U.S. patent application number 14/236190 was filed with the patent office on 2014-07-10 for lubricant composition for internal combustion engine oil.
This patent application is currently assigned to IDEMITSU KOSAN CO., LTD.. The applicant listed for this patent is Hiroshi Fujita, Yasunori Shimizu. Invention is credited to Hiroshi Fujita, Yasunori Shimizu.
Application Number | 20140194329 14/236190 |
Document ID | / |
Family ID | 47629420 |
Filed Date | 2014-07-10 |
United States Patent
Application |
20140194329 |
Kind Code |
A1 |
Shimizu; Yasunori ; et
al. |
July 10, 2014 |
LUBRICANT COMPOSITION FOR INTERNAL COMBUSTION ENGINE OIL
Abstract
The present invention provides a lubricating oil composition for
internal combustion engines which includes 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.gtoreq.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.ltoreq.M.ltoreq.0.12; and C: 0.03.ltoreq.P.ltoreq.0.06 and
M<0.05. The lubricating oil composition for internal combustion
engines 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.
Inventors: |
Shimizu; Yasunori; (London,
GB) ; Fujita; Hiroshi; (Chiba, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Shimizu; Yasunori
Fujita; Hiroshi |
London
Chiba |
|
GB
JP |
|
|
Assignee: |
IDEMITSU KOSAN CO., LTD.
Chiyoda-du, Tokyo
JP
|
Family ID: |
47629420 |
Appl. No.: |
14/236190 |
Filed: |
August 3, 2012 |
PCT Filed: |
August 3, 2012 |
PCT NO: |
PCT/JP12/69911 |
371 Date: |
March 18, 2014 |
Current U.S.
Class: |
508/186 |
Current CPC
Class: |
C10M 169/045 20130101;
C10N 2030/42 20200501; C10N 2020/04 20130101; C10N 2060/14
20130101; C10M 2219/082 20130101; C10M 133/56 20130101; C10N
2030/06 20130101; C10M 2223/045 20130101; C10M 2215/223 20130101;
C10M 2215/064 20130101; C10N 2040/25 20130101; C10M 2229/02
20130101; C10M 141/12 20130101; C10M 2207/026 20130101; C10N
2030/45 20200501; C10M 2215/08 20130101; C10M 2219/085 20130101;
C10M 2207/262 20130101; C10M 2203/1025 20130101; C10N 2030/44
20200501; C10M 2215/28 20130101; C10N 2030/43 20200501; C10N
2010/04 20130101; C10M 2215/28 20130101; C10N 2060/14 20130101;
C10M 2203/1025 20130101; C10N 2020/02 20130101; C10M 2203/1025
20130101; C10N 2020/02 20130101; C10M 2215/28 20130101; C10N
2060/14 20130101 |
Class at
Publication: |
508/186 |
International
Class: |
C10M 141/12 20060101
C10M141/12 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 3, 2011 |
JP |
2011-170580 |
Aug 3, 2011 |
JP |
2011-170581 |
Aug 3, 2011 |
JP |
2011-170582 |
Claims
1. A lubricating oil composition comprising a boronated imide-based
dispersant, or comprising the boronated imide-based dispersant and
a non-boronated imide-based dispersant, in which a boron content B,
in mass %, of the boronated imide-based dispersant and a nitrogen
content N, in mass %, of the boronated imide-based dispersant or
the boronated imide-based dispersant and the non-boronated
imide-based dispersant satisfy formula (I): N.gtoreq.B+0.05 (I),
and a phosphorus content P, in mass %, and a content M, in mass %,
of a metal component of a metallic detergent on the basis of a
total amount of the composition satisfy any one of the following
requirements A to C: A: P<0.03 and M<0.05; B: P<0.03 and
0.05.ltoreq.M.ltoreq.0.12; and C: 0.03.ltoreq.P.ltoreq.0.06 and
M<0.05.
2. The lubricating oil composition of claim 1, wherein B and N
satisfy formula (II): N.gtoreq.B+0.1 (II).
3. The lubricating oil composition of claim 1, further comprising
an anti-wear agent comprising sulfur.
4. The lubricating oil composition of claim 3, wherein the
anti-wear agent is a disulfide compound represented by formula (3):
R.sup.1OOC-A.sup.1-S.sub.2-A.sup.2-COOR.sup.2 (3) wherein R.sup.1
and R.sup.2 are each independently a hydrocarbon group having 1 to
30 carbon atoms which may comprise an oxygen atom, a sulfur atom or
a nitrogen atom; and A.sup.1 and A.sup.2 are each independently a
divalent hydrocarbon group having 1 to 12 carbon atoms.
5. The lubricating oil composition of claim 1, comprising the
boronated imide-based dispersant and the non-boronated imide-based
dispersant.
6. The lubricating oil composition of claim 1, wherein P and M
satisfy requirement A.
7. The lubricating oil composition of claim 1, wherein P and M
satisfy requirement B.
8. The lubricating oil composition of claim 1, wherein P and M
satisfy requirement C.
9. The lubricating oil composition of claim 2, comprising the
boronated imide-based dispersant and the non-boronated imide-based
dispersant.
10. The lubricating oil composition of claim 2, wherein P and M
satisfy requirement A.
11. The lubricating oil composition of claim 2, wherein P and M
satisfy requirement B.
12. The lubricating oil composition of claim 2, wherein P and M
satisfy requirement C.
13. The lubricating oil composition of claim 2, further comprising
an anti-wear agent comprising sulfur.
Description
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 a metal component derived from
a metal-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 (CO.sub.2) as a global
worming substance, various harmful substances such as particular
matters (PM), hydrocarbons (HC), carbon monoxide (CO) and nitrogen
oxides (NO.sub.x). Among these substances, very strict regulation
values have been imposed on PM and NO.sub.x. 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.
[0003] It has recently reported that active sites of the three-way
catalyst tend to be poisoned with phosphorus components in engine
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.
[0004] 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.
[0005] 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.
[0006] 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
therein.
PRIOR ART DOCUMENTS
Patent Documents
[0007] Patent Document 1: JP 2010-528155A
SUMMARY OF THE INVENTION
Problems to be Solved by the Invention
[0008] 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
[0009] 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.
[0010] Thus, the present invention relates to the following
aspects. [0011] 1. 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 imide-based
dispersant or derived from the boronated imide-based dispersant and
the non-boronated imide-based dispersant satisfy the following
formula (I):
[0011] N.gtoreq.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.ltoreq.M.ltoreq.0.12; and
C: 0.03.ltoreq.P.ltoreq.0.06 and M<0.05. [0012] 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):
[0012] N.gtoreq.B+0.1 (II). [0013] 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. [0014] 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 following general formula (3):
[0014] R.sup.1OOC-A.sup.1-S.sub.2-A.sup.2-COOR.sup.2 (3)
wherein R.sup.1 and R.sup.2 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 A.sup.1 and A.sup.2 are each
independently a divalent hydrocarbon group having 1 to 12 carbon
atoms.
Effect of the Invention
[0015] 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.
[0016] 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
[0017] 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
imide-based dispersant or derived from the boronated imide-based
dispersant and the non-boronated imide-based dispersant satisfy the
following formula (I):
N.gtoreq.B+0.05 (I).
[0018] 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.gtoreq.B+0.1 (II)
can be further enhanced in the above effect.
[0019] 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.
[0020] The non-boronated imide-based dispersant is usually referred
to merely as an imide-based dispersant. As the non-boronated
imide-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).
##STR00001##
[0021] 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.
[0022] 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.
[0023] 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.degree. 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
imides.
[0024] 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.
[0025] 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.
[0026] 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.
[0027] 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
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.
[0028] 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]
[0029] In the case A, the following requirement is satisfied:
P<0.03 and M<0.05.
[0030] 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.
[0031] 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.
[0032] 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.
[0033] 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.
[0034] 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.
[Case B]
[0035] In the case B, the following requirement is satisfied:
P<0.03 and 0.05.ltoreq.M.ltoreq.0.12.
[0036] 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 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.
[0037] 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.
[0038] 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.
[0039] 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 more preferably not less than
0.05% and not more than 0.08% by mass.
[0040] 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.
[0041] The metallic detergents may be used alone or in combination
of any two or more thereof.
[0042] 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.
[Case C]
[0043] In the case C, the following requirement is satisfied:
0.03.ltoreq.P.ltoreq.0.06 and M<0.05.
[0044] 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.
[0045] When the phosphorus content in the composition is not less
than 0.03% by mass, the resulting composition can be further
enhanced in wear resistance. On the other hand, when the phosphorus
content in the composition is not more than 0.06% 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.
[0046] 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.
[0047] 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 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.
[0048] 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.sup.1OOC-A.sup.1-S.sub.2-A.sup.2-COOR.sup.2 (3)
wherein R.sup.1 and R.sup.2 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 A.sup.1 and A.sup.2 are each
independently a divalent hydrocarbon group having 1 to 12 carbon
atoms.
[0049] 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,
1,1-bis(1-methoxycarbonylethyl)disulfide,
1,1-bis(1-methoxycarbonyl-n-propyl)disulfide,
1,1-bis(1.sup.-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,
.alpha.,.alpha.-bis(.alpha.-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-methoxycarbonyl-1-phenylethyl)disulfide.
[0050] The content of the sulfur-based anti-wear agent in the
composition is preferably from 0.05 to 5% by mass 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.
[0051] 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.
[0052] 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.
[0053] 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.
[0054] Further examples of the viscosity index improver include
non-dispersed type or dispersed type ethylene-.alpha.-olefin
copolymers (in which the .alpha.-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 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-.alpha.-olefin copolymers and hydrogenated products
thereof is from 800 to 300000 and preferably from 10000 to
200000.
[0055] 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-d-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-methyl-6-t-butyl phenol); 4,4'-butylidene
bis(3-methyl-6-t-butyl phenol); 4,4'-isopropylidene
bis(2,6-di-t-butylphenol);2,2'-methylenebis(4-methyl-6-nonyl
phenol); 2,2'-isobutylidene bis(4,6-dimethyl phenol);
2,2'-methylene bis(4-methyl-6-cyclohexyl phenol);
2,6-di-t-butyl-4-methyl phenol; 2,6-di-t-butyl-4-ethyl phenol;
2,4-dimethyl-6-t-butyl phenol; 2,6-di-t-amyl-p-cresol;
2,6-di-t-butyl-4-(N,N'-dimethylaminomethyl phenol);
4,4'-thiobis(2-methyl-6-t-butyl phenol);
4,4'-thiobis(3-methyl-6-t-butyl phenol);
2,2'-thiobis(4-methyl-6-t-butyl phenol);
bis(3-methyl-4-hydroxy-5-t-butyl benzyl)sulfide;
bis(3,5-di-t-butyl-4-hydroxybenzyl)sulfide;
n-octadecyl-3-(4-hydroxy-3,5-di-t-butylphenyl)propionate; and
2,2'-thio[diethyl-bis-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate].
Among these phenol-based antioxidants, especially preferred are
bisphenol-based antioxidants and ester group-containing
phenol-based antioxidants.
[0056] 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 .alpha.-naphtyl amine; phenyl-.alpha.-naphtyl
amine; and alkyl-substituted phenyl-.alpha.-naphtyl amines such as
butyl phenyl-a-naphtyl amine, pentyl phenyl-.alpha.-naphtyl amine,
hexyl phenyl-.alpha.-naphtyl amine, heptyl phenyl-.alpha.-naphtyl
amine, octyl phenyl-.alpha.-naphtyl amine and nonyl
phenyl-.alpha.-naphtyl amine. Among these amine-based antioxidants,
preferred are dialkyl diphenyl amine-based antioxidants and naphtyl
amine-based antioxidants.
[0057] 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.
[0058] Examples of the rust inhibitor include alkyl benzene
sulfonates, dinonyl naphthalene sulfonate, alkenyl succinic acid
esters and polyhydric alcohol esters.
[0059] The amounts of the above other additives compounded in the
composition may be appropriately selected from an ordinary
practical range.
[0060] 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").
[0061] 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").
[0062] 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).
[0063] Examples of the synthetic oils include poly-.alpha.-olefins
such as .alpha.-olefin oligomers having 8 to 14 carbon atoms,
polybutene, polyol esters and alkyl benzenes.
[0064] 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.
[0065] 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.
[0066] The kinematic viscosity of the base oil as measured at
100.degree. C. is preferably in the range of from 1.5 to 50
mm.sup.2/s, more preferably from 3 to 30 mm.sup.2/s and still more
preferably from 3 to 15 mm.sup.2/s. When the kinematic viscosity of
the base oil as measured at 100.degree. C. is 1.5 mm.sup.2/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.degree. C. is 50 mm.sup.2/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.
[0067] 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.
[0068] Also, the base oil preferably has a sulfur content of 50 ppm
by mass or less as measured according to JIS K 2541. When the
sulfur content of the base oil is 50 ppm by mass 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.
[0069] Further, the base oil preferably has a % C.sub.A 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 %
C.sub.A 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 %
C.sub.A value of the base oil is 3.0 or less, the resulting
lubricating oil composition can exhibit a good oxidation stability.
The % C.sub.A value of the base oil is more preferably 1.0 or less
and more preferably 0.5 or less.
EXAMPLES
[0070] 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.
[0071] 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>
[0072] 1. Quantitative Determination of Boron, Phosphorus and
Calcium
[0073] Measured according to ASTM D5185. [0074] 2. Quantitative
Determination of Nitrogen
[0075] Measured according to JIS K2609. [0076] 3. Sulfur
Content
[0077] Measured according to JIS K2541.
<Performance of Lubricating Oil Composition>
[0078] 4. Evaluation of Wear Resistance
[0079] 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
[0080] Test specimens: Cylinder (standard material: SUJ2); disk
(Si-containing aluminum: AA (Aluminum Association of America)
Standard "A390") [0081] Test temperature: 130.degree. C. [0082]
Load: 200 N [0083] Amplitude: 3.0 mm [0084] Frequency: 20 Hz [0085]
Test time: 1 h
Examples A1 to A10 and Comparative Examples A1 to A8
[0086] 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.
[0087] The respective components used for preparing the lubricating
oil compositions are as follows. [0088] (1) Base oil 1:
Hydrogenation refined mineral oil (100 N) ; 40.degree. C. kinematic
viscosity: 21.0 mm.sup.2/s; 100.degree. C. kinematic viscosity: 4.5
mm.sup.2/s; viscosity index: 127; sulfur content: less than 5 ppm
by mass [0089] (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 [0090] (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 [0091]
(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 [0092] (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 [0093] (6) Sulfur-based anti-wear
agent: [0094] Bis(n-octoxycarbonylmethyl)disulfide; sulfur content:
158 ppm by mass [0095] (7) Metal-based detergent: Ca salicylate;
base number (perchloric acid method): 270 mg KOH/g [0096] (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 [0097] (9) Other additives:
Mixture of an antioxidant (phenol-based antioxidant and amine-based
antioxidant), a metal deactivator (alkyl benzotriazole) and a
defoaming agent (silicone-based compound).
TABLE-US-00001 [0097] TABLE 1 Examples A1 A2 A3 A4 A5 A6 A7 A8 A9
A10 Amounts compounded (% by mass) Base oil bal.*.sup.1 bal.*.sup.1
bal.*.sup.1 bal.*.sup.1 bal.*.sup.1 bal.*.sup.1 bal.*.sup.1
bal.*.sup.1 bal.*.sup.1 bal.*.sup.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 2.0 --
-- Non-boronated imide 2 2.0 5.0 5.0 7.0 7.0 7.0 7.0 7.0 5.0 5.0
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 Metallic detergent -- -- -- -- -- -- -- -- -- 0.4
Phosphorus-based anti-wear agent -- -- -- -- -- -- -- -- 0.3 --
Other additives 2.4 2.4 2.4 2.4 2.4 2.4 2.4 2.4 2.4 2.4
Formulations of composition (% by mass) 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 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.*.sup.1:
Balance
TABLE-US-00002 TABLE 2 Comparative Examples A1 A2 A3 A4 A5 A6 A7 A8
Amounts compounded (% by mass) Base oil bal.*.sup.1 bal.*.sup.1
bal.*.sup.1 bal.*.sup.1 bal.*.sup.1 bal.*.sup.1 bal.*.sup.1
bal.*.sup.1 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 -- -- -- Non-boronated imide 2 -- 7.0 -- -- -- -- -- --
Sulfur-based extreme pressure agent 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0
Metallic detergent -- -- -- -- -- -- -- 0.5 Phosphorus-based
anti-wear agent -- -- -- -- -- 0.4 0.3 -- Other additives 2.4 2.4
2.4 2.4 2.4 2.4 2.4 2.4 Formulations of composition (% by mass) N
content: derived from a dispersant 0.04 0.11 0.06 0.12 0.20 0.06
0.06 0.06 B content: derived from a dispersant -- -- 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.*.sup.1: Balance
[0098] The followings were recognized from Tables 1 and 2.
[0099] (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 A1 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.
[0100] 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 A1 to A10
(Comparative Examples A1 to A8).
[0101] (2) The lubricating oil compositions according to the
present invention (Examples A1 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.
Examples B1 to B9 and Comparative Examples B1 to B7
[0102] 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.
[0103] 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 A1 to A10 and Comparative
Examples A1 to A8.
TABLE-US-00003 TABLE 3 Examples B1 B2 B3 B4 B5 B6 B7 B8 B9 Amounts
compounded (% by mass) Base oil bal.*.sup.1 bal.*.sup.1 bal.*.sup.1
bal.*.sup.1 bal.*.sup.1 bal.*.sup.1 bal.*.sup.1 bal.*.sup.1
bal.*.sup.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 -- Non-boronated imide 2 2.0
5.0 5.0 5.0 7.0 7.0 7.0 7.0 5.0 Sulfur-based extreme pressure agent
1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 Metallic detergent 0.5 0.5 0.5
0.5 0.5 0.5 0.5 0.5 0.5 Phosphorus-based anti-wear agent -- -- --
-- -- -- -- -- 0.3 Other additives 2.4 2.4 2.4 2.4 2.4 2.4 2.4 2.4
2.4 Formulations of composition (% by mass) N content: derived from
a dispersant 0.20 0.11 0.11 0.25 0.25 0.17 0.20 0.24 0.11 B
content: derived from a dispersant 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.*.sup.1: Balance
TABLE-US-00004 TABLE 4 Comparative Examples B1 B2 B3 B4 B5 B6 B7
Amounts compounded (% by mass) Base oil bal.*.sup.1 bal.*.sup.1
bal.*.sup.1 bal.*.sup.1 bal.*.sup.1 bal.*.sup.1 bal.*.sup.1
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 -- --
Non-boronated imide 2 -- 7.0 -- -- -- -- -- Sulfur-based extreme
Pressure agent 1.0 1.0 1.0 1.0 1.0 1.0 1.0 Metallic detergent 0.5
0.5 0.5 0.5 0.5 -- 1.0 Phosphorus-based anti-wear agent -- -- -- --
-- 0.3 -- Other additives 2.4 2.4 2.4 2.4 2.4 2.4 2.4 Formulations
of composition (% by mass) N content: derived from a dispersant
0.04 0.11 0.06 0.12 0.20 0.06 0.06 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.*.sup.1:
Balance
[0104] The followings were recognized from Tables 3 and 4.
[0105] (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 B1 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.
[0106] 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).
[0107] (2) The lubricating oil compositions according to the
present invention (Examples B1 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.
Examples C1 to C10 and Comparative Examples C1 to C8
[0108] 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.
[0109] 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 A1 to A10 and Comparative
Examples A1 to A8.
TABLE-US-00005 TABLE 5 Examples C1 C2 C3 C4 C5 C6 C7 C8 C9 C10
Amounts compounded (% by mass) Base oil bal.*.sup.1 bal.*.sup.1
bal.*.sup.1 bal.*.sup.1 bal.*.sup.1 bal.*.sup.1 bal.*.sup.1
bal.*.sup.1 bal.*.sup.1 bal.*.sup.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 --
-- Non-boronated imide 2 2.0 5.0 5.0 5.0 7.0 7.0 7.0 7.0 5.0 5.0
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 Metallic detergent -- -- -- -- -- -- -- -- 0.2 0.4
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 Other additives 2.4 2.4 2.4 2.4 2.4 2.4 2.4 2.4 2.4 2.4
Formulations of composition (% by mass) 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 B
content: derived from a dispersant 0.14 0.05 0.05 0.19 0.04 0.08
0.12 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 S content 0.27 0.27 0.30 0.27 0.27
0.27 0.27 0.27 0.27 0.27 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
0.441 (mm) Note bal.*.sup.1: Balance
TABLE-US-00006 TABLE 6 Comparative Examples C1 C2 C3 C4 C5 C6 C7 C8
Amounts compounded (% by mass) Base oil bal.*.sup.1 bal.*.sup.1
bal.*.sup.1 bal.*.sup.1 bal.*.sup.1 bal.*.sup.1 bal.*.sup.1
bal.*.sup.1 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 -- -- -- Non-boronated imide 2 -- 7.0 -- -- -- -- -- --
Sulfur-based extreme pressure agent 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0
Metallic detergent -- -- -- -- -- -- -- 0.5 Phosphorus-based
anti-wear agent 0.4 0.4 0.4 0.4 0.4 0.5 0.4 -- Other additives 2.4
2.4 2.4 2.4 2.4 2.4 2.4 2.4 Formulations of composition (% by mass)
N content: derived from a dispersant 0.04 0.11 0.06 0.12 0.20 0.06
0.06 0.06 B content: derived from a dispersant 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.*.sup.1:
Balance
[0110] The followings were recognized from Tables 5 and 6.
[0111] (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 C1 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.
[0112] In contrast, the lubricating oil compositions incapable of
satisfying the formula (I) all were deteriorated in wear resistance
for aluminum materials (Comparative Examples C1 to C8).
[0113] (2) The lubricating oil compositions according to the
present invention (Examples C1 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
[0114] The lubricating oil composition for internal combustion
engines according to the present invention is excellent in wear
resistance for aluminum materials. Thus, according to the present
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.
[0115] 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.
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