U.S. patent application number 11/887684 was filed with the patent office on 2008-12-18 for multifunctional lubricant additive package.
Invention is credited to Clark V. Cooper, Hongmei Wen.
Application Number | 20080312116 11/887684 |
Document ID | / |
Family ID | 37433747 |
Filed Date | 2008-12-18 |
United States Patent
Application |
20080312116 |
Kind Code |
A1 |
Wen; Hongmei ; et
al. |
December 18, 2008 |
Multifunctional Lubricant Additive Package
Abstract
The present invention provides a multifunctional lubricant
additive package or composition for improving load-carrying
capacity, scuffing (scoring) resistance, and other performance
characteristics of a lubricant. The composition includes a
molybdenum compound, a secondary zinc dithiophosphate compound, an
aryl or alkyl phosphite compound, and a compound having an
alkylthiocarbamoyl group. The present invention further provides a
method for improving the performance characteristics of a
lubricant. The method includes mixing a lubricant base stock or a
fully-formulated lubricant with the above-described multifunctional
lubricant additive composition.
Inventors: |
Wen; Hongmei; (South
Windsor, CT) ; Cooper; Clark V.; (Arlington,
VA) |
Correspondence
Address: |
PRATT & WHITNEY
400 MAIN STREET, MAIL STOP: 132-13
EAST HARTFORD
CT
06108
US
|
Family ID: |
37433747 |
Appl. No.: |
11/887684 |
Filed: |
November 4, 2005 |
PCT Filed: |
November 4, 2005 |
PCT NO: |
PCT/US2005/039766 |
371 Date: |
October 2, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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60625416 |
Nov 4, 2004 |
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Current U.S.
Class: |
508/364 ;
508/370; 508/421; 508/555 |
Current CPC
Class: |
C10M 2219/068 20130101;
C10N 2030/06 20130101; C10N 2040/02 20130101; C10M 141/10 20130101;
C10M 141/08 20130101; C10N 2040/13 20130101; C10M 2207/289
20130101; C10M 2223/041 20130101; C10M 137/02 20130101; C10N
2040/04 20130101; C10M 2223/04 20130101; C10M 137/04 20130101; C10N
2030/10 20130101; C10M 2223/049 20130101; C10M 2223/045 20130101;
C10M 2219/066 20130101; C10N 2040/25 20130101; C10M 129/76
20130101; C10M 2207/289 20130101; C10M 2207/289 20130101; C10M
2219/068 20130101; C10N 2010/12 20130101; C10M 2223/045 20130101;
C10N 2010/04 20130101; C10M 2219/068 20130101; C10N 2010/12
20130101; C10M 2223/045 20130101; C10N 2010/04 20130101 |
Class at
Publication: |
508/364 ;
508/370; 508/421; 508/555 |
International
Class: |
C10M 141/08 20060101
C10M141/08; C10M 137/02 20060101 C10M137/02; C10M 133/06 20060101
C10M133/06 |
Goverment Interests
GOVERNMENT RIGHTS IN THE INVENTION
[0002] The invention was made by or under contract with the
National Institute of Standards and Technology of the United States
Government under contract number: 70NANB0H3048.
Claims
1. A multifunctional lubricant additive composition comprising: (a)
a molybdenum compound of the general formula: ##STR00011## wherein
X.sup.1 is an oxygen or sulfur atom and R.sup.3 and R.sup.4 are
each independently a C.sub.nH.sub.2n+1 alkyl group, wherein n is an
integer of about 2.ltoreq.n.ltoreq.10, and m is an integer of about
0.ltoreq.m.ltoreq.4; (b) a secondary zinc dithiophosphate compound
of the general formula: ##STR00012## wherein R.sup.3, R.sup.4,
R.sup.5, and R.sup.6 are each a C.sub.hH.sub.2h+1 secondary alkyl
groups of the formula: ##STR00013## wherein h is an integer of
about 3.ltoreq.h.ltoreq.11, wherein R.sup.7 and R.sup.8 are each a
C.sub.iH.sub.2i+1 alkyl group, and i is an integer of about
1.ltoreq.i.ltoreq.5; (c) an aryl or alkyl phosphite compound of the
general formula: ##STR00014## wherein R.sup.9, R.sup.10, R.sup.11,
R.sup.12, R.sup.13, and R.sup.14 are each a C.sub.jH.sub.2j+1 alkyl
group, and j is an integer of about 1.ltoreq.j.ltoreq.20, wherein
the alkyl groups exhibit tertiary structures, and; (d) a compound
having at least one alkylthiocarbamoyl group of the general
formula: ##STR00015## wherein R.sup.15, R.sup.16, R.sup.17, and
R.sup.18 are each C.sub.kH.sub.2k+1 alkyl groups, and k is an
integer of about 1.ltoreq.k.ltoreq.30, and R.sup.15, R.sup.16,
R.sup.17, and R.sup.18 optionally form a ring structure with the
nitrogen atom to which they are bonded; wherein (A) is a chain of
sulfur atoms, S.sub.n, or S--(CH.sub.2).sub.m--S, and n is an
integer of about 1.ltoreq.n.ltoreq.10, and m is an integer of about
1.ltoreq.m.ltoreq.6; wherein the total amount of compounds (a) to
(d) is about 15% or less by mole, based on the total amount of
lubricant.
2. A composition according to claim 1, wherein compound (a) is
present in an amount from about 0.1% to about 6% by mole based on
the total amount of lubricant.
3. A composition according to claim 1, wherein compound (a) is
present in an amount from about 0.1% to about 3% by mole based on
the total amount of lubricant.
4. A composition according to claim 1, wherein compound (b) is
present in an amount from about 0.1% to about 6% by mole based on
the total amount of lubricant.
5. A composition according to claim 1, wherein compound (b) is
present in an amount from about 0.1% to about 3% by mole based on
the total amount of lubricant.
6. A composition according to claim 1, wherein compound (c) is
present in an amount from about 0.1% to about 6% by mole based on
the total amount of lubricant.
7. A composition according to claim 1, wherein compound (c) is
present in an amount from about 0.1% to about 3% by mole based on
the total amount of lubricant.
8. A composition according to claim 1, wherein compound (d) is
present in an amount from about 0.1% to about 6% by mole based on
the total amount of lubricant.
9. A composition according to claim 1, wherein compound (d) is
present in an amount from about 0.1% to about 3% by mole based on
the total amount of lubricant.
10. A composition according to claim 1, wherein the lubricant is
selected from a group consisting of: gear oil, bearing oil, sliding
surface lubrication oil, chain lubricating oil, and engine oil.
11. A method of improving the performance characteristics of a
lubricant, comprising the step of: mixing a lubricant with a
multifunctional lubricant additive composition comprising: a) a
compound represented by the general formula: ##STR00016## wherein
X.sup.1 is an oxygen or sulfur atom and R.sup.3 and R.sup.4 are
each a C.sub.nH.sub.2n+1 alkyl group, wherein n is an integer of
about 2.ltoreq.n.ltoreq.10, and m is an integer of about
0.ltoreq.m.ltoreq.4; (b) a compound represented by the general
formula: ##STR00017## wherein R.sup.3, R.sup.4, R.sup.5, and
R.sup.6 are each a C.sub.hH.sub.2h+1 secondary alkyl group
represented by the formula: ##STR00018## wherein h is an integer of
about 3.ltoreq.h.ltoreq.11; wherein R.sup.7 and R.sup.8 are each a
C.sub.iH.sub.2i+1 alkyl group, and i is an integer of about
1.ltoreq.i.ltoreq.5; (c) a compound represented by the general
formula: ##STR00019## wherein R.sup.9, R.sup.10, R.sup.11,
R.sup.12, R.sup.13, and R.sup.14 are each a C.sub.jH.sub.2j+1 alkyl
group, and j is an integer of about 1.ltoreq.j.ltoreq.20, wherein
the alkyl groups exhibit tertiary structures, and; (d) a compound
represented by the general formula: ##STR00020## wherein R.sup.15,
R.sup.16, R.sup.17, and R.sup.18 are each a C.sub.kH.sub.2k+1 alkyl
group, and k is an integer of about 1.ltoreq.k.ltoreq.30, and
R.sup.15, R.sup.16, R.sup.17, and R.sup.18 optionally form a ring
structure with the nitrogen atom to which they are bonded; wherein
(A) is a chain of sulfur atoms, S.sub.n, or S--(CH.sub.2).sub.m--S,
and n is an integer of about 1.ltoreq.n.ltoreq.10, and m is an
integer of about 1.ltoreq.m.ltoreq.6; wherein the total amount of
compounds (a) to (d) is equal to or less than about 15% by mole,
based on the total amount of lubricant.
12. A method according to claim 11, wherein compound (a) is present
in an amount from about 0.1% to about 6% by mole based on the total
amount of lubricant.
13. A method according to claim 11, wherein compound (a) is present
in an amount from about 0.1% to about 3% by mole based on the total
amount of lubricant.
14. A method according to claim 11, wherein compound (b) is present
in an amount from about 0.1% to about 6% by mole based on the total
amount of lubricant.
15. A method according to claim 11, wherein compound (b) is present
in an amount from about 0.1% to about 3% by mole based on the total
amount of lubricant.
16. A method according to claim 11, wherein compound (c) is present
in an amount from about 0.1% to about 6% by mole based on the total
amount of lubricant.
17. A method according to claim 11, wherein compound (c) is present
in an amount from about 0.1% to about 3% by mole based on the total
amount of lubricant.
18. A method according to claim 11, wherein compound (d) is present
in an amount from about 0.1% to about 6% by mole based on the total
amount of lubricant.
19. A method according to claim 11, wherein compound (d) is present
in an amount from about 0.1% to about 3% by mole based on the total
amount of lubricant.
20. A method according to claim 11, wherein the lubricant is
selected from a group consisting of: gear oil, bearing oil, sliding
surface lubrication oil, chain lubricating oil, and engine oil.
21. A multi-functional lubricant comprising: a base lubricant; and
at least one additive selected from the group consisting of: a
molybdenum compound, a secondary zinc dithiophosphate compound, an
aryl or alkyl phosphite compound, and a compound having at least
one alkylthiocarbamoyl group, wherein (a) the molybdenum compound
has the general formula: ##STR00021## wherein X.sup.1 is an oxygen
or sulfur atom and R.sup.3 and R.sup.4 are each independently a
C.sub.nH.sub.2n+1 alkyl group, wherein n is an integer of about
2.ltoreq.n.ltoreq.10, and m is an integer of about
0.ltoreq.m.ltoreq.4; (b) the secondary zinc dithiophosphate
compound has the general formula: ##STR00022## wherein R.sup.3,
R.sup.4, R.sup.5; and R.sup.6 are each a C.sub.hH.sub.2h+1
secondary alkyl groups of the formula: ##STR00023## wherein h is an
integer of about 3.ltoreq.h.ltoreq.11, wherein R.sup.7 and R.sup.8
are each a C.sub.iH.sub.2i+1 alkyl group, and i is an integer of
about 1.ltoreq.i.ltoreq.5; (c) the aryl or alkyl phosphite compound
has the general formula: ##STR00024## wherein R.sup.9, R.sup.10,
R.sup.11, R.sup.12, R.sup.13 and R.sup.14 are each a
C.sub.jH.sub.2j+1 alkyl group, and j is an integer of about
1.ltoreq.j.ltoreq.20, wherein the alkyl groups exhibit tertiary
structures, and; (d) the compound having at least one
alkylthiocarbamoyl group has the general formula: ##STR00025##
wherein R.sup.15, R.sup.16, R.sup.17, and R.sup.18 are each
C.sub.kH.sub.2k+1 alkyl groups, and k is an integer of about
1.ltoreq.k.ltoreq.30, and R.sup.15, R.sup.16, R.sup.17, and
R.sup.18 optionally form a ring structure with the nitrogen atom to
which they are bonded; wherein (A) is a chain of sulfur atoms,
S.sub.n, or S--(CH.sub.2).sub.m--S, and n is an integer of about
1.ltoreq.n.ltoreq.10, and m is an integer of about
1.ltoreq.m.ltoreq.6; wherein the total amount of compounds (a) to
(d) is about 15% or less by mole, based on the total amount of
lubricant.
22. The multifunctional lubricant additive composition of claim 1,
wherein the molar ratio of constituent compounds (a), (b), (c) and
(d) is about 1:1:1:1.
23. The multifunctional lubricant additive composition of claim 1,
wherein the molar ratio of constituent compounds (a) and (b) is
about 1:1.
24. The multifunctional lubricant additive composition of claim 1,
wherein the molar ratio of constituent compounds (a), (b), (c) and
(d) is about 10:10:5:1.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims the benefit of U.S.
Provisional Application No. 60/625,416 filed Nov. 4, 2004, and is
related to the following co-pending and commonly-owned applications
which were filed herewith and are hereby incorporated by reference
in full: "Lubricant Additive Packages for Improving Load-Carrying
Capacity and Surface Fatigue Life" (Attorney Docket No. 0002290WOU,
EH-11605), U.S. patent application Ser. No. ______; "Lubricants
Containing Multifunctional Additive Packages Therein for Improving
Load-Carrying Capacity, Increasing Surface Fatigue Life and
Reducing Friction" (Attorney Docket No. 0002294WOU, EH-11697), U.S.
patent application Ser. No. ______; and "Multifunctional Lubricant
Additive Package for a Rough Mechanical Component Surface"
(Attorney Docket No. 0002295WOU, EH-11698), U.S. patent application
Ser. No. ______.
BACKGROUND OF THE INVENTION
[0003] 1. Field of the Invention
[0004] The present invention relates to a multifunctional lubricant
additive composition or package for improving the performance
characteristics of a lubricant. More particularly, the present
invention relates to a multifunctional lubricant additive
composition or package for providing a lubricant with superior
performance characteristics such as improved load-carrying ability,
anti-scuffing (anti-scoring) capacity, friction reduction, and
improved surface-fatigue life.
[0005] 2. Description of Related Art
[0006] Mechanical systems such as manual or automatic
transmissions; single and multi-speed aviation transmissions,
including but not limited to those used to propel rotorcraft and
those used to alter the rotational speed of the sections within gas
turbine engines; push-belt type continuous variable transmissions;
and traction drive continuous variable transmissions, have large
surface areas of contact portions or zones. These contact portions
or zones, such as drive rolling surfaces, and gear and ball-and
roller bearings, are known to be susceptible to high surface
pressures. In addition, internal combustion engines and other
propulsion devices, especially those that are common for
high-performance and racing applications, are subject to taxing
demands in the form of inertial loading, high sliding and/or
rolling speeds, and marginal lubrication. Moreover, the need for
reducing friction, resistance, and fatigue within larger contact
zones of mechanical systems is increased by many recently developed
transmission systems that are designed to be miniaturized or
weight-reduced to maximize transmission throughput capacity.
[0007] To address these severe application demands, lubricants,
especially those containing specific additives, play a critical
role in protecting and minimizing the wear and scuffing (scoring)
of surfaces. The lubricants generally reduce principal damage
accumulation mechanisms of lubricated components caused by surface
fatigue and overloading.
[0008] Examples of known lubricants are discussed in the following
publications, which are hereby incorporated in full by reference:
Phillips, W. D., Ashless phosphorus-containing lubricating oil
additives; Lubricant Additives Chemistry and Application 45-111 (L.
R. Rudick, Marcel Dekker, Inc. 2003); and Kenbeck, D. and T. F.
Buenemann, Organic Modifiers; Lubricant Additives Chemistry and
Application 203-222 (L. R. Rudick, Marcel Dekker, Inc. 2003).
[0009] Recently developed system-optimization approaches for
increasing overall power throughput of mechanical systems,
underscore the need for new and better performing lubricant
additives. By reducing friction, wear, pressure, and improving
scoring (scuffing) resistance, these additives prolong surface
fatigue life for lubricated contacts within transmission systems
and propulsive devices.
[0010] The present invention provides lubricant additives for
improving the performance characteristics, such as load carrying
capacity of mechanical systems. Combining the additive composition
provided by this invention with lubricant stocks, and optionally
other additives, results in a fully formulated lubricant with many
performance advantages such as reduction in friction, wear and
scuffing (scoring).
SUMMARY OF THE INVENTION
[0011] The present invention provides a lubricant additive
comprising elements or components that are intended to enhance the
performance characteristics of a lubricant base stock or fully
formulated lubricant, including anti-wear (AW), extreme pressure
(EP), friction modifying (FM) and surface fatigue life (SFL)
modifying compositions.
[0012] In a preferred embodiment, this invention provides a
multifunctional lubricant additive composition for improving the
performance characteristics of a natural or synthetic lubricant for
use in transmission fluid products that meet both civil and
military specifications.
[0013] In another embodiment, the present invention provides a
multifunctional composition for use in improving performance of
metals and alloys of power transmission components, including
gears, bearings, splines, shafts, and springs.
[0014] In another embodiment, this invention provides a
multifunctional lubricant additive composition for improving the
performance characteristics of engines and related propulsive
devices used to power automobiles, both stock (production) and
specialty (e.g. racing and other high performance) varieties, and
heavy on- and off-road equipment, such as farm implements and
construction equipment.
[0015] In another embodiment the present invention provides a
multifunctional lubricant additive composition capable of being
combined with lubricant stocks and other additives to produce a
fully formulated lubricant that beneficially reduces friction and
scuffing (scoring), and increases resistance to surface
degradation, including but not limited to, fatigue including micro
and macro pitting and wear.
[0016] In yet another embodiment, the present invention provides a
multifunctional lubricant additive composition for improving the
performance characteristics of a lubricant, which includes one or
more of the following components:
[0017] (a) a molybdenum compound represented by the general
formula:
##STR00001##
[0018] wherein X.sup.1 is an oxygen or sulfur atom and R.sup.3 and
R.sup.4 are each independently a C.sub.nH.sub.2n+1 alkyl group,
wherein n is an integer of about 2.ltoreq.n.ltoreq.10, and m is an
integer of about 0.ltoreq.m.ltoreq.4;
[0019] (b) a secondary zinc dithiophosphate compound represented by
the general formula:
##STR00002##
[0020] wherein R.sup.3, R.sup.4, R.sup.5, and R.sup.6 are each a
C.sub.hH.sub.2h+1 secondary alkyl group represented by the
formula:
##STR00003##
[0021] wherein h is an integer of about 3.ltoreq.h.ltoreq.11,
wherein R.sup.7 and R.sup.8 are each a C.sub.iH.sub.2i+1 alkyl
group, and i is an integer of about 1.ltoreq.i.ltoreq.5;
[0022] (c) an aryl or alkyl phosphite compound represented by the
general formula:
##STR00004##
[0023] wherein R.sup.9, R.sup.10, R.sup.11, R.sup.12, R.sup.13 and
R.sup.14 are each a C.sub.jH.sub.2j+1 alkyl group, and j is an
integer of about 1.ltoreq.j.ltoreq.20, wherein the alkyl groups
exhibit tertiary structures, and;
[0024] (d) a compound having at least one alkylthiocarbamoyl group
represented by the general formula:
##STR00005##
[0025] wherein R.sup.15, R.sup.16, R.sup.17, and R.sup.18 are each
a C.sub.kH.sub.2k+1 alkyl group, k is an integer of about
1.ltoreq.k.ltoreq.30, and R.sup.15, R.sup.16, R.sup.17, and
R.sup.18 optionally form a ring structure with the nitrogen atom to
which they are bonded; wherein (A) is a chain of sulfur atoms,
S.sub.n, or S--(CH.sub.2).sub.m--S, n is an integer of about
1.ltoreq.n.ltoreq.10, and m is an integer of about
1.ltoreq.m.ltoreq.6; wherein the total amount of compounds (a) to
(d) is equal to or less than about 15% by mole, based on the total
amount of lubricant.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] The FIGURE shows the relationship between the average
traction (friction) coefficient and average load stage for various
lubricants. The vertical arrows 11, 21, 31 indicate the average
scuffing (scoring) failure load stage (load carrying capacity) of
Hatco HXL-7944 Oil 10, Exxon-Mobil Jet Oil II 20; and Formulation
#4 30, respectively. A higher scuffing (scoring) failure load stage
indicates greater load-carrying capacity of the lubricant.
DETAILED DESCRIPTION OF THE INVENTION
[0027] The present invention provides a multifunctional lubricant
additive composition for improving the performance characteristics
of a lubricant base stock or fully formulated lubricant. Preferably
the composition includes the following components set forth below:
(I) about 0.1% to about 6% by mole concentration of a molybdenum
compound (a), based on the total amount of lubricant; (II) about
0.1% to about 6% by mole concentration of a secondary zinc dialkyl
dithiophosphate compound (b), based on the total amount of
lubricant; (III) about 0.1% to about 6% by mole concentration of an
aryl or alkyl phosphite compound (c), based on the total amount of
lubricant; and (IV) about 0.1% to about 6% by mole concentration of
an alkylthiocarbamoyl compound (d), based on the total amount of
lubricant, wherein the total concentration of the four additives in
the composition will not exceed about 15% by mole based on the
total amount of the lubricant.
[0028] The multifunctional lubricant additive composition is
prepared from the following components:
[0029] (a) a molybdenum compound represented by the general
formula:
##STR00006##
[0030] wherein X.sup.1 is an oxygen or sulfur atom and R.sup.3 and
R.sup.4 are each independently a C.sub.nH.sub.2n+1 alkyl group,
wherein n is an integer of about 2.ltoreq.n.ltoreq.10, preferably
about 4.ltoreq.n.ltoreq.6, and m is an integer of about
0.ltoreq.m.ltoreq.4.
[0031] (b) a secondary zinc dithiophosphate compound (or zinc
dialkyl dithiophosphate compound) represented by the general
formula:
##STR00007##
[0032] wherein R.sup.3, R.sup.4, R.sup.5, and R.sup.6 are each a
C.sub.hH.sub.2h+1 secondary alkyl group represented by the
formula:
##STR00008##
[0033] wherein h is an integer of about 3.ltoreq.h.ltoreq.11,
preferably about 4.ltoreq.h.ltoreq.6; wherein R.sup.7 and R.sup.8
are each C.sub.iH.sub.2i+1 alkyl groups, and i is an integer of
about 1.ltoreq.i.ltoreq.5, preferably about
1.ltoreq.l.ltoreq.3;
[0034] (c) an aryl or alkyl phosphite compound represented by the
general formula:
##STR00009##
[0035] wherein R.sup.9, R.sup.10, R.sup.11, R.sup.12, R.sup.13, and
R.sup.14 are each a C.sub.jH.sub.2j+1 alkyl group, and j is an
integer of about 1.ltoreq.j.ltoreq.20, preferably about
4.ltoreq.j.ltoreq.8, wherein the alkyl groups exhibit tertiary
structures, and;
[0036] (d) a compound having at least one alkylthiocarbamoyl group
represented by the general formula:
##STR00010##
[0037] wherein R.sup.15, R.sup.16, R.sup.17, and R.sup.18 are each
a C.sub.kH.sub.2k+1 alkyl group, and k is an integer of about
1.ltoreq.k.ltoreq.30, preferably about 4.ltoreq.k.ltoreq.8, and
R.sup.15, R.sup.16, R.sup.17, and R.sup.18 optionally form a ring
structure with the nitrogen atom to which they are bonded; wherein
(A) is a chain of sulfur atoms, S.sub.n, or S--(CH.sub.2).sub.m--S,
and n is an integer of about 1.ltoreq.n.ltoreq.10, preferably about
1.ltoreq.n.ltoreq.6, and m is an integer of about
1.ltoreq.m.ltoreq.6, preferably about 1.ltoreq.m.ltoreq.3; wherein
the total amount of compounds (a) to (d) is equal to or less than
about 15% by mole, based on the total amount of lubricant.
[0038] Compound (a) of the multifunctional lubricant additive
composition is present in an amount from about 0.1% to about 6% by
mole, based on the total amount of lubricant. In a preferred
embodiment, compound (a) is present in an amount from about 0.1% to
about 3% by mole, based on the total amount of lubricant.
[0039] Compound (b) of the multifunctional lubricant additive
composition is present in an amount from about 0.1% to about 6% by
mole, based on the total amount of lubricant. In a preferred
embodiment, compound (b) is present in an amount from about 0.1% to
about 3% by mole, based on the total amount of lubricant.
[0040] Compound (c) of the multifunctional lubricant additive
composition is present in an amount from about 0.1% to about 6% by
mole, based on the total amount of lubricant. In a preferred
embodiment, compound (c) is present in an amount from about 0.1% to
about 3% by mole, based on the total amount of lubricant.
[0041] Compound (d) of the multifunctional lubricant additive
composition is present in an amount from about 0.1% to about 6% by
mole based on the total amount of lubricant. In a preferred
embodiment, compound (d) is present in an amount from about 0.1% to
about 3% by mole based on the total amount of lubricant.
[0042] Lubricants that the present invention can improve include
but are not limited to gear oil, bearing oil, sliding surface
lubrication oil, chain lubricating oil, and engine oil. In a
preferred embodiment, various types of lubricants, greases,
especially synthetic polyol ester (POE) based lubricants, can be
used as lubricant bases.
[0043] The present invention is useful as an additive composition
for natural and synthetic aviation (aerospace) and automotive
lubricants. Moreover, a combination of the multifunctional additive
composition with the above-described lubricants improves
transmission power throughput and system power density.
[0044] Specific uses also include turbine engine and transmission
oils designed to meet government civil (FAA) and military (DoD)
specification and requirements. Additional uses of the
multifunctional additive composition include the demonstrated
ability to improve scuffing (scoring) performance of metals and
alloys that are commonly used for power transmission components,
including but not limited to gears, bearings, splines, shafts, and
springs. As such, these improvements decrease the incidence of
component and system failure and rejection during customer
acceptance test protocols (ATPs). The additive composition also
improves pitting (surface) fatigue life and reduces the rate of
component and system degradation due to wear and other
phenomena.
[0045] In another embodiment, the present invention provides a
method of improving the performance characteristics of a lubricant.
The method comprises the step of:
[0046] mixing a lubricant with a multifunctional lubricant additive
composition that includes at least one of the compounds (a) to (d)
of the above-described multifunctional lubricant additive
composition thereby producing a fully formulated lubricant. For
this embodiment, the molar concentration of compounds (a) to (d)
may be varied to achieve a desired effect, provided however, that
the total amount of the four additives is about 15% or less by mole
based on the total amount of lubricant.
[0047] The following formulations and experimental results
illustrate some non-limiting embodiments of the multifunctional
additive compositions of this invention.
Formulation #4
[0048] In this embodiment, a multifunctional additive package was
added to Hatco HXL-7994 oil to create Formulation #4. Hatco
HXL-7994 oil was specially prepared by Hatco to replicate
Exxon-Mobil Jet Oil II, but without Exxon-Mobil Jet Oil II's
anti-wear additive tricresyl phosphate (TCP). Hatco HXL-7994 oil
contains an anti-oxidant package and a yellow metal corrosion
inhibitor and uses a 5 cSt polyol ester base stock, HXL-1570,
having the typical properties noted in Table A below.
TABLE-US-00001 TABLE A Properties of HXL-1570 PROPERTY TYPICAL
VALUES Viscosity, cSt @ 100.degree. C. 4.95 Viscosity, cSt @
40.degree. C. 24 Viscosity, cSt @ -40.degree. C. 7500 Viscosity
Index 133 Specific Gravity 25/25.degree. C. 0.985 Appearance Clear
yellow liquid Hydroxyl, mg KOH/g 2 Density, lbs/usg 15.5.degree. C.
8.25 Fire Point 2.82 Evaporation Loss % (6.5 h @ 204.degree. C.) 4
Avg. Molecular Weight 570
Formulation #4 contained the following additives:
TABLE-US-00002 Product Additive Mole % CAS# Formula Supplier Name
Compound Molybdenum, bis(ditridecyl- 0.5 71342-89-7
C54H108Mo2N2O2S6 R T MolyVan (a) carbamodithioato) di-u- Vanderbilt
822/# oxodioxo-di-sulfurized 29150 Compound Zinc O,O- 0.5 6990-43-8
C16H36O4P2S4Zn Flexsys Vocol (b) dibutylphosphorodithioate ZBPD
Compound Tris-(2,4-di-tertiary-butyl- 0.5 31570-04-4 C42H63O3P
Strem 15-7720 (c) phenyl) Phosphite Chemicals Compound
Tetra-n-butylthluram 0.4 1634-02-2 C18H36N2S4 R T 40850 (d)
Vanderbilt
[0049] This multifunctional additive package of Formulation #4
increased the load-carrying capacity of the Hatco HXL-7994 oil by
about 3.94 times, which is superior to conventional oils such as
Exxon-Mobil Jet Oil II (a standard version of MIL-PRF-23699, a 5
cSt gas turbine engine oil), which typically has excellent
lubricant performance as compared to other brands and versions of
MIL-PRF-23699 oil. As can be seen in the FIGURE, the Hatco HXL-7994
oil 10 had an average scuffing (scoring) failure load stage of
about 5.7 (arrow 11), the Exxon-Mobil Jet Oil II 20 had an average
scuffing (scoring) failure load stage of about 19.2 (arrow 21), and
Formulation #4 30 had an average scuffing (scoring) failure load
stage of about 22.5 (arrow 31), which indicates that Formulation #4
has a load carrying capacity about 3.94 times greater than that of
the Hatco HXL-7994 oil.
Experimental Results
[0050] The experimental results for Formulation #4 of this
invention and the two reference oils (Hatco HXL-7994 oil and
Exxon-Mobil Jet Oil II) were obtained using a generally accepted
modified variation of the Wedeven Associates, Inc. WAM Load
Capacity Test Method ("WAM Test"). The WAM Test is designed to
evaluate the loading capacity of lubricants and load bearing
surfaces by evaluating the wear, tear, and scuffing (scoring)
thereof over a large temperature range.
[0051] Table B below shows a summary of the WAM Test conditions
that were utilized to test various lubricants of this
invention.
TABLE-US-00003 TABLE B Ball: AISI 9310; Ra: 10-12 .mu.in Rolling
Velocity: 158 in/sec Disc: AISI 9310; Ra: 6 .mu.in Sliding
Velocity: 345 in/sec Ball Velocity: 234 in/sec Entraining Velocity:
158 in/sec Disc Velocity: 234 in/sec Velocity Vector Angle (Z):
95.degree. Disc Hardness: 62.5-63.5 HRC Temperature: Ambient
(~22.degree. C.) Ball Hardness: 62.5-63.5 HRC
[0052] For a detailed description of the WAM Test, see WAM High
Speed Load Capacity Test Method, SAE Aerospace AIR4978, Revision B,
2002, and U.S. Pat. No. 5,679,883 to Wedeven, both of which are
hereby incorporated in full by reference.
[0053] High load-carrying oils frequently result in test suspension
at load stage 30 without a scuffing (scoring) event. To
differentiate candidate formulations that reach test suspension,
tests can be run with a modified test protocol. The modified test
protocol operates at a lower entraining velocity than the standard
test protocol, which reduces the EHD film thickness and increases
the test severity by causing greater asperity interaction. The test
essentially operates at a reduced film thickness to surface
roughness (h/.sigma.) ratio.
[0054] The modified test protocol was developed for high
load-carrying oils used for aviation gearboxes. These oils include
the DOD-PRF-85734 oils for the U.S. Navy and the Def Stan 91-100
oils for the U.K. Ministry of Defense. With the modified test
protocol, the highest load-carrying oils currently used in military
aircraft experience scuffing (scoring) failures at load stages that
range from approximately 19 to 28.
AISI 9310 Specimen Preparation:
[0055] Formulation #4, the Hatco HXL-7944 oil, and the Exxon-Mobil
Jet Oil II were comparatively evaluated for scuffing (scoring)
resistance using a load capacity test method developed for the US
Navy. The test method used ball and disc specimens. The ball
specimens were 13/16-inch diameter, and the disc specimens were 4
inches in diameter and 1/2 inch thick. Material composition,
hardness and surface finish were closely controlled. The specimens
were fabricated from AISI 9310 steel, a surface-carburizing alloy
that is very common for gear applications.
[0056] AISI 9310 balls, or "Hard Ground" balls were heat-treated
and ground in a ball manufacturing process. The balls were
fabricated through the hard grinding stage. The surface finish
following this operational stage was between about 10-12 microinch
Ra.
[0057] The composition, hardness and surface finish of the
specimens are given below:
TABLE-US-00004 Disc Specimens Hardness (HRC) Surface Finish
(.mu.in. Ra) AISI 9310 63 6 Pyrowear 63 60-61 6 Pyrowear 53 60-61
1-2 superfinished
Scuffing (Scoring) Results:
[0058] The scuffing (scoring) results of Formulation #4, the Hatco
HXL-7944 oil, and the reference oil Exxon-Mobil Jet Oil II) are
summarized in Table C and shown in the FIGURE.
TABLE-US-00005 TABLE C Average Micro- Macro- Scuffing scuff scuff
(Scoring) (score) (score) Failure Test Lubricant Ball Disc/t.d.
Stage Stage Stage UTLCC6 HXL-7944 UTLCC6-9a 9-10a/3.2 4 16 (Base
Oil) UTLCC7 HXL-7944 UTLCC6-9b 9-10a/3.1 6 20 (Base Oil) UTLCc8
HXL-7944 UTLCC5-9b 9-10a/3.0 7.16 17 5.7 (Base Oil) UTLCC16
Formulation #4 UTLCC16-9a 9-10b/2.9 24 UTLCC17 Formulation #4
UTLCC16-9b 9-10b/2.8 21 22.5 UTLCC1 Exxon-Mobil SBAD12-9a 9-10a/3.7
25 Jet Oil II UTLCC2 Exxon-Mobil SBAD12-9b 9-10a/3.6 15 Jet Oil II
UTLCC3 Exxon-Mobil UTLCC3-9a 9-10a/3.5 24 Jet Oil II UTLCC4
Exxon-Mobil UTLCC3-9b 9-10a/3.4 25 Jet Oil II UTLCC5 Exxon-Mobil
UTLCC5-9a 9-10a/3.3 7 15 19.2 Jet Oil II
[0059] The load carrying capacity is indicated by an average
scuffing (scoring) failure stage (load stage). Increased
performance is observed with higher load stages. As shown in Table
C, our experimental results show that the average scuffing
(scoring) failure stage of Formulation #4 is about 22.5. This
scuffing (scoring) load is 3.94 times greater than that of the
Hatco HXL-7944 oil, which delivered an average scuffing (scoring)
failure stage of 5.7. The load carrying capacity of Formulation #4
is also superior to that of Exxon-Mobil Jet Oil II, which delivered
an average scuffing (scoring) failure stage of 19.2.
[0060] While the embodiments described above are directed to
lubricants of the polyol ester (POE) type, a skilled artisan would
recognize that the compositions apply equally to other lubricant
stock compositions including, but not limited to, lubricants
comprising grease, mineral (hydrocarbon-based), polyalkylene glycol
(PAG), aromatic naphthalene (AN), alkyl benzenes (AB) and
polyalphaolefin (PAO) types.
[0061] It should therefore be understood that the foregoing
description is only illustrative of the present invention. A
skilled artisan, without departing from the present invention, can
devise various alternatives and modifications. Accordingly, the
present invention is intended to embrace all such alternatives,
modifications and variations that fall within the scope of the
appended claims.
* * * * *