Note: Descriptions are shown in the official language in which they were submitted.
CA 02538768 2009-05-29
VEGETABLE OIL LUBRICANT COMPRISING ALL-HYDROPROCESSED SYNTHETIC
OILS
BACKGROUND OF THE INVENTION
The present, invention is directed to lubricant compositions. Specifically, it
relates
to vegetable oil based lubricants that comprise synthetic oils made by all-
hydroprocessing routes. More specifically, it relates to lubricants that
provide enhanced
properties including viscosity index, pour points, low temperature
pumpability, low
volatility, oxidation stability, electrical insulating value, the ability to
formulate different
viscosities, and microbial biodegradability.
It is generally known that vegetable oil based lubricants can be formed using
additives including the non-lube portion of natural vacuum gas oil feedstock.
Historically,
base oil manufacturers have often used traditional chemical-solvent refining
processes to
remove the undesirable non-tube molecules from the gas oil portion of the
crude oil.
Such refining is considered a subtraction process in that the solvents do not
change the
molecular structure of the desired product. To, further enhance the
characteristics of the
solvent refined base oil, hydrogenation (i.e., hydrofinishing) is sometimes
used to
saturate the molecules making them less susceptible to oxidative degradation
when used
as a lubricant. It is generally recognized that hydrofinishing associated with
solvent
processes, although useful, is typically very mild, resulting in minimal
change to the
primary, secondary, and tertiary structure of the finished product.
Viscosity Index (VI) measures the resistance of an oil to viscosity change as
temperature changes. The higher the VI, the more stable the viscosity over a
wide
temperature range. In other words, the higher the VI, the less an oil will
thicken as it
gets cold and the less it will thin out at higher temperatures --providing
better lubricant
performance at both temperature extremes.
Hydrocracking and hydroisomerization are refining processes that use catalyst
and
hydrogen at high pressure to make high-quality lubricant base oils.
Hydrocracking is
1
CA 02538768 2006-03-10
WO 2005/026300 PCT/US2004/030030
used to improve VI and remove impurities, while hydroisomerization converts
wax
molecules into high quality lubricant components.
Groups I, II, and III are broad categories of base stocks developed by the
American Petroleum Institute for the purpose of creating guidelines for
licensing engine
oils. Typically, solvent-refined base oils fall into Group I, while
hydroprocessed base
stocks fall into Group II. Unconventional Base Oils (UCBOs) or Very-High VI
stocks
are normally categorized as Group III.
Group II+, though not an official API designation is a term used increasingly
to
describe Group II stocks of higher VI (110-119) and lower volatility than
typical group II
stocks.
Group I oils contain high levels of sulfur and aromatics, which are compounds
that can diminish performance. Hydroprocessed Group II and III oils have lower
levels
of these impurities, which result in enhanced oxidation performance for fully-
formulated
lubricants.
Recent refining processes have formed a new class of synthetic oils. For
example, a technical paper by the Chevron Products Company entitled: "The
Synthetic
Nature Of Group III Base Oils", Presented at the 1999 Lubricants & Waxes
Meeting,
November 11-12, Houston TX (National Petrochemical & Refiners Association)
discloses an all-hydroprocessing manufacturing route that combines three
catalytic
processes to significantly and selectively change the size, shape, and
heteroatom content
of the molecules to improve their lubricating properties. Hydrogen is added at
high
temperature and pressure in all three steps to make oil of exceptional
stability. Impurities
such as sulfur and nitrogen are essentially completely removed. In Group III
manufacturing, feedstock is converted to saturates, which are enriched in
isoparaffins.
Reactive species, such as those containing aromatics, sulfur, and nitrogen are
virtually
gone and species that create problems with low temperature performance, such
as normal
paraffins, are also eliminated. Finally, the paper concludes the analysis of
the feed and
product from a commercial Group III production run, which shows that a vast
majority of
feed molecules are synthetically altered by the three catalytic processes used
to make
modem all-hydroprocessed Group III base oils. These results support the claim
that
2
CA 02538768 2006-03-10
WO 2005/026300 PCT/US2004/030030
modern Group III base oils, made utilizing an all-hydroprocessing route, are
essentially
man-made or synthetic and have advantages over old technology hydrocracked
base oils.
In addition, their high performance in lubricant applications allows them to
be used in
high performance products often formulated with traditional synthetics such as
polyalphaolefin (PAO). The reference did not teach the use of all-
hydroprocessed group
III base oils as a raw material for the preparation of biodegradable vegetable
oil based
lubricants.
Patents that generally disclose lubricants that can be formed using vegetable
oil
and group III oils include U.S. Pat. No. 6,103,673; U.S. Pat. No. 6,251,840;
U.S. Pat. No.
6,451,745; and U.S. Pat. No. 6,528,458 all of which are from the Lubrizol
Corporation
(Wickliffe, OH). Additional patents include U.S. Pat. No. 6,303,547 and U.S.
Pat. No.
6,444,622 both from the Ethyl Corporation (Richmond, VA).
U.S. Patent No. 6,528,458 discloses that compositions comprising (a) an oil of
lubricating viscosity; (b) 2,5-dimercapto-1,3,4-thiadiazole (DMTD), a
derivative of
DMTD, or mixtures thereof, (c) a friction modifier; and (d) a dispersant, are
useful for
lubricating a transmission having a plurality of wet clutches and a plurality
of partial
power transmission shafts, wherein shifting of gears occurs by a process
comprising
synchronization of an engaged and a non-engaged partial transmission shaft and
engagement of a wet clutch.
U.S. Patent No. 6,451,745 discloses that a continuously variable transmission
can
be lubricated by supplying to them a composition of (a) an oil of lubricating
viscosity; (b)
a dispersant; and (c) a detergent. At least one of the dispersant (b) and the
detergent (c) is
a borated species, and the amount of boron present in the composition is
sufficient to
impart improved friction and anti-seizure properties to the composition when
employed
in said transmission.
U.S. Patent No. 6,444,622 discloses mixtures of the reaction product of at
least
one C5-C60 carboxylic acid and at least one amine selected from the group
comprising:
guanidine, aminoguanidine, urea, thioruea and salts thereof and a phosphorus-
containing
dispersant are useful as gear oil additives.
U.S. Patent No. 6,303,547 discloses that the reaction product of at least one
C5-
C60 carboxylic acid and at least one amine selected from the group comprising:
3
CA 02538768 2006-03-10
WO 2005/026300 PCT/US2004/030030
guanidine, aminoguanidine, urea, thioruea and salts thereof is useful as a
gear oil
additive.
U.S. Patent No. 6,251,840 discloses a lubricating/functional fluid composition
which exhibits in use improved antiwear and antifoaming properties. The
improvements
result from use of 2,5-dimercapto-1,3,4-thiadiazole and derivatives thereof
together with
silicone and/or fluorosilicone antifoam agents.
U.S. Patent No. 6,103,673 discloses a composition comprising of an oil of
lubricating viscosity; a shear stable viscosity modifier; at least 0.1 percent
by weight of
an overbased metal salt; at least 0.1 percent by weight of at least one
phosphorus
compound; and 0.1 to 0.25 percent by weight of a combination of at least two
friction
modifiers provides an improved fluid for continuously variable transmissions.
At least
one of the friction modifiers is selected from the group comprising: zinc
salts of fatty
acids having at least 10 carbon atoms, hydrocarbyl imidazolines containing at
least 12
carbon atoms in the hydrocarbyl group, and borated epoxides. The total amount
of the
friction modifiers is limited to those amounts which provide a metal-to-metal
coefficient
of friction of at least about 0.120 as measured at 110 C by ASTM-G-77.
The references do not disclose enabling lubricant formulations containing a
combination of vegetable oil and hydroprocessed base oils (group III) and thus
fail to
teach or suggest the advantages associated with such formulations. Because all-
hydroprocessed Group III stocks are manufactured with no solvent refining
steps, when it
comes to purity, they far surpass Group II or III base oils made in "hybrid"
plants that
maintain some solvent processing. In fact, they contain the lowest levels of
impurities
currently available in mineral-based oils, which, in turn gives them a
significant
performance advantage.
All-hydroprocessing includes three steps as follows: hydrocracking,
hydroisomerization, and hydrofinishing. In the first step, hydrocracking, the
majority of
sulfur, nitrogen, and essentially all other non-hydrocarbon impurities are
removed and
most aromatics are saturated via hydrogen addition. Molecular reshaping of
remaining
saturated species occurs as rings are opened and paraffin isomers are
redistributed, driven
by thermodynamics with reaction rates facilitated by catalysts. Clean fuels
are by-
products of this and subsequent steps of the process. In the second step,
4
CA 02538768 2009-05-29
hydroisomerization, n-paraffins and other molecules with waxy side chains are
isomerized into branched molecules with much lower pour points. The majority
of
remaining aromatics are saturated and the majority of remaining sulfur and
nitrogen species are removed. In the final step, hydrofinishing, any remaining
non-isoparaffin impurities (sulfur species, nitrogen species, aromatics, and
olefins) are removed to trace levels.
Environmental issues related to discarded and/or spent lubricants are also
concerns that need to be addressed. For example, biodegradable resistant
lubricants can stress an ecosystem when improperly discarded or accidentally
discharged into the environment. The invasive and persistent nature of such
materials continues to be a health concern in aquatic and landfill
environments.
To overcome these issues, research efforts continue to explore new raw
materials and/or new combinations of raw materials to provide improved-
lubricants having a higher degree of microbial biodegradability.
Patents that teach biodegradable lubricants include U.S. Pat. No.
5,736,493; U.S. Pat. No. 6,383,992; U.S. Pat. No. 5,863,872; U.S. Pat. No.
5,990,055; U.S. Pat. No. 6,624,124; U.S. Pat. No. 6,620,772; and U.S. Pat. No.
6,534,454 all of which are from Renewable Lubricants, Inc. (Hartville, OH).
The
patents describe a combination of natural oils, synthetic oils, and
antioxidants to
provide effective lubricant compositions. Other related patents that teach the
importance of vegetable oil based compositions and their biodegradability
includes U.S. Pat. No. 6,300,292 granted to Nippon Mitsubishi Oil Corporation.
Although the lubricants described above have effective lubricating and
biodegradable properties, in the spirit of continuous improvement, alternative
compositions and the improvements there from. are needed.
Therefore, there remains a need for vegetable oil based lubricants,
comprising synthetic oils made by all-hydroprocessing routes, which provide
enhanced properties including viscosity index, pour points, low temperature
pumpability, low volatility, oxidation stability, electrical insulating value,
the
ability to formulate different viscosities, and microbial biodegradability.
SUMMARY OF THE INVENTION
5
CA 02538768 2006-03-10
WO 2005/026300 PCT/US2004/030030
The present invention is directed to vegetable oil based lubricants using all-
hydroprocessed synthetic based oils. The lubricants are shown to provide
enhanced
properties including viscosity index, pour point, low temperature pumpability,
low
volatility, oxidation stability, electrical insulating value, and microbial
biodegradability.
The lubricants of the present invention comprise:
1) at least one vegetable oil selected from the group comprising: natural
vegetable oil, synthetic vegetable oil, genetically modified vegetable
oil, and mixtures thereof:
2) at least one all-hydroprocessed synthetic base oil having a sulfur
content equal to or less than 0.03 percent, saturates equal to or greater
than 90 percent, and a viscosity index equal to or greater than 120: and
3) at least one antioxidant.
The lubricants are characterized as having enhanced microbial biodegradability
making them environmentally friendly. Surprisingly, some compositions can have
an all-
hydroprocessed based oil content greater than about 60% and pass ultimate
biodegradability test method ASTM D-5864 Pwl. Ultimate biodegradability Pwl is
the
fastest and most complete type of biodegradation as defined by ASTM D-5864.
Furthermore, the inventive compositions have excellent rheological properties
and a
super high viscosity index of about 120 to 200, making them particularly
useful as
hydraulic oils, transmission fluids, engine oils, gear oil, rock drill oils,
circulating oils,
drip oils, spindle oils, compressor oils, grease base oils, corrosion
inhibitor oils, heat
transfer oils, cable oils, chain oils, general purpose oils, metal working
oils, and electrical
insulating oils.
In another aspect, the present invention discloses a method for the
preparation of
vegetable oil based lubricants comprising the steps of:
1) providing at least one vegetable oil selected from the group comprising:
natural vegetable oil, synthetic vegetable oil, genetically modified vegetable
oil, and mixtures thereof:
2) providing at least one all-hydroprocessed synthetic base oil having a
sulfur
content equal to or less than 0.03 percent, saturates equal to or greater than
90
percent, and a viscosity index equal to or greater than 120;
6
CA 02538768 2006-03-10
WO 2005/026300 PCT/US2004/030030
3) providing at least one antioxidant; then
blending 1), 2), and 3) to form said lubricant.
Another aspect of the invention relates to a method of enhancing the
lubrication
of mechanical equipment comprising the steps of:
a) providing at least one lubricant comprising:
1) at least one vegetable oil selected from the group comprising: natural
vegetable oil, synthetic vegetable oil, genetically modified vegetable oil,
and mixtures thereof;
2) at least one all-hydroprocessed synthetic base oil having a sulfur content
equal to or less than 0.03 percent, saturates equal to or greater than 90
percent, and a viscosity index equal to or greater than 120;
3) at least one antioxidant; then
b) adding an effective amount of said lubricant into said equipment.
In accordance with one aspect of the present invention, a lubricant
composition
includes at least one vegetable oil selected from the group comprising:
natural vegetable
oil, synthetic vegetable oil, genetically modified vegetable oil, and mixtures
thereof, at
least one synthetic base oil having a sulfur content equal to or less than
about 0.03
percent and saturates equal to or greater than about 90 percent, and at least
one
antioxidant.
In accordance with another aspect of the present invention, the vegetable oil
is
selected from the group comprising: sunflower oil, canola oil, soybean oil,
corn oil,
peanut oil, palm oil, castor bean oil, cotton oil, lesquerella oil, crambe
oil, safflower oil,
high oleic sunflower oil, high oleic canola oil, high oleic soybean oil, high
oleic corn oil,
high oleic peanut oil, high oleic cotton oil, high oleic safflower oil, and
mixtures thereof.
In accordance with another aspect of the present invention, the vegetable oil
is
present in an amount greater than about 10%, based on total weight.
In accordance with another aspect of the present invention, the vegetable oil
is
present in an amount less than about 90%, based on total weight.
In accordance with another aspect of the present invention, the vegetable oil
is
present in a range from about 10% to about 90%, based on total weight.
7
CA 02538768 2006-03-10
WO 2005/026300 PCT/US2004/030030
In accordance with another aspect of the present invention, the vegetable oil
is
present in a range from about 30% to about 70%, based on total weight.
In accordance with another aspect of the present invention, the vegetable oil
is
present in a range from about 40% to about 60%, based on total weight.
In accordance with another aspect of the present invention, the base oil is an
all-
hydroprocessed synthetic base oil.
In accordance with another aspect of the present invention, the base oil is
present
in an amount greater than about 10%, based on total weight.
In accordance with another aspect of the present invention, the base oil is
present
in an amount less than about 90%, based on total weight.
In accordance with another aspect of the present invention, the base oil is
present
in a range from about 10% to about 90%, based on total weight.
In accordance with another aspect of the present invention, the base oil is
present
in a range from about 30% to about 70%, based on total weight.
In accordance with another aspect of the present invention, the base oil is
present
in a range from about 40% to about 60%, based on total weight.
In accordance with another aspect of the present invention, the antioxidant is
selected from the group comprising: amines, phenols, and mixtures thereof.
In accordance with another aspect of the present invention, the antioxidant is
present in a range from about 0.01% to about 5.0%, based on total weight.
In accordance with another aspect of the present invention, the antioxidant is
present in a range from about 0.25% to about 1.5%, based on total weight.
In accordance with another aspect of the present invention, the antioxidant is
present in a range from about 0.5% to about 1.0%, based on total weight.
In accordance with another aspect of the present invention, the composition
further includes at least one additive, the additive chosen from the group
comprising:
anti-wear inhibitor, extreme pressure additive, friction modifier, rust
inhibitor, corrosion
inhibitor, pour point depressant, tackifier, viscosity modifier, metal
deactivator, foam
inhibitor, emulsifier, and demulsifier.
In accordance with another aspect of the present invention, the at least one
additive is a phosphorous amine salt of the formula:
8
CA 02538768 2006-03-10
WO 2005/026300 PCT/US2004/030030
X
11
(R9O),,,-P-(XNR1OR22R23)õ
H
wherein R9 and R10 are independently aliphatic groups containing from about I
up to
about 24 carbon atoms, R22 and R23 are independently hydrogen or aliphatic
groups
containing from about 1 up to about 18 aliphatic carbon atoms, the sum of m
and n is 3
and X is oxygen or sulfur.
In accordance with another aspect of the present invention, the phosphorous
amine salt includes R9 contains from about 8 up to 18 carbon atoms, R10 is
CH3
I
R11-C-
I
CH3
wherein R11 is an aliphatic group containing from about 6 up to about 12
carbon atoms,
R22 and R23 are hydrogen, m is 2, n is l and X is oxygen.
In accordance with another aspect of the present invention, the at least one
additive is chosen from the group comprising (in the following list, the
different additives
are separated by semicolons): phosphorous amine salt having the formula:
X
11 +
(R90),, -P-(XNR10R22R?3)õ
H
wherein R9 and R10 are independently aliphatic groups containing from about 1
up to
about 24 carbon atoms, R22 and R23 are independently hydrogen or aliphatic
groups
containing from about 1 up to about 18 aliphatic carbon atoms, the sum of m
and n is 3
and X is oxygen or sulfur; phosphorous amine salt having the formula:
X
11 +
(R9O),,,-P-(1fNR1OR22R23),
H
wherein R9 and R10 are independently aliphatic groups containing from about 1
up to
about 24 carbon atoms, R22 and R23 are independently hydrogen or aliphatic
groups
containing from about 1 up to about 18 aliphatic carbon atoms, the sum of m
and n is 3
9
CA 02538768 2006-03-10
WO 2005/026300 PCT/US2004/030030
and X is oxygen or sulfur, wherein R9 contains from about 8 up to 18 carbon
atoms, R10
is
CE6
I
R11-C-
CH3
wherein R11 is an aliphatic group containing from about 6 up to about 12
carbon atoms,
R22 and R23 are hydrogen, m is 2, n is 1 and X is oxygen; phosphorous compound
having
the formula:
Rig
Rig/P=X
RM
wherein R19, R20, and R21 are independent hydrogen, an aliphatic or alkoxy
group
containing from I up to about 12 carbon atoms, or an aryl or aryloxy group
wherein the
aryl group is phenyl or naphthyl and the aryloxy group is phenoxy or naphthoxy
and X is
oxygen or sulfur; N-acyl derivative of sarcosine having the formula:
R8C=0
I
CH3NCH2COOH
wherein R8 is an aliphatic group containing from I up to about 24 carbon
atoms. In one
embodiment, R8 contains from 6 to 24 carbon atoms, and in one embodiment from
12 to
18 carbon atoms. An example of an additive of N-acyl derivative of sarcosine
is N-
methyl-N-(1-oxo-9-octadecenyl) glycine wherein R8 is a heptadecenyl group;
imidazoline; triazole; substituted triazole; tolu-triazole; alkylated
polystyrene; polyalkyl
methacrylate; ethylene vinyl acetate; polyisobutylenes; polymethacrylates;
olefin
copolymer; ester of styrene maleic anyhdride copolymer; hydrogenated styrene-
diene
copolymer; hydrogenated radial polyisoprene; alkylated polystyrene; fumed
silica;
complex ester; and food grade tackifier.
In accordance with another aspect of the present invention, the anti-wear
inhibitor
is from about 0.1 % to about 4% by total weight, the corrosion inhibitor is
from about
0.01% to about 4% by total weight, the metal deactivator is from about 0.05%
to about
CA 02538768 2006-03-10
WO 2005/026300 PCT/US2004/030030
0.3% by total weight, the pour point depressant is from about 0.2% to about 4%
by total
weight, and the viscosity modifier is from about 0.5% to about 30% by total
weight.
In accordance with another aspect of the present invention, the corrosion
inhibitor
is from about 0.05% to about 2% by total weight, the metal deactivator is from
about
0.05% to about 0.2% by total weight, and the viscosity modifier is from about
1% to
about 20% by total weight.
In accordance with another aspect of the present invention, the synthetic base
oil
has a viscosity index equal to or greater than about 120.
In accordance with another aspect of the present invention, the composition
has
an oxidation characteristic in a range from about 60 to about 600 minutes.
In accordance with another aspect of the present invention, the oxidation
characteristic is in a range from about 200 to about 400 minutes.
In accordance with another aspect of the present invention, the base oil is at
least
one oil chosen from the group comprising: synthetic ester base oil,
polyalphaolefin,
unrefined oil, refined oil, re-refined oil, and mixtures thereof.
In accordance with another aspect of the present invention, a method of making
a
lubricant composition includes the steps of providing at least one vegetable
oil selected
from the group comprising: natural vegetable oil, synthetic vegetable oil,
genetically
modified vegetable oil, and mixtures thereof, providing at least one synthetic
base oil
having a sulfur content equal to or less than about 0.03 percent and saturates
equal to or
greater than about 90 percent, providing at least one antioxidant, and
blending together
the vegetable oil, the base oil, and the at least one antioxidant.
In accordance with another aspect of the present invention, a lubricant
composition includes at least one vegetable oil selected from the group
comprising:
sunflower oil, canola oil, soybean oil, corn oil, peanut oil, palm oil, castor
bean oil, cotton
oil, lesquerella oil, crambe oil, safflower oil, high oleic sunflower oil,
high oleic canola
oil, high oleic soybean oil, high oleic corn oil, high oleic peanut oil, high
oleic cotton oil,
high oleic safflower oil, and mixtures thereof, wherein the at least one
vegetable oil is
present in a range from about 40% to about 60%, at least one synthetic base
oil having a
sulfur content equal to or less than about 0.03 percent, saturates equal to or
greater than
about 90 percent, and a viscosity index equal to or greater than about 120,
wherein the
11
CA 02538768 2009-05-29
base oil is present in a range from about 40% to about 60%, at least one
antioxidant selected from the group comprising amines, phenols, and mixtures
thereof, wherein the antioxidant is present in a range from about 0.5% to
about
1.0%, and at least one additive, the additive chosen from the group
comprising:
anti-wear inhibitor, extreme pressure additive, friction modifier, rust
inhibitor,
corrosion inhibitor, pour point depressant, tackifier, viscosity modifier,
metal
deactivator, foam inhibitor, emulsifier, and'demulsifier, wherein the
corrosion
inhibitor is about 0.05% to about 2% by total weight, the metal deactivator is
about 0.05% to about 0.2% by total weight, the pour point depressant is about
0.2% to about 4% by total weight, and the viscosity modifier is about 1% to
about 20% by total weight.
In accordance with another aspect of the present invention, a mechanical
device containing at least one lubricant,. the at least one lubricant includes
at
least one vegetable oil selected from the group comprising: natural vegetable
oil,
synthetic vegetable oil, genetically modified vegetable oil, and mixtures
thereof,
at least one synthetic base oil having a sulfur content equal to or less than
0.03
percent, saturates equal to or greater than 90 percent, and a viscosity index
equal to or greater than 120, and at least one antioxidant, wherein the
lubricant
has a viscosity index greater than 120 and passes biodegradability test method
ASTM D-5864 (Pwl).
Other aspects, objects, features, and advantages of the present invention
would be apparent to one ordinarily skilled in the art from the following
detailed
description illustrating the embodiments.
DETAILED DESCRIPTION OF THE INVENTION
The compositions of the present invention comprise at least one vegetable
oil selected from the group comprising: natural vegetable oil, synthetic
vegetable
oil, genetically modified vegetable oil, and mixtures thereof. In one
embodiment
of the invention, the vegetable oils include safflower, canola, peanut, corn,
rapeseed, sunflower, cottonseed, lesquerella, palm, castor, meadow foam, and
soybean. Suitable vegetable oils are further described in U.S. Pat. No.
6,534,454
131. In another embodiment of the present invention, the vegetable oils are
high
oleic sunflower and high oleic canola, primarily because of availability. In
one
12
CA 02538768 2009-05-29
embodiment of the present invention, the vegetable oil is present in the
composition in a range of from about 10 percent to about 90 percent, in
another
embodiment the vegetable oil is from about 30 percent to about 70 percent, and
in another embodiment, the vegetable oil is from about 40 percent to about 60
percent. A vegetable content greater than 90, although still contemplated
within
the present invention, is less desirable in that there is a reduction in
oxidation
and cold temperature stability.
The composition of the present invention comprises at least one all-
hydroprocessed synthetic base oil (group III). All-hydroprocessed synthetic
base
oils are available in the industry from base oil producers like Chevron and
can be
produced in different viscosity ranges but are normally in 2, 4, and 7
centistokes
(cSt) @ 100 C. The all-hydroprocessed base oil is present in the composition
in a
range of from about 10 percent to about 90 percent, and in one embodiment,
from about 30 percent to about 70 percent, and in another embodiment, from
about 40 percent to about 60 percent. A Group III base oil content greater
than
80 percent is less desirable in that there is a reduction in biodegradability.
The composition of the' present invention comprises at least one anti-
oxidant. In one embodiment of the present invention, the antioxidants include
amine and/or phenol, but other antioxidants may be used. The antioxidant is
present in the composition in a range of from about .01 percent to about 5.0
percent, and in one embodiment, from about 0.25 percent to about 1.5 percent,
and in another embodiment from about 0.5 percent to about 1.0 percent. The
lubricant has an oxidation characteristic using ASTM D-2272 in a range of from
about 60 to about 600 minutes, and in one embodiment from about 200 minutes
to about 400 minutes. This test method uses an oxygen pressured bomb to
evaluate the oxidation stability of new and in service turbine oils having the
same composition (base stock and additives) in the presence of water and a
copper catalyst coil at 150 C or according to the selected standard.
Other Base Oils
If desired, the inventive lubricant may contain other oils comprising (1)
synthetic ester base oil, (2) a polyalphaolefin, or (3) unrefined, refined,
or.re-
refined oils, and mixtures of (1), (2), and (3). The base oils can be present
in
13
CA 02538768 2009-05-29
the composition in a range of from about 10 percent to about 80 percent, and
in
one embodiment, from about 30 percent to about 70 percent, and in another
embodiment, from about 40 percent to about 60 percent.
If desired, the inventive lubricant may contain other ingredients/additives
including antiwear inhibitors, rust/corrosion inhibitors, pour point
depressants,
tackifiers, viscosity improvers, metal deactivators, extreme pressure (EP)
additives, friction modifiers, foam inhibitors, emulsifiers, or demulsifiers.
The additives in this invention include:
The Anti-wear Inhibitor, Extreme Pressure Additive and Friction Modifier
To prevent wear on the metal surface, the present invention utilizes an
anti-wear inhibitor/EP additive and friction modifier. Anti-wear inhibitors,
EP
additives, and fiction modifiers are available off the shelf from a variety of
vendors and manufacturers. Some of these additives can perform more than
one task.and any may be utilized in the present invention that is food grade.
One
food grade product that can provide anti-wear, EP, reduced friction and
corrosion
inhibition is phosphorous amine salt of the formula:
x
{I +
(R90)õ-P-(XNR10RRRU)),
H-
wherein R9 and R10 are independently aliphatic groups containing from about 1
up to about 24 carbon atoms, R22 and R23 are independently hydrogen or
aliphatic groups containing from about 1 up to about 18 aliphatic carbon
atoms,
the sum of m and n is 3 and X is oxygen or sulfur. In one embodiment, R9
contains from about 8 up to 18 carbon atoms, R10 is
CH3
I
R'1-C-
1
CH3
wherein R11 is an aliphatic group containing from about 6 up to about 12
carbon
atoms, R22 and R23 are hydrogen, m is 2, n is 1 and X is oxygen. An example of
one such phosphorous amine salt is Irgalube 349, which is commercially
14
CA 02538768 2009-05-29
available from Ciba-Geigy.
Another food grade anti-wear/EP inhibitor/friction modifier is phosphorous
compound of the formula:
R19
\
R20_P=X
/
R21
wherein R19, R20, and R21 are independent hydrogen, an aliphatic or alkoxy
group
containing from 1 up to about 12 carbon atoms, or an aryl or aryloxy group
wherein the aryl group is phenyl or naphthyl and the aryloxy group is phenoxy
or
naphthoxy and X is oxygen or sulfur. An example of one such phosphorus
compound is triphenyl phosphothionate (TPPT), which is commercially available
from Ciba-Geigy under the trade name Irgalube R TPPT.
The anti-wear inhibitors, EP, and friction modifiers.are typically about 0.1
to about 4 weight percent of the lubricant composition- and may be used
separately or in combination.
The Corrosion Inhibitor
20* To prevent corrosion of the metal surfaces, the present invention utilizes
a
corrosion inhibitor. Corrosion inhibitors are available off the shelf from a
variety
of vendors and manufacturers. Any corrosion inhibitor may be utilized in the
present invention that is food grade.
The corrosion inhibitor is typically about 0.01 to about 4 weight percent of
the lubricant composition.
In one, embodiment, the corrosion inhibitor is comprised of a corrosion
additive and a metal deactivator. The corrosion inhibitor and the metal
deactivator can be food grade and comply with FDA regulations. One additive is
the N-acyl derivative of sarcosine, which has the formula:
R8C=O
CH3NCH2COOH
CA 02538768 2006-03-10
WO 2005/026300 PCT/US2004/030030
wherein R8 is an aliphatic group containing from 1 up to about 24 carbon
atoms. In one
embodiment, R8 contains from 6 to 24 carbon atoms and in another embodiment,
from 12
to 18 carbon atoms. An example of an additive of N-acyl derivative of
sarcosine is N-
methyl-N-(1-oxo-9-octadecenyl) glycine wherein R8 is a heptadecenyl group.
This
derivative is available from Ciba-Geigy under the trade name Sarkosyl O.
Another additive is imidazoline of the formula:
N
Rte/
N
R180H
wherein R17 is an aliphatic group containing from I up to about 24 carbon
atoms and R' 8
is an alkylene group containing from I up to about 24 carbon atoms. In one
embodiment,
R17 is an alkenyl group containing from 12 to 18 carbon atoms. In one
embodiment, R18
contains from 1 to 4 carbon atoms and in another embodiment, R18 is an
ethylene group.
An example of one such imadazoline has the formula:
N
CH3(CH2)7CH=CH(CH2)7 -/
N
CH2CH2OH
and is commercially available from Ciba-Geigy under the trade name Amine O.
Typically, the corrosion additive is about 0.01 to about 4 weight percent of
the
lubricant composition. If the additive is the N-acyl derivative of sarcosine,
then, in one
embodiment, it is about 0.1 to about 1 weight percent of the lubricant
composition. If the
additive is imidazoline, then, in one embodiment, it is about 0.05 to about 2
weight
percent of the lubricant composition. The lubricant can include more than one
corrosion
additive. For example, the lubricant can include both the N-acyl derivative of
sarcosine
and imidazoline.
The Metal Deactivator
One metal deactivator is triazole or substituted triazole. For example, toly-
triazole or tolu-triazole may be utilized in the present invention. However,
in one
16
CA 02538768 2009-05-29
embodiment the triazole is tolu-triazole sold commercially by Ciba-Geigy under
the trade name Irgamet@ 39, which is a food grade triazole.
Typically, the metal deactivator is about 0.05 to about 0.3 weight percent
of the lubricant composition. If the metal activator is Irgamet -39, then it
is
about 0.05 to about 0.2 weight percent of the lubricant composition.
Although the anti-wear inhibitor and the corrosion inhibitor have been
described separately, they can be included in a single chemical additive. For
example, both the anti-wear inhibitor and the corrosion inhibitor are included
in
the non-food grade additive Lubrizol 5186B, which is available from Lubrizol
Corporation. In one embodiment, Lubrizol 5186B is about 0.5 to about 2
weight percent of the lubricant composition and, in another embodiment, about
-1.25 weight percent of the lubricant. Another example where both the anti-
wear
inhibitor and the corrosion inhibitor are included in the non-food grade
additive is
Ciba-Geigy 3050A. In.one embodiment, Ciba-Geigy 3050A is about 0.4 to about
1.75 weight percent of the lubricant composition and, in another embodiment,
about 0.95 weight percent of the lubricant.
The Pour Point Depressant
There is a natural stiffening at low temperatures of vegetable oils,
especially vegetable oils with a high monounsaturation content. This is
analogous
to the. stiffening of honey or molasses at a reduced temperature. To maintain
the
"pour" or "flow" of a vegetable oil at reduced temperatures, it becomes
necessary to add a pour point depressant.
Pour point depressants are available off the shelf from a variety of vendors
and manufacturers. Any pour point depressant may be utilized in the present
invention. In one embodiment, however, the pour point depressant is an
alkylated polystyrene or a polyalkyl methacrylate.
Two different reaction routes are envisioned in preparing the
alkylated polystyrenes. The first route involves reacting either an alkyl
chloride or an alkene with styrene to form an alkylated styrene. The
alkylated styrene is then polymerized to form an alkylated polystyrene. In the
second route styrene is polymerized to form polystyrene, and propylene, or
butylenes, or mixtures thereof are polymerized to form polypropylene,
polybutylenes, or mixtures of polypropylenes and polybutylenes, also known as
17
CA 02538768 2006-03-10
WO 2005/026300 PCT/US2004/030030
polyalkylenes. The polystyrene is then alkylated with the polyalkylenes to
form the
alkylated polystyrenes.
One pour point depressant in the class of alkylated polystyrene is Keil-FloTM
150,
available from Ferro Corporation - Petroleum Additives, 3000 Sheffield Avenue,
Hammond, Indiana 46327.
The polyalkyl methacrylates suitable for use in the present invention are
prepared
by the polymerization of C1 - C30 methacrylates. Preparation of these polymers
may
further include the use of acrylic monomers having nitrogen-containing
functional
groups, hydroxy groups, and/or alkoxy groups which provide additional
properties to the
polyalkyl methacrylates such as improved dispersancy. The polyalkyl
methacrylates, in
one embodiment, have a number average molecular weight of from about 10,000 to
about
250,000 and in one embodiment, 20,000 to 200,000. The polyalkyl methacrylates
may be
prepared by conventional methods of free-radical or anionic polymerization.
One pour
point depressant in the class of polyalkyl methacrylates is 10-310 available
from
RohMax, USA, Delran, NJ 08075.
The pour point depressant is typically about 0.2 to about 4 weight percent of
the
lubricant composition.
Viscosity Modifier, Thickener and Tackifier
Optionally, the lubricant may further include an additive from the group
comprising viscosity modifiers, which includes, but is not limited to,
ethylene vinyl
acetate, polyisobutylenes, polybutenes, polymethacrylates, olefin copolymers,
esters of
styrene maleic anyhdride copolymers, hydrogenated styrene-diene copolymers,
hydrogenated radial polyisoprene, alkylated polystyrene, fumed silicas,
complex esters,
and food grade tackifiers like natural rubber solubilized in food grade oils.
The addition of a food grade viscosity modifier, thickener, and/or tackifier
provides adhesiveness and improves the viscosity and viscosity index of the
lubricant.
Some applications and environmental conditions may require an additional tacky
surface
film that protects equipment from corrosion and wear. In this embodiment, the
viscosity
modifier, thickener/tackifier is about 1 to about 20 weight percent of the
lubricant.
However, the viscosity modifier, thickener/tackifier can be from about 0.5 to
about 30
weight percent. An example of a food grade material that can be used in this
invention is
18
CA 02538768 2006-03-10
WO 2005/026300 PCT/US2004/030030
Functional V-584, a natural rubber viscosity modifier/tackifier, which is
available from
Functional Products, Inc., Macedonia, Ohio and Indopol H-1500, a polybutene
viscosity
modifier from PB North American, Naperville, Illinois. Another example is a
complex
ester CG 5000 that is also a multifunctional product, viscosity modifier, pour
point
depressant, and friction modifier from Inolex Chemical Co. Philadelphia, PA.
The lubricants described in the present invention are useful in applications
including hydraulic oils, transmission fluids, engine oils, gear oil, rock
drill oil,
circulating oils, drip oils, spindle oils, compressor oils, grease base oils,
corrosion
inhibitor oils, heat transfer oils, cable oils, chain oils, general purpose
oils, metal working
oils, and electrical insulating oils.
The lubricants described in the present invention can be made using a simple
blend procedure wherein the components are mixed together using mechanical
agitation.
Prior to the blending process, the components may be heated to enhance the
blending
and/or mixing process.
Test Methods
The following test methods were used to characterize the lubricant
compositions of the
present invention:
Formulation Number 1 ISO 32 Hydraulic Fluid
Viscosity @40 C ASTM D-4453 29.65 cSt
Viscosity @100 C ASTM D-4453 6.43 cSt
Viscosity index ASTM D-22707 178
4-ball wear ASTM D-41729 .37
Rust ASTM D-6654 Pass Clean
Oxidation ASTM D-22728 550 to 600
Low temperature pumpability ASTM D-468410 1,900 cP @ -25 C
3,200 cP @ -30 C
Demulsification ASTM D-14016 40/40/0
Flash point ASTM D-921 226 C
Pour point ASTM D-972 -36
Electrical insulating value ASTM D-8775 16 kv
Biodegradability ASTM D-586411 65%
1. Flash and Fire Points by Cleveland Open Cup Tester - This test method
describes the
determination of the flash and fire point of petroleum products by a manual
Cleveland
open cup apparatus or an automated Cleveland open cup apparatus. This test
method is
applicable to all petroleum products with flash points above 79 C (175 F)
and below
400 C (752 F) except fuel oils.
19
CA 02538768 2006-03-10
WO 2005/026300 PCT/US2004/030030
2. Pour Point of Petroleum Products - This test method is intended for use on
any
petroleum product. A procedure suitable for black specimens, cylinder stock,
and
nondistillate fuel oil is described in.
3. Kinematic Viscosity of Transparent and Opaque Liquids (the Calculation of
Dynamic
Viscosity) - This test method specifies a procedure for the determination of
the kinematic
viscosity, v, of liquid petroleum products, both transparent and opaque, by
measuring the
time for a volume of liquid to flow under gravity through a calibrated glass
capillary
viscometer. The dynamic viscosity, rl, can be obtained by multiplying the
kinematic
viscosity, v, by the density, p, of the liquid. The result obtained from this
test method is
dependent upon the behavior of the sample and is intended for application to
liquids for
which primarily the shear stress and shear rates are proportional (Newtonian
flow
behavior). If, however, the viscosity varies significantly with the rate of
shear, different
results may be obtained from viscometers of different capillary diameters. The
procedure
and precision values for residual fuel oils, which under some conditions
exhibit non-
Newtonian behavior, have been included. The range of kinematic viscosities
covered by
this test method is from 0.2 to 300 000 mm2/s at all temperatures.
4. Rust-Preventing Characteristics of Inhibited Mineral Oil in the Presence of
Water -
This test method covers the evaluation of the ability of inhibited mineral
oils, particularly
steam-turbine oils, to aid in preventing the rusting of ferrous parts should
water become
mixed with the oil. This test method is also used for testing other oils, such
as hydraulic
oils and circulating oils. Provision is made in the procedure for testing
heavier-than-
water fluids. For synthetic fluids, such as phosphate ester types, the plastic
holder and
beaker cover should be made of a chemically resistant material, such as
polytetrafluoroethylene (PTFE).
5. Standard Test Method for Dielectric Breakdown Voltage of Insulating Liquids
Using
Disk Electrodes - This test method is for determining the electrical breakdown
voltage of
insulating liquid specimens. The breakdown test uses ac voltage in the power-
frequency
range from 45 to 65 Hz. This test method is used to judge if the disk
electrode
breakdown voltage requirements are met for insulating liquids, as delivered
from the
manufacturer, that have never been filtered or dried. This procedure is used
to determine
CA 02538768 2006-03-10
WO 2005/026300 PCT/US2004/030030
the breakdown voltage of liquids in which any insoluble breakdown products
easily settle
during the interval between the required repeated breakdown tests. These
liquids include
petroleum oils, hydrocarbons, and askarels (PCB) used as insulating and
cooling liquids
in transformers, cables, and similar apparatus. The procedure may be used to
obtain the
dielectric breakdown of silicone fluid as specified in Test Methods D 2225,
provided the
discharge energy into the sample is less than 20 mJ (milli joule) per
breakdown for five
consecutive breakdowns.
6. Water Separability of Petroleum Oils and Synthetic Fluid - This test method
covers
measurement of the ability of petroleum oils or synthetic fluids to separate
from water.
Although developed specifically for steam-turbine oils having viscosities of
28.8-90 cSt
(mm2/s) at 40 C, this test method can be used to test oils of other types
having various
viscosities and synthetic fluids. It is recommended, however, that the test
temperature be
raised to 82 1 C when testing products more viscous than 90 cSt (mm 2/s) at
40 C. For
higher viscosity oils where there is insufficient mixing of oil and water,
Test Method D
2711, is recommended. Other test temperatures such as 25 C can also be used.
When
testing synthetic fluids whose relative densities are greater than that of
water, the
procedure is unchanged, but it should be noted that the water will probably
float on the
emulsion or liquid.
7. Standard Practice for Calculating Viscosity Index From Kinematic Viscosity
at 40 C
and 100 C - This test method specifies the procedures for calculating the
viscosity index
of petroleum products, such as lubricating oils, and related materials from
their kinematic
viscosities at 40 C and 100 C.
8. Oxidation Stability of Steam Turbine Oils by Rotating Pressure Vessel -
This test
method utilizes an oxygen-pressured vessel to evaluate the oxidation stability
of new and
in-service turbine oils having the same composition (base stock and additives)
in the
presence of water and a copper catalyst coil at 150 C.
9. Wear Preventive Characteristics of Lubricating Fluid (Four Ball Method) -
This test
method covers a procedure for making a preliminary evaluation of the anti-wear
21
CA 02538768 2006-03-10
WO 2005/026300 PCT/US2004/030030
properties of fluid lubricants in sliding contact by means of the Four-Ball
Wear Test
Machine.
10. Determination of Yield Stress and Apparent Viscosity of Engine Oils at Low
Temperature - This test method covers the measurement of the yield stress and
viscosity
of engine oils after cooling at controlled rates over a period exceeding 45 h
to a final test
temperature between -10 C and -40 C. The viscosity measurements are made at a
shear
stress of 525 Pa over a shear rate of 0.4 to 15 s-1. This test method is
applicable for
unused oils, sometimes referred to as fresh oils, designed for both light duty
and heavy
duty engine applications. It also has been shown to be suitable for used
diesel oils. This
test method uses the millipascal second (mPa-s) as the unit of viscosity.
11. Standard Test Method for Determining Aerobic Aquatic Biodegradation of
Lubricants or Their Components - This test method covers the determination of
the
degree of aerobic aquatic biodegradation of fully formulated lubricants or
their
components on exposure to an inoculum under laboratory conditions. This test
method is
intended to specifically address the difficulties associated with testing
water insoluble
materials and complex mixtures such as are found in many lubricants. This test
method
is designed to be applicable to all lubricants that are not volatile and are
not inhibitory at
the test concentration to the organisms present in the inoculum. The percent
of
biodegradability rating is explained in ASTM D-6046, Table 2 Environmental
Persistence Classification-Aerobic Fresh Water. The persistence designations
are Pwl
(with %CO2 > 60% in 28 days), Pw2 (> 60% in 84 days), Pw3 (> 40% in 84 days),
and
Pw4 (< 40% in 84 days). Ultimate Biodegradability Pwl is the best rating.
Formulating Examples:
1. Formulation ISO 32 Hydraulic Fluid having a biodegradability rating of Pwl
at 65%
Component %Weight
Trisun 90 HO 46.05
Chevron 4R 50.00
Ciba 3050A 0.95
RhMx 10-310 2.00
Irgamet 39 0.10
RLI AO 0.90
Viscosity @ 40 C 29.65 cSt
22
CA 02538768 2010-01-19
Viscosity @ 100 C 6.43 cSt
Viscosity Index 178
2. Formulation shows an ISO 32 Fluid with Chevron 4R greater than 60% of the
total base oil and passed ASTM D-5864 as Ultimate Biodegradable rating Pwl at
60.9%
Component % Weight
Canola HO (high oleic) 37.85
Chevron 4R 60.00
LZ 5186B 1.25
RLI AO 0.90
Viscosity @ 40 C 23.76 cSt
Viscosity @ 100 C 5.43 cSt
Viscosity Index 176
3. Formulation ISO 68 Hydraulic Fluid having a Ultimate Biodegradable rating
Pwl at
65%
Component % Weight
Canola HO 53.85
Chevron 4R 30.00
CG 5000 9. 00
Indopol H-1500 3.00
LZ 5186B 1.25
RhMx 10-310 2.00
RLI AO 0.90
Viscosity @ 40 C 67.77 cSt
Viscosity @ 100 C 12.71 cSt
Viscosity Index 190
In the above formulations, Chevron 4R is an all-hydroprocessed Group III oil
available from Chevron, CG 5000 is a synthetic ester available from Inolex, LZ
5186B is
a non-food grade additive available from the Lubrizol corporation, RhMx 10-310
is a
pour point depressant in the class of polyalkyl methacrylates available from
RohMax,
Ciba 3050A is a non-food grade additive available from Ciba Geigy, Irgamet 39
is a food
grade triazole available from Ciba-Geigy, RLI AO is an antioxidant available
from
Renewable Lubricants, Inc., TriSun@ 90 is a high oleic sunflower oil and
Canola HO is a
high oleic canola oil available from AC Humko, and Indopol@ H1500 is a
polybutene
viscosity modifier available from BP North American.
The above examples have been depicted solely for the purpose of
exemplification
and are not intended to restrict the scope or embodiments of the invention.
The
invention is further illustrated with reference to the claims that follow
thereto.
Other than in the operating examples, or where otherwise indicated, all
numbers
expressing quantities of ingredients, reaction conditions, and so forth used
in the
23
CA 02538768 2006-03-10
WO 2005/026300 PCT/US2004/030030
specification and claims are to be understood as being modified in all
instances by the
term "about." Accordingly, unless indicated to the contrary, the numerical
parameters set
forth in the following specification and attached claims are approximations
that may vary
depending upon the desired properties sought to be obtained by the present
invention. At
the very least, and not as an attempt to limit the application of the doctrine
of equivalents
to the scope of the claims, each numerical parameter should at least be
construed in light
of the number of reported significant digits and by applying ordinary rounding
techniques.
Notwithstanding that the numerical ranges and parameters setting forth the
broad
scope of the invention are approximations, the numerical values set forth in
the specific
examples are reported as precisely as possible. Any numerical value, however,
inherently contain certain errors necessarily resulting from the standard
deviation found
in their respective testing measurements.
The invention has been described with reference to several embodiments.
Obviously, modifications and alterations will occur to others upon a reading
and
understanding of the specification. It is intended by applicant to include all
such
modifications and alterations insofar as they come within the scope of the
appended
claims or the equivalents thereof.
Having thus described the invention, it is now claimed:
24
