High-temperature-resistant lubricating oil as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of lubricating oil, and particularly relates to high-temperature-resistant lubricating oil as well as a preparation method and application thereof. The lubricating oil comprises the following components: 1-5% of stearic acid modified inorganic oxide; 3-7% of dibutyl phosphate ammonium salt; 2-6% of a metal salt; 0.5-3% of a viscosity index improver; 2-6% of a nonionic surfactant; the total percentage is 100%. The lubricant disclosed by the invention not only has excellent wear resistance, but also has excellent high-temperature oxidation resistance and demulsibility.

Description

Technical Field

[0001] The invention belongs to the technical field of lubricating oils, and in particular relates to a high temperature resistant lubricating oil and a preparation method and application thereof. Background Art

[0002] Lubricating oil for mechanical equipment is a substance used to reduce friction and wear between mechanical parts. It can form a protective film to reduce direct contact between metal surfaces, thereby extending the service life of equipment and improving mechanical efficiency. There are many types of lubricating oils, including mineral oils, synthetic oils and semi-synthetic oils, which are selected according to different working environments and mechanical requirements. The correct use and replacement of lubricating oils is essential to maintain the performance of mechanical equipment.

[0003] When choosing the right lubricant for mechanical equipment, you need to pay attention to its performance indicators and applicable scope. For example, oxidation resistance: Lubricants will be attacked by oxygen during use, resulting in performance degradation. Lubricants with excellent oxidation resistance can extend the oil change cycle and reduce maintenance costs; anti-wear: During the operation of mechanical equipment, friction will occur between parts. Lubricants with excellent anti-wear properties can effectively reduce wear and extend the service life of the equipment.

[0004] However, as some mechanical equipment often operates at high temperatures, the movement of molecules at high temperatures intensifies, which often leads to reduced oxidation resistance and wear resistance. Therefore, there is an urgent need to develop a lubricant with excellent oxidation resistance and wear resistance at high temperatures. Summary of the invention

[0005] In a first aspect, the present invention provides a high temperature resistant lubricating oil, the lubricating oil comprising the following components:

[0006] Stearic acid modified inorganic oxide 1-5%;

[0007] Dibutyl phosphate ammonium salt 3-7%;

[0008] Metal salt 2-6%;

[0009] Viscosity index improver 0.5-3%;

[0010] Nonionic surfactant 2-6%;

[0011] Base oil is replenished to 100%.

[0012] Furthermore, the lubricating oil comprises the following components by mass fraction:

[0013] Stearic acid modified inorganic oxide 2.2-3%;

[0014] Dibutyl ammonium phosphate 4.5-5.5%;

[0015] Metal salt 2.4-3.2%;

[0016] Viscosity index improver 1.2-1.8%;

[0017] Nonionic surfactant 2.5-3.2%;

[0018] Base oil is replenished to 100%.

[0019] In the system of the present invention, dibutyl ammonium phosphate alone can improve the wear resistance of lubricating oil at low temperatures, but at a high temperature of 220°C, the improvement in the wear resistance of lubricating oil is limited. In the system of the present invention, the use of stearic acid-modified inorganic oxides and dibutyl ammonium phosphate can synergistically enhance the high-temperature wear resistance of lubricating oil. It is speculated that this is because the stearic acid-modified inorganic oxide can act as a colloid nucleus to allow dibutyl ammonium phosphate and other components in the lubricating oil to be adsorbed around it to form a special structure, which can form a dense chemical friction-resistant film at high temperature and can effectively reduce relative friction during sliding.

[0020] As a preferred technical solution of the present invention, the preparation method of the stearic acid-modified inorganic oxide comprises:

[0021] (1) mixing stearic acid and ethanol, then adding an inorganic oxide, and reflux reacting at 70-90° C. for 20-40 minutes to obtain a modified product;

[0022] (2) The modified product is cooled to room temperature, filtered, washed with anhydrous ethanol for 3-6 times, and then dried to obtain a stearic acid-modified inorganic oxide.

[0023] As a preferred embodiment of the present invention, the inorganic oxide is selected from at least one of calcium oxide, magnesium oxide, zinc oxide and zirconium oxide, preferably zirconium oxide.

[0024] As a preferred technical solution of the present invention, the average particle size of the inorganic oxide is 20,000-50,000 mesh, preferably 30,000 mesh.

[0025] The zirconium oxide in the present invention can be obtained commercially, for example, the zirconium oxide is purchased from Nangong Xindun Alloy Welding Material Spraying Co., Ltd., and its average particle size is 30,000 meshes.

[0026] As a preferred technical solution of the present invention, in step (1), the mass ratio of stearic acid, ethanol and inorganic oxide is (5-20):100:(50-80), preferably (8-12):100:(60-70).

[0027] The drying method in step (2) of the present invention is not particularly limited and can be a conventional drying method in the art as long as the anhydrous ethanol can be removed. The present invention will not elaborate on it in detail.

[0028] As a preferred technical solution of the present invention, the metal salt is selected from rare earth metal salts, copper carboxylates and zinc dialkyl dithiophosphates.

[0029] As a preferred technical solution of the present invention, the mass ratio of the rare earth metal salt, the copper carboxylate and the zinc dialkyl dithiophosphate is 1:(1-5):(2-10), preferably 1:(2-2.5):(3-5).

[0030] As a preferred technical solution of the present invention, the zinc dialkyl dithiophosphate is selected from zinc bisoctyl dithiophosphate and / or secondary alkyl dialkyl dithiophosphate, preferably zinc bisoctyl dithiophosphate.

[0031] As a preferred technical solution of the present invention, the rare earth metal salt is selected from cerium stearate.

[0032] As a preferred technical solution of the present invention, the copper carboxylate is selected from C 18-24 Copper alkenyl succinate, for example copper 2-octadecenyl succinate.

[0033] Zinc dialkyl dithiophosphate has certain antioxidant properties in lubricating oil, but cannot play a good antioxidant role under high temperature conditions. In the present invention, the synergistic effect of rare earth metal salts, copper carboxylates and zinc dialkyl dithiophosphates can better increase the antioxidant properties of lubricants, especially can further increase the high-temperature antioxidant properties of lubricating oils. The reasons are speculated to be: at high temperatures, cerium ions can inhibit the diffusion of copper ions and zinc ions, reduce the occurrence of oxidation reactions, and at the same time, the long chains in cerium stearate and 2-octadecene copper succinate can effectively hinder oxidation reactions in the system.

[0034] As a preferred technical solution of the present invention, the viscosity index improver is selected from at least one of polymethacrylate viscosity index improvers, succinimide ethylene-propylene copolymer viscosity index improvers and polyisobutylene viscosity index improvers, preferably polymethacrylate viscosity index improvers.

[0035] The polymethacrylate viscosity index improver in the present invention is commercially available, for example, viscosity index improver T602 HB PMA.

[0036] As a preferred technical solution of the present invention, the nonionic surfactant is selected from XP-70 and poloxamer.

[0037] As a preferred technical solution of the present invention, the mass ratio of XP-70 to poloxamer is 1:(1-5), preferably 1:(2-2.5).

[0038] In the present invention, the inventors found that the anti-emulsification performance of the lubricating oil modified with stearic acid and inorganic oxide was reduced. In order to modify the performance, the inventors initially added poloxamer as a demulsifier to reduce the anti-emulsification performance of the modified lubricating oil. However, the study found that the effect was not particularly obvious, but its mechanism was not clear. In the study, it was unexpectedly found that the use of XP-70 and poloxamer together can better increase the anti-emulsification of the lubricating oil. This may be because XP-70 can effectively react with stearic acid-modified inorganic oxides to form a special oil-in-water phenomenon, and poloxamer has a good water separation effect on oil-in-water emulsions.

[0039] As a preferred technical solution of the present invention, the base oil is selected from one or more of API Class I, Class II, Class III, Class IV and Class V, preferably a combination of Class II base oil and Class III base oil.

[0040] As a preferred technical solution of the present invention, the mass ratio of the combination of the Group II base oil and the Group III base oil is 1:(3-5).

[0041] As a preferred technical solution of the present invention, the Class II base oil is selected from Class II paraffin base oil 250N and / or Class II paraffin base oil 150N, preferably Class II paraffin base oil 250N.

[0042] As a preferred technical solution of the present invention, the Group III base oil is selected from Group III base oil 150SN and / or Group III base oil 500SN, preferably Group III base oil 150SN.

[0043] In a second aspect, the present invention provides a method for preparing the high temperature resistant lubricating oil according to the first aspect of the present invention, the preparation method comprising:

[0044] S1: mixing the viscosity index improver and the base oil to obtain a mixture A;

[0045] S2: mixing the mixture A with a nonionic surfactant, dibutyl ammonium phosphate and a metal salt for a second time to obtain a mixture B;

[0046] S3: performing a third mixing of the mixed material B and the stearic acid-modified inorganic oxide to obtain a high temperature resistant lubricating oil.

[0047] As a preferred technical solution of the present invention, the first mixing condition includes: stirring at a speed of 1000r / min-1500r / min for 20-30min at 80-100°C.

[0048] As a preferred technical solution of the present invention, the second mixing condition includes: stirring at a speed of 1000r / min-1500r / min for 1-2h at 65-75°C.

[0049] As a preferred technical solution of the present invention, the third mixing condition includes: stirring at a speed of 2000r / min-2500r / min at 50-60°C for 1-2h.

[0050] In a third aspect, the present invention provides the use of the high temperature resistant lubricating oil described in the first aspect of the present invention in mechanical equipment.

[0051] Compared with the prior art, the present invention has at least the following beneficial effects:

[0052] (1) In the present invention, the stearic acid-modified inorganic oxide interacts with dibutyl ammonium phosphate and other components in the system to make the lubricating oil have excellent wear resistance;

[0053] (2) The specific nonionic surfactant selected in the present invention can improve the defect of reduced anti-emulsification performance of lubricating oil caused by modified inorganic oxides;

[0054] (3) The specific metal salt selected in the present invention enables the lubricating oil to have excellent high temperature resistance. DETAILED DESCRIPTION

[0055] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0056] Example 1

[0057] According to the mass fraction, prepare: 2.5% stearic acid modified inorganic oxide; 5% dibutyl ammonium phosphate; 3% metal salt; 1.5% viscosity index improver; 3% nonionic surfactant; base oil supplemented to 100%;

[0058] The preparation method of the stearic acid-modified inorganic oxide comprises: (1) mixing stearic acid and ethanol, then adding zirconium oxide (purchased from Nangong Xindun Alloy Welding Material Spraying Co., Ltd., with an average particle size of 30,000 mesh), and reflux reaction at 80° C. for 30 minutes to obtain a modified product; (2) cooling the modified product to room temperature, filtering, washing with anhydrous ethanol for 5 times, and then drying to obtain the stearic acid-modified inorganic oxide; the mass ratio of stearic acid, ethanol and zirconium oxide is 10:100:65;

[0059] The metal salt is selected from rare earth metal salt, copper carboxylate and zinc dialkyl dithiophosphate; the mass ratio of rare earth metal salt, copper carboxylate and zinc dialkyl dithiophosphate is 1:2.3:4; the zinc dialkyl dithiophosphate is zinc dioctyl dithiophosphate; the rare earth metal salt is cerium stearate; the copper carboxylate is 2-octadecenyl copper succinate;

[0060] The viscosity index improver is viscosity index improver T602 HB PMA;

[0061] The nonionic surfactants are XP-70 and poloxamer; the mass ratio of XP-70 to poloxamer is 1:2.4;

[0062] The base oil is a combination of Class II base oil and Class III base oil; the mass ratio of the combination of Class II base oil and Class III base oil is 1:4; the Class II base oil is Class II paraffin base oil 250N; the Class III base oil is Class III base oil 150SN;

[0063] A method for preparing a high-temperature resistant lubricating oil comprises: S1, stirring a viscosity index improver and a base oil at 95°C at a speed of 1200 r / min for 25 minutes to obtain a mixture A; S2, stirring the mixture A with a nonionic surfactant, dibutyl ammonium phosphate and a metal salt at 70°C at a speed of 1200 r / min for 1.5 hours to obtain a mixture B; S3, stirring the mixture B with a stearic acid-modified inorganic oxide at 55°C at a speed of 2000 r / min for 1.5 hours to obtain a high-temperature resistant lubricating oil.

[0064] Example 2

[0065] According to the mass fraction, prepare: 3% of stearic acid modified inorganic oxide; 4.5% of dibutyl ammonium phosphate; 2.4% of metal salt; 1.2% of viscosity index improver; 2.5% of nonionic surfactant; and add the base oil to 100%.

[0066] The preparation method of stearic acid modified inorganic oxide comprises: (1) mixing stearic acid and ethanol, then adding zirconium oxide (purchased from Nangong Xindun Alloy Welding Material Spraying Co., Ltd., with an average particle size of 30000 mesh), and reflux reaction at 70°C for 40 minutes to obtain a modified product; (2) cooling the modified product to room temperature, filtering, washing with anhydrous ethanol for 5 times, and then drying to obtain a stearic acid modified inorganic oxide; the mass ratio of stearic acid, ethanol and zirconium oxide is 8:100:60;

[0067] The metal salt is selected from rare earth metal salt, copper carboxylate and zinc dialkyl dithiophosphate; the mass ratio of rare earth metal salt, copper carboxylate and zinc dialkyl dithiophosphate is 1:2:4; the zinc dialkyl dithiophosphate is zinc dioctyl dithiophosphate; the rare earth metal salt is cerium stearate; the copper carboxylate is 2-octadecenyl copper succinate;

[0068] The viscosity index improver is viscosity index improver T602 HB PMA;

[0069] The nonionic surfactants are XP-70 and poloxamer; the mass ratio of XP-70 to poloxamer is 1:2;

[0070] The base oil is a combination of Class II base oil and Class III base oil; the mass ratio of the combination of Class II base oil and Class III base oil is 1:5; the Class II base oil is Class II paraffin base oil 250N; the Class III base oil is Class III base oil 150SN;

[0071] A method for preparing a high-temperature resistant lubricating oil comprises: S1, stirring a viscosity index improver and a base oil at 100°C at a rotation speed of 1500 r / min for 30 minutes to obtain a mixture A; S2, stirring the mixture A with a nonionic surfactant, dibutyl ammonium phosphate and a metal salt at 75°C at a rotation speed of 1500 r / min for 2 hours to obtain a mixture B; S3, stirring the mixture B with a stearic acid-modified inorganic oxide at 60°C at a rotation speed of 2500 r / min for 2 hours to obtain a high-temperature resistant lubricating oil.

[0072] Comparative Example 1

[0073] According to the mass fraction, prepare: dibutyl ammonium phosphate 7.5%; metal salt 3%; viscosity index improver 1.5%; non-ionic surfactant 3%; base oil supplemented to 100%;

[0074] The metal salt is selected from rare earth metal salt, copper carboxylate and zinc dialkyl dithiophosphate; the mass ratio of rare earth metal salt, copper carboxylate and zinc dialkyl dithiophosphate is 1:2.3:4; the zinc dialkyl dithiophosphate is zinc dioctyl dithiophosphate; the rare earth metal salt is cerium stearate; the copper carboxylate is 2-octadecenyl copper succinate;

[0075] The viscosity index improver is viscosity index improver T602 HB;

[0076] The nonionic surfactant sub-surfactants are XP-70 and poloxamer; the mass ratio of XP-70 to poloxamer is 1:2.4;

[0077] The base oil is a combination of Class II base oil and Class III base oil; the mass ratio of the combination of Class II base oil and Class III base oil is 1:4; the Class II base oil is Class II paraffin base oil 250N; the Class III base oil is Class III base oil 150SN;

[0078] A method for preparing a high-temperature resistant lubricating oil comprises: S1, stirring a viscosity index improver and a base oil at 95°C at a rotation speed of 1200 r / min for 25 minutes to obtain a mixture A; S2, stirring the mixture A with a nonionic surfactant, dibutyl ammonium phosphate and a metal salt at 70°C at a rotation speed of 1200 r / min for 1.5 hours to obtain a high-temperature resistant lubricating oil.

[0079] Comparative Example 2

[0080] According to the mass fraction, prepare: 7.5% stearic acid modified inorganic oxide; 3% metal salt; 1.5% viscosity index improver; 3% nonionic surfactant; base oil supplemented to 100%;

[0081] The preparation method of the stearic acid-modified inorganic oxide comprises: (1) mixing stearic acid and ethanol, then adding zirconium oxide (purchased from Nangong Xindun Alloy Welding Material Spraying Co., Ltd., with an average particle size of 30,000 mesh), and reflux reaction at 80° C. for 30 minutes to obtain a modified product; (2) cooling the modified product to room temperature, filtering, washing with anhydrous ethanol for 5 times, and then drying to obtain the stearic acid-modified inorganic oxide; the mass ratio of stearic acid, ethanol and zirconium oxide is 10:100:65;

[0082] The metal salt is selected from rare earth metal salt, copper carboxylate and zinc dialkyl dithiophosphate; the mass ratio of rare earth metal salt, copper carboxylate and zinc dialkyl dithiophosphate is 1:2.3:4; the zinc dialkyl dithiophosphate is zinc dioctyl dithiophosphate; the rare earth metal salt is cerium stearate; the copper carboxylate is 2-octadecenyl copper succinate;

[0083] The viscosity index improver is viscosity index improver T602 HB PMA;

[0084] The nonionic surfactants are XP-70 and poloxamer; the mass ratio of XP-70 to poloxamer is 1:2.4;

[0085] The base oil is a combination of Class II base oil and Class III base oil; the mass ratio of the combination of Class II base oil and Class III base oil is 1:4; the Class II base oil is Class II paraffin base oil 250N; the Class III base oil is Class III base oil 150SN;

[0086] A method for preparing a high-temperature resistant lubricating oil comprises: S1, stirring a viscosity index improver and a base oil at 95°C at a rotation speed of 1200 r / min for 25 minutes to obtain a mixture A; S2, stirring the mixture A, a nonionic surfactant and a metal salt at 70°C at a rotation speed of 1200 r / min for 1.5 hours to obtain a mixture B; S3, stirring the mixture B and a stearic acid-modified inorganic oxide at 55°C at a rotation speed of 2000 r / min for 1.5 hours to obtain a high-temperature resistant lubricating oil.

[0087] Comparative Example 3

[0088] The method according to Example 1 is different in that:

[0089] The metal salt is selected from rare earth metal salt and zinc dialkyl dithiophosphate; the mass ratio of the rare earth metal salt to the zinc dialkyl dithiophosphate is 1:2.5; the zinc dialkyl dithiophosphate is dioctyl zinc dithiophosphate; and the rare earth metal salt is cerium stearate.

[0090] Comparative Example 4

[0091] The method according to Example 1 is different in that:

[0092] The metal salt is selected from copper carboxylate and zinc dialkyl dithiophosphate; the mass ratio of copper carboxylate to zinc dialkyl dithiophosphate is 1:2; the zinc dialkyl dithiophosphate is zinc dioctyl dithiophosphate; and the copper carboxylate is 2-octadecenyl copper succinate.

[0093] Comparative Example 5

[0094] The method according to Example 1 is different in that:

[0095] The nonionic surfactant is poloxamer.

[0096] Comparative Example 6

[0097] The method according to Example 1 is different in that:

[0098] The nonionic surfactant is XP-70.

[0099] Performance Testing

[0100] 1. High temperature oxidation resistance: A rotating oxygen bomb was used, referring to the standard of SH / T0193, and the lubricating oils in the examples and comparative examples were used as test samples (50 g), oxygen pressure was 620 KPa (25°C), 55.6 g copper coil, 5 mL distilled water, experimental temperature was 220°C, and the reaction started timing. The time required when the oxygen pressure dropped by 175 KPa was taken as the oxidation induction time. The longer the oxidation induction time, the better the high temperature oxidation resistance of the oil.

[0101] 2. High temperature anti-wear test: The lubricating oils in the embodiments and comparative examples were used as test samples for high temperature anti-wear test. The high temperature anti-wear test of the oil was carried out using the SRV-IV high frequency reciprocating friction tester of the German OPTIMOL company. The test conditions were load 300N, frequency 20Hz, stroke 2mm, temperature 220℃. The anti-wear performance of the test sample was judged by the size of the wear spot diameter. The smaller the wear spot diameter, the better the high temperature wear resistance.

[0102] 3. Anti-emulsification property: According to GB / T 7305 standard method, the lubricating oils in the examples and comparative examples were used as test samples for anti-emulsification performance test: 40 mL of the test sample and distilled water were respectively put into a measuring cylinder, stirred at a speed of 1500 r / min for 5 min at a test temperature of 54°C, and the separation time of the lubricating oil and water (40 oil-40 water-0 emulsion layer) mL was recorded. The shorter the separation time, the better the anti-emulsification property of the oil.

[0103] The test results are shown in Table 1:

[0104] Table 1 Performance test results

[0105]

[0106] It can be seen from the above performance test results that the lubricant in the present invention not only has excellent wear resistance, but also has excellent high temperature oxidation resistance and anti-emulsification properties.

[0107] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A high temperature resistant lubricating oil, characterized in that: The lubricating oil comprises the following components: Stearic acid modified inorganic oxide 1-5%; Dibutyl phosphate ammonium salt 3-7%; Metal salt 2-6%; Viscosity index improver 0.5-3%; Nonionic surfactant 2-6%; Base oil is replenished to 100%.

2. The high temperature resistant lubricating oil according to claim 1, characterized in that: The preparation method of the stearic acid-modified inorganic oxide comprises: (1) mixing stearic acid and ethanol, then adding an inorganic oxide, and reflux reacting at 70-90° C. for 20-40 minutes to obtain a modified product; (2) The modified product is cooled to room temperature, filtered, washed with anhydrous ethanol for 3-6 times, and then dried to obtain a stearic acid-modified inorganic oxide.

3. The high temperature resistant lubricating oil according to claim 2, characterized in that: The inorganic oxide is selected from at least one of calcium oxide, magnesium oxide, zinc oxide and zirconium oxide; in step (1), the mass ratio of stearic acid, ethanol and inorganic oxide is (5-20):100:(50-80), preferably (8-12):100:(60-70).

4. The high temperature resistant lubricating oil according to any one of claims 1 to 3, characterized in that: The metal salt is selected from rare earth metal salts, copper carboxylates and zinc dialkyl dithiophosphates.

5. The high temperature resistant lubricating oil according to claim 4, characterized in that: The mass ratio of the rare earth metal salt, the copper carboxylate and the zinc dialkyl dithiophosphate is 1:(1-5):(2-10).

6. The high temperature resistant lubricating oil according to claim 4, characterized in that: The zinc dialkyl dithiophosphate is selected from bis-octyl zinc dithiophosphate and / or secondary alkyl dialkyl zinc dithiophosphate; the rare earth metal salt is selected from cerium stearate; and the copper carboxylate is selected from C18-24 alkenyl copper succinate.

7. The high temperature resistant lubricating oil according to any one of claims 1 to 3, characterized in that: The viscosity index improver is selected from at least one of polymethacrylate viscosity index improvers, succinimide ethylene-propylene copolymer viscosity index improvers and polyisobutylene viscosity index improvers; the base oil is selected from one or more of API Class I, Class II, Class III, Class IV and Class V.

8. The high temperature resistant lubricating oil according to any one of claims 1 to 3, characterized in that: The nonionic surfactant is selected from XP-70 and poloxamer.

9. A method for preparing the high temperature resistant lubricating oil according to any one of claims 1 to 8, characterized in that: The preparation method comprises: S1: mixing the viscosity index improver and the base oil to obtain a mixture A; S2: mixing the mixture A with a nonionic surfactant, dibutyl ammonium phosphate and a metal salt for a second time to obtain a mixture B; S3: performing a third mixing of the mixed material B and the stearic acid-modified inorganic oxide to obtain a high temperature resistant lubricating oil.

10. Use of the high temperature resistant lubricating oil according to any one of claims 1 to 8 in mechanical equipment.

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