U.S. patent application number 11/050865 was filed with the patent office on 2005-09-08 for environmentally friendly grease composition.
This patent application is currently assigned to Montana State University. Invention is credited to Johnson, Duane L., Rhodes, Blaine N..
Application Number | 20050197260 11/050865 |
Document ID | / |
Family ID | 34914813 |
Filed Date | 2005-09-08 |
United States Patent
Application |
20050197260 |
Kind Code |
A1 |
Johnson, Duane L. ; et
al. |
September 8, 2005 |
Environmentally friendly grease composition
Abstract
An environmentally friendly grease composition is provided
comprising (a) a vegetable oil and (b) a cellulose fiber. The
grease may further comprise glycerin; a rust inhibitor; and/or a
fatty acid ester, lecithin, phosphatidyl choline, or a combination
thereof.
Inventors: |
Johnson, Duane L.;
(Kalispell, MT) ; Rhodes, Blaine N.; (Bellevue,
WA) |
Correspondence
Address: |
MORGAN LEWIS & BOCKIUS LLP
1111 PENNSYLVANIA AVENUE NW
WASHINGTON
DC
20004
US
|
Assignee: |
Montana State University
|
Family ID: |
34914813 |
Appl. No.: |
11/050865 |
Filed: |
February 7, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60542189 |
Feb 5, 2004 |
|
|
|
Current U.S.
Class: |
508/216 ;
508/428; 508/491; 508/505 |
Current CPC
Class: |
C10M 169/02 20130101;
C10M 2223/04 20130101; C10M 2223/10 20130101; C10M 2207/281
20130101; C10N 2020/063 20200501; C10N 2030/10 20130101; C10N
2030/02 20130101; C10M 2207/401 20130101; C10M 2207/289 20130101;
C10N 2030/06 20130101; C10M 2207/125 20130101; C10M 2209/126
20130101; C10N 2020/081 20200501; C10N 2050/10 20130101; C10N
2020/02 20130101; C10M 2207/022 20130101 |
Class at
Publication: |
508/216 ;
508/491; 508/505; 508/428 |
International
Class: |
C10M 169/00 |
Claims
What is claimed is:
1. A grease composition comprising (a) a vegetable oil and (b) a
cellulose fiber.
2. The grease composition of claim 1, wherein the vegetable oil is
present in an amount of from about 60 weight % to about 90 weight
%, and the cellulose fiber is present in an amount of from about 2
weight % to about 15 weight %.
3. The grease composition of claim 1, further comprising
glycerin.
4. The grease composition of claim 3, wherein the glycerin is
present in an amount up to about 12 weight %.
5. The grease composition of claim 1, further comprising a fatty
acid ester, lecithin, phosphatidyl choline, or a combination
thereof.
6. The grease composition of claim 5, wherein the fatty acid ester,
lecithin, phosphatidyl choline, or combination thereof is present
in an amount of from about 2 weight % to about 20 weight %.
7. The grease composition of claim 6, wherein the fatty acid ester
is sorbitan mono-oleate.
8. The grease composition of claim 1, further comprising a rust
inhibitor.
9. The grease composition of claim 8, wherein the rust inhibitor is
present in an amount up to about 0.5 weight %.
10. The grease composition of claim 1, further comprising an
extreme pressure additive.
11. The grease composition of claim 10, wherein the extreme
pressure additive comprising sulfur is present in an amount of from
about 0.1 weight % to about 2 weight %.
12. The grease composition of claim 1, wherein the vegetable oil is
selected from the group consisting of canola, soy, linseed, tung,
corn, safflower, sunflower, peanut, palm, palm kernel, coconut, and
camelina oils.
13. The grease composition of claim 12, wherein the vegetable oil
is canola oil.
14. The grease composition of claim 1, wherein the cellulose is
derived from wood pulp, cotton, kenaf, flax, or a mixture
thereof.
15. The grease composition of claim 1, wherein the vegetable oil
has a viscosity of from about 35 cSt at 40.degree. C. to about 44
cSt at 40.degree. C.
16. The grease composition of claim 1, wherein the grease has a
viscosity of from about 450 cSt at 40.degree. C. to about 470 cSt
at 40.degree. C.
17. A grease composition comprising canola oil, cellulose fiber,
sorbitan mono-oleaste, glycerin, and a rust inhibitor.
18. The grease composition of claim 17, wherein the canola oil is
present in an amount of from about 70 weight % to about 80 weight
%, the cellulose fiber is present in an amount of from about 5
weight % to about 10 weight %, the sorbitan mono-oleate is present
in an amount of from about 7 weight % to about 13 weight %, the
glycerin is present in an amount of from about 5 weight % to about
10 weight %, and the rust inhibitor is present in an amount of from
about 0.1 weight % to about 0.3 weight %.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional
application 60/542,189, filed on Feb. 5, 2004, which is
incorporated herein by reference.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not applicable
INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT
DISC
[0003] Not applicable
SEQUENCE LISTING
[0004] Not applicable
FIELD OF THE INVENTION
[0005] The present invention relates to environmentally friendly
grease compositions.
BACKGROUND OF THE INVENTION
[0006] The American Society for Testing and Materials (ASTM D288
standard definition of the terms relating to petroleum) defines a
lubricating grease as a solid to semi-fluid product of dispersion
comprising a thickening agent and a liquid lubricant. The liquid
lubricant is often a non-polar liquid oil, and the thickening agent
is often a polar paste, which is usually a soap comprised of a
metal reacted or complexed with a fatty acid. Other ingredients
imparting special properties may also be included. Typically,
greases are employed in dynamic rather than static
applications.
[0007] Lubricating greases are generally lost to the environment
rather than being recycled or reused. The National Lubricating
Grease Institute Grease Survey for 2000 estimates that 500,000
lbs/year of lubricating greases are discarded to the environment in
the United States. This loss of lubricating greases is deleterious
to the environment, in part because of the toxicity of the metals
that comprise the soap. Although some metals used in the thickening
agent can also be relatively environmentally benign (for example,
if the metal is calcium or sodium), the alkalinity of the
associated polar compounds is often lethal to beneficial
microorganisms. Consequently, greases often do not pass
environmental persistence testing and thus are not considered to be
environmentally friendly.
[0008] The food industry is another area in which toxic greases are
a problem. Hodson discloses the benefits of using non-toxic
food-grade lubricants in food processing applications. D. Hodson,
Food-grade Lubricants Reduce Contamination Threats for Food and
Beverage Manufacturers, MACHINERY LUBRICATION January-February
2004, (24-27). If a plant uses a nonfood-grade lubricant, the U.S.
Food and Drug Administration (FDA) mandates that a batch of food
contaminated with the lubricant (i.e., at any measurable level
greater than 0 ppm) must be discarded. On the other hand, if a
certified food-grade lubricant is used, the FDA allows up to 10 ppm
in the food as an acceptable contamination level.
[0009] Attempts to formulate environmentally friendly, non-toxic
lubricating greases have been deficient. Grease formulations based
on inorganic or mineral thickeners, such as bentonite clay or fumed
silica, in place of the soap are generally less toxic than
metal-based thickeners. Because of the relative hardness of the
inorganic compound, however, the lubricating properties of the
greases are limited.
[0010] Oostemam, for example, discloses a grease based on a
synthetic ester oil, a lithium/calcium thickener and other
biodegradable ingredients. Oosterman, P., Biodegradable Grease for
All Bearing Applications, MACHINERY LUBRICATION, January-February
2004 (84-87). Although the study discloses acceptable lubrication
performance characteristics in bearing applications, there is no
specific disclosure regarding the biodegradability performance.
[0011] Accordingly, there is a need in the art for environmentally
friendly, biodegradable and/or non-toxic lubricating greases that
have good lubricating properties.
SUMMARY OF THE INVENTION
[0012] In one embodiment, the invention is directed to an
environmentally friendly grease composition comprising a vegetable
oil and a cellulose fiber.
[0013] In other embodiments the grease may further comprise
glycerin; a rust inhibitor; and/or a fatty acid ester, lecithin,
phosphatidyl choline, or a mixture thereof.
[0014] In another embodiment, the grease composition comprises
canola oil in an amount of from about 70 weight % to about 80
weight %, cellulose fiber in an amount of from about 5 weight % to
about 10 weight %, sorbitan mono-oleate in an amount of from about
7 weight % to about 13 weight %, glycerin in an amount of from
about 5 weight % to about 10 weight %, and a rust inhibitor in an
amount of from about 0.1 weight % to about 0.3 weight %.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Not applicable
DETAILED DESCRIPTION OF THE INVENTION
[0016] All publications and patent applications herein are
incorporated by reference to the same extent as if each individual
publication or patent application was specifically and individually
indicated to be incorporated by reference.
[0017] The following description includes information that may be
useful in understanding the present invention. It is not an
admission that any of the information provided herein is prior art
or relevant to the presently claimed inventions, or that any
publication specifically or implicitly referenced is prior art.
[0018] Unless defined otherwise, all technical and scientific terms
used herein have the same meaning as commonly understood by one of
ordinary skill in the art to which this invention belongs. Although
any methods and materials similar or equivalent to those described
herein can be used in the practice or testing of the present
invention, the preferred methods and materials are described.
[0019] In one embodiment, the invention is directed to an
environmentally friendly grease composition comprising a vegetable
oil and a cellulose fiber. The grease can be used, for example, as
a lubricant.
[0020] The first component of the present grease composition is a
vegetable oil. Vegetable oil, as used herein, means a substance
derived from a plant, generally from the seed or nut of a plant,
comprising glycerides of fatty acids. Examples of vegetable oils
used in the greases of the invention, include, but are not limited
to, canola, soy, linseed, tung, corn, safflower, sunflower, peanut,
palm, palm kernel, coconut, camelina, oiticica, and cottonseed
oils. In one embodiment of the invention, the vegetable oil
comprises canola oil.
[0021] The vegetable oil used in the grease of the present
invention can also be vegetable oil that has been heat-bodied,
telemerized, hydrogenated, partially hydrogenated, or
trans-esterified. As used herein, heat-bodied oils are fatty acids
exposed to temperatures high enough to cause them to form cyclic
ring structures, typically with extended legs of hydrocarbon
chains. As used herein, telemerized oils are vegetable oils,
wherein a dicarboxylic acid links two of the hydroxyl positions of
a triglyceride. As used herein, hydrogenated oils are oils which
have been exposed to hydrogen gas in order to saturate or partially
saturate the carbon atoms. As used herein, trans-esterified oils
are oils wherein the unsaturated hydrocarbon side chains of the
fatty acids are changed from the cis configuration to the trans
configuration. This can be accomplished via a
hydrogenation/dehydrogenation reaction.
[0022] The vegetable oils of the invention are generally present in
the grease in an amount of from about 40 weight % to about 95
weight %.
[0023] In one embodiment of the invention, the vegetable oil is
present in the grease in an amount of from about 60 weight % to
about 90 weight %.
[0024] In one embodiment of the invention, the vegetable oil is
present in the grease in an amount of from about 70 weight % to
about 80 weight %.
[0025] Without wishing to be bound by theory, it is believed that
vegetable oil acts as an environmentally friendly, non-toxic
lubricating component in the grease.
[0026] The second component of the present grease composition is a
cellulose fiber. Cellulose fiber, as used herein, means a fiber,
i.e., a solid characterized by a relatively high tenacity and an
extremely high ratio of length to diameter (on the order of several
hundred to one), of a polysaccharide comprising anhydroglucose
units joined by an oxygen linkage that form molecular chains that
are essentially linear. Examples of sources from which cellulose
can be obtained include, but are not limited to, cotton, wood pulp,
flax, and kenaf.
[0027] The cellulose fibers of the invention are generally present
in the grease in an amount of from about 1 weight % to about 20
weight %.
[0028] In one embodiment of the invention, the cellulose fibers are
present in an amount of from about 2 weight % to about 15 weight
%.
[0029] In one embodiment of the invention, the cellulose fibers are
present in an amount of from about 5 weight % to about 10 weight
%.
[0030] Without wishing to be bound by theory, it is believed that
the cellulose fiber acts as an environmentally friendly, non-toxic
thickening agent in the grease.
[0031] In one embodiment, the grease composition of the present
invention comprises glycerin.
[0032] Glycerin is generally present in the grease in an amount of
up to about 15 weight %.
[0033] In one embodiment of the invention, glycerin is used in the
grease in an amount of about 12 weight %.
[0034] In one embodiment of the invention, glycerin is used in an
amount of from about 5 weight % to about 10 weight %.
[0035] Without wishing to be bound by theory, it is believed that
glycerin acts as an environmentally friendly, non-toxic thickening
agent additive, in part assisting with emulsification.
[0036] In one embodiment, the grease composition of the present
invention comprises a fatty acid ester, lecithin, phosphatidyl
choline, or a combination thereof.
[0037] A fatty acid ester, as used herein, means an ester formed by
reacting a fatty acid with an alcohol. Suitable fatty acids
include, but are not limited to, caproic acid, lauric acid,
myristic acid, palmitic, stearic, oleaic, linoleic, and linolenic
acid. Suitable alcohols include, but are not limited to, mono and
polyhydroxy substituted hydrocarbons having between 1 and 20 carbon
atoms, preferably polyhydroxy hydrocarbons having between 5 and 12
carbons, for example, sorbitol. Examples of fatty acid esters used
in the greases of the invention, include, but are not limited to,
sorbiatan monolaurate, sorbitan monostearate, and sorbitan
mono-oleate. In one embodiment, the preferred fatty acid comprises
sorbitan mono-oleate.
[0038] Phosphatidyl choline, as used herein, has the formula 1
[0039] wherein --OC(O)R is derived from a fatty acid, and wherein R
and R.sub.1 are saturated or unsaturated hydrocarbons, preferably
with 6-22 carbon atoms.
[0040] Lecithin, as used herein, means a mixture of neutral and
polar lipids and phosphatidyl choline molecules having a variety of
--OC(O)R groups.
[0041] The fatty acid ester, lecithin, or mixture thereof is
generally present in the grease in an amount of from about 1 weight
% to about 30 weight %. In a preferred embodiment, the fatty acid
ester, lecithin, or mixture thereof is present in an amount of from
2 weight % to about 20 weight %. In a more preferred embodiment,
the fatty acid ester, lecithin, or mixture thereof is present in an
amount of from about 7 weight % to about 13 weight %.
[0042] Without wishing to be bound by theory, it is believed that
the fatty acid ester, lecithin, phosphatidyl choline, or a
combination thereof acts as a coupling agent between the non-polar
liquid and the polar fiber surface, as well as a lubrication aid to
the grease. Again, without wishing to be bound by theory, it is
believed that the molecules of the above-listed compounds have both
a polar and a non-polar component (e.g., in sorbitan mono-oleate,
the polar component is the alcohol portion of the molecule, and the
non-polar component is the hydrocarbon chain), and this
characteristic aids in maintaining the grease structure.
[0043] In one embodiment, the grease composition of the invention
comprises a rust inhibitor. The rust-inhibitor may be selected
from, for example, neutral or overbased petroleum or synthetic oil
metal sulfonates such as neutral or overbased calcium sulfonates,
neutral or overbased barium sulfonates, neutral or overbased zinc
sulfonates; metal soaps; partially esterified polyhydric alcohols
such as sorbitan fatty acid esters; amines; phosphoric acid; or
linear or branched alcohol esters of phosphates. In one embodiment
of the invention the rust inhibitor is Maxhib OS-4300, a
proprietary mixture of phosphate esters, commercially available
from Rutgers Organics Corporation of Piedmont, S.C.
[0044] The rust additive is generally present in the grease of the
present invention in an amount less than about 2 weight %.
[0045] In one embodiment, the rust additive is present in the
grease of the present invention in an amount less than about 0.5
weight %.
[0046] In one embodiment, the rust additive is present in the
grease of the present invention in an amount of from about 0.1
weight % to about 0.3 weight %.
[0047] In one embodiment, the grease composition of the invention
comprises an extreme pressure additive. The extreme pressure
additive can be a sulfurized oil or a sulfurized fat.
[0048] The extreme pressure additive is generally present in the
grease compositions of the invention in an amount from about 0.05
weight % to about 5 weight %.
[0049] In one embodiment, the extreme pressure additive is present
in an amount of from about 0.1 weight % to about 2 weight %.
[0050] The viscosities of both the vegetable oil in the grease and
the grease itself are important parameters used to characterize the
grease's performance. The vegetable oils used in the greases of the
present invention have viscosities of from about 30 centiStokes
(cSt) to about 50 centiStokes (cSt) at 40.degree. C.
[0051] In one embodiment, the vegetable oils of the present
invention have viscosities of from about 35 cSt to about 44 cSt at
40.degree. C.
[0052] The grease of the present invention generally has a
viscosity in the range of from about 400 cSt at 40.degree. C. to
about 500 cSt at 40.degree. C.
[0053] In one embodiment, the grease of the present invention has a
viscosity of from about 450 cSt at 40.degree. C. to about 470 cSt
at 40.degree. C.
[0054] As used herein, the drop point of grease is the temperature
at which the grease passes from a semi-solid to a liquid state.
Generally, the drop point is measured using ASTM D-566.
[0055] Biodegradability, as used herein means a measure of how
quickly and completely the greases of the present invention break
down in the environment. The grease compositions of the present
invention are environmentally friendly, i.e., they break down
quickly and completely in the environment. Tests used to test the
biodegradability of the greases of the present invention, include,
but are not limited to the OECD 301B test or CEC-L33-A-93 test.
According to the 301B test developed by OECD (Organization for
Economic Cooperation and Development), a compound is judged to be
biodegradable when the amount of CO.sub.2 gas generated by
bacterial decomposition (test period: 28 days) accounts for 60% or
higher of the total theoretical amount of CO.sub.2 gas calculated
based upon the amount of carbon in a sample. The test of
CEC-L33-A-93 was developed by CEC (Coordinating European Council),
and is generally used for testing the biodegradability of engine
oils for two stroke cycle outboard motors. This test is also widely
used to evaluated the biodegradability of water-insoluble
lubricating oils such as hydraulic oils and grease. In this test, a
sample and a source of microorganisms are cultured with shaking at
25.degree. C. for 21 days and are then extracted with carbon
tetrachloride. The infrared absorption spectrum of the extract is
determined and the absorption intensity due to the methylene groups
in the sample is quantified to calculate the biodegradability rate
(%) of the sample. Those giving 67% or higher biodegradability
rates are acceptable in this test.
[0056] In one embodiment, the greases of the present invention are
manufactured by first mixing the vegetable oil with a fatty acid
ester, lecithin, phosphatidyl choline, or a combination thereof and
a rust inhibitor until the components are dissolved. Then, the
cellulose fiber and glycerol are added to the dissolved mixture
until the desired viscosity and drop point are reached.
[0057] The grease compositions of the present invention exhibit
excellent lubrication characteristics, and are biodegradable and/or
less toxic than conventional greases.
EXAMPLES
[0058] The grease compositions of the invention are illustrated by
the following examples, which are merely indicative of the nature
of the present invention, and should not be construed as limiting
the scope of the invention, nor of the appended claims, in any
manner.
[0059] Without further description, it is believed that one of
ordinary skill in the art can, using the preceding description and
the following illustrative examples, make and utilize the compounds
of the present invention and practice the claimed methods. The
following working examples therefore, specifically point out the
preferred embodiments of the present invention, and are not to be
construed as limiting in any way the remainder of the
disclosure.
Example 1
[0060] A grease formulation composed of about 74 weight % canola
oil, about 7 weight % cellulose fiber, about 9.8 weight % sorbitan
mono-oleate, about 0.2 weight % Maxhib OS-4300 rust inhibitor, and
about 7 weight % glycerin was prepared for testing. Two tests were
performed to evaluate the lubricity and stability characteristics
of the grease. The two tests were D2266: Four Ball Wear Properties
and D942: Oxidation Stability of Lubricating Grease. The tests
results were as follows:
1 ASTM D2266: Four Ball Wear Properties: Scar diameter: 0.6 mm
Time: 1 hour Load: 40 Kgf ASTM D942: Oxidation Stability of
Lubricating Grease Pressure Drop: 39.36 psi Test Duration: 100
hours Test Temperature: 99.degree. C.
[0061] The foregoing detailed description has been given for
clearness of understanding only and no unnecessary limitations
should be understood therefrom as modifications will be obvious to
those skilled in the art.
[0062] While the invention has been described in connection with
specific embodiments thereof, it will be understood that it is
capable of further modifications and this application is intended
to cover any variations, uses, or adaptations of the invention
following, in general, the principles of the invention and
including such departures from the present disclosure as come
within known or customary practice within the art to which the
invention pertains and as may be applied to the essential features
hereinbefore set forth and as follows in the scope of the appended
claims.
[0063] All publications cited herein are incorporated herein by
reference for the purpose of disclosing and describing specific
aspects of the invention for which the publication is cited.
* * * * *