U.S. patent application number 16/123137 was filed with the patent office on 2019-03-28 for lubricating oil compositions with viscosity and deposit control.
The applicant listed for this patent is ExxonMobil Research and Engineering Company. Invention is credited to Smruti A. DANCE, Douglas E. DECKMAN, Luca SALVI.
Application Number | 20190093040 16/123137 |
Document ID | / |
Family ID | 65806564 |
Filed Date | 2019-03-28 |
View All Diagrams
United States Patent
Application |
20190093040 |
Kind Code |
A1 |
DECKMAN; Douglas E. ; et
al. |
March 28, 2019 |
LUBRICATING OIL COMPOSITIONS WITH VISCOSITY AND DEPOSIT CONTROL
Abstract
A method for improving viscosity control, while maintaining or
improving deposit control, of a lubricating oil in an engine or
other mechanical component lubricated with the lubricating oil by
using as the lubricating oil a formulated oil. The formulated oil
has a composition including a lubricating oil base stock as a major
component, and at least one polymeric aminic antioxidant, as a
minor component. The at least one polymeric aminic antioxidant is
the polymerization reaction product of one or more unsubstituted or
hydrocarbyl-substituted diphenyl amines, one or more unsubstituted
or hydrocarbyl-substituted phenyl naphthyl amines, or both one or
more of unsubstituted or hydrocarbyl-substituted diphenylamine with
one or more unsubstituted or hydrocarbyl-substituted phenyl
naphthylamine. The lubricating oil base stock is present in an
amount from 1 to 85 weight percent and the at least one polymeric
aminic antioxidant is present in an amount from 0.1 to 5 weight
percent.
Inventors: |
DECKMAN; Douglas E.;
(Easton, PA) ; DANCE; Smruti A.; (Robbinsville,
NJ) ; SALVI; Luca; (Haddonfield, NJ) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
ExxonMobil Research and Engineering Company |
Annandale |
NJ |
US |
|
|
Family ID: |
65806564 |
Appl. No.: |
16/123137 |
Filed: |
September 6, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62561889 |
Sep 22, 2017 |
|
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C10M 2215/065 20130101;
C10N 2030/041 20200501; C10M 129/74 20130101; C10M 2207/026
20130101; C10N 2030/08 20130101; C10N 2040/25 20130101; C10M 133/12
20130101; C10M 2215/064 20130101; C10M 2207/2835 20130101; C10M
169/04 20130101; C10N 2030/02 20130101; C10N 2030/10 20130101; C10M
2215/064 20130101; C10M 2215/065 20130101; C10M 2207/026 20130101;
C10M 2207/289 20130101 |
International
Class: |
C10M 133/12 20060101
C10M133/12; C10M 129/74 20060101 C10M129/74 |
Claims
1. A method for improving viscosity control, while maintaining or
improving deposit control, of a lubricating oil in an engine or
other mechanical component lubricated with the lubricating oil by
using as the lubricating oil a formulated oil, said formulated oil
having a composition comprising a lubricating oil base stock as a
major component; and at least one polymeric aminic antioxidant, as
a minor component; wherein the at least one polymeric aminic
antioxidant is the polymerization reaction product of one or more
unsubstituted or hydrocarbyl-substituted diphenyl amines, one or
more unsubstituted or hydrocarbyl-substituted phenyl naphthyl
amines, or both one or more of unsubstituted or
hydrocarbyl-substituted diphenylamine with one or more
unsubstituted or hydrocarbyl-substituted phenyl naphthylamine;
wherein the lubricating oil base stock is present in an amount from
1 to 85 weight percent, based on the total weight of the
lubricating oil; and wherein the at least one polymeric aminic
antioxidant is present in an amount from 0.1 to 5 weight percent,
based on the total weight of the lubricating oil.
2. The method of claim 1 wherein, in an engine oil Bulk Oxidation
Test, the number of hours to 200% increase in kinematic viscosity
at 40.degree. C. is increased as compared to the number of hours to
200% increase in kinematic viscosity at 40.degree. C. of a
lubricating oil containing a minor amount of an antioxidant other
than the polymeric aminic antioxidant.
3. The method of claim 1 wherein, in deposit measurements of the
lubricating oil by thermo-oxidation engine oil simulation (TEOST
33C) measured by ASTM D6335, the amount of total deposits is
reduced or maintained as compared to the amount of total deposits
in a lubricating oil containing a minor component other than the at
least one polymeric aminic antioxidant.
4. The method of claim 1 wherein, in deposit measurements of the
lubricating oil by thermo-oxidation engine oil simulation (MHT
TEOST) measured by ASTM D7097, the amount of total deposits is
reduced or maintained as compared to the amount of total deposits
in a lubricating oil containing a minor component other than the at
least one polymeric aminic antioxidant
5. 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.
6. The method of claim 5 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.
7. The method of claim 5 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.
8. The method of claim 5 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.
9. The method of claim 5 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.
10. The method of claim 1 wherein the at least one polymeric aminic
antioxidant is the polymerization reaction product of ##STR00015##
wherein (A) and (B) each range from zero to 10, provided (A)+(B) is
at least 2; R.sup.2 is a styrene or C1 to C30 alkyl, R.sup.3 is a
styrene or C1 to C30 alkyl, q and y individually range from 0 to up
to the valence of the aryl group to which the respective R groups
are attached.
11. The method of claim 10 wherein the at least one polymeric
aminic antioxidant is a polymerization reaction product comprising:
(A)(A), (A)(B), (B)(B), (A)(A)(B), (A)(A)(A), (A)(B)(A), (B)(B)(B),
(B)(B)(A), (A)(A)(A)(A), (A)(A)(B)(B), (A)(A)(A)(B), (B)(B)(B)(B),
(B)(B)(B)(A), (A)(A)(A)(A)(A), (A)(B)(A)(B)(A), (A)(B)(B)(B)(A), or
mixtures thereof.
12. The method of claim 10 wherein the at least one polymeric
aminic antioxidant is the polymerization reaction product formed by
any combination of: ##STR00016## wherein R is H, C.sub.4H.sub.9,
C.sub.8H.sub.17, or C.sub.9H.sub.19; and/or ##STR00017##
13. The method of claim 1 wherein the at least one polymeric aminic
antioxidant is a polymerization reaction product selected from the
group consisting of: ##STR00018## wherein R.sup.2 is a styrene or
C1 to C30 alkyl, R.sup.3 is a styrene or C1 to C30 alkyl, R.sup.4
is a styrene or C1 to C30 alkyl, p, q and y individually range from
0 to up to the valence of the aryl group to which the respective R
groups are attached.
14. The method of claim 1 wherein the lubricating oil base stock is
present in an amount from 5 to 45 weight percent, based on the
total weight of the lubricating oil.
15. The method of claim 1 wherein the at least one polymeric aminic
antioxidant is present in an amount from 0.1 to 2.5 weight percent,
based on the total weight of the lubricating oil.
16. The method of claim 1 wherein the formulated oil further
comprises one or more of a viscosity modifier, dispersant,
detergent, other antioxidant, pour point depressant, corrosion
inhibitor, metal deactivator, seal compatibility additive,
anti-foam agent, inhibitor, and anti-rust additive.
17. The method of claim 16 wherein the other antioxidant comprises
at least one aromatic amine antioxidant, at least one phenolic
antioxidant, or mixtures thereof; wherein the at least one aromatic
amine antioxidant is present in an amount from 0.1 to 5 weight
percent, based on the total weight of the lubricating oil; and
wherein the at least one phenolic antioxidant is present in an
amount from 0.1 to 1 weight percent, based on the total weight of
the lubricating oil.
18. The method of claim 1 wherein the lubricating oil is a
passenger vehicle engine oil (PVEO) or a commercial vehicle engine
oil (CVEO).
19. A lubricating oil having a composition comprising a lubricating
oil base stock as a major component; and at least one polymeric
aminic antioxidant, as a minor component; wherein the at least one
polymeric aminic antioxidant is the polymerization reaction product
of one or more unsubstituted or hydrocarbyl-substituted diphenyl
amines, one or more unsubstituted or hydrocarbyl-substituted phenyl
naphthyl amines, or both one or more of unsubstituted or
hydrocarbyl-substituted diphenylamine with one or more
unsubstituted or hydrocarbyl-substituted phenyl naphthylamine;
wherein the lubricating oil base stock is present in an amount from
1 to 85 weight percent, based on the total weight of the
lubricating oil; and wherein the at least one polymeric aminic
antioxidant is present in an amount from 0.1 to 5 weight percent,
based on the total weight of the lubricating oil.
20. The lubricating oil of claim 19 wherein oxidative stability is
improved, and deposit control is maintained or improved, in an
engine or other mechanical component lubricated with the
lubricating oil, as compared to oxidative stability and deposit
control achieved using a lubricating oil other than the lubricating
oil.
21. The lubricating oil of claim 19 wherein, in an engine oil Bulk
Oxidation Test, the number of hours to 200% increase in kinematic
viscosity at 40.degree. C. is increased as compared to the number
of hours to 200% increase in kinematic viscosity at 40.degree. C.
of a lubricating oil containing a minor amount of an antioxidant
other than the polymeric aminic antioxidant.
22. The lubricating oil of claim 19 wherein, in deposit
measurements of the lubricating oil by thermo-oxidation engine oil
simulation (TEOST 33C) measured by ASTM D6335, the amount of total
deposits is reduced or maintained as compared to the amount of
total deposits in a lubricating oil containing a minor component
other than the at least one polymeric aminic antioxidant.
23. The lubricating oil of claim 19 wherein, in deposit
measurements of the lubricating oil by thermo-oxidation engine oil
simulation (MHT TEOST) measured by ASTM D7097, the amount of total
deposits is reduced or maintained as compared to the amount of
total deposits in a lubricating oil containing a minor component
other than the at least one polymeric aminic antioxidant
24. The lubricating oil of claim 19 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;
25. The lubricating oil of claim 24 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.
26. The lubricating oil of claim 24 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.
27. The lubricating oil of claim 24 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.
28. The lubricating oil of claim 24 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.
29. The lubricating oil of claim 19 wherein the at least one
polymeric aminic antioxidant is the polymerization reaction product
of ##STR00019## wherein (A) and (B) each range from zero to 10,
provided (A)+(B) is at least 2; R.sup.2 is a styrene or C1 to C30
alkyl, R.sup.3 is a styrene or C1 to C30 alkyl, q and y
individually range from 0 to up to the valence of the aryl group to
which the respective R groups are attached.
30. The lubricating oil of claim 29 wherein the at least one
polymeric aminic antioxidant is a polymerization reaction product
comprising: (A)(A), (A)(B), (B)(B), (A)(A)(B), (A)(A)(A),
(A)(B)(A), (B)(B)(B), (B)(B)(A), (A)(A)(A)(A), (A)(A)(B)(B),
(A)(A)(A)(B), (B)(B)(B)(B), (B)(B)(B)(A), (A)(A)(A)(A)(A),
(A)(B)(A)(B)(A), (A)(B)(B)(B)(A), or mixtures thereof.
31. The lubricating oil of claim 29 wherein the at least one
polymeric aminic antioxidant is the polymerization reaction product
formed by any combination of: ##STR00020## wherein R is H,
C.sub.4H.sub.9, C.sub.4H.sub.17, or C.sub.9H.sub.19; and/or
##STR00021##
32. The lubricating oil of claim 19 wherein the at least one
polymeric aminic antioxidant is a polymerization reaction product
selected from the group consisting of: ##STR00022## wherein R.sup.2
is a styrene or C1 to C30 alkyl, R.sup.3 is a styrene or C1 to C30
alkyl, R.sup.4 is a styrene or C1 to C30 alkyl, p, q and y
individually range from 0 to up to the valence of the aryl group to
which the respective R groups are attached.
33. The lubricating oil of claim 19 wherein the lubricating oil
base stock is present in an amount from 5 to 45 weight percent,
based on the total weight of the lubricating oil
34. The lubricating oil of claim 19 wherein the at least one
polymeric aminic antioxidant is present in an amount from 0.1 to
2.5 weight percent, based on the total weight of the lubricating
oil.
35. The lubricating oil of claim 19 which further comprises one or
more of a viscosity modifier, dispersant, detergent, other
antioxidant, pour point depressant, corrosion inhibitor, metal
deactivator, seal compatibility additive, anti-foam agent,
inhibitor, and anti-rust additive.
36. The lubricating oil of claim 35 wherein the other antioxidant
comprises at least one aromatic amine antioxidant, at least one
phenolic antioxidant, or mixtures thereof; wherein the at least one
aromatic amine antioxidant is present in an amount from 0.1 to 5
weight percent, based on the total weight of the lubricating oil;
and wherein the at least one phenolic antioxidant is present in an
amount from 0.1 to 1 weight percent, based on the total weight of
the lubricating oil.
37. The lubricating oil of claim 19 which is a passenger vehicle
engine oil (PVEO) or a commercial vehicle engine oil (CVEO).
38. A method for improving oxidative stability, while maintaining
or improving deposit control, of a lubricating oil in an engine or
other mechanical component lubricated with the lubricating oil by
using as the lubricating oil a formulated oil, said formulated oil
having a composition comprising a lubricating oil base stock as a
major component; and at least one polymeric aminic antioxidant, as
a minor component; wherein the at least one polymeric aminic
antioxidant is the polymerization reaction product of one or more
unsubstituted or hydrocarbyl-substituted diphenyl amines, one or
more unsubstituted or hydrocarbyl-substituted phenyl naphthyl
amines, or both one or more of unsubstituted or
hydrocarbyl-substituted diphenylamine with one or more
unsubstituted or hydrocarbyl-substituted phenyl naphthylamine;
wherein the lubricating oil base stock is present in an amount from
1 to 85 weight percent, based on the total weight of the
lubricating oil; and wherein the at least one polymeric aminic
antioxidant is present in an amount from 0.1 to 5 weight percent,
based on the total weight of the lubricating oil.
39. The method of claim 38 wherein oxidative stability is improved,
and deposit control is maintained or improved, as compared to
oxidative stability and deposit control achieved using a
lubricating oil other than the formulated oil.
40. The method of claim 38 wherein, in an engine oil Bulk Oxidation
Test, the number of hours to 200% increase in kinematic viscosity
at 40.degree. C. is increased as compared to the number of hours to
200% increase in kinematic viscosity at 40.degree. C. of a
lubricating oil containing a minor amount of an antioxidant other
than the polymeric aminic antioxidant.
41. The method of claim 38 wherein, in deposit measurements of the
lubricating oil by thermo-oxidation engine oil simulation (TEOST
33C) measured by ASTM D6335, the amount of total deposits is
reduced or maintained as compared to the amount of total deposits
in a lubricating oil containing a minor component other than the at
least one polymeric aminic antioxidant.
42. The method of claim 38 wherein, in deposit measurements of the
lubricating oil by thermo-oxidation engine oil simulation (MHT
TEOST) measured by ASTM D7097, the amount of total deposits is
reduced or maintained as compared to the amount of total deposits
in a lubricating oil containing a minor component other than the at
least one polymeric aminic antioxidant.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional
Application Ser. No. 62/561,889 filed Sep. 22, 2017, which is
herein incorporated by reference in its entirety.
FIELD
[0002] This disclosure relates to engine lubricating oils with
viscosity control and deposit control. In particular, this
disclosure relates to lubricating oils, methods for improving
viscosity control and deposit control of a lubricating oil in an
engine or other mechanical component lubricated with the
lubricating oil, and methods for improving oxidative stability and
deposit control, of a lubricating oil in an engine or other
mechanical component 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] Lubricant oxidative stability is one of the key parameters
controlling oil life, which translates in oil drain interval in
practical terms. Additionally, deposit formation is an issue
associated with the decomposition of the base stock molecules
mostly propagated by oxidative chain reactions. There are several
conventional approaches to improve the resistance to oxidation of a
finished lubricant product, but most products are formulated using
small molecules such as diphenylamine (DPA) or a phenolic
antioxidant.
[0004] Improved oxidation stability is necessary to increase oil
life 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.
[0005] What is needed is newly designed lubricants 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 that enable extended oil life in
combination with desired deposit control and cleanliness
performance.
SUMMARY
[0006] This disclosure relates to engine lubricating oils with
viscosity control and deposit control. In particular, this
disclosure relates to lubricating oils, methods for improving
viscosity control and deposit control of a lubricating oil in an
engine or other mechanical component lubricated with the
lubricating oil, and methods for improving oxidative stability and
deposit control, of a lubricating oil in an engine or other
mechanical component 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.
[0007] This disclosure also relates in part to a method for
improving viscosity control, while maintaining or improving deposit
control, of a lubricating oil in an engine or other mechanical
component lubricated with the lubricating oil by using as the
lubricating oil a formulated oil.
[0008] The formulated oil has a composition comprising a
lubricating oil base stock as a major component, and at least one
polymeric aminic antioxidant, as a minor component. The at least
one polymeric aminic antioxidant is the polymerization reaction
product of one or more unsubstituted or hydrocarbyl-substituted
diphenyl amines, one or more unsubstituted or
hydrocarbyl-substituted phenyl naphthyl amines, or both one or more
of unsubstituted or hydrocarbyl-substituted diphenylamine with one
or more unsubstituted or hydrocarbyl-substituted phenyl
naphthylamine. The lubricating oil base stock is present in an
amount from about 1 to about 85 weight percent, based on the total
weight of the lubricating oil. The at least one polymeric aminic
antioxidant is present in an amount from about 0.1 to about 5
weight percent, based on the total weight of the lubricating
oil.
[0009] This disclosure further relates in part to a method for
improving viscosity control, while maintaining or improving deposit
control, of a lubricating oil in an engine or other mechanical
component lubricated with the lubricating oil by using as the
lubricating oil a formulated oil. The formulated oil has a
composition comprising a lubricating oil base stock as a major
component, and at least one polymeric aminic antioxidant, as a
minor component. 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 about 4 carbon atoms. The at least one
polymeric aminic antioxidant is the polymerization reaction product
of one or more unsubstituted or hydrocarbyl-substituted diphenyl
amines, one or more unsubstituted or hydrocarbyl-substituted phenyl
naphthyl amines, or both one or more of unsubstituted or
hydrocarbyl-substituted diphenylamine with one or more
unsubstituted or hydrocarbyl-substituted phenyl naphthylamine. The
lubricating oil base stock is present in an amount from about 1 to
about 85 weight percent, based on the total weight of the
lubricating oil. The at least one polymeric aminic antioxidant is
present in an amount from about 0.1 to about 5 weight percent,
based on the total weight of the lubricating oil.
[0010] This disclosure yet further relates in part to a lubricating
oil having a composition comprising a lubricating oil base stock as
a major component, and at least one polymeric aminic antioxidant,
as a minor component. The at least one polymeric aminic antioxidant
is the polymerization reaction product of one or more unsubstituted
or hydrocarbyl-substituted diphenyl amines, one or more
unsubstituted or hydrocarbyl-substituted phenyl naphthyl amines, or
both one or more of unsubstituted or hydrocarbyl-substituted
diphenylamine with one or more unsubstituted or
hydrocarbyl-substituted phenyl naphthylamine. The lubricating oil
base stock is present in an amount from about 1 to about 85 weight
percent, based on the total weight of the lubricating oil. The at
least one polymeric aminic antioxidant is present in an amount from
about 0.1 to about 5 weight percent, based on the total weight of
the lubricating oil.
[0011] This disclosure still further relates in part to a
lubricating oil having a composition comprising a lubricating oil
base stock as a major component, and at least one polymeric aminic
antioxidant, as a minor component. 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 about 4 carbon atoms. The
at least one polymeric aminic antioxidant is the polymerization
reaction product of one or more unsubstituted or
hydrocarbyl-substituted diphenyl amines, one or more unsubstituted
or hydrocarbyl-substituted phenyl naphthyl amines, or both one or
more of unsubstituted or hydrocarbyl-substituted diphenylamine with
one or more unsubstituted or hydrocarbyl-substituted phenyl
naphthylamine. The lubricating oil base stock is present in an
amount from about 1 to about 85 weight percent, based on the total
weight of the lubricating oil. The at least one polymeric aminic
antioxidant is present in an amount from about 0.1 to about 5
weight percent, based on the total weight of the lubricating
oil.
[0012] This disclosure also relates in part to a method for
improving oxidative stability, while maintaining or improving
deposit control, of a lubricating oil in an engine or other
mechanical component lubricated with the lubricating oil by using
as the lubricating oil a formulated oil. The formulated oil has a
composition comprising a lubricating oil base stock as a major
component, and at least one polymeric aminic antioxidant, as a
minor component. The at least one polymeric aminic antioxidant is
the polymerization reaction product of one or more unsubstituted or
hydrocarbyl-substituted diphenyl amines, one or more unsubstituted
or hydrocarbyl-substituted phenyl naphthyl amines, or both one or
more of unsubstituted or hydrocarbyl-substituted diphenylamine with
one or more unsubstituted or hydrocarbyl-substituted phenyl
naphthylamine. The lubricating oil base stock is present in an
amount from about 1 to about 85 weight percent, based on the total
weight of the lubricating oil. The at least one polymeric aminic
antioxidant is present in an amount from about 0.1 to about 5
weight percent, based on the total weight of the lubricating
oil.
[0013] This disclosure further relates in part to a method for
improving oxidative stability, while maintaining or improving
deposit control, of a lubricating oil in an engine or other
mechanical component lubricated with the lubricating oil by using
as the lubricating oil a formulated oil. The formulated oil has a
composition comprising a lubricating oil base stock as a major
component, and at least one polymeric aminic antioxidant, as a
minor component. 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 about 4 carbon atoms. The at least one
polymeric aminic antioxidant is the polymerization reaction product
of one or more unsubstituted or hydrocarbyl-substituted diphenyl
amines, one or more unsubstituted or hydrocarbyl-substituted phenyl
naphthyl amines, or both one or more of unsubstituted or
hydrocarbyl-substituted diphenylamine with one or more
unsubstituted or hydrocarbyl-substituted phenyl naphthylamine. The
lubricating oil base stock is present in an amount from about 1 to
about 85 weight percent, based on the total weight of the
lubricating oil. The at least one polymeric aminic antioxidant is
present in an amount from about 0.1 to about 5 weight percent,
based on the total weight of the lubricating oil.
[0014] It has been surprisingly found that, in accordance with this
disclosure, oxidative stability is improved, and deposit control is
maintained or improved, as compared to oxidative stability and
deposit control achieved using a lubricating oil other than the
formulated oil.
[0015] In particular, it has been surprisingly found that, for oil
life assessed using the engine oil Bulk Oxidation Test (BOT) and
the Oxidative Stability Test (OST) as described herein, the number
of hours to 200% increase in kinematic viscosity at 40.degree. C.
is increased as compared to the number of hours to 200% increase in
kinematic viscosity at 40.degree. C. of a lubricating oil
containing a minor amount of an antioxidant other than the
polymeric aminic antioxidant.
[0016] More, in particular, it has been surprisingly found that, in
deposit measurements of the lubricating oil by thermo-oxidation
engine oil simulation (TEOST 33C) measured by ASTM D6335, the
amount of total deposits is reduced or maintained as compared to
the amount of total deposits in a lubricating oil containing a
minor component other than the at least one polymeric aminic
antioxidant. It has been also surprisingly found that the benefits
associated with the invention are exhibited with a modified version
of the WIT TEOST (ASTM D7097).
[0017] Other objects and advantages of the present disclosure will
become apparent from the detailed description that follows.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 shows chemical structures and nomenclature of
illustrative antioxidants used in lubricating oil formulations in
accordance with the Examples.
[0019] FIG. 2 shows tabulated results of Bulk Oxidation Test (BOT)
performance as a function of antioxidant selection in accordance
with the Examples.
[0020] FIG. 3 shows tabulated results of TEOST 33C performance as a
function of antioxidant selection in accordance with the
Examples.
[0021] FIG. 4 shows tabulated results of antioxidant package
evaluation based on Bulk Oxidation Test (BOT) and Oxidation
Stability Test (OST) methods in accordance with the Examples.
[0022] FIG. 5 shows tabulated results of antioxidant package
evaluation based on Bulk Oxidation Test (BOT), in particular, the
effect of phenolic antioxidants included in the formulations, in
accordance with the Examples.
[0023] FIG. 6 shows tabulated results of antioxidant packages based
on Bulk Oxidation Test, TEOST 33C (ASTM D6335), and modified WIT
TEOST (ASTM D7097 run at 300.degree. C.).
DETAILED DESCRIPTION
[0024] 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.
[0025] In accordance with this disclosure, in using polymeric
antioxidants containing amine functional groups, oxidative
stability is increased (e.g., by more than 3 times), as measured by
Bulk Oxidation Test (BOT), when comparing the performance of a
traditional small molecule antioxidant. It has been found that the
use of phenolic antioxidant can lead to decreased oxidative
stability when employed above a relatively small treat rate. Using
a high level of aminic antioxidant can provide similar oxidative
stability benefits, however, when used at these high treat rates,
the deposit control as measured by TEOST 33C is unacceptable per
industry requirements. In contrast, in accordance with this
disclosure, when polymerized aminic antioxidants are used in the
formulation, excellent oxidation and viscosity control are observed
along with unexpected and significant improvement in deposit
control.
[0026] Also, in accordance with this disclosure, a method is
provided to improve oxidative stability through the lifetime of a
lubricant through selection of polymerized aminic antioxidants in
combination with Group V base stocks. Additionally, the deposit
control characteristics as measured by TEOST 33C and modified WIT
TEOST tests, track the ranking observed in oxidation control with
the best candidates also show lowest deposit.
[0027] Further, in accordance with this disclosure, finished
lubricants can be designed that are capable of controlling
oxidation and oil thickening for long durations (e.g., 2-3 times
longer) as compared to conventional lubricants. This disclosure
also enables extended oil life in combination with superior deposit
control and cleanliness performance through a balance of
antioxidant chemistry, in light of the negative performance in
oxidation control observed when employing similarly high
concentrations of hindered phenol, and in light of the deposit
debits observed when employing diphenylamine antioxidants at high
treat rates.
[0028] Employing polymeric aminic antioxidants allows for an
exponential improvement in oxidative stability, highlighting
potential synergies with traditional aminic antioxidants, which
debits are observed in the presence of increasing amounts of
phenolic antioxidants. In addition, when targeting the same level
of oxidation performance with traditional small molecule
antioxidants (e.g., diphenylamine and hindered phenol) as is seen
with polymeric aminic antioxidants, there are negative performance
impacts observed in the areas of high temperature deposits and
decreased oxidative stability in some cases.
Branched Polyol Ester Lubricating Oil Base Stocks
[0029] Branched polyol esters comprise a useful 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.
[0030] 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.
[0031] 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.
[0032] 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.
[0033] 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.
[0034] 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 carboxylic acids
containing at least about 4 carbon atoms, preferably branched
C.sub.5 to C30 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.
[0035] 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.
[0036] Mixtures of branched polyol 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.
[0037] The branched polyol ester can be present in an amount of
from about 1 to about 50 weight percent, or from about 5 to about
45 weight percent, or from about 10 to about 40 weight percent, or
from about 15 to about 35 weight percent, or from about 20 to about
30 weight percent, based on the total weight of the formulated
oil.
Polymeric Aminic Antioxidants
[0038] Polymeric aminic antioxidants are the polymerization
reaction products of one or more unsubstituted or
hydrocarbyl-substituted diphenyl amines, one or more unsubstituted
or hydrocarbyl-substituted phenyl naphthyl amines or both one or
more of unsubstituted or hydrocarbyl-substituted diphenylamine with
one or more unsubstituted or hydrocarbyl-substituted phenyl
naphthylamine. A representative schematic is presented below:
##STR00001##
wherein (A) and (B) each range from zero to 10, preferably zero to
5, more preferably zero to 3, most preferably 1 to 3, provided
(A)+(B) is at least 2; R.sup.2 is a styrene or C1 to C30 alkyl,
R.sup.3 is a styrene or C1 to C30 alkyl, q and y individually range
from 0 to up to the valence of the aryl group to which the
respective R groups are attached; for example:
##STR00002##
wherein R.sup.2 is a styrene or C1 to C30 alkyl, R.sup.3 is a
styrene or C1 to C30 alkyl, R.sup.4 is a styrene or C1 to C30
alkyl, preferably R.sup.2 is a C1 to C30 alkyl, R.sup.3 is a C1 to
C30 alkyl, R.sup.4 is a C1 to C30 alkyl, more preferably R.sup.2 is
a C4 to C10 alkyl, R.sup.3 is a C4 to C10 alkyl and R.sup.4 is a C4
to C10 alkyl, p, q and y individually range from 0 to up to the
valence of the aryl group to which the respective R groups are
attached, preferably at least one of p, q and y range from 1 to up
to the valence of the aryl group to which the respective R group(s)
are attached, more preferably p, q and y each individually range
from at least 1 to up to the valence of the aryl group to which the
respective R groups are attached.
[0039] In a preferred embodiment, the at least one polymeric aminic
antioxidant is the polymerization reaction product formed by any
combination of (A) and (B) above including, but not limited to,
(A)(A), (A)(B), (B)(B), (A)(A)(B), (A)(A)(A), (A)(B)(A), (B)(B)(B),
(B)(B)(A), (A)(A)(A)(A), (A)(A)(B)(B), (A)(A)(A)(B), (B)(B)(B)(B),
(B)(B)(B)(A), (A)(A)(A)(A)(A), (A)(B)(A)(B)(A) (A)(B)(B)(B)(A), and
the like.
[0040] In another preferred embodiment, the at least one polymeric
aminic antioxidant is the polymerization reaction product formed by
any combination of:
##STR00003##
wherein R is H, C.sub.4H.sub.9, C.sub.4H.sub.7, or C.sub.9H.sub.19;
and/or
##STR00004##
[0041] In a further preferred embodiment, the at least one
polymeric aminic antioxidant is the polymerization reaction product
formed by any combination of:
##STR00005##
[0042] In yet a further preferred embodiment, the at least one
polymeric aminic antioxidant is the polymerization reaction product
formed by any combination of:
##STR00006##
[0043] Other more extensive oligomers are within the scope of this
disclosure, but materials of formulae (a), (b), (c) and (d) are
preferred.
[0044] The polymeric aminic antioxidant may contain nonpolymerized
aryl amine antioxidant starting materials as a result of the
preparation procedure. Additional monomeric amine antioxidants may
be added to the lubricant to impart desired properties. Examples of
monomeric amine antioxidants include but are not limited to
diphenyl amine, alkylated diphenyl amines, styrenated diphenyl
amines, phenyl-N-naphthyl amine, alkylated phenyl-N-naphthyl
amines, styrenated phenyl-N-naphthyl amines, phenothiazine,
alkylated phenothiazine, and styrenated phenothiazine. Other
antioxidants such as hindered phenols and zinc dithiophosphates can
also be added to the lubricant in addition to the polymerized amine
antioxidant.
[0045] The polymeric aminic antioxidants useful in this disclosure
can be prepared by conventional polymerization reactions. See, for
example, U.S. Pat. Nos. 6,426,324 and 8,623,795. An illustrative
polymerization reaction for preparing preferred polymeric aminic
antioxidants useful in this disclosure is set forth below. The
product of the reaction can yield more than the two oligomers shown
below, for example, any combination of (A) and (B) below including,
but not limited to, (A)(A), (A)(B), (B)(B), (A)(A)(B), (A)(A)(A),
(A)(B)(A), (B)(B)(B), (B)(B)(A), (A)(A)(A)(A), (A)(A)(B)(B),
(A)(A)(A)(B), (B)(B)(B)(B), (B)(B)(B)(A), (A)(A)(A)(A)(A),
(A)(B)(A)(B)(A), (A)(B)(B)(B)(A), and the like.
##STR00007##
[0046] The polymeric aminic antioxidant is present in an amount in
the range 0.1 to 10 wt % (active ingredient), preferably 0.1 to 5
wt % (active ingredient), or 0.1 to 4 wt % (active ingredient), or
0.1 to 2.5 wt % (active ingredient) or 0.1 to 1.5 wt % (active
ingredient), or 1.5 to 4 wt % (active ingredient), of polymerized
aminic antioxidant exclusive of any unpolymerized aryl amine which
may be present or any added antioxidants.
Other Lubricating Oil Base Stocks
[0047] 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.
[0048] 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
[0049] 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.
[0050] 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.
[0051] 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.
[0052] 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,
C2 to about C32 alphaolefins with the C.sub.8 to about C16
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, 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.
[0053] 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 C14 to Cis olefins are
described in U.S. Pat. No. 4,218,330.
[0054] 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 naphthylene 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.
[0055] 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.
[0056] Mixtures of alkylated naphthalene 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.
[0057] The alkylated naphthalene can be present in an amount of
from about 30 to about 99.8 weight percent, or from about 35 to
about 95 weight percent, or from about 40 to about 90 weight
percent, or from about 45 to about 85 weight percent, or from about
50 to about 80 weight percent, or from about 55 to about 75 weight
percent, or from about 60 to about 70 weight percent, based on the
total weight of the formulated oil.
[0058] 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.
[0059] 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.
[0060] 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 C6 up to about C60 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.
[0061] 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.
[0062] 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.
[0063] 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.
[0064] 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.
[0065] 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).
[0066] 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.
[0067] 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.
[0068] 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).
[0069] 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.
[0070] 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 III, IV, and V
may be preferable.
Other Additives
[0071] The formulated lubricating oil useful in the present
disclosure may additionally contain one or more of the other
commonly used lubricating oil performance additives including but
not limited to other 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.
Other Antioxidants
[0072] Other antioxidants may be used in combination with the
polymeric aminic antioxidants. 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.
[0073] Monomeric amine antioxidants are unsubstituted or
hydrocarbon-substituted diphenyl amines, unsubstituted or
hydrocarbyl-substituted phenyl naphthyl amines and unsubstituted or
hydrocarbyl-substituted phenothiazines wherein the
hydrocarbyl-substituted group is styrene or a C1 to C30 alkyl
group, preferably a C1 to C10 alkyl group, more preferably a C4 to
C10 alkyl group. Other monomeric aryl amines have been described in
the patent literature.
[0074] Useful antioxidants include amine antioxidants, preferably
aromatic amine antioxidants. Other useful antioxidants include
phenolic antioxidants (e.g., hindered phenolic antioxidants).
Aromatic amine antioxidants may be used alone or in combination
with phenolic antioxidants. Typical examples of amine 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)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 20
carbon atoms, and preferably contains from 6 to 12 carbon atoms.
The aliphatic group is an 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.
[0075] Typical aromatic amine antioxidants have alkyl substituent
groups of at least 6 carbon atoms. Examples of aliphatic groups
include hexyl, heptyl, octyl, nonyl, and decyl. Generally, the
aliphatic groups will not contain more than 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. Particular
examples of aromatic amine antioxidants useful in the present
disclosure include: p,p'-dioctyldiphenylamine;
t-octylphenyl-alpha-naphthylamine; phenyl-alpha-naphthylamine; and
p-octylphenyl-alpha-naphthylamine.
[0076] Illustrative aromatic amine antioxidants that may be used in
combination with the polymeric aminic antioxidants include, for
example, the following:
##STR00008##
[0077] Illustrative phenolic antioxidants that may be used in
combination with the polymeric aminic antioxidants include, for
example, the following:
##STR00009##
[0078] The arylamines antioxidants may be used individually or in
combination. Such additives may be used in an amount of 0.01 to 5
weight percent, preferably 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.
[0079] The phenolic antioxidants may be used individually or in
combination. The phenolic antioxidants may provide potential
benefits in other performance aspects. Such additives may be used
in an amount of 0.01 to 1 weight percent, preferably 0.01 to 0.75
weight percent, more preferably zero to less than 0.5 weight
percent. Higher amounts of phenolic antioxidants could result in
decreased oxidative stability and deposit control.
Dispersants
[0080] 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.
[0081] 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.
[0082] 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. 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.
[0083] 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.
[0084] 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.
[0085] 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.
[0086] 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.
[0087] 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.
[0088] 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.
[0089] 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.
[0090] 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.
[0091] 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.
[0092] 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.
[0093] 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).
[0094] 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.
[0095] 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).
[0096] 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.
[0097] 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.
[0098] 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 C4 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.
[0099] 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.
[0100] 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.
[0101] 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 C60 to C1000, or
from C70 to C300, or from C70 to C200. 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.
[0102] 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).
[0103] 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
[0104] 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.
[0105] 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.
[0106] 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.
[0107] The organic acid or inorganic acid is preferably selected
from a sulfur-containing acid, a carboxylic acid, a
phosphorus-containing acid, and mixtures thereof.
[0108] 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.
[0109] Salts that contain a substantially stochiometric amount of
the metal are described as neutral salts and have a total base
number (TBN, as measured by ASTM D2896) of from 0 to 80. Many
compositions are overbased, containing large amounts of a metal
base that is achieved by reacting an excess of a metal compound (a
metal hydroxide or oxide, for example) with an acidic gas (such as
carbon dioxide). Useful detergents can be neutral, mildly
overbased, or highly overbased. These detergents can be used in
mixtures of neutral, overbased, highly overbased calcium
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.
[0110] 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.
[0111] 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
##STR00010##
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.
[0112] 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.
[0113] Alkaline earth metal phosphates are also used as detergents
and are known in the art.
[0114] 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.
[0115] 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.
[0116] 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.
[0117] 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
[0118] Viscosity modifiers (also known as viscosity index improvers
(VI improvers), and viscosity improvers) can be included in the
lubricant compositions of this disclosure.
[0119] Viscosity modifiers provide lubricants with high and low
temperature operability. These additives impart shear stability at
elevated temperatures and acceptable viscosity at low
temperatures.
[0120] 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.
[0121] 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.
[0122] 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".
[0123] 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).
[0124] 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.
[0125] 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.
[0126] 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)
[0127] 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
[0128] 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
[0129] 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
[0130] 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.
[0131] 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
[0132] 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.
[0133] 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.
[0134] 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.
[0135] Illustrative alkoxylated fatty acid esters include, for
example, polyoxyethylene stearate, fatty acid polyglycol ester, and
the like. These can include polyoxypropylene stearate,
polyoxybutylene stearate, polyoxyethylene isosterate,
polyoxypropylene isostearate, polyoxyethylene palmitate, and the
like.
[0136] 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.
[0137] 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.
[0138] 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.
[0139] Illustrative fatty alcohol ethers include, for example,
stearyl ether, myristyl ether, and the like. Alcohols, including
those that have carbon numbers from C.sub.3 to C.sub.50, can be
ethoxylated, propoxylated, or butoxylated to form the corresponding
fatty alkyl ethers. The underlying alcohol portion can preferably
be stearyl, myristyl, C.sub.11-C.sub.13 hydrocarbon, oleyl,
isosteryl, and the like.
[0140] The lubricating oils of this disclosure exhibit desired
properties, e.g., wear control, in the presence or absence of a
friction modifier.
[0141] 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
[0142] 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.
[0143] 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".
[0144] 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.
[0145] 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.
[0146] 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.
[0147] 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 Dispersant 0.1-20 0.1-8 Detergent
0.1-20 0.1-8 Antioxidant 0.1-10 0.1-5 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
[0148] 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.
[0149] The following non-limiting examples are provided to
illustrate the disclosure.
Examples
[0150] Several engine oil candidates were formulated as shown in
FIGS. 2-6. All of the ingredients used in the candidate formulated
oils were commercially available. The chemical structures and
nomenclature of illustrative antioxidants used in the candidate
formulated oils are shown in FIG. 1. The difference amongst the
polymeric antioxidant (AO) materials is related to the degree of
oligomerization achieved. The Group V base stocks used in this
study are labeled in FIGS. 2-6 as follows for ease of reference.
(E1) refers to TMP ester with alkyl carbon chain length of 7. (E2)
refers to TMP ester with linear alkyl carbon chain length of 9.
(E3) refers to TMP ester with branched alkyl carbon chain length of
9. (E4) refers to a pentaerythritol ester (i.e. Nycobase
1040X).
[0151] The candidates shown in Tables 2-5 are fully formulated
lubricants where the balance of the formulation is generically
referred to as Reference Fluid 1, 2, 3 or 4. The reference fluids
contain typical base stocks combined with dispersants, detergents,
antiwear additives, friction modifiers, and the like. Four
different base formulations were used through the data presented
herein, RF1, RF2, RF3, RF4 and RF5 which are similar in nature with
slight differences in either the base oil composition or the treat
rate of some additives optimized for other performance aspects.
RF1, RF2, RF3, RF4 and RF5 are approximately 60%, or 65%, or 70%,
or 75%, or 80%, or 85%, or 90%, of a combination of base stocks.
The combination of additives amount to 10%, or 15%, or 20%, or 25%,
or 30%, or 35%, or 40%.
[0152] Oil life was assessed using two oxidation tests, the Bulk
Oxidation Test (BOT) and the Oxidation Stability Test (OST).
[0153] In the BOT, an aliquot of the candidate formulated oil (100
gm), was placed in a vessel maintained at a fix temperature of
165.degree. C., with air bubbling in the oil at a 500 cc/min+/-25
cc/min. The vessel was loaded with 3.5 mg of a catalyst to deliver
45 ppm of metal ions to accelerate the oxidation. The kinematic
viscosity at 40.degree. C. (KV40) was monitored over time, and the
candidate was considered "oxidized" when the KV40 increased over
200% as compared to the starting measurement.
[0154] In the OST, a vial was loaded with 10 mL of sample, and 50
ppm of Fe in an oil soluble form. There was a head pressure of air
of 50 psi and air was bubbled in the vial at 125 ml/min. The test
was run maintaining the temperature at 170.degree. C. and, at a
pre-determined interval, a small aliquot of the sample was taken
out to measure the viscosity at 40.degree. C. The measurement of
the viscosity at 40.degree. C. was similar to ASTM D445 and the
results comparable. Once the viscosity increases over 200% compared
to the initial viscosity, the oil was considered condemned.
[0155] FIG. 2 shows tabulated results of BOT performance as a
function of antioxidant selection. In this group of candidates, a
good result in the BOT is defined as greater than 200 hours to
break, or greater than 250 hours to break, or greater than 300
hours to break, or greater than 350 hours to break, or greater than
400 hours to break. The balance of the material considered in this
section is either lumped in RF1 or RF2. FIG. 2 shows tabulated
results obtained in the BOT where the CE 1 and CE 7 break at 161
and 215 hours respectively. When the formulation employs polymeric
aminic antioxidant G in combination with higher amounts of Group V
base stock (E3), the fluid can last over 500 hours in the BOT (IE
1). Leaving out the large amount of E3 while still using polymeric
AO G at 3.3% treat rate of active ingredient, the performance is
still good (319 hours--IE 2) but not as outstanding as observed in
IE 1. The comparison between IE 1 and IE 2 highlights the
synergetic effect of using both a polymeric AO and a high amount of
an oxidative stable ester such as (E3). The candidate formulation
blended with just 10% polyol ester (E4) does not reach the 200
hours mark in this test (CE 6), therefore confirming that the
polymeric aminic antioxidant is responsible for the improved
performance and not the diluent oil that is used to deliver the
additive. Using a high amount of Polymeric AO I (IE 3), excellent
performance (347 hours) are observed consistently with the data
obtained in IE 2. Similar excellent performance in this test is
observed when using a high treat rate of traditional diphenyl
amines and hindered phenol antioxidants (IE 4).
[0156] In additional testing, deposit formation of each product was
compared using a thermo-oxidation engine oil simulation (TEOST 33C)
measured by ASTM D6335.
[0157] FIG. 3 shows tabulated results of TEOST 33C performance as a
function of antioxidant selection. A good result in the TEOST test
is defined as less than 30 mg, or less than 25 mg, or less than 20
mg, or less than 15 mg, or less than 10 mg. The deposit control as
measured by TEOST 33C shows that the oils formulated to last longer
in the BOT also provide the lowest deposit rating. Particularly,
the polymeric aminic antioxidant provides results of about 12 mg
(IE 1 and IE 2) for a reduction of about 50% deposit, as compared
to the reference fluid formulated with the conventional
aminic/phenolic antioxidant package (CE 1). A parallel performance
ranking is evident comparing the BOT performance of these three
candidates where IE 1 and IE 2 broke after 512 and 319 hours
respectively, while CE 1 broke after only 161 hours. Additionally,
when using 4% of either AO D (CE 9) or AO C (CE 10), the deposit
was 32.5 and 43.3 mg respectively. However, when using about 3% of
Polymeric AO G (IE 1 and IE 2), or when using 4% of Polymeric AO I
(IE 3), the deposit was 11.5, 11.8 and 7.9 mg. IE 1, IE 2 and IE 6
also had very strong performance in the BOT. Using a high treat
rate of AO D (IE 4), the deposit control was to be considered
acceptable (25.6 mg), while excellent BOT performance was obtained
as well (464 hours). Based on the results discussed so far, there
was no need to further compare TEOST 33C data versus BOT
performance. For example, looking at CE 9, CE 10, CE 11 and IE 6,
the expectation is that they would all have excellent BOT
performance, and that the main difference will be only related to
deposit control as measured by TEOST 33C.
[0158] Considering that industry requirements set the passing limit
at 30 mg, the choice of the right antioxidant is critical to pass
the test. This is an unexpected result given that one could expect
more degradation from a polymer/oligomer that could lead to more
deposit formation. Interestingly, when using a small amount of
Polymeric AO G without any additional antioxidant, the deposit
drops below 10 mg (IE 5). In this instance, the deposit control was
the relevant performance being assessed. BOT was directionally
worse as compared to the other Inventive Examples, but it was to be
expected given the overall low treat rate of antioxidants. Further,
a direct comparison of CE 11 and IE 6, highlights the directional
debit brought by using a large amount of a small antioxidant
molecule such as AO D that provided a deposit of 32.4 mg when using
5% of this material (CE 11). By dropping the amount of AO D, while
introducing 1.6% of polymeric AO I, the deposit was reduced by 50%
(IE 6).
[0159] FIG. 4 shows tabulated results of antioxidant package
evaluation based on both the BOT and the OST methods. A good result
in the BOT is defined as greater than 200 hours to break, or
greater than 250 hours to break, or greater than 300 hours to
break, or greater than 350 hours to break, or greater than 400
hours to break. A good result in the OST test is defined as greater
than 70 hours to break, or greater than 50 hours to break, or
greater than 40 hours to break. In FIG. 4, the candidates were
blended using Reference Fluid 3 (RF 3) as the balance of the
material. The oxidative stability of several candidate formulations
was evaluated by varying the amount and type of the antioxidant
(AO) including in the matrix AO A, AO C, AO E, AO F, poly AO G and
poly AO H. Increasing amounts of polymeric aminic antioxidants lead
to better performance, however the hours to break did not exceed
the 380 mark in the BOT (compare IE 7 vs. IE 8, CE 13 vs. CE 14, CE
15 vs. CE 16 and CE 17 vs. IE 9).
[0160] The OST, a different oxidation method, provided very similar
response to what observed in BOT, thus providing an alternative and
consistent option for additional evaluation. All the formulations
in FIG. 4 contain a similar amount of phenolic antioxidant, which
seems to affect the performance negatively. This is likely the
reason why CE 13-17 do not exceed the 230 hours mark in the
BOT.
[0161] FIG. 5 shows tabulated results of antioxidant package
evaluation based on BOT, in particular looking at the negative
effect of phenolic antioxidants when included in the formulations
in high concentration (CE 20). In FIG. 5, the candidates were
blended using Reference Fluid 4 (RF 4) as the balance of the
material, and a good result in the BOT is defined as greater than
200 hours to break, or greater than 250 hours to break, or greater
than 300 hours to break, or greater than 350 hours to break, or
greater than 400 hours to break. Based on the findings in FIGS.
2-4, the performance of several finished lubricants formulated
without phenolic antioxidants were evaluated, and they all lasted
well over 400 hours (IE 10-18). As a control, the last candidate,
CE 20 in FIG. 5 contained the highest amount of phenolic
antioxidant (AO E) evaluated in this study, and it provided the
lowest oxidative stability in the family, going from formulations
capable of lasting for almost 800 hours (IE 17) to a product
lasting 165 hours (CE 20) which is lower than what measured with CE
7 (FIG. 2--215 hours) and similar to CE 1 (FIG. 2--161 hours).
Remarkably, the candidates prepared with 5% of poly AO H (IE 14)
did not break before 600 hours, which is at least 3 times better
than the results obtained with CE 7 and about 4 times better than
what observed with CE 1.
[0162] In additional testing, deposit formation of several products
were compared using a modified thermo-oxidation engine oil
simulation (MHT TEOST measured by ASTM D7097). The only difference
compared to the standardASTM D7097 method was the operating
temperature that being changed from 285.degree. C. to 300.degree.
C.
[0163] FIG. 6 shows tabulated results of TEOST 33C performance as a
function of antioxidant selection. Each candidate was also compared
using the BOT and the modified MHT TEOST. A good result in the
modified MHT TEOST test is defined as less than 35 mg, or less than
25 mg, or less than 20 mg, or less than 15 mg, or less than 10 mg.
As it was shown in the previous tables, the deposit control as
measured by TEOST 33C showed that the oils formulated to last
longer in the BOT also provided the lowest deposit rating.
Increasing levels of polymeric antioxidant such as "I" offers
significant benefits when used in combination with either a
traditional diphenyl amine like "C". Particularly, the polymeric
aminic antioxidant provides a deposit reduction in the modified MHT
TEOST ranging from 49 mg in CE21, to 31 and 19 mg respectively in
IE19 and IE20. Similar deposit reductions were observed in this
test looking at CE22 (26 mg) versus IE21 (15 mg) and IE22 (9 mg).
The deposit reduction was even more significant when looking at the
combination of Polymeric AO "I" in combination with traditional DPA
"A". For example, the deposits in the modified MHT TEOST as
measured in CE23 was 39 mg, which went down to 22 mg and 16 mg in
IE23 and IE24 respectively. When the RF5 is blended using 2% of DPA
"A", CE24 showed good deposit control to begin with (14 mg), but
the addition of Polymeric AO "I" provided a further improvement as
shown in IE25 (12 mg) and IE26 (5 mg). The results seen with
Polymeric AO "I" can be expected to be replicated with any other
Polymeric AOs considered in the study and others of similar
molecular structure.
[0164] It has been found that by employing a polymeric aminic
antioxidant in lubricating oil formulations, viscosity control is
improved exponentially in the finished formulations designed for
engine oil applications. Also, it was found that the polymeric
aminic antioxidants are compatible with other aminic antioxidants.
It was further observed that phenolic antioxidants did not provide
significant benefits at the standard treat rates, and moreover
phenolic antioxidants clearly bring debits when used in higher
concentrations.
PCT and EP Clauses:
[0165] 1. A method for improving viscosity control, while
maintaining or improving deposit control, of a lubricating oil in
an engine or other mechanical component lubricated with the
lubricating oil by using as the lubricating oil a formulated oil,
said formulated oil having a composition comprising a lubricating
oil base stock as a major component; and at least one polymeric
aminic antioxidant, as a minor component; wherein the at least one
polymeric aminic antioxidant is the polymerization reaction product
of one or more unsubstituted or hydrocarbyl-substituted diphenyl
amines, one or more unsubstituted or hydrocarbyl-substituted phenyl
naphthyl amines, or both one or more of unsubstituted or
hydrocarbyl-substituted diphenylamine with one or more
unsubstituted or hydrocarbyl-substituted phenyl naphthylamine;
wherein the lubricating oil base stock is present in an amount from
1 to 85 weight percent, based on the total weight of the
lubricating oil; and wherein the at least one polymeric aminic
antioxidant is present in an amount from 0.1 to 5 weight percent,
based on the total weight of the lubricating oil.
[0166] 2. The method of clause 1 wherein, in an engine oil Bulk
Oxidation Test, the number of hours to 200% increase in kinematic
viscosity at 40.degree. C. is increased as compared to the number
of hours to 200% increase in kinematic viscosity at 40.degree. C.
of a lubricating oil containing a minor amount of an antioxidant
other than the polymeric aminic antioxidant; or wherein, in deposit
measurements of the lubricating oil by thermo-oxidation engine oil
simulation (TEOST 33C) measured by ASTM D6335, the amount of total
deposits is reduced or maintained as compared to the amount of
total deposits in a lubricating oil containing a minor component
other than the at least one polymeric aminic antioxidant; or
wherein, in deposit measurements of the lubricating oil by
thermo-oxidation engine oil simulation (MHT TEOST) measured by ASTM
D7097, the amount of total deposits is reduced or maintained as
compared to the amount of total deposits in a lubricating oil
containing a minor component other than the at least one polymeric
aminic antioxidant.
[0167] 3. The method of clauses 1 and 2 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.
[0168] 4. The method of clauses 1-3 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;
and 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.
[0169] 5. The method of clauses 1-4 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.
[0170] 6. The method of clauses 1-5 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.
[0171] 7. The method of clauses 1-6 wherein the at least one
polymeric aminic antioxidant is the polymerization reaction product
of
##STR00011##
wherein (A) and (B) each range from zero to 10, provided (A)+(B) is
at least 2; R.sup.2 is a styrene or C1 to C30 alkyl, R.sup.3 is a
styrene or C1 to C30 alkyl, q and y individually range from 0 to up
to the valence of the aryl group to which the respective R groups
are attached.
[0172] 8. The method of clause 7 wherein the at least one polymeric
aminic antioxidant is a polymerization reaction product comprising:
(A)(A), (A)(B), (B)(B), (A)(A)(B), (A)(A)(A), (A)(B)(A), (B)(B)(B),
(B)(B)(A), (A)(A)(A)(A), (A)(A)(B)(B), (A)(A)(A)(B), (B)(B)(B)(B),
(B)(B)(B)(A), (A)(A)(A)(A)(A), (A)(B)(A)(B)(A), (A)(B)(B)(B)(A), or
mixtures thereof.
[0173] 9. The method of clauses 1-8 wherein the at least one
polymeric aminic antioxidant is the polymerization reaction product
formed by any combination of:
##STR00012##
wherein R is H, C.sub.4H.sub.9, C.sub.8H.sub.17, or
C.sub.9H.sub.19; and/or
##STR00013##
[0174] 10. The method of clauses 1-9 wherein the at least one
polymeric aminic antioxidant is a polymerization reaction product
selected from the group consisting of:
##STR00014##
wherein R.sup.2 is a styrene or C1 to C30 alkyl, R.sup.3 is a
styrene or C1 to C30 alkyl, R.sup.4 is a styrene or C1 to C30
alkyl, p, q and y individually range from 0 to up to the valence of
the aryl group to which the respective R groups are attached.
[0175] 11. The method of clauses 1-10 wherein the lubricating oil
base stock is present in an amount from 5 to 45 weight percent,
based on the total weight of the lubricating oil; and wherein the
at least one polymeric aminic antioxidant is present in an amount
from 0.1 to 2.5 weight percent, based on the total weight of the
lubricating oil.
[0176] 12. The method of clauses 1-11 wherein the formulated oil
further comprises one or more of a viscosity modifier, dispersant,
detergent, other antioxidant, pour point depressant, corrosion
inhibitor, metal deactivator, seal compatibility additive,
anti-foam agent, inhibitor, and anti-rust additive.
[0177] 13. The method of clause 12 wherein the other antioxidant
comprises at least one aromatic amine antioxidant, at least one
phenolic antioxidant, or mixtures thereof; wherein the at least one
aromatic amine antioxidant is present in an amount from 0.1 to 5
weight percent, based on the total weight of the lubricating oil;
and wherein the at least one phenolic antioxidant is present in an
amount from 0.1 to 1 weight percent, based on the total weight of
the lubricating oil.
[0178] 14. A lubricating oil having a composition comprising a
lubricating oil base stock as a major component; and at least one
polymeric aminic antioxidant, as a minor component; wherein the at
least one polymeric aminic antioxidant is the polymerization
reaction product of one or more unsubstituted or
hydrocarbyl-substituted diphenyl amines, one or more unsubstituted
or hydrocarbyl-substituted phenyl naphthyl amines, or both one or
more of unsubstituted or hydrocarbyl-substituted diphenylamine with
one or more unsubstituted or hydrocarbyl-substituted phenyl
naphthylamine; wherein the lubricating oil base stock is present in
an amount from 1 to 85 weight percent, based on the total weight of
the lubricating oil; and wherein the at least one polymeric aminic
antioxidant is present in an amount from 0.1 to 5 weight percent,
based on the total weight of the lubricating oil.
[0179] 15. A method for improving oxidative stability, while
maintaining or improving deposit control, of a lubricating oil in
an engine or other mechanical component lubricated with the
lubricating oil by using as the lubricating oil a formulated oil,
said formulated oil having a composition comprising a lubricating
oil base stock as a major component; and at least one polymeric
aminic antioxidant, as a minor component; wherein the at least one
polymeric aminic antioxidant is the polymerization reaction product
of one or more unsubstituted or hydrocarbyl-substituted diphenyl
amines, one or more unsubstituted or hydrocarbyl-substituted phenyl
naphthyl amines, or both one or more of unsubstituted or
hydrocarbyl-substituted diphenylamine with one or more
unsubstituted or hydrocarbyl-substituted phenyl naphthylamine;
wherein the lubricating oil base stock is present in an amount from
1 to 85 weight percent, based on the total weight of the
lubricating oil; and wherein the at least one polymeric aminic
antioxidant is present in an amount from 0.1 to 5 weight percent,
based on the total weight of the lubricating oil.
[0180] 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.
[0181] 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.
[0182] 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