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DESCRIPTION
LUBRICANT COMPOSITION FOR INTERNAL COMBUSTION ENGINE OIL
TECHNICAL FIELD
[0001]
The present invention relates to a lubricating oil composition
for internal combustion engines which can exhibit a good wear
resistance for aluminum materials even when reducing a phosphorus
content and a content of ametal component derived fromametal-based
detergent in the composition.
BACKGROUND ART
[0002]
In recent years, for the purpose of reducing environmental
burdens, strict regulations against exhaust gases have been
successively introduced in automobile industries. The exhaust
gases contain, in addition to carbon dioxide (CO2) as a global
worming substance, various harmful substances such as particular
matters (PM) , hydrocarbons (HC) , carbon monoxide (CO) and nitrogen
oxides (NO) . Among these substances, very strict regulation
values have been imposed on PM and NO. As the measure for reducing
an amount of these substances discharged, gasoline automobiles
are provided with a three-way catalyst, whereas diesel automobiles
are provided with a diesel particulate filter (DPF) . The exhaust
gases are cleaned by passing through these members, and then
discharged into atmospheric air.
It has recently reported that active sites of the three-way
catalyst tend to be poisoned with phosphorus components in engine
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oils to thereby cause deterioration in a catalyst performance
thereof, and ashes derived from metal components are deposited
on DPF to thereby reduce a service life of DPF. At present, in
ILSAC Standard and JASO Standard as standards for engine oils,
the upper limits of the phosphorus content and ash content in the
engine oils have been established, and the engine oils having less
contents of these substances have now been developed.
[0003]
On the other hand, from the viewpoint of improving a fuel
consumption, parts of an engine or a transmission are formed of
a nonferrous metal material for reducing a weight thereof. Of
the nonferrous metal materials, an aluminum alloy, in particular,
an Al-Si alloy, has been frequently employed. However, the
conventional engine oils contain anti-wear agents such as zinc
dithiophosphate (ZnDTP) which are intended to mainly cause a
reaction for forming a coating film on Fe. Therefore, there is
such a fear that the oils are deteriorated in wear resistance for
aluminum materials such as Al-Si alloy.
In consequence, intense studies have been made to provide
good anti-wear agents for aluminum materials (for example, refer
to Patent Document 1) . However, these anti-wear agents have failed
to exhibit a sufficient effect unless they are used in combination
with ZnDTP having a large phosphorus content. Therefore, there
still remains such a problem that the conventional engine oils
have an adverse influence on an exhaust gas post-treatment device.
Thus, there is a strong demand for a lubricating oil
composition for internal combustion engines which can exhibit an
excellent wear resistance for aluminum materials even with a
reduced phosphorus content or without any phosphorus content
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therein.
PRIOR ART DOCUMENTS
PATENT DOCUMENTS
[0004]
Patent Document 1: JP 2010-528155A
SUMMARY OF THE INVENTION
PROBLEMS TO BE SOLVED BY THE INVENTION
[0005]
Under the aforementioned circumstances, an object of the
present invention is to provide a lubricating oil composition for
internal combustion engines which is excellent in wear resistance
for aluminum materials and can be considerably reduced in content
of ZnDTP having a large phosphorus content or a metallic detergent
while maintaining a good wear resistance for aluminum materials.
MEANS FOR SOLVING THE PROBLEMS
[0006]
As a result of intense and extensive researches for developing
the above desirable lubricating oil composition for internal
combustion engines, the present inventors have found that when
controlling a nitrogen content and a boron content derived from
an imide-based dispersant and a boronated imide-based dispersant
in the composition, the above object can be achieved. The present
invention has been accomplished on the basis of the above finding.
[0007]
Thus, the present invention relates to the following aspects.
1. A lubricating oil composition for internal combustion engines,
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including a boronated imide-based dispersant, or the boronated
imide-based dispersant and a non-boronated imide-based dispersant,
in which a boron content (B % by mass) derived from the boronated
imide-based dispersant and a nitrogen content (N % by mass ) derived
from the boronated imide-based dispersant or derived from the
boronated imide-based dispersant and the non-boronated
imide-based dispersant satisfy the following formula (I):
N B + 0.05 (I);
and a phosphorus content (P % by mass) and a content of a metal
component (M % by mass) derived from a metallic detergent on the
basis of a total amount of the composition satisfy any of the
following requirements A to C:
A: P < 0.03 and M < 0.05;
B: P < 0.03 and 0.05 M 0.12; and
C: 0.03 P 0.06 and M < 0.05.
2. The lubricating oil composition for internal combustion engines
as described in the above aspect 1, wherein the boron content (B %
by mass) derived from the boronated imide-based dispersant and
the nitrogen content (N % by mass) derived from the boronated
imide-based dispersant or derived from the boronated imide-based
dispersant and the non-boronated imide-based dispersant satisfy
the following formula (II):
N B + 0.1 (II).
3. The lubricating oil composition for internal combustion engines
as described in the above aspect 1 or 2, further including a
sulfur-based anti-wear agent.
4. The lubricating oil composition for internal combustion engines
as described in the above aspect 3, wherein the sulfur-based
anti-wear agent is a disulfide compound represented by the
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1
following general formula (3):
R100C-A1-S2-A2-000R2 (3)
wherein R1 and R2 are each independently a hydrocarbon group having
1 to 30 carbon atoms which may contain an oxygen atom, a sulfur
atom or a nitrogen atom; and A1 and A2 are each independently a
divalent hydrocarbon group having 1 to 12 carbon atoms.
EFFECT OF THE INVENTION
[0008]
In accordance with the present invention, it is possible to
provide a lubricating oil composition for internal combustion
engines which is excellent in wear resistance for aluminum
materials and can be considerably reduced in content of ZnDTP having
a large phosphorus content or a metallic detergent while
maintaining a good wear resistance for aluminum materials.
Therefore, it is also possible to provide a lubricating oil
composition for internal combustion engines which is capable of
reducing an adverse influence on an exhaust gas post-treatment
device while maintaining a good wear resistance for aluminum
materials.
EMBODIMENTS FOR CARRYING OUT THE INVENTION
[0009]
The present invention relates to a lubricating oil composition
for internal combustion engines, including a boronated imide-based
dispersant, or the boronated imide-based dispersant and a
non-boronated imide-based dispersant, in which a boron content
(B % by mass) derived from the boronated imide-based dispersant,
and a nitrogen content (N % by mass) derived from the boronated
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imide-based dispersant or derived from the boronatedimide-based
dispersant and the non-boronated imide-based dispersant satisfy
the following formula (I):
N B + 0.05 (I).
[0010]
The composition capable of satisfying the above formula (I)
can be enhanced in wear resistance. In addition, the composition
capable of satisfying the following formula (II):
N B + 0.1 (II)
can be further enhanced in the above effect.
[0011]
As described above, in the present invention, the boronated
imide-based dispersant is used, if required, in combination with
the non-boronated imide-based dispersant.
The non-boronated imide-based dispersant is usually referred
to merely as an imide-based dispersant. As the non-boronated
Lmide-based dispersant, there may be suitably used polybutenyl
succinic acid imides. The polybutenyl succinic acid imides
include compounds represented by the following general formulae
(1) and (2).
[0012]
0
Pi13 0 y./ePIB
N-(CH2CH2NH ___________________________ CH2CH2N ( 1)
n-1
0 0
[0013]
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o
PIB\c_<
N--(CH2CH2NH)-H ( 2)
0
[0014]
In these general formulae , PIB represents a polybutenyl group .
The number-average molecular weight of PIB is usually from 800
to 3500 and preferably from 900 to 2000. When the number-average
molecular weight of PIB is 800 or more, there is no fear that the
resulting composition is deteriorated in dispersibility. When
the number-average molecular weight of PIB is 3500 or less, there
is no fear that the resulting composition is deteriorated in storage
stability.
Also, in the above general formulae (1) and (2), n is usually
an integer of from 1 to 5 and preferably from 2 to 4. When n lies
within the above-specified range, there is no fear that the
resulting composition is deteriorated in dispersibility.
[0015]
The method for producing the above polybutenyl succinic acid
imides is not particularly limited, and the polybutenyl succinic
acid imides may be produced by any known methods. For example,
polybutene and maleic anhydride are reacted with each other at
a temperature of from 100 to 200 C to obtain polybutenyl succinic
acid, and then the thus obtained polybutenyl succinic acid is
reacted with a polyamine such as diethylenetriamine,
triethylenetetramine, tetraethylenepentamine and
pentaethylenehexamine to obtain the polybutenyl succinic acid
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imides.
[0016]
On the other hand, as the preferred boronated imide-based
dispersant used in the present invention, there may be mentioned
those boronated polybutenyl succinic acid imides obtained by
reacting the above non-boronated imide-based dispersant
represented by the above general formula (1) or (2) with a boron
compound.
[0017]
Examples of the boron compound include boric acid, a boric
acid salt and a boric acid ester. Specific examples of the boric
acid include orthoboric acid, metaboric acid and paraboric acid.
Suitable examples of the boric acid salt include ammonium salts,
e.g., ammonium borates such as ammonium metaborate, ammonium
tetraborate, ammonium pentaborate and ammonium octaborate.
Suitable examples of the boric acid ester include esters of boric
acid and an alkyl alcohol (preferably having 1 to 6 carbon atoms),
for example, monomethyl borate, dimethyl borate, trimethyl borate,
monoethyl borate, diethyl borate, triethyl borate, monopropyl
borate, dipropyl borate, tripropyl borate, monobutyl borate,
dibutyl borate and tributyl borate.
The mass ratio of the boron content B to the nitrogen content
N (B/N) in the boronated polybutenyl succinic acid imides is
preferably from 0.1 to 3 and more preferably from 0.2 to 2.
[0018]
Meanwhile, in the lubricating oil composition for internal
combustion engines according to the present invention, the contents
of the above boronated succinic acid imide-based dispersant and
non-boronated succinic acid imide-based dispersant (imide-based
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dispersant) are not particularly limited as long as they can satisfy
the above formula (I), and are each preferably from 0.1 to 15%
by mass and more preferably from 0.5 to 10% by mass. When the
content of each of the dispersants is 0.1% by mass or more, the
resulting composition can exhibit a good detergency and a good
dispersibility. When the content of each of the dispersants is
15% by mass or less , the resulting composition can exhibit an effect
of enhancing a detergency and a dispersibility thereof
corresponding to the increased content.
[0019]
In the lubricating oil composition for internal combustion
engines according to the present invention, it is further required
that a phosphorus content (P % by mass) and a content of a metal
component (M % by mass) derived from a metallic detergent satisfy
any of the following requirements A to C. The respective cases
where the requirements A to C are satisfied are described below.
[Case A]
In the case A, the following requirement is satisfied:
P < 0.03 and M < 0.05.
That is, the phosphorus content in the lubricating oil
composition is less than 0.03% by mass on the basis of a total
amount of the composition, whereas the content of the metal
component derived from the metallic detergent in the lubricating
oil composition is less than 0.05% by mass on the basis of a total
amount of the composition.
When the phosphorus content in the composition is less than
0.03% by mass, poisoning of active sites of a three-way catalyst
can be suppressed, so that a service life of the catalyst can be
extended. Therefore, the phosphorus content in the composition
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is preferably 0.01% by mass or less, more preferably 0.005% by
mass or less and still more preferably 0.001% by mass or less.
Also, when the content of the metal component derived from
the metal-based detergent in the composition is less than 0.05%
by mass, deposition of ashes derived from the metal component on
DPF can be suppressed, so that a service life of DPF can be extended .
Therefore, the content of the metal component in the composition
is preferably 0.01% by mass or less, more preferably 0.005% by
mass or less and still more preferably 0.001% by mass or less.
[0020]
In order to reduce the phosphorus content in the composition
to less than 0.03% by mass, it is required that the amount of a
phosphorus-containing anti-wear agent compounded in the
composition is reduced, or the composition is free from such an
anti-wear agent. Therefore, zinc dithiophosphate (ZnDTP)
extensively used as an extremely excellent anti-wear agent in
conventional lubricating oils for internal combustion engines must
be restricted or prohibited frombeing included in the composition.
In addition, in order to control the content of the metal
component derived from the metallic detergent in the composition
to less than 0.05% by mass, the metallic detergent must also be
restricted or prohibited from being included in the composition.
[0021]
[Case B]
In the case B, the following requirement is satisfied:
P < 0.03 and 0.05 M 0.12.
That is, the phosphorus content in the lubricating oil
composition is less than 0.03% by mass on the basis of a total
amount of the composition, whereas the content of the metal
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component derived from the metallic detergent in the lubricating
oil composition is not less than 0.05% by mass and not more than
0.12% by mass on the basis of a total amount of the composition.
When the phosphorus content in the composition is less than
0.03% by mass, poisoning of active sites of a three-way catalyst
can be suppressed, so that a service life of the catalyst can be
extended. Therefore, the phosphorus content in the composition
is preferably 0.01% by mass or less, more preferably 0.005% by
mass or less and still more preferably 0.001% by mass or less.
In order to reduce the phosphorus content in the composition
to less than 0.03% by mass, it is required that the amount of a
phosphorus-containing anti-wear agent compounded in the
composition is reduced, or the composition is free from such an
anti-wear agent. Therefore, zinc dithiophosphate (ZnDTP)
extensively used as an extremely excellent anti-wear agent in
conventional lubricating oils for internal combustion engines must
be restricted or prohibited from being included in the composition.
[0022]
In addition, when the content of the metal component derived
from the metallic detergent in the composition is not less than
0.05% by mass, the resulting composition can be further enhanced
in detergency as required for lubricating oils for internal
combustion engines. On the other hand, when the content of the
metal component derived from the metallic detergent in the
composition is not more than 0.12% by mass or less, deposition
of ashes derived from the metal component on DPF can be suppressed,
so that a service life of DPF can be extended. Therefore, the
content of the metal component in the composition is preferably
not less than 0.05% by mass and not more than 0.10% by mass, and
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=
more preferably not less than 0.05% and not more than 0.08% by
mass.
Suitable examples of the metallic detergent from which the
metal component is derived include sulfonates, phenates,
salicylates and naphthenates of alkali metals (such as Na and
K) and alkali earth metals (such as Ca, Mg and Ba). Among these
metallic detergents, preferred are Ca sulfonate, Ca phenate and
Ca salicylate. The base number of these metallic detergents is
preferably from 0 to 500 mg KOH/g, more preferably from 150 to
400 mg KOH/g and still more preferably from 200 to 350 mg KOH/g
as measured by a perchloric acid method.
The metallic detergents may be used alone or in combination
of any two or more thereof.
The content of the metallic detergent in the composition may
be appropriately selected so as to adjust the content of the metal
component derived from the metallic detergent in the composition
to the above-specified range.
[0023]
[Case C]
In the case C, the following requirement is satisfied:
0.03 P 0.06 and M < 0.05.
That is, the phosphorus content in the lubricating oil
composition is not less than 0.03% by mass and not more than 0.06%
by mass on the basis of a total amount of the composition, whereas
the content of the metal component derived from the metallic
detergent in the lubricating oil composition is less than 0.05%
by mass on the basis of a total amount of the composition.
When the phosphorus content in the composition is not less
than 0.03% by mass, the resulting composition can be further
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enhanced in wear resistance . On the other hand, when the phosphorus
content in the composition is not more than 0 . 0 6% by mass , poisoning
of active sites of a three-way catalyst can be suppressed, so that
a service life of the catalyst can be extended. Therefore, the
phosphorus content in the composition is preferably not less than
0.03% by mass and not more than 0.05% by mass.
The above phosphorus content may be controlled by adjusting
an amount of the phosphorus-based anti-wear agent compounded in
the composition. Typical examples of the phosphorus-based
anti-wear agent include dithiophosphoric acid metal salts such
as zinc dithiophosphate (ZnDTP) and molybdenum dithiophosphate
(MoDTP); phosphoric acid esters or phosphorous acid esters (such
as organic phosphoric acid esters , organic phosphorous acid esters ,
alkyl or aryl acid phosphates, alkyl or aryl hydrogen phosphites
and amine salts of these compounds); thiophosphoric acid esters;
and thiophosphorous acid esters. Among these phosphorus-based
anti-wear agents, preferred is zinc dithiophosphate, i.e., zinc
dihydrocarbyl dithiophosphate (in which the hydrocarbyl group is
an alkyl group preferably having 1 to 18 carbon atoms and more
preferably 2 to 12 carbon atoms, an alkenyl group, an arylalkyl
group or an alkaryl group), and more preferred are zinc dialkyl
dithiophosphates containing a secondary alkyl group having 3 to
8 carbon atoms.
[0024]
On the other hand, when the content of the metal component
derived from the metallic detergent in the composition is less
than 0.05% by mass, deposition of ashes derived from the metal
component on DPF can be suppressed, so that a service life of DPF
can be extended. Therefore, the content of the metal component
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in the composition is preferably 0.01% by mass or less, more
preferably 0.005% by mass or less and still more preferably 0.001%
by mass or less.
[0025]
The lubricating oil composition for internal combustion
engines according to the present invention preferably further
contains a sulfur-based anti-wear agent. Preferred examples of
the sulfur-based anti-wear agent include those phosphorus-free
sulfur-based anti-wear agents such as sulfurized oils and fats,
sulfurized fatty acids, sulfurized esters, sulfurized olefins and
dihydrocarbyl polysulfides . Among these sulfur-based anti-wear
agents, more preferred are disulfide compounds represented by the
following general formula (3) :
R]-000-A1-S2-A2-000R2 (3)
wherein RI- and R2 are each independently a hydrocarbon group having
1 to 30 carbon atoms which may contain an oxygen atom, a sulfur
atom or a nitrogen atom; and A1 and A2 are each independently a
divalent hydrocarbon group having 1 to 12 carbon atoms.
[0026]
Specific examples of the sulfur-containing compound
represented by the above general formula (3) include
bis (methoxycarbonylmethyl) disulfide,
bis (ethoxycarbonylmethyl) disulfide,
bis (n-propoxycarbonylmethyl) disulfide,
bis (isopropoxycarbonylmethyl) disulfide,
bis (n-butoxycarbonylmethyl) disulfide,
bis (n-octoxycarbonylmethyl) disulfide,
bis (n-dodecyloxycarbonylmethyl) disulfide,
bis ( cyclopropoxycarbonylmethyl) disulfide,
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1,1-bis(1-methoxycarbonylethyl)disulfide,
1,1-bis(1-methoxycarbonyl-n-propyl)disulfide,
1,1-bis(1-methoxycarbonyl-n-butyl)disulfide,
1,1-bis(1-methoxycarbonyl-n-hexyl)disulfide,
1,1-bis(1-methoxycarbonyl-n-octyl)disulfide,
1,1-bis(1-methoxycarbonyl-n-dodecyl)disulfide,
2,2-bis(2-methoxycarbonyl-n-propyl)disulfide,
a,a-bis(a-methoxycarbonylbenzyl)disulfide,
1,1-bis(2-methoxycarbonylethyl)disulfide,
1,1-bis(2-ethoxycarbonylethyl)disulfide,
1,1-bis(2-n-propoxycarbonylethyl)disulfide,
1,1-bis(2-isopropoxycarbonylethyl)disulfide,
1,1-bis(2-cyclopropoxycarbonylethyl)disulfide,
1,1-bis(2-methoxycarbonyl-n-propyl)disulfide,
1,1-bis(2-methoxycarbonyl-n-butyl)disulfide,
1,1-bis(2-methoxycarbonyl-n-hexyl)disulfide,
1,1-bis(3-methoxycarbonyl-n-propyl)disulfide,
2,2-bis(3-methoxycarbonyl-n-pentyl)disulfide and
1,1-bis(2-methoxycarbony1-1-phenylethyl)disulfide.
[0027]
The content of the sulfur-based anti-wear agent in the
composition is preferably from 0 . 05 to 5% bymass andmore preferably
from 0. 1 to 3% bymass on the basis of a total amount of the composition.
When the content of the sulfur-based anti-wear agent in the
composition is 0.05% by mass or more, the resulting composition
can exhibit a sufficient wear resistance. When the content of
the sulfur-based anti-wear agent in the composition is 5% by mass
or less, the resulting composition is free from occurrence of
corrosion.
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[0028]
The lubricating oil composition according to the present
invention may further contain other additives used in
conventionally known lubricating oil compositions such as
lubricating oils for internal combustion engines unless they give
any adverse influence on the conditions of the phosphorus content
and the content of the metal component as required in the present
invention. Examples of the other additives include the other
friction reducing agent, a viscosity index improver, a pour point
depressant, an antioxidant and a rust inhibitor.
Specific examples of the other friction reducing agent include
ash-free friction reducing agents such as fatty acid ester-based
compounds, fatty amine-based compounds and higher alcohol-based
compounds.
[0029]
Examples of the viscosity index improver include so-called
non-dispersed type viscosity index improvers such as copolymers
of various methacrylic acid esters or an optional combination of
the methacrylic acid esters and hydrogenated products thereof,
and so-called dispersed type viscosity index improvers such as
copolymers obtained by further copolymerizing various nitrogen
compound-containing methacrylic acid esters with the above
compounds.
Further examples of the viscosity index improver include
non-dispersed type or dispersed type ethylene-a-olefin copolymers
( in which the a-olefin include, for example, propylene, 1-butene,
1-pentene, etc.) and hydrogenated products thereof,
polyisobutylene and hydrogenated products thereof, hydrogenated
styrene-diene copolymers, styrene-maleic anhydride ester
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copolymers and polyalkyl styrenes. The molecular weight
(number-average molecular weight) of these viscosity index
improvers is, for example, as follows. The number-average
molecular weight of the dispersed type or non-dispersed type
polymethacrylates is from 5000 to 1000000 and preferably from
100000 to 800000. The number-average molecular weight of the
polyisobutylene and hydrogenated products thereof is from 800 to
5000. The number-average molecular weight of the ethylene-a-olefin
copolymers and hydrogenated products thereof is from 800 to 300000
and preferably from 10000 to 200000.
[0030]
Examples of the antioxidant include phenol-based
antioxidants and amine-based antioxidants. Examples of the
phenol-based antioxidants
include 4,4'-methylene
bis(2,6-di-t-butyl phenol); 4,4'-bis(2,6-di-t-butyl phenol);
4,4'-bis(2-methyl-6-t-butyl phenol); 2,2'-
methylene
bis(4-ethyl-6-t-butyl phenol); 2,2'-
methylene
bis(4-methy1-6-t-butyl phenol); 4,4'-
butylidene
bis(3-methy1-6-t-butyl phenol); 4,4'-
isopropylidene
bis (2, 6-di-t-butyl phenol) ; 2, 2 ' -methylene bis (4-methy1-6-nonyl
phenol); 2,2'-isobutylidene
bis(4,6-dimethyl phenol);
2,2'-methylene bis(4-methyl-6-cyclohexyl
phenol);
2,6-di-t-buty1-4-methyl phenol; 2,6-di-t-buty1-4-ethyl phenol;
2,4-dimethy1-6-t-butyl phenol; 2,6-
di-t-amyl-p-cresol;
2,6-di-t-buty1-4-(N,W-dimethylaminomethyl phenol);
4,4'-thiobis(2-methy1-6-t-butyl
phenol);
4,4'-thiobis(3-methy1-6-t-butyl
phenol);
2,2'-thiobis(4-methyl-6-t-butyl
phenol);
bis(3-methy1-4-hydroxy-5-t-butyl
benzyl)sulfide;
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=
bis(3,5-di-t-buty1-4-hydroxybenzyl)sulfide;
n-octadecy1-3-(4-hydroxy-3,5-di-t-butylphenyl)propionate; and
2,2'-thio[diethyl-bis-3-(3,5-di-t-buty1-4-hydroxyphenyl)propi
nate]. Among these phenol-based antioxidants, especially
preferred are bisphenol-based antioxidants and ester
group-containing phenol-based antioxidants.
[0031]
Examples of the amine-based antioxidants include monoalkyl
diphenyl amine-based antioxidants such as monooctyl diphenyl amine
and monononyl diphenyl amine; dialkyl diphenyl amine-based
antioxidants such as 4,4'-dibutyl diphenyl amine, 4,4'-dipentyl
diphenyl amine, 4,4'-dihexyl diphenyl amine, 4,4'-diheptyl
diphenyl amine, 4,4'-dioctyl diphenyl amine and 4,4'-dinonyl
diphenyl amine; polyalkyl diphenyl amine-based antioxidants such
as tetrabutyl diphenyl amine, tetrahexyl diphenyl amine,
tetraoctyl diphenyl amine and tetranonyl diphenyl amine; and
naphtyl amine-based antioxidants. Specific examples of the
naphtyl amine-based antioxidants include a-naphtyl amine;
phenyl-a-naphtyl amine; and alkyl-substituted phenyl-a-naphtyl
amines such as butyl phenyl-a-naphtyl amine, pentyl
phenyl-a-naphtyl amine, hexyl phenyl-a-naphtyl amine, heptyl
phenyl-a-naphtyl amine, octyl phenyl-a-naphtyl amine and nonyl
phenyl-a-naphtyl amine. Among these amine-based antioxidants,
preferred are dialkyl diphenyl amine-based antioxidants and
naphtyl amine-based antioxidants.
These antioxidants may be used alone or in combination of
any two or more thereof. In particular, it is preferred that one
or more kinds of the phenol-based antioxidants are used in
combination with one or more kinds of the amine-based antioxidants.
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=
[0032]
Examples of the rust inhibitor include alkyl benzene
sulfonates, dinonyl naphthalene sulfonate, alkenyl succinic acid
esters and polyhydric alcohol esters.
The amounts of the above other additives compounded in the
composition may be appropriately selected from an ordinary
practical range.
[0033]
The lubricating oil composition having such a performance
as aimed by the present invention can be obtained by compounding
the various additives mentioned above in a base oil for lubricants
(hereinafter occasionally referred to merely as a "base oil") .
The base oil used in the present invention is not particularly
limited, and may be appropriately selected from conventionally
known mineral base oils (hereinafter also referred to merely as
"mineral oils") and conventionally known synthetic base oils
(hereinafter also referred to merely as "synthetic oils") .
Examples of the mineral oils include distilled oils obtained
by subjecting a paraffin base crude oil, an intermediate base crude
oil or a naphthene base crude oil to atmospheric distillation,
or subjecting a residue oil obtained from the atmospheric
distillation to distillation under reduced pressure, and refined
oils obtained by subjecting these oils to ordinary purification
treatments. Specific examples of the refined oils include
solvent-refined oils, hydrogenation refined oils, hydrocracked
oils, dewaxed oils and clay-treated oils as well as isomerized
oils of waxes (such as slack wax) .
Examples of the synthetic oils include poly-a-olefins such
as a-olefin oligomers having 8 to 14 carbon atoms, polybutene,
- 19 -
CA 02843554 2014-01-29
polyol esters and alkyl benzenes.
In the present invention, as the base oil, the above mineral
oils may be used alone or in combination of any two or more thereof.
Also, the above synthetic oils may be used alone or in combination
of any two or more thereof. Further, one or more kinds of the
mineral oils may be used in combination with one or more kinds
of the synthetic oils.
In addition, the content of the base oil in the composition
is preferably 70% by mass or more, and more preferably 80% by mass
or more.
[0034]
The kinematic viscosity of the base oil as measured at 100 C
is preferably in the range of from 1.5 to 50 mm2/5, more preferably
from 3 to 30 mm2/5 and still more preferably from 3 to 15 mm2/s.
When the kinematic viscosity of the base oil as measured at 100 C
is 1.5 mm2/s or more, the resulting lubricating oil composition
hardly suffers from evaporation loss. When the kinematic
viscosity of the base oil as measured at 100 C is 50 mm2/s or less,
power loss owing to a viscosity resistance of the resulting
lubricating oil composition can be suppressed, so that the
composition can exhibit a good effect of improving a fuel
consumption.
In addition, the viscosity index of the base oil is preferably
80 or more, more preferably 90 or more, and still more preferably
100 or more. The base oil having a viscosity index of 80 or more
has a less change in viscosity depending upon temperature and
therefore can exhibit a stable lubricating performance.
[0035]
Also, the base oil preferably has a sulfur content of 50 ppm
- 20 -
CA 02843554 2014-01-29
by mass or less as measured according to JIS K 2541. When the
sulfur content of the base oil is 50 ppmbymass or less , the resulting
lubricating oil composition can exhibit an effect of enhancing
a wear resistance of a low-friction slide material. The sulfur
content of the base oil is more preferably 30 ppm by mass or less
and still more preferably 20 ppm by mass or less.
Further, the base oil preferably has a %CA value of 3.0 or
less as measured by ring analysis from the viewpoint of a good
stability of the resulting lubricating oil composition. The %CA
value according to ring analysis as used herein means a proportion
(percentage) of an aromatic component in the base oil which is
calculated by a ring analysis n-d-M method. When the %CA value
of the base oil is 3.0 or less, the resulting lubricating oil
composition can exhibit a good oxidation stability. The %CA value
of the base oil is more preferably 1.0 or less and more preferably
0.5 or less.
EXAMPLES
[0036]
The present invention will be described in more detail by
referring to the following examples, etc. However, it should be
noted that these examples are only illustrative and not intended
to limit the invention thereto.
Meanwhile, the formulations and performance of the
lubricating oil composition for internal combustion engines
(hereinafter also referred to merely as a "lubricating oil
composition") were measured by the following methods.
<Formulations of Lubricating Oil Composition>
1. Quantitative Determination of Boron, Phosphorus and Calcium
-21-
CA 02843554 2014-01-29
Measured according to ASTM D5185.
2. Quantitative Determination of Nitrogen
Measured according to JIS K2609.
3. Sulfur Content
Measured according to JIS K2541.
<Performance of Lubricating Oil Composition>
4. Evaluation of Wear Resistance
Using an SRV friction tester (reciprocating type friction
tester), a cylinder and a disk as test specimens were subjected
to friction test under the following conditions to measure a size
of wear scar generated on the cylinder.
Testing Conditions
-Test specimens: Cylinder (standard material: SUJ2); disk
(Si-containing aluminum: AA (Aluminum Association of America)
Standard "A390")
.Test temperature: 130 C
.Load: 200 N
.Amplitude: 3.0 mm
.Frequency: 20 Hz
-Test time: 1 h
[0037]
Examples Al to A10 and Comparative Examples Al to A8
The lubricating oil compositions having formulations as shown
in Tables 1 and 2 were prepared and subjected to measurement of
a wear resistance. The results are shown in Tables 1 and 2.
[0038]
The respective components used for preparing the lubricating
oil compositions are as follows.
(1) Base oil 1: Hydrogenation refined mineral oil (100 N); 40 C
- 22-
CA 02843554 2014-01-29
=
kinematic viscosity: 21.0 mm2/s; 1000C kinematic viscosity: 4.5
ITIM2/S; viscosity index: 127; sulfur content: less than 5 ppm by
mass
(2) Boronated imide 1: Boronated polybutenyl succinic acid
monoimide; number-average molecular weight of polybutenyl group:
950; base number (perchloric acid method) : 30 . 6 mg KOH/g; nitrogen
content: 1.8% by mass; boron content: 2.1% by mass
(3) Boronated imide 2: Boronated polybutenyl succinic acid
bisimide; number-average molecular weight of polybutenyl group:
950; base number (perchloric acid method): 25 mg KOH/g; nitrogen
content: 1.2% by mass; boron content: 1.3% by mass
(4) Non-boronated imide 1: Polybutenyl succinic acid monoimide;
number-average molecular weight of polybutenyl group: 950; base
number (perchloric acid method): 44 mg KOH/g; nitrogen content:
2.1% by mass
(5) Non-boronated imide 2: Polybutenyl succinic acid bisimide;
number-average molecular weight of polybutenyl group: 1300; base
number (perchloric acid method) : 11. 9 mg KOH/g; nitrogen content:
1.0% by mass
(6) Sulfur-based anti-wear agent:
Bis (n-octoxycarbonylmethyl) disulfide; sulfur content: 158 ppmby
mass
(7) Metal-based detergent : Ca salicylate; base number (perchloric
acid method): 270 mg KOH/g
(8) Phosphorus-based anti-wear agent: Zinc dithioalkyl
dithiophosphate; Zn content: 9.0% by mass; phosphorus content:
8.0% by mass; sulfur content: 17.1% by mass; alkyl group: mixture
of a secondary butyl group and a secondary hexyl group
(9) Other additives: Mixture of an antioxidant (phenol-based
- 23 -
CA 02843554 2014-01-29
=
antioxidant and amine-based antioxidant), a metal deactivator
(alkyl benzotriazole) and a defoaming agent (silicone-based
compound).
- 24 -
[0039]
TABLE 1
Examples
A1 A2 A3 A4 A5 A6 A7 A8 A9 A10
Amounts compounded (% by mass)
Base oil bal." bal." bal." bal." bal." bal."
bal." bal." bal." bal."
Boronated imide 1 7.0 - 7.0 2.0 -
- 2.0 5.0 - -
Boronated imide 2 - 4.0 4.0 - 4.0
6.0 6.0 6.0 4.0 4.0
Non-boronated imide 1 2.0 - - 7.0 2.0
2.0 2.0 2.0 - - n
H
Non-boronated imide 2 2.0 5.0 5.0 7.0 7.0
7.0 7.0 7.0 5.0 5.0 0
Sulfur-based extreme pressure agent 1.0 1.0 1.0 1.0 1.0
1.0 1.0 1.0 1.0 1.0 1.)
co
a,
Metallic detergent - - - - -
- - -
ul
Phosphorus-based anti-wear agent - - - - -
- - - 0.3 - ul
a,
Other additives 2.4 2.4 2.4 2.4 2.4
2.4 2.4 2.4 2.4 2.4 1.)
0
Formulations of composition (% by
H
.P
I
mass)
. 0
H
N content: derived from a
dispersant 0.20 0.11 0.25 0.25 0.17 0.20 0.24 0.30
0.11 0.11 1
I.)
-
ko
B content: derived from a
dispersant 0.14 0.05 0.19 0.04 0.05 0.08 0.12 0.18
0.05 0.05
.,
P content 0 0 0 0
0 0 0 0 0.02 0 '
-
Metal content: derived from a 0 0 0 0 0
0 0 0 0 0.04
metallic detergent
S content 0.21 0.21 0.21 0.21
0.21 0.21 0.21 0.21 0.25 0.21
Evaluation results
SRV test: width of wear on cylinder
0.452 0.433 0.472 0.356 0.361 0.322 0.318 0.381 0.411 0.460
(mm)
Note bal. *1: Balance
-25-
,
[0040]
TABLE 2
Comparative Examples
Al A2 A3 A4 A5 A6 A7 A8
Amounts compounded (% by mass)
- * *1 ari
*1
Base oil bal.1 bal.-*I
bal. bal. bal. bal. bal. bal.
Boronated imide 1 - - - 4.0
8.0 - - -
Boronated imide 2 - - 4.0 -
- 4.0 4.0 4.0
Non-boronated imide 1 2.0 2.0 - 2.0
2.0 - - - n
..
Non-boronated imide 2 - 7.0 - -
- - - - 0
Sulfur-basedextremepressureagent 1.0 1.0 1.0 1.0
1.0 1.0 1.0 1.0 I.)
co
a,
Metallic detergent - - - -
- - -
in
Phosphorus-based anti-wear agent - - - -
- 0.4 0.3 - in
a,
Other additives 2.4 2.4 2.4 2.4
2.4 2.4 2.4 2.4 N)
0
H
Formulations of composition (% by
I
mass)
=, 0
H
Ncontent:derivedfromadispersant 0.04 0.11 0.06 0.12 0.20 0.06 0.06 0.06
1
I.)
.
h ko
Bcontent:derivedfrmnadispersant - - 0.05 0.08
0.16 0.05 0.05 0.05
P content 0 0 0
0 0 0.03 0.02 0 .
Metal content: derived from a
0 0 0 0 0 0 0 0.05
metallic detergent
S content 0.21 0.21 0.21 0.21
0.21 0.27 0.25 0.21
Evaluation results
SRV test: width of wear on cylinder
0.538 0.603 0.593 0.589
0.622 0.588 0.585 0.627
(mm)
Note bal. *1: Balance
-26-
CA 02843554 2014-01-29
=
=
[0041]
The followings were recognized from Tables 1 and 2.
(1) The lubricating oil compositions capable of satisfying
the formula (I) according to the present invention were excellent
in wear resistance for aluminum materials (Examples Al to A10).
In particular, the lubricating oil compositions obtained in
Examples A4 to A8 which were capable of satisfying the formula
(II) were further excellent in wear resistance for aluminum
materials.
In contrast, the lubricating oil compositions incapable of
satisfying the formula (I) were deteriorated in wear resistance
for aluminum materials as compared to the above compositions
according to the present invention obtained in Examples Al to A10
(Comparative Examples Al to A8).
(2) The lubricating oil compositions according to the present
invention (Examples Al to A10) exhibited a good wear resistance
even when they had no P content. In addition, the lubricating
oil compositions according to the present invention were extremely
reduced in both of P content and content of the metal component
derived from the metallic detergent, and therefore were extremely
excellent in effects of preventing poisoning of a three-way
catalyst and suppressing deterioration in service life of DPF.
[0042]
Examples Bl to 39 and Comparative Examples B1 to 37
The lubricating oil compositions having formulations as shown
in Tables 3 and 4 were prepared and subjected to measurement of
a wear resistance. The results are shown in Tables 3 and 4.
[0043]
The respective components used for preparing the lubricating
- 27-
CA 02843554 2014-01-29
-
oil compositions as well as the methods for measuring the
formulations and performance of the respective compositions were
the same as those used in Examples Al to A10 and Comparative Examples
Al to A8.
- 28 -
,
[0044]
TABLE 3
Examples
B1 B2 B3 B4 B5 B6 B7 B8 B9
Amounts compounded (% by mass)
Base oil
bal.*1 bal:1 bal:1 bal .*1 bal. ba1.*1 bal. bal. 1 bal.*1
Boronated imide 1 7.0 - - 7.0
2.0 - - 2.0 -
Boronated imide 2 - 4.0 4.0 4.0
- 4.0 6.0 6.0 4.0
Non-boronated imide 1 2.0 - - -
7.0 2.0 2.0 2.0 - n
Non-boronated imide 2 2.0 5.0 5.0 5.0
7.0 7.0 7.0 7.0 5.0 o
Sulfur-based extreme pressure agent 1.0 1.0 1.0 1.0
1.0 1.0 1.0 1.0 1.0 I.)
co
Metallic detergent 0.5 0.5 0.5 0.5
0.5 0.5 0.5 0.5 0.5 w
in
Phosphorus-based anti-wear agent - - - -
- - - - 0.3 in
a,
Other additives 2.4 2.4 2.4 2.4
2.4 2.4 2.4 2.4 2.4 "
o
H
Formulations of composition (% by
a,
I
mass)
o
= H..
1
N content: derived froma dispersant 0.20 0.11 0.11 0.25
0.25 0.17 0.20 0.24 0.11 I.)
ko
B content: derived fromadispersant 0.14 0.05 0.05 0.19
0.04 0.05 0.08 0.12 0.05
P content 0 0 0 0
0 0 0 0 0.02 '
Metal content (Ca): derived from a
0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05
metallic detergent
S content 0.21 0.21 0.21 0.21
0.21 0.21 0.21 0.21 0.25
Evaluation results
SRV test: width of wear-on cylinder
0.472 0.460 0.444 0.496 0.389 0.381 0.331 0.366 0.457
(mm)
Note bal. *1: Balance
- 29 -
[0045]
TABLE 4
Comparative Examples
B1 B2 B3 B4 B5 B6 B7
Amounts compounded (% by mass)
Base oil ba1:1 bal.'I bal.T1
bal.''1 bal.ci bal.T1 bal.T1
Boronated imide 1 - - - 4.0
8.0 - -
Boronated imide 2 - - 4.0 -
- 4.0 4.0
Non-boronated imide 1 2.0 2.0 - 2.0
2.0 - - n
Non-boronated imide 2 - 7.0 - -
- - - 0
I.)
Sulfur-based extreme pressure agent 1.0 1.0 1.0 1.0
1.0 1.0 1.0 co
Metallic detergent 0.5 0.5 0.5 0.5
0.5 - 1.0 w
ul
-
ul
Phosphorus-based anti-wear agent - - - -
- 0.3 -
Other additives 2.4 2.4 2.4 2.4
2.4 2.4 2.4 "
0
H
Formulations of composition (% by
mass)
. 0
H
N content: derived from a dispersant
0.04 0.11 0.06 0.12 0.20 0.06 0.06 1
"
,
q3.
B content: derived from a dispersant
0.00 0.00 0.05 0.08 0.16 0.05 0.05
P content 0 0 0
0 0 0.02 0 '
Metal content (Ca): derived from a
0.05 0.05 0.05 0.05 0.05 0 0.10
metallic detergent
S content 0.21 0.21 0.21
0.21 0.21 0.25 0.21
Evaluation results
SRV test: width of wear on cylinder
0.566 0.594 0.594 0.600
0.612 0.585 0.614
(mm)
Note bal. *1: Balance
-30-
CA 02843554 2014-01-29
[0046]
The followings were recognized from Tables 3 and 4.
(1) The lubricating oil compositions capable of satisfying
the formula (I) according to the present invention were excellent
in wear resistance for aluminum materials (Examples Bl to B9).
In particular, the lubricating oil compositions obtained in
Examples B5 to B8 which were capable of satisfying the formula
(II) were further excellent in wear resistance for aluminum
materials.
In contrast, the lubricating oil compositions incapable of
satisfying the formula (I) all were deteriorated in wear resistance
for aluminum materials (Comparative Examples B1 to B7).
(2) The lubricating oil compositions according to the present
invention (Examples Bl to B9) exhibited a good wear resistance
even when they had substantially no P content. In addition, the
lubricating oil compositions according to the present invention
exhibited an extremely reduced P content, and therefore were
extremely excellent in effect of preventing poisoning of a
three-way catalyst. In addition, the content of the metal
component derived from the metallic detergent in the lubricating
oil compositions according to the present invention was 0.05% by
mass or more, so that the compositions exhibited a very good
detergency owing to inclusion of an adequate amount of the metallic
detergent therein. On the other hand, the content of the metal
component derived from the metallic detergent in the lubricating
oil compositions according to the present invention was 0.12% by
mass or less, so that the compositions also exhibited a good effect
of suppressing deterioration in service life of DPF.
[0047]
- 31-
CA 02843554 2014-01-29
=
Examples 01 to C10 and Comparative Examples Cl to C8
The lubricating oil compositions having formulations as shown
in Tables 5 and 6 were prepared and subjected to measurement of
a wear resistance. The results are shown in Tables 5 and 6.
[0048]
The respective components used for preparing the lubricating
oil compositions as well as the methods for measuring the
formulations and performance of the respective compositions were
the same as those used in Examples Al to A10 and Comparative Examples
Al to A8.
- 32 -
)
[0049]
TABLE 5
Examples
01 C2 03 C4 C5 C6 C7 08 C9 C10
Amounts compounded (% by mass)
Base oil bal.*1 bal.*1 bal.*1 bal.*1 bal.*1
bal.*1 bal.*1 bal.*1 bal.*1 bal.*1
Boronated imide 1 7.0 - - 7.0
2.0 - 2.0 5.0 - -
Boronated imide 2 - 4.0 4.0 4.0 -
6.0 6.0 6.0 4.0 4.0
Non-boronated imide 1 2.0 - - -
7.0 2.0 2.0 2.0 - - o
Non-boronated imide 2 2.0 5.0 5.0 5.0
7.0 7.0 7.0 7.0 5.0 5.0 0
iv
Sulfur-based extreme pressure agent 1.0 _ 1.0 1.0
1.0 1.0 1.0 1.0 1.0 1.0 1.0 co
a,
Metallic detergent - - - - -
- - - 0.2 0.4 u.)
in
in
Phosphorus-based anti-wear agent 0.4 0.4 0.5 0.4
0.4 0.4 0.4 0.4 0.4 0.4 a,
Other additives 2.4 2.4 2.4 2.4
2.4 2.4 2.4 2.4 2.4 2.4 "
0
H
Formulations of composition (% by
a,
I
mass)
. 0
H
1
N content: derived from a dispersant 0.20 0.11 0.11
0.25 0.25 0.20 0.24 0.30 0.11 0.11 iv
q3.
B content:
derived from a dispersant 0.140.05 0.19 0.04 0.08 _4Ø12 0.18
0.05 0.05
P content 0.03 0.03
0.04 0.03 0.03 0.03 0.03 0.03 0.03 0.03 '
Metal content (Ca) : derived from a 0 0 0 0 0
0 0 0 0.02 0.04
metallic detergent
Evaluation results
...
SRV test: width of wear on cylinder
0.432 0.408 0.386 0.463 0.325 0.302 0.315 0.351 0.434 0.941
(mm)
Note bal. *1: Balance
- 33 -
I
[0050]
TABLE 6
Comparative Examples
C1 02 03 C4 C5 C6 C7 C8
Amounts compounded (% by mass)
4,1 .-4ii.1. 4,1
Base oil bal. bal bal. bal.
bal. bal. bal. bal.
Boronated imide 1 - - _ - 4.0
8.0 - --_
Boronated imide 2 - - 4.0 -
- 4.0 4.0 4.0
Non-boronated imide 1 2.0 2.0 -
Non-boronated imide 2 -7.0 - -
- - - -
,
0
Sulfur-basedextremepressureagent 1.0 1.0 1.0 1.0
1.0 1.0 1.0 1.0 I.)
co
Metallic detergent - - - -
- - - 0.5
w
co
Phosphorus-based anti-wear agent 0.4 0.4 0.4 0.4
0.4 0.5 0.4 - co
.1,
Other additives 2.4 2.4 2.4 2.4
2.4 2.4 2.4 2.4 I.)
0
Formulations of composition (% by
H
FP
I
mass)
0
H
N content: derived from a dispersant 0.04 0.11 0.06 0.12
0.20 0.06 0.06 0.06 1
I.)
B content: derived from a dispersant 4 0.00 0.00 = 0.05 0.08
0.16 0.05 0.05 0.05 '
'
P content 0.03 0.03 0.03 0.03
0.03 0.04 0.03 0
Metal content (Ca): derived from a
0 0 0 0 0 0 0 0.05
metallic detergent
S content 0.27 0.27 0.27 0.27
0.27 0.30 0.27 0.21
Evaluation results
SRV test: width of wear on cylinder
0.511 0.567 0.575 0.560 0.599 0.414 0.588 0.627
(mm)
Note bal. *1: Balance
- 34 -
CA 02843554 2014-01-29
4
[0051]
The followings were recognized from Tables 5 and 6.
(1) The lubricating oil compositions capable of satisfying
the formula (I) according to the present invention were excellent
in wear resistance for aluminum materials (Examples 01 to C10).
In particular, the lubricating oil compositions obtained in
Examples C5 to C8 which were capable of satisfying the formula
(II) were further excellent in wear resistance for aluminum
materials.
In contrast, the lubricating oil compositions incapable of
satisfying the formula (I) all were deteriorated in wear resistance
for aluminum materials (Comparative Examples 01 to 08).
(2) The lubricating oil compositions according to the present
invention (Examples Cl to C10) were still more excellent in wear
resistance since the P content therein was 0.03% by mass or more.
In addition, the P content in the lubricating oil compositions
according to the present invention was 0.06% by mass or less, so
that the compositions exhibited a good effect of preventing
poisoning of a three-way catalyst. In addition, the content of
the metal component in the lubricating oil compositions according
to the present invention was less than 0.05% by mass, so that the
compositions were extremely excellent in effect of suppressing
deterioration in service life of DPF.
INDUSTRIAL APPLICABILITY
[0052]
The lubricating oil composition for internal combustion
engines according to the present invention is excellent in wear
resistance for aluminummaterials . Thus, according to the present
- 35 -
CA 02843554 2014-01-29
=
invention, it is possible to provide a lubricating oil composition
for internal combustion engines which can be considerably reduced
= in content of ZnDTP having a large phosphorus content or a metallic
detergent while maintaining a wear resistance for aluminum
materials.
Therefore, the lubricating oil composition according to the
present invention can be usefully used as a lubricating oil
composition for internal combustion engines which is capable of
reducing an adverse influence on an exhaust gas post-treatment
device for internal combustion engines which is formed of an
aluminum material.
- 36 -
