Low-ash-content high-performance engine lubricating oil composition and preparation method thereof

Abstract

The invention discloses a low-ash high-performance engine lubricating oil composition. The low-ash high-performance engine lubricating oil composition comprises at least two metal detergents; at least three antioxidants; a sulfur-containing anti-wear agent; at least one friction reducing agent; at least one viscosity index improver; at least one pour point depressant; at least one anti-foaming agent; and at least two base oils. The invention also discloses a preparation method of the lubricating oil composition, which specifically comprises the following steps: adding the base oil into a blending kettle, heating and stirring, adding the anti-foaming agent, the pour point depressant and the viscosity index improver, continuously stirring, sequentially adding the antioxidant, the metal detergent, the sulfur-containing anti-wear agent and the antifriction agent, and uniformly stirring to obtain the lubricating oil composition. According to the invention, ZDDP is compounded with an amine or naphthylamine high-temperature antioxidant to form an antioxidant compound system, and then a chalcogenide anti-wear agent is compounded, so that the oil product has excellent high-temperature oxidation resistance and low-temperature wear resistance at the same time; after the alkyl salicylate detergents with different base numbers are compounded, the ash content of an oil product can be controlled to be not greater than 0.8%.

Description

Technical Field

[0001] The invention belongs to the technical field of lubricating oil additives, and in particular relates to a low-ash high-performance engine lubricating oil composition, and also relates to a preparation method of the low-ash high-performance engine lubricating oil composition. Background Art

[0002] The continuous updating of vehicle and engine technology and the continuous improvement of vehicle fuel economy requirements have led to the requirements for gasoline engine oils mainly reflected in the improvement of performance such as emissions, fuel economy and engine durability, and have also continuously promoted the upgrading of gasoline engine oil products. GF-6 specification gasoline engine oil includes seven bench tests, including the program IIIH high temperature oxidation test, program IVB valve system wear test, program VG low temperature sludge test, VIE / VIF energy saving test, program VIII bearing corrosion test, program IX (LSPI) low speed pre-ignition test and program X timing chain wear test. In addition to the improvement of traditional high temperature oxidation performance, high temperature detergency, low temperature sediment dispersion performance, energy saving performance and other performance requirements of gasoline engine oil, special attention will be paid to the low speed pre-ignition performance, low temperature anti-wear performance and increasingly stringent fuel economy requirements unique to gasoline direct injection engines, aiming to evaluate the various performances of gasoline engine oils on new engines to the greatest extent. At the same time, in order to reduce the impact on the gasoline engine GPF exhaust after-treatment device and meet the stringent requirements of the National VI emission standards for particulate emissions, the ash content of the ILSACGF-6 standard gasoline engine oil product developed is no more than 0.8%. Summary of the invention

[0003] The object of the present invention is to provide a low-ash high-performance engine lubricating oil composition having excellent high-temperature oxidation resistance and low-temperature anti-wear performance, and the ash content is not more than 0.8%.

[0004] Another object of the present invention is to provide a method for preparing a low-ash high-performance engine lubricating oil composition.

[0005] The technical scheme adopted by the present invention is a low-ash high-performance engine lubricating oil composition, which contains: A, at least two metal detergents, containing 2.5-3.5% of component A; B, at least three antioxidants, containing 1.5-3.0% of component B; C, a sulfur-containing anti-wear agent, containing 0.1-1.0% of component C; D, at least one friction reducer, containing 0.1-1.0% of component D; E, at least one viscosity index improver, containing 3.0-10.0% of component E; F, at least one pour point depressant, containing 0.2-0.5% of component F; G, at least one anti-foaming agent, containing 0.001-0.010% of component G; H, at least two base oils, containing 80.0-90.0% of component H.

[0006] The present invention is also characterized in that:

[0007] The metal detergent is any two or more of low-base alkyl salicylate, medium-base alkyl salicylate and high-base alkyl salicylate.

[0008] The antioxidant is any three or more of butyl octyl zinc dithiophosphate, dioctyl zinc dithiophosphate, isopropyl isooctyl zinc dithiophosphate, aniline ashless antioxidant, and naphthylamine ashless antioxidant;

[0009] The sulfur-containing anti-wear agent is any one of diester disulfide, disulfide, sulfurized fat, and thiophene derivatives.

[0010] The pour point depressant is any one or two of alkyl naphthalene or poly-α-olefin; the viscosity index improver is a non-dispersed ethylene-propylene copolymer.

[0011] The antifoaming agent is any two or three of dimethyl silicone oil, alkyl acrylic acid copolymer and alkyl polyamide; the friction reducer is any one or two of fatty amine and high molecular organic ester.

[0012] The base oil is a combination of two or more hydrogenated base oils whose performance meets the requirements of API Class III base oil standards.

[0013] Another technical solution adopted by the present invention is a method for preparing a low-ash high-performance engine lubricating oil composition, which specifically comprises: adding a base oil into a blending kettle, heating to 60-80°C and stirring for 2 hours, adding an anti-foaming agent and continuing to stir for 2 hours, then adding a pour point depressant and a viscosity index improver and continuing to stir for 2 hours, then adding an antioxidant, a metal detergent, a sulfur-containing antiwear agent, and a friction reducer in sequence, and continuing to stir at 60-80°C for 4 hours to obtain a low-ash high-performance engine lubricating oil composition.

[0014] The beneficial effects of the present invention are as follows: the present invention adopts ZDDP to compound aniline or naphthylamine high-temperature antioxidants to form an antioxidant compound system, and then compound sulfur-based anti-wear agents, thereby ensuring that the oil product has excellent high-temperature antioxidant performance while taking into account low-temperature anti-wear performance; after compounding with alkyl salicylate detergents with different base values, the ash content of the oil product can be controlled to be no more than 0.8%, and the oil product has excellent high-temperature detergency and good resistance to low-speed pre-ignition performance. DETAILED DESCRIPTION

[0015] The present invention is described in detail below in conjunction with specific implementation modes.

[0016] The low-ash high-performance engine lubricating oil composition of the present invention comprises:

[0017] A, at least two metal detergents, containing 2.5-3.5% of component A, preferably 2.5-3.0%;

[0018] The metal detergent is any two or more of low-base alkyl salicylate, medium-base alkyl salicylate, and high-base alkyl salicylate; the alkyl salicylate is calcium alkyl salicylate, magnesium alkyl salicylate, or magnesium sulfonate;

[0019] In order to make the composition have excellent high-temperature antioxidant performance and low-temperature anti-wear performance, and at the same time not make the ash content too large (greater than 0.8%) due to improving the high-temperature detergency of the oil, various additives were systematically and comprehensively investigated. Metal detergents are the main source of ash in oil products. In order to ensure that the ash content of oil products is not more than 0.8%, the laboratory conducted a comprehensive performance investigation on calcium salts and magnesium salts of salicylates with different alkalinity values ​​and different ash contents. Magnesium salts have poorer high-temperature detergency than calcium salts, but the ash content is smaller; high-alkali calcium salts have excellent high-temperature detergency compared to low-alkali calcium salts, but the ash content is larger; with the continuous increase of alkalinity, the high-temperature detergency of oil products shows a positive trend, but the ash content also increases continuously. In order to have good high-temperature detergency and small ash content at the same time, medium-alkali salicylate detergents are used as the main component, and low-alkali and ultra-high-alkali salicylate detergents are used as auxiliary components. Under the condition of ensuring that the ash content is not more than 0.8%, the oil products have good high-temperature detergency.

[0020] B, at least three antioxidants, containing 1.5-3.0% of component B, preferably 1.5.0-2.5%;

[0021] The antioxidant is any three or more of butyl octyl zinc dithiophosphate, dioctyl zinc dithiophosphate, isopropyl isooctyl zinc dithiophosphate, aniline ashless antioxidant, and naphthylamine ashless antioxidant;

[0022] Aniline antioxidants are free radical chain reaction terminator antioxidants. When the temperature is higher than 120°C, the nitro radicals generated in the early stage of the decomposition and oxidation process can react with secondary alkyl radicals to form N-secondary alkyl diphenylamine intermediates, and the intermediates undergo thermal molecular rearrangement to form ketones and regenerated alkyl diphenylamine. At high temperatures, a complete inhibition cycle can capture an alkyl peroxy radical and an alkyl radical. The resonance of naphthylamine radicals formed by naphthylamine antioxidants is relatively stable, and dimerization or polymerization is formed while maintaining the -NH- group. Alkyl-substituted naphthylamine antioxidants are more oil-soluble than unsubstituted naphthylamines, and the stability of naphthylamine radicals is increased due to alkyl substitution, making their antioxidant effect better. Therefore, under high temperature conditions, aniline antioxidants and naphthylamine antioxidants have better antioxidant properties than traditional phenolic and amine antioxidants. The present invention uses aniline antioxidants or naphthylamine antioxidants for the first time to replace traditional phenolic and amine antioxidants. After being used in combination with the antioxidant and corrosion inhibitor ZDDP, the high-temperature antioxidant performance of the oil is greatly improved, and the PDSC oxidation induction period at 210°C is increased to more than 30 minutes.

[0023] C, a sulfur-containing antiwear agent, containing 0.1-1.0% of component C, preferably 0.5-1.0%;

[0024] The sulfur-containing anti-wear agent is any one of diester disulfide, disulfide, sulfurized fat, and thiophene derivative;

[0025] After the sulfur-based anti-wear agent is decomposed, the adsorption film formed on the friction surface is strong, showing excellent anti-wear performance and anti-wear retention performance. After adding the sulfur-based anti-wear agent, the two long-cycle wear bench tests of Program IVB and Program X were passed at one time.

[0026] D, at least one friction reducer, containing 0.1-1.0% of component D, preferably 0.5-1.0%;

[0027] The friction reducer is any one or two of aliphatic amine and high molecular weight organic ester;

[0028] The added ashless organic friction reducers such as fatty amines and high molecular weight organic esters mainly achieve the purpose of reducing friction by physically adsorbing on the friction surface to form an adsorption film that is easy to shear. They are less consumed during use and therefore have a strong ability to reduce friction. At the same time, they can also help the oil to maintain a low ash content to a certain extent.

[0029] E, at least one viscosity index improver, containing 3.0-10.0% of component E, preferably 5.0-10.0%;

[0030] The viscosity index improver is a non-dispersed ethylene-propylene copolymer;

[0031] F, at least one pour point depressant, containing 0.2-0.5% of component F, preferably 0.2-0.4%;

[0032] The pour point depressant is any one or two of alkyl naphthalene or poly-alpha olefin;

[0033] G, at least one antifoaming agent, containing 0.001-0.010% of component G, preferably 0.003-0.005%;

[0034] The antifoaming agent is any two or three of dimethyl silicone oil, alkyl acrylic acid copolymer, and alkyl polyamide;

[0035] H, at least two base oils, containing 80.0-90.0% of H component, preferably 80.0-85.0%;

[0036] The base oil is a combination of two or more high viscosity index hydrogenated base oils whose performance meets the requirements of API Class III base oil standards. The base oil is 100% hydrogenated base oil.

[0037] Base oil is the largest part of gasoline engine oil, and the quality and performance of base oil have an important impact on the quality and performance of finished oil. With the development of gasoline engine oil specifications, more and more stringent requirements are put forward for the evaporation loss, viscosity-temperature performance, sulfur content, etc. of oil products. Traditional solvent refining process base oil (Class I base oil) is increasingly unsuitable for the blending of high-performance gasoline engine oil products due to large evaporation loss and poor low-temperature starting performance. Class III base oil produced by hydrogenation process is widely used in high-performance internal combustion engine oil products due to its similar performance and low cost compared to PAO.

[0038] The preparation method of the low-ash high-performance engine lubricating oil composition of the present invention is specifically as follows: adding base oil into a stainless steel blending kettle with a stirrer, heating to 60-80°C and stirring for 2 hours, adding an anti-foaming agent and continuing to stir for 2 hours, then adding a pour point depressant and a viscosity index improver and continuing to stir for 2 hours, then adding an antioxidant, a metal detergent, a sulfur-containing anti-wear agent, and a friction reducer in sequence, and continuing to stir at 60-80°C for 4 hours until the mixture is uniform, thereby obtaining a low-ash high-performance engine lubricating oil composition.

[0039] The lubricating oil composition of the present invention has a sulfur content of 0.30-0.35% (mass), a phosphorus content of 0.06-0.07% (mass), a base number of 8.4-8.6 mgKOH / g, a sulfated ash content of 0.75-0.8% (mass), has excellent high-temperature oxidation resistance, fuel economy and low-temperature anti-wear performance, and has passed seven bench tests in the GF-6 standard requirements, including the program IIIH high-temperature oxidation test, the program IVB valve system wear test, the program VG low-temperature sludge test, the VIE / VIF energy-saving test, the program VIII bearing corrosion test, the program IX (LSPI) low-speed pre-ignition test and the program X timing chain wear test.

[0040] In order to screen the base oil and additive components, the present invention adopts simulation test methods such as hot pipe oxidation, coking test, PDSC (induction period) and HTCBT long-cycle oxidation test to evaluate the high-temperature detergency and dispersibility of the oil products and the high-temperature oxidation stability. The simulation test conditions are: the hot pipe oxidation test temperature is set at 280°C; the PDSC oxidation induction period is set at 210°C; the coking test plate temperature is set at 320°C, and the oil temperature is set at 150°C; the HTCBT oxidation test temperature is set at 175°C, and the time is set at 168h.

[0041] Example 1

[0042] Taking the production of 100 kg of the product of the present invention as an example, the raw materials and their mass ratios are as follows:

[0043]

[0044] Example 2

[0045] Taking the production of 100 kg of the product of the present invention as an example, the raw materials and their mass ratios are as follows:

[0046]

[0047] Example 3

[0048] Taking the production of 100 kg of the product of the present invention as an example, the raw materials and their mass ratios are as follows:

[0049] The dibutyl octyl diphenylamine ashless antioxidant in the above Example 1 is replaced by diisooctyl diphenylamine of the same mass, and the other components are of the same mass.

[0050] Example 4

[0051] Taking the production of 100 kg of the product of the present invention as an example, the raw materials and their mass ratios are as follows:

[0052] The dibutyl octyl diphenylamine ashless antioxidant in the above Example 1 is replaced by a naphthylamine antioxidant of the same mass, and the other components are of the same mass.

[0053] Example 5

[0054] Taking the production of 100 kg of the product of the present invention as an example, the raw materials and their mass ratios are as follows:

[0055] The diester disulfide antiwear agent in the above Example 2 was replaced with a sulfurized fat antiwear agent of the same mass, and the other components were of the same mass.

[0056] Example 6

[0057] Taking the production of 100 kg of the product of the present invention as an example, the raw materials and their mass ratios are as follows:

[0058] The diester disulfide antiwear agent in the above Example 2 was replaced with a thiophene derivative of the same mass, and the other components were of the same mass.

[0059] In order to verify the effect of the present invention, the engine lubricating oil prepared in the embodiment of the present invention was subjected to laboratory simulation performance evaluation and engine bench test, and the test results are as follows:

[0060] 1. Laboratory simulation evaluation of the comprehensive cleaning and anti-oxidation performance of the lubricating oil composition of the present invention

[0061] Table 1 Simulation test data of lubricating oil composition of the present invention

[0062]

[0063] As shown in Table 1, the ash content of the lubricating oil of the present invention is not more than 0.8%, and the test data such as the hot pipe test rating and the PDSC oxidation induction time are good, showing good high-temperature oxidation resistance. In the 168h HTCBT long-cycle oxidation test, the corrosion resistance of copper and lead is good.

[0064] 2. Laboratory wear performance evaluation of the lubricating oil composition of the present invention

[0065] Table 2 Wear performance simulation test data of the lubricating oil composition of the present invention

[0066]

[0067] As shown in Table 2, after adding 3% and 6% soot, the wear amount of the lubricating oil of the present invention is small, not more than 0.62um. Comparing the wear spot diameter of the oil before and after the long-cycle oxidation test HTCBT, it can be seen that the wear spot diameter has a certain increase but the amplitude is small, between 0.15mm and 0.20mm, and the lubricating oil shows good anti-wear retention ability.

[0068] 3. Engine bench test of the lubricating oil composition of Example 2 of the present invention

[0069] Table 3 Bench test results of lubricating oil composition of Example 2 of the present invention

[0070]

[0071]

[0072] It can be seen from the data in Table 3 that the lubricating oil composition of Example 2 of the present invention passed seven bench tests required by the SP / GF-6 quality index, namely, the Procedure IIIH high temperature oxidation test, the Procedure IVB valve train wear test, the Procedure VG low temperature sludge test, the VIE / VIF energy saving test, the Procedure VIII bearing corrosion test, the Procedure IX (LSPI) low speed pre-ignition test and the Procedure X timing chain wear test.

Claims

1. A low-ash high-performance engine lubricating oil composition, characterized in that: It contains: A. At least two metal detergents, containing 2.5-3.5% of component A; B. At least three antioxidants, containing 1.5-3.0% of component B; C. A sulfur-containing antiwear agent, containing 0.1-1.0% of component C; D, at least one friction reducer, containing 0.1-1.0% of component D; E, at least one viscosity index improver, containing 3.0-10.0% of component E; F, at least one pour point depressant, containing 0.2-0.5% of component F; G, at least one antifoaming agent, containing 0.001-0.010% of component G; H. At least two base oils, containing 80.0-90.0% of H component.

2. The low-ash high-performance engine lubricating oil composition according to claim 1, characterized in that: The metal detergent is any two or more of low-base alkyl salicylate, medium-base alkyl salicylate, and high-base alkyl salicylate.

3. The low-ash high-performance engine lubricating oil composition according to claim 1, characterized in that: The antioxidant is any three or more of butyl octyl zinc dithiophosphate, dioctyl zinc dithiophosphate, isopropyl isooctyl zinc dithiophosphate, aniline ashless antioxidant, and naphthylamine ashless antioxidant.

4. The low-ash high-performance engine lubricating oil composition according to claim 1, characterized in that: The sulfur-containing anti-wear agent is any one of diester disulfide, disulfide, sulfurized fat, and thiophene derivatives.

5. The low-ash high-performance engine lubricating oil composition according to claim 1, characterized in that: The pour point depressant is any one or two of alkyl naphthalene or poly-alpha olefin; the viscosity index improver is a non-dispersed ethylene-propylene copolymer.

6. The low-ash high-performance engine lubricating oil composition according to claim 1, characterized in that: The antifoaming agent is any two or three of dimethyl silicone oil, alkyl acrylic acid copolymer, and alkyl polyamide; the friction reducer is any one or two of fatty amine and high molecular organic ester.

7. The low-ash high-performance engine lubricating oil composition according to claim 1, characterized in that: The base oil is a composition of two or more hydrogenated base oils whose performance meets the requirements of API Class III base oil standards.

8. The method for preparing a low-ash high-performance engine lubricating oil composition according to any one of claims 1 to 7, characterized in that: Specifically, the base oil is added into a blending kettle, the temperature is raised to 60-80°C and stirred for 2 hours, an anti-foaming agent is added and stirring is continued for 2 hours, a pour point depressant and a viscosity index improver are added and stirring is continued for 2 hours, an antioxidant, a metal detergent, a sulfur-containing antiwear agent and a friction reducer are added in sequence, stirring is continued at 60-80°C for 4 hours, and a low-ash high-performance engine lubricating oil composition can be obtained.

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