CN102690711A - Lubricant composition for gasoline engine - Google Patents

Abstract

The invention relates to a gasoline engine lubricating oil composition, which has a phosphorus content of not more than 0.08% and a sulfated ash content of not more than 0.9%. The composition of the present invention includes the following components: A>composite antioxidant, at least including the following components: (1) alkylated diphenylamine antioxidant; (2) thiophenol ester type antioxidant; (3) non- Necessary thioether phenolic antioxidant; B> polyisobutylene succinimide ashless dispersant and/or boronated polyisobutylene succinimide dispersant; C> salicylate alkaline earth metal detergent; D> Zinc dialkyl dithiophosphate; E > oil-soluble organic molybdenum friction modifier; F > ashless friction modifier; G > major amount of lubricating oil base oil. The invention exerts the synergistic effect among the additives, can meet the anti-oxidation performance required by high-grade gasoline engine lubricating oil, and can provide excellent piston cleaning performance, anti-wear performance and ability to control viscosity growth at the same time.

Description

A kind of gasoline engine lubricating oil composition

technical field

The present invention relates to a lubricating oil composition, in particular to a lubricating oil composition for a gasoline engine.

Background technique

The high power and miniaturization of gasoline engines reduce the airflow around the engine, which increases the requirements for the anti-oxidation ability of engine lubricating oil and the ability to inhibit piston deposits. With the increasingly stringent emission regulations, the requirements for engine emissions are becoming more and more stringent, which also puts forward higher requirements for the performance of engine lubricating oil. The upgrading of gasoline engine lubricating oil has also continued to increase the requirements for oil anti-oxidation, piston cleaning, sludge dispersion, and anti-wear performance. At present, the product specifications of high-end gasoline engine lubricating oil have been upgraded to the International Lubricant Standardization and Certification Committee ( SM/GF-4, SN/GF-5 grades developed by ILSAC) and American Petroleum Institute (API).

The oxidation stability of gasoline engine lubricating oil is an extremely important control index. During use, lubricating oil is affected by factors such as operating temperature, metal catalysis, combustion products and blow-by gas, and gradually loses its antioxidant activity, and is prone to oxidative deterioration, resulting in the detergency, dispersibility and wear resistance of the oil. Rapid destruction, increased viscosity, increased acid products, the formation of varnish and deposits, causing damage to engine components.

Zinc dialkyl dithiophosphate (ZDDP) is a phosphorus-containing multi-effect additive with excellent anti-oxidation, anti-wear and anti-corrosion properties. The use of phosphorus-containing additives as lubricating oil components is subject to regulation because phosphorus-containing additives can enter the catalytic converter through exhaust gas recirculation or blow-by processes, and accumulate on active metal sites, poisoning the catalyst, thereby reducing catalyst efficiency and shortening its service life. Standard restrictions. The limitation requirements for phosphorus content in high-grade gasoline engine lubricating oil standards are: the mass fraction of phosphorus content in SL oil products is required to be less than 0.1%, and the mass fraction of phosphorus content in SM and SN grade oil products is required to be less than 0.08%.

The engine evaluation test of anti-oxidation viscosity growth of high-grade gasoline engine lubricating oil has been developed from 64 hours of program III E to 80 hours of program III F, and now 100 hours of program III G, while the viscosity increase requirement has been reduced from no more than 375% to 275% and 150%, the requirements for suppressing viscosity growth are greatly increased. At the same time, the requirements for the detergency of pistons are becoming more and more stringent. The TEOST-MHT test for simulating high-temperature deposits on pistons has grown from no more than 45 mg for SL to 35 mg for SM and SN specifications. Therefore, the requirements for anti-oxidation performance have increased significantly.

Strict restrictions on phosphorus content in lubricating oils for high-end gasoline engines make it impossible to meet the requirements of oxidation stability simply by using ZDDP with a specified content, and auxiliary antioxidants are required in lubricating oil formulations. Seeking more effective antioxidant additives has always been the goal of those skilled in the art.

The lubricating oil formula with low sulfate ash can effectively reduce coking and carbon deposits on the top of the piston, reduce valve wear, prevent deflagration and excessive carbon deposits in the combustion chamber, and keep spark plugs clean. In addition, low ash content can reduce corrosive oxidation products, reduce corrosion and wear of engine components, and prolong the safe operation period of the engine and the service life of components. Good engine oil detergency extends filter life and reduces maintenance costs. Therefore, low ash is the development direction of gasoline engine lubricating oil.

CN100460490C introduces an antioxidant component composed of alkylated diphenylamine and ester-type shielding phenol, which can greatly improve the antioxidant capacity of oil products. This patent does not mention the application of thiophenol ester type antioxidant and thioether phenol type antioxidant.

US20080076686 describes a low-sulfur, low-phosphorus, low-zinc lubricating oil composition suitable for internal combustion engines using low-sulfur fuels, including alkaline detergents and dispersants, hindered phenolic antioxidants or alkylated diphenylamine antioxidants, It has strong high temperature detergency and anti-wear ability. This patent does not mention the application of thiophenol ester type antioxidant and thioether phenol type antioxidant.

Contents of the invention

The invention provides a gasoline engine lubricating oil composition, which has excellent anti-oxidation performance, high-temperature cleaning performance and anti-wear performance, and can meet the requirements of SL/GF-3, SM/GF-4, SN/GF-5 Performance requirements for high-grade gasoline engine lubricants.

The gasoline engine lubricating oil composition provided by the invention comprises the following components:

A>Composite antioxidants, including at least the following components: alkylated diphenylamine antioxidants, thiophenol ester antioxidants, optional thioetherphenol antioxidants;

B> polyisobutylene succinimide ashless dispersant and/or boronated polyisobutylene succinimide dispersant;

C>one or more salicylate alkaline earth metal detergents;

D > at least one zinc dialkyldithiophosphate;

E>one or more oil-soluble organic molybdenum friction modifiers;

F>one or more ashless friction modifiers;

G>The main amount of lubricating oil base oil;

Other additives such as rust inhibitors, pour point depressants, viscosity index improvers (VM), antifoam agents, etc. may also be present in the lubricating oil composition of the present invention.

Specifically, the gasoline engine lubricating oil composition of the present invention comprises the following components:

A>Composite antioxidants, including at least the following components: (1) alkylated diphenylamine antioxidants; (2) thiophenol ester antioxidants; (3) non-essential thioether phenol antioxidants .

(1) The structural formula of alkylated diphenylamine is:

Wherein R ¹ and R ² are each H or C ₁ -C ₁₂ alkyl, preferably C ₄ -C ₉ alkyl, the position is at the para or ortho position of the amino group, preferably tert-butyl and/or isooctyl base.

The alkylated diphenylamine accounts for 50%-95% of the total mass of the composite antioxidant, preferably 60%-90%. Alkylated diphenylamine can be selected from IRGANOX L-01 and IRGANOX L-57 produced by BASF in Germany, T534 produced by Beijing Xingpu Company, LZ5150A produced by Lubrizol Lanlian Additive Co., Ltd., VANLUBE NA produced by Vanderbilt in the United States, VANLUBE 961, dioctyl diphenylamine VANLUBE 81, p-, p-diisooctyl diphenylamine RC7001 produced by Rheinland Chemical Company.

The preferred alkylated diphenylamine antioxidant is tert-butyl/isooctyl diphenylamine (such as T534 produced by Beijing Xingpu Company).

(2) The structural formula of thiophenol ester type antioxidant is:

Wherein R ³ and R ⁴ are each H or C ₁ -C ₁₂ alkyl, preferably C ₁ -C ₉ alkyl, most preferably methyl and/or tert-butyl. Wherein m and n are integers between 0-10, preferably 0, 1 or 2.

The thiophenol ester type antioxidant accounts for 5%-50% of the total mass of the composite antioxidant, preferably 8%-30%. The preferred thiophenol ester type antioxidant is 2,2'-thiobis[3-(3,5-di-tert-butyl-4-hydroxyphenyl) ethyl propionate] (such as Sichuan Yongye Chemical Co., Ltd. Antioxidant 1035 produced by the company, IRGANOX L115 produced by BASF, Germany).

(3) The structural formula of thioether phenolic antioxidant is:

Wherein R ⁵ and R ⁶ are each H or C ₁ -C ₁₂ alkyl, preferably C ₁ -C ₉ alkyl, most preferably methyl and/or tert-butyl. Wherein q is an integer between 0-10, preferably 0, 1 or 2.

The thioether phenol antioxidant accounts for 0-20% of the total mass of the composite antioxidant, preferably 1%-15%. The preferred thioether phenol type antioxidant is thiobis-(3,5-di-tert-butyl-4-hydroxybenzyl) (such as the methylene 4426-S produced by Changzhou Lingchi Chemical Co., Ltd., the Lowinox produced by U.S. Great Lakes Corporation) TBP-6, Irganox 1081 produced by BASF, Germany).

In a preferred embodiment, the composite antioxidant of the present invention consists of the following components: (1) tert-butyl/isooctyl diphenylamine; (2) 2,2'-thiobis[3-(3, 5-di-tert-butyl-4-hydroxyphenyl)propionate]; (3) Thiobis-(3,5-di-tert-butyl-4-hydroxybenzyl).

The composite antioxidant of component A accounts for 0.1%-10% of the total mass of the lubricating oil composition of the present invention, preferably 0.2%-6%, most preferably 0.3%-5%.

B> is selected from polyisobutylene succinimide ashless dispersants and/or boronated polyisobutylene succinimide dispersants.

The number average molecular weight of the polyisobutylene (PIB) part in the polyisobutylene succinimide ashless dispersant is 800-4000, preferably 900-3000, most preferably 1000-2400. This component can be selected from T161 produced by Suzhou Special Oil Factory, T161A and T161B produced by Additive Factory of Jinzhou Petrochemical Branch, LZL157 produced by Lubrizol Additive Co., Ltd., LZ6418 and LZ6420 produced by Lubrizol Corporation, and produced by Afton Corporation Hitec646 et al.

The number average molecular weight of the polyisobutylene part in the borated polyisobutylene succinimide dispersant is 500-4000, preferably 700-2500, most preferably 1000-2300. This component can be selected from MX3316 produced by Agip Petroli Company, Hitec648, Hitec7714 produced by Afton Corporation and LZ935 produced by Lubrizol Corporation.

Component B is preferably a mixture of polyisobutylene succinimide ashless dispersant and boronated polyisobutylene succinimide dispersant, the mass ratio between the two can be arbitrary, and the preferred ratio is 1:1 to 3: between 1.

Component B accounts for 0.5%-10% of the total mass of the lubricating oil composition of the present invention, preferably 1.5%-8%, most preferably 3%-6%.

C>one or more salicylate alkaline earth metal detergents, the alkaline earth metals can be magnesium, calcium, preferably in the salicylate alkaline earth metal detergents with a base value of (10-450) mgKOH/g One or more of them, preferably high-basic calcium salicylate with a base value of (200-450) mgKOH/g and medium-basic value calcium salicylate with a base value of (100-<200) mgKOH/g The mass ratio between the two can be arbitrary, and the preferred ratio is between 0.5:1 and 4:1. Component C can be LZL109A, LZL109B, LZL112 produced by Lubrizol Lanlian Additive Co., Ltd., C9371, C9372, C9375, C9006, C9012 produced by Infineum Company, etc.

Component C accounts for 0.2%-10%, preferably 0.8%-8%, and most preferably 1.2%-6% of the total mass of the lubricating oil composition.

D>One or more selected from zinc dialkyldithiophosphate, the alkyl group in the zinc dialkyldithiophosphate is an alkyl group containing 2 to 12 carbon atoms, preferably containing 2 Alkyl to 8 carbon atoms, can be ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, n-pentyl, isopentyl, n-hexyl, isohexyl, n-octyl base, 2-ethylhexyl, cyclohexyl, methylcyclopentyl. Zinc dialkyldithiophosphate can be T202 and T203 produced by Wuxi Nanfang Petroleum Additive Co., Ltd., primary alkyl T202, primary alkyl T203, primary-secondary alkyl T204, and secondary alkyl T205 produced by Jinzhou Petrochemical Branch Additive Factory. LZ1371 and LZ1375 produced by Lubrizol, C9417, C9425 and C9426 produced by Infineum, Hitec7169 and Hitec1656 produced by Afton, etc.

The addition amount of component D in the lubricating oil composition is preferably such that the mass fraction of phosphorus element does not exceed 0.08%, preferably 0.05%-0.08%.

E>Selected from molybdenum dialkyldithiophosphate, oxymolybdenum dialkyldithiophosphate, molybdenum dialkyldithiocarbamate, molybdenum xanthate, molybdenum thioxanthate, trinuclear molybdenum sulfide One or more of oil-soluble organic molybdenum friction modifiers such as compounds, molybdenum amine complexes, and molybdenum esters. The above-mentioned organic molybdenum compounds have organic groups containing sufficient carbon atoms to make the organic molybdenum compounds soluble In or dispersed in the base oil, generally the number of carbon atoms is between 6-60, preferably between 10-50. The oil-soluble organic molybdenum friction modifier can be selected from MolyVan L, 822, 855 produced by Vanderbilt Company of the United States, 515, 525, 710 produced by Asahi Denka Company of Japan, etc.

Component E accounts for 0.01%-5% of the total mass of the lubricating oil composition, preferably 0.02%-2%, most preferably 0.05%-1.2%.

F>One or more selected from fatty acid polyol esters, fatty amines, fatty amides and other ashless friction modifiers, wherein the aliphatic hydrocarbon group is a saturated or unsaturated hydrocarbon group with a carbon number of 6-60 , preferably a saturated or unsaturated hydrocarbon group with 10-50 carbon atoms. The fatty acid polyalcohol esters include monoesters, diesters or polyols of compounds such as fatty acid glycerides, fatty acid pentaerythritol esters, fatty acid ethylene glycol esters, fatty acid succinic acid esters, fatty acid ethanolamine esters, fatty acid diethanolamine esters, and fatty acid triethanolamine esters. Esters, such as monoglyceride oleate, diglyceride oleate, monopentaerythritol stearate, ethylene glycol diester, oleic acid diethanolamine monoester, oleic acid triethanolamine monoester, etc. Aliphatic amines include Hydrocarbyl substituted monoamines or polyamines, alkoxylated hydrocarbyl substituted monoamines or polyamines and alkyl ether amines, etc., such as ethoxylated tallow fatty amines and ethoxylated tallow fatty ether amines, fatty Examples of family amides include oleamide, cocamide, and the like. Component F can be selected from F10, F20, etc. of BASF, Germany.

Component F accounts for 0.02%-5% of the total mass of the lubricating oil composition, preferably 0.05%-2%, most preferably 0.1%-1%;

G > Major amount of lubricating oil base oil, which may be selected from mineral oils and synthetic lubricating oils or mixtures thereof.

The mineral oils may range in viscosity from light distillate mineral oils to heavy distillate mineral oils, including liquid paraffinic oils and hydrorefined, solvent-treated mineral oils of the paraffinic, naphthenic and mixed paraffinic-naphthenic type, Usually divided into I, II, III base oils, common brand names include I type 150SN, 600SN, II type 100N, 150N, etc.

Synthetic lubricating oils include polymeric hydrocarbon oils, alkylbenzenes and derivatives thereof. Specific examples of polymeric hydrocarbon oils include, but are not limited to, polybutene, polypropylene, propylene-isobutylene copolymers, chlorinated polybutene, poly(1- Hexene), poly(1-octene), poly(1-decene), common commercial brands include PAO4, PAO6, PAO8, PAO10, etc. Specific examples of alkylbenzene and its derivatives include but are not limited to Dialkylbenzenes, tetradecylbenzenes, dinonylbenzenes, alkylated diphenyl ethers and alkylated diphenylsulfides and their derivatives, analogues and homologues.

Another suitable type of synthetic lubricating oil is an ester oil, including dicarboxylic acids (such as phthalic acid, succinic acid, alkyl and alkenyl succinic acid, maleic acid, azelaic acid, suberic acid, sebacic acid, etc. acid, fumaric acid, adipic acid, linoleic acid dimer, malonic acid, alkylmalonic acid, alkenylmalonic acid) and various alcohols (such as butanol, hexanol, dodecane Alcohol, 2-ethylhexyl alcohol, ethylene glycol, propylene glycol) generated by the condensation reaction of ester or complex ester. Specific examples of these esters include, but are not limited to, dibutyl adipate, bis(2-ethylhexyl) sebacate, di-n-hexyl fumarate, dioctyl sebacate, di(2-ethylhexyl) azelate, Isooctyl, diisodecyl azelate, dioctyl phthalate, didecyl phthalate, bis(eicosyl) sebacate, 2-ethyl linoleic acid dimer Hexyl diester.

Another suitable type of synthetic lubricating oil is Fischer-Tropsch synthetic hydrocarbon oil and lubricating oil base oil obtained by processing such synthetic hydrocarbon oil through hydroisomerization, hydrocracking, dewaxing and other processes.

The base oil is preferably lubricating base oil with a viscosity index greater than 80, a mass fraction of saturated hydrocarbons greater than 90%, and a mass fraction of sulfur less than 0.03%.

The following other additives may also be present in the lubricating oil composition of the present invention:

Rust inhibitors can be selected from nonionic polyoxyalkylene polyols and their esters, polyoxyalkylene phenolic anionic alkylsulfonic acids, aliphatic monobasic acids or polybasic acids, etc. Common examples include dodecenylsuccinic acid, sorbic acid Sugar Alcohol Monooleate, Sorbitan Trioleate, etc.

Pour point depressants, or lube oil flow improvers, lower the minimum temperature at which a fluid flows or can be poured. Typical additives are dialkyl fumarate/vinyl acetate copolymers with alkyl groups ranging from C8 to C18, polyalkylmethacrylates, etc. Common commercial brands include T803, VX385, etc.

Suitable viscosity index improvers are polyisobutylene, copolymers of ethylene with propylene and higher Q-olefins, polymethacrylates/salts, polyalkylmethacrylates, methacrylates/salts copolymers, unsaturated di Copolymers of carboxylic acids and vinyl compounds, copolymers of styrene and acrylates, styrene/isoprene, styrene/butadiene, and partially hydrogenated copolymers of isoprene/butadiene, And partially hydrogenated homopolymers of butadiene and isoprene and isoprene/divinylbenzene, common commercial brands are LZ7070, LZ7065, LZ7067, LZ7077 of Lubrizol Company, SV260 and SV261 of Infineum Company, T614 etc. They may constitute from 0.01% to 20% of the total mass of the lubricating oil composition.

The anti-foaming agent can be polysiloxane type, such as silicone oil or polydimethylsiloxane.

The lubricating oil composition of the present invention can be prepared by the following method: each additive (including one or more of composite antioxidants) is added to the base oil respectively, or the additives are mixed to form a concentrate and then added to the base oil Heat and mix in medium temperature, the mixing temperature is between 40°C-90°C, and the mixing time is between 1-6 hours.

The invention exerts the synergistic effect among the additives, improves the anti-oxidation performance and high-temperature anti-wear performance of the lubricating oil composition, and simultaneously provides good piston cleanliness and the ability to control viscosity growth. The composition of the present invention has a phosphorus content of no more than 0.08% by mass fraction and a sulfate ash content of no more than 0.9% by mass fraction, and can meet the requirements of SL/GF-3, SM/GF-4, SN/GF-5 and other high-grade Lubricating oil requirements for gasoline engines.

Detailed ways

Further describe characteristics of the present invention with example below.

Composite antioxidant preparation example 1-5

Add antioxidants T534, 1035, and methylidene 4426-S into the mixing container in proportion, heat at 60°C-90°C under normal pressure, and stir for 1 hour-2 hours to obtain a uniform transparent light yellow viscous liquid. Invented component A composite antioxidant. See Table 1 for the composition ratio (mass fraction) of the composite antioxidant preparation examples 1-5.

Table 1

serial number Antioxidant T534 Antioxidant 1035 Antioxidant Methylidene 4426-S Composite antioxidant preparation example 1 90% 10% Composite antioxidant preparation example 2 80% 20% Composite antioxidant preparation example 3 70% 30% Composite antioxidant preparation example 4 70% 25% 5% Composite antioxidant preparation example 5 70% 20% 10%

Embodiment 1-7 and comparative example 1,2,3-1,3-2

Embodiment 1-7 is the composition and main properties of the gasoline engine lubricating oil of the present invention. Put each component into the mixing container in proportion, heat at 45°C-80°C under normal pressure, and stir for 1 hour-2 hours to prepare SM/GF-4 low-phosphorus and low-ash gasoline engine lubrication with a viscosity grade of 5W-30 Oil. In comparative examples 1, 2, and 3-1, single-component antioxidants were added, namely T534, 1035, and methylene 4426-S, respectively. In comparative example 3-2, a double-component antioxidant prepared by the method of patent CN100460490C was added. Composite antioxidant, wherein embodiment 1 and comparative example 1, embodiment 2 and comparative example 2 respectively have all identical formulas except antioxidant, and embodiment 3 and comparative example 3-1, 3-2 also have All the same formula composition except antioxidant. See Table 2 for the composition ratios (mass fractions) of Examples 1-7 and Comparative Examples 1, 2, 3-1, and 3-2.

Examples 1-7 and Comparative Examples 1, 2, 3-1 and 3-2 were subjected to a pressurized differential scanning calorimetry test (PDSC), a high temperature deposit evaluation test (TEOST-MHT), ASTM D4742 thin layer oxidation Test (TFOUT) and Viscosity Growth Test (VIT). The PDSC set temperature is 220°C, the TEOST-MHT test adopts the ASTM D7097 method, the deposition rod temperature is 285°C, the reaction time is 24h, the test condition of the viscosity growth test (VIT) is 160°C, and the oxygen flow rate is 5L/h. The rate of change in viscosity growth (Δv) is 375% of the time. The specific results are shown in Table 3.

table 3

oil sample PDSC/min TEOST-MHT/mg TFOUT/min VIT-Δv(375%)/h Example 1 28.2 22.7 138 95 Example 2 31.4 23.2 146 94 Example 3 34.9 19.7 158 93 Example 4 35.3 21.7 158 92 Example 5 - - 151 - Example 6 - - 167 - Example 7 - - 146 - Comparative example 1 24.4 27.6 129 84 Comparative example 2 26.7 26.8 131 86 Comparative example 3-1 28.5 26.0 134 87 Comparative example 3-2 29.8 25.4 143 92

As can be seen from Table 3, at a high temperature of 220 ° C, the lubricating oil composition effectively improves the oxidation induction period (PDSC) of the oil product, and the oxidation induction period of the embodiment is 15% higher than the oxidation induction period of the oil product in the corresponding example ~ 25%, the lubricating oil composition has a 15% reduction in deposit formation in terms of controlled deposit formation (TEOST), while slightly better than comparative example.

The results of high-temperature anti-wear properties are shown in Table 4. The high-frequency reciprocating friction tester (HFRR) was used to conduct high-temperature anti-wear tests for oil products. The test conditions were load 1000g, frequency 20Hz, stroke 1mm, and temperature 150°C. It can be seen from Table 4 that the wear scar diameter of the embodiment of the present invention is smaller than that of the comparative example, showing better anti-wear ability.

Table 4

Example 8-13

The SM/GF-4 low-phosphorus and low-ash gasoline engine lubricating oil composition with a viscosity grade of 5W-40 was obtained by the same preparation method as in the previous examples. The speckle dispersion test was carried out for Examples 8-13, and the formulation composition and dispersion test results are shown in Table 5. Wherein embodiment 8-11 adds the mixture of polyisobutylene succinimide and boron-containing polyisobutylene succinimide, and what adds in embodiment 12, 13 is the dispersant of single component.

table 5

The spot dispersion test method is to add 30% of program VG engine oil sludge to the test oil, ultrasonically disperse it for 6 minutes, heat it in an oven at 200°C for 2 hours, then drop the oil on the filter paper, measure the diameter of the oil spot dispersion circle and the oil sludge dispersion after 24 hours The ratio of the ring diameters is the dispersion index. The higher the dispersion index, the better the dispersibility of the oil.

From the results in Table 5, it can be seen that the oil formulated with the dispersant has better dispersibility than the oil formulated with the dispersant alone.

Examples 14-17

The SM/GF-4 low-phosphorus and low-ash gasoline engine lubricating oil composition with a viscosity grade of 5W-30 was obtained by the same preparation method as in the previous examples. The coke-forming test was carried out for Examples 14-17, and the formula composition and coke-forming test results are shown in Table 6. Wherein embodiment 14,15 added the mixture of high alkali value calcium salicylate and middle alkali value calcium salicylate, and what added in embodiment 16,17 were single-component high alkali value calcium salicylate and Medium base value calcium salicylate.

Table 6

The equipment used in the coke plate test is the 25B-19 coke plate tester produced by Japan Meitech Company. This test simulates the working conditions of the engine crankcase and cylinder liner piston ring lubricating oil circulation, so that the test oil is continuously heated and oxidized into coke. process. The test time is 6 hours, the oil temperature is 150°C, and the plate temperature is 310°C.

As can be seen from the results in Table 6, the formula oil product using the mixture of high alkali value calcium salicylate and medium alkali value calcium salicylate and the formula oil product of independent high alkali value calcium salicylate or medium alkali value calcium salicylate Compared with better cleaning performance.

Example 18

ILSAC and API Specifications SL/GF-3, SM/GF-4, SN/GF-5 require passing Procedure III G Bench Tests to test engine lubricating oils for high temperature oxidative thickening, high temperature piston deposits and high temperature cams Ejector wear performance. The engine test used a 1996 General Motors 3800ml Series II, water-cooled 4-cycle V-6 gasoline engine as the test device. The Sequence IIIG test engine was of top-valve design and operated on unleaded gasoline. The engine was run for 100 hours at 125bhp, 3600rpm and an oil temperature of 150°C, interrupted at 20-hour intervals for oil level checks. At the end of the test, the wear of the cam lobes and ejector pins was measured.

In order to meet the requirements of SL/GF-3 and SM/GF-4 specifications, the used oil after the test must meet the viscosity increase of not more than 150%, the weighted average piston deposit score of not less than 3.5, the average cam lobe and ejector rod abrasion and not exceeding 60 microns. The SN/GF-5 specification standard requires that after the test, the used oil should meet the viscosity increase of no more than 150%, the weighted average piston deposit score of no less than 4.0, and the average cam lobe and ejector rod wear sum of no more than 60 microns. The test results of the III G engine bench that adopt the 5W-30SM/GF-4 gasoline engine lubricating oil that embodiment 3 is deployed are shown in Table 7.

Table 7

As can be seen from the results in Table 7, the III G engine bench results of the lubricating oil composition of Example 3 not only meet the SL/GF-3, SM/GF-4 specification requirements, but also meet the SN/GF-5 specification requirements, indicating that the lubrication The oil composition has excellent high-temperature anti-oxidation ability, remarkable ability to inhibit high-temperature deposits and high-temperature anti-wear ability.

Claims (20)

1. A gasoline engine lubricating oil composition, comprising the following components: A>Composite antioxidant, which at least includes the following components: alkylated diphenylamine antioxidant, thiophenol ester type antioxidant and optional thioether phenol type antioxidant, the composite antioxidant accounts for 0.1%-10% of the total mass of the lubricating oil composition; B> polyisobutylene succinimide ashless dispersant and/or boronated polyisobutylene succinimide dispersant, accounting for 0.5%-10% of the total mass of the lubricating oil composition; C>one or more salicylate alkaline earth metal detergents, accounting for 0.2%-10% of the total mass of the lubricating oil composition; D>at least one zinc dialkyldithiophosphate, accounting for 0.1%-5% of the total mass of the lubricating oil composition; E>one or more oil-soluble organic molybdenum friction modifiers, accounting for 0.01%-5% of the total mass of the lubricating oil composition; F>one or more ashless friction modifiers, accounting for 0.02%-5% of the total mass of the lubricating oil composition; G > major amount of lube base oil. 2. according to the described lubricating oil composition of claim 1, it is characterized in that, the structural formula of described alkylated diphenylamine antioxidant is:

Wherein R ¹ and R ² are each H or C ₁ -C ₁₂ alkyl; The structural formula of described thiophenol ester type antioxidant is:

Wherein R ³ and R ⁴ are each H or C ₁ -C ₁₂ alkyl, m and n are integers between 0-10; The structural formula of the thioether phenol type antioxidant is:

Wherein R ⁵ and R ⁶ are each H or C ₁ -C ₁₂ alkyl, and q is an integer between 0-10. 3. The lubricating oil composition according to claim 2, wherein said R ¹ and R ² are C ₄ -C ₉ alkyl, and said R ³ and R ⁴ are C ₁ -C ₉ alkane group, the R ⁵ and R ⁶ are C ₁ -C ₉ alkyl. 4. According to the lubricating oil composition described in any one of claims 1-3, it is characterized in that, the alkylated diphenylamine accounts for 50%-95% of the total mass of the composite antioxidant, and the thiophenol ester type The antioxidant accounts for 5%-50% of the total mass of the composite antioxidant, and the thioether phenol type antioxidant accounts for 0-20% of the total mass of the composite antioxidant. 5. According to the lubricating oil composition according to any one of claims 1-3, it is characterized in that, the alkylated diphenylamine accounts for 60%-90% of the total mass of the composite antioxidant, and the thiophenol ester type The antioxidant accounts for 8%-30% of the total mass of the composite antioxidant, and the thioether phenol type antioxidant accounts for 1%-15% of the total mass of the composite antioxidant. 6. The lubricating oil composition according to any one of claims 1-3, wherein the composite antioxidant accounts for 0.2%-6% of the total mass of the lubricating oil composition. 7. according to the described lubricating oil composition of claim 1, it is characterized in that, the number average molecular weight of the polyisobutylene part in the polyisobutylene succinimide ashless dispersant is 800-4000, and the borated polyisobutylene butylene The number average molecular weight of the polyisobutylene part in the imide dispersant is 500-4000. 8. according to the described lubricating oil composition of claim 1, it is characterized in that, the mass ratio between described polyisobutylene succinimide ashless dispersant and boronated polyisobutylene succinimide dispersant is in Between 1:1 and 3:1. 9. according to the described lubricating oil composition of claim 1, it is characterized in that, described polyisobutylene succinimide ashless dispersant and/or boronated polyisobutylene succinimide dispersant account for total lubricating oil composition 1.5%-8% of mass. 10. The lubricating oil composition according to claim 1, wherein the salicylate alkaline earth metal detergent is selected from magnesium salicylate and/or calcium salicylate. 11. according to the described lubricating oil composition of claim 1, it is characterized in that, described salicylate alkaline earth metal detergent is selected from the high alkali value calcium salicylate and the alkali value of 200-450mgKOH/g 100-<200mgKOH/g mixture of calcium salicylate with medium alkali value. 12. The lubricating oil composition according to claim 11, characterized in that the mass ratio of high-basic calcium salicylate and medium-basic calcium salicylate is between 0.5:1 and 4:1. 13. The lubricating oil composition according to any one of claims 1, 10-12, characterized in that the salicylate alkaline earth metal detergent accounts for 0.8%-8% of the total mass of the lubricating oil composition. 14. The lubricating oil composition according to claim 1, wherein the alkyl group of the zinc dialkyldithiophosphate is an alkyl group having 2 to 12 carbon atoms. 15. The lubricating oil composition according to claim 1, characterized in that, the amount of zinc dialkyl dithiophosphate in the lubricating oil composition is calculated at 0.05%-0.08% based on the mass fraction of phosphorus element between. 16. according to the described lubricating oil composition of claim 1, it is characterized in that, described oil-soluble organic molybdenum friction modifier is selected from molybdenum dialkyldithiophosphate, molybdenum dialkyldithiophosphate, two One or more of molybdenum alkyl dithiocarbamate, molybdenum xanthate, molybdenum thioxanthate, trinuclear molybdenum sulfur complex, molybdenum amine complex and molybdenum ester. 17. The lubricating oil composition according to claim 1, wherein the oil-soluble organic molybdenum friction modifier accounts for 0.02%-2% of the total mass of the lubricating oil composition. 18. The lubricating oil composition according to claim 1, wherein the ashless friction modifier is selected from one or more of aliphatic polyol esters, aliphatic amines and aliphatic amides. 19. The lubricating oil composition according to claim 1 or 18, wherein the ashless friction modifier accounts for 0.05%-2% of the total mass of the lubricating oil composition. 20. The lubricating oil composition according to claim 1, wherein the viscosity index of the lubricating base oil is greater than 80, the mass fraction of saturated hydrocarbons is greater than 90%, and the mass fraction of sulfur is less than 0.03%.