U.S. patent application number 13/729465 was filed with the patent office on 2014-07-03 for ultra-low saps lubricants for internal combustion engines.
This patent application is currently assigned to Chevron Oronite LLC. The applicant listed for this patent is Katsumi Umehara, Willem Van Dam. Invention is credited to Katsumi Umehara, Willem Van Dam.
Application Number | 20140187455 13/729465 |
Document ID | / |
Family ID | 51017842 |
Filed Date | 2014-07-03 |
United States Patent
Application |
20140187455 |
Kind Code |
A1 |
Umehara; Katsumi ; et
al. |
July 3, 2014 |
ULTRA-LOW SAPS LUBRICANTS FOR INTERNAL COMBUSTION ENGINES
Abstract
Disclosed is an ultra-low SAPS lubricating oil composition
comprising: an oil of lubricating viscosity; an aromatic
dicarboxylic acid treated dispersant supplying at least 0.30 wt %
of the aromatic dicarboxylic acid to said lubricating oil
composition; an ashless peroxide decomposer present at a treat rate
of from about 0.4 to 5.0 wt %; a metal deactivator wherein the
metal deactivator is present at a treat rate of greater than 0.08
wt %; wherein said lubricating oil composition contains less than
1000 ppm sulfur, less than 300 ppm phosphorus and less than 0.25 wt
% sulfated ash.
Inventors: |
Umehara; Katsumi; (San
Rafael, CA) ; Van Dam; Willem; (Bellaire,
TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Umehara; Katsumi
Van Dam; Willem |
San Rafael
Bellaire |
CA
TX |
US
US |
|
|
Assignee: |
Chevron Oronite LLC
San Ramon
CA
|
Family ID: |
51017842 |
Appl. No.: |
13/729465 |
Filed: |
December 28, 2012 |
Current U.S.
Class: |
508/280 ;
508/290; 508/292; 508/506 |
Current CPC
Class: |
C10N 2030/10 20130101;
C10N 2060/00 20130101; C10M 2207/142 20130101; C10N 2030/43
20200501; C10N 2030/12 20130101; C10N 2030/42 20200501; C10M 141/06
20130101; C10M 2215/066 20130101; C10M 2215/223 20130101; C10M
2215/28 20130101; C10N 2040/25 20130101; C10N 2030/45 20200501 |
Class at
Publication: |
508/280 ;
508/290; 508/292; 508/506 |
International
Class: |
C10M 133/44 20060101
C10M133/44 |
Claims
1. An ultra-low SAPS lubricating oil composition comprising: an oil
of lubricating viscosity; an aromatic dicarboxylic acid treated
dispersant supplying at least 0.30 wt % of the aromatic
dicarboxylic acid to said lubricating oil composition; an ashless
peroxide decomposer present at a treat rate of from about 0.4 to
5.0 wt %; a metal deactivator wherein the metal deactivator is
present at a treat rate of greater than 0.08 wt %; wherein said
lubricating oil composition contains less than 1000 ppm sulfur,
less than 300 ppm phosphorus and less than 0.25 wt % sulfated
ash.
2. The composition of claim 1, wherein the aromatic dicarboxylic
acid treated dispersant is selected from an aromatic dicarboxylic
acid treated bis-succinimide, an aromatic dicarboxylic acid treated
mono-succinimide, or mixtures thereof.
3. The composition of claim 1, wherein the aromatic dicarboxylic
acid treated dispersant is a mono-succinimide.
4. The composition of claim 1, wherein the aromatic dicarboxylic
acid treated dispersantis a bis-succinimide.
5. The composition of claim 1, wherein the aromatic dicarboxylic
acid is selected from the group consisting of phthalic acid,
isophthalic, and terephthalic acid,
6. The composition of claim 1, wherein the aromatic dicarboxylic
acid is terephthalic acid.
7. The composition of claim 1, wherein the amount of aromatic
dicarboxylic acid supplied to the lubricating oil composition is
from 0.30 to 10 wt %.
8. The composition of claim 1, wherein the amount of aromatic
dicarboxylic acid supplied to the lubricating oil composition is
from 0.35 to 7 wt %.
9. The composition of claim 1, wherein the amount of aromatic
dicarboxylic acid supplied to the lubricating oil composition is
from 0.40 to 5 wt %.
10. The composition of claim 1, wherein the amount of aromatic
dicarboxylic acid supplied to the lubricating oil composition is
from 0.45 to 3 wt %.
11. The composition of claim 1, wherein the ashless peroxide
decomposer is a compound according to formula 1: ##STR00004##
wherein R.sub.1 and R.sub.2 and R.sub.3 and R.sub.4 are each
independently selected from the group consisting of alkyl from 1 to
20 carbon atoms, more preferably alkyl from 1 to 10 carbon atoms
and even more preferably lower alkyl from 1 to six carbon
atoms.
12. The composition of claim 4, wherein the ashless peroxide
decomposer is N,N,N',N'-tetramethyl-naphthalene-1,8-diamine.
13. The composition of claim 1, wherein the metal deactivator is
present at a treat rate of from about 0.08 to 3.0 wt %.
14. The composition of claim 1, wherein the metal deactivator is
selected from benzotriazole, tolyltriozole, and mixtures
thereof.
15. The composition of claim 1, wherein the metal deactivator is
benzotriazole.
16. The composition of claim 1, wherein the metal deactivator is
tolyltriozole.
17. The composition of claim 1, wherein said lubricating oil
composition contains less than 800 ppm sulfur, less than 200 ppm
phosphorous, and less than 0.20 wt % sulfated ash from the additive
package.
18. The composition of claim 1, wherein said lubricating oil
composition contains less than 500 ppm sulfur, less than 100 ppm
phosphorous, and less than 0.15 wt % sulfated ash from the additive
package.
19. The composition of claim 1, wherein said lubricating oil
composition contains less than 300 ppm sulfur, less than 50 ppm
phosphorous, and less than 0.10 wt % sulfated ash from the additive
package.
20. The composition of claim 1, wherein said lubricating oil
composition contains less than 100 ppm sulfur, 0 ppm phosphorous,
and less than 0.05 wt % sulfated ash from the additive package.
21. The composition of claim 1, wherein said lubricating oil
composition contains less than 50 ppm sulfur, 0 ppm phosphorus and
less than 0.05 wt % sulfated ash from the additive package.
22. A method of lubricating an engine with an ultra-low SAPS
lubricating oil composition comprising: an oil of lubricating
viscosity; an aromatic dicarboxylic acid treated dispersant
supplying at least 0.30 wt % of the aromatic dicarboxylic acid to
said lubricating oil composition; an ashless peroxide decomposer
present at a treat rate of from about 0.4 to 5.0 wt %; a metal
deactivator wherein the metal deactivator is present at a treat
rate of greater than 0.08 wt %; wherein said lubricating oil
composition contains less than 1000 ppm sulfur, less than 300 ppm
phosphorus and less than 0.25 wt % sulfated ash.
23. The method of claim 22, wherein the aromatic dicarboxylic acid
treated dispersant is selected from an aromatic dicarboxylic acid
treated bis-succinimide, an aromatic dicarboxylic acid treated
mono-succinimide, or mixtures thereof.
24. The method of claim 22, wherein the aromatic dicarboxylic acid
treated dispersant is an aromatic dicarboxylic acid treated
bis-succinimide.
25. The method of claim 22, wherein the aromatic dicarboxylic acid
treated dispersant is an aromatic dicarboxylic acid treated
mono-succinimide.
26. The method of claim 22, wherein the aromatic dicarboxylic acid
is selected from the group consisting of phthalic acid,
isophthalic, and terephthalic acid.
27. The method of claim 22, wherein the aromatic dicarboxylic acid
is terephthalic acid.
28. The method of claim 22, wherein the amount of aromatic
dicarboxylic acid supplied to the lubricating oil composition is
from 0.30 to 10 wt %.
29. The method of claim 22, wherein the amount of aromatic
dicarboxylic acid supplied to the lubricating oil composition is
from 0.35 to 7 wt %.
30. The method of claim 22, wherein the amount of aromatic
dicarboxylic acid supplied to the lubricating oil composition is
from 0.40 to 5 wt %.
31. The method of claim 22, wherein the amount of aromatic
dicarboxylic acid supplied to the lubricating oil composition is
from 0.45 to 3 wt %.
32. The method of claim 22, wherein the ashless peroxide decomposer
is a compound according to formula 1: ##STR00005## wherein R.sub.1
and R.sub.2 and R.sub.3 and R.sub.4 are each independently selected
from the group consisting of alkyl from 1 to 20 carbon atoms, more
preferably alkyl from 1 to 10 carbon atoms and even more preferably
lower alkyl from 1 to six carbon atoms.
33. The method of claim 22, wherein the ashless peroxide decomposer
is N,N,N',N'-tetramethyl-naphthalene-1,8-diamine.
34. The method of claim 22, wherein the metal deactivator is
present at a treat rate of from about 0.08 to 3.0 wt %.
35. The method of claim 22, wherein the metal deactivator is
selected from benzotriazole, tolyltriozole, and mixtures
thereof.
36. The method of claim 22, wherein the metal deactivator is
benzotriazole.
37. The method of claim 22, wherein the metal deactivator is
tolyltriozole.
38. The method of claim 22, wherein said lubricating oil
composition contains less than 800 ppm sulfur, less than 200 ppm
phosphorous, and less than 0.20 wt % sulfated ash from the additive
package.
39. The method of claim 22, wherein said lubricating oil
composition contains less than 500 ppm sulfur, less than 100 ppm
phosphorous, and less than 0.15 wt % sulfated ash from the additive
package.
40. The method of claim 22, wherein said lubricating oil
composition contains less than 300 ppm sulfur, less than 0 ppm
phosphorous, and less than 0.10 wt % sulfated ash from the additive
package.
41. The method of claim 22, wherein said lubricating oil
composition contains less than 100 ppm sulfur, 0 ppm phosphorous,
and less than 0.05 wt % sulfated ash from the additive package.
42. The method of claim 22, wherein said lubricating oil
composition contains less than 50 ppm sulfur, 0 ppm phosphorus and
less than 0.05 wt % sulfated ash from the additive package.
43. A method of making a low SAPS lubricating oil composition,
comprising mixing together: an oil of lubricating viscosity; an
aromatic dicarboxylic acid treated dispersantsupplying at least
0.30 wt % aromatic dicarboxylic acid to said lubricating oil
composition; an ashless peroxide decomposer present at a treat rate
of from about 0.4 to 5.0 wt %; a metal deactivator wherein the
metal deactivator is present at a treat rate of greater than 0.08
wt %; wherein said lubricating oil composition contains less than
1000 ppm sulfur, less than 300 ppm phosphorus and less than 0.25 wt
% sulfated ash.
Description
FIELD OF THE INVENTION
[0001] The present invention generally relates to Ultra-Low SAPS
lubricants for Internal Combustion Engines.
BACKGROUND OF THE INVENTION
[0002] When formulating motor oils for use in an automotive engine,
there are a number of seemingly conflicting drivers which must be
balanced. On the one hand there is a desire to formulate with
additives which contain metals, sulfur and phosphorus because they
have a proven track record for performance. These additives are
known to impart wear and corrosion resistance to the oil and reduce
deposit formation in the engine. This resistance is necessary as
the demand for long life lubricants increases. However, the use of
these additives is constrained by environmental legislation.
[0003] During the 1950s and 1960s a number of studies were
undertaken to determine the source of air pollution which was
becoming a problem in metropolitan areas. Automotive exhaust was
indicated as a contributing factor. As a result, laws were put in
place at the national and state levels to regulate the allowable
limits for emissions of certain regulated chemicals. In response to
these regulations, engine manufacturers have introduced exhaust gas
after-treatment devices to clean up the emitted exhaust gas of
internal combustion engines. Commonly used on spark ignited engines
are oxidation catalysts, and commonly used on compression ignition
engines are Diesel Particulate Filters (DPF) combined with an
oxidation catalyst, and NOx reduction catalysts. The oxidation
catalysts are used to decrease carbon monoxide (CO) and hydrocarbon
emissions by oxidation. The catalysts utilized can be poisoned when
they interact with certain metals or phosphorus. Limitations on
sulfated ash, phosphorus, and sulfur levels (SAPS) in motor oils
have been put in place to enable the use of exhaust gas
after-treatment devices.
[0004] Commercial lubricants for internal combustion engines are
commonly formulated in such a way that the SAPS content of the
lubricant falls just below those limits. It is assumed by those
skilled in the art of formulating engine lubricants that lowering
the treat rates of SAPS containing performance additives far below
those restrictions causes the performance of the lubricant to
deteriorate to the point of unacceptability.
[0005] In addition to the CO and particle limits on emissions,
there are efforts being made to reduce carbon dioxide (CO.sub.2)
emissions from vehicles. As CO.sub.2 is a product of the combustion
of hydrocarbon based fuels, the most direct means to reduce
CO.sub.2 emissions is to reduce fuel consumption. Deterioration of
exhaust gas after-treatment devices can lead to increased fuel
consumption. Accumulation of sulfated ash in diesel particulate
filters can lead to increased engine backpressure and consequent
fuel consumption increase. Also, when NOx [a generic term for
mono-nitrogen oxides NO and NO.sub.2 (nitric oxide and nitrogen
dioxide) reduction catalysts are poisoned by sulfur, regeneration
requires additional fuel injections, causing the total fuel
consumption to increase. For these reasons the question of how
deterioration of exhaust gas after-treatment devices can be
minimized is more important than ever.
[0006] In general, the following patent art teaches elements of the
proposed invention, but none are capable of solving the complex
problem of high temperature corrosion, wear and deposit formation
which result when Sulfated Ash, Phosphorous, and Sulfur (SAPS) are
taken to nearly zero levels.
[0007] U.S. Patent Application No. 20030224948 discloses an
additive formulation comprising one or more ec-treated dispersants,
borated dispersants, and a dispersed aromatic dicarboxylic acid
corrosion inhibitor; a dispersant inhibitor package comprising one
or more ec-treated dispersants, borated dispersants, and a
dispersed aromatic dicarboxylic acid corrosion inhibitor; a
lubricating oil comprising said dispersant inhibitor package; and a
method for lubricating engines.
[0008] U.S. Patent Application No. 20100152079 discloses a
lubricant composition containing an oil of lubricating viscosity, a
N,N,N',N'-tetramethyl-naphthalene-1,8-diamine, and at least one
additive selected from antioxidants, detergents, dispersants which
together provide superior oxidation inhibition for automotive and
truck crankcase lubricants.
[0009] U.S. Patent Application No. 20080139425 discloses an
additive package, useful in a lubricant composition, which
comprises: a diluent; and a hydrocarbyl substituted triazole
compound, with the proviso that the lubricant is substantially free
of compounds containing phosphorus. This additive package is
selected for its ability to protect lead and silver bearings found
in medium speed diesel engines including railroad engines.
[0010] European Patent Application No. 0758016 discloses an
additive combination comprising an aromatic amine anti-oxidant and
a "B" compound. The combination contains 1 pt. wt. of boron per 250
pts. of nitrogen in the amine. The oils exemplified are blended
with a standard additive package and are not essentially free of
SAPS derived from the components. U.S. Patent Application No.
20080020953 discloses a lubricating oil composition which contains
lube base oil comprising mineral oil and/or synthetic oil, ash-free
dispersant (in mass %) (0.01-0.14) based on nitrogen amount,
antioxidant and sulfated ash (1.2 or less). The antioxidant
contains dialkyldiphenyl amine (0.3-5) and hindered phenol compound
(0-2.5). The dispersant contains alkenyl- or alkyl-succinimide
and/or boron compound derivative (0.05 or less) in terms of
nitrogen amount. All example oils contain approximately 1% Sulfated
Ash (SASH).
[0011] U.S. Pat. No. 7,026,273 discloses a crankcase lubricating
oil composition, for an internal combustion engine, which comprises
an admixture of oil and boron-containing additive, and preset
amounts of phosphorus and sulfur. This patent family teaches
lubricating oil compositions containing (a) a boron-containing
additive and one or more co-additives, wherein the lubricating oil
composition has greater than 200 ppm by mass of boron, less than
600 ppm by mass of phosphorus and less than 4000 ppm by mass of
sulfur, based on the mass of the oil composition. All example
lubricants contain approximately 1% SASH.
[0012] U.S. Patent Application No. 20060058200 discloses a
lubricating oil composition for internal combustion engines, which
contains a major amount of oil of lubricating viscosity, (a) at
least one nitrogen-containing dispersant, the dispersant providing
to the oil a nitrogen content of at least 0.075 wt. % nitrogen, the
dispersant having a polyalkenyl backbone which has a molecular
weight range of about 900 to 3000, and (b) an oil soluble or oil
dispersible source of boron, present in an amount so as to provide
a ratio of wt. % nitrogen to wt. % boron in the oil composition of
about 3:1 to 5:1, wherein said lubricating oil composition has a
sulfur content of up to 0.3 wt. %, a phosphorus content of up to
0.08 wt. %, a sulfated ash content of up to 0.80 wt. %. These oils
are low SAPS, but not significantly below the current mandated
levels. They still contain ZnDTP and metal detergents.
[0013] Japanese Patent No. 2922675 discloses a lubricating oil
composition for coping with strict regulation of exhaust gas which
contains 0.5-8 wt. % a (3,5-di-tert-butyl-4-hydroxyphenol)
carboxylic acid alkyl ester(s) as an ash-free cleaner, 3-12 wt. %
succinimide type ash-free dispersant(s) and 0.1-3 wt. % phenol type
ash-free antioxidant(s) in a lubricating base oil comprising a
mineral and a synthetic oil(s). These lubricants are designed to
not precipitate when in contact with methanol fuel.
[0014] U.S. Patent Application No. 20080020952 discloses a
lubricant oil composition for contacting metal materials containing
lead which comprises a lubricant base oil, an optional zinc
dithiophosphate present in 0.08 wt % or less, and an additive
selected from organic molybdenum compound excluding molybdenum
thiophosphate, boric acid ester and/or derivatives, a mixture of
the two, or organic molybdenum compound, boric acid modified alkyl
or alkenyl succinic acid imide. These oils are low in Zn salts, but
still contain metallic detergents.
[0015] U.S. Patent Application No. 20060009366 discloses an oil
composition for lubricating internal combustion engines which
comprises base oil and at least 1.4 wt % of an aminic and/or
phenolic antioxidant, wherein said lubricating oil composition is
phosphorus free. These lubricants are formulated to be free of
phosphorus antiwear additives, but are not free of metallic
detergents. They are neither low ash nor low sulfur.
[0016] U.S. Patent Application No. 20040106527 discloses a
lubricating oil composition for use in internal combustion engines,
used along with a gasoline fuel having sulfur content of less than
10 ppm by weight, which has a phosphorous content of no more than
0.05 wt. %. These lubricants are again low P without limiting
sulfur or ash.
[0017] Although some of these references address one problem that
occurs when the SAPS levels in a lubricant are limited, commercial
lubricants must pass a battery of tests to be qualified. None of
the references above address the multitude of high temperature
corrosive wear and deposition issues which an oil needs to face in
order to be qualified for sale. For a real solution to the problem
of delivering low SAPS oils, it is desirable to be able to balance
protection of the exhaust gas after treatment system with the
performance expected of a modern lubricant in order to be truly
viable.
SUMMARY OF THE INVENTION
[0018] With the existing limitations of Low SAPS, all applicable
emission requirements for modern engines can be met. The currently
existing lubricants have Low SAPS restrictions including: sulfated
ash limits of <0.8 wt % for PCMO (Passenger Car Motor Oil) or
<1.0 wt % for HDEO (Heavy Duty Engine Oil); phosphorus limits of
<0.08 wt % for both PCMO and HDEO; and sulfur limits of <0.3
wt % for both PCMO and HDEO.
[0019] If exhaust gas after-treatment devices are harmed by sulfur,
phosphorus and sulfated ash, then minimizing SAPS levels should
maximize the lifetime of the exhaust gas after-treatment devices.
An evaluation was done to determine which lubrication performance
gaps arise when a conventional fully formulated lubricant is
stripped of all the performance enhancing additives that contribute
to SAPS. As expected, the performance tests run on those SAPS free
lubricants indicate clearly unacceptable performance. However, with
the subsequent addition of alternative performance enhancing
additives which do not contribute to SAPS or only contribute minor
amounts of SAPS, Ultra-Low SAPS experimental lubricants were
created which, much to our surprise, gave acceptable performance.
The resultant prototype lubricants consist of components which are
built up of the elements H, O, N, and C, with very minor amounts of
other elements. In some embodiments, SAPS levels derived from the
components in the additive package can be essentially zero.
[0020] "Ultra-Low SAPS` lubricating oil compositions are defined
as: lubricating oil compositions wherein Sulfur is present at less
than 1000 ppm, Phosphorous is present at less than 300 ppm, and
Sulfated Ash is present at less than 0.25 wt %. In some embodiments
S (Sulfur) is present at <1000 ppm, <800 ppm, <500 ppm,
<300 ppm, <100 ppm, <50 ppm, <10 ppm, and could be
zero; P (Phosphorous) is present at <300 ppm, <200 ppm,
<100 ppm, <50 ppm, <10 ppm, and could be zero; and
Sulfated Ash is present as <0.25 wt %, <0.20 wt %, <0.15
wt %, <0.10 wt %, <0.05 wt %, <0.01 wt % and could be 0 wt
% in the finished lubricant.
[0021] In one embodiment of the present invention the lubricating
oil composition contains less than 800 ppm sulfur, less than 200
ppm phosphorous, and less than 0.20 wt % sulfated ash.
[0022] In one embodiment of the present invention the lubricating
oil composition contains less than 500 ppm sulfur, less than 100
ppm phosphorous, and less than 0.15 wt % sulfated ash.
[0023] In one embodiment of the present invention the lubricating
oil composition contains less than 300 ppm sulfur, less than 50 ppm
phosphorous, and less than 0.10 wt % sulfated ash.
[0024] In one embodiment of the present invention the lubricating
oil composition contains less than 100 ppm sulfur, 0 ppm
phosphorous, and less than 0.05 wt % sulfated ash.
[0025] In one embodiment of the present invention the lubricating
oil composition contains less than 50 ppm sulfur, 0 ppm
phosphorous, and less than 0.05 wt % sulfated ash.
[0026] In accordance with one embodiment of the present invention,
there is provided an ultra-low SAPS lubricating oil composition
comprising: [0027] an oil of lubricating viscosity; [0028] an
aromatic dicarboxylic acid treated dispersant supplying at least
0.30 wt. % aromatic dicarboxylic acid to said lubricating oil
composition; [0029] an ashless peroxide decomposer present at a
treat rate of from about 0.4 to 5.0 wt %; [0030] a metal
deactivator wherein the metal deactivator is present at a treat
rate of greater than 0.08 wt %; [0031] wherein said lubricating oil
composition contains less than 1000 ppm sulfur, less than 300 ppm
phosphorus and less than 0.25 wt % sulfated ash.
[0032] In accordance with another embodiment of the present
invention, there is provided a method of lubricating an engine with
an ultra-low SAPS lubricating oil composition comprising: [0033] an
oil of lubricating viscosity; [0034] an aromatic dicarboxylic acid
treated dispersant supplying at least 0.30 wt. % aromatic
dicarboxylic acid to said lubricating oil composition; [0035] an
ashless peroxide decomposer present at a treat rate of from about
0.4 to 5.0 wt %; [0036] a metal deactivator wherein the metal
deactivator is present at a treat rate of greater than 0.08 wt %;
[0037] wherein said lubricating oil composition contains less than
1000 ppm sulfur, less than 300 ppm phosphorus and less than 0.25 wt
% sulfated ash.
DETAILED DESCRIPTION OF THE INVENTION
[0038] In general, provided herein is a process for preparing an
ultra-low SAPS lubricating oil composition comprising: [0039] an
oil of lubricating viscosity; [0040] an aromatic dicarboxylic acid
treated dispersant supplying at least 0.30 wt. % aromatic
dicarboxylic acid to said lubricating oil composition; [0041] an
ashless peroxide decomposer present at a treat rate of from about
0.4 to 5.0 wt %; [0042] a metal deactivator wherein the metal
deactivator is present at a treat rate of greater than 0.08 wt %;
[0043] wherein said lubricating oil composition contains less than
1000 ppm sulfur, less than 300 ppm phosphorus and less than 0.25 wt
% sulfated ash.
[0044] Also provided herein is a method of lubricating an engine
with an ultra-low SAPS lubricating oil composition comprising:
[0045] an oil of lubricating viscosity; [0046] an aromatic
dicarboxylic acid treated dispersant at least 0.30 wt. % aromatic
dicarboxylic acid to said lubricating oil composition; [0047] an
ashless peroxide decomposer present at a treat rate of from about
0.4 to 5.0 wt %; [0048] a metal deactivator wherein the metal
deactivator is present at a treat rate of greater than 0.08 wt %;
[0049] wherein said lubricating oil composition contains less than
1000 ppm sulfur, less than 300 ppm phosphorus and less than 0.25 wt
% sulfated ash.
[0050] The aromatic dicarboxylic acid treated dispersant employed
in the present invention is a succinimide salt of one or more
aromatic dicarboxylic acids. Certain embodiments of the aromatic
dicarboxylic acid treated dispersant employed in the present
invention are described in published U.S. Patent Application No.
20030224948; and U.S. Pat. Nos. 3,287,271; 3,692,681; and
3,374,174, all of which are incorporated herein in their
entirety.
[0051] In one embodiment, the aromatic dicarboxylic acid treated
dispersant of the present invention may comprise one or more
dispersants having the general formula (I):
##STR00001##
[0052] where R.sup.1 is one or more polyisobutenyl groups with a
number average molecular weight of about 1100-1500, and Z is one or
more protonated poly amino radicals having from about 3 to about 7
nitrogen atoms, more preferably from about 4 to about 5 nitrogen
atoms and about 8 to about 20 carbon atoms.
[0053] In one embodiment, the aromatic dicarboxylic acid is
preferably selected from the group consisting of phthalic acid,
isophthalic acid, and terephthalic acid. In a further embodiment,
the aromatic dicarboxyllic acid may be substituted on the aromatic
ring or rings with one or more hydrocarbyl substituents such as
alkyl. In another embodiment, this invention may employ a WW
combination of one or more of the aromatic dicarboxylic acids
described herein. In one embodiment, the aromatic dicarboxylic acid
employed in the present invention is preferably terephthalic
acid.
[0054] In one embodiment, the aromatic dicarboxylic acid is present
in an amount in the range of about 0.30 to 10 wt %, based on the
total weight of the lubricating oil composition. In one embodiment,
the aromatic dicarboxylic acid is present in an amount in the range
of about 0.35 to 7 wt %, based on the total weight of the
lubricating oil composition. In one embodiment, the aromatic
dicarboxylic acid is present in an amount in the range of about
0.40 to 5 wt %, based on the total weight of the lubricating oil
composition. In one embodiment, the aromatic dicarboxylic acid is
present in an amount in the range of about 0.45 to 3 wt %, based on
the total weight of the lubricating oil composition. Preferably the
aromatic dicarboxylic acid is present in an amount of at least 0.40
wt %, based on the total weight of the lubricating oil
composition.
[0055] In one embodiment, the aromatic dicarboxylic acid treated
dispersant of the present invention is preferably terephthalic
acid. In one embodiment, the terephthalic acid is present in the
lubricating oil composition in an amount in the range of about 0.30
to 10 wt %. In one embodiment, the terephthalic acid is present in
the lubricating oil composition in an amount in the range of about
0.35 to 7 wt %. In one embodiment, the terephthalic acid is present
in the lubricating oil composition in an amount in the range of
about 0.40 to 5 wt %. In one embodiment, the terephthalic acid is
present in the lubricating oil composition in an amount in the
range of about 0.45 to 3 wt %. Preferably the terephthalic acid is
present in the lubricating oil composition in an amount of at least
0.40 wt %.
[0056] In one embodiment, the aromatic dicarboxylic acid treated
dispersant of the present invention comprise one or more
succinimide salts of terephthalic acid.
[0057] The aromatic dicarboxylic acid treated dispersant of this
invention may be synthesized as described in U.S. Pat. Nos.
3,287,271; 3,692,681; and 3,374,174, all of which are incorporated
herein in their entirety.
[0058] In one embodiment, the aromatic dicarboxylic acid treated
dispersant of this invention may be synthesized by reacting about
1100 to about 1500, preferably about 1300 molecular weight
polyisobutenyl succinic anhydride (PIBSA) with one or more
polyamines, preferably one or more heavy polyamines (HPA) at an
amine/PIBSA CMR (Charge Mole Ratio) of about 0.4 to about 0.6,
preferably about 0.45. This produces a reaction product that may
then be reacted with terephthalic acid.
[0059] In another embodiment, the aromatic dicarboxylic acid
treated dispersant of this invention may be synthesized by the
reaction of PIBSA with polyamine and terephthalic acid.
Diethylenetriamine (DETA) may be used as the polyamine in this
reaction. Any polyamine may be used.
[0060] In another embodiment, the aromatic dicarboxylic acid
treated dispersant of this invention may be synthesized as follows.
One or more PIBSAs may be reacted with one or more polyamines to
produce one or more succinimides by heating the mixture, with or
without diluent, at a temperature of from about 110.degree. C. to
about 200.degree. c., preferably about 150.degree. C. to about
170.degree. c., for 1 to 20 hours. Heating for about 3 to about 6
hours is preferred. Reactants may be mixed and then heated or
heating may occur while the reactants are being mixed. During the
heating period, water of the reaction may be removed by any means
known in the art. Any PIBSA may be used. This includes thermal
PIBSA made from conventional PIB or high reactivity PIB,
chlorination PIBSA, a mixture of thermal and chlorination PIBSA,
sulfonic acid catalyzed PIBSA, PolyPIBSA, or Terpolymer PIBSA. A
mixture of PIBSA and a copolymer may also be used. An amine/PIBSA
charge mole ratio (CMR) of about 0.4 to 0.6 may be used. A
preferred CMR (Charge Mole Ratio) may be about 0.4 to about 0.5.
After heating, the reaction mixture may be cooled to about
110.degree. C. to about 150.degree. c., preferably about
130.degree. C. to about 135.degree. C. Terephthalic acid may then
be added. About 2% to about 5% terephthalic acid, preferably about
2.5% to about 3.5% by weight, based on the succinimide weight may
be used. This mixture may then be heated for about 1 to about 10
hours, preferably about 2 to about 4 hours. The mixture may then be
filtered.
[0061] In another embodiment, this invention may comprise one or
more dispersants synthesized by reacting 1000 molecular weight
polyisobutenesuccinic anhydride (PIBSA) with tetraethylenepentamine
(TEPA) using an amine/PIBSA charge mole ratio (CMR) of 0.71. This
produces a reaction product, which may then be reacted with
terephthalic acid to form an aromatic dicarboxylic acid treated
dispersant.
[0062] In one embodiment, the aromatic dicarboxylic acid treated
dispersant of this invention supplying at least 0.30 wt. % aromatic
dicarboxylic acid is an aromatic dicarboxylic acid treated
succinimide dispersant. Examples of succinmide dispersants include,
but are not limited to, mono-succinamide and di-succinamide, and
combinations thereof.
[0063] In one embodiment, the succinmide dispersant is a
polyisobutenyl succinimide. The polyisobutenyl succinimide is
prepared by reacting a polyalkylene polyamine and polyisobutenyl
succinic anhydride under reactive conditions, wherein the
polyisobutenyl group has an average molecular weight in the range
of about 500 to 5,000, preferably about 700 to 3,000, more
preferably about 900 to 2,500, and most preferably about 950.
[0064] The aromatic dicarboxylic acid treated dispersant will
generally contain from 2.8 to 3.2 wt. % aromatic dicarboxylic
acid.
[0065] Suitable polyalkylene polyamines include ethylenediamine,
diethylenetriamine, triethylenetetramine, and
tetraethylenepentamine. The polyisobutenyl-succinimide may be
further modified by post-treatment with an aromatic carboxylic
acid, boric acid or cyclic carbonate.
[0066] Preferred amines for reaction to form the succinimide are
polyamines having from 2 to 60 carbon atoms and from 2 to 12
nitrogen atoms per molecule, and particularly preferred are the
polyalkyleneamines represented by the formula
NH.sub.2(CH.sub.2).sub.n--(NH(CH.sub.2).sub.n).sub.m--NH.sub.2
wherein n is 2 to 3 and m is 0 to 10. Illustrative are ethylene
diamine, diethylene triamine, triethylene tetramine, tetraethylene
pentamine, tetrapropylene pentamine, pentaethylene hexamine and the
like, as well as the commercially available mixtures of such
polyamines. Amines including other groups such as hydroxy, alkoxy,
amide, nitride and imidazoline groups may also be used, as may
polyoxyalkylene polyamines. The amines are reacted with the alkenyl
succinic acid or anhydride in conventional ratios of about 1:1 to
10:1, preferably 1:1 to 3:1, moles of alkenyl succinic acid or
anhydride to polyamine, and preferably in a ratio of about 1:1,
typically by heating the reactants to from 100 degree to 250 degree
C., preferably 125 degree to 175 degree C., for 1 to 10, preferably
2 to 6, hours.
[0067] In one embodiment, the oil soluble ashless peroxide
decomposer is as described U.S. Patent Application No. 20100152079
which is incorporated in its entirety.
[0068] The oil soluble ashless peroxide is a compound according to
formula I:
##STR00002##
[0069] wherein R.sub.1 and R.sub.2 and R.sub.3 and R.sub.4 are each
independently selected from the group consisting of alkyl from 1 to
20 carbon atoms, more preferably alkyl from 1 to 10 carbon atoms
and even more preferably lower alkyl from 1 to six carbon atoms.
The alkyl groups above, can have either a straight chain or a
branched chain, which are fully saturated hydrocarbon chain; for
example, methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl,
octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl,
pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, and the
like, and isomers and mixtures thereof. An example of a suitable
hindered amine that may be used in the present invention is
N,N,N',N'-tetramethyl-naphthalene-1,8-diamine and sold by
Sigma-Aldrich as Proton-Sponge.TM.. The
N,N,N',N'-tetramethyl-naphthalene-1,8-diamine is a strained
molecule due to the close proximity to the dimethylamine groups.
The free base is destabilized by the steric inhibition of
resonance, van der Walls repulsions, and lone pair interactions.
These strains are typically relieved by monoprotonation and
formation of an intramolecular hydrogen bond and thus can
effectively alter the equilibrium constant of the hydroperoxide
decomposition reaction. This imparts a high basicity relative to
normal aliphatic amines or aromatic amines and which is necessary
to deprotonate a hydroperoxide. Deprotonation of the peroxide would
render the oxygen-oxygen bond more stable toward decomposition into
radicals. The strong basicity of the
N,N,N',N'-tetramethyl-naphthalene-1,8-diamine can be ascribed to
the operation of several factors, e.g. the steric inhibition of
conjugation in the free base, relief of nonbonded repulsions,
including a little lone pair/lone pair repulsion, stabilization of
the cation by the hydrogen bonding, etc. Clearly the
N,N,N',N'-tetramethyl-naphthalene-1,8-diamine structure is
compromise involving several factors including a twist in the
naphthalene ring system, favorable lone pair/n overlap, lone
pair/methyl nonbonded interactions, and lone pair/lone pair
repulsion.
[0070] The compounds of formula I are selected with sufficient
alkyl groups to be oil soluble in the lubricating composition and
thus the compound of formula I are combined with an oil of
lubricating viscosity. The concentration of the compound of formula
I in the lubricating composition can vary depending upon the
requirements, applications and effect or degree of synergy desired.
In a preferred embodiment of the invention, a practical
N,N,N',N'-tetraalkyl-naphthalene-1,8-diamine use range in the
lubricating composition is from about 0.4 to 10.0 wt %, and
preferably from 0.5 to 3.0 wt %. based on the total weight of the
lubricating oil composition. The
N,N,N',N'-tetraalkyl-naphthalene-1,8-diamine compound of formula I
can be used as a complete or partial replacement for commercially
available antioxidants currently used in lubricant formulations and
can be in combination with other additives typically found in motor
oils and fuels. When used in combination with other types of
antioxidants or additives used in oil formulations, synergistic
and/or additive performance effects may also be obtained with
respect to improved antioxidancy, antiwear, frictional and
detergency and high temperature engine deposit properties. Such
other additives can be any presently known or later-discovered
additives used in formulating lubricating oil compositions. The
lubricating oil additives typically found in lubricating oils are,
for example, dispersants, detergents, corrosion/rust inhibitors,
antioxidants, anti-wear agents, anti-foamants, friction modifiers,
seal swell agents, emulsifiers, VI improvers, pour point
depressants, and the like.
[0071] Inhibition of free radical-mediated oxidation is one of the
most important reactions in organic substrates and is commonly used
in rubbers, polymers and lubrication oils; namely, since these
chemical products may undergo oxidative damage by the autoxidation
process. Hydrocarbon oxidation is a three step process which
comprises: initiation, propagation and termination. Oxidative
degradation and the reaction mechanisms are dependent upon the
specific hydrocarbons, temperatures, operating conditions,
catalysts such as metals, etc., which more detail can be found in
Chapter 4 of Mortier R. M. et al., 1992, "Chemistry and Technology
of Lubricants Initiation", VCH Publishers, Inc.; incorporated
herein by reference in its entirety. Initiation involves the
reaction of oxygen or nitrogen oxides (NO.sub.x) on a hydrocarbon
molecule. Typically, initiation starts by the abstraction of
hydrocarbon proton. This may result in the formation of hydrogen
peroxide (HOOH) and radicals such as alkyl radicals (R.) and peroxy
radicals (ROO.). During the propagation stage, hydroperoxides may
decompose, either on their own or in the presence of catalysts such
as metal ions, to alkoxy radicals (R.) and peroxy radicals. These
radicals can react with the hydrocarbons to form a variety of
additional radicals and reactive oxygen containing compounds such
as alcohols, aldehydes, ketones and carboxylic acids; which again
can further polymerize or continue chain propagation. Termination
results from the self termination of radicals or by reacting with
oxidation inhibitors.
[0072] The uncatalyzed oxidation of hydrocarbons at temperatures of
up to about 120.degree. C. primarily leads to alkyl-hydroperoxides,
dialkylperoxides, alcohols, ketones; as well as the products which
result from cleavage of dihydroperoxides such as diketones,
keto-aldehydes hydroxyketones and so forth. At higher temperatures
(above 120.degree. C.) the reaction rates are increased and
cleavage of the hydroperoxides plays a more important role. Since
autoxidation is a free-radical chain reaction, it therefore, can be
inhibited at the initiation and/or propagation steps. Hydroperoxide
decomposers convert the hydroperoxides into non-radical products
and thus prevent the chain propagation reaction. Traditionally
organosulfur and organophosphorous containing additives have been
employed for this purpose typically eliminating hydroperoxides via
acid catalyzed decomposition or oxygen transfer. However as
mentioned previously, increased concerns regarding total sulfur
and/or phosphorous content in finished lubricating oil has led to
efforts to reduce or eliminate sulfur and phosphorous in lubricant
oil formulations. The oil soluble ashless peroxide decomposer
according to formula I is a potent decomposer which converts
hydroperoxides into non-radical products and thus prevent the chain
propagation reaction.
[0073] The oil soluble ashless peroxide decomposer compound
according to formula I is effective by itself when employed in a
lubricating oil composition. The oil soluble ashless peroxide
decomposer compound according to formula I can function as an
antioxidant and can also be employed in combination with other free
radical antioxidants.
[0074] In one embodiment sulfur is present in the lubricating oil
composition at less than 1000 ppm, less than 800 ppm, less than 500
ppm, less than 300 ppm, less than 100 ppm less than 50 ppm, less
than 10 ppm, and 0 ppm.
[0075] In one embodiment phosphorous is present in the lubricating
oil composition at less than 300 ppm, less than 200 ppm, less than
100 ppm, less than 50 ppm, less than 10 ppm, and 0 ppm.
[0076] In one embodiment sulfated ash is present in the lubricating
oil composition at less than 0.25 wt %, less than 0.20 wt %, less
than 0.15 wt %, less than 0.10 wt %, less than 0.05 wt %, less than
0.01 wt %., and 0 wt.
[0077] In one embodiment of the present invention the lubricating
oil composition contains less than 800 ppm sulfur, less than 200
ppm phosphorous, and less than 0.20 wt % sulfated ash.
[0078] In one embodiment of the present invention the lubricating
oil composition contains less than 500 ppm sulfur, less than 100
ppm phosphorous, and less than 0.15 wt % sulfated ash.
[0079] In one embodiment of the present invention the lubricating
oil composition contains less than 300 ppm sulfur, less than 50 ppm
phosphorous, and less than 0.10 wt % sulfated ash.
[0080] In one embodiment of the present invention the lubricating
oil composition contains less than 100 ppm sulfur, 0 ppm
phosphorous, and less than 0.05 wt % sulfated ash.
[0081] In one embodiment of the present invention the lubricating
oil composition contains less than 50 ppm sulfur, 0 ppm
phosphorous, and less than 0.05 wt % sulfated ash.
[0082] In another embodiment, the lubricating oil composition
comprises an ashless metal deactivator. Some non-limiting examples
of suitable metal deactivators include disalicylidene
propylenediamine, triazole derivatives, thiadiazole derivatives,
and mercaptobenzimidazoles.
[0083] The metal deactivator component of the present invention is
preferably an aromatic triazole or an alkyl-substituted aromatic
triazole; for example, benzotriazole, tolyltriazole, or mixtures
thereof. The most preferred triazole for use is tolyltriazole. The
metal deactivator is employed at concentrations of about 0.1-0.5 wt
%; preferably about 0.1-0.4 wt. %; preferably about 0.1-0.3 wt. %;
and more preferably about 0.1-0.2 wt. %. Metal deactivators are
useful in improving the corrosion protection of copper and copper
alloys.
[0084] The aromatic dicarboxylic acid treated dispersant will
generally contain from 2.8 to 3.2 wt. % terephthalic acid.
The Oil of Lubricating Viscosity
[0085] The base oil of lubricating viscosity for use in the
lubricating oil compositions of this invention is typically present
in a major amount, e.g., an amount of greater than 50 wt. %,
preferably greater than about 70 wt. %, more preferably from about
80 to about 99.5 wt. % and most preferably from about 85 to about
98 wt. %, based on the total weight of the composition. The
expression "base oil" as used herein shall be understood to mean a
base stock or blend of base stocks which is a lubricant component
that is produced by a single manufacturer to the same
specifications (independent of feed source or manufacturer's
location); that meets the same manufacturer's specification; and
that is identified by a unique formula, product identification
number, or both. The base oil for use herein can be any presently
known or later-discovered base oil of lubricating viscosity used in
formulating lubricating oil compositions for any and all such
applications, e.g., engine oils, marine cylinder oils, functional
fluids such as hydraulic oils, gear oils, transmission fluids, etc.
Additionally, the base oils for use herein can optionally contain
viscosity index improvers, e.g., polymeric alkylmethacrylates;
olefinic copolymers, e.g., an ethylene-propylene copolymer or a
styrene-butadiene copolymer; and the like and mixtures thereof.
[0086] As one skilled in the art would readily appreciate, the
viscosity of the base oil is dependent upon the application.
Accordingly, the viscosity of a base oil for use herein will
ordinarily range from about 2 to about 2000 centistokes (cSt) at
100.degree. Centigrade (C). Generally, individually the base oils
used as engine oils will have a kinematic viscosity range at
100.degree. C. of about 2 cSt to about 30 cSt, preferably about 3
cSt to about 16 cSt, and most preferably about 4 cSt to about 12
cSt and will be selected or blended depending on the desired end
use and the additives in the finished oil to give the desired grade
of engine oil, e.g., a lubricating oil composition having an SAE
Viscosity Grade of 0W, 0W-16, 0W-20, 0W-30, 0W-40, 0W-50, 0W-60,
5W, 5W-20, 5W-30, 5W-40, 5W-50, 5W-60, 10W, 10W-20, 10W-30, 10W-40,
10W-50, 15W, 15W-20, 15W-30, 15W-40, 20W-40 or 20W-50. Oils used as
gear oils can have viscosities ranging from about 2 cSt to about
2000 cSt at 100.degree. C.
[0087] Base stocks may be manufactured using a variety of different
processes including, but not limited to, distillation, solvent
refining, hydrogen processing, oligomerization, esterification, and
rerefining. Rerefined stock shall be substantially free from
materials introduced through manufacturing, contamination, or
previous use. The base oil of the lubricating oil compositions of
this invention may be any natural or synthetic lubricating base
oil. Suitable hydrocarbon synthetic oils include, but are not
limited to, oils prepared from the polymerization of ethylene or
from the polymerization of 1-olefins to provide polymers such as
polyalphaolefin or PAO oils, or from hydrocarbon synthesis
procedures using carbon monoxide and hydrogen gases such as in a
Fischer-Tropsch process. For example, a suitable base oil is one
that comprises little, if any, heavy fraction; e.g., little, if
any, lube oil fraction of viscosity 20 cSt or higher at 100.degree.
C.
[0088] The base oil may be derived from natural lubricating oils,
synthetic lubricating oils or mixtures thereof. Suitable base oil
includes base stocks obtained by isomerization of synthetic wax and
slack wax, as well as hydrocracked base stocks produced by
hydrocracking (rather than solvent extracting) the aromatic and
polar components of the crude. Suitable base oils include those in
all API categories I, II, III, IV and V as defined in API
Publication 1509, 14th Edition, Addendum I, December 1998. Group IV
base oils are polyalphaolefins (PAO). Group V base oils include all
other base oils not included in Group I, II, III, or IV. Although
Group II, III and IV base oils are preferred for use in this
invention, these base oils may be prepared by combining one or more
of Group I, II, III, IV and V base stocks or base oils.
[0089] Useful natural oils include mineral lubricating oils such
as, for example, liquid petroleum oils, solvent-treated or
acid-treated mineral lubricating oils of the paraffinic, naphthenic
or mixed paraffinic-naphthenic types, oils derived from coal or
shale, animal oils, vegetable oils (e.g., rapeseed oils, castor
oils and lard oil), and the like.
[0090] Useful synthetic lubricating oils include, but are not
limited to, hydrocarbon oils and halo-substituted hydrocarbon oils
such as polymerized and interpolymerized olefins, e.g.,
polybutylenes, polypropylenes, propylene-isobutylene copolymers,
chlorinated polybutylenes, poly(1-hexenes), poly(1-octenes),
poly(1-decenes), and the like and mixtures thereof; alkylbenzenes
such as dodecylbenzenes, tetradecylbenzenes, dinonylbenzenes,
di(2-ethylhexyl)-benzenes, and the like; polyphenyls such as
biphenyls, terphenyls, alkylated polyphenyls, and the like;
alkylated diphenyl ethers and alkylated diphenyl sulfides and the
derivative, analogs and homologs thereof and the like.
[0091] Other useful synthetic lubricating oils include, but are not
limited to, oils made by polymerizing olefins of less than 5 carbon
atoms such as ethylene, propylene, butylenes, isobutene, pentene,
and mixtures thereof. Methods of preparing such polymer oils are
well known to those skilled in the art.
[0092] Additional useful synthetic hydrocarbon oils include liquid
polymers of alpha olefins having the proper viscosity. Especially
useful synthetic hydrocarbon oils are the hydrogenated liquid
oligomers of C.sub.6 to C.sub.12 alpha olefins such as, for
example, 1-decene trimer.
[0093] Another class of useful synthetic lubricating oils include,
but are not limited to, alkylene oxide polymers, i.e.,
homopolymers, interpolymers, and derivatives thereof where the
terminal hydroxyl groups have been modified by, for example,
esterification or etherification. These oils are exemplified by the
oils prepared through polymerization of ethylene oxide or propylene
oxide, the alkyl and phenyl ethers of these polyoxyalkylene
polymers (e.g., methyl poly propylene glycol ether having an
average molecular weight of 1,000, diphenyl ether of polyethylene
glycol having a molecular weight of 500-1000, diethyl ether of
polypropylene glycol having a molecular weight of 1,000-1,500,
etc.) or mono- and polycarboxylic esters thereof such as, for
example, the acetic esters, mixed C.sub.3-C.sub.8 fatty acid
esters, or the C.sub.13 oxo acid diester of tetraethylene
glycol.
[0094] Yet another class of useful synthetic lubricating oils
include, but are not limited to, the esters of dicarboxylic acids
e.g., phthalic acid, succinic acid, alkyl succinic acids, alkenyl
succinic acids, maleic acid, azelaic acid, suberic acid, sebacic
acid, fumaric acid, adipic acid, linoleic acid dimer, malonic
acids, alkyl malonic acids, alkenyl malonic acids, etc., with a
variety of alcohols, e.g., butyl alcohol, hexyl alcohol, dodecyl
alcohol, 2-ethylhexyl alcohol, ethylene glycol, diethylene glycol
monoether, propylene glycol, etc. Specific examples of these esters
include dibutyl adipate, di(2-ethylhexyl)sebacate, di-n-hexyl
fumarate, dioctyl sebacate, diisooctyl azelate, diisodecyl azelate,
dioctyl phthalate, didecyl phthalate, dieicosyl sebacate, the
2-ethylhexyl diester of linoleic acid dimer, the complex ester
formed by reacting one mole of sebacic acid with two moles of
tetraethylene glycol and two moles of 2-ethylhexanoic acid and the
like.
[0095] Esters useful as synthetic oils also include, but are not
limited to, those made from carboxylic acids having from about 5 to
about 12 carbon atoms with alcohols, e.g., methanol, ethanol, etc.,
polyols and polyol ethers such as neopentyl glycol, trimethylol
propane, pentaerythritol, dipentaerythritol, tripentaerythritol,
and the like.
[0096] Silicon-based oils such as, for example, polyalkyl-,
polyaryl-, polyalkoxy- or polyaryloxy-siloxane oils and silicate
oils, comprise another useful class of synthetic lubricating oils.
Specific examples of these include, but are not limited to,
tetraethyl silicate, tetra-isopropyl silicate,
tetra-(2-ethylhexyl)silicate, tetra-(4-methyl-hexyl)silicate,
tetra-(p-tert-butylphenyl)silicate,
hexyl-(4-methyl-2-pentoxy)disiloxane, poly(methyl)siloxanes,
poly(methylphenyl)siloxanes, and the like. Still yet other useful
synthetic lubricating oils include, but are not limited to, liquid
esters of phosphorous containing acids, e.g., tricresyl phosphate,
trioctyl phosphate, diethyl ester of decane phosphionic acid, etc.,
polymeric tetrahydrofurans and the like.
[0097] The lubricating oil may be derived from unrefined, refined
and rerefined oils, either natural, synthetic or mixtures of two or
more of any of these of the type disclosed hereinabove. Unrefined
oils are those obtained directly from a natural or synthetic source
(e.g., coal, shale, or tar sands bitumen) without further
purification or treatment. Examples of unrefined oils include, but
are not limited to, a shale oil obtained directly from retorting
operations, a petroleum oil obtained directly from distillation or
an ester oil obtained directly from an esterification process, each
of which is then used without further treatment. Refined oils are
similar to the unrefined oils except they have been further treated
in one or more purification steps to improve one or more
properties. These purification techniques are known to those of
skill in the art and include, for example, solvent extractions,
secondary distillation, acid or base extraction, filtration,
percolation, hydrotreating, dewaxing, etc. Rerefined oils are
obtained by treating used oils in processes similar to those used
to obtain refined oils. Such rerefined oils are also known as
reclaimed or reprocessed oils and often are additionally processed
by techniques directed to removal of spent additives and oil
breakdown products.
[0098] Lubricating oil base stocks derived from the
hydroisomerization of wax may also be used, either alone or in
combination with the aforesaid natural and/or synthetic base
stocks. Such wax isomerate oil is produced by the
hydroisomerization of natural or synthetic waxes or mixtures
thereof over a hydroisomerization catalyst.
[0099] Natural waxes are typically the slack waxes recovered by the
solvent dewaxing of mineral oils; synthetic waxes are typically the
wax produced by the Fischer-Tropsch process.
Lubricating Oil Additives
[0100] The lubricating oil compositions of the present invention
may also contain other conventional additives for imparting
auxiliary functions to give a finished lubricating oil composition
in which these additives are dispersed or dissolved. For example,
the lubricating oil compositions can be blended with antioxidants,
anti-wear agents, ashless dispersants, detergents, rust inhibitors,
dehazing agents, demulsifying agents, metal deactivating agents,
friction modifiers, pour point depressants, antifoaming agents,
co-solvents, package compatibilisers, corrosion-inhibitors, dyes,
extreme pressure agents and the like and mixtures thereof. A
variety of the additives are known and commercially available.
These additives, or their analogous compounds, can be employed for
the preparation of the lubricating oil compositions of the
invention by the usual blending procedures.
[0101] Examples of antioxidants include, but are not limited to,
aminic types, e.g., diphenylamine, phenyl-alpha-napthyl-amine,
N,N-di(alkylphenyl)amines; and alkylated phenylene-diamines;
phenolics such as, for example, BHT, sterically hindered alkyl
phenols such as 2,6-di-tert-butylphenol, 2,6-di-tert-butyl-p-cresol
and 2,6-di-tert-butyl-4-(2-octyl-3-propanoic) phenol; and mixtures
thereof. The antioxidants of the present invention can be aminic,
phenolic, or mixtures thereof.
[0102] Examples of antiwear agents include, but are not limited to,
zinc dialkyldithiophosphates and zinc diaryldithiophosphates, e.g.,
those described in an article by Born et al. entitled "Relationship
between Chemical Structure and Effectiveness of Some Metallic
Dialkyl- and Diaryl-dithiophosphates in Different Lubricated
Mechanisms", appearing in Lubrication Science 4-2 Jan. 1992, see
for example pages 97-100; aryl phosphates and phosphites,
sulfur-containing esters, phosphosulfur compounds, metal or
ash-free dithiocarbamates, xanthates, alkyl sulfides and the like
and mixtures thereof.
[0103] Representative examples of ashless dispersants include, but
are not limited to, amines, alcohols, amides, or ester polar
moieties attached to the polymer backbones via bridging groups. An
ashless dispersant of the present invention may be, for example,
selected from oil soluble salts, esters, amino-esters, amides,
imides, and oxazolines of long chain hydrocarbon substituted mono
and dicarboxylic acids or their anhydrides; thiocarboxylate
derivatives of long chain hydrocarbons, long chain aliphatic
hydrocarbons having a polyamine attached directly thereto; and
Mannich condensation products formed by condensing a long chain
substituted phenol with formaldehyde and polyalkylene
polyamine.
[0104] Carboxylic dispersants are reaction products of carboxylic
acylating agents (acids, anhydrides, esters, etc.) comprising at
least about 34 and preferably at least about 54 carbon atoms with
nitrogen containing compounds (such as amines), organic hydroxy
compounds (such as aliphatic compounds including monohydric and
polyhydric alcohols, or aromatic compounds including phenols and
naphthols), and/or basic inorganic materials. These reaction
products include imides, amides, and esters.
[0105] Succinimide dispersants are a type of carboxylic dispersant.
They are produced by reacting hydrocarbyl-substituted succinic
acylating agent with organic hydroxy compounds, or with amines
comprising at least one hydrogen atom attached to a nitrogen atom,
or with a mixture of the hydroxy compounds and amines. The term
"succinic acylating agent" refers to a hydrocarbon-substituted
succinic acid or a succinic acid-producing compound, the latter
encompasses the acid itself. Such materials typically include
hydrocarbyl-substituted succinic acids, anhydrides, esters
(including half esters) and halides.
[0106] Succinic-based dispersants have a wide variety of chemical
structures. One class of succinic-based dispersants may be
represented by the formula:
##STR00003##
wherein each R.sup.1 is independently a hydrocarbyl group, such as
a polyolefin-derived group. Typically the hydrocarbyl group is an
alkyl group, such as a polyisobutyl group. Alternatively expressed,
the R.sup.1 groups can contain about 40 to about 500 carbon atoms,
and these atoms may be present in aliphatic forms. R.sup.2 is an
alkylene group, commonly an ethylene (C.sub.2H.sub.4) group.
Examples of succinimide dispersants include those described in, for
example, U.S. Pat. Nos. 3,172,892, 4,234,435 and 6,165,235.
[0107] The polyalkenes from which the substituent groups are
derived are typically homopolymers and interpolymers of
polymerizable olefin monomers of 2 to about 16 carbon atoms, and
usually 2 to 6 carbon atoms. The amines which are reacted with the
succinic acylating agents to form the carboxylic dispersant
composition can be monoamines or polyamines.
[0108] Succinimide dispersants are referred to as such since they
normally contain nitrogen largely in the form of imide
functionality, although the amide functionality may be in the form
of amine salts, amides, imidazolines as well as mixtures thereof.
To prepare a succinimide dispersant, one or more succinic
acid-producing compounds and one or more amines are heated and
typically water is removed, optionally in the presence of a
substantially inert organic liquid solvent/diluent. The reaction
temperature can range from about 80.degree. C. up to the
decomposition temperature of the mixture or the product, which
typically falls between about 100.degree. C. to about 300.degree.
C. Additional details and examples of procedures for preparing the
succinimide dispersants of the present invention include those
described in, for example, U.S. Pat. Nos. 3,172,892, 3,219,666,
3,272,746, 4,234,435, 6,165,235 and 6,440,905.
[0109] Suitable ashless dispersants may also include amine
dispersants, which are reaction products of relatively high
molecular weight aliphatic halides and amines, preferably
polyalkylene polyamines. Examples of such amine dispersants include
those described in, for example, U.S. Pat. Nos. 3,275,554,
3,438,757, 3,454,555 and 3,565,804.
[0110] Suitable ashless dispersants may further include "Mannich
dispersants," which are reaction products of alkyl phenols in which
the alkyl group contains at least about 30 carbon atoms with
aldehydes (especially formaldehyde) and amines (especially
polyalkylene polyamines). Examples of such dispersants include
those described in, for example, U.S. Pat. Nos. 3,036,003,
3,586,629. 3,591,598 and 3,980,569.
[0111] Suitable ashless dispersants may also be post-treated
ashless dispersants such as post-treated succinimides, e.g.,
post-treatment processes involving borate or ethylene carbonate as
disclosed in, for example, U.S. Pat. Nos. 4,612,132 and 4,746,446;
and the like as well as other post-treatment processes. The
carbonate-treated alkenyl succinimide is a polybutene succinimide
derived from polybutenes having a molecular weight of about 450 to
about 3000, preferably from about 900 to about 2500, more
preferably from about 1300 to about 2400, and most preferably from
about 2000 to about 2400, as well as mixtures of these molecular
weights. Preferably, it is prepared by reacting, under reactive
conditions, a mixture of a polybutene succinic acid derivative, an
unsaturated acidic reagent copolymer of an unsaturated acidic
reagent and an olefin, and a polyamine, such as disclosed in U.S.
Pat. No. 5,716,912, the contents of which are incorporated herein
by reference.
[0112] An example of a suitable ashless dispersant is a borated
dispersant. Borated dispersants may be formed by boronating
(borating) an ashless dispersant having basic nitrogen and/or at
least one hydroxyl group in the molecule, such as a succinimide
dispersant, succinamide dispersant, succinic ester dispersant,
succinic ester-amide dispersant, Mannich base dispersant, or
hydrocarbyl amine or polyamine dispersant. Methods that can be used
for boronating the various types of ashless dispersants described
above are described, for example, in U.S. Pat. Nos. 4,455,243 and
4,652,387.
[0113] Suitable ashless dispersants may also be polymeric, which
are interpolymers of oil-solubilizing monomers such as decyl
methacrylate, vinyl decyl ether and high molecular weight olefins
with monomers containing polar substitutes. Examples of polymeric
dispersants include those described in, for example, U.S. Pat. Nos.
3,329,658; 3,449,250 and 3,666,730.
[0114] In one preferred embodiment of the present invention, an
ashless dispersant for use in the lubricating oil composition is a
bis-succinimide derived from a polyisobutenyl group having a number
average molecular weight of about 700 to about 2300. The
dispersant(s) for use in the lubricating oil compositions of the
present invention are preferably non-polymeric (e.g., are mono- or
bis-succinimides).
[0115] Generally, the one or more ashless dispersants are present
in the lubricating oil composition in an amount ranging from about
0.01 wt. % to about 20 wt. %, based on the total weight of the
lubricating oil composition.
[0116] Representative examples of metal detergents include
sulphonates, alkylphenates, sulfurized alkyl phenates,
carboxylates, salicylates, phosphonates, and phosphinates.
Commercial products are generally referred to as neutral or
overbased. Overbased metal detergents are generally produced by
carbonating a mixture of hydrocarbons, detergent acid, for example:
sulfonic acid, alkylphenol, carboxylate etc., metal oxide or
hydroxides (for example calcium oxide or calcium hydroxide) and
promoters such as xylene, methanol and water. For example, for
preparing an overbased calcium sulfonate, in carbonation, the
calcium oxide or hydroxide reacts with the gaseous carbon dioxide
to form calcium carbonate. The sulfonic acid is neutralized with an
excess of CaO or Ca(OH).sub.2, to form the sulfonate.
[0117] Metal-containing or ash-forming detergents function as both
detergents to reduce or remove deposits and as acid neutralizers or
rust inhibitors, thereby reducing wear and corrosion and extending
engine life. Detergents generally comprise a polar head with a long
hydrophobic tail. The polar head comprises a metal salt of an
acidic organic compound. The salts may contain a substantially
stoichiometric amount of the metal in which case they are usually
described as normal or neutral salts, and would typically have a
total base number or TBN (as can be measured by ASTM D2896) of from
0 to about 80. A large amount of a metal base may be incorporated
by reacting excess metal compound (e.g., an oxide or hydroxide)
with an acidic gas (e.g., carbon dioxide). The resulting overbased
detergent comprises neutralized detergent as the outer layer of a
metal base (e.g., carbonate) micelle. Such overbased detergents may
have a TBN of about 150 or greater, and typically will have a TBN
of from about 250 to about 450 or more.
[0118] Detergents that may be used include oil-soluble neutral and
overbased sulfonates, phenates, sulfurized phenates,
thiophosphonates, salicylates, and naphthenates and other
oil-soluble carboxylates of a metal, particularly the alkali or
alkaline earth metals, e.g., barium, sodium, potassium, lithium,
calcium, and magnesium. The most commonly used metals are calcium
and magnesium, which may both be present in detergents used in a
lubricant, and mixtures of calcium and/or magnesium with sodium.
Particularly convenient metal detergents are neutral and overbased
calcium sulfonates having TBN of from about 20 to about 450,
neutral and overbased calcium phenates and sulfurized phenates
having TBN of from about 50 to about 450 and neutral and overbased
magnesium or calcium salicylates having a TBN of from about 20 to
about 450. Combinations of detergents, whether overbased or neutral
or both, may be used.
[0119] In one embodiment, the detergent can be one or more alkali
or alkaline earth metal salts of an alkyl-substituted
hydroxyaromatic carboxylic acid. Suitable hydroxyaromatic compounds
include mononuclear monohydroxy and polyhydroxy aromatic
hydrocarbons having 1 to 4, and preferably 1 to 3, hydroxyl groups.
Suitable hydroxyaromatic compounds include phenol, catechol,
resorcinol, hydroquinone, pyrogallol, cresol, and the like. The
preferred hydroxyaromatic compound is phenol.
[0120] The alkyl substituted moiety of the alkali or alkaline earth
metal salt of an alkyl-substituted hydroxyaromatic carboxylic acid
is derived from an alpha olefin having from about 10 to about 80
carbon atoms. The olefins employed may be linear, isomerized
linear, branched or partially branched linear. The olefin may be a
mixture of linear olefins, a mixture of isomerized linear olefins,
a mixture of branched olefins, a mixture of partially branched
linear or a mixture of any of the foregoing.
[0121] In one embodiment, the mixture of linear olefins that may be
used is a mixture of normal alpha olefins selected from olefins
having from about 12 to about 30 carbon atoms per molecule. In one
embodiment, the normal alpha olefins are isomerized using at least
one of a solid or liquid catalyst.
[0122] In another embodiment, the olefins are a branched olefinic
propylene oligomer or mixture thereof having from about 20 to about
80 carbon atoms, i.e., branched chain olefins derived from the
polymerization of propylene. The olefins may also be substituted
with other functional groups, such as hydroxy groups, carboxylic
acid groups, heteroatoms, and the like. In one embodiment, the
branched olefinic propylene oligomer or mixtures thereof have from
about 20 to about 60 carbon atoms. In one embodiment, the branched
olefinic propylene oligomer or mixtures thereof have from about 20
to about 40 carbon atoms.
[0123] In one embodiment, at least about 75 mole % (e.g., at least
about 80 mole %, at least about 85 mole %, at least about 90 mole
%, at least about 95 mole %, or at least about 99 mole %) of the
alkyl groups contained within the alkali or alkaline earth metal
salt of an alkyl-substituted hydroxyaromatic carboxylic acid such
as the alkyl groups of an alkaline earth metal salt of an
alkyl-substituted hydroxybenzoic acid detergent are a C.sub.20 or
higher. In another embodiment, the alkali or alkaline earth metal
salt of an alkyl-substituted hydroxyaromatic carboxylic acid is an
alkali or alkaline earth metal salt of an alkyl-substituted
hydroxybenzoic acid that is derived from an alkyl-substituted
hydroxybenzoic acid in which the alkyl groups are the residue of
normal alpha-olefins containing at least 75 mole % C.sub.20 or
higher normal alpha-olefins.
[0124] In another embodiment, at least about 50 mole % (e.g., at
least about 60 mole %, at least about 70 mole %, at least about 80
mole %, at least about 85 mole %, at least about 90 mole %, at
least about 95 mole %, or at least about 99 mole %) of the alkyl
groups contained within the alkali or alkaline earth metal salt of
an alkyl-substituted hydroxyaromatic carboxylic acid such as the
alkyl groups of an alkali or alkaline earth metal salt of an
alkyl-substituted hydroxybenzoic acid are about C.sub.14 to about
C.sub.18.
[0125] The resulting alkali or alkaline earth metal salt of an
alkyl-substituted hydroxyaromatic carboxylic acid will be a mixture
of ortho and para isomers. In one embodiment, the product will
contain about 1 to 99% ortho isomer and 99 to 1% para isomer. In
another embodiment, the product will contain about 5 to 70% ortho
and 95 to 30% para isomer.
[0126] The alkali or alkaline earth metal salts of an
alkyl-substituted hydroxyaromatic carboxylic acid can be neutral or
overbased. Generally, an overbased alkali or alkaline earth metal
salt of an alkyl-substituted hydroxyaromatic carboxylic acid is one
in which the BN of the alkali or alkaline earth metal salts of an
alkyl-substituted hydroxyaromatic carboxylic acid has been
increased by a process such as the addition of a base source (e.g.,
lime) and an acidic overbasing compound (e.g., carbon dioxide).
[0127] Overbased salts may be low overbased, e.g., an overbased
salt having a BN below about 100. In one embodiment, the BN of a
low overbased salt may be from about 5 to about 50. In another
embodiment, the BN of a low overbased salt may be from about 10 to
about 30. In yet another embodiment, the BN of a low overbased salt
may be from about 15 to about 20.
[0128] Overbased detergents may be medium overbased, e.g., an
overbased salt having a BN from about 100 to about 250. In one
embodiment, the BN of a medium overbased salt may be from about 100
to about 200. In another embodiment, the BN of a medium overbased
salt may be from about 125 to about 175.
[0129] Overbased detergents may be high overbased, e.g., an
overbased salt having a BN above about 250. In one embodiment, the
BN of a high overbased salt may be from about 250 to about 450.
[0130] Sulfonates may be prepared from sulfonic acids which are
typically obtained by the sulfonation of alkyl substituted aromatic
hydrocarbons such as those obtained from the fractionation of
petroleum or by the alkylation of aromatic hydrocarbons. Examples
included those obtained by alkylating benzene, toluene, xylene,
naphthalene, diphenyl or their halogen derivatives. The alkylation
may be carried out in the presence of a catalyst with alkylating
agents having from about 3 to more than 70 carbon atoms. The
alkaryl sulfonates usually contain from about 9 to about 80 or more
carbon atoms, preferably from about 16 to about 60 carbon atoms per
alkyl substituted aromatic moiety.
[0131] The oil soluble sulfonates or alkaryl sulfonic acids may be
neutralized with oxides, hydroxides, alkoxides, carbonates,
carboxylate, sulfides, hydrosulfides, nitrates, borates and ethers
of the metal. The amount of metal compound is chosen having regard
to the desired TBN of the final product but typically ranges from
about 100 to about 220 wt. % (preferably at least about 125 wt. %)
of that stoichiometrically required.
[0132] Metal salts of phenols and sulfurized phenols are prepared
by reaction with an appropriate metal compound such as an oxide or
hydroxide and neutral or overbased products may be obtained by
methods well known in the art. Sulfurized phenols may be prepared
by reacting a phenol with sulfur or a sulfur containing compound
such as hydrogen sulfide, sulfur monohalide or sulfur dihalide, to
form products which are generally mixtures of compounds in which 2
or more phenols are bridged by sulfur containing bridges.
[0133] Generally, the one or more detergents are present in the
lubricating oil composition in an amount ranging from about 0.01
wt. % to about 10 wt. %, based on the total weight of the
lubricating oil composition.
[0134] Examples of rust inhibitors include, but are not limited to,
nonionic polyoxyalkylene agents, e.g., polyoxyethylene lauryl
ether, polyoxyethylene higher alcohol ether, polyoxyethylene
nonylphenyl ether, polyoxyethylene octylphenyl ether,
polyoxyethylene octyl stearyl ether, polyoxyethylene oleyl ether,
polyoxyethylene sorbitol monostearate, polyoxyethylene sorbitol
monooleate, and polyethylene glycol monooleate; stearic acid and
other fatty acids; dicarboxylic acids; metal soaps; fatty acid
amine salts; metal salts of heavy sulfonic acid; partial carboxylic
acid ester of polyhydric alcohol; phosphoric esters; (short-chain)
alkenyl succinic acids; partial esters thereof and
nitrogen-containing derivatives thereof; synthetic
alkarylsulfonates, e.g., metal dinonylnaphthalene sulfonates; and
the like and mixtures thereof.
[0135] Examples of friction modifiers include, but are not limited
to, alkoxylated fatty amines; borated fatty epoxides; fatty
phosphites, fatty epoxides, fatty amines, borated alkoxylated fatty
amines, metal salts of fatty acids, fatty acid amides, glycerol
esters, borated glycerol esters; and fatty imidazolines as
disclosed in U.S. Pat. No. 6,372,696, the contents of which are
incorporated by reference herein; friction modifiers obtained from
a reaction product of a C.sub.4 to C.sub.75, preferably a C.sub.6
to C.sub.24, and most preferably a C.sub.6 to C.sub.20, fatty acid
ester and a nitrogen-containing compound selected from the group
consisting of ammonia, and an alkanolamine and the like and
mixtures thereof.
[0136] Examples of antifoaming agents include, but are not limited
to, polymers of alkyl methacrylate; polymers of dimethylsilicone
and the like and mixtures thereof.
[0137] Examples of a pour point depressant include, but are not
limited to, polymethacrylates, alkyl acrylate polymers, alkyl
methacrylate polymers, di(tetra-paraffin phenol)phthalate,
condensates of tetra-paraffin phenol, condensates of a chlorinated
paraffin with naphthalene and combinations thereof. In one
embodiment, a pour point depressant comprises an ethylene-vinyl
acetate copolymer, a condensate of chlorinated paraffin and phenol,
polyalkyl styrene and the like and combinations thereof. The amount
of the pour point depressant may vary from about 0.01 wt. % to
about 10 wt. %.
[0138] Examples of a demulsifier include, but are not limited to,
anionic surfactants (e.g., alkyl-naphthalene sulfonates, alkyl
benzene sulfonates and the like), nonionic alkoxylated alkylphenol
resins, polymers of alkylene oxides (e.g., polyethylene oxide,
polypropylene oxide, block copolymers of ethylene oxide, propylene
oxide and the like), esters of oil soluble acids, polyoxyethylene
sorbitan ester and the like and combinations thereof. The amount of
the demulsifier may vary from about 0.01 wt. % to about 10 wt.
%.
[0139] Examples of a corrosion inhibitor include, but are not
limited to, half esters or amides of dodecylsuccinic acid,
phosphate esters, thiophosphates, alkyl imidazolines, sarcosines
and the like and combinations thereof. The amount of the corrosion
inhibitor may vary from about 0.01 wt. % to about 5 wt. %.
[0140] The corrosion inhibitor component can be a
non-polycarboxylate moiety containing thiadiazole. Preferably, the
thiadiazole comprises at least one of
2,5-dimercapto-1,3,4-thiadiazole;
2-mercapto-5-hydrocarbylthio-1,3,4-thiadiazoles;
2-mercapto-5-hydrocarbyldithio-1,3,4-thiadiazoles;
2,5-bis(hydrocarbylthio and
2,5-bis(hydrocarbyldithio)-1,3,4-thiadiazoles. The more preferred
compounds are the 1,3,4-thiadiazoles, especially the
2-hydrocarbyldithio-5-mercapto-1,3,4-dithiadiazoles and the
2,5-bis(hydrocarbyldithio)-1,3,4-thiadiazoles, a number of which
are available as articles of commerce. Most preferably, a non
polycarboxylate containing thiadiazole containing about 4.0 wt %
2,5-dimercapto-1,3,4-thiadiazole, which may be either Ethyl
Corporation's Hitec.RTM. 4313 or Lubrizol Corporation's
Lubrizol.RTM. 5955A, is used. Hitec.RTM. 4313 may be obtained from
Ethyl Corporation, Richmond, Va. and Lubrizol.RTM. 5955A may be
obtained from Lubrizol Corporation, Wycliffe, Ohio.
[0141] Examples of an extreme pressure agent include, but are not
limited to, sulfurized animal or vegetable fats or oils, sulfurized
animal or vegetable fatty acid esters, fully or partially
esterified esters of trivalent or pentavalent acids of phosphorus,
sulfurized olefins, dihydrocarbyl polysulfides, sulfurized
Diels-Alder adducts, sulfurized dicyclopentadiene, sulfurized or
co-sulfurized mixtures of fatty acid esters and monounsaturated
olefins, co-sulfurized blends of fatty acid, fatty acid ester and
alpha-olefin, functionally-substituted dihydrocarbyl polysulfides,
thia-aldehydes, thia-ketones, epithio compounds, sulfur-containing
acetal derivatives, co-sulfurized blends of terpene and acyclic
olefins, and polysulfide olefin products, amine salts of phosphoric
acid esters or thiophosphoric acid esters and the like and
combinations thereof. The amount of the extreme pressure agent may
vary from about 0.01 wt. % to about 5 wt. %.
[0142] Each of the foregoing additives, when used, is used at a
functionally effective amount to impart the desired properties to
the lubricant. Thus, for example, if an additive is a friction
modifier, a functionally effective amount of this friction modifier
would be an amount sufficient to impart the desired friction
modifying characteristics to the lubricant. Generally, the
concentration of each of these additives, when used, may range,
unless otherwise specified, from about 0.001% to about 20% by
weight, and in one embodiment about 0.01% to about 10% by weight
based on the total weight of the lubricating oil composition.
[0143] In another embodiment of the invention, the lubricating oil
additives of the present invention may be provided as an additive
package or concentrate in which the additives are incorporated into
a substantially inert, normally liquid organic diluent such as, for
example, mineral oil, naphtha, benzene, toluene or xylene to form
an additive concentrate. These concentrates usually contain from
about 20% to about 80% by weight of such diluent. Typically, a
neutral oil having a viscosity of about 4 to about 8.5 cSt at
100.degree. C. and preferably about 4 to about 6 cSt at 100.degree.
C. will be used as the diluent, though synthetic oils, as well as
other organic liquids which are compatible with the additives and
finished lubricating oil can also be used.
[0144] The following examples are presented to exemplify
embodiments of the invention but are not intended to limit the
invention to the specific embodiments set forth. Unless indicated
to the contrary, all parts and percentages are by weight. All
numerical values are approximate. When numerical ranges are given,
it should be understood that embodiments outside the stated ranges
may still fall within the scope of the invention. Specific details
described in each example should not be construed as necessary
features of the invention.
EXAMPLES
[0145] The following examples are intended for illustrative
purposes only and do not limit in any way the scope of the present
invention.
[0146] Baseline performance is exemplified by a standard GF-5 oil.
This oil has SAPS levels near the mandated limit: sulfur of 0.2 wt
%, phosphorus of 0.075 wt % and sulfated ash of 1.1 wt %.
[0147] When all additives contributing to SAPS levels were removed
(Ultra-Low SAPS oil A) the performance on the High Temperature
Corrosion Bench Test (HTCBT), Ball Rust Test (BRT) and
Thermo-oxidation engine oil simulation test at moderately high
temperature (TEOST MHT-4) dropped to unacceptable levels (Table
1).
TABLE-US-00001 TABLE 1 Oil Baseline GF5 oil Ultra-Low SAPS oil A
HTCBT (Cu/Pb) 10/32 13/338 BRT 124 25 TEOST MHT-4 44.7 160.3
[0148] Comparative examples Ultra-Low SAPS oils A to H and
inventive example 1 are shown in Table 2. In Table 2, the unit for
S (Sulfur), and P (Phosphorous) is ppm, and for Ash (Sulfated Ash)
is wt % in the fully formulated lubricating oil.
[0149] The performance of each oil was evaluated using: [0150] (a)
The High Temperature Corrosion Bench Test (HTCBT) ASTM D6594
(Version 08). Passing levels for the HTCBT are: Copper are less
than 20 ppm; and Lead less than 120 ppm. [0151] (b) Ball Rust Test
(BRT) ASTM D6557 (Version 10a). Passing for the BRT is greater than
100 Average Grey Value (AVG). [0152] (c) Thermo-oxidation engine
oil simulation test at moderately high temperature (TEOST MHT-4)
ASTM D7097 (Version 09). Passing for the TEOST MHT-4 is less than
45 mg.
TABLE-US-00002 [0152] TABLE 2 Examples A B C D E F G H 1 Aromatic
dicarboxylic acid 7.2 14.4 treated dispersant, wt % Aromatic
dicarboxylic acid in 0.23 0.46 Lubricating Oil Composition, wt %
Dispersant A, wt % 2 6.5 6.5 6.5 DispersantB, wt % 6.5 13 13 Aminic
AO, wt % 0.4 1.5 1.5 1 0.4 0.4 0.4 0.4 0.4 Phenolic AO, wt % 0.5 3
3 3 3 3 3 3 Decomposer, wt % 1 0.6 0.6 0.3 0.6 0.6 Metal
Deactivator, wt % 0.2 0.2 0.05 0.2 0.05 0.2 HTCBT Cu 13 20 2 29 4
16 8 18 20 HTCBT PB 322 828 832 338 743 854 999 10 9 BRT 25 21 26
71 34 119 64 52 103 TEOST MHT-4 160.3 57.2 26 101.2 70.9 46.8 38.2
46.4 36.1 S 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 P
0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 Ash 0.00 0.00
0.00 0.00 0.00 0.00 0.00 0.00 0.00 S (Group II Baseoil) 8.3 7.6 7.6
7.9 7.7 7.1 7.1 7.6 7.0 P (Group II Baseoil) 0.0 0.0 0.0 0.0 0.0
0.0 0.0 0.0 0.0 Ash Group II Baseoil) 0.0 0.0 0.0 0.0 0.0 0.0 0.0
0.0 0.0 S (Group III Baseoil) 4.9 4.5 4.4 4.6 4.5 4.1 4.1 4.4 4.1 P
(Group III Baseoil) 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Ash Group
III Baseoil) 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
[0153] In Table 2, the unit for S (Sulfur), and P (Phosphorous) is
ppm and for Ash (Sulfated Ash) is wt % in the fully formulated
lubricating oil.
[0154] The components in Table 2 are described below:
Aromatic Dicarboxylic Acid Treated Dispersant:
[0155] An oil concentrate of aromatic dicarboxylic acid treated
succinimide. Comparative example H has 0.23 wt % acid from the
aromatic dicarboxylic acid treated succinimide dispersant.
Inventive example 1 has 0.46 wt % acid from the aromatic
dicarboxylic acid treated succinimide dispersant.
Dispersant A:
[0156] An oil concentrate of ethylene carbonate-treated succinimide
derived from 2300 MW PIBSA and heavy polyamine (HPA).
Dispersant B:
[0157] A succinimide synthesized from 2300 MW PIBSA and heavy
polyamine (HPA).
Decomposer:
[0158] The ashless peroxide decomposer according to Formula I in
the present specification.
[0159] Table 3 is a Pass/Fail summary of Comparative Examples A to
H and Inventive Example 1 in the HT CBT (Cu, Pb), BRT and TEOST
tests.
TABLE-US-00003 TABLE 3 TEST Cu Pb BRT TEOST Comparative Example A
Pass Fail Fail Fail Comparative Example B Pass Fail Fail Fail
Comparative Example C Pass Fail Fail Pass Comparative Example D
Fail Fail Fail Fail Comparative Example E Pass Fail Fail Fail
Comparative Example F Pass Fail Pass Fail Comparative Example G
Pass Fail Fail Pass Comparative Example H Pass Pass Fail Fail
Inventive Example 1 Pass Pass Pass Pass
* * * * *