JP2001262172A - Lubricating oil composition for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lubricating oil for an internal combustion engine, capable of exhibiting excellent lubricating properties and a fuel cost saving effect even in the presence of a soot. SOLUTION: This lubricating oil composition for an internal combustion engine useful in an internal combustion engine causing a soot comprises a base oil of a lubricating oil, sulfurized oxymolybdenum dithiocarbamate of general formula (1) as a component (A) and sulfurized oxymolybdenum dithiophosphate of general formula (2) (R1 to R8 are each a hydrocarbon group; and X1 to X8 are each sulfur or oxygen) as a compound (B). The composition exhibits excellent lubricating properties as a lubricating oil for an internal combustion engine such as a diesel engine, a direct injection engine, etc., causing a soot.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a lubricating oil composition for an internal combustion engine.

[0002]

2. Description of the Related Art At present, the situation surrounding automobiles is becoming stricter, such as fuel efficiency regulations and exhaust gas regulations. Behind this are environmental issues such as global warming, air pollution and acid rain, and resource protection from concerns over the limited depletion of petroleum energy. As a countermeasure, improving fuel efficiency is currently the most effective. In order to save fuel consumed by automobiles, that is, to promote so-called fuel saving, the weight of the automobile itself, the improvement of the engine, etc., as well as the improvement of the automobile itself, as well as the reduction of the viscosity of engine oil to prevent friction loss in the engine, Improvement of engine oil, such as addition of a good friction modifier, is also an important factor. The engine oil acts as a lubricant between the piston and the liner, but since there is much fluid lubrication in this part, friction loss can be reduced by reducing the viscosity of the engine oil. For this reason, in recent years, the viscosity of engine oil has been reduced, but problems such as deterioration of sealability and increase in wear due to the reduction in viscosity have newly occurred.
Engine oil also plays an important role in lubrication of valve trains, bearings, etc., but in this area, mixed lubrication and boundary lubrication are common, so reducing the viscosity of engine oil causes increased wear. ing. Therefore, a friction modifier, an extreme pressure agent, and the like are added for the purpose of reducing friction loss due to lowering the viscosity of engine oil and preventing wear.

[0003] Organic molybdenum compounds have an excellent friction reducing effect and are therefore added to various lubricating oils, but they are particularly effective in reducing fuel consumption in engine oils and are indispensable for fuel saving oils. Is becoming an additive. Even if the fuel-saving oil exhibits excellent fuel-saving performance at the new oil stage, it cannot be said to be an excellent fuel-saving oil unless the performance can be maintained for a long time. Therefore, is it possible to maintain the friction reducing effect even after long-term use (long drainability)?
This is an important theme required for current fuel-saving oil.

Among the organic molybdenum compounds having excellent fuel-saving effects, oxymolybdenum sulfide dialkyldithiocarbamate is particularly attracting attention. This compound has long been known as a lubricant. For example, Japanese Patent Publication No. 53-31646 discloses that oxymolybdenum dialkyl dithiocarbamate having an alkyl group having 1 to 24 carbon atoms and having a specific ratio of sulfur atom to oxygen atom is used as a lubricant. Is described. In addition, Japanese Patent Publication No. 6-4 / 1992 discloses an improved solubility of oxymolybdenum dialkyl dithiocarbamate in base oil.
No. 7675 describes an asymmetric alkyl group oxymolybdenum dialkyldithiocarbamate.

[0005]

The above organic molybdenum compounds have been mainly used in gasoline engine oils, and various formulations have been developed. However, when an organic molybdenum compound is blended into a diesel engine oil and used, there is a problem that the effect is not sufficiently exhibited as compared with a gasoline engine oil. Although there are various differences between a gasoline engine and a diesel engine, there is a suit (soot) as a factor that greatly affects the engine oil. In diesel engines, it has been shown that suits are generated by the combustion of fuel and are mixed into engine oil. It is also known that suits occur in gasoline engines as well as in so-called direct injection engines that inject gasoline directly into the engine cylinder. By the way, in engine oil,
A dispersant is used for the purpose of dispersing mixed sludge and the like. JP-A-10-183153 and JP-A-11-212278 describe that alkenyl succinimide compounds having specific physical properties can be suitably used for diesel engine oil.

The present inventors presume that the suitability of the organomolybdenum compound in the lubricating oil is not sufficient for engines such as diesel engines and direct injection engines in which suits are generated. As a result of studying the combination with various additives, it was found that a lubricating oil containing a specific additive can exhibit excellent fuel-saving effects even in the presence of a suit, and was used for the development of the lubricating oil composition of the present invention. Successful.

[0007]

That is, the present invention relates to a lubricating base oil which is represented by the following general formula (1) as a component (A):

[0008]

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(Wherein, R ^{1 to} R ⁴ represent a hydrocarbon group;
X ^{1 to} X ⁴ represent a sulfur atom or an oxygen atom. A) oxymolybdenum dithiocarbamate represented by the formula:
As the component (B), the following general formula (2)

[0010]

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(Wherein, R ^{5 to} R ⁸ represent a hydrocarbon group;
X ^{5 to} X ⁸ represent a sulfur atom or an oxygen atom. Sulfided oxymolybdenum dithiophosphate represented by the formula (1): a lubricating oil composition for an internal combustion engine used in an internal combustion engine in which a suit is generated.

[0012]

DETAILED DESCRIPTION OF THE INVENTION The component (A) of the present invention is a sulfurized oxymolybdenum dithiocarbamate represented by the general formula (1). The component (B) of the present invention is sulfurized oxymolybdenum dithiophosphate represented by the general formula (2). In the general formulas (1) and (2), R ¹
To R ⁸ is a hydrocarbon group, for example, an alkyl group, an alkenyl group, an aryl group, a cycloalkyl group, a cycloalkenyl group. R ^{1 to} R ⁸ may be the same or different from each other.

Examples of the alkyl group include methyl, ethyl, propyl, isopropyl, butyl, isobutyl,
Tert-butyl, tert-butyl, pentyl, isopentyl, secondary pentyl, neopentyl, tert-pentyl, hexyl, secondary hexyl, heptyl, secondary heptyl, octyl, 2-ethylhexyl, secondary octyl, nonyl, secondary nonyl, decyl , 2nd grade decyl, undecyl,
Secondary undecyl, dodecyl, secondary dodecyl, tridecyl, isotridecyl, secondary tridecyl, tetradecyl,
Secondary tetradecyl, hexadecyl, secondary hexadecyl,
Stearyl, icosyl, docosyl, tetracosyl, triacontyl, 2-butyloctyl, 2-butyldecyl,
2-hexyloctyl, 2-hexyldecyl, 2-octyldecyl, 2-hexyldecyl, 2-octyldodecyl, 2-decyltetradecyl, 2-dodecylhexadecyl, 2-hexadecyloctadecyl, 2-tetradecyloctadecyl, monomethyl Branched-isostearyl and the like.

Examples of the alkenyl group include vinyl, allyl, propenyl, butenyl, isobutenyl, pentenyl, isopentenyl, hexenyl, heptenyl, octenyl, nonenyl, decenyl, undecenyl, dodecenyl, tetradecenyl, oleyl and the like. Examples of the aryl group include phenyl, toluyl, xylyl,
Cumenyl, mesityl, benzyl, phenethyl, styryl, cinnamyl, benzhydryl, trityl, ethylphenyl, propylphenyl, butylphenyl, pentylphenyl, hexylphenyl, heptylphenyl, octylphenyl, nonylphenyl, decylphenyl, undecylphenyl, dodecylphenyl, Examples include phenylphenyl, benzylphenyl, styrenated phenyl, p-cumylphenyl, α-naphthyl, and β-naphthyl groups.

Examples of the cycloalkyl group and cycloalkenyl group include, for example, cyclopentyl, cyclohexyl, cycloheptyl, methylcyclopentyl, methylcyclohexyl, methylcycloheptyl, cyclopentenyl, cyclohexenyl, cycloheptenyl, methylcyclopentenyl, methylcyclohexenyl, methylcyclohepenyl Tenyl and the like.

Of these, R ^{1 to} R ⁸ represent an alkyl group,
It is preferably an alkenyl group or an aryl group. More specifically, R ^{1 to} R ⁴ in the general formula (1), that is, an alkyl group having 8 to 13 carbon atoms in the case of oxymolybdenum sulfide dithiocarbamate, R ^{5 to} R ⁸ in the general formula (2),
That is, in the case of sulfurized oxymolybdenum dithiophosphate, an alkyl group having 6 to 13 carbon atoms is preferable. this is,
If the carbon number is too small, the oil solubility becomes poor, and if the carbon number is too large, the melting point becomes high, handling becomes poor, and the activity becomes low.

In the general formulas (1) and (2),
X ¹ to X ^4, X ⁵ to X ⁸ are each a sulfur atom or an oxygen atom may be all a sulfur atom or an oxygen atom of ^{X 1 ~X 4, X 5 ~X} 8, 4 one of X ¹ X ⁴ or X ^{5 to} X ⁸ may each be a sulfur atom or an oxygen atom. However, when lubricity and corrosiveness are considered, the ratio of sulfur atom / oxygen atom is 1/3 to 3/1. Is particularly preferred.

The addition amounts of the components (A) and (B) are not particularly limited. However, if both the addition amounts are too small, the friction reducing effect is not sufficient, and if the addition amounts are too large, sludge and corrosion tend to be caused. There is. Therefore, the amount added
The component (A) and the component (B) are each preferably 10 to 2,000 mass ppm, more preferably 50 to 1,500 mass pp, based on the amount of molybdenum relative to the lubricating base oil.
m, more preferably 100 to 1,000 ppm by mass.

The lubricating oil composition for an internal combustion engine of the present invention is further improved in oxidation stability and long drainability by adding zinc dithiophosphate represented by the following general formula (3) as component (C). I do.

[0020]

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In the general formula (3), R ⁹ and R ¹⁰ are hydrocarbon groups. As R ⁹ and R ¹⁰ , an alkyl group,
Alkenyl groups and aryl groups are preferred. Among these, an alkyl group having 3 to 14 carbon atoms is preferable. Also, R ⁹
And two or more kinds of zinc dithiophosphates having different R ¹⁰ from each other may be used in combination. a is 0 to 1/3, and a = 0
Is called neutral zinc dithiophosphate and a = 1
In the case of / 3, it is called basic zinc dithiophosphate. When zinc dithiophosphate is added to the lubricating base oil, the amount of addition is not particularly limited, but it is preferable to add a certain amount in order to exert a practical friction reducing effect and antioxidant effect, while on the other hand a very large amount If added, it may cause sludge generation. Therefore, the amount of phosphorus is preferably 0.001 to 3% by mass, more preferably 0.005 to 2% by mass, and still more preferably 0. 0.01 to 1% by mass.

Further, the lubricating oil composition for an internal combustion engine of the present invention comprises:
(D1) metal detergent, (D2)
Ashless dispersant, (D3) compound containing phosphorus atom, (D
4) a compound containing a phosphorus atom and a sulfur atom, (D5)
A compound containing a sulfur atom and no metal atom, (D
6) an antioxidant, (D7) an organometallic compound, (D8) an oiliness improver containing no metal, phosphorus and sulfur atoms, (D9) a rust preventive, (D10) a viscosity index improver,
11) metal deactivator, (D12) defoamer, (D13)
Solid lubricants and the like can be added.

(D1) Examples of the metal detergent include metal sulfonates, metal phenates, metal salicylates,
Metal phosphonate and the like. Examples of the metal sulfonate include (mono or di) alkyl benzene sulfonic acid metal salt, (mono or di) alkyl naphthalene sulfonic acid metal salt, and petroleum sulfonic acid metal salt.
Examples of the metal phenate include (mono or di) alkylphenol metal salts, thiobis {(mono or di) alkylphenol} metal salts, and methylene bis {(mono or di) alkylphenol} metal salts. Examples of metal salicylates include (mono or di) alkyl salicylic acid metal salts, thiobis {(mono or di) alkyl salicylic acid metal salts, and methylene bis} (mono or di)
Alkyl salicylic acid metal salts and the like. As the metal atom, an alkali metal or an alkaline earth metal is preferable, and calcium, magnesium, and barium are more preferable.

The compounds represented by the above-mentioned chemical names are generally called neutral salts. A basic or overbased metal detergent which has been basified with a metal oxide or metal hydroxide while blowing carbon dioxide into these neutral salts is preferably used. The overbased product is usually contained in the form of a carbonate. The total base number (TBN) of these basic or overbased metal detergents is typically 100
It is about 500 mgKOH / g. Most preferred among these metal detergents are neutral, basic or overbased calcium salicylates or calcium sulfonates. The preferable addition amount of (D1) is about 0.5 to 15% by mass based on the lubricating base oil.

(D2) Examples of the ashless dispersant include succinimide, benzylamine, succinate, and boron-modified products thereof. As the succinimide, for example, a succinic acid having a polyalkenyl group such as a polybutenyl group having a molecular weight of about 300 to 4,000, and a polyethylene polyamine such as ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, and pentaethylenehexamine. Monoimide or bisimide, or a boric acid-modified product thereof; a Mannich reaction product of phenol having a polyalkenyl group, formaldehyde, and polyethylene polyamine, and the like. The nitrogen content in the ashless dispersant is usually about 0.5 to 2.0% by mass. Among these ashless dispersants, preferred is succinimide or a boron-modified product thereof. The preferable addition amount of (D2) is about 0.5 to 20% by mass based on the lubricating base oil.

Examples of the compound containing a phosphorus atom as the component (D3) include organic phosphorus compounds such as phosphine, phosphine oxide, phosphinite, phosphonite, phosphinate, phosphite, phosphonate, phosphate, and phosphoramidate.
These compounds mainly improve lubricity and wear resistance, but may also act as antioxidants.

Examples of the organic phosphine represented by (R) ₃ P include, for example, tributylphosphine, trihexylphosphine, trioctylphosphine, tri (2-ethylhexyl) phosphine, trinonylphosphine, tridecylphosphine, trilaurylphosphine, trimyristyl. Examples include phosphine, tripalmityl phosphine, tristearyl phosphine, trioleyl phosphine, triphenyl phosphine, and tricresyl phosphine. (R) The ₂ P- (CH ₂₎ alkylidene bis phosphine represented by _n -P (R) ₂ For example, methylenebis (dibutylphosphine), methylenebis (dihexylphosphine), methylenebis (dioctyl phosphine), methylenebis (di-2 Ethylhexylphosphine), methylenebis (dinonylphosphine), methylenebis (didecylphosphine), methylenebis (dilaurylphosphine), methylenebis (dimyristylphosphine), methylenebis (dipalmitylphosphine), methylenebis (distearylphosphine), methylenebis (geo) Rail phosphine), methylene bis (diphenyl phosphine), methylene bis (dicresyl phosphine) and the like.

Examples of the organic phosphine oxide represented by (R) ₃ P ＝ O include, for example, tributylphosphine oxide, trihexylphosphine oxide, trioctylphosphine oxide, tri (2-ethylhexyl) phosphine oxide, trinonylphosphine oxide, tridecyl Examples include phosphine oxide, trilauryl phosphine oxide, trimyristyl phosphine oxide, tripalmityl phosphine oxide, tristearyl phosphine oxide, trioleyl phosphine oxide, triphenyl phosphine oxide, and tricresyl phosphine oxide.

Examples of the organic phosphite represented by (RO) ₃ P include, for example, monobutyl phosphite, dibutyl phosphite, and tributyl phosphite (these are abbreviated as “mono / di / tributyl phosphite”.
The same applies hereinafter), mono / di / trihexyl phosphite, mono / di / trioctyl phosphite, mono / di / tri (2-ethylhexyl) phosphite, mono / di / trinonyl phosphite, mono / di / tridecyl Phosphite, mono / di / trilauryl phosphite, mono / di /
Trimyristyl phosphite, mono / di / tripalmityl phosphite, mono / di / tristearyl phosphite, mono / di / trioleyl phosphite, mono / di /
Triphenyl phosphite, mono / di / tricresyl phosphite and the like. Examples of other phosphites include pentaerythritol diphosphite, pentaerythritol tetraphosphite, and alkylidenebisphosphite.

Examples of the organic phosphate represented by (RO) ₃ P ＝ O include monobutyl phosphate, dibutyl phosphate, and tributyl phosphate (these are collectively abbreviated as “mono / di / tributyl phosphate”; the same applies hereinafter). / Di / trihexyl phosphate, mono / di / trioctyl phosphate, mono / di /
Tri (2-ethylhexyl) phosphate, mono / di /
Trinonyl phosphate, mono / di / tridecyl phosphate, mono / di / trilauryl phosphate, mono /
Di / trimyristyl phosphate, mono / di / tripalmityl phosphate, mono / di / tristearyl phosphate, mono / di / trioleyl phosphate, mono /
Di / triphenyl phosphate, mono / di / tricresyl phosphate and the like. Further, a phosphate having a polyoxyalkylene group, for example, a phosphate of lauryl alcohol ethylene oxide and / or propylene oxide adduct, and the like can also be mentioned.

Of these phosphates, mono- or diphosphates are called acidic phosphates and may be used after neutralization with a base such as an alkali or an amine. Examples of the alkali include metal hydroxides such as lithium hydroxide, sodium hydroxide, potassium hydroxide, magnesium hydroxide, and calcium hydroxide. Examples of the amine include ammonia; methylamine, dimethylamine, ethylamine, diethylamine, (iso) propylamine, di (iso) propylamine, butylamine, hexylamine, octylamine, decylamine, dodecylamine, tridecylamine, cetylamine, and coconut. Alkylamines such as alkylamine, alkylamine derived from soybean oil, alkylamine derived from tallow, oleylamine and stearylamine; monoethanolamine, N-methylmonoethanolamine, N-ethylmonoethanolamine, diethanolamine, N-methyldiethanolamine, N -Ethyldiethanolamine, triethanolamine, 2-amino-2-methyl-1-propanol, 2
-Amino-2-methyl-1,3-propanediol, aminoethylethanolamine, N, N, N ', N'-tetrakis (hydroxyethyl) ethylenediamine, N,
Alkanolamines such as N, N ', N'-tetrakis (2-hydroxypropyl) ethylenediamine or alkylene oxide adducts thereof; N-butyldiethanolamine, N-hexyldiethanolamine, N-
Octyldiethanolamine, N-decyldiethanolamine, N-cocoalkyldiethanolamine, alkyldiethanolamine derived from N-soy oil, alkyldiethanolamine derived from N-tallow, N-oleyldiethanolamine, N-stearyldiethanolamine, N, N-
Dibutyl monoethanolamine, N, N-dihexyl monoethanolamine, N, N-dioctyl monoethanolamine, N, N-didecyl monoethanolamine,
N, N-bis (cocoalkyl) monoethanolamine,
N, N-bis (alkyl derived from soybean oil) monoethanolamine, N, N-bis (alkyl derived from tallow) monoethanolamine, N-dioleyl monoethanolamine, N-
Examples thereof include N-long-chain alkylalkanolamines such as distearyl monoethanolamine, and alkylene oxide adducts thereof. Examples of the phosphoramidate include those obtained by subjecting the above-mentioned phosphate and the above-mentioned amine to a condensation reaction. The preferable addition amount of the component (D3) is about 0.1 to 5% by mass based on the lubricating base oil.

Examples of the compound containing a phosphorus atom and a sulfur atom as the component (D4) include trithiophosphite and thiophosphate. These compounds mainly improve lubricity and wear resistance, but may also act as antioxidants.

As the organic trithiophosphite represented by (RS) ₃ P, for example, monobutyl trithiophosphite, dibutyl trithiophosphite, tributyl trithiophosphite (these are collectively abbreviated as “mono / di / tributyl phosphite”) The same shall apply hereinafter), mono / di / trihexyltrithiophosphite, mono / di /
Trioctyl trithiophosphite, mono / di / tri (2-ethylhexyl) trithiophosphite, mono /
Di / trinonyl trithiophosphite, mono / di / tridecyl trithiophosphite, mono / di / trilauryl trithiophosphite, mono / di / trimyristyl trithiophosphite, mono / di / tripalmityl trithiophosphite, mono / Di / tristearyltrithiophosphite, mono / di / trioleyltrithiophosphite, mono / di / triphenyltrithiophosphite, mono / di / tricresyltrithiophosphite and the like.

Examples of the organic thiophosphate represented by (RO) ₃ P = S include, for example, monobutyl thiophosphate, dibutyl thiophosphate, and tributyl thiophosphate (these are abbreviated as “mono / di / tributyl thiophosphate”. The same applies hereinafter), mono / di / trihexyl thiophosphate, mono / di / trioctyl thiophosphate, mono / di / tri (2-ethylhexyl) thiophosphate, mono / di / trinonyl thiophosphate, mono / di / tridecyl Thiophosphate, mono / di / trilauryl thiophosphate, mono / di / trimyristyl thiophosphate, mono / di / tripalmityl thiophosphate, mono / di / tristearyl thiophosphate, mono / di / trioleyl thiophosphate, mono / Ji / Tori Phenylthiophosphate, mono /
And di / tricresylthiophosphate.
Further, dithiophosphoric acid dimers can also be used. (D
4) A preferable addition amount of the component is 0.1 to the lubricating base oil.
It is about 1 to 5% by mass.

Examples of the compound containing a sulfur atom as the component (D5) and containing no metal atom include lard sulfide, sulfide fish oil, sulfide whale oil, sulfide soybean oil, sulfide pinene oil,
Sulfurized coconut oil, other than sulfurized fatty acid-derived compounds such as sulfurized fatty acids, other than sulfurized single bonds, organic mono- or polysulfides, polyolefin sulfides such as isobutylene, 1,3,4-thiadiazole derivatives, thiuram disulfide, And dithiocarbamic acid esters.

The organic mono- or polysulfide is represented by the following general formula (D5-1) R-S _x -R (D5-1) (wherein R represents a hydrocarbon group and x represents a number of about 1 to about 10). Is a compound represented by the formula:
Dimethyl monosulfide, dimethyl disulfide,
Dimethyl polysulfide (these are abbreviated as “dimethyl mono / di / polysulfide”; the same applies hereinafter), diethyl mono / di / polysulfide, dipropyl mono / di / polysulfide, diisopropyl mono /
Di / polysulfide, dibutyl mono / di / polysulfide, diisobutyl mono / di / polysulfide, ditertiary butyl mono / di / polysulfide, dipentyl mono / di / polysulfide, diisopentyl mono / di / polysulfide, dineopentyl mono / di / polysulfide , Ditertiary pentyl mono / di / polysulfide, dihexyl mono / di / polysulfide, diheptyl mono / di / polysulfide, dioctyl mono / di / polysulfide, di (2-ethylhexyl) mono / di / polysulfide, dinonyl mono / di /
Polysulfide, ditercharinonyl mono / di / polysulfide, didecyl mono / di / polysulfide,
Diundecyl mono / di / polysulfide, didodecyl mono / di / polysulfide, ditridecyl mono / di /
Polysulfide, diisotridecyl mono / di / polysulfide, ditetradecyl mono / di / polysulfide, dihexadecyl mono / di / polysulfide, distearyl mono / di / polysulfide, diisostearyl mono / di / polysulfide, dioleyl mono / di /
Polysulfide, diicosyl mono / di / polysulfide, didocosyl mono / di / polysulfide, ditetracosyl mono / di / polysulfide, ditriacontyl mono / di / polysulfide, diphenyl mono / di /
Polysulfide, ditolyl mono / di / polysulfide, dixylyl mono / di / polysulfide, dicumenyl mono / di / polysulfide, dimesityl mono / di / polysulfide, dibenzyl mono / di / polysulfide, diphenethyl mono / di / polysulfide, distyryl mono / di / polysulfide, dicinamyl monosulfide Polysulfide, dibenzhydryl mono / di / polysulfide, ditrityl mono / di / polysulfide, di (ethylphenyl) mono / di / polysulfide, di (propylphenyl) mono / di / polysulfide, di (butylphenyl) mono / di / polysulfide, Di (pentylphenyl) mono / di / polysulfide, di (hexylphenyl) mono / di / polysulfide, di (heptyl) Phenyl) mono / di / polysulfide, di (octylphenyl) mono / di / polysulfide, di (nonylphenyl) mono / di / polysulfide, di (decylphenyl) mono / di / polysulfide, di (undecylphenyl) mono / di / Polysulfide, di (dodecylphenyl) mono / di / polysulfide, di (phenylphenyl) mono / di / polysulfide, di (benzylphenyl) mono / di / polysulfide, di (styrenated phenyl) mono / di / polysulfide, di ( (p-cumylphenyl) mono / di / polysulfide, dicyclopentyl mono / di / polysulfide, dicyclohexyl mono / di / polysulfide, dicycloheptyl mono / di / polysulfide, di (methylcyclopentyl) mono / di / polysulfide Di (methylcyclohexyl) mono / di / polysulfide, di (methylcycloheptyl) mono / di / polysulfide, etc .; di (hydrocarbyl sulfide); di (ethylhydroxyphenyl) mono / di / polysulfide, di (propylhydroxyphenyl) mono / Di / polysulfide, di (butylhydroxyphenyl) mono / di / polysulfide, di (pentylhydroxyphenyl) mono / di / polysulfide, di (hexylhydroxyphenyl) mono / di / polysulfide, di (heptylhydroxyphenyl) mono / di / Polysulfide, di (octylhydroxyphenyl) mono / di / polysulfide, di (nonylhydroxyphenyl) mono / di / polysulfide, di (decylhydroxyphenyl) mono / di / poly And dihydrocarbylphenol sulfides such as sulfide, di (undecylhydroxyphenyl) mono / di / polysulfide, and di (dodecylhydroxyphenyl) mono / di / polysulfide.

The 1,3,4-thiadiazole derivative has the following general formula (D5-2)

[0038]

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(Wherein, R represents a hydrocarbon group or a hydrocarbon group containing a sulfur atom).

Examples of the sulfur-containing hydrocarbon group include 5-thianonyl, 2,5-dithianonyl, 3,4-
Dithiahexyl, 4,5-dithiahexyl, 3,4,5
-Trithiaheptyl, 3,4,5,6-tetrathiaoctyl, 5-thia-2-heptenyl, 4-thiacyclohexyl, 1,4-dithianaphthyl, 5- (methylthio) octyl, 4- (ethylthio) -2 -Pentenyl, 4-
(Methylthio) cyclohexyl, 4-mercaptophenyl, 4- (methylthio) phenyl, 4- (hexylthio) benzyl, stearyldithio, lauryldithio, octyldithio, stearylthio, laurylthio, octylthio, N, N-dialkyldithiocarbamoyl and the like. Among them, a group in which 2 to 4 sulfur atoms are continuously bonded is particularly preferable. Thiuram disulfide has the following general formula (D5-3)

[0041]

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(R represents a hydrocarbon group, and R ′ represents a sulfur atom, a divalent hydrocarbon group or a divalent hydrocarbon group containing a sulfur atom.) R ′ is-
S (-S) _n - (. Where, n is the number of 0 or 1 or more) groups represented by a methylene _{group, -S (-S) n (-CH} 2) n -S (-
S) _n- (where n is the same or different, and is 0 or 1 or more). R is preferably a chain hydrocarbon group having 4 or more carbon atoms. Dithiocarbamic acid ester is represented by the following general formula (D5-4)

[0043]

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(R represents a hydrocarbon group, R ′ represents a hydrogen atom, a hydrocarbon group or a group represented by COOR ″, and R ″ represents a hydrocarbon group.) (D
5) The preferable addition amount of the component is 0.1 to the lubricating base oil.
It is about 1 to 10% by mass.

As the antioxidant as the component (D6),
For example, phenol-based antioxidants, amine-based antioxidants, sulfur-based antioxidants and the like can be mentioned. Examples of the phenolic antioxidant include 2,6-di-tert.-
Butylphenol (hereinafter, tert.-butyl is referred to as “t-
Butyl ". ), 2,6-di-t-butyl-p
-Cresol, 2,6-di-tert-butyl-4-methylphenol, 2,6-di-tert-butyl-4-ethylphenol, 2,4-dimethyl-6-tert-butylphenol,
4,4'-methylenebis (2,6-di-t-butylphenol), 4,4'-bis (2,6-di-t-butylphenol), 4,4'-bis (2-methyl-6-t -Butylphenol), 2,2′-methylenebis (4-methyl-6-t-butylphenol), 2,2′-methylenebis (4-ethyl-6-t-butylphenol), 4,
4'-butylidenebis (3-methyl-6-t-butylphenol), 4,4'-isopropylidenebis (2,6
-Di-t-butylphenol), 2,2'-methylenebis (4-methyl-6-cyclohexylphenol),
2,2'-methylenebis (4-methyl-6-nonylphenol), 2,2'-isobutylidenebis (4,6-dimethylphenol), 2,6-bis (2'-hydroxy-3'-t- Butyl-5'-methylbenzyl) -4-methylphenol, 3-tert-butyl-4-hydroxyanisole, 2-tert-butyl-4-hydroxyanisole,
Stearyl 3- (4-hydroxy-3,5-di-tert-butylphenyl) propionate, 3- (4-hydroxy-
Oleyl 3,5-di-t-butylphenyl) propionate, dodecyl 3- (4-hydroxy-3,5-di-t-butylphenyl) propionate, 3- (4-hydroxy-3,5-di- tert-butylphenyl) decyl propionate, octyl 3- (4-hydroxy-3,5-di-t-butylphenyl) propionate, tetrakis-3- (4
-Hydroxy-3,5-di-t-butylphenyl) propionyloxymethyldimethane, 3- (4-hydroxy-3,5-di-t-butylphenyl) propionic acid glycerin monoester, 3- (4-hydroxy −3,5-
Ester of di-t-butylphenyl) propionic acid with glycerin monooleyl ether, butylene glycol 3- (4-hydroxy-3,5-di-t-butylphenyl) propionate, 3- (4-hydroxy-
3,5-di-t-butylphenyl) propionic acid thiodiglycol ester, 4,4'-thiobis (3-methyl-6-t-butylphenol), 4,4'-thiobis (2-methyl-6-t -Butylphenol), 2,2 ′
-Thiobis (4-methyl-6-t-butylphenol), 2,6-di-t-butyl-α-dimethylamino-
p-cresol, 2,6-di-tert-butyl-4- (N,
N'-dimethylaminomethylphenol), bis (3
5-di-tert-butyl-4-hydroxybenzyl) sulfide, tris {(3,5-di-tert-butyl-4-hydroxyphenyl) propionyl-oxyethyl} isocyanurate, tris (3,5-di-tert-) Butyl-4-hydroxyphenyl) isocyanurate, 1,3,5-tris (3,5-di-tert-butyl-4-hydroxybenzyl) isocyanurate, bis {2-methyl-4- (3-
n-alkylthiopropionyloxy) -5-t-butylphenyl disulfide, 1,3,5-tris (4-
t-butyl-3-hydroxy-2,6-dimethylbenzyl) isocyanurate, tetraphthaloyl-di (2,6
-Dimethyl-4-t-butyl-3-hydroxybenzyl sulfide), 6- (4-hydroxy-3,5-di-)
t-butylanilino) -2,4-bis (octylthio)
-1,3,5-triazine, 2,2-thio- {diethyl-bis-3- (3,5-di-tert-butyl-4-hydroxyphenyl)} propionate, N, N′-hexamethylenebis ( 3,5-di-t-butyl-4-hydroxy-
Hydrocinamide), 3,5-di-t-butyl-4-hydroxy-benzyl-phosphate diester, bis (3-methyl-4-hydroxy-5-t-butylbenzyl) sulfide, 3,9-bis [1, 1-dimethyl-2-Δβ-
(3-t-butyl-4-hydroxy-5-methylphenyl) propionyloxydiethyl] -2,4,8,10
-Tetraoxaspiro [5,5] undecane, 1,1,
3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, 1,3,5-trimethyl-2,
4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene, bis {3,3′-bis-
(4'-Hydroxy-3'-t-butylphenyl) butyric acid @ glycol ester.

As the amine antioxidant, for example, 1
-Naphthylamine, phenyl-1-naphthylamine, p
-Naphthylamine-based antioxidants such as -octylphenyl-1-naphthylamine, p-nonylphenyl-1-naphthylamine, p-dodecylphenyl-1-naphthylamine and phenyl-2-naphthylamine; N, N'-diisopropyl-p-phenylenediamine , N, N'-diisobutyl-p-phenylenediamine, N, N'-diphenyl-p-phenylenediamine, N, N'-di-β-naphthyl-p-phenylenediamine, N-phenyl-N'-isopropyl- p-phenylenediamine, N-cyclohexyl-N'-phenyl-p-phenylenediamine, N-
1,3-dimethylbutyl-N′-phenyl-p-phenylenediamine, dioctyl-p-phenylenediamine,
Phenylenediamine antioxidants such as phenylhexyl-p-phenylenediamine and phenyloctyl-p-phenylenediamine; dipyridylamine, diphenylamine, p, p'-di-n-butyldiphenylamine, p,
p'-di-t-butyldiphenylamine, p, p'-di-t-pentyldiphenylamine, p, p'-dinonyldiphenylamine, p, p'-didecyldiphenylamine, p, p'-didodecyldiphenylamine, p , P '
-Distyryldiphenylamine, p, p'-dimethoxydiphenylamine, 4,4'-bis (4-α, α-dimethylbenzoyl) diphenylamine, p-isopropoxydiphenylamine, dipyridylamine, and other diphenylamine-based antioxidants; phenothiazine, N And phenothiazine-based antioxidants such as -methylphenothiazine, N-ethylphenothiazine, 3,7-dioctylphenothiazine, phenothiazine carboxylate, and phenoselenazine.

Examples of the sulfur-based antioxidants include dioctylthiodipropionate, didecylthiodipropionate, dilaurylthiodipropionate, dimyristylthiodipropionate, distearylthiodipropionate, laurylstearylthiodipropionate. Pionate, dimyristylthiodipropionate, distearyl-β,
β'-thiodibutyrate, (3-octylthiopropionic acid) pentaerythritol tetraester, (3-decylthiopropionic acid) pentaerythritol tetraester, (3-laurylthiopropionic acid) pentaerythritol tetraester, (3-stearyl Thiopropionic acid) pentaerythritol tetraester, (3
-Oleylthiopropionic acid) pentaerythritol tetraester, (3-laurylthiopropionic acid)-
4,4'-thiodi (3-methyl-5-t-butyl-4-
Phenol) ester, 2-mercaptobenzimidazole, 2-mercaptomethylbenzimidazole, 2-
Benzimidazole disulfide, dilauryl sulfide, amylthioglycolate and the like. (D
6) A preferable addition amount of the component is 0.1 to the lubricating base oil.
It is about 01 to 5% by mass.

The organometallic compound as the component (D7) improves abrasion resistance and oxidation resistance. Specifically, for example, hexanoic acid, octanoic acid, pelargonic acid, decanoic acid, lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, behenic acid, linoleic acid, lithium fatty acid such as linolenic acid or lithium of naphthenic acid ,
Examples thereof include sodium, potassium, magnesium, calcium, barium, titanium, zinc, lead, tin, iron, cadmium, cobalt, nickel, manganese, strontium, titanium, vanadium, copper, antimony, bismuth, and tungsten salts. Fatty acids have 12 to 1 carbon atoms
About 8 is preferable. In addition, for example, metal salts of dithiophosphate, metal salts of dithiocarbamic acid, metal salts of mercaptobenzothiazole, metal salts of mercaptobenzimidazole, metal salts of benzamidothiophenol and the like can also be mentioned. The metal atom is the metal atom exemplified above.

Further, as the organic molybdenum compound, for example, a fatty acid molybdenum salt, oxymolybdenum sulfide xanthate, a reaction product of molybdenum trioxide with an acid phosphate, a reaction product of molybdenum trioxide with a fatty acid diethanolamide, and a molybdenum trioxide Examples thereof include a reaction product of glycerin monofatty acid ester, a reaction product of succinimide, carboxylic acid amide or Mannich base or a boride thereof and molybdenum trioxide, and a reaction product of primary or secondary amine with molybdenum trioxide. The component (D8) is
It is an oiliness improver containing no metal, phosphorus and sulfur atoms. For example, hexanoic acid, octanoic acid, pelargonic acid, decanoic acid, lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, behenic acid, linoleic acid, fatty acids such as linolenic acid; Olive oil, cacao butter, kapok oil, white mustard oil, sesame oil, rice bran oil, safflower oil, shea nut oil, cinnamon oil, soybean oil, teaseed oil, camellia oil, corn oil, rapeseed oil, palm oil, palm kernel oil, Castor oil, sunflower oil, cottonseed oil, coconut oil, wood wax, peanut oil, horse fat, beef tallow, beef tallow, beef tallow, lard, goat fat, sheep fat, milk fat, fish oil, whale oil, etc., or hydrides thereof Or partially saponified products; epoxidized oils such as epoxidized soybean oil and epoxidized linseed oil; epoxies such as butyl epoxy stearate and octyl epoxy stearate Esters; dibasic acids such as glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, dodecandioic acid and dimer acid; hydroxystearic acids such as ricinoleic acid (castor oil fatty acid) and 12-hydroxystearic acid Or an ester of the polycondensate with a fatty acid;

Higher alcohols such as lauryl alcohol, myristyl alcohol, palmityl alcohol, stearyl alcohol, oleyl alcohol, behenyl alcohol; higher amines such as laurylamine, myristylamine, palmitylamine, stearylamine, oleylamine, behenylamine; laurylamide; Higher amides such as myristylamide, palmitylamide, stearylamide, oleylamide, and behenylamide; diethanolamides such as lauryl diethanolamide, myristyl diethanolamide, palmityl diethanolamide, stearyl diethanolamide, oleyl diethanolamide, and behenyl diethanolamide; hexane Acid mono /
Di / triglyceride, octanoic acid mono / di / triglyceride, decanoic acid mono / di / triglyceride, lauric acid mono / di / triglyceride, myristic acid mono / di / triglyceride, palmitic acid mono / di / triglyceride, stearic acid mono / di / Glycerides such as triglyceride, oleic acid mono / di / triglyceride, behenic acid mono / di / triglyceride, etc .; polyglycerin hexanoate, polyglyceryl octanoate, polyglycerin decanoate, polyglycerol laurate, polyglycerol myristate Polyglycerol esters such as polyglycerin palmitate, polyglycerin stearate, polyglycerin oleate, polyglycerin behenate;

Sorbitan hexanoate, sorbitan octoate, sorbitan decanoate,
Sorbitan esters such as sorbitan laurate ester, sorbitan myristate ester, sorbitan palmitate ester, sorbitan stearate ester, sorbitan oleate ester and sorbitan behenate ester; (poly) glycerin monooctyl ether;
(Poly) glycerin ethers such as (poly) glycerin monodecyl ether, (poly) glycerin monolauryl ether, (poly) glycerin monooleyl ether, (poly) glycerin monostearyl ether; ethylene oxide, propylene oxide, dodecane Those to which an α-olefin oxide such as -1,2-oxide is added are exemplified. The preferable addition amount of the component (D8) is about 0.05 to 10% by mass based on the lubricating base oil.

The component (D9) is a rust preventive. For example,
Sulfonate, sodium nitrite, calcium oxide paraffin wax, magnesium oxide paraffin wax, alkali metal salt of tallow fatty acid, alkaline earth metal salt or amine salt, alkenyl succinic acid or alkenyl succinic acid half ester (exemplified as the above metal detergent) Alkenyl group has a molecular weight of about 100 to 300), sorbitan monoester, pentaerythritol monoester, glycerin monoester, nonylphenol ethoxylate, lanolin fatty acid ester, and lanolin fatty acid calcium salt. The preferable addition amount of the component (D9) is about 0.1 to 15% by mass based on the lubricating base oil.

The component (D10) is a viscosity index improver.
For example, poly (C1-18) alkyl methacrylate,
(C1-18) alkyl acrylate and (C1-18)
Copolymer of alkyl methacrylate, copolymer of diethylaminoethyl methacrylate and (C1-18) alkyl methacrylate, copolymer of ethylene and (C1-18) alkyl methacrylate, polyisobutylene, polyalkylstyrene, copolymer of ethylene and propylene And a copolymer of styrene and maleic acid ester, a copolymer of styrene and maleic amide, a hydrogenated copolymer of styrene and butadiene, and a hydrogenated copolymer of styrene and isoprene. The average molecular weight is 10,000 to 1,50
It is about 0000. The preferable addition amount of the component (D10) is about 0.1 to 20% by mass based on the lubricating base oil.

The component (D11) is a metal deactivator. For example, N, N'-salicylidene-1,2-propanediamine, alizarin, tetraalkylthiuram disulfide, benzotriazole, benzimidazole, 2-alkyldithiobenzimidazole, 2-alkyldithiobenzothiazole, 2- (N, N -Dialkyldithiocarbamoyl) benzothiazole, 2,5-bis (alkyldithio) -1,3,4-thiadiazole,
2,5-bis (N, N-dialkyldithiocarbamoyl) -1,3,4-thiadiazole and the like.
The preferable addition amount of the component (D11) is about 0.01 to 5% by mass based on the lubricating base oil.

The component (D12) is an antifoaming agent. For example, polydimethyl silicone, trifluoropropyl methyl silicone, colloidal silica, polyalkyl acrylate, polyalkyl methacrylate, alcohol ethoxy / propoxylate, fatty acid ethoxy / propoxylate, sorbitan partial fatty acid ester and the like can be mentioned. The preferable addition amount of the component (D12) is about 0.001 to 1% by mass based on the lubricating base oil.

The component (D13) is a solid lubricant. For example, graphite, molybdenum disulfide, polytetrafluoroethylene, fatty acid alkaline earth metal salts, mica, cadmium dichloride, cadmium diiodide, calcium fluoride, lead iodide, lead oxide, titanium carbide, titanium nitride, aluminum silicate , Antimony oxide, cerium fluoride, polyethylene, diamond powder, silicon nitride, boron nitride fluorocarbon, melamine isocyanurate and the like. The preferable addition amount of the component (D13) is about 0.005 to 2% by mass based on the lubricating base oil.

One or more of the above-mentioned component (D) can be appropriately added to the lubricating oil composition for an internal combustion engine of the present invention. It is preferable to add at least (D1) a metal detergent, (D2) an ashless dispersant, or (D6) an antioxidant to the lubricating oil composition for an internal combustion engine of the present invention.

The lubricating base oil which can be used in the present invention is a lubricating base oil comprising a mineral oil, a synthetic oil or a mixture thereof. The kinematic viscosity of the lubricating base oil of the lubricating oil composition for an internal combustion engine of the present invention is not particularly limited, but is preferably 100 ° C.
1 to 50 mm ² / s at 40 ° C. and 10 to 1,000 mm ²
/ S, viscosity index (VI) is preferably 100 or more,
It is more preferably 120 or more, and most preferably 135 or more.

The mineral oil used as the base oil of the lubricating oil composition for an internal combustion engine of the present invention is separated from natural crude oil, and is produced by appropriately distilling and refining.
Main component of mineral oil is hydrocarbon (mostly paraffins)
And further contains a monocyclic naphthene component, a bicyclic naphthene component, an aromatic component, and the like. These are hydrorefined, solvent dewaxed, solvent extracted, solvent dewaxed, hydrodewaxed, contact dewaxed,
Base oils that have been subjected to purification such as hydrocracking, alkali distillation, washing with sulfuric acid, and clay treatment can also be preferably used. These purification means are appropriately combined, and it is effective to repeat the same treatment in a plurality of stages. For example, (A) a method in which a distillate is subjected to a solvent extraction treatment, or a solvent extraction treatment, followed by a hydrogenation treatment, followed by washing with sulfuric acid;
(B) a method of dewaxing after distilling oil after hydrotreating, (C) a method of distilling oil after solvent extraction, and (D) a method of distilling oil after solvent extraction, and clay treatment. (E) distillate oil is subjected to two-stage or three-stage hydrotreatment, or alkali distillation or sulfuric acid washing treatment, and (F) distillate oil is hydrotreated or hydrogenated. After the chemical conversion treatment, a method of alkali distillation or sulfuric acid washing treatment, or a method of mixing these treated oils is effective.

By performing these treatments, it is possible to remove aromatic components, sulfur content, nitrogen content and the like in the unrefined mineral oil. According to the present technology, these impurities can be removed to a trace amount or less, but the aromatic component has an effect of making the lubricating oil additive easy to dissolve. There is also. For example, the sulfur content and the nitrogen content in the currently used highly refined mineral oil are 0.01% by mass or less, and in some cases 0.005% by mass or less.
On the other hand, the content of the aromatic component is 1% by mass or less, and in some cases, the content is 0.1% by mass.
Some of them have a content of not more than 05% by mass and others have a content of about 3% by mass.

The synthetic oil used as a base oil of the lubricating oil composition for an internal combustion engine of the present invention is a chemically synthesized lubricating oil, for example, poly-α-olefin, polyisobutylene (polybutene). , Diester, polyol ester, aromatic polycarboxylic acid ester, phosphate ester,
Examples include silicate esters, polyalkylene glycols, polyphenyl ethers, silicones, fluorinated compounds, alkylbenzenes, and the like. Among these, poly-α-
Olefin, polyisobutylene (polybutene), diester, polyol ester, polyalkylene glycol and the like can be preferably used as the base oil of the lubricating oil composition for an internal combustion engine of the present invention.

Examples of the poly-α-olefin include 1
-Hexene, 1-octene, 1-nonene, 1-decene,
Examples thereof include those obtained by polymerizing or oligomerizing 1-dodecene, 1-tetradecene, and the like, and those obtained by hydrogenating them. Examples of the diester include glutaric acid,
Examples include dibasic acids such as adipic acid, azelaic acid, sebacic acid and dodecane diacid, and diesters of alcohols such as 2-ethylhexanol, octanol, decanol, dodecanol and tridecanol. Examples of the polyol ester include neopentyl glycol, trimethylolethane, trimethylolpropane, glycerin, pentaerythritol, sorbitol, dipentaerythritol, tripentaerythritol, or a polyol such as an alkylene oxide adduct thereof, butyric acid, isobutyric acid, Esters with fatty acids such as valeric acid, isovaleric acid, pivalic acid, capric acid, caproic acid, caprylic acid, lauric acid, myristic acid, palmitic acid, stearic acid, and oleic acid. Examples of the polyalkylene glycol include polyethylene glycol, polypropylene glycol, polyethylene glycol monomethyl ether, mono- or dimethyl ether of a block or random copolymer of ethylene oxide / propylene oxide, and the like.

Each of these synthetic oils is chemically synthesized and therefore is a single substance or a mixture of homologues. Therefore, for example, synthetic oils such as poly-α-olefins, polyisobutylene (polybutene), diesters, polyol esters, and polyalkylene glycols include benzene, which is an impurity contained in mineral oil, polycyclic fused aromatic components, thiophene, and the like. Of sulfur, nitrogen such as indole and carbazole are not included.

The content of the alkali metal in the lubricating oil composition for an internal combustion engine of the present invention is preferably not more than 0.02% by mass in terms of the total amount of the alkali metal contained in the lubricating oil composition. It is more preferable that the content be 01% by mass or less.
The case where an alkali metal is mixed in a lubricating oil composition is generally the case where the removal of the alkali metal as a catalyst or a raw material in a separation, purification, or synthesis process of a base oil has not been completely performed. Is mentioned. In addition, also in the process of synthesizing a lubricating oil additive, an alkali metal or a salt thereof is often used as a raw material or a catalyst, and there are cases where they are not completely removed. Sulfur oxymolybdenum dithiocarbamate and sulfurized oxymolybdenum dithiophosphate often use an inorganic material containing an alkali metal during the production process. Further, there may be mentioned a case where sodium nitrite or sodium sulfonate is used as a rust preventive, or an alkali metal compound is added as a cleaning dispersant.

The nitrogen content in the lubricating oil composition for an internal combustion engine of the present invention is preferably 0.01% by mass or more in terms of the total amount of nitrogen contained in the lubricating oil composition, and is preferably 0.03% by mass. %, More preferably at least 0.05% by mass. The case where nitrogen is contained in the lubricating oil composition refers to the case where nitrogen is contained in the component (A) of the present invention. In addition, for example, when an amine-based antioxidant is used as an antioxidant, a dithiocarbamate derivative is used. When used, the case where a fatty acid amide is used and the like are exemplified.
The lubricating oil composition for an internal combustion engine of the present invention is used for an internal combustion engine that generates a suit. Examples of the internal combustion engine that generates a suit include a diesel engine and a direct injection engine.

[0066]

The present invention will be described more specifically with reference to the following examples. In the following examples, parts and% are based on mass unless otherwise specified.

Example 1: Lubricating base oil, component (A)
Using the components (B), (C) and (D) described below, the lubricating oil composition for internal combustion engines of the present invention and the comparative product were blended into the compositions shown in Table 1 below. Lubricating oil compositions were prepared, the coefficient of friction of these lubricating oil compositions was measured by the following method, and the lubricity in the presence of a suit was evaluated.

(I) Lubricating base oil Base oil 1: Mineral oil-based high VI oil. Kinematic viscosity 4.1 mm ^{2 / s (} 100 ° C.), 18.3 mm ²
/ S (40 ° C.), viscosity index (VI) = 126 Synthetic oil consisting of 80% of poly-α-olefin obtained by oligomerization of base oil 2: 1-decene and 20% of polyol ester. Kinematic viscosity 4.0 mm ^{2 / s (} 100 ° C.), 16.9 mm ²
/ S (40 ° C.), viscosity index (VI) = 138 Base oil 3: A mixed base oil obtained by mixing base oil 1 and base oil 2 at a ratio of 1: 1.

(Ii) Component (A) (A-1): In the general formula (1), R ^{1 to} R ⁴ = 2-ethylhexyl group S / O of X ^{1 to} X ⁴ = 2.0 / 2.0 (A-2): In the general formula (1), R ¹ = R ² = 2-ethylhexyl group, R ³ = R ⁴ = isotridecyl group S / O of X ^{1 to} X ⁴ = 2.0 / 2.0 ( A-3): In the general formula (1), R ^{1 to} R ⁴ = isotridecyl group S / O of X ^{1 to} X ⁴ = 2.0 / 2.0 (A-4): In the general formula (1), R ^{1 to} R ⁴ = octadecyl group S / O of X ^{1 to} X ⁴ = 2.0 / 2.0

(Ii) Component (B) (B-1): In the general formula (2), R ^{5 to} R ⁸ = 2-ethylhexyl group S / O of X ^{5 to} X ⁸ = 2.0 / 2.0 (B-2): In the general formula (2), R ^{5 to} R ⁸ = octadecyl group S / O of X ^{5 to} X ⁸ = 2.0 / 2.0 (B-3): In the general formula (2) , R ⁵ = R ⁶ = 2- ethylhexyl group, noted S / O = 2.0 / 2.0 of the R ⁷ = R ⁸ = isotridecyl group X ⁵ to X ^8, and isotridecyl group, to give isobutene by trimerization This is a group derived from isotridecyl alcohol synthesized from the obtained dodecene by the oxo method.

(Iii) Component (C) (C-1): In the general formula (3), R ⁹ = R ¹⁰ = 2-ethylhexyl group neutral salt / basic salt = 95/5 (mass ratio) (C -2): In the general formula (3), a mixture of R ⁹ = R ¹⁰ = secondary propyl group and secondary hexyl group, neutral salt / basic salt = 95/5 (mass ratio) (C-3): general In the formula (3), R ⁹ = R ¹⁰ = dodecyl group neutral salt / basic salt = 95/5 (mass ratio)

(Iv) Component (D) (D-1): overbased calcium alkylbenzene sulfonate (metal detergent), TBN (total base number) = 300 (D-2): polybutenyl bissuccinimide (Ashless dispersant), average molecular weight 1,800 (D-3): phenyl-α-naphthylamine (antioxidant)

(V) Method of Measuring Friction Coefficient 1% of carbon black was added to each of the lubricating oil compositions for internal combustion engines of the present invention and the comparative lubricating oil compositions shown in Table 1 and sufficiently stirred with a stirrer. For each of these lubricating oil compositions, the friction coefficient was measured using a SRV measuring tester under the line contact conditions of a cylinder-on-plate. Upper cylinder is φ15 × 22mm, plate is φ
The cylinder was set 24 × 6.85 mm perpendicularly to the sliding direction on the plate, and was subjected to reciprocating vibration to measure the friction coefficient. The material of the cylinder and the plate is S
UJ-2. Detailed measurement conditions are as follows. <Measurement conditions> Load: 400 N Temperature: 100 ° C. Measurement time: 15 minutes Amplitude: 1.0 mm Cycle: 50 Hz The measurement results of these friction coefficients are shown in Table 1.

[0074]

[Table 1]

[0075]

The effect of the present invention is to provide a lubricating oil composition for an internal combustion engine which exhibits excellent lubricity even in the presence of a suit. The lubricating oil composition for an internal combustion engine of the present invention can be suitably used as a lubricating oil for a diesel engine, a direct injection engine, and the like.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (Reference) C10N 10:12 C10N 10:12 30:02 30:02 30:04 30:04 30:06 30:06 30 : 10 30:10 30:12 30:12 30:14 30:14 30:18 30:18 40:25 40:25 50:08 50:08 (72) Inventor Yoko Saito 7-2 Higashiogu, Arakawa-ku, Tokyo No. 35 Asahi Denka Kogyo Co., Ltd. F term (reference) 4H104 BG02C BG04C BG10C BG12C BH02C BH03C BH06C BH07C BH11C EB03 EB05 EB07 EB09 EB10 EB11 EB13 FA02 FA06 LA01 LA02 LA03 LA11 LA09 LA09 LA09

Claims (4)

[Claims] 1. A lubricating base oil, as a component (A), represented by the following general formula (1): (Wherein, R ^{1 to} R ⁴ represent a hydrocarbon group, and X ^{1 to} X ⁴ represent a sulfur atom or an oxygen atom.) The following oxymolybdenum dithiocarbamate represented by the following formula: General formula (2) (Wherein, R ^{5 to} R ⁸ represent a hydrocarbon group, and X ^{5 to} X ⁸ represent a sulfur atom or an oxygen atom); a sulfurized oxymolybdenum dithiophosphate represented by the formula: A lubricating oil composition for an internal combustion engine used in an internal combustion engine in which cracks occur. 2. The lubricating oil composition for an internal combustion engine according to claim 1, wherein the internal combustion engine is a diesel engine or a direct injection engine. Further, as the component (C), the following general formula (3): (Wherein, R ⁹ and R ¹⁰ represent a hydrocarbon group;
Represents 1/3 number. 3. The lubricating oil composition for an internal combustion engine according to claim 1, which comprises a zinc dithiophosphate represented by the formula: 4. The following components (D1) to (D13): (D1) a metal detergent (D2) an ashless dispersant (D3) a compound containing a phosphorus atom (D4) a compound containing a phosphorus atom and a sulfur atom (D5) Compound containing a sulfur atom and not containing a metal atom (D6) Antioxidant (D7) Organometallic compound (D8) Oiliness improver not containing a metal atom, phosphorus atom and sulfur atom (D9) Rust inhibitor (D10) Viscosity index improver (D11) Metal deactivator (D12) Antifoaming agent (D13) Solid lubricant It contains one or more types of any one of Claims 1-3. Lubricating oil composition for internal combustion engines.