U.S. patent application number 12/598052 was filed with the patent office on 2010-07-29 for method of lubricating an aluminum silicate composite surface with a lubricant comprising ashless, sulphur, phosphorous free antiwear agent.
This patent application is currently assigned to THE LUBRIZOL CORPORATION. Invention is credited to Mark Davies, Rodney J. McAtee.
Application Number | 20100190669 12/598052 |
Document ID | / |
Family ID | 39595487 |
Filed Date | 2010-07-29 |
United States Patent
Application |
20100190669 |
Kind Code |
A1 |
Davies; Mark ; et
al. |
July 29, 2010 |
Method of Lubricating an Aluminum Silicate Composite Surface with a
Lubricant Comprising Ashless, Sulphur, Phosphorous Free Antiwear
Agent
Abstract
The present invention relates to a method of lubricating an
aluminium-composite surface by supplying to the aluminium composite
surface (typically an internal combustion engine aluminium surface)
a lubricating composition comprising an oil of lubricating
viscosity and an ashless antiwear agent.
Inventors: |
Davies; Mark; (Belper,
GB) ; McAtee; Rodney J.; (Southend, GB) |
Correspondence
Address: |
THE LUBRIZOL CORPORATION;ATTN: DOCKET CLERK, PATENT DEPT.
29400 LAKELAND BLVD.
WICKLIFFE
OH
44092
US
|
Assignee: |
THE LUBRIZOL CORPORATION
WICKLIFFE
OH
|
Family ID: |
39595487 |
Appl. No.: |
12/598052 |
Filed: |
May 15, 2008 |
PCT Filed: |
May 15, 2008 |
PCT NO: |
PCT/US08/63663 |
371 Date: |
March 17, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60939951 |
May 24, 2007 |
|
|
|
Current U.S.
Class: |
508/283 ;
508/110; 508/287; 508/304; 508/370; 508/436; 508/496; 508/555 |
Current CPC
Class: |
C10M 2223/043 20130101;
C10M 2223/045 20130101; C10N 2030/45 20200501; C10M 2215/08
20130101; C10N 2030/43 20200501; C10M 2207/042 20130101; C10M
2215/28 20130101; C10M 2207/24 20130101; C10M 2219/089 20130101;
C10M 2215/12 20130101; C10M 2207/281 20130101; C10M 2207/289
20130101; C10M 2215/224 20130101; C10M 2215/082 20130101; C10N
2030/42 20200501; C10M 2207/028 20130101; C10M 2219/046 20130101;
C10N 2040/25 20130101; C10M 141/08 20130101; C10M 2207/288
20130101; C10M 2207/262 20130101; C10M 2207/282 20130101; C10M
2227/066 20130101; C10M 141/10 20130101; C10M 2215/086 20130101;
C10M 2215/223 20130101; C10M 2219/068 20130101; C10N 2030/06
20130101; C10M 2219/068 20130101; C10N 2010/12 20130101; C10M
2223/045 20130101; C10N 2010/12 20130101; C10M 2219/068 20130101;
C10N 2010/12 20130101; C10M 2223/045 20130101; C10N 2010/12
20130101 |
Class at
Publication: |
508/283 ;
508/110; 508/496; 508/555; 508/287; 508/304; 508/436; 508/370 |
International
Class: |
C10M 133/46 20060101
C10M133/46; C10M 169/04 20060101 C10M169/04; C10M 129/72 20060101
C10M129/72; C10M 133/16 20060101 C10M133/16; C10M 133/44 20060101
C10M133/44; C10M 129/66 20060101 C10M129/66; C10M 137/08 20060101
C10M137/08; C10M 137/10 20060101 C10M137/10 |
Claims
1-20. (canceled)
21. A method of lubricating an internal combustion engine
comprising an aluminium composite surface, the method comprising
supplying to the aluminium composite surface a lubricating
composition comprising an oil of lubricating viscosity and an
ashless, phosphorus-free, sulphur-free antiwear agent.
22. The method of claim 1, wherein the aluminium composite surface
is an aluminium-silicate surface.
23. The method of claim 1, wherein the ashless antiwear agent is
derived from at least one of a hydroxy-carboxylic acid di-ester, a
hydroxy-carboxylic acid di-amide, a hydroxy-carboxylic acid imide,
a hydroxy-carboxylic acid di-imide, a hydroxy-carboxylic acid
ester-amide, a hydroxy-carboxylic acid ester-imide, and a
hydroxy-carboxylic acid imide-amide.
24. The method of claim 1, wherein the ashless antiwear agent is
represented by a compound of Formula (1a) and/or (1b): ##STR00002##
wherein n' is 0 to 10, 01 to 6, 0 to 4, 1 to 4, or 1 to 2 for
Formula (1b), and 1 to 10, 1 to 4, or 1 to 2 for Formula (1a); p is
1 to 5, or 1 to 2, or 1; Y and Y' are independently --O--, >NH,
>NR.sup.3, or an imide group formed by taking together both Y
and Y' groups in (1b) or two Y groups in (1a) and forming a
R.sup.1--N< group between two >C.dbd.O groups; X is
independently --CH.sub.2--, >CHR.sup.4 or >CR.sup.4R.sup.5,
>CHOR.sup.6, or >C(CO.sub.2R.sup.6).sub.2,
>C(OR.sup.6)CO.sub.2R.sup.6,
>C(CH.sup.2OR.sup.6)CO.sub.2R.sup.6, --CH.sub.3,
--CH.sub.2R.sup.4 or CHR.sup.4R.sup.5, --CH.sub.2OR.sup.6, or
--CH(CO.sub.2R.sup.6).sub.2, .dbd.C--R.sup.6, or mixtures thereof
to fulfill the valence of Formula (1a) and/or (1b), with the
proviso that .dbd.C--R.sup.6 only applies to Formula (1a); R.sup.1
and R.sup.2 are independently hydrocarbyl groups, typically
containing 1 to 150, 4 to 30, 6 to 20, 10 to 20, or 11 to 18 carbon
atoms; R.sup.3 is a hydrocarbyl group; R.sup.4 and R.sup.5 are
independently keto-containing groups (such as acyl groups), ester
groups or hydrocarbyl groups; and R.sup.6 is independently hydrogen
or a hydrocarbyl group, typically containing 1 to 150 carbon
atoms.
25. The method of claim 24, wherein Y and Y' are both --O--.
26. The method of claim 21 wherein the ashless antiwear agent is
derived from tartaric acid or citric acid.
27. The method of claim 21, wherein the ashless antiwear agent is
present at 0.05 to 10 wt % of the lubricating composition.
28. The method of claim 21, wherein the ashless antiwear agent is
present at 0.1 to 5 wt % of the lubricating composition.
29. The method of claim 21, wherein the lubricating composition is
further characterised as having at least one of (i) a sulphur
content of 0.8 wt % or less, (ii) a phosphorus content of 0.2 wt %
or less, or (iii) a sulphated ash content of 2 wt % or less.
30. The method of claim 21, wherein the lubricating composition is
characterised as having (i) a sulphur content of 0.5 wt % or less,
(ii) a phosphorus content of 0.1 wt % or less, and (iii) a
sulphated ash content of 1.5 wt % or less.
31. The method of claim 21, wherein the lubricating composition
further comprises at least one of a friction modifier, a viscosity
modifier, an antioxidant, an overbased detergent, a succinimide
dispersant, or mixtures thereof.
32. The method of claim 31, wherein the friction modifier is
selected from the group consisting of long chain fatty amides, long
chain fatty esters, long chain fatty epoxide derivatives, long
chain fatty imidazolines, and amine salts of alkylphosphoric
acids.
33. The method of claim 21, wherein the lubricating composition
further comprises a phosphorus-containing antiwear agent.
34. The method of claim 21, wherein the lubricating composition
further comprises further comprising a molybdenum compound, wherein
the molybdenum compound is selected from the group consisting of
molybdenum dialkyldithiophosphates, molybdenum dithiocarbamates,
amine salts of molybdenum compounds, and mixtures thereof.
35. The method of claim 34, wherein the molybdenum compound is
present in an amount to provide 0.5 ppm to 2000 ppm of
molybdenum.
36. The method of claim 21, wherein the lubricating composition
further comprises an overbased detergent, wherein the overbased
detergent is selected from the group consisting of
non-sulphur-containing phenates, sulphur-containing phenates,
sulphonates, salixarates, salicylates, and mixtures thereof.
Description
FIELD OF INVENTION
[0001] The invention provides a method of lubricating an
aluminium-alloy or aluminium composite surface by supplying to the
surface a lubricating composition comprising an oil of lubricating
viscosity and an ashless antiwear agent. The invention further
provides a lubricating composition suitable for lubricating the
aluminium-alloy or aluminium composite surface.
BACKGROUND OF THE INVENTION
[0002] It is well known for lubricating oils to contain a number of
additives used to protect the mechanical devices such as internal
combustion engines from wear, soot deposits and acidity build up. A
common antiwear additive for engine lubricating oils is zinc
dialkyldithiophosphate (ZDDP). It is believed that ZDDP antiwear
additives protect the engine by forming a protective film on metal
surfaces.
[0003] In recent years engine lubricants containing phosphorus
compounds and sulphur have been shown to contribute in part to
particulate emissions, and emissions of other pollutants. In
addition, sulphur and phosphorus tend to poison the catalysts used
in catalytic converters, resulting in a reduction in performance of
said catalysts.
[0004] Other developments in engine technology, such as new engine
design, employ non-ferric components or whole engines. Typically
non-ferric engines or components thereof, are based on
aluminium-alloy, silicates, oxides, or other ceramic materials.
However, well known antiwear agents ZDDP, are believed to result in
poorer engine wear performance in aluminium-alloy based engine
compared with ferric based engines.
[0005] In addition, with increasing control of emissions (often
associated with contributing to NO.sub.x formation, SO.sub.x
formation, formation of sulphated ash and reducing the efficiency
of after-treatment catalytic converters) there a desire towards
reduced amounts of sulphur, phosphorus and sulphated ash in engine
oils. However, reducing the levels of antiwear additives such as
ZDDP, is likely to increase wear and result in other detrimental
performance of an engine.
[0006] US Patent Application 2006/0025315 discloses a method of
lubricating an aluminium alloy surface with a lubricating
composition containing an effective friction reducing amount of an
oil soluble tri-nuclear organo-molybdenum compound.
[0007] Canadian Patent CA 1 183 125 discloses lubricants for
gasoline engines containing alkyl-ester tartrates, where the sum of
carbon atoms on the alkyl groups is at least 8.
[0008] Consequently, it would be desirable to provide an
alternative antiwear agent capable of at least one of (i) reducing
or preventing phosphorus emissions, (ii) reducing or preventing
sulphur emissions, and (iii) wholly or partially replacing ZDDP in
lubricating oils. The present invention provides an antiwear agent
capable of achieving at least one of (i), (ii) or (iii). In
addition it may also be desirable for the antiwear agent to not
have a detrimental affect on other components of a mechanical
device e.g., a seal or to provide lead and/or copper corrosion
inhibition.
SUMMARY OF THE INVENTION
[0009] In one embodiment the invention provides a method of
lubricating an aluminium-alloy or aluminium composite surface
comprising supplying to the aluminium-alloy or aluminium composite
surface a lubricating composition comprising an oil of lubricating
viscosity and an ashless, phosphorus-free, sulphur-free antiwear
agent.
[0010] In one embodiment the aluminium-alloy or aluminium composite
surface is an aluminium-silicate surface.
[0011] In one embodiment the invention provides a method of
lubricating an internal combustion engine comprising an
aluminium-alloy or aluminium composite surface, the method
comprising supplying to the surface a lubricating composition
comprising an oil of lubricating viscosity and an ashless,
phosphorus-free, sulphur-free antiwear agent.
[0012] In one embodiment invention provides for the use of a
lubricating composition comprising an ashless antiwear agent to
lubricate an aluminium-alloy or aluminium composite surface. In one
embodiment the invention provides for the use of a lubricating
composition comprising an ashless antiwear agent to lubricate an
internal combustion engine comprising an aluminium-alloy or
aluminium composite surface.
[0013] In one embodiment the invention provides a lubricating
composition comprising an ashless, phosphorus-free, sulphur-free
antiwear agent, and wherein the lubricating composition is
characterised as having at least one of (i) a sulphur content of
0.8 wt % or less, (ii) a phosphorus content of 0.2 wt % or less, or
(iii) a sulphated ash content of 2 wt % or less.
[0014] In one embodiment the invention provides a lubricating
composition comprising an ashless, phosphorus-free, sulphur-free
antiwear agent, and wherein the lubricating composition is
characterised as having (i) a sulphur content of 0.5 wt % or less,
(ii) a phosphorus content of 0.1 wt % or less, and (iii) a
sulphated ash content of 1.5 wt % or less.
[0015] In one embodiment the lubricating compositions disclosed
herein further comprises a molybdenum compound. Examples of a
suitable molybdenum compound include molybdenum
dialkyldithiophosphates, molybdenum dithiocarbamates, amine salts
of molybdenum compounds, or mixtures thereof.
[0016] In different embodiments the lubricating compositions
disclosed herein contain 0 ppm to 500 ppm, or 5 ppm to 300 ppm, or
20 ppm to 250 ppm of molybdenum. In certain embodiments a
molybdenum compound is present in an amount to provide 0.5 ppm to
2000 ppm, 1 ppm to 700 ppm, or 20 ppm to 250 ppm molybdenum.
DETAILED DESCRIPTION OF THE INVENTION
[0017] The present invention provides a lubricating composition and
a method for lubricating an engine as disclosed above.
Ashless Antiwear Agent
[0018] In one embodiment the ashless, phosphorus-free, sulphur-free
antiwear agent includes imides, di-esters, di-amides, di-imides,
ester-amides, ester-imides, imide-amides. In one embodiment the
antiwear agent includes imides, di-esters, di-amides, or
ester-amides.
[0019] In one embodiment the ashless antiwear agent includes a
compound derived from a hydroxycarboxylic acid.
[0020] In one embodiment the ashless antiwear agent is derived from
at least one of a hydroxy-carboxylic acid di-ester, a
hydroxy-carboxylic acid di-amide, a hydroxy-carboxylic acid
di-imide, a hydroxy-carboxylic acid ester-amide, a
hydroxy-carboxylic acid ester-imide, and a hydroxy-carboxylic acid
imide-amide. In one embodiment the ashless antiwear agent is
derived from at least one of the group consisting of a
hydroxy-carboxylic acid di-ester, a hydroxy-carboxylic acid
di-amide, and a hydroxy-carboxylic acid ester-amide.
[0021] Examples of a suitable a hydroxycarboxylic acid include
citric acid, tartaric acid, malic acid (or hydroxy-succinic acid),
lactic acid, oxalic acid, glycolic acid, hydroxy-propionic acid,
hydroxyglutaric acid, or mixtures thereof. In one embodiment
ashless antiwear agent is derived from tartaric acid, citric acid,
hydroxy-succinic acid, dihydroxy mono-acids, mono-hydroxy diacids,
or mixtures thereof. In one embodiment the ashless antiwear agent
includes a compound derived from tartaric acid. In another
embodiment it is derived from citric acid.
[0022] US Patent Application 2005/198894 discloses suitable
hydroxycarboxylic acid compounds, and methods of preparing the
same.
[0023] Canadian Patent 1183125; US Patent Publication numbers
2006/0183647 and US-2006-0079413; U.S. Patent Application No.
60/867,402; and British Patent 2 105 743 A, all disclose examples
of suitable tartaric acid derivatives.
[0024] In one embodiment the di-esters, di-amides, di-imides,
ester-amide, ester-imide, imide-amide compounds are derived from a
compound of Formula (1a) and/or (1b). In one embodiment the
di-esters, di-amides, ester-amide, compounds are derived from a
compound of Formula (1a) and/or (1b).
[0025] A detailed description of methods for preparing suitable
tartrimides (by reacting tartaric acid with a primary amine) is
disclosed in U.S. Pat. No. 4,237,022.
[0026] In one embodiment the ashless antiwear agent includes imide,
di-esters, di-amides, ester-amide derivatives of tartaric acid.
[0027] The ashless antiwear agent of the invention, typically a
tartrate, may also function as rust and corrosion inhibitors,
friction modifiers, antiwear agents and demulsifiers.
[0028] In one embodiment the ashless antiwear agent is represented
by a compound of Formula (1 a) and/or (1b):
##STR00001##
wherein
[0029] n is 0 to 10, 0 to 6, 0 to 4, 1 to 4, or 1 to 2 for Formula
(1b), and 1 to 10, 1 to 4, or 1 to 2 for Formula (1a);
[0030] p is 1 to 5, or 1 to 2, or 1;
[0031] Y and Y' are independently --O--, >NH, >NR.sup.3, or
an imide group formed by taking together both Y and Y' groups in
(1b) or two Y groups in (1a) and forming a R.sup.1--N< group
between two >C.dbd.O groups;
[0032] X is independently --CH.sub.2--, >CHR.sup.4 or
>CR.sup.4R.sup.5, >CHOR.sup.6, or
>C(CO.sub.2R.sup.6).sub.2, >C(OR.sup.6)CO.sub.2R.sup.6,
>C(CH.sup.2OR.sup.6)CO.sub.2R.sup.6, --CH.sub.3,
--CH.sub.2R.sup.4 or --CHR.sup.4R.sup.5, --CH.sub.2OR.sup.6, or
--CH(CO.sub.2R.sup.6).sub.2, .dbd.C--R.sup.6, or mixtures thereof
to fulfill the valence of Formula (1a) and/or (1b), with the
proviso that .dbd.C--R.sup.6 only applies to Formula (1a), the
.dbd.C referring to three single bonds to the carbon atom;
[0033] R.sup.1 and R.sup.2 are independently hydrocarbyl groups,
typically containing 1 to 150, 4 to 30, or 6 to 20, or 10 to 20, or
11 to 18 carbon atoms;
[0034] R.sup.3 is a hydrocarbyl group;
[0035] R.sup.4 and R.sup.5 are independently keto-containing groups
(such as acyl groups), ester groups or hydrocarbyl groups; and
[0036] R.sup.6 is independently hydrogen or a hydrocarbyl group,
typically containing 1 to 150, or 4 to 30 carbon atoms.
[0037] In one embodiment the compound of Formula (1b) contains an
imide group. The imide group is typically formed by taking together
the Y and Y' groups and forming a R.sup.1--N< group between two
>C.dbd.O groups.
[0038] In one embodiment the compound of Formula (1a) and/or (1b)
has n, X, and R.sup.1, R.sup.2 and R.sup.6 defined as follows: n is
1 to 2, X is >CHOR.sup.6; and R.sup.1, R.sup.2 and R.sup.6 are
independently hydrocarbyl groups containing 4 to 30 carbon
atoms.
[0039] In one embodiment Y and Y' are both --O--.
[0040] In one embodiment the compound of Formula (1a) and/or (1b)
has n, X, Y, Y' and R.sup.1, R.sup.2 and R.sup.6 defined as
follows: n is 1 to 2, X is >CHOR.sup.6; Y and Y' are both --O--,
and R.sup.1, R.sup.2 and R.sup.6 are independently hydrocarbyl
groups containing 4 to 30 carbon atoms.
[0041] The di-esters, di-amides, di-imides, ester-amide,
ester-imide, imide-amide compounds of Formula (1a) and/or (1b) may
be prepared by reacting a dicarboxylic acid (such as tartaric
acid), with an amine or alcohol, optionally in the presence of a
known esterification catalyst. The amine or alcohol typically has
sufficient carbon atoms to fulfill the requirements of R.sup.1
and/or R.sup.2 as defined in Formula (1a) and/or (1b). Derivatives
of the hydroxycarboxylic acid include imides, di-esters, di-amides,
di-imides (applicable for tetra-acids and higher), ester-amides,
ester-imides (applicable for tri-acids and higher, such as citric
acid), imide-amides (applicable for tri-acids and higher, such as
citric acid). In one embodiment the antiwear agent includes imides,
di-esters, di-amides, or ester-amides.
[0042] In one embodiment R.sup.1 and R.sup.2 are independently
linear or branch hydrocarbyl groups. In one embodiment the
hydrocarbyl groups are branched. In one embodiment the hydrocarbyl
groups are linear. The R.sup.1 and R.sup.2 may be incorporated into
Formula (1a) and/or (1b) by either an amine or an alcohol. The
alcohol includes both monohydric alcohol and polyhydric
alcohol.
[0043] In one embodiment the ashless antiwear agent is derived from
a compound of Formula (1b).
[0044] Examples of a suitable branched alcohol include
2-ethylhexanol, isotridecanol, Guerbet alcohols, or mixtures
thereof.
[0045] Examples of a monohydric alcohol include methanol, ethanol,
propanol, butanol, pentanol, hexanol, heptanol, octanol, nonanol,
decanol, undecanol, dodecanol, tridecanol, tetradecanol,
pentadecanol, hexadecanol, heptadecanol, octadecanol, nonadecanol,
eicosanol, or mixtures thereof. In one embodiment the monohydric
alcohol contains 5 to 20 carbon atoms.
[0046] The alcohol includes either a monohydric alcohol or a
polyhydric alcohol. Examples of a suitable polyhydric alcohol
include ethylene glycol, propylene glycol, 1,3-butylene glycol,
2,3-butylene glycol, 1,5-pentane diol, 1,6-hexane diol, glycerol,
sorbitol, pentaerythritol, trimethylolpropane, starch, glucose,
sucrose, methylglucoside, or mixtures thereof. In one embodiment
the polyhydric alcohol is used in a mixture along with a monohydric
alcohol. Typically, in such a combination the monohydric alcohol
constitutes at least 60 mole percent, or at least 90 mole percent
of the mixture.
[0047] In one embodiment ashless antiwear agent is derived from
tartaric acid. The tartaric acid used for preparing the tartrates
of the invention can be commercially available (for instance
obtained from Sargent Welch), and it is likely to exist in one or
more isomeric forms such as d-tartaric acid, l-tartaric acid or
mesotartaric acid, often depending on the source (natural) or
method of synthesis (e.g. from maleic acid). These derivatives can
also be prepared from functional equivalents to the diacid readily
apparent to those skilled in the art, such as esters, acid
chlorides, or anhydrides.
[0048] When the compound of Formula (1a) and/or (1b) is derived
from tartaric acid, resultant tartrates may be solid, semi-solid,
or oil depending on the particular alcohol used in preparing the
tartrate. For use as additives in oleaginous compositions including
lubricating and fuel compositions the tartrates are advantageously
soluble and/or stably dispersible in such oleaginous compositions.
For example, compositions intended for use in oils are typically
oil-soluble and/or stably dispersible in an oil in which they are
to be used. The term "oil-soluble" as used in this specification
and appended claims does not necessarily mean that all the
compositions in question are miscible or soluble in all proportions
in all oils. Rather, it is intended to mean that the composition is
soluble in an oil (mineral, synthetic, etc.) in which it is
intended to function to an extent which permits the solution to
exhibit one or more of the desired properties. Similarly, it is not
necessary that such "solutions" be true solutions in the strict
physical or chemical sense. They may instead be micro-emulsions or
colloidal dispersions which, for the purpose of this invention,
exhibit properties sufficiently close to those of true solutions to
be, for practical purposes, interchangeable with them within the
context of this invention.
[0049] The ashless antiwear agent of the may be present at 0.01 wt
% to 20 wt %, or 0.05 to 10 wt %, or 0.1 to 5 wt % of the
lubricating composition.
Oils of Lubricating Viscosity
[0050] The lubricating composition comprises an oil of lubricating
viscosity. Such oils include natural and synthetic oils, oil
derived from hydrocracking, hydrogenation, and hydrofinishing,
unrefined, refined and re-refined oils and mixtures thereof.
[0051] Unrefined oils are those obtained directly from a natural or
synthetic source generally without (or with little) further
purification treatment.
[0052] Refined oils are similar to the unrefined oils except they
have been further treated in one or more purification steps to
improve one or more properties. Purification techniques are known
in the art and include solvent extraction, secondary distillation,
acid or base extraction, filtration, percolation and the like.
[0053] Re-refined oils are also known as reclaimed or reprocessed
oils, and are obtained by processes similar to those used to obtain
refined oils and often are additionally processed by techniques
directed to removal of spent additives and oil breakdown
products.
[0054] Natural oils useful in making the inventive lubricants
include animal oils, vegetable oils (e.g., castor oil), mineral
lubricating oils such as liquid petroleum oils and solvent-treated
or acid-treated mineral lubricating oils of the paraffinic,
naphthenic or mixed paraffinic-naphthenic types and oils derived
from coal or shale or mixtures thereof.
[0055] Synthetic lubricating oils are useful and include
hydrocarbon oils such as polymerised and interpolymerised olefins
(e.g., polybutylenes, polypropylenes, propyleneisobutylene
copolymers); poly(1-hexenes), poly(1-octenes), poly(1-decenes), and
mixtures thereof; alkyl-benzenes (e.g. dodecylbenzenes,
tetradecylbenzenes, dinonylbenzenes, di-(2-ethylhexyl)-benzenes);
polyphenyls (e.g., biphenyls, terphenyls, alkylated polyphenyls);
alkylated diphenyl ethers and alkylated diphenyl sulphides and the
derivatives, analogs and homologs thereof or mixtures thereof.
[0056] Other synthetic lubricating oils include polyol esters (such
as Prolube.RTM.3970), diesters, liquid esters of
phosphorus-containing acids (e.g., tricresyl phosphate, trioctyl
phosphate, and the diethyl ester of decane phosphonic acid), or
polymeric tetrahydrofurans. Synthetic oils may be produced by
Fischer-Tropsch reactions and typically may be hydroisomerised
Fischer-Tropsch hydrocarbons or waxes. In one embodiment oils may
be prepared by a Fischer-Tropsch gas-to-liquid synthetic procedure
as well as other gas-to-liquid oils.
[0057] Oils of lubricating viscosity may also be defined as
specified in the American Petroleum Institute (API) Base Oil
Interchangeability Guidelines. The five base oil groups are as
follows: Group I (sulphur content >0.03 wt %, and/or <90 wt %
saturates, viscosity index 80-120); Group II (sulphur content
.ltoreq.0.03 wt %, and .gtoreq.90 wt % saturates, viscosity index
80-120); Group III (sulphur content .ltoreq.0.03 wt %, and
.gtoreq.90 wt % saturates, viscosity index .gtoreq.120); Group IV
(all polyalphaolefins (PAOs)); and Group V (all others not included
in Groups I, II, III, or IV). The oil of lubricating viscosity
comprises an API Group I, Group II, Group III, Group IV, Group V
oil or mixtures thereof. Often the oil of lubricating viscosity is
an API Group I, Group II, Group III, Group IV oil or mixtures
thereof. Alternatively the oil of lubricating viscosity is often an
API Group II, Group III or Group IV oil or mixtures thereof.
[0058] The amount of the oil of lubricating viscosity present is
typically the balance remaining after subtracting from 100 wt % the
sum of the amount of the ashless antiwear agent and the other
performance additives.
[0059] The lubricating composition may be in the form of a
concentrate and/or a fully formulated lubricant. If the ashless
antiwear agent is in the form of a concentrate (which may be
combined with additional oil to form, in whole or in part, a
finished lubricant), the ratio of the of components of the
invention to the oil of lubricating viscosity and/or to diluent oil
include the ranges of 1:99 to 99:1 by weight, or 80:20 to 10:90 by
weight.
Other Performance Additives
[0060] The composition optionally comprises other performance
additives. The other performance additives comprise at least one of
metal deactivators, viscosity modifiers, detergents, friction
modifiers, antiwear agents (other than the ashless antiwear agent
of the invention), corrosion inhibitors, dispersants, dispersant
viscosity modifiers, extreme pressure agents, antioxidants, foam
inhibitors, demulsifiers, pour point depressants, seal swelling
agents and mixtures thereof. Typically, fully-formulated
lubricating oil will contain one or more of these performance
additives.
[0061] In one embodiment the lubricating composition comprises the
ashless antiwear agent and further comprises at least one of a
viscosity modifier, an antioxidant, an overbased detergent, a
succinimide dispersant, or mixtures thereof.
[0062] In one embodiment the lubricating composition comprising the
ashless antiwear agent further comprises a phosphorus-containing
antiwear agent.
[0063] In one embodiment the lubricating composition comprising the
ashless antiwear agent further comprises a molybdenum compound.
Detergents
[0064] The lubricant composition optionally further comprises other
known neutral or overbased detergents. Suitable detergent
substrates include phenates, sulphur containing phenates,
sulphonates, salixarates, salicylates, carboxylic acid, phosphorus
acid, mono- and/or di-thiophosphoric acid, alkyl phenol, sulphur
coupled alkyl phenol compounds, or saligenins. Various overbased
detergents and their methods of preparation are described in
greater detail in numerous patent publications, including
WO2004/096957 and references cited therein. The detergent substrate
is typically salted with a metal such as calcium, magnesium,
potassium, sodium, or mixtures thereof. In one embodiment the
lubricating composition further includes an overbased detergent.
Typically the overbased detergent includes phenates, sulphur
containing phenates, sulphonates, salixarates, salicylates, or
mixtures thereof.
[0065] The detergent may be present at 0 wt % to 10 wt %, or 0.1 wt
% to 8 wt %, or 1 wt % to 4 wt %, or greater than 4 to 8 wt %.
Dispersants
[0066] Dispersants are often known as ashless-type dispersants
because, prior to mixing in a lubricating oil composition, they do
not contain ash-forming metals and they do not normally contribute
any ash forming metals when added to a lubricant and polymeric
dispersants. Ashless type dispersants are characterised by a polar
group attached to a relatively high molecular weight hydrocarbon
chain. Typical ashless dispersants include N-substituted long chain
alkenyl succinimides. Examples of N-substituted long chain alkenyl
succinimides include polyisobutylene succinimide with number
average molecular weight of the polyisobutylene substituent in the
range 350 to 5000, or 500 to 3000. Succinimide dispersants and
their preparation are disclosed, for instance in U.S. Pat. No.
3,172,892 or U.S. Pat. No. 4,234,435. Succinimide dispersants are
typically the imide formed from a polyamine, typically a
poly(ethyleneamine).
[0067] In one embodiment the invention further comprises at least
one polyisobutylene succinimide dispersant derived from
polyisobutylene with number average molecular weight in the range
350 to 5000, or 500 to 3000. The polyisobutylene succinimide may be
used alone or in combination with other dispersants.
[0068] In one embodiment the invention further comprises at least
one dispersant derived from polyisobutylene succinic anhydride, an
amine and zinc oxide to form a polyisobutylene succinimide complex
with zinc. The polyisobutylene succinimide complex with zinc may be
used alone or in combination.
[0069] Another class of ashless dispersant is Mannich bases.
Mannich dispersants are the reaction products of alkyl phenols with
aldehydes (especially formaldehyde) and amines (especially
polyalkylene polyamines). The alkyl group typically contains at
least 30 carbon atoms.
[0070] The dispersants may also be post-treated by conventional
methods by a reaction with any of a variety of agents. Among these
are boron, urea, thiourea, dimercaptothiadiazoles, carbon
disulphide, aldehydes, ketones, carboxylic acids,
hydrocarbon-substituted succinic anhydrides, maleic anhydride,
nitriles, epoxides, and phosphorus compounds.
[0071] The dispersant may be present at 0 wt % to 20 wt %, or 0.1
wt % to 15 wt %, or 0.1 wt % to 10 wt %, or 1 wt % to 6 wt %, or 7
wt % to 12 wt % of the lubricating composition.
Antioxidants
[0072] Antioxidant compounds are known and include for example,
sulphurised olefins, alkylated diphenylamines (typically di-nonyl
diphenylamine, octyl diphenylamine, di-octyl diphenylamine),
hindered phenols, molybdenum compounds (such as molybdenum
dithiocarbamates), or mixtures thereof. Antioxidant compounds may
be used alone or in combination. The antioxidant may be present in
ranges 0 wt % to 20 wt %, or 0.1 wt % to 10 wt %, or 1 wt % to 5 wt
%, of the lubricating composition.
[0073] The hindered phenol antioxidant often contains a secondary
butyl and/or a tertiary butyl group as a sterically hindering
group. The phenol group is often further substituted with a
hydrocarbyl group and/or a bridging group linking to a second
aromatic group. Examples of suitable hindered phenol antioxidants
include 2,6-di-tert-butylphenol, 4-methyl-2,6-di-tert-butylphenol,
4-ethyl-2,6-di-tert-butylphenol, 4-propyl-2,6-di-tert-butylphenol
or 4-butyl-2,6-di-tert-butylphenol, or
4-dodecyl-2,6-di-tert-butylphenol. In one embodiment the hindered
phenol antioxidant is an ester and may include, e.g., Irganox.TM.
L-135 from Ciba. A more detailed description of suitable
ester-containing hindered phenol antioxidant chemistry is found in
U.S. Pat. No. 6,559,105.
[0074] Suitable examples of molybdenum dithiocarbamates which may
be used as an antioxidant include commercial materials sold under
the trade names such as Molyvan 822.TM. and Molyvan.TM. A from R.
T. Vanderbilt Co., Ltd., and Adeka Sakura-Lube.TM. S-100, S-165 and
S-600 from Asahi Denka Kogyo K. K and mixtures thereof.
Viscosity Modifiers
[0075] Viscosity modifiers include hydrogenated copolymers of
styrene-butadiene, ethylene-propylene copolymers, polyisobutenes,
hydrogenated styrene-isoprene polymers, hydrogenated isoprene
polymers, polymethacrylates, polyacrylates, polyalkyl styrenes,
hydrogenated alkenyl aryl conjugated diene copolymers, polyolefins,
esters of maleic anhydride-styrene copolymers.
Dispersant Viscosity Modifiers
[0076] Dispersant viscosity modifiers (often referred to as DVM),
include functionalised polyolefins, for example, ethylene-propylene
copolymers that have been functionalized with the reaction product
of maleic anhydride and an amine; polymethacrylates functionalised
with an amine, or esterified maleic anhydride-styrene copolymers
reacted with an amine.
[0077] The total amount of viscosity modifier and/or dispersant
viscosity modifier may be 0 wt % to 20 wt %, or 0.1 wt % to 15 wt
%, or 0.1 wt % to 10 wt %, of the lubricating composition
Antiwear Agents
[0078] The lubricant composition optionally further comprises at
least one other antiwear agent other than the ashless antiwear
agent of the invention. Examples of suitable antiwear agents
include phosphate esters, sulphurised olefins, sulphur-containing
anti-wear additives including metal dihydrocarbyldithiophosphates
(such as zinc dialkyldithiophosphates or molybdenum
dialkyldithiophosphates), thiocarbamate-containing compounds
including, thiocarbamate esters, alkylene-coupled thiocarbamates,
and bis(S-alkyldithio carbamyl) disulphides.
[0079] The dithiocarbamate-containing compounds may be prepared by
reacting a dithiocarbamate acid or salt with an unsaturated
compound. The dithiocarbamate containing compounds may also be
prepared by simultaneously reacting an amine, carbon disulphide and
an unsaturated compound. Generally, the reaction occurs at a
temperature of 25.degree. C. to 125.degree. C. U.S. Pat. Nos.
4,758,362 and 4,997,969 describe dithiocarbamate compounds and
methods of making them.
[0080] Examples of suitable olefins that may be sulphurised to form
the sulphurised olefin include propylene, butylene, isobutylene,
pentene, hexane, heptene, octane, nonene, decene, undecene,
dodecene, undecene, tridecene, tetradecene, pentadecene,
hexadecene, heptadecene, octadecene, nonadecene, eicosene or
mixtures thereof. In one embodiment, hexadecene, heptadecene,
octadecene, nonadecene, eicosene or mixtures thereof and their
dimers, trimers and tetramers are especially useful olefins.
Alternatively, the olefin may be a Diels-Alder adduct of a diene
such as 1,3-butadiene and an unsaturated ester, such as
butylacrylate.
[0081] Another class of sulphurised olefin includes fatty acids and
their esters. The fatty acids are often obtained from vegetable oil
or animal oil and typically contain 4 to 22 carbon atoms. Examples
of suitable fatty acids and their esters include triglycerides,
oleic acid, linoleic acid, palmitoleic acid or mixtures thereof.
Often, the fatty acids are obtained from lard oil, tall oil, peanut
oil, soybean oil, cottonseed oil, sunflower seed oil or mixtures
thereof. In one embodiment fatty acids and/or ester are mixed with
olefins such as .alpha.-olefins.
[0082] In an alternative embodiment, the ashless antiwear agent
(which may also be described as a friction modifier) may be a
monoester of a polyol and an aliphatic carboxylic acid, often an
acid containing 12 to 24 carbon atoms. Often the monoester of a
polyol and an aliphatic carboxylic acid is in the form of a mixture
with a sunflower oil or the like, which may be present in the
ashless antiwear agent mixture include 5 to 95, or in other
embodiments 10 to 90, or 20 to 85, or 20 to 80 weight percent of
said mixture. The aliphatic carboxylic acids (especially a
monocarboxylic acid) which form the esters are those acids
typically containing 12 to 24 or 14 to 20 carbon atoms. Examples of
carboxylic acids include dodecanoic acid, stearic acid, lauric
acid, behenic acid, and oleic acid.
[0083] Polyols include diols, triols, and alcohols with higher
numbers of alcoholic OH groups. Polyhydric alcohols include
ethylene glycols, including di-, tri- and tetraethylene glycols;
propylene glycols, including di-, tri- and tetrapropylene glycols;
glycerol; butane diol; hexane diol; sorbitol; arabitol; mannitol;
sucrose; fructose; glucose; cyclohexane diol; erythritol; and
pentaerythritols, including di- and tripentaerythritol. Often the
polyol is diethyl-ene glycol, triethylene glycol, glycerol,
sorbitol, pentaerythritol or dipentaerythritol. The commercial
material known as glycerol monoleate is believed to include about
60.+-.5 percent by weight of the chemical species "glycerol
monooleate," along with 35.+-.5 percent glycerol dioleate, and less
than about 5 percent trioleate and oleic acid. The amounts of the
monoesters, described below, are the amounts of the commercial
grade material.
[0084] The antiwear agent may be present in ranges including 0 wt %
to 15 wt %, or 0 wt % to 10 wt %, or 0.05 wt % to 5 wt %, or 0.1 wt
% to 3 wt % of the lubricating composition.
[0085] In one embodiment the lubricating composition is free of
zinc dihydrocarbyl dithiophosphate. In one embodiment the
lubricating composition further includes zinc dihydrocarbyl
dithiophosphate.
Extreme Pressure Agents
[0086] Extreme Pressure (EP) agents that are soluble in the oil
include sulphur- and chlorosulphur-containing EP agents,
chlorinated hydrocarbon EP agents and phosphorus EP agents.
Examples of such EP agents include chlorinated wax; organic
sulphides and polysulphides such as dibenzyldisulphide,
bis(chlorobenzyl) disulphide, dibutyl tetrasulphide, sulphurised
methyl ester of oleic acid, sulphurised alkylphenol, sulphurised
dipentene, sulphurised terpene, and sulphurised Diels-Alder
adducts; phosphosulphurised hydrocarbons such as the reaction
product of phosphorus sulphide with turpentine or methyl oleate;
phosphorus esters such as the dihydrocarbon and trihydrocarbon
phosphites, e.g., dibutyl phosphite, diheptyl phosphite,
dicyclohexyl phosphite, pentylphenyl phosphite; dipentylphenyl
phosphite, tridecyl phosphite, distearyl phosphite and
polypropylene substituted phenol phosphite; metal thiocarbamates
such as zinc dioctyldithiocarbamate and barium heptylphenol diacid;
amine salts of alkyl and dialkylphosphoric acids, including, for
example, the amine salt of the reaction product of a
dialkyldithiophosphoric acid with propylene oxide; and mixtures
thereof.
Friction Modifiers
[0087] In one embodiment the further comprises a friction modifier,
or mixtures thereof. Typically the friction modifier may be present
in ranges including 0 wt % to 10 wt %, or 0.05 wt % to 8 wt %, or
0.1 wt % to 4 wt %.
[0088] Examples of suitable friction modifiers include long chain
fatty acid derivatives of long chain fatty acid derivatives of
amines, esters, or epoxides; fatty imidazolines (that is to say,
long chain fatty amides, long chain fatty esters, long chain fatty
epoxide derivatives, long chain fatty imidazolines); and amine
salts of alkylphosphoric acids.
[0089] Friction modifiers may also encompass materials such as
sulphurised fatty compounds and olefins, molybdenum
dialkyldithiophosphates, molybdenum dithiocarbamates, sunflower oil
or monoester of a polyol and an aliphatic carboxylic acid (all
these friction modifiers have been described as antioxidants or
antiwear agents).
[0090] In one embodiment the friction modifier friction modifier is
selected from the group consisting of long chain fatty amides, long
chain fatty esters, long chain fatty epoxide derivatives, long
chain fatty imidazolines, and amine salts of alkylphosphoric acids;
fatty alkyl tartrates such as C12-14 tartrates; fatty alkyl
tartrimides (such as tridecyl tartrimide, oleyl tartrimide, or
2-ethylhexyl tartrimide); and fatty alkyl tartramides
[0091] In one embodiment the friction modifier is a long chain
fatty acid ester (previously described above as an ashless antiwear
agent). In another embodiment the long chain fatty acid ester is a
mono-ester and in another embodiment the long chain fatty acid
ester is a (tri)glyceride.
Other Additives
[0092] Other performance additives such as corrosion inhibitors
include those described in paragraphs 5 to 8 of US Application
US05/038319 (filed on Oct. 25, 2004 McAtee and Boyer as named
inventors), octylamine octanoate, condensation products of
dodecenyl succinic acid or anhydride and a fatty acid such as oleic
acid with a polyamine. In one embodiment the corrosion inhibitors
include the Synalox.RTM. corrosion inhibitor. The Synalox.RTM.
corrosion inhibitor is typically a homopolymer or copolymer of
propylene oxide. The Synalox.RTM. corrosion inhibitor is described
in more detail in a product brochure with Form No. 118-01453-0702
AMS, published by The Dow Chemical Company. The product brochure is
entitled "SYNALOX Lubricants, High-Performance Polyglycols for
Demanding Applications."
[0093] Metal deactivators including derivatives of benzotriazoles
(typically tolyltriazole), dimercaptothiadiazole derivatives,
1,2,4-triazoles, benzimidazoles, 2-alkyldithiobenzimidazoles, or
2-alkyldithiobenzothiazoles; foam inhibitors including copolymers
of ethyl acrylate and 2-ethylhexylacrylate and optionally vinyl
acetate; demulsifiers including trialkyl phosphates, polyethylene
glycols, polyethylene oxides, polypropylene oxides and (ethylene
oxide-propylene oxide) polymers; pour point depressants including
esters of maleic anhydride-styrene, polymethacrylates,
polyacrylates or polyacrylamides.
INDUSTRIAL APPLICATION
[0094] The lubricating composition may be utilised in a range
aluminium-alloy or aluminium composite surfaces typically found in
mechanical devices. The mechanical devices include an internal
combustion engine, a gearbox, an automatic transmission, a
hydraulic device or a turbine. Typically the lubricating
composition may be an engine oil, a gear oil, an automatic
transmission oil, a hydraulic fluid, a turbine oil, a metal working
fluid or a circulating oil. In one embodiment the mechanical device
is an internal combustion engine.
[0095] As used herein, the terms "aluminium-alloy" and "aluminium
composite" are used interchangeably to describe a surface
comprising aluminium and another component intermixed or reacted on
a microscopic or nearly microscopic level, regardless of the
detailed structure thereof. This would include any conventional
alloys with metals other than aluminium as well as composite or
alloy-like structures with non-metallic elements or compounds such
as with ceramic-like materials. The aluminium-alloy or aluminium
composite thus includes aluminium silicates, aluminium oxides, or
other ceramic materials. In one embodiment the aluminium-alloy is
an aluminium-silicate surface.
[0096] In one embodiment the internal combustion engine may be a
diesel fuelled engine, a gasoline fuelled engine, a natural gas
fuelled engine or a mixed gasoline/alcohol fuelled engine. In one
embodiment the internal combustion engine may be a diesel fuelled
engine and in another embodiment a gasoline fuelled engine.
[0097] The internal combustion engine may be a 2-stroke or 4-stroke
engine. Suitable internal combustion engines include marine diesel
engines, aviation piston engines, low-load diesel engines, and
automobile and truck engines.
[0098] The lubricant composition for an internal combustion engine
may be suitable for any engine lubricant irrespective of the
sulphur, phosphorus or sulphated ash (ASTM D-874) content. The
sulphur content of the engine oil lubricant may be 1 wt % or less,
or 0.8 wt % or less, or 0.5 wt % or less, or 0.3 wt % or less. In
one embodiment the sulphur content may be in the range of 0.001 wt
% to 0.5 wt %, or 0.01 wt % to 0.3 wt %. The phosphorus content may
be 0.2 wt % or less, or 0.1 wt % or less, or 0.085 wt % or less, or
even 0.06 wt % or less, 0.055 wt % or less, or 0.05 wt % or less.
In one embodiment the phosphorus content may be 100 ppm to 1000
ppm, or 325 ppm to 700 ppm. The total sulphated ash content may be
2 wt % or less, or 1.5 wt % or less, or 1.1 wt % or less, or 1 wt %
or less, or 0.8 wt % or less, or 0.5 wt % or less. In one
embodiment the sulphated ash content may be 0.05 wt % to 0.9 wt %,
or 0.1 wt % or 0.2 wt % to 0.45 wt %.
[0099] In one embodiment the lubricating composition is an engine
oil,
[0100] wherein the lubricating composition is characterised as
having (i) a sulphur content of 0.5 wt % or less, (ii) a phosphorus
content of 0.1 wt % or less, and (iii) a sulphated ash content of
1.5 wt % or less. In another embodiment the sulphur content is 0.4
wt % or less, the phosphorus content is 0.08 wt % or less, and the
sulphated ash is 1 wt % or less. In yet another embodiment the
sulphur content is 0.3 wt % or less, the phosphorus content is 0.05
wt % or less, and the sulphated ash is 0.8 wt % or less.
[0101] In one embodiment the lubricating composition is suitable
for a 2-stroke or a 4-stroke marine diesel internal combustion
engine. In one embodiment the marine diesel combustion engine is a
2-stroke engine. The ashless antiwear agent of the invention may be
added to a marine diesel lubricating composition at 0.01 to 20 wt
%, or 0.05 to 10 wt %, or 0.1 to 5 wt %.
[0102] The following examples provide illustrations of the
invention. These examples are non-exhaustive and are not intended
to limit the scope of the invention.
EXAMPLES
Example 1
[0103] A lubricating composition is prepared containing 1 wt % of
di-2-ethylhexyl tartrate, 0.6 wt % of other antiwear agents, 7.9 wt
% of dispersants, 1.5 wt % of detergents, 3.6 wt % of antioxidants,
6.1 wt % of viscosity modifier, 0.1 wt % of corrosion inhibitor,
and 0.1 wt % of friction modifier. The lubricating composition has
a sulphated ash content of 0.6 wt %, a phosphorus content of about
570 ppm, and a sulphur content of 0.17 wt %.
Comparative Example 1
[0104] is similar to Example 1 except the composition does not
contain the di-2-ethylhexyl tartrate.
[0105] Example 1 and Comparative Example 1 are evaluated by
employing the lubricating compositions in an internal combustion
engine fitted with an aluminium silicate liner and a steel top
ring. The engine is then run under varying loads and speeds and
wear analysis is conducted when the engine is running at 5000 rpm.
Data obtained from the wear analysis (wear rate of nanometers per
hour) of the aluminium silicate liner is as follows:
TABLE-US-00001 Example Wear Rate (nm/h) Example 1 0.5 Comparative
Example 1 2.1
[0106] Overall the results indicate that lubricating an
aluminium-alloy surface with a lubricating composition as disclosed
herein is capable of at least one of (i) reducing or preventing
phosphorus emissions, (ii) reducing or preventing sulphur
emissions, and (iii) wholly or partially replacing ZDDP in
lubricating oils, and (iv) having no detrimental affect on other
components of the internal combustion engine.
[0107] It is known that some of the materials described above may
interact in the final formulation, so that the components of the
final formulation may be different from those that are initially
added. The products formed thereby, including the products formed
upon employing lubricant composition of the present invention in
its intended use, may not be susceptible of easy description.
Nevertheless, all such modifications and reaction products are
included within the scope of the present invention; the present
invention encompasses lubricant composition prepared by admixing
the components described above.
[0108] Each of the documents referred to above is incorporated
herein by reference. Except in the Examples, or where otherwise
explicitly indicated, all numerical quantities in this description
specifying amounts of materials, reaction conditions, molecular
weights, number of carbon atoms, and the like, are to be understood
as modified by the word "about." Unless otherwise indicated, each
chemical or composition referred to herein should be interpreted as
being a commercial grade material which may contain the isomers,
by-products, derivatives, and other such materials which are
normally understood to be present in the commercial grade. However,
the amount of each chemical component is presented inclusive of any
solvent or diluent oil, which may be customarily present in the
commercial material, unless otherwise indicated. It is to be
understood that the upper and lower amount, range, and ratio limits
set forth herein may be independently combined. Similarly, the
ranges and amounts for each element of the invention may be used
together with ranges or amounts for any of the other elements.
[0109] As used herein, the term "hydrocarbyl substituent" or
"hydrocarbyl group" is used in its ordinary sense, which is
well-known to those skilled in the art. Specifically, it refers to
a group having a carbon atom directly attached to the remainder of
the molecule and having predominantly hydrocarbon character.
Examples of hydrocarbyl groups include:
[0110] (i) hydrocarbon substituents, that is, aliphatic (e.g.,
alkyl or alkenyl), alicyclic (e.g., cyclo alkyl, cycloalkenyl)
substituents, and aromatic-, aliphatic-, and alicyclic-substituted
aromatic substituents, as well as cyclic substituents wherein the
ring is completed through another portion of the molecule (e.g.,
two substituents together form a ring);
[0111] (ii) substituted hydrocarbon substituents, that is,
substituents containing non-hydrocarbon groups which, in the
context of this invention, do not alter the predominantly
hydrocarbon nature of the substituent (e.g., halo (especially
chloro and fluoro), hydroxy, alkoxy, mercapto, alkylmercapto,
nitro, nitroso, and sulphoxy);
[0112] (iii) hetero substituents, that is, substituents which,
while having a predominantly hydrocarbon character, in the context
of this invention, contain other than carbon in a ring or chain
otherwise composed of carbon atoms.
[0113] Heteroatoms include sulphur, oxygen, nitrogen, and encompass
substituents as pyridyl, furyl, thienyl and imidazolyl. In general,
no more than two, preferably no more than one, non-hydrocarbon
substituent will be present for every ten carbon atoms in the
hydrocarbyl group; typically, there will be no non-hydrocarbon
substituents in the hydrocarbyl group.
[0114] As will be evident, the antiwear agent described herein may
be an oil-soluble derivative of a molecule containing a first
carboxy group and at least one additional --OH, --NHR, or .dbd.O
moiety separated from the carbon of said first carboxy group by a
chain of 2 or 3 atoms, where R is hydrogen or alkyl, e.g, C1-6
alkyl.
[0115] While the invention has been explained in relation to its
preferred embodiments, it is to be understood that various
modifications thereof will become apparent to those skilled in the
art upon reading the specification. Therefore, it is to be
understood that the invention disclosed herein is intended to cover
such modifications as fall within the scope of the appended
claims.
* * * * *