U.S. patent application number 13/533259 was filed with the patent office on 2013-01-03 for low viscosity engine oil with superior engine wear protection.
This patent application is currently assigned to EXXONMOBIL RESEARCH AND ENGINEERING COMPANY. Invention is credited to Douglas Edward Deckman, Kevin John Kelly, Kristen A. Lyon, William L. Maxwell.
Application Number | 20130005622 13/533259 |
Document ID | / |
Family ID | 46466946 |
Filed Date | 2013-01-03 |
United States Patent
Application |
20130005622 |
Kind Code |
A1 |
Lyon; Kristen A. ; et
al. |
January 3, 2013 |
LOW VISCOSITY ENGINE OIL WITH SUPERIOR ENGINE WEAR PROTECTION
Abstract
An engine oil lubricant composition comprising a major amount of
base oil and an effective amount of a zinc dialkyl dithio
phosphate, a polymeric viscosity index improver and a mixture of
alkaline earth metal detergents provides improved fuel efficiency
while providing excellent wear in an engine.
Inventors: |
Lyon; Kristen A.; (West
Deptford, NJ) ; Kelly; Kevin John; (Mullica Hill,
NJ) ; Maxwell; William L.; (Pilesgrove, NJ) ;
Deckman; Douglas Edward; (Mullica Hill, NJ) |
Assignee: |
EXXONMOBIL RESEARCH AND ENGINEERING
COMPANY
Annandale
NJ
|
Family ID: |
46466946 |
Appl. No.: |
13/533259 |
Filed: |
June 26, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61502673 |
Jun 29, 2011 |
|
|
|
Current U.S.
Class: |
508/192 ;
508/369 |
Current CPC
Class: |
C10M 2215/28 20130101;
C10N 2040/253 20200501; C10M 2205/06 20130101; C10M 2205/04
20130101; C10N 2040/255 20200501; C10N 2020/02 20130101; C10M
2207/262 20130101; C10M 2219/046 20130101; C10M 2205/0285 20130101;
C10N 2030/06 20130101; C10M 2203/1025 20130101; C10M 2223/045
20130101; C10M 2205/022 20130101; C10N 2040/25 20130101; C10M
171/02 20130101; C10N 2030/54 20200501; C10N 2030/45 20200501; C10M
2207/2805 20130101; C10M 2223/045 20130101; C10N 2010/04 20130101;
C10M 2207/262 20130101; C10N 2010/04 20130101; C10M 2219/046
20130101; C10N 2010/04 20130101; C10M 2205/06 20130101; C10N
2020/073 20200501; C10N 2060/02 20130101; C10M 2205/04 20130101;
C10M 2205/06 20130101; C10M 2205/022 20130101; C10M 2205/024
20130101; C10M 2215/28 20130101; C10M 2215/28 20130101; C10M
2203/1025 20130101; C10N 2020/02 20130101; C10M 2203/1025 20130101;
C10N 2020/02 20130101; C10M 2223/045 20130101; C10N 2010/04
20130101; C10M 2207/262 20130101; C10N 2010/04 20130101; C10M
2219/046 20130101; C10N 2010/04 20130101; C10M 2205/06 20130101;
C10N 2020/073 20200501; C10N 2060/02 20130101 |
Class at
Publication: |
508/192 ;
508/369 |
International
Class: |
C10M 169/04 20060101
C10M169/04 |
Claims
1. An engine oil lubricant composition comprising a major amount of
base oil and an effective amount of a zinc dialkyl dithio
phosphate, a polymeric viscosity index improver and a mixture of
alkaline earth metal detergents, wherein said engine oil lubricant
composition has having a sulfated ash content of less than about
0.8 wt % and an HTHS of less than about 2.9 cP at 150.degree.
C.
2. The lubricant composition of claim 1, wherein the alkaline earth
metal detergents are selected from metallic salicylates and
sulfonates.
3. The lubricant composition of claim 2, wherein the metallic
salicylates and sulfonates are selected from calcium and
magnesium.
4. The lubricant composition of claim 1, wherein the polymeric
viscosity index improver has a weight average molecular weight
greater than about 500,000.
5. The lubricant composition of claim 4, wherein the polymeric
viscosity index improver has a number average molecular weight
greater than about 300,000.
6. The lubricant composition of claim 1, wherein the polymeric
viscosity index improver is selected from a hydrogenated star
polyisoprene, styrene-isoprene block co-polymer and
ethylene-propylene copolymer.
7. The lubricant composition of claim 1, wherein the ZDDP is a
secondary dialkyldithiophosphate.
8. The lubricant composition of claim 1, further comprising a
mixture of at least two dispersants wherein at least one dispersant
is a borated succinimide.
9. A engine oil lubricant composition comprising a major amount of
base oil and an effective amount of a zinc dialkyl dithio
phosphate, a polymeric viscosity modifier present in an amount of
less than about 1.0 wt % solid polymer content and a mixture of
detergents selected from salicylates and sulfonates, wherein said
engine oil lubricant composition has having a sulfated ash content
of less than about 0.8 wt %.
10. A method for improving fuel efficiency and wear in an engine,
said method comprising i) adding to said engine an engine oil
lubricant composition having a sulfated ash content of about 0.8%
wt % and an HTHS of about 2.9 cP at 150.degree. C., said lubricant
composition comprising a zinc dialkyl dithio phosphate, a polymeric
viscosity modifier and a mixture of alkaline earth metal
detergents.
11. The method of claim 10, wherein the alkaline earth metal
detergents are selected from metallic salicylates and
sulfonates.
12. The method of claim 11, wherein the metallic salicylates and
sulfonates are selected from calcium and magnesium.
13. The method of claim 10, wherein the polymeric viscosity index
improver has a weight average molecular weight greater than about
500,000.
14. The method of claim 13, wherein the polymeric viscosity index
improver has a number average molecular weight greater than about
300,000.
15. The method of claim 10, wherein the polymeric viscosity index
improver is selected from a hydrogenated star polyisoprene,
styrene-isoprene block co-polymer and ethylene-propylene
copolymer.
16. The method of claim 1, wherein the ZDDP is a secondary dialkyl
dithiophosphate.
17. The method of claim 1, further comprising a mixture of at least
two dispersants wherein at least one dispersant is a borated
succinimide.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to U.S. Provisional
Application Ser. No. 61/502,673 filed Jun. 29, 2011, herein
incorporated by reference in its entirety.
FIELD OF THE INVENTION
[0002] This invention relates to a lubricant oil composition having
a sulfated ash content of about 0.6 wt % and a high-temperature
high-shear (HTHS) viscosity of lower than 2.9 cP at 150.degree. C.
that provides excellent engine wear protection and improved fuel
efficiency and use thereof.
BACKGROUND OF THE INVENTION
[0003] Fuel efficiency requirements for passenger vehicles are
becoming increasingly more stringent. New legislation in the United
States and European Union within the past few years has set fuel
economy and emissions targets not readily achievable with today's
vehicle and lubricant technology. In order to improve lubricant
fuel economy performance, reduction of viscosity is typically the
best path; however, present day lubricant oils with a high
temperature high shear (HTHS) viscosity of less than 2.9 cP at
150.degree. C. would not be expected to be able to provide
acceptable passenger vehicle diesel engine durability
performance.
[0004] HTHS is the measure of a lubricant's viscosity under severe
engine conditions. Under high temperatures and high stress
conditions viscosity index improver degradation can occur. As this
happens, the viscosity of the oil decreases which may lead to
increased engine wear. HTHS is measured using ASTM D4683, which is
incorporated herein by reference.
[0005] In view of the more strict requirements, manufacturers are
moving towards the use of diesel engines. Diesel engines are more
prone to filter plugging due to high sulfated ash content of the
lubricant. For this reason, diesel engine vehicle manufacturers
generally recommend lubricants with reduced sulfated ash
levels.
[0006] Despite the advances in lubricant oil formulation
technology, there remains a need for an engine oil lubricant that
effectively improves fuel economy while providing superior antiwear
performance.
SUMMARY OF THE INVENTION
[0007] In accordance with a first aspect of the invention, there is
provided an engine oil lubricant composition comprising a major
amount of base oil and an effective amount of a zinc dialkyl dithio
phosphate, a polymeric viscosity index improver and a mixture of
alkaline earth metal detergents. The engine oil lubricant
composition has a sulfated ash content of less than about 0.8 wt %
and an HTHS of less than about 2.9 cP at 150.degree. C.
[0008] In another aspect of the invention, there is provided a
method for improving fuel efficiency and wear in an engine. The
method comprising adding to an engine, an engine oil lubricant
composition having a sulfated ash content of about 0.8 wt % and an
HTHS of about 2.9 cP at 150.degree. C. The lubricant composition
comprises a zinc dialkyl dithio phosphate, a polymeric viscosity
modifier and a mixture of alkaline earth metal detergents.
[0009] Other objects and advantages of the present invention will
become apparent from the detailed description that follows.
DETAILED DESCRIPTION
[0010] It has now been found that an engine oil lubricant
composition comprising a major amount of base oil and an effective
amount of a zinc dialkyl dithio phosphate, a polymeric viscosity
index improver and a mixture of alkaline earth metal detergents
provides improved fuel efficiency while providing excellent wear in
an engine. The engine oil lubricant composition has a sulfated ash
content of less than about 0.8 wt % and an HTHS of less than about
2.9 cP at 150.degree. C.
[0011] A wide range of lubricating base oils is known in the art.
Lubricating base oils that are useful in the present invention 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.
[0012] 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.API.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. The table
below it summarizes properties of each of these five groups.
Base Oil Properties
TABLE-US-00001 [0013] Base Oil Properties Saturates Sulfur
Viscosity 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
[0014] 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.
[0015] Group II and/or Group III hydroprocessed or hydrocracked
basestocks, including synthetic oils such as polyalphaolefins,
alkyl aromatics and synthetic esters are also well known basestock
oils.
[0016] 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.
[0017] The number average molecular weights of the PAOs, which are
known materials and generally available on a major commercial scale
from suppliers such as ExxonMobil Chemical Company, Chevron
Phillips Chemical Company, BP, and others, typically vary from
about 250 to about 3,000, although PAO's may be made in viscosities
up to about 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.
[0018] 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 U.S. Pat. No. 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.
[0019] 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 his-phenol A, alkylated thiodiphenol,
and the like. The aromatic can be mono-alkylated, dialkylated,
polyalkylated, and the like. The aromatic can be mono- or
poly-functionalized. The hydrocarbyl groups can also be comprised
of mixtures of alkyl groups, alkenyl groups, alkynyl, cycloalkyl
groups, cycloalkenyl groups and other related hydrocarbyl groups.
The hydrocarbyl groups can range from about C.sub.6 up to about
C.sub.60 with a range of about C.sub.8 to about C.sub.20 often
being preferred. A mixture of hydrocarbyl groups is often
preferred, and up to about three such substituents may be present.
The hydrocarbyl group can optionally contain sulfur, oxygen, and/or
nitrogen containing substituents. The aromatic group can also be
derived from natural (petroleum) sources, provided at least about
5% of the molecule is comprised of an above-type aromatic moiety.
Viscosities at 100.degree. C. of approximately 3 cSt to about 50
cSt are preferred, with viscosities of approximately 3.4 cSt to
about 20 cSt often being more preferred for the hydrocarbyl
aromatic component. In one embodiment, an alkyl naphthalene where
the alkyl group is primarily comprised of 1-hexadecene is used.
Other alkylates of aromatics can be advantageously used.
Naphthalene or methyl naphthalene, for example, can be alkylated
with olefins such as octene, decene, dodecene, tetradecene or
higher, mixtures of similar olefins, and the like. Useful
concentrations of hydrocarbyl aromatic in a lubricant oil
composition can be about 2% to about 25%, preferably about 4% to
about 20%, and more preferably about 4% to about 15%, depending on
the application.
[0020] 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.
[0021] 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 dipenta-erythritol) 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.
[0022] Suitable synthetic ester components include the esters of
trimethylol propane, trimethylol butane, trimethylol ethane,
pentaerythritol and/or dipenta-erythritol 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).
[0023] 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.
[0024] 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.
[0025] The base oil constitutes the major component of the engine
oil lubricant composition of the present invention and typically is
present in an amount ranging from about 50 to about 99 wt %, e.g.,
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
conveniently has a kinematic viscosity, according to ASTM
standards, of about 2.5 cSt to about 12 cSt (or mm.sup.2/s) at
100.degree. C. and preferably of about 2.5 cSt to about 9 cSt (or
mm.sup.2/s) at 100.degree. C. Mixtures of synthetic and natural
base oils may be used if desired.
[0026] The engine oil lubricant composition of the present
invention has an sulfated ash content of less than about 0.8 wt %
and an HTHS of less than about 2.9 cP at 150.degree. C., preferably
about 2.7 cP at 150.degree. C.
[0027] 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 dialkyldithio-phosphate 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 % of the total
lubricant composition.
[0028] 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".
[0029] 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.
[0030] 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.
[0031] 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.
[0032] 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.
[0033] 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 TEPA can vary from about 1:1 to about 5:1.
Representative examples are shown in U.S. Pat. Nos. 3,087,936;
3,172,892; 3,219,666; 3,272,746; 3,322,670; and 3,652,616,
3,948,800; and Canada Pat. No. 1,094,044.
[0034] 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.
[0035] Succinate ester amides are formed by condensation reaction
between alkenyl succinic anhydrides and alkanol amities. For
example, suitable alkanol amines include ethoxylated
polyalkylpolyamines, propoxylated polyalkylpoly-amines and
polyalkenylpolyamines such as polyethylene polyamines. One example
is propoxylated hexamethylenediamine. Representative examples are
shown in U.S. Pat. No. 4,426,305.
[0036] The molecular weight of the alkenyl succinic anhydrides used
in the preceding paragraphs will typically range between 800 and
2,500. 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.
[0037] Mannich base dispersants are made from the reaction of
alkylphenols, formaldehyde, and amines. See U.S. Pat. No.
4,767,551, which is incorporated herein by reference. Process aids
and catalysts, such as oleic acid and sulfonic acids, can also be
part of the reaction mixture. Molecular weights of the alkylphenols
range from 800 to 2,500. Representative examples are shown in U.S.
Pat. Nos. 3,697,574; 3,703,536; 3,704,308; 3,751,365; 3,756,953;
3,798,165; and 3,803,039.
[0038] 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.
[0039] 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.
[0040] Preferred dispersants include borated and non-borated
succinimides, including those derivatives from mono-succinimides,
bis-succinimides, and/or mixtures of mono- and bis-succinimides,
wherein the hydrocarbyl succinimide is derived from a
hydrocarbylene group such as polyisobutylene having a Mn of from
about 500 to about 5000 or 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 %.
[0041] Viscosity index improvers (also known as VI improvers,
viscosity modifiers, and viscosity improvers) provide lubricants
with high and low temperature operability. These additives impart
shear stability at elevated temperatures and acceptable viscosity
at low temperatures.
[0042] Suitable viscosity index improvers include high molecular
weight hydrocarbons, polyesters and viscosity index improver
dispersants that function as both a viscosity index improver and a
dispersant. Typical molecular weights of these polymers are between
about 10,000 to 1,000,000, more typically about 20,000 to 500,000,
and even more typically between about 50,000 and 200,000.
[0043] Examples of suitable viscosity index improvers are linear or
star-shaped polymers and copolymers of methacrylate, butadiene,
olefins, or alkylated styrenes. Polyisobutylene is a commonly used
viscosity index improver. Another suitable viscosity index improver
is polymethacrylate (copolymers of various chain length alkyl
methacrylates, for example), some formulations of which also serve
as pour point depressants. Other suitable viscosity index improvers
include copolymers of ethylene and propylene, hydrogenated block
copolymers of styrene and isoprene, and polyacrylates (copolymers
of various chain length acrylates, for example). Specific examples
include styrene-isoprene or styrene-butadiene based polymers of
50,000 to 200,000 molecular weight.
[0044] Olefin copolymers, are commercially available from Chevron
Oronite Company LLC under the trade designation "PARATONE.RTM."
(such as "PARATONE.RTM. 8921" and "PARATONE.RTM. 8941"); from Afton
Chemical Corporation under the trade designation "HiTEC.RTM." (such
as "HiTEC.RTM., 5850B"; and from The Lubrizol Corporation under the
trade designation "Lubrizol.RTM. 7067C". Polyisoprene polymers are
commercially available from Infineum International Limited, e.g.
under the trade designation "SV200"; diene-styrene copolymers are
commercially available from Infineum International Limited, e.g.
under the trade designation "SV 260".
[0045] Viscosity index improvers may be used in an amount of about
0.01 to 4 wt %, preferably about 0.01 to 2 wt %, on a solid polymer
basis.
[0046] 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.
[0047] Salts that contain a substantially stoichiometric amount of
the metal are described as neutral salts and have a total base
number (TBN, as measured by ASTM D2896) of from 0 to 80. Many
compositions are overbased, containing large amounts of a metal
base that is achieved by reacting an excess of a metal compound (a
metal hydroxide or oxide, for example) with an acidic gas (such as
carbon dioxide). Useful detergents can be neutral, mildly
overbased, or highly overbased.
[0048] It is desirable for at least some detergent to be overbased.
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 about 150 or higher, often about 250 to 450
or more. Preferably, the overbasing cation is sodium, calcium, or
magnesium. A mixture of detergents of differing TBN can be used in
the present invention.
[0049] Preferred detergents include the alkali or alkaline earth
metal salts of sulfonates, phenates, carboxylates, phosphates, and
salicylates.
[0050] 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.
[0051] 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 hook 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.
[0052] 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.
[0053] Metal salts of carboxylic acids are also useful as
detergents. These carboxylic acid detergents may be prepared by
reacting a basic metal compound with at least one carboxylic acid
and removing free water from the reaction product. These compounds
may be overbased to produce the desired TBN level. Detergents made
from salicylic acid are one preferred class of detergents derived
from carboxylic acids. Useful salicylates include long chain alkyl
salicylates. One useful family of compositions is of the
formula
##STR00001##
where 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
C.sub.11, preferably C.sub.13 or greater. R may be optionally
substituted with substituents that do not interfere with the
detergent's function. M is preferably, calcium, magnesium, or
barium. More preferably, M is calcium.
[0054] 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.
[0055] Alkaline earth metal phosphates are also used as
detergents.
[0056] 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.
[0057] Preferred detergents 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 %, preferably, about
0.1 to 3.5 wt %.
[0058] 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.
[0059] Useful antioxidants include hindered phenols. These phenolic
antioxidants may be ashless (metal-free) phenolic compounds or
neutral or basic metal salts of certain phenolic compounds. Typical
phenolic antioxidant compounds are the hindered phenolics which are
the ones which contain a sterically hindered hydroxyl group, and
these include those derivatives of dihydroxy aryl compounds in
which the hydroxyl groups are in the o- or p-position to each
other. Typical phenolic antioxidants include the hindered phenols
substituted with C.sub.6+ alkyl groups and the alkylene coupled
derivatives of these hindered phenols. Examples of phenolic
materials of this type 2-t-butyl-4-heptyl phenol; 2-t-butyl-4-octyl
phenol; 2-t-butyl-4-dodecyl phenol; 2,6-di-t-butyl-4-heptyl phenol;
2,6-di-t-butyl-4-dodecyl phenol; 2-methyl-6-t-butyl-4-heptyl
phenol; and 2-methyl-6-t-butyl-4-dodecyl phenol. Other useful
hindered mono-phenolic antioxidants may include for example
hindered 2,6-di-alkyl-phenolic proprionic ester derivatives.
Bis-phenolic antioxidants may also be advantageously used in
combination with the instant 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).
[0060] Non-phenolic oxidation inhibitors which may be used include
aromatic amine antioxidants and these may be used either as such or
in combination with phenolics. Typical examples of non-phenolic
antioxidants include: alkylated and non-alkylated aromatic amines
such as aromatic monoamines of the formula R.sup.8R.sup.9R.sup.10N
where R.sup.8 is an aliphatic, aromatic or substituted aromatic
group, R.sup.9 is an aromatic or a substituted aromatic group, and
R.sup.10 is H, alkyl, aryl or R.sup.11S(O).sub.XR.sup.12 where
R.sup.11 is an alkylene, alkenylene, or aralkylene group, R.sup.12
is a higher alkyl group, or an alkenyl, aryl, or alkaryl group, and
x is 0, 1 or 2. The aliphatic group R.sup.8 may contain from 1 to
about 20 carbon atoms, and preferably contains from about 6 to 12
carbon atoms. The aliphatic group is a saturated aliphatic group.
Preferably, both R.sup.8 and R.sup.9 are aromatic or substituted
aromatic groups, and the aromatic group may be a fused ring
aromatic group such as naphthyl. Aromatic groups R.sup.8 and
R.sup.9 may be joined together with other groups such as S.
[0061] 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.
[0062] Sulfurized alkyl phenols and alkali or alkaline earth metal
salts thereof also are useful antioxidants.
[0063] Preferred antioxidants include hindered phenols, arylamines.
These antioxidants may be used individually by type or in
combination with one another. Such additives may be used in an
amount of about 0.01 to 5 wt %, preferably about 0.01 to 1.5 wt %,
more preferably zero to less than 1.5 wt %, most preferably
zero.
[0064] 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
poly-methacrylates, 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 %.
[0065] 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 %.
[0066] 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 percent and
often less than 0.1 percent.
[0067] A friction modifier is any material or materials that can
alter the coefficient of friction of a surface lubricated by any
lubricant or fluid containing such material(s). Friction modifiers,
also known as friction reducers, or lubricity agents or oiliness
agents, and other such agents that change the ability of base oils,
formulated lubricant compositions, or functional fluids, to modify
the coefficient of friction of a lubricated surface may be
effectively used in combination with the base oils or lubricant
compositions of the present 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 Mo, Sb, Sn, Fe, Cu, Zn, and others. 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 O, N, S, or P, individually or in
combination. In particular, Mo-containing compounds can be
particularly effective such as for example Mo-dithiocarbamates,
Mo(DTC), Mo-dithiophosphates, Mo(DTP), Mo-amines, Mo(Am),
Mo-alcoholates, Mo-alcohol-amides, etc. See U.S. Pat. Nos.
5,824,627; 6,232,276; 6,153,564; 6,143,701; 6,110,878; 5,837,657;
6,010,987; 5,906,968; 6,734,150; 6,730,638; 6,689,725; 6,569,820;
and WO 99/66013; WO 99/47629; WO 98/26030.
[0068] Ashless friction modifiers may have 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. Polar
groups in friction modifiers may include hydrocarbyl groups
containing effective amounts of O, N, S, or 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.
[0069] Useful concentrations of friction modifiers may range from
about 0.01 wt. % to 10-15 wt % or more, often with a preferred
range of about 0.1 wt % to 5 wt %. Concentrations of
molybdenum-containing materials are often described in terms of Mo
metal concentration. Advantageous concentrations of Mo may range
from about 10 ppm to 3000 ppm or more, and often with a preferred
range of about 20-2000 ppm, and in some instances a more preferred
range of about 30-1000 ppm. Friction modifiers of all types may be
used alone or in mixtures with the materials of this invention.
Often mixtures of two or more friction modifiers, or mixtures of
friction modifier(s) with alternate surface active material(s), are
also desirable.
[0070] When lubricating oil compositions contain one or more of the
additives discussed above, the additive(s) are blended into the
composition in an amount sufficient for it to perform its intended
function. Typical amounts of such additives useful in the present
invention are shown in Table A below.
[0071] 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 the table
below, 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 1 Typical Amounts of Various Lubricant Oil
Components Approximate wt % Approximate Compound (Useful) wt %
(Preferred) Detergent 0.01-6 0.01-4 Dispersant 0.1-20 0.1-8
Friction Modifier 0.01-5 0.01-1.5 Viscosity Index Improver 0.0-4
0.01-4, more preferably (solid polymer basis) 0.01-2, most
preferably Antioxidant 0.1-5 0.1-1.5 Anti-wear Additive 0.01-6
0.01-4 Pour Point Depressant 0.0-5 0.01-1.5 (PPD) Anti-foam Agent
0.001-3 0.001-0.15 Base stock or base oil Balance Balance
[0072] The foregoing additives are all commercially available
materials. These additives may be added independently but are
usually precombined in packages which can be obtained from
suppliers of lubricant oil additives. Additive packages with a
variety of ingredients, proportions and characteristics are
available and selection of the appropriate package will take the
requisite use of the ultimate composition into account.
[0073] The following non-limiting examples are provided to
illustrate the invention.
[0074] Lubricating oil compositions according to the invention were
prepared using a blend of PAO, ester and Group III base oils.
[0075] In addition to a metal detergent, viscosity index improver,
and ZDDP, the composition included borated and non-borated ashless
dispersant, phenolic and aminic antioxidants, defoamant, pour point
depressant, friction modifier and seal swelling agent.
[0076] Representative formulations are given in Table 2.
TABLE-US-00003 TABLE 2 Invention Invention Comp. Comp. Comp. Comp.
Comp. Formulation Ex. 1 Ex. 2 Ex. 3 Ex. 4 Ex. 5 Ex. 6 Ex. 7
Viscosity Grade 0W-20 0W-20 0W-30 0W-20 5W-30 5W-30 5W-30
Component, wt % Salicylate and/or 2.20 1.80 2.25 1.50 3.52 3.52
1.50 Sulfonate Detergent Friction Modifier 0.15 0.15 0.15 0.48 0.73
0.77 0.40 Viscosity Index Improver 0.57 0.57 0.37 0.56 0.71 0.66
0.86 (solid polymer content) ZDDP 0.80 0.91 0.80 0.74 0.75 0.85
0.86 Dispersant 7.97 7.10 8.20 4.55 4.25 6.10 4.55
(Borated/Non-Borated) Other Addtives 2.12 1.87 2.12 1.90 1.90 1.90
1.90 (antioxidant, defoamant, PPD, seal swell agent) Base oil
balance balance balance balance balance balance balance Formulated
Oil 8.6 8.8 12.1 8.5 11.0 11.1 10.8 KV@100 C., cSt Sulfated Ash 0.6
0.6 0.6 0.9 1.0 1.0 0.9 Sulfur 0.2 0.2 0.2 0.2 0.2 0.2 0.2
[0077] Among the features of the composition of the invention is
that they have demonstrated both unexpected combination of wear and
fuel efficiency performance. For instance, fuel economy is improved
by at least 3.2% as measured in the M111 FE engine test and while
the wear performance is improved relative to the comparison oils.
Additionally, the composition of the invention is a low sulfated
ash, low sulfur composition.
[0078] Performance evaluation of the formulations is given in Table
3-6. The following engine tests were performed to measure wear and
fuel economy of the engine oil lubricant composition of the present
invention: TU3M, Sequence IIIG (ASTM D7320), OM646LA and M111FE,
all of which are incorporated herein by reference.
TABLE-US-00004 TABLE 3 Invention Invention Comp. Comp. Comp. Comp.
Comp. Description Ex. 1 Ex. 2 Ex. 3 Ex. 4 Ex. 5 Ex. 6 Ex. 7 HTHS,
cP 2.7 2.8 3.5 2.6 3.0 3.0 3.0 at 150.degree. C. Viscosity Grade
0W-20 0W-20 0W-30 0W-20 5W-30 5W-30 5W-30 Engine Test Parameter
TU3M Valve Train Scuffing Wear CEC Average cam 1.9 3.8 2 3.4 3.6 7
2.9 L-038-94 wear, .mu.m Maximum 3.2 4.5 2.6 5.5 5.5 8 5.0 cam
wear, .mu.m
TABLE-US-00005 TABLE 4 Invention Invention Comp. Comp. Comp. Comp.
Comp. Description Ex. 1 Ex. 2 Ex. 3 Ex. 4 Ex. 5 Ex. 6 Ex. 7 HTHS,
cP 2.7 2.8 3.5 2.6 3.0 3.0 3.0 at 150.degree. C. Viscosity Grade
0W-20 0W-20 0W-30 0W-20 5W-30 5W-30 5W-30 Engine Test Parameter
Sequence IIIG Wear and Oil ASTM D7320 Thickening Average cam 14 20
34 15 46 41 12 and lifter wear, .mu.m
TABLE-US-00006 TABLE 5 Invention Invention Comp. Comp. Comp. Comp.
Comp. Description Ex. 1 Ex. 2 Ex. 3 Ex. 4 Ex. 5 Ex. 6 Ex. 7 HTHS,
cP 2.7 2.8 3.5 2.6 3.0 3.0 3.0 at 150.degree. C. Viscosity Grade
0W-20 0W-20 0W-30 0W-20 5W-30 5W-30 5W-30 Engine Test Parameter
OM646LA Wear CEC Main bearing 0.0 0.2 0.4 0.2 NA 0.7 0.7 L-099-08
wear, .mu.m Conrod bearing 0.0 0.1 0.2 0.2 NA 0.3 0.5 wear, .mu.m
Cam wear outlet 55.0 27.9 67.3 89.7 NA 63.2 118.6 (avg. max wear 8
cams), .mu.m Cam wear inlet 39.9 41.8 58.1 71.4 NA 58.8 79.3 (avg.
max wear 8 cams), .mu.m
TABLE-US-00007 TABLE 6 Invention Invention Comp. Comp. Comp. Comp.
Comp. Description Ex. 1 Ex. 2 Ex. 3 Ex. 4 Ex. 5 Ex. 6 Ex. 7 HTHS,
cP 2.7 2.8 3.5 2.6 3.0 3.0 3.0 at 150.degree. C. Viscosity Grade
0W-20 0W-20 0W-30 0W-20 5W-30 5W-30 5W-30 Engine Test Parameter
M111FE Fuel Economy CEC Fuel Economy 3.5 3.4 2.6 NA 3.1 NA 2.9
L-054-96 Improvement, %
[0079] As can be seen from the foregoing Tables, the composition of
the invention provided improved antiwear properties white providing
a substantial improvement in fuel economy when compared to the
other oils identified.
[0080] It will thus be seen that the objects set forth above, among
those apparent in the preceding description, are efficiently
attained and since certain changes may be made in carrying out the
present invention without departing from the spirit and scope of
the invention, it is intended that all matter contained in the
above description and shown in the accompanying drawing be
interpreted as illustrative and not in a limiting sense.
[0081] It is also understood that the following claims are intended
to cover all of the generic and specific features of the invention
herein described and all statements of the scope of the invention,
which as a matter of language, might be said to fall
therebetween.
* * * * *
References