Low-viscosity high-flash-point alpha-olefin polymer as well as preparation method and application thereof

Abstract

The invention relates to the technical field of high polymer materials, in particular to a low-viscosity and high-flash-point alpha-olefin polymer as well as a preparation method and application thereof. The preparation method of the alpha-olefin polymer comprises the following steps: carrying out polymerization reaction on an alpha-olefin monomer, wherein a reaction system consists of the alpha-olefin monomer, an organic solvent, a co-initiator and an electron donor; and the coinitiator is one or more of SbCl4, SnCl4, ZnCl2, MnCl4, FeCl2, FeCl3, CoCl2 and NiCl2. The invention also discloses a preparation method of the catalyst. By optimizing a polymerization system, a polymer containing C8-C12 linear alpha-olefin is synthesized, and lubricating oil products with different repetitive unit contents, different kinematic viscosities and different flash points (openings) are prepared. Compared with other lubricating oil products, the product disclosed by the invention has a higher flash point (opening point) under the same kinematic viscosity condition, so that the volatility of the lubricating oil product is smaller, and the storage, transportation and use safety is higher.

Description

Technical Field

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

[0002] Polyalphaolefin (PAO), which can be made from C8-C 12 Linear α-olefins (LAO) are prepared through polymerization and hydrogenation reactions. PAO has the characteristics of high viscosity index, low pour point, low oil volatility loss and excellent high temperature oxidation stability, especially its comprehensive performance of viscosity-temperature performance, low temperature performance and thermal oxidation stability is good. It is currently considered to be the most promising synthetic lubricant. PAO plays an irreplaceable role in cutting-edge fields such as aerospace and military industry. It is also an important raw material for the production of high-end lubricants in industries such as advanced automobiles, wind power, high-speed rail, and intelligent manufacturing.

[0003] In the prior art, some researchers have used TiCl4 / Al(Et)3 as a catalyst system to catalyze the reaction of mixed C at a reaction temperature of 65-85°C. 10 Preparation of medium viscosity PAO base oil from olefins. Under the optimized polymerization reaction conditions, the conversion rate of the polymerization product is 63.29%, and the kinematic viscosity of the base oil at 100℃ is 27.11mm 2 / s, viscosity index is 124, pour point is -45℃. (TiCl4 / Al(Et)3 catalytic mixed C 10 Research on medium-viscosity PAO base oil for olefin synthesis, Progress in Fine Petrochemicals, 2021, 22(02): 46-50). In "Synthesis and Properties of Decene-1 Poly-α-olefin Synthetic Oil", BF3 was used as a catalyst and n-butanol as an initiator. Under the conditions of 30°C and 0.4MPa, trimers and tetramers of 1-decene can be prepared. The conversion rate of 1-decene can reach 99.8%, providing a new experimental method for low-viscosity, high-viscosity index, and low-freezing-point PAO products (Journal of Liaoning Petrochemical University, 2005, 25(03): 24-27). However, the above-mentioned existing technologies still have defects such as harsh reaction conditions, low conversion rate of polymerization products, uncontrollable polymerization reactions, and high raw material costs. Therefore, there is still room for further improvement in practical applications. Summary of the invention

[0004] The present invention provides a low-viscosity and high-flash-point alpha-olefin polymer and a preparation method and application thereof, so as to solve the defect of low flash point of the alpha-olefin polymer in the prior art, thereby achieving additive-free and improving the safety performance of oil products.

[0005] The present invention provides a preparation method of an alpha-olefin polymer, comprising: subjecting an alpha-olefin monomer to a polymerization reaction, wherein the reaction system consists of the alpha-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.

[0006] The present invention finds that the above reaction system can effectively control the production of α-olefin polymers with lower viscosity and higher flash point under relatively mild conditions, thereby significantly improving 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 an α-olefin polymer with a higher flash point and low viscosity.

[0009] Preferably, the organic solvent is one or more of alkanes, halogenated hydrocarbons, tetrahydrofuran and cyclopropanone.

[0010] More preferably, the organic solvent is one or more of ethylene dichloride, methylene chloride and n-hexane.

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

[0012] Preferably, the alcohol is methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, tert-butanol, n-pentanol, isopentanol, pentaerythrin, 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-dimethyl 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-butyl alcohol and isopentanol.

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

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

[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: temperature of 30-40° C.; time of 2-3 h.

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

[0019] (1) using an organic solvent to dilute an α-olefin monomer to a concentration of 1.0 to 2.5 M, and then precooling to 0 to 30° C. to obtain a monomer solution;

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

[0021] (3) Precooled ethanol is added to the reaction system, the precipitate is precipitated with an alcoholic substance, the solvent is removed, and the α-olefin polymer is obtained after vacuum drying.

[0022] The present invention also provides an alpha-olefin polymer, which is prepared by the above preparation method.

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

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

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

[0026] The present invention provides a low-viscosity and high-flash-point α-olefin polymer and a preparation method and application thereof, by optimizing the polymerization system, synthesizing a C8-C 12The polymer of linear α-olefin is effectively controlled to prepare lubricating oil products with different repeating unit contents, lower kinematic viscosity and higher flash point (opening). Compared with other lubricating oil products, under the same kinematic viscosity conditions, the product of the present invention has a higher flash point (opening), making the lubricating oil product less volatile and safer in storage, transportation and use. The functionality of the material is improved without adding harmful additives, making its application in the emerging lubricating oil industry possible, and it has a broader prospect. DETAILED DESCRIPTION

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

[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 are conventional means well known to those skilled in the art.

[0029] In the present invention, the polymer 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 and a flow rate of 1 mL / min.

[0030] The present invention uses the TensorⅡ Fourier transform infrared spectrometer of Bruker Spectroscopy to measure the infrared spectrum (FTIR) of the polymer. The sample to be tested is completely dissolved in n-hexane and evenly applied on a potassium bromide (KBr) sheet that has been fully ground and pressed. KBr is used as the background as a reference, the test temperature is 25°C, and the scanning range is set to 400-4000cm -1 .

[0031] The kinematic viscosity of lubricating oil is tested by the method specified in GB / T 265. The detector consists of a light-emitting diode and a phototransistor. When the sample flows into the detector, the instrument starts timing automatically and stops timing when it flows out of the detector. The kinematic viscosity value of the lubricating oil is obtained by multiplying the flow time by the viscosity tube constant.

[0032] Flash point is an important safety indicator for the transportation and use of lubricating oil. Under specified experimental conditions, the lowest temperature at which a certain ignition source vaporizes and ignites is defined as the flash point. Generally, the flash point of oil products is required to be 20 to 30°C higher than the use temperature. The flash point determination includes two methods: open cup flash point (Cleveland open cup test) and closed cup flash point (Pensky-Martin closed cup method). When the flash point of the same oil sample is determined, the open cup method is 20 to 30°C higher than the closed cup method. The flash point determination of lubricating oil often adopts the open cup flash point determination method. The open cup flash point of PAO is determined in accordance with GB / T 267-1988 "Determination of Flash Point and Fire Point of Petroleum Products".

[0033] Example 1 Polyalphaolefin-1

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

[0035] Under the protection of high-purity N2, 240g of 1-decene and 1L of n-hexane were added to the reactor, and stirred to dissolve at room temperature so that the concentration of 1-decene in the reaction system was 2mol / L. iPrOH (isopropanol), 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°C, the polymerization reaction time was 90min, and then 20mL of ethanol was added to terminate the reaction; after termination, the material was stirred in a large amount of ethanol and then washed three times with ethanol. The obtained polymer was vacuum dried at 40°C to obtain a dried α-olefin polymer, whose M n 430 g·mol -1 , M w / M n =1.05.

[0036] The kinematic viscosity of the poly-α-olefin-1 at 100°C is 10.17 mm 2 / s, and the flash point is 288°C. Compared with the comparative example PAO1, the flash point is 22°C higher at the same kinematic viscosity at 100°C, and it has better safety performance.

[0037] Example 2 Polyalphaolefin-2

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

[0039] The kinematic viscosity of the poly-α-olefin-2 at 100°C is 7.89 mm 2 / s, and the flash point is 280°C. Compared with the comparative example PAO2, the flash point is 20°C higher at the same kinematic viscosity at 100°C, and it has better safety performance.

[0040] Example 3 Polyalphaolefin-3

[0041] This embodiment provides an α-olefin polymer, and its preparation method is the same as that of Example 1, except that the reaction time is 30 min, the concentration of 1-decene in the reaction system is 1 mol / L, wherein the molar ratio of FeCl3, iPrOH and 1-decene is 0.06:0.084:1, and the M n 250 g·mol -1 , M w / M n =1.05.

[0042] The kinematic viscosity of the poly-α-olefin-3 at 100°C is 5.82 mm 2 / s, and the flash point is 250°C. Compared with the comparative example PAO3, the flash point is 4°C higher at the same kinematic viscosity at 100°C, and it has better safety performance.

[0043] Example 4 Polyalphaolefin-4

[0044] The present embodiment provides an α-olefin polymer, and its preparation method includes the following steps: under the protection of high-purity N2, 240g 1-decene and 1L n-hexane are added to the reactor, and the mixture is stirred and dissolved at room temperature so that the concentration of 1-decene in the reaction system is 2mol / L. iPrOH, FeCl3 and dichloromethane are added to the above reaction system to initiate the polymerization of 1-decene, wherein 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 90min, and then 20mL of ethanol is added to terminate the reaction; after termination, the material is stirred in a large amount of ethanol and then washed three times with ethanol. The obtained polymer is vacuum dried at 40°C to obtain a dried α-olefin polymer, and its M n 1130 g·mol -1 , M w / M n =1.13.

[0045] The kinematic viscosity of the poly-α-olefin-4 at 100°C is 38.2 mm 2 / s, flash point is 288℃.

[0046] Example 5 Polyalphaolefin-5

[0047] The present embodiment provides an α-olefin polymer, and its preparation method includes the following steps: under the protection of high-purity N2, 60g 1-decene and 1L n-hexane are added to the reactor, and the mixture is stirred and dissolved at room temperature so that the concentration of 1-decene in the reaction system is 0.5mol / L. iPrOH, FeCl3 and dichloromethane are added to the above reaction system to initiate the 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°C, the polymerization reaction time is 30min, and then 20mL of ethanol is added to terminate the reaction; after termination, the material is stirred in a large amount of ethanol and then washed three times with ethanol. The obtained polymer is vacuum dried at 40°C to obtain a dried α-olefin polymer, and its M n 140 g·mol -1 , M w / M n =1.02.

[0048] The kinematic viscosity of the poly-α-olefin-5 at 100°C is 4.0 mm 2 / s, flash point is 232℃.

[0049] Example 6 Polyalphaolefin-6

[0050] The present embodiment provides an α-olefin polymer, and its preparation method includes the following steps: under the protection of high-purity N2, 240g 1-decene and 1L n-hexane are added to the reactor, and the mixture is stirred and dissolved at room temperature so that the concentration of 1-decene in the reaction system is 2mol / L. Tert-butanol, SnCl4 and dichloromethane are added to the above reaction system to initiate the polymerization of 1-decene, wherein the molar ratio of SnCl4, tert-butanol and 1-decene is 0.06:0.084:1. The polymerization reaction temperature is 50°C, the polymerization reaction time is 90min, and then 20mL of ethanol is added to terminate the reaction; after termination, the material is stirred in a large amount of ethanol and then washed three times with ethanol. The obtained polymer is vacuum dried at 40°C to obtain a dried α-olefin polymer, and its M n 416 g·mol -1 , M w / M n =1.34.

[0051] The kinematic viscosity of the poly-α-olefin-6 at 100°C is 10.03 mm 2 / s, flash point is 263℃.

[0052] Comparative Example 1

[0053] This comparative example provides an α-olefin polymer, and its preparation method is basically the same as that of Example 1, except that the 1L n-hexane solution is replaced with 70ml water and 930ml dichloromethane solution.

[0054] The results showed that the product yield was almost 0.

[0055] Comparative Example 2 PAO1 model is SpectraSyn TM 10

[0056] PAO1 kinematic viscosity (100℃) is 10mm 2 / s, the flash point (open) is 266°C.

[0057] Comparative Example 3 PAO2 model is SpectraSyn TM 8

[0058] PAO2 kinematic viscosity (100℃) is 8mm 2 / s, flash point (open) is 260℃.

[0059] Comparative Example 4 PAO3 model is SpectraSyn TM 6

[0060] PAO3 kinematic viscosity (100℃) is 5.8mm 2 / s, the flash point (open) is 246°C.

[0061] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing an α-olefin polymer, characterized in that: include: The α-olefin monomer is polymerized, and the reaction system consists of the 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.

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

3. The method for preparing an α-olefin polymer according to claim 1 or 2, characterized in that: The organic solvent is one or more of alkane, halogenated hydrocarbon, tetrahydrofuran and cyclopropanone.

4. The method for preparing an α-olefin polymer according to any one of claims 1 to 3, characterized in that: The electron donor is an alcohol and / or an alkyl-substituted phenol compound; the alcohol is methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, tert-butanol, n-pentanol, isopentanol, pentaerythrin, 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- One or more of 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; preferably, the electron donor is one or more of isopropanol, tert-butyl alcohol and isoamyl alcohol.

5. The method for preparing an α-olefin polymer according to any one of claims 1 to 4, characterized in that: The α-olefin polymer contains C8-C 12 The linear structural unit, the α-olefin monomer is 1-octene, 1-nonene, 1-decene, 1-undecene or 1-dodecene; preferably, in the monomer solution, the concentration of the α-olefin monomer is 1.0-2.5M.

6. The method for preparing an 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 an α-olefin polymer according to any one of claims 1 to 6, characterized in that: include: (1) using an organic solvent to dilute an α-olefin monomer to a concentration of 1.0 to 2.5 M, and then precooling to 0 to 30° C. to obtain a monomer solution; (2) mixing the monomer solution with a co-initiator and an electron donor, and reacting at 0 to 100° C. for 5 to 150 minutes; (3) Precooled ethanol is added to the reaction system, the precipitate is precipitated with an alcoholic substance, the solvent is removed, and the α-olefin polymer is obtained after vacuum drying.

8. An α-olefin polymer, characterized in that The compound is prepared by the preparation method according to 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 to 700 g·mol -1 , 100℃ kinematic viscosity is 2~40mm 2 / s, the open flash point is 230-300°C; preferably, the number average molecular weight of the α-olefin polymer is 420-540 g·mol -1 , 100℃ kinematic viscosity is 2~10mm 2 / s, the open flash point is 270~300℃.

10. A lubricating oil, characterized in that: It contains the α-olefin polymer according to claim 8 or 9.