U.S. patent application number 17/453587 was filed with the patent office on 2022-05-12 for engine oil lubricant compostions and methods for making same with steel corrosion protection.
The applicant listed for this patent is ExxonMobil Research and Engineering Company. Invention is credited to Michael L. Blumenfeld, Mark L. Bushey, Douglas E. Deckman, David G.L. Holt, Nicholas W. McBride.
Application Number | 20220145206 17/453587 |
Document ID | / |
Family ID | 1000005974583 |
Filed Date | 2022-05-12 |
United States Patent
Application |
20220145206 |
Kind Code |
A1 |
McBride; Nicholas W. ; et
al. |
May 12, 2022 |
ENGINE OIL LUBRICANT COMPOSTIONS AND METHODS FOR MAKING SAME WITH
STEEL CORROSION PROTECTION
Abstract
Provided is a low sulfated ash engine oil lubricant composition
containing organic friction modifiers with improved fuel economy
and corrosion resistance. The lubricant composition includes one or
more metal free corrosion inhibitors having an organic acid group
and/or one or more organo metallic naphthalene molecules having a
ASTM D2896 total base number less than 3 mg KOH/g. The resulting
lubricant composition improves ASTM D6557 corrosion protection for
low sulfated ash engine oils containing organic friction modifiers,
while maintaining exceptional fuel economy performance.
Inventors: |
McBride; Nicholas W.;
(Morristown, NJ) ; Deckman; Douglas E.; (Easton,
PA) ; Bushey; Mark L.; (Hellertown, PA) ;
Holt; David G.L.; (Center Valley, PA) ; Blumenfeld;
Michael L.; (Annandale, NJ) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
ExxonMobil Research and Engineering Company |
Annandale |
NJ |
US |
|
|
Family ID: |
1000005974583 |
Appl. No.: |
17/453587 |
Filed: |
November 4, 2021 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
63110716 |
Nov 6, 2020 |
|
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C10N 2010/04 20130101;
C10M 125/22 20130101; C10M 129/74 20130101; C10N 2030/04 20130101;
C10N 2030/12 20130101; C10M 135/10 20130101; C10N 2040/252
20200501; C10N 2030/52 20200501; C10N 2040/255 20200501; C10M
2219/044 20130101; C10N 2030/54 20200501; C10M 2207/283 20130101;
C10M 169/04 20130101 |
International
Class: |
C10M 129/74 20060101
C10M129/74; C10M 169/04 20060101 C10M169/04; C10M 125/22 20060101
C10M125/22; C10M 135/10 20060101 C10M135/10 |
Claims
1. An engine oil lubricant composition, comprising: about 40 wt %
to about 90 wt % of at least one base oil; about 0.1 wt % to about
5 wt % of an organic friction modifier; about 1 wt % to about 6 wt
% of at least one detergent comprising magnesium or calcium; about
0.01 wt % to about 1 wt % of a corrosion inhibitor having at least
one organic acid moiety or organic salt thereof; wherein the engine
oil lubricant composition has a sulfated ash content of 0.5 wt % or
less, and an HTHS (ASTM D4683) of less than or equal to 3.7 cP at
150.degree. C.
2. The lubricant composition of claim 1, wherein the composition
comprises 0.1 wt % to about 1.0 wt % of an organic friction
modifier.
3. The lubricant composition of claim 1, wherein the organic
friction modifier is an alkyl or alkylene glyceride ester.
4. The lubricant composition of claim 1, wherein the at least one
detergent comprises magnesium or calcium sulfonate or a mixture
thereof.
5. The lubricating engine oil of claim 1, wherein the corrosion
inhibitor having a naphthenate, naphthalene sulfonate, or at least
one organic acid or organic salt moiety improves the ball rust test
(ASTM D6557) average gray value (AGV) by at least 25%.
6. The lubricating engine oil of claim 1, wherein the corrosion
inhibitor having a naphthenate, naphthalene sulfonate, or at least
one organic acid or organic salt moiety improves the ball rust test
(ASTM D6557) average gray value (AGV) by at least 50%.
7. The lubricating engine oil of claim 1, wherein the corrosion
inhibitor having a naphthenate, naphthalene sulfonate, or at least
one organic acid or organic salt moiety improves the ball rust test
(ASTM D6557) average gray value (AGV) by at least 100%.
8. The lubricating engine oil of claim 1, wherein the corrosion
inhibitor having at least one organic acid or organic salt of an
alkyl or alkylene substituted naphthenate or naphthalene sulfonate
moiety.
9. The lubricating engine oil of claim 1, wherein the corrosion
inhibitor is zinc naphthenate.
10. The lubricating engine oil of claim 1, wherein the corrosion
inhibitor is the barium salt of dinonyl, naphthylenesulfonic
acid.
11. The lubricating engine oil of claim 1, wherein the corrosion
inhibitor is calcium dinonylnaphthalene sulfonate.
12. The lubricating engine oil of claim 1, wherein the corrosion
inhibitor is zinc dinonylnaphthalene sulfonate.
13. The lubricating engine oil of claim 1, wherein the corrosion
inhibitor having at least one organic acid or organic salt of a
carboxylate moiety.
14. The lubricating engine oil of claim 1, wherein the corrosion
inhibitor is the imidazoline reaction product of oleic acid and
amino-ethyl 2-ethylhexyl amine plus free oleic acid.
15. The lubricating engine oil of claim 1, wherein the corrosion
inhibitor is a sixteen carbon chain alkylated succinic anhydride
reacted with 1,3 propane diol.
16. The lubricating engine oil of claim 1, wherein the corrosion
inhibitor having at least one organic salt moiety with a counter
ion from the alkali, alkaline earth, transition metal, metalloid,
or post transition metal groups.
17. The lubricating engine oil of claim 1, wherein the corrosion
inhibitor having at least one organic salt moiety with a calcium,
magnesium, lithium, sodium, barium, zinc, or copper counter
ion.
18. An engine oil lubricant composition, comprising: about 40 wt %
to about 90 wt % of at least one base oil; about 0.1 wt % to about
5 wt % of an organic friction modifier; about 1 wt % to about 6 wt
% of at least one detergent comprising magnesium or calcium; about
0.01 wt % to about 1 wt % of a corrosion inhibitor comprising an
organo-metallic naphthalene compound; wherein the engine oil
lubricant composition has a sulfated ash content of 0.5 wt % or
less, and an HTHS (ASTM D4683) of less than or equal to 3.7 cP at
150.degree. C.
19. The lubricating engine oil of claim 18, wherein the corrosion
inhibitor having at least one organic acid or organic salt of an
alkyl or alkylene substituted naphthenate or naphthalene sulfonate
moiety.
20. The lubricating engine oil of claim 18, wherein the corrosion
inhibitor is selected from zinc naphthenate, the barium salt of
dinonylnaphthylenesulfonic acid, calcium dinonylnaphthalene
sulfonate, and zinc dinonylnaphthalene sulfonate.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional
Application No. 63/110,716, filed on Nov. 6, 2020, the entire
contents of which are incorporated herein by reference.
FIELD OF THE INVENTION
[0002] Embodiments of the present invention generally relate to low
sulfated ash engine oil lubricant compositions and methods for
making same. Such compostions are useful for gasoline and diesel
engines and provide a combination of excellent aftertreatment
device protection, steel corrosion protection, and fuel
efficiency.
DESCRIPTION OF THE RELATED ART
[0003] A major challenge in engine oil formulation is
simultaneously achieving aftertreatment device protection while
also maintaining fuel economy performance and providing steel
corrosion protection.
[0004] Fuel efficiency requirements for passenger vehicles are
becoming increasingly more stringent. The combustion of 1 gallon of
gasoline produces about 19.5 pounds of carbon dioxide (CO.sub.2).
So technology that improves fuel economy (i.e. more miles per
gallon of combustion) will necessarily reduce CO.sub.2 emissions.
New legislation in the United States and European Union within the
past few years has set fuel economy and carbon emissions targets
not readily achievable with today's vehicle and lubricant
technology. In Europe, for example, CO.sub.2 emission requirements
for gasoline passenger cars have dropped from 130 g CO.sub.2/km in
2015 to 95 in 2021, to 81 in 2025 and to 59 in 2030. Due to these
more stringent governmental regulations for vehicle fuel
consumption and carbon emissions, use of passenger car diesel
engines or gasoline direct injection engines, or gasoline hybrid
engines are becoming more prevalent.
[0005] To meet the future carbon dioxide emission requirements,
engine oil formulations often contain organic friction modifiers to
help reduce friction, which helps improves engine efficiency and
fuel economy. A major challenge in engine oil formulations
containing organic friction modifiers, however, is the high surface
activity that can lead to more corrosion, which leads to engine
inefficiencies and thus lower fuel economy.
[0006] Another major challenge in engine oil formulations is
aftertreatment device durability. Diesel Particulate Filters (DPFs)
and Gasoline Particulate Filters (GPFs), for example, are exhaust
aftertreatment devices used to control particulate matter and
particulate number emissions and are negatively impacted by
metallic species contained in engine oil formulations. Sulfated Ash
(ASTM D874) is a common measure of the metals content of an engine
oil formulation. In the ASTM D874 test, an engine oil is evaporated
to a residue and then reacted with sulfuric acid at 775.degree. C.
This converts metals calcium (Ca), magnesium (Mg), zinc (Zn),
molybdenum (Mo), sodium (Na) in the residue to a sulfated "ash",
which is then weighed.
[0007] To provide aftertreatment device durability, engine oils are
typically formulated to have .ltoreq.1.0 wt % ash or 0.9 wt % ash
or 0.8 wt % ash or 0.5 wt % of sulfated ash. A major source of the
sulfated ash is from metallic detergents that are used to provide
piston cleanliness and neutralize acids that are formed from
combustion. As ash levels are reduced, metallic detergent levels
are also reduced, which limits the ability of an engine oil to
neutralize acidic species.
[0008] There is a need, therefore, for improved engine oil
formulations capable of achieving aftertreatment device protection
while also providing fuel economy performance and steel corrosion
protection.
SUMMARY
[0009] Low sulfated ash engine oil lubricant compositions are
provided. The engine oil lubricant compositions can have a sulfated
ash content of 0.5 wt % or less, and an HTHS (ASTM D4683) of less
than or equal to 3.7 cP at 150.degree. C. In at least one specific
embodiment, the composition can include about 40 wt % to about 90
wt % of at least one base oil, about 0.1 wt % to about 5 wt % of an
organic friction modifier, about 1 wt % to about 6 wt % of at least
one detergent comprising magnesium or calcium, and about 0.01 wt %
to about 1 wt % of a corrosion inhibitor having at least one
organic acid or organic salt group. In at least one other specific
embodiment, the composition can include about 40 wt % to about 90
wt % of at least one base oil, about 0.1 wt % to about 5 wt % of an
organic friction modifier, about 1 wt % to about 6 wt % of at least
one detergent comprising magnesium or calcium, and about 0.01 wt %
to about 1 wt % of a corrosion inhibitor comprising an
organo-metallic naphthalene compound.
DETAILED DESCRIPTION
[0010] It has been surprisingly discovered that metal free
corrosion inhibitors having an organic acid or organic salt group
can improve ASTM D6557 corrosion protection for low sulfated ash
engine oils containing organic friction modifiers, while
maintaining exceptional fuel economy performance. It has also been
surprisingly discovered that organo metallic naphthalene molecules
having a ASTM D2896 total base number less than 3 mg KOH/g can
improve ASTM D6557 corrosion protection for low sulfated ash engine
oils containing organic friction modifiers, while maintaining
exceptional fuel economy performance.
[0011] The ASTM D6557 test is a steel corrosion test where a 5.6 mm
diameter steel ball is placed in a test tube with 10 mL of engine
oil. The test tube with engine oil and steel ball is then placed on
a mechanical shaker. An acid mixture of hydrochloric acid (HCl),
hydrobromic acid (HBr), and acetic acid is continuously added to
the test tube. The test is conducted for 18 hours at 48.degree. C.
Afterwhich, the steel ball is removed, rinsed, and the
reflectivitiy of the ball is measured. New balls have a
reflectivity of about 133 average gray value units ("AGV"). A
reduction in average gray value indicates that corrosion has
occurred.
[0012] In the following discussion and in the claims, the terms
"including" and "comprising" are used in an open-ended fashion, and
thus should be interpreted to mean "including, but not limited to."
The phrase "consisting essentially of" means that the
described/claimed composition does not include any other components
that will materially alter its properties by any more than 5% of
that property, and in any case does not include any other component
to a level greater than 3 mass %. The term "or" is intended to
encompass both exclusive and inclusive cases, i.e., "A or B" is
intended to be synonymous with "at least one of A and B," unless
otherwise expressly specified herein. The term "wt %" means
percentage by weight, "vol %" means percentage by volume, "mol %"
means percentage by mole, "ppm" means parts per million, and "ppm
wt" and "wppm" are used interchangeably and mean parts per million
on a weight basis. All concentrations herein, unless otherwise
stated, are expressed on the basis of the total amount of the
composition in question.
Base Oils
[0013] 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.
[0014] Groups I, II, III, IV and V are broad categories of base oil
stocks developed and defined by the American Petroleum Institute
(API Publication 1509; www.AP1.org) to create guidelines for
lubricant base oils. Group I base stocks generally have a viscosity
index of between about 80 to 120 and contain greater than about
0.03% sulfur and/or less than about 90% saturates. Group II base
stocks generally have a viscosity index of between about 80 to 120,
and contain less than or equal to about 0.03% sulfur and greater
than or equal to about 90% saturates. Group III stocks generally
have a viscosity index greater than about 120 and contain less than
or equal to about 0.03% sulfur and greater than about 90%
saturates. Group IV includes polyalphaolefins (PAO). Group V base
stock includes base stocks not included in Groups I-IV.
[0015] Non-limiting exemplary Group V base stocks include alkylated
naphthalene base stock, ester base stock, aliphatic ether base
stock, aryl ether base stock, ionic liquid base stock, and
combinations thereof.
TABLE-US-00001 TABLE 1 Base oil properties of each of these five
groups. Viscosity Saturates Sulfur Index Group I <90 &/or
>0.03% & .gtoreq.80 & < 120 Group II .gtoreq.90 &
.ltoreq.0.03% & .gtoreq.80 & < 120 Group III .gtoreq.90
& .ltoreq.0.03% & .gtoreq.120 Group IV Includes
polyalphaolefins (PAO) Group V All other base oil stocks not
included in Groups I, II, III, or IV
Base Oil Properties
[0016] 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.
[0017] 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 base stock
oils.
[0018] 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.
[0019] The number average molecular weights of the PAOs, which are
known materials and generally available on a major commercial scale
from suppliers such as ExxonMobil Chemical Company, Chevron
Phillips Chemical Company, BP, and others, typically vary from
about 250 g/mol to about 3,000 g/mol, although PAO's may be made in
viscosities up to about 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 about C.sub.32 alphaolefins with the C.sub.8
to about C.sub.16 alphaolefins, such as 1-octene, 1-decene,
1-dodecene and the like, being preferred. The preferred
polyalphaolefins are poly-1-octene, poly-1-decene and
poly-1-dodecene and mixtures thereof and mixed olefin-derived
polyolefins. However, the dimers of higher olefins in the range of
C.sub.14 to C.sub.18 may be used to provide low viscosity
basestocks 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
(100.degree. C.).
[0020] 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.
[0021] The hydrocarbyl aromatics can be used as base oil or base
oil component and can be any hydrocarbyl molecule that contains at
least about 5% of its weight derived from an aromatic moiety such
as a benzenoid moiety or naphthenoid moiety, or their derivatives.
These hydrocarbyl aromatics include alkyl benzenes, alkyl
naphthalenes, alkyl diphenyl oxides, alkyl naphthols, alkyl
diphenyl sulfides, alkylated bis-phenol A, alkylated thiodiphenol,
and the like. The aromatic can be mono-alkylated, dialkylated,
polyalkylated, and the like. The aromatic can be mono- or
poly-functionalized. The hydrocarbyl groups can also be comprised
of mixtures of alkyl groups, alkenyl groups, alkynyl, cycloalkyl
groups, cycloalkenyl groups and other related hydrocarbyl groups.
The hydrocarbyl groups can range from about C.sub.6 up to about
C.sub.60 with a range of about C.sub.8 to about C.sub.20 often
being preferred. A mixture of hydrocarbyl groups is often
preferred, and up to about three such substituents may be present.
The hydrocarbyl group can optionally contain sulfur, oxygen, and/or
nitrogen containing substituents. The aromatic group can also be
derived from natural (petroleum) sources, provided at least about
5% of the molecule is comprised of an above-type aromatic moiety.
Viscosities at 100.degree. C. of approximately 1.8 cSt to about 50
cSt are preferred, with viscosities of approximately 2.2 cSt to
about 20 cSt often being more preferred for the hydrocarbyl
aromatic component. In one embodiment, an alkyl naphthalene where
the alkyl group is primarily comprised of 1-hexadecene is used.
Other alkylates of aromatics can be advantageously used.
Naphthalene or methyl naphthalene, for example, can be alkylated
with olefins such as octene, decene, dodecene, tetradecene or
higher, mixtures of similar olefins, and the like. Useful
concentrations of hydrocarbyl aromatic in a lubricant oil
composition can be about 2% to about 25%, preferably about 4% to
about 20%, and more preferably about 4% to about 15%, depending on
the application.
[0022] 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.
[0023] Particularly useful synthetic esters are those which are
obtained by reacting one or more polyhydric alcohols, preferably
the hindered polyols (such as the neopentyl polyols, e.g.,
neopentyl glycol, trimethylol ethane,
2-methyl-2-propyl-1,3-propanediol, trimethylol propane,
pentaerythritol and dipentaerythritol) with alkanoic acids
containing at least about 4 carbon atoms, preferably C.sub.5 to
C.sub.30 acids such as saturated straight chain fatty acids
including caprylic acid, capric acid, lauric acid, myristic acid,
palmitic acid, stearic acid, arachic acid, and behenic acid, or the
corresponding branched chain fatty acids or unsaturated fatty acids
such as oleic acid, or mixtures of any of these materials.
[0024] Suitable synthetic ester components include the esters of
trimethylol propane, trimethylol butane, trimethylol ethane,
pentaerythritol and/or dipentaerythritol with one or more
monocarboxylic acids containing from about 5 to about 10 carbon
atoms. These esters are widely available commercially, for example,
the Mobil P-41 and P-51 esters of ExxonMobil Chemical Company.
[0025] 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.
[0026] 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.
[0027] The base oil constitutes the major component of the engine
oil lubricant composition and typically is present in an amount
ranging from about 50 to about 99 wt %, e.g., from 70 to 90 wt % or
from about 85 to about 95 wt %, 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 has a
kinematic viscosity, according to ASTM standards, of about 1.0 cSt
to about 16.0 cSt (100.degree. C.), preferably of about 1.0 cSt to
about 12.0 cSt (100.degree. C.), more preferably of about 2.0 cSt
to about 8.0 cSt (100.degree. C.) and even more preferably of about
2.0 cSt to about 4.0 cSt (100.degree. C.). Mixtures of synthetic
and natural base oils may be used if desired. As used herein, the
base stock name is associated with the ASTM D445 kinematic
viscosity at 100.degree. C. of the base stock. For instance, PAO 4
has an ASTM D445 100.degree. C. kinematic viscosity of 4 cSt; GTL 3
has a D445 100.degree. C. kinematic viscosity of 3 cSt.
[0028] The engine oil lubricant composition of the present
invention can have an ASTM D4683 High Temperature High Shear (HTHS)
viscosity of less than or equal to 3.7 cP at 150.degree. C., or
less than or equal to 2.9 cP at 150.degree. C., or less than or
equal to 2.6 cP at 150.degree. C., or less than or equal to 2.3 cP
at 150.degree. C., and preferably about 2.6 cP at 150.degree. C.
HTHS viscosity is the measure of a lubricant's viscosity under
severe engine conditions, is measured using ASTM D4683.
Viscosity Modifiers (VM)
[0029] Viscosity modifiers are also known as VI improvers,
viscosity index improvers and viscosity improvers. Suitable
viscosity modifiers provide lubricants with high temperature and
low temperature operability. Suitable viscosity modifiers also
impart shear stability at elevated temperatures and acceptable
viscosity at low temperatures. Suitable viscosity modifiers may be
or may include one or more linear or star-shaped polymers and/or
copolymers of methacrylate, butadiene, olefins, isoprene or
alkylated styrenes, polyisobutylene, polymethacrylate,
ethylene-propylene, hydrogenated block copolymer of styrene and
isoprene, polyacrylates, styrene-isoprene block copolymer,
styrene-butadiene copolymer, ethylene-propylene copolymer,
hydrogenated star polyisoprene, and combinations thereof.
[0030] As used herein, the term "polymer" refers to any two or more
of the same or different repeating units/mer units or units. The
term "homopolymer" refers to a polymer having units that are the
same. The term "copolymer" refers to a polymer having two or more
units that are different from each other, and includes terpolymers
and the like. The term "terpolymer" refers to a polymer having
three units that are different from each other. The term
"different" refers to units indicates that the units differ from
each other by at least one atom or are different isomerically.
Likewise, the definition of polymer, as used herein, includes
homopolymers, copolymers, and the like. Furthermore, the term
"styrenic block copolymer" refers to any copolymer that includes
units of styrene and a mid-block.
[0031] Suitable olefin copolymers, for example, 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". Suitable polyisoprene polymers, for example,
are commercially available from Infineum International Limited,
e.g. under the trade designation "SV200". Suitable diene-styrene
copolymers, for example, are commercially available from Infineum
International Limited, e.g. under the trade designation "SV
260".
[0032] One particularly suitable viscosity modifier is
polyisobutylene. Another particularly suitable viscosity modifier
is polymethacrylate, which can also serve as pour point depressant.
Other particularly suitable viscosity modifiers include copolymers
of ethylene and propylene, hydrogenated block copolymers of styrene
and isoprene, and polyacrylates. Specific examples include
styrene-isoprene and styrene-butadiene based polymers of 50,000
g/mol to 200,000 g/mol molecular weight.
[0033] Suitable viscosity modifiers may further include high
molecular weight hydrocarbons, polyesters and dispersants that
function as both a viscosity modifier and a dispersant. Typical
molecular weights of these polymers may range between about 10,000
g/mol and about 2,000,000 g/mol, more typically about 20,000 g/mol
and about 1,500,000 g/mol, and even more typically between about
50,000 g/mol and about 1,200,000 g/mol.
[0034] At least one viscosity modifier may be included in the
engine oil lubricant composition at a concentration of from 0.1 to
5 wt %, or 0.1 to 8 wt %, or 0.1 to 14 wt %, or 0.5 to 10 wt %, or
0.01 to 2 wt %, or 1.0 to 7.5 wt %, or 1.5 to 5 wt %. At least one
viscosity modifier may also be included in the engine oil lubricant
composition at a concentration ranging from a low of about about
0.1 wt %, about 0.3 wt %, or about 0.5 wt % to a high of about 5 wt
%, about 8 wt %, or about 16 wt %. At least one viscosity modifier
concentration may also range from a low of about about 0.1 wt %,
about 0.5 wt %, or about 1.0 wt % to a high of about 8 wt %, about
12 wt %, or about 14 wt %. The foregoing viscosity modifier
concentrations are based on a polymer concentrate basis in terms of
the total weight of the lubricating composition.
Friction Modifiers (FM)
[0035] A friction modifier is any material or two or more materials
that can alter the coefficient of friction of a surface lubricated
by a lubricant or fluid containing such material(s). Friction
modifiers, also known as friction reducers, or lubricity agents or
oiliness agents, and other such agents that change the ability of
base oils, formulated lubricant compositions, or functional fluids,
to modify the coefficient of friction of a lubricated surface may
be effectively used in combination with the base oils or lubricant
compositions of the present invention if desired. Friction
modifiers that lower the coefficient of friction are particularly
advantageous in combination with the base oils and lube
compositions of this invention. Friction modifiers may include
metal-containing compounds or materials as well as ashless
compounds or materials, or mixtures thereof. Metal-containing
friction modifiers may include metal salts or metal-ligand
complexes where the metals may include alkali, alkaline earth, or
transition group metals. Such metal-containing friction modifiers
may also have low-ash characteristics. Transition metals may
include molybdenum (Mo), antimony (Sb), tin (Sn), iron (Fe), copper
(Cu), zinc (Zn), and others. Such suitable ligands may include
hydrocarbyl derivative of alcohols, polyols, glycerols, partial
ester glycerols, thiols, carboxylates, carbamates, thiocarbamates,
dithiocarbamates, phosphates, thiophosphates, dithiophosphates,
amides, imides, amines, thiazoles, thiadiazoles, dithiazoles,
diazoles, triazoles, and other polar molecular functional groups
containing effective amounts of oxygen (O), nitrogen (N), sulfur
(S), or phosphorus (P), individually or in combination.
[0036] Ashless friction modifiers can also be used. Suitable
ashless friction modifiers may include hydroxyl-containing
hydrocarbyl base oils, glycerides, partial glycerides, glyceride
derivatives, fatty organic acids, fatty amines, and sulfurized
fatty acids. Fatty acids include short-chain fatty acids,
medium-chain fatty acids, long-chain fatty acids, and very
long-chain fatty acids. Short-chain fatty acids have carbon chains
of between one and five carbon atoms. Medium-chain fatty acids have
carbon chains of between six and twelve carbon atoms. Long-chain
fatty acids have carbon chains of between thirteen and and
twenty-one carbon atms. Very long-chain fatty acids have carbon
chains greater than twenty-one carbons. These carbon chains can be
saturated or unsaturated. Suitable ashless friction modifiers may
also include lubricant materials that contain effective amounts of
polar groups, for example, hydroxyl-containing hydrocarbyl base
oils, glycerides, partial glycerides, glyceride derivatives, and
the like. Suitable ashless friction modifiers may include alkyl or
alkylene fatty acid esters of glycerides, alkyl or alkylene
glyceride esters. Polar groups in friction modifiers may include
hydrocarbyl groups containing effective amounts of oxygen (O),
nitrogen (N), sulfur (S), or phosphorus (P), individually or in
combination. Other friction modifiers that may be particularly
effective include, for example, salts (both ash-containing and
ashless derivatives) of fatty acids, fatty alcohols, fatty amides,
fatty esters, hydroxyl-containing carboxylates, and comparable
synthetic long-chain hydrocarbyl acids, alcohols, amides, esters,
hydroxy carboxylates, and the like. In some instances fatty organic
acids, fatty amines, and sulfurized fatty acids may be used as
suitable friction modifiers. In some instances, friction modifiers
containing ethylene-oxide, oligomers of ethylene oxide, or polymer
segments of ethylene oxide are effective.
[0037] Ashless friction modifiers may be or may include polymeric
and/or non-polymeric molecules. A suitable polymeric friction
modifier may have a weight average molecular weight (Mw) of 3,000
g/mol or more; 4,000 g/mol or more; 5,000 g/mol or more; 6,000
g/mol or more; 7,000 g/mol or more; 8,000 g/mol or more; 9,000
g/mol or more; 10,000 g/mol or more; 15,000 g/mol or more; 20,000
g/mol or more; 30,000 g/mol or more; 40,000 g/mol or more; or
45,000 g/mol or more. The molecular weight of suitable polymeric
friction modifiers may also range from a low of about 3,000 g/mol,
about 4,000 g/mol, or about 5,000 g/mol to a high of about 10,000
g/mol; about 30,000 g/mol, or about 50,000 g/mol. The molecular
weight of suitable polymeric friction modifiers may also range from
about 3,000 g/mol to 15,000 g/mol; about 4,000 g/mol to about
12,000 g/mol; about 3,000 g/mol to about 9,000 g/mol; about 3,000
g/mol to about 7,000 g/mol. The molecular weight of suitable
polymeric friction modifiers may also be about 3,000 g/mol, about
4,000 g/mol, about 5,000 g/mol, about 6,000 g/mol, about 7,000
g/mol, about 8,000 g/mol, or about 9,000 g/mol. A particularly
suitable polymeric friction modifier is or includes ethylene oxide
(EtO), oligomers of ethylene oxide, or polymers of ethylene
oxide.
Other Additives
[0038] The engine oil lubricant composition may also include one or
more other additives typical for engine oils. These other additives
may include any one or more anti-wear additives, dispersants,
detergents, antioxidants, pour point depressant, corrosion
inhibitors, anti-rust additives, metal deactivators, seal
compatibility additives, and anti-foam agents. These other
additives may be provided to the lubricant composition in the form
of an additive package. The additive packages may be incorporated
into the engine lubricant compositions at loadings of about 9 wt %
to about 15 wt %, or about 10 to about 14.5 wt %, or about 11 to
about 14 wt %, based on the total weight of the composition. The
additive packages may also be incorporated into the engine
lubricant compositions at loadings ranging from a low of about 5 wt
%, about 7 wt %, about 9 wt %, or about 10 wt % to a high of about
11 wt %, about 14 wt %, about 14.5 wt %, or about 15 wt %, based on
the total weight of the composition.
Antiwear
[0039] While there are many different types of antiwear additives,
for several decades the principal antiwear additive for internal
combustion engine crankcase oils is a metal alkylthiophosphate and
more particularly a metal dialkyldithiophosphate in which the metal
constituent is zinc, or zinc dialkyldithiophosphate (ZDDP). ZDDP
can be primary, secondary 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. The ZDDP is typically used in amounts
of from about 0.4 to 1.4 wt % of the total lubricant oil
composition, although more or less can often be used
advantageously. Preferably, the ZDDP is a secondary ZDDP and
present in an amount of from about 0.6 to 1.0 wt %, or from 0.6 to
0.91 wt % of the total lubricant composition.
[0040] 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".
Dispersants
[0041] During engine operation, oil-insoluble oxidation byproducts
are produced. Dispersants help keep these byproducts in solution,
thus diminishing their deposition on metal surfaces. Dispersants
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.
[0042] Suitable dispersants typically contain a polar group
attached to a relatively high molecular weight hydrocarbon chain.
The polar group typically contains at least one element of
nitrogen, oxygen, or phosphorus. Typical hydrocarbon chains contain
50 to 400 carbon atoms.
[0043] Chemically, many dispersants may be characterized as
phenates, sulfonates, sulfurized phenates, salicylates,
naphthenates, stearates, carbamates, thiocarbamates, phosphorus
derivatives. A particularly useful class of dispersants are the
alkenylsuccinic derivatives, typically produced by the reaction of
a long chain substituted alkenyl succinic compound, usually a
substituted succinic anhydride, with a polyhydroxy or polyamino
compound. The long chain 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.
[0044] Hydrocarbyl-substituted succinic acid compounds are popular
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.
[0045] Succinimides are formed by the condensation reaction between
alkenyl succinic anhydrides and amines. Molar ratios can vary
depending on the polyamine. For example, the molar ratio of alkenyl
succinic anhydride to polyethylene amines (TEPA, tetra-ethylene
penta-amine) can vary from about 1:1 to about 5:1. Representative
examples are shown in U.S. Pat. Nos. 3,087,936; 3,172,892;
3,219,666; 3,272,746; 3,322,670; and 3,652,616, 3,948,800; and
Canada Pat. No. 1,094,044.
[0046] Succinate esters are formed by the condensation reaction
between alkenyl succinic anhydrides and alcohols or polyols. Molar
ratios can vary depending on the alcohol or polyol used. For
example, the condensation product of an alkenyl succinic anhydride
and pentaerythritol is a useful dispersant.
[0047] Succinate ester amides are formed by condensation reaction
between alkenyl 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.
[0048] The molecular weight of the alkenyl succinic anhydrides used
in the preceding paragraphs will typically range between 800 and
2,500 g/mol. The above products can be post-reacted with various
reagents such as sulfur, oxygen, formaldehyde, carboxylic acids
such as oleic acid, and boron compounds such as borate esters or
highly borated dispersants. The dispersants can be borated with
from about 0.1 to about 5 moles of boron per mole of dispersant
reaction product.
[0049] 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 g/mol. 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.
[0050] Typical high molecular weight aliphatic acid modified
Mannich condensation products useful in this invention can be
prepared from high molecular weight alkyl-substituted
hydroxyaromatics or HN(R).sub.2 group-containing reactants.
[0051] 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.
[0052] 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 molecular
weight number average (Mn) of from about 500 to about 5000 g/mol or
a mixture of such hydrocarbylene groups. Other preferred
dispersants include succinic acid-esters and amides,
alkylphenol-polyamine-coupled Mannich adducts, their capped
derivatives, and other related components. Such additives may be
used in an amount of about 0.1 to 20 wt %, preferably about 0.5 to
8 wt %.
Detergents
[0053] Detergents are commonly used in lubricating compositions. 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.
[0054] 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 mg KOH/g.
It is desirable for at least some detergent to be overbased, which
means the detergent contains 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). Overbased detergents help neutralize acidic impurities
produced by the combustion process and become entrapped in the oil.
Typically, the overbased material has a ratio of metallic ion to
anionic portion of the detergent of about 1.05:1 to 50:1 on an
equivalent basis. More preferably, the ratio is from about 4:1 to
about 25:1. The resulting detergent is an overbased detergent that
will typically have a TBN of greater than 80 mg KOH/g, such as 80
to 450; 85 to 450 or 150 to 450 mg KOH/g. Useful detergents can
also have a TBN that ranges from a low of about 81 mg KOH/g, about
90 mg KOH/g, or about 100 mg KOH/g to a high of about 200, 300, or
450 mg KOH/g. Preferably, the overbasing cation is sodium (Na),
calcium (Ca), or magnesium (Mg). A mixture of detergents of
differing TBN can be also used.
[0055] Preferred detergents include the alkali or alkaline earth
metal salts of sulfonates, phenates, carboxylates, phosphates, and
salicylates. Sulfonates may be prepared from sulfonic acids that
are typically obtained by sulfonation of alkyl substituted aromatic
hydrocarbons. Hydrocarbon examples include those obtained by
alkylating benzene, toluene, xylene, naphthalene, biphenyl and
their halogenated derivatives (chlorobenzene, chlorotoluene, and
chloronaphthalene, for example). The alkylating agents typically
have about 3 to 70 carbon atoms. The alkaryl sulfonates typically
contain about 9 to about 80 carbon or more carbon atoms, more
typically from about 16 to 60 carbon atoms.
[0056] Klamann in "Lubricants and Related Products", op cit
discloses a number of overbased metal salts of various sulfonic
acids which are useful as detergents and dispersants in lubricants.
The book entitled "Lubricant Additives", C. V. Smallheer and R. K.
Smith, published by the Lezius-Hiles Co. of Cleveland, Ohio (1967),
similarly discloses a number of overbased sulfonates that are
useful as dispersants/detergents.
[0057] 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.
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. 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.
[0058] 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 following
structure:
##STR00001##
[0059] In Structure 1 above, R is a hydrogen atom or an alkyl group
having 1 to about 30 carbon atoms, n is an integer from 1 to 4, and
M is an alkaline earth metal. Preferred R groups are alkyl chains
of at least C11, preferably C13 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.
[0060] 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.
[0061] Alkaline earth metal phosphates may also be used as
detergents.
[0062] 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, for example.
[0063] Preferred detergents may include calcium phenates, calcium
sulfonates, calcium salicylates, magnesium phenates, magnesium
sulfonates, magnesium salicylates and other related components
(including borated detergents). Typically, the total detergent
concentration is about 0.01 to about 6.0 wt %, or 0.01 to 4 wt %,
or 0.01 to 3 wt %, or 0.01 to 2.2 wt %, or 0.01 to 1.5 wt % and
preferably, about 0.1 to 3.5 wt %.
Antioxidants
[0064] 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.
[0065] Useful antioxidants may include hindered phenols. These
phenolic antioxidants may be ashless (metal-free) phenolic
compounds or neutral or basic metal salts of certain phenolic
compounds. Typical phenolic antioxidant compounds are the hindered
phenolics which are the ones which contain a sterically hindered
hydroxyl group, and these include those derivatives of dihydroxy
aryl compounds in which the hydroxyl groups are in the o- or
p-position to each other. Typical phenolic antioxidants include the
hindered phenols substituted with C.sub.6+ alkyl groups and the
alkylene coupled derivatives of these hindered phenols. Examples of
phenolic materials of this type 2-t-butyl-4-heptyl phenol;
2-t-butyl-4-octyl phenol; 2-t-butyl-4-dodecyl phenol;
2,6-di-t-butyl-4-heptyl phenol; 2,6-di-t-butyl-4-dodecyl phenol;
2-methyl-6-t-butyl-4-heptyl phenol; and
2-methyl-6-t-butyl-4-dodecyl phenol. Other useful hindered
mono-phenolic antioxidants may include for example hindered
2,6-di-alkyl-phenolic proprionic ester derivatives. Bis-phenolic
antioxidants may also be advantageously used in combination with
the instant invention. 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).
[0066] Non-phenolic oxidation inhibitors which may be used include
aromatic amine antioxidants and these may be used either as such or
in combination with phenolics. Typical examples of non-phenolic
antioxidants include: alkylated and non-alkylated aromatic amines
such as aromatic monoamines of the formula R.sup.8R.sup.9R.sup.10N
where R.sup.8 is an aliphatic, aromatic or substituted aromatic
group, R.sup.9 is an aromatic or a substituted aromatic group, and
R.sup.10 is H, alkyl, aryl or R.sup.11S(O).sub.XR.sup.12 where
R.sup.11 is an alkylene, alkenylene, or aralkylene group, R.sup.12
is a higher alkyl group, or an alkenyl, aryl, or alkaryl group, and
x is 0, 1 or 2. The aliphatic group R.sup.8 may contain from 1 to
about 20 carbon atoms, and preferably contains from about 6 to 12
carbon atoms. The aliphatic group is a saturated aliphatic group.
Preferably, both R.sup.8 and R.sup.9 are aromatic or substituted
aromatic groups, and the aromatic group may be a fused ring
aromatic group such as naphthyl. Aromatic groups R.sup.8 and
R.sup.9 may be joined together with other groups such as
sulfur.
[0067] Typical aromatic amines antioxidants have alkyl substituent
groups of at least about 6 carbon atoms. Examples of aliphatic
groups include hexyl, heptyl, octyl, nonyl, and decyl. Generally,
the aliphatic groups will not contain more than about 14 carbon
atoms. The general types of amine antioxidants useful in the
present compositions include diphenylamines, phenyl naphthylamines,
phenothiazines, imidodibenzyls and diphenyl phenylene diamines.
Mixtures of two or more aromatic amines are also useful. Polymeric
amine antioxidants can also be used. Particular examples of
aromatic amine antioxidants useful in the present invention
include: p,p'-dioctyldiphenylamine;
t-octylphenyl-alpha-naphthylamine; phenyl-alphanaphthylamine; and
p-octylphenyl-alpha-naphthylamine. Sulfurized alkyl phenols and
alkali or alkaline earth metal salts thereof may also be useful
antioxidants.
[0068] Preferred antioxidants include hindered phenols, arylamines.
These antioxidants may be used individually by type or in
combination with one another.
[0069] Antioxidants may be used in an amount of about 0.01 to 5 wt
%, preferably about 0.01 to 1.5 wt %, more preferably zero to less
than 1.5 wt %, most preferably zero, based on the total weight of
the engine oil lubricant.
Pour Point Depressants
[0070] Conventional pour point depressants (also known as lube oil
flow improvers) may be added to the compositions of the present
invention if desired. These pour point depressant may be added to
lubricating compositions of the present invention to lower the
minimum temperature at which the fluid will flow or can be poured.
Examples of suitable pour point depressants include
polymethacrylates, polyacrylates, polyarylamides, condensation
products of haloparaffin waxes and aromatic compounds, vinyl
carboxylate polymers, and terpolymers of dialkylfumarates, vinyl
esters of fatty acids and allyl vinyl ethers. U.S. Pat. Nos.
1,815,022; 2,015,748; 2,191,498; 2,387,501; 2,655,479; 2,666,746;
2,721,877; 2,721,878; and 3,250,715 describe useful pour point
depressants and/or the preparation thereof. Such additives may be
used in an amount of about 0.01 to 5 wt %, preferably about 0.01 to
1.5 wt %, based on the total weight of the engine oil
lubricant.
Corrosion Inhibitors (CI)
[0071] One or more corrosion inhibitors may be added to the
lubricating oil compositions. Corrosion inhibitors are additives
that protect lubricated metal surfaces against chemical attack by
water or other contaminants. Corrosion inhibitors may also be used
to reduce the degradation of metallic parts that are in contact
with the lubricating oil composition. As used herein, corrosion
inhibitors include anti-rust additives, metal deactivators, and
metal passivators.
[0072] One type of corrosion inhibitor is a polar compound that
wets the metal surface preferentially, protecting it with a film of
oil. Another type of corrosion inhibitor absorbs water by
incorporating it in a water-in-oil emulsion so that only oil
touches the metal surface. Yet another type of corrosion inhibitor
chemically adheres to the metal to produce a non-reactive surface.
Suitable corrosion inhibitors include organic salts including zinc
dithiophosphates, metal phenolates, neutral metal sulfonates (e.g.,
calcium sulfonate, magnesium sulfonate, barium sulfonate, zinc
sulfonate, etc.), metal naphthenates (e.g., zinc naphthenate,
barium naphthenate, calcium naphthenate, magnesium naphthenate,
etc.), fatty acids and amines. Other suitable corrosion inhibitors
include, for example, aryl thiazines, alkyl substituted
dimercaptothiodiazoles, alkyl substituted dimercaptothiadiazoles,
thiazoles, triazoles, non-ionic polyoxyalkylene polyols and esters
thereof, polyoxyalkylene phenols, anionic alkyl sulfonic acids, and
the like, and mixtures thereof.
[0073] Illustrative corrosion inhibitors may include, for example,
(short-chain) alkyl and alkenyl succinic acids, partial esters
thereof and nitrogen-containing derivatives thereof; and petroleum
sulfonates, synthetic sulfonates, synthetic alkarylsulfonates, such
as metal alkylbenzene sulfonates, and metal dinonylnaphthalene
sulfonates. Corrosion inhibitors also include, for example,
monocarboxylic acids which have from 8 to 30 carbon atoms, alkyl or
alkenyl succinates or partial esters thereof, hydroxy-fatty acids
which have from 12 to 30 carbon atoms and derivatives thereof,
sarcosines which have from 8 to 24 carbon atoms and derivatives
thereof, amino acids and derivatives thereof, naphthenic acid and
derivatives thereof, lanolin fatty acid, mercapto-fatty acids and
paraffin oxides.
[0074] Particularly preferred corrosion inhibitors include, for
example, monocarboxylic acids (C.sub.8-C.sub.30), caprylic acid,
pelargonic acid, decanoic acid, undecanoic acid, lauric acid,
myristic acid, palmitic acid, stearic acid, arachic acid, behenic
acid, cerotic acid, montanic acid, melis sic acid, oleic acid,
docosanic acid, erucic acid, eicosenic acid, beef tallow fatty
acid, soy bean fatty acid, coconut oil fatty acid, linolic acid,
linoleic acid, tall oil fatty acid, 12-hydroxystearic acid,
laurylsarcosinic acid, myritsylsarcosinic acid, palmitylsarcosinic
acid, stearylsarcosinic acid, oleylsarcosinic acid, alkylated
(C.sub.8-C.sub.20) phenoxyacetic acids, lanolin fatty acid and
C.sub.8-C.sub.24 mercapto-fatty acids.
[0075] Examples of polybasic carboxylic acids which function as
corrosion inhibitors include alkenyl (C.sub.10-C.sub.100) succinic
acids and ester derivatives thereof, dimer acid,
N-acyl-N-alkyloxyalkyl aspartic acid esters (U.S. Pat. No.
5,275,749). Examples of the alkylamines which function as corrosion
inhibitors or as reaction products with the above carboxylates to
give amides and the like are represented by primary amines such as
laurylamine, coconut-amine, n-tridecylamine, myristylamine,
n-pentadecylamine, palmitylamine, n-heptadecylamine, stearylamine,
n-nonadecylamine, n-eicosylamine, n-heneicosylamine,
n-docosylamine, n-tricosylamine, n-pentacosylamine, oleylamine,
beef tallow-amine, hydrogenated beef tallow-amine and soy
bean-amine. Examples of the secondary amines include dilaurylamine,
di-coconut-amine, di-n-tri decyl amine, dimyristylamine,
di-n-pentadecylamine, dipalmitylamine, di-n-pentadecylamine,
distearylamine, di-n-nonadecylamine, di-n-eicosylamine,
di-n-heneicosylamine, di-n-docosylamine, di-n-tricosylamine,
di-n-pentacosyl-amine, dioleylamine, di-beef tallow-amine,
di-hydrogenated beef tallow-amine and di-soy bean-amine. Examples
of the aforementioned alkylenediamines, alkylated alkylenediamines,
and N-alkylpolyalkyenediamines include: ethylenediamines such as
laurylethylenediamine, coconut ethylenediamine,
n-tridecylethylenediamine-, myristylethylenediamine,
n-pentadecylethylenediamine, palmitylethylenediamine,
n-heptadecylethylenediamine, stearylethylenediamine,
n-nonadecylethylenediamine, n-eicosylethylenediamine,
n-heneicosylethylenediamine, n-docosylethylendiamine,
n-tricosylethylenediamine, n-pentacosylethylenediamine,
oleylethylenediamine, beef tallow-ethylenediamine, hydrogenated
beef tallow-ethylenediamine and soy bean-ethylenediamine;
propylenediamines such as laurylpropylenediamine, coconut
propylenediamine, n-tridecylpropylenediamine,
myristylpropylenediamine, n-pentadecylpropylenediamine,
palmitylpropylenediamine, n-heptadecylpropylenediamine,
stearylpropylenediamine, n-nonadecylpropylenediamine,
n-eicosylpropylenediamine, n-heneicosylpropylenediamine,
n-docosylpropylendiamine, n-tricosylpropylenediamine,
n-pentacosylpropylenediamine, diethylene triamine (DETA) or
triethylene tetramine (TETA), oleylpropylenediamine, beef
tallow-propylenediamine, hydrogenated beef tallow-propylenediamine
and soy bean-propylenediamine; butylenediamines such as
laurylbutylenediamine, coconut butylenediamine,
n-tridecylbutylenediamine-myristylbutylenediamine,
n-pentadecylbutylenediamine, stearylbutylenediamine,
n-eicosylbutylenediamine, n-heneicosylbutylenedia-mine,
n-docosylbutylendiamine, n-tricosylbutylenediamine,
n-pentacosylbutylenediamine, oleylbutylenediamine, beef
tallow-butylenediamine, hydrogenated beef tallow-butylenediamine
and soy bean butylenediamine; and pentylenediamines such as
laurylpentylenediamine, coconut pentylenediamine,
myristylpentylenediamine, palmitylpentylenediamine,
stearylpentylenediamine, oleyl-pentylenediamine, beef
tallow-pentylenediamine, hydrogenated beef tallow-pentylenediamine
and soy bean pentylenediamine.
[0076] Other illustrative corrosion inhibitors include
2,5-dimercapto-1,3,4-thiadiazoles and derivatives thereof,
mercaptobenzothiazoles, alkyltriazoles and benzotriazoles. Examples
of dibasic acids useful as corrosion inhibitors, which are used in
the present disclosure, are sebacic acid, adipic acid, azelaic
acid, dodecanedioic acid, 3-methyladipic acid, 3-nitrophthalic
acid, 1,10-decanedicarboxylic acid, and fumaric acid. The corrosion
inhibitors may be a straight or branch-chained, saturated or
unsaturated monocarboxylic acid or ester thereof which are
optionally sulfurized in an amount up to 35 wt %. Preferably the
acid is a C.sub.4 to C.sub.22 straight chain unsaturated
monocarboxylic acid. The preferred concentration of this additive
is from 0.001 wt % to 0.35 wt % of the total lubricant composition.
The preferred monocarboxylic acid is sulfurized oleic acid.
Alternatively, other suitable materials include oleic acid itself,
valeric acid and erucic acid. An illustrative corrosion inhibitor
includes a triazole as previously defined. The triazole should be
used at a concentration from 0.005 wt % to 0.25 wt % of the total
composition. The preferred triazole is tolylotriazole which is
suitably included in the compositions of the disclosure. Also
suitably included in compositions are triazoles, thiazoles and
certain diamine compounds which are useful as metal deactivators or
metal passivators. Examples include triazole, benzotriazole and
substituted benzotriazoles such as alkyl substituted derivatives.
The alkyl substituent generally contains up to 15 carbon atoms,
preferably up to 8 carbon atoms. The triazoles optionally contain
other substituents on the aromatic ring such as halogens, nitro,
amino, mercapto, etc. Examples of suitable compounds are
benzotriazole and the tolyltriazoles, ethylbenzotriazoles,
hexylbenzotriazoles, octylbenzotriazoles, chlorobenzotriazoles and
nitrobenzotriazoles. Benzotriazole and tolyltriazole are
particularly preferred. A straight or branched chain saturated or
unsaturated monocarboxylic acid which is optionally sulfurized in
an amount which is up to 35 wt %; or an ester of such an acid; and
a triazole or alkyl derivatives thereof, or short chain alkyl of up
to 5 carbon atoms; n is zero or an integer between 1 and 3
inclusive; and is hydrogen, morpholino, alkyl, amido, amino,
hydroxy or alkyl or aryl substituted derivatives thereof; or a
triazole selected from 1,2,4 triazole, 1,2,3 triazole,
5-anilo-1,2,3,4-thiatriazole, 3-amino-1,2,4 triazole,
1-H-benzotriazole-1-yl-methylisocyanide,
methylene-bis-benzotriazole and naphthotriazole.
[0077] Other illustrative corrosion inhibitors may include
2-mercaptobenzothiazole, dialkyl-2,5-dimercapto-1,3,4-thiadiazole;
N,N'-disalicylideneethylenediamine,
N,N'-disalicylidenepropylenediamine, N-salicylideneethylamine,
N,N'-disalicylideneethyldiamine; triethylenediamine,
ethylenediaminetetraacetic acid; zinc dialkyldithiophosphates and
dialkyl dithiocarbamates, and the like.
[0078] Other illustrative corrosion inhibitors may include a yellow
metal passivator. The term "yellow metal" refers to a metallurgical
grouping that includes, for example, brass and bronze alloys,
aluminum bronze, phosphor bronze, copper, copper nickel alloys, and
beryllium copper, and the like. Typical yellow metal passivators
include, for example, benzotriazole, tolutriazole, tolyltriazole,
mixtures of sodium tolutriazole and tolyltriazole, imidazole,
benzimidazole, imidazoline, pyrimidine, and derivatives thereof,
and combinations thereof. In one particular and non-limiting
embodiment, a compound containing tolyltriazole is selected.
[0079] The one or more metal corrosion inhibitors may be present in
amounts ranging from about 0.01 wt % to about 5.0 wt %, preferably
about 0.01 wt % to about 3.0 wt %, and more preferably from about
0.01 wt % to about 1.5 wt %, based on the total weight of the
engine oil lubricant composition.
Seal Compatibility Agents
[0080] Seal compatibility agents help to swell elastomeric seals by
causing a chemical reaction in the fluid or physical change in the
elastomer. Suitable seal compatibility agents for lubricating oils
include organic phosphates, aromatic esters, aromatic hydrocarbons,
esters (butylbenzyl phthalate, for example), and polybutenyl
succinic anhydride. Such additives may be used in an amount of
about 0.01 to 3 wt %, preferably about 0.01 to 2 wt %, based on the
total weight of the engine oil lubricant.
Anti-Foam
[0081] 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 wt % and
often less than 0.1 wt %, based on the total weight of the engine
oil lubricant composition.
[0082] When lubricating oil compositions contain any 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. Illustrative amounts of such additives that can be used
in the engine oil lubricants described herein are shown in Table 1
below.
[0083] Note that many of the additives are shipped from the
manufacturer and used with a certain amount of base oil diluent in
the formulation. Accordingly, the weight amounts in Table 2, as
well as other amounts mentioned in this specification, are directed
to the amount of active ingredient (that is the non-diluent portion
of the ingredient). The wt % indicated below are based on the total
weight of the lubricating oil composition.
TABLE-US-00002 TABLE 2 Typical Amounts of Various Lubricant Oil
Components Approximate Approximate Compound wt % (Useful) wt %
(Preferred) Detergent 0.01-6 0.01-4.sup. Dispersant 0.1-20 0.1-8
Friction Modifier 0.01-5 0.01-1.5 Viscosity Modifier (solid 0.1-8
0.1-6 polymer basis) Antioxidant 0.1-5 0.1-2.0 Anti-wear Additive
0.01-6 0.01-4.sup. Pour Point Depressant 0.0-5 0.01-1.5 Anti-foam
Agent 0.001-3 0.001-0.15 Steel Corrosion Inhibitor 0.001-1
0.001-0.5 Base stock or base oil Balance Balance
[0084] The foregoing additives may be added independently or may be
pre-combined 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. The additive package may be
incorporated into the engine oil lubricant compositions at loadings
of about 9 wt % to about 15 wt %, or about 10 wt % to about 14.5 wt
%, or about 11 wt % to about 14 wt %, based on the total weight of
the lubricant composition.
Examples
[0085] The foregoing discussion can be further described with
reference to the following non-limiting examples. In the examples
that follow, the effects on fuel economy and thus CO.sub.2
emissions of 0.5 wt % sulfated ash 5W-30 base formulations (i.e.
"low ash" formulations) were studied using an organic friction
modifier in combination with different detergents and corrosion
inhibitors.
[0086] Two 0.5 wt % sulfated ash 5W-30 base formulations were
prepared, Base Formulation 1 ("BF1") and Base Formulation 2
("BF2"). BF1 and BF2 were identical except that BF2 further
included 0.7 wt % of a mixed glyceride friction modifier. Both BF1
and BF2 were formulated with a 64 mg KOH/g ASTM D2896 TBN calcium
salicylate detergent (2.3% Ca) as the only detergent additive.
Table 3 summarizes the BF1 and BF2 formulations as well as the
measured ash content and fuel economies for each.
TABLE-US-00003 TABLE 3 Lubricant formulation and fuel economy test
results Base Formulation 1 Base Formulation 2 ("BF1") ("BF2") Base
oil, wt % 77.34 76.64 Mixed Glyceride Friction 0.7 Modifier, wt %
64 mg KOH/g Calcium 4.4 4.4 Salicylate Detergent, wt % Other
Additives, wt % 18.26 18.26 KV100, ASTM D445, cSt 11.3 10.9
HTHS150, ASTM D4683, cP 3.18 3.25 CCS-35C, ASTM D5293, cP 6975 7280
ASTM D5185 Ca, ppm 1000 1000 ASTM D5185 B, ppm 92 92 ASTM D5185 Mg,
ppm 0 0 ASTM D5185 Mo, ppm 180 180 ASTM D5185 Zn, ppm 830 830 ASTM
D5185 P, ppm 770 770 ASTM D874 Ash, wt % 0.51 0.51 ASTM D8114 VIE
FEI 1, % 1.4 2.1 ASTM D8114 VIE FEI 2, % 2.9 4.6
[0087] The ash content was measured according to ASTM D874.
Sulfated ash values were calculated using the following factors
(F): Ca--3.4, Mg--4.95, B--3.22, Zn--1.25, Mo--1.5. where
calculated sulfated ash is given by Equation 1.
Calculated Sulfated Ash (weight %)=.SIGMA.M.sub.iF.sub.i Eq. 1
[0088] Where M.sub.i equals the metal concentration in weight % and
F.sub.i equals the sulfated ash factor for the metal.
[0089] Table 3 shows that the presence of the mixed glyceride
friction modifier in BF2 produced a significant increase in fuel
economy, as measured by the ASTM-D8114 Sequence VIE fuel economy
test in the presence of the 64 mg KOH/g ASTM D2896 TBN calcium
salicylate detergent. The initial fuel economy (FEI 1) and aged
fuel economy (FEI 2) of BF2 with the 0.7 wt % of a mixed glyceride
friction modifier increased significantly compared to BF1 (having
none of the mixed glyceride friction modifier). Such significant
increase in fuel economy necessarily results in significantly
reduced CO.sub.2 emissions.
[0090] Eight different corrosion inhibitors (Additives 1 to 8) were
then added to the BF2 formulation to determine effects on corrosion
protection as determined by ASTM D6557. Additive 1 was an
imidazoline, which is a reaction product of oleic acid and
amino-ethyl 2-ethylhexyl amine, and has no pendent organic acid
groups.
[0091] Additives 2, 3, and 7 contained organic acid groups.
Specifically, Additive 2 was an imidazoline reaction product of
oleic acid and amino-ethyl 2-ethylhexyl amine plus free oleic acid.
Additive 3 was a C16 alkylated succinic anhydride reacted with 1,3
propane diol. Additive 7 was an ashless ester/amide/carboxylate
having the following structure:
##STR00002##
[0092] Additives 4, 5, 6, and 8 were organic salts (organo-metallic
molecules) having ASTM D2896 total base numbers (TBN) less than 3
mg KOH/g. Specifically, Additive 4 was a barium salt of dinonyl,
naphthylenesulfonic acid having a ASTM D2896 TBN of less than 1 mg
KOH/g and a Ba content of 6.65 wt %. Additive 5 was zinc
dinonylnaphthalene sulfonate having a ASTM D2896 TBN of 1.9 mg
KOH/g and a Zn content of 2.9 wt %. Additive 6 was zinc naphthenate
having a ASTM D2896 TBN of 2.9 mg KOH/g and a Zn content of 10 wt
%. Additive 8 was calcium dinonylnaphthalene sulfonate having a
ASTM D2896 TBN of less than 1 mg KOH/g and a Ca content of 2.1 wt
%.
[0093] Table 4 summarizes the lubricant formulations and ball rust
test results measured according to ASTM D6557. All weights are wt %
based on the total weight of the lubricant.
TABLE-US-00004 TABLE 4 Formulation Summary for ASTM D6557 BRT
Testing (AGV). TABLE 4 ADDITIVE BF2 1 2 3 4 5 6 7 8 BRT AGV CEx.1
100 33 CEx.2 99.5 0.5 19 CEx.3 99.0 1.00 40 Ex.1 99.95 0.05 72 Ex.2
99.8 0.20 76 Ex.3 99.5 0.5 76 Ex.4 99.0 1.00 60 Ex.5 99.95 0.05 62
Ex.6 99.8 0.20 62 Ex.7 99.5 0.5 77 Ex.8 99.0 1.00 79 Ex.9 99.5 0.50
66 Ex.10 99.0 1.00 57 Ex.11 99.5 0.50 74 Ex.12 99.0 1.00 82 Ex.13
99.95 0.05 74 Ex.14 99.8 0.20 74 Ex.15 99.5 0.5 76 Ex.16 99.0 1.00
88 Ex.17 99.95 0.05 52 Ex.18 99.8 0.20 60 Ex.19 99.5 0.5 70 Ex.20
99.0 1.00 52 Ex.21 99.95 0.05 74 Ex.22 99.8 0.20 74 Ex.23 99.5 0.5
68 Ex.24 99.0 1.00 65
[0094] The ASTM D6557 steel corrosion performance for Base
Formulation 2 was 33 AGV. This is considered a poor result;
however, this is not unexpected because the formulation ash level
of 0.5% was low. As seen in Table 4 above, the addition of 1 wt %
of the Additives 1 to 8 to Base Formulation 2 improved the steel
corrosion performance (AGV) to 40, 60, 79, 57, 82, 88, 52, and 65,
respectively. The AGV results with Additives 2 through 8 were
significantly improved. Only the 0.5 wt % addition of Additive 1
did not improve the steel corrosion performance (AGV decreased to
19).
[0095] The addition of 0.5 wt % of each Additive 1 to 8 changed the
AGV results to 19, 76, 77, 66, 74, 76, 70, and 68 AGV respectively.
Additive 1 did not improve the corrosion performance. The results
for Additives 2 through 8 were significant improvements.
[0096] The addition of 0.2 wt % of Additives 2, 3, 6, 7, and 8
significantly improved the AGV results to 76, 69, 64, 60, and 74
AGV respectively.
[0097] The addition of 0.05 wt % of Additives 2, 3, 6, 7, and 8
changed the AGV results to 72, 62, 74, 52, and 74 AGV respectively,
which are significant improvements and similar to the improvements
gained by the 0.2 wt % addition of these same additives.
[0098] Two other detergents were studied in combination with
Additive 3 (C16 alkylated succinic anhydride, reacted with 1,3
propane diol) in a 0.5 wt % sulfated ash 5W-30 base formulation
("BF3"). In these examples, BF3 was similar to BF2, except the 64
mg KOH/g TBN calcium salicylate detergent in BF2 was replaced with
a 405 mg KOH/g TBN magnesium sulfonate detergent and a 300 mg KOH/g
TBN calcium sulfonate detergent in the amounts reported below in
Table 5. The 405 mg KOH/g TBN magnesium sulfonate detergent
contained 9.1 wt % Mg and the 300 mg KOH/g TBN calcium sulfonate
detergent contained 11.6 wt % Ca. The amount of each detergent was
selected to provide a sulfated ash value of 0.5% to the fully
formulated lubricant. To these formulations, 0.05 wt % of Additive
3 was used.
TABLE-US-00005 TABLE 5 Alternate Detergent Combinations Evaluated
in the BRT CEx.4 CEx.5 CEx.6 Ex.25 Ex.26 Ex.27 Base oil, wt % 80.28
80.17 80.23 80.23 80.12 80.18 Mixed Glyceride 0.7 0.7 0.7 0.7 0.7
0.7 Friction Modifier, wt % Other additives, wt % 18.26 18.26 18.26
18.26 18.26 18.26 Additive 3, wt % 0.05 0.05 0.05 Mg Sulfonate, 405
TBN, wt % 0.76 0.38 0.76 0.38 Ca Sulfonate, 300 TBN, wt % 0.87 0.43
0.87 0.43 BRT AGV, % 41 29 33 47 35 39
[0099] These additives were then tested to determine their
effectiveness on corrosion protection as determined by the ASTM
D6557 ball rust test (ASTM D6557 BRT).
[0100] With the 405 mg KOH/g TBN magnesium sulfonate detergent
(CEx.4), the BRT result was 41. Adding 0.05 wt % of Additive 3 (Ex.
25) increased the BRT result from 41 to 47 AGV. With the 300 mg
KOH/g TBN calcium sulfonate detergent (CEx.5), the BRT result was
29. Adding 0.05 wt % of Additive 3 (Ex.26) increased the BRT result
from 29 to 35 AGV. With a mix of the 405 mg KOH/g TBN magnesium
sulfonate detergent and the 300 TBN calcium sulfonate detergent
(CEx.6), the BRT result was 33. Adding 0.05 wt % of Additive 3
(Ex.27) increased the BRT result from 33 to 39 AGV.
[0101] These formulations show the additives that provided a BRT
benefit for the Ca salicylate (Ex. 1 to 24) also provided a benefit
for either Mg sulfonate (Ex. 25), Ca sulfonate (Ex. 26), or a mix
of Mg sulfonate and Ca sulfonate (Ex. 27). This is a significant
benefit for formulating engine oils with all magnesium or calcium
or a mix of magnesium and calcium.
[0102] It was also unexpected that the organic salt
(organo-metallic) naphthalene additives (Additives 4, 5, 6, and 8)
with very low TBN values (less than 3 mg KOH/g) were effective in
the ball rust test that is performed in the presence of organic and
inorganic acids. TBN is often associated with the ability to
neutralize the acidic species to prevent corrosion. The higher the
TBN value, the better the ability to neutralize the acidity.
Because the TBN of Additives 4, 5, 6, and 8 were less than 3 mg
KOH/g, and those additives caused an increase in BRT results means
these improvements were not from acid neutralization, which was
nothing short of surprising and unexpected.
[0103] Even more unexpected was that Additives 2, 3, and 7 provided
effective BRT results of 19 or more. Additives 2, 3, and 7
contained organic acid groups, which are known to promote corrosion
such as lead corrosion. It was nothing short of surprising and
unexpected that Additives 2, 3, and 7 with organic acid groups
provided effective corrosion results in the presence of a calcium
salicylate detergent and mixed glyceride friction modifier, which
exhibited excellent fuel economy and thus lower CO.sub.2
emissions.
[0104] Certain embodiments and features have been described using a
set of numerical upper limits and a set of numerical lower limits.
It should be appreciated that ranges including the combination of
any two values, e.g., the combination of any lower value with any
upper value, the combination of any two lower values, and/or the
combination of any two upper values are contemplated unless
otherwise indicated. Certain lower limits, upper limits and ranges
appear in one or more claims below. All numerical values are
"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.
[0105] Various terms have been defined above. To the extent a term
used in a claim can be not defined above, it should be given the
broadest definition persons in the pertinent art have given that
term as reflected in at least one printed publication or issued
patent. Furthermore, all patents, test procedures, and other
documents cited in this application are fully incorporated by
reference to the extent such disclosure can be not inconsistent
with this application and for all jurisdictions in which such
incorporation can be permitted.
[0106] While certain preferred embodiments of the present invention
have been illustrated and described in detail above, it can be
apparent that modifications and adaptations thereof will occur to
those having ordinary skill in the art. It should be, therefore,
expressly understood that such modifications and adaptations may be
devised without departing from the basic scope thereof, and the
scope thereof can be determined by the claims that follow.
* * * * *
References