Note: Descriptions are shown in the official language in which they were submitted.
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HIGH EFFICIENCY ENGINE OIL COMPOSITIONS
Inventors: Hisanari ONOUCHI and Isao TANAKA
Applicant: Chevron Japan Ltd.
FIELD OF THE DISCLOSURE
[0001] The present disclosure relates to lubricating oil compositions for
internal combustion
engines wherein the compositions offer improved fuel economy.
BACKGROUND AND SUMMARY
[0002] Many different lubricating compositions have been tried in the prior
art. Unfortunately,
prior art lubricating oils often include added friction modifiers which have
been discovered to
sometimes cause detrimental effects on the vehicle's engine. Such detrimental
effects may
include, for example, increased deposit formation, increased seal failure,
and/or decreased seal
life. In addition, if friction modifiers are present in the oil with, for
example, certain anti-wear
additives, then the friction modifier may at least partially out-compete the
anti-wear additive
for limited surface sites. This could result in increased engine component
wear because anti-
wear films are not formed on at least some surfaces in need of wear
protection.
[0003] What is needed are new cost-effective and efficient lubricating oil
compositions that
improve fuel economy. It would be desirable if such lubricating oil
compositions did not need
to employ friction modifiers that may negatively impact performance.
[0004] Advantageously, the present application pertains to low viscosity
lubricating oil
compositions that may significantly improve fuel economy and do not include
significant
amounts of added friction modifiers. In one embodiment, the application
pertains to a
lubricating oil composition for an internal combustion engine which exhibits
improved fuel
economy comprising a major amount of oil of lubricating viscosity, an alkaline
earth metal
sulfonate detergent providing 1200-2200ppm of metal to the lubricating oil
composition, and
a comb-shaped polymethacrylate viscosity modifier having a PSSI of less than
15. The
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lubricating oil composition may be an OW-8, an OW-12, an OW-16, or an OW-20
SAE viscosity
grade; be substantially free of a friction modifier; and may have a viscosity
index of greater
than 200.
[0005] In another embodiment the application relates to a method for improving
fuel economy
in an internal combustion engine comprising lubricating said engine with the
aforementioned
lubricating oil compositions and, if desired, operating said engine for
improved fuel economy.
DETAILED DESCRIPTION
Definitions
[0006] The following terms will be used throughout the specification and will
have the
following meanings unless otherwise indicated.
[0007] The term "a major amount" of oil of lubricating viscosity refers to
where the amount of
base oil is at least 40 wt. % of the lubricating oil composition. In some
embodiments, "a major
amount" refers to an amount of the base oil more than 50 wt. %, more than 60
wt. %, more
than 70 wt. %, more than 80 wt. %, or more than 90 wt. % of the lubricating
oil composition.
[0008] In the following description, all numbers disclosed herein are
approximate values,
regardless of whether the word "about" or "approximate" is used in connection
therewith. They
may vary by 1 percent, 2 percent, 5 percent, or, sometimes, 10 to 20 percent.
[0009] The term "internal combustion engine" refers to any engine in which the
combustion
of a fuel occurs with an oxidizer in a combustion chamber which is a component
of a working
fluid flow circuit. Internal combustion engines are employed in hybrid
vehicles and often
operate at lower temperatures than internal combustion engines on traditional
vehicles.
[0010] "HOB" refers to high overbased with a TBN above 250 on an actives basis
and "LOB"
refers to low overbased with a TBN below 100 on an actives basis.
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[0011] The term "Total Base Number" or "TBN" refers to the level of alkalinity
in an oil
sample, which indicates the ability of the composition to continue to
neutralize corrosive acids,
in accordance with ASTM Standard No. D2896 or equivalent procedure. The test
measures
the change in electrical conductivity, and the results are expressed as
mgKOH/g (the equivalent
number of milligrams of KOH needed to neutralize 1 gram of a product).
Therefore, a high
TBN reflects strongly overbased products and, as a result, a higher base
reserve for neutralizing
acids.
[0012] Commonly used friction modifiers in engine oil application can be
categorized into two:
organic friction modifier such as glycerol monooleate and inorganic friction
modifier such as
molybdenum dithiocarbamates. There are many different types of organic or
inorganic friction
modifiers. Typically, organic friction modifiers are used in 0.1-1wt% range
while inorganic
modifier are in 100-1000ppm metal concentration range. The term "substantially
free" means
less than 0.1wt% for organic friction modifiers or less than 100ppm metal
concentration when
used in connection with "substantially free" of a friction modifier.
The Oil of Lubricating Viscosity
[0013] The lubricating oil compositions disclosed herein generally comprise at
least one oil of
lubricating viscosity. Any base oil known to a skilled artisan can be used as
the oil of
lubricating viscosity disclosed herein. Some base oils suitable for preparing
the lubricating oil
compositions have been described in Mortier et al., "Chemistry and Technology
of Lubricants,"
2nd Edition, London, Springer, Chapters 1 and 2 (1996); and A. Sequeria, Jr.,
"Lubricant Base
Oil and Wax Processing," New York, Marcel Decker, Chapter 6, (1994); and D. V.
Brock,
Lubrication Engineering, Vol. 43, pages 184-5, (1987), all of which are
incorporated herein by
reference.
[0014] Generally, the amount of the base oil in the lubricating oil
composition is a "a major
amount" of oil of lubricating viscosity as defined above.
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[0015] In certain embodiments, the base oil is or comprises any natural or
synthetic lubricating
base oil fraction. Some non-limiting examples of synthetic oils include oils,
such as
polyalphaolefins or PA0s, prepared from the polymerization of at least one
alpha-olefin, such
as ethylene, or from hydrocarbon synthesis procedures using carbon monoxide
and hydrogen
gases, such as the Fisher-Tropsch process.
[0016] In some embodiments, the base oil has a kinematic viscosity at 100 C.
from about 2.5
centistokes (cSt) to about 20 cSt, from about 4 centistokes (cSt) to about 20
cSt, or from about
cSt to about 16 cSt. The kinematic viscosity of the base oils or the
lubricating oil
compositions disclosed herein can be measured according to ASTM D 445, which
is
incorporated herein by reference.
[0017] In other embodiments, the base oil is or comprises a base stock or
blend of base stocks.
In further embodiments, the base stocks are manufactured using a variety of
different processes
including, but not limited to, distillation, solvent refining, hydrogen
processing,
oligomerization, esterification, and rerefining. In some embodiments, the base
stocks comprise
a rerefined stock. In further embodiments, the rerefined stock shall be
substantially free from
materials introduced through manufacturing, contamination, or previous use.
[0018] In some embodiments, the base oil comprises one or more of the base
stocks in one or
more of Groups I-V as specified in the American Petroleum Institute (API)
Publication 1509,
Fourteen Edition, December 1996 (i.e., API Base Oil Interchangeability
Guidelines for
Passenger Car Motor Oils and Diesel Engine Oils), which is incorporated herein
by reference.
The API guideline defines a base stock as a lubricant component that may be
manufactured
using a variety of different processes. Groups I, II and III base stocks are
mineral oils, each
with specific ranges of the amount of saturates, sulfur content and viscosity
index. Group IV
base stocks are polyalphaolefins (PAO). Group V base stocks include all other
base stocks not
included in Group I, II, III, or IV.
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[0019] In some embodiments, the base oil comprises one or more of the base
stocks in Group
I, II, III, IV, V or a combination thereof In other embodiments, the base oil
comprises one or
more of the base stocks in Group II, III, IV or a combination thereof. In
further embodiments,
the base oil comprises one or more of the base stocks in Group II, III, IV or
a combination
thereof wherein the base oil has a kinematic viscosity from about 2.5
centistokes (cSt) to about
20 cSt, from about 4 cSt to about 20 cSt, or from about 5 cSt to about 16 cSt
at 100 C.
[0020] The base oil may be selected from the group consisting of natural oils
of lubricating
viscosity, synthetic oils of lubricating viscosity and mixtures thereof In
some embodiments,
the base oil includes base stocks obtained by isomerization of synthetic wax
and slack wax, as
well as hydrocrackate base stocks produced by hydrocracking (rather than
solvent extracting)
the aromatic and polar components of the crude. In other embodiments, the base
oil of
lubricating viscosity includes natural oils, such as animal oils, vegetable
oils, mineral oils (e.g.,
liquid petroleum oils and solvent treated or acid-treated mineral oils of the
paraffinic,
naphthenic or mixed paraffinic-naphthenic types), oils derived from coal or
shale, and
combinations thereof Some non-limiting examples of animal oils include bone
oil, lanolin,
fish oil, lard oil, dolphin oil, seal oil, shark oil, tallow oil, and whale
oil. Some non-limiting
examples of vegetable oils include castor oil, olive oil, peanut oil, rapeseed
oil, corn oil, sesame
oil, cottonseed oil, soybean oil, sunflower oil, safflower oil, hemp oil,
linseed oil, Lung oil,
oiticica oil, jojoba oil, and meadow foam oil. Such oils may be partially or
fully hydrogenated.
[0021] In some embodiments, the synthetic oils of lubricating viscosity
include hydrocarbon
oils and halo-substituted hydrocarbon oils such as polymerized and inter-
polymerized olefins,
alkylbenzenes, polyphenyls, alkylated diphenyl ethers, alkylated diphenyl
sulfides, as well as
their derivatives, analogues and homologues thereof, and the like. In other
embodiments, the
synthetic oils include alkylene oxide polymers, interpolymers, copolymers and
derivatives
thereof wherein the terminal hydroxyl groups can be modified by
esterification, etherification,
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and the like. In further embodiments, the synthetic oils include the esters of
dicarboxylic acids
with a variety of alcohols. In certain embodiments, the synthetic oils include
esters made from
C5 to C12 monocarboxylic acids and polyols and polyol ethers. In further
embodiments, the
synthetic oils include tri-alkyl phosphate ester oils, such as tri-n-butyl
phosphate and tri-iso-
butyl phosphate.
[0022] In some embodiments, the synthetic oils of lubricating viscosity
include silicon-based
oils (such as the polyakyl-, polyaryl-, polyalkoxy-, polyaryloxy-siloxane oils
and silicate oils).
In other embodiments, the synthetic oils include liquid esters of phosphorus-
containing acids,
polymeric tetrahydrofurans, polyalphaolefins, and the like.
[0023] Base oil derived from the hydroisomerization of wax may also be used,
either alone or
in combination with the aforesaid natural and/or synthetic base oil. Such wax
isomerate oil is
produced by the hydroisomerization of natural or synthetic waxes or mixtures
thereof over a
hydroisomerization catalyst.
[0024] In further embodiments, the base oil comprises a poly-alpha-olefin
(PAO). In general,
the poly-alpha-olefins may be derived from an alpha-olefin having from about 2
to about 30,
from about 4 to about 20, or from about 6 to about 16 carbon atoms. Non-
limiting examples
of suitable poly-alpha-olefins include those derived from octene, decene,
mixtures thereof, and
the like. These poly-alpha-olefins may have a viscosity from about 2 to about
15, from about
3 to about 12, or from about 4 to about 8 centistokes at 100 C. In some
instances, the poly-
alpha-olefins may be used together with other base oils such as mineral oils.
[0025] In further embodiments, the base oil comprises a polyalkylene glycol or
a polyalkylene
glycol derivative, where the terminal hydroxyl groups of the polyalkylene
glycol may be
modified by esterification, etherification, acetylation and the like. Non-
limiting examples of
suitable polyalkylene glycols include polyethylene glycol, polypropylene
glycol,
polyisopropylene glycol, and combinations thereof Non-limiting examples of
suitable
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polyalkylene glycol derivatives include ethers of polyalkylene glycols (e.g.,
methyl ether of
polyisopropylene glycol, diphenyl ether of polyethylene glycol, diethyl ether
of polypropylene
glycol, etc.), mono- and polycarboxylic esters of polyalkylene glycols, and
combinations
thereof In some instances, the polyalkylene glycol or polyalkylene glycol
derivative may be
used together with other base oils such as poly-alpha-olefins and mineral
oils.
[0026] In further embodiments, the base oil comprises any of the esters of
dicarboxylic acids
(e.g., phthalic acid, succinic acid, alkyl succinic acids, alkenyl succinic
acids, maleic acid,
azelaic acid, suberic acid, sebacic acid, fumaric acid, adipic acid, linoleic
acid dimer, malonic
acid, alkyl malonic acids, alkenyl malonic acids, and the like) with a variety
of alcohols (e.g.,
butyl alcohol, hexyl alcohol, dodecyl alcohol, 2-ethylhexyl alcohol, ethylene
glycol, diethylene
glycol monoether, propylene glycol, and the like). Non-limiting examples of
these esters
include dibutyl adipate, di(2-ethylhexyl) sebacate, di-n-hexyl fumarate,
dioctyl sebacate,
diisooctyl azelate, diisodecyl azelate, dioctyl phthalate, didecyl phthalate,
dieicosyl sebacate,
the 2-ethylhexyl diester of linoleic acid dimer, and the like.
[0027] In further embodiments, the base oil comprises a hydrocarbon prepared
by the Fischer-
Tropsch process. The Fischer-Tropsch process prepares hydrocarbons from gases
containing
hydrogen and carbon monoxide using a Fischer-Tropsch catalyst. These
hydrocarbons may
require further processing in order to be useful as base oils. For example,
the hydrocarbons
may be dewaxed, hydroisomerized, and/or hydrocracked using processes known to
a person of
ordinary skill in the art.
[0028] In further embodiments, the base oil comprises an unrefined oil, a
refined oil, a
rerefined oil, or a mixture thereof Unrefined oils are those obtained directly
from a natural or
synthetic source without further purification treatment. Non-limiting examples
of unrefined
oils include shale oils obtained directly from retorting operations, petroleum
oils obtained
directly from primary distillation, and ester oils obtained directly from an
esterification process
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and used without further treatment. Refined oils are similar to the unrefined
oils except the
former have been further treated by one or more purification processes to
improve one or more
properties. Many such purification processes are known to those skilled in the
art such as
solvent extraction, secondary distillation, acid or base extraction,
filtration, percolation, and
the like. Rerefined oils are obtained by applying to refined oils processes
similar to those used
to obtain refined oils. Such rerefined oils are also known as reclaimed or
reprocessed oils and
often are additionally treated by processes directed to removal of spent
additives and oil
breakdown products.
Alkaline Earth Metal Sulfonate Detergent
[0029] The lubricating oil compositions typically comprise an alkaline earth
metal sulfonate
detergent. The alkaline earth metal sulfonate detergent is not particularly
limited but in some
embodiments comprises magnesium sulfonate detergent, a calcium sulfonate
detergent, or a
mixture thereof In some embodiments the sulfonate detergent may be at least
partially
replaced or supplemented with a phenate based detergent.
[0030] The amount and type of alkaline earth metal sulfonate and/or phenate
detergent may
vary but typically is selected to provide at least about 1200, or at least
about 1300, or at least
about 1400 ppm of metal to the lubricating oil composition. On the other hand,
the amount
and type of alkaline earth metal sulfonate detergent is usually selected to
provide less than
about 2200, or less than about 2100, or less than about 2000 ppm of metal to
the lubricating oil
composition.
[0031] The lubricating oil composition may comprise a second detergent in
addition to the
alkaline earth metal detergent described above so long as the second detergent
does not
negatively affect the enhanced fuel efficiency of the compositions. Some non-
limiting
examples of suitable metal detergent include sulfurized or unsulfurized alkyl
or alkenyl
phenates, alkyl or alkenyl aromatic sulfonates, borated sulfonates, sulfurized
or unsulfurized
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metal salts of multi-hydroxy alkyl or alkenyl aromatic compounds, alkyl or
alkenyl hydroxy
aromatic sulfonates, sulfurized or unsulfurized alkyl or alkenyl naphthenates,
metal salts of
alkanoic acids, metal salts of an alkyl or alkenyl multiacid, and chemical and
physical mixtures
thereof Other non-limiting examples of suitable metal detergents include metal
sulfonates,
phenates, salicylates, phosphonates, thiophosphonates and combinations thereof
The metal
can be any metal suitable for making sulfonate, phenate, salicylate or
phosphonate detergents.
Non-limiting examples of suitable metals include alkali metals, alkaline
metals and transition
metals. In some embodiments, the metal is Ca, Mg, Ba, K, Na, Li or the like.
[0032] Some suitable detergents have been described in Mortier et al.,
"Chemistry and
Technology of Lubricants," 2nd Edition, London, Springer, Chapter 3, pages 75-
85 (1996); and
Leslie R. Rudnick, "Lubricant Additives: Chemistry and Applications," New
York, Marcel
Dekker, Chapter 4, pages 113-136 (2003), both of which are incorporated herein
by reference.
[0033] The detergent may comprise at least one high overbased (TBN above 250
on an actives
basis) sulfonate detergent such as high overbased calcium sulfonate and at
least one non-
sulfonate detergent such as a phenate detergent.
[0034] Additional detergents that may be used include oil-soluble overbased
sulfonate, non-
sulfonate containing phenate, sulfurized phenates, salixarate, salicylate,
saligenin, complex
detergents and naphthenate detergents and other oil-soluble
alkylhydroxybenzoates of a metal,
particularly the alkali or alkaline earth metals, e.g., barium, sodium,
potassium, lithium,
calcium, and magnesium. The most commonly used metals are calcium and
magnesium, which
may both be present in detergents used in a lubricant, and mixtures of calcium
and/or
magnesium with sodium.
[0035] Overbased metal detergents are generally produced by carbonating a
mixture of
hydrocarbons, detergent acid, for example: sulfonic acid, alkylhydroxybenzoate
etc., metal
oxide or hydroxides (for example calcium oxide or calcium hydroxide) and
promoters such as
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xylene, methanol and water. For example, for preparing an overbased calcium
sulfonate, in
carbonation, the calcium oxide or hydroxide reacts with the gaseous carbon
dioxide to form
calcium carbonate. The sulfonic acid is neutralized with an excess of CaO or
Ca(OH)2, to form
the sulfonate.
[0036] Overbased detergents may be low overbased, e.g., an overbased salt
having a TBN
below 100 on an actives basis. In one aspect, the TBN of a low overbased salt
may be from
about from about 10, from about 20, or from about 30 to about 100. In another
aspect, the TBN
of a low overbased salt may be from about 30 to about 80. Overbased detergents
may be
medium overbased, e.g., an overbased salt having a TBN from about 100 to about
250 on an
actives basis. In one aspect, the TBN of a medium overbased salt may be from
about 100 to
about 200. In another aspect, the TBN of a medium overbased salt may be from
about 125 to
about 175. Overbased detergents may be high overbased, e.g., an overbased salt
having a TBN
above 250 on an actives basis. In one aspect, the TBN of a high overbased salt
may be from
about 250 to about 800 on an actives basis.
[0037] In one aspect, the detergent can be one or more alkali or alkaline
earth metal salts of an
alkyl-substituted hydroxyaromatic carboxylic acid. Suitable hydroxyaromatic
compounds
include mononuclear monohydroxy and polyhydroxy aromatic hydrocarbons having 1
to 4,
and preferably 1 to 3, hydroxyl groups. Suitable hydroxyaromatic compounds
include phenol,
catechol, resorcinol, hydroquinone, pyrogallol, cresol, and the like.
Non-dispersant Comb Polymethacrylate
[0038] The non-dispersant comb polymethacrylate (comb PMA) is a comb-shaped
polymer
that can be used as a viscosity modifier or viscosity index improver. In one
embodiment the
comb PMA used herein has a Permanent Shear Stability Index (PSSI) of less than
15, or less
than 10, or less than 5, or less than 1 according to A5TMD7109(Kurt Orbahn
Shear Stability).
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[0039] In one embodiment, the non-dispersant comb PMA has a weight average
molecular
weight (Mw) of 300,000 g/mol to 600,000 g/mol, 350,000 g/mol to 550,000 g/mol,
375,000
g/mol to 500,000 g/mol, or 390,000 g/mol to 460,000 g/mol.
[0040] In one embodiment, the non-dispersant comb PMA has a number average
molecular
weight (Mn) of 35,000 g/mol to 105,000 g/mol, 45,000 g/mol to 95,000 g/mol,
55,000 g/mol
to 85,000 g/mol, or 65,000 g/mol to 75,000 g/mol. In another embodiment, the
non-dispersant
comb PMA has a number average molecular weight (Mn) of 150,000 g/mol to
250,000 g/mol
or 200,000 g/mol to 215,000 g/mol.
[0041] In one embodiment, the non-dispersant comb PMA has a Shear Stability
Index (SSI) of
0.1 to 1.0, 0.2 to 0.9, or 0.3 to 0.8.
[0042] The non-dispersant comb PMA of the lubricating oil composition can be
described as
set forth in US 2017/0298287A1 and JP2019014802, the disclosures of which is
incorporated
herein by reference. The non-dispersant comb PMA can be provided by Viscoplex0
Viscosity
Index Improver 3-201 and/or 3-162, which are available from Evonik.
[0043] According to one embodiment, the non-dispersant comb PMA is provided by
the
compound referred to as Viscoplex0 3-201, which includes, as a main resin
component, a
comb PMA. This non-dispersant comb PMA has a weight average molecular weight
(Mw) of
420,000 g/mol, a number average molecular weight (Mn) of 70,946 g/mol, and a
Mw/Mn of
5.92. The compound has at least a constituent unit derived from a macromonomer
having a
Mn of 500 or more. The non-dispersant comb PMA is present in an amount of 19
wt. %, based
on the total weight of the compound.
[0044] According to another embodiment, the non-dispersant comb PMA is
provided by the
compound referred to as Viscoplex0 3-162, which also includes, as a main resin
component,
a comb PMA. This non-dispersant comb PMA has a weight average molecular weight
(Mw)
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of 399,292 g/mol, a number average molecular weight (Mn) of 205,952 g/mol, a
Mw/Mn of
1.94, and a Permanent Shear Stability Index (PSSI) of 0.6 as measured by ASTM
D7109.
[0045] According to another embodiment, the non-dispersant comb PMA is
provided by a
combination of compounds, for example a combination of the Viscoplex0 3-201
and the
Viscoplex0 3-162.
[0046] The non-dispersant comb PMA is typically present in an amount of 0.5
wt. % to 25 wt.
%, 1 wt. % to 20 wt. %, 2 wt. % to 18 wt. %, 4 wt. % to 16 wt. %, or 5 wt. %
to 15 wt. %, based
on the total weight of the lubricating oil composition.
[0047] It has been unexpectedly discovered that non-dispersant comb PMA
viscosity modifiers
provide enhanced performance compared to other viscosity modifiers such as
linear
poly(meth)acrylates (PMA), olefin copolymers (OCP), and hydrogenated star-
diene (HSD)
type viscosity index improvers. Linear poly(meth)acrylate viscosity modifiers
are generally
synthesized by simple free-radical copolymerization of a mixture of different
alkyl
methacrylates. Unlike comb-type PMAs, conventional linear PMAs are
characterized by
predominantly short alkyl chain lengths present (typically 1-50 carbons) and
the lack of long
alkyl chain macromonomers which give comb polymers their characteristic shape.
See U.S.
Patent Nos. 3,607,749 and 8,778,857, and European Patent 0225,598. Olefin
copolymer
viscosity modifiers typically comprise ethylene and propylene and in some
cases may contain
a diene as a third monomer. See, e.g., U.S. Patent Nos. 7,402,235 and
5,391,617, and European
Patent 0638,611. Hydrogenated styrene-diene type viscosity index improvers can
be prepared
by copolymerizing styrene and butadiene and hydrogenating the unsaturated
copolymers. The
hydrogenated styrene-diene copolymers can be linear block copolymers or star-
shaped. See
U.S. Pat. Nos. 4,116,917, 3,772,196 and 4,788,316 for examples of HSD
copolymers as
viscosity modifiers in lubricating oils.
Other Properties of the Lubrication Oil Compositions of the Present
Application
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[0048] The lubricating oil compositions of the present application are
generally either an OW-
8, an OW-12, an OW-16, or an OW-20 SAE viscosity grade.
[0049] The lubricating oil compositions generally have a viscosity index of
greater than about
200, or greater than about 205, or greater than about 210, or greater than
about 220, or greater
than about 240 up to about 270 or more.
[0050] The lubricating oil compositions generally improve fuel economy. The
degree of fuel
economy improvement (FEI as described below) may vary depending upon the
specific
lubricating oil composition, the engine employed, and other factors. In some
cases, the
compositions described herein exhibit a fuel economy improvement (FEI) of at
least about 1%,
or at least about 1.5%, or at least about 2% up to as much as 4% or higher.
Other Additives May Be Added that Are Consistent with the Above Ingredients
and
Properties
[0051] To the extent that it is consistent with the ingredients and properties
of the lubricating
composition described above, the lubricating oil composition may further
comprise at least an
additive or a modifier (hereinafter designated as "additive") that can impart
or improve any
desirable property of the lubricating oil composition. Any additive known to a
person of
ordinary skill in the art may be used in the lubricating oil compositions
disclosed herein. Some
suitable additives have been described in Mortier et al., "Chemistry and
Technology of
Lubricants," 2nd Edition. London, Springer, (1996); and Leslie R. Rudnick,
"Lubricant
Additives: Chemistry and Applications," New York, Marcel Dekker (2003), both
of which are
incorporated herein by reference. In some embodiments, the additive can be
selected from the
group consisting of antioxidants, antiwear agents, detergents, rust
inhibitors, demulsifiers,
friction modifiers, multi-functional additives, viscosity index improvers,
pour point
depressants, foam inhibitors, metal deactivators, dispersants, corrosion
inhibitors, lubricity
improvers, thermal stability improvers, anti-haze additives, icing inhibitors,
dyes, markers,
static dissipaters, biocides and combinations thereof
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[0052] A particularly suitable combination of additives comprises glycerol in
the amounts
described above, a dispersant additive such as ethylene carbonate post treated
bissuccinimide,
an antiwear additive such as zinc dialkyl diothiophosphate such as one derived
from a primary
alcohol, and a detergent composition as described above comprising at least
one high overbased
sulfonate detergent (e.g., a high overbased calcium sulfonate) and at least
one non-sulfonate
detergent (e.g., a phenate detergent). The zinc dialkyl dithiophosphate is a
primary,
secondary zinc dialkyl dithiophosphate, or a combination thereof and may be
present at 3 wt.
% or less (e.g., 0.1 to 1.5 wt. %, or 0.5 to 1.0 wt %) of the lubricating oil
composition. The
dispersant such as ethylene carbonate post treated bissuccinimide may be
present at 0.1 to 10
wt. % (e.g., 0.5 to 8, 0.7 to 7, 0.7 to 6, 0.7 to 6, 0.7 to 5, 0.7 to 4 wt.
%), based on the total
weight of the lubricating oil composition.
[0053] In general, the concentration of each of the additives in the
lubricating oil composition,
when used, may range from about 0.001 wt. % to about 10 wt. %, from about 0.01
wt. % to
about 5 wt. %, or from about 0.1 wt. % to about 2.5 wt. %, based on the total
weight of the
lubricating oil composition. Further, the total amount of the additives in the
lubricating oil
composition may range from about 0.001 wt. % to about 20 wt. %, from about
0.01 wt. % to
about 10 wt. %, or from about 0.1 wt. % to about 5 wt. %, based on the total
weight of the
lubricating oil composition.
Antiwear agents
[0054] Optionally, the lubricating oil composition disclosed herein can
comprise one or more
antiwear agents. Antiwear agents reduce wear of metal parts. Suitable anti-
wear agents include
dihydrocarbyl dithiophosphate metal salts such as zinc dihydrocarbyl
dithiophosphates
(ZDDP) of the following structure:
Zn[S-P(=S)(0R1)(0R2)12
wherein 12.' and R2 may be the same of different hydrocarbyl radicals having
from 1 to 18 (e.g.,
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2 to 12) carbon atoms and including radicals such as alkyl, alkenyl, aryl,
arylalkyl, alkaryl and
cycloaliphatic radicals. Particularly preferred as R' and R2 groups are alkyl
groups having
from 2 to 8 carbon atoms (e.g., the alkyl radicals may be ethyl, n-propyl,
isopropyl, n-butyl,
isobutyl, sec-butyl, n-pentyl, isopentyl, n-hexyl, isohexyl, 2-ethylhexyl). In
order to obtain oil
solubility, the total number of carbon atoms (i.e., R' + R2) will be at least
5. The zinc
dihydrocarbyl dithiophosphate can therefore comprise zinc dialkyl
dithiophosphates. The zinc
dialkyl dithiophosphate is a primary, secondary zinc dialkyl dithiophosphate,
or a combination
thereof ZDDP may be present at 3 wt. % or less (e.g., 0.1 to 1.5 wt. %, or 0.5
to 1.0 wt %) of
the lubricating oil composition.
Dispersants
[0055] Optionally, the lubricating oil composition disclosed herein can
further comprise a
dispersant. Dispersants maintain in suspension materials resulting from
oxidation during
engine operation that are insoluble in oil, thus preventing sludge
flocculation and precipitation
or deposition on metal parts. Dispersants useful herein include nitrogen-
containing, ashless
(metal-free) dispersants known to effective to reduce formation of deposits
upon use in gasoline
and diesel engines. Suitable dispersants include hydrocarbyl succinimides,
hydrocarbyl
succinamides, mixed ester/amides of hydrocarbyl-substituted succinic acid,
hydroxyesters of
hydrocarbyl-substituted succinic acid, and Mannich condensation products of
hydrocarbyl-
substituted phenols, formaldehyde and polyamines. Also suitable are
condensation products of
polyamines and hydrocarbyl-substituted phenyl acids. Mixtures of these
dispersants can also
be used.
[0056] Basic nitrogen-containing ashless dispersants are well-known
lubricating oil additives
and methods for their preparation are extensively described in the patent
literature. Preferred
dispersants are the alkenyl succinimides and succinamides where the alkenyl-
substituent is a
long-chain of preferably greater than 40 carbon atoms. These materials are
readily made by
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reacting a hydrocarbyl-substituted dicarboxylic acid material with a molecule
containing amine
functionality. Examples of suitable amines are polyamines such as polyalkylene
polyamines,
hydroxy-substituted polyamines and polyoxyalkylene polyamines. As is known in
the art, the
dispersants may be post-treated (e.g., with a boronating agent, ethylene
carbonate, or a cyclic
carbonate). Nitrogen-containing ashless (metal-free) dispersants are basic,
and contribute to
the TBN of a lubricating oil composition to which they are added, without
introducing
additional sulfated ash. Dispersants may be present at 0.1 to 10 wt. % (e.g.,
0.5 to 8, 0.7 to 7,
0.7 to 6, 0.7 to 6, 0.7 to 5, 0.7 to 4 wt. %), based on an actives level, of
the lubricating oil
composition. Nitrogen from the dispersants is present from greater than 0.0050
to 0.30 wt. %
(e.g., greater than 0.0050 to 0.10 wt. %, 0.0050 to 0.080 wt. %, 0.0050 to
0.060 wt. %, 0.0050
to 0.050 wt. %, 0.0050 to 0.040 wt. %, 0.0050 to 0.030 wt. %) based on the
weight of the
dispersants in the finished oil.
Antioxidants
[0057] Optionally, the lubricating oil composition disclosed herein can
further comprise an
additional antioxidant that can reduce or prevent the oxidation of the base
oil. Any antioxidant
known by a person of ordinary skill in the art may be used in the lubricating
oil composition.
Non-limiting examples of suitable antioxidants include amine-based
antioxidants (e.g., alkyl
diphenylamines, phenyl-.alpha.-naphthylamine, alkyl or aralkyl substituted
phenyl-.alpha.-
naphthylamine, alkylated p-phenylene diamines, tetramethyl-
diaminodiphenylamine and the
like), phenolic antioxidants (e.g., 2-tert-butylphenol, 4-methyl-2,6-di-tert-
butylphenol, 2,4,6-
tri-tert-butylphenol, 2,6-di-tert-butyl-p-cresol, 2,6-di-tert-butylphenol,
4,4'-methylenebis-(2,6-
di-tert-butylphenol), 4,4'-thiobis(6-di-tert-butyl-o-cresol) and the like),
sulfur-based
antioxidants (e.g., dilaury1-3,3'-thiodipropionate, sulfurized phenolic
antioxidants and the like),
phosphorous-based antioxidants (e.g., phosphites and the like), zinc
dithiophosphate, oil-
soluble copper compounds and combinations thereof. The amount of the
antioxidant may vary
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from about 0.01 wt. % to about 10 wt. %, from about 0.05 wt. % to about 5 wt.
%, or from
about 0.1 wt. % to about 3 wt. %, based on the total weight of the lubricating
oil composition.
Some suitable antioxidants have been described in Leslie R. Rudnick,
"Lubricant Additives:
Chemistry and Applications," New York. Marcel Dekker, Chapter 1, pages 1-28
(2003), which
is incorporated herein by reference.
Friction Modifiers
As described above, the lubricating oil compositions disclosed herein are
generally
substantially free of a friction modifier. "Substantially free" is defined
above as comprising
less than about 50 ppm. In some instances the lubricating oil compositions
disclosed herein
comprises less than about 25 ppm or even 0 ppm of a friction modifier.
Friction modifiers that
are typically excluded from the lubricating oil compositions disclosed herein
are fatty
carboxylic acids; derivatives (e.g.; alcohol, esters, borate(' esters, amides,
metal salts and the
like) of fatty carboxylic acid; mono-, di- or tri-alkyi substituted phosphoric
acids or phosphonic
acids; derivatives (e.g., esters, amides, metal salts and the like) of mono-,
di- or tri-alkyl
substituted phosphoric acids or phosphonic acids; mono-, di- or tri-alkyl
substituted arnines;
mono- or di-alkyl substituted amides; alkoxylated fatty amines; boratecl fatty
epmddes; fatty
phosphites; fatty epoxides, fatty amines, borated alkoxylated fatty amines,
metal salts of fatty
acids, fatty acid amides, glycerol esters, borate(' glycerol esters; fatty
imida.zolines; reaction
products of a C4 to C75, or a C6 to C24, or a C6E0 C20, fatty acid ester and a
nitrogen-containing
compound selected from the group consisting of ammonia, and an alkanolarnine;
molybdenum
dithiocarhamates (MoDTC); molybdenUIT3 dithiophosphates (MoDTP); mol-ybderium
amines;
molybdenum alcoholates; and molybdenum alcohol-am ides.%;
Pour Point Depressants
[0058] The lubricating oil composition disclosed herein can optionally
comprise a pour point
depressant that can lower the pour point of the lubricating oil composition.
Any pour point
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depressant known by a person of ordinary skill in the art may be used in the
lubricating oil
composition. Non-limiting examples of suitable pour point depressants
include
polymethacrylates, alkyl acrylate polymers, alkyl methacrylate polymers,
di(tetra-paraffin
phenol)phthalate, condensates of tetra-paraffin phenol, condensates of a
chlorinated paraffin
with naphthalene and combinations thereof In some embodiments, the pour point
depressant
comprises an ethylene-vinyl acetate copolymer, a condensate of chlorinated
paraffin and
phenol, polyalkyl styrene or the like. The amount of the pour point depressant
may vary from
about 0.01 wt. % to about 10 wt. %, from about 0.05 wt. % to about 5 wt. %, or
from about 0.1
wt. % to about 3 wt. %, based on the total weight of the lubricating oil
composition. Some
suitable pour point depressants have been described in Mortier et al.,
"Chemistry and
Technology of Lubricants," 2nd Edition, London, Springer, Chapter 6, pages 187-
189 (1996);
and Leslie R. Rudnick, "Lubricant Additives: Chemistry and Applications," New
York, Marcel
Dekker, Chapter 11, pages 329-354 (2003), both of which are incorporated
herein by reference.
Demulsifiers
[0059] The lubricating oil composition disclosed herein can optionally
comprise a demulsifier
that can promote oil-water separation in lubricating oil compositions that are
exposed to water
or steam. Any demulsifier known by a person of ordinary skill in the art may
be used in the
lubricating oil composition. Non-limiting examples of suitable demulsifiers
include anionic
surfactants (e.g., alkyl-naphthalene sulfonates, alkyl benzene sulfonates and
the like), nonionic
alkoxylated alkylphenol resins, polymers of alkylene oxides (e.g.,
polyethylene oxide,
polypropylene oxide, block copolymers of ethylene oxide, propylene oxide and
the like), esters
of oil soluble acids, polyoxyethylene sorbitan ester and combinations thereof
The amount of
the demulsifier may vary from about 0.01 wt. % to about 10 wt. %, from about
0.05 wt. % to
about 5 wt. %, or from about 0.1 wt. % to about 3 wt. %, based on the total
weight of the
lubricating oil composition. Some suitable demulsifiers have been described in
Mortier et al.,
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"Chemistry and Technology of Lubricants," 2nd Edition. London, Springer,
Chapter 6, pages
190-193 (1996), which is incorporated herein by reference.
Foam Inhibitors
[0060] The lubricating oil composition disclosed herein can optionally
comprise a foam
inhibitor or an anti-foam that can break up foams in oils. Any foam inhibitor
or anti-foam
known by a person of ordinary skill in the art may be used in the lubricating
oil composition.
Non-limiting examples of suitable anti-foams include silicone oils or
polydimethylsiloxanes,
fluorosilicones, alkoxylated aliphatic acids, polyethers (e.g., polyethylene
glycols), branched
polyvinyl ethers, alkyl acrylate polymers, alkyl methacrylate polymers,
polyalkoxyamines and
combinations thereof. In some embodiments, the anti-foam comprises glycerol
monostearate,
polyglycol palmitate, a trialkyl monothiophosphate, an ester of sulfonated
ricinoleic acid,
benzoylacetone, methyl salicylate, glycerol monooleate, or glycerol dioleate.
The amount of
the anti-foam may vary from about 0.01 wt. %to about 5 wt. %, from about 0.05
wt. % to about
3 wt. %, or from about 0.1 wt. % to about 1 wt. %, based on the total weight
of the lubricating
oil composition. Some suitable anti-foams have been described in Mortier et
al., "Chemistry
and Technology of Lubricants," 2nd Edition, London, Springer, Chapter 6, pages
190-193
(1996), which is incorporated herein by reference.
Corrosion Inhibitors
[0061] The lubricating oil composition disclosed herein can optionally
comprise a corrosion
inhibitor that can reduce corrosion. Any corrosion inhibitor known by a person
of ordinary
skill in the art may be used in the lubricating oil composition. Non-limiting
examples of
suitable corrosion inhibitor include half esters or amides of dodecylsuccinic
acid, phosphate
esters, thiophosphates, alkyl imidazolines, sarcosines and combinations
thereof The amount
of the corrosion inhibitor may vary from about 0.01 wt. % to about 5 wt. %,
from about 0.05
wt. % to about 3 wt. %, or from about 0.1 wt. % to about 1 wt. %, based on the
total weight of
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the lubricating oil composition. Some suitable corrosion inhibitors have been
described in
Mortier et al., "Chemistry and Technology of Lubricants," 2nd Edition, London,
Springer,
Chapter 6, pages 193-196 (1996), which is incorporated herein by reference.
Extreme Pressure Agents
[0062] The lubricating oil composition disclosed herein can optionally
comprise an extreme
pressure (EP) agent that can prevent sliding metal surfaces from seizing under
conditions of
extreme pressure. Any extreme pressure agent known by a person of ordinary
skill in the art
may be used in the lubricating oil composition. Generally, the extreme
pressure agent is a
compound that can combine chemically with a metal to form a surface film that
prevents the
welding of asperities in opposing metal surfaces under high loads. Non-
limiting examples of
suitable extreme pressure agents include sulfurized animal or vegetable fats
or oils, sulfurized
animal or vegetable fatty acid esters, fully or partially esterified esters of
trivalent or
pentavalent acids of phosphorus, sulfurized olefins, dihydrocarbyl
polysulfides, sulfurized
Diels-Alder adducts, sulfurized dicyclopentadiene, sulfurized or co-sulfurized
mixtures of fatty
acid esters and monounsaturated olefins, co-sulfurized blends of fatty acid,
fatty acid ester and
alpha-olefin, functionally-substituted dihydrocarbyl polysulfides, thia-
aldehydes, thia-ketones,
epithio compounds, sulfur-containing acetal derivatives, co-sulfurized blends
of terpene and
acyclic olefins, and polysulfide olefin products, amine salts of phosphoric
acid esters or
thiophosphoric acid esters and combinations thereof The amount of the extreme
pressure
agent may vary from about 0.01 wt. % to about 5 wt. %, from about 0.05 wt. %
to about 3 wt.
%, or from about 0.1 wt. % to about 1 wt. %, based on the total weight of the
lubricating oil
composition. Some suitable extreme pressure agents have been described in
Leslie R. Rudnick,
"Lubricant Additives: Chemistry and Applications," New York, Marcel Dekker,
Chapter 8,
pages 223-258 (2003), which is incorporated herein by reference.
Rust Inhibitors
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[0063] The lubricating oil composition disclosed herein can optionally
comprise a rust
inhibitor that can inhibit the corrosion of ferrous metal surfaces. Any rust
inhibitor known by
a person of ordinary skill in the art may be used in the lubricating oil
composition. Non-limiting
examples of suitable rust inhibitors include oil-soluble monocarboxylic acids
(e.g., 2-
ethylhexanoic acid, lauric acid, myristic acid, palmitic acid, oleic acid,
linoleic acid, linolenic
acid, behenic acid, cerotic acid and the like), oil-soluble polycarboxylic
acids (e.g., those
produced from tall oil fatty acids, oleic acid, linoleic acid and the like),
alkenylsuccinic acids
in which the alkenyl group contains 10 or more carbon atoms (e.g.,
tetrapropenylsuccinic acid,
tetradecenylsuccinic acid, hexadecenylsuccinic acid, and the like); long-chain
alpha,omega-
dicarboxylic acids having a molecular weight in the range of 600 to 3000
daltons and
combinations thereof The amount of the rust inhibitor may vary from about 0.01
wt. % to
about 10 wt. %, from about 0.05 wt. % to about 5 wt. %, or from about 0.1 wt.
% to about 3
wt. %, based on the total weight of the lubricating oil composition.
[0064] Other non-limiting examples of suitable rust inhibitors include
nonionic
polyoxyethylene surface active agents such as polyoxyethylene lauryl ether,
polyoxyethylene
higher alcohol ether, polyoxyethylene nonyl phenyl ether, polyoxyethylene
octyl phenyl ether,
polyoxyethylene octyl stearyl ether, polyoxyethylene oleyl ether,
polyoxyethylene sorbitol
monostearate, polyoxyethylene sorbitol mono-oleate, and polyethylene glycol
mono-oleate.
Further non-limiting examples of suitable rust inhibitor include stearic acid
and other fatty
acids, dicarboxylic acids, metal soaps, fatty acid amine salts, metal salts of
heavy sulfonic acid,
partial carboxylic acid ester of polyhydric alcohol, and phosphoric ester.
Multifunctional Additives
[0065] In some embodiments, the lubricating oil composition comprises at least
a
multifunctional additive. Some non-limiting examples of suitable
multifunctional additives
include sulfurized oxymolybdenum dithiocarbamate, sulfurized oxymolybdenum
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organophosphorodithioate, oxymolybdenum monoglyceride, oxymolybdenum
diethylate
amide, amine-molybdenum complex compound, and sulfur-containing molybdenum
complex
compound.
Viscosity Modifiers
[0066] In certain embodiments, the lubricating oil composition comprises at
least a viscosity
modifier. Some non-limiting examples of suitable viscosity modifiers
include
polymethacrylate type polymers, ethylene-propylene copolymers, styrene-
isoprene
copolymers, hydrated styrene-isoprene copolymers, polyisobutylene, and
dispersant type
viscosity modifiers.
Metal Deactivators
[0067] In some embodiments, the lubricating oil composition comprises at least
a metal
deactivator. Some non-limiting examples of suitable metal deactivators include
disalicylidene
propylenediamine, triazole derivatives, thiadiazole derivatives, and
mercaptobenzimidazoles.
Additive Concentrate Formulations
[0068] The additives disclosed herein may be in the form of an additive
concentrate having
more than one additive. The additive concentrate may comprise a suitable
diluent, such as a
hydrocarbon oil of suitable viscosity. Such diluent can be selected from the
group consisting
of natural oils (e.g., mineral oils), synthetic oils and combinations thereof
Some non-limiting
examples of the mineral oils include paraffin-based oils, naphthenic-based
oils, asphaltic-based
oils and combinations thereof Some non-limiting examples of the synthetic base
oils include
polyolefin oils (especially hydrogenated alpha-olefin oligomers), alkylated
aromatic,
polyalkylene oxides, aromatic ethers, and carboxylate esters (especially
diester oils) and
combinations thereof In some embodiments, the diluent is a light hydrocarbon
oil, both natural
or synthetic. Generally, the diluent oil can have a viscosity from about 13
centistokes to about
35 centistokes at 40° C.
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[0069] Generally, it is desired that the diluent readily solubilizes the
lubricating oil soluble
additive and provides an oil additive concentrate that is readily soluble in
the lubricant base oil
stocks or fuels. In addition, it is desired that the diluent not introduce any
undesirable
characteristics, including, for example, high volatility, high viscosity, and
impurities such as
heteroatoms, to the lubricant base oil stocks and thus, ultimately to the
finished lubricant or
fuel.
[0070] The present application further provides an oil soluble additive
concentrate composition
comprising an inert diluent and from 2.0% to 90% by weight, preferably 10% to
50% by weight
based on the total concentrate, of an oil soluble additive composition
according to the present
application.
[0071] The oil lubricating compositions comprising the additives described
above may be
employed in a method for improving fuel economy in an internal combustion
engine
comprising lubricating said engine with the lubricating oil composition
comprising the
additives and operating the engine.
[0072] The following examples are presented to exemplify embodiments but are
not intended
to limit the application to the specific embodiments set forth. Unless
indicated to the contrary,
all parts and percentages are by weight. All numerical values are approximate.
When
numerical ranges are given, it should be understood that embodiments outside
the stated ranges
may still fall within the scope of the application. Specific details described
in each example
should not be construed as necessary features.
Examples
[0073] The following examples are intended for illustrative purposes only and
do not limit in
any way the scope.
Example 1
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[0074] An SAE OW-8 lubricating oil was preparing by blending the following
components
together with a 2.5 cSt Group III base oil:
A) 3.5 wt% of a succinimide dispersant
B) 1700 ppm in terms of calcium content of an overbased calcium sulfonate
detergent
with a TBN of 410 mg KOH/g
C) 750 ppm in terms of phosphorus content of a secondary ZnDTP
D) 1.0 wt% of a phenolic antioxidant
E) 7.1 wt% of a comb-type PMA viscosity modifier
F) 5 ppm of a silicon-based foam inhibitor
The lubricating oil composition of example 1 had a KV100 of 4.34 cSt, a KV40
of 13.43, and
a viscosity index of 272.
Comparative Example 1
[0075] The lubricating oil of comparative example 1 was formulated identically
to example 1,
except that the comb-type PMA viscosity modifier was replaced with 3.78 wt% of
a linear
dispersant PMA viscosity modifier. The lubricating oil composition of
comparative example
1 had a KV100 of 4.80 cSt, a KV40 of 17.12, and a viscosity index of 226.
Comparative Example 2
[0076] The lubricating oil of comparative example 2 was formulated identically
to example 1,
except that the comb-type PMA viscosity modifier was replaced with 5.78 wt% of
a olefin
copolymer viscosity modifier. In addition, 0.40 wt% of a pour point depressant
was added.
The lubricating oil composition of comparative example 2 had a KV100 of 4.74
cSt, a KV40
of 19.65, and a viscosity index of 171.
Comparative Example 3
[0077] The lubricating oil of comparative example 3 was formulated identically
to example 1,
except that the calcium sulfonate detergent was replaced with an equal amount
(on a calcium
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basis) of calcium salicylate detergent with a TBN of 410 mg KOH/g. The
lubricating oil
composition of comparative example 3 had a KV100 of 4.37 cSt, a KV40 of 13.48,
and a
viscosity index of 275.
Comparative Example 4
[0078] The lubricating oil of comparative example 4 was formulated identically
to example 1,
except that in addition, 70ppm, in terms of boron, of a borated ester friction
modifier was
blended into the composition.
Comparative Example 5
[0079] The lubricating oil of comparative example 5 was formulated identically
to example 1,
except that in addition 660 ppm, in terms of molybdenum, of MoDTC was blended
into the
composition.
Example 2
[0080] The lubricating oil of example 2 was formulated identically to example
1, except that a
4 cSt Group III base oil was used instead to produce a lubricating oil
composition with an SAE
OW-16 viscosity grade. The lubricating oil composition of example 2 had a
KV100 of 6.29
cSt, a KV40 of 26.02, and a viscosity index of 208.
Comparative Example 6
[0081] The lubricating oil of comparative example 6 was formulated identically
to example 2,
except that the calcium sulfonate detergent was replaced with an equal amount
(on a calcium
basis) of calcium salicylate detergent with a TBN of 410 mg KOH/g. The
lubricating oil
composition of comparative example 6 had a KV100 of 6.32 cSt, a KV40 of 25.90,
and a
viscosity index of 211.
Fuel Economy Test in Toyota 2ZR-FXE (JASO M366)
[0082] The lubricating oil compositions above were tested for their fuel
economy performance
in a gasoline motored engine (Toyota 2ZR-FXE 1.8L L-4). The detailed
configuration of the
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test equipment and conditions can be found in SAE paper 2019-01-2296 Jikuya,
H., Mori, S.,
Yamamori, K., and Hirano, S., "Development of Firing Fuel Economy Engine Dyno
Test
Procedure for JASO Ultra Low Viscosity Engine Oil Standard (JASO GLV-1)," SAE
Technical Paper 2019-01-2296, 2019, which paper is hereby incorporated by
reference. The
test oils are pre-conditioned in the engine operating at 1350 rpm for 10 hours
at an oil
temperature of 88 C. The fuel consumption of the test oils are measured over
a 4-hour period,
and compared against the fuel consumption of a baseline calibration (BC) oil.
[0083] The BC oil used in the test method described above is different from
JASO BC oil and
the viscometric of the BC oil is shown below.
Typical value BC oil
KV100 (cSt) 7.5
KV40 (cSt) 43.4
HTHS150 (mPas) 2.6
HTHS100 (mPas) 6.0
[0084] The fuel economy improvement (FEI) is calculated for the candidate oil
test as relative
improvement (% change) to the average of two BC oils as shown below. A higher
FEI value
indicates overall better fuel economy performance.
[TFC = (1FCi X tPowerE-1 X [wt. Factoril)
-- No M Po w,e1-
TFC : Total Fuel Consumption (kg/h)
FCi : Fuel Consumption rate at stage-i (kg/h)
Power i : Actual Power Output at stage-i (kW)
Nom Power i : Nominal Power Output at stage-i (kW)
[FEI(0.4)1 . u=rFcti.CF31-1-1TFCBCAD 2--1TFCCANI
- 100
IITFCBC131-1-1TFCBCAD-#-2
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FEI : Fuel Economy Improvement (%)
TFCBCB : TFC of the BC oil before the candidate test oil (kg/h)
TFCCAN : TFC of the candidate test oil (kg/h)
TFCBCA : TFC of the BC oil after the candidate test oil (kg/h)
[0085] Table 1
Example 1 Comp. Comp. Comp. Comp. Comp. Example Comp. Ex.
Ex. 1 Ex. 2 Ex. 3 Ex. 4 Ex. 5 2 .. 6
SAE viscosity 0W-8 0W-8 0W-8 0W-8 0W-8 0W-8 0W-16 0W-
16
grade
Detergent Sulfonate Sulfonate Sulfonate Salicy late Sulfonate Sulfonate
Sulfonate Salicylate
Type
Moly from 0 0 0 0 0 660 0 0
FM (ppm)
Boated ester 0 0 0 0 0.3 0 0 0
friction
modifier
Viscosity Comb linear d. OCP Comb Comb Comb Comb Comb
Modifier PMA PMA PMA PMA PMA PMA PMA
KV100 4.34 4.80 4.74 4.37 4.36 4.45 6.29 6.32
KV40 13.43 17.12 19.65 13.48 13.48 13.67 26.02 ..
25.90
HTHS@ 74 1 . . 174
1.74 1.70 1.73 1.76 2.36 2.37
150 C
Toyota 2ZR 2.13 1.19 1.60 1.67 1.93 1.82 1.13 0.83
FXE FEI (%)
[0086] The FEI results of example 1 versus comparative examples 1 and 2 shows
that the comb
PMA gives better fuel economy compared to a linear dispersant PMA or an OCP
viscosity
modifier. Replacing the sulfonate with a salicylate detergent also resulted in
lower fuel
economy values, as shown by comparative example 3. Furthermore, a combination
of
sulfonate detergent and comb PMA in the absence of any additional FMs
outperforms
comparative example 4, which contains boron-based friction modifiers. It was
also
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CA 03234926 2024-04-10
WO 2023/084360
PCT/IB2022/060512
demonstrated that the combination of comb PMA and sulfonate without added FMs
(Example
2 vs Comparative Example 6) is effective in a higher viscosity formulation.
[0087] It will be understood that various modifications may be made to the
embodiments
disclosed herein. Therefore the above description should not be construed as
limiting, but
merely as exemplifications of preferred embodiments. For example, the
functions described
above and implemented for operating are for illustration purposes only. Other
arrangements
and methods may be implemented by those skilled in the art without departing
from the scope
and spirit of this application. Moreover, those skilled in the art will
envision other
modifications within the scope and spirit of the claims appended hereto.
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