A low viscosity high flash point alpha-olefin polymer, its preparation method and application

Abstract

This invention relates to the field of polymer materials technology, and more particularly to a low-viscosity, high-flash-point α-olefin polymer, its preparation method, and its applications. The preparation method of the α-olefin polymer includes: polymerizing α-olefin monomers; the reaction system consists of α-olefin monomers, an organic solvent, a co-initiator, and an electron donor; the co-initiator is one or more of SbCl4, SnCl4, ZnCl2, MnCl4, FeCl2, FeCl3, CoCl2, and NiCl2. This invention, by optimizing the polymerization system, synthesizes a polymer containing C8-C... 12 This invention relates to polymers of linear α-olefins and enables the preparation of lubricating oils with varying repeating unit content, kinematic viscosity, and flash point (open cup). Compared to other lubricating oils, under the same kinematic viscosity conditions, the products of this invention exhibit a higher flash point (open cup), resulting in lower volatility and enhanced safety during storage, transportation, and use.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of high molecular materials, and in particular relates to a low-viscosity high-flash-point alpha-olefin polymer and a preparation method and application thereof. BACKGROUND

[0002] Poly-alpha-olefins (PAO) can be prepared by polymerization and hydrogenation of C8-C 12 Linear alpha-olefins (LAO) are prepared by polymerization and hydrogenation. PAO has the characteristics of high viscosity index, low pour point, low oil product volatilization loss, and excellent high-temperature oxidation stability, especially its comprehensive performance of viscosity-temperature performance, low-temperature performance, and thermal oxidation stability is good, and it is currently considered to be the most potential synthetic lubricating oil. PAO plays an irreplaceable role in the fields of aerospace, military, etc., and is also an important raw material for producing high-grade lubricating oil for high-grade automobile, wind power, high-speed rail, intelligent manufacturing, etc.

[0003] In the prior art, researchers use TiCl4 / Al(Et)3 as a catalyst system to catalyze mixed C 10 olefins under the reaction condition of 65-85℃. Under the optimized polymerization reaction condition, the conversion rate of the polymerization product is 63.29%, the 100℃ kinematic viscosity of the base oil is 27.11mm 2 / s, the viscosity index is 124, and the pour point is -45℃. (Research on viscosity PAO base oil in the synthesis of mixed C 10 olefins, Fine Petroleum Chemical Industry Progress, 2021, 22(02): 46-50). In "Synthesis and properties of decene-1 poly-alpha-olefin synthetic oil", BF3 is used as a catalyst and n-butanol is used as an initiator to prepare the trimer and tetramer of 1-decene under the condition of 30℃ and 0.4MPa. The conversion rate of 1-decene can reach 99.8%, which provides a new experimental method for low-viscosity, high-viscosity index, and low-freezing-point PAO products (Journal of Liaoning University of Petroleum and Chemical Technology, 2005, 25(03): 24-27). However, the above prior art still has defects such as harsh reaction conditions, low conversion rate of polymerization product, uncontrollable polymerization reaction, and high cost of raw materials, so there is still room for improvement in actual application. SUMMARY

[0004] The present application provides a low-viscosity high-flash-point alpha-olefin polymer and a preparation method and application thereof, to solve the defect of low flash point of alpha-olefin polymer in the prior art, and to improve the safety performance of the oil product without adding additives.

[0005] The present application provides a method for preparing alpha-olefin polymer, comprising: polymerizing alpha-olefin monomer, the reaction system is composed of alpha-olefin monomer, organic solvent, co-initiator and electron donor; the co-initiator is one or more of SbCl4, SnCl4, ZnCl2, MnCl4, FeCl2, FeCl3, CoCl2 and NiCl2.

[0006] The present application finds that the above reaction system can effectively control the alpha-olefin polymer to have lower viscosity and higher flash point under relatively mild conditions, and significantly improve the safety performance of oil products.

[0007] Preferably, the co-initiator is one or more of SbCl4, SnCl4, ZnCl2, MnCl4, FeCl2, FeCl3, CoCl2 and NiCl2.

[0008] More preferably, when the co-initiator is FeCl3, it is more conducive to controlling the reaction system to obtain alpha-olefin polymer with higher flash point and lower viscosity.

[0009] Preferably, the organic solvent is one or more of alkane, halogenated hydrocarbon, tetrahydrofuran and cyclohexanone.

[0010] More preferably, the organic solvent is one or more of dichloroethane, dichloromethane and n-hexane.

[0011] Preferably, the electron donor is alcohol and / or alkyl-substituted phenol compound.

[0012] Preferably, the alcohol is one or more of methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, tert-butanol, n-pentanol, isoamyl alcohol, amyl alcohol, n-hexanol, n-heptanol, n-octanol, 2,2-dimethylpropanol, 2,3-dimethyl-2-butanol, 3,3-dimethyl-2-butanol, 2-ethylbutanol, 2-methylpentanol, 3-ethyl-2-pentanol, 2,4-dimethylpentanol, 2-methyl-2-hexanol, 2-ethylbutanol, 2,3-dimethylpentanol, 2,4-dimethylpentanol, 2,3,4-trimethyl-3-pentanol, 2-methyl-3-ethylpentanol, 3,4-dimethylhexanol, 3-methylheptanol, 2-propylpentanol and 2-ethylhexanol; the alkyl-substituted phenol compound is one or more of 2-methylphenol, 3-methylphenol, 4-methylphenol, 2-ethylphenol, 2,6-di-tert-butylphenol and 2,6-di-tert-butyl-4-methylphenol.

[0013] More preferably, the electron donor is one or more of isopropanol, tert-butanol and isoamyl alcohol.

[0014] Preferably, the alpha-olefin polymer contains C8-C 12The α-olefin monomer is 1-octene, 1-nonene, 1-decene, 1-undecene or 1-dodecene.

[0015] More preferably, the concentration of the α-olefin monomer in the monomer solution is 1.0-2.5 M.

[0016] Preferably, the molar ratio of the co-initiator to the α-olefin monomer is 0.005-0.08:1, and the molar ratio of the electron donor to the co-initiator is 0.2-1.4:1.

[0017] Preferably, the reaction conditions of the polymerization reaction include a temperature of 30-40℃ and a time of 2-3h.

[0018] Preferably, the method for preparing the α-olefin polymer includes the following steps:

[0019] (1) diluting the α-olefin monomer to a concentration of 1.0-2.5 M using an organic solvent, and then pre-cooling to 0-30℃ to obtain a monomer solution;

[0020] (2) mixing the monomer solution with a co-initiator and an electron donor, and reacting at 0-100℃ for 5-150 min;

[0021] (3) adding pre-cooled ethanol to the reaction system, precipitating the precipitate with an alcohol, removing the solvent, and vacuum drying to obtain the α-olefin polymer.

[0022] The application also provides an α-olefin polymer prepared by the above method.

[0023] Preferably, the number average molecular weight of the α-olefin polymer is 140-700 g·mol -1 , the kinematic viscosity at 100℃ is 2-40 mm 2 / s, and the open flash point is 230-300℃.

[0024] More preferably, the number average molecular weight of the α-olefin polymer is 420-540 g·mol -1 , the kinematic viscosity at 100℃ is 2-10 mm 2 / / s, and the open flash point is 270-300℃.

[0025] The application also provides a lubricating oil containing the above α-olefin polymer.

[0026] The application provides an α-olefin polymer with low viscosity and high flash point, a preparation method and application thereof. By optimizing the polymerization system, a C8-C 12The linear alpha-olefin polymer is used to prepare lubricating oil products with different repeat unit content, low kinematic viscosity and high flash point (open cup). Compared with other lubricating oil products, the product of the present application has higher flash point (open cup) under the same kinematic viscosity condition, so that the lubricating oil product has less volatility, higher safety in storage, transportation and use. The functionality of the material is improved without adding harmful additives, which makes it possible to be applied in the emerging lubricating oil industry and has a more promising future. DETAILED DESCRIPTION

[0027] The preferred embodiments of the present application will be described in detail below. Although the following only shows several preferred embodiments of the present application, it does not constitute a limitation on the scope or implementation method of the present application.

[0028] Unless otherwise specified, the various raw materials used in the examples and comparative examples are commercially available conventional raw materials, and the technical means used is conventional means known to those skilled in the art.

[0029] In the present application, the polymerization product is characterized by gel permeation chromatography (GPC) to obtain its M n and molecular weight distribution index (M w / M n ) with tetrahydrofuran as the mobile phase at a flow rate of 1 mL / min.

[0030] In the present application, the infrared spectrum (FTIR) of the polymer is determined by using a Fourier transform infrared spectrometer Tensor II of Bruker Spectroscopic Instruments Co., Ltd. The sample to be tested is completely dissolved in n-hexane and uniformly coated on a potassium bromide (KBr) flake which is formed by grinding and pressing. The KBr is used as the background as a reference, the test temperature is 25℃, and the scanning range is set to 400-4000 cm -1 .

[0031] The kinematic viscosity of the lubricating oil product is detected by the method specified in GB / T 265. The detector is composed of a light-emitting diode and a photosensitive triode. When the sample flows into the detector, the instrument starts to automatically time, and the timing is terminated when the sample flows out of the detector. The kinematic viscosity value of the lubricating oil product is obtained by multiplying the flow time by the viscosity tube constant.

[0032] The flash point is an important safety index for lubricating oil transportation and use. Under the specified experimental conditions, the lowest temperature at which vaporization and ignition occur using a certain ignition source is defined as the flash point. Generally, the flash point of oil products is required to be higher than the use temperature by 20-30℃. The determination of the flash point includes two determination methods, i.e., the open flash point (Cleveland open cup experiment) and the closed flash point (Pensky-Martin closed cup method). The open flash point is 20-30℃ higher than the closed flash point when the flash points of the same oil sample are determined. The open flash point determination method is usually used for the determination of the flash point of lubricating oil. The open flash point of PAO is determined according to GB / T 267-1988 "Determination of flash and fire points of petroleum products".

[0033] Example 1 Poly-α-olefin-1

[0034] This example provides an α-olefin polymer, and the preparation method thereof comprises the following steps:

[0035] Under the protection of high-purity N2, 240 g of 1-decene and 1 L of n-hexane were added to a reactor, and were stirred and dissolved at room temperature to make the concentration of 1-decene in the reaction system 2 mol / L. iPrOH (isopropyl alcohol), FeCl3 and dichloromethane were added to the above reaction system to initiate the polymerization of 1-decene, wherein the molar ratio of FeCl3, iPrOH and 1-decene was 0.06:0.084:1. The polymerization reaction temperature was 50℃, the polymerization reaction time was 90 min, and then 20 mL of ethanol was added to terminate the reaction; after termination, the material was stirred out in a large amount of ethanol, and then was washed with ethanol for three times. The obtained polymer was vacuum dried at 40℃ to obtain the dried α-olefin polymer, and the M n was 430 g·mol -1 -1. w / M n was 1.05.

[0036] The 100℃ kinematic viscosity of the above poly-α-olefin-1 was 10.17 mm 2 / s, and the flash point was 288℃. Compared with the comparative example PAO1, the flash point was 22℃ higher under the condition of equivalent 100℃ kinematic viscosity, and the safety performance was more excellent.

[0037] Example 2 Poly-α-olefin-2

[0038] This example provides an α-olefin polymer, and the preparation method thereof is the same as that of Example 1, and the difference lies in that the reaction time is 60 min, the concentration of 1-decene in the reaction system is 1 mol / L, and the molar ratio of FeCl3, iPrOH and 1-decene is 0.06:0.084:1, and the M n was 350 g·mol -1 -1. w / M n was 1.03.

[0039] The poly-alpha-olefin-2 has a kinematic viscosity at 100°C of 7.89 mm 2 / s, and a flash point of 280°C. Compared with the comparative example PAO2, the flash point is 20°C higher, and the safety performance is more excellent under the condition of equivalent kinematic viscosity at 100°C.

[0040] Example 3 Poly-alpha-olefin-3

[0041] This example provides an alpha-olefin polymer, the preparation method of which comprises the following steps: under the protection of high-purity N2, 240 g of 1-decene and 1 L of n-hexane are added to a reactor, and stirring and dissolution are performed at room temperature, so that the concentration of 1-decene in the reaction system is 2 mol / L. iPrOH, FeCl3 and dichloromethane containing an initiator for initiating polymerization of 1-decene are added to the above reaction system, and the molar ratio of FeCl3, iPrOH and 1-decene is 0.06:0.084:1. The polymerization reaction temperature is 80°C, the polymerization reaction time is 90 min, then 20 mL of ethanol is added to terminate the reaction; after termination, the material is stirred out in a large amount of ethanol, and then washed with ethanol for three times. The obtained polymer is vacuum dried at 40°C, and the dried alpha-olefin polymer is obtained, and the M n is 250 g·mol -1 , M w / M n = 1.05.

[0042] The poly-alpha-olefin-3 has a kinematic viscosity at 100°C of 5.82 mm 2 / s, and a flash point of 250°C. Compared with the comparative example PAO3, the flash point is 4°C higher, and the safety performance is more excellent under the condition of equivalent kinematic viscosity at 100°C.

[0043] Example 4 Poly-alpha-olefin-4

[0044] This example provides an alpha-olefin polymer, the preparation method of which comprises the following steps: under the protection of high-purity N2, 240 g of 1-decene and 1 L of n-hexane are added to a reactor, and stirring and dissolution are performed at room temperature, so that the concentration of 1-decene in the reaction system is 2 mol / L. iPrOH, FeCl3 and dichloromethane containing an initiator for initiating polymerization of 1-decene are added to the above reaction system, and the molar ratio of FeCl3, iPrOH and 1-decene is 0.06:0.084:1. The polymerization reaction temperature is 80°C, the polymerization reaction time is 90 min, then 20 mL of ethanol is added to terminate the reaction; after termination, the material is stirred out in a large amount of ethanol, and then washed with ethanol for three times. The obtained polymer is vacuum dried at 40°C, and the dried alpha-olefin polymer is obtained, and the M n is 1130 g·mol -1 , M w / M n = 1.13.

[0045] The poly-alpha-olefin-4 has a kinematic viscosity at 100°C of 38.2 mm 2 / s, and a flash point of 288°C.

[0046] Example 5 Poly-alpha-olefin-5

[0047] The embodiment provides an alpha-olefin polymer, and a preparation method thereof comprises the following steps: under the protection of high-purity N2, 60g of 1-decene and 1L of n-hexane are added into a reactor, and stirring and dissolution are carried out at room temperature, so that the concentration of 1-decene in the reaction system is 0.5mol / L. The above reaction system is added with iPrOH, FeCl3 and dichloromethane to initiate polymerization of 1-decene, wherein the molar ratio of FeCl3, iPrOH and 1-decene is 0.02:0.028:1. The polymerization reaction temperature is 80 DEG C, the polymerization reaction time is 30min, then 20ml of ethanol is added to terminate the reaction, and after termination, the product is stirred out in a large amount of ethanol, and then washed with ethanol for three times. The obtained polymer is vacuum dried at 40 DEG C, so that the dried alpha-olefin polymer is obtained, the M n of which is 140g·mol -1 , and the M w / M n is 1.02.

[0048] The 100 DEG C kinematic viscosity of the above poly-alpha-olefin-5 is 4.0mm 2 / s, and the flash point is 232 DEG C.

[0049] Example 6 poly-alpha-olefin-6

[0050] The embodiment provides an alpha-olefin polymer, and a preparation method thereof comprises the following steps: under the protection of high-purity N2, 240g of 1-decene and 1L of n-hexane are added into a reactor, and stirring and dissolution are carried out at room temperature, so that the concentration of 1-decene in the reaction system is 2mol / L. The above reaction system is added with iPrOH, SnCl4 and dichloromethane to initiate polymerization of 1-decene, wherein the molar ratio of SnCl4, iPrOH and 1-decene is 0.06:0.084:1. The polymerization reaction temperature is 50 DEG C, the polymerization reaction time is 90min, then 20ml of ethanol is added to terminate the reaction, and after termination, the product is stirred out in a large amount of ethanol, and then washed with ethanol for three times. The obtained polymer is vacuum dried at 40 DEG C, so that the dried alpha-olefin polymer is obtained, the M n of which is 416g·mol -1 , and the M w / M n is 1.34.

[0051] The 100 DEG C kinematic viscosity of the above poly-alpha-olefin-6 is 10.03mm 2 / s, and the flash point is 263 DEG C.

[0052] Comparative example 1

[0053] The comparative example provides an alpha-olefin polymer, and a preparation method thereof is basically same as that of the example 1, and the difference is that the 1L of n-hexane solution is replaced by 70ml of water and 930ml of dichloromethane solution.

[0054] The results show that the product yield is almost 0.

[0055] Comparative Example 2 PAO1 was SpectraSyn 1000 TM 10

[0056] PAO1 had a kinematic viscosity (100°C) of 10 mm 2 / s and a flash point (open cup) of 266°C.

[0057] Comparative Example 3 PAO2 was SpectraSyn 800 TM 8

[0058] PAO2 had a kinematic viscosity (100°C) of 8 mm 2 / s and a flash point (open cup) of 260°C.

[0059] Comparative Example 4 PAO3 was SpectraSyn 600 TM 6

[0060] PAO3 had a kinematic viscosity (100°C) of 5.8 mm 2 / s and a flash point (open cup) of 246°C.

[0061] Finally, it should be noted that the above examples are merely used to illustrate the technical solutions of the present application, and are not intended to limit the same; even though the present application has been described in detail with reference to the foregoing examples, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing examples, or make equivalent replacements for some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for preparing an α-olefin polymer, characterized in that, include: The polymerization reaction of α-olefin monomers comprises an α-olefin monomer, an organic solvent, a co-initiator, and an electron donor. The co-initiator is one or more of SbCl4, SnCl4, ZnCl2, MnCl4, FeCl2, FeCl3, CoCl2, and NiCl2. The organic solvent is one or more of alkanes, halogenated hydrocarbons, tetrahydrofuran, and cycloacetone. The electron donor is an alcohol and / or an alkyl-substituted phenolic compound. The α-olefin monomer is 1-octene, 1-nonene, 1-decene, 1-undecene, or 1-dodecene.

2. The method for preparing the α-olefin polymer according to claim 1, characterized in that, The co-initiator is FeCl3.

3. The method for preparing the α-olefin polymer according to claim 1, characterized in that, The alcohol is methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, tert-butanol, n-pentanol, isopentanol, pentapentanol, n-hexanol, n-heptanol, n-octanol, 2,2-dimethylpropanol, 2,3-dimethyl-2-butanol, 3,3-dimethyl-2-butanol, 2-ethylbutanol, 2-methylpentanol, 3-ethyl-2-pentanol, 2,4-dimethylpentanol, 2-methyl-2-hexanol, 2-ethylbutanol, 2,3-dimethylpentanol. The alkyl-substituted phenolic compound is one or more of 2,4-dimethylpentanol, 2,3,4-trimethyl-3-pentanol, 2-methyl-3-ethylpentanol, 3,4-dimethylhexanol, 3-methylheptanol, 2-propylpentanol, and 2-ethylhexanol; the alkyl-substituted phenolic compound is one or more of 2-methylphenol, 3-methylphenol, 4-methylphenol, 2-ethylphenol, 2,6-di-tert-butylphenol, and 2,6-di-tert-butyl-4-methylphenol.

4. The method for preparing the α-olefin polymer according to claim 3, characterized in that, The electron donor is one or more of isopropanol, tert-butanol, and isoamyl alcohol.

5. The method for preparing the α-olefin polymer according to claim 1, characterized in that, The concentration of the α-olefin monomer in the monomer solution is 1.0~2.5 M.

6. The method for preparing the α-olefin polymer according to any one of claims 1 to 5, characterized in that, The molar ratio of the co-initiator to the α-olefin monomer is 0.005~0.08:1, and the molar ratio of the electron donor to the co-initiator is 0.2~1.5:

1.

7. The method for preparing the α-olefin polymer according to any one of claims 1 to 5, characterized in that, include: (1) Dilute the α-olefin monomer to a concentration of 1.0~2.5 M using an organic solvent, and then pre-cool it to 0~30 °C to obtain a monomer solution; (2) Mix the monomer solution with the co-initiator and electron donor, and react at 0~100 °C for 5~150 min; (3) Add pre-cooled ethanol to the reaction system, use alcohol to precipitate the precipitate, remove the solvent, and dry under vacuum to obtain α-olefin polymer.

8. An α-olefin polymer, characterized in that, It is prepared by the preparation method described in any one of claims 1 to 7.

9. The α-olefin polymer according to claim 8, characterized in that, The number-average molecular weight of the α-olefin polymer is 140~700 g·mol⁻¹. -1 The kinematic viscosity at 100℃ is 2~40 mm. 2 / s, with an open flash point of 230~300 ℃.

10. The α-olefin polymer according to claim 9, characterized in that, The number-average molecular weight of the α-olefin polymer is 420~540 g·mol⁻¹. -1 The kinematic viscosity at 100℃ is 2~10 mm. 2 / s, with an open flash point of 270~300 ℃.

11. A lubricating oil, characterized in that, It contains the α-olefin polymer according to any one of claims 8-10.