regarding polymerization reaction conditions, increasing ethylene pressure increases polymerization activity and product molecular weight, but chain walking is relatively weakened, resulting in a decrease in the degree of branching. Increasing the polymerization temperature enhances chain walking and increases the degree of branching, but may cause catalyst deactivation, resulting in reduced activity. Therefore, while current α-diimine nickel-palladium catalysts can produce oily polyethylene, the low long-chain branch content results in a high pour point and extremely poor low-temperature fluidity, making it difficult to meet the requirements for use as a lubricant base oil. In addition, although high temperature (>50°C) is beneficial to improving the branching degree and long-chain branch content of the product, the poor thermal stability of the catalyst leads to a significant decrease in its activity.

[0005] For example, Acta Polymerica Sinica published a study on the synthesis of α-diimine nickel-palladium complexes and their catalytic oligomerization of mixed decene. The document specifically describes that the diimine nickel-palladium catalyst has unique chain-walking characteristics, and that the catalytic performance and chain-walking process can be further regulated by designing the catalyst structure to prepare polyolefin products with excellent performance. The α-diimine nickel-palladium complex with a camphene skeleton was specifically synthesized and characterized. The nickel catalyst has good catalytic activity, and the linear monomer can be almost completely oligomerized by combining the isomerization process of the monomer. The resulting product is a highly branched, low-molecular-weight oily polyolefin product with a high viscosity index (>170) and a low pour point (<-30°C), which has good application prospects in the field of lubricant base oils. However, this technical solution still requires long-chain α-olefins as raw materials, which has the disadvantages of expensive raw materials and limited sources.

[0006] The Polymer Bulletin also discloses the application of a large steric backbone strategy in α-diimine nickel palladium olefin polymerization catalysts and specifically introduces the application of this strategy in α-diimine nickel palladium olefin polymerization catalysts, including ethylene polymerization, α-olefin polymerization, ethylene and polar monomer copolymerization, styrene monomer polymerization, and alternating copolymerization of carbon monoxide and styrene. However, this review only uses α-diimine nickel catalysts to catalyze ethylene polymerization to produce resin polymers, and does not study or provide relevant theories or conclusions on the control of the chain-carrying effect of α-diimine nickel palladium olefin polymerization catalysts with large steric backbones.

[0007] Chinese patent document CN106397261A discloses a diimine ligand compound and a preparation method thereof. The structural formula of the diimine ligand compound is:

[0008]

[0009] Among them, R 1 -R 10 The catalyst composition prepared by the method of the document is used for ethylene homopolymerization, and the polymerization activity can reach up to 3.84×10 6 g·mol -1 (Ni)·h -1 The obtained polymer has the characteristics of high molecular weight and narrow molecular weight distribution. However, this technical solution is aimed at high molecular weight polyethylene products, not low molecular weight polyethylene oil, and the product cannot be used as lubricant base oil.

[0010] Chinese patent document CN106397264A discloses a diimine ligand compound and a preparation method thereof. The structural formula of the diimine ligand compound is:

[0011]

[0012] In the structural formula, R 1 -R 10 The catalyst composition prepared by the method disclosed in this document exhibits high polymerization activity under high-temperature polymerization conditions (50-100°C) for ethylene homopolymerization, and the resulting polymer has high molecular weight and a narrow molecular weight distribution. However, this technical solution is also targeted at high-molecular-weight polyethylene products, not low-molecular-weight polyethylene oils, which cannot be used as lubricant base oils.

[0013] Chinese patent document CN102786435A discloses a catalytic system for preparing highly branched alkanes from olefins. The structure of the catalyst is as follows:

[0014]

[0015] The catalyst composition prepared by the method disclosed in this document is used in ethylene homopolymerization to produce an oily, highly branched alkane mixture. However, this technical solution suffers from a low content of long-chain branches in the product, resulting in a high pour point that makes it difficult to meet the requirements for industrial production of lubricant base oils. Furthermore, the ligand synthesis process in this technical solution is lengthy, making separation and purification difficult.

[0016] Therefore, the development of high-temperature resistant nickel-palladium catalysts to catalyze the oligomerization of ethylene to produce highly branched polyethylene oil with high long-chain branching content as a synthetic lubricant base oil is of great significance, but also faces huge challenges. Summary of the Invention

[0017] The present invention aims to overcome the problems of expensive raw materials and complex product separation processes in the existing production of poly-α-olefin lubricating oils using long-chain α-olefins as raw materials; as well as the conflicts between catalyst temperature resistance and product branching, between catalytic activity and product molecular weight, and low pour point and poor viscosity-temperature properties of the final oil resulting from low long-chain branching content in the production of polyethylene oil using ethylene as raw material. The present invention provides an imine-amine complex, a double-imine-amine nickel complex, a preparation method, a nickel-based catalyst, and applications. The polyethylene oil obtained by catalyzing ethylene polymerization using this double-imine-amine nickel complex as a main catalyst under the activation of a co-catalyst and at a relatively high polymerization temperature is not only highly branched, with a low molecular weight and narrow distribution, and a high long-chain branch content, but also exhibits excellent viscosity-temperature properties, stability, and a low pour point. Furthermore, it can replace high-quality PAO lubricating base oils for use as a high-end lubricant. Furthermore, the overall reaction conditions are mild, the catalytic activity is high, the ethylene monomer is inexpensive, the production process is simple, and the product is easy to separate.

[0018] To achieve the above object, the present invention provides the following technical solutions:

[0019] An imine-amine ligand compound having the structure shown in the following formula III:

[0020]

[0021] Wherein, R1 is methyl, phenyl or tert-butyl; R2 is hydrogen, methyl or methoxy.

[0022] Optionally, R1 is phenyl and R2 is methoxy.

[0023] The present invention also provides a method for preparing the compound of formula III, comprising the following steps:

[0024]

[0025] Step 1: Condensation of the compound of formula I with acenaphthenequinone to obtain the compound of formula II,

[0026] Step 2: Prepare the compound of formula III by reacting the compound of formula II.

[0027] In step 1, conventional conditions for the reaction of ketones / aldehydes with amines to produce imines can be used.

[0028] Optionally, in step 2, in a nitrogen atmosphere, the compound of formula II is reacted with trimethylaluminum to prepare the compound of formula III; preferably, the reaction temperature is 100-130° C., and the time is 4-8 hours; the molar ratio of the compound of formula II to trimethylaluminum is 1.5-3:1.

[0029] The present invention also provides a di-imine-amine nickel complex having the structure shown in the following formula IV:

[0030]

[0031] Wherein, R1 is methyl, phenyl or tert-butyl; R2 is hydrogen, methyl or methoxy; X is chlorine or bromine.

[0032] The present invention also provides a method for preparing the compound of formula IV, comprising the following steps:

[0033]

[0034] The compound of formula III reacts with anhydrous NiX2 to obtain the compound of formula IV.

[0035] Optionally, the molar ratio of the compound of formula III to anhydrous NiX2 is 2 to 3:1.

[0036] The compound of formula IV can be prepared by using conventional methods in the art to form metal coordination compounds with ligands and metal compounds.

[0037] Preferably, the compound of formula III is reacted with anhydrous NiX2 in acetonitrile under reflux for 20-28 hours until the reaction is completed, and then the solvent is recovered and washed to obtain the compound of formula IV.

[0038] The catalytic process of the present invention works as follows: by designing a rigid, heavily sterically hindered dibenzo-barrelene skeleton and introducing an electron-donating group at the para position of aniline, the thermal stability and chain-moving ability of the catalyst can be significantly improved. Simultaneously, the large steric hindrance of the skeleton does not significantly increase the axial steric effect of the catalyst, facilitating chain transfer reactions to produce low-molecular-weight products. Combined with a co-catalyst, chain transfer can also be achieved, resulting in a low-molecular-weight, highly branched polyethylene oil with a high content of long-chain branches, thereby producing a polyethylene oil with excellent oxidative stability and viscosity-temperature performance.

[0039] The present invention also provides a nickel-based catalyst, comprising a main catalyst and a co-catalyst; the main catalyst is the above-mentioned double-imine-amine nickel complex, and the co-catalyst is an alkyl aluminum compound.

[0040] The metal catalyst provided by the present invention is a late transition metal α-diimine nickel catalyst that can effectively catalyze ethylene polymerization. Because the chain running process during ethylene polymerization catalyzed by the late transition metal nickel catalyst is different from that of early transition metal catalysts (Ziegler-Natta (ZN) catalysts or metallocene catalysts), the catalytic ethylene polymerization produces highly branched polyethylene oil. Furthermore, the metal catalyst provided by the present invention can catalyze ethylene polymerization at high temperatures with high activity to produce a highly branched, low-molecular-weight polyethylene oil. The overall reaction has high catalytic activity, the ethylene monomer is inexpensive and abundant in source, the production process is simple, the resulting oily product and the gaseous ethylene feedstock are easily separated, and the production cost is low.

[0041] Preferably, the molar ratio of the main catalyst to the co-catalyst is 1:50-2000.

[0042] Preferably, the alkyl aluminum compound is selected from one or more of diethylaluminum monochloride, diethylaluminum dichloride, methylaluminoxane and modified methylaluminoxane.

[0043] The present invention also provides an application of the nickel-based catalyst in the preparation of low molecular weight highly branched polyethylene oil.

[0044] Optionally, the metal catalyst is used to directly catalyze ethylene polymerization to obtain low molecular weight highly branched polyethylene oil.

[0045] The present invention also provides a polyethylene oil having a weight-average molecular weight of 1 to 5 kg / mol, a molecular weight distribution of 1.1 to 1.5, a degree of branching of 70 to 140 / 1000C, a long-chain branch content of 30 mol% to 50 mol%; a pour point of -20 to -50°C; and a viscosity index of 140 to 181.

[0046] Optionally, the polyethylene oil is prepared by directly catalyzing ethylene polymerization using the above-mentioned nickel-based catalyst.

[0047] Optionally, the polymerization temperature for directly catalyzing ethylene polymerization using the metal catalyst to obtain low molecular weight highly branched polyethylene oil is 30-100°C, and the ethylene pressure is 1-10atm. Preferably, the polymerization temperature is 40-80°C and the pressure is 1-5atm.

[0048] Specifically, polyethylene oils with different apparent viscosities can be prepared by regulating ethylene pressure and polymerization temperature.

[0049] Compared with the prior art, the advantages of the technical solution of the present invention are:

[0050] 1. The imine-amine ligand compound provided by the present invention can be coordinated with a transition metal (such as iron, cobalt, nickel or palladium, preferably nickel) to form a metal complex that can be used as a main catalyst. In the presence of a co-catalyst, it catalyzes ethylene polymerization at high temperature with high activity to obtain a highly branched low-molecular-weight polyethylene oil, thereby resolving the contradiction between the temperature resistance of the catalyst and the branching degree of the product, as well as the contradiction between the catalytic activity and the molecular weight of the product.

[0051] 2. Using the nickel-based catalyst provided by the present invention to directly catalyze ethylene polymerization to obtain a low-molecular-weight, highly branched polyethylene oil with a narrow molecular weight distribution, a high degree of branching, and stable performance, thereby solving the problem of low pour point and poor viscosity-temperature properties of the final oil product due to low long-chain branch content. The polyethylene oil obtained by catalysis has a weight-average molecular weight of 1 to 5 kg / mol, a narrow molecular weight distribution of 1.1 to 1.5, a degree of branching of 70 to 140 / 1000°C, a long-chain branch content of 30 to 50 mol%, a pour point of -20 to -50°C, and a viscosity index of 140 to 181 (preferably, the polyethylene oil has a weight-average molecular weight of 2 to 4 kg / mol, a molecular weight distribution of 1.1 to 1.4, a degree of branching of 80 to 120 / 1000°C, a long-chain branch content of 30 to 50 mol%, a pour point of -30 to -50°C, and a viscosity index of 150 to 181). Due to its narrow distribution, high degree of branching and high content of long chain branches, polyethylene oil has stable performance, low pour point, high viscosity index, excellent stability and viscosity-temperature performance, and can replace high-quality PAO lubricant base oil.

[0052] 3. The preparation method of low molecular weight, highly branched polyethylene oil provided by the present invention has mild conditions, high catalytic activity of nickel-based catalyst, low price of ethylene monomer, simple production process, easy separation of products and low production cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 This is the GPC spectrum of the polyethylene oil obtained in Example 41 of the present invention. DETAILED DESCRIPTION

[0054] The present invention is described in detail below by way of examples. It is necessary to point out that the following examples are only used to further illustrate the present invention and are not to be construed as limiting the scope of protection of the present invention. Those skilled in the art may make some non-essential improvements and adjustments to the present invention based on the above disclosure.

[0055] In the following examples, experimental methods where specific conditions are not specified generally follow conditions conventional in the art or those recommended by the manufacturer. Raw materials and reagents used, unless otherwise specified, are commercially available from conventional markets. Any non-substantial variations or substitutions made by those skilled in the art based on the present invention are intended to be within the scope of the present invention.

[0056] The structural formula of the double imine amine nickel complex in each embodiment is as follows:

[0057]

[0058] In Formula IV, R1 can be selected from methyl, phenyl or tert-butyl; R2 is selected from hydrogen, methyl or methoxy; and X is chlorine or bromine. Specifically:

[0059] Iminamine ligand L1, R1 is methyl, R2 is hydrogen;

[0060] Iminamine ligand L2, R1 is methyl, R2 is methyl;

[0061] Iminamine ligand L3, R1 is methyl, R2 is methoxy;

[0062] Iminamine ligand L4, R1 is phenyl, R2 is hydrogen;

[0063] Iminamine ligand L5, R1 is phenyl, R2 is methyl;

[0064] Iminamine ligand L6, R1 is phenyl, R2 is methoxy;

[0065] Iminamine ligand L7, R1 is tert-butyl, R2 is hydrogen;

[0066] Iminamine ligand L8, R1 is tert-butyl, R2 is methyl;

[0067] Iminamine ligand L9, R1 is tert-butyl, R2 is methoxy;

[0068] Bis-imino-amine nickel complex 1-Cl, R1 is methyl, R2 is hydrogen, and X is chlorine;

[0069] Bis-ligand imine-amine nickel complex 1-Br, R1 is methyl, R2 is hydrogen, and X is bromine;

[0070] Bis-imino-amine nickel complex 2-Cl, R1 is methyl, R2 is methyl, and X is chlorine;

[0071] Bis-imino-amine nickel complex 2-Br, R1 is methyl, R2 is methyl, and X is bromine;

[0072] Bis-imino-amine nickel complex 3-Cl, R1 is methyl, R2 is methoxy, and X is chlorine;

[0073] Bis-imino-amine nickel complex 3-Br, R1 is methyl, R2 is methoxy, and X is bromine;

[0074] Bis-imino-amine nickel complex 4-Cl, R1 is phenyl, R2 is hydrogen, and X is chlorine;

[0075] Bis-imino-amine nickel complex 4-Br, R1 is phenyl, R2 is hydrogen, and X is bromine;

[0076] Bis-imino-amine nickel complex 5-Cl, R1 is phenyl, R2 is methyl, and X is chlorine;

[0077] Bis-imino-amine nickel complex 5-Br, R1 is phenyl, R2 is methyl, and X is bromine;

[0078] Bis-imino-amine nickel complex 6-Cl, R1 is phenyl, R2 is methoxy, and X is chlorine;

[0079] Bis-imino-amine nickel complex 6-Br, R1 is phenyl, R2 is methoxy, and X is bromine;

[0080] Bis-imino-amine nickel complex 7-Cl, R1 is tert-butyl, R2 is hydrogen, and X is chlorine;

[0081] Bis-ligand imine amine nickel complex 7-Br, R1 is tert-butyl, R2 is hydrogen, and X is bromine;

[0082] Bis-imino-amine nickel complex 8-Cl, R1 is tert-butyl, R2 is methyl, and X is chlorine;

[0083] Bis-imino-amine nickel complex 8-Br, R1 is tert-butyl, R2 is methyl, and X is bromine;

[0084] Bis-imino-amine nickel complex 9-Cl, R1 is tert-butyl, R2 is methoxy, and X is chlorine;

[0085] Bis-imino-amine nickel complex 9-Br, R1 is tert-butyl, R2 is methoxy, and X is bromine.

[0086] Each diligand imine amine nickel complex is prepared by the following reaction formula:

[0087]

[0088] In the following examples, the weight-average molecular weight and molecular weight distribution (PDI) of the prepared polyethylene oil were measured by gel permeation chromatography (GPC); the degree of branching of the polyethylene oil was calculated based on H-NMR spectroscopy; the kinematic viscosity and viscosity index of the prepared polyethylene oil were measured and calculated according to the national standard GB / T 265-88, and the pour point was measured according to the French standard GB / T 3535-2006 for the determination of the pour point of petroleum products.

[0089] Synthesis of imine-amine ligands

[0090] Example 1

[0091] This embodiment provides an imine-amine ligand L1, and its synthesis method is as follows.

[0092] Synthesis of Ligand L1: Acenaphthenequinone (10 mmol) and o-toluidine (21 mmol) were added to methanol, followed by a catalytic amount of formic acid. The mixture was allowed to react at room temperature for 24 hours. The solvent was removed by rotary evaporation, and the resulting solid was recrystallized from ethanol to initially yield the α-diimine ligand. The α-diimine ligand (6 mmol) was then dissolved in an appropriate amount of toluene solution. Trimethylaluminum (10 mmol) was added under nitrogen, and the reaction was stirred at 100°C for 6 hours. After cooling, the reaction was terminated with an excess of sodium hydroxide / ice water solution. After extraction with ethyl acetate, the organic phase was rotary evaporated to remove the solvent, yielding a crude solid product. The imine-amino ligand L1 was finally obtained after recrystallization from ethanol in a 79.2% yield. 1 H NMR(400MHz, CDCl3):7.88-6.56(m,14H,Ar-H),3.89(s,1H,NH),2.02(s,6H,CH3),1.94(s,3H,CH3).C 27 H 24 Elemental analysis of N2: theoretical values: C, 86.13; H, 6.43; N, 7.44%. Found: C, 86.30; H, 6.81; N, 7.29%.

[0093] Example 2

[0094] This embodiment provides an imine-amine ligand L2, and its synthesis method is as follows.

[0095] According to the synthesis method of Example 1, 2,4-methylaniline was used instead of o-toluidine to finally obtain ligand L2 with a yield of 75.3%. 1 H NMR(400MHz, CDCl3):7.84-6.52(m,12H,Ar-H),3.92(s,1H,NH),2.07(s,6H,CH3),2.02(s,6H,CH3),1.92(s,3H,CH3).C 29 H 28 Elemental analysis of N2: theoretical values: C, 86.10; H, 6.98; N, 6.92%. Found: C, 86.36; H, 6.74; N, 6.70%.

[0096] Example 3

[0097] This embodiment provides an imine-amine ligand L3, and its synthesis method is as follows.

[0098] According to the synthesis method of Example 1, 4-methoxy-2-methylaniline was used instead of o-toluidine to finally obtain ligand L3 with a yield of 61.1%. 1H NMR(400MHz, CDCl3):7.88-6.50(m,12H,Ar-H),3.96(s,1H,NH),3.70(s,6H,OCH3),2.34(s,6H,CH3),1.88(s,3H,CH3).C 29 H 28 Theoretical value of N2O2 elemental analysis: C, 79.79; H, 6.47; N, 6.42. Measured value: C, 79.55; H, 6.60; N, 6.68%.

[0099] Example 4

[0100] This embodiment provides an imine-amine ligand L4, and its synthesis method is as follows.

[0101] According to the synthesis method of Example 1, 2-aminobiphenyl was used instead of o-toluidine to finally obtain ligand L4 with a yield of 76.5%. 1 H NMR(400MHz, CDCl3):7.84-6.56(m,24H,Ar-H),3.88(s,1H,NH),1.92(s,3H,CH3).C 37 H 28 Elemental analysis of N2: theoretical values: C, 88.77; H, 5.64; N, 5.60%. Found: C, 88.62; H, 5.41; N, 5.37%.

[0102] Example 5

[0103] This embodiment provides an imine-amine ligand L5, and its synthesis method is as follows.

[0104] According to the synthesis method of Example 1, 2-phenyl-4-methylaniline was used instead of o-toluidine to finally obtain ligand L5 with a yield of 75.8%. 1 H NMR(400MHz, CDCl3):7.90-6.52(m,22H,Ar-H),3.90(s,1H,NH),2.05(s,6H,CH3),1.91(s,3H,CH3).C 39 H 32 Elemental analysis of N2: theoretical values: C, 88.60; H, 6.10; N, 5.30%. Found: C, 88.41; H, 5.90; N, 5.66%.

[0105] Example 6

[0106] This embodiment provides an imine-amine ligand L6, and its synthesis method is as follows.

[0107] According to the synthesis method of Example 1, 2-phenyl-4-methoxyaniline was used instead of o-toluidine to finally obtain ligand L6 with a yield of 75.3%. 1 H NMR(400MHz, CDCl3):7.92-6.54(m,22H,Ar-H),3.89(s,1H,NH),3.70(s,6H,OCH3),1.92(s,3H,CH3).C 39 H 32 Theoretical N2O2 elemental analysis: C, 83.54; H, 5.75; N, 5.00%. Found: C, 83.65; H, 5.50; N, 4.73%.

[0108] Example 7

[0109] This embodiment provides an imine-amine ligand L7, and its synthesis method is as follows.

[0110] According to the synthesis method of Example 1, o-tert-butylaniline was used instead of o-toluidine to finally obtain ligand L7 with a yield of 82.0%. 1 H NMR(400MHz, CDCl3):7.90-6.85(m,14H,Ar-H),3.88(s,1H,NH),1.86(s,3H,CH3),1.37(s,18H,CH3).C 33 H 36 Elemental analysis of N2: theoretical values: C, 86.04; H, 7.88; N, 6.08%. Found: C, 86.22; H, 7.75; N, 5.92%.

[0111] Example 8

[0112] This embodiment provides an imine-amine ligand L8, and its synthesis method is as follows.

[0113] According to the synthesis method of Example 1, 2-tert-butyl-4-methylaniline was used instead of o-toluidine to finally obtain ligand L8 with a yield of 79.6%. 1 H NMR(400MHz, CDCl3):7.88-6.84(m,12H,Ar-H),3.84(s,1H,NH),2.03(s,6H,CH3),1.86(s,3H,CH3),1.40(s,18H,CH3).C 35 H 40 Elemental analysis of N2: theoretical values: C, 86.02; H, 8.25; N, 5.73%. Found: C, 86.05; H, 8.31; N, 5.64%.

[0114] Example 9

[0115] This embodiment provides an imine-amine ligand L9, and its synthesis method is as follows.

[0116] According to the synthesis method of Example 1, 2-tert-butyl-4-methoxyaniline was used instead of o-toluidine to finally obtain ligand L8 with a yield of 79.6%. 1 H NMR(400MHz, CDCl3):7.90-6.80(m,12H,Ar-H),3.80(s,1H,NH),3.72(s,6H,OCH3),1.86(s,3H,CH3),1.44(s,18H,CH3).C 35 H 40 Elemental analysis of N2O2: theoretical values: C, 80.73; H, 7.74; N, 5.38%. Found: C, 80.55; H, 7.51; N, 5.64%.

[0117] Synthesis of nickel complexes

[0118] Example 10

[0119] This embodiment provides a diligand imineamine nickel complex 1-Cl, and its synthesis method is as follows.

[0120] Synthesis of the diliganded imine-amine nickel complex 1-Cl: Under anhydrous and oxygen-free conditions, ligand L1 (8.4 mmol) and anhydrous NiCl2 (4 mmol) were added to a side-necked flask and refluxed in ultra-dry acetonitrile for approximately 24 hours. After cooling to room temperature, the mixture was concentrated by evaporation, the solvent was filtered, and the catalyst solid was obtained after multiple washings with dry n-hexane. The yield was 81.2%. 54 H 48 Elemental analysis of N4Cl2Ni: C, 73.49; H, 5.48; N, 6.35%. Found: C, 73.67; H, 5.32; N, 6.10%.

[0121] Example 11

[0122] This embodiment provides a diligand imineamine nickel complex 1-Br, and its synthesis method is as follows.

[0123] Synthesis of the di-ligand imine-amine nickel complex 1-Br: The di-ligand imine-amine nickel complex 1-Br was obtained by reacting the imine-amine nickel ligand L1 with anhydrous NiBr2. The specific steps were the same as those in Example 10, and the reaction yield was 82.4%. 54 H 48 Elemental analysis of N4Br2Ni: theoretical values: C, 66.76; H, 4.98; N, 5.77%. Found: C, 66.49; H, 4.81, N, 5.58%.

[0124] Example 12

[0125] This embodiment provides a diligand imineamine nickel complex 2-Cl, and its synthesis method is as follows.

[0126] Synthesis of the di-ligand imine-amine nickel complex 2-Cl: The di-ligand imine-amine nickel complex 2-Cl was obtained by reacting the imine-amine nickel ligand L2 with anhydrous NiCl2. The specific steps were the same as those in Example 10, and the reaction yield was 80.7%. 58 H 56 Elemental analysis of N4Cl2Ni: theoretical values: C, 74.21; H, 6.01; N, 6.25%. Found: C, 74.09, H, 5.94; N, 6.01%.

[0127] Example 13

[0128] This embodiment provides a diligand imineamine nickel complex 2-Br, and its synthesis method is as follows.

[0129] Synthesis of the di-ligand imine-amine nickel complex 2-Br: The di-ligand imine-amine nickel complex 2-Br was obtained by reacting the imine-amine nickel ligand L2 with anhydrous NiBr2. The specific steps were the same as those in Example 10, and the reaction yield was 77.4%. 58 H 56 Elemental analysis of N4Br2Ni: theoretical values: C, 67.79; H, 5.49; N, 5.45%. Found: C, 67.48; H, 5.67; N, 5.62%.

[0130] Example 14

[0131] This embodiment provides a diligand imineamine nickel complex 3-Cl, and its synthesis method is as follows.

[0132] Synthesis of the di-ligand imine-amine nickel complex 3-Cl: The di-ligand imine-amine nickel complex 3-Cl was obtained by reacting the imine-amine nickel ligand L3 with anhydrous NiCl2. The specific steps were the same as those in Example 10, and the reaction yield was 78.8%. 58 H 56 Elemental analysis of N₄O₄Cl₂Ni: theoretical values: C, 69.48; H, 5.63; N, 5.59%. Found values: C, 69.88; H, 5.82; N, 5.80%.

[0133] Example 15

[0134] This embodiment provides a diligand imineamine nickel complex 3-Br, and its synthesis method is as follows.

[0135] Synthesis of the di-ligand imine-amine nickel complex 3-Br: The di-ligand imine-amine nickel complex 3-Br was obtained by reacting the imine-amine nickel ligand L3 with anhydrous NiBr2. The specific steps were the same as those in Example 10, and the reaction yield was 80.2%. 58 H 56 Elemental analysis of N₄O₄Br₂Ni: theoretical values: C, 63.82; H, 5.17; N, 5.13%. Found values: C, 63.61; H, 4.99; N, 5.02%.

[0136] Example 16

[0137] This embodiment provides a diligand imineamine nickel complex 4-Cl, and its synthesis method is as follows.

[0138] Synthesis of the di-ligand imine-amine nickel complex 4-Cl: The di-ligand imine-amine nickel complex 4-Cl was obtained by reacting the imine-amine nickel ligand L4 with anhydrous NiCl2. The specific steps were the same as those in Example 10, and the reaction yield was 81.3%. 74 H 56 Elemental analysis of N4Cl2Ni: theoretical values: C, 78.59; H, 4.99; N, 4.95%. Found: C, 78.39; H, 4.72; N, 4.78%.

[0139] Example 17

[0140] This embodiment provides a diligand imineamine nickel complex 4-Br, and its synthesis method is as follows.

[0141] Synthesis of the di-ligand imine-amine nickel complex 4-Br: The di-ligand imine-amine nickel complex 4-Br was obtained by reacting the imine-amine nickel ligand L4 with anhydrous NiBr2. The specific steps were the same as those in Example 10, and the reaction yield was 79.4%. 74 H 56 Elemental analysis of N4Br2Ni: theoretical values: C, 72.87; H, 4.63; N, 4.59%. Found values: C, 72.67; H, 4.41; N, 4.82%.

[0142] Example 18

[0143] This embodiment provides a diligand imineamine nickel complex 5-Cl, and its synthesis method is as follows.

[0144] Synthesis of the di-ligand imine-amine nickel complex 5-Cl: The di-ligand imine-amine nickel complex 5-Cl was obtained by reacting the imine-amine nickel ligand L5 with anhydrous NiCl2. The specific steps were the same as those in Example 10, and the reaction yield was 80.3%. 78 H 64Elemental analysis of N4Cl2Ni: C, 78.93%; H, 5.43%; N, 4.72%. Found: C, 78.67%; H, 5.32%; N, 4.66%.

[0145] Example 19

[0146] This embodiment provides a diligand imineamine nickel complex 5-Br, the synthesis method of which is as follows.

[0147] Synthesis of the di-ligand imine-amine nickel complex 5-Br: The di-ligand imine-amine nickel complex 5-Br was obtained by reacting the imine-amine nickel ligand L5 with anhydrous NiBr2. The specific steps were the same as those in Example 10, and the reaction yield was 84.1%. 78 H 64 Elemental analysis of N4Br2Ni: C, 73.43; H, 5.06; N, 4.39%. Found: C, 73.79; H, 5.01; N, 4.67.

[0148] Example 20

[0149] This embodiment provides a diligand imineamine nickel complex 6-Cl, and its synthesis method is as follows.

[0150] Synthesis of the di-ligand imine-amine nickel complex 6-Cl: The di-ligand imine-amine nickel complex 6-Cl was obtained by reacting the imine-amine nickel ligand L6 with anhydrous NiCl2. The specific steps were the same as those in Example 10, and the reaction yield was 80.3%. 78 H 64 Elemental analysis of N₄O₄Cl₂Ni: theoretical values: C, 74.89; H, 5.16; N, 4.48%. Found values: C, 74.66; H, 5.30; N, 4.28%.

[0151] Example 21

[0152] This embodiment provides a diligand imineamine nickel complex 6-Br, and its synthesis method is as follows.

[0153] Synthesis of the di-ligand imine-amine nickel complex 6-Br: The di-ligand imine-amine nickel complex 6-Br was obtained by reacting the imine-amine nickel ligand L6 with anhydrous NiBr2. The specific steps were the same as those in Example 10, and the reaction yield was 81.7%. 78 H 64 Elemental analysis of N₄O₄Br₂Ni: theoretical values: C, 69.92%; H, 4.81%; N, 4.18%. Found values: C, 69.78%; H, 4.71%; N, 4.02%.

[0154] Example 22

[0155] This embodiment provides a diligand imineamine nickel complex 7-Cl, and its synthesis method is as follows.

[0156] Synthesis of the di-ligand imine-amine nickel complex 7-Cl: The di-ligand imine-amine nickel complex C-Cl was obtained by reacting the imine-amine nickel ligand L7 with anhydrous NiCl2. The specific steps were the same as those in Example 10, and the reaction yield was 80.2%. 66 H 72 Elemental analysis of N4Cl2Ni: theoretical values: C, 75.43; H, 6.91; N, 5.33%. Found: C, 75.62; H, 6.78; N, 5.22%.

[0157] Example 23

[0158] This embodiment provides a diligand imineamine nickel complex 7-Br, and its synthesis method is as follows.

[0159] Synthesis of the di-ligand imine-amine nickel complex 7-Br: The di-ligand imine-amine nickel complex 7-Br was obtained by reacting the imine-amine nickel ligand L7 with anhydrous NiBr2. The specific steps were the same as those in Example 10, and the reaction yield was 81.2%. 66 H 72 Elemental analysis of N4Br2Ni: theoretical values: C, 69.55; H, 6.37; N, 4.92%. Found: C, 69.23; H, 6.28; N, 4.81%.

[0160] Example 24

[0161] This embodiment provides a diligand imineamine nickel complex 8-Cl, and its synthesis method is as follows.

[0162] Synthesis of the di-ligand imine-amine nickel complex 8-Cl: The di-ligand imine-amine nickel complex 8-Cl was prepared by reacting the imine-amine nickel ligand L8 with anhydrous NiCl2. The specific steps were the same as those in Example 10, and the reaction yield was 76.7%. 70 H 80 Elemental analysis of N4Cl2Ni: theoretical values: C, 75.95; H, 7.28; N, 5.06%. Found: C, 75.78; H, 7.10; N, 4.92%.

[0163] Example 25

[0164] This embodiment provides a diligand imineamine nickel complex 8-Br, and its synthesis method is as follows.

[0165] Synthesis of the di-ligand imine-amine nickel complex 8-Br: The di-ligand imine-amine nickel complex 8-Br was obtained by reacting the imine-amine nickel ligand L8 with anhydrous NiBr2. The specific steps were the same as those in Example 10, and the reaction yield was 79.4%.70 H 80 Elemental analysis of N4Br2Ni: theoretical values: C, 70.30; H, 6.74; N, 4.68%. Found: C, 70.27; H, 6.51; N, 4.49%.

[0166] Example 26

[0167] This embodiment provides a diligand imineamine nickel complex 9-Cl, and its synthesis method is as follows.

[0168] Synthesis of the di-ligand imine-amine nickel complex 9-Br: The di-ligand imine-amine nickel complex 9-Cl was obtained by reacting the imine-amine nickel ligand L9 with anhydrous NiCl2. The specific steps were the same as those in Example 10, and the reaction yield was 81.2%. 70 H 80 Elemental analysis of N₄O₄Cl₂Ni: theoretical values: C, 71.80; H, 6.89; N, 4.78%. Found values: C, 71.63; H, 6.74; N, 4.81%.

[0169] Example 27

[0170] This embodiment provides a diligand imineamine nickel complex 9-Br, and its synthesis method is as follows.

[0171] Synthesis of the di-ligand imine-amine nickel complex 9-Br: The di-ligand imine-amine nickel complex 9-Br was obtained by reacting the imine-amine nickel ligand L9 with anhydrous NiBr2. The specific steps were the same as those in Example 10, and the reaction yield was 84.1%. 70 H 80 Theoretical elemental analysis values ​​of N4O4Br2Ni: C, 66.73; H, 6.40; N, 4.45%. Found values: C, 66.59; H, 6.32; N, 4.67%.

[0172] Preparation of polyethylene oil

[0173] Example 28

[0174] This embodiment provides the application of a nickel catalyst in the synthesis of low molecular weight highly branched polyethylene oil. The specific preparation method of the polyethylene oil is as follows.

[0175] Under anhydrous and oxygen-free conditions, 60mL of dry toluene, 4mmol of diethylaluminum monochloride (Al / Ni=200), and 20μmol of nickel-based complex 1-Cl were added to a reactor, 1atm of ethylene was introduced, and ethylene polymerization was carried out at 40°C for 3h. The product mixture was poured into 5% hydrochloric acid-acidified ethanol for washing, and the crude product was separated and rotary evaporated to obtain a crude product. The crude product was eluted and separated by silica gel column and rotary evaporated to obtain 30.5g of product. The polyethylene oil prepared was measured by GPC to have a weight-average molecular weight of 2990g / mol and PDI=1.48. The branching degree was measured by nuclear magnetic hydrogen spectrum to be 72 / 1000C, the long chain branching was 22 / 1000C, and the long chain branching content was 30.6mol%. The kinematic viscosity at 100°C was 32mm according to the national standard. 2 / s, viscosity index is 160 and pour point is -29℃.

[0176] Example 29

[0177] This embodiment provides a polyethylene oil, and the preparation method thereof is as follows.

[0178] The polymerization conditions were the same as in Example 28, except that 20 μmol of the nickel-based complex 1-Br was used instead of 1-Cl to obtain 21.2 g of polyethylene oil. The polyethylene oil had a weight-average molecular weight of 3192 g / mol, a PDI of 1.47, a degree of branching of 85 / 1000C, a long-chain branch content of 26 / 1000C, and a long-chain branch content of 30.6 mol%. The viscosity at 100°C was 45 mm 2 / s, viscosity index is 156, and pour point is -29℃.

[0179] Example 30

[0180] This embodiment provides a polyethylene oil, and the preparation method thereof is as follows.

[0181] The polymerization conditions were the same as in Example 28, except that 20 μmol of the nickel-based complex 2-Cl was used instead of 1-Cl to obtain 20.9 g of polyethylene oil. The polyethylene oil had a weight-average molecular weight of 3105 g / mol, a PDI of 1.47, a degree of branching of 86 / 1000C, a long-chain branch content of 29 / 1000C, and a long-chain branch content of 33.7 mol%. The viscosity at 100°C was 47 mm 2 / s, viscosity index is 157, and pour point is -32℃.

[0182] Example 31

[0183] This embodiment provides a polyethylene oil, and the preparation method thereof is as follows.

[0184] The polymerization conditions were the same as in Example 28, except that 20 μmol of the nickel-based complex 2-Br was used instead of 1-Cl to obtain 21.7 g of polyethylene oil. The polyethylene oil had a weight-average molecular weight of 3217 g / mol, a PDI of 1.45, a branching degree of 100 / 1000C, a long-chain branch content of 34 / 1000C, and a long-chain branch content of 34.0 mol%. The viscosity at 100°C was 55 mm 2 / s, viscosity index is 162, and pour point is -32℃.

[0185] Example 32

[0186] This embodiment provides a polyethylene oil, and the preparation method thereof is as follows.

[0187] The polymerization conditions were the same as in Example 28, except that 20 μmol of the nickel-based complex 3-Cl was used instead of 1-Cl to obtain 12.5 g of polyethylene oil. The polyethylene oil had a weight-average molecular weight of 3306 g / mol, a PDI of 1.40, a degree of branching of 103 / 1000C, a long-chain branch content of 38 / 1000C, and a long-chain branch content of 36.9 mol%. The viscosity at 100°C was 49 mm 2 / s, viscosity index is 177, and pour point is -35℃.

[0188] Example 33

[0189] This embodiment provides a polyethylene oil, and the preparation method thereof is as follows.

[0190] The polymerization conditions were the same as those in Example 28, except that 20 μmol of the nickel-based complex 3-Br was used instead of 1-Cl to obtain 22.0 g of polyethylene oil. The polyethylene oil had a weight-average molecular weight of 3411 g / mol, a PDI of 1.29, a degree of branching of 115 / 1000C, a long-chain branch content of 37 / 1000C, and a long-chain branch content of 32.2 mol%. The viscosity at 100°C was 45 mm 2 / s, viscosity index is 176, and pour point is -30℃.

[0191] Example 34

[0192] This embodiment provides a polyethylene oil, and the preparation method thereof is as follows.

[0193] The polymerization conditions were the same as those in Example 28, except that 20 μmol of the nickel-based complex 4-Cl was used instead of 1-Cl to obtain 23.2 g of polyethylene oil. The polyethylene oil had a weight-average molecular weight of 3516 g / mol, a PDI of 1.15, a degree of branching of 125 / 1000C, a long-chain branch content of 45 / 1000C, and a long-chain branch content of 36.0 mol%. The viscosity at 100°C was 40 mm 2 / s, viscosity index is 175, and pour point is -33℃.

[0194] Example 35

[0195] This embodiment provides a polyethylene oil, and the preparation method thereof is as follows.

[0196] The polymerization conditions were the same as those in Example 28, except that 20 μmol of the nickel-based complex 4-Br was used instead of 1-Cl to obtain 21.9 g of polyethylene oil. The polyethylene oil had a weight-average molecular weight of 3385 g / mol, a PDI of 1.35, a degree of branching of 107 / 1000C, a long-chain branch content of 33 / 1000C, and a long-chain branch content of 30.8 mol%. The viscosity at 100°C was 41 mm / s. 2 / s, viscosity index is 165, and pour point is -28℃.

[0197] Example 36

[0198] This embodiment provides a polyethylene oil, and the preparation method thereof is as follows.

[0199] The polymerization conditions were the same as in Example 28, except that 20 μmol of catalyst 5-Cl was used instead of 1-Cl to obtain 24.1 g of polyethylene oil. The polyethylene oil had a weight-average molecular weight of 3616 g / mol, a PDI of 1.21, a degree of branching of 131 / 1000C, a long-chain branch content of 47 / 1000C, and a long-chain branch content of 35.9 mol%. The viscosity at 100°C was 49 mm 2 / s, viscosity index is 165, and pour point is -33℃.

[0200] Example 37

[0201] This embodiment provides a polyethylene oil, and the preparation method thereof is as follows.

[0202] The polymerization conditions were the same as those in Example 28, except that 20 μmol of the nickel-based complex 5-Br was used instead of 1-Cl to obtain 25.5 g of polyethylene oil. The polyethylene oil had a weight-average molecular weight of 3465 g / mol, a PDI of 1.30, a degree of branching of 121 / 1000C, a long-chain branch content of 44 / 1000C, and a long-chain branch content of 36.4 mol%. The viscosity at 100°C was 55 mm 2 / s, viscosity index is 171, and pour point is -33℃.

[0203] Example 38

[0204] This embodiment provides a polyethylene oil, and the preparation method thereof is as follows.

[0205] The polymerization conditions were the same as in Example 28, except that 20 μmol of the nickel-based complex 6-Cl was used instead of 1-Cl to obtain 35.5 g of polyethylene oil. The polyethylene oil had a weight-average molecular weight of 3702 g / mol, a PDI of 1.19, a degree of branching of 140 / 1000C, a long-chain branch content of 70 / 1000C, and a long-chain branch content of 50.0 mol%. The viscosity at 100°C was 32 mm / s. 2 / s, viscosity index is 180, and pour point is -50℃.

[0206] Example 39

[0207] This embodiment provides a polyethylene oil, and the preparation method thereof is as follows.

[0208] The polymerization conditions were the same as in Example 28, except that 20 μmol of the nickel-based complex 6-Br was used instead of 1-Cl to obtain 34.1 g of polyethylene oil. The polyethylene oil had a weight-average molecular weight of 3593 g / mol, a PDI of 1.26, a degree of branching of 127 / 1000C, a long-chain branch content of 53 / 1000C, and a long-chain branch content of 41.7 mol%. The viscosity at 100°C was 51 mm / s. 2 / s, viscosity index is 169, and pour point is -39℃.

[0209] Example 40

[0210] This embodiment provides a polyethylene oil, and the preparation method thereof is as follows.

[0211] The polymerization conditions were the same as in Example 28, except that 20 μmol of the nickel-based complex 7-Cl was used instead of 1-Cl to obtain 19.5 g of polyethylene oil. The polyethylene oil had a weight-average molecular weight of 4105 g / mol, a PDI of 1.39, a degree of branching of 134 / 1000C, a long-chain branch content of 60 / 1000C, and a long-chain branch content of 44.8 mol%. The viscosity at 100°C was 44 mm 2 / s, viscosity index is 175, and pour point is -41℃.

[0212] Example 41

[0213] This embodiment provides a polyethylene oil, and the preparation method thereof is as follows.

[0214] The same polymerization conditions as in Example 28 were used, but 20 μmol of the nickel-based complex 7-Br was used instead of 1-Cl to obtain 19.1 g of polyethylene oil. Figure 1 It can be seen that the polyethylene oil prepared in this example has a weight average molecular weight of 3752 g / mol, a PDI of 1.33, a branching degree of 122 / 1000C, a long chain branch of 45 / 1000C, and a long chain branch content of 36.9 mol%. The viscosity at 100°C is 63 mm 2 / s, viscosity index is 189 and pour point is -35℃.

[0215] Example 42

[0216] This embodiment provides a polyethylene oil, and the preparation method thereof is as follows.

[0217] The polymerization conditions were the same as in Example 28, except that 20 μmol of the nickel-based complex 8-Cl was used instead of 1-Cl to obtain 16.5 g of polyethylene oil. The polyethylene oil had a weight-average molecular weight of 4328 g / mol, a PDI of 1.35, a degree of branching of 116 / 1000C, a long-chain branch content of 49 / 1000C, and a long-chain branch content of 42.2 mol%. The viscosity at 100°C was 52 mm / s. 2 / s, viscosity index is 177, and pour point is -39℃.

[0218] Example 43

[0219] This embodiment provides a polyethylene oil, and the preparation method thereof is as follows.

[0220] The polymerization conditions were the same as in Example 28, except that 20 μmol of the nickel-based complex 8-Br was used instead of 1-Cl to obtain 15.3 g of polyethylene oil. The polyethylene oil had a weight-average molecular weight of 3752 g / mol, a PDI of 1.33, a degree of branching of 119 / 1000C, a long-chain branch content of 38 / 1000C, and a long-chain branch content of 31.9 mol%. The viscosity at 100°C was 61 mm / s. 2 / s, viscosity index is 166, and pour point is -30℃.

[0221] Example 44

[0222] This embodiment provides a polyethylene oil, and the preparation method thereof is as follows.

[0223] The polymerization conditions were the same as those in Example 28, except that 20 μmol of the nickel-based complex 9-Cl was used instead of 1-Cl to obtain 21.5 g of polyethylene oil. The polyethylene oil had a weight-average molecular weight of 4093 g / mol, a PDI of 1.18, a degree of branching of 133 / 1000C, a long-chain branch content of 56 / 1000C, and a long-chain branch content of 42.1 mol%. The viscosity at 100°C was 40 mm 2 / s, viscosity index is 175, and pour point is -39℃.

[0224] Example 45

[0225] This embodiment provides a polyethylene oil, and the preparation method thereof is as follows.

[0226] The polymerization conditions were the same as in Example 28, except that 20 μmol of the nickel-based complex 9-Br was used instead of 1-Cl to obtain 21.3 g of polyethylene oil. The polyethylene oil had a weight-average molecular weight of 3019 g / mol, a PDI of 1.31, a degree of branching of 125 / 1000C, a long-chain branch content of 48 / 1000C, and a long-chain branch content of 38.4 mol%. The viscosity at 100°C was 55 mm 2 / s, viscosity index is 176, and pour point is -36℃.

[0227] Example 46

[0228] This embodiment provides a polyethylene oil, and the preparation method thereof is as follows.

[0229] The polymerization conditions were the same as in Example 28, except that 4 mmol of ethylaluminum dichloride was used instead of diethylaluminum monochloride to obtain 21.3 g of polyethylene oil. The polyethylene oil had a weight-average molecular weight of 3019 g / mol, a PDI of 1.31, a degree of branching of 125 / 1000C, a long-chain branch content of 47 / 1000C, and a long-chain branch content of 37.6 mol%. The viscosity at 100°C was 55 mm 2 / s, viscosity index is 176, and pour point is -36℃.

[0230] Example 47

[0231] This embodiment provides a polyethylene oil, and the preparation method thereof is as follows.

[0232] The polymerization conditions were the same as in Example 28, except that 4 mmol of methylaluminoxane was used instead of diethylaluminum monochloride to obtain 19.8 g of polyethylene oil. The polyethylene oil had a weight-average molecular weight of 2036 g / mol, a PDI of 1.35, a degree of branching of 98 / 1000C, a long-chain branch of 35 / 1000C, and a long-chain branch content of 35.7 mol%. The viscosity at 100°C was 87 mm / s. 2 / s, viscosity index is 166, and pour point is -33℃.

[0233] Example 48

[0234] This embodiment provides a polyethylene oil, and the preparation method thereof is as follows.

[0235] The polymerization conditions were the same as in Example 28, except that 4 mmol of modified methylaluminoxane was used instead of diethylaluminum monochloride to obtain 15.2 g of polyethylene oil. The polyethylene oil had a weight-average molecular weight of 2096 g / mol, a PDI of 1.33, a degree of branching of 107 / 1000C, a long-chain branch content of 38 / 1000C, and a long-chain branch content of 35.5 mol%. The viscosity at 100°C was 69 mm / s. 2 / s, viscosity index is 160 and pour point is -33℃.

[0236] Example 49

[0237] This embodiment provides a polyethylene oil, and the preparation method thereof is as follows.

[0238] The polymerization conditions were the same as in Example 28, but the reaction temperature was 30°C instead of 40°C. 17.6 g of polyethylene oil was obtained. The polyethylene oil had a weight-average molecular weight of 3650 g / mol, a PDI of 1.17, a degree of branching of 135 / 1000C, a long-chain branch content of 51 / 1000C, and a long-chain branch content of 37.8 mol%. The viscosity at 100°C was 36 mm 2 / s, viscosity index is 175, and pour point is -36℃.

[0239] Example 50

[0240] This embodiment provides a polyethylene oil, and the preparation method thereof is as follows.

[0241] The polymerization conditions were the same as in Example 28, but the reaction temperature was 60°C instead of 40°C. 18.7 g of polyethylene oil was obtained. The polyethylene oil had a weight-average molecular weight of 3678 g / mol, a PDI of 1.22, a degree of branching of 141 / 1000C, a long-chain branch content of 54 / 1000C, and a long-chain branch content of 38.3 mol%. The viscosity at 100°C was 38 mm 2 / s, viscosity index is 177, and pour point is -36℃.

[0242] Example 51

[0243] This embodiment provides a polyethylene oil, and the preparation method thereof is as follows.

[0244] The polymerization conditions were the same as in Example 28, but the reaction temperature was 80°C instead of 40°C. 15.4 g of polyethylene oil was obtained. The polyethylene oil had a weight-average molecular weight of 3622 g / mol, a PDI of 1.36, a degree of branching of 133 / 1000C, a long-chain branch of 55 / 1000C, and a long-chain branch content of 41.4 mol%. The viscosity at 100°C was 45 mm 2 / s, viscosity index is 170 and pour point is -39℃.

[0245] Example 52

[0246] This embodiment provides a polyethylene oil, and the preparation method thereof is as follows.

[0247] The polymerization conditions were the same as in Example 28, except that the reaction temperature was 100°C instead of 40°C. 10.2 g of polyethylene oil was obtained. The polyethylene oil had a weight-average molecular weight of 3650 g / mol, a PDI of 1.17, a degree of branching of 113 / 1000C, a long-chain branch content of 41 / 1000C, and a long-chain branch content of 36.3 mol%. The viscosity at 100°C was 59 mm 2 / s, viscosity index is 181, and pour point is -33℃.

[0248] Example 53

[0249] This embodiment provides a polyethylene oil, and the preparation method thereof is as follows.

[0250] The polymerization conditions were the same as in Example 28, but the polymerization pressure was 5 atm instead of 1 atm. 27.3 g of polyethylene oil was obtained. The polyethylene oil had a weight-average molecular weight of 2933 g / mol, a PDI of 1.41, a degree of branching of 105 / 1000C, a long-chain branch content of 38 / 1000C, and a long-chain branch content of 35.2 mol%. The viscosity at 100°C was 67 mm 2 / s, viscosity index is 145, and pour point is -33℃.

[0251] Example 54

[0252] This embodiment provides a polyethylene oil, and the preparation method thereof is as follows.

[0253] The polymerization conditions were the same as in Example 28, but the polymerization pressure was 8 atm instead of 1 atm. 29.1 g of polyethylene oil was obtained. The polyethylene oil had a weight-average molecular weight of 2986 g / mol, a PDI of 1.45, a degree of branching of 99 / 1000C, a long-chain branch content of 31 / 1000C, and a long-chain branch content of 31.3 mol%. The viscosity at 100°C was 65 mm 2 / s, viscosity index is 140, and pour point is -30℃.

[0254] Example 55

[0255] This embodiment provides a polyethylene oil, and the preparation method thereof is as follows.

[0256] The polymerization conditions were the same as in Example 28, but the polymerization pressure was 10 atm instead of 1 atm. 33.3 g of polyethylene oil was obtained. The polyethylene oil had a weight-average molecular weight of 2261 g / mol, a PDI of 1.49, a degree of branching of 86 / 1000C, a long-chain branch content of 36 / 1000C, and a long-chain branch content of 41.9 mol%. The viscosity at 100°C was 65 mm 2 / s, viscosity index is 140, and pour point is -39℃.

[0257] Example 56

[0258] This embodiment provides a polyethylene oil, and the preparation method thereof is as follows.

[0259] The polymerization conditions were the same as those in Example 28, except that 1 mmol of diethylaluminum monochloride was added (Al / Ni = 50:1). 12.5 g of polyethylene oil was obtained. The prepared polyethylene oil had a weight-average molecular weight of 2955 g / mol, a PDI of 1.22, a degree of branching of 116 / 1000C, a long-chain branch content of 42 / 1000C, and a long-chain branch content of 36.2 mol%. The viscosity at 100°C was 75 mm 2 / s, viscosity index is 153, and pour point is -33℃.

[0260] Example 57

[0261] This embodiment provides a polyethylene oil, and the preparation method thereof is as follows.

[0262] The polymerization conditions were the same as in Example 28, except that 2 mmol of diethylaluminum monochloride was added (Al / Ni = 100:1). 13.8 g of polyethylene oil was obtained. The prepared polyethylene oil had a weight-average molecular weight of 2865 g / mol, a PDI of 1.28, a degree of branching of 135 / 1000C, a long-chain branch of 51 / 1000C, and a long-chain branch content of 37.8 mol%. The viscosity at 100°C was 65 mm 2 / s, viscosity index is 163, and pour point is -36℃.

[0263] Example 58

[0264] This embodiment provides a polyethylene oil, and the preparation method thereof is as follows.

[0265] The polymerization conditions were the same as in Example 28, except that 40 mmol of diethylaluminum monochloride was added (Al / Ni = 2000:1). 19.8 g of polyethylene oil was obtained. The prepared polyethylene oil had a weight-average molecular weight of 5685 g / mol, a PDI of 1.36, a degree of branching of 138 / 1000C, a long-chain branch content of 42 / 1000C, and a long-chain branch content of 30.4 mol%. The viscosity at 100°C was 91 mm / s. 2 / s, viscosity index is 144, and pour point is -29℃.

[0266] Comparative Example 1

[0267] This comparative example is similar to Example 38, except that a different nickel-based complex (main catalyst) is used. The nickel-based complex used in this comparative example is Ni-10. The preparation method of Ni-10 is to use the α-diimine ligand prepared in Example 4 according to the method in Example 16. The specific structure is as follows:

[0268]

[0269] The polyethylene oil prepared in this comparative example was 7.9 g, with a weight average molecular weight of 4035 g / mol, a PDI of 1.65, a branching degree of 72 / 1000C, a long chain branch of 12 / 1000C, and a long chain branch content of 16.7 mol%. The viscosity at 100°C was 82 mm 2 / s, viscosity index is 111, pour point is -10℃.

[0270] Complex Ni-10 catalyzes ethylene polymerization at 40°C to obtain 7.9 g of product, and complex 6-Cl obtains 35.5 g of product under the same conditions. Compared with complex 6-Cl, the activity of complex C10 is significantly reduced; the branching degree of the obtained product is reduced, the long chain branch content is reduced, the PDI becomes wider and the pour point is significantly reduced.

[0271] Comparative Example 2

[0272] This comparative example is similar to Example 51, the only difference being that a different nickel-based complex (main catalyst) is used. The nickel-based complex used in this comparative example is Ni-10, and ultimately no polyethylene oil is produced.

[0273] Complex Ni-10 catalyzed ethylene polymerization at 80°C without generating any product, while complex 1-Cl polymerized under the same conditions to obtain 15.4 g of product. Compared with complex 1-Cl, the thermal stability and activity of complex C10 were significantly reduced, and it was inactivated at high temperature.

[0274] In summary, the results of the above examples and comparative examples show that the imine-amine nickel complex provided by the present invention can be used as a main catalyst. In combination with a co-catalyst, it can catalyze ethylene polymerization with high activity at low ethylene pressure to produce highly branched, low-molecular-weight polyethylene oil. This polyethylene oil has a low pour point and excellent viscosity-temperature performance, making it suitable for use in place of high-quality PAO lubricant base oils. The nickel-based catalyst provided by the present invention has significantly better thermal stability than the α-diimine catalyst system based on the acenaphthenyl skeleton. The entire reaction conditions are mild, the catalytic activity is high, the ethylene monomer is inexpensive, the production process is simple, the product is easily separated, and the production cost is low.

[0275] Of course, the present invention may have many other embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art may make various corresponding changes and modifications based on the present invention, but these corresponding changes and modifications should all fall within the scope of protection of the claims of the present invention.

Claims

1. A diligand imine amine nickel complex, characterized in that: It has the structure shown in the following formula IV: Wherein, R1 is methyl, phenyl or tert-butyl; R2 is hydrogen, methyl or methoxy; X is chlorine or bromine.

2. A method for preparing a compound of formula IV, characterized in that: The steps include: The compound of formula III reacts with NiX2 to obtain the compound of formula IV.

3. A nickel-based catalyst, characterized in that The invention comprises a main catalyst and a co-catalyst; the main catalyst is the double-coordinated imine-amine nickel complex according to claim 1, and the co-catalyst is an alkyl aluminum compound.

4. The nickel-based catalyst according to claim 3, wherein The molar ratio of the main catalyst to the co-catalyst is 1:50-2000.

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