U.S. patent application number 16/719387 was filed with the patent office on 2020-06-25 for low viscosity lubricating oil compositions with increasing flash point.
The applicant listed for this patent is ExxonMobil Research and Engineering Company. Invention is credited to Joseph S. Bair, Smruti A. Dance, Zhisheng Gao, Andrew E. Taggi.
Application Number | 20200199482 16/719387 |
Document ID | / |
Family ID | 69185694 |
Filed Date | 2020-06-25 |
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United States Patent
Application |
20200199482 |
Kind Code |
A1 |
Dance; Smruti A. ; et
al. |
June 25, 2020 |
Low Viscosity Lubricating Oil Compositions With Increasing Flash
Point
Abstract
This disclosure relates to a lubricating oil having a
lubricating oil base stock as a major component, and one or more
lubricating oil additives as a minor component. The lubricating oil
base stock has at least one first ester that is partially
esterified, and at least one second ester that is fully esterified.
The lubricating oil has a flash point from about 125.degree. C. to
about 225.degree. C. as determined by ASTM D-93, and a kinematic
viscosity (KV.sub.100) from about 1 to about 5 at 100.degree. C. as
determined by ASTM D-445. The at least one first ester and the at
least one second ester are present in an amount such that, as the
flash point of the lubricating oil is increased, the kinematic
viscosity (KV.sub.100) of the lubricating oil is decreased or
maintained. This disclosure also relates to a method for increasing
flash point, while decreasing or maintaining viscosity, of a
lubricating oil in an engine or other mechanical component
lubricated with the lubricating oil by using the lubricating
oil.
Inventors: |
Dance; Smruti A.; (Warren,
NJ) ; Taggi; Andrew E.; (New Hope, PA) ; Bair;
Joseph S.; (Bangor, PA) ; Gao; Zhisheng;
(Flemington, NJ) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
ExxonMobil Research and Engineering Company |
Annandale |
NJ |
US |
|
|
Family ID: |
69185694 |
Appl. No.: |
16/719387 |
Filed: |
December 18, 2019 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62782497 |
Dec 20, 2018 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C10M 2207/2835 20130101;
C10M 105/32 20130101; C10M 129/70 20130101; C10M 129/76 20130101;
C10M 2209/1033 20130101; C10M 2207/2805 20130101; C10N 2020/02
20130101; C10M 2207/2815 20130101; C10M 2207/289 20130101; C10M
2207/2895 20130101; C10N 2030/02 20130101; C10M 2207/281 20130101;
C10M 2205/0206 20130101; C10M 169/04 20130101 |
International
Class: |
C10M 169/04 20060101
C10M169/04; C10M 129/70 20060101 C10M129/70; C10M 129/76 20060101
C10M129/76 |
Claims
1. A composition comprising: at least one first ester that is
partially esterified; and at least one second ester that is fully
esterified; wherein the composition has a flash point from
125.degree. C. to 225.degree. C. as determined by ASTM D-93;
wherein the composition has a kinematic viscosity (KV.sub.100) from
1 to 5 at 100.degree. C. as determined by ASTM D-445; and wherein
the at least one first ester and the at least one second ester are
present in an amount such that, as the flash point of said
composition is increased, the kinematic viscosity (KV.sub.100) of
said composition is decreased or maintained.
2. The composition of claim 1 wherein the at least one first ester
is present in an amount from 1 to 40 weight percent, based on the
total weight of the composition; and the at least one second ester
is present in an amount from 60 to 99 weight percent, based on the
total weight of the composition.
3. The composition of claim 1 wherein the at least one first ester
has a high hydroxyl content, and wherein the hydroxyl content is
from 0.1 to 1 free hydroxyl group per molecule.
4. The composition of claim 1 wherein the at least one first ester
comprises at least one partially esterified polyol ester of a
monocarboxylic acid.
5. The composition of claim 1 wherein the at least one first ester
is derived by reacting one or more polyhydric alcohols with one or
more monocarboxylic acids; wherein the one or more polyhydric
alcohols comprise neopentyl glycol, trimethylol ethane,
2-methyl-2-propyl-1,3-propanediol, trimethylol propane,
pentaerythritol, dipentaerythritol, tripentaerythritol, or
tetrapentaerythritol; and wherein the one or more monocarboxylic
acids comprise acetic acid, propionic acid, butanoic acid,
pentanoic acid, hexanoic acid, heptanoic acid, octanoic acid,
nonanoic acid, decanoic acid, undecanoic acid, dodecanoic acid,
tridecanoic acid, tetradecanoic acid, pentadecanoic acid,
3-methylbutanoic acid, 2-methylbutanoic acid, 2-ethylhexanoic acid,
2,4-dimethylpentanoic acid, 3,3,5-trimethylhexanoic acid, benzoic
acid, caprylic acid, capric acid, lauric acid, myristic acid,
palmitic acid, stearic acid, arachic acid, behenic acid, or oleic
acid.
6. The composition of claim 1 wherein the at least one first ester
comprises partially esterified neopentyl glycol sesquipelargonate,
partially esterified trimethylolpropane pelargonate, partially
esterified neopentyl glycol ester, partially esterified
2-methyl-2-propyl-1,3-propanediol ester, partially esterified
trimethylol ethane ester, partially esterified trimethylol propane
ester, partially esterified pentaerythritol ester, partially
esterified dipentaerythritol ester, partially esterified
tripentaerythrit
7. The composition of claim 1 wherein the at least one second ester
is derived by reacting one or more monoalkanoic acids with one or
more monoalkanols; where the one or more monoalkanoic acids
comprise butanoic acid, pentanoic acid, hexanoic acid, heptanoic
acid, octanoic acid, nonanoic acid, decanoic acid, undeanoic acid,
dodecanoic acid, tridecanoic acid, tetradecanoic acid,
pentadecanoic acid, hexadecanoic acid, and their isomers; and
wherein the one or more monalkanols comprise butyl alcohol, pentyl
alcohol, hexyl alcohol, heptyl alcohol, octyl alcohol, nonyl
alcohol, decyl alcohol, dodecyl alcohol, tridecyl alcohol,
tetradecyl alcohol, pentadecyl alcohol, hexadecyl alcohol, and
their isomers.
8. The composition of claim 1 wherein the at least one second ester
is derived by reacting one or more dibasic acids with one or more
monoalkanols; wherein the one or more dibasic acids comprise
phthalic acid, succinic acid, sebacic acid, fumaric acid, adipic
acid, azelaic acid, linoleic acid dimer, malonic acid, alkyl
malonic acid, or alkenyl malonic acid; and wherein the one or more
monoalkanols comprise pentyl alcohol, hexyl alcohol, heptyl
alcohol, octyl alcohol, nonyl alcohol, decyl alcohol, dodecyl
alcohol, tridecyl alcohol, tetradecyl alcohol, pentadecyl alcohol,
hexadecyl alcohol, and their isomers.
9. The composition of claim 1 wherein the at least one second ester
comprises dibutyl adipate, di(2-ethylhexyl) sebacate, di-n-hexyl
fumarate, dioctyl sebacate, diisooctyl azelate, diisodecyl azelate,
dioctyl phthalate, didecyl phthalate, dieicosyl sebacate,
tripropylene glycol dipelargonate, 2-ethylhexyl palmitate, octyl
octanoate, or trimethyl-l-hexyl trimethylhexanoate.
10. The composition of claim 1 which has a flash point from
130.degree. C. to 220.degree. C. as determined by ASTM D-93, a
viscosity (Kv.sub.100) from 1 to 4 at 100.degree. C. as determined
by ASTM D-445, and a Noack volatility of no greater than 50 percent
as determined by ASTM D-5800.
11. The composition of claim 1 which is a lubricating oil base
stock.
12. A lubricating oil comprising a lubricating oil base stock as a
major component, and one or more lubricating oil additives as a
minor component; wherein the lubricating oil base stock comprises:
at least one first ester that is partially esterified; and at least
one second ester that is fully esterified; wherein the lubricating
oil has a flash point from 125.degree. C. to 225.degree. C. as
determined by ASTM D-93; wherein the lubricating oil has a
kinematic viscosity (KV.sub.100) from 1 to 5 at 100.degree. C. as
determined by ASTM D-445; and wherein the at least one first ester
and the at least one second ester are present in an amount such
that, as the flash point of said lubricating oil is increased, the
kinematic viscosity (KV.sub.100) of said lubricating oil is
decreased or maintained.
13. A method for increasing flash point, while decreasing or
maintaining viscosity, of a lubricating oil in an engine or other
mechanical component lubricated with the lubricating oil by using
as the lubricating oil a formulated oil comprising a lubricating
oil base stock as a major component, and one or more lubricating
oil additives as a minor component; wherein the lubricating oil
base stock comprises: at least one first ester that is partially
esterified; and at least one second ester that is fully esterified;
wherein the lubricating oil has a flash point from 125.degree. C.
to 225.degree. C. as determined by ASTM D-93; wherein the
lubricating oil has a kinematic viscosity (KV.sub.100) from 1 to 5
at 100.degree. C. as determined by ASTM D-445; and wherein the at
least one first ester and the at least one second ester are present
in an amount such that, as the flash point of said lubricating oil
is increased, the kinematic viscosity (KV.sub.100) of said
lubricating oil is decreased or maintained.
14. A method for increasing flash point and thermal conductivity,
while decreasing or maintaining viscosity, of a lubricating oil in
an engine or other mechanical component lubricated with the
lubricating oil by using as the lubricating oil a formulated oil
comprising a lubricating oil base stock as a major component, and
one or more lubricating oil additives as a minor component; wherein
the lubricating oil base stock comprises: at least one partially
esterified ester; wherein the lubricating oil has a flash point
from 125.degree. C. to 225.degree. C. as determined by ASTM D-93;
wherein the lubricating oil has a kinematic viscosity (KV.sub.100)
from 1 to 5 at 100.degree. C. as determined by ASTM D-445; and
wherein the lubricating oil has a thermal conductivity from 0.1
W/m.K to 0.2 W/m.K as determined by ASTM D-2717; wherein the at
least one partially esterified ester is present in an amount such
that, as the flash point and thermal conductivity of said
lubricating oil are increased, the kinematic viscosity (KV.sub.100)
of said lubricating oil is decreased or maintained.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional
Application No. 62/782,497, filed on Dec. 20, 2018, the entire
contents of which are incorporated herein by reference.
[0002] This application is related to U.S. Provisional Application
No. 62/782,491, filed on Dec. 20, 2018, the entire contents of
which are incorporated herein by reference.
FIELD
[0003] This disclosure relates to low viscosity, low volatility,
high flash point compositions that include a mixed ester system, a
lubricating oil base stock and lubricating oil containing the
composition, and a method for increasing flash point, while
decreasing or essentially maintaining viscosity, of a lubricating
oil in an engine or other mechanical component lubricated with the
lubricating oil by using as the lubricating oil a formulated oil
containing the composition.
BACKGROUND
[0004] Lubricants in commercial use today are prepared from a
variety of natural and synthetic base stocks admixed with various
additive packages and solvents depending upon their intended
application. The base stocks typically include mineral oils,
polyalphaolefins (PAO), gas-to-liquid base oils (GTL), silicone
oils, phosphate esters, diesters, polyol esters, and the like.
[0005] A major trend for lubricants including passenger car engine
oils (PCEOs) is an overall improvement in quality as higher quality
base stocks become more readily available. Typically the highest
quality lubricant products are formulated with base stocks such as
PAOs or GTL stocks admixed with various additive packages.
[0006] For improving energy efficiency and fuel economy, base oil
viscosity is very important. Substantial improved fuel economy
(>2%) requires breakthrough in: (1) base oil volatility (2)
durability and (3) friction. Friction losses occur between the
moving components within the engine. Models developed to date
indicate that fuel economy is heavily influenced by the lubricant
properties at high shear. The base stock contributes a greater
proportion of the total viscosity under high shear conditions than
under low shear. Lowering base stock viscosity is likely to have
the largest impact on future energy efficiency gains.
[0007] Lubricant-related performance characteristics such as low
volatility and fuel economy are extremely advantageous attributes
as measured by a variety of bench and engine tests. It is known
that adding friction modifiers to a lubricant formulation imparts
frictional benefits at wide range of temperatures, consequently
improving the lubricant energy efficiency performance. Adding
increased levels of friction modifier, however, can invite high
temperature performance issues. For example, excessive wear,
deposits, and varnish are undesirable consequences of high levels
of friction modifier in an engine oil formulation. In addition,
friction modifiers can be corrosive to certain metals and alloys
used in typical engine design.
[0008] Therefore, there is need for better additive and base stock
technology for lubricant compositions that will meet ever more
stringent requirements of lubricant users. In particular, there is
a need for advanced additive technology and synthetic base stocks
for simultaneously achieving low friction and energy efficiency
while maintaining acceptable wear and deposit performance.
[0009] The present disclosure also provides many additional
advantages, which shall become apparent as described below.
SUMMARY
[0010] This disclosure provides compositions that include mixed
ester compounds having desirable low viscosity, low volatility and
high flash point properties that are important for simultaneously
achieving low friction and high energy efficiency while maintaining
acceptable wear and deposit performance. Thus, the compositions of
this disclosure provide a solution to achieve enhanced fuel economy
and energy efficiency.
[0011] This disclosure relates in part to a composition having at
least one first ester that is partially esterified, and at least
one second ester that is fully esterified. The composition has a
flash point from about 125.degree. C. to about 225.degree. C. as
determined by ASTM D-93, and a kinematic viscosity (KV.sub.100)
from about 1 to about 5 at 100.degree. C. as determined by ASTM
D-445. The at least one first ester and the at least one second
ester are present in an amount such that, as the flash point of the
composition is increased, the kinematic viscosity (KV.sub.100) of
the composition is decreased or essentially maintained.
[0012] As used herein, "partially esterified ester" would be when
you react a polyol with fewer equivalents of carboxylic acid than
the total number of hydroxyls present on the polyol. For example,
if the polyol has 3 hydroxyl groups, and you add fewer than 3
equivalents of carboxylic acid, then the polyol will be "partially
esterified" in that the reaction will be incomplete due to
insufficient carboxylic acid and there will be some free hydroxyl
groups.
[0013] This disclosure also relates in part to a lubricating oil
having a lubricating oil base stock as a major component, and one
or more lubricating oil additives as a minor component. The
lubricating oil base stock has at least one first ester that is
partially esterified, and at least one second ester that is fully
esterified. The lubricating oil has a flash point from about
125.degree. C. to about 225.degree. C. as determined by ASTM D-93,
and a kinematic viscosity (KV.sub.100) from about 1 to about 5 at
100.degree. C. as determined by ASTM D-445. The at least one first
ester and the at least one second ester are present in an amount
such that, as the flash point of the lubricating oil is increased,
the kinematic viscosity (KV.sub.100) of the lubricating oil is
decreased or essentially maintained.
[0014] This disclosure further relates in part to a method for
increasing flash point, while decreasing or maintaining viscosity,
of a lubricating oil in an engine or other mechanical component
lubricated with the lubricating oil by using as the lubricating oil
a formulated oil comprising a lubricating oil base stock as a major
component, and one or more lubricating oil additives as a minor
component. The lubricating oil base stock has at least one first
ester that is partially esterified, and at least one second ester
that is fully esterified. The lubricating oil has a flash point
from about 125.degree. C. to about 225.degree. C. as determined by
ASTM D-93, and a kinematic viscosity (KV.sub.100) from about 1 to
about 5 at 100.degree. C. as determined by ASTM D-445. The at least
one first ester and the at least one second ester are present in an
amount such that, as the flash point of the lubricating oil is
increased, the kinematic viscosity (KV.sub.100) of the lubricating
oil is decreased or essentially maintained.
[0015] This disclosure yet further relates in part to a method for
increasing flash point and thermal conductivity, while decreasing
or maintaining viscosity, of a lubricating oil in an engine or
other mechanical component lubricated with the lubricating oil by
using as the lubricating oil a formulated oil comprising a
lubricating oil base stock as a major component, and one or more
lubricating oil additives as a minor component. The lubricating oil
base stock has at least one partially esterified ester. The
lubricating oil has a flash point from about 125.degree. C. to
about 225.degree. C. as determined by ASTM D-93, a kinematic
viscosity (KV.sub.100) from about 1 to about 5 at 100.degree. C. as
determined by ASTM D-445, and a thermal conductivity from about 0.1
W/m.K to about 0.2 W/m.K at 40.degree. C. as determined by ASTM
D-2717. The at least one partially esterified ester is present in
an amount such that, as the flash point and thermal conductivity of
the lubricating oil are increased, the kinematic viscosity
(KV.sub.100) of the lubricating oil is decreased or essentially
maintained.
[0016] It has been surprisingly found that, in accordance with this
disclosure, lubricant compositions having a mixed ester base stock
system exhibit increased flash point from about 125.degree. C. to
about 225.degree. C. as determined by ASTM D-93, while maintaining
or lowering kinematic viscosity (KV.sub.100) from about 1 to about
5 at 100.degree. C. as determined by ASTM D-445.
[0017] It has also been surprisingly found that, in accordance with
this disclosure, lubricant compositions having a mixed ester base
stock system exhibit increased thermal conductivity from about 0.1
W/m.K to about 0.2 W/m.K at 40.degree. C. as determined by ASTM
D-2717, and increased flash point from about 125.degree. C. to
about 225.degree. C. as determined by ASTM D-93, while maintaining
or lowering kinematic viscosity (KV.sub.100) from about 1 to about
5 at 100.degree. C. as determined by ASTM D-445.
[0018] Further objects, features and advantages of the present
disclosure will be understood by reference to the following
drawings and detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] FIG. 1 shows flash point and viscosity data for base stock
mixtures containing poly alphaolefin (PAO)/poly alkyleneglycol
(PAG), in accordance with Example 1.
[0020] FIG. 2 shows flash point and viscosity data for base stock
mixtures containing poly alphaolefin (PAO)/tripropylene glycol
dipelargonate, in accordance with Example 1.
[0021] FIG. 3 shows flash point and viscosity data for base stock
mixtures containing poly alphaolefin (PAO)/2-ethylhexyl palmitate,
in accordance with Example 2.
[0022] FIG. 4 shows flash point and viscosity data for base stock
mixtures containing octyl octanoate (fully esterified linear
monoester)/neopentyl glycol sesquipelargonate (50% esterified), in
accordance with Example 3.
[0023] FIG. 5 shows flash point and viscosity data for base stock
mixtures containing octyl octanoate (fully esterified linear
monoester)/trimethylolpropane pelargonate (66.7% esterified), in
accordance with Example 3.
[0024] FIG. 6 shows flash point and viscosity data for base stock
mixtures containing trimethyl-1-hexyl trimethylhexanoate (fully
esterified)/2-ethylhexyl palmitate (fully esterified), in
accordance with Example 4.
[0025] FIG. 7 shows flash point and viscosity data for base stock
mixtures containing trimethyl-1-hexyl trimethylhexanoate (fully
esterified)/trimethylolpropane pelargonate (66.7% esterified), in
accordance with Example 4.
[0026] FIG. 8 shows flash point and viscosity data for base stock
mixtures containing trimethyl-1-hexyl trimethylhexanoate (fully
esterified)/neopentyl glycol sesquipelargonate (50% esterified), in
accordance with Example 4.
[0027] FIG. 9 shows thermal conductivity data for
trimethylolpropane pelargonate, alkyl naphthalene, poly alphaolefin
(PAO), and poly alkyleneglycol (PAG) base stocks, in accordance
with Example 5.
DETAILED DESCRIPTION
Definitions
[0028] "About" or "approximately." All numerical values within the
detailed description and the claims herein are modified by "about"
or "approximately" the indicated value, and take into account
experimental error and variations that would be expected by a
person having ordinary skill in the art.
[0029] "Major amount" as it relates to components included within
the lubricating oils of the specification and the claims means
greater than or equal to 50 wt. %, or greater than or equal to 60
wt. %, or greater than or equal to 70 wt. %, or greater than or
equal to 80 wt. %, or greater than or equal to 90 wt. % based on
the total weight of the lubricating oil.
[0030] "Minor amount" as it relates to components included within
the lubricating oils of the specification and the claims means less
than 50 wt. %, or less than or equal to 40 wt. %, or less than or
equal to 30 wt. %, or greater than or equal to 20 wt. %, or less
than or equal to 10 wt. %, or less than or equal to 5 wt. %, or
less than or equal to 2 wt. %, or less than or equal to 1 wt. %,
based on the total weight of the lubricating oil.
[0031] "Essentially free" as it relates to components included
within the lubricating oils of the specification and the claims
means that the particular component is at 0 weight % within the
lubricating oil, or alternatively is at impurity type levels within
the lubricating oil (less than 100 ppm, or less than 20 ppm, or
less than 10 ppm, or less than 1 ppm).
[0032] "Other lubricating oil additives" as used in the
specification and the claims means other lubricating oil additives
that are not specifically recited in the particular section of the
specification or the claims. For example, other lubricating oil
additives may include, but are not limited to, antioxidants,
detergents, dispersants, antiwear additives, corrosion inhibitors,
viscosity modifiers, metal passivators, pour point depressants,
seal compatibility agents, antifoam agents, extreme pressure
agents, friction modifiers and combinations thereof.
[0033] "Other mechanical component" as used in the specification
and the claims means an electric vehicle component, a hybrid
vehicle component, a power train, a driveline, a transmission, a
gear, a gear train, a gear set, a compressor, a pump, a hydraulic
system, a bearing, a bushing, a turbine, a piston, a piston ring, a
cylinder liner, a cylinder, a cam, a tappet, a lifter, a gear, a
valve, or a bearing including a journal, a roller, a tapered, a
needle, and a ball bearing.
[0034] "Hydrocarbon" refers to a compound consisting of carbon
atoms and hydrogen atoms.
[0035] "Alkane" refers to a hydrocarbon that is completely
saturated. An alkane can be linear, branched, cyclic, or
substituted cyclic.
[0036] "Olefin" refers to a non-aromatic hydrocarbon comprising one
or more carbon-carbon double bond in the molecular structure
thereof.
[0037] "Mono-olefin" refers to an olefin comprising a single
carbon-carbon double bond.
[0038] "Cn" group or compound refers to a group or a compound
comprising carbon atoms at total number thereof of n. Thus, "Cm-Cn"
group or compound refers to a group or compound comprising carbon
atoms at a total number thereof in the range from m to n. Thus, a
C1-C50 alkyl group refers to an alkyl group comprising carbon atoms
at a total number thereof in the range from 1 to 50.
[0039] "Carbon backbone" refers to the longest straight carbon
chain in the molecule of the compound or the group in question.
"Branch" refer to any substituted or unsubstituted hydrocarbyl
group connected to the carbon backbone. A carbon atom on the carbon
backbone connected to a branch is called a "branched carbon."
[0040] "Epsilon-carbon" in a branched alkane refers to a carbon
atom in its carbon backbone that is (i) connected to two hydrogen
atoms and two carbon atoms and (ii) connected to a branched carbon
via at least four (4) methylene (CH.sub.2) groups. Quantity of
epsilon carbon atoms in terms of mole percentage thereof in a
alkane material based on the total moles of carbon atoms can be
determined by using, e.g., .sup.13C NMR.
[0041] "Alpha-carbon" in a branched alkane refers to a carbon atom
in its carbon backbone that is with a methyl end with no branch on
the first 4 carbons. It is also measured in mole percentage using
.sup.13C NMR.
[0042] "T/P methyl" in a branched alkane refers to a methyl end and
a methyl in the 2 position. It is also measured in mole percentage
using .sup.13C NMR.
[0043] "P-methyl" in a branched alkane refers to a methyl branch
anywhere on the chain, except in the 2 position. It is also
measured in mole percentage using .sup.13C NMR.
[0044] "SAE" refers to SAE International, formerly known as Society
of Automotive Engineers, which is a professional organization that
sets standards for internal combustion engine lubricating oils.
[0045] "SAE J300" refers to the viscosity grade classification
system of engine lubricating oils established by SAE, which defines
the limits of the classifications in rheological terms only.
[0046] "Base stock" or "base oil" interchangeably refers to an oil
that can be used as a component of lubricating oils, heat transfer
oils, hydraulic oils, grease products, and the like.
[0047] "Lubricating oil" or "lubricant" interchangeably refers to a
substance that can be introduced between two or more surfaces to
reduce the level of friction between two adjacent surfaces moving
relative to each other. A lubricant base stock is a material,
typically a fluid at various levels of viscosity at the operating
temperature of the lubricant, used to formulate a lubricant by
admixing with other components. Non-limiting examples of base
stocks suitable in lubricants include API Group I, Group II, Group
III, Group IV, and Group V base stocks. PAOs, particularly
hydrogenated PAOs, have recently found wide use in lubricants as a
Group IV base stock, and are particularly preferred. If one base
stock is designated as a primary base stock in the lubricant,
additional base stocks may be called a co-base stock.
[0048] All kinematic viscosity values in this disclosure are as
determined pursuant to ASTM D445. Kinematic viscosity at
100.degree. C. is reported herein as KV100, and kinematic viscosity
at 40.degree. C. is reported herein as KV40. Unit of all KV100 and
KV40 values herein is cSt unless otherwise specified. When
describing the kinematic viscosity at 100.degree. C. is
"essentially" maintained, the kinematic viscosity at 100.degree. C.
is expected to vary less than 0.2 cSt as measured by ASTM D445.
[0049] All viscosity index ("VI") values in this disclosure are as
determined pursuant to ASTM D2270.
[0050] All Noack volatility ("NV") values in this disclosure are as
determined pursuant to ASTM D5800 unless specified otherwise. Unit
of all NV values is wt %, unless otherwise specified.
[0051] All pour point values in this disclosure are as determined
pursuant to ASTM D5950 or D97.
[0052] All CCS viscosity ("CCSV") values in this disclosure are as
determined pursuant to ASTM 5293. Unit of all CCSV values herein is
millipascal second (mPas), which is equivalent to centipoise),
unless specified otherwise. All CCSV values are measured at a
temperature of interest to the lubricating oil formulation or oil
composition in question. Thus, for the purpose of designing and
fabricating engine oil formulations, the temperature of interest is
the temperature at which the SAE J300 imposes a minimal CCSV.
[0053] All percentages in describing chemical compositions herein
are by weight unless specified otherwise. "Wt. %" means percent by
weight.
Lubricating Oil Compositions of This Disclosure
[0054] The compositions of this disclosure include a mixed ester
base system. These compositions exhibit increasing flash point
while maintaining or decreasing viscosity, which make them
attractive as Group V synthetic base stocks in high performance,
fuel economy lubricant applications.
[0055] The compositions of this disclosure containing the mixed
ester base stocks have advantageous characteristics including low
volatility, high flash point and low viscosity.
[0056] It has been found that outstanding low viscosity, low
volatility and high flash point properties can be attained in an
engine or a gear box lubricated with a lubricating oil by using as
the lubricating oil a formulated oil in accordance with this
disclosure. In particular, a lubricating oil base stock comprising
a mixed ester system exhibits low viscosity, low volatility, and
high flash point, which helps to prolong the useful life of
lubricants and significantly improve the durability and resistance
of lubricants when exposed to high temperatures. The lubricating
oils of this disclosure are particularly advantageous as passenger
vehicle engine oil (PVEO) or gear box oil products.
[0057] This disclosure provides high performance base stocks based
on a mixed ester system. Examples include fluid mixtures of 1-20%
of mid-to high hydroxyester and 80-99% fully esterified materials.
In addition, combinations of 1-20% mid-to high hydroxyester and
80-99% highly branched esters are also beneficial. In certain
cases, lower levels of highly branched esters from 1-20% in
combination with 80-99% mid-to high hydroxyester is also
beneficial.
[0058] Base stocks having a mixed ester system can be blended with
lubricating oil base fluids in order to optimize lubricating
properties, as described herein. In an embodiment, the base stocks
having a mixed ester system can be blended with lubricating oil
base fluids, to form bimodal blends.
[0059] The mixed ester base stock systems of this disclosure having
low volatility, high flash point and low viscosity are of
significant importance for simultaneously achieving low friction
and high fuel economy while maintaining acceptable wear and deposit
performance.
[0060] In an embodiment, this disclosure relates to a composition
having at least one first ester that is partially esterified, and
at least one second ester that is branched and is fully esterified.
The composition has a flash point from about 125.degree. C. to
about 225.degree. C. as determined by ASTM D-93, and a kinematic
viscosity (KV.sub.100) from about 1 to about 5 at 100.degree. C. as
determined by ASTM D-445. The at least one first ester and the at
least one second ester are present in an amount such that, as the
flash point of the composition is increased, the kinematic
viscosity (KV.sub.100) of the composition is decreased or
essentially maintained.
[0061] In another embodiment, this disclosure relates to a
composition having at least one first ester that is branched and is
fully esterified, and at least one second ester that is branched
and is fully esterified. The composition has a flash point from
about 125.degree. C. to about 225.degree. C. as determined by ASTM
D-93, and a kinematic viscosity (KV.sub.100) from about 1 to about
5 at 100.degree. C. as determined by ASTM D-445. The at least one
first ester and the at least one second ester are present in an
amount such that, as the flash point of the composition is
increased, the kinematic viscosity (KV.sub.100) of the composition
is decreased or essentially maintained.
[0062] In still another embodiment, this disclosure relates to a
lubricating oil having a lubricating oil base stock as a major
component, and one or more lubricating oil additives as a minor
component. The lubricating oil base stock has at least one first
ester that is partially esterified, and at least one second ester
that is branched and is fully esterified. The lubricating oil has a
flash point from about 125.degree. C. to about 225.degree. C. as
determined by ASTM D-93, and a kinematic viscosity (KV.sub.100)
from about 1 to about 5 at 100.degree. C. as determined by ASTM
D-445. The at least one first ester and the at least one second
ester are present in an amount such that, as the flash point of the
lubricating oil is increased, the kinematic viscosity (KV.sub.100)
of the lubricating oil is decreased or essentially maintained.
[0063] In yet another embodiment, this disclosure relates to a
lubricating oil having a lubricating oil base stock as a major
component, and one or more lubricating oil additives as a minor
component. The lubricating oil base stock has at least one first
ester that is branched and is fully esterified, and at least one
second ester that is branched and is fully esterified. The
lubricating oil has a flash point from about 125.degree. C. to
about 225.degree. C. as determined by ASTM D-93, and a kinematic
viscosity (KV.sub.100) from about 1 to about 5 at 100.degree. C. as
determined by ASTM D-445. The at least one first ester and the at
least one second ester are present in an amount such that, as the
flash point of the lubricating oil is increased, the kinematic
viscosity (KV.sub.100) of the lubricating oil is decreased or
essentially maintained.
[0064] In another embodiment, this disclosure relates to a method
for increasing flash point, while decreasing or maintaining
viscosity, of a lubricating oil in an engine or other mechanical
component lubricated with the lubricating oil by using as the
lubricating oil a formulated oil having a lubricating oil base
stock as a major component, and one or more lubricating oil
additives as a minor component. The lubricating oil base stock has
at least one first ester that is partially esterified, and at least
one second ester that is branched and is fully esterified. The
lubricating oil has a flash point from about 125.degree. C. to
about 225.degree. C. as determined by ASTM D-93, and a kinematic
viscosity (KV.sub.100) from about 1 to about 5 at 100.degree. C. as
determined by ASTM D-445. The at least one first ester and the at
least one second ester are present in an amount such that, as the
flash point of the lubricating oil is increased, the kinematic
viscosity (KV.sub.100) of the lubricating oil is decreased or
essentially maintained.
[0065] In still another embodiment, this disclosure relates to a
method for increasing flash point, while decreasing or maintaining
viscosity, of a lubricating oil in an engine or other mechanical
component lubricated with the lubricating oil by using as the
lubricating oil a formulated oil having a lubricating oil base
stock as a major component, and one or more lubricating oil
additives as a minor component. The lubricating oil base stock has
at least one first ester that is branched and is fully esterified,
and at least one second ester that is branched and is fully
esterified. The lubricating oil has a flash point from about
125.degree. C. to about 225.degree. C. as determined by ASTM D-93,
and a kinematic viscosity (KV.sub.100) from about 1 to about 5 at
100.degree. C. as determined by ASTM D-445. The at least one first
ester and the at least one second ester are present in an amount
such that, as the flash point of the lubricating oil is increased,
the kinematic viscosity (KV.sub.100) of the lubricating oil is
decreased or essentially maintained. Mixed Ester Base Stocks
[0066] The base lubricating oil compositions of this disclosure can
be comprised of mixed ester systems. Suitable mixed ester base
systems include, for example, fully esterified esters, partially
esterified esters, branched fully esterified esters, and branched
partially esterified esters.
[0067] In an embodiment, the partially esterified esters comprise a
partially esterified polyol ester of a monocarboxylic acid.
[0068] The partially esterified esters can be derived by reacting
one or more polyhydric alcohols with one or more monocarboxylic
acids. The one or more polyhydric alcohols can be branched or
unbranched and include, for example, neopentyl glycol, trimethylol
ethane, 2-methyl-2-propyl-1,3-propanediol, trimethylol propane,
pentaerythritol, dipentaerythritol, tripentaerythritol, or
tetrapentaerythritol. The one or more monocarboxylic acids can be
branched or unbranched and include, for example, acetic acid,
propionic acid, butanoic acid, pentanoic acid, hexanoic acid,
heptanoic acid, octanoic acid, nonanoic acid, decanoic acid,
undecanoic acid, dodecanoic acid, tridecanoic acid, tetradecanoic
acid, pentadecanoic acid, 3-methylbutanoic acid, 2-methylbutanoic
acid, 2-ethylhexanoic acid, 2,4-dimethylpentanoic acid,
3,3,5-trimethylhexanoic acid, benzoic acid, caprylic acid, capric
acid, lauric acid, myristic acid, palmitic acid, stearic acid,
arachic acid, behenic acid, or oleic acid.
[0069] Illustrative partially esterified esters include, for
example, partially esterified neopentyl glycol sesquipelargonate,
partially esterified trimethylolpropane pelargonate, partially
esterified neopentyl glycol ester, partially esterified
2-methyl-2-propyl-1,3-propanediol ester, partially esterified
trimethylol ethane ester, partially esterified trimethylol propane
ester, partially esterified pentaerythritol ester, partially
esterified dipentaerythritol ester, partially esterified
tripentaerythritol ester, partially esterified tetrapentaerythritol
ester, or mixtures thereof. The partially esterified esters can be
branched or unbranched.
[0070] Reaction conditions for the reaction of the one or more
polyhydric alcohols with the one or more monocarboxylic acids, such
as temperature, pressure and contact time, may also vary greatly
and any suitable combination of such conditions may be employed
herein. The reaction temperature may range between about 25.degree.
C. to about 250.degree. C., and preferably between about 30.degree.
C. to about 200.degree. C., and more preferably between about
60.degree. C. to about 150.degree. C. Normally the reaction is
carried out under ambient pressure and the contact time may vary
from a matter of seconds or minutes to a few hours or greater. The
reactants can be added to the reaction mixture or combined in any
order. The stir time employed can range from about 0.5 to about 48
hours, preferably from about 1 to 36 hours, and more preferably
from about 2 to 24 hours.
[0071] The fully esterified esters can be derived by reacting one
or more monoalkanoic acids with one or more monoalkanols. The one
or more monoalkanoic acids can be branched or unbranched and
include, for example, butanoic acid, pentanoic acid, hexanoic acid,
heptanoic acid, octanoic acid, nonanoic acid, decanoic acid,
undeanoic acid, dodecanoic acid, tridecanoic acid, tetradecanoic
acid, pentadecanoic acid, hexadecanoic acid, and their isomers. The
one or more monalkanols can be branched or unbranched and include,
for example, butyl alcohol, pentyl alcohol, hexyl alcohol, heptyl
alcohol, octyl alcohol, nonyl alcohol, decyl alcohol, dodecyl
alcohol, tridecyl alcohol, tetradecyl alcohol, pentadecyl alcohol,
hexadecyl alcohol, and their isomers.
[0072] Illustrative fully esterified esters include, for example,
dibutyl adipate, di(2-ethylhexyl) sebacate, di-n-hexyl fumarate,
dioctyl sebacate, diisooctyl azelate, diisodecyl azelate, dioctyl
phthalate, didecyl phthalate, dieicosyl sebacate, tripropylene
glycol dipelargonate, 2-ethylhexyl palmitate, octyl octanoate,
trimethyl-1-hexyl trimethylhexanoate, or mixtures thereof. The
fully esterified esters can be branched or unbranched.
[0073] Reaction conditions for the reaction of the one or more
monoalkanoic acids with the one or more monoalkanols, such as
temperature, pressure and contact time, may also vary greatly and
any suitable combination of such conditions may be employed herein.
The reaction temperature may range between about 25.degree. C. to
about 250.degree. C., and preferably between about 30.degree. C. to
about 200.degree. C., and more preferably between about 60.degree.
C. to about 150.degree. C. Normally the reaction is carried out
under ambient pressure and the contact time may vary from a matter
of seconds or minutes to a few hours or greater. The reactants can
be added to the reaction mixture or combined in any order. The stir
time employed can range from about 0.5 to about 48 hours,
preferably from about 1 to 36 hours, and more preferably from about
2 to 24 hours.
[0074] The fully esterified esters and partially esterified esters
useful in this disclosure can exhibit a wide range of amount of
esterification, for example, esterification amount of at least
100%, or at least about 90%, or at least about 80%, or at least
about 70%, or at least about 60%, or at least about 50%, or at
least about 40%, or at least about 30%, or at least about 20%, or
at least about 10%.
[0075] As used herein, low to mid-hydroxyesters include those
esters having at least about 50% esterification, and
high-hydroxyesters include those esters having less than about 50%
esterification (e.g., 33% esterification).
[0076] Illustrative high performance mixed ester base stock systems
include, for example, mixtures of 1-20% of mid-to high hydroxyester
and 80-99% fully esterified materials. In addition, combinations of
1-20% mid-to high hydroxyester and 80-99% highly branched esters
are also beneficial. In certain cases, lower levels of highly
branched esters from 1-20% in combination with 80-99% mid-to high
hydroxyester is also beneficial.
[0077] The mixed ester base stock systems of this disclosure
conveniently have a kinematic viscosity, according to ASTM
standards, of about 1 cSt to about 5 cSt (or mm.sup.2/s) at
100.degree. C. and preferably of about 1.25 cSt to about 4.75 cSt
(or mm.sup.2/s) at 100.degree. C., often more preferably from about
1.3 cSt to about 4.5 cSt at 100.degree. C., even more preferably
from 1.5 to 3.0 cSt at 100.degree. C.
[0078] Mixtures of mixed ester base stocks may be used if desired.
Bi-modal, tri-modal, and additional combinations of mixtures of
mixed ester base stocks and optional Group I, II, III, IV, and/or V
base stocks may be used if desired. With mixtures of mixed ester
base stocks and Group I, II, III, IV, and/or V base stocks, the
mixed ester base stock is present is an amount ranging from about 5
to about 99 weight percent or from about 10 to about 95 weight
percent, preferably from about 50 to about 99 weight percent or
from about 70 to about 95 weight percent, and more preferably from
about 85 to about 95 weight percent, based on the total weight of
the composition. Preferably, with mixtures of mixed ester base
stocks and Group I, II, III, IV, and/or V base stocks, the mixed
ester base stock is present is an amount ranging from about 50 to
about 99 weight percent or from about 55 to about 95 weight
percent, preferably from about 60 to about 99 weight percent or
from about 70 to about 95 weight percent, and more preferably from
about 85 to about 95 weight percent, based on the total weight of
the composition.
[0079] The mixed ester base stock system typically is present in an
amount ranging from about 5 to about 99 weight percent or from
about 10 to about 95 weight percent, preferably from about 50 to
about 99 weight percent or from about 70 to about 95 weight
percent, and more preferably from about 85 to about 95 weight
percent, based on the total weight of the composition.
[0080] Preferably, the mixed ester base stock system constitutes
the major component of the engine, or other mechanical component,
oil lubricant composition of the present disclosure and typically
is present in an amount ranging from greater than about 50 to about
99 weight percent or from about 55 to about 95 weight percent,
preferably from about 60 to about 99 weight percent or from about
70 to about 95 weight percent, and more preferably from about 85 to
about 95 weight percent, based on the total weight of the
composition.
[0081] Examples of techniques that can be employed to characterize
the compositions formed by the process described above include, but
are not limited to, analytical gas chromatography, nuclear magnetic
resonance, thermogravimetric analysis (TGA), inductively coupled
plasma mass spectrometry, differential scanning calorimetry (DSC),
volatility and viscosity measurements.
[0082] Examples of techniques that can be employed to characterize
the compositions formed by the process described above include, but
are not limited to, analytical gas chromatography, nuclear magnetic
resonance, thermogravimetric analysis (TGA), inductively coupled
plasma mass spectrometry, differential scanning calorimetry (DSC),
volatility and viscosity measurements.
[0083] This disclosure provides lubricating oils useful as engine
oils and in other applications characterized by an increasing flash
point while maintaining or decreasing viscosity. The lubricating
oils are based on high quality base stocks including a major
portion of a mixed ester base stock system with a hydrocarbon base
fluid such as a PAO or GTL as described herein. The lubricating oil
base stock can be any oil boiling in the lube oil boiling range,
typically between about 100 to 450.degree. C. In the present
specification and claims, the terms base oil(s) and base stock(s)
are used interchangeably.
Lubricating Oil Base Stocks
[0084] A wide range of lubricating oils is known in the art.
Lubricating oils that are useful in the present disclosure are both
natural oils and synthetic oils. Natural and synthetic oils (or
mixtures thereof) can be used unrefined, refined, or rerefined (the
latter is also known as reclaimed or reprocessed oil). Unrefined
oils are those obtained directly from a natural or synthetic source
and used without added purification. These include shale oil
obtained directly from retorting operations, petroleum oil obtained
directly from primary distillation, and ester oil obtained directly
from an esterification process. Refined oils are similar to the
oils discussed for unrefined oils except refined oils are subjected
to one or more purification steps to improve the at least one
lubricating oil property. One skilled in the art is familiar with
many purification processes. These processes include solvent
extraction, secondary distillation, acid extraction, base
extraction, filtration, and percolation. Rerefined oils are
obtained by processes analogous to refined oils but using an oil
that has been previously used as a feed stock.
[0085] Groups I, II, III, IV and V are broad categories of base oil
stocks developed and defined by the American Petroleum Institute
(API Publication 1509; www.API.org) to create guidelines for
lubricant base oils. Group I base stocks generally have a viscosity
index of between about 80 to 120 and contain greater than about
0.03% sulfur and less than about 90% saturates. Group II base
stocks generally have a viscosity index of between about 80 to 120,
and contain less than or equal to about 0.03% sulfur and greater
than or equal to about 90% saturates. Group III stock generally has
a viscosity index greater than about 120 and contains less than or
equal to about 0.03% sulfur and greater than about 90% saturates.
Group IV includes polyalphaolefins (PAO). Group V base stocks
include base stocks not included in Groups I-IV. The table below
summarizes properties of each of these five groups.
TABLE-US-00001 Base Oil Properties Saturates Sulfur Viscosity Index
Group I <90 and/or >0.03% and .gtoreq.80 and <120 Group II
.gtoreq.90 and .ltoreq.0.03% and .gtoreq.80 and <120 Group III
.gtoreq.90 and .ltoreq.0.03% and .gtoreq.120 Group IV Includes
polyalphaolefins (PAO) products Group V All other base oil stocks
not included in Groups I, II, III or IV
[0086] Natural oils include animal oils, vegetable oils (castor oil
and lard oil, for example), and mineral oils. Animal and vegetable
oils possessing favorable thermal oxidative stability can be used.
Of the natural oils, mineral oils are preferred. Mineral oils vary
widely as to their crude source, for example, as to whether they
are paraffinic, naphthenic, or mixed paraffinic-naphthenic. Oils
derived from coal or shale are also useful in the present
disclosure. Natural oils vary also as to the method used for their
production and purification, for example, their distillation range
and whether they are straight run or cracked, hydrorefined, or
solvent extracted.
[0087] Group II and/or Group III hydroprocessed or hydrocracked
base stocks, as well as synthetic oils such as polyalphaolefins,
alkyl aromatics and synthetic esters, i.e. Group IV and Group V
oils are also well known base stock oils.
[0088] Synthetic oils include hydrocarbon oil such as polymerized
and interpolymerized olefins (polybutylenes, polypropylenes,
propylene isobutylene copolymers, ethylene-olefin copolymers, and
ethylene-alphaolefin copolymers, for example). Polyalphaolefin
(PAO) oil base stocks, the Group IV API base stocks, are a commonly
used synthetic hydrocarbon oil. By way of example, PAOs derived
from C.sub.8, C.sub.10, C.sub.12, C.sub.14 olefins or mixtures
thereof may be utilized. See U.S. Pat. Nos. 4,956,122; 4,827,064;
and 4,827,073, which are incorporated herein by reference in their
entirety. Group IV oils, that is, the PAO base stocks have
viscosity indices preferably greater than 130, more preferably
greater than 135, still more preferably greater than 140.
[0089] Esters in a minor amount may be useful in the lubricating
oils of this disclosure. Additive solvency and seal compatibility
characteristics may be secured by the use of esters such as the
esters of dibasic acids with monoalkanols and the polyol esters of
monocarboxylic acids. Esters of the former type include, for
example, the esters of dicarboxylic acids such as phthalic acid,
succinic acid, sebacic acid, fumaric acid, adipic acid, linoleic
acid dimer, malonic acid, alkyl malonic acid, alkenyl malonic acid,
etc., with a variety of alcohols such as butyl alcohol, hexyl
alcohol, dodecyl alcohol, 2-ethylhexyl alcohol, etc. Specific
examples of these types of esters include dibutyl adipate,
di(2-ethylhexyl) sebacate, di-n-hexyl fumarate, dioctyl sebacate,
diisooctyl azelate, diisodecyl azelate, dioctyl phthalate, didecyl
phthalate, dieicosyl sebacate, etc.
[0090] Particularly useful synthetic esters are those which are
obtained by reacting one or more polyhydric alcohols, preferably
the hindered polyols such as the neopentyl polyols; e.g., neopentyl
glycol, trimethylol ethane, 2-methyl-2-propyl-1,3-propanediol,
trimethylol propane, pentaerythritol and dipentaerythritol with
alkanoic acids containing at least about 4 carbon atoms, preferably
C.sub.5 to C.sub.30 acids such as saturated straight chain fatty
acids including caprylic acid, capric acids, lauric acid, myristic
acid, palmitic acid, stearic acid, arachic acid, and behenic acid,
or the corresponding branched chain fatty acids or unsaturated
fatty acids such as oleic acid, or mixtures of any of these
materials.
[0091] Esters should be used in an amount such that the improved
wear and corrosion resistance provided by the lubricating oils of
this disclosure are not adversely affected.
[0092] Non-conventional or unconventional base stocks and/or base
oils include one or a mixture of base stock(s) and/or base oil(s)
derived from: (1) one or more Gas-to-Liquids (GTL) materials, as
well as (2) hydrodewaxed, or hydroisomerized/cat (and/or solvent)
dewaxed base stock(s) and/or base oils derived from synthetic wax,
natural wax or waxy feeds, mineral and/or non-mineral oil waxy feed
stocks such as gas oils, slack waxes (derived from the solvent
dewaxing of natural oils, mineral oils or synthetic oils; e.g.,
Fischer-Tropsch feed stocks), natural waxes, and waxy stocks such
as gas oils, waxy fuels hydrocracker bottoms, waxy raffinate,
hydrocrackate, thermal crackates, foots oil or other mineral,
mineral oil, or even non-petroleum oil derived waxy materials such
as waxy materials recovered from coal liquefaction or shale oil,
linear or branched hydrocarbyl compounds with carbon number of
about 20 or greater, preferably about 30 or greater and mixtures of
such base stocks and/or base oils.
[0093] GTL materials are materials that are derived via one or more
synthesis, combination, transformation, rearrangement, and/or
degradation/deconstructive processes from gaseous carbon-containing
compounds, hydrogen-containing compounds and/or elements as feed
stocks such as hydrogen, carbon dioxide, carbon monoxide, water,
methane, ethane, ethylene, acetylene, propane, propylene, propyne,
butane, butylenes, and butynes. GTL base stocks and/or base oils
are GTL materials of lubricating viscosity that are generally
derived from hydrocarbons; for example, waxy synthesized
hydrocarbons, that are themselves derived from simpler gaseous
carbon-containing compounds, hydrogen-containing compounds and/or
elements as feed stocks. GTL base stock(s) and/or base oil(s)
include oils boiling in the lube oil boiling range (1)
separated/fractionated from synthesized GTL materials such as, for
example, by distillation and subsequently subjected to a final wax
processing step which involves either or both of a catalytic
dewaxing process, or a solvent dewaxing process, to produce lube
oils of reduced/low pour point; (2) synthesized wax isomerates,
comprising, for example, hydrodewaxed or hydroisomerized cat and/or
solvent dewaxed synthesized wax or waxy hydrocarbons; (3)
hydrodewaxed or hydroisomerized cat and/or solvent dewaxed
Fischer-Tropsch (F-T) material (i.e., hydrocarbons, waxy
hydrocarbons, waxes and possible analogous oxygenates); preferably
hydrodewaxed or hydroisomerized/followed by cat and/or solvent
dewaxing dewaxed F-T waxy hydrocarbons, or hydrodewaxed or
hydroisomerized/followed by cat (or solvent) dewaxing dewaxed, F-T
waxes, or mixtures thereof.
[0094] GTL base stock(s) and/or base oil(s) derived from GTL
materials, especially, hydrodewaxed or hydroisomerized/followed by
cat and/or solvent dewaxed wax or waxy feed, preferably F-T
material derived base stock(s) and/or base oil(s), are
characterized typically as having kinematic viscosities at
100.degree. C. of from about 2 mm.sup.2/s to about 50 mm.sup.2/s
(ASTM D445). They are further characterized typically as having
pour points of -5.degree. C. to about -40.degree. C. or lower (ASTM
D97). They are also characterized typically as having viscosity
indices of about 80 to about 140 or greater (ASTM D2270).
[0095] In addition, the GTL base stock(s) and/or base oil(s) are
typically highly paraffinic (>90% saturates), and may contain
mixtures of monocycloparaffins and multicycloparaffins in
combination with non-cyclic isoparaffins. The ratio of the
naphthenic (i.e., cycloparaffin) content in such combinations
varies with the catalyst and temperature used. Further, GTL base
stock(s) and/or base oil(s) typically have very low sulfur and
nitrogen content, generally containing less than about 10 ppm, and
more typically less than about 5 ppm of each of these elements. The
sulfur and nitrogen content of GTL base stock(s) and/or base oil(s)
obtained from F-T material, especially F-T wax, is essentially nil.
In addition, the absence of phosphorous and aromatics make this
materially especially suitable for the formulation of low SAP
products.
[0096] The term GTL base stock and/or base oil and/or wax isomerate
base stock and/or base oil is to be understood as embracing
individual fractions of such materials of wide viscosity range as
recovered in the production process, mixtures of two or more of
such fractions, as well as mixtures of one or two or more low
viscosity fractions with one, two or more higher viscosity
fractions to produce a blend wherein the blend exhibits a target
kinematic viscosity.
[0097] The GTL material, from which the GTL base stock(s) and/or
base oil(s) is/are derived is preferably an F-T material (i.e.,
hydrocarbons, waxy hydrocarbons, wax).
[0098] Base oils for use in the formulated lubricating oils useful
in the present disclosure are any of the variety of oils
corresponding to API Group I, Group II, Group III, Group IV, Group
V and Group VI oils and mixtures thereof, preferably API Group II,
Group III, Group IV, Group V and Group VI oils and mixtures
thereof, more preferably the Group III to Group VI base oils due to
their exceptional volatility, stability, viscometric and
cleanliness features. Minor quantities of Group I stock, such as
the amount used to dilute additives for blending into formulated
lube oil products, can be tolerated but should be kept to a
minimum, i.e. amounts only associated with their use as
diluent/carrier oil for additives used on an "as received" basis.
Even in regard to the Group II stocks, it is preferred that the
Group II stock be in the higher quality range associated with that
stock, i.e. a Group II stock having a viscosity index in the range
100<VI<120.
[0099] In addition, the GTL base stock(s) and/or base oil(s) are
typically highly paraffinic (>90% saturates), and may contain
mixtures of monocycloparaffins and multicycloparaffins in
combination with non-cyclic isoparaffins. The ratio of the
naphthenic (i.e., cycloparaffin) content in such combinations
varies with the catalyst and temperature used. Further, GTL base
stock(s) and/or base oil(s) and hydrodewaxed, or
hydroisomerized/cat (and/or solvent) dewaxed base stock(s) and/or
base oil(s) typically have very low sulfur and nitrogen content,
generally containing less than about 10 ppm, and more typically
less than about 5 ppm of each of these elements. The sulfur and
nitrogen content of GTL base stock(s) and/or base oil(s) obtained
from F-T material, especially F-T wax, is essentially nil. In
addition, the absence of phosphorous and aromatics make this
material especially suitable for the formulation of low sulfur,
sulfated ash, and phosphorus (low SAP) products.
[0100] The base stock component of the present lubricating oils
will typically be from 50 to 99 weight percent of the total
composition (all proportions and percentages set out in this
specification are by weight unless the contrary is stated) and more
usually in the range of 80 to 99 weight percent.
Other Additives
[0101] The formulated lubricating oil useful in the present
disclosure may additionally contain one or more of the other
commonly used lubricating oil performance additives including but
not limited to dispersants, other detergents, corrosion inhibitors,
rust inhibitors, metal deactivators, other anti-wear agents and/or
extreme pressure additives, anti-seizure agents, wax modifiers,
viscosity index improvers, viscosity modifiers, fluid-loss
additives, seal compatibility agents, other friction modifiers,
lubricity agents, anti-staining agents, chromophoric agents,
defoamants, demulsifiers, emulsifiers, densifiers, wetting agents,
gelling agents, tackiness agents, colorants, and others. For a
review of many commonly used additives, see Klamann in Lubricants
and Related Products, Verlag Chemie, Deerfield Beach, FL; ISBN
0-89573-177-0. Reference is also made to "Lubricant Additives
Chemistry and Applications" edited by Leslie R. Rudnick, Marcel
Dekker, Inc. New York, 2003 ISBN: 0-8247-0857-1.
[0102] The types and quantities of performance additives used in
combination with the instant disclosure in lubricant compositions
are not limited by the examples shown herein as illustrations.
Viscosity Improvers
[0103] Viscosity improvers (also known as Viscosity Index
modifiers, and VI improvers) increase the viscosity of the oil
composition at elevated temperatures which increases film
thickness, while having limited effect on viscosity at low
temperatures.
[0104] Suitable viscosity improvers include high molecular weight
hydrocarbons, polyesters and viscosity index improver dispersants
that function as both a viscosity index improver and a dispersant.
Typical molecular weights of these polymers are between about
10,000 to 1,000,000, more typically about 20,000 to 500,000, and
even more typically between about 50,000 and 200,000.
[0105] Examples of suitable viscosity improvers are polymers and
copolymers of methacrylate, butadiene, olefins, or alkylated
styrenes. Polyisobutylene is a commonly used viscosity index
improver. Another suitable viscosity index improver is
polymethacrylate (copolymers of various chain length alkyl
methacrylates, for example), some formulations of which also serve
as pour point depressants. Other suitable viscosity index improvers
include copolymers of ethylene and propylene, hydrogenated block
copolymers of styrene and isoprene, and polyacrylates (copolymers
of various chain length acrylates, for example). Specific examples
include styrene-isoprene or styrene-butadiene based polymers of
50,000 to 200,000 molecular weight.
[0106] The amount of viscosity modifier may range from zero to 8 wt
%, preferably zero to 4 wt %, more preferably zero to 2 wt % based
on active ingredient and depending on the specific viscosity
modifier used.
Antioxidants
[0107] Typical antioxidants include phenolic antioxidants, aminic
antioxidants and oil-soluble copper complexes.
[0108] The phenolic antioxidants include sulfurized and
non-sulfurized phenolic antioxidants. The terms "phenolic type" or
"phenolic antioxidant" used herein includes compounds having one or
more than one hydroxyl group bound to an aromatic ring which may
itself be mononuclear, e.g., benzyl, or poly-nuclear, e.g.,
naphthyl and spiro aromatic compounds. Thus "phenol type" includes
phenol per se, catechol, resorcinol, hydroquinone, naphthol, etc.,
as well as alkyl or alkenyl and sulfurized alkyl or alkenyl
derivatives thereof, and bisphenol type compounds including such
bi-phenol compounds linked by alkylene bridges sulfuric bridges or
oxygen bridges. Alkyl phenols include mono- and poly-alkyl or
alkenyl phenols, the alkyl or alkenyl group containing from about
3-100 carbons, preferably 4 to 50 carbons and sulfurized
derivatives thereof, the number of alkyl or alkenyl groups present
in the aromatic ring ranging from 1 to up to the available
unsatisfied valences of the aromatic ring remaining after counting
the number of hydroxyl groups bound to the aromatic ring.
[0109] Generally, therefore, the phenolic anti-oxidant may be
represented by the general formula:
(R).sub.x--Ar--(OH).sub.y
where Ar is selected from the group consisting of:
##STR00001##
wherein R is a C.sub.3-C.sub.100 alkyl or alkenyl group, a sulfur
substituted alkyl or alkenyl group, preferably a C.sub.4-C.sub.50
alkyl or alkenyl group or sulfur substituted alkyl or alkenyl
group, more preferably C.sub.3-C.sub.100 alkyl or sulfur
substituted alkyl group, most preferably a C.sub.4-C.sub.50 alkyl
group, R.sup.G is a C.sub.1-C.sub.100 alkylene or sulfur
substituted alkylene group, preferably a C.sub.2-C.sub.50 alkylene
or sulfur substituted alkylene group, more preferably a
C.sub.2-C.sub.2 alkylene or sulfur substituted alkylene group, y is
at least 1 to up to the available valences of Ar, x ranges from 0
to up to the available valances of Ar-y, z ranges from 1 to 10, n
ranges from 0 to 20, and m is 0 to 4 and p is 0 or 1, preferably y
ranges from 1 to 3, x ranges from 0 to 3, z ranges from 1 to 4 and
n ranges from 0 to 5, and p is 0.
[0110] Preferred phenolic anti-oxidant compounds are the hindered
phenolics and phenolic esters which contain a sterically hindered
hydroxyl group, and these include those derivatives of dihydroxy
aryl compounds in which the hydroxyl groups are in the o- or
p-position to each other. Typical phenolic anti-oxidants include
the hindered phenols substituted with C.sub.1+alkyl groups and the
alkylene coupled derivatives of these hindered phenols. Examples of
phenolic materials of this type 2-t-butyl-4-heptyl phenol;
2-t-butyl-4-octyl phenol; 2-t-butyl-4-dodecyl phenol;
2,6-di-t-butyl-4-heptyl phenol; 2,6-di-t-butyl-4-dodecyl phenol;
2-methyl-6-t-butyl-4-heptyl phenol; 2-methyl-6-t-butyl-4-dodecyl
phenol; 2,6-di-t-butyl-4 methyl phenol; 2,6-di-t-butyl-4-ethyl
phenol; and 2,6-di-t-butyl 4 alkoxy phenol; and
##STR00002##
[0111] Phenolic type anti-oxidants are well known in the
lubricating industry and commercial examples such as Ethanox.RTM.
4710, Irganox.RTM. 1076, Irganox.RTM. L1035, Irganox.RTM. 1010,
Irganox.RTM. L109, Irganox.RTM. L118, Irganox.RTM. L135 and the
like are familiar to those skilled in the art. The above is
presented only by way of exemplification, not limitation on the
type of phenolic anti-oxidants which can be used.
[0112] The phenolic anti-oxidant can be employed in an amount in
the range of about 0.1 to 3 wt %, preferably about 1 to 3 wt %,
more preferably 1.5 to 3 wt % on an active ingredient basis.
[0113] Aromatic amine anti-oxidants include phenyl-.alpha.-naphthyl
amine which is described by the following molecular structure:
##STR00003##
wherein R.sup.2 is hydrogen or a C.sub.1 to C.sub.14 linear or
C.sub.3 to C.sub.14 branched alkyl group, preferably C.sub.1 to
C.sub.10 linear or C.sub.3 to C.sub.10 branched alkyl group, more
preferably linear or branched C.sub.6 to C.sub.8 and n is an
integer ranging from 1 to 5 preferably 1. A particular example is
Irganox L06.
[0114] Other aromatic amine anti-oxidants include other alkylated
and non-alkylated aromatic amines such as aromatic monoamines of
the formula R.sup.8R.sup.9R.sup.10N where R.sup.8 is an aliphatic,
aromatic or substituted aromatic group, R.sup.9 is an aromatic or a
substituted aromatic group, and R.sup.10 is H, alkyl, aryl or
R.sup.11S(O).sub.xR.sup.12 where R.sup.11 is an alkylene,
alkenylene, or aralkylene group, R.sup.12 is a higher alkyl group,
or an alkenyl, aryl, or alkaryl group, and x is 0, 1 or 2. The
aliphatic group R.sup.8 may contain from 1 to about 20 carbon
atoms, and preferably contains from about 6 to 12 carbon atoms. The
aliphatic group is a saturated aliphatic group. Preferably, both
R.sup.8 and R.sup.9 are aromatic or substituted aromatic groups,
and the aromatic group may be a fused ring aromatic group such as
naphthyl. Aromatic groups R.sup.8 and R.sup.9 may be joined
together with other groups such as S.
[0115] Typical aromatic amines anti-oxidants have alkyl substituent
groups of at least about 6 carbon atoms. Examples of aliphatic
groups include hexyl, heptyl, octyl, nonyl, and decyl. Generally,
the aliphatic groups will not contain more than about 14 carbon
atoms. The general types of such other additional amine
anti-oxidants which may be present include diphenylamines,
phenothiazines, imidodibenzyls and diphenyl phenylene diamines.
Mixtures of two or more of such other additional aromatic amines
may also be present. Polymeric amine antioxidants can also be
used.
[0116] Another class of anti-oxidant used in lubricating oil
compositions and which may also be present are oil-soluble copper
compounds. Any oil-soluble suitable copper compound may be blended
into the lubricating oil. Examples of suitable copper antioxidants
include copper dihydrocarbyl thio- or dithio-phosphates and copper
salts of carboxylic acid (naturally occurring or synthetic). Other
suitable copper salts include copper dithiacarbamates, sulphonates,
phenates, and acetylacetonates. Basic, neutral, or acidic copper
Cu(I) and or Cu(II) salts derived from alkenyl succinic acids or
anhydrides are known to be particularly useful.
[0117] Such antioxidants may be used individually or as mixtures of
one or more types of anti-oxidants, the total amount employed being
an amount of about 0.50 to 5 wt %, preferably about 0.75 to 3 wt %
(on an as-received basis).
Detergents
[0118] In addition to the alkali or alkaline earth metal salicylate
detergent which is an essential component in the present
disclosure, other detergents may also be present. While such other
detergents can be present, it is preferred that the amount employed
be such as to not interfere with the synergistic effect
attributable to the presence of the salicylate. Therefore, most
preferably such other detergents are not employed.
[0119] If such additional detergents are present, they can include
alkali and alkaline earth metal phenates, sulfonates, carboxylates,
phosphonates and mixtures thereof. These supplemental detergents
can have total base number (TBN) ranging from neutral to highly
overbased, i.e. TBN of 0 to over 500, preferably 2 to 400, more
preferably 5 to 300, and they can be present either individually or
in combination with each other in an amount in the range of from 0
to 10 wt %, preferably 0.5 to 5 wt % (active ingredient) based on
the total weight of the formulated lubricating oil. As previously
stated, however, it is preferred that such other detergent not be
present in the formulation. Such additional other detergents
include by way of example and not limitation calcium phenates,
calcium sulfonates, magnesium phenates, magnesium sulfonates and
other related components (including borated detergents).
Friction Modifiers
[0120] A friction modifier is any material or materials that can
alter the coefficient of friction of a surface lubricated by any
lubricant or fluid containing such material(s). Friction modifiers,
also known as friction reducers, or lubricity agents or oiliness
agents, and other such agents that change the ability of base oils,
formulated lubricant compositions, or functional fluids, to modify
the coefficient of friction of a lubricated surface may be
effectively used in combination with the base oils or lubricant
compositions of the present disclosure if desired. Friction
modifiers that lower the coefficient of friction are particularly
advantageous in combination with the base oils and lube
compositions of this disclosure.
[0121] Illustrative friction modifiers may include, for example,
organometallic compounds or materials, or mixtures thereof.
Illustrative organometallic friction modifiers useful in the
lubricating engine oil formulations of this disclosure include, for
example, molybdenum amine, molybdenum diamine, an
organotungstenate, a molybdenum dithiocarbamate, molybdenum
dithiophosphates, molybdenum amine complexes, molybdenum
carboxylates, and the like, and mixtures thereof. Similar tungsten
based compounds may be preferable.
[0122] Other illustrative friction modifiers useful in the
lubricating engine oil formulations of this disclosure include, for
example, alkoxylated fatty acid esters, alkanolamides, polyol fatty
acid esters, borated glycerol fatty acid esters, fatty alcohol
ethers, and mixtures thereof.
[0123] Illustrative alkoxylated fatty acid esters include, for
example, polyoxyethylene stearate, fatty acid polyglycol ester, and
the like. These can include polyoxypropylene stearate,
polyoxybutylene stearate, polyoxyethylene isosterate,
polyoxypropylene isostearate, polyoxyethylene palmitate, and the
like.
[0124] Illustrative alkanolamides include, for example, lauric acid
diethylalkanolamide, palmic acid diethylalkanolamide, and the like.
These can include oleic acid diethyalkanolamide, stearic acid
diethylalkanolamide, oleic acid diethylalkanolamide,
polyethoxylated hydrocarbylamides, polypropoxylated
hydrocarbylamides, and the like.
[0125] Illustrative polyol fatty acid esters include, for example,
glycerol mono-oleate, saturated mono-, di-, and tri-glyceride
esters, glycerol mono-stearate, and the like. These can include
polyol esters, hydroxyl-containing polyol esters, and the like.
[0126] Illustrative borated glycerol fatty acid esters include, for
example, borated glycerol mono-oleate, borated saturated mono-,
di-, and tri-glyceride esters, borated glycerol mono-sterate, and
the like. In addition to glycerol polyols, these can include
trimethylolpropane, pentaerythritol, sorbitan, and the like. These
esters can be polyol monocarboxylate esters, polyol dicarboxylate
esters, and on occasion polyoltricarboxylate esters. Preferred can
be the glycerol mono-oleates, glycerol dioleates, glycerol
trioleates, glycerol monostearates, glycerol distearates, and
glycerol tristearates and the corresponding glycerol
monopalmitates, glycerol dipalmitates, and glycerol tripalmitates,
and the respective isostearates, linoleates, and the like. On
occasion the glycerol esters can be preferred as well as mixtures
containing any of these. Ethoxylated, propoxylated, butoxylated
fatty acid esters of polyols, especially using glycerol as
underlying polyol can be preferred.
[0127] Illustrative fatty alcohol ethers include, for example,
stearyl ether, myristyl ether, and the like. Alcohols, including
those that have carbon numbers from C3 to C5, can be ethoxylated,
propoxylate, or butoxylated to form the corresponding fatty alkyl
ethers. The underlying alcohol portion can preferably be stearyl,
myristyl, C11-C13 hydrocarbon, oleyl, isosteryl, and the like.
[0128] Useful concentrations of friction modifiers may range from
0.01 weight percent to 5 weight percent, or about 0.1 weight
percent to about 2.5 weight percent, or about 0.1 weight percent to
about 1.5 weight percent, or about 0.1 weight percent to about 1
weight percent. Concentrations of molybdenum-containing materials
are often described in terms of Mo metal concentration.
Advantageous concentrations of Mo may range from 25 ppm to 2000 ppm
or more, and often with a preferred range of 50-1500 ppm. Friction
modifiers of all types may be used alone or in mixtures with the
materials of this disclosure. Often mixtures of two or more
friction modifiers, or mixtures of friction modifier(s) with
alternate surface active material(s), are also desirable.
Dispersants
[0129] During engine operation, oil-insoluble oxidation byproducts
are produced. Dispersants help keep these byproducts in solution,
thus diminishing their deposition on metal surfaces. Dispersants
may be ashless or ash-forming in nature. Preferably, the dispersant
is ashless. So called ashless dispersants are organic materials
that form substantially no ash upon combustion. For example,
non-metal-containing or borated metal-free dispersants are
considered ashless. In contrast, metal-containing detergents
discussed above form ash upon combustion.
[0130] Suitable dispersants typically contain a polar group
attached to a relatively high molecular weight hydrocarbon chain.
The polar group typically contains at least one element of
nitrogen, oxygen, or phosphorus. Typical hydrocarbon chains contain
50 to 400 carbon atoms.
[0131] A particularly useful class of dispersants are the
alkenylsuccinic derivatives, typically produced by the reaction of
a long chain substituted alkenyl succinic compound, usually a
substituted succinic anhydride, with a polyhydroxy or polyamino
compound. The long chain group constituting the oleophilic portion
of the molecule which confers solubility in the oil, is normally a
polyisobutylene group. Many examples of this type of dispersant are
well known commercially and in the literature. Exemplary patents
describing such dispersants are U.S. Pat. Nos. 3,172,892;
3,219,666; 3,316,177 and 4,234,435. Other types of dispersants are
described in U.S. Pat. Nos. 3,036,003; and 5,705,458.
[0132] Hydrocarbyl-substituted succinic acid compounds are popular
dispersants. In particular, succinimide, succinate esters, or
succinate ester amides prepared by the reaction of a
hydrocarbon-substituted succinic acid compound preferably having at
least 50 carbon atoms in the hydrocarbon substituent, with at least
one equivalent of an alkylene amine are particularly useful.
[0133] Succinimides are formed by the condensation reaction between
alkenyl succinic anhydrides and amines. Molar ratios can vary
depending on the amine or polyamine. For example, the molar ratio
of alkenyl succinic anhydride to TEPA can vary from about 1:1 to
about 5:1.
[0134] Succinate esters are formed by the condensation reaction
between alkenyl succinic anhydrides and alcohols or polyols. Molar
ratios can vary depending on the alcohol or polyol used. For
example, the condensation product of an alkenyl succinic anhydride
and pentaerythritol is a useful dispersant.
[0135] Succinate ester amides are formed by condensation reaction
between alkenyl succinic anhydrides and alkanol amines. For
example, suitable alkanol amines include ethoxylated
polyalkylpolyamines, propoxylated polyalkylpolyamines and
polyalkenylpolyamines such as polyethylene polyamines. One example
is propoxylated hexamethylenediamine.
[0136] The molecular weight of the alkenyl succinic anhydrides will
typically range between 800 and 2,500. The above products can be
post-reacted with various reagents such as sulfur, oxygen,
formaldehyde, carboxylic acids such as oleic acid, and boron
compounds such as borate esters or highly borated dispersants. The
dispersants can be borated with from about 0.1 to about 5 moles of
boron per mole of dispersant reaction product.
[0137] Mannich base dispersants are made from the reaction of
alkylphenols, formaldehyde, and amines. Process aids and catalysts,
such as oleic acid and sulfonic acids, can also be part of the
reaction mixture. Molecular weights of the alkylphenols range from
800 to 2,500.
[0138] Typical high molecular weight aliphatic acid modified
Mannich condensation products can be prepared from high molecular
weight alkyl-substituted hydroxyaromatics or HN(R).sub.2
group-containing reactants.
[0139] Examples of high molecular weight alkyl-substituted
hydroxyaromatic compounds are polypropylphenol, polybutylphenol,
and other polyalkylphenols. These polyalkylphenols can be obtained
by the alkylation, in the presence of an alkylating catalyst, such
as BF.sub.3, of phenol with high molecular weight polypropylene,
polybutylene, and other polyalkylene compounds to give alkyl
substituents on the benzene ring of phenol having an average
600-100,000 molecular weight.
[0140] Examples of HN(R).sub.2 group-containing reactants are
alkylene polyamines, principally polyethylene polyamines. Other
representative organic compounds containing at least one
HN(R).sub.2 group suitable for use in the preparation of Mannich
condensation products are well known and include the mono- and
di-amino alkanes and their substituted analogs, e.g., ethylamine
and diethanol amine; aromatic diamines, e.g., phenylene diamine,
diamino naphthalenes; heterocyclic amines, e.g., morpholine,
pyrrole, pyrrolidine, imidazole, imidazolidine, and piperidine;
melamine and their substituted analogs.
[0141] Examples of alkylene polyamine reactants include
ethylenediamine, diethylene triamine, triethylene tetraamine,
tetraethylene pentaamine, pentaethylene hexamine, hexaethylene
heptaamine, heptaethylene octaamine, octaethylene nonaamine,
nonaethylene decamine, and decaethylene undecamine and mixture of
such amines having nitrogen contents corresponding to the alkylene
polyamines, in the formula H.sub.2N-(Z-NH--).sub.nH, mentioned
before, Z is a divalent ethylene and n is 1 to 10 of the foregoing
formula. Corresponding propylene polyamines such as propylene
diamine and di-, tri-, tetra-, pentapropylene tri-, tetra-, penta-
and hexaamines are also suitable reactants. The alkylene polyamines
are usually obtained by the reaction of ammonia and dihalo alkanes,
such as dichloro alkanes. Thus the alkylene polyamines obtained
from the reaction of 2 to 11 moles of ammonia with 1 to 10 moles of
dichloroalkanes having 2 to 6 carbon atoms and the chlo
[0142] Aldehyde reactants useful in the preparation of the high
molecular products useful in this disclosure include the aliphatic
aldehydes such as formaldehyde (also as paraformaldehyde and
formalin), acetaldehyde and aldol (.beta.-hydroxybutyraldehyde).
Formaldehyde or a formaldehyde-yielding reactant is preferred.
[0143] Preferred dispersants include borated and non-borated
succinimides, including those derivatives from mono-succinimides,
bis-succinimides, and/or mixtures of mono- and bis-succinimides,
wherein the hydrocarbyl succinimide is derived from a
hydrocarbylene group such as polyisobutylene having a Mn of from
about 500 to about 5000 or a mixture of such hydrocarbylene groups.
Other preferred dispersants include succinic acid-esters and
amides, alkylphenol-polyamine-coupled Mannich adducts, their capped
derivatives, and other related components. Such additives may be
used in an amount of about 0.1 to 20 wt %, preferably about 0.1 to
8 wt %, more preferably about 1 to 6 wt % (on an as-received basis)
based on the weight of the total lubricant.
Pour Point Depressants
[0144] Conventional pour point depressants (also known as lube oil
flow improvers) may also be present. Pour point depressant may be
added to lower the minimum temperature at which the fluid will flow
or can be poured. Examples of suitable pour point depressants
include alkylated naphthalenes polymethacrylates, polyacrylates,
polyarylamides, condensation products of haloparaffin waxes and
aromatic compounds, vinyl carboxylate polymers, and terpolymers of
dialkylfumarates, vinyl esters of fatty acids and allyl vinyl
ethers. Such additives may be used in amount of about 0.0 to 0.5 wt
%, preferably about 0 to 0.3 wt %, more preferably about 0.001 to
0.1 wt % on an as-received basis.
Corrosion Inhibitors/Metal Deactivators
[0145] Corrosion inhibitors are used to reduce the degradation of
metallic parts that are in contact with the lubricating oil
composition. Suitable corrosion inhibitors include aryl thiazines,
alkyl substituted dimercapto thiodiazoles thiadiazoles and mixtures
thereof. Such additives may be used in an amount of about 0.01 to 5
wt %, preferably about 0.01 to 1.5 wt %, more preferably about 0.01
to 0.2 wt %, still more preferably about 0.01 to 0.1 wt % (on an
as-received basis) based on the total weight of the lubricating oil
composition.
Seal Compatibility Additives
[0146] Seal compatibility agents help to swell elastomeric seals by
causing a chemical reaction in the fluid or physical change in the
elastomer. Suitable seal compatibility agents for lubricating oils
include organic phosphates, aromatic esters, aromatic hydrocarbons,
esters (butylbenzyl phthalate, for example), and polybutenyl
succinic anhydride and sulfolane-type seal swell agents such as
Lubrizol 730-type seal swell additives. Such additives may be used
in an amount of about 0.01 to 3 wt %, preferably about 0.01 to 2 wt
% on an as-received basis.
Anti-Foam Agents
[0147] Anti-foam agents may advantageously be added to lubricant
compositions. These agents retard the formation of stable foams.
Silicones and organic polymers are typical anti-foam agents. For
example, polysiloxanes, such as silicon oil or polydimethyl
siloxane, provide antifoam properties. Anti-foam agents are
commercially available and may be used in conventional minor
amounts along with other additives such as demulsifiers; usually
the amount of these additives combined is less than 1 percent,
preferably 0.001 to about 0.5 wt %, more preferably about 0.001 to
about 0.2 wt %, still more preferably about 0.0001 to 0.15 wt % (on
an as-received basis) based on the total weight of the lubricating
oil composition.
Inhibitors and Antirust Additives
[0148] Anti-rust additives (or corrosion inhibitors) are additives
that protect lubricated metal surfaces against chemical attack by
water or other contaminants. One type of anti-rust additive is a
polar compound that wets the metal surface preferentially,
protecting it with a film of oil. Another type of anti-rust
additive absorbs water by incorporating it in a water-in-oil
emulsion so that only the oil touches the surface. Yet another type
of anti-rust additive chemically adheres to the metal to produce a
non-reactive surface. Examples of suitable additives include zinc
dithiophosphates, metal phenolates, basic metal sulfonates, fatty
acids and amines. Such additives may be used in an amount of about
0.01 to 5 wt %, preferably about 0.01 to 1.5 wt % on an as-received
basis.
[0149] In addition to the ZDDP anti-wear additives which are
essential components of the present disclosure, other anti-wear
additives can be present, including zinc dithiocarbamates,
molybdenum dialkyldithiophosphates, molybdenum dithiocarbamates,
other organo molybdenum-nitrogen complexes, sulfurized olefins,
etc.
[0150] The term "organo molybdenum-nitrogen complexes" embraces the
organo molybdenum-nitrogen complexes described in U.S. Pat. No.
4,889,647. The complexes are reaction products of a fatty oil,
dithanolamine and a molybdenum source. Specific chemical structures
have not been assigned to the complexes. U.S. Pat. No. 4,889,647
reports an infrared spectrum for a typical reaction product of that
disclosure; the spectrum identifies an ester carbonyl band at 1740
cm.sup.-1 and an amide carbonyl band at 1620 cm.sup.-1. The fatty
oils are glyceryl esters of higher fatty acids containing at least
12 carbon atoms up to 22 carbon atoms or more. The molybdenum
source is an oxygen-containing compound such as ammonium
molybdates, molybdenum oxides and mixtures.
[0151] Other organo molybdenum complexes which can be used in the
present disclosure are tri-nuclear molybdenum-sulfur compounds
described in EP 1 040 115 and WO 99/31113 and the molybdenum
complexes described in U.S. Pat. No. 4,978,464.
[0152] In the above detailed description, the specific embodiments
of this disclosure have been described in connection with its
preferred embodiments. However, to the extent that the above
description is specific to a particular embodiment or a particular
use of this disclosure, this is intended to be illustrative only
and merely provides a concise description of the exemplary
embodiments. Accordingly, the disclosure is not limited to the
specific embodiments described above, but rather, the disclosure
includes all alternatives, modifications, and equivalents falling
within the true scope of the appended claims. Various modifications
and variations of this disclosure will be obvious to a worker
skilled in the art and it is to be understood that such
modifications and variations are to be included within the purview
of this application and the spirit and scope of the claims.
EXAMPLES
[0153] Typical base stock mixtures have a logarithmic viscosity
relationship as well as a logarithmic volatility relationship. It
is known that higher base stock viscosity correlates to lower
volatility, lower vapor pressure and higher flash point. In
accordance with this disclosure, it is advantageous to have base
stock mixtures that deviate from this traditional relationship such
that low volatility/high flash point are achieved with low
viscosity. In particular, the base stocks of this disclosure that
exhibit properties such as high flash point and low viscosity are
extremely advantageous for improved fuel economy, minimizing power
loss due to friction and ensuring safe operation of high power
engines operating at high temperature.
Example 1
[0154] Comparative examples illustrating traditional flash point
and viscosity relationships are shown in FIGS. 1 and 2. As shown in
FIGS. 1 and 2, base stock mixtures containing poly alphaolefin
(PAO)/poly alkyleneglycol (PAG) and poly alphaolefin
(PAO)/tripropylene glycol dipelargonate exhibit no unexpected
increase in flash point at low viscosity. Flash point was
determined by ASTM D-93. Kinematic viscosity (KV.sub.100) was
determined by ASTM D-445.
[0155] FIG. 1 shows flash point and viscosity data for base stock
mixtures containing poly alphaolefin (PAO)/poly alkyleneglycol
(PAG). The mixtures exhibit traditional flash point and viscosity
relationships, that is a higher base stock viscosity correlates to
lower volatility, lower vapor pressure and higher flash point.
[0156] FIG. 2 shows flash point and viscosity data for base stock
mixtures containing poly alphaolefin (PAO)/tripropylene glycol
dipelargonate. The mixtures exhibit traditional flash point and
viscosity relationships, that is a higher base stock viscosity
correlates to lower volatility, lower vapor pressure and higher
flash point.
Example 2
[0157] As shown in FIG. 3, base stock mixtures containing poly
alphaolefin (PAO)/2-ethylhexyl palmitate exhibit traditional flash
point relationships. However, the viscosity relationship of the
mixture containing 60% ester is lower than expected. Flash point
was determined by ASTM D-93. Kinematic viscosity (KV.sub.100) was
determined by ASTM D-445.
[0158] FIG. 3 shows flash point and viscosity data for base stock
mixtures containing poly alphaolefin (PAO)/2-ethylhexyl palmitate.
The mixtures exhibit traditional flash point relationships, but an
unexpected viscosity relationship.
Example 3
[0159] As shown in FIGS. 4 and 5, when linear monoesters (fully
esterified) are mixed with mid to high-hydroxyesters (66.7 and 50%
esterified), the viscosity relationship remains consistent with a
traditional logarithmic correlation, however the flash point is
elevated unexpectedly. Flash point was determined by ASTM D-93.
Kinematic viscosity (KV.sub.100) was determined by ASTM D-445.
[0160] FIG. 4 shows flash point and viscosity data for base stock
mixtures containing octyl octanoate (fully esterified linear
monoester)/neopentyl glycol sesquipelargonate (50% esterified). The
mixtures exhibit traditional viscosity relationships, but an
unexpected flash point relationship. In these blends, it is
preferred to have 0 to 20% neopentyl glycol sesquipelargonate (50%
esterified).
[0161] FIG. 5 shows flash point and viscosity data for base stock
mixtures containing octyl octanoate (fully esterified linear
monoester)/trimethylolpropane pelargonate (66.7% esterified). The
mixtures exhibit traditional viscosity relationships, but an
unexpected flash point relationship. In these blends, it is
preferred to have 0 to 15% trimethylolpropane pelargonate (66.7%
esterified).
Example 4
[0162] As shown in FIGS. 6 and 7, when branched esters (fully
esterified) are mixed together or with mid-to high-hydroxyesters
(66.7% and 50% esterified), flash point unexpectedly increases and
viscosity unexpectedly decreases resulting in low volatility, low
viscosity systems. Flash point was determined by ASTM D-93.
Kinematic viscosity (KV.sub.100) was determined by ASTM D-445.
[0163] FIG. 6 shows flash point and viscosity data for base stock
mixtures containing trimethyl-1-hexyl trimethylhexanoate (fully
esterified)/2-ethylhexyl palmitate (fully esterified). The mixtures
exhibit an unexpected viscosity relationship and flash point
relationship. In these blends, it is preferred to have 0 to 40%
2-ethylhexyl palmitate (fully esterified)
[0164] FIG. 7 shows flash point and viscosity data for base stock
mixtures containing trimethyl-1-hexyl trimethylhexanoate (fully
esterified)/trimethylolpropane pelargonate (66.7% esterified). The
mixtures exhibit an unexpected viscosity relationship and flash
point relationship. In these blends, it is preferred to have 0 to
20% trimethylolpropane pelargonate (66.7% esterified).
[0165] FIG. 8 shows flash point and viscosity data for base stock
mixtures containing trimethyl-1-hexyl trimethylhexanoate (fully
esterified)/neopentyl glycol sesquipelargonate (50% esterified).
The mixtures exhibit an unexpected viscosity relationship and flash
point relationship. In these blends, it is preferred to have 0 to
40% neopentyl glycol sesquipelargonate (50% esterified).
Example 5
[0166] In addition to imparting increased flash point and constant
or diminished viscosity, the use of partially hydroxylated esters
leads to an improvement in the thermal conductivity of the
formulation. For example, trimethylolpropane pelargonate exhibits
significantly higher thermal conductivity than other base oils of
comparable viscosity. The combination of increased flash point and
improved thermal conductivity at constant or decreased viscosity is
very desirable from both a safety as well as a performance
standpoint.
[0167] FIG. 9 shows thermal conductivity data for
trimethylolpropane pelargonate, alkyl naphthalene, poly alphaolefin
(PAO), and poly alkyleneglycol (PAG) base stocks. Thermal
conductivity was determined by ASTM D-7896. Flash point was
determined by ASTM D-93. Kinematic viscosity (KV.sub.100) was
determined by ASTM D-445.
Additional Embodiments
[0168] Embodiment 1. A composition comprising: [0169] at least one
first ester that is partially esterified; and [0170] at least one
second ester that is fully esterified; [0171] wherein the
composition has a flash point from 125.degree. C. to 225.degree. C.
as determined by ASTM D-93; [0172] wherein the composition has a
kinematic viscosity (KV.sub.100) from 1 to 5 at 100.degree. C. as
determined by ASTM D-445; and [0173] wherein the at least one first
ester and the at least one second ester are present in an amount
such that, as the flash point of said composition is increased, the
kinematic viscosity (KV.sub.100) of said composition is decreased
or maintained.
[0174] Embodiment 2. The composition of embodiment 1 wherein the at
least one first ester is present in an amount from 1 to 40 weight
percent, based on the total weight of the composition; and the at
least one second ester is present in an amount from 60 to 99 weight
percent, based on the total weight of the composition.
[0175] Embodiment 3. The composition of embodiment 1 wherein the at
least one first ester has a high hydroxyl content, and wherein the
hydroxyl content is from 0.1 to 1 free hydroxyl group per
molecule.
[0176] Embodiment 4. The composition of embodiment 1 wherein the at
least one first ester comprises at least one partially esterified
polyol ester of a monocarboxylic acid.
[0177] Embodiment 5. The composition of embodiment 1 wherein the at
least one first ester is derived by reacting one or more polyhydric
alcohols with one or more monocarboxylic acids; wherein the one or
more polyhydric alcohols comprise neopentyl glycol, trimethylol
ethane, 2-methyl-2-propyl-1,3-propanediol, trimethylol propane,
pentaerythritol, dipentaerythritol, tripentaerythritol, or
tetrapentaerythritol; and wherein the one or more monocarboxylic
acids comprise acetic acid, propionic acid, butanoic acid,
pentanoic acid, hexanoic acid, heptanoic acid, octanoic acid,
nonanoic acid, decanoic acid, undecanoic acid, dodecanoic acid,
tridecanoic acid, tetradecanoic acid, pentadecanoic acid,
3-methylbutanoic acid, 2-methylbutanoic acid, 2-ethylhexanoic acid,
2,4-dimethylpentanoic acid, 3,3,5-trimethylhexanoic acid, benzoic
acid, caprylic acid, capric acid, lauric acid, myristic acid,
palmitic acid, stearic acid, arachic acid, behenic acid, or oleic
acid.
[0178] Embodiment 6. The composition of embodiment 1 wherein the at
least one first ester comprises partially esterified neopentyl
glycol sesquipelargonate, partially esterified trimethylolpropane
pelargonate, partially esterified neopentyl glycol ester, partially
esterified 2-methyl-2-propyl-1,3-propanediol ester, partially
esterified trimethylol ethane ester, partially esterified
trimethylol propane ester, partially esterified pentaerythritol
ester, partially esterified dipentaerythritol ester, partially
esterified tripentaerythrit
[0179] Embodiment 7. The composition of embodiment 1 wherein the at
least one second ester is derived by reacting one or more
monoalkanoic acids with one or more monoalkanols; where the one or
more monoalkanoic acids comprise butanoic acid, pentanoic acid,
hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid,
decanoic acid, undeanoic acid, dodecanoic acid, tridecanoic acid,
tetradecanoic acid, pentadecanoic acid, hexadecanoic acid, and
their isomers; and wherein the one or more monalkanols comprise
butyl alcohol, pentyl alcohol, hexyl alcohol, heptyl alcohol, octyl
alcohol, nonyl alcohol, decyl alcohol, dodecyl alcohol, tridecyl
alcohol, tetradecyl alcohol, pentadecyl alcohol, hexadecyl alcohol,
and their isomers.
[0180] Embodiment 8. The composition of embodiment 1 wherein the at
least one second ester is derived by reacting one or more dibasic
acids with one or more monoalkanols; wherein the one or more
dibasic acids comprise phthalic acid, succinic acid, sebacic acid,
fumaric acid, adipic acid, azelaic acid, linoleic acid dimer,
malonic acid, alkyl malonic acid, or alkenyl malonic acid; and
wherein the one or more monoalkanols comprise pentyl alcohol, hexyl
alcohol, heptyl alcohol, octyl alcohol, nonyl alcohol, decyl
alcohol, dodecyl alcohol, tridecyl alcohol, tetradecyl alcohol,
pentadecyl alcohol, hexadecyl alcohol, and their isomers.
[0181] Embodiment 9. The composition of embodiment 1 wherein the at
least one second ester comprises dibutyl adipate, di(2-ethylhexyl)
sebacate, di-n-hexyl fumarate, dioctyl sebacate, diisooctyl
azelate, diisodecyl azelate, dioctyl phthalate, didecyl phthalate,
dieicosyl sebacate, tripropylene glycol dipelargonate, 2-ethylhexyl
palmitate, octyl octanoate, or trimethyl-l-hexyl
trimethylhexanoate.
[0182] Embodiment 10. The composition of embodiment 1 which has a
flash point from 130.degree. C. to 220.degree. C. as determined by
ASTM D-93, a viscosity (Kv.sub.100o) from 1 to 4 at 100.degree. C.
as determined by ASTM D-445, and a Noack volatility of no greater
than 50 percent as determined by ASTM D-5800.
[0183] Embodiment 11. The composition of embodiment 1 which is a
lubricating oil base stock.
[0184] Embodiment 12. A lubricating oil comprising a lubricating
oil base stock as a major component, and one or more lubricating
oil additives as a minor component; wherein the lubricating oil
base stock comprises: [0185] at least one first ester that is
partially esterified; and [0186] at least one second ester that is
fully esterified; [0187] wherein the lubricating oil has a flash
point from 125.degree. C. to 225.degree. C. as determined by ASTM
D-93; [0188] wherein the lubricating oil has a kinematic viscosity
(KV.sub.100) from 1 to 5 at 100.degree. C. as determined by ASTM
D-445; and [0189] wherein the at least one first ester and the at
least one second ester are present in an amount such that, as the
flash point of said lubricating oil is increased, the kinematic
viscosity (KV.sub.100) of said lubricating oil is decreased or
maintained.
[0190] Embodiment 13. The lubricating oil of embodiment 12 wherein
the at least one first ester is present in an amount from 1 to 40
weight percent, based on the total weight of the lubricating oil;
and the at least one second ester is present in an amount from 60
to 99 weight percent, based on the total weight of the lubricating
oil.
[0191] Embodiment 14. The lubricating oil of embodiment 12 wherein
the at least one first ester has a high hydroxyl content, and
wherein the hydroxyl content is from 0.1 to 1 free hydroxyl group
per molecule.
[0192] Embodiment 15. The lubricating oil of embodiment 12 wherein
the at least one first ester comprises at least one partially
esterified polyol ester of a monocarboxylic acid.
[0193] Embodiment 16. The lubricating oil of embodiment 12 wherein
the at least one first ester is derived by reacting one or more
polyhydric alcohols with one or more monocarboxylic acids; wherein
the one or more polyhydric alcohols comprise neopentyl glycol,
trimethylol ethane, 2-methyl-2-propyl-1,3-propanediol, trimethylol
propane, pentaerythritol, dipentaerythritol, tripentaerythritol, or
tetrapentaerythritol; and wherein the one or more monocarboxylic
acids comprise acetic acid, propionic acid, butanoic acid,
pentanoic acid, hexanoic acid, heptanoic acid, octanoic acid,
nonanoic acid, decanoic acid, undecanoic acid, dodecanoic acid,
tridecanoic acid, tetradecanoic acid, pentadecanoic acid,
3-methylbutanoic acid, 2-methylbutanoic acid, 2-ethylhexanoic acid,
2,4-dimethylpentanoic acid, 3,3,5-trimethylhexanoic acid, benzoic
acid, caprylic acid, capric acid, lauric acid, myristic acid,
palmitic acid, stearic acid, arachic acid, behenic acid, or oleic
acid.
[0194] Embodiment 17. The lubricating oil of embodiment 12 wherein
the at least one first ester comprises partially esterified
neopentyl glycol sesquipelargonate, partially esterified
trimethylolpropane pelargonate, partially esterified neopentyl
glycol ester, partially esterified
2-methyl-2-propyl-1,3-propanediol ester, partially esterified
trimethylol ethane ester, partially esterified trimethylol propane
ester, partially esterified pentaerythritol ester, partially
esterified dipentaerythritol ester, partially esterified
tripentaerythritol ester, or partially esterified
tetrapentaerythritol ester.
[0195] Embodiment 18. The lubricating oil of embodiment 12 wherein
the at least one second ester is derived by reacting one or more
monoalkanoic acids with one or more monoalkanols; where the one or
more monoalkanoic acids comprise butanoic acid, pentanoic acid,
hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid,
decanoic acid, undeanoic acid, dodecanoic acid, tridecanoic acid,
tetradecanoic acid, pentadecanoic acid, hexadecanoic acid, and
their isomers; and wherein the one or more monalkanols comprise
butyl alcohol, pentyl alcohol, hexyl alcohol, heptyl alcohol, octyl
alcohol, nonyl alcohol, decyl alcohol, dodecyl alcohol, tridecyl
alcohol, tetradecyl alcohol, pentadecyl alcohol, hexadecyl alcohol,
and their isomers.
[0196] Embodiment 19. The lubricating oil of embodiment 12 wherein
the at least one second ester is derived by reacting one or more
dibasic acids with one or more monoalkanols; wherein the one or
more dibasic acids comprise phthalic acid, succinic acid, sebacic
acid, fumaric acid, adipic acid, azelaic acid, linoleic acid dimer,
malonic acid, alkyl malonic acid, or alkenyl malonic acid; and
wherein the one or more monoalkanols comprise pentyl alcohol, hexyl
alcohol, heptyl alcohol, octyl alcohol, nonyl alcohol, decyl
alcohol, dodecyl alcohol, tridecyl alcohol, tetradecyl alcohol,
pentadecyl alcohol, hexadecyl alcohol, and their isomers.
[0197] Embodiment 20. The lubricating oil of embodiment 12 wherein
the at least one second ester comprises dibutyl adipate,
di(2-ethylhexyl) sebacate, di-n-hexyl fumarate, dioctyl sebacate,
diisooctyl azelate, diisodecyl azelate, dioctyl phthalate, didecyl
phthalate, dieicosyl sebacate, tripropylene glycol dipelargonate,
2-ethylhexyl palmitate, octyl octanoate, or trimethyl-l-hexyl
trimethylhexanoate.
[0198] Embodiment 21. The lubricating oil of embodiment 12 which
has a flash point from 130.degree. C. to 220.degree. C. as
determined by ASTM D-93, a viscosity (Kv.sub.100) from 1 to 4 at
100.degree. C. as determined by ASTM D-445, and a Noack volatility
of no greater than 50 percent as determined by ASTM D-5800.
[0199] Embodiment 22. The lubricating oil of embodiment 12 wherein
the lubricating oil base stock comprises a Group I, II, III, IV or
V base oil stock.
[0200] Embodiment 23. The lubricating oil of embodiment 12 wherein
the lubricating oil additives comprise one or more of an antiwear
additive, viscosity improver, antioxidant, detergent, dispersant,
pour point depressant, corrosion inhibitor, metal deactivator, seal
compatibility additive, anti-foam agent, inhibitor, friction
modifi
[0201] Embodiment 24. The lubricating oil of embodiment 12 which is
a passenger vehicle engine oil (PVEO) or a commercial vehicle
engine oil (CVEO).
[0202] Embodiment 25. A method for increasing flash point, while
decreasing or maintaining viscosity, of a lubricating oil in an
engine or other mechanical component lubricated with the
lubricating oil by using as the lubricating oil a formulated oil
comprising a lubricating oil base stock as a major component, and
one or more lubricating oil additives as a minor component; wherein
the lubricating oil base stock comprises: [0203] at least one first
ester that is partially esterified; and [0204] at least one second
ester that is fully esterified; [0205] wherein the lubricating oil
has a flash point from 125.degree. C. to 225.degree. C. as
determined by ASTM D-93; [0206] wherein the lubricating oil has a
kinematic viscosity (KV.sub.100) from 1 to 5 at 100.degree. C. as
determined by ASTM D-445; and [0207] wherein the at least one first
ester and the at least one second ester are present in an amount
such that, as the flash point of said lubricating oil is increased,
the kinematic viscosity (KV.sub.100) of said lubricating oil is
decreased or maintained.
[0208] Embodiment 26. The method of embodiment 25 wherein the at
least one first ester is present in an amount from 1 to 40 weight
percent, based on the total weight of the lubricating oil; and the
at least one second ester is present in an amount from 60 to 99
weight percent, based on the total weight of the lubricating
oil.
[0209] Embodiment 27. The method of embodiment 25 wherein the at
least one first ester has a high hydroxyl content, and wherein the
hydroxyl content is from 0.1 to 1 free hydroxyl group per
molecule.
[0210] Embodiment 28. The method of embodiment 25 wherein the at
least one first ester comprises at least one partially esterified
polyol ester of a monocarboxylic acid.
[0211] Embodiment 29. The method of embodiment 25 wherein the at
least one first ester is derived by reacting one or more polyhydric
alcohols with one or more monocarboxylic acids; wherein the one or
more polyhydric alcohols comprise neopentyl glycol, trimethylol
ethane, 2-methyl-2-propyl-1,3-propanediol, trimethylol propane,
pentaerythritol, dipentaerythritol, tripentaerythritol, or
tetrapentaerythritol; and wherein the one or more monocarboxylic
acids comprise acetic acid, propionic acid, butanoic acid,
pentanoic acid, hexanoic acid, heptanoic acid, octanoic acid,
nonanoic acid, decanoic acid, undecanoic acid, dodecanoic acid,
tridecanoic acid, tetradecanoic acid, pentadecanoic acid,
3-methylbutanoic acid, 2-methylbutanoic acid, 2-ethylhexanoic acid,
2,4-dimethylpentanoic acid, 3,3,5-trimethylhexanoic acid, benzoic
acid, caprylic acid, capric acid, lauric acid, myristic acid,
palmitic acid, stearic acid, arachic acid, behenic acid, or oleic
acid.
[0212] Embodiment 30. The method of embodiment 25 wherein the at
least one first ester comprises partially esterified neopentyl
glycol sesquipelargonate, partially esterified trimethylolpropane
pelargonate, partially esterified neopentyl glycol ester, partially
esterified 2-methyl-2-propyl-1,3-propanediol ester, partially
esterified trimethylol ethane ester, partially esterified
trimethylol propane ester, partially esterified pentaerythritol
ester, partially esterified dipentaerythritol ester, partially
esterified tripentaerythritol ester, or partially esterified
tetrapentaerythritol ester.
[0213] Embodiment 31. The method of embodiment 25 wherein the at
least one second ester is derived by reacting one or more
monoalkanoic acids with one or more monoalkanols; where the one or
more monoalkanoic acids comprise butanoic acid, pentanoic acid,
hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid,
decanoic acid, undeanoic acid, dodecanoic acid, tridecanoic acid,
tetradecanoic acid, pentadecanoic acid, hexadecanoic acid, and
their isomers; and wherein the one or more monalkanols comprise
butyl alcohol, pentyl alcohol, hexyl alcohol, heptyl alcohol, octyl
alcohol, nonyl alcohol, decyl alcohol, dodecyl alcohol, tridecyl
alcohol, tetradecyl alcohol, pentadecyl alcohol, hexadecyl alcohol,
and their isomers.
[0214] Embodiment 32. The method of embodiment 25 wherein the at
least one second ester is derived by reacting one or more dibasic
acids with one or more monoalkanols; wherein the one or more
dibasic acids comprise phthalic acid, succinic acid, sebacic acid,
fumaric acid, adipic acid, azelaic acid, linoleic acid dimer,
malonic acid, alkyl malonic acid, or alkenyl malonic acid; and
wherein the one or more monoalkanols comprise pentyl alcohol, hexyl
alcohol, heptyl alcohol, octyl alcohol, nonyl alcohol, decyl
alcohol, dodecyl alcohol, tridecyl alcohol, tetradecyl alcohol,
pentadecyl alcohol, hexadecyl alcohol, and their isomers.
[0215] Embodiment 33. The method of embodiment 25 wherein the at
least one second ester comprises dibutyl adipate, di(2-ethylhexyl)
sebacate, di-n-hexyl fumarate, dioctyl sebacate, diisooctyl
azelate, diisodecyl azelate, dioctyl phthalate, didecyl phthalate,
dieicosyl sebacate, tripropylene glycol dipelargonate, 2-ethylhexyl
palmitate, octyl octanoate, or trimethyl-l-hexyl
trimethylhexanoate.
[0216] Embodiment 34. The method of embodiment 25 wherein the
lubricating oil has a flash point from 130.degree. C. to
220.degree. C. as determined by ASTM D-93, a viscosity (Kv.sub.100)
from 1 to 4 at 100.degree. C. as determined by ASTM D-445, and a
Noack volatility of no greater than 50 percent as determined by
ASTM D-5800.
[0217] Embodiment 35. The method of embodiment 25 wherein the
lubricating oil base stock comprises a Group I, II, III, IV or V
base oil stock.
[0218] Embodiment 36. The method of embodiment 25 wherein the
lubricating oil additives comprise one or more of an antiwear
additive, viscosity improver, antioxidant, detergent, dispersant,
pour point depressant, corrosion inhibitor, metal deactivator, seal
compatibility additive, anti-foam agent, inhibitor, friction
modifier, and anti-rust additive.
[0219] Embodiment 37. A method for increasing flash point and
thermal conductivity, while decreasing or maintaining viscosity, of
a lubricating oil in an engine or other mechanical component
lubricated with the lubricating oil by using as the lubricating oil
a formulated oil comprising a lubricating oil base stock as a major
component, and one or more lubricating oil additives as a minor
component; wherein the lubricating oil base stock comprises: [0220]
at least one partially esterified ester; [0221] wherein the
lubricating oil has a flash point from 125.degree. C. to
225.degree. C. as determined by ASTM D-93; [0222] wherein the
lubricating oil has a kinematic viscosity (KV.sub.100) from 1 to 5
at 100.degree. C. as determined by ASTM D-445; and [0223] wherein
the lubricating oil has a thermal conductivity from 0.1 W/m.K to
0.2 W/m.K as determined by ASTM D-2717; [0224] wherein the at least
one partially esterified ester is present in an amount such that,
as the flash point and thermal conductivity of said lubricating oil
are increased, the kinematic viscosity (KV.sub.100) of said
lubricating oil is decreased or maintained.
[0225] Embodiment 38. The method of embodiment 37 wherein the at
least one partially esterified ester is present in an amount from 1
to 40 weight percent, based on the total weight of the lubricating
oil.
[0226] Embodiment 39. The method of embodiment 37 wherein the at
least one partially esterified ester has a high hydroxyl content,
and wherein the hydroxyl content is from 0.1 to 1 free hydroxyl
group per molecule.
[0227] Embodiment 40. The method of embodiment 37 wherein the at
least one partially esterified ester comprises at least one
partially esterified polyol ester of a monocarboxylic acid.
[0228] Embodiment 41. The method of embodiment 37 wherein the at
least one first ester is derived by reacting one or more polyhydric
alcohols with one or more monocarboxylic acids; wherein the one or
more polyhydric alcohols comprise neopentyl glycol, trimethylol
ethane, 2-methyl-2-propyl-1,3-propanediol, trimethylol propane,
pentaerythritol, dipentaerythritol, tripentaerythritol, or
tetrapentaerythritol; and wherein the one or more monocarboxylic
acids comprise acetic acid, propionic acid, butanoic acid,
pentanoic acid, hexanoic acid, heptanoic acid, octanoic acid,
nonanoic acid, decanoic acid, undecanoic acid, dodecanoic acid,
tridecanoic acid, tetradecanoic acid, pentadecanoic acid,
3-methylbutanoic acid, 2-methylbutanoic acid, 2-ethylhexanoic acid,
2,4-dimethylpentanoic acid, 3,3,5-trimethylhexanoic acid, benzoic
acid, caprylic acid, capric acid, lauric acid, myristic acid,
palmitic acid, stearic acid, arachic acid, behenic acid, or oleic
acid.
[0229] Embodiment 42. The method of embodiment 37 wherein the at
least one first ester comprises partially esterified neopentyl
glycol sesquipelargonate, partially esterified trimethylolpropane
pelargonate, partially esterified neopentyl glycol ester, partially
esterified 2-methyl-2-propyl-1,3-propanediol ester, partially
esterified trimethylol ethane ester, partially esterified
trimethylol propane ester, partially esterified pentaerythritol
ester, partially esterified dipentaerythritol ester, partially
esterified tripentaerythritol ester, or partially esterified
tetrapentaerythritol ester.
[0230] Embodiment 43. The method of embodiment 37 wherein the
lubricating oil has a flash point from 130.degree. C. to
220.degree. C. as determined by ASTM D-93, a viscosity (Kv.sub.100)
from 1 to 4 at 100.degree. C. as determined by ASTM D-445, and a
Noack volatility of no greater than 50 percent as determined by
ASTM D-5800.
[0231] Embodiment 44. The method of embodiment 37 wherein the
lubricating oil base stock comprises a Group I, II, III, IV or V
base oil stock.
[0232] Embodiment 45. The method of embodiment 37 wherein the
lubricating oil further comprises one or more of an antiwear
additive, viscosity improver, antioxidant, detergent, dispersant,
pour point depressant, corrosion inhibitor, metal deactivator, seal
compatibility additive, anti-foam agent, inhibitor, friction
modifier, and anti-rust additive.
[0233] All patents and patent applications, test procedures (such
as ASTM methods, UL methods, and the like), and other documents
cited herein are fully incorporated by reference to the extent such
disclosure is not inconsistent with this disclosure and for all
jurisdictions in which such incorporation is permitted.
[0234] When numerical lower limits and numerical upper limits are
listed herein, ranges from any lower limit to any upper limit are
contemplated. While the illustrative embodiments of the disclosure
have been described with particularity, it will be understood that
various other modifications will be apparent to and can be readily
made by those skilled in the art without departing from the spirit
and scope of the disclosure. Accordingly, it is not intended that
the scope of the claims appended hereto be limited to the examples
and descriptions set forth herein but rather that the claims be
construed as encompassing all the features of patentable novelty
which reside in the present disclosure, including all features
which would be treated as equivalents thereof by those skilled in
the art to which the disclosure pertains.
[0235] The present disclosure has been described above with
reference to numerous embodiments and specific examples. Many
variations will suggest themselves to those skilled in this art in
light of the above detailed description. All such obvious
variations are within the full intended scope of the appended
claims.
* * * * *
References