U.S. patent application number 15/549139 was filed with the patent office on 2018-01-18 for use of glycerides of hydroxy polycarboxylic acids as anti-camshaft-wear additives in lubricants and fuels.
The applicant listed for this patent is Castrol Limited. Invention is credited to Aldo Guiducci, Gordon Lamb, Kevin West.
Application Number | 20180016511 15/549139 |
Document ID | / |
Family ID | 52746269 |
Filed Date | 2018-01-18 |
United States Patent
Application |
20180016511 |
Kind Code |
A1 |
Guiducci; Aldo ; et
al. |
January 18, 2018 |
Use of Glycerides of Hydroxy Polycarboxylic Acids as
Anti-Camshaft-Wear Additives in Lubricants and Fuels
Abstract
This invention relates to the use of an oil-soluble mono-, di-,
or tri-glyceride of at least one hydroxy polycarboxylic acid, or a
derivative thereof, as an anti-camshaft-wear additive in a
non-aqueous lubricant composition and/or in a fuel composition.
Inventors: |
Guiducci; Aldo; (Reading,
Berkshire, GB) ; Lamb; Gordon; (Shanghai, CN)
; West; Kevin; (Reading, Berkshire, GB) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Castrol Limited |
Reading, Berkshire |
|
GB |
|
|
Family ID: |
52746269 |
Appl. No.: |
15/549139 |
Filed: |
December 17, 2015 |
PCT Filed: |
December 17, 2015 |
PCT NO: |
PCT/EP2015/080229 |
371 Date: |
August 4, 2017 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C10M 129/76 20130101;
C10N 2040/25 20130101; C10M 2207/288 20130101; C10M 2207/30
20130101; C10L 1/191 20130101; C10M 2207/289 20130101; C10L 10/08
20130101; C10L 1/1915 20130101; C10L 2290/24 20130101; C10L 1/18
20130101; C10M 129/78 20130101; C10N 2030/06 20130101; C10M 2203/10
20130101 |
International
Class: |
C10M 129/76 20060101
C10M129/76; C10L 1/18 20060101 C10L001/18; C10M 129/78 20060101
C10M129/78; C10L 10/08 20060101 C10L010/08 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 6, 2015 |
GB |
1502026.6 |
Claims
1-17. (canceled)
18. A method of improving anti-camshaft-wear properties of a
non-aqueous lubricant composition and/or fuel composition
comprising admixing an oil-soluble mono-, di-, or tri-glyceride of
at least one hydroxy polycarboxylic acid, or a derivative thereof,
in the non-aqueous lubricant composition and/or in the fuel
composition.
19. The method of claim 18, wherein the oil-soluble mono-, di-, or
tri-glyceride of at least one hydroxy polycarboxylic acid, or a
derivative thereof, reduces camshaft wear as measured in the
OM646LA engine test.
20. The method of claim 18, wherein the lubricant composition is
used to lubricate an internal combustion engine.
21. The method of claim 20, wherein the oil-soluble mono-, di-, or
tri-glyceride of at least one hydroxy polycarboxylic acid, or a
derivative thereof, is provided in a liquid fuel composition used
to operate the internal combustion engine, and a portion at least,
of said glyceride ingresses into the lubricating oil composition
during operation of said engine.
22. The method of claim 18, wherein the hydroxy polycarboxylic acid
has at least one hydroxy group which is in an alpha position with
respect to a carboxylic moiety.
23. The method of claim 22, wherein the hydroxy polycarboxylic acid
is citric acid.
24. The method of claim 18, wherein the glyceride is a glyceride of
at least one hydroxy polycarboxylic acid and at least one second
carboxylic acid which is a saturated, mono-unsaturated or
poly-unsaturated, branched or linear, monocarboxylic or
polycarboxylic acid having 4 to 22 carbon atoms, or a derivative
thereof.
25. The method of claim 18, wherein the glyceride is a glyceride of
at least one hydroxy polycarboxylic acid and a mono-unsaturated C4
to C22 monocarboxylic acid, or a derivative thereof.
26. The method of claim 18, wherein the glyceride is a glyceride of
at least one hydroxy polycarboxylic acid and a polyunsaturated C4
to C22 monocarboxylic acid, or a derivative thereof.
27. The method of claim 25, wherein the glyceride is a glyceride of
at least one hydroxy polycarboxylic acid and a mono-unsaturated or
polyunsaturated Cis monocarboxylic acid, or a derivative
thereof.
28. The method of claim 27, wherein the glyceride is a glyceride of
citric acid and a mono-unsaturated or polyunsaturated C18
monocarboxylic acid, or a derivative thereof.
29. The method of claim 25, wherein the mono-unsaturated or
polyunsaturated C4 to C22 carboxylic acid is linear.
30. The method of claim 18, wherein the glyceride is a glyceride of
citric acid and oleic acid, a glyceride of citric acid and linoleic
acid or a mixture thereof.
31. The method of claim 24, wherein the carboxylic acid having 4 to
22 carbon atoms is a polycarboxylic acid and the derivative is an
ester of a carboxylic acid moiety of said polycarboxylic acid.
32. The method of claim 18, wherein the derivative of the glyceride
is an ether of the hydroxy moiety of the hydroxy polycarboxylic
acid.
33. The method of claim 18, wherein the derivative of the glyceride
is an ester of the hydroxy moiety of the hydroxy polycarboxylic
acid.
34. The method of claim 18, wherein the derivative of the glyceride
is an ester of a carboxylic acid moiety of the hydroxy
polycarboxylic acid.
35. The method of claim 19, wherein the oil-soluble mono-, di-, or
tri-glyceride of at least one hydroxy polycarboxylic acid, or a
derivative thereof, is present in an amount of 0.1 to 5% by weight.
Description
[0001] This invention relates to anti-camshaft-wear additives and
their use in lubricant compositions and fuel compositions.
[0002] It is known to use anti-wear additives and/or friction
modifiers in lubricant compositions. It is also known to use
anti-wear additives and/or friction modifiers in fuel compositions
for internal combustion engines.
[0003] The ingress of fuel and fuel additives into the crankcase
lubricant of an internal combustion engine is known, for example
from paragraph 2 of the abstract of SAE paper 2001-01-1962 by C. Y.
Thiel et al. "The Fuel Additive/lubricant Interactions: . . . "
[0004] Zinc dihydrocarbyl dithiophosphates (ZDDP) have been used as
anti-wear additives in lubricant compositions for many years. A
disadvantage of these additives is that, when used to lubricate
internal composition engines, they give rise to ash which
contributes to particulate matter in the exhaust emissions from the
internal combustion engines. It is therefore desirable to reduce
the amount of ash-forming additives used for lubricating internal
combustion engines. It is also desirable to reduce the amount of
zinc and/or phosphorus and/or sulphur in the exhaust emissions from
internal combustion engines. A range of anti-wear additives and/or
friction modifiers which contain neither zinc nor phosphorus, or at
least contain them in reduced amounts, have therefore been
produced.
[0005] Various methods have been developed for testing the
effectiveness of wear reducing additives, including both
ash-forming and ashless additives. A particularly widely used test
is the Sequence IVA test, and a number of organic, ashless
anti-wear components are known to improve performance in these
tests. However, whilst the Sequence IVA test is the key wear test
in the API test sequences, it is not applicable for European ACEA
specifications. The key engine wear test for ACEA specifications is
the diesel OM646LA test. Generally, organic, ashless anti-wear
additives, for example oleamide, that are known to improve
performance in the Sequence IVA test do not give similar benefits
in the OM646LA test. The OM646LA test particularly measures
camshaft wear, and it would therefore be useful to identify
ashless, anti-wear additives that function as anti-camshaft-wear
additives in lubricant compositions, or in fuel compositions when
the fuels are used to lubricate internal combustion engines and at
least a portion of the additives ingress into the lubricating
composition during operation of said engine; for example additives
which enable compositions containing the additives to pass the
OM646LA engine test.
[0006] International patent application publication WO 2008/124191
relates to the use of one or more oil-soluble fatty acid esters of
a polyol in a lubricating oil composition having a base oil
comprising a major amount of a gas-to-liquid (GTL) derived base
oil. Polyols are said to include diols, triols and the like. It is
stated therein that the esters of the polyols are those of
carboxylic acids having 12 to 24 carbon atoms According to WO
2008/124191, preferably the fatty acid ester is a fatty acid ester
of glycerol, more preferably, a monoester of glycerol and most
preferably, the ester is glycerol monooctadecanoate. WO 2008/124191
does not describe the use of glycerides of hydroxy polycarboxylic
acids.
[0007] International patent application publication WO 2011/161406
relates to the use of an oil-soluble mono-, di-, or tri-glyceride
of at least one hydroxy polycarboxylic acid, or a derivative
thereof, as an anti-wear additive and/or friction modifier in a
non-aqueous lubricant composition and/or in a fuel composition.
According to WO 2011/161406, lubricant compositions comprising the
oil-soluble mono-, di-, or tri-glyceride of at least one hydroxy
polycarboxylic acid, or a derivative thereof, may be used to
lubricate internal combustion engines. It is stated that in one
embodiment, the hydroxy polycarboxylic acid has at least one
hydroxy group which is in an alpha position with respect to a
carboxylic moiety. Particularly desirable results are said to have
been obtained with additives in which the glyceride is a glyceride
of citric acid and oleic acid, a glyceride of citric acid and
linoleic acid, or a mixture thereof. WO 2011/161406 does not
describe the use of oil-soluble mono-, di-, or tri-glycerides of at
least one hydroxy polycarboxylic acid, or derivatives thereof, as
anti-camshaft-wear additives.
[0008] There remains a need for alternative compositions exhibiting
anti-camshaft-wear properties, for example for use in non-aqueous
lubricant compositions and/or for use in internal combustion engine
fuel compositions.
[0009] Thus, according to the present invention there is provided
the use of an oil-soluble mono-, di-, or tri-glyceride of at least
one hydroxy polycarboxylic acid, or a derivative thereof, as an
anti-camshaft-wear additive in a non-aqueous lubricant composition
and/or in a fuel composition.
[0010] Also according to another aspect of the present invention
there is provided a method of improving the anti-camshaft-wear
properties of an oil of lubricating viscosity, which method
comprises admixing said oil with an effective amount of at least
one additive which is an oil-soluble mono-, di-, or tri-glyceride
of at least one hydroxy polycarboxylic acid, or a derivative
thereof.
[0011] The present invention solves the technical problem defined
above by the use as an anti-camshaft-wear additive of an
oil-soluble mono-, di-, or tri-glyceride of at least one hydroxy
polycarboxylic acid, or a derivative thereof.
[0012] In at least some examples, the use of an oil-soluble mono-,
di-, or tri-glyceride of at least one hydroxy polycarboxylic acid,
or a derivative thereof, as an anti-camshaft-wear additive in a
non-aqueous lubricant composition and/or in a fuel composition
reduces camshaft wear as measured in the OM646LA engine test.
[0013] Uses of the non-aqueous lubricant composition incorporating
an oil-soluble mono-, di-, or tri-glyceride of at least one hydroxy
polycarboxylic acid, or a derivative thereof, as an
anti-camshaft-wear additive include all conventional lubricant
purposes, for example to lubricate internal combustion engines. In
at least some examples, the lubricating oil composition may
initially be free of oil-soluble mono-, di-, or tri-glycerides of
hydroxy polycarboxylic acids, or derivatives thereof, or contain
only very low amounts thereof, the oil-soluble mono-, di-, or
tri-glyceride of at least one hydroxy polycarboxylic acid, or a
derivative thereof, instead being provided in liquid fuel
composition used to operate an internal combustion engine, and at
least a portion of said glyceride ingressing into the lubricating
oil composition to act as an anti-camshaft-wear additive during the
operation of said engine.
[0014] The amount of oil-soluble mono-, di- or tri-glyceride of at
least one hydroxy polycarboxylic acid, or a derivative thereof,
used as an anti-camshaft-wear additive in a non-aqueous lubricant
composition in accordance with the present invention includes any
amount suitable to reduce camshaft wear, for example an amount
sufficient for the composition to pass the OM646LA engine test, for
example from 0.1 to 5% by weight, from 0.2 to 2.5% by weight or
from 0.5 to 1% by weight.
[0015] In at least some examples, the numerical percentages
referenced in this application may be preceded by the word
"about."
[0016] The amount of oil-soluble mono-, di-, or tri-glyceride of at
least one hydroxy polycarboxylic acid, or a derivative thereof,
used as an anti-camshaft-wear additive in a fuel composition in
accordance with the present invention includes any amount suitable
to cause a lubricating oil composition used to provide lubrication
to an internal combustion engine fueled by the liquid fuel
composition to have anti-camshaft-wear properties following the
ingress of the oil-soluble mono-, di-, or tri-glyceride of at least
one hydroxy polycarboxylic acid, or a derivative thereof, into
lubricating oil composition during operation of said engine, for
example sufficient to provide amounts as discussed above.
[0017] In at least some examples, the hydroxy polycarboxylic acid
of the oil-soluble mono-, di-, or tri-glyceride of at least one
hydroxy carboxylic acid, or a derivative thereof, used as an
anti-camshaft-wear additive has at least one hydroxy group or
derivative (for example ether or ester) thereof, which is in an
alpha position with respect to a carboxylic moiety.
[0018] In at least some examples, each hydroxy polycarboxylic acid
independently has from 4 to 22 carbon atoms, for example 4 to 15
carbon atoms. In at least some examples, the oil-soluble mono-,
di-, or tri-glyceride of at least one hydroxy polycarboxylic acid,
or derivative thereof, has from 16 to 80 carbon atoms. The number
of carbon atoms in the glyceride may affect its solubility in oil
of lubricating viscosity and/or in liquid fuel.
[0019] By oil-soluble is meant that the glyceride is soluble in an
oil of lubricating viscosity and/or a liquid fuel, suitably in an
anti-camshaft-wear improving amount, for example in an amount by
weight of at least 200 ppm in an oil of lubricating viscosity
and/or in an amount by weight of at least 10 ppm in a liquid fuel.
In at least some examples, the solubility is determined at ambient
temperature, for example at 20.degree. C. Methods of determining
the solubility include those for determining solubility at
atmospheric pressure.
[0020] Suitable hydroxy polycarboxylic acids include: [0021] citric
acid (also sometimes called 3-carboxy-3-hydroxy pentanedioic acid;
2-hydroxypropane-1,2,3- tricarboxylic acid; or
3-hydroxypentanedioic acid-3-carboxylic acid); [0022] tartaric acid
(also sometimes called 2,3-dihydroxybutanedioic acid; or
2,3-dihydroxysuccinic acid); [0023] malic acid (also sometimes
called hydroxybutanedioic acid); [0024] monohydroxy trimesic acid;
and [0025] hydrogenated monohydroxy trimesic acid (sometimes also
called 1,3,5 tricarboxy, 2-hydroxy cyclohexane).
[0026] Examples of the oil-soluble mono-, di-, or tri-glyceride of
at least one hydroxy polycarboxylic acid, or a derivative thereof,
include a di-, or tri-glyceride which is a glyceride of at least
one hydroxy polycarboxylic acid and at least one second carboxylic
acid which is a saturated, mono-unsaturated or poly-unsaturated,
branched or linear, monocarboxylic or polycarboxylic acid having 4
to 22 carbon atoms, or a derivative thereof.
[0027] In at least some examples, the second carboxylic acid is
saturated, mono-unsaturated or poly-unsaturated. Suitably, the
second carboxylic acid is unsaturated. In at least some examples,
the second carboxylic acid is branched or linear. In at least some
examples, the second carboxylic acid is a monocarboxylic or
polycarboxylic acid. If the second carboxylic acid is a
polycarboxylic acid, the derivative of the glyceride includes those
in which the glyceride is an ester of the second carboxylic acid
group.
[0028] Suitable saturated second carboxylic acids include caproic
acid, caprylic acid, capric acid, lauric acid, myristic acid,
palmitic acid, stearic acid and arachidic acid. Suitable
unsaturated second carboxylic acids include oleic acid, linoleic
acid, linolenic acid, myristoleic acid, palmitoleic acid, sapienic
acid, erucic acid (also known as cis-13-docosenoic acid) and
brassidic acid.
[0029] In at least some examples, the glyceride is a glyceride of
citric acid and oleic acid, a glyceride of citric acid and linoleic
acid or a mixture thereof.
[0030] In at least some examples, the mono-, di-, or tri-glyceride
of at least one hydroxy polycarboxylic acid or derivative thereof
is represented by the general formula (I):
##STR00001##
wherein RO, OR' and OR'' independently represent: [0031] --OH;
[0032] a saturated, mono-unsaturated or poly-unsaturated, branched
or linear, monocarboxylic or polycarboxylic group having from 4 to
22 carbon atoms or an ether or an ester thereof; or [0033] a
hydroxy polycarboxylic acid moiety or an ether and/or ester
thereof, provided that at least one of RO, OR' and OR'' is a
hydroxy polycarboxylic acid moiety or an ether and/or ester
thereof.
[0034] In at least some examples, in formula (I) at least one of
RO, OR' and OR'' is a hydroxy polycarboxylic acid moiety or an
ether and/or ester thereof and at least one of RO, OR' and OR'' is
a saturated, mono-unsaturated or poly-unsaturated, branched or
linear, monocarboxylic or polycarboxylic group having from 4 to 22
carbon atoms or an ester thereof.
[0035] In at least some examples, in formula (I) the hydroxy
polycarboxylic moiety acid has at least one hydroxy group or
derivative (for example ether or ester) thereof which is in an
alpha position with respect to a carboxylic moiety.
[0036] In at least some examples, in formula (I) each hydroxy
polycarboxylic moiety independently has from 4 to 22 carbon atoms.
In formula (I) the hydroxy polycarboxylic moiety, in at least some
examples, is derivable from acids including, for example, citric
acid, tartaric acid, malic acid, monohydroxy trimesic acid and
hydrogenated monohydroxy trimesic acid.
[0037] In at least some examples, in formula (I), when present,
each saturated, branched or linear, monocarboxylic or
polycarboxylic group having from 4 to 22 carbon atoms or an ester
thereof, is derivable from saturated carboxylic acids or their
halide equivalents. Suitable saturated carboxylic acids include,
for example, caproic acid, caprylic acid, capric acid, lauric acid,
myristic acid, palmitic acid, stearic acid and arachidic acid. In
formula (I) when present, each mono-unsaturated or
poly-unsaturated, branched or linear, monocarboxylic or
polycarboxylic group having from 4 to 22 carbon atoms or an ester
thereof may be derivable from unsaturated carboxylic acids or their
halide equivalents. Suitable mono-unsaturated acids include, for
example, oleic acid, myristoleic acid, palmitoleic acid, sapienic
acid, erucic acid and brassidic acid. Suitable polyunsaturated
acids include, for example, linoleic acid and linolenic acid.
[0038] In at least some examples, the glyceride is a glyceride of
at least one hydroxy polycarboxylic acid and a saturated C.sub.4 to
C.sub.22 polycarboxylic acid, or a derivative thereof. Suitable
polycarboxylic acids include branched and linear acids. In at least
some examples, the glyceride is a glyceride of at least one hydroxy
polycarboxylic acid and a mono-unsaturated or polyunsaturated
C.sub.4 to C.sub.22 polycarboxylic acid, or a derivative thereof.
Suitable polycarboxylic acids include branched or linear acids. In
at least some examples, the glyceride is a glyceride of at least
one hydroxy polycarboxylic acid and a saturated C.sub.4 to C.sub.22
monocarboxylic acid, or a derivative thereof. Suitable
monocarboxylic acids include branched and linear acids. Suitable
saturated C.sub.16 monocarboxylic acids include palmitic acid.
Suitable saturated C.sub.18 monocarboxylic acids include stearic
acid. In at least some examples, the glyceride is a glyceride of at
least one hydroxy polycarboxylic acid and a mono-unsaturated or
polyunsaturated C.sub.4 to C.sub.22 monocarboxylic acid, or a
derivative thereof. Suitable unsaturated monocarboxylic acids
include branched and linear acids. In at least some examples, the
glyceride is a glyceride of at least one hydroxy polycarboxylic
acid and an unsaturated C.sub.18 monocarboxylic acid, or a
derivative thereof. Suitable monocarboxylic acids include branched
or linear acid. Suitable hydroxy polycarboxylic acids include
citric acid. The glyceride additive may be a glyceride of citric
acid and an unsaturated C.sub.18 monocarboxylic acid, or a
derivative thereof. Suitable unsaturated C.sub.18 monocarboxylic
acids include oleic acid and linoleic acid.
[0039] In at least some examples, the glyceride is a citric acid
ester of a mono-glyceride of a saturated, mono-unsaturated or
polyunsaturated, branched or linear, monocarboxylic or
polycarboxylic C.sub.4 to C.sub.22 carboxylic acid, for example a
C.sub.16 or C.sub.18 carboxylic acid, for example palmitic acid,
stearic acid, oleic acid or linoleic acid. Suitable glycerides
include citric acid esters of mono-glyceride made from vegetable
oil, for example sunflower and/or palm oil. Suitable glycerides
include citric acid esters of mono-glyceride made from edible,
refined sunflower and palm based oil. Suitably, the glyceride is a
glyceride of citric acid and oleic acid, a glyceride of citric acid
and linoleic acid or a mixture thereof. A suitable source of
glycerides of citric acid with oleic acid and/or linoleic acid is
GRINSTED CITREM SP70 (Trade Mark) which is available from Danisco.
GRINSTED CITREM SP70 is believed to be a citric acid ester of
mono-glyceride made from edible, refined sunflower and palm based
oil. GRINSTED CITREM SP70 is also believed to comprise at least one
diglyceride having the structural formula (II):
##STR00002##
wherein --Y-- represents a C.sub.16 hydrocarbyl moiety which is
mono- or di-unsaturated.
[0040] Thus, diglycerides having structural formula (II) include a
glyceride of citric acid and oleic acid and a glyceride of citric
acid and linoleic acid. This corresponds to a structure of formula
(I) in which (i) RO represents a carboxyl group having 18 carbon
atoms, which may be derivable from oleic acid and/or linoleic acid,
(ii) OR' represents a hydroxy moiety, and (iii) OR'' represents a
hydroxy polycarboxylic acid moiety, which may be derivable from
citric acid.
[0041] GRINSTED.RTM. CITREM N 12 VEG from Danisco is believed to be
a neutralised citric acid ester of mono-glyceride made from edible,
fully hydrogenated palm based oil. It was found to be unsuitable
because it was not oil soluble.
[0042] The use of GRINSTED.RTM. CITREM 2-IN-1 from Danisco as a
carboxylic acid anionic surfactant is described in paragraphs
[0167] to [0171] of US patent application publication US
2008/0176778. US 2008/0176778 relates to conveyor lubricants
including emulsion of a lipophilic compound and an emulsifier
and/or an anionic surfactant (title). The lipophilic compound is
said to include water insoluble organic compounds including two or
more ester linkages and in one embodiment is said to be a water
insoluble organic compound including three or more oxygen atoms. It
is stated that in one embodiment, the lipophilic compound is an
ester including a di-, tri-, or poly-hydric alcohol, such as
glycerol, with 2 or more of the hydroxy groups each being coupled
to a carboxylic acid as an ester group (paragraph [0033]). In the
example at paragraphs [0167] to [0171], two triglyceride lubricant
compositions were tested. Lubricant A was said to contain an
emulsion of 10 wt % of a caprylate, caprate, cocoate triglyceride
in water to which was added the anionic surfactant 1.5 wt %
lecithin (sold under the trade name Terradrill V408, Cognis) and
the emulsifier 1.5 wt % 20 mol ethoxysorbitan monostearate (sold
under the trade name Tween 60V, ICI). Lubricant B was said to
contain 1.5 wt % citrate ester, said to be a carboxylic acid
anionic surfactant sold under the name GRINSTED.RTM. CITREM 2-IN-1,
Danisco in place of the Terradrill V408. According to paragraph
[0171], Triglyceride lubricants including anionic surfactant worked
well as dry conveyor lubricants and effectively lubricated after
water was applied to the conveyor. According to paragraph [0061] of
US 2008/0176778, the composition therein can include any variety of
anionic surfactants that are effective to increase the ability of
the lipophilic emulsion to withstand application of water to the
conveyor. Examples are given in paragraphs [0065] to [0075] of ten
classes of anionic surfactant.
[0043] According to paragraph [0029] of US patent application
publication US 2009/0152502, hydrophilic emulsifier CITREM is a
composition of matter containing citric esters of mono- and
diglycerides of edible fatty acids. It is also stated therein that
edible fatty acids have, in particular, 6 to 24 carbon atoms.
[0044] The glyceride may be an ester of citric acid with a partial
glyceride, for example mono- or di- glyceride or mixtures thereof,
which have free hydroxy groups. Suitable partial glycerides include
those derived from fatty acids with 12 to 18 carbon atoms,
including for example those derived from coconut oil fatty acids
and palm oil fatty acids. Examples include Lamegin.RTM. ZE 306,
Lamegin.RTM. ZE 609 and Lamegin.RTM. ZE 618 (Cognis Deutschland
GmbH & Co. KG). Thus, suitable glycerides include a citric acid
ester of the monoglyceride of hydrogenated tallow fatty acid, for
example Lamegin.RTM. ZE 309, or an ester of diacetyl tartaric acid
with monoglyceride of hydrogenated tallow fatty acid, for example
Lamegin.RTM. DW 8000, or citric acid ester based on sunflower oil
fatty acid monoglyceride, for example Lamegin.RTM. ZE 609 FL. Such
esters are described, for example, in U.S. Pat. No. 5,770,185 and
US 2010/0087319.
[0045] In at least some examples, the derivative of the glyceride
is an ester of the at least one hydroxy polycarboxylic acid moiety.
Suitable esters include esters of a carboxylic acid moiety of the
hydroxy polycarboxylic acid. In at least some examples, each
carboxylic acid moiety of the hydroxy polycarboxylic acid is
independently derivatisable as an ester. Suitable ester derivatives
include hydrocarbyl esters, in which the hydrocarbyl moiety has,
for example, from 4 to 22 carbon atoms. In at least some examples,
the hydrocarbyl moieties include alkyl moieties which have, for
example, from 4 to 22 carbon atoms. In at least some examples, the
hydrocarbyl moiety comprises one or more hetero atoms, for example
nitrogen and/or oxygen.
[0046] In at least some examples, the derivative of the glyceride
is an ether or an ester of the hydroxy moiety of the hydroxy
polycarboxylic acid. In at least some examples, if more than one
hydroxy moiety is present in the mono-, di-, or tri-glyceride of at
least one hydroxy polycarboxylic acid, each hydroxy moiety is, for
example, independently derivatisable as an ether or an ester.
Suitable ethers include hydrocarbyl ethers. In at least some
examples, the hydrocarbyl moiety of each ether independently has
from 1 to 22 carbon atoms, for example, from 1 to 18 carbon atoms.
In at least some examples, the hydrocarbyl moiety of each ether is
independently an alkyl moiety. Suitable alkyl moieties of each
ether independently include alkyl moieties containing from 1 to 22
carbon atoms, for example, from 1 to 18 carbon atoms. In at least
some examples, the hydrocarbyl moiety of each ether independently
comprises one or more hetero atoms, for example nitrogen and/or
oxygen. In at least some examples, each ester is independently a
hydrocarbyl ester. In at least some examples, the hydrocarbyl
moiety of each ester has from 4 to 22 carbon atoms. Suitable
hydrocarbyl moieties of each ester independently include alkyl
moieties. In at least some examples, the alkyl moiety of each ester
may independently have from 4 to 22 carbon atoms. The hydrocarbyl
moiety of each ester independently comprises one or more hetero
atoms, for example nitrogen and/or oxygen.
[0047] If the saturated, mono-unsaturated or polyunsaturated,
branched or linear carboxylic acid having 4 to 22 carbon atoms is a
polycarboxylic acid, the derivative of the glyceride, in at least
some examples, is an ester of a carboxylic acid moiety of one or
more of the at least one saturated, mono-unsaturated or
poly-unsaturated, branched or linear, polycarboxylic acid
containing from 4 to 22 carbon atoms, if present. In at least some
examples, each ester independently is a hydrocarbyl ester. Suitable
hydrocarbyl moieties of each ester independently include those
containing from 4 to 22 carbon atoms. In at least some examples,
the hydrocarbyl moiety is an alkyl moiety. Suitable alkyl moieties
of each ester independently include those containing from 4 to 22
carbon atoms. In at least some examples, the hydrocarbyl moiety of
each ester independently comprises one or more hetero atoms, for
example nitrogen and/or oxygen.
[0048] The oil-soluble mono-, di-, or tri-glycerides of at least
one hydroxy polycarboxylic acid and derivatives thereof may be made
by methods known in the art. Suitable methods for the preparation
of the di- and tri-glycerides include the partial hydrolysis of a
fat to produce a mono-glyceride followed by esterification with a
hydroxy polycarboxylic acid. Suitable methods for the preparation
of the mono-glycerides include esterification of glycerol with a
hydroxy polycarboxylic acid. In at least some examples, the
hydrocarbyl ether derivatives are made from corresponding
hydrocarbyl halides.
[0049] The oil-soluble mono-, di-, or tri-glycerides of at least
one hydroxy polycarboxylic acid and derivatives thereof do not
contain zinc or molybdenum, that is, they are molybdenum-free and
zinc-free. They also are sulphur-free and phosphorus-free.
[0050] GRINSTED CITREM SP70 (Trade Mark) has low volatility and has
low toxicity.
Lubricant Compositions
[0051] In at least some examples, the oil-soluble mono-, di-, or
tri-glycerides of at least one hydroxy polycarboxylic acid, or
derivatives thereof, are used as anti-camshaft-wear additives in
any suitable lubricant compositions. Similarly, in at least some
examples, the oil-soluble mono-, di-, or tri-glycerides of at least
one hydroxy polycarboxylic acid, or derivatives thereof, are used
to improve the camshaft wear properties of any conventional
lubricant composition. Further details of suitable lubricant
compositions are set out herein. In at least some examples, the
lubricant composition comprises a major amount of oil of
lubricating viscosity and a minor amount of at least one additive.
Major amount means greater than 50% and minor amount means less
than 50% by weight.
[0052] In at least some examples, the lubricant composition and the
oil of lubricating viscosity may comprise base oil. Base oil
comprises at least one base stock. In at least some examples, the
lubricant composition comprises one or more additives other than
the mono-, di-, or tri-glyceride of at least one hydroxy
polycarboxylic acid. In at least some examples, the lubricant
composition and/or the oil of lubricating viscosity comprises base
oil in an amount of from greater than 50% to about 99.5% by weight,
for example from about 85% to about 95% by weight.
[0053] The base stocks may be defined as Group I, II, III, IV and V
base stocks according to API standard 1509, "ENGINE OIL LICENSING
AND CERTIFICATION SYSTEM", April 2007 version 16.sup.th edition
Appendix E, as set out in Table 1.
[0054] Group I, Group II and Group III base stocks may be derived
from mineral oils. Group I base stocks are typically manufactured
by known processes comprising solvent extraction and solvent
dewaxing, or solvent extraction and catalytic dewaxing. Group II
and Group III base stocks are typically manufactured by known
processes comprising catalytic hydrogenation and/or catalytic
hydrocracking, and catalytic hydroisomerisation. A suitable Group I
base stock is AP/E core 150, for example, available from
ExxonMobil. Suitable Group II basestocks include EHC 50 and EHC
110, for example, available from ExxonMobil. Suitable group III
base stocks include Yubase 4 and Yubase 6 available, for example,
from SK Lubricants. Suitable Group V base stocks include ester base
stocks, for example Priolube 3970, available from Croda
International plc. Suitable Group IV base stocks include
hydrogenated oligomers of alpha olefins. Suitably, the oligomers
may be made by free radical processes, Zeigler catalysis or by
cationic Friedel-Crafts catalysis. Polyalpha olefin base stocks may
be derived from C8, C10, C12, C14 olefins and mixtures of one or
more thereof.
TABLE-US-00001 TABLE 1 Saturated Sulphur content hydrocarbon (% by
weight) content (% ASTM D2622 by weight) or D4294 or ASTM D4927 or
Viscosity Index Group D2007 D3120 ASTM D2270 I <90 and/or
>0.03 and .gtoreq.80 and <120 II .gtoreq.90 and .ltoreq.0.03
and .gtoreq.80 and <120 III .gtoreq.90 and .ltoreq.0.03 and
.gtoreq.120 IV polyalpha olefins V all base stocks not in Groups I,
II, III or IV
[0055] In at least some examples, the lubricant composition and the
oil of lubricating viscosity comprise one or more base oil and/or
base stock which is/are natural oil, mineral oil (sometimes called
petroleum-derived oil or petroleum-derived mineral oil),
non-mineral oil and mixtures thereof. Natural oils include animal
oils, fish oils, and vegetable oils. Mineral oils include
paraffinic oils, naphthenic oils and paraffinic-naphthenic oils.
Mineral oils may also include oils derived from coal or shale.
[0056] Suitable base oils and base stocks may be derived from
processes such as chemical combination of simpler or smaller
molecules into larger or more complex molecules (for example
polymerisation, oligomerisation, condensation, alkylation,
acylation).
[0057] Suitable base stocks and base oils may be derived from
gas-to-liquids materials, coal-to-liquids materials,
biomass-to-liquids materials and combinations thereof.
[0058] Suitable gas-to-liquids (sometimes also referred to as GTL
materials) include these obtained by one or more process steps of
synthesis, combination, transformation, rearrangement, degradation
and combinations of two or more thereof applied to gaseous
carbon-containing compounds. Suitable GTL derived base stocks and
base oils include those obtained from the Fischer-Tropsch synthesis
process in which synthesis gas comprising a mixture of hydrogen and
carbon monoxide is catalytically converted to hydrocarbons, usually
waxy hydrocarbons that are generally converted to lower-boiling
materials hydroisomerisation and/or dewaxing (see, for example, WO
2008/124191).
[0059] Suitable biomass-to-liquids (sometimes also referred to as
BTL) materials include those manufactured from compounds of plant
origin, for example by hydrogenation of carboxylic acids or
triglycerides to produce linear paraffins, followed by
hydroisomerisation to produced branched paraffins (see, for
example, WO-2007-068799-A).
[0060] Suitable coal-to-liquids materials include those made by
gasifying coal to make synthesis gas which is then converted to
hydrocarbons.
[0061] In at least some examples, the base oil and/or oil of
lubricating viscosity have a kinematic viscosity at 100.degree. C.
in the range of 2 to 100 cSt, for example in the range of 3 to 50
cSt or in the range 3.5 to 25 cSt.
[0062] In at least some examples, the lubricant composition is a
multi-grade lubricating oil composition according to the API
classification xW-y where x is 0, 5, 10, 15 or 20 and y is 20, 30,
40, 50 or 60 as defined by SAE J300 2004, for example 5W-20, 5W-30,
or OW-20. In at least some examples, the lubricant composition has
a High Temperature High Shear rate (HTHS) viscosity at 150.degree.
C. of at least 2.6 cP, for example as measured according to ASTM
D4683, CEC L-36-A-90 or ASTM D5481.
[0063] In at least some examples, the lubricant composition has an
HTHS viscosity at 150.degree. C. according to ASTM D4683 of from 1
to <2.6 cP, for example about 1.8 cP.
[0064] Methods of preparing the lubricant compositions include
admixing an oil of lubricating viscosity with an effective amount
of at least one additive which is an oil-soluble mono-, di-, or
tri-glyceride of at least one hydroxy polycarboxylic acid, or a
derivative thereof, optionally together with one or more other
lubricant additive.
[0065] Uses and methods of improving the anti-camshaft-wear
properties of an oil of lubricating viscosity according to the
present invention, include admixing an oil of lubricating viscosity
with an effective amount of at least one additive which is an
oil-soluble mono-, di-, or tri-glyceride of at least one hydroxy
polycarboxylic acid, or a derivative thereof.
[0066] In at least some examples, the oil of lubricating viscosity
is admixed with at least one additive in one or more steps by
methods known in the art. In at least some examples, the additives
are admixed as one or more additive concentrates or part additive
package concentrates, optionally comprising solvent or diluent. In
at least some examples, the oil of lubricating viscosity is
prepared by admixing in one or more steps by methods known in the
art, one or more base oils and/or base stocks, optionally with one
or more additives and/or part additive package concentrates. In at
least some examples, the additives, additive concentrates and/or
part additive package concentrates are admixed with oil of
lubricating viscosity or components thereof in one or more steps by
methods known in the art.
Other Anti-Wear Additives
[0067] In at least some examples, the lubricant composition further
comprises at least one anti-wear additive other than the additive
which is an oil-soluble mono-, di-, or tri-glyceride of at least
one hydroxy polycarboxylic acid, or a derivative thereof. Such
other anti-wear additives include ash-producing additives and
ashless additives. Examples of such other anti-wear additives
include non-phosphorus containing additives, for example
sulphurised olefins. Examples of such other anti-wear additives
also include phosphorus-containing anti-wear additives. Examples of
suitable ashless phosphorus-containing anti-wear additives include
trilauryl phosphite and triphenylphosphorothionate and those
disclosed in paragraph [0036] of US 2005/0198894. Examples of
suitable ash-forming, phosphorus-containing anti-wear additives
include dihydrocarbyl dithiophosphate metal salts. Examples of
suitable metals of the dihydrocarbyl dithiophosphate metal salts
include alkali and alkaline earth metals, aluminium, lead, tin,
molybdenum, manganese, nickel, copper and zinc. Suitable
dihydrocarbyl dithiophosphate metal salts include zinc
dihydrocarbyl dithiophosphates (ZDDP). Suitable ZDDP's include
those comprising hydrocarbyl groups independently having 1 to 18
carbon atoms, for example 2 to 13 carbon atoms or 3 to 18 carbon
atoms, or for example 2 to 12 carbon atoms or 3 to 13 carbon atoms,
for example 3 to 8 carbon atoms. Examples of suitable hydrocarbyl
groups include alkyl, cycloalkyl and alkaryl groups, examples of
which include those comprising ether or ester linkages, and also
those that comprise substituent groups, for example halogen or
nitro groups. Suitable hydrocarbyl groups include alkyl groups
including, for example, linear and/or branched alkyl groups
including, for example, those containing from 3 to 8 carbon atoms.
Suitable ZDDP's include those comprising hydrocarbyl groups which
are a mixture of secondary alkyl groups and primary alkyl groups,
for example 90 mol. % secondary alkyl groups and 10 mol. % primary
alkyl groups.
[0068] The oil-soluble mono-, di-, or tri-glyceride of at least one
hydroxy polycarboxylic acid, or a derivative thereof, additive may
reduce the amount of phosphorus- and/or zinc-containing anti-wear
additive which might be required to achieve a desired amount of
anti-wear properties for the lubricant composition.
[0069] In at least some examples, phosphorus-containing anti-wear
additives are present in the lubricating oil composition at a
concentration of 10 to 6000 ppm by weight of phosphorus, for
example 10 to 1000 ppm by weight of phosphorus, or 200 to 1400 ppm
by weight of phosphorus, or 200 to 800 ppm by weight of phosphorus
or 200 to 600 ppm by weight of phosphorus.
[0070] It has been found that the presence in the lubricant
composition of at least one oil-soluble mono-, di-, or
tri-glyceride of at least one hydroxy polycarboxylic acid, or a
derivative thereof, may assist in the performance of anti-wear
additives, such as for example, zinc dihydrocarbyl dithiophosphate
additives. This may reduce the amount of metals, for example zinc,
present in the lubricant composition.
[0071] This may also reduce the amount of phosphorus-containing
anti-wear additives in the lubricant composition, which in turn may
reduce the amount of phosphorus in the exhaust emissions when the
lubricant is used to lubricate an internal combustion engine. The
reduction in the amount of phosphorus in the exhaust emissions may
have benefits for any exhaust after treatment system.
[0072] This may also reduce the amount of sulphur-containing
anti-wear additives in the lubricant composition, which in turn may
reduce the amount of sulphur in exhauster emissions when the
lubricant is used to lubricant an internal combustion engine. The
reduction in the amount of sulphur in exhauster emissions may have
benefits for any exhaust after treatment system.
Other Friction Modifiers.
[0073] In at least some examples, the lubricant composition
comprises at least one friction modifier other than the additive
which is an oil-soluble mono-, di-, or tri-glyceride of at least
one hydroxy polycarboxylic acid, or a derivative thereof. Such
other friction modifiers may be ash-producing additives or ashless
additives. Examples of such other friction modifiers include fatty
acid derivatives including, for example, fatty acid esters, amides,
amines, and ethoxylated amines. Examples of ester friction
modifiers include esters of glycerol, for example mono-, di-, and
tri-oleates, mono-palmitates and mono-myristates, for example
glycerol monooleate. Examples of such other friction modifiers also
include molybdenum compounds, for example organo molybdenum
compounds, molybdenum dialkyldithiocarbamates, molybdenum
dialkylthiophosphates, molybdenum disulphide, tri-molybdenum
cluster dialkyldithiocarbamates, non-sulphur molybdenum compounds
and the like. Suitable molybdenum-containing compounds are
described, for example, in EP-1533362-A1, for example, in
paragraphs [0101] to [0117].
[0074] Examples of friction modifiers other than the additive which
is an oil-soluble mono-, di-, or tri-glyceride of at least one
hydroxy polycarboxylic acid, or a derivative thereof, also include
a combination of an alkoxylated hydrocarbyl amine and a polyol
partial ester of a saturated or unsaturated fatty acid or a mixture
of such esters, for example as described in WO 93/21288.
[0075] In at least some examples, the oil-soluble mono-, di-, or
tri-glyceride of at least one hydroxy polycarboxylic acid, or a
derivative thereof, is used as an alternative to other friction
modifiers and/or to reduce the amount of such other friction
modifiers that might be required to achieve a desired friction
property for the lubricant composition. This may reduce the amount
of metals, for example molybdenum, present in the lubricant
composition.
[0076] In at least some examples, friction modifiers other than the
additive which is an oil-soluble mono-, di-, or tri-glyceride of at
least one hydroxy polycarboxylic acid, or a derivative thereof,
which are fatty acid derivative friction modifiers are present in
the lubricating oil composition at a concentration of 0.01 to 5% by
weight actives, for example in the range of 0.01 to 1.5% by weight
actives.
[0077] In at least some examples, molybdenum containing friction
modifiers are present in the lubricating oil composition at a
concentration of 10 to 1000 ppm by weight molybdenum, for example
in the range of 400 to 600 ppm by weight.
Other Additives.
[0078] In at least some examples, the lubricant composition also
comprises other additives. Examples of such other additives include
dispersants (metallic and non-metallic), dispersant viscosity
modifiers, detergents (metallic and non-metallic), viscosity index
improvers, viscosity modifiers, pour point depressants, rust
inhibitors, corrosion inhibitors, antioxidants (sometimes also
called oxidation inhibitors), anti-foams (sometimes also called
anti-foaming agents), seal swell agents (sometimes also called seal
compatibility agents), extreme pressure additives (metallic,
non-metallic, phosphorus containing, non-phosphorus containing,
sulphur containing and non-sulphur containing), surfactants,
demulsifiers, anti-seizure agents, wax modifiers, lubricity agents,
anti-staining agents, chromophoric agents and metal
deactivators.
Dispersants
[0079] Dispersants (also called dispersant additives) help hold
solid and liquid contaminants, for example resulting from oxidation
of the lubricant composition during use, in suspension and thus
reduce sludge flocculation, precipitation and/or deposition for
example on lubricated surfaces. They generally comprise long-chain
hydrocarbons, to promote oil-solubility, and a polar head capable
of associating with material to be dispersed. Examples of suitable
dispersants include oil soluble polymeric hydrocarbyl backbones
each having one or more functional groups which are capable of
associating with particles to be dispersed. The functional groups
may be amine, alcohol, amine-alcohol, amide or ester groups. In at
least some examples, the functional groups are attached to the
hydrocarbyl backbone through bridging groups. In at least some
examples, more than one dispersant is present in the lubricant
composition.
[0080] Examples of suitable ashless dispersants include oil soluble
salts, esters, amino-esters, amides, imides and oxazolines of long
chain hydrocarbon-substituted mono- and polycarboxylic acids or
anhydrides thereof; thiocarboxylate derivatives of long chain
hydrocarbons; long chain aliphatic hydrocarbons having polyamine
moieties attached directly thereto; Mannich condensation products
formed by condensing a long chain substituted phenol with
formaldehyde and polyalkylene polyamine; Koch reaction products and
the like. Examples of suitable dispersants include derivatives of
long chain hydrocarbyl-substituted carboxylic acids, for example in
which the hydrocarbyl group has a number average molecular weight
of up to 20000, for example 300 to 20000, 500 to 10000, 700 to 5000
or less than 15000. Examples of suitable dispersants include
hydrocarbyl-substituted succinic acid compounds, for example
succinimide, succinate esters or succinate ester amides and in
particular, polyisobutenyl succinimide dispersants. Suitable
dispersants include those that are borated or non-borated. A
suitable non-borated dispersant is ADX 222.
Dispersant Viscosity Modifiers.
[0081] Additionally or alternatively, in at least some examples,
dispersancy is provided by polymeric compounds capable of providing
viscosity index improving properties and dispersancy. Such
compounds are generally known as dispersant viscosity improver
additives or multifunctional viscosity improvers. Methods of
preparing such suitable dispersant viscosity modifiers include
chemically attaching functional moieties (for example, amines,
alcohols and amides) to polymers which tend to have number average
molecular weights of at least 15000, for example in the range 20000
to 600000 (for example, as determined by gel permeation
chromatography or light scattering methods). Examples of suitable
dispersant viscosity modifiers and methods of making them are
described in WO99/21902, WO2003/099890 and WO2006/099250. In at
least some examples, more than one dispersant viscosity modifier is
present in the lubricant composition.
Detergents
[0082] Detergents (also called detergent additives) may help reduce
high temperature deposit formation, for example on pistons in
internal combustion engines, including, for example,
high-temperature varnish and lacquer deposits, by helping to keep
finely divided solids in suspension in the lubricant composition.
Detergents may also have acid-neutralising properties. In at least
some examples, ashless (that is non-metal containing) detergents
are present. Metal-containing detergent comprises at least one
metal salt of at least one organic acid, which is called soap or
surfactant. Detergents may be overbased, in which the detergent
comprises an excess of metal in relation to the stoichiometric
amount required to neutralise the organic acid. The excess metal is
usually in the form of a colloidal dispersion of metal carbonate
and/or hydroxide. Examples of suitable metals include Group I and
Group 2 metals, for example calcium, magnesium and combinations
thereof. In at least some examples, more than one metal is
present.
[0083] Examples of suitable organic acids include sulphonic acids,
phenols (sulphurised or sulphurised and including, for example,
phenols with more than one hydroxy group, phenols with fused
aromatic rings, phenols which have been modified, for example
alkylene bridged phenols, and Mannich base-condensed phenols and
saligenin-type phenols, produced, for example, by reaction of
phenol and an aldehyde under basic conditions) and sulphurised
derivatives thereof, and carboxylic acids including, for example,
aromatic carboxylic acids (for example, hydrocarbyl-substituted
salicylic acids and sulphurised derivatives thereof, for example
hydrocarbyl substituted salicylic acid and derivatives thereof). In
at least some examples, more than one type of organic acid is
present.
[0084] In at least some examples, additionally or alternatively,
non-metallic detergents are present. Suitable non-metallic
detergents are described for example in U.S. Pat. No.
7,622,431.
[0085] In at least some examples, more than one detergent is
present in the lubricant composition and/or additive
concentrate.
Viscosity Index Improvers/Viscosity Modifiers
[0086] Viscosity index improvers (also called viscosity modifiers,
viscosity improvers or VI improvers) impart high and low
temperature operability to a lubricant composition and facilitate
it remaining shear stable at elevated temperatures whilst also
exhibiting acceptable viscosity and fluidity at low
temperatures.
[0087] Examples of suitable viscosity modifiers include high
molecular weight hydrocarbon polymers (for example,
polyisobutylene, copolymers of ethylene and propylene and higher
alpha-olefins); polyesters (for example, polymethacrylates);
hydrogenated poly(styrene-co-butadiene or isoprene) polymers and
modifications (for example, star polymers); and esterified
poly(styrene-co-maleic anhydride) polymers. Oil-soluble viscosity
modifying polymers generally have number average molecular weights
of at least 15,000 to 1,000,000, preferably 20,000 to 600,000, as
determined by gel permeation chromatography or light scattering
methods.
[0088] Viscosity modifiers may have additional functions as
multifunction viscosity modifiers. In at least some examples, more
than one viscosity index improver is present.
Pour Point Depressants
[0089] Pour point depressants (also called lube oil improvers or
lube oil flow improvers), lower the minimum temperature at which
the lubricant will flow and can be poured. Examples of suitable
pour point depressants include C.sub.8 to C.sub.18 dialkyl
fumarate/vinyl acetate copolymers, methacrylates, polyacrylates,
polyarylamides, polymethacrylates, polyalkyl methacrylates, vinyl
fumarates, styrene esters, condensation products of haloparaffin
waxes and aromatic compounds, vinyl carboxylate polymers,
terpolymers of dialkyfumarates, vinyl esters of fatty acids and
allyl vinyl ethers, wax naphthalene and the like.
[0090] In at least some examples, more than one pour point
depressant is present.
Rust inhibitors
[0091] Rust inhibitors generally protect lubricated metal surfaces
against chemical attack by water or other contaminants. Examples of
suitable rust inhibitors include non-ionic polyoxyalkylene polyols
and esters thereof, polyoxyalkylene phenols, polyoxyalkylene
polyols, anionic alkyl sulphonic acids, zinc dithiophosphates,
metal phenolates, basic metal sulphonates, fatty acids and
amines.
[0092] In at least some examples, more than one rust inhibitor is
present.
Corrosion Inhibitors
[0093] Corrosion inhibitors (also called anti-corrosive agents)
reduce the degradation of metallic parts contacted with the
lubricant composition. Examples of corrosion inhibitors include
phosphosulphurised hydrocarbons and the products obtained by the
reaction of phosphosulphurised hydrocarbon with an alkaline earth
metal oxide or hydroxide, non-ionic polyoxyalkylene polyols and
esters thereof, polyoxyalkylene phenols, thiadiazoles, triazoles
and anionic alkyl sulphonic acids. Examples of suitable epoxidised
ester corrosion inhibitors are described in US2006/0090393.
[0094] In at least some examples, more than one corrosion inhibitor
is present.
Antioxidants
[0095] Antioxidants (sometimes also called oxidation inhibitors)
reduce the tendency of oils to deteriorate in use. Evidence of such
deterioration might include, for example, the production of
varnish-like deposits on metal surfaces, the formation of sludge
and viscosity increase. ZDDP's exhibit some antioxidant
properties.
[0096] Examples of suitable antioxidants other than ZDDP's include
alkylated diphenylamines, N-alkylated phenylenediamines,
phenyl-.alpha.-naphthylamine, alkylated
phenyl-.alpha.-naphthylamines, dimethylquinolines,
trimethyldihydroquinolines and oligomeric compositions derived
therefrom, hindered phenolics (including ashless (metal-free)
phenolic compounds and neutral and basic metal salts of certain
phenolic compounds), aromatic amines (including alkylated and
non-alkylated aromatic amines), sulphurised alkyl phenols and
alkali and alkaline earth metal salts thereof, alkylated
hydroquinones, hydroxylated thiodiphenyl ethers,
alkylidenebisphenols, thiopropionates, metallic dithiocarbamates,
1,3,4-dimercaptothiadiazole and derivatives, oil soluble copper
compounds (for example, copper dihydrocarbyl thio- or
thio-phosphate, copper salts of a synthetic or natural carboxylic
acid, for example a C.sub.8 to C.sub.18 fatty acid, an unsaturated
acid or a branched carboxylic acid, for example basic, neutral or
acidic Cu.sup.I and/or Cu.sup.II salts derived from alkenyl
succinic acids or anhydrides), alkaline earth metal salts of
alkylphenolthioesters, for example containing C.sub.5 to C.sub.12
alkyl side chains, calcium nonylphenol sulphide, barium
t-octylphenyl sulphide, dioctylphenylamine, phosphosulphised or
sulphurised hydrocarbons, oil soluble phenates, oil soluble
sulphurised phenates, calcium dodecylphenol sulphide,
phosphosulphurised hydrocarbons, sulphurised hydrocarbons,
phosphorus esters, low sulphur peroxide decomposers and the
like.
[0097] In at least some examples, more than one anti-oxidant is
present. In at least some examples, more than one type of
anti-oxidant is present.
Antifoams
[0098] Anti-foams (sometimes also called anti-foaming agents)
retard the formation of stable foams. Examples of suitable
anti-foam agents include silicones, organic polymers, siloxanes
(including poly siloxanes and (poly) dimethyl siloxanes, phenyl
methyl siloxanes), acrylates and the like.
[0099] In at least some examples, more than one anti-foam is
present.
Seal Swell Agents
[0100] Seal swell agents (sometimes also called seal compatibility
agents or elastomer compatibility aids) help to swell elastomeric
seals, for example by causing a reaction in the fluid or a physical
change in the elastomer. Examples of suitable seal swell agents
include long chain organic acids, organic phosphates, aromatic
esters, aromatic hydrocarbons, esters (for example butylbenzyl
phthalate) and polybutenyl succinic anhydride.
[0101] In at least some examples, more than one seal swell agent is
present.
Other Additives
[0102] In at least some examples, other additives are present in
the lubricant composition and these include, for example, extreme
pressure additives (including metallic, non-metallic, phosphorus
containing, non-phosphorus containing, sulphur containing and
non-sulphur containing extreme pressure additives), surfactants,
demulsifiers, anti-seizure agents, wax modifiers, lubricity agents,
anti-staining agents, chromophoric agents and metal
deactivators.
[0103] Some additives may exhibit more than one function.
[0104] The amount of demulsifier, if present, might be higher than
in conventional lubricants to off-set any emulsifying effect of the
mono-, di-, or tri-glyceride additive.
Solvent
[0105] The additive concentrate for a lubricant composition may
comprise solvent. Examples of suitable solvents include highly
aromatic, low viscosity base stocks, for example 100N, 60N and
100SP base stocks.
[0106] The representative suitable and more suitable independent
amounts of additives (if present) in the lubricant composition are
given in Table 2. The concentrations expressed in Table 2 are by
weight of active additive compounds, that is, independent of any
solvent or diluent.
[0107] In at least some examples, more than one of each type of
additive is present. Within each type of additive, in at least some
examples, more than one class of that type of additive is present.
In at least some examples, more than one additive of each class of
additive is present. In at least some examples, additives are
supplied by manufacturers and suppliers in solvents or
diluents.
TABLE-US-00002 TABLE 2 Lubricant Composition Suitable amount More
suitable amount (actives), if present (actives), if present
ADDITIVE TYPE (by weight) (by weight) Oil-soluble mono-, di-, or
tri-glyceride of at 0.02 to 5% 0.1 to 2.5% least one hydroxy
polycarboxylic acid, or a derivative thereof Phosphorus-containing
anti-wear additives corresponding to 10 corresponding to 10 to 6000
ppm P to 1000 ppm P Molybdenum-containing anti-wear additives
corresponding to 10 corresponding to 40 to 1000 ppm Mo to 600 ppm
Mo Boron-containing anti-wear additives corresponding to 10
corresponding to 50 to 250 ppm B to 100 ppm B Friction modifiers
other than the mono-, di-, 0.01 to 5% 0.01 to 1.5% or tri-glyceride
of at least one hydroxy polycarboxylic acid, or a derivative
thereof Molybdenum-containing friction modifiers corresponding to
10 corresponding to 400 to 1000 ppm Mo to 600 ppm Mo Dispersants
0.1 to 20% 0.1 to 8% Detergents 0.01 to 6% 0.01 to 4% Viscosity
index improvers 0.01 to 20% 0.01 to 15% Pour point depressants 0.01
to 5% 0.01 to 1.5% Corrosion and/or rust inhibitors 0.01 to 5% 0.01
to 1.5% Anti-oxidants 0.1 to 10% 0.5 to 5% Antifoams containing
silicon corresponding to 1 corresponding to 1 to to 20 ppm Si 10
ppm Si
Lubricant Applications.
[0108] In at least some examples, the mono-, di-, or tri-glyceride
of at least one hydroxy polycarboxylic acid, or a derivative
thereof, is used as an anti-camshaft-wear additive in a non-aqueous
lubricant composition and/or in a fuel composition.
[0109] In at least some examples, the oil-soluble mono-, di-, or
tri-glyceride of at least one hydroxy polycarboxylic acid, or a
derivative thereof, is used as an anti-camshaft-wear additive in a
lubricant composition which is a power transmission fluid for
example as an automatic transmission fluid, a fluid in a clutch
(for example a dual clutch), a gear lubricant, or in other
automotive applications and the like.
[0110] In at least some examples, the mono-, di-, or tri-glyceride
of at least one hydroxy polycarboxylic acid, or a derivative
thereof, is used as an anti-camshaft-wear additive in a non-aqueous
lubricant composition and/or in a fuel composition used to
lubricate a solid surface, including for example metallic surfaces
and non-metallic surfaces. Suitable metallic surfaces include
surfaces of ferrous based materials, for example cast iron and
steels; surfaces of aluminium-based solids, for example
aluminium-silicon alloys; surfaces of metal matrix compositions;
surfaces of copper and copper alloys; surfaces of lead and lead
alloys; surfaces of zinc and zinc alloys; and surfaces of
chromium-plated materials. Suitable non-metallic surfaces include
surfaces of ceramic materials; surfaces of polymer materials;
surfaces of carbon-based materials; and surfaces of glass. Other
surfaces which may be lubricated include surfaces of coated
materials, for example surfaces of hybrid materials for example
metallic materials coated with non-metallic materials and
non-metallic materials coated with metallic materials; surfaces of
diamond-like carbon coated materials and SUMEBore.TM. materials for
example, as described in Sulzer technical review 4/2009 pages
11-13.
[0111] In at least some examples, the oil-soluble, mono-, di-, or
tri-glyceride of at least one hydroxy polycarboxylic acid, or a
derivative thereof, is used in a non-aqueous lubricant composition
and/or in a fuel composition to lubricate a surface at any typical
temperature which might be encountered in a lubricating
environment, for example at a temperature such as may be
encountered in an internal combustion engine, for example a
temperature in the range of ambient to 250.degree. C., e.g. 90 to
120.degree. C. Typical ambient temperature is 20.degree. C., but in
at least some examples, is less than 20.degree. C., for example
0.degree. C. or lower.
Internal Combustion Engine Lubrication.
[0112] In at least some examples, the oil-soluble mono-, di-, or
tri-glyceride of at least one hydroxy polycarboxylic acid, or a
derivative thereof, is used as an anti-camshaft-wear additive in a
lubricant composition which is used to lubricate an internal
combustion engine, for example as a crankcase lubricant. Examples
of suitable engines include spark-ignition, internal combustion
engines, and compression-ignition, internal combustion engines. In
at least some examples, the internal combustion engine is a
spark-ignition internal combustion engine used in automotive or
aviation applications. Suitable internal combustion engines include
two-stroke compression-ignition engines and, in at least the
examples, the oil-soluble mono-, di-, or tri-glyceride of at least
one hydroxy polycarboxylic acid, or a derivative thereof, is used
as an anti-camshaft-wear additive in a system oil lubricant
composition and/or a cylinder oil lubricant composition used to
lubricate the engine. In at least some examples, the two-stroke
compression-ignition engine is used in marine applications.
[0113] In at least some examples, additionally, or alternatively
the mono-, di- or tri-glyceride of at least one hydroxy
polycarboxylic acid, or a derivative thereof, is present in the
fuel for an internal combustion engine. In use, the oil-soluble,
mono-, di- or tri-glyceride of at least one hydroxy polycarboxylic
acid, or a derivative thereof, passes with or without fuel into a
lubricant composition used to lubricate the engine, for example as
a crankcase lubricant, and thereby provides anti-camshaft-wear
benefits to the engine.
[0114] Typically, the rate of ingress of fuel into crankcase
lubricant is higher for spark-ignition internal combustion engines
than for compression-ignition engines. However, the rate at which
fuel ingresses into the crankcase lubricant for
compression-ignition engines may depend and may increase depending
upon the use of post-injection strategies for operation of the
engine.
Fuels
[0115] In at least some examples, the oil-soluble mono-, di- or
tri-glyceride of at least one hydroxy polycarboxylic acid, or a
derivative thereof, is used as anti-camshaft-wear additives in any
suitable fuel compositions.
[0116] Suitable liquid fuels, particularly for internal combustion
engines, include hydrocarbon fuels, oxygenate fuels and
combinations thereof. Hydrocarbon fuels may be derived from mineral
sources and/or from renewable sources such as biomass (e.g.
biomass-to-liquid sources) and/or from gas-to-liquid sources and/or
from coal-to-liquid sources. Suitable sources of biomass include
sugar (e.g. sugar to diesel fuel) and algae. Suitable oxygenate
fuels include alcohols, for example straight and/or branched chain
alkyl alcohols having from 1 to 6 carbon atoms, esters, for example
fatty acid alkyl esters and ethers, for example methyl tert butyl
ether. Suitable fuels may also include LPG-diesel fuels (LPG being
liquefied petroleum gas). In at least some examples, the fuel
composition is an emulsion. In at least some examples, the fuel
composition is not an emulsion.
[0117] Suitable fatty acid alkyl esters include methyl, ethyl,
propyl, butyl and hexyl esters. In at least some examples, the
fatty acid alkyl ester is a fatty acid methyl ester. In at least
some examples, the fatty acid alkyl ester has 8 to 25 carbon atoms,
for example 12 to 25 carbon atoms, for example 16 to 18 carbon
atoms. In at least some examples, the fatty acid is saturated. In
at least some examples, the fatty acid is unsaturated. In at least
some examples, the fatty acid alkyl ester is acyclic. Methods of
preparing such fatty acid alkyl esters include esterification of
one or more fatty acids and/or by transesterification of one or
more triglycerides of fatty acids. In at least some examples, the
triglycerides is obtained from vegetable oils, for example castor
oil, soyabean oil, cottonseed oil, sunflower oil, rapeseed oil
(which is sometimes called canola oil), Jatropha oil or palm oil,
or obtained from tallow (for example, sheep and/or beef tallow),
fish oil or used cooking oil. Suitable fatty acid alkyl esters
include rapeseed oil methyl ester (RME), soya methyl ester or
combinations thereof.
[0118] In at least some examples, the fuel compositions are
prepared by admixing in one or more steps a hydrocarbon fuel, an
oxygenate fuel, or a combination thereof, with an effective amount
of at least one additive which is a mono-, di- or tri-glyceride of
at least one hydroxy polycarboxylic acid, or a derivative thereof,
and optionally at least one other fuel additive.
[0119] In at least some examples, the use and the method of
improving the anti-camshaft-wear properties of a liquid fuel of the
present invention comprises admixing in one or more steps said
liquid fuel (which may be, for example, a hydrocarbon fuel, an
oxygenate fuel or a combination thereof) with an effective amount
of at least one additive which is a mono-, di- or tri-glyceride of
at least one hydroxy polycarboxylic acid, or a derivative thereof,
and optionally at least one other fuel additive.
[0120] In at least some examples, the fuel is admixed with at least
one additive in one or more steps by methods known in the art. In
at least some examples, the additives are admixed as one or more
additive concentrates or part additive package concentrates,
optionally comprising solvent or diluent. In at least some
examples, the hydrocarbon fuel, oxygenate fuel or combination
thereof is prepared by admixing in one or more steps by methods
known in the art, one or more base fuels and components therefor,
optionally with one or more additives and/or part additive package
concentrates. In at least some examples, the additives, additive
concentrates and/or part additive package concentrates is admixed
with the fuel or components therefor in one or more steps by
methods known in the art.
Fuels For Compression-Ignition Engines.
[0121] In at least some examples, the fuel composition comprising
an oil-soluble, mono-, di- or tri-glyceride of at least one hydroxy
polycarboxylic acid, or a derivative thereof, as an
anti-camshaft-wear additive is suitable for use in an internal
combustion engine which is a compression-ignition internal
combustion engine, suitably a direct injection diesel engine, for
example of the rotary pump, in-line pump, unit pump, electronic
unit injector or common rail type, or in an indirect injection
diesel engine. In at least some examples, the fuel composition is
suitable for use in heavy and/or light duty diesel engines.
[0122] In at least some examples, the fuel composition for
compression-ignition internal combustion engines has a sulphur
content of up to 500 ppm by weight, for example up to 15 ppm by
weight or up to 10 ppm by weight. In at least some examples, the
fuel composition for compression-ignition internal combustion
engines meets the requirements of the EN590 standard, for example
as set out in BS EN 590:2009.
[0123] In at least some examples, oxygenate components in the fuel
composition for compression-ignition internal combustion engines
include fatty acid alkyl esters, for example fatty acid methyl
esters. In at least some examples, the fuel comprises one or more
fatty acid methyl esters complying with EN 14214 at a concentration
of up to 7% by volume. In at least some examples, oxidation
stability enhancers are present in the fuel composition, comprising
one or more fatty acid alkyl or methyl esters, for example at a
concentration providing an action similar to that obtained with
1000 mg/kg of 3,5-di-tert-butyl-4-hydroxy-toluol (also called
butylated hydroxy-toluene or BHT). In at least some examples, dyes
and/or markers are present in the fuel composition for
compression-ignition internal combustion engines.
[0124] In at least some examples, the fuel composition for
compression-ignition internal combustion engines have one or more
of the following, for example, as defined according to BS EN
590:2009:--a minimum cetane number of 51.0, a minimum cetane index
of 46.0, a density at 15.degree. C. of 820.0 to 845.0 kg/m.sup.3, a
maximum polycyclic aromatic content of 8.0% by weight, a flash
point above 55.degree. C., a maximum carbon residue (on 10%
distillation) of 0.30% by weight, a maximum water content of 200
mg/kg, a maximum contamination of 24 mg/kg, a class 1 copper strip
corrosion (3 h at 50.degree. C.), a minimum oxidation stability
limit of 20 h according to EN 15751 and a maximum oxidation
stability limit of 25 g/m.sup.3 according to EN ISO 12205, a
maximum limit for lubricity corrected wear scar diameter at
60.degree. C. of 460 .mu.m, a minimum viscosity at 40.degree. C. of
2.00 mm.sup.2/s and a maximum viscosity at 40.degree. C. of 4.50
mm.sup.2/s, <65% by volume distillation recovery at 250.degree.
C., a minimum distillation recovery at 350.degree. C. of 85% by
volume and a maximum of 95% by volume recovery at 360.degree.
C.
[0125] In at least some examples, the fuel composition suitable for
use in a compression-ignition internal combustion engine further
comprises at least one friction modifier other than the additive
which is a mono-, di- or tri-glyceride of at least one hydroxy
polycarboxylic acid, or a derivative thereof. Such other friction
modifiers include compounds described herein as friction modifiers
for lubricant compositions and additive concentrates for lubricant
compositions.
[0126] In at least some examples, the fuel composition suitable for
use with a compression-ignition internal combustion engine further
comprises at least one lubricity additive. Suitable lubricity
additives include tall oil fatty acids, mono- and di-basic acids
and esters.
[0127] In at least some examples, the fuel composition suitable for
use in a compression-ignition internal combustion engine further
comprises independently one or more cetane improver, one or more
detergent, one or more anti-oxidant, one or more anti-foam, one or
more demulsifier, one or more cold flow improver, one or more pour
point depressant, one or more biocide, one or more odorant, one or
more colorant (sometimes called dyes), one or more marker, one or
more spark aiders and/or combinations of one or more thereof. In at
least some examples, other suitable additives are present,
including one or more thermal stabilizers, metal deactivators,
corrosion inhibitors, antistatic additives, drag reducing agents,
emulsifiers, dehazers, anti-icing additives, antiknock additives,
anti-valve-seat recession additives, surfactants and combustion
improvers, for example as described in EP-2107102-A.
[0128] In at least some examples, the additive concentrate for a
fuel composition for a compression-ignition internal combustion
engine comprises one or more solvents, for example carrier oils
(for example, mineral oils), polyethers (which may be capped or
uncapped), non-polar solvents (for example, toluene, xylene, white
spirits and those sold by Shell companies under the trade mark
"SHELLSOL"), and polar solvents (for example esters and alcohols
e.g. hexanol, 2-ethylhexanol, decanol, isotridecanol and alcohol
mixtures, for example those sold by Shell companies under the trade
mark "LINEVOL", e.g. LINEVOL 79 alcohol which is a mixture of
C.sub.7-9 primary alcohols, or a C.sub.12-14 alcohol mixture which
is commercially available.
[0129] Suitable cetane improvers include 2-ethyl hexyl nitrate,
cyclohexyl nitrate and di-tert-butyl peroxide. Suitable antifoams
include siloxanes. Suitable detergents include polyolefin
substituted succinimides and succinimides of polyamines, for
example polyisobutylene succinimides, polyisobutylene amine
succinimides, aliphatic amines, Mannich bases and amines and
polyolefin (e.g. polyisobutylene) maleic anhydride. Suitable
antioxidants include phenolic antioxidants (for example
2,6-di-tert-butylphenol) and aminic antioxidants (for example
N,N'-di-sec-butyl-p-phenylenediamine). Suitable anti-foaming agents
include polyether-modified polysiloxanes.
[0130] The representative suitable and more suitable independent
amounts of additives (if present) in the fuel composition suitable
for a compression-ignition engine are given in Table 3. The
concentrations expressed in Table 3 are by weight of active
additive compounds that is, independent of any solvent or
diluent.
[0131] In at least some examples, the additives in the fuel
composition suitable for use in compression-ignition internal
combustion engines are suitably present in a total amount in the
range of 100 to 1500 ppm by weight.
TABLE-US-00003 TABLE 3 Fuel composition for compression- ignition
internal combustion engine Suitable amount More suitable (actives),
if amount (actives), if present present Additive type (ppm by
weight) (ppm by weight) Oil-soluble mono-, di-, or tri- 20 to 500
20 to 200 glyceride of at least one hydroxy polycarboxylic acid, or
a derivative thereof Lubricity additives 1 to 200 50 to 200 Cetane
improvers 50 to 2000 100 to 1200 Detergents 20 to 300 50 to 200
Anti-oxidants 1 to 100 2 to 50 Anti foams 1 to 50 5 to 20
Demulsifiers 1 to 50 5 to 25 Cold flow improvers 10 to 500 50 to
100
Fuels For Spark-ignition Engines.
[0132] In at least some examples, the fuel composition comprising
an oil-soluble, mono-, di- or tri-glyceride of at least one hydroxy
polycarboxylic acid, or a derivative thereof, as an
anti-camshaft-wear additive is suitable for use in an internal
combustion engine which is a spark-ignition internal combustion
engine.
[0133] In at least some examples, the fuel composition for
spark-ignition internal combustion engines has a sulphur content of
up to 50.0 ppm by weight, for example up to 10.0 ppm by weight.
[0134] In at least some examples, the fuel composition for
spark-ignition internal combustion engines is leaded or
unleaded.
[0135] In at least some examples, the fuel composition for
spark-ignition internal combustion engines meets the requirements
of EN 228, for example as set out in BS EN 228:2008. In at least
some examples, the fuel composition for spark-ignition internal
combustion engines meets the requirements of ASTM D 4814-09b.
[0136] In at least some examples, the fuel composition for
spark-ignition internal combustion engines has one or more of the
following, for example, as defined according to BS EN 228:2008:--a
minimum research octane number of 95.0, a minimum motor octane
number of 85.0 a maximum lead content of 5.0 mg/l, a density of
720.0 to 775.0 kg/m.sup.3, an oxidation stability of at least 360
minutes, a maximum existent gum content (solvent washed) of 5
mg/100 ml, a class 1 copper strip corrosion (3 h at 50.degree. C.),
clear and bright appearance, a maximum olefin content of 18.0% by
weight, a maximum aromatics content of 35.0% by weight, and a
maximum benzene content of 1.00% by volume.
[0137] In at least some examples, oxygenate components in the fuel
composition for spark-ignition internal combustion engines include
straight and/or branched chain alkyl alcohols having from 1 to 6
carbon atoms, for example methanol, ethanol, n-propanol, n-butanol,
isobutanol, tert-butanol. In at least some examples, oxygenate
components in the fuel composition for spark-ignition internal
combustion engines include ethers, for example having 5 or more
carbon atoms. In at least some examples, the fuel composition has a
maximum oxygen content of 2.7% by mass. In at least some examples,
the fuel composition has maximum amounts of oxygenates, as
specified in EN 228, for example methanol: 3 0% by volume, ethanol:
5.0% by volume, iso-propanol: 10.0% by volume, iso-butyl alcohol:
10.0% by volume, tert-butanol: 7.0% by volume, ethers (C.sub.5 or
higher): 10% by volume and other oxygenates (subject to suitable
final boiling point): 10.0% by volume. In at least some examples,
the fuel composition comprises ethanol complying with EN 15376 at a
concentration of up to 5.0% by volume.
[0138] In at least some examples, the fuel composition suitable for
use in a spark-ignition internal combustion engine further
comprises at least one friction modifier other than the additive
which is a mono-, di- or tri-glyceride of at least one hydroxy
polycarboxylic acid, or a derivative thereof. In at least some
examples, such other friction modifiers include compounds described
herein as friction modifiers for lubricant compositions and
additive concentrates for lubricant compositions.
[0139] In at least some examples, the fuel composition suitable for
use in a spark-ignition internal combustion engine further
comprises independently one or more detergent, one or more octane
improver, one or more friction modifier, one or more anti-oxidant,
one or more valve seat recession additive, one or more corrosion
inhibitor, one or more anti-static agent, one or more odorant, one
or more colorant, one or more marker and/or combinations of one or
more thereof.
[0140] In at least some examples, the additive concentrate for a
fuel composition for a spark-ignition internal combustion engine
comprises one or more solvents, for example polyethers and aromatic
and/or aliphatic hydrocarbons, for example heavy naphtha e.g.
Solvesso (Trade mark), xylenes and kerosine.
[0141] Suitable detergents include poly isobutylene amines (PIB
amines) and polyether amines.
[0142] Suitable octane improvers include N-methyl aniline, methyl
cyclopentadienyl manganese tricarbonyl (MMT) (for example present
at a concentration of up to 120 ppm by weight), ferrocene (for
example present at a concentration of up to 16 ppm by weight) and
tetra ethyl lead (for example present at a concentration of up to
0.7 g/l, e.g. up to 0.15 g/l).
[0143] Suitable anti-oxidants include phenolic anti-oxidants (for
example 2,4-di-tert-butylphenol and
3,5-di-tert-butyl-4-hydroxyphenylpropionic acid) and aminic
anti-oxidants (for example para-phenylenediamine, dicyclohexylamine
and derivatives thereof).
[0144] Suitable corrosion inhibitors include ammonium salts of
organic carboxylic acids, amines and heterocyclic aromatics, for
example alkylamines, imidazolines and tolyltriazoles.
[0145] In at least some examples, valve seat recession additives
are present at a concentration of up to 15000 ppm by weight, for
example up to 7500 ppm by weight.
[0146] The representative suitable and more suitable independent
amounts of additives (if present) in the fuel composition suitable
for a spark-ignition engine are given in Table 4. The
concentrations expressed in Table 4 are by weight of active
additive compounds that is, independent of any solvent or
diluent.
[0147] In at least some examples, the additives in the fuel
composition suitable for use in spark-ignition internal combustion
engines are present in a total amount in the range of 20 to 25000
ppm by weight.
TABLE-US-00004 TABLE 4 Fuel composition for spark-ignition internal
combustion engine Suitable amount More suitable (actives), if
amount (actives), if present present Additive type (ppm by weight)
(ppm by weight) Oil-soluble mono-, di-, or tri- 20 to 500 20 to 200
glyceride of at least one hydroxy polycarboxylic acid, or a
derivative thereof Friction modifiers other than 10 to 500 25 to
150 mono-, di-, or tri-glyceride of at least one hydroxy
polycarboxylic acid, or a derivative thereof Detergents 10 to 2000
50 to 300 Octane improvers 50 to 20000 Anti-oxidants 1 to 100 10 to
50 Anti-static agents 0.1 to 5 0.5 to 2
[0148] The invention will now be described by way of example only
with reference to the following experiments and examples in which
examples according to the present invention are labeled numerically
as Example 1, Example 2, etc. and experiments not according to the
present invention are labeled alphabetically as Experiment A,
Experiment B, etc.
Preparation of Lubricant Compositions.
[0149] A lubricant composition (Lubricant A) was prepared to model
a typical lubricant composition suitable for passenger cars with
either compression-ignition or spark-ignition internal combustion
engines. The lubricant composition was made by admixing additives
as in a commercially available additive package containing
dispersant, calcium sulphonate and calcium phenate detergents,
antioxidant, antifoam and ZDDP with Group III base oil, a pour
point depressant and a viscosity modifier.
[0150] A lubricant composition (Lubricant B) was prepared in the
same way as Lubricant A, but with the addition of 0.2% by weight of
oleamide.
[0151] A lubricant composition (Lubricant 1) according to the
invention was prepared in the same way as Lubricant A, but with the
addition of 0.5 Citrem SP 70 (Trade Mark) (a diglyceride of citric
acid and oleic/linoleic acid).
[0152] A lubricant composition (Lubricant C) was prepared to model
a typical lubricant composition suitable for passenger cars with
either compression-ignition or spark-ignition internal combustion
engines. The lubricant composition was made by admixing additives
as in a commercially available additive package containing
dispersant, calcium sulphonate and calcium phenate detergents,
antioxidant, antifoam and ZDDP with Group I and III base oils, a
pour point depressant and a viscosity modifier.
[0153] A lubricant composition (Lubricant D) was prepared in the
same way as Lubricant C, but with the addition of 0.2% by weight of
oleamide.
[0154] A lubricant composition (Lubricant 2) according to the
invention was prepared in the same way as Lubricant C, but with the
addition of 0.5% Citrem SP 70 (Trade Mark) (a diglyceride of citric
acid and oleic/linoleic acid).
[0155] Lubricants A to D are not according to the present invention
because the lubricant compositions do not contain an oil-soluble
mono-, di-, or tri-glyceride of at least one hydroxy polycarboxylic
acid, or a derivative thereof, in particular a diglyceride of
citric acid and an unsaturated C.sub.18 carboxylic acid (e.g. oleic
and/or linoleic acid), for example Citrem SP70 (Trade Mark).
Lubricants 1 and 2 are according to the present invention.
Anti-Wear Testing of Lubricant Compositions.
[0156] 1. Sequence IVA Engine Test
[0157] Sequence IVA engine tests according to ASTM test method ASTM
D6891 were undertaken for Lubricants A and B, as well as for
Lubricant 1. The Sequence IVA test is an industry standard test
used to evaluate the camshaft wear protection of internal
combustion engine lubricant compositions. This test method is
designed to simulate extended engine idling vehicle operation. The
primary result is camshaft lobe wear (measured at seven locations
around each of the twelve lobes) and the pass/fail criteria for the
test include a maximum average seven-location cam lobe wear of 90
microns (.mu.m).
[0158] The results for the tests are shown in Table 5. Experiments
A and B are not according to the present invention because the
lubricant compositions do not contain an oil-soluble mono-, di-, or
tri-glyceride of at least one hydroxy polycarboxylic acid, or a
derivative thereof, in particular a diglyceride of citric acid and
an unsaturated C.sub.18 carboxylic acid (e.g. oleic and/or linoleic
acid), for example Citrem SP70 (Trade Mark). Example 1 is according
to the present invention.
[0159] The results in Table 5 show that both oleamide and an
oil-soluble mono-, di-, or tri-glyceride of at least one hydroxy
polycarboxylic acid, or a derivative thereof, in particular a
diglyceride of citric acid and an unsaturated C.sub.18 carboxylic
acid (e.g. oleic and/or linoleic acid), for example Citrem SP70
(Trade Mark), significantly reduce cam lobe wear and are thus
effective as anti-camshaft-wear additives in the Sequence IVA
test.
TABLE-US-00005 TABLE 5 Treat rate Average Anti- of anti- cam lobe
camshaft- wear wear wear additive (micron, Lubricant additive (wt.
%) .mu.m) Expt. A A -- -- 42.56 Expt. B B Oleamide 0.2% 24.38
Example 1 1 Citrem 0.5% 22.17 SP70
[0160] 2. OM646LA Engine Test
[0161] OM646LA (CEC L-99-08) engine tests were undertaken for
Lubricants C and D, as well as for Lubricant 2. This 300 hour
cyclic test uses a 4 cylinder 2.2L diesel OM646 DE 22 LA engine to
evaluate engine lubricant performance with respect to engine wear
and overall cleanliness, as well as piston cleanliness and ring
sticking, under severe operating conditions. The primary result is
cam wear, although bore polish, cylinder wear and tappet wear may
also be measured.
[0162] The results for the tests are shown in Table 6. Experiments
C and D are not according to the present invention because the
lubricant compositions do not contain an oil-soluble mono-, di-, or
tri-glyceride of at least one hydroxy polycarboxylic acid, or a
derivative thereof, in particular a diglyceride of citric acid and
an unsaturated C.sub.18 carboxylic acid (e.g. oleic and/or linoleic
acid), for example Citrem SP70 (Trade Mark). Example 2 is according
to the present invention.
[0163] The results in Table 6 show that there is moderately high
camshaft wear in the OM646LA test in respect of Lubricant C, which
contains no anti-camshaft-wear additive (Experiment C). No
appreciable reduction in camshaft wear is observed as a result of
the presence of oleamide additive in Lubricant D (Experiment D). In
contrast, a significant reduction in camshaft wear is observed for
Lubricant 2, containing Citrem SP70 (trade mark) (Example 2). Thus,
the results demonstrate that an oil-soluble mono-, di-, or tri-
glyceride of at least one hydroxy polycarboxylic acid, or a
derivative thereof, in particular a diglyceride of citric acid and
an unsaturated C.sub.18 carboxylic acid (e.g. oleic and/or linoleic
acid), for example Citrem SP70 (Trade Mark), is effective as an
anti-camshaft-wear additive in the OM646LA test.
TABLE-US-00006 TABLE 6 Experiment Experiment C D Example 2
Lubricant C D 2 Anti-Camshaft-Wear -- Oleamide Citrem SP70 Additive
Treat rate of Anti-Camshaft- -- 0.2% 0.9% Wear Additive (wt. %)
Avg. Inlet camshaft (mm) 60.06 63.7 39.1 Avg. Outlet camshaft (mm)
111.4 105 35.7
In contrast to known anti-wear additives, such as oleamide, an
oil-soluble mono-, di-, or tri-glyceride of at least one hydroxy
polycarboxylic acid, or a derivative thereof, in particular a
diglyceride of citric acid and an unsaturated C.sub.18 carboxylic
acid (e.g. oleic and/or linoleic acid), for example Citrem SP70
(Trade Mark), is surprisingly effective as an anti-camshaft-wear
additive in both Sequence IVA and OM646LA wear tests.
* * * * *