U.S. patent application number 15/667066 was filed with the patent office on 2018-02-08 for lubricating engine oil for improved wear protection and fuel efficiency.
The applicant listed for this patent is ExxonMobil Research and Engineering Company. Invention is credited to Michael L. Alessi, Van An Du, Steven M. Jetter, Steven Kennedy, Sarah E. Parker.
Application Number | 20180037841 15/667066 |
Document ID | / |
Family ID | 61071978 |
Filed Date | 2018-02-08 |
United States Patent
Application |
20180037841 |
Kind Code |
A1 |
Alessi; Michael L. ; et
al. |
February 8, 2018 |
LUBRICATING ENGINE OIL FOR IMPROVED WEAR PROTECTION AND FUEL
EFFICIENCY
Abstract
Provided are lubricating engine oils including a lubricating oil
base stock as a major component having a base oil viscosity at 100
deg. C. ranging from 4.5 to 7.5 cSt, and a carboxylic
functionalized polymer dispersant with aromatic amine
functionality, as a minor component, wherein the lubricating engine
oils have a cold crank simulator viscosity at -30 deg. C. of less
than 8500 mPas. The lubricating engine oils may provide improved
engine wear protection at equivalent fuel efficiency or improved
fuel efficiency at equivalent engine wear protection compared to a
lubricating engine oil containing a dispersant as a minor component
other than the carboxylic functionalized polymer with aromatic
amine functionality. Methods of making the lubricating engine oil
are also provided. The lubricating engine oils are useful in
internal combustion engines including direct injection, gasoline
and diesel engines.
Inventors: |
Alessi; Michael L.; (Rose
Valley, PA) ; Jetter; Steven M.; (Hightstown, NJ)
; Kennedy; Steven; (West Chester, PA) ; Parker;
Sarah E.; (Philadelphia, PA) ; Du; Van An;
(Hamburg, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
ExxonMobil Research and Engineering Company |
Annandale |
NJ |
US |
|
|
Family ID: |
61071978 |
Appl. No.: |
15/667066 |
Filed: |
August 2, 2017 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62370371 |
Aug 3, 2016 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C10M 149/06 20130101;
C10M 2207/34 20130101; C10N 2030/06 20130101; C10N 2030/54
20200501; C10N 2030/68 20200501; C10M 2217/043 20130101; C10M
2203/1025 20130101; C10M 2215/28 20130101; F01M 9/02 20130101; C10M
2203/003 20130101; C10N 2040/25 20130101; C10N 2030/02 20130101;
C10N 2040/252 20200501; C10M 2205/022 20130101; C10M 101/02
20130101; C10M 159/12 20130101; C10N 2040/255 20200501; C10M
2217/06 20130101; C10M 169/041 20130101; C10M 2203/1006 20130101;
C10M 133/56 20130101; C10M 2205/0285 20130101; C10M 2203/1025
20130101; C10N 2020/02 20130101; C10M 2205/022 20130101; C10M
2205/024 20130101; C10M 2209/084 20130101; C10N 2060/09 20200501;
C10M 2205/022 20130101; C10M 2205/024 20130101; C10M 2205/08
20130101; C10M 2209/086 20130101; C10N 2060/09 20200501; C10M
2205/022 20130101; C10M 2205/024 20130101; C10M 2209/086 20130101;
C10N 2060/09 20200501; C10M 2203/1025 20130101; C10N 2020/02
20130101; C10M 2205/022 20130101; C10M 2205/024 20130101; C10M
2209/084 20130101; C10N 2060/09 20200501; C10M 2205/022 20130101;
C10M 2205/024 20130101; C10M 2205/08 20130101; C10M 2209/086
20130101; C10N 2060/09 20200501; C10M 2205/022 20130101; C10M
2205/024 20130101; C10M 2209/086 20130101; C10N 2060/09
20200501 |
International
Class: |
C10M 169/04 20060101
C10M169/04; C10M 159/12 20060101 C10M159/12; C10M 101/02 20060101
C10M101/02 |
Claims
1. A multi-grade lubricating engine oil comprising a lubricating
oil base stock as a major component, and a carboxylic
functionalized polymer dispersant with aromatic amine
functionality, as a minor component, wherein the lubricating engine
oil base oil viscosity at 100 deg. C. ranges from 4.5 to 7.5 cSt,
wherein the lubricating engine oil has a cold crank simulator
viscosity at -30 deg. C. of less than 8500 mPas and wherein fuel
efficiency as measured by HTHS (ASTM D4683) and/or engine wear
protection as measured by HFRR wear scar (ISO Provisional Standard,
TC22/SC7N959, 1995) are improved or maintained as compared to fuel
efficiency and engine wear protection achieved using a multi-grade
lubricating engine oil containing a dispersant as a minor component
other than the carboxylic functionalized polymer with aromatic
amine functionality.
2. The oil of claim 1, wherein the lubricating oil base stock is
selected from the group consisting of a Group I base stock, a Group
II base stock, a Group III base stock, a Group IV base stock, Group
V base stock and combinations thereof.
3. The oil of claim 1, wherein the major component ranges from 50
to 99 wt. % and the minor component ranges from 1 to 15 wt. %,
based on the total weight of the oil.
4. The oil of claim 1, wherein the carboxylic functionalized
polymer dispersant includes a polymer backbone comprising grafted
ethylene-propylene (EP) copolymer, or grafted terpolymers of
ethylene, propylene and non-conjugated diene, or a combination
thereof.
5. The oil of claim 1, wherein the aromatic amine functionality
includes an amine group having at least 3 aromatic groups.
6. The oil of claim 5, wherein the amine group having at least 3
aromatic groups is selected from the group consisting of
bis[p-(p-aminoanilino)phenyl]-methane,
2-(7-amino-acridin-2-ylmethyl)-N-4-{4-[4-(4-amino-phenylamino)-benzyl]-ph-
enyl}-benzene-1,4-diamine,
N.sup.4-{4-[4-(4-amino-phenylamino)-benzyl]-phenyl}-2-[4-(4-amino-phenyla-
mino)-cyclohexa-1,5-dienylmethyl]-benzene-1,4-diamine,
N-[4-(7-amino-acridin-2-ylmethyl)-phenyl]-benzene-1,4-diamine, and
combinations thereof.
7. The oil of claim 1, further including a non-low viscosity
dispersant at from 0.1 to 10 wt. %, based on the total weight of
the oil.
8. The oil of claim 7, wherein the non-low viscosity dispersant is
selected from the group consisting of succinimides, succinate
esters, succinate ester amides, alkylphenol-polyamine-coupled
Mannich adducts and combinations thereof.
9. The oil of claim 1, further comprising one or more of an
anti-wear additive, viscosity index improver, antioxidant,
detergent, pour point depressant, corrosion inhibitor, metal
deactivator, seal compatibility additive, anti-foam agent,
inhibitor, and anti-rust additive.
10. The oil of claim 1, wherein the lubricating engine oil is a
heavy duty diesel engine oil (HDEO).
11. The oil of claim 1, wherein the lubricating engine oil has a
HTHS viscosity of less than 3.5 cSt.
12. The oil of claim 1, wherein the lubricating engine oil has a
HFRR average wear scar of less than or equal to 202 .mu.m.
13. A method for improving engine wear protection while maintaining
or improving fuel efficiency, in an engine lubricated with a
lubricating oil by using as the lubricating oil a formulated oil,
said formulated oil having a composition comprising a lubricating
oil base stock as a major component; and a carboxylic
functionalized polymer dispersant with aromatic amine
functionality, as a minor component, wherein the lubricating oil
base oil viscosity at 100 deg. C. ranges from 4.5 to 7.5 cSt,
wherein the lubricating oil has a cold crank simulator viscosity at
-30 deg. C. of less than 8500 mPas and wherein the engine wear
protection is improved by at least 10% as compared to the engine
wear protection achieved using a formulated oil containing a
dispersant as a minor component other than the carboxylic
functionalized polymer with aromatic amine functionality.
14. The method of claim 13, wherein the lubricating oil base stock
is selected from the group consisting of a Group I base stock, a
Group II base stock, a Group III base stock, a Group IV base stock,
Group V base stock and combinations thereof.
15. The method of claim 13, wherein the major component ranges from
50 to 99 wt. % and the minor component ranges from 1 to 15 wt. %,
based on the total weight of the oil.
16. The method of claim 13, wherein the carboxylic functionalized
polymer dispersant includes a polymer backbone comprising grafted
ethylene-propylene (EP) copolymer, or grafted terpolymers of
ethylene, propylene and non-conjugated diene, or a combination
thereof.
17. The method of claim 13, wherein the aromatic amine
functionality includes an amine group having at least 3 aromatic
groups.
18. The method of claim 17, wherein the amine group having at least
3 aromatic groups is selected from the group consisting of
bis[p-(p-aminoanilino)phenyl]-methane,
2-(7-amino-acridin-2-ylmethyl)-N-4-{4-[4-(4-amino-phenylamino)-benzyl]-ph-
enyl}-benzene-1,4-diamine,
N.sup.4-{4-[4-(4-amino-phenylamino)-benzyl]-phenyl}-2-[4-(4-amino-phenyla-
mino)-cyclohexa-1,5-dienylmethyl]-benzene-1,4-diamine,
N-[4-(7-amino-acridin-2-ylmethyl)-phenyl]-benzene-1,4-diamine, and
combinations thereof.
19. The method of claim 13, further including a non-low viscosity
dispersant at from 0.1 to 10 wt. %, based on the total weight of
the oil.
20. The method of claim 19, wherein the non-low viscosity
dispersant is selected from the group consisting of succinimides,
succinate esters, succinate ester amides,
alkylphenol-polyamine-coupled Mannich adducts and combinations
thereof.
21. The method of claim 13, further comprising one or more of an
anti-wear additive, viscosity index improver, antioxidant,
detergent, pour point depressant, corrosion inhibitor, metal
deactivator, seal compatibility additive, anti-foam agent,
inhibitor, and anti-rust additive.
22. The method of claim 13, wherein the lubricating oil has a high
shear viscosity at least 10% greater than a formulated oil
containing a dispersant as a minor component other than the
carboxylic functionalized polymer with aromatic amine
functionality.
23. The method of claim 13, wherein the lubricating oil has a HTHS
viscosity of less than 3.5 cSt.
24. The method of claim 13, wherein the lubricating engine oil has
a HFRR average wear scar of less than or equal to 202 .mu.m.
25. A method for improving fuel efficiency while maintaining or
improving wear protection, in an engine lubricated with a
lubricating oil by using as the lubricating oil a formulated oil,
said formulated oil having a composition comprising a lubricating
oil base stock as a major component; and a carboxylic
functionalized polymer dispersant with aromatic amine
functionality, as a minor component, wherein the lubricating oil
base oil viscosity at 100 deg. C. ranges from 4.5 to 7.5 cSt,
wherein the lubricating oil has a cold crank simulator viscosity at
-30 deg. C. of less than 8500 mPas, and wherein the fuel efficiency
is improved by at least 10% as compared to the fuel efficiency
achieved using a formulated oil containing a dispersant as a minor
component other than the carboxylic functionalized polymer with
aromatic amine functionality.
26. The method of claim 25, wherein the lubricating oil base stock
is selected from the group consisting of a Group I base stock, a
Group II base stock, a Group III base stock, a Group IV base stock,
Group V base stock and combinations thereof.
27. The method of claim 25, wherein the major component ranges from
50 to 99 wt. % and the minor component ranges from 1 to 15 wt. %,
based on the total weight of the oil.
28. The method of claim 25, wherein the carboxylic functionalized
polymer dispersant includes a polymer backbone comprising grafted
ethylene-propylene (EP) copolymer, or grafted terpolymers of
ethylene, propylene and non-conjugated diene, or a combination
thereof.
29. The method of claim 25, wherein the aromatic amine
functionality includes an amine group having at least 3 aromatic
groups.
30. The method of claim 29, wherein the amine group having at least
3 aromatic groups is selected from the group consisting of
bis[p-(p-aminoanilino)phenyl]-methane,
2-(7-amino-acridin-2-ylmethyl)-N-4-{4-[4-(4-amino-phenylamino)-benzyl]-ph-
enyl}-benzene-1,4-diamine,
N.sup.4-{4-[4-(4-amino-phenylamino)-benzyl]-phenyl}-2-[4-(4-amino-phenyla-
mino)-cyclohexa-1,5-dienylmethyl]-benzene-1,4-diamine,
N-[4-(7-amino-acridin-2-ylmethyl)-phenyl]-benzene-1,4-diamine, and
combinations thereof.
31. The method of claim 25, further including a non-low viscosity
dispersant at from 0.1 to 10 wt. %, based on the total weight of
the oil.
32. The method of claim 31, wherein the non-low viscosity
dispersant is selected from the group consisting of succinimides,
succinate esters, succinate ester amides,
alkylphenol-polyamine-coupled Mannich adducts and combinations
thereof.
33. The method of claim 25, further comprising one or more of an
anti-wear additive, viscosity index improver, antioxidant,
detergent, pour point depressant, corrosion inhibitor, metal
deactivator, seal compatibility additive, anti-foam agent,
inhibitor, and anti-rust additive.
34. The method of claim 25, wherein the lubricating oil has a HTHS
viscosity (ASTM D4683) at least 10% lower than a formulated oil
containing a dispersant as a minor component other than the
carboxylic functionalized polymer with aromatic amine
functionality.
35. The method of claim 25, wherein the engine is an internal
combustion engine selected from the group consisting of a direct
injection engine, a gasoline engine, and a diesel engine.
36. The method of claim 25, wherein the lubricating oil has a HTHS
viscosity of less than 3.5 cSt.
37. The method of claim 25, wherein the lubricating engine oil has
a HFRR average wear scar of less than or equal to 202 .mu.m.
38. A method of making a lubricating engine oil comprising:
providing a lubricating oil base stock having a base oil viscosity
at 100 deg. C. ranging from 4.5 to 7.5 cSt, and a carboxylic
functionalized polymer dispersant with aromatic amine
functionality, and blending from 50 to 99 wt. %, based on the total
weight of the oil, of the lubricating oil base stock with from 1 to
15 wt. %, based on the total weight of the oil, of the carboxylic
functionalized polymer dispersant with aromatic amine functionality
to form the lubricating engine oil, wherein the lubricating engine
oil has a cold crank simulator viscosity at -30 deg. C. of less
than 8500 mPas.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional
Application Ser. No. 62/370,371 filed Aug. 3, 2016, which is herein
incorporated by reference in its entirety.
FIELD
[0002] This disclosure relates to improving wear protection, while
maintaining or improving fuel economy, in an engine lubricated with
a lubricating oil by including a low viscosity carboxylic
functionalized polymer dispersant in the lubricating oil. This
disclosure also relates to improving to fuel efficiency, while
maintaining or improving wear protection, in an engine lubricated
with a lubricating oil by including a low viscosity carboxylic
functionalized polymer dispersant in the lubricating oil.
BACKGROUND
[0003] Improved energy efficiency and fuel economy are of
ever-increasing importance in many industries, including the
automotive and commercial freight industries. Automotive OEMs are
demanding lower viscosity lubricants to provide additional fuel
efficiency and help bridge the gap between current technology and
the levels of fuel economy demanded by new government regulation.
Typically, this trend towards lower viscosity raises concerns with
customers who are concerned about the durability of their equipment
and demand superior wear protection.
[0004] In particular fuel efficiency requirements for passenger
vehicles are becoming increasingly more stringent. New legislation
in the United States and European Union within the past few years
has set fuel economy and emissions targets not readily achievable
with today's vehicle and lubricant technology.
[0005] To address these increasing standards, automotive original
equipment manufacturers are demanding better fuel economy as a
lubricant-related performance characteristic, while maintaining
wear protection requirements. Lubricating oil formulations
typically strike a balance between the need for wear protection and
the desire for fuel efficiency because the viscosity of the final
fluid has a strong impact on both characteristics, but in opposite
directions. The higher a lubricating oil's viscosity, the thicker
the lubricating film entrained between metal-to-metal contacts will
be, increasing wear protection. However, a higher viscosity
lubricating oil will possess more internal fluid traction, which
reduces fuel efficiency.
[0006] High molecular weight additives used in lubricating oils,
such as dispersants, can greatly increase the kinematic viscosity
and high-temperature high-shear viscosity of a lubricating oil
formulation. Dispersants are necessary components that allow engine
lubricants to achieve required dispersancy performance of soot,
water, and other contaminants at treat levels up to 10 wt % of the
formulation. Consequently, the addition of a dispersant typically
has a significant impact on the viscosity of the lubricating
oil.
[0007] Heavy-duty engine oils, such as 5W-30 SAE grade lubricating
oils, utilize "standard" PIBSA-PAM (polyisobutylene succinic
anhydride-polyamine) dispersants and lower base oil viscosity than
the disclosed invention.
[0008] Despite the advances in lubricant oil formulation
technology, there exists a need for an engine oil lubricant that
effectively improves wear protection, while maintaining or
improving fuel efficiency.
SUMMARY
[0009] This disclosure relates in part to a method for improving
engine wear protection, while maintaining or improving fuel
efficiency, in an engine lubricated with a lubricating oil by
providing to the engine a lubricating oil including a lubricating
oil base stock as a major component, and a carboxylic
functionalized polymer dispersant with aromatic amine
functionality, as a minor component in the lubricating oil, wherein
the lubricating oil has a base oil viscosity at 100 deg. C. ranging
from 4.5 to 7.5 cSt, and wherein the lubricating oil has a cold
crank simulator viscosity at -30 deg. C. of less than 8500 mPas.
The lubricating oils of this disclosure are useful in internal
combustion engines including direct injection, gasoline and diesel
engines.
[0010] This disclosure also relates in part to a method for
improving fuel efficiency, while maintaining or improving engine
wear protection, in an engine lubricated with a lubricating oil by
providing to the engine a lubricating oil including a lubricating
oil base stock as a major component, and a carboxylic
functionalized polymer dispersant with aromatic amine
functionality, as a minor component in the lubricating oil, wherein
the lubricating oil has a base oil viscosity at 100 deg. C. ranging
from 4.5 to 7.5 cSt, and wherein the lubricating oil has a cold
crank simulator viscosity at -30 deg. C. of less than 8500
mPas.
[0011] This disclosure further relates in part to a multi-grade
lubricating engine oil having a composition comprising a
lubricating oil base stock as a major component, and a carboxylic
functionalized polymer dispersant with aromatic amine
functionality, as a minor component, wherein the multi-grade
lubricating engine oil has a base oil viscosity at 100 deg. C.
ranging from 4.5 to 7.5 cSt, and wherein the multi-grade
lubricating engine oil has a cold crank simulator viscosity at -30
deg. C. of less than 8500 mPas. The carboxylic functionalized
polymer dispersant with aromatic amine functionality includes a
polymer backbone comprising grafted ethylene-propylene (EP)
copolymers, or grafted terpolymers of ethylene, propylene and
non-conjugated diene, or a combination of grafted EP copolymers and
grafted EP non-conjugated diene terpolymers. The carboxylic acid
functionality is grafted either onto the polymer backbone, within
the polymer backbone or as a terminal group on the polymer
backbone. The amine group has at least 3 aromatic groups and may be
selected from the group consisting of
bis[p-(p-aminoanilino)phenyl]-methane,
2-(7-amino-acridin-2-ylmethyl)-N-4-{4-[4-(4-amino-phenylamino)-benzyl]-ph-
enyl}-benzene-1,4-diamine,
N.sup.4-{4-[4-(4-amino-phenylamino)-benzyl]-phenyl}-2-[4-(4-amino-phenyla-
mino)-cyclohexa-1,5-dienylmethyl]-benzene-1,4-diamine,
N-[4-(7-amino-acridin-2-ylmethyl)-phenyl]-benzene-1,4-diamine, and
combinations thereof. Fuel efficiency and wear protection are
improved or maintained as compared to fuel efficiency and wear
protection achieved using a lubricating engine oil containing a
dispersant as a minor component other than the carboxylic
functionalized polymer.
[0012] This disclosure further relates to a method of method of
making a lubricating engine oil including the steps of: providing a
lubricating oil base stock having a base oil viscosity at 100 deg.
C. ranging from 4.5 to 7.5 cSt, and a carboxylic functionalized
polymer dispersant with aromatic amine functionality, and blending
from 50 to 99 wt. %, based on the total weight of the oil, of the
lubricating oil base stock with from 1 to 15 wt. %, based on the
total weight of the oil, of the carboxylic functionalized polymer
dispersant with aromatic amine functionality to form the
lubricating engine oil, wherein the lubricating engine oil has a
cold crank simulator viscosity at -30 deg. C. of less than 8500
mPas.
[0013] It has been surprisingly found that, in accordance with this
disclosure, improvements in engine wear protection while
maintaining or improving fuel economy are obtained in an engine
lubricated with a lubricating oil, by including a carboxylic
functionalized polymer dispersant with aromatic amine functionality
as a minor component in the lubricating oil. It has also been
surprisingly found that, in accordance with this disclosure,
improvements in engine fuel efficiency while maintaining or
improving engine wear protection are obtained in an engine
lubricated with a lubricating oil, by including a carboxylic
functionalized polymer dispersant with aromatic amine functionality
as a minor component in the lubricating oil.
[0014] Other objects and advantages of the present disclosure will
become apparent from the detailed description that follows.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 shows an inventive formulation embodiment of this
disclosure, in particular, individual contributions of components
and viscometric properties to three baseline formulations
(comparative examples) used in the Examples. Formulation details
are shown in weight percent based on the total weight percent of
the formulation, of various formulations.
[0016] FIG. 2 shows another inventive formulation embodiment of
this disclosure, in particular, individual contributions of
components and viscometric properties to another baseline
formulation (comparative example) used in the Examples. Formulation
details are shown in weight percent based on the total weight
percent of the formulation, of various formulations.
[0017] FIG. 3 graphically depicts ultrashear viscosities of
inventive lubricating oil formulation E and comparative lubricating
oil formulation F.
[0018] FIG. 4 shows two inventive formulations of this disclosure,
and in particular, individual contributions of components and
viscometric properties to one comparative formulation used in the
Examples for a 2.6 cSt HTHS viscosity formulation with a Group III
basestock.
[0019] FIG. 5 shows two more inventive formulations of this
disclosure, and in particular, individual contributions of
components and viscometric properties to another comparative
formulation used in the Examples for a 2.9 cSt HTHS viscosity
formulation with a Group III basestock.
[0020] FIG. 6 shows two more inventive formulations of this
disclosure, and in particular, individual contributions of
components and viscometric properties to another comparative
formulation used in the Examples for a 3.2 cSt HTHS viscosity
formulation with a Group III basestock.
[0021] FIG. 7 shows two inventive formulations of this disclosure,
and in particular, individual contributions of components and
viscometric properties to one comparative formulation used in the
Examples for a 2.6 cSt HTHS viscosity formulation with a Group II
basestock.
[0022] FIG. 8 shows two more inventive formulations of this
disclosure, and in particular, individual contributions of
components and viscometric properties to another comparative
formulation used in the Examples for a 2.9 cSt HTHS viscosity
formulation with a Group II basestock.
[0023] FIG. 9 shows two more inventive formulations of this
disclosure, and in particular, individual contributions of
components and viscometric properties to another comparative
formulation used in the Examples for a 3.2 cSt HTHS viscosity
formulation with a Group II basestock.
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] It has now been found that improved engine wear protection
can be achieved by using in a lubricating oil as a minor component
a carboxylic functionalized polymer dispersant with aromatic amine
functionality that results in a significantly higher lubricating
oil viscosity while maintaining fuel efficiency compared to a
lubricating oil including a conventional dispersant. In particular,
at an equivalent fuel efficiency as measured by HTHS (ASTM D4683)
viscosity, the high shear viscosity of a lubricating oil including
as a minor component a carboxylic functionalized polymer dispersant
with aromatic amine functionality is increased by at least 2%, or
at least 4%, or at least 6%, or at least 8% or at least 10%
compared to a comparable lubricating oil including a conventional
dispersant as opposed to the carboxylic functionalized polymer
dispersant. These increases in high shear viscosity for the
lubricating oils including a carboxylic functionalized polymer
dispersant with aromatic amine functionality translates directly
into equivalent increases in engine wear protection of least 2%, or
at least 4%, or at least 6%, or at least 8% or at least 10%. These
carboxylic functionalized polymer dispersants with aromatic amine
functionality are also referred to herein as low viscosity
dispersants. These low viscosity dispersants are distinct from
prior art non-low viscosity dispersants, which are referred to
below.
[0026] It has also been found that fuel efficiency, as measured by
HTHS, can be delivered with improved engine protection by an oil
containing as a minor component a carboxylic functionalized polymer
dispersant with aromatic amine functionality is increased by at
least 4%, or at least 6%, or at least 10%, or at least 17%. It has
been shown that HFRR can be related to wear protection of the
engine. It has also been found that the HFRR wear scar can be
reduced for lubricating oils including a carboxylic functionalized
polymer dispersant with aromatic amine functionality by at least
2%, or at least 4%, or at least 6%, or at least 8%, or at least 10%
compared to similar lubricating oils using a conventional
dispersant(s). The HFRR wear scar depth in microns of inventive
lubricating oils including the carboxylic functionalized polymer
dispersant with aromatic amine functionality may be less than or
equal to 205, or less than or equal to 202, or less than or equal
to 200, or less than or equal to 195, or less than or equal to 190,
or less than or equal to 185, or less than or equal to 180, or less
than or equal to 175, or less than or equal to 170. or less than or
equal to 165, or less than or equal to 160, or less than or equal
to 155.
[0027] It has now also been found that improved engine wear
protection can be achieved by using in a lubricating oil as a minor
component a carboxylic functionalized polymer dispersant with
aromatic amine functionality that results in a significantly higher
lubricating oil viscosity while maintaining fuel efficiency
compared to a lubricating oil including a conventional dispersant.
In particular, at an equivalent fuel efficiency as measured by HTHS
(ASTM D4683) viscosity, the high shear viscosity of a lubricating
oil including as a minor component a carboxylic functionalized
polymer dispersant with aromatic amine functionality is increased
by at least 2%, or at least 4%, or at least 6%, or at least 8% or
at least 10% compared to a comparable lubricating oil including a
conventional dispersant as opposed to the carboxylic functionalized
polymer dispersant. These increases in high shear viscosity for the
lubricating oils including a carboxylic functionalized polymer
dispersant with aromatic amine functionality translates directly
into equivalent increases in engine wear protection of least 2%, or
at least 4%, or at least 6%, or at least 8% or at least 10%. These
carboxylic functionalized polymer dispersants with aromatic amine
functionality are also referred to herein as low viscosity
dispersants. These low viscosity dispersants are distinct from
prior art non-low viscosity dispersants, which are referred to
below.
[0028] It has also been found that improved fuel efficiency can be
achieved by using in a lubricating oil as a minor component a
carboxylic functionalized polymer dispersant with aromatic amine
functionality while maintaining wear protection compared to a
lubricating oil including a conventional dispersant. In particular,
at an equivalent engine wear protection level as measured by high
shear viscosity, the HTHS viscosity of the lubricating oil is
decreased by at least 2%, or at least 4%, or at least 6%, or at
least 8% or at least 10% compared to a comparable lubricating oil
including a conventional dispersant as opposed to the carboxylic
functionalized polymer dispersant. These decreases in HTHS
viscosity translate directly and equivalently into increases in
fuel efficiency of at least 2%, or at least 4%, or at least 6%, or
at least 8% or at least 10%.
[0029] The formulated oil preferably comprises a lubricating oil
base stock as a major component, and a carboxylic functionalized
polymer dispersant with aromatic amine functionality, as a minor
component. The lubricating oils of this disclosure are particularly
advantageous as heavy duty diesel engine oil (HDEO) products.
[0030] The formulated oils of the instant disclosure are
particularly suited for API multi-grade lubricating oils, and in
particular heavy-duty engine oils, such as SAE 5W-30 grade oil. In
these multi-grade oils of the instant disclosure, the low viscosity
carboxylic functionalized polymer dispersant allows for a higher
base oil viscosity than in conventional multi-grade lubricating
oils, which provides for improved wear protection of the engine. In
particular, the base oil viscosity (as defined in the Examples
section) at 100 deg. C. of the multi-grade lubricating oils of the
instant disclosure may range from 4.5 to 7.5 cSt, or from 5.0 to
7.0 cSt, or from 5.5 to 6.5 cSt, or from 5.8 to 6.2 cSt. The
multi-grade formulated oils including the low viscosity carboxylic
functionalized polymer dispersant of the instant disclosure may
have a cold crank simulator viscosity at -30 deg. C. (ASTM D5293)
of less than 8500 mPas, or less than 8000 mPas, or less than 7500
mPas, or less than 7000 mPas, or less than 6600 mPas. In contrast,
conventional lubricating oils of the same viscosity grade, which
include PIBSA-PAM (polyisobutylene succinic anhydride-polyamine)
dispersants, have a lower base oil viscosity at 100 deg. C. and
more particularly a base oil viscosity of less than 5.5 cSt, or
even more particularly a base oil viscosity of less than 5.0 cSt,
which yields significantly worse wear protection of the engine.
[0031] The lubricating oils of this disclosure provide excellent
engine protection including friction reduction and anti-wear
performance. The lubricating oils of this disclosure provide
improved fuel efficiency. A lower HTHS viscosity engine oil
generally provides superior fuel economy to a higher HTHS viscosity
product. This benefit may be demonstrated for the lubricating oils
of this disclosure in track testing, such as SAE J1321 fuel
consumption testing.
[0032] The lubricating engine oils of this disclosure have a
composition sufficient to pass wear protection requirements of one
or more engine tests selected from Cummins ISM, Cummins ISB, and
others.
Lubricating Oil Base Stocks
[0033] 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.
[0034] 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 80 to 120 and contain greater than 0.03% sulfur and/or
less than 90% saturates. Group II base stocks have a viscosity
index of between 80 to 120, and contain less than or equal to 0.03%
sulfur and greater than or equal to 90% saturates. Group III stocks
have a viscosity index greater than 120 and contain less than or
equal to 0.03% sulfur and greater than 90% saturates. Group IV
includes polyalphaolefins (PAO). Group V base stock includes base
stocks not included in Groups I-IV. The table below summarizes
properties of each of these five groups.
TABLE-US-00001 Base Oil Properties Saturates Sulfur Viscosity Index
Group I <90 and/or >0.03% and .gtoreq.80 and <120 Group II
.gtoreq.90 and .ltoreq.0.03% and .gtoreq.80 and <120 Group III
.gtoreq.90 and .ltoreq.0.03% and .gtoreq.120 Group IV
polyalphaolefins (PAO) Group V All other base oil stocks not
included in Groups I, II, III or IV
[0035] 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.
[0036] Group II and/or Group III hydroprocessed or hydrocracked
basestocks, including synthetic oils such as polyalphaolefins,
alkyl aromatics and synthetic esters are also well known basestock
oils.
[0037] 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.
[0038] 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 250
to 3,000, although PAO's may be made in viscosities up to 100 cSt
(100.degree. C.). The PAOs are typically comprised of relatively
low molecular weight hydrogenated polymers or oligomers of
alphaolefins which include, but are not limited to, C.sub.2 to
C.sub.32 alphaolefins with the C.sub.8 to C.sub.16 alphaolefins,
such as 1-octene, 1-decene, 1-dodecene and the like, being
preferred. The preferred polyalphaolefins are poly-1-octene,
poly-1-decene and poly-1-dodecene and mixtures thereof and mixed
olefin-derived polyolefins. However, the dimers of higher olefins
in the range of C.sub.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. Mixtures of PAO
fluids having a viscosity range of 1.5 to approximately 100 cSt or
more may be used if desired.
[0039] 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. No. 4,149,178 or 3,382,291 may be
conveniently used herein. Other descriptions of PAO synthesis are
found in the following U.S. Pat. Nos. 3,742,082; 3,769,363;
3,876,720; 4,239,930; 4,367,352; 4,413,156; 4,434,408; 4,910,355;
4,956,122; and 5,068,487. The dimers of the C.sub.14 to C.sub.18
olefins are described in U.S. Pat. No. 4,218,330.
[0040] 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.
[0041] 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 3 cSt to 50
cSt, preferably 3 cSt to 30 cSt, more preferably 3.5 cSt to 25 cSt,
as exemplified by GTL 4 with kinematic viscosity of 4.0 cSt at
100.degree. C. and a viscosity index of 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 -20.degree. C. or lower, and under some conditions may have
advantageous pour points of -25.degree. C. or lower, with useful
pour points of -30.degree. C. to -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.
[0042] The hydrocarbyl aromatics can be used as base oil or base
oil component and can be any hydrocarbyl molecule that contains at
least 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 C.sub.6 up to C.sub.60 with a range of C.sub.8 to
C.sub.20 often being preferred. A mixture of hydrocarbyl groups is
often preferred, and up to 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 5% of
the molecule is comprised of an above-type aromatic moiety.
Viscosities at 100.degree. C. of approximately 3 cSt to 50 cSt are
preferred, with viscosities of approximately 3.4 cSt to 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 2% to 25%,
preferably 4% to 20%, and more preferably 4% to 15%, depending on
the application.
[0043] 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.
[0044] Esters comprise a useful base stock. Additive solvency and
seal compatibility characteristics may be secured by the use of
esters such as the esters of dibasic acids with monoalkanols and
the polyol esters of monocarboxylic acids. Esters of the former
type include, for example, the esters of dicarboxylic acids such as
phthalic acid, succinic acid, alkyl succinic acid, alkenyl succinic
acid, maleic acid, azelaic acid, suberic acid, sebacic acid,
fumaric acid, adipic acid, linoleic acid dimer, malonic acid, alkyl
malonic acid, alkenyl malonic acid, etc., with a variety of
alcohols such as butyl alcohol, hexyl alcohol, dodecyl alcohol,
2-ethylhexyl alcohol, etc. Specific examples of these types of
esters include dibutyl adipate, di(2-ethylhexyl) sebacate,
di-n-hexyl fumarate, dioctyl sebacate, diisooctyl azelate,
diisodecyl azelate, dioctyl phthalate, didecyl phthalate, dieicosyl
sebacate, etc.
[0045] Particularly useful synthetic esters are those which are
obtained by reacting one or more polyhydric alcohols, preferably
the hindered polyols (such as the neopentyl polyols, e.g.,
neopentyl glycol, trimethylol ethane,
2-methyl-2-propyl-1,3-propanediol, trimethylol propane,
pentaerythritol and dipentaerythritol) with alkanoic acids
containing at least 4 carbon atoms, preferably C.sub.5 to C.sub.30
acids such as saturated straight chain fatty acids including
caprylic acid, capric acid, lauric acid, myristic acid, palmitic
acid, stearic acid, arachic acid, and behenic acid, or the
corresponding branched chain fatty acids or unsaturated fatty acids
such as oleic acid, or mixtures of any of these materials.
[0046] Suitable synthetic ester components include the esters of
trimethylol propane, trimethylol butane, trimethylol ethane,
pentaerythritol and/or dipentaerythritol with one or more
monocarboxylic acids containing from 5 to 10 carbon atoms. These
esters are widely available commercially, for example, the Mobil
P-41 and P-51 esters of ExxonMobil Chemical Company.
[0047] Also useful are esters derived from renewable material such
as coconut, palm, rapeseed, soy, sunflower and the like. These
esters may be monoesters, di-esters, polyol esters, complex esters,
or mixtures thereof. These esters are widely available
commercially, for example, the Mobil P-51 ester of ExxonMobil
Chemical Company.
[0048] Engine oil formulations containing renewable esters are
included in this disclosure. For such formulations, the renewable
content of the ester is typically greater than 70 weight percent,
preferably more than 80 weight percent and most preferably more
than 90 weight percent.
[0049] 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.
[0050] 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.
[0051] 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.
[0052] 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 2 mm.sup.2/s to 50 mm.sup.2/s (ASTM D445).
They are further characterized typically as having pour points of
-5.degree. C. to -40.degree. C. or lower (ASTM D97). They are also
characterized typically as having viscosity indices of 80 to 140 or
greater (ASTM D2270).
[0053] 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 10 ppm, and more
typically less than 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.
[0054] 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.
[0055] The GTL material, from which the GTL base stock(s) and/or
base oil(s) is/are derived is preferably a F-T material (i.e.,
hydrocarbons, waxy hydrocarbons, wax).
[0056] 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) and hydrodewaxed, or
hydroisomerized/cat (and/or solvent) dewaxed base stock(s) and/or
base oil(s) typically have very low sulfur and nitrogen content,
generally containing less than 10 ppm, and more typically less than
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 material especially suitable
for the formulation of low sulfur, sulfated ash, and phosphorus
(low SAP) products.
[0057] Base oils for use in the formulated lubricating oils useful
in the present disclosure are any of the variety of oils
corresponding to API Group I, Group II, Group III, Group IV, and
Group V oils and mixtures thereof, preferably API Group II, Group
III, Group IV, and Group V oils and mixtures thereof, more
preferably the Group III to Group V base oils due to their
exceptional volatility, stability, viscometric and cleanliness
features. Minor quantities of Group I stock, such as the amount
used to dilute additives for blending into formulated lube oil
products, can be tolerated but should be kept to a minimum, i.e.
amounts only associated with their use as diluent/carrier oil for
additives used on an "as-received" basis. Even in regard to the
Group II stocks, it is preferred that the Group II stock be in the
higher quality range associated with that stock, i.e. a Group II
stock having a viscosity index in the range 100<VI<120.
[0058] The base oil constitutes the major component of the engine
oil lubricant composition of the present disclosure and typically
is present in an amount ranging from 50 to 99 weight percent,
preferably from 70 to 95 weight percent, and more preferably from
85 to 95 weight percent, based on the total weight of the
composition. The base oil may be selected from any of the synthetic
or natural oils typically used as crankcase lubricating oils for
spark-ignited and compression-ignited engines. The base oil
conveniently has a kinematic viscosity, according to ASTM
standards, of 2.5 cSt to 12 cSt (or mm.sup.2/s) at 100.degree. C.
and preferably of 2.5 cSt to 9 cSt (or mm.sup.2/s) at 100.degree.
C. Mixtures of synthetic and natural base oils may be used if
desired. Bi-modal mixtures of Group I, II, III, IV, and/or V base
stocks may be used if desired.
Carboxylic Functionalized Polymer Dispersants (Low Viscosity
Dispersants)
[0059] The carboxylic functionalized polymer dispersant which is
functionalized with an aromatic amine may be a carboxylic
functionalized polymer. The carboxylic functionalized polymer
backbone may be a copolymer or a terpolymer, provided that it
contains at least one carboxylic acid functionality or a reactive
equivalent of carboxylic acid functionality (e.g., anhydride or
ester). The carboxylic functionalized polymer has a carboxylic acid
functionality (or a reactive equivalent of carboxylic acid
functionality) grafted onto the backbone, or alternatively within
the polymer backbone, or alternatively as a terminal group on the
polymer backbone.
[0060] The carboxylic functionalized polymer described herein may
be grafted with grafted ethylene-propylene (EP) copolymers,
terpolymers of ethylene, propylene and non-conjugated diene (such
as dicyclopentadiene or butadiene), or combinations of EP
copolymers and EP non-conjugated diene terpolymers. With regard to
grafting of EP copolymers, U.S. Pat. Nos. 4,632,769; 4,517,104; and
4,780,228 are incorporated by reference in their entirety. With
regard to grafting of EP non-conjugated diene terpolymers, U.S.
Pat. Nos. 5,798,420 and 5,538,651 are incorporated by reference in
their entirety.
[0061] The polymer backbone (other than a polyisobutylene) of the
present disclosure may have a number average molecular weight (by
gel permeation chromatography, polystyrene standard), which may be
up to 150,000 or higher, e.g., 1,000 or 5,000 to 150,000 or to
120,000 or to 100,000. An example of a suitable number average
molecular weight range includes 10,000 to 50,000, or 6,000 to
15,000, or 30,000 to 50,000. In one embodiment, the polymer
backbone has a number average molecular weight of greater than
5,000, for instance, greater than 5000 to 150,000. Other
combinations of the above-identified molecular weight limitations
are also contemplated.
[0062] The carboxylic functionalized polymer dispersant which is
functionalized with an aromatic amine has a backbone which is
functionalized with an amine group having at least 3 aromatic
groups, or alternatively at least 4 aromatic groups. As used herein
the phrase "an aromatic group" is used in the ordinary sense of the
term and is known to be defined by Huckel theory of 4n+2.pi.
electrons per ring system. Accordingly, one aromatic group of the
invention may have 6, or 10, or 14.pi. electrons. Hence a benzene
ring has 6.pi. electrons, a naphthylene ring has 10.pi. electrons
and an acridine group has 14.pi. electrons.
[0063] The amine having at least 3 aromatic groups, or at least may
be reacted with the carboxylic functionalized polymer under known
reaction conditions. The reaction conditions are known to a person
skilled in the art for forming imides and/or amides of carboxylic
functionalized polymers.
[0064] Non-limiting examples of suitable amines having at least 3
aromatic groups may be bis[p-(p-aminoanilino)phenyl]-methane,
2-(7-amino-acridin-2-ylmethyl)-N-4-{4-[4-(4-amino-phenylamino)-benzyl]-ph-
enyl}-benzene-1,4-diamine,
N.sup.4-{4-[4-(4-amino-phenylamino)-benzyl]-phenyl}-2-[4-(4-amino-phenyla-
mino)-cyclohexa-1,5-dienylmethyl]-benzene-1,4-diamine,
N-[4-(7-amino-acridin-2-ylmethyl)-phenyl]-benzene-1,4-diamine, or
mixtures thereof.
[0065] In one embodiment the amine having at least 3 aromatic
groups may be bis[p-(p-aminoanilino)phenyl]-methane,
2-(7-amino-acridin-2-ylmethyl)-N-4-{4-[4-(4-amino-phenylamino)-benzyl]-ph-
enyl}-benzene-1,4-diamine or mixtures thereof.
[0066] The amine having at least 3 aromatic groups may be prepared
by a process comprising reacting an aldehyde with an amine
(typically 4-aminodiphenylamine). The resultant amine may be
described as an alkylene coupled amine having at least 3 aromatic
groups, at least one --NH2 functional group, and at least 2
secondary or tertiary amino groups.
[0067] The aldehyde may be aliphatic, alicyclic or aromatic. The
aliphatic aldehyde may be linear or branched. Examples of a
suitable aromatic aldehyde include benzaldehyde or o-vanillin.
Examples of an aliphatic aldehyde include formaldehyde (or a
reactive equivalent thereof such as formalin or paraformaldehyde),
ethanal or propanal. Typically the aldehyde may be formaldehyde or
benzaldehyde.
[0068] The process may be carried out at a reaction temperature in
the range of 40 degree C. to 180 degree C., or 50 degree C. to 170
degree C. The reaction may or may not be carried out in the
presence of a solvent. Examples of suitable solvents include
diluent oil, benzene, t-butyl benzene, toluene, xylene,
chlorobenzene, hexane, tetrahydrofuran, or mixtures thereof. The
reaction may be performed in either air or an inert atmosphere.
Examples of suitable inert atmosphere include nitrogen or argon,
typically nitrogen. Alternatively, the amine having at least 3
aromatic groups may also be prepared by the methodology described
in Berichte der Deutschen Chemischen Gesellschaft (1910), 43,
728-39.
[0069] The carboxylic functionalized polymer dispersant with
aromatic amine functionality may be incorporated into the
lubricating oil at from 0.1 to 20 wt. %, or from 1 to 15 wt. %, or
from 3 to 12 wt. %, or from 5 to 10 wt. %, or from 7 to 8 wt. % of
the total lubricating oil composition. Other combinations of the
above-identified loadings are also contemplated.
[0070] The carboxylic functionalized polymer dispersant may also be
combined with other dispersants (described below and referred to as
non-low viscosity dispersants) to provide a lubricating oil with a
combination of a carboxylic functionalized polymer dispersant and
another non-low viscosity dispersant. The other dispersants
(non-low viscosity dispersants) may be incorporated into the
lubricating oil at from 0.1 to 20 wt. %, or from 0.1 to 10 wt. %,
or from 0.5 to 4 wt. %, or from 0.5 to 8 wt. %, or from 1 to 9 wt.
%, or from 2 to 8 wt. %, or from 3 to 7 wt. %, or from 4 to 6 wt. %
of the total lubricating oil composition.
[0071] Further details regarding the carboxylic functionalized
polymer dispersant which is functionalized with an aromatic amine
may be found within U.S. Pat. No. 8,557,753, which is herein
incorporated by reference in its entirety.
Other Non-Low Viscosity Dispersants
[0072] 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.
[0073] 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 to
nitrogen, oxygen, or phosphorus. Typical hydrocarbon chains contain
50 to 400 carbon atoms.
[0074] A particularly useful class of dispersants are the
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; 3,215,707; 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.
[0075] 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.
[0076] 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 1:1 to 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 U.S. Pat. Nos. 3,652,616, 3,948,800; and Canada Patent No.
1,094,044.
[0077] 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.
[0078] 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.
[0079] 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 0.1 to 5 moles of boron
per mole of dispersant reaction product.
[0080] 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.
[0081] 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.
[0082] 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.
[0083] 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
500 to 5000, or from 1000 to 3000, or 1000 to 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.
[0084] Such non-low viscosity dispersants may be used in an amount
of 0.1 to 20 weight percent, preferably 0.5 to 8 weight percent, or
more preferably 0.5 to 4 weight percent. On an active ingredient
basis, such additives may be used in an amount of 0.06 to 14 weight
percent, preferably 0.3 to 6 weight percent. The hydrocarbon
portion of the dispersant atoms can range from C.sub.60 to
C.sub.400, or from C.sub.70 to C.sub.300, or from C.sub.70 to
C.sub.200. These dispersants may contain both neutral and basic
nitrogen, and mixtures of both. Dispersants can be end-capped by
borates and/or cyclic carbonates.
[0085] 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 20 weight percent to 80 weight percent, or
from 40 weight percent to 60 weight percent, of active dispersant
in the "as delivered" dispersant product.
Other Lubricating Oil Additives
[0086] 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 friction modifiers, antiwear agents, other
detergents, 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, 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.
[0087] 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.
Friction Modifiers
[0088] Friction modifiers useful in this disclosure are any
materials that can alter the coefficient of friction of a surface
lubricated by any lubricant or fluid containing such material(s).
Organic 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 can be effectively used in combination with the
base oils or lubricant compositions of the present disclosure.
Organic friction modifiers that lower the coefficient of friction
are particularly advantageous in combination with the base oils and
lube compositions of this disclosure. The organic friction
modifiers can be sub-grouped into metal-containing organic complex
friction modifiers and other organic friction modifiers, which are
discussed below.
A. Metal-Containing Organic Complex Friction Modifiers
[0089] Metal-containing organic complex friction modifiers useful
in this disclosure are any materials that can alter the coefficient
of friction of a surface lubricated by any lubricant or fluid
containing such material(s). Metal-containing organic complex
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 can be effectively used in combination with the
base oils or lubricant compositions of the present disclosure.
Metal-containing organic complex friction modifiers that lower the
coefficient of friction are particularly advantageous in
combination with the base oils and lube compositions of this
disclosure.
[0090] Preferred metal-containing organic complex friction
modifiers useful in the lubricating engine oil formulations of this
disclosure include tungsten organic complex compounds or molybdenum
organic complex compounds. Illustrative tungsten or molybdenum
organic complex compounds include, for example, tungsten
dithiophosphates or molybdenum dithiophosphates represented by the
formula
##STR00001##
wherein M is tungsten or molybdenum, R.sup.1 and R.sup.2 are the
same or different, each of R.sup.1 and R.sup.2 contains from 1 to
30 carbon atoms and are an alkyl group, a cycloalkyl group, an aryl
group or an alkylaryl group, and x and y are positive real numbers
satisfying the equation x+y=4. Other illustrative tungsten or
molybdenum organic complex compounds include, for example, tungsten
or molybdenum dithiocarbamates represented by the formula
##STR00002##
wherein M is tungsten or molybdenum, R.sup.3 and R.sup.4 are the
same or different, each of R.sup.3 and R.sup.4 contains from 1 to
30 carbon atoms and are an alkyl group, a cycloalkyl group, an aryl
group or an alkylaryl group, and m and n are positive real numbers
satisfying the equation: m+n=4. Such a tungsten or molybdenum
dithiocarbamate may be in the form of a dimer or trimer, being
fully sulfurized or containing residual oxygen. Additionally,
illustrative examples may include tungsten or molybdenum organic
complexes of which amine-based salts of tungsten or molybdenum
oxides and tungsten or molybdenum amine complexes are more
preferred.
[0091] Illustrative tungsten organic complex compounds useful in
the lubricating engine oil formulations of this disclosure are
described, for example, in U.S. Pat. Nos. 4,529,526 and 4,266,945,
the disclosures of which are incorporated herein by reference.
Other illustrative tungsten organic complex compounds useful in the
lubricating engine oil formulations of this disclosure are
described, for example, in U.S. Patent Application Publication Nos.
2004/0214731 and 2007/0042917, the disclosures of which are
incorporated herein by reference.
[0092] The metal-containing organic complex friction modifier
constitutes the minor component of the engine oil lubricant
composition of the present disclosure and typically is present in
an amount ranging from 0.01 weight percent to 5 weight percent,
preferably from 0.01 weight percent to 3.5 weight percent, and more
preferably from 0.01 weight percent to 2.5 weight percent, based on
the total weight of the composition. The concentration of the
metal-containing organic complex friction modifier should be
sufficient to provide from 20 parts per million (ppm) to 500 ppm of
metal (e.g., tungsten or molybdenum), preferably from 40 ppm to 400
ppm of metal (e.g., tungsten or molybdenum), and more preferably
from 50 ppm to 250 ppm of metal (e.g., tungsten or molybdenum), to
the composition.
B. Other Organic Friction Modifiers
[0093] Illustrative other organic friction modifiers useful in the
lubricating engine oil formulations of this disclosure include, for
example, an alkoxylated fatty acid ester, alkanolamide, glycerol
fatty acid ester, borated glycerol fatty acid ester, and fatty
alcohol ether. Mixtures of the organic friction modifiers are also
useful in the lubricating engine oil formulations of this
disclosure.
[0094] 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.
[0095] 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.
[0096] Illustrative glycerol fatty acid esters include, for
example, glycerol mono-oleate, glycerol mono-stearate, and the
like. These can include polyol esters and hydroxyl-containing
polyol esters. 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.
[0097] Illustrative borated glycerol fatty acid esters include, for
example, borated glycerol mono-oleate, borated glycerol
mono-sterate, and the like.
[0098] Illustrative fatty alcohol ethers include, for example,
stearyl ether, myristyl ether, and the like. Alcohols, including
those that have carbon numbers from C=3 to C=50, can be
ethoxylated, propoxylate, 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.
[0099] Preferred organic friction modifiers of this disclosure
include an ethoxylated fatty acid ester and stearyl ether,
isostearyl ether, or palmitic ether, and mixtures thereof. A
preferred organic friction modifier mixture of this disclosure
comprises an ethoxylated fatty acid ester and a stearyl ether. A
preferred formulation of this disclosure comprises a lubricating
oil base stock that includes a Group I, Group II, Group III, Group
IV and/or Group V base oil, a tungsten or molybdenum organic
complex friction modifier, and an organic friction modifier
comprising an ethoxylated fatty acid ester or a stearyl ether.
Another preferred formulation of this disclosure comprises a
lubricating oil base stock that includes a Group I, Group II, Group
III, Group IV and/or Group V base oil, a tungsten or molybdenum
organic complex friction modifier, and an organic friction modifier
mixture that includes an ethoxylated fatty acid ester and a stearyl
ether.
[0100] Useful concentrations of organic friction modifiers may
range from 0.01 weight percent to 10-15 weight percent or more,
often with a preferred range of 0.1 weight percent to 5 weight
percent, or 0.1 weight percent to 2.5 weight percent. In organic
friction modifier mixtures, the weight ratio of the first friction
modifier to the other friction modifier can range from 0.1:1 to
1:0.1.
Antiwear Additives
[0101] A metal alkylthiophosphate and more particularly a metal
dialkyl dithio phosphate in which the metal constituent is zinc, or
zinc dialkyl dithio phosphate (ZDDP) is 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 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.
[0102] 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".
[0103] The ZDDP is typically used in amounts of from 0.4 weight
percent to 1.2 weight percent, preferably from 0.5 weight percent
to 1.0 weight percent, and more preferably from 0.6 weight percent
to 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 0.6 to 1.0 weight percent of the total weight of the
lubricating oil.
[0104] Low phosphorus engine oil formulations are included in this
disclosure. For such formulations, the phosphorus content is
typically less than 0.12 weight percent preferably less than 0.10
weight percent and most preferably less than 0.085 weight
percent.
Viscosity Index Improvers
[0105] Viscosity index improvers (also known as VI improvers,
viscosity modifiers, and viscosity improvers) can be included in
the lubricant compositions of this disclosure.
[0106] Viscosity index improvers provide lubricants with high and
low temperature operability. These additives impart shear stability
at elevated temperatures and acceptable viscosity at low
temperatures.
[0107] Suitable viscosity index improvers include high molecular
weight hydrocarbons, polyesters and viscosity index improver
dispersants that function as both a viscosity index improver and a
dispersant. Typical molecular weights of these polymers are between
10,000 to 1,500,000, more typically 20,000 to 1,200,000, and even
more typically between 50,000 and to 1,000,000.
[0108] Examples of suitable viscosity index improvers are linear or
star-shaped polymers and copolymers of methacrylate, butadiene,
olefins, or alkylated styrenes. Polyisobutylene is a commonly used
viscosity index improver. Another suitable viscosity index improver
is polymethacrylate (copolymers of various chain length alkyl
methacrylates, for example), some formulations of which also serve
as pour point depressants. Other suitable viscosity index improvers
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.
[0109] 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". Polyisoprene polymers are
commercially available from Infineum International Limited, e.g.
under the trade designation "SV200"; diene-styrene copolymers are
commercially available from Infineum International Limited, e.g.
under the trade designation "SV 260".
[0110] In an embodiment of this disclosure, the viscosity index
improvers may be used in an amount of less than 2.0 weight percent,
preferably less than 1.0 weight percent, and more preferably less
than 0.5 weight percent, based on the total weight of the
formulated oil or lubricating engine oil. Viscosity improvers are
typically added as concentrates, in large amounts of diluent
oil.
[0111] In another embodiment of this disclosure, the viscosity
index improvers may be used in an amount of from 0.25 to 2.0 weight
percent, preferably 0.15 to 1.0 weight percent, and more preferably
0.05 to 0.5 weight percent, based on the total weight of the
formulated oil or lubricating engine oil.
Detergents
[0112] 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 acid,
carboxylic acid, phosphorous acid, phenol, or mixtures thereof. The
counterion is typically an alkaline earth or alkali metal.
[0113] 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.
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.
[0114] 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.
[0115] Metal salts of carboxylic acids are also useful as
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
##STR00003##
where R is an alkyl group having 1 to 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, or barium. More preferably, M is calcium.
[0116] 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.
[0117] Alkaline earth metal phosphates are also used as detergents
and are known in the art.
[0118] 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.
[0119] Preferred detergents include calcium phenates, calcium
sulfonates, calcium salicylates, magnesium phenates, magnesium
sulfonates, magnesium salicylates 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.
[0120] The detergent concentration in the lubricating oils of this
disclosure can range from 1.0 to 6.0 weight percent, preferably 2.0
to 5.0 weight percent, and more preferably from 2.0 weight percent
to 4.0 weight percent, based on the total weight of the lubricating
oil.
[0121] 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 20 weight percent to 80 weight percent, or from 40 weight
percent to 60 weight percent, of active detergent in the "as
delivered" detergent product.
Antioxidants
[0122] 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.
[0123] Useful antioxidants include hindered phenols. These phenolic
antioxidants may be ashless (metal-free) phenolic compounds or
neutral or basic metal salts of certain phenolic compounds. Typical
phenolic antioxidant compounds are the hindered phenolics which are
the ones which contain a sterically hindered hydroxyl group, and
these include those derivatives of dihydroxy aryl compounds in
which the hydroxyl groups are in the o- or p-position to each
other. Typical phenolic antioxidants include the hindered phenols
substituted with C.sub.6+ alkyl groups and the alkylene coupled
derivatives of these hindered phenols. Examples of phenolic
materials of this type 2-t-butyl-4-heptyl phenol; 2-t-butyl-4-octyl
phenol; 2-t-butyl-4-dodecyl phenol; 2,6-di-t-butyl-4-heptyl phenol;
2,6-di-t-butyl-4-dodecyl phenol; 2-methyl-6-t-butyl-4-heptyl
phenol; and 2-methyl-6-t-butyl-4-dodecyl phenol. Other useful
hindered mono-phenolic antioxidants may include for example
hindered 2,6-di-alkyl-phenolic propionic ester derivatives.
Bis-phenolic antioxidants may also be advantageously used in
combination with the instant disclosure. Examples of ortho-coupled
phenols include: 2,2'-bis(4-heptyl-6-t-butyl-phenol);
2,2'-bis(4-octyl-6-t-butyl-phenol); and
2,2'-bis(4-dodecyl-6-t-butyl-phenol). Para-coupled bisphenols
include for example 4,4'-bis(2,6-di-t-butyl phenol) and
4,4'-methylene-bis(2,6-di-t-butyl phenol).
[0124] Effective amounts of one or more catalytic antioxidants may
also be used. The catalytic antioxidants comprise an effective
amount of a) one or more oil soluble polymetal organic compounds;
and, effective amounts of b) one or more substituted
N,N'-diaryl-o-phenylenediamine compounds or c) one or more hindered
phenol compounds; or a combination of both b) and c). Catalytic
antioxidants are more fully described in U.S. Pat. No. 8,048,833,
herein incorporated by reference in its entirety.
[0125] Non-phenolic oxidation inhibitors which may be used include
aromatic amine antioxidants and these may be used either as such or
in combination with phenolics. Typical examples of non-phenolic
antioxidants include: alkylated and non-alkylated aromatic amines
such as aromatic monoamines of the formula R.sup.8R.sup.9R.sup.10N
where R.sup.8 is an aliphatic, aromatic or substituted aromatic
group, R.sup.9 is an aromatic or a substituted aromatic group, and
R.sup.10 is H, alkyl, aryl or R.sup.11S(O).sub.XR.sup.12 where
R.sup.11 is an alkylene, alkenylene, or aralkylene group, R.sup.12
is a higher alkyl group, or an alkenyl, aryl, or alkaryl group, and
x is 0, 1 or 2. The aliphatic group R.sup.8 may contain from 1 to
20 carbon atoms, and preferably contains from 6 to 12 carbon atoms.
The aliphatic group is a saturated aliphatic group. Preferably,
both R.sup.8 and R.sup.9 are aromatic or substituted aromatic
groups, and the aromatic group may be a fused ring aromatic group
such as naphthyl. Aromatic groups R.sup.8 and R.sup.9 may be joined
together with other groups such as S.
[0126] Typical aromatic amines 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. Polymeric
amine antioxidants can also be used. Particular examples of
aromatic amine antioxidants useful in the present disclosure
include: p,p'-dioctyldiphenylamine;
t-octylphenyl-alpha-naphthylamine; phenyl-alphanaphthylamine; and
p-octylphenyl-alpha-naphthylamine.
[0127] Sulfurized alkyl phenols and alkali or alkaline earth metal
salts thereof also are useful antioxidants.
[0128] Preferred antioxidants include hindered phenols, arylamines.
These antioxidants may be used individually by type or in
combination with one another. Such additives may be used in an
amount of 0.01 to 10 weight percent, preferably 0.01 to 5 weight
percent, more preferably 1 to less than 4 weight percent, even more
preferably 2 to less than 3.5 weight percent.
Pour Point Depressants (PPDs)
[0129] 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 0.01 to 5 weight percent, preferably 0.01 to
1.5 weight percent.
Seal Compatibility Agents
[0130] 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 0.01
to 3 weight percent, preferably 0.01 to 2 weight percent.
Antifoam Agents
[0131] 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
[0132] 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.
[0133] 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 0.01 to 5 weight percent, preferably 0.01
to 1.5 weight percent.
[0134] 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.
[0135] 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) Dispersant 0.1-20 0.1-8 Detergent 0.1-20 0.1-8 Friction
Modifier 0.01-5 0.01-1.5 Antioxidant 0.1-5 0.1-3 Pour Point
Depressant 0.0-5 0.01-1.5 (PPD) Anti-foam Agent 0.001-3 0.001-0.15
Viscosity Index Improver 0.1-2 0.1-1 (solid polymer basis)
Anti-wear 0.2-3 0.5-1 Inhibitor and Antirust 0.01-5 0.01-1.5
[0136] 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.
[0137] The following non-limiting examples are provided to
illustrate the disclosure.
EXAMPLES
[0138] Base oil viscosity for the purpose of this disclosure is
defined as the kinematic viscosity at 100 deg. C. of the
combination of base stocks used in the lubricating engine oil (no
additives included). In the Examples and Figures, Group III (A) is
4 cSt Yubase 4 supplied by SK Lubricants, which is a hydrocracked
and catalyst dewaxed basestock. Group III (B) is a 4 or 8 cSt base
oil supplied by Shell, which is produced via Fischer Tropsch
Synthesis.
[0139] To demonstrate the advantages of the disclosed lubricating
oils including carboxylic functionalized polymer dispersants, the
viscometric profiles of comparative 5W-30 engine oils blended with
conventional dispersants are displayed with their formulations in
FIG. 1. Formulation A is the first inventive example, in which a
carboxylic functionalized polymer dispersant with aromatic amine
functionality (also referred to as low-viscosity dispersant) is
included as part of the total dispersant content (3% low-viscosity
dispersant out of 10% total dispersant). The conventional
dispersant used at 7 wt. % of the lubricating oil was a
conventional PIBSA-PAM disperstant. Formulation B is identical to
Formulation A but uses only conventional dispersant (0%
low-viscosity dispersant out of 10% total dispersant). Formulation
C represents 5W-30 grade engine oil, utilizing a commercial
additive package containing conventional dispersant). Formulation D
represents a 5W-30 grade engine oil using a conventional PIBSA-PAM
dispersant at 9.85 wt. % loading).
[0140] In addition, these formulations were adjusted to the same
HTHS viscosity (indicative of fuel economy benefits) by shifting
base oil viscometrics and the full profile of viscometric
properties were assessed again as shown in FIG. 2. Formulation E is
similar to Formulation A in FIG. 1 (Inventive Example 1); however,
the base oil content was adjusted to achieve a HTHS viscosity of
3.4 cSt. Formulation F is similar to Formulation C in FIG. 1
(Comparative Example 2); however, the base oil content was adjusted
to achieve a HTHS viscosity of 3.4 cSt.
[0141] HTHS viscosity is generally accepted as a proxy for fuel
economy measurement in heavy duty engines. The lower the HTHS, the
more fuel economy benefit is typically observed. In the case of
Formulations E and F, the HTHS viscosities were adjusted to be
equivalent so that a relevant comparison of wear protection at
equivalent "fuel economy" might be achieved. This comparison is
addressed below by measuring viscosity under even greater shear as
a proxy for film thickness (see Example 3 below).
[0142] The HFRR tests were all conducted in a High Frequency
Reciprocating Rig (HFRR) test (ISO Provisional Standard,
TC22/SC7N959, 1995). This test is designed to predict wear
performance of diesel fuels. A modified procedure was developed to
evaluate the wear characteristics of lubricants. The High Frequency
Reciprocating Rig (HFRR) was used under the following conditions.
This method runs the HFRR rig for 30 min at 100.degree. C. with a
400 g load, 400 HZ, and 1 mm stroke length. In this test, the wear
scar diameter of a loaded steel ball is the measure of the wear
performance of the lubricant. The repeatability of the HFRR test is
.+-.1.0 to 2.0%.
Example 1
[0143] Formulations A and B both contain 10 wt % dispersants but
formulation A includes 3% carboxylic functionalized polymer
dispersant with aromatic amine functionality (low-viscosity
dispersant) while formulation B uses only conventional dispersants.
The KV100, KV40, CCS at -30C (ASTM D5293), and HTHS (ASTM D4683) of
Formulation A are all lower than Formulation B (see FIG. 1). Lower
viscosity, especially lower HTHS viscosity, is understood to convey
fuel economy benefits. In addition, the substitution of 3%
conventional dispersant in Formulation B causes Formulation B to
fail the CCS requirement (<6600 cSt at -30 C) for 5W grade oils.
Without the 3% of carboxylic functionalized polymer dispersant with
aromatic amine functionality, Formulation A could not be classified
as a 5W-30 oil.
Example 2
[0144] Formulation A is an SAE 5W-30 grade oil which includes
carboxylic functionalized polymer dispersant with aromatic amine
functionality at 3 wt %. Formulations C and D are to competitive
SAE 5W-30 grade oils that do not contain carboxylic functionalized
polymer dispersant with aromatic amine functionality. The KV100,
KV40, CCS at -30 C, and HTHS of Formulation A is lower than those
of Formulations C and D (see FIG. 1). The Base Oil Viscosity of
Formulation A is 5.99 cSt at 100 deg. C., which is higher than the
base oil viscosity readings for Formulations C (4.87 cSt) and D
(5.01 cSt), which are competitive products whose full viscometric
profile classifies them in the same SAE viscosity grade category.
As a result, a thicker film under shear is expected for formulation
A compared to formulations C and D, which provides better wear
protection in engines.
Example 3
[0145] Formulation E contains the same base oils and additives as
Formulation A, including 3 wt % carboxylic functionalized polymer
dispersant with aromatic amine functionality, but has been adjusted
using base oil mixture to have an HTHS viscosity of 3.4 cP.
Formulation F contains the same base oils and additives as
Formulation C, including 0 wt % carboxylic functionalized polymer
dispersant with aromatic amine functionality, but has been adjusted
using base oil mixture to have an HTHS viscosity of 3.4 cP. The
viscosity of these two formulations was tested under very high
shear conditions at 100 deg. C. FIG. 3 graphically depicts the
ultrashear viscosities of formulations E (inventive) and F
(comparative) at 100 deg. C. In FIG. 3, the circle shaped points
are for formulation E and show the unexpectedly higher shear
viscosity for the lubricating engine oil including the carboxylic
functionalized polymer dispersant which is functionalized with an
aromatic amine. In FIG. 3, the triangle shaped points are for
formulation F and show the lower shear viscosity for the
lubricating engine oil including the conventional dispersant. The
shear experienced by the formulations in these tests exceeds the
shear rate of the HTHS test. At all shear conditions, Formulation E
shows a higher viscosity than Formulation F. Higher viscosity under
shear indicates a thicker lubricant film under these conditions and
correspondingly increased wear protection. Because formulation E
(inventive) and formulation F (comparative) have the same HTHS
viscosity of 3.4 cP, they would have comparable fuel efficiency.
However, inventive formulation E with its higher shear viscosity
than comparative formulation F will have improved engine wear
protection.
Example 4
[0146] To demonstrate the advantages of the disclosed lubricating
oils including carboxylic functionalized polymer dispersants, the
viscometric profiles of comparative 5W-30 engine oils blended with
conventional dispersants are displayed with their formulations in
FIG. 4. Formulation GA is the comparative example, in which 10% of
the dispersant used is a conventional PIBSA-PAM dispersant.
Inventive example, formulation GB is identical to Formulation GA
but also uses the carboxylic functionalized polymer dispersant with
aromatic functionality along with conventional dispersant (5%
low-viscosity dispersant out of 10% total dispersant). Inventive
formulation GC also uses the carboxylic functionalized polymer
dispersant with aromatic functionality along with conventional
dispersant (10% low-viscosity dispersant out of 10% total
dispersant). The formulations were adjusted to equivalent HTHS
viscosity (2.6 cSt) and tested in HFRR to indicate wear protection.
As can be seen in FIG. 4, increased levels of the carboxylic
functionalized polymer dispersant with aromatic functionality
enables increasing base oil viscosity, which leads to lower HFRR
wear scars at equivalent HTHS.
Example 5
[0147] To demonstrate the advantages of the disclosed lubricating
oils including carboxylic functionalized polymer dispersants, the
viscometric profiles of comparative 5W-30 engine oils blended with
conventional dispersants are displayed with their formulations in
FIG. 5. Formulation GD is the comparative example, in which 10% of
the dispersant used is a conventional PIBSA-PAM dispersant.
Inventive example, formulation GE is identical to Formulation GD
but also uses the carboxylic functionalized polymer dispersant with
aromatic functionality along with conventional dispersant (5%
low-viscosity dispersant out of 10% total dispersant). Inventive
formulation GF also uses the carboxylic functionalized polymer
dispersant with aromatic functionality along with conventional
dispersant (10% low-viscosity dispersant out of 10% total
dispersant). The formulations were adjusted to equivalent HTHS
viscosity (2.9) and tested in HFRR to indicate wear protection. As
can be seen in FIG. 5, increased levels of the carboxylic
functionalized polymer dispersant with aromatic functionality
enables higher base oil viscosity, which leads to lower HFRR wear
scars at equivalent HTHS.
Example 6
[0148] To demonstrate the advantages of the disclosed lubricating
oils including carboxylic functionalized polymer dispersants, the
viscometric profiles of comparative 5W-30 engine oils blended with
conventional dispersants are displayed with their formulations in
FIG. 6. Formulation GG is the comparative example, in which 10% of
the dispersant used is a conventional PIBSA-PAM dispersant.
Inventive example, formulation GH is identical to Formulation GG
but also uses the carboxylic functionalized polymer dispersant with
aromatic functionality along with conventional dispersant (5%
low-viscosity dispersant out of 10% total dispersant). Inventive
formulation GI also uses the carboxylic functionalized polymer
dispersant with aromatic functionality along with conventional
dispersant (10% low-viscosity dispersant out of 10% total
dispersant). The formulations were adjusted to equivalent HTHS
viscosity (3.2) and tested in HFRR to indicate wear protection. As
can be seen in FIG. 6, increased levels of the carboxylic
functionalized polymer dispersant with aromatic functionality
enables higher base oil viscosity, which leads to lower HFRR wear
scars at equivalent HTHS.
Example 7
[0149] To demonstrate the advantages of the disclosed lubricating
oils including carboxylic functionalized polymer dispersants, the
viscometric profiles of comparative 5W-30 engine oils blended with
conventional dispersants are displayed with their formulations in
FIG. 7. Formulation GJ is the comparative example, in which 10% of
the dispersant used is a conventional PIBSA-PAM dispersant.
Inventive example, formulation GK is similar to Formulation GJ but
also uses the carboxylic functionalized polymer dispersant with
aromatic functionality along with conventional dispersant (5%
low-viscosity dispersant out of 10% total dispersant). Inventive
formulation GL also uses the carboxylic functionalized polymer
dispersant with aromatic functionality at 10%, but with a blend of
two different viscosity Group II base stocks. The formulations were
adjusted to equivalent HTHS viscosity (2.6 cSt) and tested in HFRR
to indicate wear protection. As can be seen in FIG. 7, increased
levels of the carboxylic functionalized polymer dispersant with
aromatic functionality enables increasing base oil viscosity, which
leads to lower HFRR wear scars at equivalent HTHS.
Example 8
[0150] To demonstrate the advantages of the disclosed lubricating
oils including carboxylic functionalized polymer dispersants, the
viscometric profiles of comparative 5W-30 engine oils blended with
conventional dispersants are displayed with their formulations in
FIG. 8. Formulation GM is the comparative example, in which 10% of
the dispersant used is a conventional PIBSA-PAM dispersant.
Inventive example, formulation GN is identical to Formulation GM
but also uses the carboxylic functionalized polymer dispersant with
aromatic functionality along with conventional dispersant (5%
low-viscosity dispersant out of 10% total dispersant). Inventive
formulation GO also uses the carboxylic functionalized polymer
dispersant with aromatic functionality along with conventional
dispersant (10% low-viscosity dispersant out of 10% total
dispersant). The formulations were adjusted to equivalent HTHS
viscosity (2.9) and tested in HFRR to indicate wear protection. As
can be seen in FIG. 8, increased levels of the carboxylic
functionalized polymer dispersant with aromatic functionality
enables higher base oil viscosity, which leads to lower HFRR wear
scars at equivalent HTHS.
Example 9
[0151] To demonstrate the advantages of the disclosed lubricating
oils including carboxylic functionalized polymer dispersants, the
viscometric profiles of comparative 5W-30 engine oils blended with
conventional dispersants are displayed with their formulations in
FIG. 9. Formulation GP is the comparative example, in which 10% of
the dispersant used is a conventional PIBSA-PAM dispersant.
Inventive example, formulation GQ is identical to Formulation GP
but also uses the carboxylic functionalized polymer dispersant with
aromatic functionality along with conventional dispersant (5%
low-viscosity dispersant out of 10% total dispersant). Inventive
formulation GR also uses the carboxylic functionalized polymer
dispersant with aromatic functionality along with conventional
dispersant (10% low-viscosity dispersant out of 10% total
dispersant). The formulations were adjusted to equivalent HTHS
viscosity (3.2) and tested in HFRR to indicate wear protection. As
can be seen in FIG. 9, increased levels of the carboxylic
functionalized polymer dispersant with aromatic functionality
enables higher base oil viscosity, which leads to lower HFRR wear
scars at equivalent HTHS.
PCT/EP Clauses:
[0152] 1. A multi-grade lubricating engine oil comprising a
lubricating oil base stock as a major component, and a carboxylic
functionalized polymer dispersant with aromatic amine
functionality, as a minor component, wherein the lubricating engine
oil base oil viscosity at 100 deg. C. ranges from 4.5 to 7.5 cSt,
wherein the lubricating engine oil has a cold crank simulator
viscosity at -30 deg. C. of less than 8500 mPas and wherein fuel
efficiency as measured by HTHS (ASTM D4683) and/or engine wear
protection as measured by HFRR wear scar (ISO Provisional Standard,
TC22/SC7N959, 1995) are improved or maintained as compared to fuel
efficiency and engine wear protection achieved using a multi-grade
lubricating engine oil containing a dispersant as a minor component
other than the carboxylic functionalized polymer with aromatic
amine functionality.
[0153] 2. The oil of clause 1, wherein the lubricating oil base
stock is selected from the group consisting of a Group I base
stock, a Group II base stock, a Group III base stock, a Group IV
base stock, Group V base stock and combinations thereof.
[0154] 3. The oil of clauses 1-2, wherein the major component
ranges from 50 to 99 wt. % and the minor component ranges from 1 to
15 wt. %, based on the total weight of the oil.
[0155] 4. The oil of clauses 1-3, wherein the carboxylic
functionalized polymer dispersant includes a polymer backbone
comprising grafted ethylene-propylene (EP) copolymer, or grafted
terpolymers of ethylene, propylene and non-conjugated diene, or a
combination thereof.
[0156] 5. The oil of clauses 1-4, wherein the aromatic amine
functionality includes an amine group having at least 3 aromatic
groups.
[0157] 6. The oil of clause 5, wherein the amine group having at
least 3 aromatic groups is selected from the group consisting of
bis[p-(p-aminoanilino)phenyl]-methane,
2-(7-amino-acridin-2-ylmethyl)-N-4-{4-[4-(4-amino-phenylamino)-benzyl]-ph-
enyl}-benzene-1,4-diamine,
N.sup.4-{4-[4-(4-amino-phenylamino)-benzyl]-phenyl}-2-[4-(4-amino-phenyla-
mino)-cyclohexa-1,5-dienylmethyl]-benzene-1,4-diamine,
N-[4-(7-amino-acridin-2-ylmethyl)-phenyl]-benzene-1,4-diamine, and
combinations thereof.
[0158] 7. The oil of clauses 1-6, further including a non-low
viscosity dispersant at from 0.1 to 10 wt. %, based on the total
weight of the oil.
[0159] 8. The oil of clause 7, wherein the non-low viscosity
dispersant is selected from the group consisting of succinimides,
succinate esters, succinate ester amides,
alkylphenol-polyamine-coupled Mannich adducts and combinations
thereof.
[0160] 9. The oil of clauses 1-8, further comprising one or more of
an anti-wear additive, viscosity index improver, antioxidant,
detergent, pour point depressant, corrosion inhibitor, metal
deactivator, seal compatibility additive, anti-foam agent,
inhibitor, and anti-rust additive.
[0161] 10. The oil of clauses 1-9, wherein the lubricating engine
oil is a heavy duty diesel engine oil (HDEO).
[0162] 11. A method for improving engine wear protection while
maintaining or improving fuel efficiency, in an engine lubricated
with a lubricating oil by using as the lubricating oil a formulated
oil, said formulated oil having a composition comprising a
lubricating oil base stock as a major component; and a carboxylic
functionalized polymer dispersant with aromatic amine
functionality, as a minor component, wherein the lubricating oil
base oil viscosity at 100 deg. C. ranges from 4.5 to 7.5 cSt,
wherein the lubricating oil has a cold crank simulator viscosity at
-30 deg. C. of less than 8500 mPas and wherein the engine wear
protection as measured by HFRR wear scar (ISO Provisional Standard,
TC22/SC7N959, 1995) is improved by at least 10% as compared to the
engine wear protection achieved using a formulated oil containing a
dispersant as a minor component other than the carboxylic
functionalized polymer with aromatic amine functionality.
[0163] 12. A method for improving fuel efficiency while maintaining
or improving wear protection, in an engine lubricated with a
lubricating oil by using as the lubricating oil a formulated oil,
said formulated oil having a composition comprising a lubricating
oil base stock as a major component; and a carboxylic
functionalized polymer dispersant with aromatic amine
functionality, as a minor component, wherein the lubricating oil
base oil viscosity at 100 deg. C. ranges from 4.5 to 7.5 cSt,
wherein the lubricating oil has a cold crank simulator viscosity at
-30 deg. C. of less than 8500 mPas, and wherein the fuel efficiency
as measured by HTHS (ASTM D4683) is improved by at least 10% as
compared to the fuel efficiency achieved using a formulated oil
containing a dispersant as a minor component other than the
carboxylic functionalized polymer with aromatic amine
functionality.
[0164] 13. A method of making a lubricating engine oil comprising:
providing a lubricating oil base stock having a base oil viscosity
at 100 deg. C. ranging from 4.5 to 7.5 cSt, and a carboxylic
functionalized polymer dispersant with aromatic amine
functionality, and blending from 50 to 99 wt. %, based on the total
weight of the oil, of the lubricating oil base stock with from 1 to
15 wt. %, based on the total weight of the oil, of the carboxylic
functionalized polymer dispersant with aromatic amine functionality
to form the lubricating engine oil, wherein the lubricating engine
oil has a cold crank simulator viscosity at -30 deg. C. of less
than 8500 mPas.
[0165] 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.
[0166] 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.
[0167] 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