Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02742292 2016-09-22
TITLE
Lubrication of Internal Combustion Engines in the Presence of Water
Contaminant
FIELD OF INVENTION
The invention provides a method of lubricating an internal combustion
engine in the presence of a contaminant amount of water. The invention
further relates to the use of a derivative of a hydroxy-carboxylic acid as a
rust
inhibitor.
qACKGROUND OF THE. INVENTION
[00011 Many modern lubricating
oil formulations require the addition of
rust inhibitors to prevent or inhibit rust formation, most often caused by
water
contacting a ferro-metallic based surface. The water is believed to originate
as
a fuel combustion by-product. The water is believed to ingress through
equipment seals or engine blow-by during operation. Some of the contaminant
water may then reside in the crankcase, thereby contaminating the lubricant,
In
most instances the amount of water may be up to 50 ppm or less (typically less
than 25 ppm). In order to overcome the rust formation, detergents and other
ash-containing additives have been employed. However, recent trends towards
reducing the sulphur, sulphated ash and phosphorus levels of lubricants may
result in increased occurrences of rust formation.
[0002] The problem highlighted
above is believed to be increased for
mechanical devices (typically internal combustion engines) where there may be
significant amounts of water contacting the ferro-metallic based surface. This
example may be exacerbated in salt water e.g., sea water. For example,
internal
combustion engines used in recreational modes of transport like power boats,
snowmobiles, jet-skis, or all-terrain vehicles may be susceptible. Internal
combustion engines may be outboards, inboards or stern drive engines.
[0(1031 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. The tartrates are disclosed as antiwear agents.
[0004] International Publications WO 2006/044411, WO 2006/147704 and
WO 2008/147700
CA 02742292 2016-09-22
disclose lubricating compositions
containing tartrates and/or
tartrimidcs in lubricants for internal combustion engines requiring reduced
amounts of sulphur, sulphated ash, and phosphorus. The lubricant composition
has anti-wear or anti-fatigue properties. The lubricating compositions are
suitable for road vehicles.
[00051 U.S. Patent 4,237,022
discloses tartrimides useful as additives in
lubricants and fuels for effective reduction in squeal and friction as well as
improvement in fuel economy.
100061 US Patent 5,338,470 and
International Publication WO 2005/087904
disclose lubricants containing at least one hydroxycarboxylic acid ester or
hydroxy polycarboxylic acid (in particular citrates). The lubricant
composition
has anti-wear or anti-fatigue properties.
[00071 EBLANN
[0008] None of the references
disclosed above have contemplated reduction
or prevention of iron corrosion (may also be referred to as rust inhibition).
SUMMARY OF 'THE iNvEgrroN
[00091 The inventors of the
present invention have discovered that a
lubricating composition containing an amide, ester or imide derivative of a
hydroxy-earboxylic acid , a method and use as disclosed herein is capable of
providing rust inhibition, in particular in the internal combustion engines
disclosed herein.
(0010f in one embodiment the
invention provides a method for lubricating
an internal combustion engine using a lubricating composition comprising:
(a) an oil of lubricating viscosity;
(b) either:
(i) an amide, ester or imide derivative of a hydroxy-carboxylic
acid , or
(ii) a monoestcr of a polyol and an aliphatic carboxylic acid; and
(c) a contaminant amount of water, wherein the water is present at 500
ppm or more.
2
CA 02742292 2011-04-29
WO 2010/053893
PCT/US2009/063054
[0011] The amide, ester or imide derivative of a hydroxy-carboxylic acid,
the monoester of a polyol and an aliphatic carboxylic acid, or mixtures
thereof
may be present in the lubricating composition at 0.01 wt % to 2 wt %, or 0.1
wt
% to 1 wt %, or 0.2 wt % to 0.6 wt % of the lubricating composition.
[0012] In one embodiment the invention provides a method of lubricating
an
internal combustion engine with an engine capacity of six litres or less
comprising supplying to said engine a lubricating composition comprising:
(a) an oil of lubricating viscosity;
(b) either:
(i) an amide, ester or imide derivative of a hydroxy-carboxylic
acid, or
(ii) a monoester of a polyol and an aliphatic carboxylic acid; and
(c) a contaminant amount of water, wherein the water is present at 500
ppm or more.
[0013] In one embodiment the invention provides for the use of an amide,
ester or imide derivative of a hydroxy-carboxylic acid as a rust inhibitor in
a
water-contaminated lubricant for an internal combustion engine with an engine
capacity of six litres or less.
[0014] In one embodiment the invention provides for the use of monoester
of a polyol and an aliphatic carboxylic acid as a rust inhibitor in a water-
contaminated lubricant for an internal combustion engine with an engine
capacity of six litres or less.
DETAILED DESCRIPTION OF THE INVENTION
[0015] The present invention provides a method and use as disclosed
above.
Contaminant Water
[0016] The contaminant water may be present in the lubricating
composition at
550 ppm or more, 600 ppm or more, or 750 ppm or more. In one embodiment the
amount of contaminant water in the lubricating composition may be at least
0.09 wt % to 3 wt %, or 0.1 wt % to 0.5 wt % water. The water may be fresh
water or salt water, or sea water. The sea water contains various salts of
magnesium, sodium, potassium, and calcium. Examples include magnesium,
sodium, potassium, and calcium chlorides, carbonates and bromides. A person
3
CA 02742292 2011-04-29
WO 2010/053893
PCT/US2009/063054
skilled in the art will appreciate that the contaminant water is typically
incorporated into the lubricating composition during normal use of the
internal
combustion engine with an engine capacity of six litres or less.
Amide, Ester or Imide Derivative of a Hydroxy-Carboxylic Acid
[0017] The amide, ester or imide derivative of a hydroxy-carboxylic acid
(typically a hydroxy-polycarboxylic acid), or mixtures thereof may be
employed in the present invention as rust inhibitors (i.e., reduce or prevent
corrosion of iron).
[0018] In one embodiment the amide, ester or imide derivative of a
hydroxy-carboxylic acid may be at least one of a hydroxy-polycarboxylic acid
di-ester, a hydroxy-polycarboxylic acid di-amide, a hydroxy-polycarboxylic
acid di-imide, a hydroxy-polycarboxylic acid ester-amide, a hydroxy-
polycarboxylic acid ester-imide, and a hydroxy-polycarboxylic acid imide-
amide. In one embodiment the amide, ester or imide derivative of a hydroxy-
polycarboxylic acid may be derived from at least one of the group consisting
of
a hydroxy-polycarboxylic acid di-ester, a hydroxy-polycarboxylic acid di-
amide, and a hydroxy-polycarboxylic acid ester-amide.
[0019] Examples of a suitable hydroxycarboxylic acid include mandelic
acid, malic acid, citric acid, tartaric acid, lactic acid, glycolic acid,
hydroxy-
propionic acid, hydroxyglutaric acid, or mixtures thereof. In one embodiment
the amide, ester or imide derivative of a hydroxy-carboxylic acid may be
derived from tartaric acid, citric acid, hydroxy-succinic acid, dihydroxy mono-
acids, mono-hydroxy diacids, or mixtures thereof. In one embodiment the
amide, ester or imide derivative of a hydroxy-carboxylic acid include a
compound derived from tartaric acid or citric acid. In one embodiment the
amide, ester or imide derivative of a hydroxy-carboxylic acid may include a
compound derived from tartaric acid.
[0020] In one embodiment the derivative of a hydroxy-carboxylic acid is
either an ester or imide. The ester derivative of a hydroxy-carboxylic acid
may
be a tartrate. The imide derivative of a hydroxy-carboxylic acid may be a
tartrimide, that is, a tartarimide..
4
CA 02742292 2011-04-29
WO 2010/053893
PCT/US2009/063054
[0021] In one embodiment the rust inhibitor is provided by an imide
derivative of a hydroxy-carboxylic acid.
[0022] US Patent Applications US 60/939949 (filed May 24, 2007), now
W02008/147704, and US 60/939952 (filed May 24, 2007), now
W02008/147700, disclose suitable hydroxycarboxylic acid compounds, and
methods of preparing the same.
[0023] Canadian Patent 1 183 125; US Patent Publication numbers
2006/0183647 and US-2006-0079413; US Patent Application number
60/867402 now W02008/067259; and British Patent 2 105 743 A, all disclose
examples of suitable tartaric acid derivatives.
[0024] In one embodiment the amide, ester or imide derivative of a
hydroxy-carboxylic acid may be represented by Formula (1) (that is, la or lb):
7
fty 11) N
(XN
\ P
Formula (la)
or
0 0
R1 y 11 (4. 11 Y R2
Formula (lb)
wherein
n' is 0 to 10 for Formula (lb), and 1 to 10 for Formula (la);
p is 1 to 5;
Y and Y' are independently -0-, >NH, >NR3, or an imide group formed
by taking together both Y and Y' groups in (lb) or two Y groups in (la) and
forming a Ri-N< group between two >C=0 groups;
X is independently -CH2-, >CHR4 or >CR4R5, >CHOR6, or >C(CO2R6)2,
or >C(0R6)CO2R6, or -CH3, -CH2R4 or CHR4R5, -CH2OR6, or -CH(CO2R6)2,
C-R6 (where equals three valences, and may only apply to Formula (la)) or
mixtures thereof to fulfill the valence of Formula (la) and/or (lb) (typically
the
CA 02742292 2011-04-29
WO 2010/053893
PCT/US2009/063054
compound of Formula (la) or (lb) has at least one X that is hydroxyl-
containing (i.e., >CHOR6, wherein R6 is hydrogen));
Rl and R2 are independently hydrocarbyl groups, typically containing 1
to 150, or 4 to 30, or 8 to 15 carbon atoms;
R3 is a hydrocarbyl group;
R4 and R5 are independently keto-containing groups (such as acyl
groups), ester groups or hydrocarbyl groups; and
R6 is independently hydrogen or a hydrocarbyl group, typically
containing 1 to 150, or 4 to 30, or 8 to 15 carbon atoms.
[0025] In one embodiment the compound of Formula (1) contains an imide
group. The imide group is typically formed by taking together the Y and Y'
groups and forming a Ri-N< group between two >C=0 groups.
[0026] In one embodiment the compound of Formula (1) has m, n, X, and
Rl, R2 and R6 defined as follows: m is 0 or 1, n is 1 to 2, X is >CHOR6, and
Rl,
R2 and R6 are independently hydrocarbyl groups containing 4 to 30 carbon
atoms.
[0027] In one embodiment Y and Y' are both -0-.
[0028] In one embodiment the compound of Formula (1) has m, n, X, Y, Y'
and Rl, R2 and R6 defined as follows: m is 0 or 1, n is 1 to 2, X is >CHOR6; Y
and Y' are both -0-, and Rl, R2 and R6 are independently hydrogen or
hydrocarbyl groups containing 4 to 30 carbon atoms.
[0029] The di-esters, di-amides, ester-amide, ester-imide compounds of
Formula (1) may be prepared by reacting a dicarboxylic acid (such as tartaric
acid), with an amine or alcohol, optionally in the presence of a catalyst. In
the
case of ester-imide compounds it is necessary to have at least three
carboxylic
acid groups (such as citric acid). The amine or alcohol typically has
sufficient
carbon atoms to fulfill the requirements of Rl and/or R2 as defined in Formula
(1).
[0030] In one embodiment Rl and R2 are independently linear or branched
hydrocarbyl groups. In one embodiment the hydrocarbyl groups are branched.
In one embodiment the hydrocarbyl groups are linear. The Rl and R2 may be
incorporated into Formula (1) by either an amine or an alcohol. The alcohol
6
CA 02742292 2011-04-29
WO 2010/053893
PCT/US2009/063054
includes both monohydric alcohol and polyhydric alcohol. The carbon atoms
of the alcohol may be linear chains, branched chains, or mixtures thereof.
[0031] Examples of a suitable branched alcohol include 2-ethylhexanol,
isotridecanol, Guerbet alcohols, or mixtures thereof
[0032] 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.
[0033] 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-pentanediol,
1,6-hexanediol, 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.
[0034] The tartaric acid used for preparing the tartrates of the
invention is
commercially available, and it is likely to exist in one or more isomeric
forms
such as d-tartaric acid, 1-tartaric acid, d,l-tartaric acid, or mesotartaric
acid,
often depending on the source (natural) or method of synthesis (from maleic
acid). For example a racemic mixture of d-tartaric acid and 1-tartaric acid is
obtained from a catalysed oxidation of maleic acid with hydrogen peroxide
(with tungstic acid catalyst). These derivatives may also be prepared from
functional equivalents to the diacid readily apparent to those skilled in the
art,
such as esters, acid chlorides, or anhydrides.
[0035] When the compound of Formula (1) 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 a lubricating
composition 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
7
CA 02742292 2011-04-29
WO 2010/053893
PCT/US2009/063054
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.
Monoester of a Polyol and an Aliphatic Carboxylic Acid
[0036] In one embodiment the lubricating composition includes the
monoester of a polyol and an aliphatic carboxylic acid, or mixtures thereof.
The monoester of a polyol and an aliphatic carboxylic acid may be an acid
containing 12 to 24 carbon atoms. Often the monoester of a polyol and an
aliphatic carboxylic acid may be in the form of a mixture with a sunflower oil
or the like, which may be present in 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.
[0037] 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. The polyol may be
diethylene glycol, triethylene glycol, glycerol, sorbitol, pentaerythritol or
dip entaerythritol.
8
CA 02742292 2011-04-29
WO 2010/053893
PCT/US2009/063054
[0038] The
commercially available monoester known as "glycerol
monooleate" is believed to include 60 + 5 percent by weight of the chemical
species glycerol monooleate, along with 35 + 5 percent glycerol dioleate, and
less than 5 percent trioleate and oleic acid. The amounts of the monoesters,
described above, are calculated based on the actual, corrected, amount of
polyol
monoester present in any such mixture.
[0039] In one
embodiment both the amide, ester or imide derivative of a
hydroxy-carboxylic acid and the monoester of a polyol and an aliphatic
carboxylic acid may have hydroxy groups attached to adjacent carbon atoms
(i.e, said compounds may be described as being derived from a vicinal diol).
Oils of Lubricating Viscosity
[0040] 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.
[0041]
Unrefined oils are those obtained directly from a natural or synthetic
source generally without (or with little) further purification treatment.
[0042] 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.
[0043] 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.
[0044] 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.
9
CA 02742292 2011-04-29
WO 2010/053893
PCT/US2009/063054
[0045] Synthetic lubricating oils are useful and include hydrocarbon oils
such as polymerised and interpolymerised olefins (typically hydrogenated)
(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); diphenyl alkanes, alkylated diphenyl alkanes, alkylated diphenyl
ethers and alkylated diphenyl sulphides and the derivatives, analogs and
homologs thereof or mixtures thereof.
[0046] Other synthetic lubricating oils include polyol esters (such as
Priolube03970), 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.
[0047] 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
<0.03 wt %, and >90 wt % saturates, viscosity index 80-120); Group III
(sulphur content <0.03 wt %, and >90 wt % saturates, viscosity index >120);
Group IV (all polyalphaolefins (PA0s)); and Group V (all others not included
in Groups I, II, III, or IV). The oil of lubricating viscosity includes 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.
[0048] 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 compound of the invention and the other performance additives.
CA 02742292 2011-04-29
WO 2010/053893
PCT/US2009/063054
[0049] The
lubricating composition may be in the form of a concentrate
and/or a fully formulated lubricant. If the lubricating composition of the
invention (comprising the additives disclosed herein above 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 these additives to the oil of
lubricating
viscosity and/or to diluent oil in the concentrate or the lubricant include
the
ranges of 1:99 to 99:1 by weight, or 10:90 to 80:20 by weight.
Other Performance Additives
[0050] The
composition optionally includes other performance additives.
The other performance additives comprise at least one of metal deactivators,
viscosity modifiers, detergents, friction modifiers, antiwear agents,
corrosion
inhibitors, dispersants, dispersant viscosity modifiers, extreme pressure
agents,
antioxidants, foam inhibitors, demulsifiers, emulsifiers, pour point
depressants,
seal swelling agents and mixtures thereof.
Typically, fully-formulated
lubricating oil will contain one or more of these performance additives.
[0051] In one
embodiment the lubricating composition of the invention
further includes at least one of a friction modifier, a viscosity modifier, an
antioxidant, an overbased detergent, a succinimide dispersant, or mixtures
thereof.
[0052] In one
embodiment the lubricating composition of the invention
further includes at least one of a viscosity modifier, an antioxidant, an
overbased detergent, a succinimide dispersant, or mixtures thereof.
Detergents
[0053] In one
embodiment the lubricating composition further includes one
or more neutral or overbased detergents. Suitable known detergents or
detergent substrates include phenates, sulphur containing phenates,
sulphonates, salixarates, salicylates, carboxylic acid, phosphorus acid, mono-
and/or di- thiophosphoric acids, alkyl phenols, 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 W02004/096957 and references cited therein. The
detergent
11
CA 02742292 2011-04-29
WO 2010/053893
PCT/US2009/063054
substrate may be salted with a metal such as calcium, magnesium, potassium,
sodium, or mixtures thereof.
[0054] In one embodiment the overbased detergent is selected from the
group consisting of phenates, sulphur containing phenates, sulphonates,
salixarates, salicylates, and mixtures thereof. Typically the selected
overbased
detergent includes calcium or magnesium phenates, sulphur containing
phenates, sulphonates, salixarates, saliginens, salicylates, or mixtures
thereof.
[0055] In one embodiment the detergent may be a calcium salicylate. In
one
embodiment the detergent may be a calcium sulphonate. In one embodiment
the invention the detergent may be a mixture of a calcium sulphonate and a
calcium salicylate.
[0056] In one embodiment the detergent may be a calcium phenate. In one
embodiment the detergent may be a calcium sulphonate. In one embodiment
the invention the detergent may be a mixture of a calcium sulphonate and a
calcium phenate.
[0057] The detergent may be present at 0 wt % to 10 wt %, or 0.1 wt % to
8
wt %, or 1 wt % to 4 wt % (on an oil free basis i.e., an actives basis) of the
lubricating composition.
Dispersants
[0058] 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. 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
US
Patent 3,172,892 or US Patent 4,234,435. Succinimide dispersants are typically
the imide formed from a polyamine, typically a poly(ethyleneamine).
12
CA 02742292 2011-04-29
WO 2010/053893
PCT/US2009/063054
[0059] In one
embodiment the invention further includes at least one
dispersant which is a polyisobutylene succinimide derived from a
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.
[0060] In one
embodiment the invention further includes 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.
[0061] Another
class of ashless dispersant includes 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.
[0062] 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.
[0063] The
dispersant may be present (on an oil free basis i.e., an actives
basis) 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 % of the lubricating composition.
Antioxidants
[0064]
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 (on an oil free basis
i.e., an actives basis) of 0 wt % to 20 wt %, or 0.1 wt % to 10 wt %, or 1 wt
%
to 5 wt %, of the lubricating composition.
13
CA 02742292 2011-04-29
WO 2010/053893
PCT/US2009/063054
[0065] The
hindered phenol antioxidant often contains a secondary butyl
and/or a tertiary butyl group as a sterically hindering group. The phenol
group
may be further substituted with a hydrocarbyl group (typically linear or
branched alkyl) and/or a bridging group linking to a second aromatic group.
Examples of suitable hindered phenol antioxidants include 2,6-di-tert-
butylpheno1, 4-methy1-2,6-di-tert-butylpheno1, 4-ethy1-2,6-di-tert-
butylpheno1,
4-propy1-2,6-di-tert-butylphenol or 4-butyl-2,6-di-tert-butylphenol, or 4-
dodecy1-2,6-di-tert-butylpheno1. In one embodiment the hindered phenol
antioxidant may be an ester and may include, e.g., IrganoxTM L-135 from Ciba.
A more detailed description of suitable ester-containing hindered phenol
antioxidant chemistry is found in US Patent 6,559,105.
[0066] In one
embodiment the lubricating composition further includes a
molybdenum compound.
[0067] The
molybdenum compound is selected from the group consisting of
molybdenum dialkyldithiophosphates, molybdenum dithiocarbamates, amine
salts of molybdenum compounds, and mixtures thereof.
[0068]
Suitable examples of molybdenum dithiocarbamates which may be
used as an antioxidant include commercial materials sold under the trade names
such as Molyvan 822TM and MolyvanTM A from R. T. Vanderbilt Co., Ltd., and
Adeka Sakura-LubeTM S-100, S-165 S-515, and S-600 from Asahi Denka
Kogyo K. K and mixtures thereof.
[0069] When
present, the molybdenum compound may provide 5 ppm to
300 ppm, or 20 ppm to 250 ppm of molybdenum to the lubricating composition.
Viscosity Modifiers
[0070]
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
arene conjugated diene copolymers, polyolefins, esters of maleic anhydride-
styrene copolymers.
14
CA 02742292 2016-01-28
Dispersant Viscosity Modifiers
[0071] Dispersant
viscosity modifiers (often referred to as DVM), include
functionalised polyolefins, for example, ethylene-propylene copolymers that
have been functionalized with an acylating agent such as maleic anhydride and
an amine; polymethacrylates functionalised with an amine, or styrene-maleic
anhydride copolymers reacted with an amine.
Antiwear Agents
[0072] In one
embodiment the lubricating composition further includes an
antiwear agent.
[0073] The additional
antiwear agent may be either ashless or ash-forming.
Typically ashless antiwear agents do not contain metal, whereas ash-forming do
contain metal.
[0074] The antiwear
agent may be present (on an oil free basis i.e., an
actives basis) 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.
[0075] In one
embodiment the lubricating composition further includes a
phosphorus-containing antiwear agent. Typically the phosphorus-containing
antiwear agent may be present in an amount to deliver the ranges of phosphorus
described below in the subject matter under the sub-heading "Industrial
Application".
[0076] Examples of
suitable antiwear agents include phosphate esters,
sulphurised olefins, sulphur-containing anti-wear additives including metal
di hydrocarbyldith iophosphatcs (such as primary or secondary zinc
dialky ldithiophosphates, or molybdenum
dialkyldithiophosphates),
molybdenum thiocarbamate-containing compounds including thiocarbamate
esters, alkylene-coupled thiocarbamates, and bis(S-alkyldithiocarbamyl)
disulphides.
[0077] Examples of
suitable zinc dialkyldithiophosphates include those
disclosed in PCT Publication WO 2008/011339 (entitled
"Method of Lubricating
an Internal Combustion Engine and Improving the Efficiency of the Emissions
Control System of the Engine") or in PCT Publication WO/2008/011338
(entitled
"Lubricating Oil Composition and Method of Improving Efficiency of
CA 02742292 2011-04-29
WO 2010/053893
PCT/US2009/063054
Emissions Control System"). Both applications claim priority from July 17,
2006. The
zinc dialkyldithiophosphates or dialkylphosphates in one
embodiment may be defined as a zinc salt of a mixture of phosphorus-
containing compounds represented by the formula:
R7--..õõ,. j 1
O\ //
p _ J 2 _
R8 H
-0'*----
wherein in formula, J1 and J2 are independently S or 0, and R7 and R8 may be
independently hydrocarbyl groups, the average total number of carbon atoms in
R7 plus R8 for the mixture of phosphorus-containing compounds being at least
9.5; wherein R7 and R8 are characterised in that (i) 4 to 70 mole percent of
such
groups contain 2 to 4 carbon atoms and (ii) 30 to 96 mole percent such groups
contain 5 to 12 carbon atoms; and wherein, in less than 8 mole percent of the
molecules of the formula in the mixture of phosphorus-containing compounds,
each of R7 and R8 contain 2 to 4 carbon atoms and in greater than 11 mole
percent of the molecules of the formula in said mixture R7 has 2 to 4 carbon
atoms and R8 has 5 to 12 carbon atoms; and wherein, within the formula, the
average total number of hydrogen atoms in R7 and R8 on carbon atoms located
beta to the 0 atoms is at least 7.25.
[0078] 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 C to 125 C. US Patents 4,758,362
and 4,997,969 describe dithiocarbamate compounds and methods of making
them.
[0079]
Examples of suitable olefins that may be sulphurised to form an
sulphurised olefin include propylene, butylene, isobutylene, pentene, hexane,
heptene, octane, nonene, decene, undecene, dodecene, undecyl, tridecene,
tetradecene, pentadecene, hexadecene, heptadecene, octadecene, octadecenene,
16
CA 02742292 2011-04-29
WO 2010/053893
PCT/US2009/063054
nonodecene, eicosene or mixtures thereof. In one embodiment, hexadecene,
heptadecene, octadecene, octadecenene, nonodecene, 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.
[0080] 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.
Extreme Pressure Agents
[0081] 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, dioleyl phosphite, di-2-ethylhexyl
phosphite.
didodecylphosphite, di-C12-14a1ky1 phosphite, pentylphenyl phosphite;
dip entylphenyl 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.
17
CA 02742292 2016-01-28
Friction Modifiers
[0082] In one embodiment the further includes a friction modifier, or
mixtures thereof. Typically the friction modifier may be present (on an oil
free
basis i.e., an actives basis) in ranges including 0 wt % to 10 wt %, or 0.05
wt %
to 8 wt %, or 0.1 wt % to 4 wt %.
[0083] Examples of suitable friction modifiers include long chain fatty
acid
derivatives of amines, esters, or epoxides; fatty imidazolines such as
condensation products of carboxylic acids and polyalkylene-polyamines; amine
salts of alkylphosphoric acids; fatty alkyl tartrates; fatty alkyl
tartrimidcs; or
fatty alkyl tartramides. A more detailed description of the tartrates and
tartrimides are disclosed above. The tartrimides and tartrates in addition to
performing as a rust inhibitor as described above, may also perform as a
friction modifier.
[0084] 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).
[0085] In one embodiment the friction modifier friction modifier is
selected
from the group consisting of long chain fatty acid derivatives of amines,
esters, or
epoxides; fatty alkyl tartrates; fatty alkyl tartrimides; and fatty alkyl
tartramides.
[0086] In one embodiment the friction modifier may be a long chain fatty
acid
ester (previously described above as an ashless antiwcar agent). In one
embodiment
the long chain fatty acid ester may be a mono-ester e.g. glycerol monooleate
and in
one embodiment the long chain fatty acid ester may be a (tri)glyceride.
Other Additives
[0087] Other performance additives such as corrosion inhibitors include
those described in paragraphs 5 to 8 of PCT Publication 2009/0156446
(McAtee and Boyer as named inventors), octylamine
octanoatc, 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 Synalox0 corrosion inhibitor. The Synalox0
18
CA 02742292 2011-04-29
WO 2010/053893
PCT/US2009/063054
corrosion inhibitor is typically a homopolymer or copolymer of propylene
oxide. The Synalox0 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."
[0088] 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
may be useful. Foam inhibitors that may be useful in the compositions of the
invention include 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.
[0089] Pour
point depressants that may be useful in the compositions of the
invention include polyalphaolefins, esters of maleic anhydride-styrene,
poly(meth)acrylates, polyacrylates or polyacrylamides.
Industrial Application
[0090] In one
embodiment the internal combustion engine may be a diesel
fueled engine, a gasoline fueled engine, a natural gas fueled engine or a
mixed
gasoline/alcohol fueled engine. In one embodiment the internal combustion
engine may be a diesel fueled engine and in one embodiment a gasoline fueled
engine.
[0091] In one
embodiment the internal combustion engine capacity may be
six litres or less, or three litres or less, one litre or less, 0.5 litres or
less, or 0.2
to 0.45 litres. The engine capacity may be described as engine displacement.
Engine displacement is defined as the total volume of air/fuel mixture an
engine
draws during one complete cycle. Engine displacement may also be described as
the
19
CA 02742292 2016-01-28
total volume swept as the piston or pistons move from top dead centre to
bottom
dead centre.
[0092] In one embodiment the internal combustion engine may be an
outboard engine, inboard engine or stern drive engine.
[0093] An outboard engine is described in the National Marine
Manufacturers Association October 1 2004 (revised 5 April2005) Certification
Procedure Manual for understanding of engines .
[00941 In one embodiment the internal combustion engine may be a gasoline
4-cycle engine.
[0095] In one embodiment the internal combustion engine may be a gasoline
4-cycle outboard engine.
[0096] As used herein the components of the internal combustion engine
include all of the parts of the engine derived from metal lubricated by an
engine
lubricant. This includes for example, cylinder liners, camshafts, piston heads
etc.
[0097] In one embodiment the internal combustion engine contains ferric
components. The ferric components include metallic iron, steel, FeO, Fe304 or
other materials containing iron.
[0098] In one embodiment the internal combustion engine contains
components of an aluminium-alloy. The aluminium-alloy includes aluminium
silicates, aluminium oxides, or other ceramic materials. In one embodiment the
aluminium-alloy is an aluminium-silicate surface.
[0099] The lubricating 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 200 ppm to 600 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
CA 02742292 2011-04-29
WO 2010/053893
PCT/US2009/063054
one embodiment the sulphated ash content may be 0.05 wt % to 0.9 wt %, or
0.1 wt % to 0.2 wt % to 0.45 wt %.
[0100] In one embodiment the lubricating composition may be an engine
oil, wherein the lubricating composition may be characterised as having (i) a
sulphur content of 0.5 wt % or less, (ii) a phosphorus content of 0.07 wt % or
less, and (iii) a sulphated ash content of 1.5 wt % or less.
[0101] In one embodiment the lubricating composition may be characterised
as having (i) a sulphur content of 0.5 wt % or less, (ii) a phosphorus content
of
0.12 wt % or less, and (iii) a sulphated ash content of 1 wt % or less.
[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
[0103] Comparative Example 1 (CE1): is a passenger car lubricant
containing 800 ppm of phosphorus (phosphorus from zinc
dialkylthiophosphate), glycerol monooleate and molybdenum dithiocarbamate.
The lubricant contains at most 25 ppm (and ideally no) water.
[0104] Comparative Example 2 (CE2): is a passenger car lubricant
containing 800 ppm of phosphorus (phosphorus from zinc
dialkylthiophosphate) and a tartrate ester. The lubricant contains at most 25
ppm (and ideally no) water.
Testing
[0105] CE1 and CE2 are evaluated for copper and lead corrosion by ASTM
methods D6594 and D130. The lubricants are evaluated in Sequence VIII test.
[0106] The results obtained for CE1 and CE2 are:
21
CA 02742292 2011-04-29
WO 2010/053893
PCT/US2009/063054
Tests CE1 CE2
ASTM D6594
Change in lead mass (mg) 217 13
Change in copper mass (mg) 11 4
Copper rating (ASTM D130) 4C 1B
Sequence VIII Test
Final Bearing Weight Loss (mg) 34.1 6.6
(pass limit max. 26 mg)
[0107] Overall the results obtained when comparing CE2 to CE1 indicate
that lubricants containing tartrates are useful for reducing copper and lead
corrosion in a passenger car lubricant.
[0108] Comparative Example 3 (CE3): is a commercially available outboard
engine lubricant. The lubricant is expected to be exposed to contaminant
amounts of water during operation.
[0109] Comparative Example 4 (CE4): is another commercially available
outboard engine lubricant. The lubricant contains an overbased detergent
known to be capable of reducing rust formation. The lubricant is expected to
be exposed to contaminant amounts of water during operation.
[0110] Example 1 (EX1): is an outboard engine lubricant containing 800
ppm of phosphorus (phosphorus from zinc dialkylthiophosphate) and a C12-14
alkyl tartrate ester. The lubricant is expected to be exposed to contaminant
amounts of water during operation.
[0111] Example 2 (EX2): is an outboard engine lubricant containing 800
ppm of phosphorus (phosphorus from zinc dialkylthiophosphate) and a C18
alkyl tartrimide. The lubricant is expected to be exposed to contaminant
amounts of water during operation.
[0112] Example 3 (EX3): is an outboard engine lubricant containing 800
ppm of phosphorus (phosphorus from zinc dialkylthiophosphate) and glycerol
monooleate. The lubricant is expected to be exposed to contaminant amounts
of water during operation.
22
CA 02742292 2016-01-28
Testing
[0113] CE3, CE4, EX1, EX2 and EX3 are evaluated for copper and lead
corrosion by ASTM methods D6594. The results obtained are:
ASTM D6594 CE3 CE4 EX1 EX2 EX3
Change in copper mass (mg) 15 6 18 46 12
Change in lead mass (mg) 2 3 3 22 19
[0114] The results show that although tartrates, tartrimides and glycerol
monooleate are useful for solving copper and lead corrosion in many lubricant
formulations, they do not appear to be as effective in outboard formulations
for
reducing copper and lead corrosion.
[0115] CE3, CE4, EX1, EX2 and EX3 are then evaluated for rust inhibition
in a humidity cabinet (ASTM method D1748-02) to determine the tendency to
corrode various metals, specifically iron. The steel strips of the test are
suspended in the humidity cabinet at 49 C for 100 hours. The steel strips are
rated on a scale of 0 to 100 %. Typically lower percent ratings indicate
reduced surface rust formation. The results obtained are:
Humidity Cabinet CE3 CE4 EX1 EX2 EX3
Rating (% surface with rust) 40-50 5-10 2-5 0 0
[0116] CE4, EX1 and EX2 are evaluated in 4-cycle watercraft test entitled
Corrosion Salt Fog Test. The test is described in the National Marine
Manufacturers Association October 1 2004/ (revised 5 April 2005 Certification
Procedure Manual for understanding of engines) pages 7 to 13. Each sample is
evaluated by comparing the rating to a standard reference run concurrently in
the same cabinet. The average percent rust of the candidate is calculated from
4 individual runs. Typically, passing candidates have a percent rust less than
that obtained for a reference oil calculated in the same manner. The results
obtained from the test are:
23
CA 02742292 2016-01-28
Salt Fog Test CE3 CE4 EX1 EX2 EX3
Percent Rust Candidate 50 46 14 2 2
Percent Rust Reference 30 35 35 25 25
[0117] Overall the results obtained for EX1, EX2 and EX3 indicate that
lubricants containing tartrates, tartrimides or glycerol monooleate reduce
rust
formation in outboard engines.
[0118] 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 lubricating 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 lubricating composition prepared by admixing the components
described above.
[0119]
Except in the Examples, or where otherwise explicitly indicated, all
numerical quantities in this description specifying amounts of materials, reac-
tion 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 exclusive 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. Multiple groups represented by the
same symbol in the formulae described above, may be the same or different.
24
CA 02742292 2011-04-29
WO 2010/053893
PCT/US2009/063054
[0120] 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:
(i) hydrocarbon substituents, that is, aliphatic (e.g., alkyl or alkenyl),
alicyclic (e.g., cycloalkyl, 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);
(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);
(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, and
encompass substituents as pyridyl, furyl, thienyl and imidazolyl; and
(iv) heteroatoms, including sulphur, oxygen, and nitrogen. 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.
[0121] 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.
