U.S. patent application number 13/192179 was filed with the patent office on 2013-01-31 for turbine oil comprising an ester component.
This patent application is currently assigned to Chevron U.S.A.. The applicant listed for this patent is Nicole A. Ketterer, Mark E. Okazaki. Invention is credited to Nicole A. Ketterer, Mark E. Okazaki.
Application Number | 20130029891 13/192179 |
Document ID | / |
Family ID | 47597707 |
Filed Date | 2013-01-31 |
United States Patent
Application |
20130029891 |
Kind Code |
A1 |
Okazaki; Mark E. ; et
al. |
January 31, 2013 |
TURBINE OIL COMPRISING AN ESTER COMPONENT
Abstract
Provided is a turbine oil formulation comprised of a base oil
selected from the group consisting of Group II, III and IV base
oils and mixtures thereof, and an ester component comprised of at
least one diester or triester species having ester links on
adjacent carbons. The formulation exhibits less than 6 mg of
sludge/100 ml of turbine oil, and is imminently suitable for use as
a turbine oil.
Inventors: |
Okazaki; Mark E.; (San
Ramon, CA) ; Ketterer; Nicole A.; (San Ramon,
CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Okazaki; Mark E.
Ketterer; Nicole A. |
San Ramon
San Ramon |
CA
CA |
US
US |
|
|
Assignee: |
Chevron U.S.A.
San Ramon
CA
|
Family ID: |
47597707 |
Appl. No.: |
13/192179 |
Filed: |
July 27, 2011 |
Current U.S.
Class: |
508/279 ;
508/496; 508/506 |
Current CPC
Class: |
C10M 2203/1025 20130101;
C10N 2030/02 20130101; C10N 2040/135 20200501; C10M 2207/026
20130101; C10M 2219/066 20130101; Y02P 30/20 20151101; C10N 2070/00
20130101; C10M 129/74 20130101; C10M 141/06 20130101; C10N 2030/04
20130101; C10N 2040/12 20130101; C10M 2215/223 20130101; C10N
2030/64 20200501; C10M 2205/173 20130101; C10M 2215/064 20130101;
C10M 2207/283 20130101; C10M 169/04 20130101; C10M 2207/123
20130101; C10N 2030/10 20130101; C10M 2205/0285 20130101; C10M
2203/1025 20130101; C10N 2020/02 20130101; C10M 2203/1025 20130101;
C10N 2020/02 20130101 |
Class at
Publication: |
508/279 ;
508/506; 508/496 |
International
Class: |
C10M 129/72 20060101
C10M129/72; C10M 133/44 20060101 C10M133/44 |
Claims
1. A turbine oil comprised of a base oil selected from the group
consisting of Group II, III, IV base oils and mixtures thereof, and
an ester component comprised of at least one diester or triester
species having ester links on adjacent carbons, with the turbine
oil having less than 6 mg of sludge/100 ml of turbine oil as
determined by Cincinnati Milacron Thermal A test.
2. The turbine oil of claim 1, wherein the turbine oil has less
than 3 mg of sludge/100 ml of turbine oil.
3. The turbine oil of claim 1, further comprising at least one
antioxidant other than a phenolic antioxidant.
4. The turbine oil of claim 3, wherein the antioxidant comprises an
amine antioxidant.
5. The turbine oil of claim 3, wherein the antioxidant comprises a
mixture of aminic and phenolic antioxidants.
6. The turbine oil of claim 3, wherein the antioxidant comprises a
mixture of dithiocarbamate, tolutriazole and phenolic
antioxidants.
7. The turbine oil of claim 1, wherein the base oil is a GTL base
oil.
8. The turbine oil of claim 1, wherein the base oil comprises less
than 5 wt % aromatics.
9. The turbine oil of claim 1, wherein the turbine oil comprises
from 0.5 to 15 wt % of the ester component.
10. The turbine oil of claim 9, wherein the turbine oil comprises
from 5 to 10 wt % of the ester component.
11. The turbine oil of claim 1, wherein the turbine oil comprises
at least one other additive component selected from the group
consisting of detergents, anti-wear agents, metal deactivators,
corrosion inhibitors, rust inhibitors, friction modifiers,
anti-foaming agents, viscosity index improvers, demulsifying
agents, emulsifying agents, antioxidants, complexing agents,
extreme pressure additives, pour point depressants, and
combinations thereof.
12. The turbine oil of claim 1, wherein the turbine oil has VI of
at least 90, and having an RPVOT oxidative stability of from at
least 250 minutes.
13. The turbine oil of claim 1, wherein the ester component
comprises a diester species having the following structure:
##STR00006## wherein R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are
identical or independently selected from hydrocarbon groups having
from 2 to 17 carbon atoms.
14. The turbine oil of claim 1, wherein the ester component
comprises a diester species derived from a process comprising: a)
epoxidizing an olefin having from about 8 to about 16 carbon atoms
to form an epoxide comprising an epoxide ring; b) opening the
epoxide ring of step a) and forming a diol; c) esterifying the diol
of step b) with an esterifying species to form a diester species,
wherein the esterifying species is selected from the group
consisting of carboxylic acids, acyl halides, acyl anhydrides, and
combinations thereof, wherein the esterifying species has a carbon
number of from 2 to 18.
15. The turbine oil of claim 1, wherein the ester component
comprises a diester species derived from a process comprising: a)
epoxidizing an olefin having from about 8 to about 16 carbon atoms
to form an epoxide comprising an epoxide ring; and b) reacting the
epoxide comprising the epoxide ring with an esterifying species to
form a diester species, wherein the esterifying species is selected
from the group consisting of carboxylic acids, acyl halides, acyl
anhydrides, and combinations thereof, wherein the esterifying
species has a carbon number of from 2 to 18.
16. The turbine oil of claim 1, wherein the ester component
comprises a triester species having the following structure:
##STR00007## wherein R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are
identical or independently selected from hydrocarbon groups having
from 2 to 20 carbon atoms and wherein "n" is an integer from 2 to
20.
17. The turbine oil of claim 1, wherein the ester component
comprises a triester species having the following structure:
##STR00008## wherein R.sub.2, R.sub.3, and R.sub.4 are identical or
independently selected from C.sub.2 to C.sub.20 hydrocarbon
groups.
18. The turbine oil of claim 1, wherein the ester component
comprises a triester species derived from a process comprising: a)
esterifying a mono-unsaturated fatty acid having from 10 to 22
carbon atoms with an alcohol thereby forming an unsaturated ester;
b) epoxidizing the unsaturated ester in step a) thereby forming an
epoxy-ester species comprising an epoxide ring; c) opening the ring
of the epoxy-ester species in step b) thereby forming a dihydroxy
ester; and d) esterifying the dihydroxy ester in step c) with an
esterifying species to form a triester species, wherein the
esterifying species is selected from the group consisting of
carboxylic acids, acyl halides, acyl anhydrides, and combinations
thereof, and wherein the esterifying species has a carbon number of
from 2 to 19.
19. The turbine oil of claim 1, wherein the ester component
comprises a triester species derived from a process comprising: a)
reducing a monosaturated fatty acid to a corresponding unsaturated
alcohol; b) epoxidizing the unsaturated alcohol to an epoxy fatty
alcohol; c) opening a ring of the epoxy fatty alcohol to make a
corresponding triol; and d) esterifying the triol of step c) with
an esterifying species to form a triester species, wherein the
esterifying species is selected from the group consisting of
carboxylic acids, acyl halides, acyl anhydrides, and combinations
thereof, and wherein the esterifying species has a carbon number of
from 2 to 19.
20. The turbine oil of claim 1, wherein the ester component
comprises a triester species derived from a process comprising: a)
reducing a monosaturated fatty acid to a corresponding unsaturated
alcohol; b) epoxidizing the unsaturated alcohol to form a fatty
alcohol epoxide; and c) esterifying the fatty alcohol epoxide with
an esterifying species to form a triester species, wherein the
esterifying species is selected from the group consisting of
carboxylic acids, acyl halides, acyl anhydrides, and combinations
thereof, and wherein the esterifying species has a carbon number of
from 2 to 19.
21. The turbine oil of claim 1, wherein the ester component is
prepared using an esterifying species which is a carboxylic
acid.
22. The turbine oil of claim 21, wherein the carboxylic acid is
derived from a bio-derived fatty acid.
23. The turbine oil of claim 21, wherein the carboxylic acid is
derived from alcohols generated by a Fischer-Tropsch process.
24. The turbine oil of claim 1, having copper corrosion better than
3 A as determined by ASTM D130-10.
Description
FIELD OF THE INVENTION
[0001] This invention relates to turbine oil compositions and their
manufacture, and specifically to turbine oils comprised of an ester
species having ester links on adjacent carbons. The use of such
esters can provide biodegradable turbine oils having reduced
sludge.
BACKGROUND
[0002] Esters have been used as lubricating oils for over 50 years.
They are used in a variety of applications ranging from jet engines
to refrigeration. In fact, esters were the first synthetic
crankcase motor oils in automotive applications. However, esters
have largely given way to polyalphaolefins (PAOs) due to the lower
cost of PAOs and their formulation similarities to mineral oils. In
fully synthetic motor oils, however, esters are almost always used
in combination with PAOs to balance the effect on seals, additive
solubility, volatility reduction, and energy efficiency improvement
by enhanced lubricity.
[0003] Ester-based lubricants, in general, have excellent
lubrication properties due to the polarity of the ester molecules
of which they are comprised. Due to the polarity of the ester
functionality, esters have a stronger affinity for metal surfaces
than PAOs and mineral oils. As a result, they are very effective in
establishing protective films on metal surfaces, such protective
films serving to mitigate the wear of such metals. Such lubricants
are less volatile than the traditional lubricants and tend to have
much higher flash points and much lower vapor pressures. Ester
lubricants are excellent solvents and dispersants, and can readily
solvate and disperse the degradation by-products of oils, i.e.,
they greatly reduce sludge buildup. While ester lubricants are
relatively stable to thermal and oxidative processes, the ester
functionalities give microbes a handle with which to do their
biodegrading more efficiently and more effectively than their
mineral oil-based analogues--thereby rendering them more
environmentally-friendly. However, as previously alluded to, the
preparation of esters is more involved and more costly than that of
their PAO counterparts.
[0004] Recently, novel diester-based lubricant compositions and
their corresponding manufacture have been described in Miller et
al., United States Patent Application Publication No. 20080194444
A1, published Aug. 14, 2008; and in Miller et al., United States
Patent Publication No. 20090198075 A1, published Aug. 6, 2009. The
diester syntheses described in these patent applications render the
economics of diester lubricant formulations more favorable.
[0005] Increased usage of Group II (and higher) base oils in
finished lubricants such as turbine oils has coincided with an
increased awareness of insoluble formation in the finished
lubricants. Such an increase in insolubles formation is
particularly detrimental in turbine oils. Providing a turbine oil
with good properties but less sludge build-up would be of great
benefit to the industry.
SUMMARY
[0006] Provided is a turbine oil formulation comprised of a base
oil selected from the group consisting of Group II, III and IV base
oils and mixtures thereof, and an ester component comprised of at
least one diester or triester species having ester links on
adjacent carbons. The formulation exhibits less than 6 mg of
sludge/100 ml of turbine oil as determined by the Cincinnati
Milacron Thermal A test, and is imminently suitable for use as a
turbine oil.
[0007] Among other factors, the present turbine oil formulation
comprising the present diester and triester species having ester
links on adjacent carbons, provides a turbine oil with a good
balance of properties while also providing a biodegradable
alternative. In particular, the turbine oil exhibits reduced
sludge, and can also exhibit improved copper appearance and
improved oxidation stability in RPVOT. The starting olefins and
carboxylic acids used in preparing the diesters and triesters also
provides an economical manufacturing route.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0008] The present invention is directed to a turbine oil
composition having an ester component. The ester component is
comprised of at least one diester or triester species having ester
links on adjacent carbons, which ester component can also be
bio-derived.
[0009] In some embodiments, bio-derived (i.e., derived from a
renewable biomass source) fatty (carboxylic) acid moieties are
reacted with Fischer-Tropsch (FT)/gas-to-liquids (GTL) reaction
products and/or by-products (i.e., .alpha.-olefins) to yield
bio-derived diester and triester species that can then be
selectively blended with base stock (oil) and one or more additive
species to yield a turbine oil finished lubricant product having a
biomass-derived component.
[0010] Because biolubricants and biofuels are increasingly
capturing the public's attention and becoming topics of focus for
many in the oil industry, the use of biomass in the making of
turbine oils could be attractive from several different
perspectives (e.g., renewability, regulatory, economic, etc.). As
biomass is utilized in the making of the present ester component of
the turbine oil described herein, such a turbine oil is deemed to
be a biolubricant--or at the very least, they are deemed to
comprise a bio-derived component.
DEFINITIONS
[0011] "Lubricants," as defined herein, are substances (usually a
fluid under operating conditions) introduced between two moving
surfaces so to reduce the friction and wear between them. This
definition is intended to include greases, whose viscosity drops
dramatically upon application of shear.
[0012] Herein, "base oil" will be understood to mean the single
largest component (by weight) of a lubricant composition. Base oils
are categorized into five groups (I-V) by the American Petroleum
Institute (API). See API Publication Number 1509. The API Base Oil
Category, as shown in the following table (Table 1), is used to
define the compositional nature and/or origin of the base oil.
TABLE-US-00001 TABLE 1 Base Oil Category Sulfur (%) Saturates (%)
Viscosity Index Group I >0.03 and/or <90 80 to 120 Group II
<0.03 and >90 80 to 120 Group III <0.03 and >90 >120
Group IV All polyalphaolefins (PAOs) Group V All others not
included in Groups I, II, III or IV (e.g., esters)
[0013] "Mineral base oils," as defined herein, are those base oils
produced by the refining of a crude oil.
[0014] "Centistoke," abbreviated "cSt," is a unit for kinematic
viscosity of a fluid (e.g., a lubricant), wherein 1 centistoke
equals 1 millimeter squared per second (1 cSt=1 mm.sup.2/s). See,
e.g., ASTM Standard Guide and Test Method D 2270-04. Herein, the
units cSt and mm.sup.2/s are used interchangeably.
[0015] With respect to describing molecules and/or molecular
fragments herein, "R.sub.n," where "n" is an index, refers to a
hydrocarbon group, wherein the molecules and/or molecular fragments
can be linear and/or branched.
[0016] As defined herein, "C.sub.n," where "n" is an integer,
describes a hydrocarbon molecule or fragment (e.g., an alkyl group)
wherein "n" denotes the number of carbon atoms in the fragment or
molecule.
[0017] The term "carbon number" is used herein in a manner
analogous to that of "C.sub.n." A difference, however, is that
carbon number refers to the total number of carbon atoms in a
molecule (or molecular fragment) regardless of whether or not it is
purely hydrocarbon in nature. Linoleic acid, for example, has a
carbon number of 18.
[0018] The term "internal olefin," as used herein, refers to an
olefin (i.e., an alkene) having a non-terminal carbon-carbon double
bond (C.dbd.C). This is in contrast to ".alpha.-olefins" which do
bear a terminal carbon-carbon double bond.
[0019] The term "vicinal," as used herein, refers to the attachment
of two functional groups (substituents) to adjacent carbons in a
hydrocarbon-based molecule, e.g., vicinal diesters.
[0020] The term "fatty acid moiety," as used herein, refers to any
molecular species and/or molecular fragment comprising the acyl
component of a fatty (carboxylic) acid.
[0021] The prefix "bio," as used herein, refers to an association
with a renewable resource of biological origin, such as resource
generally being exclusive of fossil fuels. Such an association is
typically that of derivation, i.e., a bio-ester derived from a
biomass precursor material.
[0022] "Fischer-Tropsch products," as defined herein, refer to
molecular species derived from a catalytically-driven reaction
between CO and H.sub.2 (i.e., "syngas"). See, e.g., Dry, "The
Fischer-Tropsch process: 1950-2000," vol. 71(3-4), pp. 227-241,
2002; Schulz, "Short history and present trends of Fischer-Tropsch
synthesis," Applied Catalysis A, vol. 186, pp. 3-12, 1999; Claeys
and Van Steen, "Fischer-Tropsch Technology," Chapter 8, pp.
623-665, 2004.
[0023] "Gas-to-liquids," as used herein, refers to Fischer-Tropsch
processes for generating liquid hydrocarbons and hydrocarbon-based
species (e.g., oxygenates).
[0024] The term "comprising" means including the elements or steps
that are identified following that term, but any such elements or
steps are not exhaustive, and an embodiment can include other
elements or steps.
[0025] "Copper Appearance" refers to the copper corrosion caused by
the turbine oil as determined by ASTM D130-10, "Standard Test
Method for Corrosiveness to Copper from Petroleum Products by
Copper Strip Test." The lower the number and letter the less
corrosion indicated.
[0026] "RPVOT" refers to the oxidation stability of the turbine oil
itself, as determined by ASTM D2272-11, "Standard Test Method for
Oxidation Stability of Steam Turbine Oils by Rotating Pressure
Vessel."
[0027] The ability of the turbine oil to prevent the rusting of
ferrous parts should water become mixed with the oil is determined
by ASTM D665-06, "Standard Test Method for Rust-Preventing
Characteristics of Inhibited Mineral Oil in the Presence of
Water."
[0028] The test method for determining the relative changes that
occur in an oil during use under oxidizing conditions is measured
using ASTM D974-08, "Standard Test Method for Acid and Base Number
by Color-Indicator Titration."
[0029] The thermal stability of hydrocarbon based oils is
determined by ASTM D2070-91, "Standard Test Method for Thermal
Stability of Hydraulic Oils."
Base Oils Used in the Turbine Oils
[0030] The present turbine oils comprise a base oil selected from
the group consisting of Group II, III, IV base oils and mixtures
thereof. The Group II, III and IV base oils are as understood and
shown in Table 1, which include Gas-to-Liquid (GTL) derived based
oils. In some embodiments, the base oils contain less than 10 wt %,
and more likely less than 5 wt % aromatics. The base oil is then
combined with a quantity of an ester component, which is either a
diester or triester species, or a mixture thereof, which ester
component species has ester links on adjacent carbons. The quantity
of ester component is generally in the range of from 0.5 to 15 wt %
based on the turbine oil formulation. In some embodiments, the
quantity of ester component will range from 5 to 10 wt %. In one
embodiment, an additive is also combined with the base oil and
ester component. The additive can be added to the base oil first,
the ester first, or upon combining all individual components. In
some embodiments, the additive comprises an antioxidant composition
comprised of at least one antioxidant other than a phenolic
antioxidant.
Diester Component
[0031] In some embodiments, the ester component combined with the
base oil comprises a diester species having the following chemical
structure:
##STR00001##
where R.sub.1, R.sub.2, R.sub.3, and R.sub.4 are the same or
independently selected from a C.sub.2 to C.sub.17 carbon
fragment.
[0032] Regarding the above-mentioned diester species, selection of
R.sub.1, R.sub.2, R.sub.3, and R.sub.4 can follow any or all of
several criteria. For example, in some embodiments, R.sub.1,
R.sub.2, R.sub.3, and R.sub.4 are selected such that the kinematic
viscosity of the composition at a temperature of 100.degree. C. is
typically 3 mm.sup.2/sec or greater. In some or other embodiments,
R.sub.1, R.sub.2, R.sub.3, and R.sub.4 are selected such that the
pour point of the resulting electrical insulating oil is
-10.degree. C. or lower, -25.degree. C. or lower; or even
-40.degree. C. or lower. In some embodiments, R.sub.1 and R.sub.2
are selected to have a combined carbon number (i.e., total number
of carbon atoms) of from 6 to 14. In these or other embodiments,
R.sub.3 and R.sub.4 are selected to have a combined carbon number
of from 10 to 34. Depending on the embodiment, such resulting
diester species can have a molecular mass between 340 atomic mass
units (a.m.u.) and 780 a.m.u.
[0033] In some embodiments, the ester component is substantially
homogeneous in terms of its diester component. In some or other
embodiments, the diester component comprises a variety (i.e., a
mixture) of diester species.
[0034] In some embodiments, the diester component comprises at
least one diester species derived from a C.sub.8 to C.sub.16 olefin
and a C.sub.2 to C.sub.18 carboxylic acid. Typically, the diester
species are made by reacting each --OH group (on the intermediate)
with a different acid, but such diester species can also be made by
reacting each --OH group with the same acid.
[0035] In some of the above-described embodiments, the diester
component combined with the base oil to prepare the turbine oil
comprises a diester species selected from the group consisting of
decanoic acid 2-decanoyloxy-1-hexyl-octyl ester and its isomers,
tetradecanoic acid-1-hexyl-2-tetradecanoyloxy-octyl esters and its
isomers, dodecanoic acid 2-dodecanoyloxy-1-hexyl-octyl ester and
its isomers, hexanoic acid 2-hexanoyloxy-1-hexy-octyl ester and its
isomers, octanoic acid 2-octanoyloxy-1-hexyl-octyl ester and its
isomers, hexanoic acid 2-hexanoyloxy-1-pentyl-heptyl ester and
isomers, octanoic acid 2-octanoyloxy-1-pentyl-heptyl ester and
isomers, decanoic acid 2-decanoyloxy-1-pentyl-heptyl ester and
isomers, decanoic acid-2-cecanoyloxy-1-pentyl-heptyl ester and its
isomers, dodecanoic acid-2-dodecanoyloxy-1-pentyl-heptyl ester and
isomers, tetradecanoic acid 1-pentyl-2-tetradecanoyloxy-heptyl
ester and isomers, tetradecanoic acid
1-butyl-2-tetradecanoyloxy-hexy ester and isomers, dodecanoic
acid-1-butyl-2-dodecanoyloxy-hexyl ester and isomers, decanoic acid
1-butyl-2-decanoyloxy-hexyl ester and isomers, octanoic acid
1-butyl-2-octanoyloxy-hexyl ester and isomers, hexanoic acid
1-butyl-2-hexanoyloxy-hexyl ester and isomers, tetradecanoic acid
1-propyl-2-tetradecanoyloxy-pentyl ester and isomers, dodecanoic
acid 2-dodecanoyloxy-1-propyl-pentyl ester and isomers, decanoic
acid 2-decanoyloxy-1-propyl-pentyl ester and isomers, octanoic acid
1-2-octanoyloxy-1-propyl-pentyl ester and isomers, hexanoic acid
2-hexanoyloxy-1-propyl-pentyl ester and isomers, and mixtures
thereof.
Methods of Making the Diester Components
[0036] Methods which can be employed in making the diesters are
further described in U.S. Patent Application Publications
2009/0159837 and 2009/0198075, which publications are incorporated
by reference herein in their entirety.
[0037] More specifically, in some embodiments, the processes for
making the above-mentioned diester species, comprise the following
steps: epoxidizing an olefin (or quantity of olefins) having a
carbon number of from 8 to 16 to form an epoxide comprising an
epoxide ring; opening the epoxide ring to form a diol; and
esterifying (i.e., subjecting to esterification) the diol with an
esterifying species to form a diester species, wherein such
esterifying species are selected from the group consisting of
carboxylic acids, acyl acids, acyl halides, acyl anhydrides, and
combinations thereof; wherein such esterifying species have a
carbon number from 2 to 18; and wherein the diester species have a
viscosity of 3 mm.sup.2/sec or more at a temperature of 100.degree.
C.
[0038] Furthermore, the diester species can be prepared by
epoxidizing an olefin having from about 8 to about 16 carbon atoms
to form an epoxide comprising an epoxide ring. The epoxidized
olefin is reacted directly with an esterifying species to form a
diester species, wherein the esterifying species is selected from
the group consisting of carboxylic acids, acyl halides, acyl
anhydrides, and combinations thereof, wherein the esterifying
species has a carbon number of from 2 to 18, and wherein the
diester species has a viscosity and a pour point suitable for use
as an electrical insulating oil.
[0039] In some embodiments, where a quantity of such diester
species is formed, the quantity of diester species can be
substantially homogeneous, or it can be a mixture of two or more
different such diester species.
[0040] In some such above-described method embodiments, the olefin
used is a reaction product of a Fischer-Tropsch process. In these
or other embodiments, the carboxylic acid can be derived from
alcohols generated by a Fischer-Tropsch process and/or it can be a
bio-derived fatty acid.
[0041] In some embodiments, the olefin is an .alpha.-olefin (i.e.,
an olefin having a double bond at a chain terminus). In such
embodiments, it is usually necessary to isomerize the olefin so as
to internalize the double bond. Such isomerization is typically
carried out catalytically using a catalyst such as, but not limited
to, crystalline aluminosilicate and like materials and
aluminophosphates. See, e.g., U.S. Pat. Nos. 2,537,283; 3,211,801;
3,270,085; 3,327,014; 3,304,343; 3,448,164; 4,593,146; 3,723,564
and 6,281,404; the last of which claims a crystalline
aluminophosphate-based catalyst with 1-dimensional pores of size
between 3.8 .ANG. and 5 .ANG..
[0042] As an example of such above-described isomerizing,
Fischer-Tropsch alpha olefins (.alpha.-olefins) can be isomerized
to the corresponding internal olefins followed by epoxidation. The
epoxides can then be transformed to the corresponding diols via
epoxide ring opening followed by di-acylation (i.e.,
di-esterification) with the appropriate carboxylic acids or their
acylating derivatives. It is typically necessary to convert alpha
olefins to internal olefins because diesters of alpha olefins,
especially short chain alpha olefins, tend to be solids or waxes.
"Internalizing" alpha olefins followed by transformation to the
diester functionalities introduces branching along the chain which
reduces the pour point of the intended products. The ester groups
with their polar character would further enhance the viscosity of
the final product. Adding ester branches will increase the carbon
number and hence viscosity. It can also decrease the associated
pour and cloud points. It is typically preferable to have a few
longer branches than many short branches, since increased branching
tends to lower the viscosity index (VI).
[0043] Regarding the step of epoxidizing (i.e., the epoxidation
step), in some embodiments, the above-described olefin (in one
embodiment an internal olefin) can be reacted with a peroxide
(e.g., H.sub.2O.sub.2) or a peroxy acid (e.g., peroxyacetic acid)
to generate an epoxide. See, e.g., D. Swern, in Organic Peroxides
Vol. II, Wiley-Interscience, New York, 1971, pp. 355-533; and B.
Plesnicar, in Oxidation in Organic Chemistry, Part C, W.
Trahanovsky (ed.), Academic Press, New York 1978, pp. 221-253.
Olefins can be efficiently transformed to the corresponding diols
by highly selective reagent such as osmium tetra-oxide (M.
Schroder, Chem. Rev. vol. 80, p. 187, 1980) and potassium
permanganate (Sheldon and Kochi, in Metal-Catalyzed Oxidation of
Organic Compounds, pp. 162-171 and 294-296, Academic Press, New
York, 1981).
[0044] Regarding the step of epoxide ring opening to the
corresponding diol, this step can be acid-catalyzed or
based-catalyzed hydrolysis. Exemplary acid catalysts include, but
are not limited to, mineral-based Bronsted acids (e.g., HCl,
H.sub.2SO.sub.4, H.sub.3PO.sub.4, perhalogenates, etc.), Lewis
acids (e.g., TiCl.sub.4 and AlCl.sub.3) solid acids such as acidic
aluminas and silicas or their mixtures, and the like. See, e.g.,
Chem. Rev. vol. 59, p. 737, 1959; and Angew. Chem. Int. Ed., vol.
31, p. 1179, 1992. Based-catalyzed hydrolysis typically involves
the use of bases such as aqueous solutions of sodium or potassium
hydroxide.
[0045] Regarding the step of esterifying (esterification), an acid
is typically used to catalyze the reaction between the --OH groups
of the diol and the carboxylic acid(s). Suitable acids include, but
are not limited to, sulfuric acid (Munch-Peterson, Org. Synth., V,
p. 762, 1973), sulfonic acid (Allen and Sprangler, Org. Synth.,
III, p. 203, 1955), hydrochloric acid (Eliel et al., Org. Synth.,
IV, p. 169, 1963), and phosphoric acid (among others). In some
embodiments, the carboxylic acid used in this step is first
converted to an acyl chloride (via, e.g., thionyl chloride or
PCl.sub.3). Alternatively, an acyl chloride could be employed
directly. Wherein an acyl chloride is used, an acid catalyst is not
needed and a base such as pyridine, 4-dimethylaminopyridine (DMAP)
or triethylamine (TEA) is typically added to react with an HCl
produced. When pyridine or DMAP is used, it is believed that these
amines also act as a catalyst by forming a more reactive acylating
intermediate. See, e.g., Fersh et al., J. Am. Chem. Soc., vol. 92,
pp. 5432-5442, 1970; and Hofle et al., Angew. Chem. Int. Ed. Engl.,
vol. 17, p. 569, 1978.
[0046] Regardless of the source of the olefin, in some embodiments,
the carboxylic acid used in the above-described method is derived
from biomass. In some such embodiments, this involves the
extraction of some oil (e.g., triglyceride) component from the
biomass and hydrolysis of the triglycerides of which the oil
component is comprised so as to form free carboxylic acids.
Triester Component
[0047] In some embodiments, the ester component combined with the
base oil comprises a triester species having the following chemical
structure:
##STR00002##
wherein R.sub.1, R.sub.2, R.sub.3, and R.sub.4 are the same or
independently selected from C.sub.2 to C.sub.20 hydrocarbon groups
(groups with a carbon number from 2 to 20), and wherein "n" is an
integer from 2 to 20.
[0048] Regarding the above-mentioned triester species, selection of
R.sub.1, R.sub.2, R.sub.3, and R.sub.4, and n can follow any or all
of several criteria. For example, in some embodiments, R.sub.1,
R.sub.2, R.sub.3, and R.sub.4 and n are selected such that the
kinematic viscosity of the composition at a temperature of
100.degree. C. is typically 3 mm.sup.2/sec or greater. In some or
other embodiments, R.sub.1, R.sub.2, R.sub.3, and R.sub.4 and n are
selected such that the pour point of the resulting electrical
insulating oil is -10.degree. C. or lower, e.g., -25.degree. C. or
even -40.degree. C. or lower. In some embodiments, R.sub.1 is
selected to have a total carbon number of from 6 to 12. In these or
other embodiments, R.sub.2 is selected to have a carbon number of
from 1 to 20. In these or other embodiments, R.sub.3 and R.sub.4
are selected to have a combined carbon number of from 4 to 36. In
these or other embodiments, n is selected to be an integer from 5
to 10. Depending on the embodiment, such resulting triester species
can typically have a molecular mass between 400 atomic mass units
(a.m.u.) and 1100 a.m.u., and more typically between 450 a.m.u. and
1000 a.m.u.
[0049] In some embodiments, the ester component is substantially
homogeneous in terms of its triester component. In some other
embodiments, the triester component comprises a variety (i.e., a
mixture) of such triester species. In these or other embodiments,
such above-described triester components further comprise one or
more triester species.
[0050] In some of the above-described embodiments, the triester
component combined with the base oil to prepare the turbine oil
comprises one or more triester species of the type
9,10-bis-alkanoyloxy-oetadecanoic acid alkyl ester and isomers and
mixtures thereof, where the alkyl is selected from the group
consisting of methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl,
octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl,
pentadecyl, hexadecyl, and octadecyl; and where the alkanoyloxy is
selected from the group consisting of ethanoyloxy, propanoyoxy,
butanoyloxy, pentanoyloxy, hexanoyloxy, heptanoyloxy, octanoyloxy,
nonaoyloxy, decanoyloxy, undacanoyloxy, dodecanoyloxy,
tridecanoyloxy, tetradecanoyloxy, pentaclecanoyloxy,
hexadeconoyloxy, and octadecanoyloxy,
9,10-bis-hexanoyloxy-octadecanoic acid hexyl ester and
9,10-bis-decanoyloxy-octadecanoic acid decyl ester are exemplary
such triesters.
Methods of Making the Triester Component
[0051] One method of preparing the triester species is described in
U.S. Pat. No. 7,544,645, which is incorporated herein by reference
in its entirety.
[0052] More specifically, in some embodiments, processes for making
the above-mentioned triester species comprises the following steps:
esterifying (i.e., subjecting to esterification) a mono-unsaturated
fatty acid (or quantity of mono-unsaturated fatty acids) having a
carbon number of from 10 to 22 with an alcohol to form an
unsaturated ester (or a quantity thereof); epoxidizing the
unsaturated ester to form an epoxy-ester species comprising an
epoxide ring; opening the epoxide ring of the epoxy-ester species
to form a dihydroxy-ester: and esterifying the dihydroxy-ester with
an esterifying species to form a triester species, wherein such
esterifying species are selected from the group consisting of
carboxylic acids, acyl halides, acyl anhydrides, and combinations
thereof; and wherein such esterifying species have a carbon number
of from 2 to 19.
[0053] In another embodiment, the method can comprise reducing a
monosaturated fatty acid to the corresponding unsaturated alcohol.
The unsaturated alcohol is then epoxidized to an epoxy fatty
alcohol. The ring of the epoxy fatty alcohol is opened to make the
corresponding triol; and then the triol is esterified with an
esterifying species to form a triester species, wherein the
esterifying species is selected from the group consisting of
carboxylic acids, acyl halides, acyl anhydrides, and combinations
thereof, and wherein the esterifying species has a carbon number of
from 2 to 19. The structure of the triester prepared by the
foregoing method would be as follows:
##STR00003##
wherein R.sub.2, R.sub.3, and R.sub.4 are typically the same or
independently selected from C.sub.2 to C.sub.20 hydrocarbon groups,
and are more typically selected from C.sub.4 to C.sub.12
hydrocarbon groups.
[0054] In another embodiment, the method can comprise reducing a
monosaturated fatty acid to the corresponding unsaturated alcohol;
epoxidizing the unsaturated alcohol to an epoxy fatty alcohol; and
esterifying the fatty alcohol epoxide with an esterifying species
to form a triester species, wherein the esterifying species is
selected from the group consisting of carboxylic acids, acyl
halides, acyl anhydrides, and combinations thereof, and wherein the
esterifying species has a carbon number of from 2 to 19.
[0055] In some embodiments, where a quantity of such triester
species is formed, the quantity of triester species can be
substantially homogeneous, or it can be a mixture of two or more
different such triester species. Additionally or alternatively, in
some embodiments, such methods further comprise a step of blending
the triester composition(s) with one or more diester species.
[0056] In some embodiments, such methods produce compositions
comprising at least one triester species of the type
9,10-bis-alkanoyloxy-octadecanoic acid alkyl ester and isomers and
mixtures thereof where the alkyl is selected from the group
consisting of methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl,
octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl,
pentadecyl, hexadecyl, and octadecyl; and where the alkanoyloxy is
selected from the group consisting of ethanoyloxy, propanoyoxy,
butanoyloxy, pentanoyloxy, hexanoyloxy, heptanoyloxy, octanoyloxy,
nonaoyloxy, decanoyloxy, undacanoyloxy, dodecanoyloxy,
tridecanoyloxy, tetradecanoyloxy, pentadecanoyloxy,
hexadeconoyloxy, and octadecanoyloxy. Exemplary such triesters
include, but not limited to, 9,10-bis-hexanoyloxy-octadecanoic acid
hexyl ester; 9,10-bis-octanoyloxy-octadecanoic acid hexyl ester;
9,10-bis-decanoyloxy-octadecanoic acid hexyl ester;
9,10-bis-dodecanoyoxy-octadecanoic acid hexyl ester;
9,10-bis-hexanoyloxy-octadecanoic acid decyl ester;
9,10-bis-decanoyloxy-octadecanoic acid decyl ester;
9,10-bis-octanoyloxy-octadecanoic acid decyl ester;
9,10-bis-dodecanoyloxy-octadecanoic acid decyl ester;
9,10-bis-hexanoyloxy-octadecanoic acid octyl ester;
9,10-bis-octanoyloxy-octadecanoic acid octyl ester:
9,10-bis-decanoyloxy-octadecanoic acid octyl ester;
9,10-bis-dodecanoyloxy-octadecanoic acid octyl ester;
9,10-bis-hexanoyloxy-octadecanoic acid dodecyl ester;
9,10-bis-octanoyloxy-octadecanoic acid dodecyl ester;
9,10-bis-decanoyloxy-octadecanoic acid dodecyl ester;
9,10-bis-doclecanoyloxy-octadecanoic acid dodecyl ester; and
mixtures thereof.
[0057] In some such above-described method embodiments, the
mono-unsaturated fatty acid can be a bio-derived fatty acid. In
some or other such above-described method embodiments, the
alcohol(s) can be FT-produced alcohols.
[0058] In some such above-described method embodiments, the step of
esterifying (i.e., esterification) the mono-unsaturated fatty acid
can proceed via an acid-catalyzed reaction with an alcohol using,
e.g., H.sub.2SO.sub.4 as a catalyst. In some or other embodiments,
the esterifying can proceed through a conversion of the fatty
acid(s) to an acyl halide (chloride, bromide, or iodide) or acyl
anhydride, followed by reaction with an alcohol.
[0059] Regarding the step of epoxidizing (i.e., the epoxidation
step), in some embodiments, the above-described mono-unsaturated
ester can be reacted with a peroxide (e.g., H.sub.2O.sub.2) or a
peroxy acid (e.g., peroxyacetic acid) to generate an epoxy-ester
species. See, e.g., D. Swern, in Organic Peroxides Vol. II,
Wiley-Interscience, New York, 1971, pp. 355-533; and B. Plesnicar,
in Oxidation in Organic Chemistry, Part C, W. Trahanovsky (ed.),
Academic Press, New York 1978, pp. 221-253. Additionally or
alternatively, the olefinic portion of the mono-unsaturated ester
can be efficiently transformed to the corresponding dihydroxy ester
by highly selective reagents such as osmium tetra-oxide (M.
Schroder, Chem. Rev. vol. 80, p. 187, 1980) and potassium
permanganate (Sheldon and Kochi, in Metal-Catalyzed Oxidation of
Organic Compounds, pp. 162-171 and 294-296, Academic Press, New
York, 1981).
[0060] Regarding the step of epoxide ring opening to the
corresponding dihydroxy-ester, this step is usually an
acid-catalyzed hydrolysis. Exemplary acid catalysts include, but
are not limited to, mineral-based Bronsted acids (e.g., HCl,
H.sub.2SO.sub.4, H.sub.3PO.sub.4, perhalogenates, etc.), Lewis
acids (e.g., TiCl.sub.4 and AlCl.sub.3), solid acids such as acidic
aluminas and silicas or their mixtures, and the like. See, e.g.,
Chem. Rev. vol. 59, p. 737, 1959; and Angew. Chem. Int. Ed., vol.
31, p. 1179, 1992. The epoxide ring opening to the diol can also be
accomplished by base-catalyzed hydrolysis using aqueous solutions
of KOH or NaOH.
[0061] Regarding the step of esterifying the dihydroxy-ester to
form a triester, an acid is typically used to catalyze the reaction
between the --OH groups of the diol and the carboxylic acid(s).
Suitable acids include, but are not limited to, sulfuric acid
(Munch-Peterson, Org. Synth., V, p. 762, 1973), sulfonic acid
(Allen and Sprangler, Org. Synth., III, p. 203, 1955), hydrochloric
acid (Eliel et al., Org. Synth., IV, p. 169, 1963), and phosphoric
acid (among others). In some embodiments, the carboxylic acid used
in this step is first converted to an acyl chloride (or another
acyl halide) via, e.g., thionyl chloride or PCl3. Alternatively, an
acyl chloride (or other acyl halide) could be employed directly.
Where an acyl chloride is used, an acid catalyst is not needed and
a base such as pyridine, 4-dimethylaminopyridine (DMAP) or
triethylamine (TEA) is typically added to react with an HCl
produced. When pyridine or DMAP is used, it is believed that these
amines also act as a catalyst by forming a more reactive acylating
intermediate. See, e.g., Fersh et al., J. Am. Chem. Soc., vol. 92,
pp. 5432-5442, 1970; and Hofle et al., Angew. Chem. Int. Ed. Engl.,
vol. 17, p. 569, 1978. Additionally or alternatively, the
carboxylic acid could be converted into an acyl anhydride and/or
such species could be employed directly.
[0062] Regardless of the source of the mono-unsaturated fatty acid,
in some embodiments, the carboxylic acids (or their acyl
derivatives) used in the above-described methods are derived from
biomass. In some such embodiments, this involves the extraction of
some oil (e.g., triglyceride) component from the biomass and
hydrolysis of the triglycerides of which the oil component is
comprised so as to form free carboxylic acids.
[0063] In some particular embodiments, wherein the above-described
method uses oleic acid for the mono-unsaturated fatty acid, the
resulting triester is of the type:
##STR00004##
wherein R.sub.2, R.sub.3 and R.sub.4 are typically the same or
independently selected from C.sub.2 to C.sub.20 hydrocarbon groups,
and are more typically selected from C.sub.4 to C.sub.12
hydrocarbon groups.
[0064] Using a synthetic strategy in accordance with that outlined
above, oleic acid can be converted to triester derivatives
(9,10-bis-hexanoyloxy-octadecanoic acid hexyl ester) and
(9,10-bis-decanoyloxy-octadecanoic acid decyl ester). Oleic acid is
first esterified to yield a mono-unsaturated ester. The
mono-unsaturated ester is subjected to an epoxidation agent to give
an epoxy-ester species, which undergoes ring-opening to yield a
dihydroxy ester, which can then be reacted with an acyl chloride to
yield a triester product.
[0065] The strategy of the above-described synthesis utilizes the
double bond functionality in oleic acid by converting it to the
diol via double bond epoxidation followed by epoxide ring opening.
Accordingly, the synthesis begins by converting oleic acid to the
appropriate alkyl oleate followed by epoxidation and epoxide ring
opening to the corresponding diol derivative (dihydroxy ester).
[0066] Variations (i.e., alternate embodiments) on the
above-described processes include, but are not limited to,
utilizing mixtures of isomeric olefins and or mixtures of olefins
having a different number of carbons. This leads to diester
mixtures and triester mixtures in the ester component.
[0067] Variations on the above-described processes include, but are
not limited to, using carboxylic acids derived from FT alcohols by
oxidation.
[0068] The present turbine oils, comprised of the base oil and
ester component, show excellent properties as a lubricating oil for
turbines. One of the most important characteristics is reduced
sludge. The turbine oil composition will generally have less than 6
mg of sludge/100 ml of turbine oil as determined by the Cincinnati
Milacron Thermal A Test. In some embodiments, the turbine oil
exhibits less than 3 mg of sludge/100 ml of turbine oil. This
overcomes a major problem which has been observed with regard to
insoluble formation in turbine oils. By combining the present
synthetic ester component, comprised of at least one diester or
triester species having ester links on adjacent carbons, with a
Group II, III and/or IV base oil, the present turbine oil
exhibiting reduced sludge can be obtained.
[0069] In another embodiment, the turbine oil also contains an
additive component. Antioxidants are additives which can be
successfully used, which are known to the industry. In some
embodiments, the antioxidant comprises at least one antioxidant
other than a phenolic antioxidant, e.g., an amine antioxidant.
Mixtures of antioxidants can be used, e.g., a mixture of aminic and
phenolic antioxidants or a mixture of dithiocarbamate, tolutriazole
and phenolic antioxidants. It has been found that favorable results
are achieved when antioxidants other than phenolic antioxidants are
used, whether in the absence of a phenolic antioxidant or in
mixture with a phenolic antioxidant.
[0070] Other additive components which can be used in the present
turbine oil for their respective functions include detergents,
anti-wear agents, metal deactivators, corrosion inhibitors, rust
inhibitors, friction modifiers, anti-foaming agents, viscosity
index improvers, demulsifying agents, emulsifying agents,
antioxidants, complexing agents, extreme pressure additives, pour
point depressants, and combinations thereof.
[0071] In addition to reduced sludge, in some embodiments, the
present turbine oils exhibit improved copper appearance, as
measured by ASTM D130-10, and improved oxidation stability in
RPVOT. The copper appearance indicates minimal copper corrosion,
generally better than 3 A as determined by ASTM D130-10. The RPVOT
oxidative stability, as measured by ASTM D22272-11, is at least 250
minutes, and in some embodiments is over 1000 minutes.
[0072] The combination of the base oil, ester component and any
additives can be achieved by any suitable mixing means. Generally,
the final turbine oil is comprised of from 0.5 to 15 wt % of the
ester component and has a VI of at least 90.
[0073] The following examples are provided to demonstrate, and/or
more fully illustrate, particular embodiments of the present
invention. It should be appreciated by those of skill in the art
that the methods disclosed in the examples which follow merely
represent exemplary embodiments of the present invention. However,
those of skill in the art should, in light of the present
disclosure, appreciate that many changes can be made in the
specific embodiments described and still obtain a like or similar
result without departing from the spirit and scope of the present
invention.
Example 1
Synthesis of a diol from Tetradecene
[0074] In a 3-neck 3-liter reaction flask equipped with an overhead
stirrer and placed in an ice bath, 260 grams of 30% hydrogen
peroxide (2.3 mol. H.sub.2O.sub.2) was added to 650 grams of 88 wt
% formic acid (12.4 mol). To this mixture, 392 grams (2 mol.) of a
mixture of tetradecene isomers (1-tetradecene, 2-tetradecene,
3-tetradecece, 4-tetradecene, 5-tetradecene, 6-tetradecene and
7-tetradecene) was added drop-wise via an addition funnel over a
45-minute period while keeping the reaction temperature below
45.degree. C. Once the addition of the olefins was complete, the
reaction was allowed to stir while cooling in an ice bath to
prevent a rise in the temperature above 40-45.degree. C., for 2
hrs. The ice bath was then removed and the reaction was allowed to
stir at room temperature overnight. The reaction mixture was
concentrated with a rotary evaporator in a hot water bath at about
30 mmHg to remove most of the water and formic acid. Then, 400 ml
of ice-cold 1M solution of sodium hydroxide was added in small
portions and carefully to the remaining reaction concentrate. Once
all the sodium hydroxide solution was added, the mixture was
allowed to stir for an additional 2 hours at about 75-80.degree. C.
The mixture was then diluted with 500 ml ethyl acetate and
transferred to a separatory funnel. The organic layer was separated
and the aqueous layer was extracted 3 times with ethyl acetate (300
ml each). The ethyl acetate extracts were all combined and dried
over anhydrous MgSO.sub.4. Filtration, followed by concentration on
a rotary evaporator at reduced pressure in a hot water bath yielded
a tetradecenes-diol mixture as a waxy substance in 96% yield (443
grams). The tetradecenes-diols were characterized by infrared (IR)
and nuclear magnetic resonance (NMR) spectroscopes, as well as
gas-chromatography/mass spectrometry (GC/MS).
Example 2
Synthesis of the Diester
[0075] In a 3-neck 1 L reaction flask equipped with an overhead
stirrer, reflux condenser, and a dropping funnel, 440 grams (0.95
mol) of the tetradecenes-diol mixture (prepared as described above
in Example 1), 1148 grams (5.7 mol) lauric acid, and 17.5 grams of
85 wt % H.sub.3PO.sub.4 (0.15 mol) were all mixed together. The
resulting mixture was heated to 150.degree. C. and stirred for
several hours while monitoring the progress of the reaction by NMR
spectral and GC/MS analysis. After stirring for 6 hours, the
reaction was complete and the mixture cooled down to room
temperature. The reaction mixture was washed with 1000 ml water and
the organic layer was separated using a separatory funnel. The
organic layer was further rinsed with brine solution (1000 ml of
saturated sodium chloride solution). The resulting mixture was then
distilled at 220.degree. C. and 100 mmHg (Torr) to remove excess
lauric acid. The diester product (the remaining residue in the
distillation flask) was recovered as faint clear yellow oil in 84%
yield (1000 grams). The mixture of diesters' product was
hydrogenated to remove any residual olefins that could have formed
by elimination during the esterification reaction. The final
product, a colorless oil, was analyzed by IR and NMR spectroscopes,
and by GC/MS.
[0076] The reactions and molecular transformation sequence is
##STR00005##
for the epoxidation of 7-tetradecene, which is typical for all
epoxidation and dihydroxylation of all other olefins via this
method.
Example 3
Comparative Runs
[0077] Turbine oils were prepared by combining 5 wt % of the
foregoing prepared diester of Example 2 with three different
commercial Group II turbine oils: Turbine Oil-1; Turbine Oil-2; and
Turbine Oil-3, which is an amine free version of Turbine Oil-2. The
basic turbine oils already contained any additives, e.g.,
antioxidants. The physical characteristics and properties of the
prepared turbine oils were then tested. The basic turbine oils,
without the diester component, were also tested. The results are
shown in Table 2 below. The amounts of the components of each
Turbine Oil are noted in Table 2 in wt % of the overall turbine
formulation.
TABLE-US-00002 TABLE 2 TURBINE OIL-1 TURBINE OIL-2 TURBINE OIL-3
EXP# 1 2 3 4 5 6 COMP. Asian Group II Oil 150 x x X x x x
(hydrotreated API grp II basestock) Asian Group II Oil 600 x x X x
x x (hydrotreated API group II basestock) Diesters (bio-derived 5 5
5 diester) wt % Additive package 1 1 comprising aminic and phenolic
antioxidants and low acidity corrosion inhibitor Succinic acid
corrosion 0.02 0.02 0.02 0.02 inhibitor Acrylic Foam inhibitor
0.0625 0.0625 0.05 0.05 Additive package 1 1 comprising phenolic
and dithiocarbamate antioxidants, and low acidity corrosion
inhibitor Pour point depressant 0.1 0.1 Polyacrylate foam 0.0075
0.0075 inhibitor Phenolic antioxidant 0.5 0.5 Low-acidity corrosion
0.12 0.12 inhibitor Viscosity at 40 C., cSt 33.40 32.13 33.23 31.98
33.27 32.01 Viscosity at 100 C., cSt 5.713 5.526 5.697 5.511 5.702
5.51 TESTING: Cincinnati Milacron Thermal A Copper Wt. Change, mg
0.9000 1.000 2.300 .300 2.000 1.800 Copper, Appearance, 1B 3A 2E 2E
3A 2E (ASTM D130) Sludge/100 ml oil, mg 1.95 7.75 5.10 6.50 6.50
3.55 Vis change at 40 C., % 0.51 .34 2.59 2.25 1.62 1.75 D974-Tan;
Start 0.19 0.07 0.23 0.10 0.22 0.10 MGKOH/g D974-Tan; END 0.07 0.03
0.07 0.04 0.06 0.06 MGKOH/g rust 24 h 665B Pass/Pass Pass/Pass
Pass/Pass Pass/Pass Pass/Pass Pass/Pass RPVOT (2272) 1666 1738 1120
1660 483 466
[0078] From the foregoing results, it can be seen that the present
turbine oils containing the ester component can exhibit excellent
and improved reduced sludge deposits. Note in particular the
results of the Turbine Oil-1 and Turbine Oil-2. Improved copper
appearance and oxidative stability can also be realized. Overall,
an improved turbine oil is achieved by utilizing the ester
component, which also offers an option of biodegradable turbine
oils having reduced sludge.
[0079] All patents and publications referenced herein are hereby
incorporated by reference to the extent not inconsistent herewith.
It will be understood that certain of the above-described
structures, functions, and operations of the above-described
embodiments are not necessary to practice the present invention and
are included in the description simply for completeness of an
exemplary embodiment or embodiments. In addition, it will be
understood that specific structures, functions, and operations set
forth in the above-described referenced patents and publications
can be practiced in conjunction with the present invention, but
they are not essential to its practice. It is therefore to be
understood that the invention may be practiced otherwise than as
specifically described without actually departing from the spirit
and scope of the present invention as defined by the appended
claims.
* * * * *