CN102690708B - Lubricant composition for ethanol engine - Google Patents

Abstract

The invention relates to an ethanol engine lubricating oil composition, comprising the following components: A>composite antioxidant, at least comprising the following components: (1) alkylated diphenylamine antioxidant; (2) thiophenol ester type Antioxidant; (3) optional thioetherphenol type antioxidant; B>polyisobutylene succinimide; C>mixture of calcium sulfonate and sodium sulfonate; D>zinc dialkyldithiophosphate ; E > dialkyl dithiocarbamate; F > metal deactivator; G > major amount of lube base oil. The invention exerts the synergistic effect among the additives, can meet the high-temperature anti-oxidation performance required by the ethanol engine lubricating oil, and can provide excellent piston cleaning performance, high-low temperature anti-wear performance and excellent viscosity growth control ability.

Description

A kind of ethanol engine lubricating oil composition

technical field

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

Background technique

In today's international energy shortage, ethanol gasoline has attracted worldwide attention as an alternative fuel, and it has been widely used in various parts of our country. Since ethanol gasoline is environmentally friendly and energy-saving, it is beneficial to alleviate the shortage of oil resources and improve the atmospheric environment. Therefore, promoting the use of ethanol gasoline for vehicles is a strategic measure of the country and is of great significance to the sustainable development of the national economy. In order to maintain the good running state of the ethanol fuel vehicle engine for a long time, it is very important to research and develop new engine lubricating oil specially for the characteristics of ethanol fuel.

Ethanol gasoline for vehicles is a new type of automobile fuel formed by mixing denatured fuel ethanol and gasoline in a certain proportion. Ethanol gasoline fuel is more likely to cause corrosion to the engine, and its combustion products such as acetic acid and sulfide enter the lubricating oil with the fuel, which will cause the oil to oxidize and deteriorate, the alkali value will decrease rapidly, and the sludge will aggravate. Wear of rings and cylinder walls. Therefore, high-efficiency antioxidants must be used in engine lubricating oils used for ethanol fuels to inhibit oil deterioration. Compared with an engine that only uses gasoline, an engine that uses ethanol fuel (10%-100% ethanol) has significant wear on the engine cylinder liner, piston ring, and intake and exhaust valves, so the ethanol gasoline engine lubricating oil Anti-oxidation, anti-rust, anti-wear performance requirements are high. Seeking more effective antioxidant additives and developing high-performance engine lubricating oils for ethanol fuel engines have always been the goals of those skilled in the art.

CN100460490C introduces an antioxidant component composed of alkylated diphenylamine and phenolic ester, which can greatly improve the antioxidant capacity of oil products.

US20090111722A describes a lubricating oil composition for wear protection of an engine when ethanol fuel is used. The overbasic value calcium salt detergent contained in the composition can reduce engine wear caused by using ethanol fuel and prolong the oil changing period of lubricating oil.

Contents of the invention

The invention provides an ethanol engine lubricating oil composition, which has excellent anti-oxidation performance and simultaneously provides good high-temperature detergency and anti-wear performance.

The ethanol 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;

C>A mixture of calcium sulfonate and sodium sulfonate;

D > at least one zinc dialkyldithiophosphate;

E>one or more dialkyldithiocarbamates;

F>one or more metal deactivators;

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 ethanol engine lubricating oil composition of the present invention includes 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> selected from polyisobutylene succinimide ashless 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.

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> is selected from the mixture of calcium sulfonate and sodium sulfonate, preferably a high base value calcium sulfonate with a base value of (200-450) mgKOH/g and a high base value with a base value of (200-450) mgKOH/g A mixture of sodium sulfonate, the mass ratio between the two is between 1:1 and 4:1. Component C can be selected from T101, T102, T103 produced by Shanghai Refining Additive Factory, T106 produced by Jinzhou Petrochemical Additive Factory, LZ6478, LZ6446, LZ75, LZ78 produced by Lubrizol Corporation, Hitec611, Hitec614 produced by Afton Corporation, Jinzhou Kangtai KT5448 produced by Lubricant Additive Co., Ltd., OLOA246S, OLOA249S produced by Chevron Oronite 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.

Component D accounts for 0.1%-5%, preferably 0.3%-3%, and most preferably 0.5%-2% of the total mass of the lubricating oil composition.

E>One or more selected from dialkyldithiocarbamate, the alkyl group in the dialkyldithiocarbamate is an alkyl group containing 2 to 12 carbon atoms, preferably is an alkyl group containing 2 to 8 carbon atoms, which can be ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, n-pentyl, isopentyl, n-hexyl, isohexyl base, n-octyl, 2-ethylhexyl. Dialkyl dithiocarbamate can be selected from T323 produced by Jinzhou Xinxing Petroleum Additive Co., Ltd., 7723 produced by Vanderbilt, etc.

Component E accounts for 0.02%-5% of the total mass of the lubricating oil composition, preferably 0.05%-2%, most preferably 0.1%-0.5%.

F>One or more metal deactivators selected from triazole derivatives, thiazole derivatives and thiadiazole derivatives, commonly used metal deactivators include benzothiazole, tolyltriazole, octyltriazole , 2-mercaptobenzothiazole, 2,5-dimercapto-1,3,4-thiadiazole, 2-mercapto-5-hydrocarbon-substituted-1,3,4-thiadiazole, 2-dimercapto-5 -Dithio-1,3,4-thiadiazole, N,N-dihexylaminomethylenebenzenetriazole, 2-mercaptobenzothiadiazole, etc., the commercial brands are T551, T561, T706, etc., can Choose T551, T561, T706, etc. produced by Jinzhou Kangtai Lubricating Oil Additive Co., Ltd.

Component F accounts for 0.01%-0.5% of the total mass of the lubricating oil composition, preferably 0.03%-0.25%, most preferably 0.05%-0.15%.

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, It is usually divided into Group I, II, and III base oils. Common commercial brands include Type I 150SN, 600SN, HVI 500, HVI 750, Type II 100N, 150N, Type III base oil S-8, 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, di(2-ethylhexyl)benzenes, derivatives of alkylbenzenes including alkylated diphenyl ethers and alkylated diphenyl sulfides and their Derivatives, Analogs 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 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, T148, 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 and 90°C, and the mixing time is between 1 hour and 6 hours.

The present invention selects a variety of ashless antioxidants with synergistic effects to optimize the combination, and compound suitable detergents, dispersants and other functional additives, resulting in a significant anti-oxidation effect, which significantly enhances high-temperature anti-wear performance and piston cleaning Performance, able to meet the lubrication requirements of ethanol fueled 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 1-5 and comparative example 1,2,3-1,3-2,4

Examples 1-5 are the composition and main properties of the lubricating oil composition of the present invention. The components are added in proportion to the mixing container, heated at 45°C-80°C under normal pressure, and stirred for 1 hour-2 hours to prepare a lubricating oil composition with a viscosity grade of 10W-40. In comparative examples 1, 2, and 3-1, single-component antioxidants were added, namely T534, 1035, and methylene 4426-S, and in comparative example 3-2, a double-component antioxidant prepared by the method of patent CN100460490C was added. Divide compound antioxidant, wherein embodiment 1 and comparative example 1, embodiment 2 and comparative example 2 have all identical formulas except antioxidant respectively, and embodiment 3 and comparative example 3-1, 3-2 also have All the same formula forms except antioxidant, and the difference between embodiment 4 and comparative example 4 is that di-n-butyl dithiocarbamate is added in embodiment 4, and di-n-butyl dithiocarbamate is not added in comparative example 4. Thiocarbamate. The composition ratios of Examples 1-5 and Comparative Examples 1, 2, 3-1, 3-2, and 4 are shown in Table 2.

The ASTM D4742 thin-layer oxidation test (TFOUT) and pressurized differential scanning calorimetry test (PDSC) were carried out on Examples 1-5, Comparative Examples 1, 2, 3-1, 3-2 and commercially available ethanol engine lubricating oil. The set temperature of PDSC was 220°C, and the specific results are shown in Table 3.

table 3

oil sample TFOUT/min PDSC/min Example 1 158 36.4 Example 2 153 39.1 Example 3 150 37.7 Example 4 163 37.2 Example 5 167 38.4 Comparative example 1 148 31.8 Comparative example 2 143 25.3 Comparative example 3-1 139 27.9 Comparative example 3-2 145 33.2 commercial oil* 131 18.3

*Commercially available oil is SJ 10W-40 special oil for ethanol gasoline engine of Great Wall Alcohol Star.

It can be seen from Table 3 that the lubricating oil composition effectively improves the oxidation induction period of the oil. The TFOUT test shows that the oxidation induction period of the examples is 15%-25% higher than that of the corresponding comparison examples, and the PDSC test shows that the oxidation induction periods of the examples are better than those of the comparison examples.

The results of high-temperature anti-wear performance are shown in Table 4. The high-temperature anti-wear test of oil products was carried out using the SRV friction testing machine. The test conditions were load 300N, frequency 50Hz, stroke 1mm, and temperature 120°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

oil sample SRV mill diameter/mm Example 1 0.66 Example 4 0.64 Comparative example 1 0.69 Comparative example 2 0.71 Comparative example 3-1 0.69 Comparative example 4 0.76 commercial oil* 0.70

*Commercially available oil is Great Wall Alcohol Star ethanol gasoline engine special oil SJ 10W-40

The results of Example 4 and Comparative Example 4 show that the use of dibutyl dithiocarbamate in the lubricating oil composition significantly improves the high-temperature anti-wear effect of the oil.

Embodiment 6-9 and comparative example 5-7

0.5 ml of hydrochloric acid was added to 50 g of the oil products of Examples 6-9 and Comparative Examples 5-7 respectively, and the oil was aged by a rotating oxygen bomb test. The test instrument consists of a pressure bomb and an oil bath, the pressure bomb rotates 30° with the horizontal plane, the oil bath is kept at 150°C, oxygenated at 620kPa (90psi) at room temperature, and aged for 2h. The aging test was repeated 6 times, and each 300ml of the oil was obtained for the coke-forming test. The formula composition and coke-forming test results of the examples and comparative examples are shown in Table 5. Wherein embodiment 6,7,8,9 added the mixture of overbasic calcium sulfonate and overbasic sodium sulfonate, and in comparative example 5 and 6, added respectively was single-component overbasic calcium sulfonate , High base value sodium sulfonate, the difference between Comparative Example 7 and Example 6 is that no metal deactivator 2-mercaptobenzothiadiazole was added in Comparative Example 7.

table 5

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 5 hours, the oil temperature is 150°C, and the plate temperature is 310°C.

As can be seen from the results in Table 5, the mixture of overbasic calcium sulfonate and overbasic sodium sulfonate has better detergency and acid neutralization ability compared with independent overbasic calcium sulfonate or overbasic sodium sulfonate . The addition of 2-mercaptobenzothiadiazole also surprisingly results in better detergency retention and higher acid neutralization.

Example 10

The BRT ball rust test is an alternative to the program II D engine bench test, and is mainly used to evaluate the corrosion resistance and rust resistance of engine oil. During the entire 18-hour bench test, the metal ball protected by the test oil was continuously exposed to acidic liquid and air. After the test, the gray scale test is carried out through the strength of the metal ball reflective surface to determine the corrosion area, so as to evaluate the anti-corrosion ability of the test oil. The injection rate of acetic acid/hydrobromic acid/hydrochloric acid/deionized water is 0.19 ml/hour, the air flow is 40 ml/min, and the oil temperature is 48°C.

The above-mentioned ball rust test was carried out on Example 7 of the present invention. The total base number TBN of the test oil was 8.7, and the ball rust test result was 126, indicating that the composition of the present invention has excellent base number retention and anti-corrosion capabilities.

Claims (6)

1. an ethanol engine lubricating oil composition comprises following component:

A > composite antioxidant, account for the 0.2%-6% of lubricating oil composition total mass, at least comprise following component: (1) alkylated diphenylamine oxidation inhibitor; (2) sulfophenates type oxidation inhibitor; (3) thioether phenol type antioxidant;

Said alkylated diphenylamine is the tertiary butyl/di-iso-octyldiphenylamine, accounts for the 60-90% of composite antioxidant total mass;

Said sulfophenates type oxidation inhibitor is 2,2 '-thiobis [3-(3,5-di-tert-butyl-hydroxy phenyl) ethyl propionate], account for the 8-30% of composite antioxidant total mass;

Said thioether phenol type antioxidant is thiobis-(3,5-di-t-butyl-4-hydroxyl benzyl), accounts for the 1-15% of composite antioxidant total mass;

B > polyisobutene succinimide ashless dispersant, in polyisobutene succinimide, the number-average molecular weight of polyisobutene part is 800-4000, accounts for the 1.5%-8% of lubricating oil composition total mass;

C > mixture of calcium sulfonate with high base number and sulfonate with high base number sodium, mass ratio between calcium sulfonate with high base number and sulfonate with high base number sodium is between 1:1 to 4:1, account for the 0.8%-8% of lubricating oil composition total mass, the base number of described calcium sulfonate with high base number is 200-450mgKOH/g, and the base number of sulfonate with high base number sodium is 200-450mgKOH/g;

D > at least one zinc dialkyl dithiophosphate, account for the 0.1%-5% of lubricating oil composition total mass;

E > one or more dialkyl dithio amino formates, account for the 0.02%-5% of lubricating oil composition total mass;

F > one or more metal passivators, comprise 2-sulfydryl diazosulfide, account for the 0.01%-0.5% of lubricating oil composition total mass;

G > the main lubricant base of measuring.

2. according to lubricating oil composition claimed in claim 1, it is characterized in that, the alkyl of described zinc dialkyl dithiophosphate is the alkyl that contains 2 to 12 carbon atoms.

3. according to lubricating oil composition claimed in claim 1, it is characterized in that, described zinc dialkyl dithiophosphate accounts for the 0.3%-3% of lubricating oil composition total mass.

4. according to lubricating oil composition claimed in claim 1, it is characterized in that, the alkyl of described dialkyl dithio amino formate is the alkyl that contains 2 to 12 carbon atoms.

5. according to lubricating oil composition claimed in claim 1, it is characterized in that, described dialkyl dithio amino formate accounts for the 0.05%-2% of lubricating oil composition total mass.

6. according to lubricating oil composition claimed in claim 1, it is characterized in that, described metal passivator accounts for the 0.03%-0.25% of lubricating oil composition total mass.