U.S. patent application number 16/666645 was filed with the patent office on 2020-05-07 for lubricating oil compositions having improved cleanliness and wear performance.
The applicant listed for this patent is ExxonMobil Research and Engineering Company. Invention is credited to Smruti Dance, Douglas E. Deckman, Luca Salvi, Jordan C. Smith.
Application Number | 20200140775 16/666645 |
Document ID | / |
Family ID | 68582481 |
Filed Date | 2020-05-07 |
![](/patent/app/20200140775/US20200140775A1-20200507-D00001.png)
![](/patent/app/20200140775/US20200140775A1-20200507-D00002.png)
![](/patent/app/20200140775/US20200140775A1-20200507-D00003.png)
![](/patent/app/20200140775/US20200140775A1-20200507-D00004.png)
![](/patent/app/20200140775/US20200140775A1-20200507-D00005.png)
![](/patent/app/20200140775/US20200140775A1-20200507-D00006.png)
![](/patent/app/20200140775/US20200140775A1-20200507-D00007.png)
![](/patent/app/20200140775/US20200140775A1-20200507-M00001.png)
United States Patent
Application |
20200140775 |
Kind Code |
A1 |
Smith; Jordan C. ; et
al. |
May 7, 2020 |
LUBRICATING OIL COMPOSITIONS HAVING IMPROVED CLEANLINESS AND WEAR
PERFORMANCE
Abstract
A method for improving wear protection, while maintaining or
improving deposit control and cleanliness, in an engine or other
mechanical component lubricated with a lubricating oil by using as
the lubricating oil a formulated oil. The formulated oil has a
composition including a lubricating oil base stock as a major
component, and one or more lubricating oil additives including at
least one borated detergent, as a minor component. The at least one
borated detergent comprises a borated alkaline earth metal
sulfonate. The borated alkaline earth metal sulfonate is present in
an amount sufficient to provide a total boron concentration of
about 300 parts per million or greater in the formulated oil. Wear
protection is improved, and deposit control and cleanliness are
maintained or improved, as compared to wear protection, deposit
control and cleanliness achieved using a lubricating oil containing
a borated additive other than the at least one borated alkaline
earth metal sulfonate.
Inventors: |
Smith; Jordan C.; (Spring,
TX) ; Dance; Smruti; (Warren, NJ) ; Deckman;
Douglas E.; (Easton, PA) ; Salvi; Luca;
(Haddonfield, NJ) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
ExxonMobil Research and Engineering Company |
Annandale |
NJ |
US |
|
|
Family ID: |
68582481 |
Appl. No.: |
16/666645 |
Filed: |
October 29, 2019 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
62755646 |
Nov 5, 2018 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C10N 2030/06 20130101;
C10N 2040/25 20130101; C10M 2207/262 20130101; C10M 2215/04
20130101; C10M 2215/082 20130101; C10M 2201/062 20130101; C10M
159/24 20130101; C10N 2030/54 20200501; C10M 2207/2805 20130101;
C10M 2207/144 20130101; C10N 2030/04 20130101; C10M 2203/1025
20130101; C10M 2203/1006 20130101; C10N 2030/52 20200501; C10N
2030/45 20200501; C10M 2219/046 20130101; C10M 2215/28 20130101;
C10M 2205/0285 20130101; C10M 169/04 20130101; C10M 2207/289
20130101; C10M 2205/223 20130101; C10M 2219/046 20130101; C10N
2010/04 20130101; C10N 2060/14 20130101; C10M 2215/28 20130101;
C10N 2060/14 20130101; C10M 2215/082 20130101; C10N 2010/12
20130101; C10M 2201/062 20130101; C10N 2010/12 20130101; C10M
2207/262 20130101; C10N 2010/04 20130101; C10M 2207/144 20130101;
C10N 2010/04 20130101; C10M 2203/1025 20130101; C10N 2020/02
20130101; C10M 2215/28 20130101; C10N 2060/14 20130101; C10M
2207/289 20130101; C10N 2060/14 20130101; C10M 2219/046 20130101;
C10N 2010/04 20130101; C10N 2060/14 20130101 |
International
Class: |
C10M 139/00 20060101
C10M139/00; C10M 169/04 20060101 C10M169/04; C10M 135/10 20060101
C10M135/10; C10M 141/12 20060101 C10M141/12 |
Claims
1. A method for improving wear protection, while maintaining or
improving deposit control and cleanliness, in an engine or other
mechanical component lubricated with a lubricating oil by using as
the lubricating oil a formulated oil, said formulated oil having a
composition comprising a lubricating oil base stock as a major
component; and one or more lubricating oil additives, as a minor
component; wherein the one or more lubricating oil additives
comprise at least one borated detergent; wherein the at least one
borated detergent comprises a borated alkaline earth metal
sulfonate; wherein the borated alkaline earth metal sulfonate is
present in an amount sufficient to provide a total boron
concentration of about 300 parts per million or greater in the
formulated oil; and wherein wear protection is improved, and
deposit control and cleanliness are maintained or improved, as
compared to wear protection, deposit control and cleanliness
achieved using a lubricating oil containing a borated additive
other than the at least one borated alkaline earth metal
sulfonate.
2. The method of claim 1 wherein, in wear measurements of the
lubricating oil by a Sequence IVB engine test, intake lifter wear
(mm.sup.3) is improved as compared to intake lifter wear (mm.sup.3)
achieved using a lubricating oil containing a borated additive
other than the at least one borated alkaline earth metal
sulfonate.
3. The method of claim 1 wherein, in deposit measurements of the
lubricating oil by thermo-oxidation engine oil simulation (TEOST
33C) measured by ASTM D6335, the amount of total deposits is
maintained or reduced as compared to the amount of total deposits
in a lubricating oil containing a borated additive other than the
at least one borated alkaline earth metal sulfonate.
4. The method of claim 1 wherein wear control is improved and
deposit, varnish and sludge control, and fuel efficiency are
maintained or improved as compared to wear control, deposit,
varnish and sludge control, and fuel efficiency achieved using a
lubricating oil containing a borated additive other than the at
least one borated alkaline earth metal sulfonate.
5. The method of claim 1 wherein, in deposit measurements of the
lubricating oil by thermo-oxidation engine oil simulation (TEOST
33C) measured by ASTM D6335, the amount of total deposits is less
than about 30 mg.
6. The method of claim 1 wherein the borated alkaline earth metal
sulfonate detergent comprises borated calcium sulfonate.
7. The method of claim 1 wherein the borated alkaline earth metal
sulfonate is present in an amount sufficient to provide a total
boron concentration of about 350 parts per million or greater, or
about 400 parts per million or greater, or about 450 parts per
million or greater, or about 500 parts per million or greater, or
about 550 parts per million or greater, or about 600 parts per
million or greater, or about 650 parts per million or greater, or
about 700 parts per million or greater, or about 750 parts per
million or greater, or about 800 parts per million or greater, or
about 850 parts per million or greater, or about 900 parts per
million or greater, or about 950 parts per million or greater, or
about 1000 parts per million or greater, in the formulated oil.
8. The method of claim 1 wherein the one or more lubricating oil
additives further comprise an alkaline earth metal sulfonate
detergent system or a mixed alkaline earth metal sulfonate
detergent system.
9. The method of claim 8 wherein the mixed alkaline earth metal
sulfonate detergent system comprises a calcium/magnesium sulfonate
detergent system.
10. The method of claim 1 wherein the total amount of soap
delivered by the at least one borated detergent is less than about
1.0 weight percent of the lubricating oil.
11. The method of claim 1 wherein the lubricating oil base stock
comprises a Group I, Group II, Group III, Group IV or Group V base
oil.
12. The method of claim 1 wherein the at least one borated
detergent is present in an amount of from about 0.001 weight
percent to about 20 weight percent, based on the total weight of
the formulated oil.
13. The method of claim 1 wherein the lubricating oil base stock is
present in an amount of from about 6 weight percent to about 95
weight percent, based on the total weight of the formulated
oil.
14. The method of claim 1 wherein the one or more lubricating oil
additives further comprise one or more of an antiwear additive,
viscosity modifier, antioxidant, other detergent, dispersant, pour
point depressant, corrosion inhibitor, metal deactivator, seal
compatibility additive, anti-foam agent, inhibitor, friction
modifier, and anti-rust additive.
15. The method of claim 1 wherein the lubricating oil is a
passenger vehicle engine oil (PVEO).
16. A lubricating oil composition comprising a lubricating oil base
stock as a major component, and one or more lubricating oil
additives, as a minor component; wherein the one or more
lubricating oil additives comprise at least one borated detergent;
wherein the at least one borated detergent comprises a borated
alkaline earth metal sulfonate; wherein the borated alkaline earth
metal sulfonate is present in an amount sufficient to provide a
total boron concentration of about 300 parts per million or greater
in the lubricating oil; and wherein wear protection is improved,
and deposit control and cleanliness are maintained or improved, in
an engine or other mechanical component lubricated with the
lubricating oil, as compared to wear protection, deposit control
and cleanliness achieved using a lubricating oil containing a
borated additive other than the at least one borated alkaline earth
metal sulfonate.
17. The lubricating oil composition of claim 16 wherein, in wear
measurements of the lubricating oil by a Sequence IVB engine test,
intake lifter wear (mm.sup.3) is improved as compared to intake
lifter wear (mm.sup.3) achieved using a lubricating oil containing
a borated additive other than the at least one borated alkaline
earth metal sulfonate.
18. The lubricating oil composition of claim 16 wherein, in deposit
measurements of the lubricating oil by thermo-oxidation engine oil
simulation (TEOST 33C) measured by ASTM D6335, the amount of total
deposits is maintained or reduced as compared to the amount of
total deposits in a lubricating oil containing a borated additive
other than the at least one borated alkaline earth metal
sulfonate.
19. The lubricating oil composition of claim 16 wherein wear
control is improved and deposit, varnish and sludge control, and
fuel efficiency are maintained or improved as compared to wear
control, deposit, varnish and sludge control, and fuel efficiency
achieved using a lubricating oil containing a borated additive
other than the at least one borated alkaline earth metal
sulfonate.
20. The lubricating oil composition of claim 16 wherein, in deposit
measurements of the lubricating oil by thermo-oxidation engine oil
simulation (TEOST 33C) measured by ASTM D6335, the amount of total
deposits is less than about 30 mg.
21. The lubricating oil composition of claim 16 wherein the borated
alkaline earth metal sulfonate detergent comprises borated calcium
sulfonate.
22. The lubricating oil composition of claim 16 wherein the borated
alkaline earth metal sulfonate is present in an amount sufficient
to provide a total boron concentration of about 350 parts per
million or greater, or about 400 parts per million or greater, or
about 450 parts per million or greater, or about 500 parts per
million or greater, or about 550 parts per million or greater, or
about 600 parts per million or greater, or about 650 parts per
million or greater, or about 700 parts per million or greater, or
about 750 parts per million or greater, or about 800 parts per
million or greater, or about 850 parts per million or greater, or
about 900 parts per million or greater, or about 950 parts per
million or greater, or about 1000 parts per million or greater, in
the lubricating oil.
23. The lubricating oil composition of claim 16 wherein the one or
more lubricating oil additives further comprise an alkaline earth
metal sulfonate detergent system or a mixed alkaline earth metal
sulfonate detergent system.
24. The lubricating oil composition of claim 23 wherein the mixed
alkaline earth metal sulfonate detergent system comprises a
calcium/magnesium sulfonate detergent system.
25. The lubricating oil composition of claim 16 wherein the total
amount of soap delivered by the at least one borated detergent is
less than about 1.5 weight percent of the lubricating oil.
26. The lubricating oil composition of claim 16 wherein the
lubricating oil base stock comprises a Group I, Group II, Group
III, Group IV or Group V base oil.
27. The lubricating oil composition of claim 16 wherein the at
least one borated detergent is present in an amount of from about
0.001 weight percent to about 20 weight percent, based on the total
weight of the lubricating oil.
28. The lubricating oil composition of claim 16 wherein the
lubricating oil base stock is present in an amount of from about 6
weight percent to about 95 weight percent, based on the total
weight of the lubricating oil.
29. The lubricating oil composition of claim 16 wherein the one or
more lubricating oil additives further comprise one or more of an
antiwear additive, viscosity modifier, antioxidant, other
detergent, dispersant, pour point depressant, corrosion inhibitor,
metal deactivator, seal compatibility additive, anti-foam agent,
inhibitor, friction modifier, and anti-rust additive.
30. The lubricating oil composition of claim 16 which is a
passenger vehicle engine oil (PVEO).
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional
Application No. 62/755,646, filed on Nov. 5, 2018, the entire
contents of which is incorporated herein by reference.
FIELD
[0002] This disclosure relates to methods for improving wear
control, while maintaining or improving deposit control and
cleanliness, in an engine or other mechanical component lubricated
with a lubricating oil, through the use of a formulated lubricating
oil. This disclosure also relates to lubricating oil compositions
having specific borated detergents which are effective for
improving wear control, while maintaining or improving deposit
control and cleanliness, at high boron concentrations, in an engine
or other mechanical component lubricated with the lubricating oil.
The lubricating oils are useful in internal combustion engines.
BACKGROUND
[0003] Lubricant-related performance characteristics such as high
temperature deposit and varnish control, fuel economy and wear
protection are extremely advantageous attributes as measured by a
variety of bench and engine tests. A lubricating oil additive
system can significantly impact cleanliness over a wide temperature
range as well as fuel efficiency and wear.
[0004] High boron levels in a passenger vehicle engine oil (PVEO)
can provide significant improvements in wear protection in industry
specification engine tests. However, high boron levels can also be
detrimental to cleanliness in the TEOST 33C bench test.
[0005] A PVEO has several responsibilities including wear
protection, decreased friction, heat transfer, and the like.
Improving one performance characteristic of the lubricant to the
detriment of another is undesirable, but sometimes unavoidable.
Borated additives are well known as effective antiwear additives;
however, their use has been limited to lower concentrations due to
cleanliness debits at higher concentrations.
[0006] Formulating a PVEO requires a careful balance of additive
chemistry to achieve the desired performance characteristics in
terms of wear, cleanliness, fuel economy, LSPI prevention, etc.
[0007] A major challenge in engine oil formulation is
simultaneously achieving wear, deposit, and varnish control while
also maintaining fuel economy performance, over a broad temperature
range. Improved cleanliness and wear performance of lubricants are
of significant importance for future specifications. Additionally,
such lubricants must not compromise on other performance dimensions
(such as fuel economy). Therefore, it is important to formulate
lubricants which can deliver step-out performance across a broad
range of performance dimensions. More methods that provide the
combination of wear protection and improved cleanliness will enable
greater lubricant formulation flexibility, differentiation.
[0008] What is needed is an additive system that enables a
formulator to design a PVEO with higher boron concentrations which
provide superior wear protection, while also maintaining
appropriate cleanliness performance.
SUMMARY
[0009] This disclosure relates to methods for improving wear
control, while maintaining or improving deposit control and
cleanliness, in an engine or other mechanical component lubricated
with a lubricating oil, through the use of a formulated lubricating
oil. This disclosure also relates to lubricating oil compositions
having specific borated detergents (i.e., borated alkaline earth
metal sulfonates) as described herein, that are effective for
improving wear control, while maintaining or improving deposit
control and cleanliness, at high boron concentrations (e.g., a
total boron concentration of about 300 parts per million or greater
in the lubricating oil), in an engine or other mechanical component
lubricated with the lubricating oil. The lubricating oils are
useful in internal combustion engines.
[0010] This disclosure relates in part to a method for improving
wear protection, while maintaining or improving deposit control and
cleanliness, in an engine or other mechanical component lubricated
with a lubricating oil by using as the lubricating oil a formulated
oil. The formulated oil has a composition comprising a lubricating
oil base stock as a major component, and one or more lubricating
oil additives, as a minor component. The one or more lubricating
oil additives comprise at least one borated detergent. The at least
one borated detergent comprises a borated alkaline earth metal
sulfonate. The borated alkaline earth metal sulfonate is present in
an amount sufficient to provide a total boron concentration of
about 300 parts per million or greater in the formulated oil. Wear
protection is improved, and deposit control and cleanliness are
maintained or improved, as compared to wear protection, deposit
control and cleanliness achieved using a lubricating oil containing
a borated additive other than the at least one borated alkaline
earth metal sulfonate.
[0011] This disclosure also relates in part to a lubricating oil
composition comprising a lubricating oil base stock as a major
component, and one or more lubricating oil additives, as a minor
component. The one or more lubricating oil additives comprise at
least one borated detergent. The at least one borated detergent
comprises a borated alkaline earth metal sulfonate. The borated
alkaline earth metal sulfonate is present in an amount sufficient
to provide a total boron concentration of about 300 parts per
million or greater in the lubricating oil. Wear protection is
improved, and deposit control and cleanliness are maintained or
improved, in an engine or other mechanical component lubricated
with the lubricating oil, as compared to wear protection, deposit
control and cleanliness achieved using a lubricating oil containing
a borated additive other than the at least one borated alkaline
earth metal sulfonate.
[0012] It has been surprisingly found that, in accordance with this
disclosure, improvements in wear control, deposit control and
cleanliness are obtained, through the use of lubricating oil
compositions having specific borated detergents (i.e., borated
alkaline earth metal sulfonates) as described herein, and having
high boron concentrations (e.g., a total boron concentration of
about 300 parts per million or greater in the lubricating oil).
[0013] In particular, it has been surprisingly found that, in
accordance with this disclosure, using a lubricating oil containing
a specific borated detergent (i.e., borated alkaline earth metal
sulfonate) as described herein, at high boron concentrations (e.g.,
a total boron concentration of about 300 parts per million or
greater in the lubricating oil), in wear measurements of the
lubricating oil by a Sequence IVB engine test, intake lifter wear
(mm.sup.3) is improved as compared to intake lifter wear (mm.sup.3)
achieved using a lubricating oil containing a borated additive
other than the at least one borated alkaline earth metal sulfonate
as described herein.
[0014] Also, in particular, it has been surprisingly found that, in
accordance with this disclosure, in deposit measurements of the
lubricating oil by thermo-oxidation engine oil simulation (TEOST
33C) measured by ASTM D6335, the amount of total deposits is
maintained or reduced as compared to the amount of total deposits
in a lubricating oil containing a borated additive other than the
at least one borated alkaline earth metal as described herein.
[0015] Other objects and advantages of the present disclosure will
become apparent from the detailed description that follows.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 shows the properties of various borated additives
used in FIGS. 2-6, in accordance with the Examples.
[0017] FIG. 2 shows a comparison of Sequence IVB wear results and
TEOST 33C deposit results, in which lubricant formulations used
either a salicylate/sulfonate detergent mix or a pure sulfonate
detergent system at multiple boron concentrations, in accordance
with the Examples.
[0018] FIG. 3 shows TEOST 33C results for various borated additives
at high boron levels in a fully formulated oil, in accordance with
the Examples.
[0019] FIG. 4 shows TEOST 33C deposits versus boron concentration
for lubricants with a mixed calcium salicylate/magnesium sulfonate
detergent system at a soap level of 1.11% and 1.18%, in accordance
with the Examples.
[0020] FIG. 5 shows TEOST 33C deposits versus boron concentration
for lubricants with a mixed calcium/magnesium sulfonate detergent
system at a soap level of 0.59% by weight, in accordance with the
Examples.
[0021] FIG. 6 shows TEOST 33C deposits versus boron concentration
for lubricants with either a mixed calcium salicylate/magnesium
sulfonate detergent system or a mixed calcium/magnesium sulfonate
detergent system at soap levels of 0.70%, 1.07%, or 1.11% by
weight, in accordance with the Examples.
DETAILED DESCRIPTION
Definitions
[0022] "About" or "approximately"--All numerical values within the
detailed description and the claims herein are modified by "about"
or "approximately" the indicated value, and take into account
experimental error and variations that would be expected by a
person having ordinary skill in the art.
[0023] "Major amount" as it relates to components included within
the lubricating oils of the specification and the claims means
greater than or equal to 50 wt. %, or greater than or equal to 60
wt. %, or greater than or equal to 70 wt. %, or greater than or
equal to 80 wt. %, or greater than or equal to 90 wt. % based on
the total weight of the lubricating oil.
[0024] "Minor amount" as it relates to components included within
the lubricating oils of the specification and the claims means less
than 50 wt. %, or less than or equal to 40 wt. %, or less than or
equal to 30 wt. %, or less than or equal to 20 wt. %, or less than
or equal to 10 wt. %, or less than or equal to 5 wt. %, or less
than or equal to 2 wt. %, or less than or equal to 1 wt. %, based
on the total weight of the lubricating oil.
[0025] "Essentially free" as it relates to components included
within the lubricating oils of the specification and the claims
means that the particular component is at 0 weight % within the
lubricating oil, or alternatively is at impurity type levels within
the lubricating oil (less than 100 ppm, or less than 20 ppm, or
less than 10 ppm, or less than 1 ppm).
[0026] "Other lubricating oil additives" as used in the
specification and the claims means other lubricating oil additives
that are not specifically recited in the particular section of the
specification or the claims. For example, other lubricating oil
additives may include, but are not limited to, antioxidants,
detergents, dispersants, antiwear additives, corrosion inhibitors,
viscosity modifiers, metal passivators, pour point depressants,
seal compatibility agents, antifoam agents, extreme pressure
agents, friction modifiers and combinations thereof.
[0027] "Alkyl group" refers to a saturated hydrocarbyl group
consisting of carbon and hydrogen atoms.
[0028] "Hydrocarbyl group" refers to a group consisting of hydrogen
and carbon atoms only. A hydrocarbyl group can be saturated or
unsaturated, linear or branched, cyclic or acyclic, and aromatic or
non-aromatic.
[0029] "Hydrocarbon" refers to a compound consisting of carbon
atoms and hydrogen atoms.
[0030] "Alkane" refers to a hydrocarbon that is completely
saturated. An alkane can be linear, branched, cyclic, or
substituted cyclic.
[0031] "Olefin" refers to a non-aromatic hydrocarbon comprising one
or more carbon-carbon double bond in the molecular structure
thereof.
[0032] "Mono-olefin" refers to an olefin comprising a single
carbon-carbon double bond.
[0033] "Cn" group or compound refers to a group or a compound
comprising carbon atoms at total number thereof of n. Thus, "Cm-Cn"
group or compound refers to a group or compound comprising carbon
atoms at a total number thereof in the range from m to n. Thus, a
C1-C50 alkyl group refers to an alkyl group comprising carbon atoms
at a total number thereof in the range from 1 to 50.
[0034] "Carbon backbone" refers to the longest straight carbon
chain in the molecule of the compound or the group in question.
"Branch" refer to any substituted or unsubstituted hydrocarbyl
group connected to the carbon backbone. A carbon atom on the carbon
backbone connected to a branch is called a "branched carbon."
[0035] "Epsilon-carbon" in a branched alkane refers to a carbon
atom in its carbon backbone that is (i) connected to two hydrogen
atoms and two carbon atoms and (ii) connected to a branched carbon
via at least four (4) methylene (CH.sub.2) groups. Quantity of
epsilon carbon atoms in terms of mole percentage thereof in a
alkane material based on the total moles of carbon atoms can be
determined by using, e.g., .sup.13C NMR.
[0036] "SAE" refers to SAE International, formerly known as Society
of Automotive Engineers, which is a professional organization that
sets standards for internal combustion engine lubricating oils.
[0037] "SAE J300" refers to the viscosity grade classification
system of engine lubricating oils established by SAE, which defines
the limits of the classifications in rheological terms only.
[0038] "Base stock" or "base oil" interchangeably refers to an oil
that can be used as a component of lubricating oils, heat transfer
oils, hydraulic oils, grease products, and the like.
[0039] "Lubricating oil" or "lubricant" interchangeably refers to a
substance that can be introduced between two or more surfaces to
reduce the level of friction between two adjacent surfaces moving
relative to each other. A lubricant base stock is a material,
typically a fluid at various levels of viscosity at the operating
temperature of the lubricant, used to formulate a lubricant by
admixing with other components. Non-limiting examples of base
stocks suitable in lubricants include API Group I, Group II, Group
III, Group IV, and Group V base stocks. PAOs, particularly
hydrogenated PAOs, have recently found wide use in lubricants as a
Group IV base stock, and are particularly preferred. If one base
stock is designated as a primary base stock in the lubricant,
additional base stocks may be called a co-base stock.
[0040] "In the vicinity of" a given temperature means within the
range from 10.degree. C. lower than that temperature to 10.degree.
C. higher than that temperature.
[0041] "Substantially saturated" means at least 90%, preferably at
least 95%, more preferably at least 98%, by mole, of the molecules
in question are saturated, based on the total moles of the relevant
molecules.
[0042] "Substantially free" of the monomer(s) means a material
comprises the monomer(s) at a total concentration thereof, of no
more than 5%, preferably no more than 3%, more preferably no more
than 1%, by weight, based on the total weight of the material.
[0043] All kinematic viscosity values in this disclosure are as
determined pursuant to ASTM D445. Kinematic viscosity at
100.degree. C. is reported herein as KV100, kinematic viscosity at
40.degree. C. is reported herein as KV40 and kinematic viscosity at
25.degree. C. is reported herein as KV25. Units of all KV100, KV40
and KV25 values herein are cSt unless otherwise specified.
[0044] All viscosity index ("VI") values in this disclosure are as
determined pursuant to ASTM D2270.
[0045] All Noack volatility ("NV") values in this disclosure are as
determined pursuant to ASTM D5800 unless specified otherwise. Unit
of all NV values is wt %, unless otherwise specified.
[0046] All pour point values in this disclosure are as determined
pursuant to ASTM D5950 or D97.
[0047] All CCS viscosity ("CCSV") values in this disclosure are as
determined pursuant to ASTM 5293. Unit of all CCSV values herein is
millipascal second (mPas, which is equivalent to centipoise),
unless specified otherwise. All CCSV values are measured at a
temperature of interest to the lubricating oil formulation or oil
composition in question. Thus, for the purpose of designing and
fabricating engine oil formulations, the temperature of interest is
the temperature at which the SAE J300 imposes a minimal CCSV.
[0048] All percentages in describing chemical compositions herein
are by weight unless specified otherwise. "Wt. %" means percent by
weight.
Lubricating Oils and Methods of this Disclosure
[0049] High boron levels in a passenger vehicle engine oil (PVEO)
can provide significant improvements in wear protection in industry
specification engine tests. However, high boron levels can also be
detrimental to cleanliness in the TEOST 33C bench test. This
disclosure demonstrates lubricant compositions that are able to
incorporate more than 300 ppm boron while still maintaining
acceptable cleanliness in the TEOST 33C test.
[0050] A PVEO has several responsibilities including wear
protection, decreased friction, heat transfer, and the like.
Improving one performance characteristic of the lubricant to the
detriment of another is undesirable, but sometimes unavoidable.
Borated additives are well known as effective antiwear additives;
however, their use has been limited to lower concentrations due to
cleanliness debits at higher concentrations. The use of a specific
borated detergent (i.e., borated alkaline earth metal sulfonate) as
described herein enables a formulator to design a PVEO with higher
boron concentrations which provide superior wear protection, while
also maintaining appropriate cleanliness performance.
[0051] This disclosure relates to the use of a specific borated
detergent (i.e., borated alkaline earth metal sulfonate) as
described herein in PVEO. It has been observed that lubricants with
mixed sulfonate/salicylate detergent systems and in full sulfonate
detergent systems, borated dispersants with boron levels above
around 300 parts per million (ppm) in the formulated oil result in
increased TEOST 33C deposits. Use of the specific borated detergent
(i.e., borated alkaline earth metal sulfonate) of this disclosure
as the source of boron significantly improves TEOST 33C
deposits.
[0052] It has now been found that, at high boron concentrations
(e.g., a total boron concentration of about 300 parts per million
or greater in the lubricating oil), improvements in wear control,
deposit control and cleanliness can be obtained, through the use of
lubricating oil compositions having a specific borated detergent
(i.e., borated alkaline earth metal sulfonate) as described
herein.
[0053] In an embodiment, the lubricating oil compositions of this
disclosure contain a specific type of borated detergent (for
example, a borated alkaline earth metal sulfonate) along with other
typical lubricant additives. When all ingredients are present in
the appropriate concentrations, and at high boron concentrations
(e.g., a total boron concentration of about 300 parts per million
or greater in the lubricating oil), the lubricating oil
formulations of this disclosure provide improved cleanliness and
deposit control while also minimizing wear as shown by bench and
engine testing in the Examples.
[0054] The present disclosure provides, at high boron
concentrations (e.g., a total boron concentration of about 300
parts per million or greater in the lubricating oil), lubricant
compositions with excellent wear control, deposit control and
cleanliness performance properties attained through the use of
lubricating oil compositions having specific borated detergents
(i.e., borated alkaline earth metal sulfonates) as described
herein. Antiwear additives are generally required for reducing wear
in operating equipment where two solid surfaces engage in contact.
In the absence of antiwear chemistry, the surfaces can rub together
causing material loss on one or both surfaces which can eventually
lead to equipment malfunction and failure. Antiwear additives can
produce a protective surface layer which reduces wear and material
loss. Most commonly the materials of interest are metals such as
steel and other iron-containing alloys. However, other materials
such as ceramics, polymer coatings, diamond-like carbon,
corresponding composites, and the like can also be used to produce
durable surfaces in modern equipment. The lubricant compositions of
this disclosure can provide wear control, deposit control and
cleanliness performance properties, at high boron concentrations
(e.g., a total boron concentration of about 300 parts per million
or greater in the lubricating oil), through the use of lubricating
oil compositions having specific borated detergents (i.e., borated
alkaline earth metal sulfonates) as described herein.
[0055] The lubricant compositions of this disclosure provide
advantaged wear, including advantaged wear and friction,
performance, and deposit control and cleanliness performance, at
high boron concentrations (e.g., a total boron concentration of
about 300 parts per million or greater in the lubricating oil), in
the lubrication of internal combustion engines, power trains,
drivelines, transmissions, gears, gear trains, valve trains, gear
sets, and the like, through the use of lubricating oil compositions
having specific borated detergents (i.e., borated alkaline earth
metal sulfonates) as described herein.
[0056] Also, the lubricant compositions of this disclosure provide
advantaged wear, including advantaged wear and friction,
performance, and deposit control and cleanliness performance, at
high boron concentrations (e.g., a total boron concentration of
about 300 parts per million or greater in the lubricating oil), in
the lubrication of mechanical components, which can include, for
example, pistons, piston rings, cylinder liners, cylinders, cams,
tappets, lifters, bearings (journal, roller, tapered, needle, ball,
and the like), gears, valves, and the like, through the use of
lubricating oil compositions having specific borated detergents
(i.e., borated alkaline earth metal sulfonates) as described
herein.
[0057] Further, the lubricant compositions of this disclosure
provide advantaged wear, including advantaged wear and friction,
performance, and deposit control and cleanliness performance, at
high boron concentrations (e.g., a total boron concentration of
about 300 parts per million or greater in the lubricating oil), as
a component in lubricant compositions, which can include, for
example, lubricating liquids, semi-solids, solids, greases,
dispersions, suspensions, material concentrates, additive
concentrates, and the like.
[0058] Also, the lubricant compositions of this disclosure provide
advantaged wear, including advantaged wear and friction,
performance, and deposit control and cleanliness performance, at
high boron concentrations (e.g., a total boron concentration of
about 300 parts per million or greater in the lubricating oil), in
spark-ignition internal combustion engines, compression-ignition
internal combustion engines, mixed-ignition (spark-assisted and
compression) internal combustion engines, and the like, through the
use of lubricating oil compositions having specific borated
detergents (i.e., borated alkaline earth metal sulfonates) as
described herein.
[0059] Further, the lubricant compositions of this disclosure
provide advantaged wear, including advantaged wear and friction,
performance, and deposit control and cleanliness to performance, at
high boron concentrations (e.g., a total boron concentration of
about 300 parts per million or greater in the lubricating oil),
through the use of lubricating oil compositions having specific
borated detergents (i.e., borated alkaline earth metal sulfonates)
as described herein, on lubricated surfaces that include, for
example, the following: metals, metal alloys, non-metals, non-metal
alloys, mixed carbon-metal composites and alloys, mixed
carbon-nonmetal composites and alloys, ferrous metals, ferrous
composites and alloys, non-ferrous metals, non-ferrous composites
and alloys, titanium, titanium composites and alloys, aluminum,
aluminum composites and alloys, magnesium, magnesium composites and
alloys, ion-implanted metals and alloys, plasma modified surfaces;
surface modified materials; coatings; mono-layer, multi-layer, and
gradient layered coatings; honed surfaces; polished surfaces;
etched surfaces; textured surfaces; micro and nano structures on
textured surfaces; super-finished surfaces; diamond-like carbon
(DLC), DLC with high-hydrogen content, DLC with moderate hydrogen
content, DLC with low-hydrogen content, DLC with near-zero hydrogen
content, DLC composites, DLC-metal compositions and composites,
DLC-nonmetal compositions and composites; ceramics, ceramic oxides,
ceramic nitrides, FeN, CrN, ceramic carbides, mixed ceramic
compositions, and the like; polymers, thermoplastic polymers,
engineered polymers, polymer blends, polymer alloys, polymer
composites; materials compositions and composites containing dry
lubricants, that include, for example, graphite, carbon,
molybdenum, molybdenum disulfide, polytetrafluoroethylene,
polyperfluoropropylene, polyperfluoroalkylethers, and the like.
Lubricating Oil Base Stocks and Co-Base Stocks
[0060] A wide range of lubricating base oils is known in the art.
Lubricating base oils that are useful in the present disclosure are
natural oils, mineral oils and synthetic oils, and unconventional
oils (or mixtures thereof) can be used unrefined, refined, or
rerefined (the latter is also known as reclaimed or reprocessed
oil). Unrefined oils are those obtained directly from a natural or
synthetic source and used without added purification. These include
shale oil obtained directly from retorting operations, petroleum
oil obtained directly from primary distillation, and ester oil
obtained directly from an esterification process. Refined oils are
similar to the oils discussed for unrefined oils except refined
oils are subjected to one or more purification steps to improve at
least one lubricating oil property. One skilled in the art is
familiar with many purification processes. These processes include
solvent extraction, secondary distillation, acid extraction, base
extraction, filtration, and percolation. Rerefined oils are
obtained by processes analogous to refined oils but using an oil
that has been previously used as a feed stock.
[0061] Groups I, II, III, IV and V are broad base oil stock
categories developed and defined by the American Petroleum
Institute (API Publication 1509; www.API.org) to create guidelines
for lubricant base oils. Group I base stocks have a viscosity index
of between about 80 to 120 and contain greater than about 0.03%
sulfur and/or less than about 90% saturates. Group II base stocks
have a viscosity index of between about 80 to 120, and contain less
than or equal to about 0.03% sulfur and greater than or equal to
about 90% saturates. Group III stocks have a viscosity index
greater than about 120 and contain less than or equal to about
0.03% sulfur and greater than about 90% saturates. Group IV
includes polyalphaolefins (PAO). Group V base stock includes base
stocks not included in Groups I-IV. The table below summarizes
properties of each of these five groups.
TABLE-US-00001 Base Oil Properties Saturates Sulfur Viscosity Index
Group I <90 and/or >0.03% and .gtoreq.80 and <120 Group II
.gtoreq.90 and .ltoreq.0.03% and .gtoreq.80 and <120 Group III
.gtoreq.90 and .ltoreq.0.03% and .gtoreq.120 Group IV
polyalphaolefins (PAO) Group V All other base oil stocks not
included in Groups I, II, III or IV
[0062] Natural oils include animal oils, vegetable oils (castor oil
and lard oil, for example), and mineral oils. Animal and vegetable
oils possessing favorable thermal oxidative stability can be used.
Of the natural oils, mineral oils are preferred. Mineral oils vary
widely as to their crude source, for example, as to whether they
are paraffinic, naphthenic, or mixed paraffinic-naphthenic. Oils
derived from coal or shale are also useful. Natural oils vary also
as to the method used for their production and purification, for
example, their distillation range and whether they are straight run
or cracked, hydrorefined, or solvent extracted.
[0063] Group II and/or Group III hydroprocessed or hydrocracked
base stocks are also well known base stock oils.
[0064] Synthetic oils include hydrocarbon oil. Hydrocarbon oils
include oils such as polymerized and interpolymerized olefins
(polybutylenes, polypropylenes, propylene isobutylene copolymers,
ethylene-olefin copolymers, and ethylene-alphaolefin copolymers,
for example). Polyalphaolefin (PAO) oil base stocks are commonly
used synthetic hydrocarbon oil. By way of example, PAOs derived
from C.sub.8, C.sub.10, C.sub.12, C.sub.14 olefins or mixtures
thereof may be utilized. See U.S. Pat. Nos. 4,956,122; 4,827,064;
and 4,827,073.
[0065] The number average molecular weights of the PAOs, which are
known materials and generally available on a major commercial scale
from suppliers such as ExxonMobil Chemical to Company, Chevron
Phillips Chemical Company, BP, and others, typically vary from
about 250 to about 3,000, although PAO's may be made in viscosities
up to about 150 cSt (100.degree. C.). The PAOs are typically
comprised of relatively low molecular weight hydrogenated polymers
or oligomers of alphaolefins which include, but are not limited to,
C.sub.2 to about C.sub.32 alphaolefins with the C.sub.8 to about
C.sub.16 alphaolefins, such as 1-octene, 1-decene, 1-dodecene and
the like, being preferred. The preferred polyalphaolefins are
poly-1-octene, poly-1-decene and poly-1-dodecene and mixtures
thereof and mixed olefin-derived polyolefins. However, the dimers
of higher olefins in the range of C.sub.12 to C.sub.18 may be used
to provide low viscosity base stocks of acceptably low volatility.
Depending on the viscosity grade and the starting oligomer, the
PAOs may be predominantly dimers, trimers and tetramers of the
starting olefins, with minor amounts of the lower and/or higher
oligomers, having a viscosity range of 1.5 cSt to 12 cSt. PAO
fluids of particular use may include 3 cSt, 3.4 cSt, and/or 3.6 cSt
and combinations thereof. Mixtures of PAO fluids having a viscosity
range of 1.5 cSt to approximately 150 cSt or more may be used if
desired. Unless indicated otherwise, all viscosities cited herein
are measured at 100.degree. C.
[0066] The PAO fluids may be conveniently made by the
polymerization of an alphaolefin in the presence of a
polymerization catalyst such as the Friedel-Crafts catalysts
including, for example, aluminum trichloride, boron trifluoride or
complexes of boron trifluoride with water, alcohols such as
ethanol, propanol or butanol, carboxylic acids or esters such as
ethyl acetate or ethyl propionate. For example, the methods
disclosed by U.S. Pat. Nos. 4,149,178 or 3,382,291 may be
conveniently used herein. Other descriptions of PAO synthesis are
found in the following U.S. Pat. Nos. 3,742,082; 3,769,363;
3,876,720; 4,239,930; 4,367,352; 4,413,156; 4,434,408; 4,910,355;
4,956,122; and 5,068,487. The dimers of the C.sub.14 to C.sub.18
olefins are described in U.S. Pat. No. 4,218,330.
[0067] Other useful lubricant oil base stocks include wax isomerate
base stocks and base oils, comprising hydroisomerized waxy stocks
(e.g. waxy stocks such as gas oils, slack waxes, fuels hydrocracker
bottoms, etc.), hydroisomerized Fischer-Tropsch waxes,
Gas-to-Liquids (GTL) base stocks and base oils, and other wax
isomerate hydroisomerized base stocks and base oils, or mixtures
thereof. Fischer-Tropsch waxes, the high boiling point residues of
Fischer-Tropsch synthesis, are highly paraffinic hydrocarbons with
very low sulfur content. The hydroprocessing used for the
production of such base stocks may use an amorphous
hydrocracking/hydroisomerization catalyst, such as one of the
specialized lube hydrocracking (LHDC) catalysts or a crystalline
hydrocracking/hydroisomerization catalyst, preferably a zeolitic
catalyst. For example, one useful catalyst is ZSM-48 as described
in U.S. Pat. No. 5,075,269, the disclosure of which is incorporated
herein by reference in its entirety. Processes for making to
hydrocracked/hydroisomerized distillates and
hydrocracked/hydroisomerized waxes are described, for example, in
U.S. Pat. Nos. 2,817,693; 4,975,177; 4,921,594 and 4,897,178 as
well as in British Patent Nos. 1,429,494; 1,350,257; 1,440,230 and
1,390,359. Each of the aforementioned patents is incorporated
herein in their entirety. Particularly favorable processes are
described in European Patent Application Nos. 464546 and 464547,
also incorporated herein by reference. Processes using
Fischer-Tropsch wax feeds are described in U.S. Pat. Nos. 4,594,172
and 4,943,672, the disclosures of which are incorporated herein by
reference in their entirety.
[0068] Gas-to-Liquids (GTL) base oils, Fischer-Tropsch wax derived
base oils, and other wax-derived hydroisomerized (wax isomerate)
base oils may be advantageously used in the instant disclosure, and
may have useful kinematic viscosities at 100.degree. C. of about 2
cSt to about 50 cSt, preferably about 2 cSt to about 30 cSt, more
preferably about 3 cSt to about 25 cSt, as exemplified by GTL 4
with kinematic viscosity of about 4.0 cSt at 100.degree. C. and a
viscosity index of about 141. These Gas-to-Liquids (GTL) base oils,
Fischer-Tropsch wax derived base oils, and other wax-derived
hydroisomerized base oils may have useful pour points of about
-20.degree. C. or lower, and under some conditions may have
advantageous pour points of about -25.degree. C. or lower, with
useful pour points of about -30.degree. C. to about -40.degree. C.
or lower. Useful compositions of Gas-to-Liquids (GTL) base oils,
Fischer-Tropsch wax derived base oils, and wax-derived
hydroisomerized base oils are recited in U.S. Pat. Nos. 6,080,301;
6,090,989, and 6,165,949 for example, and are incorporated herein
in their entirety by reference.
[0069] The hydrocarbyl aromatics can be used as a base oil or base
oil component and can be any hydrocarbyl molecule that contains at
least about 5% of its weight derived from an aromatic moiety such
as a benzenoid moiety or naphthenoid moiety, or their derivatives.
These hydrocarbyl aromatics include alkyl benzenes, alkyl
naphthalenes, alkyl biphenyls, alkyl diphenyl oxides, alkyl
naphthols, alkyl diphenyl sulfides, alkylated bis-phenol A,
alkylated thiodiphenol, and the like. The aromatic can be
mono-alkylated, dialkylated, polyalkylated, and the like. The
aromatic can be mono- or poly-functionalized. The hydrocarbyl
groups can also be comprised of mixtures of alkyl groups, alkenyl
groups, alkynyl, cycloalkyl groups, cycloalkenyl groups and other
related hydrocarbyl groups. The hydrocarbyl groups can range from
about C.sub.6 up to about C.sub.60 with a range of about C.sub.8 to
about C.sub.20 often being preferred. A mixture of hydrocarbyl
groups is often preferred, and up to about three such substituents
may be present. The hydrocarbyl group can optionally contain
sulfur, oxygen, and/or nitrogen containing substituents. The
aromatic group can also be derived from natural (petroleum)
sources, provided at least about 5% of the molecule is comprised of
an above-type aromatic moiety. Viscosities at 100.degree. C. of
approximately 2 cSt to about 50 cSt are preferred, with viscosities
of approximately 3 cSt to about 20 cSt often being more preferred
for the hydrocarbyl aromatic component. In one embodiment, an alkyl
naphthalene where the alkyl group is primarily comprised of
1-hexadecene is used. Other alkylates of aromatics can be
advantageously used. Naphthalene or methyl naphthalene, for
example, can be alkylated with olefins such as octene, decene,
dodecene, tetradecene or higher, mixtures of similar olefins, and
the like. Alkylated naphthalene and analogues may also comprise
compositions with isomeric distribution of alkylating groups on the
alpha and beta carbon positions of the ring structure. Distribution
of groups on the alpha and beta positions of a naphthalene ring may
range from 100:1 to 1:100, more often 50:1 to 1:50 Useful
concentrations of hydrocarbyl aromatic in a lubricant oil
composition can be about 2% to about 50%, preferably about 4% to
about 20%, and more preferably about 4% to about 15%, depending on
the application.
[0070] Alkylated aromatics such as the hydrocarbyl aromatics of the
present disclosure may be produced by well-known Friedel-Crafts
alkylation of aromatic compounds. See Friedel-Crafts and Related
Reactions, Olah, G. A. (ed.), Inter-science Publishers, New York,
1963. For example, an aromatic compound, such as benzene or
naphthalene, is alkylated by an olefin, alkyl halide or alcohol in
the presence of a Friedel-Crafts catalyst. See Friedel-Crafts and
Related Reactions, Vol. 2, part 1, chapters 14, 17, and 18, See
Olah, G. A. (ed.), Inter-science Publishers, New York, 1964. Many
homogeneous or heterogeneous, solid catalysts are known to one
skilled in the art. The choice of catalyst depends on the
reactivity of the starting materials and product quality
requirements. For example, strong acids such as AlCl.sub.3,
BF.sub.3, or HF may be used. In some cases, milder catalysts such
as FeCl.sub.3 or SnCl.sub.4 are preferred. Newer alkylation
technology uses zeolites or solid super acids.
[0071] Esters comprise a useful base stock. Additive solvency and
seal compatibility characteristics may be secured by the use of
esters such as the esters of dibasic acids with monoalkanols and
the polyol esters of monocarboxylic acids. Esters of the former
type include, for example, the esters of dicarboxylic acids such as
phthalic acid, succinic acid, alkyl succinic acid, alkenyl succinic
acid, maleic acid, azelaic acid, suberic acid, sebacic acid,
fumaric acid, adipic acid, linoleic acid dimer, malonic acid, alkyl
malonic acid, alkenyl malonic acid, etc., with a variety of
alcohols such as butyl alcohol, hexyl alcohol, dodecyl alcohol,
2-ethylhexyl alcohol, etc. Specific examples of these types of
esters include dibutyl adipate, di(2-ethylhexyl) sebacate,
di-n-hexyl fumarate, dioctyl sebacate, diisooctyl azelate,
diisodecyl azelate, dioctyl phthalate, didecyl phthalate, dieicosyl
sebacate, etc.
[0072] Particularly useful synthetic esters are those which are
obtained by reacting one or more polyhydric alcohols, preferably
the hindered polyols (such as the neopentyl polyols, e.g.,
neopentyl glycol, trimethylol ethane,
2-methyl-2-propyl-1,3-propanediol, trimethylol propane,
pentaerythritol and dipentaerythritol) with alkanoic acids
containing at least about 4 carbon atoms, preferably C.sub.5 to
C.sub.30 acids such as saturated straight chain fatty acids
including caprylic acid, capric acid, lauric acid, myristic acid,
palmitic acid, stearic acid, arachic acid, and behenic acid, or the
corresponding branched chain fatty acids or unsaturated fatty acids
such as oleic acid, or mixtures of any of these materials.
[0073] Suitable synthetic ester components include the esters of
trimethylol propane, trimethylol butane, trimethylol ethane,
pentaerythritol and/or dipentaerythritol with one or more
monocarboxylic acids containing from about 5 to about 10 carbon
atoms. These esters are widely available commercially, for example,
the Mobil A-41 and A-51 esters of ExxonMobil Chemical Company.
[0074] Also useful are esters derived from renewable material such
as coconut, palm, rapeseed, soy, sunflower and the like. These
esters may be monoesters, di-esters, polyol esters, complex esters,
or mixtures thereof. These esters are widely available
commercially, for example, the EsterexNP 343 ester of ExxonMobil
Chemical Company.
[0075] Engine oil formulations containing renewable esters are
included in this disclosure. For such formulations, the renewable
content of the ester is typically greater than about 70 weight
percent, preferably more than about 80 weight percent and most
preferably more than about 90 weight percent.
[0076] Other useful fluids of lubricating viscosity include
non-conventional or unconventional base stocks that have been
processed, preferably catalytically, or synthesized to provide high
performance lubrication characteristics.
[0077] Non-conventional or unconventional base stocks/base oils
include one or more of a mixture of base stock(s) derived from one
or more Gas-to-Liquids (GTL) materials, as well as
isomerate/isodewaxate base stock(s) derived from natural wax or
waxy feeds, mineral and or non-mineral oil waxy feed stocks such as
slack waxes, natural waxes, and waxy stocks such as gas oils, waxy
fuels hydrocracker bottoms, waxy raffinate, hydrocrackate, thermal
crackates, or other mineral, mineral oil, or even non-petroleum oil
derived waxy materials such as waxy materials received from coal
liquefaction or shale oil, and mixtures of such base stocks.
[0078] GTL materials are materials that are derived via one or more
synthesis, combination, transformation, rearrangement, and/or
degradation/deconstructive processes from gaseous carbon-containing
compounds, hydrogen-containing compounds and/or elements as feed
stocks such as hydrogen, carbon dioxide, carbon monoxide, water,
methane, ethane, ethylene, acetylene, propane, propylene, propyne,
butane, butylenes, and butynes. GTL base stocks and/or base oils
are GTL materials of lubricating viscosity that are generally
derived from hydrocarbons; for example, waxy synthesized
hydrocarbons, that are themselves derived from simpler gaseous
carbon-containing compounds, hydrogen-containing compounds and/or
elements as feed stocks. GTL base stock(s) and/or base oil(s)
include oils boiling in the lube oil boiling range (1)
separated/fractionated from synthesized GTL materials such as, for
example, by distillation and subsequently subjected to a final wax
processing step which involves either or both of a catalytic
dewaxing process, or a solvent dewaxing process, to produce lube
oils of reduced/low pour point; (2) synthesized wax isomerates,
comprising, for example, hydrodewaxed or hydroisomerized cat and/or
solvent dewaxed synthesized wax or waxy hydrocarbons; (3)
hydrodewaxed or hydroisomerized cat and/or solvent dewaxed
Fischer-Tropsch (F-T) material (i.e., hydrocarbons, waxy
hydrocarbons, waxes and possible analogous oxygenates); preferably
hydrodewaxed or hydroisomerized/followed by cat and/or solvent
dewaxing dewaxed F-T waxy hydrocarbons, or hydrodewaxed or
hydroisomerized/followed by cat (or solvent) dewaxing dewaxed, F-T
waxes, or mixtures thereof.
[0079] GTL base stock(s) and/or base oil(s) derived from GTL
materials, especially, hydrodewaxed or hydroisomerized/followed by
cat and/or solvent dewaxed wax or waxy feed, preferably F-T
material derived base stock(s) and/or base oil(s), are
characterized typically as having kinematic viscosities at
100.degree. C. of from about 2 mm.sup.2/s to about 50 mm.sup.2/s
(ASTM D445). They are further characterized typically as having
pour points of -5.degree. C. to about -40.degree. C. or lower (ASTM
D97). They are also characterized typically as having viscosity
indices of about 80 to about 140 or greater (ASTM D2270).
[0080] In addition, the GTL base stock(s) and/or base oil(s) are
typically highly paraffinic (>90% saturates), and may contain
mixtures of monocycloparaffins and multicycloparaffins in
combination with non-cyclic isoparaffins. The ratio of the
naphthenic (i.e., cycloparaffin) content in such combinations
varies with the catalyst and temperature used. Further, GTL base
stock(s) and/or base oil(s) typically have very low sulfur and
nitrogen content, generally containing less than about 10 ppm, and
more typically less than about 5 ppm of each of these elements. The
sulfur and nitrogen content of GTL base stock(s) and/or base oil(s)
obtained from F-T material, especially F-T wax, is essentially nil.
In addition, the absence of phosphorus and aromatics make this
materially especially suitable for the formulation of low SAP
products.
[0081] The term GTL base stock and/or base oil and/or wax isomerate
base stock and/or base oil is to be understood as embracing
individual fractions of such materials of wide viscosity range as
recovered in the production process, mixtures of two or more of
such fractions, as well as mixtures of one or two or more low
viscosity fractions with one, two or more higher viscosity
fractions to produce a blend wherein the blend exhibits a target
kinematic viscosity.
[0082] The GTL material, from which the GTL base stock(s) and/or
base oil(s) is/are derived is preferably an F-T material (i.e.,
hydrocarbons, waxy hydrocarbons, wax).
[0083] Base oils for use in the formulated lubricating oils useful
in the present disclosure are any of the variety of oils
corresponding to API Group I, Group II, Group III, Group IV, and
Group V oils and mixtures thereof, preferably API Group II, Group
III, Group IV, and Group V oils and mixtures thereof, more
preferably the Group III to Group V base oils due to their
exceptional volatility, stability, viscometric and cleanliness
features. Minor quantities of Group I stock, such as the amount
used to dilute additives for blending into formulated lube oil
products, can be tolerated but should be kept to a minimum, i.e.
amounts only associated with their use as diluent/carrier oil for
additives used on an "as-received" basis. Even in regard to the
Group II stocks, it is preferred that the Group II stock be in the
higher quality range associated with that stock, i.e. a Group II
stock having a viscosity index in the range 100<VI<120.
[0084] The base oil constitutes the major component of the engine
oil lubricant composition of the present disclosure and typically
is present in an amount ranging from about 6 to about 99 weight
percent or from about 6 to about 95 weight percent, preferably from
about 50 to about 99 weight percent or from about 70 to about 95
weight percent, and more preferably from about 85 to about 95
weight percent, based on the total weight of the composition. The
base oil may be selected from any of the synthetic or natural oils
typically used as crankcase lubricating oils for spark-ignited and
compression-ignited engines. The base oil conveniently has a
kinematic viscosity, according to ASTM standards, of about 2.5 cSt
to about 18 cSt (or mm.sup.2/s) at 100.degree. C. and preferably of
about 2.5 cSt to about 12.5 cSt (or mm.sup.2/s) at 100.degree. C.,
often more preferably from about 2.5 cSt to about 10 cSt. Mixtures
of synthetic and natural base oils may be used if desired.
Bi-modal, tri-modal, and additional combinations of mixtures of
Group I, II, III, IV, and/or V base stocks may be used if
desired.
[0085] The co-base stock component is present in an amount
sufficient for providing solubility, compatibility and dispersancy
of polar additives in the lubricating oil. The co-base stock
component is present in the lubricating oils of this disclosure in
an amount from about 1 to about 99 weight percent, preferably from
about 5 to about 95 weight percent, and more preferably from about
10 to about 90 weight percent.
Borated Detergents
[0086] Illustrative borated detergents useful in this disclosure
include, for example, borated alkaline earth metal sulfonates,
borated alkaline earth metal salicylates, and mixtures thereof.
[0087] A typical borated detergent is an anionic material that
contains a long chain hydrophobic portion of the molecule and a
smaller anionic or oleophobic hydrophilic portion of the molecule.
The anionic portion of the borated detergent is typically derived
from an organic acid such as a sulfur-containing acid, carboxylic
acid (e.g., salicylic acid), phosphorus-containing acid, phenol, or
mixtures thereof. The counterion is typically an alkaline earth or
alkali metal. The borated detergent can be overbased.
[0088] The borated detergent can be a metal salt of an organic or
inorganic acid, a metal salt of a phenol, or mixtures thereof. The
metal can be an alkali metal, an alkaline earth metal, and mixtures
thereof. The organic or inorganic acid is selected from an
aliphatic organic or inorganic acid, a cycloaliphatic organic or
inorganic acid, an aromatic organic or inorganic acid, and mixtures
thereof.
[0089] The metal can be an alkali metal, an alkaline earth metal,
and mixtures thereof. Particularly, the metal can be calcium (Ca),
magnesium (Mg), and mixtures thereof.
[0090] The organic acid or inorganic acid can be a
sulfur-containing acid, a carboxylic acid, a phosphorus-containing
acid, and mixtures thereof.
[0091] In an embodiment, the borated metal salt of an organic or
inorganic acid or the borated metal salt of a phenol can be borated
calcium sulfonate, borated magnesium sulfonate, a borated overbased
detergent, and mixtures thereof.
[0092] Salts that contain a substantially stochiometric amount of
the metal are described as neutral salts and have a total base
number (TBN, as measured by ASTM D2896) of from 0 to 80. Many
compositions are overbased, containing large amounts of a metal
base that is achieved by reacting an excess of a metal compound (a
metal hydroxide or oxide, for example) with an acidic gas (such as
carbon dioxide). Useful borated detergents can be neutral, mildly
overbased, or highly overbased. These borated detergents can be
used in mixtures of neutral, overbased, highly overbased calcium
sulfonates and/or magnesium sulfonates. The TBN ranges can vary
from low, medium to high TBN products, including as low as 0 to as
high as 600. The TBN delivered by the detergent is between 1 and
20. The TBN delivered by the detergent can be between 1 and 12.
Mixtures of low, medium, high TBN can be used, along with mixtures
of calcium and magnesium metal based detergents, and including
sulfonates, phenates and carboxylates. A borated detergent mixture
with a metal ratio of 1, in conjunction of a borated detergent with
a metal ratio of 2, and as high as a detergent with a metal ratio
of 5, can be used.
[0093] Borated alkaline earth phenates are another useful class of
borated detergent. These borated detergents can be made by reacting
alkaline earth metal hydroxide or oxide (CaO, Ca(OH).sub.2, BaO,
Ba(OH).sub.2, MgO, Mg(OH).sub.2, for example) with an alkyl phenol
or sulfurized alkylphenol. Useful alkyl groups include straight
chain or branched C.sub.1-C.sub.30 alkyl groups, particularly,
C.sub.4-C.sub.20 or mixtures thereof. Examples of suitable phenols
include isobutylphenol, 2-ethylhexylphenol, nonylphenol, dodecyl
phenol, and the like. It should be noted that starting alkylphenols
may contain more than one alkyl substituent that are each
independently straight chain or branched and can be used from 0.5
to 6 weight percent. When a non-sulfurized alkylphenol is used, the
sulfurized product may be obtained by methods well known in the
art. These methods include heating a mixture of alkylphenol and
sulfurizing agent (including elemental sulfur, sulfur halides such
as sulfur dichloride, and the like) and then reacting the
sulfurized phenol with an alkaline earth metal base.
[0094] Borated alkaline earth metal phosphates are also used as
detergents and are known in the art.
[0095] Borated detergents may be simple detergents or what is known
as hybrid or complex detergents. The latter borated detergents can
provide the properties of two borated detergents without the need
to blend separate materials. See U.S. Pat. No. 6,034,039.
[0096] Illustrative borated detergents include borated calcium
sulfonates, borated magnesium sulfonates, and other related
components, and mixtures thereof. Illustrative mixtures of borated
detergents include borated calcium sulfonate and borated magnesium
sulfonate. Borated overbased detergents are also used.
[0097] The borated detergents useful in this disclosure are present
in an amount sufficient to provide a total boron concentration of
about 100 parts per million, or about 150 parts per million, or
about 200 parts per million, or about 250 parts per million, or
about 300 parts per million, or about 350 parts per million, or
about 400 parts per million, or about 450 parts per million, or
about 500 parts per million, or about 550 parts per million, or
about 600 parts per million, or about 650 parts per million, or
about 700 parts per million, or about 750 parts per million, or
about 800 parts per million, or about 850 parts per million, or
about 900 parts per million, or about 950 parts per million, or
about 1000 parts per million, or greater in the lubricating
oil.
[0098] The borated detergents useful in this disclosure can provide
select levels of soap content to the lubricating oil compositions.
By one approach, the borated detergent provides a lower soap
content, e.g., about 0.2 to about 0.9 percent soap content, or
about 0.3 to about 0.8 percent soap content, or about 0.4 to about
0.7 percent soap content, to the final lubricating oil
composition.
[0099] In other approaches, the borated detergent provides a higher
soap content, e.g., about 0.6 to about 1.5 percent soap, or about
0.7 to about 1.4 percent soap, or about 0.8 to about 1.3 percent
soap, to the final lubricating oil composition.
[0100] In still other approaches, when the borated alkaline earth
metal sulfonate soap comprises about 100 percent of the total
borated detergent soap, the total amount of soap delivered is about
0.1 weight percent to about 1.0 weight percent, preferably about
0.4 weight percent to about 0.6 weight percent, more preferably 0.5
weight percent, of the lubricating oil.
[0101] Soap content generally refers to the amount of neutral
organic acid salt and reflects a detergent's cleansing ability, or
detergency, and dirt suspending ability. The soap content can be
determined by the following formula, using an exemplary calcium
sulfonate detergent represented by
(RSO.sub.3).sub.vCa.sub.w(CO.sub.3).sub.x(OH).sub.y with v, w, x,
and y denoting the number of sulfonate groups, the number of
calcium atoms, the number of carbonate groups, and the number of
hydroxyl groups respectively):
soap content = formula weight of [ ( RSO 3 ) 2 Ca ] effective
formula weight .times. 100 ##EQU00001##
[0102] Effective formula weight is the combined weight of all the
atoms that make up the formula
(RSO.sub.3).sub.vCa.sub.w(CO.sub.3).sub.x(OH).sub.y plus that of
any other lubricant components. Further discussion on determining
soap content can be found in Fuels and Lubricants Handbook,
Technology, Properties, Performance, and Testing, George Totten,
editor, ASTM International, 2003, the relevant portions thereof
incorporated herein by reference.
[0103] In the lubricating oil composition of this disclosure, when
mixtures of borated sulfonate detergents are used, of the same or
different TBN, the weight ratio of a first borated sulfonate
detergent to a second borated sulfonate detergent is from about
1:200 to about 200:1, or from about 1:100 to about 100:1, or from
about 1:50 to about 50:1, or from about 1:25 to about 25:1, or from
about 1:10 to about 10:1, or from about 1:5 to about 5:1.
[0104] The borated detergent concentration in the lubricating oils
of this disclosure can range from about 0.001 weight percent to
about 20 weight percent, or about 0.01 weight percent to about 10
weight percent, or about 0.5 to about 6.0 weight percent, or about
0.6 to 5.0 weight percent, or from about 0.8 weight percent to
about 4.0 weight percent, based on the total weight of the
lubricating oil.
[0105] As used herein, the borated detergent concentrations are
given on an "as delivered" basis. Typically, the active detergent
is delivered with a process oil. The "as delivered" detergent
typically contains from about 20 weight percent to about 100 weight
percent, or from about 40 weight percent to about 60 weight
percent, of active detergent in the "as delivered" detergent
product.
Other Additives
[0106] The formulated lubricating oil useful in the present
disclosure may additionally contain one or more of the other
commonly used lubricating oil performance additives including but
not limited to antiwear additives, dispersants, other detergents,
viscosity modifiers, corrosion inhibitors, rust inhibitors, metal
deactivators, extreme pressure additives, anti-seizure agents, wax
modifiers, viscosity modifiers, fluid-loss additives, seal
compatibility agents, lubricity agents, anti-staining agents,
chromophoric agents, defoamants, demulsifiers, densifiers, wetting
agents, gelling agents, tackiness agents, colorants, and others.
For a review of many commonly used additives, see Klamann in
Lubricants and Related Products, Verlag Chemie, Deerfield Beach,
Fla.; ISBN 0-89573-177-0. Reference is also made to "Lubricant
Additives" by M. W. Ranney, published by Noyes Data Corporation of
Parkridge, N J (1973); see also U.S. Pat. No. 7,704,930, the
disclosure of which is incorporated herein in its entirety. These
additives are commonly delivered with varying amounts of diluent
oil, that may range from 5 weight percent to 50 weight percent.
[0107] The additives useful in this disclosure do not have to be
soluble in the lubricating oils. Insoluble additives in oil can be
dispersed in the lubricating oils of this disclosure.
[0108] The types and quantities of performance additives used in
combination with the instant disclosure in lubricant compositions
are not limited by the examples shown herein as illustrations.
Antiwear Additives
[0109] A metal alkylthiophosphate and more particularly a metal
dialkyl dithio phosphate in which the metal constituent is zinc, or
zinc dialkyl dithio phosphate (ZDDP) can be a useful component of
the lubricating oils of this disclosure. ZDDP can be derived from
primary alcohols, secondary alcohols or mixtures thereof ZDDP
compounds generally are of the formula
Zn[SP(S)(OR.sup.1)(OR.sup.2)].sub.2
where R.sup.1 and R.sup.2 are C.sub.1-C.sub.18 alkyl groups,
preferably C.sub.2-C.sub.12 alkyl groups. These alkyl groups may be
straight chain or branched. Alcohols used in the ZDDP can be
propanol, 2-propanol, butanol, secondary butanol, pentanols,
hexanols such as 4-methyl-2-pentanol, n-hexanol, n-octanol, 2-ethyl
hexanol, alkylated phenols, and the like. Mixtures of secondary
alcohols or of primary and secondary alcohol can be preferred.
Alkyl aryl groups may also be used.
[0110] Preferable zinc dithiophosphates which are commercially
available include secondary zinc dithiophosphates such as those
available from for example, The Lubrizol Corporation under the
trade designations "LZ 677A", "LZ 1095" and "LZ 1371", from for
example Chevron Oronite under the trade designation "OLOA 262" and
from for example Afton Chemical under the trade designation "HITEC
7169".
[0111] The ZDDP is typically used in amounts of from about 0.3
weight percent to about 1.5 weight percent, preferably from about
0.4 weight percent to about 1.2 weight percent, more preferably
from about 0.5 weight percent to about 1.0 weight percent, and even
more preferably from about 0.6 weight percent to about 0.8 weight
percent, based on the total weight of the lubricating oil, although
more or less can often be used advantageously. Preferably, the ZDDP
is a secondary ZDDP and present in an amount of from about 0.6 to
1.0 weight percent of the total weight of the lubricating oil.
Dispersants
[0112] During engine operation, oil-insoluble oxidation byproducts
are produced. Dispersants help keep these byproducts in solution,
thus diminishing their deposition on metal surfaces. Dispersants
used in the formulation of the lubricating oil may be ashless or
ash-forming in nature. Preferably, the dispersant is ashless. So
called ashless dispersants are organic materials that form
substantially no ash upon combustion. For example,
non-metal-containing dispersants are considered ashless. In
contrast, metal-containing detergents discussed above form ash upon
combustion.
[0113] Suitable dispersants typically contain a polar group
attached to a relatively high molecular weight hydrocarbon chain.
The polar group typically contains at least one element of
nitrogen, oxygen, or phosphorus. Typical hydrocarbon chains contain
50 to 400 carbon atoms.
[0114] Illustrative dispersants useful in this disclosure include,
for example, (poly)alkenylsuccinic derivatives, polyisobutylene
succinimide (PIBSA) having a basic nitrogen content of about 1% or
greater, succinimides, hydrocarbyl-substituted succinic acids,
hydrocarbyl-substituted succinic anhydride derivatives, or mixtures
thereof, all having a basic nitrogen content of about 1% or
greater.
[0115] A useful class of dispersants are the (poly)alkenylsuccinic
derivatives, typically produced by the reaction of a long chain
hydrocarbyl substituted succinic compound, usually a hydrocarbyl
substituted succinic anhydride, with a polyhydroxy or polyamino
compound. The long chain hydrocarbyl group constituting the
oleophilic portion of the molecule which confers solubility in the
oil, is normally a polyisobutylene group. Many examples of this
type of dispersant are well known commercially and in the
literature. Exemplary U.S. patents describing such dispersants are
U.S. Pat. Nos. 3,172,892; 3,2145,707; 3,219,666; 3,316,177;
3,341,542; 3,444,170; 3,454,607; 3,541,012; 3,630,904; 3,632,511;
3,787,374 and 4,234,435. Other types of dispersant are described in
U.S. Pat. Nos. 3,036,003; 3,200,107; 3,254,025; 3,275,554;
3,438,757; 3,454,555; 3,565,804; 3,413,347; 3,697,574; 3,725,277;
3,725,480; 3,726,882; 4,454,059; 3,329,658; 3,449,250; 3,519,565;
3,666,730; 3,687,849; 3,702,300; 4,100,082; 5,705,458. A further
description of dispersants may be found, for example, in European
Patent Application No. 471 071, to which reference is made for this
purpose.
[0116] Hydrocarbyl-substituted succinic acid and
hydrocarbyl-substituted succinic anhydride derivatives are useful
dispersants. In particular, succinimide, succinate esters, or
succinate ester amides prepared by the reaction of a
hydrocarbon-substituted succinic acid compound preferably having at
least 50 carbon atoms in the hydrocarbon substituent, with at least
one equivalent of an alkylene amine are particularly useful.
[0117] Succinimides are formed by the condensation reaction between
hydrocarbyl substituted succinic anhydrides and amines. Molar
ratios can vary depending on the polyamine. For example, the molar
ratio of hydrocarbyl substituted succinic anhydride to TEPA can
vary from about 1:1 to about 5:1. Representative examples are shown
in U.S. Pat. Nos. 3,087,936; 3,172,892; 3,219,666; 3,272,746;
3,322,670; and 3,652,616, 3,948,800; and Canada Patent No.
1,094,044.
[0118] Succinate esters are formed by the condensation reaction
between hydrocarbyl substituted succinic anhydrides and alcohols or
polyols. Molar ratios can vary depending on the alcohol or polyol
used. For example, the condensation product of a hydrocarbyl
substituted succinic anhydride and pentaerythritol is a useful
dispersant.
[0119] Succinate ester amides are formed by condensation reaction
between hydrocarbyl substituted succinic anhydrides and alkanol
amines. For example, suitable alkanol amines include ethoxylated
polyalkylpolyamines, propoxylated polyalkylpolyamines and
polyalkenylpolyamines such as polyethylene polyamines. One example
is propoxylated hexamethylenediamine. Representative examples are
shown in U.S. Pat. No. 4,426,305.
[0120] The molecular weight of the hydrocarbyl substituted succinic
anhydrides used in the preceding paragraphs will typically range
between 800 and 2,500 or more. The above products can be
post-reacted with various reagents such as sulfur, oxygen,
formaldehyde, carboxylic acids such as oleic acid. The above
products can also be post reacted with boron compounds such as
boric acid, borate esters or highly borated dispersants, to form
borated dispersants generally having from about 0.1 to about 5
moles of boron per mole of dispersant reaction product.
[0121] Suitable dispersants include succinimides, including those
derivatives from mono-succinimides, bis-succinimides, and/or
mixtures of mono- and bis-succinimides, wherein the hydrocarbyl
succinimide is derived from a hydrocarbylene group such as
polyisobutylene having a Mn of from about 500 to about 5000, or
from about 1000 to about 3000, or about 1000 to about 2000, or a
mixture of such hydrocarbylene groups, often with high terminal
vinylic groups. Other preferred dispersants include succinic
acid-esters and amides, alkylphenol-polyamine-coupled Mannich
adducts, their capped derivatives, and other related
components.
[0122] Illustrative dispersants useful in this disclosure include
those derived from polyalkenyl-substituted mono- or dicarboxylic
acid, anhydride or ester, which dispersant has a polyalkenyl moiety
with a number average molecular weight of at least 900 and from
greater than 1.3 to 1.7, preferably from greater than 1.3 to 1.6,
most preferably from greater than 1.3 to 1.5, functional groups
(mono- or dicarboxylic acid producing moieties) per polyalkenyl
moiety (a medium functionality dispersant). Functionality (F) can
be determined according to the following formula:
F=(SAP.times.M.sub.n)/((112,200.times.A.I.)-(SAP.times.98))
wherein SAP is the saponification number (i.e., the number of
milligrams of KOH consumed in the complete neutralization of the
acid groups in one gram of the succinic-containing reaction
product, as determined according to ASTM D94); M.sub.n is the
number average molecular weight of the starting olefin polymer; and
A.I. is the percent active ingredient of the succinic-containing
reaction product (the remainder being unreacted olefin polymer,
succinic anhydride and diluent).
[0123] The polyalkenyl moiety of the dispersant may have a number
average molecular weight of at least 900, suitably at least 1500,
preferably between 1800 and 3000, such as between 2000 and 2800,
more preferably from about 2100 to 2500, and most preferably from
about 2200 to about 2400. The molecular weight of a dispersant is
generally expressed in terms of the molecular weight of the
polyalkenyl moiety. This is because the precise molecular weight
range of the dispersant depends on numerous parameters including
the type of polymer used to derive the dispersant, the number of
functional groups, and the type of nucleophilic group employed.
[0124] Polymer molecular weight, specifically M.sub.n, can be
determined by various known techniques. One convenient method is
gel permeation chromatography (GPC), which additionally provides
molecular weight distribution information (see W. W. Yau, J. J.
Kirkland and D. D. Bly, "Modern Size Exclusion Liquid
Chromatography", John Wiley and Sons, New York, 1979). Another
useful method for determining molecular weight, particularly for
lower molecular weight polymers, is vapor pressure osmometry (e.g.,
ASTM D3592).
[0125] The polyalkenyl moiety in a dispersant preferably has a
narrow molecular weight distribution (MWD), also referred to as
polydispersity, as determined by the ratio of weight average
molecular weight (M.sub.w) to number average molecular weight
(M.sub.n). Polymers having a M.sub.w/M.sub.n of less than 2.2,
preferably less than 2.0, are most desirable. Suitable polymers
have a polydispersity of from about 1.5 to 2.1, preferably from
about 1.6 to about 1.8.
[0126] Suitable polyalkenes employed in the formation of the
dispersants include homopolymers, interpolymers or lower molecular
weight hydrocarbons. One family of such polymers comprise polymers
of ethylene and/or at least one C.sub.3 to C.sub.2 alpha-olefin
having the formula H.sub.2C=CHR.sup.1 wherein R.sup.1 is a straight
or branched chain alkyl radical comprising 1 to 26 carbon atoms and
wherein the polymer contains carbon-to-carbon unsaturation, and a
high degree of terminal ethenylidene unsaturation. Preferably, such
polymers comprise interpolymers of ethylene and at least one
alpha-olefin of the above formula, wherein R.sup.1 is alkyl of from
1 to 18 carbon atoms, and more preferably is alkyl of from 1 to 8
carbon atoms, and more preferably still of from 1 to 2 carbon
atoms.
[0127] Another useful class of polymers is polymers prepared by
cationic polymerization of monomers such as isobutene and styrene.
Common polymers from this class include polyisobutenes obtained by
polymerization of a C.sub.4 refinery stream having a butene content
of 35 to 75% by weight, and an isobutene content of 30 to 60% by
weight. A preferred source of monomer for making poly-n-butenes is
petroleum feedstreams such as Raffinate II. These feedstocks are
disclosed in the art such as in U.S. Pat. No. 4,952,739. A
preferred embodiment utilizes polyisobutylene prepared from a pure
isobutylene stream or a Raffinate I stream to prepare reactive
isobutylene polymers with terminal vinylidene olefins.
Polyisobutene polymers that may be employed are generally based on
a polymer chain of from 1500 to 3000.
[0128] The dispersant(s) are preferably non-polymeric (e.g., mono-
or bis-succinimides). Such dispersants can be prepared by
conventional processes such as disclosed in U.S. Patent Application
Publication No. 2008/0020950, the disclosure of which is
incorporated herein by reference.
[0129] Other suitable dispersants typically contain a polar group
attached to a relatively high molecular weight hydrocarbon chain.
The polar group typically contains at least one element of
nitrogen, oxygen, or phosphorus. Typical hydrocarbon chains contain
50 to 400 carbon atoms.
[0130] Mannich base dispersants are made from the reaction of
alkylphenols, formaldehyde, and amines. See U.S. Pat. No.
4,767,551, which is incorporated herein by reference. Process aids
and catalysts, such as oleic acid and sulfonic acids, can also be
part of the reaction mixture. Molecular weights of the alkylphenols
range from 800 to 2,500. Representative examples are shown in U.S.
Pat. Nos. 3,697,574; 3,703,536; 3,704,308; 3,751,365; 3,756,953;
3,798,165; and 3,803,039.
[0131] Typical high molecular weight aliphatic acid modified
Mannich condensation products useful in this disclosure can be
prepared from high molecular weight alkyl-substituted
hydroxyaromatics or HNR.sub.2 group-containing reactants.
[0132] Hydrocarbyl substituted amine ashless dispersant additives
are well known to one skilled in the art; see, for example, U.S.
Pat. Nos. 3,275,554; 3,438,757; 3,565,804; 3,755,433, 3,822,209,
and 5,084,197.
[0133] Polymethacrylate or polyacrylate derivatives are another
class of dispersants. These dispersants are typically prepared by
reacting a nitrogen containing monomer and a methacrylic or acrylic
acid esters containing 5-25 carbon atoms in the ester group.
Representative examples are shown in U.S. Pat. Nos. 2,100,993, and
6,323,164. Polymethacrylate and polyacrylate dispersants are
normally used as multifunctional viscosity modifiers. The lower
molecular weight versions can be used as lubricant dispersants or
fuel detergents.
[0134] The dispersant(s) can be borated by conventional means, as
generally disclosed in U.S. Pat. Nos. 3,087,936, 3,254,025 and
5,430,105.
[0135] Such dispersants may be used in an amount of about 0.001 to
20 weight percent or 0.01 to 10 weight percent, preferably about
0.5 to 8 weight percent, or more preferably 0.5 to 4 weight
percent. Or such dispersants may be used in an amount of about 2 to
12 weight percent, preferably about 4 to 10 weight percent, or more
preferably 6 to 9 weight percent. On an active ingredient basis,
such additives may be used in an amount of about 0.06 to 14 weight
percent, preferably about 0.3 to 6 weight percent.
[0136] As used herein, the dispersant concentrations are given on
an "as delivered" basis. Typically, the active dispersant is
delivered with a process oil. The "as delivered" dispersant
typically contains from about 20 weight percent to about 80 weight
percent, or from about 40 weight percent to about 60 weight
percent, of active dispersant in the "as delivered" dispersant
product.
Other Detergents
[0137] Illustrative other detergents (e.g., non-borated) useful in
this disclosure include, for example, alkali metal detergents,
alkaline earth metal detergents, or mixtures of one or more alkali
metal detergents and one or more alkaline earth metal detergents. A
typical detergent is an anionic material that contains a long chain
hydrophobic portion of the molecule and a smaller anionic or
oleophobic hydrophilic portion of the molecule. The anionic portion
of the detergent is typically derived from an organic acid such as
a sulfur-containing acid, carboxylic acid (e.g., salicylic acid),
phosphorus-containing acid, phenol, or mixtures thereof. The
counterion is typically an alkaline earth or alkali metal. The
detergent can be overbased. Non-borated or borated detergents can
be used.
[0138] The detergent can be a metal salt of an organic or inorganic
acid, a metal salt of a phenol, or mixtures thereof. The metal can
be an alkali metal, an alkaline earth metal, and mixtures thereof.
The organic or inorganic acid is selected from an aliphatic organic
or inorganic acid, a cycloaliphatic organic or inorganic acid, an
aromatic organic or inorganic acid, and mixtures thereof.
[0139] The metal can be an alkali metal, an alkaline earth metal,
and mixtures thereof. Particularly, the metal can be calcium (Ca),
magnesium (Mg), and mixtures thereof.
[0140] The organic acid or inorganic acid can be a
sulfur-containing acid, a carboxylic acid, a phosphorus-containing
acid, and mixtures thereof.
[0141] In an embodiment, the metal salt of an organic or inorganic
acid or the metal salt of a phenol can be calcium phenate,
magnesium phenate, an overbased detergent, and mixtures
thereof.
[0142] Salts that contain a substantially stochiometric amount of
the metal are described as neutral salts and have a total base
number (TBN, as measured by ASTM D2896) of from 0 to 80. Many
compositions are overbased, containing large amounts of a metal
base that is achieved by reacting an excess of a metal compound (a
metal hydroxide or oxide, for example) with an acidic gas (such as
carbon dioxide). Useful detergents can be neutral, mildly
overbased, or highly overbased. These detergents can be used in
mixtures of neutral, overbased, highly overbased calcium phenates
and/or magnesium phenates. The TBN ranges can vary from low, medium
to high TBN products, including as low as 0 to as high as 600. The
TBN delivered by the detergent is between 1 and 20. The TBN
delivered by the detergent can be between 1 and 12. Mixtures of
low, medium, high TBN can be used, along with mixtures of calcium
and magnesium metal based detergents, and including phenates and
carboxylates. A detergent mixture with a metal ratio of 1, in
conjunction of a detergent with a metal ratio of 2, and as high as
a detergent with a metal ratio of 5, can be used. Non-borated or
borated detergents can be used.
[0143] Alkaline earth phenates are another useful class of
detergent. These detergents can be made by reacting alkaline earth
metal hydroxide or oxide (CaO, Ca(OH).sub.2, BaO, Ba(OH).sub.2,
MgO, Mg(OH).sub.2, for example) with an alkyl phenol or sulfurized
alkylphenol. Useful alkyl groups include straight chain or branched
C.sub.1-C.sub.30 alkyl groups, particularly, C.sub.4-C.sub.20 or
mixtures thereof Examples of suitable phenols include
isobutylphenol, 2-ethylhexylphenol, nonylphenol, dodecyl phenol,
and the like. It should be noted that starting alkylphenols may
contain more than one alkyl substituent that are each independently
straight chain or branched and can be used from 0.5 to 6 weight
percent. When a non-sulfurized alkylphenol is used, the sulfurized
product may be obtained by methods well known in the art. These
methods include heating a mixture of alkylphenol and sulfurizing
agent (including elemental sulfur, sulfur halides such as sulfur
dichloride, and the like) and then reacting the sulfurized phenol
with an alkaline earth metal base.
[0144] Alkaline earth metal phosphates are also used as detergents
and are known in the art.
[0145] Detergents may be simple detergents or what is known as
hybrid or complex detergents. The latter detergents can provide the
properties of two detergents without the need to blend separate
materials. See U.S. Pat. No. 6,034,039.
[0146] Illustrative detergents include calcium phenates, magnesium
phenates, and other related components (including borated
detergents), and mixtures thereof. Illustrative mixtures of
detergents include calcium phenate and magnesium phenate. Overbased
detergents are also used. One example of a borated calcium
sulfonate detergent is OLOA 10400X.
[0147] The detergent concentration in the lubricating oils of this
disclosure can range from about 0.5 to about 6.0 weight percent,
preferably about 0.6 to 5.0 weight percent, and more preferably
from about 0.8 weight percent to about 4.0 weight percent, based on
the total weight of the lubricating oil. For lower soap
concentrations, the detergent concentration in the lubricating oils
of this disclosure can range from about 0.5 to about 6.0 weight
percent, preferably about 1.0 to 3.0 weight percent, and more
preferably from about 1.5 weight percent to about 2.5 weight
percent, based on the total weight of the lubricating oil. For
higher soap concentrations, the detergent concentration in the
lubricating oils of this disclosure can range from about 0.5 to
about 6.0 weight percent, preferably about 1.0 to 5.5 weight
percent, and more preferably from about 3.0 weight percent to about
4.0 weight percent, based on the total weight of the lubricating
oil.
[0148] As used herein, the detergent concentrations are given on an
"as delivered" basis. Typically, the active detergent is delivered
with a process oil. The "as delivered" detergent typically contains
from about 20 weight percent to about 100 weight percent, or from
about 40 weight percent to about 60 weight percent, of active
detergent in the "as delivered" detergent product.
Viscosity Modifiers
[0149] Viscosity modifiers (also known as viscosity index improvers
(VI improvers), and viscosity improvers) can be included in the
lubricant compositions of this disclosure.
[0150] Viscosity modifiers provide lubricants with high and low
temperature operability. These additives impart shear stability at
elevated temperatures and acceptable viscosity at low
temperatures.
[0151] Suitable viscosity modifiers include high molecular weight
hydrocarbons, polyesters and viscosity modifier dispersants that
function as both a viscosity modifier and a dispersant. Typical
molecular weights of these polymers are between about 10,000 to
1,500,000, more typically about 20,000 to 1,200,000, and even more
typically between about 50,000 and 1,000,000.
[0152] Examples of suitable viscosity modifiers are linear or
star-shaped polymers and copolymers of methacrylate, butadiene,
olefins, or alkylated styrenes. Polyisobutylene is a commonly used
viscosity modifier. Another suitable viscosity modifier is
polymethacrylate (copolymers of various chain length alkyl
methacrylates, for example), some formulations of which also serve
as pour point depressants. Other suitable viscosity modifiers
include copolymers of ethylene and propylene, hydrogenated block
copolymers of styrene and isoprene, and polyacrylates (copolymers
of various chain length acrylates, for example). Specific examples
include styrene-isoprene or styrene-butadiene based polymers of
50,000 to 200,000 molecular weight.
[0153] Olefin copolymers are commercially available from Chevron
Oronite Company LLC under the trade designation "PARATONE.RTM."
(such as "PARATONE.RTM. 8921" and "PARATONE.RTM. 8941"); from Afton
Chemical Corporation under the trade designation "HiTEC.RTM." (such
as "HiTEC.RTM. 5850B"; and from The Lubrizol Corporation under the
trade designation "Lubrizol.RTM. 7067C". Hydrogenated polyisoprene
star polymers are commercially available from Infineum
International Limited, e.g., under the trade designation "SV200"
and "SV600". Hydrogenated diene-styrene block copolymers are
commercially available from Infineum International Limited, e.g.,
under the trade designation "SV 50".
[0154] The polymethacrylate or polyacrylate polymers can be linear
polymers which are available from Evnoik Industries under the trade
designation "Viscoplex.RTM." (e.g., Viscoplex 6-954) or star
polymers which are available from Lubrizol Corporation under the
trade designation Asteric.TM. (e.g., Lubrizol 87708 and Lubrizol
87725).
[0155] Illustrative vinyl aromatic-containing polymers useful in
this disclosure may be derived predominantly from vinyl aromatic
hydrocarbon monomer. Illustrative vinyl aromatic-containing
copolymers useful in this disclosure may be represented by the
following general formula:
A-B
wherein A is a polymeric block derived predominantly from vinyl
aromatic hydrocarbon monomer, and B is a polymeric block derived
predominantly from conjugated diene monomer.
[0156] In an embodiment of this disclosure, the viscosity modifiers
may be used in an amount of less than about 10 weight percent,
preferably less than about 7 weight percent, more preferably less
than about 4 weight percent, and in certain instances, may be used
at less than 2 weight percent, preferably less than about 1 weight
percent, and more preferably less than about 0.5 weight percent,
based on the total weight of the formulated oil or lubricating
engine oil. Viscosity modifiers are typically added as
concentrates, in large amounts of diluent oil.
[0157] As used herein, the viscosity modifier concentrations are
given on an "as delivered" to basis. Typically, the active polymer
is delivered with a diluent oil. The "as delivered" viscosity
modifier typically contains from 20 weight percent to 75 weight
percent of an active polymer for polymethacrylate or polyacrylate
polymers, or from 8 weight percent to 20 weight percent of an
active polymer for olefin copolymers, hydrogenated polyisoprene
star polymers, or hydrogenated diene-styrene block copolymers, in
the "as delivered" polymer concentrate.
Antioxidants
[0158] Antioxidants retard the oxidative degradation of base oils
during service. Such degradation may result in deposits on metal
surfaces, the presence of sludge, or a viscosity increase in the
lubricant. One skilled in the art knows a wide variety of oxidation
inhibitors that are useful in lubricating oil compositions. See,
Klamann in Lubricants and Related Products, op cite, and U.S. Pat.
Nos. 4,798,684 and 5,084,197, for example.
[0159] Useful antioxidants include hindered phenols. These phenolic
antioxidants may be ashless (metal-free) phenolic compounds or
neutral or basic metal salts of certain phenolic compounds. Typical
phenolic antioxidant compounds are the hindered phenolics which are
the ones which contain a sterically hindered hydroxyl group, and
these include those derivatives of dihydroxy aryl compounds in
which the hydroxyl groups are in the o- or p-position to each
other. Typical phenolic antioxidants include the hindered phenols
substituted with C.sub.6+ alkyl groups and the alkylene coupled
derivatives of these hindered phenols. Examples of phenolic
materials of this type 2-t-butyl-4-heptyl phenol; 2-t-butyl-4-octyl
phenol; 2-t-butyl-4-dodecyl phenol; 2,6-di-t-butyl-4-heptyl phenol;
2,6-di-t-butyl-4-dodecyl phenol; 2-methyl-6-t-butyl-4-heptyl
phenol; and 2-methyl-6-t-butyl-4-dodecyl phenol. Other useful
hindered mono-phenolic antioxidants may include for example
hindered 2,6-di-alkyl-phenolic proprionic ester derivatives.
Bis-phenolic antioxidants may also be advantageously used in
combination with the instant disclosure. Examples of ortho-coupled
phenols include: 2,2'-bis(4-heptyl-6-t-butyl-phenol);
2,2'-bis(4-octyl-6-t-butyl-phenol); and
2,2'-bis(4-dodecyl-6-t-butyl-phenol). Para-coupled bisphenols
include for example 4,4'-bis(2,6-di-t-butyl phenol) and
4,4'-methylene-bis(2,6-di-t-butyl phenol).
[0160] Effective amounts of one or more catalytic antioxidants may
also be used. The catalytic antioxidants comprise an effective
amount of a) one or more oil soluble polymetal organic compounds;
and, effective amounts of b) one or more substituted
N,N'-diaryl-o-phenylenediamine compounds or c) one or more hindered
phenol compounds; or a combination of both b) and c). Catalytic
antioxidants are more fully described in U.S. Pat. No. 8,048,833,
herein incorporated by reference in its entirety.
[0161] Non-phenolic oxidation inhibitors which may be used include
aromatic amine antioxidants and these may be used either as such or
in combination with phenolics. Typical examples of non-phenolic
antioxidants include: alkylated and non-alkylated aromatic amines
such as aromatic monoamines of the formula R.sup.8R.sup.9R.sup.10N
where R.sup.8 is an aliphatic, aromatic or substituted aromatic
group, R.sup.9 is an aromatic or a substituted aromatic group, and
R.sup.10 is H, alkyl, aryl or R.sup.11S(O).sub.xR.sup.12 where
R.sup.H is an alkylene, alkenylene, or aralkylene group, R.sup.12
is a higher alkyl group, or an alkenyl, aryl, or alkaryl group, and
x is 0, 1 or 2. The aliphatic group R.sup.8 may contain from 1 to
about 20 carbon atoms, and preferably contains from about 6 to 12
carbon atoms. The aliphatic group is a saturated aliphatic group.
Preferably, both R.sup.8 and R.sup.9 are aromatic or substituted
aromatic groups, and the aromatic group may be a fused ring
aromatic group such as naphthyl. Aromatic groups R.sup.8 and
R.sup.9 may be joined together with other groups such as S.
[0162] Typical aromatic amines antioxidants have alkyl substituent
groups of at least about 6 carbon atoms. Examples of aliphatic
groups include hexyl, heptyl, octyl, nonyl, and decyl. Generally,
the aliphatic groups will not contain more than about 14 carbon
atoms. The general types of amine antioxidants useful in the
present compositions include diphenylamines, phenyl naphthylamines,
phenothiazines, imidodibenzyls and diphenyl phenylene diamines.
Mixtures of two or more aromatic amines are also useful. Polymeric
amine antioxidants can also be used. Particular examples of
aromatic amine antioxidants useful in the present disclosure
include: p,p'-di octyldiphenylamine;
t-octylphenyl-alpha-naphthylamine; phenyl-alphanaphthylamine; and
p-octylphenyl-alpha-naphthylamine.
[0163] Sulfurized alkyl phenols and alkali or alkaline earth metal
salts thereof also are useful antioxidants.
[0164] Preferred antioxidants include hindered phenols, arylamines.
These antioxidants may be used individually by type or in
combination with one another. Such additives may be used in an
amount of about 0.01 to 5 weight percent, preferably about 0.01 to
1.5 weight percent, more preferably zero to less than 1.5 weight
percent, more preferably zero to less than 1 weight percent.
Pour Point Depressants (PPDs)
[0165] Conventional pour point depressants (also known as lube oil
flow improvers) may be added to the compositions of the present
disclosure if desired. These pour point depressant may be added to
lubricating compositions of the present disclosure to lower the
minimum temperature at which the fluid will flow or can be poured.
Examples of suitable pour point depressants include
polymethacrylates, polyacrylates, polyarylamides, condensation
products of haloparaffin waxes and aromatic compounds, vinyl
carboxylate polymers, and terpolymers of dialkylfumarates, vinyl
esters of fatty acids and allyl vinyl ethers. U.S. Pat. Nos.
1,815,022; 2,015,748; 2,191,498; 2,387,501; 2,655, 479; 2,666,746;
2,721,877; 2,721,878; and 3,250,715 describe useful pour point to
depressants and/or the preparation thereof. Such additives may be
used in an amount of about 0.01 to 5 weight percent, preferably
about 0.01 to 1.5 weight percent.
Seal Compatibility Agents
[0166] Seal compatibility agents help to swell elastomeric seals by
causing a chemical reaction in the fluid or physical change in the
elastomer. Suitable seal compatibility agents for lubricating oils
include organic phosphates, aromatic esters, aromatic hydrocarbons,
esters (butylbenzyl phthalate, for example), and polybutenyl
succinic anhydride. Such additives may be used in an amount of
about 0.01 to 3 weight percent, preferably about 0.01 to 2 weight
percent.
Antifoam Agents
[0167] Anti-foam agents may advantageously be added to lubricant
compositions. These agents retard the formation of stable foams.
Silicones and organic polymers are typical anti-foam agents. For
example, polysiloxanes, such as silicon oil or polydimethyl
siloxane, provide antifoam properties. Anti-foam agents are
commercially available and may be used in conventional minor
amounts along with other additives such as demulsifiers; usually
the amount of these additives combined is less than 1 weight
percent and often less than 0.1 weight percent.
Inhibitors and Antirust Additives
[0168] Antirust additives (or corrosion inhibitors) are additives
that protect lubricated metal surfaces against chemical attack by
water or other contaminants. A wide variety of these are
commercially available.
[0169] One type of antirust additive is a polar compound that wets
the metal surface preferentially, protecting it with a film of oil.
Another type of antirust additive absorbs water by incorporating it
in a water-in-oil emulsion so that only the oil touches the metal
surface. Yet another type of antirust additive chemically adheres
to the metal to produce a non-reactive surface. Examples of
suitable additives include zinc dithiophosphates, metal phenolates,
basic metal sulfonates, fatty acids and amines. Such additives may
be used in an amount of about 0.01 to 5 weight percent, preferably
about 0.01 to 1.5 weight percent.
Friction Modifiers
[0170] A friction modifier is any material or materials that can
alter the coefficient of friction of a surface lubricated by any
lubricant or fluid containing such material(s). Friction modifiers,
also known as friction reducers, or lubricity agents or oiliness
agents, and other such agents that change the ability of base oils,
formulated lubricant compositions, or functional fluids, to modify
the coefficient of friction of a lubricated surface may be
effectively used in combination with the base oils or lubricant
compositions of the present disclosure if desired. Friction
modifiers that lower the coefficient of friction are particularly
advantageous in combination with the base oils and lube
compositions of this disclosure.
[0171] Illustrative friction modifiers may include, for example,
organometallic compounds or materials, or mixtures thereof.
Illustrative organometallic friction modifiers useful in the
lubricating engine oil formulations of this disclosure include, for
example, molybdenum amine, molybdenum diamine, an
organotungstenate, a molybdenum dithiocarbamate, molybdenum
dithiophosphates, molybdenum amine complexes, molybdenum
carboxylates, and the like, and mixtures thereof. Similar tungsten
based compounds may be preferable.
[0172] Other illustrative friction modifiers useful in the
lubricating engine oil formulations of this disclosure include, for
example, alkoxylated fatty acid esters, alkanolamides, polyol fatty
acid esters, borated glycerol fatty acid esters, fatty alcohol
ethers, and mixtures thereof.
[0173] Illustrative alkoxylated fatty acid esters include, for
example, polyoxyethylene stearate, fatty acid polyglycol ester, and
the like. These can include polyoxypropylene stearate,
polyoxybutylene stearate, polyoxyethylene isosterate,
polyoxypropylene isostearate, polyoxyethylene palmitate, and the
like.
[0174] Illustrative alkanolamides include, for example, lauric acid
diethylalkanolamide, palmic acid diethylalkanolamide, and the like.
These can include oleic acid diethyalkanolamide, stearic acid
diethylalkanolamide, oleic acid diethylalkanolamide,
polyethoxylated hydrocarbylamides, polypropoxylated
hydrocarbylamides, and the like.
[0175] Illustrative polyol fatty acid esters include, for example,
glycerol mono-oleate, saturated mono-, di-, and tri-glyceride
esters, glycerol mono-stearate, and the like. These can include
polyol esters, hydroxyl-containing polyol esters, and the like.
[0176] Illustrative borated glycerol fatty acid esters include, for
example, borated glycerol mono-oleate, borated saturated mono-,
di-, and tri-glyceride esters, borated glycerol mono-sterate, and
the like. In addition to glycerol polyols, these can include
trimethylolpropane, pentaerythritol, sorbitan, and the like. These
esters can be polyol monocarboxylate esters, polyol dicarboxylate
esters, and on occasion polyoltricarboxylate esters. Preferred can
be the glycerol mono-oleates, glycerol dioleates, glycerol
trioleates, glycerol monostearates, glycerol distearates, and
glycerol tristearates and the corresponding glycerol
monopalmitates, glycerol dipalmitates, and glycerol tripalmitates,
and the respective isostearates, linoleates, and the like. On
occasion the glycerol esters can be preferred as well as mixtures
containing any of these. Ethoxylated, propoxylated, butoxylated
fatty acid esters of polyols, especially using glycerol as
underlying polyol can be preferred.
[0177] Illustrative fatty alcohol ethers include, for example,
stearyl ether, myristyl ether, and the like. Alcohols, including
those that have carbon numbers from C.sub.3 to C.sub.50, can be
ethoxylated, propoxylated, or butoxylated to form the corresponding
fatty alkyl ethers. The underlying alcohol portion can preferably
be stearyl, myristyl, C.sub.11-C.sub.13 hydrocarbon, oleyl,
isosteryl, and the like.
[0178] The lubricating oils of this disclosure exhibit desired
properties, e.g., wear control, in the presence or absence of a
friction modifier.
[0179] Useful concentrations of friction modifiers may range from
0.01 weight percent to 5 weight percent, or about 0.1 weight
percent to about 2.5 weight percent, or about 0.1 weight percent to
about 1.5 weight percent, or about 0.1 weight percent to about 1
weight percent. Concentrations of molybdenum-containing materials
are often described in terms of Mo metal concentration.
Advantageous concentrations of Mo may range from 25 ppm to 700 ppm
or more, and often with a preferred range of 50-200 ppm. Friction
modifiers of all types may be used alone or in mixtures with the
materials of this disclosure. Often mixtures of two or more
friction modifiers, or mixtures of friction modifier(s) with
alternate surface active material(s), are also desirable.
[0180] When lubricating oil compositions contain one or more of the
additives discussed above, the additive(s) are blended into the
composition in an amount sufficient for it to perform its intended
function. Typical amounts of such additives useful in the present
disclosure are shown in Table 1 below.
[0181] It is noted that many of the additives are shipped from the
additive manufacturer as a concentrate, containing one or more
additives together, with a certain amount of base oil diluents.
Accordingly, the weight amounts in the table below, as well as
other amounts mentioned herein, are directed to the amount of
active ingredient (that is the non-diluent portion of the
ingredient). The weight percent (wt. %) indicated below is based on
the total weight of the lubricating oil composition.
TABLE-US-00002 TABLE 1 Typical Amounts of Other Lubricating Oil
Components Approximate Approximate Wt. % Wt. % Compound (Useful)
(Preferred) Borated Detergent 0.1-20 0.1-8 Dispersant 0.1-20 0.1-8
Other Detergent 0.1-20 0.1-8 Friction Modifier 0.01-5 0.01-1.5
Antioxidant 0.1-8 0.1-3 Pour Point Depressant 0.0-5 0.01-1.5 (PPD)
Anti-foam Agent 0.001-3 0.001-0.2 Viscosity Modifier (solid 0.1-2
0.1-1 polymer basis) Antiwear 0.2-3 0.5-1 Inhibitor and Antirust
0.01-5 0.01-1.5
[0182] The foregoing additives are all commercially available
materials. These additives may be added independently but are
usually precombined in packages which can be obtained from
suppliers of lubricant oil additives. Additive packages with a
variety of ingredients, proportions and characteristics are
available and selection of the appropriate package will take the
requisite use of the ultimate composition into account.
[0183] The following non-limiting examples are provided to
illustrate the disclosure.
Examples
[0184] Formulations were prepared as described herein. All of the
ingredients used herein are commercially available. PCMO (passenger
car motor oil) formulations were prepared as described herein.
[0185] The lubricating oil base stocks used in the formulations
were Group III-V base oils.
[0186] The detergents used in the formulations were calcium
salicylate (calcium salicylate A, 205 TBN, C14-18), calcium
salicylate (calcium salicylate B, 64 TBN, C14-18), calcium
sulfonate (calcium sulfonate A, 300 TBN, average of 28 carbon
length), magnesium sulfonate (magnesium sulfonate A, 405 TBN,
average of 28 carbon length), and borated calcium sulfonate
(borated detergent A, 160 TBN).
[0187] The sulfonate detergent systems used in the formulations
were combinations of the calcium sulfonate A, magnesium sulfonate
A, and/or borated detergent A.
[0188] The salicylate/sulfonate detergent systems used in the
formulations were combinations of calcium salicylate A, calcium
salicylate B, magnesium sulfonate A, and/or borated detergent
A.
[0189] The dispersants used in the formulations were borated
polyisobutenyl succinimides, borated dispersant A (0.8% boron, 1.6%
nitrogen, TBN 30, and PIB length 1300 Mn), borated to dispersant B
(2.3% boron, 1.2% nitrogen, and TBN 26), borated dispersant C (1.2%
boron, 1.2% nitrogen, and TBN 25), borated dispersant D (1.8% boron
and 2.3% nitrogen), borated dispersant E (0.6% boron, 2% nitrogen,
TBN 46),
[0190] The detergents/dispersants used in the formulations were
borated detergent/dispersant (0.1% calcium, 4.8% boron, 0.2%
nitrogen, TBN 124).
[0191] The friction modifiers used in the formulations were borated
glycerol monooleates (GMO), borated friction modifier A (2.3%
boron, TBN 10), borated friction modifier B (2.9% boron). The
properties of the borated additives are shown in FIG. 1.
[0192] The additive package used in the formulations included
conventional additives in conventional amounts. Conventional
additives used in the formulations were one or more of an
antioxidant, pour point depressant, corrosion inhibitor, metal
deactivator, seal compatibility additive, anti-foam agent,
inhibitor, anti-rust additive, optional antiwear additive, and
other optional lubricant performances additives. Other additives
used in the formulations included a mixed calcium
salicylate/magnesium sulfonate detergent system, and a mixed
calcium/magnesium sulfonate detergent system.
[0193] The tests used in the Examples included both engine tests
and bench tests. The engine tests included a wear test for
measuring intake lifter wear (mm.sup.3) by a Sequence IVB engine
test as described herein. The bench tests included a deposit test
for measuring deposits by thermo-oxidation engine oil simulation
(TEOST 33C) measured by ASTM D6335.
[0194] For purposes of this disclosure, the Sequence IVB engine
valve train wear test is a fired engine dynamometer lubricant test
which evaluates the ability of a test lubricant to reduce valve
train wear. The test method is a low temperature cyclic test, with
a total running duration of 200 hours.
[0195] The Sequence IVB (Test profile B14, version 20150707) uses a
Toyota 2NR-FE water cooled, 4 cycle, in-line cylinder, 1.5 liter
engine as the test apparatus. The engine incorporates a dual
overhead cam, four valves per cylinder (2 intake; 2 exhaust), and
direct acting mechanical bucket lifter valve train design. The
critical test parts (camshafts, direct acting mechanical bucket
lifters) are replaced each test. A 95 minute run-in schedule,
followed by a 100 hour aging schedule, for silicon (Si)
pacification, is conducted whenever the long block or cylinder head
are replaced with new components.
[0196] The Sequence IVB valve train wear test is a flush and run
type of lubricant test with one 6 minute engine oil system flush
and three 38 minute engine oil system flushes conducted prior to
the actual test start. The test sequence is repeated for 24,000
test cycles. Each cycle consists of four stages as outlined below.
The final measured values include iron concentration at 200 hours
(ppm) and average intake lifter volume loss by Keyence measurement
(mm{circumflex over ( )}3). These two parameters are related to
each other in that as wear increases, both the iron levels and the
average volume lost increase.
[0197] The Sequence IVB test is part of the draft ILSAC GF-6
specification, in particular, the draft ILSAC GF-6A Recommendations
for Passenger Car Engine Oils dated Jun. 27, 2018, and the draft
ILSAC GF-6B Recommendations for Passenger Car Engine Oils dated
Jun. 27, 2018, which are incorporated herein by reference in their
entirety.
[0198] Lubricants with high boron concentrations show reduced wear
in the Sequence IVB engine test as shown in FIG. 2. FIG. 2 shows a
comparison of Sequence IVB wear results and TEOST 33C deposit
results. The lubricant formulations used either a
salicylate/sulfonate detergent mix or a pure sulfonate detergent
system at multiple boron concentrations. TEOST 33C test results
indicate that within this formulation space, lubricants with boron
concentrations greater than 300 ppm would fail the current
API/ILSAC specification limit of 30 mg of deposits. In accordance
with this disclosure, a formulation strategy has been developed
that allows high boron concentrations for improved wear protection
while maintaining acceptable TEOST 33C cleanliness. Such strategy
broadens the formulating space for the upcoming GF-6 specification
and beyond. Preferred formulations have TEOST deposits less than
about 50 mg, more preferred formulations have TEOST deposits less
than about 40 mg, even more preferred formulations have TEOST
deposits less than about 30 mg, even more preferred formulations
have TEOST deposits less than about 25 mg, and most preferred
formulations have TEOST deposits less than about 20 mg.
[0199] Boron is generally introduced into a lubricant through one
of the performance additives, most often through either a
dispersant, detergent, friction modifier or combination of the
above. The borated additives used in the formulations in FIG. 2 are
a borated polyisobutylene succinimide plus polyamine (PIBSA/PAM)
(PIB 1300 M.sub.n) (for 100 ppm), and a borated polyisobutylene
succinimide (PIBSA) (2.3 mass % boron) (for 460 and 750 ppm) both
of which are dispersants. The borated polyisobutylene succinimide
(PIBSA) (2.3 mass % boron) is a highly borated dispersant and was
used in the formulations with higher boron concentrations to reduce
the viscometric effects of adding large amounts of dispersant to a
lubricant.
[0200] Many borated additives struggle with TEOST 33C cleanliness
when added in too high of concentrations. FIG. 3 shows the TEOST
33C results for various borated additives at high boron levels in a
fully formulated oil. Generally, as boron levels increase so does
the mass of the TEOST 33C deposits, often surpassing specification
limits. One interesting result from FIG. 3 was the decrease in
deposits when borated calcium sulfonate was added to the
formulation in higher concentrations.
[0201] A possible cause for the deposit decrease can be that
increasing the boron through borated calcium sulfonate will also
increase the soap level. It is known that TEOST 33C deposits can be
affected by soap levels so a more in-depth TEOST 33C study was
conducted using two different additive systems. Additive system 1
was designed with a mixture of calcium salicylate and magnesium
sulfonate detergents (soap level-1.1%), incorporated a Group V
ester, and used a molybdenum ester amide, while additive system 2
had a mixture of calcium sulfonate and magnesium sulfonate
detergents (soap level-0.59%), incorporated a Group V alkylated
naphthalene, and used a molybdenum oxide. Both additive systems
were similar in antioxidancy, antiwear, dispersancy, and base stock
composition. All of the test samples were matched in soap level to
one of the two reference lubricants to determine if the detergent
in borated calcium sulfonate was responsible for the improved
deposit results or if its chemistry was such that boron no longer
affected deposits. Three borated additives from FIG. 3 were chosen
to continue in further studies to determine if boron introduced
into a formulation through borated calcium sulfonate would result
in less deposits and if that effect was dependent upon the
detergent system of the lubricant.
[0202] FIG. 4 compares two borated dispersant additives in a
formulation utilizing a calcium salicylate/magnesium sulfonate
detergent system at a soap level of 1.1% by weight. Increasing
boron through the borated polyisobutylene succinimide (PIBSA) (2.3
mass % boron) significantly increases TEOST 33C deposits as was
seen earlier in FIGS. 2 and 3. The borated polyisobutylene
succinimide plus polyamine (PIBSA/PAM) (PIB 1300 Mn) and borated
calcium sulfonate show little if any correlation between boron
concentration and cleanliness.
[0203] FIG. 5 compares the same three borated additives in a
calcium/magnesium sulfonate detergent system at approximately half
the soap level (0.6%). At a lower soap level, with only sulfonate
detergents, borated calcium sulfonate is the only additive that
does not result in higher deposits when boron is increased. FIG. 6
shows TEOST 33C deposits versus boron concentration for lubricants
with a mixed calcium/magnesium sulfonate detergent system.
[0204] Prior to this disclosure, increasing boron had been shown to
provide excellent wear protection in the Sequence IVB engine test
while also resulting in poor TEOST 33C deposits. The borated
calcium sulfonate detergent additive provides an increase in boron
levels which provide better wear protection while also maintaining
acceptable TEOST 33C performance.
[0205] Despite exhibiting strong wear performance, formulations
containing high concentrations of boron (.about.300 ppm) typically
negatively impact cleanliness as seen with TEOST 33C data.
Formulations containing a borated calcium sulfonate detergent with
high boron levels (.about.300 ppm) exhibit strong wear performance
in the Sequence IVB engine test and provide strong cleanliness as
seen with TEOST 33C data.
PCT and EP Clauses:
[0206] 1. A method for improving wear protection, while maintaining
or improving deposit control and cleanliness, in an engine or other
mechanical component lubricated with a lubricating oil by using as
the lubricating oil a formulated oil, said formulated oil having a
composition comprising a lubricating oil base stock as a major
component; and one or more lubricating oil additives, as a minor
component; wherein the one or more lubricating oil additives
comprise at least one borated detergent; wherein the at least one
borated detergent comprises a borated alkaline earth metal
sulfonate; wherein the borated alkaline earth metal sulfonate is
present in an amount sufficient to provide a total boron
concentration of about 300 parts per million or greater in the
formulated oil; and wherein wear protection is improved, and
deposit control and cleanliness are maintained or improved, as
compared to wear protection, deposit control and cleanliness
achieved using a lubricating oil containing a borated additive
other than the at least one borated alkaline earth metal
sulfonate.
[0207] 2. The method of clause 1 wherein, in wear measurements of
the lubricating oil by a Sequence IVB engine test, intake lifter
wear (mm.sup.3) is improved as compared to intake lifter wear
(mm.sup.3) achieved using a lubricating oil containing a borated
additive other than the at least one borated alkaline earth metal
sulfonate.
[0208] 3. The method of clause 1 wherein, in deposit measurements
of the lubricating oil by thermo-oxidation engine oil simulation
(TEOST 33C) measured by ASTM D6335, the amount of total deposits is
maintained or reduced as compared to the amount of total deposits
in a lubricating oil containing a borated additive other than the
at least one borated alkaline earth metal sulfonate.
[0209] 4. The method of clause 1 wherein wear control is improved
and deposit, varnish and sludge control, and fuel efficiency are
maintained or improved as compared to wear control, deposit,
varnish and sludge control, and fuel efficiency achieved using a
lubricating oil containing a borated additive other than the at
least one borated alkaline earth metal sulfonate.
[0210] 5. The method of clause 1 wherein, in deposit measurements
of the lubricating oil by thermo-oxidation engine oil simulation
(TEOST 33C) measured by ASTM D6335, the amount of total deposits is
less than about 30 mg.
[0211] 6. The method of clauses 1-5 wherein the borated alkaline
earth metal sulfonate detergent comprises borated calcium
sulfonate.
[0212] 7. The method of clauses 1-5 wherein the borated alkaline
earth metal sulfonate is present in an amount sufficient to provide
a total boron concentration of about 350 parts per million or
greater, or about 400 parts per million or greater, or about 450
parts per million or greater, or about 500 parts per million or
greater, or about 550 parts per million or greater, or about 600
parts per million or greater, or about 650 parts per million or
greater, or about 700 parts per million or greater, or about 750
parts per million or greater, or about 800 parts per million or
greater, or about 850 parts per million or greater, or about 900
parts per million or greater, or about 950 parts per million or
greater, or about 1000 parts per million or greater, in the
formulated oil.
[0213] 8. The method of clauses 1-5 wherein the one or more
lubricating oil additives further comprise an alkaline earth metal
sulfonate detergent system or a mixed alkaline earth metal
sulfonate detergent system.
[0214] 9. The method of clause 8 wherein the mixed alkaline earth
metal sulfonate detergent system comprises a calcium/magnesium
sulfonate detergent system.
[0215] 10. The method of clauses 1-5 wherein the total amount of
soap delivered by the at least one borated detergent is less than
about 1.0 weight percent of the lubricating oil.
[0216] 11. The method of clauses 1-5 wherein the lubricating oil
base stock comprises a Group I, Group II, Group III, Group IV or
Group V base oil.
[0217] 12. The method of clauses 1-5 wherein the at least one
borated detergent is present in an amount of from about 0.001
weight percent to about 20 weight percent, based on the total
weight of the formulated oil.
[0218] 13. The method of clauses 1-5 wherein the lubricating oil
base stock is present in an amount of from about 6 weight percent
to about 95 weight percent, based on the total weight of the
formulated oil.
[0219] 14. The method of clauses 1-5 wherein the one or more
lubricating oil additives further comprise one or more of an
antiwear additive, viscosity modifier, antioxidant, other
detergent, dispersant, pour point depressant, corrosion inhibitor,
metal deactivator, seal compatibility additive, anti-foam agent,
inhibitor, friction modifier, and anti-rust additive.
[0220] 15. A lubricating oil composition comprising a lubricating
oil base stock as a major component, and one or more lubricating
oil additives, as a minor component; wherein the one or more
lubricating oil additives comprise at least one borated detergent;
wherein the at least one borated detergent comprises a borated
alkaline earth metal sulfonate; wherein the borated alkaline earth
metal sulfonate is present in an amount sufficient to provide a
total boron concentration of about 300 parts per million or greater
in the lubricating oil; and wherein wear protection is improved,
and deposit control and cleanliness are maintained or improved, in
an engine or other mechanical component lubricated with the
lubricating oil, as compared to wear protection, deposit control
and cleanliness achieved using a lubricating oil containing a
borated additive other than the at least one borated alkaline earth
metal sulfonate.
[0221] All patents and patent applications, test procedures (such
as ASTM methods, UL methods, and the like), and other documents
cited herein are fully incorporated by reference to the extent such
disclosure is not inconsistent with this disclosure and for all
jurisdictions in which such incorporation is permitted.
[0222] When numerical lower limits and numerical upper limits are
listed herein, ranges from any lower limit to any upper limit are
contemplated. While the illustrative embodiments of the disclosure
have been described with particularity, it will be understood that
various other modifications will be apparent to and can be readily
made by those skilled in the art without departing from the spirit
and scope of the disclosure. Accordingly, it is not intended that
the scope of the claims appended hereto be limited to the examples
and descriptions set forth herein but rather that the claims be
construed as encompassing all the features of patentable novelty
which reside in the present disclosure, including all features
which would be treated as equivalents thereof by those skilled in
the art to which the disclosure pertains.
[0223] The present disclosure has been described above with
reference to numerous embodiments and specific examples. Many
variations will suggest themselves to those skilled in this art in
light of the above detailed description. All such obvious
variations are within the full intended scope of the appended
claims.
* * * * *
References