U.S. patent application number 14/009121 was filed with the patent office on 2015-02-12 for lubricant composition and method for using the lubricant composition.
The applicant listed for this patent is Paul Francis Bastien, Cheng Chen, Brian Lee Papke. Invention is credited to Paul Francis Bastien, Cheng Chen, Brian Lee Papke.
Application Number | 20150045270 14/009121 |
Document ID | / |
Family ID | 46969550 |
Filed Date | 2015-02-12 |
United States Patent
Application |
20150045270 |
Kind Code |
A1 |
Bastien; Paul Francis ; et
al. |
February 12, 2015 |
LUBRICANT COMPOSITION AND METHOD FOR USING THE LUBRICANT
COMPOSITION
Abstract
A lubricant composition comprising: a fully formulated
commercial lubricating oil which comprises from 0.01 to 2.0 percent
by weight of an oil soluble organo-molybdenum friction modifier and
at least 0.1 percent by weight active sulfur of a surface active
sulfur donor component is effective in preventing the removal of
DLC coatings while at the same time allowing the beneficial
friction-reducing effects from the molybdenum friction modifier to
occur.
Inventors: |
Bastien; Paul Francis;
(Katy, TX) ; Chen; Cheng; (Houston, TX) ;
Papke; Brian Lee; (Sugar Land, TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Bastien; Paul Francis
Chen; Cheng
Papke; Brian Lee |
Katy
Houston
Sugar Land |
TX
TX
TX |
US
US
US |
|
|
Family ID: |
46969550 |
Appl. No.: |
14/009121 |
Filed: |
April 5, 2012 |
PCT Filed: |
April 5, 2012 |
PCT NO: |
PCT/US12/32329 |
371 Date: |
October 29, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61472905 |
Apr 7, 2011 |
|
|
|
Current U.S.
Class: |
508/364 |
Current CPC
Class: |
C10M 2223/045 20130101;
C10M 2201/066 20130101; C10N 2080/00 20130101; C10M 141/08
20130101; C10M 2219/024 20130101; C10M 2219/082 20130101; C10M
2223/04 20130101; C10M 141/12 20130101; C10N 2010/12 20130101; C10N
2030/06 20130101; C10M 2203/1006 20130101; C10M 2219/086 20130101;
C10M 2207/401 20130101; C10M 2219/022 20130101; C10M 2227/066
20130101; C10M 141/10 20130101; C10M 2219/068 20130101; C10M
2219/106 20130101; C10N 2050/025 20200501; C10M 2207/283 20130101;
C10M 2223/047 20130101 |
Class at
Publication: |
508/364 |
International
Class: |
C10M 141/10 20060101
C10M141/10 |
Claims
1. A method for improving the wear of surfaces having a
diamond-like coating comprising: preparing a lubricant composition
which comprises 0.01 to 2.0 percent by weight of an organic
molybdenum friction modifier and at least 0.1 percent by weight of
a surface active sulfur donor component; lubricating an interface
between a first surface and a second surface with the lubricant
composition wherein at least one of the first and second surfaces
has a diamond-like coating thereon; wherein no greater than 10% of
a thickness of the diamond-like coating is removed following three
hours of relative movement between the first and second surfaces
under a normal force of 200N, frequency of 20 Hz, temperature of
130.degree. C.
2. The method according to claim 1 wherein no more than 10% of the
thickness of the diamond-like coating is removed.
3. The method according to claim 1 wherein no more than 1% of the
thickness of the diamond-like coating is removed.
4. The method according to claim 1 wherein the diamond-like coating
comprises from 0% to 35% hydrogen concentration.
5. The method according to claim 1 wherein the surface active
sulfur donor component is selected from the group consisting of
aryl sulfides, alkyl sulfides, dimercaptothiodiazole, sulfurized
isobutylene, dialkylpentasulphide, and combinations thereof.
6. A lubricant composition comprising: a fully formulated
commercial lubricating oil which comprises from 0.01 to 2.0 percent
by weight of an oil soluble organo-molybdenum friction modifier and
at least 0.1 percent by weight of a surface active sulfur donor
component.
7. The lubricant composition according to claim 6 wherein the
lubricating oil is selected from the group consisting of synthetic
oils, petroleum derived oils, plant derived oils, animal derived
oils, and combinations thereof.
8. The lubricant composition according to claim 6, wherein the
organic molybdenum friction modifier is selected from the group
consisting of molybdenum dithiocarbamate, molybdenum
dialkyldithiophosphates, and combinations thereof.
9. The lubricant composition according to claim 6, wherein the
surface active sulfur donor is selected from the group consisting
of aryl sulfides, alkyl sulfides, dimercaptothiodiazole, sulfurized
isobutylene, dialkylpentasulphide, and combinations thereof.
10. (canceled)
Description
FIELD OF INVENTION
[0001] The instant invention relates to a lubricant composition and
method for using such lubricant compositions.
BACKGROUND OF THE INVENTION
[0002] Diamond-like coatings (DLC) are often used on metal surfaces
to serve as a low friction sliding material and to reduce wear; DLC
coatings are used in internal combustion engines which are
lubricated by oils. DLC coatings impart lower friction compared
with other wear-resistant hard coating materials such as TiN and
CrN. To further reduce the frictional properties of DLC-coated
lubricated engine components, and to also provide beneficial
friction reducing properties for engine components which have not
received a DLC coating, friction modifiers are added to lubricating
oils.
[0003] One of the best classes of lubricant friction modifiers are
organic molybdenum compounds such as molybdenum dithiocarbamates
(MoDTC) and molybdenum dialkyldithiophosphates (MoDTP). However,
while these friction modifiers are very effective in reducing
boundary friction in steel to steel sliding contacts, they have
been observed to remove the DLC coating in steel to DLC sliding
contacts.
[0004] Thus, lubricants with MoDTC additives are incompatible with
DLC treated parts where minimization of friction is desired. Such
incompatibility is particularly pronounced in harsh applications,
such as in DLC-coated crankcase engines, wherein in the use of high
concentrations of MoDTC friction modifiers would be particularly
useful.
[0005] Current approaches to such incompatibility include: (a) use
of lubricants without MoDTC friction modifiers, and (b) the use of
a non-hydrogenated DLC coating, which appears to be more resistant
to the aggressive removal of the DLC coating by MoDTC friction
modifiers. Neither `solution` is entirely acceptable, as they
either limit or prohibit the use of the beneficial Mo friction
modifiers, or require the use of non-hydrogenated DLC coatings
which can accelerate wear on opposing steel surfaces due to their
extreme hardness. In this regard, a softer hydrogenated DLC coating
is preferred, and is the most common commercial coating type
currently used in crankcase engine designs.
[0006] The invention provides a lubricant formulation and process
using such formulation to compatibilize MoDTC additive containing
lubricants with DLC materials.
SUMMARY OF THE INVENTION
[0007] The instant invention is a lubricant composition and a
method for using such lubricant compositions.
[0008] In one embodiment, the instant invention provides a
lubricant composition comprising: a lubricating oil which comprises
from 0.01 to 2.0 percent by weight of an oil soluble organic
molybdenum friction modifier and at least 0.1 percent by weight of
a surface active sulfur donor component.
[0009] In an alternative embodiment, the instant invention further
provides a method for improving the wear of surfaces having a
diamond-like coating comprising: preparing a lubricant composition
which comprises 0.01 to 2.0 percent by weight of an organic
molybdenum friction modifier and at least 0.1 percent by weight of
a surface active sulfur donor component; lubricating an interface
between a first surface and a second surface with the lubricant
wherein at least one of the first and second surfaces has a
diamond-like coating thereon; wherein no greater than 10% of a
thickness of the diamond-like coating is removed following three
hours of relative movement between the first and second surfaces
under a normal force of 200N, frequency of 20 Hz, temperature of
130.degree. C.
[0010] In an alternative embodiment, the instant invention provides
a lubricant composition and method for improving the wear of
surfaces having a diamond-like coating, in accordance with any of
the preceding embodiments, except that the lubricating oil is
selected from the group consisting of synthetic oils, petroleum
derived oils, plant derived oils, animal derived oils, and
combinations thereof.
[0011] In an alternative embodiment, the instant invention provides
a lubricant composition and method for improving the wear of
surfaces having a diamond-like coating, in accordance with any of
the preceding embodiments, except that the organic molybdenum
friction modifier is selected from the group consisting of an
oil-soluble organo-molybdenum compound (such as molybdenum
dithiocarbamate or molybdenum diallcyldithiophosphate, and a
surface-active organic sulfur compound (such as an aryl or alkyl
sulfide, a dimercaptothiodiazole or a metal dithiocarbamate) and
combinations thereof. Surface-active organic sulfur compounds are
most commonly classified as extreme-pressure (or EP) additives, but
the present application is not limited to those compounds
specifically identified as EP additives, as the essential
properties are the surface-activity and the ability to act as a
sulfur donor to the organo-molybdenum friction modifier.
[0012] In an alternative embodiment, the instant invention provides
a lubricant composition and method for improving the wear of
surfaces having a diamond-like coating, in accordance with any of
the preceding embodiments, except that the surface active sulfur
donor is selected from the group consisting of sulfurized vegetable
fatty oils, sulfurized olefins, thiophosphates, sulfurized
hydrocarbons, and combinations thereof.
[0013] In an alternative embodiment, the instant invention provides
a lubricant composition and method for improving the wear of
surfaces having a diamond-like coating, in accordance with any of
the preceding embodiments, except that the surface active sulfur
donor is an EP additive.
[0014] In an alternative embodiment, the instant invention provides
a lubricant composition and method for improving the wear of
surfaces having a diamond-like coating, in accordance with any of
the preceding embodiments, except that the surface active sulfur
donor is selected from dialkyl dithiophosphate ester, sulfurized
isobutylene, sulfurized vegetable fatty oils and olefins,
dialkylpentasulphide, and combinations thereof.
[0015] In an alternative embodiment, the instant invention provides
a lubricant composition and method for improving the wear of
surfaces having a diamond-like coating, in accordance with any of
the preceding embodiments, except that no more than 10% of the
thickness of the diamond-like coating is removed.
[0016] In an alternative embodiment, the instant invention provides
a lubricant composition and method for improving the wear of
surfaces having a diamond-like coating, in accordance with any of
the preceding embodiments, except that no more than 1% of the
thickness of the diamond-like coating is removed.
[0017] In an alternative embodiment, the instant invention provides
a lubricant composition and method for improving the wear of
surfaces having a diamond-like coating, in accordance with any of
the preceding embodiments, except that the diamond-like coating
comprises from 0% to 35% hydrogen concentration.
[0018] In an alternative embodiment, the instant invention provides
a lubricant composition and method for improving the wear of
surfaces having a diamond-like coating, in accordance with any of
the preceding embodiments, except that the lubricant composition
further comprises one or more lubricant additive components
selected from the group consisting of detergents, dispersants,
antiwear, and antifoam additives.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] For the purpose of illustrating the invention, there is
shown in the drawings a form that is exemplary; it being
understood, however, that this invention is not limited to the
precise arrangements and instrumentalities shown.
[0020] FIG. 1 is a profilometry scan indicating the removal of a
DLC coating using the lubricant composition of Comparative Example
1;
[0021] FIG. 2 is a profilometry scan indicating the removal of a
DLC coating using the lubricant composition of Inventive Example
1;
[0022] FIG. 3 is a profilometry scan indicating the removal of a
DLC coating using the lubricant composition of Inventive Example
2;
[0023] FIG. 4 is a profilometry scan indicating the removal of a
DLC coating using the lubricant composition of Inventive Example
3;
[0024] FIG. 5 is a profilometry scan indicating the removal of a
DLC coating using the lubricant composition of Inventive Example
4;
[0025] FIG. 6 is a profilometry scan indicating the removal of a
DLC coating using the lubricant composition of Comparative Example
2;
[0026] FIG. 7 is a profilometry scan indicating the removal of a
DLC coating using the lubricant composition of Comparative Example
3;
[0027] FIG. 8 is a profilometry scan indicating the removal of a
DLC coating using the lubricant composition of Comparative Example
4;
[0028] FIG. 9 is a profilometry scan indicating the removal of a
DLC coating using the lubricant composition of Comparative Example
5;
[0029] FIG. 10 illustrates the profilometry scans for Inventive
Examples 5-6 and Comparative Examples 6-7; and
[0030] FIG. 11 illustrates the profilometry scans for Inventive
Examples 7-8 and Comparative Example 8.
DETAILED DESCRIPTION OF THE INVENTION
[0031] The instant invention provides a lubricant composition and a
method for using such lubricant composition to reduce or eliminate
the removal of DLC material in the presence of lubricating oils
containing an organic molybdenum compound.
[0032] The lubricant composition according to the present invention
comprises: a lubricating oil which comprises from 0.01 to 2.0
percent by weight of an organic molybdenum friction modifier and at
least 0.1 percent by weight of a surface active sulfur donor
component.
[0033] In an alternative embodiment of the invention, the organic
molybdenum friction modifier is selected from the group consisting
of molybdenum dithiocarbamates (MoDTC), molybdenum
dialkyldithiophosphates (MoDTP), and combinations thereof. In a
particular embodiment, the organic molybdenum friction modifier is
MoDTC.
[0034] In some embodiments, the lubricating oil is selected from
the group consisting of synthetic oils, petroleum derived oils,
plant derived oils, animal derived oils, and combinations thereof.
In a particular embodiment, the lubricating oil is a synthetic oil.
Exemplary synthetic oils useful in the invention include lubricants
containing polyalphaolefin (PAO) or Group III lubricant basestocks.
Exemplary petroleum derived oils useful in the invention include
lubricants containing Group I or II basestocks. Exemplary plant
derived oils useful in the invention include lubricants derived
from coconut, rapeseed, soy or other plant-derived basestocks.
[0035] The organic molybdenum friction modifier is present in the
lubricating oil in an amount from 0.01 to 2.0 percent by weight.
All individual values and subranges from 0.01 to 2.0 weight percent
are included herein and disclosed herein; for example, the amount
of organic molybdenum in the lubricating oil can be from a lower
limit of 0.01, 0.05, 0.1, 0.5, 1.0, 1.5, or 1.8 weight percent to
an upper limit of 0.05, 0.1, 0.5, 1.0, 1.5, 1.8, or 2.0 weight
percent. For example, the amount of organic molybdenum in the
lubricating oil may be in the range of from 0.01 to 2.0 weight
percent, or in the alternative, the amount of organic molybdenum in
the lubricating oil may be in the range of from 0.05 to 1.5 weight
percent, or in the alternative, the amount of organic molybdenum in
the lubricating oil may be in the range of from 0.01 to 1.0 weight
percent. When more than one surface organic molybdenum friction
modifier are present in the inventive lubricant composition, the
foregoing ranges indicate the total combined amounts of all organic
molybdenum friction modifier.
[0036] Any organic molybdenum friction modifier, which can form
MoS.sub.2 in the presence of surface active sulfur, may be used in
embodiments of the invention. In one embodiment, the organic
molybdenum is selected from the group consisting of oil-soluble
organo-molybdenum compounds, and combinations thereof. In a
particular embodiment, the organic molybdenum friction modifier is
selected from the group consisting of molybdenum dithiocarbamate,
molybdenum dialkyldithiophosphate, and combinations thereof.
[0037] In an embodiment of the inventive lubricant composition, the
surface active sulfur donor is selected from the group consisting
of surface active organic sulfur compounds, including, for example,
sulfurized vegetable fatty oils, sulfurized olefins,
thiophosphates, sulfurized hydrocarbons, aryl sulfides, alkyl
sulfides, dimercaptothiodiazole, metal dithiocarbamates and
combinations thereof. In a particular embodiment, the surface
active sulfur donor is selected from the group consisting of
dialkyl dithiophosphate ester, sulfurized isobutylene, sulfurized
vegetable fatty oils and olefins, dialkylpentasulphide, and
combinations thereof.
[0038] In certain embodiments, the surface active sulfur donor is
an extreme pressure (EP) additive. Exemplary commercially available
EP additives which are surface active sulfur donors and which may
be used in embodiments of the inventive lubricant composition
include IRGALUBE 353 (available from BASF Florham Park, N.J., USA),
HiTEC 312 (available from Afton Chemical Corporation, Richmond,
Va., USA), and ADDITIN RC 2515 and 2540 (both available from Rhein
Chemie Rheinau GmbH, Mannheim, Germany).
[0039] An effective amount of a surface active sulfur donor is used
in the inventive lubricant composition and method. As used herein,
an "effective amount" is the amount which results in removal of
less than or equal to 10% of the thickness of the DLC coating.
Effective amounts of a surface active sulfur donor vary depending
upon the specific sulfur donor. In general, effective amounts range
from 0.04 wt % to 1.0 wt %. However, the upper limit can be
extended beyond 1.0 wt % as shown below in Inventive Example 5
where 3.6 wt % surface active sulfur was found to be an effective
amount. When more than one surface active sulfur donor are present
in the inventive lubricant composition, the foregoing ranges
indicate the total combined amounts of all surface active surface
donors.
TEST METHODS
Amount of Surface Active Sulfur
[0040] The amount of surface active sulfur was measured in
accordance with ASTM D1662.
Wear Testing and Removal of DLC Coating
[0041] Wear testing was conducted using an Optimol SRV-4 (available
from Optimol Instruments Pruftechnik GmbH Munich,
Germany(Optimol)), which is a modularly-structured friction and
wear testing platform. A cylinder-on-flat geometry was used using
test specimens purchased from Optimol. The hardened steel cylinder
was 11.times.15 mm (diameter.times.length). A custom sample pan
holder was manufactured to fit the 6.9.times.22 mm Optimol hardened
steel disks. The sample pan holds approximately 2 ml of an
exemplary oil, and allows fully flooded extended duration lubricant
testing to be conducted in the SRV-4. The disk specimens were
DLC-coated steel; the steel cylinder was not DLC-coated. The two
test specimens (e.g. cylinder and disk) were installed in the test
chamber and pressed together with a normal force of 200 Newtons
(N). The top specimen oscillated on the bottom specimen. The
frequency was 20 Hz, the stroke was 3.0 mm, the test temperature
was 130.degree. C. and the test duration was 180 minutes. The same
DLC coating was used in testing all Inventive and Comparative
Examples, specifically a diamond-like carbon coating available from
Bekaert Corporation (Bekaert Diamond-Like Coatings, Karreweg 13,
BE-9870 Zulte, Belgium). Wear was measured by profilometry using a
Dektak 6M model, from Bruker Instruments and recorded either during
and/or after the test.
EXAMPLES
[0042] The following examples illustrate the present invention but
are not intended to limit the scope of the invention.
Inventive Examples 1-4 and Comparative Examples 2-5
[0043] Eight commercial EP additives representing a range of
chemistries were obtained from various suppliers, as described in
Table 1. The commercial EP additives used in each of the Inventive
Examples 1-4 were surface active sulfur donors while those utilized
in Comparative Examples 2-5 were not surface active sulfur donors.
The lubricating oil used in each example lubricant composition was
a Pennzoil Platinum 5W30 formulation (API "SL" except that the
friction modifier was omitted). Each of the Inventive Examples 1-4
and Comparative Examples 2-5 further included 1 weight percent of
an organic molybdenum friction modifier, specifically, MoDTC
additives made by Adeka Corporation (Japan, under the mark
SAKURA-LUBE S515).
Comparative Example 1
[0044] The lubricant composition used in Comparative Example 1
contained a Pennzoil Platinum 5W30 (API "SL" formulation) product
top-treated with 1.0 wt % MoDTC friction modifier, specifically the
SAKURA-LUBE S515.
[0045] FIGS. 1-9 show the profilometry scans of DLC coating surface
across the wear track for each of the lubricant compositions of
Inventive Examples 1-4 and Comparative Examples 1-5 after the SRV-4
friction test was complete. The Bekaert DLC coating was
approximately 1.5 microns (1500 nm) thick. Comparative Example 1,
which contained no EP additive, exhibited complete removal of the
DLC film within the 3 hour test period. Wear testing utilizing the
lubricant compositions of Comparative Examples 2-5, each of which
contained a non-surface active sulfur donor EP additive, exhibited
complete or partial removal of the DLC film. Use of the surface
active sulfur donor EP additives in Inventive Examples 1-4 in wear
testing resulted in no observable removal of the DLC coating.
TABLE-US-00001 TABLE 1 Example EP additives Supplier Description
Inventive Example 1 IRGALUBE 353 CIBA Dialkyl dithiophosphate ester
Inventive Example 2 HiTEC 312 Afton Chemical Sulfurized isobutylene
Corporation Inventive Example 3 ADDITIN RC 2515 Rhein Chemie
Sulfurized vegetable fatty oils and olefins Comparative MoS.sub.2
Adeka Corporation Molybdenum disulfide Example 2 Comparative
SYN-O-AD 8478 ICL-IP America Phosphate esters Example 3 Inc.
Comparative ADDITIN RC 8103 Rhein Chemie Trimethyolpropaneester of
Example 4 special fatty acids Inventive Example 4 ADDITIN RC 2540
Rhein Chemie Dialkylpentasulphide Comparative SYN-O-AD 8499 ICL-IP
America Isopropylyphenyl phosphate Example 5 Inc.
Inventive Examples 5-6 and Comparative Examples 6-7
[0046] Inventive Examples 5-6 were prepared as described in
connection with Inventive Example 4 above except that the
concentration of surface active sulfur was varied; 3.6 wt % of
surface active sulfur (1 wt % ADDITIN RC 2540) in Inventive Example
5 (solid line in FIGS. 10) and 1.8 wt % of surface active sulfur
(0.5 wt % ADDITIN RC 2540) in Inventive Example 6 (dashed line in
FIG. 10).
[0047] Comparative Examples 6 and 7 were also prepared as was
Inventive Example 4 except that lower level of surface active
sulfur were used. Specifically, Comparative Example 6 (bold dotted
line in FIG. 10) contained 0.9 wt % surface active sulfur (0.25 wt
% ADDITIN RC 2540) and Comparative Example 7 (dotted line in FIG.
10) contained 0.36 wt % surface active sulfur (0.1 wt % ADDITIN RC
2540).
[0048] FIG. 10 illustrates the profilometry results following wear
testing. As can be seen, a minimum amount of 0.5 wt % ADDITIN RC
2540 was an effective amount. In contrast, lower levels of ADDITIN
RC 2540 were not effective, meaning that greater than 10% of the
DLC coating thickness was removed. However, the entire DLC coating
was not removed even at the lowest levels of ADDITIN RC 2540.
Inventive Examples 7-8 and Comparative Example 8
[0049] Inventive Examples 7-8 were prepared as described in
connection with Inventive Example 3 above except that the
concentration of surface active sulfur was varied; 0.4 wt % of
surface active sulfur (1 wt % ADDITIN RC 2515) in Inventive Example
7 (solid line in FIGS. 11) and 0.2 wt % of surface active sulfur
(0.5 wt % ADDITIN RC 2515) in Inventive Example 8 (dashed line in
FIG. 11).
[0050] Comparative Example 8 was also prepared as was Inventive
Example 3 except that lower levels of surface active sulfur were
used. Specifically, Comparative Example 8 (dotted line in FIG. 11)
contained 0.04 wt % surface active sulfur (0.1 wt % ADDITIN RC
2515).
[0051] FIG. 11 illustrates the profilometry results following wear
testing. As can be seen, a minimum amount of 0.5 wt % ADDITIN RC
2515 was an effective amount. In contrast, lower levels of ADDITIN
RC 2515, namely 0.1 wt %, were not effective. However, the entire
DLC coating was not removed even at the lowest levels of ADDITIN RC
2515.
[0052] The present invention may be embodied in other forms without
departing from the spirit and the essential attributes thereof,
and, accordingly, reference should be made to the appended claims,
rather than to the foregoing specification, as indicating the scope
of the invention.
* * * * *