U.S. patent application number 16/519039 was filed with the patent office on 2020-01-23 for lubricating oil compositions with oxidative stability in diesel engines using biodiesel fuel.
The applicant listed for this patent is ExxonMobil Research and Engineering Company. Invention is credited to Smruti A. Dance, Douglas E. Deckman, Mark P. Hagemeister, Luca Salvi, Nicole Wallace.
Application Number | 20200024538 16/519039 |
Document ID | / |
Family ID | 67539623 |
Filed Date | 2020-01-23 |
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United States Patent
Application |
20200024538 |
Kind Code |
A1 |
Deckman; Douglas E. ; et
al. |
January 23, 2020 |
LUBRICATING OIL COMPOSITIONS WITH OXIDATIVE STABILITY IN DIESEL
ENGINES USING BIODIESEL FUEL
Abstract
A method for improving oxidative stability of a lubricating oil
in a diesel engine, in which biodiesel fuel is used with diesel
fuel in the diesel engine, by using as the lubricating oil a
formulated oil. The formulated oil has a composition including at
least one Group V lubricating oil base stock. The at least one
Group V lubricating oil base stock is present in an amount from 1
to 75 weight percent, based on the total weight of the lubricating
oil. Oxidative stability is improved in a diesel engine lubricated
with the lubricating oil, as compared to oxidative stability
achieved in a diesel engine lubricated with a lubricating oil not
having the at least one Group V lubricating oil base stock, as
determined by a CEC L-109-16 Bio-Diesel Oxidation Bench test. The
lubricating oils are useful as passenger vehicle engine oil (PVEO)
products or commercial vehicle engine oil (CVEO) products.
Inventors: |
Deckman; Douglas E.;
(Easton, PA) ; Dance; Smruti A.; (Robbinsville,
NJ) ; Hagemeister; Mark P.; (Mullica Hill, NJ)
; Salvi; Luca; (Haddonfield, NJ) ; Wallace;
Nicole; (Coatesville, PA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
ExxonMobil Research and Engineering Company |
Annandale |
NJ |
US |
|
|
Family ID: |
67539623 |
Appl. No.: |
16/519039 |
Filed: |
July 23, 2019 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62701936 |
Jul 23, 2018 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C10M 2207/283 20130101;
C10M 169/04 20130101; C10M 2215/285 20130101; C10N 2010/12
20130101; C10N 2030/02 20130101; C10M 2215/08 20130101; C10M 105/38
20130101; C10N 2030/10 20130101; C10M 2207/0406 20130101; C10N
2030/45 20200501; C10M 2203/065 20130101; C10N 2010/04 20130101;
C10M 2203/06 20130101; C10M 2207/2835 20130101; C10N 2040/253
20200501; C10M 2219/083 20130101; C10N 2030/52 20200501; C10N
2030/42 20200501; C10N 2040/252 20200501; C10M 111/02 20130101;
C10M 2215/0806 20130101; C10M 105/06 20130101; C10M 105/68
20130101 |
International
Class: |
C10M 105/68 20060101
C10M105/68; C10M 105/38 20060101 C10M105/38; C10M 105/06 20060101
C10M105/06 |
Claims
1. A method for improving oxidative stability of a lubricating oil
in a diesel engine, wherein biodiesel fuel is used with diesel fuel
in the diesel engine, by using as the lubricating oil a formulated
oil, said formulated oil having a composition comprising at least
one Group V lubricating oil base stock; wherein the at least one
Group V lubricating oil base stock is present in an amount from 1
to 75 weight percent, based on the total weight of the lubricating
oil; and wherein oxidative stability is improved in a diesel engine
lubricated with the lubricating oil, as compared to oxidative
stability achieved in a diesel engine lubricated with a lubricating
oil not having the at least one Group V lubricating oil base stock,
as determined by a CEC L-109-16 Bio-Diesel Oxidation Bench
test.
2. The method of claim 1 wherein, in a CEC L-109-16 Bio-Diesel
Oxidation Bench test, the time for a relative kinematic viscosity
at 100.degree. C. (KV100) increase of 100% of said lubricating oil,
is greater than the time for a relative kinematic viscosity at
100.degree. C. (KV100) increase of 100% of a lubricating oil not
having the at least one Group V lubricating oil base stock.
3. The method of claim 2 wherein, in a CEC L-109-16 Bio-Diesel
Oxidation Bench test, the time for a relative kinematic viscosity
at 100.degree. C. (KV100) increase of 100% of said lubricating oil
is from 260 to 500 hours.
4. The method of claim 2 wherein, in a CEC L-109-16 Bio-Diesel
Oxidation Bench test, the time for a relative kinematic viscosity
at 100.degree. C. (KV100) increase of 100% of said lubricating oil,
is greater than at least 5% of the time for a relative kinematic
viscosity at 100.degree. C. (KV100) increase of 100% of a
lubricating oil not having the at least one Group V lubricating oil
base stock.
5. The method of claim 1 wherein the at least one Group V
lubricating oil base stock comprises an ester base stock, an
alkylated aromatic base stock, an amide base stock, or mixtures
thereof.
6. The method of claim 1 wherein the lubricating oil base stock
comprises at least one branched polyol ester, which is obtained by
reacting one or more polyhydric alcohols with one or more branched
mono-carboxylic acids containing at least 4 carbon atoms.
7. The method of claim 1 wherein the one or more polyhydric
alcohols are selected from the group consisting of trimethylol
propane, pentaerythritol, neopentyl glycol, trimethylol ethane,
2-methyl-2-propyl-1,3-propanediol, and dipentaerythritol.
8. The method of claim 1 wherein the one or more branched
mono-carboxylic acids containing at least 4 carbon atoms are
selected from the group consisting of 3,5,5-trimethyl hexanoic acid
(TMH), 2,2-dimethyl propionic acid (neopentanoic acid),
neoheptanoic acid, neooctanoic acid, neononanoic acid, iso-hexanoic
acid, neodecanoic acid, 2-ethyl hexanoic acid (2EH), isoheptanoic
acid, isooctanoic acid, isononanoic acid, and isodecanoic acid.
9. The method of claim 1 wherein the at least one branched polyol
ester is selected from the group consisting of trimethylol propane
ester of 3,5,5-trimethyl hexanoic acid (TMH), trimethylol propane
ester of 2,2-dimethyl propionic acid (neopentanoic acid),
trimethylol propane ester of neoheptanoic acid, trimethylol propane
ester of neooctanoic acid, trimethylol propane ester of neononanoic
acid, trimethylol propane ester of iso-hexanoic acid, trimethylol
propane ester of neodecanoic acid, trimethylol propane ester of
2-ethyl hexanoic acid (2EH), trimethylol propane ester of
isoheptanoic acid, trimethylol propane ester of isooctanoic acid,
trimethylol propane ester of isononanoic acid, and trimethylol
propane ester of isodecanoic acid.
10. The method of claim 1 wherein the at least one branched polyol
ester is selected from the group consisting of pentaerythritol
ester of 3,5,5-trimethyl hexanoic acid (TMH), pentaerythritol ester
of 2,2-dimethyl propionic acid (neopentanoic acid), pentaerythritol
ester of neoheptanoic acid, pentaerythritol ester of neooctanoic
acid, pentaerythritol ester of neononanoic acid, pentaerythritol
ester of iso-hexanoic acid, pentaerythritol ester of neodecanoic
acid, pentaerythritol ester of 2-ethyl hexanoic acid (2EH),
pentaerythritol ester of isoheptanoic acid, pentaerythritol ester
of isooctanoic acid, pentaerythritol ester of isononanoic acid, and
pentaerythritol ester of isodecanoic acid.
11. The method of claim 5 wherein the ester base stock comprises a
monoester, diester, glyceryl ester, polyether ester,
pentaerythritol ester, trimethylol propane ester, glycerol ester,
or phthalate ester; the alkylated aromatic base stock comprises an
alkylated naphthalene, alkylated anisole, alkylated diphenyl oxide,
or alkylated diphenyl sulfide; and the amide base stock comprises
an alkylated amide.
12. The method of claim 5 wherein the ester base stock comprises a
trimethylol propane ester base stock, the alkylated aromatic base
stock comprises an alkylated naphthalene base stock, and the amide
base stock comprises an alkylated amide base stock.
13. The method of claim 1 wherein the at least one Group V
lubricating oil base stock comprises is present in an amount from 1
to 70 weight percent, based on the total weight of the lubricating
oil.
14. The method of claim 1 wherein the at least one Group V
lubricating oil base stock comprises is present in an amount from 5
to 60 weight percent, based on the total weight of the lubricating
oil.
15. The method of claim 1 wherein the lubricating oil further
comprises a Group I, Group II, Group III, or Group IV base oil.
16. The method of claim 1 wherein the formulated oil further
comprises one or more of an antioxidant, viscosity modifier,
dispersant, detergent, pour point depressant, corrosion inhibitor,
metal deactivator, seal compatibility additive, anti-foam agent,
inhibitor, and anti-rust additive.
17. The method of claim 1 wherein the lubricating oil is a
passenger vehicle engine oil (PVEO) or a commercial vehicle engine
oil (CVEO).
18. A lubricating oil having a composition comprising at least one
Group V lubricating oil base stock; wherein the at least one Group
V lubricating oil base stock is present in an amount from 1 to 75
weight percent, based on the total weight of the lubricating oil;
and wherein oxidative stability is improved in a diesel engine,
wherein biodiesel fuel is used with diesel fuel in the diesel
engine, lubricated with the lubricating oil, as compared to
oxidative stability achieved in a diesel engine lubricated with a
lubricating oil not having the at least one Group V lubricating oil
base stock, as determined by a CEC L-109-16 Bio-Diesel Oxidation
Bench test.
19. The lubricating oil of claim 18 wherein, in a CEC L-109-16
Bio-Diesel Oxidation Bench test, the time for a relative kinematic
viscosity at 100.degree. C. (KV100) increase of 100% of said
lubricating oil, is greater than the time for a relative kinematic
viscosity at 100.degree. C. (KV100) increase of 100% of a
lubricating oil not having the at least one Group V lubricating oil
base stock.
20. The lubricating oil of claim 19 wherein, in a CEC L-109-16
Bio-Diesel Oxidation Bench test, the time for a relative kinematic
viscosity at 100.degree. C. (KV100) increase of 100% of said
lubricating oil is from 260 to 500 hours.
21. The lubricating oil of claim 19 wherein, in a CEC L-109-16
Bio-Diesel Oxidation Bench test, the time for a relative kinematic
viscosity at 100.degree. C. (KV100) increase of 100% of said
lubricating oil, is greater than at least 5% of the time for a
relative kinematic viscosity at 100.degree. C. (KV100) increase of
100% of a lubricating oil not having the at least one Group V
lubricating oil base stock.
22. The lubricating oil of claim 18 wherein the at least one Group
V lubricating oil base stock comprises an ester base stock, an
alkylated aromatic base stock, an amide base stock, or mixtures
thereof.
23. The lubricating oil of claim 18 wherein the lubricating oil
base stock comprises at least one branched polyol ester, which is
obtained by reacting one or more polyhydric alcohols with one or
more branched mono-carboxylic acids containing at least 4 carbon
atoms.
24. The lubricating oil of claim 18 wherein the one or more
polyhydric alcohols are selected from the group consisting of
trimethylol propane, pentaerythritol, neopentyl glycol, trimethylol
ethane, 2-methyl-2-propyl-1,3-propanediol, and
dipentaerythritol.
25. The lubricating oil of claim 18 wherein the one or more
branched mono-carboxylic acids containing at least 4 carbon atoms
are selected from the group consisting of 3,5,5-trimethyl hexanoic
acid (TMH), 2,2-dimethyl propionic acid (neopentanoic acid),
neoheptanoic acid, neooctanoic acid, neononanoic acid, iso-hexanoic
acid, neodecanoic acid, 2-ethyl hexanoic acid (2EH), isoheptanoic
acid, isooctanoic acid, isononanoic acid, and isodecanoic acid.
26. The lubricating oil of claim 18 wherein the at least one
branched polyol ester is selected from the group consisting of
trimethylol propane ester of 3,5,5-trimethyl hexanoic acid (TMH),
trimethylol propane ester of 2,2-dimethyl propionic acid
(neopentanoic acid), trimethylol propane ester of neoheptanoic
acid, trimethylol propane ester of neooctanoic acid, trimethylol
propane ester of neononanoic acid, trimethylol propane ester of
iso-hexanoic acid, trimethylol propane ester of neodecanoic acid,
trimethylol propane ester of 2-ethyl hexanoic acid (2EH),
trimethylol propane ester of isoheptanoic acid, trimethylol propane
ester of isooctanoic acid, trimethylol propane ester of isononanoic
acid, and trimethylol propane ester of isodecanoic acid.
27. The lubricating oil of claim 18 wherein the at least one
branched polyol ester is selected from the group consisting of
pentaerythritol ester of 3,5,5-trimethyl hexanoic acid (TMH),
pentaerythritol ester of 2,2-dimethyl propionic acid (neopentanoic
acid), pentaerythritol ester of neoheptanoic acid, pentaerythritol
ester of neooctanoic acid, pentaerythritol ester of neononanoic
acid, pentaerythritol ester of iso-hexanoic acid, pentaerythritol
ester of neodecanoic acid, pentaerythritol ester of 2-ethyl
hexanoic acid (2EH), pentaerythritol ester of isoheptanoic acid,
pentaerythritol ester of isooctanoic acid, pentaerythritol ester of
isononanoic acid, and pentaerythritol ester of isodecanoic
acid.
28. The lubricating oil of claim 18 wherein the ester base stock
comprises a monoester, diester, glyceryl ester, polyether ester,
pentaerythritol ester, trimethylol propane ester, glycerol ester,
or phthalate ester; the alkylated aromatic base stock comprises an
alkylated naphthalene, alkylated anisole, alkylated diphenyl oxide,
or alkylated diphenyl sulfide; and the amide base stock comprises
an alkylated amide.
29. The lubricating oil of claim 22 wherein the ester base stock
comprises a trimethylol propane ester base stock, the alkylated
aromatic base stock comprises an alkylated naphthalene base stock,
and the amide base stock comprises an alkylated amide base
stock.
30. The lubricating oil of claim 18 wherein the at least one Group
V lubricating oil base stock comprises is present in an amount from
1 to 70 weight percent, based on the total weight of the
lubricating oil.
31. The lubricating oil of claim 18 wherein the at least one Group
V lubricating oil base stock comprises is present in an amount from
5 to 60 weight percent, based on the total weight of the
lubricating oil.
32. The lubricating oil of claim 18 wherein the lubricating oil
further comprises a Group I, Group II, Group III, or Group IV base
oil.
33. The lubricating oil of claim 18 wherein the formulated oil
further comprises one or more of an antioxidant, viscosity
modifier, dispersant, detergent, pour point depressant, corrosion
inhibitor, metal deactivator, seal compatibility additive,
anti-foam agent, inhibitor, and anti-rust additive.
34. The lubricating oil of claim 18 wherein the lubricating oil is
a passenger vehicle engine oil (PVEO) or a commercial vehicle
engine oil (CVEO).
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional
Application Ser. No. 62/701,936 filed Jul. 23, 2018, which is
herein incorporated by reference in its entirety.
FIELD
[0002] This disclosure relates to lubricating oils with oxidative
stability in diesel engines using biodiesel fuel. In particular,
this disclosure relates to lubricating oils for diesel engines
using biodiesel fuel, and methods for improving oxidative stability
of a lubricating oil in a diesel engine, in which biodiesel fuel is
used with diesel fuel in the diesel engine, lubricated with the
lubricating oil. The lubricating oils of this disclosure are useful
as passenger vehicle engine oil (PVEO) products or commercial
vehicle engine oil (CVEO) products.
BACKGROUND
[0003] Lubricating oils are an essential part of modern vehicle
design for engine operation and protection. One essential feature
of engine oil is the viscosity, which must be viscous enough to
lubricate effectively without being so viscous that the engine
cannot effectively distribute the fluid to parts of the engine that
need lubrication. Viscosity is also closely linked to fuel economy,
with higher viscosity detracting from fuel efficiency. Oxidation of
molecules in lubricating oils can cause oligomerization and
eventually result in a dramatic, irreversible increase in the
viscosity of the oil. Such increase in oil viscosity can both
hamper the operation of the engine and reduce efficiency.
Antioxidant molecules are typically added to lubricating oils to
protect the composition from such oxidative degradation and control
viscosity increase during engine operation.
[0004] In the U.S., CAFE and GHG, emission regulations demand a
dramatic increase in fuel efficiency over the next few decades.
These regulations are driving automakers to downsize engines while
maintaining or even increasing engine power. As a result, engines
run at hotter temperatures on average and subject engine oils to
increasingly harsh oxidative conditions during engine operation.
This trend has accelerated the demand for improved oxidative
stability in engine oils.
[0005] To lessen the dependence on non-domestic crude oils and
promote sustainability, governments have mandated the use of
biodiesel fuel in the diesel fuel pool that is used by heavy duty
diesel vehicles and passenger car diesel vehicles. During normal
engine operation, some portion of fuel will reach the engine
crankcase. Biodiesel fuel is known to have poor chemical stability
and can further react once in the engine sump to shorten the life
of engine oils. The detrimental impact of biodiesel fuel on
lubricant life has been recognized by autobuilders and an oxidation
test which includes biodiesel fuel is now included in the ACEA 2016
specifications for gasoline, passenger car diesel, and heavy duty
diesel engine oils.
[0006] Improved oxidation stability is necessary to increase oil
life in diesel engines using biodiesel fuel and oil drain
intervals, thus reducing the amount of used oil generated as a
consequence of more frequent oil changes. Longer oil life and oil
drain intervals are key benefits that are desirable to end
customers. Traditional antioxidant packages provide standard
protection leaving the main differentiation hinging on the quality
of the base stock in the formulation.
[0007] What is needed is newly designed lubricants for diesel
engines using biodiesel fuel that are capable of controlling
oxidation and oil thickening for longer periods of time as compared
to conventional lubricants. Further, what is needed is newly
designed lubricants for diesel engines using biodiesel fuel that
enable extended oil life in combination with desired oxidative
stability.
SUMMARY
[0008] This disclosure relates to lubricating oils with oxidative
stability in diesel engines using biodiesel fuel. In particular,
this disclosure relates to lubricating oils for diesel engines
using biodiesel fuel, and methods for improving oxidative stability
of a lubricating oil in a diesel engine, in which biodiesel fuel is
used with diesel fuel in the diesel engine, lubricated with the
lubricating oil. The lubricating oils of this disclosure are useful
as passenger vehicle engine oil (PVEO) products or commercial
vehicle engine oil (CVEO) products.
[0009] This disclosure also relates in part to a method for
improving oxidative stability of a lubricating oil in a diesel
engine, in which biodiesel fuel is used with diesel fuel in the
diesel engine, by using as the lubricating oil a formulated oil.
The formulated oil has a composition comprising at least one Group
V lubricating oil base stock. The at least one Group V lubricating
oil base stock is present in an amount from about 1 to about 75
weight percent, based on the total weight of the lubricating oil.
Oxidative stability is improved in a diesel engine lubricated with
the lubricating oil, as compared to oxidative stability achieved in
a diesel engine lubricated with a lubricating oil not having the at
least one Group V lubricating oil base stock, as determined by a
CEC L-109-16 Bio-Diesel Oxidation Bench test.
[0010] This disclosure further relates in part to a lubricating oil
having a composition comprising at least one Group V lubricating
oil base stock. The at least one Group V lubricating oil base stock
is present in an amount from about 1 to about 75 weight percent,
based on the total weight of the lubricating oil. Oxidative
stability is improved in a diesel engine, in which biodiesel fuel
is used with diesel fuel in the diesel engine, lubricated with the
lubricating oil, as compared to oxidative stability achieved in a
diesel engine lubricated with a lubricating oil not having the at
least one Group V lubricating oil base stock, as determined by a
CEC L-109-16 Bio-Diesel Oxidation Bench test.
[0011] It has been surprisingly found that, for lubricating oils of
this disclosure containing at least one Group V base stock,
oxidative stability is improved in a diesel engine using biodiesel
fuel and lubricated with the lubricating oil, as compared to
oxidative stability achieved in a diesel engine using biodiesel
fuel and lubricated with a lubricating oil not having the at least
one Group V lubricating oil base stock, as determined by a CEC
L-109-16 Bio-Diesel Oxidation Bench test.
[0012] In particular, it has been surprisingly found that, for
lubricating oils of this disclosure containing at least one Group V
base stock, in a CEC L-109-16 Bio-Diesel Oxidation Bench test, the
relative kinematic viscosity at 100.degree. C. (KV100) increase
from 260 to 500 hours of the lubricating oil, is less than about
100 percent increase as compared to the relative kinematic
viscosity at 100.degree. C. (KV100) increase from 260 to 500 hours
of a lubricating oil not having the at least one Group V
lubricating oil base stock.
[0013] Other objects and advantages of the present disclosure will
become apparent from the detailed description that follows.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 shows the properties of base stocks used in the
Examples.
[0015] FIG. 2(a) shows the composition of lubricating oil
formulations with Additive System 1 and properties thereof, in
accordance with the Examples.
[0016] FIG. 2(b) shows the composition of lubricating oil
formulations with Additive System 1 and properties thereof, in
accordance with the Examples.
[0017] FIG. 2(c) shows the composition of lubricating oil
formulations with Additive System 1 and properties thereof, in
accordance with the Examples.
[0018] FIG. 2(d) shows the composition of lubricating oil
formulations with Additive System 1 and properties thereof, in
accordance with the Examples.
[0019] FIG. 2(e) shows the composition of lubricating oil
formulations with Additive System 1 and properties thereof, in
accordance with the Examples.
[0020] FIG. 2(f) shows the composition of lubricating oil
formulations with Additive System 1 and properties thereof, in
accordance with the Examples.
[0021] FIG. 3 shows the composition of lubricating oil formulations
with Additive System 2 and properties thereof, in accordance with
the Examples.
DETAILED DESCRIPTION
[0022] 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. The phrase "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. The phrase "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 greater 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. The phrase "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). The
phrase "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.
[0023] Biodiesel fuel is used in the diesel fuel pool that is used
by heavy duty diesel vehicles and passenger car diesel vehicles.
During normal engine operation, some portion of fuel will reach the
engine crankcase. Biodiesel fuel is known to have poor chemical
stability and can further react once in the engine sump to shorten
the life of engine oils.
[0024] The present disclosure provides significant improvements in
lubricant life as determined by the time to a 100% viscosity
increase for engine oils exposed to biodiesel fuel and oxidized at
150.degree. C. using the operating conditions of the CEC L-109-16
bench test. This disclosure facilitates the development of engine
oils with extended drain capabilities.
[0025] In accordance with this disclosure, lubricant oxidation
stability in the presence of biodiesel fuel is improved by greater
than 50% by using optimized base stock compositions. Base stocks
found to be particularly effective include TMP esters where the
acid segment is C7, C9, C8/C10 mix, C4 through C9, C7 through C15,
C6 through C9 when used in formulated engine oils at 50%.
[0026] The current state of the art is to meet the industry ACEA
2016 requirements in the CEC L-109-16 Bio-Diesel Oxidation Bench
test. The present disclosure identifies approaches to significantly
surpass industry requirements in the CEC L-109-16 Bio-Diesel
Oxidation Bench test. The industry standard CEC L-109-16 Bio-Diesel
Oxidation Bench test runs for 168 or 216 hours. The CEC L-109-16
oxidation bench test is conducted at 150.degree. C. An organo-iron
catalyst is added to the test oil to deliver 100 ppm Fe. Also 7%
B100 biodiesel fuel is added prior to initiating the oxidation test
to accelerate the oxidative degradation. The present disclosure
facilitates running the CEC L-109-16 Bio-Diesel Oxidation Bench
test for extended durations (.gtoreq.454 hours) to document the
benefits of this disclosure.
[0027] This disclosure relates to lubricating oils for diesel
engines using biodiesel fuel that contain at least one Group V base
stock in an amount greater than about 1, 5, 10, 20, 25, 30, 40, 50,
60, 70, 75, 80, 90 weight percent or greater. Lubricating oils
formulated with this level and Group V base stock provide
unexpectedly good oxidative stability as measured by the CEC
L-109-16 Bio-Diesel Oxidation Bench test.
[0028] In particular, for lubricating oils of this disclosure
containing at least one Group V base stock, in a CEC L-109-16
Bio-Diesel Oxidation Bench test, the relative kinematic viscosity
at 100.degree. C. (KV100) increase from 260 to 500 hours of the
lubricating oil, is less than about 100 percent increase as
compared to the relative kinematic viscosity at 100.degree. C.
(KV100) increase from 260 to 500 hours of a lubricating oil not
having the at least one Group V lubricating oil base stock.
[0029] In an embodiment, the lubricating oils of this disclosure
containing at least one Group V base stock, in a CEC L-109-16
Bio-Diesel Oxidation Bench test, the time for a relative kinematic
viscosity at 100.degree. C. (KV100) increase of 100% of the
lubricating oil, is greater than at least about 5%, or 10%, or 15%,
or 20%, or 25%, or 30%, or 35%, or 40%, or 45%, or 50%, or greater,
of the time for a relative kinematic viscosity at 100.degree. C.
(KV100) increase of 100% of a lubricating oil not having the at
least one Group V lubricating oil base stock.
[0030] In accordance with this disclosure, a method is provided to
improve oxidative stability through the lifetime of a lubricant in
diesel engines using biodiesel fuel through selection of a Group V
base stock. Specifically, when from 1-75 weight percent of a Group
V base stock is used in the formulation, the lubricant oxidation
performance is significantly improved as compared to formulations
not containing a Group V base stock.
[0031] Further, in accordance with this disclosure, finished
lubricants can be designed that are capable of controlling
oxidation and oil thickening for long durations in diesel engines
using biodiesel fuel as compared to lubricants not having a Group V
base stock. This disclosure also enables extended oil life in
combination with superior viscosity control.
[0032] Employing a Group V base stock, allows for an improvement in
oxidative stability, highlighting potential synergies with other
base stocks.
Group V Lubricating Oil Base Stocks
[0033] Group V lubricating oil base stocks useful in this
disclosure include, for example, esters (e.g., monoesters,
diesters, glyceryl esters, polyether esters, pentaerythritol
esters, trimethylol propane esters, glycerol esters, phthalate
esters), alkylated aromatics (e.g., alkylated naphthalenes,
alkylated anisole, alkylated diphenyl oxide, alkylated diphenyl
sulfide), amides (e.g., dodecanamide), and the like. Illustrative
Group V lubricating oil base stocks include, for example,
hydrocarbyl oils containing ester, carboxyl, carbonyl, ether,
aromatic, amide, or other chemical functionality. Preferred Group V
lubricating oil base stocks include branched polyol esters.
[0034] Esters comprise a useful Group V lubricating oil 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 mono-carboxylic 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.
[0035] 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.
[0036] 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 or more
carbon atoms. These esters are widely available commercially, for
example, the Mobil P-41 and P-51 esters of ExxonMobil Chemical
Company.
[0037] Preferred synthetic esters useful in this disclosure have a
kinematic viscosity at 100.degree. C. of about 3 cSt to about 50
cSt, preferably about 3 cSt to about 30 cSt, more preferably about
3.5 cSt to about 25 cSt, and even more preferably about 2 cSt to
about 8 cSt. Group V base oils useful in this disclosure preferably
comprise an ester at a concentration of about 2% to about 20%,
preferably from about 5% to about 15%.
[0038] 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, Esterex NP 343 ester of ExxonMobil
Chemical Company.
[0039] 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.
[0040] Branched polyol esters comprise a preferred base stock of
this disclosure. The branched polyol esters 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 single or
mixed branched mono-carboxylic acids containing at least about 4
carbon atoms, preferably C.sub.5 to C.sub.30 branched
mono-carboxylic acids including 2,2-dimethyl propionic acid
(neopentanoic acid), neoheptanoic acid, neooctanoic acid,
neononanoic acid, iso-hexanoic acid, neodecanoic acid, 2-ethyl
hexanoic acid (2EH), 3,5,5-trimethyl hexanoic acid (TMH),
isoheptanoic acid, isooctanoic acid, isononanoic acid, isodecanoic
acid, or mixtures of any of these materials. These branched polyol
esters include fully converted and partially converted polyol
esters.
[0041] Particularly useful polyols include, for example, neopentyl
glycol, 2,2-dimethylol butane, trimethylol ethane, trimethylol
propane, trimethylol butane, mono-pentaerythritol, technical grade
pentaerythritol, di-pentaerythritol, tri-pentaerythritol, ethylene
glycol, propylene glycol and polyalkylene glycols (e.g.,
polyethylene glycols, polypropylene glycols, 1,4-butanediol,
sorbitol and the like, 2-methylpropanediol, polybutylene glycols,
etc., and blends thereof such as a polymerized mixture of ethylene
glycol and propylene glycol). The most preferred alcohols are
technical grade (e.g., approximately 88% mono-, 10% di- and 1-2%
tri-pentaerythritol) pentaerythritol, mono-pentaerythritol,
di-pentaerythritol, neopentyl glycol and trimethylol propane.
[0042] Particularly useful branched mono-carboxylic acids include,
for example, 2,2-dimethyl propionic acid (neopentanoic acid),
neoheptanoic acid, neooctanoic acid, neononanoic acid, iso-hexanoic
acid, neodecanoic acid, 2-ethyl hexanoic acid (2EH),
3,5,5-trimethyl hexanoic acid (TMH), isoheptanoic acid, isooctanoic
acid, isononanoic acid, isodecanoic acid, or mixtures of any of
these materials. One especially preferred branched acid is
3,5,5-trimethyl hexanoic acid. The term "neo" as used herein refers
to a trialkyl acetic acid, i.e., an acid which is triply
substituted at the alpha carbon with alkyl groups.
[0043] Preferably, the branched polyol ester is derived from a
polyhydric alcohol and a branched mono-carboxylic acid. In
particular, the branched polyol ester is obtained by reacting one
or more polyhydric alcohols with one or more branched
mono-carboxylic acids containing at least about 4 carbon atoms.
[0044] Preferred branched polyol esters useful in this disclosure
include, for example, mono-pentaerythritol ester of branched
mono-carboxylic acids, di-pentaerythritol ester of branched
mono-carboxylic acids, trimethylolpropane ester of C8-C10 acids,
and the like.
[0045] Other synthetic esters that can be useful in this disclosure
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 mono caboxylic acids
containing at least about 4 carbon atoms, preferably branched
C.sub.5 to C.sub.30 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.
[0046] Other ester base oils useful in this disclosure include
adipate esters. The dialkyl adipate ester is derived from adipic
acid and a branched alkyl alcohol.
[0047] Mixtures of ester base stocks with other lubricating oil
base stocks (e.g., Groups I, II, III, IV and V base stocks) may be
useful in the lubricating oil formulations of this disclosure.
[0048] The branched polyol ester can be present in an amount of
from about 1 to about 99.8 weight percent, or from about 5 to about
95 weight percent, or from about 10 to about 90 weight percent, or
from about 15 to about 85 weight percent, or from about 20 to about
80 weight percent, or from about 25 to about 75 weight percent, or
from about 30 to about 70 weight percent, based on the total weight
of the formulated oil.
[0049] Hydrocarbyl or alkylated aromatics comprise a useful Group V
lubricating oil base stock. The hydrocarbyl aromatics can be used
as 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 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 3 cSt to about 50 cSt are preferred, with viscosities
of approximately 3.4 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. Useful concentrations of hydrocarbyl aromatic in a
lubricant oil composition can be about 2% to about 25%, preferably
about 4% to about 20%, and more preferably about 4% to about 15%,
depending on the application.
[0050] 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.
[0051] Particularly, alkylated naphthalenes comprise a useful Group
V lubricating oil base stock. The alkylated naphthalene can be used
as base oil or base oil component and can be any hydrocarbyl
molecule that contains at least about 5% of its weight derived from
a naphthenoid moiety, or its derivatives. These alkylated
naphthalenes include alkyl naphthalenes, alkyl naphthols, and the
like. The naphthenoid group can be mono-alkylated, dialkylated,
polyalkylated, and the like. The naphthenoid group can be mono- or
poly-functionalized. The naphthenoid group can also be derived from
natural (petroleum) sources, provided at least about 5% of the
molecule is comprised of the naphthenoid moiety. Viscosities at
100.degree. C. of approximately 3 cSt to about 50 cSt are
preferred, with viscosities of approximately 3.4 cSt to about 20
cSt often being more preferred for the naphthalene component. In
one embodiment, an alkyl naphthalene where the alkyl group is
primarily comprised of 1-hexadecene is used. Other alkylates of
naphthalene 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.
[0052] Alkylated naphthalenes 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 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.
[0053] The alkylated naphthalene can be present in an amount of
from about 1 to about 99.8 weight percent, or from about 5 to about
95 weight percent, or from about 10 to about 90 weight percent, or
from about 15 to about 85 weight percent, or from about 20 to about
80 weight percent, or from about 25 to about 75 weight percent, or
from about 30 to about 70 weight percent, based on the total weight
of the formulated oil. Preferred concentrations of alkylated
naphthalene may also be in the range from about 1 weight percent to
about 50 weight percent in some embodiments of the disclosure, or
preferably from about 2 weight percent to about 50 weight percent,
or more preferably from about 3 weight percent to about 50 weight
percent, or even more preferably from about 4 weight percent to
about 50 weight percent, or perhaps even more preferably from about
5 weight percent to about 50 weight percent.
[0054] Amides comprise a useful Group V lubricating oil base stock.
The amides can be used as base oil or base oil component and can be
any hydrocarbyl amide molecule that contains at least about 5% of
its weight derived from an amide moiety, or their derivatives.
These amides include, for example, N,N-dibutyldodecanamide, and the
like. Useful concentrations of amides in a lubricant oil
composition can be about 2% to about 25%, preferably about 4% to
about 20%, and more preferably about 4% to about 15%, depending on
the application.
[0055] Mixtures of the Group V lubricating oil base stocks with
other lubricating oil base stocks (e.g., Groups I, II, III and IV
base stocks) may be useful in the lubricating oil formulations of
this disclosure.
Other Lubricating Oil Base Stocks
[0056] A wide range of lubricating base oils is known in the art.
Lubricating base oils that are useful in the present disclosure are
both natural 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.
[0057] 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 .sup. <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
[0058] 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.
[0059] Group II and/or Group III hydroprocessed or hydrocracked
base stocks, including synthetic oils such as polyalphaolefins,
alkyl aromatics and synthetic esters are also well known base stock
oils.
[0060] 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.
[0061] 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 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-hexene, 1-octene, 1-decene,
1-dodecene and the like, being preferred. The preferred
polyalphaolefins are poly-1-hexene, 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.14 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, to the PAOs may be predominantly
trimers and tetramers of the starting olefins, with minor amounts
of the higher oligomers, having a viscosity range of 1.5 to 12 cSt.
PAO fluids of particular use may include 3.0 cSt, 3.4 cSt, and/or
3.6 cSt and combinations thereof. Bi-modal mixtures of PAO fluids
having a viscosity range of 1.5 to 150 cSt may be used if
desired.
[0062] 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.
[0063] 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.
[0064] 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
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.
[0065] Gas-to-Liquids (GTL) base oils, Fischer-Tropsch wax derived
base oils, and other wax-derived hydroisomerized (wax isomerate)
base oils be advantageously used in the instant disclosure, and may
have useful kinematic viscosities at 100.degree. C. of about 3 cSt
to about 50 cSt, preferably about 3 cSt to about 30 cSt, more
preferably about 3.5 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.
[0066] 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.
[0067] 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.
[0068] 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.
[0069] 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).
[0070] 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 phosphorous and aromatics make this
materially especially suitable for the formulation of low SAP
products.
[0071] 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.
[0072] 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).
[0073] 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.
[0074] This other base oil typically is present in an amount
ranging from about 0.1 to about 90 weight percent, or from about 1
to about 80 weight percent, or from about 1 to about 70 weight
percent, or from about 1 to about 60 weight percent, or from about
1 to about 50 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 ignition and compression-ignited engines. The base oil
conveniently has a kinematic viscosity, according to ASTM
standards, of about 2.5 cSt to about 12 cSt (or mm.sup.2/s) at
100.degree. C. and preferably of about 2.5 cSt to about 9 cSt (or
mm.sup.2/s) at 100.degree. C. Mixtures of synthetic and natural
base oils may be used if desired. Mixtures of Group II, III, IV,
and V may be preferable.
Lubricating Oil Additives
[0075] The formulated lubricating oil useful in the present
disclosure may additionally contain one or more of the commonly
used lubricating oil performance additives including but not
limited to antioxidants, dispersants, detergents, antiwear
additives, corrosion inhibitors, rust inhibitors, metal
deactivators, extreme pressure additives, anti-seizure agents, wax
modifiers, viscosity index improvers, viscosity modifiers,
fluid-loss additives, seal compatibility agents, friction
modifiers, lubricity agents, anti-staining agents, chromophoric
agents, defoamants, demulsifiers, emulsifiers, 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.
Antioxidants
[0076] 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.
[0077] 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).
[0078] 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.
[0079] 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.11 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.
[0080] 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'-dioctyldiphenylamine;
t-octylphenyl-alpha-naphthylamine; phenyl-alphanaphthylamine; and
p-octylphenyl-alpha-naphthylamine.
[0081] Sulfurized alkyl phenols and alkali or alkaline earth metal
salts thereof also are useful antioxidants.
[0082] 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.
Dispersants
[0083] 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 or borated metal-free dispersants are
considered ashless. In contrast, metal-containing detergents
discussed above form ash upon combustion.
[0084] 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.
[0085] A particularly 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;
8,557,753. 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.
[0086] 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.
[0087] 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.
[0088] 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.
[0089] 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.
[0090] 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.
[0091] 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.
[0092] 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.
[0093] 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.
[0094] Preferred dispersants include borated and non-borated
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.
[0095] 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.
[0096] Illustrative preferred 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).
[0097] 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.
[0098] 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).
[0099] 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.
[0100] 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.dbd.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.
[0101] 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 wt., and an isobutene content of 30 to 60% by wt. A
preferred source of monomer for making poly-n-butenes is petroleum
feed streams such as Raffinate II. These feed stocks 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.
[0102] 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.
[0103] 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.
[0104] Such dispersants may be used in an amount of about 0.01 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. The hydrocarbon
portion of the dispersant atoms can range from C.sub.60 to
C.sub.1000, or from C.sub.70 to C.sub.300, or from C.sub.70 to
C.sub.200. These dispersants may contain both neutral and basic
nitrogen, and mixtures of both. Dispersants can be end-capped by
borates and/or cyclic carbonates. Nitrogen content in the finished
oil can vary from about 200 ppm by weight to about 2000 ppm by
weight, preferably from about 200 ppm by weight to about 1200 ppm
by weight. Basic nitrogen can vary from about 100 ppm by weight to
about 1000 ppm by weight, preferably from about 100 ppm by weight
to about 600 ppm by weight.
[0105] Dispersants as described herein are beneficially useful with
the compositions of this disclosure and substitute for some or all
of the surfactants of this disclosure. Further, in one embodiment,
preparation of the compositions of this disclosure using one or
more dispersants is achieved by combining ingredients of this
disclosure, plus optional base stocks and lubricant additives, in a
mixture at a temperature above the melting point of such
ingredients, particularly that of the one or more M-carboxylates
(M=H, metal, two or more metals, mixtures thereof).
[0106] 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.
Detergents
[0107] Illustrative detergents 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 as
described herein.
[0108] The detergent is preferably a metal salt of an organic or
inorganic acid, a metal salt of a phenol, or mixtures thereof. The
metal is preferably selected from 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.
[0109] The metal is preferably selected from an alkali metal, an
alkaline earth metal, and mixtures thereof. More preferably, the
metal is selected from calcium (Ca), magnesium (Mg), and mixtures
thereof.
[0110] The organic acid or inorganic acid is preferably selected
from a sulfur-containing acid, a carboxylic acid, a
phosphorus-containing acid, and mixtures thereof.
[0111] Preferably, the metal salt of an organic or inorganic acid
or the metal salt of a phenol comprises calcium phenate, calcium
sulfonate, calcium salicylate, magnesium phenate, magnesium
sulfonate, magnesium salicylate, an overbased detergent, and
mixtures thereof.
[0112] Salts that contain a substantially stoichiometric 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
salicylate, sulfonates, phenates and/or magnesium salicylate,
sulfonates, phenates. The TBN ranges can vary from low, medium to
high TBN products, including as low as 0 to as high as 600.
Preferably the TBN delivered by the detergent is between 1 and 20.
More preferably 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, salicylates,
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. Borated
detergents can also be used.
[0113] 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, preferably, 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.
[0114] In accordance with this disclosure, metal salts of
carboxylic acids are preferred detergents. These carboxylic acid
detergents may be prepared by reacting a basic metal compound with
at least one carboxylic acid and removing free water from the
reaction product. These compounds may be overbased to produce the
desired TBN level. Detergents made from salicylic acid are one
preferred class of detergents derived from carboxylic acids. Useful
salicylates include long chain alkyl salicylates. One useful family
of compositions is of the formula
##STR00001##
where R is an alkyl group having 1 to about 30 carbon atoms, n is
an integer from 1 to 4, and M is an alkaline earth metal. Preferred
R groups are alkyl chains of at least C.sub.11, preferably C.sub.13
or greater. R may be optionally substituted with substituents that
do not interfere with the detergent's function. M is preferably,
calcium, magnesium, barium, or mixtures thereof. More preferably, M
is calcium.
[0115] Hydrocarbyl-substituted salicylic acids may be prepared from
phenols by the Kolbe reaction (see U.S. Pat. No. 3,595,791). The
metal salts of the hydrocarbyl-substituted salicylic acids may be
prepared by double decomposition of a metal salt in a polar solvent
such as water or alcohol.
[0116] Alkaline earth metal phosphates are also used as detergents
and are known in the art.
[0117] 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.
[0118] Preferred detergents include calcium sulfonates, magnesium
sulfonates, calcium salicylates, magnesium salicylates, calcium
phenates, magnesium phenates, and other related components
(including borated detergents), and mixtures thereof. Preferred
mixtures of detergents include magnesium sulfonate and calcium
salicylate, magnesium sulfonate and calcium sulfonate, magnesium
sulfonate and calcium phenate, calcium phenate and calcium
salicylate, calcium phenate and calcium sulfonate, calcium phenate
and magnesium salicylate, calcium phenate and magnesium phenate.
Overbased detergents are also preferred.
[0119] 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.
[0120] 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
[0121] Viscosity modifiers (also known as viscosity index improvers
(VI improvers), and viscosity improvers) can be included in the
lubricant compositions of this disclosure.
[0122] Viscosity modifiers provide lubricants with high and low
temperature operability. These additives impart shear stability at
elevated temperatures and acceptable viscosity at low
temperatures.
[0123] 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.
[0124] 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.
[0125] 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".
[0126] 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).
[0127] 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.
[0128] 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.
[0129] As used herein, the viscosity modifier concentrations are
given on an "as delivered" 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.
Pour Point Depressants (PPDs)
[0130] 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
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
[0131] 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
[0132] 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
[0133] 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.
[0134] 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
[0135] 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.
[0136] 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.
[0137] 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.
[0138] 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 isostearate,
polyoxypropylene isostearate, polyoxyethylene palmitate, and the
like.
[0139] 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.
[0140] 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.
[0141] 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.
[0142] 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,
isostearyl, and the like.
[0143] The lubricating oils of this disclosure exhibit desired
properties, e.g., wear control, in the presence or absence of a
friction modifier.
[0144] 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.
Antiwear Additives
[0145] 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.
[0146] 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".
[0147] 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.
[0148] 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.
[0149] 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.
[0150] 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 Compound wt % (Useful) wt %
(Preferred) Antiwear 0.1-2 0.5-1 Antioxidant 0.1-10 0.5-5
Dispersant 0.1-20 0.1-8 Detergent 0.1-20 0.1-8 Friction Modifier
0.01-5 0.01-1.5 Pour Point Depressant (PPD) 0.0-5 0.01-1.5
Anti-foam Agent 0.001-3 0.001-0.15 Viscosity Index Improver 0.0-8
0.1-6 (pure polymer basis) Inhibitor and Antirust 0.01-5
0.01-1.5
[0151] 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.
[0152] The following non-limiting examples are provided to
illustrate the disclosure.
Examples
[0153] FIG. 1 provides properties of base stocks used in this
evaluation. Several engine oil formulations were prepared having
the composition and physical properties shown in FIGS. 2(a), 2(b),
2(c), 2(d), 2(e), 2(f) and 3. All of the ingredients used in the
candidate formulated oils were commercially available.
[0154] The formulations shown in FIGS. 2(a), 2(b), 2(c), 2(d),
2(e), 2(f) and 3 are fully formulated lubricants. The formulations
contain typical base stocks combined with dispersants, detergents,
antiwear additives, friction modifiers, and the like. In
particular, the formulations shown in FIGS. 2(a), 2(b), 2(c), 2(d),
2(e) and 2(f) contain Additive System 1 described herein, and the
formulations shown in FIG. 3 contain Additive System 2 described
herein.
[0155] As used herein, "Additive System 1" contains calcium and
magnesium detergents, diphenyl amine antioxidant, hindered phenol
antioxidant, a borated dispersant, ZDDP, an ashless friction
modifier, a molybdenum amine/molybdenum ester friction modifier,
and 6.6% of a non-borated PIBSA/PAM dispersant made via thermal
processing.
[0156] As used herein, "Additive System 2" contains calcium and
magnesium detergents, diphenyl amine antioxidant, hindered phenol
antioxidant, a borated dispersant, ZDDP, an ashless friction
modifier, and 3.3% of a non-borated PIBSA/PAM dispersant made via
thermal processing.
[0157] FIGS. 2(a), 2(b), 2(c), 2(d), 2(e), 2(f) and 3 also show the
physical properties for the described engine oil formulations,
which were evaluated in an extended length CEC L-109-16 Bio-Diesel
Oxidation Bench test using 7% B100 biodiesel fuel to accelerate
lubricant oxidation. Engine oils blended with two different
additive systems (i.e., Additive Systems 1 and 2 described above)
were evaluated. Both additive systems used a mix of Ca and Mg
detergents and deliver .ltoreq.1.0% sulfated ash to the formulated
engine oil. Additive System 1 contains a higher level of dispersant
and contains an organo-molybdenum compound which delivers 160 ppm
Mo to the formulated engine oil. Additive System 2 contains a lower
level of dispersant and does not contain molybdenum. Both additive
systems deliver about 760 ppm P to the formulated oil from
ZDDP.
[0158] FIG. 2 also summarizes extended length CEC L-109-16
Bio-Diesel Oxidation Bench test results for the different
formulations having Additive System 1. Formulation 1 contains no
Group V base stock and a mix of Groups III and IV base stocks. This
formulation lasted 259 hours before the viscosity increase in the
CEC L-109-16 Bio-Diesel Oxidation Bench test reached 100%. This is
a very good result which serves as a baseline for further
improvements.
[0159] Formulations 2, 3, 4 and 5 in FIG. 2 add between 5% and 50%
of 3 different monoesters to the baseline formulations. The
addition of the monoester increased the time to 100% viscosity
increase by between 3% and 49% compared to the baseline
formulation.
[0160] Formulations 6, 7, 8, 9, 10, 11 and 12 in FIG. 2 add between
10% and 50% of 6 different diesters to the baseline formulation.
The addition of the diester increased the time to 100% viscosity
increase by between 5% and 92% compared to the baseline
formulation.
[0161] Formulations 13-25 in FIG. 2 add between 5% and 50% of
different triesters to the baseline formulation. The addition of
the triesters improved the time to 100% viscosity increase by
between 5% and 86% compared to the baseline formulation.
[0162] Formulations 26 and 27 in FIG. 2 add 25% and 15% of a
tetraester to the baseline formulation. The addition of the
tetraester increased the time to 100% viscosity increase by 37% and
17% compared to the baseline formulation.
[0163] Formulations 28-36 in FIG. 2 add between 1% and 50% of
different alkylated aromatics to the baseline formulation. The
addition of the alkylated aromatic base stocks to the baseline
formulation increased the time to 100% viscosity increase by
between 2% and 66% compared to the baseline formulation.
[0164] Formulations 37 and 38 in FIG. 2 add 10% and 50% of an amide
base stock to the baseline formulation. The addition of the amide
base stock to the baseline formulation increased the time to 100%
viscosity increase by 7% and 63%.
[0165] Formulation 40 in FIG. 2 adds 25% of a C8/C10 TMP triester
and 25% of an alkylated naphthalene base stock to the baseline
formulation. The addition of the triester and the alkylated
naphthalene base stock improved the time to 100% viscosity increase
by 70% compared to the baseline formulation.
[0166] Formulation 41 in FIG. 2 adds 5% of a triester and 10% of a
tetraester to the baseline formulation. The addition of the
triester and the tetraester increased the time to 100% viscosity
increase by 13% compared to the baseline formulation.
[0167] Formulation 42 in FIG. 2 adds 5% of a triester and 10% of an
amide base stock to the baseline formulation. The addition of the
triester and the amide base stock increased the time to 100%
viscosity increase by 24% compared to the baseline formulation.
[0168] FIG. 3 summarizes extended length CEC L-109-16 Bio-Diesel
Oxidation Bench test results for the different formulations having
Additive System 2. Formulations 43 through 51 shown in FIG. 3 use a
star viscosity modifier. Formulation 43 in FIG. 3 contains no Group
V base stock and contains only Group III base stock. This
formulation lasts 216 hours before the viscosity increase in the
CEC L-109-16 Bio-Diesel Oxidation Bench test reached 100%. This is
a very good result which serves as a baseline for further
improvements with Additive System 2. Formulation 44 in FIG. 3
contains 50% of an estolide ester, formulation 45 in FIG. 3
contains 50% of a C15/C17 diester, and formulation 46 in FIG. 3
contains 50% of a malonic acid diester. The benefit observed in the
CEC L-109-16 Bio-Diesel Oxidation Bench test over formulation 43 in
FIG. 3 was 26%, 0%, and 35% respectively. Formulations 47, 48, 49,
50, and 51 in FIG. 3 contain 50% of a C8/C10 TMP ester, a C4-C9 TMP
ester, a C7, C9, C11, C13, C15 TMP ester, a C6, C7, C9 TMP ester,
and a second C6, C7, C9 TMP ester. The benefit these formulations
provided in the CEC L-109-16 Bio-Diesel Oxidation Bench test over
baseline formulation 43 in FIG. 3 was 98, 96, 78, 103, and 98%
improvement in the time until the viscosity increase reached
100%.
[0169] Formulation 52 in FIG. 3 contains no Group V base stock,
uses a polymethacrylate viscosity modifier, and contains only Group
III base stock. This formulation lasts 216 hours before the
viscosity increase in the CEC L-109-16 Bio-Diesel Oxidation Bench
test reached 100%. Formulation 53 in FIG. 3 contains 50% of a
C8/C10 TMP ester, uses a polymethacrylate viscosity modifier, and
the increase in time before this oil reached 100% viscosity
increase was 101% versus formulation 52 in FIG. 3.
PCT and EP Clauses:
[0170] 1. A method for improving oxidative stability of a
lubricating oil in a diesel engine, wherein biodiesel fuel is used
with diesel fuel in the diesel engine, by using as the lubricating
oil a formulated oil, said formulated oil having a composition
comprising at least one Group V lubricating oil base stock; wherein
the at least one Group V lubricating oil base stock is present in
an amount from 1 to 75 weight percent, based on the total weight of
the lubricating oil; and wherein oxidative stability is improved in
a diesel engine lubricated with the lubricating oil, as compared to
oxidative stability achieved in a diesel engine lubricated with a
lubricating oil not having the at least one Group V lubricating oil
base stock, as determined by a CEC L-109-16 Bio-Diesel Oxidation
Bench test.
[0171] 2. The method of clause 1 wherein, in a CEC L-109-16
Bio-Diesel Oxidation Bench test, the time for a relative kinematic
viscosity at 100.degree. C. (KV100) increase of 100% of said
lubricating oil, is greater than the time for a relative kinematic
viscosity at 100.degree. C. (KV100) increase of 100% of a
lubricating oil not having the at least one Group V lubricating oil
base stock.
[0172] 3. The method of clause 1 wherein the lubricating oil base
stock comprises at least one branched polyol ester, which is
obtained by reacting one or more polyhydric alcohols with one or
more branched mono-carboxylic acids containing at least 4 carbon
atoms.
[0173] 4. The method of clause 1 wherein the lubricating oil base
stock comprises at least one branched polyol ester, which is
obtained by reacting one or more polyhydric alcohols with one or
more branched mono-carboxylic acids containing at least 4 carbon
atoms.
[0174] 5. The method of clause 1 wherein the one or more polyhydric
alcohols are selected from the group consisting of trimethylol
propane, pentaerythritol, neopentyl glycol, trimethylol ethane,
2-methyl-2-propyl-1,3-propanediol, and dipentaerythritol.
[0175] 6. The method of clause 1 wherein the one or more branched
mono-carboxylic acids containing at least 4 carbon atoms are
selected from the group consisting of 3,5,5-trimethyl hexanoic acid
(TMH), 2,2-dimethyl propionic acid (neopentanoic acid),
neoheptanoic acid, neooctanoic acid, neononanoic acid, iso-hexanoic
acid, neodecanoic acid, 2-ethyl hexanoic acid (2EH), isoheptanoic
acid, isooctanoic acid, isononanoic acid, and isodecanoic acid.
[0176] 7. The method of clause 1 wherein the at least one branched
polyol ester is selected from the group consisting of trimethylol
propane ester of 3,5,5-trimethyl hexanoic acid (TMH), trimethylol
propane ester of 2,2-dimethyl propionic acid (neopentanoic acid),
trimethylol propane ester of neoheptanoic acid, trimethylol propane
ester of neooctanoic acid, trimethylol propane ester of neononanoic
acid, trimethylol propane ester of iso-hexanoic acid, trimethylol
propane ester of neodecanoic acid, trimethylol propane ester of
2-ethyl hexanoic acid (2EH), trimethylol propane ester of
isoheptanoic acid, trimethylol propane ester of isooctanoic acid,
trimethylol propane ester of isononanoic acid, and trimethylol
propane ester of isodecanoic acid.
[0177] 8. The method of clause 1 wherein the at least one branched
polyol ester is selected from the group consisting of
pentaerythritol ester of 3,5,5-trimethyl hexanoic acid (TMH),
pentaerythritol ester of 2,2-dimethyl propionic acid (neopentanoic
acid), pentaerythritol ester of neoheptanoic acid, pentaerythritol
ester of neooctanoic acid, pentaerythritol ester of neononanoic
acid, pentaerythritol ester of iso-hexanoic acid, pentaerythritol
ester of neodecanoic acid, pentaerythritol ester of 2-ethyl
hexanoic acid (2EH), pentaerythritol ester of isoheptanoic acid,
pentaerythritol ester of isooctanoic acid, pentaerythritol ester of
isononanoic acid, and pentaerythritol ester of isodecanoic
acid.
[0178] 9. The method of clause 3 wherein the ester base stock
comprises a monoester, diester, glyceryl ester, polyether ester,
pentaerythritol ester, trimethylol propane ester, glycerol ester,
or phthalate ester; the alkylated aromatic base stock comprises an
alkylated naphthalene, alkylated anisole, alkylated diphenyl oxide,
or alkylated diphenyl sulfide; and the amide base stock comprises
an alkylated amide.
[0179] 10. The method of clause 3 wherein the ester base stock
comprises a trimethylol propane ester base stock, the alkylated
aromatic base stock comprises an alkylated naphthalene base stock,
and the amide base stock comprises an alkylated amide base
stock.
[0180] 11. The method of clause 1 wherein the at least one Group V
lubricating oil base stock comprises is present in an amount from 1
to 70 weight percent, based on the total weight of the lubricating
oil.
[0181] 12. The method of clause 1 wherein the at least one Group V
lubricating oil base stock comprises is present in an amount from 5
to 60 weight percent, based on the total weight of the lubricating
oil.
[0182] 13. The method of clause 1 wherein the lubricating oil
further comprises a Group I, Group II, Group III, or Group IV base
oil.
[0183] 14. The method of clause 1 wherein the formulated oil
further comprises one or more of an antioxidant, viscosity
modifier, dispersant, detergent, pour point depressant, corrosion
inhibitor, metal deactivator, seal compatibility additive,
anti-foam agent, inhibitor, and anti-rust additive.
[0184] 15. A lubricating oil having a composition comprising at
least one Group V lubricating oil base stock; wherein the at least
one Group V lubricating oil base stock is present in an amount from
1 to 75 weight percent, based on the total weight of the
lubricating oil; and wherein oxidative stability is improved in a
diesel engine, wherein biodiesel fuel is used with diesel fuel in
the diesel engine, lubricated with the lubricating oil, as compared
to oxidative stability achieved in a diesel engine lubricated with
a lubricating oil not having the at least one Group V lubricating
oil base stock, as determined by a CEC L-109-16 Bio-Diesel
Oxidation Bench test.
[0185] 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.
[0186] 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.
[0187] 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