JP2013194180A - Lubricant composition for internal combustion engine oil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lubricant composition for internal combustion engines, which can maintain high temperature cleanliness and does not deteriorate abrasion resistance, even when largely reducing a phosphorus-containing additive and a metal-based cleaner.SOLUTION: A lubricant composition for internal combustion engines comprises a base oil, a sulfur-containing heterocyclic compound represented by general formula (I), and an aminoalcohol compound having one or more amino groups and one or more hydroxyl groups in the molecule, and has a phosphorus content of <0.03 mass% and a sulfuric acid ash content of 0.3-0.6 mass% on the basis of the total amount of the composition. (Wherein, As is a sulfur-containing heterocyclic group; Rand Rare each independently H, amino, 1-50C hydrocarbon group selected from alkyl, cycloalkyl, alkenyl, cycloalkenyl and aryl, or, 1-50C heteroatom-containing group containing an atom selected from oxygen atom, nitrogen atom and sulfur atom, when these are each a hydrocarbon group; k, l, m and n are each independently an integer of 0-5).

Description

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

In recent years, strict regulations on exhaust gas have been introduced one after another in the automobile industry for the purpose of reducing environmental load, and exhaust gas aftertreatment devices have been developed. In addition to carbon dioxide (CO ₂ ), a global warming substance, exhaust gases include particulate substances (PM), hydrocarbons (HC), carbon monoxide (CO), nitrogen oxides (NO) _x ) and the like, and the regulation values for PM and NOx are very strict. As a measure for reducing these emissions, a gasoline vehicle is equipped with a three-way catalyst, and a diesel vehicle is equipped with a diesel particulate filter (DPF). As a result, the exhaust gas is cleaned and released into the atmosphere.
In recent years, it has been reported that the phosphorus content in engine oil poisons the active sites of the three-way catalyst and lowers the catalyst function. In addition, it has been reported that ash derived from metal components accumulates in the DPF and shortens the lifetime. Currently, upper limits of phosphorus and ash are established in the ILSAC standards and JASO standards, which are engine oil standards, and development of engine oils with reduced amounts of these is being promoted.

As an ashless detergent / dispersant, it has been proposed to use an amino alcohol compound as a lubricant additive (Patent Document 1).
However, since the amino alcohol-based lubricating oil additive described in Patent Document 1 does not have sufficient high-temperature cleanability, it is necessary to add a metal-based detergent. However, when metallic detergents are added to improve high-temperature cleanability, the filter-like structure of exhaust traps such as particulate traps and oxidation catalysts that oxidize unburned fuel and lubricating oil deposits (such as metal deposits). The deposits) are likely to be clogged (clogged), causing a problem of deteriorating the characteristics of the internal combustion engine.

JP 7-316576 A

  The present invention provides a lubricating oil composition for an internal combustion engine that can maintain high-temperature cleanliness and does not impair wear resistance even when the amount of phosphorus-containing additives and metal detergents is greatly reduced. It is the purpose.

  As a result of extensive research, the present inventor has found that the object can be achieved by blending a lubricating oil composition with a sulfur-containing heterocyclic compound and an amino alcohol compound. The present invention has been completed based on such findings.

（式中、Ａｓは含硫黄複素環、Ｒ¹及びＲ²はそれぞれ独立に、水素原子；アミノ基；アルキル基、シクロアルキル基、アルケニル基、シクロアルケニル基及びアリール基から選ばれる炭素数１〜５０の炭化水素基；またはこれらが炭化水素基の場合、該炭化水素基中に酸素原子、窒素原子および硫黄原子から選ばれる原子を含んでなる炭素数１〜５０のヘテロ原子含有基を表す。ｋ、ｌ、ｍ及びｎはそれぞれ独立に０〜５の整数である。）
を提供するものである。 That is, the present invention includes a base oil, a sulfur-containing heterocyclic compound represented by the following general formula (I), and an amino alcohol compound having one or more amino groups and one or more hydroxyl groups in the molecule, A lubricating oil composition for an internal combustion engine having a phosphorus content of less than 0.03% by mass and a sulfated ash content of 0.3% by mass to 0.6% by mass based on the total amount of the composition;

(In the formula, As is a sulfur-containing heterocyclic ring, R ¹ and R ² are each independently a hydrogen atom; an amino group; an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group, and an aryl group. 50 hydrocarbon group; or when these are hydrocarbon groups, it represents a C1-C50 heteroatom-containing group comprising an atom selected from an oxygen atom, a nitrogen atom and a sulfur atom in the hydrocarbon group. k, l, m and n are each independently an integer of 0 to 5.)
Is to provide.

  According to the present invention, there is provided a lubricating oil composition for an internal combustion engine that can maintain high-temperature cleanliness and does not impair wear resistance even if the additives and metal detergents containing phosphorus are greatly reduced. be able to.

式中、Ａｓは含硫黄複素環、Ｒ¹及びＲ²はそれぞれ独立に、水素原子；アミノ基；アルキル基、シクロアルキル基、アルケニル基、シクロアルケニル基及びアリール基から選ばれる炭素数１〜５０の炭化水素基；またはこれらが炭化水素基の場合、該炭化水素基中に酸素原子、窒素原子および硫黄原子から選ばれる原子を含んでなる炭素数１〜５０のヘテロ原子含有基を表す。ｋ、ｌ、ｍ及びｎはそれぞれ独立に０〜５の整数である。以下、上記各要件について説明する。 [Lubricating oil composition for internal combustion engine]
An internal combustion engine lubricating oil composition according to an embodiment of the present invention (hereinafter sometimes simply referred to as “lubricating oil composition”) includes a base oil and a sulfur-containing heterocyclic ring represented by the following general formula (I) The compound and an amino alcohol compound having one or more amino groups and one or more hydroxyl groups in the molecule, the phosphorus content based on the total amount of the composition is less than 0.03% by mass, and the sulfated ash content is 0.00. It is 3 mass% or more and 0.6 mass% or less.

In the formula, As is a sulfur-containing heterocycle, R ¹ and R ² are each independently a hydrogen atom; an amino group; an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group, and an aryl group. Or when these are hydrocarbon groups, it represents a C1-C50 heteroatom-containing group containing an atom selected from an oxygen atom, a nitrogen atom and a sulfur atom in the hydrocarbon group. k, l, m and n are each independently an integer of 0 to 5. Hereafter, each said requirement is demonstrated.

[Base oil]
There is no restriction | limiting in particular as base oil used in this invention, Arbitrary things can be suitably selected and used from the mineral oil and synthetic oil conventionally used as base oil of lubricating oil.
As the mineral oil, for example, a lubricating oil fraction obtained by distillation under reduced pressure of atmospheric residual oil obtained by atmospheric distillation of crude oil, solvent removal, solvent extraction, hydrocracking, solvent dewaxing, contact Mineral oil refined by carrying out one or more treatments such as dewaxing, hydrorefining, etc., or mineral oil produced by isomerizing wax, GTL WAX, and the like.

On the other hand, examples of the synthetic oil include polybutene, polyolefin [α-olefin homopolymer and copolymer (eg, ethylene-α-olefin copolymer)], and various esters (eg, polyol ester, dibasic acid). Ester, phosphate ester, etc.), various ethers (eg, polyphenyl ether), polyglycol, alkylbenzene, alkylnaphthalene and the like. Of these synthetic oils, polyolefins and polyol esters are particularly preferable.
In this invention, the said mineral oil may be used individually by 1 type as a base oil, and may be used in combination of 2 or more type. Moreover, the said synthetic oil may be used 1 type and may be used in combination of 2 or more type. Further, one or more mineral oils and one or more synthetic oils may be used in combination.

No particular limitation is imposed on the viscosity of the base oil, kinematic viscosity at 100 ° C. is preferably in the range of 1.5~30mm ² / s, more preferably from 3 to 30 mm ² / s, more preferably It is in the range of 3 to 15 mm ² / s.
When the kinematic viscosity at 100 ° C. is 1.5 mm ² / s or more, the evaporation loss is small, and when it is 30 mm ² / s or less, the power loss due to the viscous resistance is suppressed, and the fuel efficiency improvement effect is obtained.

As the base oil,% by ring analysis C _A content of sulfur is preferably used include: 50 ppm by mass 3.0. Here, the% C _A by ring analysis shows a proportion of aromatic content calculated by ring analysis n-d-M method (percentage). The sulfur content is a value measured according to JIS K2541.
_A base oil having a% CA of 3.0 or less and a sulfur content of 50 mass ppm or less provides a lubricating oil composition having good oxidation stability and capable of suppressing an increase in acid value and sludge formation. be able to. A more preferable% C _A is 1.0 or less, further 0.5 or less, and a more preferable sulfur content is 30 mass ppm or less.

Furthermore, the viscosity index of the base oil is preferably 70 or more, more preferably 100 or more, and still more preferably 120 or more. The base oil having a viscosity index of 70 or more has a small change in viscosity due to a change in temperature.
The pour point, which is an indicator of the low temperature fluidity of the base oil, is not particularly limited, but is usually preferably −10 ° C. or lower.

[Sulfur-containing heterocyclic compounds]
The sulfur-containing heterocyclic compound used in the present invention is represented by the following general formula (I).

上記式中、Ａｓは含硫黄複素環、Ｒ¹及びＲ²はそれぞれ独立に、水素原子；アミノ基；アルキル基、シクロアルキル基、アルケニル基、シクロアルケニル基およびアリール基から選ばれる炭素数１〜５０の炭化水素基；またはこれらが炭化水素基の場合該炭化水素基中に酸素原子、窒素原子および硫黄原子から選ばれる原子を含んでなる炭素数１〜５０のヘテロ原子含有基を表す。ｋ、ｌ、ｍ及びｎはそれぞれ独立に０〜５の整数である。
また、前記一般式（Ｉ）において、ｍ及びｎが共に０とならない、すなわち、前記含硫黄複素環の少なくとも片側に、１以上の硫黄原子が結合していることが、耐摩耗性向上の観点から好ましい。さらにこの硫黄原子は、含硫黄複素環の両側に結合していることがより好ましい。

In the above formula, As is a sulfur-containing heterocyclic ring, R ¹ and R ² are each independently a hydrogen atom; an amino group; an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group, and an aryl group. A hydrocarbon group having 50 to 50 carbon atoms; or, when these are hydrocarbon groups, a C 1-50 heteroatom-containing group containing an atom selected from an oxygen atom, a nitrogen atom and a sulfur atom in the hydrocarbon group. k, l, m and n are each independently an integer of 0 to 5.
In the general formula (I), m and n are not both 0, that is, at least one sulfur atom is bonded to at least one side of the sulfur-containing heterocyclic ring, from the viewpoint of improving wear resistance. To preferred. Furthermore, it is more preferable that this sulfur atom is bonded to both sides of the sulfur-containing heterocyclic ring.

Examples of the sulfur-containing heterocycle include, for example, each substituted or unsubstituted benzothiophene ring, naphthothiophene ring, dibenzothiophene ring, thienothiophene ring, dithienobenzene ring, thiazole ring, thiophene ring, thiazoline ring, and benzothiazole ring. , Naphthothiazole ring, isothiazole ring, benzoisothiazole ring, naphthisothiazole ring, thiadiazole ring, phenothiazine ring, phenoxathiin ring, dithiaphthalene ring, thianthrene ring, thioxanthene ring, bithiophene ring, etc. .
Among these, a thiadiazole ring is preferably used from the viewpoint of improving wear resistance. As the thiadiazole ring, a 1,3,4-thiadiazole ring is more preferable. Further, as the sulfur-containing heterocyclic compound in the present invention, a sulfur atom is bonded to the 2,5 position of the 1,3,4-thiadiazole ring. It is more preferable from the viewpoint of improving wear resistance.
Furthermore, it is particularly preferable from the viewpoint of improving wear resistance that it contains a structure in which one sulfur atom is bonded to each of the 2,5 positions of the 1,3,4-thiadiazole ring.

In the general formula (I), the alkyl group represented by R ¹ and R ² is preferably an alkyl group having 1 to 30 carbon atoms, and more preferably an alkyl group having 1 to 24 carbon atoms. Specific examples of the alkyl group include, for example, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, various hexyl groups, various octyl groups, various decyl groups, various dodecyl groups, various tetradecyl groups, various hexadecyl groups. And various octadecyl groups and various icosyl groups. The alkyl group may be substituted with an aromatic group, and examples thereof include a benzyl group and a phenethyl group.

The cycloalkyl group represented by R ¹ and R ² is preferably a cycloalkyl group having 3 to 30 carbon atoms, and more preferably a cycloalkyl group having 3 to 24 carbon atoms. Specific examples of the cycloalkyl group include a cyclopropyl group, a cyclopentyl group, a cyclohexyl group, a methylcyclopentyl group, a dimethylcyclopentyl group, a methylethylcyclopentyl group, a diethylcyclopentyl group, a methylcyclohexyl group, a dimethylcyclohexyl group, and a methylethylcyclohexyl group. And a diethylcyclohexyl group. Moreover, the cycloalkyl group may be substituted with an aromatic group, and examples thereof include a phenylcyclopentyl group and a phenylcyclohexyl group.

The alkenyl group represented by R ¹ and R ² is preferably an alkenyl group having 2 to 30 carbon atoms, and more preferably an alkenyl group having 2 to 24 carbon atoms. Specific examples of the alkenyl group include, for example, vinyl group, allyl group, 1-butenyl group, 2-butenyl group, 3-butenyl group, 1-methylvinyl group, 1-methylallyl group, 1,1-dimethylallyl group, 2 -A methylallyl group, a nonenyl group, a decenyl group, an octadecenyl group, etc. are mentioned. The alkenyl group may be substituted with an aromatic group.

The cycloalkenyl group represented by R ¹ and R ² is preferably a cycloalkenyl group having 3 to 30 carbon atoms, and more preferably a cycloalkenyl group having 3 to 24 carbon atoms. Specific examples of the cycloalkenyl group include a cyclobutenyl group and a methylcyclobutenyl group. The cycloalkenyl group may be substituted with an aromatic group.

The aryl group represented by R ¹ and R ² is preferably an aryl group having 6 to 30 carbon atoms, and more preferably an aryl group having 6 to 24 carbon atoms. Specific examples of the aryl group include phenyl group, tolyl group, xylyl group, naphthyl group, butylphenyl group, octylphenyl group, nonylphenyl group and the like.

  Examples of the sulfur-containing heterocyclic compound represented by the general formula (I) include compounds represented by the following formulas.

  In addition to the above, examples of the sulfur-containing heterocyclic compound represented by the general formula (I) include 2- (2-ethylhexylthio) thiazole, 2,4-bis (2-ethylhexylthio) thiazole, 2,5 -Bis (t-norylthio) -1,3,4-thiadiazole, 2,5-bis (dimethylhexylthio) -1,3,4-thiadiazole, 2,5-bis (octadecenylthio) -1,3 , 4-thiadiazole, 2,5-bis (methylhexadecenylthio) -1,3,4-thiadiazole, 2-octylthio-thiazoline, 2- (2-ethylhexylthio) benzothiazole, 2- (2-ethylhexylthio) ) Thiophene, 2,4-bis (2-ethylhexylthio) thiophene, 2- (2-ethylhexylthio) thiazoline, 2,5-bis (2-hydroxy) Octadecylthio) -1,3,4-thiadiazole, 2,5-bis (n-octoxycarbonylmethylthio) -1,3,4-thiadiazole, 2-mercapto-5- (2-ethylhexylthio) -1,3 , 4-thiadiazole, 2-mercapto-5- (t-norylthio) -1,3,4-thiadiazole, 2- (2-ethylhexyldithio) thiazole, 2,4-bis (2-ethylhexyldithio) thiazole, 2, 5-bis (t-noryldithio) -1,3,4-thiadiazole, 2,5-bis (dimethylhexyldithio) -1,3,4-thiadiazole, 2,5-bis (octadecenyldithio) -1 , 3,4-thiadiazole, 2,5-bis (methylhexadecenyldithio) -1,3,4-thiadiazole, 2-octyldithio-thiazolyl 2- (2-ethylhexyldithio) benzothiazole, 2- (2-ethylhexyldithio) thiophene, 2,4-bis (2-ethylhexyldithio) thiophene, 2- (2-ethylhexyldithio) thiazoline, 2,5-bis (2-hydroxyoctadecyldithio) -1,3,4-thiadiazole, 2,5-bis (n-octoxycarbonylmethyldithio) -1,3,4-thiadiazole, 2-mercapto-5- (2-ethylhexyldithio) ) -1,3,4-thiadiazole, 2-mercapto-5- (t-noryldithio) -1,3,4-thiadiazole, 2- (2-ethylhexylamino) thiazole, 2,4-bis (2-ethylhexylamino) ) Thiazole, 2,5-bis (t-norylamino) -1,3,4-thiadiazole, 2,5- Bis (dimethylhexylamino) -1,3,4-thiadiazole, 2,5-bis (octadecenylamino) -1,3,4-thiadiazole, 2,5-bis (methylhexadecenylamino)- 1,3,4-thiadiazole, 2-octylamino-thiazoline, 2- (2-ethylhexylamino) benzothiazole, 2- (2-ethylhexylamino) thiophene, 2,4-bis (2-ethylhexylamino) thiophene, 2 -(2-ethylhexylamino) thiazoline, 2,5-bis (2-hydroxyoctadecylamino) -1,3,4-thiadiazole, 2,5-bis (n-octoxycarbonylmethylamino) -1,3,4 -Thiadiazole, 2-amino-5- (2-ethylhexylamino) -1,3,4-thiadiazole, 2-amino- -(T-Norylamino) -1,3,4-thiadiazole, 2- (2-ethylhexyl) thiazole, 2,4-bis (2-ethylhexyl) thiazole, 2,5-bis (t-noryl) -1,3 , 4-thiadiazole, 2,5-bis (dimethylhexyl) -1,3,4-thiadiazole, 2,5-bis (octadecenyl) -1,3,4-thiadiazole, 2,5-bis (methylhexadece) Nyl) -1,3,4-thiadiazole, 2-octyl-thiazoline, 2- (2-ethylhexyl) benzothiazole, 2- (2-ethylhexyl) thiophene, 2,4-bis (2-ethylhexyl) thiophene, 2- (2-ethylhexyl) thiazoline, 2,5-bis (2-hydroxyoctadecyl) -1,3,4-thiadiazole, 2,5-bis (n-o Butoxycarbonyl-methyl) -1,3,4-thiadiazole, 2- (2-ethylhexyl) -1,3,4-thiadiazole, 2- (t-Noryl) -1,3,4-thiadiazole, and the like.

  In the lubricating oil composition of the present invention, the sulfur content is 0.10% by mass or more and 1.00% by mass or less based on the total amount of the composition. If the sulfur content is less than 0.10% by mass, sufficient wear resistance cannot be obtained, and if it exceeds 1.00% by mass, corrosion may occur. The sulfur content is preferably 0.12% by mass or more and 0.90% by mass or less, and more preferably 0.15% by mass or more and 0.80% by mass or less based on the total amount of the composition.

The lubricating oil composition of the present invention requires that the phosphorus content on the basis of the total amount of the composition is less than 0.03% by mass. When the phosphorus content in the composition is less than 0.03% by mass, the poisoning action of the active sites of the three-way catalyst is suppressed, and the catalyst life can be extended. Accordingly, the phosphorus content is preferably 0.02% by mass or less, and particularly preferably 0.01% by mass or less.
What is necessary is just to adjust phosphorus content with the compounding quantity of a phosphorus-type antiwear agent. Examples of typical phosphorus antiwear agents include phosphate ester and thiophosphate esters, but phosphites, alkyl hydrogen phosphites, phosphate ester amine salts, etc. are preferred. In particular, zinc dithiophosphate (ZnDTP) is preferred.

  The lubricating oil composition of the present invention requires that the sulfated ash content on the basis of the total amount of the composition be 0.3 mass% or more and 0.6 mass% or less. If the amount of sulfated ash in the composition is 0.3% by mass or more, the cleanliness required as a lubricating oil for internal combustion engines is enhanced, and if it is 0.6% by mass or less, the ash derived from the metal component is reduced. Accumulation on the DPF is suppressed, and the lifetime can be extended. Therefore, the amount of sulfated ash in the composition is preferably 0.3% by mass or more and 0.5% by mass or less, and particularly preferably 0.3% by mass or more and 0.4% by mass or less.

[Amino alcohol compound]
The amino alcohol compound has one or more amino groups and one or more hydroxyl groups in the molecule. The amino alcohol compound is a compound having an epoxy group (hereinafter referred to as (A) compound) and a compound having at least one of a primary amino group and a secondary amino group (hereinafter referred to as (B) compound). ).

<(A) Compound>
The compound (A) preferably has 6 to 40 carbon atoms. (A) If the number of carbon atoms of the compound is 6 or more, the compound is sufficiently dissolved in a lubricating base oil, and if the number of carbon atoms is 40 or less, a high base number compound is obtained. Furthermore, the preferable carbon number of the hydrocarbon group of this (A) compound is 6-30.
(A) It is preferable that the epoxy group and the hydrocarbon group have couple | bonded the (A) compound. The hydrocarbon group may be saturated or unsaturated, aliphatic or aromatic, linear or branched, or cyclic, and examples thereof include an alkyl group or an alkenyl group.
More specifically, as the hydrocarbon group, hexyl group, hexenyl group, octyl group, octenyl group, decyl group, decenyl group, dodecyl group, dodecenyl group, tetradecyl group, tetradecenyl group, hexadecyl group, hexadecenyl group, octadecyl group , Octadecenyl group, isostearyl group, decene trimer group, polybutene group and the like.

  Specific examples of the compound (A) having an epoxy group include 1,2-epoxyhexane, 1,2-epoxyoctane, 1,2-epoxydecane, 1,2-epoxydodecane, 1,2-epoxytetradecane, , 2-epoxyhexadecane, 1,2-epoxyoctadecane, 1,2-epoxyeicosane, 1,2-epoxydodecene, 1,2-epoxytetradecene, 1,2-epoxyhexadecene, 1,2-epoxyoctadecene 1,2-epoxy-2-octyldodecane and the like.

<(B) Compound>
The compound (B) preferably has a total nitrogen number of 1 to 10 and a total carbon number of 2 to 40. If the total nitrogen number is 10 or less, it is sufficiently dissolved in a lubricating base oil. If the total number of carbon atoms is 2 or more, it is sufficiently dissolved in a lubricating base oil or the like, and if it is 40 or less, a high base number compound is obtained. (B) As a compound, a primary amine, a secondary amine, and a polyalkylene polyamine are mentioned.

The primary amine preferably has a hydrocarbon group having a total carbon number of 2 to 40, and may further contain an oxygen atom. If the total carbon number of this hydrocarbon group is 2 or more, it is sufficiently dissolved in a lubricating base oil or the like, and if the total carbon number is 40 or less, a high base number compound is obtained.
Such a hydrocarbon group may be saturated or unsaturated, may be aliphatic or aromatic, may be linear or branched, and may be cyclic. For example, an alkyl group or an alkenyl group can be mentioned. More specifically, the hydrocarbon group includes an ethyl group, butyl group, butenyl group, hexyl group, hexenyl group, octyl group, octenyl group, decyl group, decenyl group, dodecyl group, dodecenyl group, tetradecyl group, tetradecenyl group. A hexadecyl group, a hexadecenyl group, an octadecyl group, an octadecenyl group, an isostearyl group, a decentrimer group, a polybutene group, and the like.
Specific examples of primary amines include ethylamine, butylamine, hexylamine, octylamine, decylamine, dodecylamine, tetradecylamine, hexadecylamine, octadecylamine, 2-ethylhexylamine, 2-decyltetradecylamine, oleylamine, ethanol Examples include amine, propanolamine, octadecyloxyethylamine, 3- (2-ethylhexyloxy) propylamine, and 12-hydroxystearylamine.

The secondary amine preferably has 2 to 40 carbon atoms in total in the hydrocarbon group, and may further contain an oxygen atom. Such a hydrocarbon group may be saturated or unsaturated, may be aliphatic or aromatic, may be linear or branched, and may be cyclic. If the total carbon number of this hydrocarbon group is 2 or more, it is sufficiently dissolved in a lubricating base oil or the like, and if the total carbon number is 40 or less, a high base number compound is obtained.
Specific examples of secondary amines include diethylamine, dibutylamine, dihexylamine, dioctylamine, didecylamine, didodecylamine, ditetradecylamine, dihexadecylamine, dioctadecylamine, di-2-ethylhexylamine, dioleylamine, methyl Examples include stearylamine, ethylstearylamine, methyl oleylamine, diethanolamine, dipropanolamine, and 2-butylaminoethanol. In addition, cyclic secondary amines such as piperidine, piperazine and morpholine can also be mentioned.

The polyalkylene polyamine has a total nitrogen number of 2 or more and 10 or less, and one alkylene group has 1 or more and 6 or less carbon atoms. This polyalkylene polyamine may further contain an oxygen atom. A total nitrogen number of 10 or less is preferable because it dissolves sufficiently in a lubricating base oil. If the number of carbon atoms of the alkylene group is 6 or less, the reactivity is sufficient, the target product can be easily obtained, and the high-temperature cleanliness and the base number maintainability are improved, which is preferable.
Specific examples of the polyalkylene polyamine include diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, dipropylenetriamine, dihexyltriamine, polyalkylenepolyamine such as N-hydroxyethyldiaminopropane, or aminoethylpiperazine, Examples include polyalkylene polyamines having cyclic alkylene amines such as 1,4-bisaminopropylpiperazine and 1-piperazine ethanol.

<Ratio of (A) compound to (B) compound>
The amino alcohol compound is a compound obtained by reacting the compound (A) with the ratio of the total number of moles of the compound (B) to the total number of moles of the compound (B) of 0.7: 1 or more and 12: 1 or less. The compound obtained by reacting at a ratio of 1: 1 or more and 10: 1 or less is more preferable. When the ratio of the total number of moles of the compound (A) to the total number of moles of the compound (B) is 0.7: 1 or more, an amino alcohol compound excellent in high temperature cleanability, high temperature stability and fine particle dispersibility is obtained. can get. On the other hand, when the ratio of the total number of moles is 12: 1 or less, an amino alcohol compound having excellent base number retention is obtained. The reaction between the compound (A) and the compound (B) is preferably performed at a temperature of about 50 ° C. to 250 ° C., more preferably about 80 ° C. to 200 ° C.

式中、Ｒ³，Ｒ⁴，Ｒ⁵は、それぞれ独立に、水素原子；アミノ基；アルキル基、シクロアルキル基、アルケニル基、シクロアルケニル基及びアリール基から選ばれる炭素数２〜３８の炭化水素基を表す。 <Structure of amino alcohol compound>
The amino alcohol compound is a reaction product of the compound (A) and the compound (B), and preferably has a structure represented by the following general formula (II).

In the formula, R ³ , R ⁴ and R ⁵ are each independently a hydrogen atom; an amino group; a hydrocarbon having 2 to 38 carbon atoms selected from an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group and an aryl group. Represents a group.

<Boron derivatives of amino alcohol compounds>
Further, the amino alcohol compound may contain a boronated amino alcohol compound that is a boron derivative thereof. The boronated amino alcohol compound is a compound obtained by reacting a boron-containing compound with the amino alcohol compound. As the boron-containing compound, boron oxide, boron halide, boric acid, boric anhydride, boric acid ester and the like can be used.
The boronated amino alcohol compound is excellent in high temperature stability, high temperature cleanability, and base number maintenance, has fine particle dispersibility, and has a low ash content. Therefore, the lubricating oil composition of the present invention containing the boronated amino alcohol compound can prevent adverse effects on particulate traps and exhaust gas purification apparatuses such as oxidation catalysts that oxidize unburned fuel and lubricating oil. It is possible to comply with exhaust gas regulations.

The reaction temperature of the boronated amino alcohol compound is preferably about 50 ° C. to 250 ° C., more preferably about 100 ° C. to 200 ° C. In carrying out the reaction, a solvent, for example, an organic solvent such as a hydrocarbon oil can be used.
The boronated amino alcohol compound is a compound obtained by reacting the amino alcohol compound and the boron-containing compound in a ratio of 1: 0.01 to 1:10. Preferably, it is a compound obtained by reacting at a ratio of 1: 0.05 or more and 1: 8 or less.
When the molar ratio is 1: 0.01 or more, a boronated amino alcohol compound excellent in high-temperature cleanability and high-temperature stability can be obtained. On the other hand, when the molar ratio is 1:10 or less, there is no problem with the solubility of the boronated amino alcohol compound in the lubricating base oil.

  The additive for lubricating oil according to the present invention contains at least one selected from an amino alcohol compound and a boronated amino alcohol compound. Such an additive for lubricating oil is suitable as an ashless cleaning dispersant.

The blending amount of at least one selected from the amino alcohol compound and the boronated amino alcohol compound and the additive for lubricating oil in the lubricating oil composition of the present invention is usually 0.01% by mass or more based on the total amount of the lubricating oil composition. It is set in a range of 50% by mass or less, preferably 0.1% by mass or more and 30% by mass or less.
In addition, at least one selected from an amino alcohol compound and a boronated amino alcohol compound, or an additive for lubricating oil can be added to the hydrocarbon oil as the fuel oil. In that case, a preferable compounding quantity is the range of 0.001 mass% or more and 1 mass% or less on the basis of the total amount.

[Additive]
In the lubricating oil composition of the present invention, conventionally known additives may be blended within a range that does not impair the effect. Examples of the additive include a dispersant, an antioxidant, a metal-based detergent, a viscosity index improver, a pour point depressant, a metal deactivator, a rust inhibitor, and an antifoaming agent.

<Dispersant>
As the dispersant, a boronated imide-based dispersant and, if necessary, a non-borated imide-based dispersant can be used. Non-boronated imide dispersants are usually referred to as imide dispersants. It is preferable to use polybutenyl succinimide as the imide-based dispersant. Examples of the polybutenyl succinimide include compounds represented by the following general formulas (1) and (2).

  PIB in these general formula (1) and (2) shows a polybutenyl group, and the number average molecular weight is 900-3500 normally, Preferably it is 1000-2000. If the average molecular weight is 900 or more, dispersibility is not inferior, and if it is 3500 or less, storage stability is not inferior. Moreover, n in the said General Formula (1) and (2) is an integer of 1-5 normally, More preferably, it is an integer of 2-4.

  Although there is no limitation in particular as a manufacturing method of the said polybutenyl succinimide, it can manufacture by a well-known method. For example, polybutenyl succinic acid obtained by reacting polybutene and maleic anhydride at 100 to 200 ° C. is obtained by reacting with polyamines such as diethylenetriamine, triethylenetetramine, tetraethylenepentamine and pentaethylenehexamine. Can do.

  As a boronated imide-based dispersant, a boronated polybutenyl succinimide obtained by reacting a boron compound with the non-borated imide-based dispersant exemplified in the above general formulas (1) and (2) is used. Is preferred.

Examples of the boron compound include boric acid, borates, and borate esters. Examples of the boric acid include orthoboric acid, metaboric acid, and paraboric acid. Examples of the borate include ammonium salts such as ammonium borate such as ammonium metaborate, ammonium tetraborate, ammonium pentaborate and ammonium octaborate. Examples of boric acid esters include esters of boric acid and alkyl alcohols (preferably having 1 to 6 carbon atoms) such as monomethyl borate, dimethyl borate, trimethyl borate, monoethyl borate, diethyl borate, and triethyl borate. Preferred examples include monopropyl borate, dipropyl borate, tripropyl borate, monobutyl borate, dibutyl borate and tributyl borate.
In addition, as for mass ratio B / N of boron content B and nitrogen content N in boronated polybutenyl succinimide, 0.1-3 are preferable, and what is 0.2-1 is preferable.

  In the lubricating oil composition for an internal combustion engine used in the present invention, the contents of the boronated succinimide dispersant and the non-boronated succinimide dispersant (imide dispersant) are not particularly limited. 0.1-15 mass% is preferable and it is more preferable that it is 0.5-10 mass%. If it is 0.1% by mass or more, good cleanability and dispersibility can be obtained, and if it is 15% by mass or less, effects of cleanliness and dispersibility commensurate with the content can be obtained.

<Antioxidant>
As antioxidant, the antioxidant which does not contain phosphorus is preferable, for example, phenol type antioxidant, amine type antioxidant, molybdenum amine complex type antioxidant, sulfur type antioxidant, etc. are mentioned.
Examples of phenolic antioxidants include 4,4′-methylenebis (2,6-di-t-butylphenol), 4,4′-bis (2,6-di-t-butylphenol), and 4,4 ′. -Bis (2-methyl-6-tert-butylphenol), 2,2'-methylenebis (4-ethyl-6-tert-butylphenol), 2,2'-methylenebis (4-methyl-6-tert-butylphenol), 4,4′-butylidenebis (3-methyl-6-tert-butylphenol), 4,4′-isopropylidenebis (2,6-di-tert-butylphenol), 2,2′-methylenebis (4-methyl-6) -Nonylphenol), 2,2'-isobutylidenebis (4,6-dimethylphenol); 2,2'-methylenebis (4-methyl-6-cyclohexylphenol), 2,6-di-t-butyl -4-methylphenol, 2,6-di-t-butyl-4-ethylphenol, 2,4-dimethyl-6-t-butylphenol, 2,6-di-t-amyl-p-cresol, 2,6 -Di-t-butyl-4- (N, N'-dimethylaminomethylphenol), 4,4'-thiobis (2-methyl-6-tert-butylphenol), 4,4'-thiobis (3-methyl- 6-t-butylphenol), 2,2′-thiobis (4-methyl-6-tert-butylphenol), bis (3-methyl-4-hydroxy-5-tert-butylbenzyl) sulfide, bis (3,5- Di-t-butyl-4-hydroxybenzyl) sulfide, n-octyl-3- (4-hydroxy-3,5-di-t-butylphenyl) propionate, n-octadecyl-3- (4-hydroxy-3, 5-di-t-butylphenyl) propionate, 2,2′-thio [diethyl-bis-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] and the like.
Among these, bisphenol-based and ester group-containing phenol-based ones are particularly preferable.

Examples of the amine antioxidant include monoalkyl diphenylamines such as monooctyl diphenylamine and monononyl diphenylamine; 4,4′-dibutyldiphenylamine, 4,4′-dipentyldiphenylamine, 4,4′-dihexyldiphenylamine, 4, Dialkyldiphenylamines such as 4′-diheptyldiphenylamine, 4,4′-dioctyldiphenylamine, and 4,4′-dinonyldiphenylamine; polyalkyldiphenylamines such as tetrabutyldiphenylamine and tetrahexyldiphenylamine; tetraoctyldiphenylamine and tetranonyldiphenylamine And α-naphthylamine, phenyl-α-naphthylamine, further butylphenyl-α-naphthylamine, pentylphenyl-α-naphthylamine Emissions, hexylphenyl -α- naphthylamine, heptylphenyl -α- naphthylamine, octylphenyl -α- naphthylamine, alkylated phenyl -α- naphthylamine, such as nonylphenyl -α- naphthylamine; and the like.
Of these, those of dialkyldiphenylamine type and naphthylamine type are preferred.

As the molybdenum amine complex-based antioxidant, a hexavalent molybdenum compound, specifically, a product obtained by reacting molybdenum trioxide and / or molybdic acid with an amine compound, for example, described in JP-A-2003-252887. The compound obtained by the production method can be used.
Although it does not restrict | limit especially as an amine compound made to react with the said hexavalent molybdenum compound, Specifically, a monoamine, diamine, a polyamine, and an alkanolamine are mentioned. More specifically, it has an alkyl group having 1 to 30 carbon atoms such as methylamine, ethylamine, dimethylamine, diethylamine, methylethylamine, and methylpropylamine (these alkyl groups may be linear or branched). Alkylamines; alkenylamines having 2 to 30 carbon atoms such as ethenylamine, propenylamine, butenylamine, octenylamine, and oleylamine (these alkenyl groups may be linear or branched); methanolamine, ethanolamine Alkanolamines having 1-30 carbon atoms such as methanolethanolamine, methanolpropanolamine, etc. (these alkanol groups may be linear or branched); methylenediamine, ethylenediamine, propylene diene And alkylenediamines having 1-30 carbon atoms such as butylenediamine; polyamines such as diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine; undecyldiethylamine, undecyldiethanolamine, dodecyldipropanolamine , Oleyldiethanolamine, oleylpropylenediamine, stearyltetraethylenepentamine and other monoamines, diamines, polyamines having a C8-20 alkyl group or alkenyl group, and heterocyclic compounds such as imidazoline; alkylene oxides of these compounds And adducts; and mixtures thereof.
Moreover, the sulfur containing molybdenum complex etc. of the succinimide described in Japanese Patent Publication No. 3-22438 and Unexamined-Japanese-Patent No. 2004-2866 can be illustrated, and specifically, the following processes (m) and (n) Can be manufactured.
(M) an acidic molybdenum compound or a salt thereof, succinimide, carboxylic acid amide, hydrocarbon monoamine, hydrocarbon polyamine, Mannich base, phosphonic acid amide, thiophosphonic acid amide, phosphoric acid amide, dispersant-type viscosity index improver, and A step of forming a molybdenum complex by reacting a basic nitrogen compound selected from the group consisting of these mixtures with a reaction temperature maintained at about 120 ° C. or lower.
(N) The product of step (m) is subjected to at least one stripping or sulfiding step or both steps. However, when the molybdenum complex is diluted with isooctane and measured in a quartz cell having an optical path length of 1 centimeter with a UV-visible spectrophotometer at a constant molybdenum concentration of 0.00025 g of molybdenum per gram of diluted molybdenum complex, a wavelength of 350 Taking sufficient time to give a molybdenum complex having an absorbance at the nanometer of less than 0.7, and maintaining the temperature of the reaction mixture in the stripping or sulfiding step below about 120 ° C.

The molybdenum complex can also be produced by the following steps (o), (p) and (q).
(O) acidic molybdenum compound or salt thereof, succinimide, carboxylic acid amide, hydrocarbon monoamine, hydrocarbon polyamine, Mannich base, phosphonic acid amide, thiophosphonic acid amide, phosphoric acid amide, dispersant-type viscosity index improver, and A step of forming a molybdenum complex by reacting a basic nitrogen compound selected from the group consisting of these mixtures with a reaction temperature maintained at about 120 ° C. or lower.
(P) stripping the product of step (o) at a temperature of about 120 ° C. or less.
(Q) The product obtained is at a temperature of about 120 ° C. or less, the molar ratio of sulfur to molybdenum is about 1: 1 or less, and the molybdenum complex diluted with isooctane is diluted with 0 Sufficient to give a molybdenum complex with an absorbance at less than 0.7 at a wavelength of 350 nanometers when measured in a quartz cell with an optical path length of 1 centimeter with a UV-visible spectrophotometer at a constant molybdenum concentration of .00025 g. The process of sulfiding over time.

  Examples of the sulfur-based antioxidant include phenothiazine, pentaerythritol-tetrakis- (3-laurylthiopropionate), didodecyl sulfide, dioctadecyl sulfide, didodecylthiodipropionate, dioctadecylthiodipropionate, dimyristyl. Examples include thiodipropionate, dodecyl octadecyl thiodipropionate, and 2-mercaptobenzimidazole.

Among such antioxidants, phenol-based antioxidants and amine-based antioxidants are preferable from the viewpoint of reducing metal content and sulfur content. Moreover, the said antioxidant may be used individually by 1 type, and 2 or more types may be mixed and used for it. Among these, from the viewpoint of the effect of oxidation stability, a mixture of one or more phenolic antioxidants and one or more amine antioxidants is preferable.
The blending amount of the antioxidant is usually preferably in the range of 0.1 to 5% by mass and more preferably in the range of 0.1 to 3% by mass based on the total amount of the composition. Moreover, the compounding quantity of a molybdenum complex is 10-1000 mass ppm in conversion of molybdenum amount on the basis of the total amount of the composition, more preferably 30-800 mass ppm, and further preferably 50-500 mass ppm.

<Metal-based detergent>
As the metallic detergent, any alkaline earth metal detergent used in lubricating oils can be used, for example, alkaline earth metal sulfonate, alkaline earth metal phenate, alkaline earth metal salicylate, and the like. And a mixture of two or more selected from.

  Alkaline earth metal sulfonates include alkaline earth metal salts of alkyl aromatic sulfonic acids obtained by sulfonated alkyl aromatic compounds having a molecular weight of 300 to 1,500, preferably 400 to 700, particularly magnesium salts and / or Or a calcium salt etc. are mentioned, A calcium salt is used preferably especially.

  Alkaline earth metal phenates include alkylphenols, alkylphenol sulfides, alkaline earth metal salts of Mannich reactants of alkylphenols, especially magnesium salts and / or calcium salts, among which calcium salts are particularly preferred.

  Examples of the alkaline earth metal salicylate include alkaline earth metal salts of alkyl salicylic acid, particularly magnesium salts and / or calcium salts, among which calcium salts are preferably used.

  The alkyl group constituting the alkaline earth metal detergent is preferably an alkyl group having 4 to 30 carbon atoms, more preferably an alkyl group having 6 to 18 carbon atoms, which may be linear or branched. These may also be primary alkyl groups, secondary alkyl groups or tertiary alkyl groups.

  Further, as the alkaline earth metal sulfonate, alkaline earth metal phenate and alkaline earth metal salicylate, the above-mentioned alkyl aromatic sulfonic acid, alkylphenol, alkylphenol sulfide, Mannich reaction product of alkylphenol, alkylsalicylic acid, etc. are directly added to magnesium and / or Or it reacts with alkaline earth metal bases such as calcium alkaline earth metal oxides and hydroxides, or once is converted to an alkali metal salt such as sodium salt or potassium salt and then substituted with alkaline earth metal salt, etc. Neutral alkaline earth metal sulfonates, neutral alkaline earth metal phenates and neutral alkaline earth metal salicylates obtained as well as neutral alkaline earth metal sulfonates, neutral alkaline earth metal phenates and neutral alkaline earths Basic alkaline earth metal sulfonate, basic alkaline earth metal phenate and basic alkaline earth metal obtained by heating metal salicylate and excess alkaline earth metal salt or alkaline earth metal base in the presence of water Obtained by reacting salicylates or neutral alkaline earth metal sulfonates, neutral alkaline earth metal phenates and neutral alkaline earth metal salicylates in the presence of carbon dioxide with alkaline earth metal carbonates or borates. Also included are overbased alkaline earth metal sulfonates, overbased alkaline earth metal phenates and overbased alkaline earth metal salicylates.

  The metal detergent used in the present invention is preferably an alkaline earth metal salicylate or alkaline earth metal phenate for the purpose of reducing the sulfur content in the composition, and more preferably an overbased salicylate or an overbased phenate, In particular, overbased calcium salicylate is preferred.

The total base number of the metal detergent used in the present invention is preferably in the range of 10 to 500 mgKOH / g, more preferably in the range of 15 to 450 mgKOH / g, and one or two or more selected from these are used in combination. be able to.
The total base number referred to here is JIS K 2501 “Petroleum products and lubricants—Test method for neutralization number”. Means the total base number by potentiometric titration method (base number / perchloric acid method) measured according to the above.

Moreover, there is no restriction | limiting in particular in the metal ratio of the metallic detergent used in this invention, Usually, 20 or less things can be used in mixture of 1 type, or 2 or more types, However, Preferably, metal ratio is 3 or less, More preferably. It is particularly preferable to use a metal detergent of 5 or less, particularly 1.2 or less, because it is excellent in oxidation stability, base number maintenance, high-temperature cleanability, and the like.
The metal ratio here is expressed by the valence of the metal element in the metal-based detergent × the metal element content (mol%) / the soap group content (mol%). The metal elements are calcium, magnesium, and the like. The soap group means a sulfonic acid group, a phenol group, a salicylic acid group, and the like.

The blending amount of the metal detergent is preferably in the range of 0.01 to 20% by mass, more preferably in the range of 0.1 to 10% by mass, and 0.5 to 5% by mass based on the total amount of the lubricating oil composition. The range of is more preferable.
When the blending amount is less than 0.01% by mass, it is difficult to obtain performances such as high-temperature cleanliness, oxidation stability, and base number maintenance, which is not preferable. On the other hand, if it is 20% by mass or less, an effect commensurate with the amount added is usually obtained, but the upper limit of the amount of the metallic detergent is as low as possible regardless of the above range. It is important to do. As a result, the metal content of the lubricating oil composition, that is, the sulfated ash content, can be reduced to prevent the deterioration of the exhaust gas purification device of the automobile.
Moreover, as long as a metal type detergent contains said prescribed amount, you may use it individually or in combination of 2 or more types.
Specifically, overbased calcium salicylate or overbased calcium phenate is particularly preferable among the metal detergents, and the polybutenyl succinic acid bisimide is particularly preferable among the ashless dispersants. The total base number of the overbased calcium salicylate and the overbased calcium phenate is preferably in the range of 100 to 500 mgKOH / g, more preferably in the range of 200 to 500 mgKOH / g.

<Viscosity index improver>
As the viscosity index improver, for example, polymethacrylate, dispersed polymethacrylate, olefin copolymer (for example, ethylene-propylene copolymer), dispersed olefin copolymer, styrene copolymer (for example, Styrene-diene copolymer, styrene-isoprene copolymer, etc.). The blending amount of the viscosity index improver is preferably in the range of 0.5 to 15% by mass, more preferably in the range of 1 to 10% by mass, based on the total amount of the lubricating oil composition, from the viewpoint of the blending effect.

<Pour point depressant>
Examples of the pour point depressant include polymethacrylate having a mass average molecular weight of about 5,000 to 50,000. The blending amount of the pour point depressant is preferably in the range of 0.1 to 2 mass%, more preferably in the range of 0.1 to 1 mass%, based on the total amount of the lubricating oil composition, from the viewpoint of the blending effect.

<Metal deactivator>
Examples of the metal deactivator include benzotriazole, tolyltriazole, thiadiazole, and imidazole compounds. The compounding amount of the metal deactivator is preferably in the range of 0.01 to 3% by mass, more preferably in the range of 0.01 to 1% by mass, based on the total amount of the lubricating oil composition.

<Rust preventive>
Examples of the rust preventive include petroleum sulfonate, alkylbenzene sulfonate, dinonylnaphthalene sulfonate, alkenyl succinate, polyhydric alcohol ester and the like. The blending amount of these rust preventives is preferably in the range of 0.01 to 1% by mass, more preferably 0.05 to 0.5% by mass, based on the total amount of the lubricating oil composition, from the viewpoint of the blending effect.

<Antifoaming agent>
Examples of the antifoaming agent include silicone oil, fluorosilicone oil, and fluoroalkyl ether. The blending amount is 0.005 on the basis of the total amount of the lubricating oil composition from the viewpoint of balance between the antifoaming effect and economy. The range of -0.5 mass% is preferable, More preferably, it is the range of 0.01-0.2 mass%.

<Other additives>
In the lubricating oil composition of the present invention, a friction modifier, an antiwear agent, and an extreme pressure agent may be further blended as necessary. In addition, this friction modifier refers to compounds other than the polar group containing compound which is an essential component of this invention. The blending amount of the friction modifier is preferably in the range of 0.01 to 2 mass%, more preferably in the range of 0.01 to 1 mass%, based on the total amount of the lubricating oil composition.
Antiwear or extreme pressure agents include zinc dithiophosphate, zinc phosphate, zinc dithiocarbamate, molybdenum dithiocarbamate, molybdenum dithiophosphate, disulfides, sulfurized olefins, sulfurized fats and oils, sulfurized esters, thiocarbonates, thiocarbonates Sulfur-containing compounds such as carbamates and polysulfides; Phosphorous esters, phosphate esters, phosphonate esters, and phosphorus-containing compounds such as amine salts or metal salts thereof; thiophosphite esters, thiophosphoric acid And sulfur and phosphorus-containing antiwear agents such as esters, thiophosphonic acid esters, and amine salts or metal salts thereof.
When blending antiwear or extreme pressure agents, it is necessary to pay attention so that the content of phosphorus and metals in the lubricant is not excessive when blending antiwear or extreme pressure agents. There is.

[Properties of lubricating oil composition for internal combustion engine]
The lubricating oil composition of the present invention has the above composition and satisfies the following properties.
(1) The sulfated ash content (JIS K2272) is 0.3 mass% or more and 0.6 mass% or less, preferably 0.3 mass% or more and 0.5 mass% or less. And,
(2) The phosphorus content (JIS-5S-38-92) is less than 0.03% by mass, preferably 0.02 mass or less.
(3) The sulfur content (JIS K2541) is 0.10% by mass or more and 1.00% by mass or less, preferably 0.12% by mass or more and 0.90% by mass or less.
The lubricating oil composition of the present invention that satisfies these properties can significantly reduce ZnDTP and metallic detergents containing phosphorus, while maintaining wear resistance and deposit resistance.

  The lubricating oil composition of the present invention can be preferably used as a lubricating oil for internal combustion engines such as motorcycles, automobiles, gasoline engines for power generation, marine use, diesel engines, gas engines, etc., and has a low phosphorus content and low sulfur content. Therefore, it is particularly suitable for an internal combustion engine equipped with an exhaust gas purification device.

EXAMPLES Next, although an Example and a comparative example demonstrate this invention further in detail, this invention is not limited to these Examples.
[Evaluation method and measurement method]
The properties and performance of the lubricating oil composition were determined by the following method.

<Phosphorus content>
It measured based on JPI-5S-38-92.
<Sulfur content>
The measurement was performed according to JIS K2541.
<Boron content>
It measured based on JPI-5S-38-92.
<Sulfated ash>
The measurement was performed according to JIS K 2272.
<Nitrogen content>
The measurement was performed according to JIS K 2609.

<Shell wear test conditions>
Using a shell wear tester, the test conditions were set to a load of 294 N, a rotation speed of 1200 rpm, a temperature of 80 ° C., and a test time of 30 minutes, and the load bearing performance of the lubricating oil composition was evaluated. The result was expressed as a wear mark (mm) of the test hard sphere.
<Hot tube test>
While maintaining the temperature of the glass tube having an inner diameter of 2 mm at 280 ° C., the test oil and air were allowed to flow through the glass tube for 16 hours. The flow rate of the test oil was 0.3 mL / hr, and the air flow rate was 10 mL / min. After 16 hours, the lacquer adhering in the glass tube was compared with the color sample, and the lacquer mass adhering to the glass tube was measured while giving a score of 10 points for transparent and 0 points for black. The higher the score and the smaller the lacquer, the higher the performance.

[Production example]
<Production Example 1: Production of amino alcohol compound 1>
In a 200 ml separable flask, 1,2-epoxyoctadecane 41.6 g (155 mmol), 1,2-epoxyoctane 9.9 g (77.3 mmol), aminoethylpiperazine (Aep) 10.0 g (77.5 mmol), Put. After making it react at 130 to 140 degreeC for 2 hours, it heated up to 170 degreeC and made it react for 2 hours. The reaction product was cooled to obtain amino alcohol compound 1. The yield of the resulting amino alcohol compound 1 was 60.3 g.
<Production Example 2: Production of amino alcohol compound 2>
The amino alcohol compound 1 obtained in Production Example 1 was reacted with boric acid to obtain an amino alcohol compound 2. Amino alcohol compound 2 is a boronated amino alcohol compound. It prepared so that content of the total boric acid might be less than 1 mass% with respect to the total amount of boronated amino alcohol compounds obtained after reaction.
<Production Example 3: Production of amino alcohol compound 3>
The amino alcohol compound 1 obtained in Production Example 1 was reacted with boric acid to obtain an amino alcohol compound 3. It prepared so that content of the total boric acid might be less than 2 mass% with respect to the total amount of the boronated amino alcohol compound obtained after reaction.
<Production Example 4: Production of amino alcohol compound 4>
A 200 ml separable flask was charged with 44.7 g (186 mmol) of 1,2-epoxyhexadecane and 8.0 g (62.0 mmol) of aminoethylpiperazine (Aep). After making it react at 130 to 140 degreeC for 2 hours, it heated up to 170 degreeC and made it react for 2 hours. The reaction product was cooled to obtain amino alcohol compound 4. The yield of the resulting amino alcohol compound 4 was 52.4 g.
<Production Example 5: Production of amino alcohol compound 5>
The amino alcohol compound 4 obtained in Production Example 4 was reacted with boric acid to obtain an amino alcohol compound 5. It prepared so that content of the total boric acid might be less than 2 mass% with respect to the total amount of the boronated amino alcohol compound obtained after reaction.

[Examples and Comparative Examples]
A base oil and additives were blended according to the blending formulation shown in Table 1 to prepare a lubricating oil composition for internal combustion engines. The properties and performance of the obtained lubricating oil composition were evaluated by the methods described above. The results are shown in Table 1.

In addition, each component used for preparation of the lubricating oil composition shown in Table 1 is as follows.
* 1: Hydrorefined mineral oil (100 N, 40 ° C. kinematic viscosity: 21.0 mm ² / s, 100 ° C. kinematic viscosity: 4.5 mm ² / s, viscosity index: 127, sulfur content: less than 5 ppm by mass)
* 2: Thiadiazole (2,5-bis (n-octyldithio) -1,3,4-thiadiazole) Sulfur content 33.5% (compound represented by formula (Ia))
* 3: Calcium finate (base number 300mgKOH / g)
* 4: Other additives: metal deactivator (alkylbenzotriazole), silicone antifoaming agent, amine antioxidant, phenolic antioxidant, dispersant (including monoimide, bisimide, boronated monoimide), viscosity Conditioner (OCP, PMA)

[Evaluation results]
From Table 1, the lubricating oil composition according to the example containing either the amino alcohol compound or the boronated amino alcohol compound and the sulfur-containing heterocyclic compound represented by the general formula (I) was scored in the hot tube test. The shell wear test results are also excellent. That is, a lubricating oil composition can be obtained that maintains high-temperature cleanliness and does not impair wear resistance even if the additives and metal detergents containing phosphorus are significantly reduced as in the examples. I understood.

Claims (8)

Base oil,
A sulfur-containing heterocyclic compound represented by the following general formula (I):
An amino alcohol compound having one or more amino groups and one or more hydroxyl groups in the molecule,
A lubricating oil composition for an internal combustion engine having a phosphorus content of less than 0.03% by mass and a sulfated ash content of 0.3% by mass to 0.6% by mass based on the total amount of the composition.

(In the formula, As is a sulfur-containing heterocyclic ring, R ¹ and R ² are each independently a hydrogen atom; an amino group; an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group, and an aryl group. 50 hydrocarbon group; or when these are hydrocarbon groups, it represents a C1-C50 heteroatom-containing group comprising an atom selected from an oxygen atom, a nitrogen atom and a sulfur atom in the hydrocarbon group. k, l, m and n are each independently an integer of 0 to 5.)   The said amino alcohol compound is a reaction product obtained by making the compound which has an epoxy group, and the compound which has at least any one of a primary amino group and a secondary amino group react. A lubricating oil composition for internal combustion engines. The lubricating oil composition for an internal combustion engine according to claim 1 or 2, wherein the amino alcohol compound has a compound represented by the following general formula (II).

(Wherein R ³ , R ⁴ and R ⁵ are each independently a hydrogen atom; an amino group; a carbon atom having 2 to 38 carbon atoms selected from an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group and an aryl group) Represents hydrogen group)   The lubricating oil composition for an internal combustion engine according to any one of claims 1 to 3, wherein the amino alcohol compound contains a boron derivative thereof.   The lubricating oil composition for an internal combustion engine according to any one of claims 1 to 4, wherein both m and n are not 0 in the general formula (I).   The lubricating oil composition for an internal combustion engine according to any one of claims 1 to 5, wherein, in the general formula (I), the sulfur-containing heterocycle is a thiadiazole ring.   The lubricating oil composition for an internal combustion engine according to claim 6, wherein the thiadiazole ring is a 1,3,4-thiadiazole ring, and a sulfur atom is bonded to positions 2 and 5 of the 1,3,4-thiadiazole ring. .   The lubricating oil composition for an internal combustion engine according to claim 7, wherein each of the 1,3,4-thiadiazole rings has one sulfur atom bonded to the 2-position and the 5-position.