U.S. patent application number 14/886261 was filed with the patent office on 2016-02-11 for natural oil based grease compositions and processes for making such compositions.
This patent application is currently assigned to Elevance Renewable Sciences, Inc.. The applicant listed for this patent is Elevance Renewable Sciences, Inc.. Invention is credited to Paul A. Bertin, Stephen A. Di Biase, Zachary Jon Hunt, Syed Q.A. Rizvi.
Application Number | 20160040093 14/886261 |
Document ID | / |
Family ID | 50349979 |
Filed Date | 2016-02-11 |
United States Patent
Application |
20160040093 |
Kind Code |
A1 |
Bertin; Paul A. ; et
al. |
February 11, 2016 |
NATURAL OIL BASED GREASE COMPOSITIONS AND PROCESSES FOR MAKING SUCH
COMPOSITIONS
Abstract
A grease composition is disclosed, having from 50 to 99 weight
percent of a lubricating base oil, from 1 to 30 weight percent of a
thickener component comprising one or more of (i) one or more
natural oil derivatives, (ii) one or more hydrogenated metathesized
natural oils and/or natural oil derivatives, (iii) one or more
amidated metathesized natural oils and/or natural oil derivatives,
(iv) one or more, or two or more, carboxylic acids and/or
derivatives thereof, and (v) one or more of a metal base compound,
and from 1 to 15 weight percent of one or more optional additives.
Processes for making grease compositions are also disclosed.
Inventors: |
Bertin; Paul A.; (Western
Springs, IL) ; Hunt; Zachary Jon; (Simpsonville,
SC) ; Rizvi; Syed Q.A.; (Painesville, OH) ; Di
Biase; Stephen A.; (River Forest, IL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Elevance Renewable Sciences, Inc. |
Woodridge |
IL |
US |
|
|
Assignee: |
Elevance Renewable Sciences,
Inc.
Woodridge
IL
|
Family ID: |
50349979 |
Appl. No.: |
14/886261 |
Filed: |
October 19, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
14200956 |
Mar 7, 2014 |
|
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14886261 |
|
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|
61774760 |
Mar 8, 2013 |
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Current U.S.
Class: |
508/488 |
Current CPC
Class: |
C10M 2205/146 20130101;
C10N 2050/10 20130101; C10M 169/02 20130101; C10N 2010/02 20130101;
C10M 2207/1265 20130101; C10N 2070/00 20130101; C10M 2205/186
20130101; C10M 2207/401 20130101; C10M 177/00 20130101; C10N
2010/04 20130101; C10M 2207/1236 20130101; C10N 2060/02 20130101;
C10M 123/02 20130101; C10M 2201/006 20130101; C10N 2030/06
20130101; C10M 2203/1006 20130101; C10M 2207/006 20130101; C10M
2207/1276 20130101; C10M 2207/166 20130101; C10M 2207/1285
20130101 |
International
Class: |
C10M 169/02 20060101
C10M169/02 |
Claims
1. A grease composition comprising: (a) from 50 to 99 weight
percent of a lubricating base oil, (b) from 1 to 30 weight percent
of a thickener component comprising one or more of (i) one or more
natural oil derivatives, (ii) one or more hydrogenated metathesized
natural oils or a natural oil derivative thereof, comprising a
hydrogenated metathesized soybean oil or a hydrogenated
metathesized soybean oil based wax, (iii) one or more carboxylic
acids and/or derivatives thereof, and (v) one or more of a metal
base compound; and (c) from 1 to 15 weight percent of one or more
optional additives.
2. The grease composition of claim 1, wherein the lubricating base
oil comprises a mineral oil, a synthetic oil, a natural oil, or a
natural oil derivative, individually or in combinations
thereof.
3. The grease composition of claim 1, wherein the natural oil
derivative is a hydrogenated natural oil selected from the group
consisting of hydrogenated canola oil, hydrogenated rapeseed oil,
hydrogenated coconut oil, hydrogenated corn oil, hydrogenated
cottonseed oil, hydrogenated olive oil, hydrogenated palm oil,
hydrogenated peanut oil, hydrogenated safflower oil, hydrogenated
sesame oil, hydrogenated soybean oil, hydrogenated sunflower oil,
hydrogenated linseed oil, hydrogenated palm kernel oil,
hydrogenated tung oil, hydrogenated jatropha oil, hydrogenated
mustard oil, hydrogenated camelina oil, hydrogenated pennycress
oil, hydrogenated castor oil, hydrogenated animal fat, individually
or in combinations thereof.
4. The grease composition of claim 3, wherein the hydrogenated
natural oil is hydrogenated castor oil.
5. The grease composition of claim 1, further comprising one or
more amidated metathesized natural oils and/or natural oil
derivatives comprising an amidated hydrogenated metathesized
soybean oil based wax.
6. The grease composition of claim 1, wherein the one or more
carboxylic acids and/or derivatives thereof comprises a
C.sub.2-C.sub.36 mono-, di-, tri-, and/or poly-carboxylic acid
and/or derivative thereof.
7. The grease composition of claim 6, wherein the C.sub.2-C.sub.36
mono-, di-, tri-, and/or poly-carboxylic acid and/or derivative
thereof comprises a hydroxy-substituted, aliphatic, cyclic,
alicyclic, aromatic, branched, saturated, unsaturated, or
heteroatom substituted, carboxylic acid or ester derivative
thereof.
8. The grease composition of claim 7, wherein the C.sub.2-C.sub.36
mono-, di-, tri-, and/or poly-carboxylic acid and/or derivative
thereof comprises a C.sub.12-C.sub.24 hydroxy carboxylic acid or
C.sub.12-C.sub.24 hydroxy ester derivative of such acids.
9. The grease composition of claim 8, wherein the C.sub.12-C.sub.24
hydroxy carboxylic acid or ester derivative of such acids is
12-hydroxystearic acid and ester derivatives.
10. The grease composition of claim 9, wherein the
C.sub.12-C.sub.24 hydroxy carboxylic acid ester derivative is
12-hydroxystearate.
11. The grease composition of claim 6, wherein the C.sub.2-C.sub.36
mono-, di-, tri-, and/or poly-carboxylic acid comprises a C.sub.2
to C.sub.12 aliphatic dicarboxylic acid.
12. The grease composition of claim 11, wherein the C.sub.2 to
C.sub.12 aliphatic dicarboxylic acid comprises azelaic acid.
13. The grease composition of claim 7, wherein the wherein the
C.sub.2-C.sub.36 mono-, di-, tri-, and/or poly-carboxylic acid
and/or derivative thereof comprises an alicyclic acid comprising
naphthenic acids and mixtures thereof.
14. The grease composition of claim 1, wherein said metal base
compound is a metal hydroxide selected from the group consisting of
calcium hydroxide, strontium hydroxide, lithium hydroxide, sodium
hydroxide, potassium hydroxide, and magnesium hydroxide.
15. The grease composition of claim 1, wherein said optional
additives are selected from the group consisting of: metal
deactivators, antioxidants, antiwear agents, rust inhibitors,
viscosity modifiers, extreme pressure agents, and corrosion
inhibitors.
16. A grease composition comprising: (a) from 89 to 93 weight
percent of a lubricating base oil, (b) from 6 to 11 weight percent
of a thickener component comprising one or more of (i) one or more
natural oil derivatives, (ii) one or more hydrogenated metathesized
natural oils or a natural oil derivative thereof, comprising a
hydrogenated metathesized soybean oil or a hydrogenated
metathesized soybean oil based wax, (iv) one or more carboxylic
acids and/or derivatives thereof, and (v) one or more of a metal
base compound; and (c) from 1 to 5 weight percent of one or more
optional additives selected from the group consisting of: metal
deactivators, antioxidants, antiwear agents, rust inhibitors,
viscosity modifiers, extreme pressure agents, and corrosion
inhibitors.
17. A grease composition comprising: (a) from 89 to 93 weight
percent of a lubricating base oil, (b) from 6 to 11 weight percent
of a thickener component comprising one or more of (i) one or more
natural oil derivatives comprising hydrogenated castor oil, (ii)
one or more hydrogenated metathesized natural oils or a natural oil
derivative thereof, comprising a hydrogenated metathesized soybean
oil or a hydrogenated metathesized soybean oil wax, (iii) one or
more carboxylic acids and/or derivatives thereof, comprising
12-hydroxystearic acid, naphthenic acids, azelaic acid, and (iv)
one or more of a metal base compound comprising lithium hydroxide.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] A claim of priority for this application under 35 U.S.C.
.sctn.119(e) is hereby made to U.S. Non-Provisional patent
application Ser. No. 14/200,956, filed Mar. 7, 2014, and U.S.
Provisional Patent Application No. 61/774,760, filed Mar. 8, 2013;
and these applications are incorporated herein by reference in
their entireties.
BACKGROUND
[0002] A wide variety of greases have been developed over the years
comprising a number of different formulations with a wide variation
in associated properties. An important component found in greases
is the thickening agent, which is often at least one metal soap,
and differences in grease formulations have often involved this
ingredient. Soap thickened greases constitute a significant segment
by far of the commercially available greases worldwide. Simple soap
greases, which are salts of long chain fatty acids and a
neutralizing agent, are probably the most predominant type of
grease in use today, with lithium 12-hydroxystearate being the
thickener most often used. Complex soap greases, which generally
comprise metal salts of a mixture of organic acids have also come
into widespread use, particularly because of the various property
advantages such type greases can possess (i.e. dropping points at
least 20.degree. C. higher than their corresponding simple soap
greases).
[0003] We have found that the incorporation of hydrogenated
metathesized natural oils and their derivatives as a thickener
component in simple and complex greases provides for greases with
reduced processing times and improved yields.
SUMMARY
[0004] In one aspect, a grease composition is disclosed. The grease
composition comprises from 50 to 99 weight percent of a lubricating
base oil, and from 1 to 30 weight percent of a thickener component.
The thickener component comprises one or more of (i) one or more
natural oil derivatives, (ii) one or more hydrogenated metathesized
natural oils and/or natural oil derivatives, (iii) one or more
amidated metathesized natural oils and/or natural oil derivatives,
(iv) one or more carboxylic acids and/or derivatives thereof, and
(v) one or more of a metal base compound. In some embodiments, the
one or more hydrogenated metathesized natural oils and/or natural
oil derivatives comprises a hydrogenated metathesized soybean oil
based wax. The grease composition may further comprise from 1 to 15
weight percent of one or more optional additives.
[0005] In another aspect, a process for preparing a simple grease
composition is disclosed. The process comprises adding from 1 to 30
weight percent of a thickener component comprising one or more of
(i) one or more natural oil derivatives, (ii) one or more
hydrogenated metathesized natural oils and/or natural oil
derivatives, (iii) one or more amidated metathesized natural oils
and/or natural oil derivatives, (iv) one or more carboxylic acids
and/or derivatives thereof, to from 50 to 99 weight percent of a
lubricating base oil, and charging this mixture to a kettle, mixer
or equivalent vessel. This mixture is then heated to a temperature
between about 140.degree. F. to 200.degree. F. for approximately
30-60 minutes, in order to dissolve the one or more carboxylic
acids and/or derivatives thereof into the lubricating base oil. One
or more of a metal base compound is then charged to this mixture in
an amount slightly in excess of the stoichiometric amount required
to neutralize the one or more carboxylic acids and/or derivatives
thereof. The mixture is then maintained at a temperature between
about 190.degree. F. to about 270.degree. F. for approximately
30-90 minutes to complete the neutralization and to effect a
substantial dehydration of the mixture. This mixture is then heated
to about 350.degree. F. to about 430.degree. F. for up to
approximately 60 minutes. Thereafter, the mixture is cooled with
the assistance of incorporating an additional amount of the
lubricating base oil and the removal of heat, to yield the grease
composition. Optionally, from 1 to 15 weight percent of one or more
additives may be added to the grease composition.
[0006] In another aspect, a process for preparing a complex grease
composition is disclosed. The process comprises adding from 1 to 30
weight percent of a thickener component comprising one or more of
(i) one or more natural oil derivatives, (ii) one or more
hydrogenated metathesized natural oils and/or natural oil
derivatives, (iii) one or more amidated metathesized natural oils
and/or natural oil derivatives, (iv) two or more carboxylic acids
and/or derivatives thereof, to from 50 to 99 weight percent of a
lubricating base oil, and charging this mixture to a kettle, mixer
or equivalent vessel. This mixture is then heated to a temperature
between about 140.degree. F. to 200.degree. F. for approximately
30-60 minutes, in order to dissolve the two or more carboxylic
acids and/or derivatives thereof into the lubricating base oil. One
or more of a metal base compound is then charged to this mixture in
an amount slightly in excess of the stoichiometric amount required
to neutralize the two or more carboxylic acids and/or derivatives
thereof. The mixture is then maintained at a temperature between
about 190.degree. F. to about 270.degree. F. for approximately
30-90 minutes to complete the neutralization and to effect a
substantial dehydration of the mixture. This mixture is then heated
to about 350.degree. F. to about 430.degree. F. for up to
approximately 60 minutes. Thereafter, the mixture is cooled with
the assistance of incorporating an additional amount of the
lubricating base oil and the removal of heat, to yield the grease
composition. Optionally, from 1 to 15 weight percent of one or more
additives may be added to the grease composition.
DETAILED DESCRIPTION
[0007] The present application relates to natural oil based grease
compositions and processes for making such compositions.
[0008] As used herein, the singular forms "a," "an," and "the"
include plural referents unless the context clearly dictates
otherwise. For example, reference to "a substituent" encompasses a
single substituent as well as two or more substituents, and the
like.
[0009] As used herein, the terms "for example," "for instance,"
"such as," or "including" are meant to introduce examples that
further clarify more general subject matter. Unless otherwise
specified, these examples are provided only as an aid for
understanding the applications illustrated in the present
disclosure, and are not meant to be limiting in any fashion.
[0010] As used herein, the following terms have the following
meanings unless expressly stated to the contrary. It is understood
that any term in the singular may include its plural counterpart
and vice versa.
[0011] As used herein, the term "natural oil" may refer to oil
derived from plants or animal sources. The term "natural oil"
includes natural oil derivatives, unless otherwise indicated.
Examples of natural oils include, but are not limited to, vegetable
oils, algae oils, animal fats, tall oils, derivatives of these
oils, combinations of any of these oils, and the like.
Representative non-limiting examples of vegetable oils include
canola oil, rapeseed oil, coconut oil, corn oil, cottonseed oil,
olive oil, palm oil, peanut oil, safflower oil, sesame oil, soybean
oil, sunflower oil, linseed oil, palm kernel oil, tung oil,
jatropha oil, mustard oil, camelina oil, pennycress oil, hemp oil,
algal oil, and castor oil. Representative non-limiting examples of
animal fats include lard, tallow, poultry fat, yellow grease, and
fish oil. Tall oils are by-products of wood pulp manufacture. In
certain embodiments, the natural oil may be refined, bleached,
and/or deodorized. In some embodiments, the natural oil may be
partially or fully hydrogenated. In some embodiments, the natural
oil is present individually or as mixtures thereof.
[0012] As used herein, the term "natural oil derivatives" may refer
to the compounds or mixture of compounds derived from the natural
oil using any one or combination of methods known in the art. Such
methods include metathesis, saponification, transesterification,
esterification, interesterification, hydrogenation (partial or
full), isomerization, amidation, oxidation, and reduction,
individually or in combinations thereof. Representative
non-limiting examples of natural oil derivatives include gums,
phospholipids, waxes (e.g. non-limiting examples such as
hydrogenated metathesized natural oil waxes and amidated
hydrogenated metathesized natural oil waxes), soapstock, acidulated
soapstock, distillate or distillate sludge, fatty acids and fatty
acid alkyl ester (e.g. non-limiting examples such as 2-ethylhexyl
ester), hydroxy substituted variations thereof of the natural oil.
For example, the natural oil derivative may be a fatty acid methyl
ester ("FAME") derived from the glyceride of the natural oil. In
some embodiments, a feedstock includes canola or soybean oil, as a
non-limiting example, refined, bleached, and deodorized soybean oil
(i.e., RBD soybean oil). Soybean oil typically comprises about 95%
weight or greater (e.g., 99% weight or greater) triglycerides of
fatty acids. Major fatty acids in the polyol esters of soybean oil
include saturated fatty acids, as a non-limiting example, palmitic
acid (hexadecanoic acid) and stearic acid (octadecanoic acid), and
unsaturated fatty acids, as a non-limiting example, oleic acid
(9-octadecenoic acid), linoleic acid (9,12-octadecadienoic acid),
and linolenic acid (9,12,15-octadecatrienoic acid). In one
embodiment, one particular natural oil derivative is hydrogenated
castor oil, which is the glyceride of 12-hydroxystearic acid. In
some embodiments, hydrogenation and saponification of castor oil
yields 12-hydroxystearic acid, which is then reacted with lithium
hydroxide or lithium carbonate to give high performance grease.
[0013] As used herein, the term "metathesis" or "metathesizing"
refers to the reacting of a feedstock in the presence of a
metathesis catalyst to form a metathesized product or "metathesized
natural oil" comprising a new olefinic compound. Metathesizing may
refer to cross-metathesis (a.k.a. co-metathesis), self-metathesis,
ring-opening metathesis, ring-opening metathesis polymerizations
("ROMP"), ring-closing metathesis ("RCM"), and acyclic diene
metathesis ("ADMET"). As a non-limiting example, metathesizing may
refer to reacting two triglycerides present in a natural oil
feedstock (self-metathesis) in the presence of a metathesis
catalyst, wherein each triglyceride has an unsaturated
carbon-carbon double bond, thereby forming a "natural oil oligomer"
having a new mixture of olefins and esters that may comprise one or
more of: metathesis monomers, metathesis dimers, metathesis
trimers, metathesis tetramers, metathesis pentamers, and higher
order metathesis oligomers (e.g., metathesis hexamers). Examples of
metathesis compositions, processes, and products are reported in R.
L. Pederson, Commercial Applications of Ruthenium Metathesis
Processes; in "Handbook of Metathesis"; Vol. 2; R. H. Grubbs Ed.;
Wiley-VCH Weinheim, Germany; 2003; pp. 491 to 510 (ISBN No.
3-527-30616-1). Of note, both intra- and inter-molecular
cross-metathesis of unsaturated fatty acid glycerides in soybean
oil results in long chain (e.g. C18 or higher) latent diacids.
[0014] As used herein, the term "metathesized natural oil" refers
to the product formed from the metathesis reaction of a natural oil
in the presence of a metathesis catalyst to form a mixture of
olefins and esters comprising one or more of: metathesis monomers,
metathesis dimers, metathesis trimers, metathesis tetramers,
metathesis pentamers, and higher order metathesis oligomers (e.g.,
metathesis hexamers). In certain embodiments, the metathesized
natural oil has been partially to fully hydrogenated, forming a
"hydrogenated metathesized natural oil." In certain embodiments,
the metathesized natural oil is formed from the metathesis reaction
of a natural oil comprising more than one source of natural oil
(e.g., a mixture of soybean oil and palm oil). In other
embodiments, the metathesized natural oil is formed from the
metathesis reaction of a natural oil comprising a mixture of
natural oils and natural oil derivatives.
[0015] As used herein, the term "dropping point," "drop point," or
"melting point" are terms that may refer to the temperature at
which the grease begins to melt. The drop point may be measured
using ASTM-D127-08 or the Mettler Drop Point FP80 system,
incorporated by reference herein.
[0016] As used herein, the term "needle penetration" may refer to
the relative hardness of the grease composition. The needle
penetration may be measured using ASTM-D1321-02a, incorporated by
reference herein.
[0017] As used herein, the term "cone penetration" may refer to the
measurement of the solidity of the grease. Penetration is the
depth, in tenths of millimeters, to which a standard cone sinks
into the grease under prescribed conditions. Thus higher
penetration numbers indicate softer grease, since the cone has sunk
deeper into the sample.
Grease Composition
[0018] The elements of a lubricating grease composition are
generally divided among three parts: lubricating base oil,
thickener, and additives. In general, the roles of these three
parts is that the base oil carries out the main role of
lubrication, the thickener structures the lubricating base oil into
a semi-solid, and the additives impart additional functionality to
the lubricating base oil and/or thickener, such as corrosion or
oxidation resistance.
Lubricating Base Oil
[0019] The lubricating base oil employed in the grease composition
can be any of the conventionally used lubricating oils, and is
preferably a mineral oil, a synthetic oil or a blend of mineral and
synthetic oils, or in some cases, natural oils and natural oil
derivatives, all individually or in combinations thereof. Mineral
lubricating oil base stocks used in preparing the greases can be
any conventionally refined base stocks derived from paraffinic,
naphthenic and mixed base crudes The lubricating base oil may
include polyolefin base stocks, of both polyalphaolefin (PAO) and
polyinternal olefin (PIO) types. Oils of lubricating viscosity
derived from coal or shale are also useful.
[0020] Examples of synthetic oils include hydrocarbon oils such as
polymerized and interpolymerized olefins (e.g., polybutylenes,
polypropylenes, propyleneisobutylene copolymers); poly(1-hexenes),
poly(1-octenes), poly(1-decenes), and mixtures thereof;
alkyl-benzenes (e.g., dodecylbenzenes, tetradecylbenzenes,
dinonylbenzenes, di-(2-ethylhexyl)-benzenes); polyphenyls (e.g.,
biphenyls, terphenyls, alkylated polyphenyls); alkylated diphenyl
ethers and alkylated diphenyl sulfides and the derivatives, analogs
and homologs thereof.
[0021] Alkylene oxide polymers and interpolymers and derivatives
thereof where the terminal hydroxyl groups have been modified by
esterification, and etherification, constitute another class of
known synthetic lubricating oils that can be used. These are
exemplified by the oils prepared through polymerization of ethylene
oxide or propylene oxide, the alkyl and aryl ethers of these
polyoxyalkylene polymers (e.g., methyl-polyisopropylene glycol
ether having a number average molecular weight of 1000, diphenyl
ether of polyethylene glycol having a molecular weight of 500-1000,
diethyl ether of polypropylene glycol having a molecular weight of
1000-1500) or mono- and polycarboxylic esters thereof, for example,
the acetic acid esters, mixed C.sub.3-8 fatty acid esters, or the
C.sub.13 Oxo acid diester of tetraethylene glycol.
[0022] Another suitable class of synthetic lubricating oils that
can be used comprises the esters of dicarboxylic acids (e.g.,
phthalic acid, succinic acid, alkyl succinic acids, alkenyl
succinic acids, maleic acid, azelaic acid, suberic acid, sebacic
acid, fumaric acid, adipic acid, linoleic acid dimer, malonic acid,
alkyl malonic acids, and alkenyl malonic acids) with a variety of
alcohols (e.g., butyl alcohol, hexyl alcohol, dodecyl alcohol,
2-ethylhexyl alcohol, ethylene glycol, diethylene glycol monoether,
and propylene glycol). Specific examples of these esters include
dibutyl adipate, di-(2-ethylhexyl) sebacate, di-n-hexyl fumarate,
dioctyl sebacate, diisooctyl azelate, diisodecyl azelate, dioctyl
phthalate, didecyl phthalate, dieicosyl sebacate, the 2-ethylhexyl
diester of linoleic acid dimer, and the complex ester formed by
reacting one mole of sebacic acid with two moles of tetraethylene
glycol and two moles of 2-ethylhexanoic acid. Esters useful as
synthetic oils also include those made from C.sub.5 to C.sub.12
monocarboxylic acids and polyols such as neopentyl glycol,
trimethylol propane, and pentaerythritol, or polyol ethers such as
dipentaerythritol, and tripentaerythritol.
[0023] Silicon-based oils such as the polyalkyl-, polyaryl-,
polyalkoxy-, or polyaryloxy-siloxane oils and silicate oils
comprise another useful class of synthetic lubricants (e.g.,
tetraethyl silicate, tetraisopropyl silicate,
tetra-(2-ethylhexyl)silicate, tetra-(4-methylhexyl)silicate,
tetra-(p-tert-butylphenyl) silicate,
hexyl-(4-methyl-2-pentoxy)disiloxane, poly(methyl)siloxanes, and
poly-(methylphenyl)siloxanes). Other synthetic lubricating oils
include liquid esters of phosphorus-containing acids (e.g.,
tricresyl phosphate, trioctyl phosphate, and the diethyl ester of
decane phosphonic acid), and polymeric tetrahydrofurans.
[0024] Unrefined, refined and re-refined oils, either natural or
synthetic (as well as mixtures of two or more of any of these) of
the type disclosed hereinabove can be used as the lubricating base
oil in the grease composition. Unrefined oils are those obtained
directly from a natural or synthetic source without further
purification treatment. For example, a shale oil obtained directly
from retorting operations, a petroleum oil obtained directly from
primary distillation or ester oil obtained directly from an
esterification process and used without further treatment would be
an unrefined oil. 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. Many such purification
techniques are known to those skilled in the art such as solvent
extraction, secondary distillation, acid or base extraction,
filtration, percolation, re-refined oils are obtained by processes
similar to those used to obtain refined oils applied to refined
oils which have been already used in service. Such re-refined oils
are also known as reclaimed or reprocessed oils and often are
additionally processed by techniques directed to removal of spent
additives and oil breakdown products.
[0025] Oils of lubricating viscosity can also be defined as
specified in the American Petroleum Institute (API) Base Oil
Interchangeability Guidelines. The five base oil groups are as
follows:
TABLE-US-00001 Base Oil Saturates Viscosity Category Sulfur (%) (%)
Index Group I >0.03 and/or <90 80-120 Group II .ltoreq.0.03
and .gtoreq.90 80-120 Group III > Group IV All polyalphaolefins
(PAOs) Group V All others not included in Groups I, II, III, or
IV
[0026] Groups I, II, and Ill are mineral oil base stocks. In some
embodiments, the oil of lubricating viscosity is a Group I, II,
III, IV, or V oil or mixtures thereof.
[0027] The lubricating base oil is present in a "major amount,"
meaning greater than about 50 weight percent of the grease
composition, preferably in the range 50 to 99 weight percent of the
grease composition, preferably 60 to 95 weight percent of the
grease composition, more preferably 70 to 92 weight percent of the
grease composition and most preferably 75 to 90 weight percent of
the grease composition. In general these lubricating oils have a
viscosity in the range of 15 to 220, preferably 30 to 150 cSt at
40.degree. C., and a viscosity index in the range of 30 to 170,
preferably 30 to 140.
Thickener
[0028] Another component in the subject grease composition is a
thickener which serves to increase the consistency of the
composition. The thickener generally comprises multiple components,
which may include one or more of the following: (i) one or more
natural oil derivatives, such as hydrogenated natural oils, (ii)
one or more hydrogenated metathesized natural oils and/or natural
oil derivatives, (iii) one or more amidated metathesized natural
oils and/or natural oil derivatives, (iv) one or more carboxylic
acids, such as 12-hydroxystearic acid (12-HSA) and azelaic acid,
and derivatives thereof, and (v) one or more of a metal base
compound, such as metal oxide, metal hydroxide, or metal carbonate,
or mixtures thereof.
[0029] The thickener may be present in a "minor amount," meaning
less than about 50 weight percent of the grease composition,
preferably in the range of 1 to 30 weight percent of the grease
composition, and more preferably 5 to 20 weight percent of the
grease composition, and most preferably 10 to 20 weight percent of
the grease composition. Generally, the function of the thickener is
to provide a physical matrix which holds the lubricating base oil
in a solid structure until operating conditions initiate
viscoelastic flow.
A. Natural Oil Derivatives and Hydrogenated Metathesized Natural
Oils
[0030] The natural oil derivatives may include one or more
hydrogenated natural oils. Such hydrogenated natural oils may
include: hydrogenated vegetable oil, hydrogenated algae oil,
hydrogenated animal fat, hydrogenated tall oil, hydrogenated
derivatives of these oils, and mixtures thereof. In one embodiment,
the hydrogenated vegetable oil is hydrogenated canola oil,
hydrogenated rapeseed oil, hydrogenated coconut oil, hydrogenated
corn oil, hydrogenated cottonseed oil, hydrogenated olive oil,
hydrogenated palm oil, hydrogenated peanut oil, hydrogenated
safflower oil, hydrogenated sesame oil, hydrogenated soybean oil,
hydrogenated sunflower oil, hydrogenated linseed oil, hydrogenated
palm kernel oil, hydrogenated tung oil, hydrogenated jatropha oil,
hydrogenated mustard oil, hydrogenated camelina oil, hydrogenated
pennycress oil, hydrogenated castor oil, hydrogenated derivatives
of these oils, and mixtures thereof. In another embodiment, the
hydrogenated natural oil is a hydrogenated animal fat such as
hydrogenated lard, hydrogenated tallow, hydrogenated poultry fat,
hydrogenated fish oil, hydrogenated derivatives of these oils, and
mixtures thereof. In some embodiments, the hydrogenated natural oil
is hydrogenated castor oil.
[0031] In some embodiments, the thickener may have a component
comprising a hydrogenated metathesized natural oil or a natural oil
derivative thereof, such as a hydrogenated metathesized natural oil
based wax. In many instances, the natural oil is metathesized and
hydrogenated to modify the physical properties of the natural oil
such that it forms a wax. Representative examples of hydrogenated
metathesized natural oils include hydrogenated metathesized
vegetable oil, hydrogenated metathesized algae oil, hydrogenated
metathesized animal fat, hydrogenated metathesized tall oil,
hydrogenated metathesized derivatives of these oils, and mixtures
thereof. In one embodiment, the hydrogenated metathesized vegetable
oil is hydrogenated metathesized canola oil, hydrogenated
metathesized rapeseed oil, hydrogenated metathesized coconut oil,
hydrogenated metathesized corn oil, hydrogenated metathesized
cottonseed oil, hydrogenated metathesized olive oil, hydrogenated
metathesized palm oil, hydrogenated metathesized peanut oil,
hydrogenated metathesized safflower oil, hydrogenated metathesized
sesame oil, hydrogenated metathesized soybean oil, hydrogenated
metathesized sunflower oil, hydrogenated metathesized linseed oil,
hydrogenated metathesized palm kernel oil, hydrogenated
metathesized tung oil, hydrogenated metathesized jatropha oil,
hydrogenated metathesized mustard oil, hydrogenated metathesized
camelina oil, hydrogenated metathesized pennycress oil,
hydrogenated metathesized castor oil, hydrogenated metathesized
derivatives of these oils, and mixtures thereof. In another
embodiment, the hydrogenated metathesized natural oil is a
hydrogenated metathesized animal fat such as hydrogenated
metathesized lard, hydrogenated metathesized tallow, hydrogenated
metathesized poultry fat, hydrogenated metathesized fish oil,
hydrogenated metathesized derivatives of these oils, and mixtures
thereof. In one embodiment, the natural oil is a hydrogenated
metathesized soybean oil ("HMSBO"). In one embodiment, S-55 is a
hydrogenated metathesized soybean oil available from Elevance
Renewable Sciences, Woodridge, Ill. In one embodiment the HMSBO has
a drop point of about 54.degree. C. (129.degree. F.), a congeal
point of about 52.degree. C. (126.degree. F.) and a needle
penetration of about 13 dmm. In another embodiment, the natural oil
is a hydrogenated metathesized soybean oil that has been vacuum
stripped to remove paraffins. In particular, this vacuum stripped
version of HMSBO, S-60, is a hydrogenated metathesized soybean oil
available from Elevance Renewable Sciences, Woodridge, Ill. In one
embodiment, this vacuum stripped HMSBO has a drop point of about
54.degree. C. (129.degree. F.) and a needle penetration of about
1.4 dmm. For the purposes of this document, this vacuum stripped
HMSBO shall also be included in the general definition of
HMSBO.
[0032] Metathesis is a catalytic reaction generally known in the
art that involves the interchange of alkylidene units among
compounds containing one or more double bonds {e.g., olefinic
compounds) via the formation and cleavage of the carbon-carbon
double bonds. Metathesis may occur between two like molecules
(often referred to as self-metathesis) and/or it may occur between
two different molecules (often referred to as cross-metathesis).
Self-metathesis may be represented schematically as shown in
Equation I.
R.sup.1--CH.dbd.CH--R.sup.2+R.sup.1--CH.dbd.CH--R.sup.2.revreaction.R.su-
p.1--CH.dbd.CH--R.sup.1+R.sup.2--CH.dbd.CH--R.sup.2 (I)
[0033] wherein R.sup.1 and R.sup.2 are organic groups.
[0034] Cross-metathesis may be represented schematically as shown
in Equation II.
R.sup.1--CH.dbd.CH--R.sup.2+R.sup.3--CH.dbd.CH--R.sup.4.revreaction.R.su-
p.1--CH.dbd.CH--R.sup.3+R.sup.1--CH.dbd.CH--R.sup.4+R.sup.2--CH.dbd.CH--R.-
sup.3+R.sup.2--CH.dbd.CH--R.sup.4+R.sup.1--CH.dbd.CH--R.sup.1+R.sup.2--CH.-
dbd.CH--R.sup.2+R.sup.3--CH.dbd.CH--R.sup.3+R.sup.4--CH.dbd.CH--R.sup.4
(II)
[0035] wherein R.sup.1, R.sup.2, R.sup.3, and R.sup.4 are organic
groups.
[0036] In one embodiment, the hydrogenated metathesized natural oil
based wax may be produced by the steps of: (a) providing a
metathesis composition; (b) providing a metathesis catalyst
comprising a transition metal; (c) metathesizing at least a portion
of the metathesis composition in the presence of the metathesis
catalyst to form a first composition comprising one or more
metathesis products and transition metal; (d) hydrogenating at
least a portion of the first composition in the presence of a
hydrogenation catalyst to form a second composition comprising one
or more hydrogenated metathesis products, transition metal, and
hydrogenation catalyst; and (e) removing at least a portion of the
hydrogenation catalyst from the second composition, wherein the
removal of the hydrogenation catalyst removes at least a portion of
the transition metal of the metathesis catalyst from the second
composition.
[0037] In some embodiments, the metathesis compositions comprise
polyol esters of unsaturated fatty acids. The polyol esters
typically comprise one or more of monoacylglycerides,
diacylglycerides, and triacylglycerides. The polyol esters are
derived, for example, from natural oils. In one embodiment, the
metathesis composition is refined, bleached, and deodorized (i.e.,
RBD) soybean oil. The metathesis compositions may include esters of
the fatty acids provided by the oils and fats and molecules with a
single hydroxy site such as fatty acid methyl esters.
[0038] As used herein, "polyol esters" refers to esters produced
from polyols. Polyols may include more than two hydroxyl groups.
These polyols may comprise from two to about 10 carbon atoms, and
may comprise from two to six hydroxyl groups, but other numbers of
carbon atoms and/or hydroxyl groups are possible as well. The
polyols may contain two to four hydroxyl moieties. Non-limiting
examples of polyols include glycerin, 1,2-propanediol,
1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 2,3-butanediol,
2-ethyl-1,3-propanediol, 2-ethyl-2-butyl-1,3-propanediol, neopentyl
glycol, 2,2,4-trimethyl-1,3-pentanediol, trimethylolpropane (TMP),
sorbitol and pentaerythritol. Very commonly, the polyol esters
employed herein are esters of glycerin, e.g., triacylglycerides, or
esters of a mixture of glycerin and one or more other polyols.
[0039] The polyol ester component may include a partial fatty acid
ester of one or more polyols and/or a polyol which is fully
esterified with fatty acids ("complete polyol fatty acid ester").
Examples of complete polyol fatty acid esters include
triacylglycerides, propylene glycol diesters and tetra esters of
pentaerythritol. Examples of suitable polyol partial esters include
fatty acid monoglycerides, fatty acid diglycerides and sorbitan
partial esters (e.g., diesters and triesters of sorbitan). In some
embodiments, the polyol may include from 2 to 6 carbon atoms and 2
to 6 hydroxyl groups. Examples of suitable polyols include
glycerol, trimethylolpropane, ethylene glycol, propylene glycol,
pentaerythritol, sorbitan and sorbitol.
[0040] In some embodiments, the polyol esters are metathesized and
hydrogenated to form wax compositions. For example, in one
embodiment, refined, bleached and deodorized (RBD) soybean oil is
self-metathesized in the presence of a metathesis catalyst to form
a metathesis product. The resulting metathesis product is then
hydrogenated without first removing the metathesis catalyst to form
a hydrogenated metathesis product in the form of a wax. In some
embodiments, the metathesis product is steam stripped and/or vacuum
stripped in order to remove or reduce hydrocarbon impurities. For
example, the metathesis product may be distilled in order to remove
or reduce hydrocarbons having a molecular weight of about 200
gram/mole or less or to remove or reduce hydrocarbons having a
molecular weight of about 300 grams/mole or less. The stripping may
be accomplished by sparging the mixture in a vessel, typically
agitated, by contacting the mixture with a gaseous stream in a
column that may contain typical distillation packing (e.g., random
or structured), or evaporating the lights in an evaporator such as
a wiped film evaporator. Typically, stripping will be conducted at
reduced pressure and at temperatures ranging from about 100.degree.
C. to 250.degree. C. The temperature may depend, for example, on
the level of vacuum used, with higher vacuum allowing for a lower
temperature and allowing for a more efficient and complete
separation of volatiles. In one embodiment, the hydrogenated
metathesized natural oil is a hydrogenated metathesized soybean oil
that is vacuum stripped to remove paraffins. In particular, S-60 is
a hydrogenated metathesized soybean oil available from Elevance
Renewable Sciences, in Woodridge, Ill. In some embodiments, the
hydrogenated metathesized natural oil and/or natural oil
derivatives may arise from bottoms streams from a metathesis
reactor, or from bottoms streams of downstream separation units
from a metathesis reactor. Such bottoms streams may be primarily
esters, where such esters may include triglycerides, diglycerides,
monoglycerides, or oligomers therefrom, or fatty acid methyl esters
("FAME"), or C.sub.10-C.sub.15 esters, C.sub.15-C.sub.18 esters, or
C.sub.18+ esters, or diesters therefrom, wherein such esters may
occur as free esters or in combinations thereof. In some
embodiments, such esters are preferably monoglycerides and/or fatty
acid methyl esters.
[0041] The term "metathesis catalyst" includes any catalyst or
catalyst system that catalyzes a metathesis reaction. Any known or
future-developed metathesis catalyst may be used, individually or
in combination with one or more additional catalysts. Non-limiting
exemplary metathesis catalysts and process conditions are described
in PCT/US2008/009635, pp. 18-47, incorporated by reference herein.
A number of the metathesis catalysts as shown are manufactured by
Materia, Inc. (Pasadena, Calif.). Additional exemplary metathesis
catalysts include, without limitation, metal carbene complexes
selected from the group consisting of molybdenum, osmium, chromium,
rhenium, and tungsten. The term "complex" refers to a metal atom,
such as a transition metal atom, with at least one ligand or
complexing agent coordinated or bound thereto. Such a ligand
typically is a Lewis base in metal carbene complexes useful for
alkyne or alkene-metathesis. Typical examples of such ligands
include phosphines, halides and stabilized carbenes. Some
metathesis catalysts may employ plural metals or metal co-catalysts
(e.g., a catalyst comprising a tungsten halide, a tetraalkyl tin
compound, and an organoaluminum compound). An immobilized catalyst
can be used for the metathesis process. An immobilized catalyst is
a system comprising a catalyst and a support, the catalyst
associated with the support. Exemplary associations between the
catalyst and the support may occur by way of chemical bonds or weak
interactions (e.g. hydrogen bonds, donor acceptor interactions)
between the catalyst, or any portions thereof, and the support or
any portions thereof. Support is intended to include any material
suitable to support the catalyst. Typically, immobilized catalysts
are solid phase catalysts that act on liquid or gas phase reactants
and products. Exemplary supports are polymers, silica or alumina.
Such an immobilized catalyst may be used in a flow process. An
immobilized catalyst can simplify purification of products and
recovery of the catalyst so that recycling the catalyst may be more
convenient.
[0042] The metathesis process can be conducted under any conditions
adequate to produce the desired metathesis products. For example,
stoichiometry, atmosphere, solvent, temperature and pressure can be
selected to produce a desired product and to minimize undesirable
byproducts. The metathesis process may be conducted under an inert
atmosphere. Similarly, if the olefin reagent is supplied as a gas,
an inert gaseous diluent can be used. The inert atmosphere or inert
gaseous diluent typically is an inert gas, meaning that the gas
does not interact with the metathesis catalyst to substantially
impede catalysis. For example, particular inert gases are selected
from the group consisting of helium, neon, argon, nitrogen and
combinations thereof.
[0043] Similarly, if a solvent is used, the solvent chosen may be
selected to be substantially inert with respect to the metathesis
catalyst. For example, substantially inert solvents include,
without limitation, aromatic hydrocarbons, such as benzene,
toluene, xylenes, etc.; halogenated aromatic hydrocarbons, such as
chlorobenzene and dichlorobenzene; aliphatic solvents, including
pentane, hexane, heptane, cyclohexane, etc.; and chlorinated
alkanes, such as dichloromethane, chloroform, dichloroethane,
etc.
[0044] In certain embodiments, a ligand may be added to the
metathesis reaction mixture. In many embodiments using a ligand,
the ligand is selected to be a molecule that stabilizes the
catalyst, and may thus provide an increased turnover number for the
catalyst. In some cases the ligand can alter reaction selectivity
and product distribution. Examples of ligands that can be used
include Lewis base ligands, such as, without limitation,
trialkylphosphines, for example tricyclohexyiphosphine and tributyl
phosphine; triarylphosphines, such as triphenylphosphine;
diarylalkylphosphines, such as, diphenylcyclohexylphosphine;
pyridines, such as 2,6-dimethylpyridine, 2,4,6-trimethylpyridine;
as well as other Lewis basic ligands, such as phosphine oxides and
phosphinites. Additives may also be present during metathesis that
increase catalyst lifetime.
[0045] Any useful amount of the selected metathesis catalyst can be
used in the process. For example, the molar ratio of the
unsaturated polyol ester to catalyst may range from about 5:1 to
about 10,000,000:1 or from about 50:1 to 500,000:1.
[0046] The metathesis reaction temperature may be a
rate-controlling variable where the temperature is selected to
provide a desired product at an acceptable rate. The metathesis
temperature may be greater than -40.degree. C., may be greater than
about -20.degree. C., and is typically greater than about 0.degree.
C. or greater than about 20.degree. C. Typically, the metathesis
reaction temperature is less than about 150.degree. C., typically
less than about 120.degree. C. An exemplary temperature range for
the metathesis reaction ranges from about 20.degree. C. to about
120.degree. C.
[0047] The metathesis reaction can be run under any desired
pressure. The total pressure may be selected to be greater than
about 10 kPa, in some embodiments greater than about 30 kPa, or
greater than about 100 kPa. Typically, the reaction pressure is no
more than about 7000 kPa, in some embodiments no more than about
3000 kPa. An exemplary pressure range for the metathesis reaction
is from about 100 kPa to about 3000 kPa.
[0048] In some embodiments, the metathesis reaction is catalyzed by
a system containing both a transition and a non-transition metal
component. The most active and largest number of catalyst systems
are derived from Group VI A transition metals, for example,
tungsten and molybdenum.
[0049] In some embodiments, the metathesis composition is
thereafter hydrogenated with one or more hydrogenation catalysts.
Such hydrogenation catalysts may comprise, for example, nickel,
copper, palladium, platinum, molybdenum, iron, ruthenium, osmium,
rhodium, or iridium. Combinations of metals may also be used.
Useful catalyst may be heterogeneous or homogeneous. In some
embodiments, the catalysts are supported nickel or sponge nickel
type catalysts.
[0050] In some embodiments, the hydrogenation catalyst comprises
nickel that has been chemically reduced with hydrogen to an active
state (i.e., reduced nickel) provided on a support. In some
embodiments, the support comprises porous silica (e.g., kieselguhr,
infusorial, diatomaceous, or siliceous earth) or alumina. The
catalyst are characterized by a high nickel surface area per gram
of nickel.
[0051] In some embodiments, the particles of supported nickel
catalyst are dispersed in a protective medium comprising hardened
triacylglyceride, edible oil, or tallow. In an exemplary
embodiment, the supported nickel catalyst is dispersed in the
protective medium at a level of about 22 wt. % nickel.
[0052] In some embodiments, the supported nickel catalysts are of
the type reported in U.S. Pat. No. 3,351,566 (Taylor et al.),
incorporated herein by reference in its entirety. These catalyst
comprise solid nickel-silica having a stabilized high nickel
surface area of 45 to 60 sq. meters per gram and a total surface
area of 225 to 300 sq. meters per gram. The catalysts are prepared
by precipitating the nickel and silicate ions from solution such as
nickel hydrosilicate onto porous silica particles in such
proportions that the activated catalyst contains 25 to 50 wt. %
nickel and a total silica content of 30 to 90 wt %. The particles
are activated by calcining in air at 600 to 900 F, then reducing
with hydrogen.
[0053] Useful catalysts having a high nickel content are described
in EP 0 168 091, incorporated herein by reference in its entirety,
wherein the catalyst is made by precipitation of a nickel compound.
A soluble aluminum compound is added to the slurry of the
precipitated nickel compound while the precipitate is maturing.
After reduction of the resultant catalyst precursor, the reduced
catalyst typically has a nickel surface area of the order of 90 to
150 sq. m per gram of total nickel. The catalysts have a
nickel/aluminum atomic ratio in the range of 2 to 10 and have a
total nickel content of more than about 66% by weight.
[0054] Useful high activity nickel/alumina/silica catalysts are
described in EP 0 167 201, incorporated herein by reference in its
entirety. The reduced catalysts have a high nickel surface area per
gram of total nickel in the catalyst.
[0055] Useful nickel/silica hydrogenation catalysts are described
in U.S. Pat. No. 6,846,772, incorporated herein by reference in its
entirety. The catalysts are produced by heating a slurry of
particulate silica (e.g. kieselguhr) in an aqueous nickel amine
carbonate solution for a total period of at least 200 minutes at a
pH above 7.5, followed by filtration, washing, drying, and
optionally calcination. The nickel/silica hydrogenation catalysts
are reported to have improved filtration properties.
[0056] Also useful are high surface area nickel/alumina
hydrogenation catalysts, for example as reported in U.S. Pat. No.
4,490,480, incorporated herein by reference in its entirety. These
catalysts typically have a total nickel content of 5 to 40% by
weight.
[0057] Commercial examples of supported nickel hydrogenation
catalysts include those available under the trade designations
"NYSOFACT", "NYSOSEL", and "NI 5248 D" (from Englehard Corporation,
Iselin, N.H.). Additional supported nickel hydrogenation catalysts
include those commercially available under the trade designations
"PRICAT 9910", "PRICAT 9920", "PRICAT 9908", "PRICAT 9936, and
"PRICAT 9925" (from Johnson Matthey Catalysts, Ward Hill,
Mass.).
[0058] Hydrogenation may be carried out in a batch or in a
continuous process and may be partial hydrogenation or complete
hydrogenation. In a representative batch process, a vacuum is
pulled on the headspace of a stirred reaction vessel and the
reaction vessel is charged with soybean oil (e.g., RBD soybean
oil). The soybean oil may be heated to a desired temperature.
Typically, the temperature ranges from about 50.degree. C. to
350.degree. C., for example, about 100.degree. C. to 300.degree. C.
or about 150.degree. C. to 250.degree. C. The desired temperature
may vary, for example, with hydrogen gas pressure. Typically, a
higher gas pressure will require a lower temperature. In a separate
container, the hydrogenation catalyst is weighed into a mixing
vessel and is slurried with a small amount of soybean oil. When the
soybean oil reaches the desired temperature, the slurry of
hydrogenation catalyst is added to the reaction vessel. Hydrogen
gas is then pumped into the reaction vessel to achieve a desired
pressure of H.sub.2 gas. Typically, the H.sub.2 gas pressure ranges
from about 15 to 3000 psig, for example, about 40 to about 100
psig. As the gas pressure increases, more specialized high-pressure
processing equipment may be required. Under these conditions the
hydrogenation reaction begins and the temperature is allowed to
increase to the desired hydrogenation temperature, where it is
maintained by cooling the reaction mass, for example, with cooling
coils. Typically, the hydrogenation temperature ranges from about
20.degree. C. to about 250.degree. C., for example, about
100.degree. C. or greater, or about 120.degree. C. to about
220.degree. C. When the desired degree of hydrogenation is reached,
the reaction mass is cooled to the desired filtration
temperature.
[0059] The amount of hydrogenation catalysts is typically selected
in view of a number of factors including, for example, the type of
hydrogenation catalyst used, the amount of hydrogenation catalyst
used, the degree of unsaturation in the metathesis product, the
desired rate of hydrogenation, the desired degree of hydrogenation
(e.g., as measure by iodine value (IV)), the purity of the reagent,
and the H.sub.2 gas pressure. In some embodiments, the
hydrogenation catalyst is used in an amount of about 10 wt. % or
less, for example, about 5 wt. % or less or about 1 wt. % or
less.
[0060] After hydrogenation, the used hydrogenation catalyst is
removed from the hydrogenated metathesized product using known
techniques such as filtration. In some embodiments, the
hydrogenation catalyst is removed using a plate and frame filter
such as those commercially available from Sparkle Filters, Inc.,
Conroe Tex. In some embodiments, the filtration is performed with
the assistance of pressure or a vacuum. In order to improve
filtering performance, a filter aid may be used. A filter aid may
be added to the metathesized product directly or it may be applied
to the filter. Representative examples of filtering aids include
diatomaceous earth, silica, alumina, and carbon. Typically, the
filtering aid is used in an amount of about 10 wt, % or less, for
example, about 5 wt. % or less or about 1 wt. % or less. Other
filtering techniques and filtering aids may also be employed to
remove the used hydrogenation catalyst. In other embodiments the
hydrogenation catalyst is removed using centrifugation followed by
decantation of the product.
[0061] After filtering, the hydrogenated metathesis products
typically contain less than about 100 ppm of the metathesis
catalyst transition metal. In other embodiments, the hydrogenated
metathesis products contain less than about 10 ppm of the
metathesis catalyst transition metal. In still other embodiments,
the hydrogenated metathesis products contain less than about 1 ppm
of the metathesis catalyst transition metal, for example, about 0.9
ppm or less, about 0.8 ppm or less, about 0.7 ppm or less, about
0.6 ppm or less, about 0.5 ppm or less, about 0.4 ppm or less,
about 0.3 ppm or less, or about 0.1 ppm or less. In exemplary
embodiments, the metathesis catalyst is a ruthenium-based catalyst
and the hydrogenated metathesis product contains less than about
0.1 ppm ruthenium.
[0062] In some embodiments, hydrogenated metathesized oil is a
mixture of compounds of at least two general types: paraffinic
compounds and triglycerides of long-chain mono-carboxylic and
di-carboxylic acids and oligomers thereof. The paraffinic compounds
typically do not react under any fat splitting conditions and exit
the reaction unaltered. Depending on the application, the
paraffinic compounds can be partly or fully removed (stripped).
Triglycerides and oligomers thereof are reacted with water or
OH.sup.-/H.sup.+ giving mainly free fatty acids corresponding to
the hydrogenated metathesized oil fatty acid profile (mono- and
di-acids) and glycerol leaving small amounts of partially
hydrolyzed hydrogenated metathesized oil composed of diglycerides,
monoglycerides, and oligomers thereof.
[0063] In some embodiments, the metathesized natural oil may be
epoxidized. The metathesized natural oil may be epoxidized via any
suitable peroxyacid. Peroxyacids (peracids) are acyl hydroperoxides
and are most commonly produced by the acid-catalyzed esterification
of hydrogen peroxide. Any peroxyacid may be used in the epoxidation
reaction. Examples of hydroperoxides that may be used include, but
are not limited to, peracetic acid, performic acid,
m-dichloroperbenzoic acid, tert-butylhydroperoxide,
triphenylsilylhydroperoxide, cumylhydroperoxide, and hydrogen
peroxide.
B. Amidated Metathesized Natural Oils
[0064] In some embodiments, the thickener may have a component
comprising an amidated hydrogenated metathesized natural oil or
natural oil derivative, such as an amidated hydrogenated
metathesized natural oil based wax. A number of valuable amide wax
compositions may be prepared by reacting an amine with an
ester-functional group of a metathesized natural oil in the
presence of a basic catalyst or heat to form an amidated
metathesized natural oil. This reaction may generate amidated
metathesized natural oil compositions having unique properties over
other forms of amide waxes, natural oils, or metathesized natural
oils. Such unique properties may include a higher drop point,
higher congeal point, improved hardness, improved malleability,
improved emulsifiability, improved functionality, improved
viscosity, and/or improved compatibility with other materials (such
as triglyceride oils and waxes, polyamides, stearic acid, ethylene
vinyl acetate copolymers, tackifier resins, and paraffins in low
concentration). In certain embodiments, it is possible to tailor
the range of certain properties (such as drop point or hardness) by
modifying the amount or type of amine used in the reaction with the
metathesized natural oil.
[0065] In certain embodiments, the metathesized natural oil in the
amidated metathesized natural oil composition has been
"hydrogenated" (i.e., full or partial hydrogenation of the
unsaturated carbon-carbon bonds in the metathesized natural oil) in
the presence of a hydrogenation catalyst to form a hydrogenated
metathesized natural oil. In one embodiment, the natural oil is
partially hydrogenated before it is subjected to the metathesis
reaction. In another embodiment, the natural oil is metathesized
prior to being subjected to partial or full hydrogenation. Any
known or future-developed hydrogenation catalysts may be used,
alone or in combination with one or more additional catalysts.
Non-limiting exemplary hydrogenation catalysts were described
previously in this document. Representative examples of
hydrogenated metathesized natural oils were described previously in
this document.
[0066] The amine compound(s) selected for the reaction with the
metathesized natural oil may be ammonia or a compound containing
one or more primary or secondary amino groups. In certain
embodiments, the amine is a mono-substituted amine having one
non-hydrogen substituted group (such as an alkyl, aryl group,
alkyl-amino group, or aryl-amino group), a di-substituted amine
having two non-hydrogen substituted groups, an amino-alcohol, or a
combination thereof. In certain non-limiting embodiments, the amine
is a mono-substituted or di-substituted amine such as: methylamine,
dimethylamine, ethylamine, diethylamine, propylamine,
dipropylamine, butylamine, dibutylamine, pentylamine,
dipentylamine, hexylamine, dihexylamine, heptylamine,
diheptylamine, octylamine, dioctylamine, or a mixture thereof. In
other non-limiting embodiments, the amine is an amino-alcohol such
as: methanolamine, dimethanolamine, ethanolamine, diethanolamine,
propanolamine, dipropanolamine, butanolamine, dibutanolamine,
pentanolamine, dipentanolamine, hexanolamine, dihexanolamine,
heptanolamine, diheptanolamine, octanolamine, dioctanolamine,
aniline, or a mixture thereof. In yet other non-limiting
embodiments, the amine is a diamine such as: ethylenediamine
(1,2-ethanediamine), 1,3-propanediamine, 1,4-butanediamine
(putrescine), 1,5-pentanediamine, 1,6-hexanediamine,
1,7-heptanediamine, 1,8-octanediamine,
1,3-bis(aminomethyl)cyclohexane, meta-xylenediamine,
1,8-naphthalenediamine, p-phenylenediamine,
N-(2-aminoethyl)-1,3-propanediamine, or a mixture thereof. In yet
other non-limiting embodiments, the amine is a triamine or
tetramine such as: diethylenetriamine, dipropylenetriamine,
dibutylenetriamine, dipentylenetriamine, dihexylenetriamine,
diheptylenetriamine, dioctylenetriamine, spermidine, melamine,
triethylenetetramine, tripropylenetetramine, tributylenetetramine,
tripentylenetetramine, trihexylenetetramine, triheptylenetetramine,
trioctylenetetramine, hexamine, or a mixture thereof. In another
embodiment, the amine is an imidazole or oxazolidine.
[0067] In one embodiment, the amine is selected from the group
consisting of: ethanolamine, diethanolamine, diethylamine,
ethylenediamine (1,2-ethanediamine), hexamethyleneamine, and
mixtures thereof. In one embodiment, the amine is ethylenediamine.
In another embodiment, the amine is diethanolamine. In some
embodiments, HMSBO may be fractionally amidated with diethanol
amine to generate an emulsifying amidated wax, A100, available from
Elevance Renewable Sciences, in Woodridge, Ill.
[0068] In certain embodiments, the amine is a polar compound that
is useful for forming a hydrous amidated metathesized natural oil
composition. The hydrous composition is capable of being water
dispersible and improving the viscosity of the wax composition.
Non-limiting examples of polar amines include amino-alcohols such
as methanolamine, dimethanolamine, ethanolamine, diethanolamine,
propanolamine, dipropanolamine, butanolamine, dibutanolamine,
pentanolamine, dipentanolamine, hexanolamine, dihexanolamine,
heptanolamine, diheptanolamine, octanolamine, dioctanolamine,
aniline, or mixtures thereof.
[0069] In other embodiments, the amine is a non-polar compound that
is useful for forming an anhydrous amidated metathesized natural
oil composition. Such anhydrous compositions may be capable of
improving the hardness and drop point of the wax composition.
[0070] In one embodiment, the amount of amine present in the
amine-metathesized natural oil reaction is between approximately
0.1 percent by weight and 30 percent by weight of the metathesized
natural oil present. In other embodiments, the amount of basic
catalyst is between approximately 0.1 percent by weight and 10
percent by weight of the metathesized natural oil or between
approximately 1 percent by weight and 15 percent by weight of the
metathesized natural oil. Alternatively, the amount of amine added
to the reaction can be expressed in terms of the ratio of amine
equivalents in the amine to ester equivalents in the metathesized
natural oil. In one embodiment, the ratio of amine equivalents to
ester equivalents is between approximately 1:100 and approximately
10:1. In another embodiment, the ratio of amine equivalents to
ester equivalents is between approximately 1:10 and approximately
5:1. In other embodiments, the ratio of amine equivalents to ester
equivalents is approximately 1:3, approximately 2:3, approximately
1:2, or approximately 1:1.
[0071] The basic catalyst that may be used to improve the reaction
rate of the amine-metathesized natural oil reaction is a basic
compound generally known to a person of skill in the art. In
certain embodiments, the basic catalyst is sodium carbonate,
lithium carbonate, sodium methanolate, potassium hydroxide, sodium
hydride, potassium butoxide, potassium carbonate, or a mixture
thereof. In certain embodiments, the basic catalyst may be added to
the reaction between the amine and metathesized natural oil in dry
form or dissolved in water.
[0072] In other embodiments, the reaction rate of the
amine-metathesized natural oil reaction is improved by heating the
amine-metathesized natural oil mixture (with or without a basic
catalyst present) to at least 100.degree. C., at least 120.degree.
C., at least 140.degree. C., at least 160.degree. C., or between
approximately 100.degree. C. and approximately 200.degree. C.
[0073] In one embodiment, the amount of basic catalyst added to the
reaction is between approximately 1 percent by weight and 10
percent by weight of the metathesized natural oil present. In other
embodiments, the amount of basic catalyst is between approximately
0.1 percent by weight and 1.0 percent by weight of the metathesized
natural oil or between approximately 0.01 percent by weight and 0.1
percent by weight of the metathesized natural oil. In another
embodiment, the amount of basic catalyst is approximately 0.5
percent by weight of the metathesized natural oil.
[0074] In one embodiment, the amine-metathesized natural oil
reaction is conducted in a nitrogen or other inert atmosphere. In
certain embodiments, the reaction is conducted under atmospheric
conditions and the reactor temperature is between approximately
80-250.degree. C., between approximately 120-180.degree. C., or
between approximately 120-160.degree. C. In certain embodiments,
the reactor temperature is held for approximately 1-24 hours,
approximately 4-24 hours, approximately 1 hour, approximately 2
hours, approximately 4 hours, or approximately 6 hours.
[0075] In certain embodiments, following the amine-metathesized
natural oil reaction, the product mixture is vacuum pumped for at
least 30 minutes or at least 1 hour to separate the water, any
unreacted amine, and/or glycerol from the amidated metathesized
natural oil product. In another embodiment, paraffin byproduct from
the metathesis and hydrogenation reactions can be separated from
the amidated metathesized natural oil product.
[0076] In certain embodiments, when the metathesized natural oil is
reacted with at least one amine in the presence of the basic
catalyst or heat, the ester functionality is replaced by an amine
to form an amidated metathesized natural oil comprising molecules
having the following structures:
##STR00001##
wherein R.sub.1 is selected from the group consisting of:
##STR00002##
wherein R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.6, R.sub.7,
R.sub.8, and R.sub.9 are independently selected from the group
consisting of hydrogen, alcohols, alkyls, aryls, alkyl-amines, and
aryl-amines, wherein R.sub.10 and R.sub.11 are independently
selected from the group consisting of:
[0077] hydrogen,
##STR00003##
and wherein X.sub.1, X.sub.2, X.sub.3, X.sub.4, X.sub.5, and
X.sub.6 are independently selected from the group consisting of
C.sub.8-C.sub.28 saturated or unsaturated alkyl chains from either
a fatty acid of a natural oil, or a derivative thereof formed by a
metathesis reaction.
[0078] In certain embodiments, R.sub.2, R.sub.3, R.sub.4, R.sub.5,
R.sub.6, R.sub.7, R.sub.8, and R.sub.9 may form at least one amine
selected from the group consisting of: methylamine, dimethylamine,
ethylamine, diethylamine, propylamine, dipropylamine, butylamine,
dibutylamine, pentylamine, dipentylamine, hexylamine, dihexylamine,
heptylamine, diheptylamine, octylamine, dioctylamine,
methanolamine, dimethanolamine, ethanolamine, diethanolamine,
propanolamine, dipropanolamine, butanolamine, dibutanolamine,
pentanolamine, dipentanolamine, hexanolamine, dihexanolamine,
heptanolamine, diheptanolamine, octanolamine, dioctanolamine,
aniline, ethylenediamine (1,2-ethanediamine), 1,3-propanediamine,
1,4-butanediamine (putrescine), 1,5-pentanediamine,
1,6-hexanediamine, 1,7-heptanediamine, 1,8-octanediamine,
1,3-bis(aminomethyl)cyclohexane, meta-xylenediamine,
1,8-naphthalenediamine, p-phenylenediamine,
N-(2-aminoethyl)-1,3-propanediamine, diethylenetriamine,
dipropylenetriamine, dibutylenetriamine, dipentylenetriamine,
dihexylenetriamine, diheptylenetriamine, dioctylenetriamine,
spermidine, melamine, triethylenetetramine, tripropylenetetramine,
tributylenetetramine, tripentylenetetramine, trihexylenetetramine,
triheptylenetetramine, trioctylenetetramine, hexamine, imidazole,
oxazolidine, or mixtures thereof.
[0079] In one embodiment, the amidated metathesized natural oil
comprises a "diacid functionality" [e.g.,
--(C.dbd.O)--X.sub.1--X.sub.2--(C.dbd.O)--]. In another embodiment,
the amidated metathesized natural oil contains the diacid
functionality and a glycerol backbone of the metathesized natural
oil.
[0080] In certain embodiments, in addition to the amidated
metathesized natural oil product, the reaction between the
metathesized natural oil and amine produces a hydroxy-metathesis
oligomer co-product having the following structure:
H--R.sub.12
wherein R.sub.12 is:
##STR00004##
wherein R.sub.13 and R.sub.14 are independently selected from the
group consisting of:
[0081] hydrogen,
##STR00005##
wherein X.sub.7, X.sub.8, and X.sub.9 are independently selected
from the group consisting of C.sub.8-C.sub.28 saturated or
unsaturated alkyl chains from either a fatty acid of a natural oil,
or a derivative thereof formed by a metathesis reaction.
C. Carboxylic Acids and Derivatives
[0082] The carboxylic acid has about 2 to about 36, preferably
about 6 to about 24, more preferably about 9 to about 20 carbon
atoms, and mono-, di-, tri-, and/or poly-acid variants,
hydroxy-substituted variants, aliphatic, cyclic, alicyclic,
aromatic, branched, aliphatic- and alicyclic-substituted aromatic,
aromatic-substituted aliphatic and alicyclic groups, saturated and
unsaturated variants, and heteroatom substituted variants thereof.
In some embodiments, the mono- or di-esters or poly-esters of these
acids thereof may be used. Non-limiting examples of such carboxylic
acids include lauric acid, azelaic acid, myristic acid, palmitic
acid, arachic acid, behenic acid, lignoceric acid, oleic acid,
linoleic acid, linolenic acid, capric acid, lignoceric acid,
decenoic acid, undecenoic acid, dodecenoic acid, ricinoleic acid,
myristoleic acid, palmitoleic acid, gadoleic acid, elaidic acid,
cis-eicosenoic acid, erucic acid, nervonic acid, 2,4-hexadienoic
acid, linoleic acid, 12-hydroxy tetradecanoic acid, 10-hydroxy
tetradeconoic acid, 12-hydroxy hexadecanoic acid, 8-hydroxy
hexadecanoic acid, 12-hydroxy icosanic acid, 16-hydroxy icosanic
acid 11,14-eicosadienoic acid, linolenic acid,
cis-8,11,14-eicosatrienoic acid, arachidonic acid,
cis-5,8,11,14,17-eicosapentenoic acid,
cis-4,7,10,13,16,19-docosahexenoic acid, all-trans-retinoic acid,
lauroleic acid, eleostearic acid, licanic acid, citronelic acid,
nervonic acid, abietic acid, abscisic acid, octanedioic acid,
nonanedioic acid (azelaic acid), decanedioic acid (sebacic acid),
undecanedioic acid, dodecanedioic acid, tridecanedioic acid,
tetradecanedioic acid, pentadecanoic acid and mixtures thereof. In
some embodiments, azelaic acid is a preferred carboxylic acid. In
some embodiments, naphthenic acids and mixtures thereof, such as
are obtainable from various petroleum sources, may be used. Other
non-limiting examples, such as hydroxystearic, hydroxy-ricinoleic,
hydroxybehenic and hydroxypalmitic acids may be used, preferably
hydroxystearic acid or esters of these acids such as 9-hydroxy-,
10-hydroxy- or 12-hydroxy-stearic acid, and most preferably
12-hydroxystearic acid.
D. Metal Base Compound
[0083] In the metal base compound, the metals themselves can be
selected from alkali metals or alkaline earth metals, such as,
without limitation, beryllium, magnesium, calcium, lithium, sodium,
potassium, strontium and barium; transition metals, without
limitation, such as titanium, vanadium, chromium, manganese, iron,
cobalt, nickel, copper, zinc, zirconium, molybdenum, palladium,
silver, cadmium, tungsten and mercury; and other metals such as
aluminum, gallium, tin, iron, lead, and lanthanoid metals, all
individually or in combinations thereof. Said metals are more
preferably selected from lithium, sodium, magnesium, aluminum,
calcium, zinc and barium. Examples of carboxylic acid metal salts
which may be conveniently used in the present invention are metal
salts of any combination of a mono- or poly-carboxylic; branched
alicyclic, cyclic, cycloalkyl, or linear, saturated or unsaturated,
mono- or poly-hydroxy substituted or unsubstituted carboxylic acid,
acid chloride or the ester of said carboxylic acid with an alcohol
such as an alcohol of about 1 to about 5 carbon atoms. As for the
base compound, the alkoxides, oxides, hydroxides, carbonates,
chlorides, and mixtures thereof of any of the aforementioned metals
are found to be especially useful. In some embodiments, hydroxides
of these aforementioned metals are preferred, and calcium
hydroxide, strontium hydroxide, magnesium hydroxide, sodium
hydroxide, and lithium hydroxide are more preferred. The metal
hydroxide is a mono- or di- or tri-valent metal or a mixture
thereof. In one embodiment the metal hydroxide is lithium hydroxide
monohydrate and can be solid or aqueous, although aqueous is
preferred.
[0084] In some embodiments, the metal base, usually a metal
hydroxide, such as lithium hydroxide or in its more commonly
available form of lithium hydroxide monohydrate, is reacted with a
carboxylic acid, usually 12-hydroxystearic acid, or with a
carboxylic acid derivative, usually 12-hydroxystearate or
hydrogenated castor oil, to form a metallic (lithium) soap. This
reaction is most often carried out in the lubricating base oil with
water also being present. The water is added to act as a reaction
solvent if the acid is used. If the carboxylic acid derivative is
used, the water acts both as reaction solvent and reactant, the
latter effect being necessary for the hydrolytic cleavage of the
ester linkages in the 12-hydroxystearate or the hydrogenated castor
oil. In some embodiments, the lithium hydroxide is reacted with two
or more carboxylic acids, such as 12-hydroxystearic acid and
azelaic acid, to form a metallic (lithium) soap.
Optional Grease Additives
[0085] Various optional additives may be incorporated into the
grease compositions of this invention, for the particular service
intended. Such optional additives that may commonly be used
include: metal deactivators, antioxidants, antiwear agents, rust
inhibitors, viscosity modifiers, extreme pressure agents, corrosion
inhibitors, and other additives recognized in the art to perform a
particular function or functions. Such additives may be present in
the range of 1 to 15 weight percent of the grease composition, and
more preferably 3 to 10 weight percent of the grease
composition.
[0086] Metal deactivators may include derivatives of
benzotriazoles, benzimidazole, 2-alkyldithiobenz-imidazoles,
2-alkyldithiobenzothiazoles,
2-(N,N-dialkyldithiocarbamoyl)-benzothiazoles,
2,5-bis(alkyl-dithio)-1,3,4-thiadiazoles,
2,5-bis(N,N-dialkyldithio-carbamoyl)-1,3,4-thiadiazoles,
2-alkyldithio-5-mercapto thiadiazoles or mixtures thereof.
Antioxidants may include a variety of chemical types including
phenate sulfides, phosphosulfurized terpenes, sulfurized esters,
aromatic amines, and hindered phenols. Antiwear agents may include
a metal thiophosphate, especially a zinc dialkyldithiophosphate; a
phosphoric acid ester or salt thereof; a phosphite; and a
phosphorus-containing carboxylic ester, ether, or amide. Rust
inhibitors may include metal sulfonates such as calcium sulfonate
or magnesium sulfonate, amine salts of carboxylic acids such as
octylamine octanoate, condensation products of dodecenyl succinic
acid or anhydride and a fatty acid such as oleic acid with a
polyamine, e.g. a polyalkylene polyamine such as
triethylenetetramine, and half esters of alkenyl succinic acids in
which the alkenyl radical contains 8 to 24 carbon atoms with
alcohols such as polyglycols.
[0087] Viscosity modifiers may include polymeric materials
including styrene-butadiene rubbers, ethylene-propylene copolymers,
polyisobutenes, hydrogenated styrene-isoprene polymers,
hydrogenated radical isoprene polymers, polymethacrylate acid
esters, polyacrylate acid esters, polyalkyl styrenes, alkenyl aryl
conjugated diene copolymers, polyolefins, polyalkylmethacrylates,
esters of maleic anhydride-styrene copolymers and mixtures thereof.
Extreme Pressure (EP) Agents may include agents that are soluble in
the oil include a sulfur or chlorosulfur EP agent, a chlorinated
hydrocarbon EP agent, or a phosphorus EP agent, or mixtures
thereof. Examples of such EP agents are chlorinated wax, organic
sulfides and polysulfides, such as benzyldisulfide,
bis-(chlorobenzyl) disulfide, dibutyl tetrasulfide, sulfurized
sperm oil, sulfurized methyl ester of oleic acid, sulfurized
alkylphenol, sulfurized dipentene, sulfurized terpene, and
sulfurized Diels-Alder adducts; phosphosulfurized hydrocarbons,
such as the reaction product of phosphorus sulfide with turpentine
or methyl oleate, phosphorus esters such as the dihydrocarbon and
trihydrocarbon phosphites, i.e., dibutyl phosphite, diheptyl
phosphite, dicyclohexyl phosphite, pentylphenyl phosphite;
dipentylphenyl phosphite, tridecyl phosphite, distearyl phosphite
and polypropylene substituted phenol phosphite, metal
thiocarbamates, such as zinc dioctyldithiocarbamate and barium
heptylphenol diacid, such as zinc dicyclohexyl phosphorodithioate
and the zinc salts of a phosphorodithioic acid combination may be
used. Corrosion inhibitors may include: mercaptobenzothiazole,
barium dinonylnaphthalene sulfonate, glycerol monooleate, sodium
nitrite, and imidazolines of tetraethylenepentamine, among
others.
Uses/Applications for the Grease Compositions
[0088] The grease compositions described herein are useful for
lubricating, sealing and protecting mechanical components such as
gears, axles, bearings, shafts, hinges and the like. Such
mechanical components are found in automobiles, trucks, bicycles,
steel mills, mining equipment, railway equipment including rolling
stock, aircraft, boats, construction equipment and numerous other
types of industrial and consumer machinery. The grease compositions
described herein may be used in various applications, including,
but not limited to, lubricating surface mining machinery (pins and
bushings, open gears in large electric shovels), constant velocity
joints (CV joints), ball bearings, journal bearings, high speed low
load machinery lubrication, low speed-high load machinery
lubrication, conveyor belt bearings lubrication, gears lubrication,
open gears lubrication, curve and flange rail lubrication, traction
motor gear lubrication, high temperature highly corrosive media
lubrication, wheel bearing lubrication of motor vehicles and
trucks, journal bearing lubrication of freight and high speed
trains, paper machinery lubrication, lawn and garden machinery
lubrication, pipe dope anti seize lubrication, automotive tie rod
ends, roof, seating and steering mechanism lubrication, jacks and
landing gear equipment lubrication, continuous castor and hot mills
bearing lubrication, lubrication of garage door mechanisms and oven
chain lubrication.
Grease Preparation
[0089] Greases can be manufactured in several consistencies as
defined by National Lubricating Grease Institute (N.L.G.I.) as
described in ASTM Method D-217 for Cone Penetration of Lubricating
Greases. Adjusting the lubricating base oil, thickener component,
and additive content will permit the manufacture of various grades
of greases.
[0090] As is well known in the art, greases are sold in various
grades depending upon the softness of the grease. The softer the
grease, the more fluid the grease. For example, very soft greases
sold under the designation NLGI 0 have a cone penetration number
from about 355 to 385, those having a cone penetration range of 310
to 340 are designated NLGI 1 and the most widely sold greases have
a cone penetration range of 265 to 295 and are designated NLGI 2.
Table 1 below shows the various NLGI grades for greases.
TABLE-US-00002 TABLE 1 NLGI Grades far greases NLGI Grade Worked
Cone Penetration (ASTM D 217) @ 77.degree. F. 000 445-475 00
400-430 0 355-385 1 310-340 2 265-295 3 220-250 4 175-205 5 130-160
6 85-115
[0091] Since there are a variety of different greases with varying
formulations and properties and since such properties can be
altered, sometimes significantly, by changes in process conditions
and apparatus, a great deal of flexibility is needed in the process
equipment for manufacturing greases. Because of the desired
flexibility and because many greases are specialty type greases
made in small amounts, most grease manufacturing has been of the
batch type.
[0092] Batch processing generally comprises the use of one or more
large kettles that may be equipped with, for example, paddle
agitation, stirring, heating, external recirculation systems
capable of pumping the contents from the bottom of the kettle to
the top, and combinations thereof. The kettles that may be utilized
herein may be of a size generally in a range of from 500 liters to
20,000 liters, preferably in a range of from 2,000 liters to 15,000
liters, and more preferably in a range of from 3,000 liters to
10,000 liters. Examples of suitable kettles include open kettles
and pressurized kettles. An example grease kettle is equipped with
stirring, heating, and an external recirculation system, capable of
pumping the contents from the bottom of the kettle to the top. The
kettles may have heating means, cooling means, paddle type
stirrers, gear-type circulation pumps, circulation line, back
pressure shear valve in said circulation line, colloid mill,
product filter, and other associated piping, valves,
instrumentation, etc. required for the commercial manufacture of
grease. The grease may also be passed through a grease mill again
to obtain a further improvement in yield and appearance, where such
mills may include a Morehouse mill, a Charlotte mill, and a Gaulin
homogenizer.
[0093] Another type of batch processor sometimes used is a
Stratco.RTM. mixer which has a different internal mixing
configuration. In this equipment, the material is circulated by an
impeller located at the bottom of the vessel, where it is possible
to obtain rapid circulation and thorough mixing.
[0094] To prepare the simple greases described herein, the various
thickener components (one or more of: carboxylic acids,
hydrogenated natural oil, and/or hydrogenated metathesized natural
oil derivative) are added to a lubricating base oil, and this
mixture is charged to a kettle, mixer, or equivalent vessel.
Preferably, these thickener components are naphthenic acid,
12-hydroxystearic acid, hydrogenated castor oil, and hydrogenated
metathesized soybean oil (S60), and the lubricating base oil is a
naphthenic pale oil. These materials are then stirred and heated to
a temperature between about 140.degree. F. to 200.degree. F. for
approximately 30-60 minutes, in order to dissolve one or more of
the acids into the lubricating base oil. The metal base, usually a
metal hydroxide such as lithium hydroxide is then charged to the
vessel, usually in an amount slightly in excess of the
stoichiometric amount required to neutralize the acid. The
temperature at this stage is usually between about 190.degree. F.
to about 270.degree. F., preferably between about 240.degree. F. to
about 260.degree. F., for a period of time (approximately 30-90
minutes) sufficient to complete the neutralization and to effect a
substantial dehydration of the mixture, i.e., the removal of 70 to
100% of the water, by venting. After venting the water vapor,
heating of the mixture is resumed and increased to about
350.degree. to about 430.degree. F., preferably between about
390.degree. F. to about 410.degree. F., and maintained at that
level for about 15 minutes to about 1 hour to ensure optimum soap
crystallization, dispersing of the acid into the mixture, and
improved yields. This increase in temperature (or "cookout") is
effected as rapidly as possible to save time and to minimize
oxidation.
[0095] Thereafter, the mixture is then transferred to a finishing
kettle or equivalent vessel for cooling. This cooling is assisted
by incorporating additional lubricating base oil into the mixture.
Mixing can be continued until the grease reaches ambient
temperatures. After about 90 minutes into this cooling phase, the
heat is removed, and at about 1 hour thereafter, optional grease
additives may be added to the finishing kettle.
[0096] In some embodiments, the grease compositions described
herein may also encompass complex greases. Complex greases are
formed by reaction of a metal-containing reagent with two or more
acids. One of the acids is (i) a hydroxy carboxylic acid or
reactive derivative thereof, such as a C9-C24 hydroxystearic acid,
preferably 9-hydroxy, 10-hydroxy, or 12-hydroxystearic acid, or the
mono- or di-esters or poly-esters thereof, and (ii) a dicarboxylic
acid, such as one or more straight or branched chain
C.sub.2-C.sub.12 dicarboxylic acids, examples of which may include
oxalic, malonic, succinic, glutaric, adipic, suberic, pimelic,
azelaic, dodecanedioic and sebacic acids, preferably azelaic acid,
or the mono- or di-esters or poly-esters thereof. Optionally, an
additional hydroxy carboxylic acid may be utilized, where such acid
has from 3 to 14 carbon atoms and can be either an aliphatic acid
such as lactic acid, 6-hydroxy decanoic acid, 3-hydroxybutanoic
acid, 4-hydroxybutanoic acid, etc. or an aromatic acid such as
parahydroxybenzoic acid, salicylic acid, 2-hydroxy-4-hexylbenzoic
acid, meta hydroxybenzoic acid, 2,5-dihydroxybenzoic acid;
2,6-dihydroxybenzoic acid; 4-hydroxy-3-methoxybenzoic acid, etc. or
a hydroxyaromatic aliphatic acid such as orthohydroxyphenyl,
metahydroxyphenyl, or parahydroxyphenyl acetic acid. A
cycloaliphatic hydroxy acid such as hydroxy cyclopentyl carboxylic
acid or hydroxynaphthenic acid could also be used. There is no
absolute industry standard defining the dropping point of a complex
grease. However, it is often accepted that minimum dropping points
of about 260.degree. C. are displayed by complex greases.
Generally, a complex grease is one which displays a dropping point
significantly higher, typically at least about 20.degree. C.
higher, than the corresponding simple metal soap grease.
[0097] To prepare the complex greases described herein, the various
thickener components (one or more of: carboxylic acids,
hydrogenated natural oil, and/or hydrogenated natural oil
derivative) are added to a lubricating base oil, and this mixture
is charged to a kettle, mixer, or equivalent vessel. Preferably,
these thickener components are naphthenic acid, 12-hydroxystearic
acid, azelaic acid, and hydrogenated metathesized soybean oil
(S60), and the lubricating base oil is a naphthenic pale oil. These
materials are then stirred and heated to a temperature between
about 140.degree. F. to 200.degree. F. for approximately 30-60
minutes, in order to dissolve one or more of the acids into the
lubricating base oil. The metal base, usually a metal hydroxide
such as lithium hydroxide is then charged to the vessel, is then
added to convert the azelaic acid to its dilithium soap (dilthium
azelate) usually in an amount slightly in excess of the
stoichiometric amount required to neutralize both acid groups of
the azelaic acid. The temperature at this stage is usually between
about 190.degree. F. to about 270.degree. F., preferably between
about 240.degree. F. to about 260.degree. F., for a period of time
(approximately 30-90 minutes) sufficient to complete the
neutralization and to effect a substantial dehydration of the
mixture, i.e., the removal of 70 to 100% of the water, by venting.
After venting the water vapor, heating of the mixture is resumed
and increased to about 350.degree. to about 430.degree. F.,
preferably between about 390.degree. F. to about 410.degree. F.,
and maintained at that level for about 15 minutes to about 1 hour
to ensure optimum soap crystallization, dispersing of the acid into
the mixture, and improved yields. This increase in temperature (or
"cookout") is effected as rapidly as possible to save time and to
minimize oxidation.
[0098] Thereafter, the mixture is then transferred to a finishing
kettle or equivalent vessel for cooling. This cooling is assisted
by incorporating additional lubricating base oil into the mixture.
Mixing can be continued until the grease reaches ambient
temperatures. After about 90 minutes into this cooling phase, the
heat is removed, and at about 1 hour thereafter, optional grease
additives may be added to the finishing kettle.
[0099] In some embodiments, the S60 component of the thickener
serves to liberate long chain (i.e. C18 and higher) dicarboxylate
salts, carboxylate salts, and glycerol upon exposure to metal
hydroxides during grease processing, thus serving as a latent
grease complexing agent. Also, since the S60 component will often
react in a similar manner to hydrogenated castor oil, simple
greases may achieve some complex character under standard
processing conditions (3 hours). The inclusion of S60 into simple
grease compositions would allow for lower processing temperatures
and increased production capacity without compensating simple
grease performance.
[0100] To illustrate the chemistry involved in this application, a
representative reaction between S60 and lithium hydroxide is shown
below:
##STR00006##
[0101] In many instances, neutralization of conventional organic
dicarboxylic acids (i.e, azelaic acid) used in the preparation of
complex greases necessitates additional water removal, whereas
dicarboxylate salts generated from S60 saponification release
glycerol which is tolerated, and often included in most grease
formulations. Carboxylate salts formed from S60 upon treatment with
alkali are proposed to enhance grease thickener structuring and
enable batch processing temperatures lower than the melt point of
12-hydroxystearic acid (.about.400.degree. F.) used to thicken
simple lithium grease. Reduced thickener kettle reaction
temperatures may reduce processing time and increase grease
throughput depending on the manufacturing protocol.
[0102] While the invention as described may have modifications and
alternative forms, various embodiments thereof have been described
in detail. It should be understood, however, that the description
herein of these various embodiments is not intended to limit the
invention, but on the contrary, the intention is to cover all
modifications, equivalents, and alternatives falling within the
spirit and scope of the invention as defined by the claims.
Further, while the invention will also be described with reference
to the following non-limiting examples, it will be understood, of
course, that the invention is not limited thereto since
modifications may be made by those skilled in the art, particularly
in light of the foregoing teachings.
EXAMPLES
Example 1
[0103] In a 100 gallon Stratco.RTM. mixer vessel, various thickener
components were added. In this step, naphthenic acid (0.2% by
weight), 12-hydroxystearic acid (4.9% by weight), hydrogenated
castor oil (1.9% by weight), and S60 (1% by weight), were added to
Pale Oil 750 (lubricating base oil), and melted into the
lubricating base oil at 170.degree. F. and mixed. After 50 minutes,
aqueous lithium hydroxide was charged to the vessel, and the
mixture heated to about 250.degree. F. to a nearly fluid
consistency, to saponify and neutralize this mixture. Thereafter,
water vapor was vented upon reaction completion, and heating was
increased to about 380.degree. F. to completely disperse the
lithium 12-HSA into the mixture. This mixture was then transferred
to a finishing kettle, at a period between 60 and 90 minutes from
the start of the experiment, an additional amount of lubricating
base oil was added dropwise for dilution. At about 90 minutes, the
heat was removed, and at about 1 hour thereafter, optional
additives were charged to the finishing kettle, and cooling resumed
until the end of the experiment at 4 hours.
[0104] It was determined that the inclusion of S60 in the thickener
matrix at 1% by weight yielded an NLGI grease (ASTM 60 stroke
worked penetration=288, 280), with a higher drop point than simple
lithium greases (415.degree. F. vs. 385.degree. F.).
Example 2
[0105] In a 100 gallon Stratco.RTM. mixer vessel, various thickener
components were added. In this step, naphthenic acid (0.34% by
weight), 12-hydroxystearic acid (7.32% by weight), azelaic acid
(2.4% by weight), and 560 (1.5% by weight), were added to Pale Oil
750 (lubricating base oil), and melted into the lubricating base
oil at 170.degree. F. and mixed. After 50 minutes, aqueous lithium
hydroxide was charged to the vessel, and the mixture heated to
about 250.degree. F. to a nearly fluid consistency, to saponify and
neutralize this mixture. Thereafter, water vapor was vented upon
reaction completion, and heating was increased to about 350.degree.
F. to completely disperse the lithium 12-HSA and azelaic acid into
the mixture. This mixture was then transferred to a finishing
kettle, at a period between 60 and 90 minutes from the start of the
experiment, an additional amount of lubricating base oil was added
dropwise for dilution. At about 90 minutes, the heat was removed,
and at about 1 hour thereafter, optional additives were charged to
the finishing kettle, and cooling resumed until the end of the
experiment at 4 hours.
[0106] It was determined that the inclusion of S60 in the thickener
matrix at 1.5% by weight yielded a complex grease (NLGI grade 2-60
stroke unworked/worked cone penetration=267, 262; 10,000 stroke-270
dmm, 100,000 stroke-293 dmm; Timken 50 lb pass; drop point
514.degree. F.).
Example 3
[0107] In an open kettle, various thickener components were added.
In this step, one or more components, such as naphthenic acid,
12-hydroxystearic acid, hydrogenated castor oil, and S60, in the
percentages by weight shown in Table 2 below, were added to Pale
Oil 750 (lubricating base oil), and melted into the lubricating
base oil at 170.degree. F. and mixed. After 50 minutes, aqueous
lithium hydroxide was charged to the vessel, and the mixture heated
to about 250.degree. F. to a nearly fluid consistency, to saponify
and neutralize this mixture. Thereafter, water vapor was vented
upon reaction completion, and heating was increased to about
380.degree. F. to completely disperse the lithium 12-HSA into the
mixture. This mixture was then transferred to a finishing kettle,
at a period between 60 and 90 minutes from the start of the
experiment, an additional amount of lubricating base oil was added
dropwise for dilution. At about 90 minutes, the heat was removed,
and at about 1 hour thereafter, optional additives were charged to
the finishing kettle, and cooling resumed until the end of the
experiment at 4 hours.
[0108] The quantities of the lubricating base oil, thickener
components, reaction conditions, and material properties of the
finished simple grease and complex grease products are shown in
Table 2.
TABLE-US-00003 TABLE 2 Simple and complex grease composition
properties 12- Hydrog. Final HSA Castor Naphthenic Azelaic Total
Reaction Drop Cone (A) (G) Acid Acid Thickener S60 Temp Point
Penetr. Exp. # Formulation (% w/w) (% w/w) (% w/w) (% w/w) (% w/w)
(% w/w) (F.) (F.) (dmm) 1 A 4.91 1.92 0.16 0.00 6.99 0 400 386 279
2 A 4.91 1.92 0.16 0.00 6.99 1 400 406 300 3 A 4.91 1.92 0.16 0.00
6.99 0 350 rt na 4 A 4.91 1.92 0.16 0.00 6.99 1 350 369 324 5 A
4.91 1.92 0.16 0.00 6.99 1.5 350 367 311 6 A 4.91 1.92 0.16 0.00
6.99 2 350 371 470 7 A 6.18 2.32 0.16 0.00 8.66 0 350 341 450 8 A
7.30 2.70 0.16 0.00 10.16 0 350 379 243 9 B 6.83 0.00 0.16 0.00
6.99 1 380 392 322 10 B 6.83 0.00 0.16 0.00 6.99 0 350 rt na 11 B
6.83 0.00 0.16 0.00 6.99 1 350 rt na 12 B 6.83 0.00 0.16 0.00 6.99
1.5 350 rt na 13 B 6.83 0.00 0.16 0.00 6.99 2 350 366 464 14 C 7.32
0 0.34 2.4 10.06 1.5 350 514 267
[0109] Compared to control experiment 3, inclusion of S60 at 1%
(experiment 4) and 1.5% (experiment 5) enabled grease formation at
near NLGI Grade 2 specification at 350.degree. F. At 2% S60
(experiment 6), the grease was extremely soft, suggesting a
threshold level had been exceeded. Control (experiment 7) showed
that the increased relative amount of 12-hydroxystearic acid and
hydrogenated castor oil in the thickener (about 8% by weight) did
not allow processing at 350.degree. F. Control (experiment 8)
showed that the increased relative amount of 12-hydroxystearic acid
and hydrogenated castor oil in the thickener (about 10% by weight)
produced a harder grease at NLGI Grade 3 specification. A pilot
scale run at 350.degree. F. for experiment 5 yielded at NLGI
specification grease (drop point of 378.degree. F., unworked/worked
cone penetration of 326/324 dmm). A pilot scale run at 350.degree.
F. for experiment 14 successfully yielded a complex grease at
350.degree. F. Experiment 9 also showed that a simple grease may be
made without the inclusion of hydrogenated castor oil, which
produced a grease at NLGI Grade 1 specifications.
* * * * *