WO2011125879A1 - Lubricant composition for an internal combustion engine - Google Patents

Abstract

The disclosed lubricant composition for an internal combustion engine comprises: (A) a polyalphaolefin that has a kinetic viscosity at 100°C of at most 5.5 mm²/s, a CCS viscosity at −35°C of at most 3,000 mPa∙s, and a NOACK of at most 12 mass%; and (B) a mineral oil with a viscosity index of at least 120. Component (A) constitutes at least 25% of the entire composition by mass.

Description

Lubricating oil composition for internal combustion engines

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

In an internal combustion engine such as a gasoline engine or a diesel engine, carbon deposition called coking may occur inside the engine during use. When coking occurs, there is a possibility of causing various obstacles due to insufficient cooling inside the engine or obstruction of the flow of the lubricating oil itself. In particular, in an engine equipped with a turbo mechanism, coking that occurs in a turbo bearing portion, a housing, or an oil supply passage is a problem.
In order to prevent the occurrence of coking, it is effective to use a low-evaporation lubricating oil. As a low-evaporation lubricating oil for an internal combustion engine, a composition containing a blend of a base oil of Group II or Group III and a low-viscosity PAO in the API classification has been proposed (see Patent Documents 1 and 2).

Special table 2008-533274 Special table 2009-510214

On the other hand, fuel efficiency is also important for lubricating oil for internal combustion engines, but low-evaporation lubricating oil generally has a high viscosity, which may deteriorate fuel efficiency. The lubricating oil compositions described in Patent Document 1 and Patent Document 2 are not necessarily sufficient with respect to the balance between low evaporation and fuel economy.

An object of the present invention is to provide a lubricating oil composition for an internal combustion engine that has a low evaporation property, excellent coking resistance, and excellent fuel economy.

In order to solve the above problems, the present invention provides the following lubricating oil composition for an internal combustion engine.
(1) (A) a polyα-olefin having a kinematic viscosity at 100 ° C. of 5.5 mm ² / s or less, a CCS viscosity at −35 ° C. of 3000 mPa · s or less, and NOACK of 12% by mass or less, and (B) viscosity A lubricating oil composition for an internal combustion engine, comprising a mineral oil having an index of 120 or more, wherein the compounding amount of the component (A) is 25% by mass or more based on the total amount of the composition.
(2) In the lubricating oil composition for an internal combustion engine described above, the kinematic viscosity at 100 ° C. of the base oil obtained by blending the component (A) and the component (B) is 4.6 mm ² / s or less. A lubricating oil composition for an internal combustion engine.
(3) A lubricating oil for an internal combustion engine, wherein the composition has a NOACK of 10% by mass or less and a CCS viscosity at −35 ° C. of 6000 mPa · s or less. Composition.
(4) The above-mentioned lubricating oil composition for internal combustion engines, wherein the blending amount of the component (B) is 20% by mass or more based on the total amount of the composition.
(5) The lubricating oil composition for internal combustion engines, wherein the component (A) is polymerized with a metallocene catalyst.
(6) In the above-described lubricating oil composition for an internal combustion engine, the component (A) is a poly α-olefin having at least one selected from α-olefins having 10 to 14 carbon atoms as a monomer. A lubricating oil composition for an internal combustion engine.
(7) The lubricating oil composition for internal combustion engines, wherein the component (A) is a trimer.

The lubricating oil composition for an internal combustion engine of the present invention is blended with PAO having a specific property and mineral oil having a specific property, so that it has low evaporation properties, excellent coking resistance, and also fuel saving. Are better. Therefore, the lubricating oil composition for internal combustion engines of the present invention is also suitable for gasoline engines and diesel engines equipped with a turbo mechanism.

The lubricating oil composition for an internal combustion engine of the present invention has, as component (A), a kinematic viscosity at 100 ° C. of 5.5 mm ² / s or less, a CCS viscosity at −35 ° C. of 3000 mPa · s or less, and NOACK of 12% by mass or less. And a mineral oil having a viscosity index of 120 or more as a component (B). Details will be described below.

(A) component:
The component (A) in the present invention is poly α-olefin (PAO) which is a polymer (oligomer) of α-olefin.
From the viewpoint of fuel economy, the kinematic viscosity at 100 ° C. of PAO as component (A) needs to be 5.5 mm ² / s or less. However, this kinematic viscosity is preferably 3 mm ² / s or more from the viewpoint of lubricity. Further, the CCS viscosity at −35 ° C. needs to be 3000 mPa · s or less. Further, NOACK is required to be 12% by mass or less from the viewpoint of low evaporation.
The number of carbon atoms of the α-olefin, which is a monomer for obtaining such PAO, is preferably from 6 to 20 from the viewpoint of low temperature properties such as viscosity index, pour point and low temperature viscosity, and evaporation, but from 8 to 16 Is more preferable, and 10 to 14 is particularly preferable. The PAO is preferably an α-olefin trimer from the viewpoints of low evaporation, coking resistance and low fuel consumption, but in order to obtain the desired properties, the carbon number of the α-olefin and its blending ratio, The degree of polymerization can be adjusted.
The polymerization catalyst of α- olefin, BF ₃ catalyst, AlCl ₃ catalyst, may be used Ziegler catalysts, such as metallocene catalysts, conventionally, the low viscosity PAO below 100 ° C. kinematic viscosity of 30mm ² / s BF ₃ AlCl ₃ catalysts have been used for low-viscosity PAOs with a catalyst of 30 mm ² / s or more, but BF ₃ catalysts and metallocene catalysts are particularly preferred from the viewpoints of low evaporation, coking resistance, and low fuel consumption.
The BF ₃ catalyst is used together with a promoter such as water, alcohol, ester, etc. Among them, alcohol, particularly 1-butanol, is preferable from the viewpoint of viscosity index, low temperature physical properties, and yield.

Examples of the metallocene catalyst include a catalyst containing a combination of a metallocene compound and a promoter. As the metallocene compound, a metallocene compound represented by the following general formula (1) is preferable.
(RC ₅ H ₄ ) ₂ MX ₂ (1)
In the general formula (1), R is a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms, M is a transition metal element of Group 4 of the periodic table, and X is covalent bond or ionic bond It is a ligand.

In the general formula (1), R is preferably a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms. Specific examples of M include titanium, zirconium, and hafnium. Among these, zirconium is preferable. Specific examples of X include a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms (preferably 1 to 10), an alkoxy group having 1 to 20 carbon atoms (preferably 1 to 10), Amino group, phosphorus-containing hydrocarbon group having 1 to 20 carbon atoms (preferably 1 to 12) (for example, diphenylphosphine group), silicon-containing carbon atom having 1 to 20 carbon atoms (preferably 1 to 12 carbon atoms) A hydrogen group (for example, trimethylsilyl group), a hydrocarbon group having 1 to 20 carbon atoms (preferably 1 to 12) or a boron compound containing halogen (for example, B (C ₆ H ₅ ) ₄ , BF _4, etc. Among these, a group selected from the group consisting of a hydrogen atom, a halogen atom, a hydrocarbon group, and an alkoxy group is preferable.

Examples of the metallocene compound represented by the general formula (1) include bis (cyclopentadienyl) zirconium dichloride, bis (methylcyclopentadienyl) zirconium dichloride, bis (ethylcyclopentadienyl) zirconium dichloride, and bis. (Iso-propylcyclopentadienyl) zirconium dichloride, bis (n-propylcyclopentadienyl) zirconium dichloride, bis (n-butylcyclopentadienyl) zirconium dichloride, bis (t-butylcyclopentadienyl) zirconium dichloride , Bis (texylcyclopentadienyl) zirconium dichloride, bis (trimethylsilylcyclopentadienyl) zirconium dichloride, bis (trimethylsilylmethylcyclopentadienyl) di Conium dichloride, bis (cyclopentadienyl) zirconium chlorohydride, bis (cyclopentadienyl) methylzirconium chloride, bis (cyclopentadienyl) ethylzirconium chloride, bis (cyclopentadienyl) methoxyzirconium chloride, bis ( Cyclopentadienyl) phenylzirconium chloride, bis (cyclopentadienyl) dimethylzirconium, bis (cyclopentadienyl) diphenylzirconium, bis (cyclopentadienyl) dineopentylzirconium, bis (cyclopentadienyl) dihydrozirconium , Bis (cyclopentadienyl) dimethoxyzirconium, and further, in the compounds described above, the chlorine atom of these compounds is bromine atom, iodine atom, hydrogen atom, Group, those replaced with a phenyl group, also include those obtained by replacing the zirconium metal centers of the compounds titanium, hafnium.

As the promoter, methylaluminoxane is preferable. There is no restriction | limiting in particular as methylaluminoxane, A conventionally well-known methylaluminoxane can be used, For example, the chain | strand-shaped methylaluminoxane represented by following General formula (2), The cyclic | annular form represented by following General formula (3) And methylaluminoxane.

In the general formula (2) and the general formula (3), p represents the degree of polymerization and is usually from 3 to 50, preferably from 7 to 40.

Examples of the method for producing methylaluminoxane include a method in which methylaluminum is brought into contact with a condensing agent such as water, but the means is not particularly limited, and the reaction may be carried out according to a known method.

The compounding ratio of the metallocene compound and methylaluminoxane is usually from 15 to 150, preferably from 20 to 120, more preferably from 25 to 100, as the methylaluminoxane / metallocene compound (molar ratio). When the blending ratio is 15 or more, catalytic activity is exhibited, and the yield of trimer or more suitable as a base oil for lubricating oil does not decrease due to the formation of α-olefin dimer. On the other hand, if the blending ratio is 150 or less, deashing and removal of the catalyst will not be incomplete.

Examples of metallocene catalysts other than the above include metallocene catalysts that use a metallocene compound having a crosslinking group. As such a metallocene compound, a metallocene compound having two crosslinking groups is preferable, and a metallocene compound having meso symmetry is particularly preferable. Examples of the metallocene catalyst using the metallocene compound having meso symmetry include (a) a metallocene compound represented by the following general formula (4) as a catalyst component, and (b) the catalyst (a) as a catalyst component. Examples thereof include a compound (b-1) capable of forming an ionic complex by reacting with a component metallocene compound or a derivative thereof, and a metallocene catalyst containing at least one component (b-2) selected from aluminoxane. .

The compound represented by the general formula (4) is a mesosymmetric compound, and in the general formula (4), M represents a metal element from group 3 to group 10 of the periodic table. X represents a σ-binding ligand, and when there are a plurality of X, a plurality of X may be the same or different, Y represents a Lewis base, and when there are a plurality of Y, a plurality of Y are the same or different It may be. A represents a hydrocarbon group having 1 to 20 carbon atoms, a halogen-containing hydrocarbon group having 1 to 20 carbon atoms, a silicon-containing group, a germanium-containing group, a tin-containing group, —O—, —CO—, —S—. _{, -SO 2 -, - Se -} , - NR 1 -, - PR 1 -, - P (O) R 1 -, - BR 1 - and -AlR ¹ - shows a bridging group selected from the two a They may be the same or different. R ¹ represents a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms or a halogen-containing hydrocarbon group having 1 to 20 carbon atoms. q is an integer from 1 to 5 and represents [(valence of M) -2], and r represents an integer from 0 to 3. E is a group represented by the following general formula (5) and the following general formula (6), and the two Es are the same.
The mesosymmetric compound refers to a transition metal compound in which two bridging groups bridge two Es in a bonding mode of (1,1 ′) (2,2 ′).

In the general formula (5) and the general formula (6), R ² represents a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, a halogen-containing hydrocarbon group having 1 to 4 carbon atoms, silicon A group selected from the group consisting of a containing group and a heteroatom-containing group is shown. When several R < ² > exists, they may mutually be same or different. The bond indicated by the wavy line represents the bond with the bridging group A.

The crosslinkable group A in the general formula (4) is preferably a group represented by the following general formula (7).

In the general formula (7), B is a skeleton of a bridging group and represents a carbon atom, a silicon atom, a boron atom, a nitrogen atom, a germanium atom, a phosphorus atom, or an aluminum atom. R ³ represents a hydrogen atom, a carbon atom, an oxygen atom, an aliphatic hydrocarbon group, an aromatic hydrocarbon group, an amine-containing group, or a halogen-containing group. n is 1 or 2.

Examples of the metallocene compound represented by the general formula (4) include (1,1′-ethylene) (2,2′-ethylene) -bis (indenyl) zirconium dichloride, (1,1′-methylene) ( 2,2′-methylene) -bis (indenyl) zirconium dichloride, (1,1′-isopropylidene) (2,2′-isopropylidene) -bis (indenyl) zirconium dichloride, (1,1′-ethylene) ( 2,2′-ethylene) -bis (3-methylindenyl) zirconium dichloride, (1,1′-ethylene) (2,2′-ethylene) -bis (4,5-benzoindenyl) zirconium dichloride, ( 1,1′-ethylene) (2,2′-ethylene) -bis (4-isopropylindenyl) zirconium dichloride, (1,1′-ethylene (2,2'-ethylene) -bis (5,6-dimethylindenyl) zirconium dichloride, (1,1'-ethylene) (2,2'-ethylene) -bis (4,7-diisopropylindenyl) zirconium Dichloride, (1,1′-ethylene) (2,2′-ethylene) -bis (4-phenylindenyl) zirconium dichloride, (1,1′-ethylene) (2,2′-ethylene) -bis (3 -Methyl-4-isopropylindenyl) zirconium dichloride, (1,1'-ethylene) (2,2'-ethylene) -bis (5,6-benzoindenyl) zirconium dichloride, (1,1'-dimethylsilylene) ) (2,2′-dimethylsilylene) bis (cyclopentadienyl) zirconium dichloride, (1,1′-dimethylsilylene) (2,2′- Methylsilylene) bis (indenyl) zirconium dichloride, (1,1′-dimethylsilylene) (2,2′-dimethylsilylene) bis (3-methylindenyl) zirconium dichloride, (1,1′-dimethylsilylene) (2 , 2'-dimethylsilylene) bis (3-n-butylindenyl) zirconium dichloride, (1,1'-dimethylsilylene) (2,2'-dimethylsilylene) bis (3-i-propylindenyl) zirconium dichloride , (1,1'-dimethylsilylene) (2,2'-dimethylsilylene) bis (3-trimethylsilylmethylindenyl) zirconium dichloride, (1,1'-dimethylsilylene) (2,2'-dimethylsilylene) bis (3-Phenylindenyl) zirconium dichloride, (1,1'-dimethyl) Silylene) (2,2'-dimethylsilylene) bis (4,5-benzoindenyl) zirconium dichloride, (1,1'-dimethylsilylene) (2,2'-dimethylsilylene) bis (4-isopropylindenyl) Zirconium dichloride, (1,1'-dimethylsilylene) (2,2'-dimethylsilylene) bis (5,6-dimethylindenyl) zirconium dichloride, (1,1'-dimethylsilylene) (2,2'-dimethyl Silylene) bis (4,7-di-i-propylindenyl) zirconium dichloride, (1,1′-dimethylsilylene) (2,2′-dimethylsilylene) bis (4-phenylindenyl) zirconium dichloride, (1 , 1'-dimethylsilylene) (2,2'-dimethylsilylene) bis (3-methyl-4-i-propyl) Ndenyl) zirconium dichloride, (1,1′-dimethylsilylene) (2,2′-dimethylsilylene) bis (5,6-benzoindenyl) zirconium dichloride, and the like, and zirconium in these compounds substituted with titanium or hafnium You can list things. Of course, it is not limited to these.

The catalyst component (b-1) of the catalyst component (b) is any compound that can react with the metallocene compound of the catalyst component (a) to form an ionic complex. Although it can be used, what is represented by the following general formula (8) or the following general formula (9) can be preferably used.
([L ¹ −R ⁴ ] ^{k +} ) _a ([Z] ⁻ ) _b (8)
([L ² ] ^{k +} ) _a ([Z] ⁻ ) _b (9)

In the general formula (8) and the general formula (9), L ¹ represents a Lewis base, L ² represents M ² , R ⁵ R ⁶ M ³ , R ⁷ ₃ C or R ⁸ M ³ . [Z] ⁻ represents a non-coordinating anion [Z ¹ ] ⁻ or [Z ² ] ⁻ . Here, [Z ¹ ] ⁻ is an anion in which a plurality of groups are bonded to the element, that is, [M ¹ G ¹ G ² ... G ^f ] ⁻ (where M ¹ is group 5 to group 15 of the periodic table). Elements, from Group 13 to Group 15 of the periodic table, G ¹ to G ^f are each a hydrogen atom, a halogen atom, an alkyl group having 1 to 20 carbon atoms, or 2 to C atoms. 40 dialkylamino groups, alkoxy groups having 1 to 20 carbon atoms, aryl groups having 6 to 20 carbon atoms, aryloxy groups having 6 to 20 carbon atoms, alkylaryl groups having 7 to 40 carbon atoms, carbon An arylalkyl group having 7 to 40 carbon atoms, a halogen-substituted hydrocarbon group having 1 to 20 carbon atoms, an acyloxy group having 1 to 20 carbon atoms, an organic metalloid group, or a heteroatom having 2 to 20 carbon atoms. Two or more of the .G ¹ illustrating a hydrocarbon group to ^{G f} may optionally form a ring .f is an integer of [(valence of central metal ^{M 1) +1].),} [Z ^{2] -} is the reciprocal of the logarithm (pKa) is -10 or less Bronsted acid alone, or a combination of Bronsted acids and Lewis acids conjugate base of the acid dissociation constant or generally conjugate acid is defined as super acid, Indicates salt. In addition, a Lewis base may be coordinated. R ⁴ represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an alkylaryl group or an arylalkyl group, and R ⁵ and R ⁶ are each a cyclopentadienyl group. , Substituted cyclopentadienyl, indenyl group or fluorenyl group, R ⁷ represents an alkyl group having 1 to 20 carbon atoms, an aryl group, an alkylaryl group or an arylalkyl group. R ⁸ represents a macrocyclic ligand such as tetraphenylporphyrin or phthalocyanine. k is an ionic valence of [L ¹ −R ⁴ ], [L ² ], an integer from 1 to 3, a is an integer of 1 or more, and b = (k × a). M ² includes elements from Group 1 to Group 3 of the Periodic Table, Group 11 to Group 13 and Group 17 of the Periodic Table, and M ³ includes Groups 7 to 12 of the Periodic Table. Indicates elements up to group.

Here, specific examples of L ¹ include ammonia, methylamine, aniline, dimethylamine, diethylamine, N-methylaniline, diphenylamine, N, N-dimethylaniline, trimethylamine, triethylamine, tri-n-butylamine, methyldiphenylamine, Amines such as pyridine, p-bromo-N, N-dimethylaniline, p-nitro-N, N-dimethylaniline; phosphines such as triethylphosphine, triphenylphosphine, diphenylphosphine; thioethers such as tetrahydrothiophene; Examples include esters such as ethyl acid; nitriles such as acetonitrile and benzonitrile.
Specific examples of R ⁴ include hydrogen, methyl group, ethyl group, benzyl group, and trityl group. Specific examples of R ⁵ and R ⁶ include cyclopentadienyl group, methylcyclopentadienyl group, Examples thereof include an ethylcyclopentadienyl group and a pentamethylcyclopentadienyl group. Specific examples of R ⁷ include phenyl group, p-tolyl group, p-methoxyphenyl group and the like, and specific examples of R ⁸ include tetraphenylporphyrin, phthalocyanine, allyl, methallyl and the like. Specific examples of M ² include Li, Na, K, Ag, Cu, Br, I, and the like. Specific examples of M ³ include Mn, Fe, Co, Ni, Zn, and the like. In [Z ¹ ] ⁻ , that is, [M ¹ G ¹ G ² ... G ^f ], specific examples of M ¹ include B, Al, Si, P, As, Sb, etc., preferably B and Al. Can be mentioned. Specific examples of G ¹ and G ² to G ^f include a dimethylamino group and a diethylamino group as a dialkylamino group; a methoxy group, an ethoxy group, an n-butoxy group, a phenoxy group and the like as an alkoxy group or an aryloxy group. Hydrocarbon groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, n-octyl, n-eicosyl, phenyl, p-tolyl, benzyl, 4- t-butylphenyl group, 3,5-dimethylphenyl group, etc .; halogen, fluorine, chlorine, bromine, iodine, etc .; heteroatom-containing hydrocarbon group, p-fluorophenyl group, 3,5-difluorophenyl group, pentachlorophenyl Group, 3,4,5-trifluorophenyl group, pentafluorophenyl group, 3, - bis (trifluoromethyl) phenyl group, bis (trimethylsilyl) such as a methyl group; pentamethyl antimony group as organic metalloid group, trimethylsilyl group, trimethylgermyl group, diphenylarsine group, dicyclohexyl antimony group, such as diphenyl boron and the like.

Specific examples of non-coordinating anions, that is, Bronsted acids having a pKa of −10 or less or conjugate bases [Z ² ] ^{— in} combination with Bronsted acids and Lewis acids include trifluoromethanesulfonic acid anions (CF ₃ SO ₃ ) ⁻ , bis (trifluoromethanesulfonyl) methyl anion, bis (trifluoromethanesulfonyl) benzyl anion, bis (trifluoromethanesulfonyl) amide, perchlorate anion (ClO ₄ ) ⁻ , trifluoroacetate anion (CF ₃ CO ₂ ) ⁻ , Hexafluoroantimony anion (SbF ₆ ) ⁻ , fluorosulfonate anion (FSO ₃ ) ⁻ , chlorosulfonate anion (ClSO ₃ ) ⁻ , fluorosulfonate anion / 5-antimony fluoride (FSO ₃ / SbF ₅ ) ⁻ , Fluorosulfonate anion / 5-arsenic fluoride (FSO ₃ / AsF ₅ ) ⁻ , trifluoromethanesulfonic acid / 5-antimony fluoride (CF ₃ SO ₃ / SbF ₅ ) ^{− and the} like.

An ionic compound that reacts with the transition metal compound of the catalyst component (a) to form an ionic complex, that is, a specific example of the catalyst component (b-1) is tetrakis (pentafluorophenylboric acid) N, N -Dimethylanilinium, triethylammonium tetraphenylborate, tri-n-butylammonium tetraphenylborate, trimethylammonium tetraphenylborate, tetraethylammonium tetraphenylborate, methyl (tri-n-butyl) ammonium tetraphenylborate, benzyltetraphenylborate (Tri-n-butyl) ammonium, dimethyldiphenylammonium tetraphenylborate, triphenyl (methyl) ammonium tetraphenylborate, trimethylanilinium tetraphenylborate, methyl tetraphenylborate Pyridinium, benzylpyridinium tetraphenylborate, methyl tetraphenylborate (2-cyanopyridinium), triethylammonium tetrakis (pentafluorophenyl) borate, tri-n-butylammonium tetrakis (pentafluorophenyl) borate, tetrakis (pentafluorophenyl) boric acid Triphenylammonium, tetrakis (pentafluorophenyl) borate tetra-n-butylammonium, tetrakis (pentafluorophenyl) tetraethylammonium borate, tetrakis (pentafluorophenyl) benzyl benzyl (tri-n-butyl) borate, tetrakis (pentafluorophenyl) ) Methyldiphenylammonium borate, tetrakis (pentafluorophenyl) triphenyl (methyl) ammonium borate , Tetrakis (pentafluorophenyl) methylanilinium borate, tetrakis (pentafluorophenyl) dimethylanilinium borate, trimethylanilinium tetrakis (pentafluorophenyl) borate, methylpyridinium tetrakis (pentafluorophenyl) borate, tetrakis (pentafluorophenyl) ) Benzylpyridinium borate, methyl tetrakis (pentafluorophenyl) borate (2-cyanopyridinium), benzyltetrakis (pentafluorophenyl) benzyl borate (2-cyanopyridinium), methyl tetrakis (pentafluorophenyl) borate (4-cyanopyridinium), Tetrakis (pentafluorophenyl) borate triphenylphosphonium, tetrakis [bis (3,5-ditrifluoromethyl) phenyl] borate Dimethylanilinium, ferrocenium tetraphenylborate, silver tetraphenylborate, trityl tetraphenylborate, tetraphenylporphyrin manganese tetraphenylborate, ferrocenium tetrakis (pentafluorophenyl) borate, tetrakis (pentafluorophenyl) boric acid (1,1′-dimethyl) Ferrocenium), tetrakis (pentafluorophenyl) decamethylferrocenium borate, silver tetrakis (pentafluorophenyl) borate, trityl tetrakis (pentafluorophenyl) borate, tetrakis (pentafluorophenyl) lithium borate, tetrakis (pentafluorophenyl) ) Sodium borate, tetrakis (pentafluorophenyl) borate tetraphenylporphyrin manganese, silver tetrafluoroborate, hexafluro Phosphate silver hexafluoroarsenate, silver perchlorate, silver trifluoroacetate, and the like of silver trifluoromethanesulfonate. These (B-1) catalyst components may be used singly or in combination of two or more.

On the other hand, examples of the aluminoxane as the catalyst component (b-2) include a chain aluminoxane represented by the following general formula (10) and a cyclic aluminoxane represented by the following general formula (11).

In the general formula (10) and the general formula (11), R ⁹ is a hydrocarbon group having 1 to 20 carbon atoms, preferably 1 to 12 alkyl group, alkenyl group, aryl group, arylalkyl group or the like, or Represents a halogen atom, and w represents an average degree of polymerization, and is usually an integer of 2 to 50, preferably an integer of 2 to 40. Each R ⁹ may be the same or different.

Examples of the method for producing the aluminoxane include a method in which an alkylaluminum is brought into contact with a condensing agent such as water, but the means is not particularly limited and may be reacted according to a known method.
For example, (1) a method in which an organoaluminum compound is dissolved in an organic solvent and contacting it with water, (2) a method in which an organoaluminum compound is initially added during polymerization, and water is added later, (3) metal There are a method of reacting crystallization water contained in a salt or the like, water adsorbed on an inorganic or organic substance with an organoaluminum compound, and (4) a method of reacting a tetraalkyldialuminoxane with a trialkylaluminum and further reacting with water. . The aluminoxane may be insoluble in toluene. These aluminoxanes may be used alone or in combination of two or more.

The use ratio of the above-mentioned (a) catalyst component and (b) catalyst component is from 10: 1 to 1: 100 in molar ratio when (b-1) catalyst component is used as (b) catalyst component. The range of 2: 1 to 1:10 is more preferable. If it deviates from the above range, the catalyst cost per unit mass polymer increases, which is not practical. When the above-mentioned (b-2) catalyst component is used, the molar ratio is preferably in the range of 1: 1 to 1: 1000000, and more preferably in the range of 1:10 to 1: 10000. When deviating from this range, the catalyst cost per unit mass polymer becomes high, which is not practical. Further, as the (b) catalyst component, the (b-1) catalyst component and the (b-2) catalyst component may be used alone or in combination of two or more.

In the present invention, an α-olefin having 10 to 14 carbon atoms is preferred as a monomer for producing PAO (hereinafter also referred to as “mPAO”) using a metallocene catalyst. From the viewpoint of viscosity index and low-temperature physical properties, a linear α-olefin is preferable. Specific examples include 1-decene, 1-dodecene, 1-tetradecene, and the like. Of these, 1-decene is particularly preferred.

The blending ratio of the metallocene compound represented by the general formula (1) or the general formula (4) and the α-olefin [metallocene compound (mmol) / α-olefin (L)] is usually 0.01 to 0.4. Up to, preferably from 0.05 to 0.3, more preferably from 0.1 to 0.2. Sufficient catalytic activity is obtained when the blending ratio is 0.01 or more, whereas when it is 0.4 or less, the yield of oligomers of trimer or more suitable as a base oil of the lubricating oil is improved, There is no incomplete removal of the catalyst.

The polymerization of the α-olefin is preferably performed in the presence of hydrogen. The amount of hydrogen added is usually from 0.1 kPa to 50 kPa, preferably from 0.5 kPa to 30 kPa, and more preferably from 1 kPa to 10 kPa. When the amount of hydrogen added is 0.1 kPa or more, sufficient catalytic activity can be obtained. On the other hand, when it is 50 kPa or less, the production of a raw material α-olefin saturated product can be reduced, and the desired yield of mPAO is obtained. Will improve.

The polymerization of the α-olefin is not limited in the reaction method, and may be performed in the absence of a solvent or in a solvent, and any method may be used. When using a reaction solvent, for example, aromatic hydrocarbons such as benzene, toluene, xylene and ethylbenzene, alicyclic hydrocarbons such as cyclopentane, cyclohexane and methylcyclohexane, and aliphatic hydrocarbons such as pentane, hexane, heptane and octane Halogenated hydrocarbons such as chloroform and dichloromethane. The temperature of the polymerization reaction is usually 0 ° C. or higher and 100 ° C. or lower, preferably 20 ° C. or higher and 80 ° C. or lower, more preferably 30 ° C. or higher and 70 ° C. or lower. By being the said range, sufficient catalyst activity is obtained and the yield of the oligomer more than a trimer suitable as a base oil of lubricating oil improves. By carrying out the polymerization by the above method, mPAO having a trimer or higher selectivity of 50% or higher can be produced.

Depending on the purpose, the mPAO obtained by the above method may be further treated. For example, in order to improve thermal stability or oxidation stability, hydrogenation may be performed. Moreover, what is necessary is just to distill, when obtaining the lubricating base oil which has a desired characteristic. The temperature of the hydrogenation treatment is usually 50 ° C. or more and 300 ° C. or less, preferably 60 ° C. or more and 250 ° C. or less, more preferably 70 ° C. or more and 200 ° C. or less, and the hydrogen pressure is usually 0.1 MPa or more and 10 MPa or less. Preferably, it is 0.5 MPa or more and 2 MPa or less, More preferably, it is 0.7 MPa or more and 1.5 MPa or less. In the hydrogenation treatment, a general hydrogenation catalyst containing Pd, Ni, or the like can be used. The temperature in distillation is usually 200 ° C. or more and 300 ° C. or less, preferably 220 ° C. or more and 280 ° C. or less, more preferably 230 ° C. or more and 270 ° C. or less, and the pressure is usually 0.1 Pa or more and 15 Pa or less, preferably Is 0.4 Pa or more and 7 Pa or less, more preferably 0.6 Pa or more and 4 Pa or less.

The mPAO obtained by the above method, mPAO after hydrogenation treatment or distillation has about 1 short chain branch per molecule (usually 0.6 or more and 1.2 or less, preferably 0.7). It is 1.1 or less, more preferably 0.8 or more and 1.0 or less. (In this specification, a methyl group, an ethyl group, and a propyl group are referred to as short-chain branches.) . Further, the short chain branch is mainly a methyl group, and the proportion of the methyl group is usually 80 mol% or more, preferably 85 mol% or more, more preferably 90 mol% or more.

In the present composition, the blending amount of the component (A) needs to be 25% by mass or more based on the total amount of the composition. If the blending amount is less than 25% by mass, the object of the present invention cannot be sufficiently achieved. Further, from the viewpoint of low evaporation, the blending amount of the component (A) is preferably 30% by mass or more, and more preferably 35% by mass or more. However, it is preferably 80% by mass or less from the viewpoint of the solubility of the additive and the compatibility with the seal rubber.

(B) component:
The component (B) in the present invention is a mineral oil having a viscosity index of 120 or more. As such mineral oil, for example, Group III hydrorefined mineral oil in the API classification is suitable.
The component (B) is blended with the component (A), thereby imparting appropriate lubricity to the composition and contributing to improvement in fuel economy.
Moreover, by mix | blending (B) component, the solubility of the additive generally used for internal combustion engines improves, and it contributes also greatly to fuel-saving property as a result.
Therefore, the component (B) is preferably blended in an amount of 20% by mass or more, more preferably 25% by mass or more based on the total amount of the composition.

In the present invention, it is preferable that kinematic viscosity at 100 ° C. in the mixed base oil by blending the above components (A) and component (B) is less than ^{4.6mm 2 / s, 4.4mm 2 /} s The following is more preferable.
When the mixed base oil has a 100 ° C. kinematic viscosity of 4.6 mm ² / s or less, it contributes to an improvement in fuel economy. However, the 100 ° C. kinematic viscosity of the mixed base oil is preferably 3 mm ² / s or more from the viewpoint of evaporability.

This composition is mainly composed of the above-mentioned mixed base oil, but it is preferable that the NOACK of the composition is 10% by mass or less and the CCS viscosity at −35 ° C. is 6000 mPa · s or less. When NOACK and the CCS viscosity at −35 ° C. are in this range, both the coking resistance and the fluidity at low temperature (fuel saving performance) are excellent, and therefore, it is suitable as a lubricating oil for an internal combustion engine.

In the lubricating oil composition of the present invention, other additives such as a viscosity index improver, a pour point depressant, a cleaning dispersant, an antioxidant, as necessary, as long as the object of the present invention is not impaired. An antiwear agent / extreme pressure agent, a friction reducing agent, a metal deactivator, a rust inhibitor, a surfactant / demulsifier, an antifoaming agent, and the like can be appropriately blended.

Examples of the viscosity index improver include 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 0.5% by mass or more and 15% by mass or less, more preferably 1% by mass or more and 10% by mass or less based on the total amount of the lubricating oil composition from the viewpoint of the blending effect.

Examples of the pour point depressant include polymethacrylate having a weight average molecular weight of about 5000 to 50,000.
The blending amount of the pour point depressant is preferably 0.1% by mass or more and 2% by mass or less, more preferably 0.1% by mass or more and 1% by mass or less, based on the total amount of the lubricating oil composition, from the viewpoint of the blending effect. is there.

As the cleaning and dispersing agent, an ashless dispersant and a metal-based cleaning agent can be used.
As the ashless dispersant, any ashless dispersant used in lubricating oils can be used. For example, a monotype succinimide compound represented by the following general formula (II) or a general formula (III) The bis-type succinimide compound represented is mentioned.

In the above formulas (II) and (III), R ¹¹ , R ¹³ and R ¹⁴ are each an alkenyl group or alkyl group having a number average molecular weight of 500 to 4,000, and R ¹³ and R ¹⁴ are the same or different. May be. The number average molecular weight of R ¹¹ , R ¹³ and R ¹⁴ is preferably from 1,000 to 4,000. R ¹² , R ¹⁵ and R ¹⁶ are each an alkylene group having 2 to 5 carbon atoms, R ¹⁵ and R ¹⁶ may be the same or different, and r represents an integer of 1 to 10, s represents 0 or an integer from 1 to 10.
When the number average molecular weight of R ¹¹ , R ¹³ and R ¹⁴ is less than 500, the solubility in the base oil decreases, and when it exceeds 4,000, the cleanliness decreases and the target performance cannot be obtained. There is a fear.
The r is preferably 2 to 5, more preferably 3 to 4.
When r is less than 1, the cleanliness is deteriorated, and when r is 11 or more, the solubility in the base oil is deteriorated.
In the above formula (III), s is preferably 1 to 4, more preferably 2 or 3.
If it is in the said range, it is preferable at the point of the cleanability and the solubility with respect to base oil.
Examples of the alkenyl group include a polybutenyl group, a polyisobutenyl group, and an ethylene-propylene copolymer, and the alkyl group is a hydrogenated form thereof.
Representative examples of suitable alkenyl groups include polybutenyl or polyisobutenyl groups. The polybutenyl group can be obtained by polymerizing a mixture of 1-butene and isobutene or high-purity isobutene. A representative example of a suitable alkyl group is a hydrogenated polybutenyl group or polyisobutenyl group.

The above alkenyl or alkyl succinimide compound is usually prepared by reacting an alkenyl succinic anhydride obtained by reaction of polyolefin with maleic anhydride, or an alkyl succinic anhydride obtained by hydrogenating it with a polyamine. Can be manufactured.
The mono-type succinimide compound and the bis-type succinimide compound described above can be produced by changing the reaction ratio of alkenyl succinic anhydride or alkyl succinic anhydride and polyamine.
As the olefin monomer forming the polyolefin, one or more of α-olefins having 2 to 8 carbon atoms can be mixed and used, but a mixture of isobutene and butene-1 is preferably used. be able to.

Polyamines include ethylenediamine, propylenediamine, butylenediamine, pentylenediamine, and other single diamines, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, di (methylethylene) triamine, dibutylenetriamine, and butylenetetramine. And polyalkylene polyamines such as pentapentylenehexamine and piperazine derivatives such as aminoethylpiperazine.

In addition to the alkenyl or alkyl succinimide compound, at least one of boron derivatives thereof and those modified with organic acids may be used.
As the boron derivative of the alkenyl or alkyl succinimide compound, those produced by a conventional method can be used.
For example, after reacting the above polyolefin with maleic anhydride to form an alkenyl succinic anhydride, the polyamine and boron oxide, boron halide, boric acid, boric anhydride, boric acid ester, and boric acid It is obtained by reacting with an intermediate obtained by reacting a boron compound such as an ammonium salt and imidizing.
Although there is no restriction | limiting in particular in the boron content in this boron derivative, A preferable boron content is 0.05 to 5 mass%, More preferably, it is 0.1 to 3 mass%.

The blending amount of the monotype succinimide compound represented by the above formula (II) or the bis type succinimide compound represented by the above formula (III) is 0.5% based on the total amount of the lubricating oil composition. The content is preferably from 15% by mass to 15% by mass, and more preferably from 1% by mass to 10% by mass.
If the blending amount is less than 0.5% by mass, the effect is hardly exhibited, and if it exceeds 15% by mass, an effect commensurate with the blending amount cannot be obtained.
Moreover, a succinimide compound may be used alone or in combination of two or more as long as it contains the specified amount.

As the metallic detergent, any alkaline earth metal detergent used for lubricating oils can be used, for example, alkaline earth metal sulfonates, alkaline earth metal phenates, alkaline earth metal salicylates, 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, particularly magnesium salts, obtained by sulfonating alkyl aromatic compounds having a molecular weight of 300 to 1,500, preferably 400 to 700. And / or calcium salts and the like, among which calcium salts are preferably used.

Examples of alkaline earth metal phenates include alkylphenols, alkylphenol sulfides, alkaline earth metal salts of Mannich reactants of alkylphenols, particularly magnesium salts and calcium salts, among which calcium salts are particularly preferably used.
Examples of the alkaline earth metal salicylates include alkaline earth metal salts of alkyl salicylic acid, particularly magnesium salts and 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 a linear or branched alkyl group having 6 to 18 carbon atoms, It may be a branch.
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 alkyl aromatic sulfonic acid, alkylphenol, alkylphenol sulfide, Mannich reaction product of alkylphenol, alkylsalicylic acid, etc. are directly used as magnesium and / or Or it reacts with alkaline earth metal bases such as alkaline earth metal oxides and hydroxides of calcium, or once replaced with alkaline earth metal salts such as sodium salts and potassium salts, etc. Neutral alkaline earth metal sulfonates, neutral alkaline earth metal phenates and neutral alkaline earth metal salicylates as well as neutral alkaline earth metal sulfonates, neutral alkaline earth metal phenates obtained by Basic alkaline earth metal sulfonates, basic alkaline earth metal sulfonates obtained by heating an alkaline earth metal salicylate and excess alkaline earth metal salts or alkaline earth metal bases in the presence of water, Basic alkaline earth metal salicylates or neutral alkaline earth metal sulfonates, neutral alkaline earth metal phenates, and neutral alkaline earth metal salicylates in the presence of carbon dioxide. Also included are overbased alkaline earth metal sulfonates, overbased alkaline earth metal phenates, and overbased alkaline earth metal salicylates obtained by reacting.

As the metallic detergent, the above neutral salts, basic salts, overbased salts, and mixtures thereof can be used, and in particular, one of overbased salicylates, overbased phenates, and overbased sulfonates. Mixing the above with neutral sulfonate is preferable in terms of cleanliness and wear resistance.

The total base number of the metal detergent is preferably 10 mgKOH / g or more and 500 mgKOH / g or less, more preferably 15 mgKOH / g or more and 450 mgKOH / g or less.
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.

The metal detergent is not particularly limited in its metal ratio, and can be used by mixing one or more of 20 or less, preferably the metal ratio is 3 or less, more preferably 1.5 or less, In particular, it is particularly preferable to use a metal-based detergent of 1.2 or less as an essential component 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 metal detergent is generally marketed in a state diluted with a light lubricating base oil or the like, and preferably has a metal content of 1% by mass to 20% by mass, preferably 2% by mass to 16% by mass. Those up to are more preferred. The compounding amount of the metal detergent is preferably 0.01% by mass or more and 20% by mass or less, more preferably 0.1% by mass or more and 10% by mass or less, based on the total amount of the composition.
If the blending amount is less than 0.01% by mass, the effect is hardly exhibited, and even if it exceeds 20% by mass, an effect commensurate with the addition cannot be obtained.
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.

Examples of the antioxidant include phenol-based antioxidants, amine-based antioxidants, molybdenum amine complex-based antioxidants, and sulfur-based antioxidants.
Examples of the phenolic antioxidant include 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-ethyl-6-t-butylphenol); 2,2'-methylenebis (4-methyl-6-t-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 2,6-di-t-butyl-4-ethylphenol; 2,4-dimethyl-6-t-butylphenol; 2,6-di-t-amyl-p-cresol; 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 amine-based antioxidants include monooctyl diphenylamine; monoalkyl diphenylamines such as monononyl diphenylamine; 4,4′-dibutyldiphenylamine; 4,4′-dipentyldiphenylamine; 4,4′-dihexyldiphenylamine; 4,4′-diheptyldiphenylamine; 4,4′-dioctyldiphenylamine; dialkyldiphenylamines such as 4,4′-dinonyldiphenylamine, tetrabutyldiphenylamine; tetrahexyldiphenylamine; tetraoctyldiphenylamine; polyalkyl such as tetranonyldiphenylamine Diphenylamine type and naphthylamine type, specifically α-naphthylamine; phenyl-α-naphthylamine; and butylphenyl-α-naphth Triethanolamine; pentylphenyl -α- naphthylamine; hexylphenyl -α- naphthylamine; heptylphenyl -α- naphthylamine; octylphenyl -α- naphthylamine; and alkyl-substituted phenyl -α- naphthylamine, such as nonylphenyl -α- naphthylamine.
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 at least one of molybdenum trioxide and molybdic acid with an amine compound, for example, JP-A-2003-252887 The compound obtained by the production method described in 1. can be used.
Although it does not restrict | limit especially as an amine compound made to react with a 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, methylpropylamine and the like (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 Amines 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; alkylenes of these compounds Examples thereof include oxide adducts; and mixtures thereof.
Examples thereof include a sulfur-containing molybdenum complex of succinimide described in JP-B-3-22438 and JP-A-2004-2866.

Examples of sulfur-based antioxidants include phenothiazine, pentaerythritol-tetrakis- (3-laurylthiopropionate), didodecyl sulfide, dioctadecyl sulfide, didodecylthiodipropionate, dioctadecylthiodipropionate, dimyristyl. Examples thereof include thiodipropionate, dodecyl octadecyl thiodipropionate, and 2-mercaptobenzimidazole.
The blending amount of these antioxidants is preferably 0.1% by mass or more and 5% by mass or less, more preferably 0.1% by mass or more and 3% by mass or less, based on the total amount of the composition.

Antiwear or extreme pressure agents include zinc dithiophosphate, zinc phosphate, zinc dithiocarbamate, disulfides, sulfurized olefins, sulfurized fats and oils, sulfurized esters, thiocarbonates, thiocarbamates, polysulfides, etc. Containing compounds; phosphorous esters, phosphate esters, phosphonate esters, and phosphorus-containing compounds such as amine salts or metal salts thereof; thiophosphites, thiophosphates, thiophosphonates, And sulfur and phosphorus containing antiwear agents such as amine salts or metal salts thereof.
A preferable blending amount of the antiwear agent or extreme pressure agent is in the range of 0.1% by mass or more and 20% by mass or less based on the total amount of the composition.
In the case of a zinc-containing compound, it is preferably 600 ppm by mass or less, more preferably 500 ppm by mass or less, and still more preferably 400 ppm by mass or less in terms of zinc (based on the total amount of the composition). Moreover, in the case of a phosphorus containing compound, 500 mass ppm or less is preferable in phosphorus conversion (composition whole quantity basis), More preferably, it is 400 mass ppm or less, More preferably, it is 300 mass ppm or less. When the blending amount of zinc is 600 mass ppm or less and the blending amount of phosphorus is 500 mass ppm or less, there is a problem that even if this composition is used, the basic compound is consumed and the oil renewal period becomes extremely short. Does not occur.

As the friction reducing agent, any compound generally used as a friction reducing agent for lubricating oils can be used. For example, it has at least one alkyl group or alkenyl group having 6 to 30 carbon atoms in the molecule. Ashless friction reducing agents such as fatty acid esters, fatty acid amides, fatty acids, aliphatic alcohols, aliphatic amines, and aliphatic ethers.
The blending amount of the friction reducing agent is preferably 0.01% by mass or more and 2% by mass or less, more preferably 0.01% by mass or more and 1% by mass or less, based on the total amount of the composition.

Examples of the metal deactivator include benzotriazole, tolyltriazole, thiadiazole, and imidazole compounds.
The compounding amount of the metal deactivator is preferably 0.01% by mass or more and 3% by mass or less, more preferably 0.01% by mass or more and 1% by mass or less, based on the total amount of the composition.

Examples of the rust preventive agent include petroleum sulfonate, alkylbenzene sulfonate, dinonylnaphthalene sulfonate, alkenyl succinate, and polyhydric alcohol ester.
The blending amount of these rust preventives is preferably 0.01% by weight or more and 1% by weight or less, more preferably 0.05% by weight or more and 0.5% by weight, based on the total amount of the lubricating oil composition, from the viewpoint of blending effects. It is as follows.

Examples of the surfactant or demulsifier include polyalkylene glycol nonionic surfactants such as polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether and polyoxyethylene alkyl naphthyl ether.
The blending amount of the surfactant or the demulsifier is preferably 0.01% by mass or more and 3% by mass or less, more preferably 0.01% by mass or more and 1% by mass or less, based on the total amount of the composition.

Examples of the antifoaming agent include silicone oil, fluorosilicone oil, and fluoroalkyl ether, and 0.005% by mass or more and 0.5% by mass on the basis of the total amount of the composition from the viewpoint of balance of defoaming effect and economy. % Or less, more preferably 0.01% by mass or more and 0.2% by mass or less.

The present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.
The properties of the lubricating oil composition (sample oil) and various performances (thin film evaporation characteristics, motoring characteristics) in each example were determined by the following methods.

(1) Kinematic viscosity at 100 ° C. Measured according to the method described in JIS K2283. The kinematic viscosity at 100 ° C. was also measured for the mixed base oil.
(2) NOACK
The amount of evaporation loss was measured according to ASTM D 5800-08.
(3) CCS viscosity (cold cranking simulator viscosity)
The shear viscosity at −35 ° C. was measured according to JIS K2010.
(4) Viscosity index The viscosity index was calculated based on the method described in JIS K2283.
(5) Thin film evaporation characteristics 0.5 g of sample oil was dropped into an aluminum container having a diameter of 35 mm, placed in a hot air thermostat and held at 175 ° C. for 24 hours, and then the residual mass of the sample oil was measured to determine the evaporation rate. Calculated.
(6) Motoring characteristics (fuel economy)
The motoring test as shown below was conducted.
Using an in-line 4-cylinder, DOHC, 1500 cc engine, drive torque was measured under conditions of oil temperatures of 60 ° C., 80 ° C., and 100 ° C., rotation speeds of 1500 rpm, 2000 rpm, and 2500 rpm, and all data (9 ) Was used as the driving torque value of the sample oil. Then, commercially available ACEA C2 5W-30 (kinematic viscosity at 100 ° C .; 10.29 mm ² / s, NOACK; 14.3% by mass, CCS viscosity (−35 ° C.); 7700 mPa · s, viscosity index 172) is used as a reference oil. The driving torque value compared to the reference oil was used as the torque improvement rate, and the motoring characteristics (fuel economy) were evaluated according to the following criteria.
A: Superior to reference oil. (Torque improvement rate compared to standard oil: 1.5% or more)
B: Superior to reference oil. (Torque improvement rate compared to standard oil: less than 1.5%)
C: Inferior to the reference oil.

Among the base oils, mPAO described later was manufactured as follows.
<Production Example: Production of 1-decene oligomer (trimer) hydrogenated product>
(A) Oligomerization of decene A three-necked flask with an internal volume of 5 liters was charged with 4 liters (21.4 mol) of decene monomer (Idemitsu Kosan Co., Ltd .: Linearlen 10) under an inert gas stream. Methylalumoxane (Al conversion: 40 mmol) dissolved in toluene was added in the same manner as biscyclopentadienylzirconium dichloride (complex mass 1168 mg: 4 mmol) dissolved in toluene. These mixtures were kept at 40 ° C. and stirred for 20 hours, and then 20 ml of methanol was added to stop the oligomerization reaction. Next, the reaction mixture was taken out of the autoclave, 4 liters of a 5 mol / liter sodium hydroxide aqueous solution was added thereto, the mixture was forcedly stirred at room temperature for 4 hours, and then a liquid separation operation was performed. The upper organic layer was removed, and unreacted decene and side reaction product decene isomers were removed by stripping.
(B) Hydrogenation of decene oligomer Cobalt trisacetylacetonate (catalyst weight: 3.0 g) in which 3 liters of decene oligomer produced in (a) was placed in an autoclave with an internal volume of 5 liters under nitrogen flow and dissolved in toluene And triisobutylaluminum diluted with toluene (30 mmol) were added. After the addition, the inside of the system was replaced with hydrogen twice, and then the temperature was raised. The hydrogen pressure was maintained at 0.9 MPa at a reaction temperature of 80 ° C. Hydrogenation proceeded immediately with exotherm, the temperature was lowered at 4 hours after the start of the reaction, and the reaction was stopped. Then, after depressurizing and taking out the contents, the reaction product is subjected to simple distillation, and a fraction at a pressure of 530 Pa in the range of a distillation temperature from 240 ° C. to 270 ° C. (1-decene trimer hydrogenated product) ).

[Examples 1 to 4, Comparative Examples 1 to 4]
A lubricating oil composition (sample oil) having the composition shown in Table 1 was prepared using the following PAO, mineral oil, and additives. The properties of each sample oil and various performances are also shown in Table 1.
PAO-1: INEOS, Durasyn 125 (kinematic viscosity at 100 ° C .; 5.196 mm ² / s, NOACK; 5.5% by mass, CCS viscosity (−35 ° C.); 2490 mPa · s, viscosity index; 143)
PAO-2: manufactured by INEOS, Durasyn 145 (kinematic viscosity at 100 ° C .; 5.194 mm ² / s, NOACK; 5.1% by mass, CCS viscosity (−35 ° C.); 2570 mPa · s, viscosity index; 145)
PAO-3: mPAO obtained in the above production example (kinematic viscosity at 100 ° C .; 3.458 mm ² / s, NOACK; 11.1% by mass, CCS viscosity (−35 ° C.); 800 mPa · s, viscosity index; 127)

PAO-4: manufactured by INEOS, Durasyn 164 (kinematic viscosity at 100 ° C .; 3.893 mm ² / s, NOACK; 14.0% by mass, CCS viscosity (−35 ° C.); 1330 mPa · s, viscosity index; 120)
PAO-5: manufactured by INEOS, Durasyn 166 (kinematic viscosity at 100 ° C .; 5.824 mm ² / s, NOACK; 6.0% by mass, CCS viscosity (−35 ° C.); 3950 mPa · s, viscosity index; 178)
Mineral oil-1: hydrorefined mineral oil (kinematic viscosity at 100 ° C .; 4.121 mm ² / s, NOACK; 14.1% by mass, CCS viscosity (−35 ° C.); 1870 mPa · s, viscosity index; 122)
Mineral oil-2: hydrorefined mineral oil (kinematic viscosity at 100 ° C .; 6.483 mm ² / s, NOACK; 7.5 mass%, CCS viscosity (−35 ° C.); 10100 mPa · s, viscosity index; 121)

Additive package: Infineum P6000 manufactured by Infineum
Viscosity index improver: polymethacrylate (mass average molecular weight 230,000, resin content 45% by mass (the compounding amount in Table 1 is the total amount including the resin content))
Pour point depressant: polyalkyl methacrylate (mass average molecular weight 6,000)

〔Evaluation results〕
As shown in Table 1, since the sample oils of Examples 1 to 4 having all of the composition of the present composition are blended with PAO having a specific property and mineral oil having a specific property, the low-evaporation property is obtained. It can be understood that it has excellent coking resistance. Moreover, since it is low viscosity, it is excellent also in fuel-saving property. It is clear from the results of the motoring test that fuel efficiency is excellent. Therefore, the present composition is suitable not only for ordinary internal combustion engines but also for gasoline engines and diesel engines having a turbo mechanism.
On the other hand, since each sample oil of the comparative example does not contain a predetermined PAO, it cannot satisfy both low evaporation (coking resistance) and fuel economy.

Claims (7)

1. (A) a polyα-olefin having a kinematic viscosity at 100 ° C. of 5.5 mm ² / s or less, a CCS viscosity at −35 ° C. of 3000 mPa · s or less, and NOACK of 12% by mass or less;
   (B) blended with mineral oil having a viscosity index of 120 or more,
   The lubricating oil composition for an internal combustion engine, wherein the blending amount of the component (A) is 25% by mass or more based on the total amount of the composition.
2. The lubricating oil composition for an internal combustion engine according to claim 1,
   A lubricating oil composition for an internal combustion engine, wherein the base oil obtained by blending the component (A) and the component (B) has a kinematic viscosity at 100 ° C. of 4.6 mm ² / s or less.
3. In the lubricating oil composition for internal combustion engines according to claim 1 or 2,
   A lubricating oil composition for an internal combustion engine, wherein the composition has a NOACK of 10% by mass or less and a CCS viscosity at −35 ° C. of 6000 mPa · s or less.
4. In the lubricating oil composition for internal combustion engines according to any one of claims 1 to 3,
   The lubricating oil composition for an internal combustion engine, wherein the blending amount of the component (B) is 20% by mass or more based on the total amount of the composition.
5. In the lubricating oil composition for an internal combustion engine according to any one of claims 1 to 4,
   The lubricating oil composition for an internal combustion engine, wherein the component (A) is polymerized with a metallocene catalyst.
6. In the lubricating oil composition for an internal combustion engine according to any one of claims 1 to 5,
   A lubricating oil composition for an internal combustion engine, wherein the component (A) is a poly α-olefin having at least one selected from α-olefins having 10 to 14 carbon atoms as a monomer.
7. The lubricating oil composition for an internal combustion engine according to any one of claims 1 to 6,
   The lubricating oil composition for an internal combustion engine, wherein the component (A) is a trimer.