U.S. patent application number 11/932975 was filed with the patent office on 2008-03-06 for engine oil compositions and preparation thereof.
This patent application is currently assigned to Chevron U.S.A. Inc.. Invention is credited to Matthew Ansari, Nancy J. Bertrand, Max I. Chang, Peter Kleijwegt, Stephen J. Miller, John M. Rosenbaum.
Application Number | 20080053868 11/932975 |
Document ID | / |
Family ID | 39150013 |
Filed Date | 2008-03-06 |
United States Patent
Application |
20080053868 |
Kind Code |
A1 |
Kleijwegt; Peter ; et
al. |
March 6, 2008 |
ENGINE OIL COMPOSITIONS AND PREPARATION THEREOF
Abstract
A multi-grade engine oil composition meeting required
specifications of manufacturers is provided. In one embodiment, the
engine oil composition contains a sufficient amount of a Pour Point
Reducing Blend Component for the engine oil to have cold crank
simulator viscosity at -20.degree. C. of less than have a cold
crank simulator viscosity at -20.degree. C. of less than 9000 cP
and a mini rotary viscometer (MRV) viscosity at -20.degree. C. of
less than 60,000 cP. The Pour Point Reducing Blend Component is
selected from 1) an isomerized Fischer-Tropsch derived bottoms
product; 2) a bottoms product prepared from an isomerized highly
waxy mineral oil, or 3) an isomerized oil having a kinematic
viscosity at 100.degree. C. of at least about 8 mm.sup.2/s made
from polyethylene plastic.
Inventors: |
Kleijwegt; Peter;
(Heinenoord, NL) ; Miller; Stephen J.; (San
Francisco, CA) ; Rosenbaum; John M.; (Richmond,
CA) ; Bertrand; Nancy J.; (Lafayette, CA) ;
Ansari; Matthew; (San Ramon, CA) ; Chang; Max I.;
(Choa Chu Kang, SG) |
Correspondence
Address: |
CHEVRON CORPORATION
P.O. BOX 6006
SAN RAMON
CA
94583-0806
US
|
Assignee: |
Chevron U.S.A. Inc.
|
Family ID: |
39150013 |
Appl. No.: |
11/932975 |
Filed: |
October 31, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11159282 |
Jun 22, 2005 |
|
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11932975 |
Oct 31, 2007 |
|
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60975713 |
Sep 27, 2007 |
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Current U.S.
Class: |
208/18 |
Current CPC
Class: |
C10N 2020/011 20200501;
C10M 2205/163 20130101; C10N 2040/253 20200501; C10N 2020/071
20200501; C10N 2020/04 20130101; C10M 2205/14 20130101; C10M 143/00
20130101; C10M 2207/401 20130101; C10M 2205/17 20130101; C10M
2205/173 20130101; C10M 2203/1006 20130101; C10N 2040/25 20130101;
C10N 2040/255 20200501; C10N 2030/42 20200501; C10M 2205/143
20130101; C10N 2030/02 20130101; C10N 2030/08 20130101; C10M
2205/16 20130101; C10N 2020/02 20130101; C10M 2205/0285 20130101;
C10M 2207/2805 20130101; C10N 2020/015 20200501 |
Class at
Publication: |
208/018 |
International
Class: |
C10M 109/00 20060101
C10M109/00 |
Claims
1. An engine oil composition meeting SAE J300 requirements
comprising: (a) a base oil selected from a natural oil, a synthetic
oil, and mixtures thereof, (b) 0.05 to 40 wt %. of at least an
additive selected from the group of metal detergents, dispersants,
wear inhibitors, anti-oxidants, friction modifiers, viscosity
modifiers, corrosion inhibitors, seal swelling agents, metal
deactivators, anti-foamants, and mixtures thereof; (c) a sufficient
amount of a Pour Point Reducing Blend Component for the engine oil
composition to have a cold crank simulator at -20.degree. C. of
less than 9000 cP and a kinematic, viscosity at 100.degree. C. as
specified according to SAE J330; wherein the Pour Point Reducing
Blend Component has an average degree of branching within a range
of 6.5 to 10 alkyl branches per 100 carbon atoms.
2. The composition of claim 1, wherein the Pour Point Reducing
Blend Component has an average degree of branching within a range
of 6.5 to 8 alkyl branches per 100 carbon atoms.
3. The composition of claim 1, wherein the sufficient amount of
Pour Point Reducing Blend Component ranges from 2 to 30 wt. % of
the engine oil composition.
4. The composition of claim 3, wherein the sufficient amount of
Pour Point Reducing Blend Component ranges from 3 to 20 wt. %.
5. The composition of claim 4, wherein the sufficient amount of
Pour Point Reducing Blend Component ranges from 4 to 15 wt. %.
6. The composition of claim 1, wherein the base oil is selected
from the group of a mineral oil, a vegetable oil, an oligomer of an
alphaolefin, an ester, an oil derived from a Fischer-Tropsch
process, and mixtures thereof.
7. The composition of claim 5, wherein the base oil is one of a
poly-alpha-olefin, an ester base oil, or mixtures thereof.
8. The composition of claim 1, wherein the Pour Point Reducing
Blend Component is selected from an isomerized Fischer-Tropsch
derived bottoms product, a bottoms product prepared from an
isomerized highly waxy mineral oil, an isomerized oil having a
kinematic viscosity at 100.degree. C. of at least about 8
mm.sup.2/s made from polyethylene plastic and mixtures thereof.
9. The composition of claim 1, wherein the Pour Point Reducing
Blend Component has an average molecular weight between 600-100
Daltons.
10. The composition of claim 1, wherein the Pour Point Reducing
Blend Component has a kinematic viscosity at 100.degree. C. of 8-22
(mm.sup.2/s) with a 10% point of the boiling range of the Pour
Point Reducing Blend Component falling between about
850-1050.degree. F.
11. The composition of claim 1, wherein the Pour Point Reducing
Blend Component has a pour point of -8 to -12.degree. C.
12. The composition of claim 1, wherein the composition comprises
less than 15 wt. % of a viscosity index modifier.
13. The composition of claim 1, wherein the composition comprises
less than 10 wt. % of a viscosity index modifier.
14. The composition of claim 12, wherein the composition comprises
less than 5 wt. % of a viscosity index modifier.
15. The composition of claim 1, wherein the composition contains at
least 10% less viscosity index modifier compared to a comparable
engine oil composition without the sufficient amount of Pour Point
Reducing Blend Component.
16. The composition of claim 1, wherein the composition results in
at least 10% less deposit under the Panel Coker Test compared to a
comparable composition without the sufficient amount of Pour Point
Reducing Blend Component.
17. The composition of claim 15, wherein the composition results in
at least 25 % less deposit under the Panel Coker Test compared to a
comparable composition without the sufficient amount of Pour Point
Reducing Blend Component.
18. The composition of claim 16, wherein the composition results in
at least 50% less deposit under the Panel Coker Test compared to a
comparable composition without the sufficient amount of Pour Point
Reducing Blend Component.
19. The composition of claim 1, wherein the composition is for use
in a gasoline engines, diesel engines, motorcycles, trucks, motor
homes, maintenance equipment, heavy equipment, street rods,
military applications, and personal watercraft motors.
20. A method to reduce the use of a viscosity index modifier in
engine oil compositions meeting SAE J300 requirements, the method
comprising adding to a base oil typically used for preparing engine
oil compositions a sufficient amount of a Pour Point Reducing Blend
Component having an average degree of branching within a range of
6.5 to 10 alkyl branches per 100 carbon atoms for the engine oil to
have a cold crank simulator viscosity at -20.degree. C. have a cold
crank simulator viscosity at -20.degree. C. of less than 9000 cP
and a mini rotary viscometer (MRV) viscosity at -20.degree. C. of
less tan 60,000 cP.
21. The method of claim 19, wherein the sufficient amount of the
Pour Point Reducing Blend Component ranges from 2 to 30 wt. % of
the engine oil composition.
22. The method of claim 19, wherein the base oil typically used for
preparing engine oil compositions is selected from the group of a
mineral oil a vegetable oil, an oligomer of an alphaolefin, an
ester, an oil derived from a Fischer-Tropsch process, and mixtures
thereof.
23. A method for preparing engine oil compositions meeting SAE J300
requirements, the method comprising blending into a mixture of: (a)
40 to 90 wt. % a base oil; (b) 0.05 to 40 wt. %. of at least an
additive selected from the group of metal detergents, dispersants,
wear inhibitors, anti-oxidants, friction modifiers, viscosity
modifiers, corrosion inhibitors, seal swelling agents, metal
deactivators, anti-foamants, and mixtures thereof, and (c) a
sufficient amount of a Pour Point Reducing Blend Component having
an average degree of branching within a range of 6.5 to 10 alkyl
branches per 100 carbon atoms for the engine oil to have cold crank
simulator viscosity at -20.degree. C. of less than have a cold
crank simulator viscosity at -20.degree. C. of less than 9000 cP
and a mini rotary viscometer (MRV) viscosity at -20.degree. C. of
less than 60,000 cP.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part of U.S. patent
application Ser. No. 11/159,282 filed Jun. 22, 2005. This
application claims priority to and benefits under 35 USC 119 of
Provisional Application U.S. Ser. No. 60/975,713 fled Sep. 27,
2007. This application claims priority to and benefits from all of
the foregoing, the disclosures of which are incorporated herein by
reference.
TECHNICAL FIELD
[0002] The invention relates generally to engine oil compositions,
and more specifically to multi-grade engine oil compositions having
a reduced level of viscosity modifiers.
BACKGROUND
[0003] Engine oil formulations have become increasingly complex
with the stringent demands made by the developing automotive
industry, e.g., lubricants which can be utilized over a wide range
of operating conditions including temperature variations. At the
same time, the formulated lubricants must also possess an ability
to impart oxidative stability, detergency, dispersancy, wear
inhibition and corrosion inhibition during its use as well as
during storage. Furthermore, the automotive industry desires
lubricants which will stay in their viscosity grades for a
substantial length of time again under both use and storage
conditions. By "multi-grade lubricants" is meant lubricants which
meet a 0.degree. F. viscosity specification and a 210.degree. F.
viscosity specification, according to SAE standard (Society of
Automotive Engineer) SAE J300.
[0004] Engine oil compositions in the prior art typically employ a
Group I, II, III, a synthetic PAO (for poly .alpha.-olefin) or
mixtures thereof as a base oil stock. The groups are broad
categories of base stocks developed by the American Petroleum
Institute (API). Viscosity index improvers (or viscosity modifiers)
are needed in engine oil compositions to meet standard viscosity
requirements of multi-grade engine oils. Viscosity index improvers
are expensive and may shear in service. Additionally, low content
of viscosity index improvers is a key to meeting European engine
deposit tests.
[0005] Recent reforming processes have formed a new class of oil,
i.e., Fischer Tropsch base oil (FTBO), wherein the oil, fraction,
or feed originates from or is produced at some stage by a
Fischer-Tropsch process, as disclosed in a number of patent
publications and applications, i.e., US 2006/0289337,
US2006/0201851, US2006/006721, US2006/0016724,US2006/10076267,
US2006/020185, US2006/013210, US2005/0241990, US2005/0077208,
US2005/0139513, US2005/0139514, US2005/0133409, US2005/0133407,
US2005/0261147, US2005/0261146, US2005/0261145, US2004/0159582,
US7018525, US708317133, U.S. application Ser. No. 11/400,570, Ser.
No. 11/535,165 and Ser. No. 11/6139,36, which are incorporated
herein by reference. In these references, a Fischer Tropsch base
oil is produced from a process in which the feed is a waxy feed
recovered from a Fischer-Tropsch synthesis. In the process, the
bottoms material collected from the hydroisomerized vacuum column
comprises a mixture of high boiling hydrocarbons, with an average
molecular weight of about 600 to 1100 Daltons (g/mol) and has a
generally high kinematic viscosity of about 8 mm.sup.2/s (cSt) to
about 22 mm.sup.2/s at 100.degree. C.
[0006] There is a need for improved engine oil compositions having
reduced levels of viscosity modifiers particularly engine oil
compositions employing alternative hydrocarbon sources such as
Fischer Tropsch base oils. There is also a need for improved engine
oil compositions meeting all the requirements of SAF J300 over a
wide low-high temperature range with reduced levels of viscosity
modifiers--with lowered deposit forming tendency at high
temperatures.
SUMMARY OF THE INVENTION
[0007] In one embodiment, there is provided an engine oil
composition meeting SAE J300 requirements comprising (a) a base
oil; (b) 0.05 to 40 wt. %. of an additive package comprising at
least one of a metal detergent, a dispersant, a wear inhibitor, an
anti-oxidant, a friction modifier a viscosity modifier, a corrosion
inhibitor, a seal swelling agent, a metal deactivator, an
anti-foamant, and mixtures thereof; and (e) a sufficient amount of
a Pour Point Reducing Blend Component for the engine oil to have a
cold crank simulator viscosity at -20.degree. C. of less than 9,000
mPas (cP) and a kinematic viscosity at 100.degree. C. as specified
according to SAE J300 for the applicable grade. The Pour Point
Reducing Blend Component has an average degree of branching within
a range of 6.5 to 10 alkyl branches per 100 carbon atoms. In one
embodiment, this sufficient amount of Pour Point Reducing Blend
Component is between 2 to 30 wt. % of the engine oil
composition
[0008] In another aspect, there is provided a method to reduce the
use of viscosity modifiers in engine oil compositions meeting SAE
J300 requirements, the method includes the step of adding to a base
oil typically used for preparing engine oil compositions a
sufficient amount of a Point Reducing Blend Component having an
average degree of branching within a range of 6.5 to 10 alkyl
branches per 100 carbon atoms for the engine oil to have a cold
crank simulator viscosity at -20.degree. C. of less than 9000 cP
and a kinematic viscosity at 100.degree. C. as specified according
to SAE J300 for the applicable grade.
[0009] In yet another aspect of preparing an engine oil composition
meeting SAE J330 requirements having a reduced level of viscosity
modifiers, the method comprising the steps of blending: (a) 40 to
90 wt. % a base oil; (b) 0.05 to 40 wt. %. of an additive package
comprising at least one of a metal detergent, a dispersant, a wear
inhibitor, an anti-oxidant, a friction modifier, a viscosity
modifier, a corrosion inhibitory a seal swelling agent, a metal
deactivator, an anti-foamant, and mixtures thereof; with (c) a
sufficient amount of a Pour Point Reducing Blend Component having
an average degree of branching within a range of 6.5 to 10 alkyl
branches per 100 carbon atoms for the engine oil to have a cold
crank simulator viscosity at -20.degree. C. of less than 9000 cP
and a kinematic viscosity at 100.degree. C. as specified according
to SAE J300 for the applicable grade.
DETAILED DESCRIPTION
[0010] The following terms will be used throughout the
specification and will have the following meanings unless otherwise
indicated.
[0011] As used herein, "multi-grade engine oil " may be used
interchangeably with "engine oil", referring to an engine oil
containing a viscosity modifier for it to have
viscosity/temperature characteristics which fall with the limits of
two different SAE numbers in SAE J300 (revised ay May 2004). For
example, 10W40 is a multi-grade engine oil with the "10W" meaning
that this oil can be pumped by the engine as well as a single-grade
SAE 10 oil can he pumped at the specified low temperature, and the
second number, 40, meaning that the viscosity of this multi-grade
oil at 100.degree. C. (212.degree. F.) operating temperature
corresponds to the viscosity of a single-grade 40 oil at same
temperature.
[0012] "Fischer-Tropsch derived" means that the product, fraction,
or feed originates from or is produced at some stage by a
Fischer-Tropsch process. As used herein, "Fischer-Tropsch base oil"
may be used interchangeably with "FT base oil," "FTBO," "GTL base
oil" (GTL; gas-to-liquid), or "Fischer-Tropsch derived base
oil."
[0013] As used herein, "Pour Point Reducing Blend Component" refers
to an isomerized waxy product with relatively high molecular
weights and a specified degree of alkyl branching in the molecule,
such that it reduces the pour point of lubricating base oil blends
containing it. Examples of a pour point reducing blend component
are disclosed in U.S. Pat. Nos. 6,150,577 and 7,053,254, and Patent
Publication No. US 2005-0247600 A1. A Pour Point Reducing Blend
Component can be: 1) an isomerized Fischer-Tropsch derived bottoms
product. 2) a bottoms product prepared from an isomerized highly
waxy mineral oil, or 3) an isomerized oil having a kinematic
viscosity at 100.degree. C. of at least about 8 mm.sup.2/s made
from polyethylene plastic.
[0014] "Pour point" is a measurement of the temperature at which a
sample of base oil will begin to flow under certain carefully
controlled conditions, which can be determined, as described in
ASTM D 5950-02.
[0015] "Kinematic viscosity" is a measurement in cSt (mm.sup.2/s)
of the resistance to flow of a fluid under gravity, determined by
ASTM D 445 (e2005). "cSt" means centistokes.
[0016] Cold-cranking simulator apparent viscosity (CCS VIS) is a
measurement in millipascal seconds, mPa.s (or centipoise (cP)) to
measure the viscometric properties of lubricating base oils under
low temperature and low shear. CCS VIS can be determined by ASTM D
5293-04.
[0017] Apparent viscosity as determined by MRV (mini rotary
viscometer). ASTM D4684-07, with yield stress reported in pascals
(Pa) and viscosity reported in mPa.s or centipoise (cP).
[0018] Oxidator BN measures the response of a lubricating, oil in a
simulated application). High values, or long times to adsorb one
liter of oxygen, indicate good stability. Oxidator BN can be
measured via a Dornte-type, oxygen absorption apparatus (R. W.
Dornte "Oxidation of White Oils," Industrial and Engineering
Chemistry, Vol. 28, page 26, 1936), under 1 atmosphere of pure
oxygen at 340.degree. F., time to absorb 1000 ml of O.sub.2 by 100
g. of oil is reported. In the Oxidator BN test, 0.8 ml of catalyst
is used per 100 grams of oil. The catalyst is a mixture of soluble
metal-naphthenates simulating the average metal analysis of used
crankcase oil. The additive package is 80 millimoles of zinc
bispolypropylenephenyldithiophosphate per 100 grams of oil.
[0019] Molecular characterizations can be performed by methods
known in the art, including Field Ionization Mass Spectroscopy
(FIMS) and n-d-M analysis (ASTM D 32308-95 (Re-approved 2005) with
normalization). In FIMS, the base oil is characterized as alkanes
and molecules with different numbers of unsaturations. The
molecules with different numbers of unsaturations may be comprised
of cycloparaffins, olefins, and aromatics. If aromatics are present
in significant amount, they would be identified as 4-unsaturations.
When olefins are present in significant amounts, they would be
identified as 1-unsaturations. The total of the 1-unsaturations,
2-unsaturations, 3-unsaturations, 4-unsaturations, 5-unsaturations,
and 6-unsaturations from the FIMS analysis, minus the wt % olefins
by proton NMR, and minus the wt % aromatics by HPLC-UV is the total
weight percent of molecules with cycloparaffinic functionality. If
the aromatics content was not measured, it was assumed to be less
than 0.1 wt % and not included in the calculation for total weight
percent of molecules with cycloparaffinic functionality. The total
weight percent of molecules with cycloparaffinic functionality is
the sum of the weight percent of molecules with monocycloparaffinic
functionality and the weight percent of molecules with
multicycloparaffinic functionality.
[0020] "Viscosity index" (VI) is an empirical, unit-less number
indicating the effect of temperature change on the kinematic
viscosity of the oil. The higher the VI of an oil the lower its
tendency to change viscosity with temperature. Viscosity index is
measured according to ASTM D 2270-04.
[0021] High temperature high shear rate viscosity (HTHS) is a
measure of a fluid's resistance to flow under conditions resembling
highly-loaded journal bearings in fired internal combustion
engines, typically 1 million s.sup.-1 at 150.degree. C. HTHS
viscosity can be measured by ASTM D 5481-04.
[0022] Brookfield viscosity is used to determine the internal
fluid-friction of a lubricant during cold temperature operation,
which can be measured by ASTM D 2983-04.
[0023] Shear stability is a measure of the amount of viscosity an
oil may lose during operation. The shear stability of an oil can be
measured by using both ASTM test methods D445-06 and D5275 (R
1998). Shear stability index is a measure of a VI improver's
contribution to an oil's percentage kinematic viscosity loss. Shear
Stability Index (SSI) can be determined using the Kurt Orbahn
method (ASTM 6278 R2002).
[0024] "Bosch injector test 90 cycles" test, as used herein, is a
test that measures the percent viscosity loss at 100.degree. C. of
the engine oil composition when evaluated using the diesel injector
apparatus as defined in CEC-L-14-A-79.
[0025] DaimlerChrysler "OM 441LA" engine test is a test developed
by the Coordinating European Council (CEC) as the CEC L-52-T-97
test. The test is part of the ACEA lubricant specifications for
heavy duty diesel engines E14, E5, E6 and E7, which measures piston
deposit formation, liner wear, bore polish, sludge formation, oil
consumption and ring sticking.
[0026] The Volkswagen or "VW TDI" test is an important measure of
engine lubrication oil quality (piston deposits) under severe
conditions, specifically for an in-line passenger car diesel
engine.
[0027] The "Panel Coker 1Test" measures the deposit forming
tendency of oil at high temperatures. The test apparatus consists
of a rectangular stainless steel reservoir, inclined 25 degrees
from horizontal. The reservoir is fitted with a machined steel
piece fitting integrally into the top of the reservoir, and framing
a 95 mm by 45 mn aluminum panel. The test panel is held in place by
a hearing element, which is fitted with thermocouple probes to
control the temperature of the aluminum test panel. A horizontal
shaft, fitted with a series of tines, is positioned above the oil.
During rotating of the shaft, the tines sweep through the test
lubricant and lubricant droplets are thrown onto the heated
aluminum test panel. In the Panel Coker test, the apparatus is
assembled forming a closed system and the test panel is heated to a
temperature in the range of 260-325.degree. C. The shaft is rotated
at 1000 rpm and the test lubricant is splashed: onto the heated,
weighted test panel. The splashing heated cycle is continued for
normally 2-6 hr, from the time the splasher is started. At the end
of the specified time period, the heat is removed, the splasher is
stopped, and the test panel is allowed to cool. The test panel is
washed, reweighed and the amount of deposit is determined. Weight
gain of the aluminum test panel (as carbonaceous/heavily oxidized
material) is an indication of the lubricant's performance under
high temperature conditions.
[0028] The term "overbased" as used herein refers to alkali metal
and alkaline earth metal alkylaryl sulfonates in which the ratio of
the number of equivalents of an alkali metal or alkaline earth
metal to the number of equivalents of the organic moiety is greater
than 1. Low overbased refers to alkali metal or alkaline earth
metal alkylaryl sulfonates having a Total Base Number (TBN) greater
than 1 and less than 20, medium overbased refers to alkali metal or
alkaline earth metal alkylaryl sulfonates having a TBN greater than
20 and less than 200. High overbased refers to alkali metal or
alkaline earth metal alkylaryl sulfonates having a TBN greater than
200,
[0029] The term "Total Base Number" or "TBN" as used herein refers
to the amount of base equivalent to milligrams of KOH in one gram
of sample. Thus, higher TBN numbers reflect more alkaline products,
and therefore a greater alkalinity. TBN was determined using ASTM D
2896 test.
[0030] The boiling range distribution of base oil, by wt %, is
determined by simulated distillation (SIMDIS) according to ASTM D
6352-04, "Boiling Range Distribution of Petroleum Distillates in
Boiling Range from 174 to 700.degree. C. Gas Chromatography."
[0031] Extent of branching in the Pour Point Reducing Blend
Component product refers to the number of alkyl branches in
carbons. Branching and branching position can be determined using
carbon-13 (.sup.13C) NMR according to the following nine-step
process. 1) Identify the CH branch centers and the CH.sub.3 branch
termination points using the DEPT Pulse sequence (Doddrell, D. T.;
D. T. Pegg; M. R. Bendall, Journal of Magnetic Resonance 1982, 48,
323ff.). 2) Verify the absence of carbons initiating multiple
branches (quaternary carbons) using the APT pulse sequence (Patt,
S. L.; J. N. Shoolery, Journal of Magnetic Resonance 1982, 46,
55ff.). 3) Assign the various branch carbon resonances to specific
branch positions and lengths using tabulated and calculated values
known in the art (Lindeman. L. P., Journal of Qualitative
Analytical Chemistry 43, 1971 1245ff; Netzel, D. A., et.al., Fuel,
60, 1981, 307ff). 4) Estimate relative branching density at
different carbon positions by comparing the integrated intensity of
the specific carbon of the methyl/alkyl group to the intensity of a
single carbon (which is equal to total integral/number of carbons
per molecule in the mixture). For the 2-methyl branch, where both
the terminal and the branch methyl occur at the same resonance
position, the intensity is divided by two before estimating the
branching density. If the 4-methyl branch fraction is calculated
and tabulated, its contribution to the 4+methyls is subtracted to
avoid double counting. 5) Calculate the average carbon number. The
average carbon number is determined by dividing the molecular
weight of the sample by 14 (the formula weight of CH.sub.2). 6) The
number of branches per molecule is the sum of the branches found in
step 4, 7) The number of alkyl branches per 100 carbon atoms is
calculated from the number of branches per molecule (step 6) times
100/average carbon number. 8) Estimate Branching Index (BI) by
.sup.1H NMR Analysis, which is presented as percentage of methyl
hydrogen (chemical shift range 0.6-1.05 ppm) among total hydrogen
as estimated by NMR in the liquid hydrocarbon composition. 9)
Estimate Branching proximity (BP) by .sup.13C NMR, which is
presented as percentage of recurring methylene carbons--which are
four or more carbons away from the end group or a branch
(represented by a NMR signal at 29.9 ppm) among total carbons as
estimated by NMR in the liquid hydrocarbon composition. The
measurements can be performed using ant Fourier Transform NMR
spectrometer, e.g., one having a magnet of 7.0 T or greater. After
verification by Mass Spectrometry, UV or an NMR survey that
aromatic carbons are absent, the spectral width for the .sup.13C
NMR studies can be limited to the saturated carbon region, 0-80 ppm
vs. TMS (tetramethylsilane). Solutions of 25-50 wt. % in
chloroform-d1 are excited by 30 degrees pulses followed by a 1.3
sec acquisition time. In order to minimize non-uniform intension
data, the broadband proton inverse-gated decoupling is used during
a 6 sec delay prior to the excitation pulse and on during
acquisition. Samples are doped with 0.03 to 0.05 M Cr (acac).sub.3
(tris (acetylacetonato)-chromium (III)) as a relaxation agent to
ensure fill intensities are observed. The DEPT and APT sequences
can be carried out according to literature descriptions with minor
deviations described in the Varian or Bruker operating manuals.
DEPT is Distortionless Enhancement by Polarization Transfer. The
DEPT 45 sequence gives a signal all carbons bonded to protons. DEPT
90 shows CH carbons only. DEPT 135 shows CH and CH.sub.3 up
CH.sub.2 180 degrees out of phase (down). APT is attached proton
test, known in the art. It allows all carbons to be seen, but if CH
and CH.sub.3 are up, then quaternaries and CH.sub.2 are down. The
branching properties of the sample can be determined by .sup.13C
NMR using the assumption in the calculations that the entire sample
was iso-paraffinic. The naphthenes content may be measured using
Field Ionization Mass Spectroscopy (FIMS).
[0032] In one embodiment, the engine oil composition comprises a
sufficient amount of at least a Pour Point Reducing Blend Component
and at least an additive in a matrix of base oil or base oil
blends.
[0033] Base Oil Component: The engine oil composition contains a
major amount of at least a base oil (or blends thereof) in an
amount ranging from 40 to 90 wt. % in one embodiment, from 50 to 80
wt. % in a second embodiment, and from 60 to 75 wt. % in a third
embodiment. Base oils suitable for use in formulating engine oil
compositions are selected from any of the synthetic or natural oils
or mixtures thereof e.g., the base oils of Groups I-VI as specified
in the American Petroleum Institute (API) Base Oil
Interchangeability Guidelines (API 1509) and ATIEL Code of Practice
for Developing Engine Oils meeting the Requirements of the ACEA Oil
Sequences.
[0034] Examples of natural oils include animal oils and vegetable
oils (e.g., castor oil, lard oil) and mineral lubricating oils such
as liquid petroleum oils and solvent treated or acid-treated
mineral lubricating oils of the paraffinic, naphthenic or mixed
paraffinicnaphthenic types. Oils derived from coal or shale are
also suitable. Further, oils derived from a Fischer-Tropsch process
are also suitable.
[0035] Examplary base oils include polymerized and interpolymerized
olefins. (e.g., polybutylenes, polypropylenes, propylene
isobutylene copolymers, etc.); poly(1-hexenes), poly-(1-octenes),
poly(1-decenes), etc. and mixtures thereof; alkylbenzenes (e.g.,
dodecylbenzenes, tetradecylbenzenes, dinonylbenzenes,
di-(2-ethylhexyl)benzenes, etc.); polyphenyls (e.g., biphenyls,
terphenyls, alkylated polyphenyls, etc.); alkylated diphenyl ethers
and the derivatives, analogs and homologs thereof, and the
like.
[0036] In one embodiment, the base oil comprises at least a
synthetic lubricating oil selected from alkylene oxide polymers and
interpolymers and derivatives thereof, where the terminal hydroxyl
groups have been modified by a process such as esterification or
etherification. Examples of these synthetic oils include
polyoxyalkylene polymers prepared by polymerization of ethylene
oxide or propylene oxide, and the alkyl and aryl ethers of
polyoxyalkylene polymers (e.g., methyl-polyiso-propylene glycol
ether having a molecular weight of 1000 Daltons or diphenyl ether
of poly-ethylene glycol having a molecular weight of 1000 to 1500
Daltons); and mono- and polycarboxylic esters thereof (e.g., acetic
acid esters, mixed C.sub.3-C.sub.8 fatty acid esters, ad C.sub.13
Oxo acid diester of tetracetylene glycol).
[0037] In another embodiment, the base oil comprises at least a
synthetic lubricating oil selected from the esters of dicarboxylic
acids (e.g., phthalic acid. succinic acid, alkyl succinic acids and
alkenyl succinic acids, maleic acid, azelaic acid, suberic acid,
sebasic acid, fumaric acid, adipic acid, linoleic acid dimer,
malonic acid, alkylmalonic acids, alkenyl malonic acids) with a
variety of alcohols (e.g., butyl alcohol, hexyl alcohol, dodecyl
alcohol, 2-ethlylhexyl alcohol, ethylene glycol, diethylene glycol
monoether, propylene glycol). Specific examples of such esters
includes dibutyl adipate, di(2-ethylhexyl) sebacate, di-n-hexyl
fumarate, dioctyl sebacate, diisooctyl azelate, diisodecyl azelate,
dioctyl phthalate, didecyl phthalate, dieicosyl sebacate, the
2-ethylhexyl diester of linoleic acid dimer, and the complex ester
formed by reacting one mole of sebacic acid with two moles of
tetraethylene glycol and two moles of 2-ethylhexanoic acid and the
like.
[0038] Esters useful as synthetic oils also include those made from
C.sub.5 to C.sub.12 monocarboxylic acids and polyols and polyol
esters such as neopentyl glycol, trimethylolpropane,
pentaerythritol, dipentaerythritol and tripentaethritol. Esters are
sometimes also useful as additives to improve certain other
properties of a finished lubricant.
[0039] In one embodiment, the base oil is a poly-alpha-olefin
(PAO). Typically, the poly-alpha-olefins are derived from monomers
having from about 4 to about 30, or from about 4 to about 20, or
from about 6 to about 16 carbon atoms. Examples of useful PAOs
include those derived from octene, decene, mixtures thereof, and
the like, e.g., 4 mm.sup.2/s at 100.degree. C. PAOs, 5 mm.sup.2/s
at 100.degree. C. PAOs, 7 mm.sup.2/s at 100.degree. C. PAOs, 8
mm.sup.2/s at 100.degree. C. PAOs, etc., and mixtures thereof. In
another embodiment, the base oil comprises mixtures of mineral oils
with poly-alpha-olefins. In yet another embodiment, the base oil
comprises a polyinternal olefin (PIO--a group VI base oil) or
mixtures thereof.
[0040] Unrefined, refined and rerefined oils, either natural or
synthetic (as well as mixtures of two or more of any of these) of
the type disclosed hereinabove can be used as the base oil.
Unrefined oils are those obtained directly from a natural or
synthetic source without further purification treatment.
[0041] In one embodiment, the engine oil composition employs a base
oil that comprises at least one of the base oils described above.
In another embodiment, the composition consists essentially of at
least one of the base oils (or blends thereof) described above.
Various engine oils can be fabricated from the base oil, including
but not limited, for example, 0W-30, 5W-30, 0W40, and 5W-40 oils.
In one embodiment, the base oil has a viscosity 100.degree. C. of 2
to 15 mm.sup.2/s. In another embodiment, the base oil has a
viscosity of 5 to 10 cSt at 100.degree. C. In a third embodiment, a
viscosity of less than 9 cSt at 100.degree. C.
[0042] Pour Point Reducing Blend Component: The engine oil
composition comprises a sufficient amount of at least a Pour Point
Reducing Blend Component to allow the level of viscosity index
improvers to be reduced significantly, while still meeting cold
temperature targets, e.g., for the engine oil composition to have
lowered cold cranking simulator viscosity (CCS). In one embodiment,
this sufficient amount of Pour Point Reducing Blend Component is
between 2-30 wt. % for the engine oil composition to have a CCS of
less than 9,000 mm.sup.2/s in the range of -15 to -40.degree. C. In
another embodiment, this sufficient amount of Pour Point Reducing
Blend Component is between 2-30 wt. % for the engine oil
composition to have a cold crank simulator viscosity at -20.degree.
C. of less than 9000 cP and a kinematic viscosity at 100.degree. C.
as specified according to SAE J300 for the applicable grade. In yet
another embodiment, the sufficient amount of Pour Point Reducing
Blend Component is sufficient for the engine oil composition to
have a mini rotary viscometer (MRV) viscosity at -20.degree. C. of
less than 60,000 cP. In yet another embodiment, the sufficient
amount is between 2-25 wt. %. In a third embodiment, this
sufficient amount is between 3 to 20 wt. %. In a fourth embodiment,
this amount is less than 15 wt. %. In a fifth embodiment, the
amount of Pour Point Reducing Blend Component is greater than 4 wt.
%.
[0043] In one embodiment, the Pour Point Reducing Blend Component
is an isomerized Fischer-Tropsch derived vacuum distillation
bottoms product, which is a high boiling syncrude fraction which
has been isomerized under controlled conditions to give a specified
degree of alkyl branching in the molecule. Syncrude prepared from
the Fischer-Tropsch process comprises a mixture of various solid,
liquid, and gaseous hydrocarbons. When the Fischer-Tropsch waxes
are converted into Fischer-Tropsch base oils by various processes,
such as by hydroprocessing and distillation, the base oils produced
fall into different narrow-cut viscosity ranges. The bottoms that
remains after recovering the lubricating base oil cuts from the
vacuum column is generally unsuitable for use as a lubricating base
oil itself and is usually recycled to a hydrocracking unit for
conversion to lower molecular weight products.
[0044] In one embodiment, the Pour Point Reducing Blend Component
is an isomerized Fischer-Tropsch derived vacuum distillation
bottoms product having an average molecular weight between 600 and
1100 Dalton and an average degree of branching in the molecules
between 6.5 and 10 alkyl branches per 100 carbon atoms. Generally,
the higher molecular weight hydrocarbons are more effective as the
Pour Point Reducing Blend Component than the lower molecular weight
hydrocarbons. In one embodiment, a higher cut point in a vacuum
distillation unit which results in a higher boiling bottoms
material is used to prepare the Pour Point Reducing Blend
Component. The higher cut point also has the advantage of resulting
in a higher yield of the distillate base oil fractions. In one
embodiment, the Pour Point Reducing Blend Component is an
isomerized Fischer-Tropsch derived vacuum distillation bottoms
product having a pour point that is at least 3.degree. C., higher
than the pour point of the distillate base oil it is blended
with.
[0045] In one embodiment, the 10 percent point of the boiling range
of the Pour Point Reducing Blend Component that is a vacuum
distillation bottoms product is between about 850.degree.
F.-1050.degree. F. (454-565.degree. C.). In another embodiment, the
Pour Point Reducing Blend Component is derived from either
Fischer-Tropsch or petroleum products, having a boiling range above
950.degree. F. (510.degree. C.), and contains at least 50 percent
by weight of paraffins. In yet another embodiment the Pour Point
Reducing Blend Component has a boiling range above 1050.degree. F.
(565.degree. C.)
[0046] In another embodiment, the Pour Point Reducing Blend
Component is an isomerized petroleum derived base oil containing
material having a boiling range above about 1050.degree. F. In one
embodiment, the isomerized bottoms material is solvent dewaxed
prior to being used as a Pour Point Reducing Blend Component. The
waxy product further separated during solvent dewaxing from the
Pour Point Reducing Blend Component were found to display excellent
improved pour point depressing properties compared to the oily
product recovered after the solvent dewaxing.
[0047] In one embodiment, the Pour Point Reducing Blend Component
has an average degree of branching in the molecules within the
range of from 6.5 to 10 alkyl branches per 100 carbon atoms. In
another embodiment, the Pour Point Reducing Blend Component has an
average degree of branching within a range of 65 to 8 alkyl
branches per 100 carbon atoms. In another embodiment, the Pour
Point Reducing Blend Component has an average molecular weight
between 600-1100 Daltons. In a third embodiment between 700-1000
Daltons. In one embodiment, the Pour Point Reducing Blend Component
has a kinematic viscosity at 110.degree. C. of 8-30 mm.sup.2/s,
with the 10% point of the boiling range of the bottoms falling
between about 850-1050.degree. F. In yet another embodiment, the
Pour Point Reducing Blend Component has a kinematic viscosity at
100.degree. C. of 15-20 mm.sup.2/s and a pour point of -8 to
12.degree. C.
[0048] In another embodiment, the Pour Point Reducing Blend
Component is an isomerized oil having a kinematic viscosity at
100.degree. C. of at least about 8 mm.sup.2/s made from
polyethylene plastic. In another embodiment, the Pour Point
Reducing Blend Component is made from waste plastic. In yet another
embodiment the Pour Point Reducing Blend Component is made from a
process comprising: pyrolysis of polyethylene plastic, separating
out a heavy fraction, hydrotreating the heavy fraction, catalytic
isomerizing the hydrotreated heavy fractions and collecting the
Pour Point Reducing Blend Component having a kinematic viscosity at
100.degree. C. of at least about 8 mm.sup.2/s. In one embodiment,
the Pour Point Reducing Blend Component derived from polyethylene
plastic has a boiling range above 1050.degree. F. (565.degree. C.),
or even a boiling range above 1200.degree. F. (649.degree. C.).
[0049] In one embodiment and in addition to the Pour Point Reducing
Blend Component, commercially available pour point depressant
additives can be optionally added in art amount from 0.05 to 1 wt.
% to optimize the low temperature fluidity of the composition.
Examples include C.sub.8-C.sub.18 dialkylfumarate vinyl acetate
copolymers, wax naphthalene condensation products, maleic
anhydride-styrene copolymers, polymethacrylates, polyacrylates,
polyacrylamides, condensation products of haloparaffin waxes and
aromatic compounds, vinyl carboxylate polymers, and terpolymers of
dialkylfumarates, vinyl esters of fatty acids, ethylene-vinyl
acetate copolymers, alkyl phenol formaldehyde condensation resins,
alkyl vinyl, ethers, olefin copolymers, and mixtures thereof.
[0050] Additional Components: In one embodiment, the engine oil
further comprises at least an additive selected from the group of
metal detergents, dispersants, wear inhibitors, oxidation
inhibitors, friction modifiers, viscosity modifiers, corrosion
inhibitors, seal swelling agents, metal deactivators, antifoamers,
and mixtures thereof, in a sufficient amount to provide the desired
effects. In one embodiment, this sufficient amount is 0.05 to 40
wt. %. In another embodiment, it is between 1 to 35 wt. %. In a
third embodiment, from 5 to 25 wt. %.
[0051] In one embodiment, the additives are incorporated as an
"additive package." As used herein, the term "additive package"
means any combination of additives listed above for engine oil
compositions. In one embodiment, the additive package is a
commercially available package, added in an amount from about 1.5%
to about 30% by weight of the finished composition. In one
embodiment the additive package is a commercially available
package, e.g., Lubrizol LZ20000 from the Lubrizol Corporation,
OLOA.TM. 55006A, OLOA.TM. 55007, OLOA.TM. 59029 from Chevron
Oronite Company LLC, etc.
[0052] Dispersants are generally used to maintain in suspension
insoluble materials resulting from oxidations during use, thus
preventing sludge flocculation and precipitation or deposition on
engine parts. In one embodiment, the composition comprises 0.3 to
about 15.0 wt. % of at least a dispersant. In a second embodiment,
from 3.0 to about 7.0 wt. % of at least a dispersant. Examples of
dispersants include nitrogen-containing ashless (metal-free)
dispersants. An ashless dispersant generally comprises an oil
soluble polymeric hydrocarbon backbone having functional groups
that are capable of associating with particles to be dispersed.
Other examples of dispersants include, but are not limited to,
amines, alcohols, amides, or ester polar moieties attached to the
polymer backbones via bridging groups.
[0053] In one embodiment, the engine oil composition comprises an
ashless dispersant selected from oil soluble salts, esters,
amino-esters, amides, imides, and oxazolines of long chain
hydrocarbon substituted mono and dicarboxylic acids or their
anhydrides, thiocarboxylate derivatives of long chain hydrocarbons,
long chain aliphatic hydrocarbons having a polyamine attached
directly thereto; and Mannich condensation products formed by
condensing a long chain substituted phenol with formaldehyde and
polyalkylene polyamine. In another embodiment, the composition
comprises at least a carboxylic dispersant. Carboxylic dispersants
arc reaction products of carboxylic acylating agents (acids,
anhydrides, esters, etc.) comprising at least 34 and preferably at
least 54 carbon atoms with nitrogen containing compounds (such as
amines) organic hydroxy, compounds (such as aliphatic compounds
including monohydric and polyhydric alcohols, or aromatic compounds
including phenols and naphthols), and/or basic inorganic materials.
These reaction products include imides, amides, and esters, e.g.,
succinimide dispersants.
[0054] Other suitable ashless dispersants may also include amine
dispersants, which are reaction products of relatively high
molecular weight aliphatic halides and amines, preferably
polyalkylene polyamines. Other examples may further include
"Mannich dispersants," which are reaction products of alkyl phenols
in which the alkyl group contains at least 30 carbon atoms with
aldehydes (especially formaldehyde) and amines (especially
polyalkylene polyamines). In other embodiments, suitable ashless
dispersants may even include post-treated dispersants. which are
obtained by reacting carboxylic, amine or Mannich dispersants with
reagents such as dimercaptothiazoles, urea, thiourea, carbon
disulfilde, aldehydes, ketones, carboxylic acids,
hydrocarbon-substituted succinic anhydrides, nitrile epoxides,
boron compounds and the like. Suitable ashless dispersants may be
polymeric, which are interpolymers of oil-solubilizing monomers
such as decyl methacrylate, vinyl decyl ether and, high molecular
weight olefins with monomers containing polar substitutes.
[0055] In one embodiment, an ethylene carbonate-treated
bissuccinimide derived from a polyisobutylene having a number
average molecular weight of about 2300 Daltons is used as the
ashless dispersant. In yet another embodiment, the engine oil
composition comprises an ethylene-carbonate treated bissuccinimide
dispersant derived from a polyisobutylene succinic anhydride,
wherein the polyisobutylene chain has a number average molecular
weight of about 2300 Daltons ("PIBSA 2300") in an amount of about
6.5 wt. %.
[0056] Viscosity Index Improvers (Modifiers): The viscosity index
of an engine oil base stock can be increased, or improved, by
incorporating therein certain polymeric materials that function as
viscosity modifiers (VM) or viscosity index improvers (VII). The
addition of the Pour Point Reducing Blend Component allows a
reduced amount of viscosity index improver(s) to be used (whether
present individually or in combination), i.e., a reduction of at
least 5% while still allowing the engine oil composition to meet
specified viscometric performance. In one embodiment, the reduction
in viscosity modifier level is at least 10%, (compared to an engine
oil composition without the Pour Point Reducing Blend
Component).
[0057] In one embodiment, the engine oil composition further
comprises a reduced amount of viscosity modifiers in an amount of
0.3 to 25 wt. %. of the final weight of the engine oil. Examples of
viscosity modifiers include polymeric materials having number
average molecular weights of from about 5,000 to about 250,000
Daltons. These viscosity modifiers can optionally be grafted with
grafting materials such as, for example, maleic anhydride, and the
grafted material can be reacted with, for example, amines, amides,
nitrogen-containing hetero cyclic compounds or alcohol, to form
multifunctional viscosity modifiers (dispersant-viscosity
modifiers). In one embodiment, the engine oil composition comprises
about 0.3 to 15 wt. % of an ethylene propylene copolymer viscosity
index modifier.
[0058] Other examples of viscosity modifiers include star polymers
e.g., a star polymer comprising isoprene/styrene/isoprene triblock.
Yet other examples of viscosity modifiers include, poly alkyl
(meth) acrylates of low Brookfield viscosity and high shear
stability, functionalized poly alkyl (meth) acrylates with
dispersant properties of high Brookfield viscosity and high shear
stability, polyisobutylene having a weight average molecular weight
ranging from 700 to 2,500 Daltons and mixtures thereof. In one
embodiment, the first poly alkyl (meth) acrylate having a weight
average molecular weight of about 125,000 to 225,000 Dalton, a
shear stability index (SSI) of 15 or less, a Brookfield viscosity
at -40.degree. C. of between about 200,000 to 600,000 cP. In one
embodiment, the second poly alkyl (meth) acrylate viscosity
modifier has a weight average molecular weight in the range 50,000
to 150,000 Dalton, a shear stability index (SSI) of about 10 or
less, and a Brookfield viscosity at -40.degree. C. of between about
10,000 to 30,000 cP. In yet another embodiment the viscosity
modifier is a graft copolymer comprising a polymer backbone which
has been grafter by reacting the polymer backbone with a reactant
comprising N-p-diphenylamine, 1,2,3,6-tetrahydrophthalimide;
4-anilinophenyl methacrylamide; 4-anilinophenyl maleimide;
4-anilinophenyl itaconamide; an acrylate or methacrylate ester of
4-hydroxydiphenylamine; a reaction product of p-aminodiphenylamine
or p-alkylaminodiphenylamine with glycidyl menthacrylate; a
reaction product of p-aminodiphenylamine with isobutyraldehyde, a
derivative of p-hydroxydiphenylamine; a derivative of
phenothiazine; a vinylogous derivative of diphenylamine.
[0059] Friction Modifiers: In one embodiment, the lubricating oil
composition further comprises a sulfur-containing molybdenum
compound. Certain sulfur-containing organo-molybdenum compounds are
known to modify friction in lubricating oil compositions, while
also offering antioxidant and antiwear credits. Examples of oil
soluble organo-molybdenum compounds include dithiocarbamates,
dithiophosphates, dithiophosphinates, xanthates, thioxanthates
sulfides, and the like, and mixtures thereof. In another
embodiment, the composition employs a molybdenum succinimide
complex as friction modifier in an amount of 0.15 to about 1.5 wt.
%. In a third embodiment, the engine oil comprises at least a
mono-, di- or triester of a tertiary hydroxyl amine and a fatty
acid as a friction modifying fuel economy additive. In another
embodiment, the friction modifier is selected from the group of
succinamic acid, succinimide, and mixtures thereof. In yet another
embodiment, the friction modifier is selected from an aliphatic
fatty amine, an ether amine, an alkoxylated aliphatic fatty amine,
an alkoxylated ether amine, an oil-soluble aliphatic carboxylic
acid, a polyol ester, a fatty acid amide, an imidazoline, tertiary
amine, a hydrocarbyl succinic anhydride or acid reacted with an
ammonia or a primary amine and mixtures thereof.
[0060] Seal swelling agents: Seal fixes are also termed seal
swelling agents or seal pacifiers. They are often employed in
lubricant or additive compositions to insure proper elastomer
sealing, and prevent premature seal failures and leakages. In one
embodiment, the composition further includes at least a seal swell
agent selected from oil-soluble, saturated, aliphatic, or aromatic
hydrocarbon esters such as di-2-ethylhexylphthalate, mineral oils
with aliphatic alcohols such as tridecyl alcohol, triphosphite
ester in combination with a hydrocarbonyl-substituted phenol, and
di-2-ethylhexylsebacate.
[0061] Corrosion inhibitors (Anti-corrosive agents): These
additives are typically added to reduce the degradation of the
metallic parts contained in the engine oil. Examples include zinc
dialkyldithiophosphate, phosphosulfurized hydrocarbons and the
products obtained by reaction of a phosphosulfurized hydrocarbon
with an alkaline earth metal oxide or hydroxide, preferably in the
presence of an alkylated phenol or of an alkylphenol thioester. In
one embodiment, the rust inhibitor or anticorrosion agents may be a
nonionic polyoxyethylene surface active agent. Nonionic
polyoxyethylene surface active agents include, but are not limited
to, polyoxyethylene lauryl ether, polyoxyethylene higher alcohol
ether, polyoxyethylene nonylphenyl ether, polyoxyethylene
octylphenyl ether, polyoxyethylene octyl stearyl ether,
polyoxyethylene oleyl ether, polyoxyethylene sorbitol monostearate,
polyoxyethylene sorbitol mono-oleate, and polyethylene glycol
monooleate. Rust inhibitors or anticorrosion agents may also be
other compounds, which include, for example, stearic acid and other
fatty acids, dicarboxylic acids, metal soaps, fatty acid amine
salts, metal salts of heavy sulfonic acid, partial carboxylic acid
ester of polyhydric alcohols, and phosphoric esters. In another
embodiment, the rust inhibitor is a calcium stearate salt.
[0062] Detergents: In engine oil compositions, metal-containing or
ash-forming detergents function both as detergents to reduce or
remove deposits and as acid neutralizers or rust inhibitors,
thereby, reducing wear and corrosion and extending engine life.
Detergents generally comprise a polar head with long hydrophobic
tail, with the polar head comprising a metal salt of an acid
organic compound.
[0063] In one embodiment, the engine oil composition contains one
or more detergents, which are normally salts, e.g., overbased
salts. Overbased salts, or overbased materials, are single phase,
homogeneous Newtonian systems characterized by a metal content in
excess of that which would be present according to the
stoichiometry of the metal and the particular acidic organic
compound reacted with the metal. In another embodiment, the engine
oil composition comprises at least a carboxylate detergents.
Carboxylate detergents, e.g., salicylates, can be prepared by
reacting an aromatic carboxylic acid with an appropriate metal
compound such as an oxide or hydroxide. In yet another embodiment,
the engine oil composition comprises at least an overbased
detergent. Examples of the overbased detergents include, but are
not limited to calcium sulfonates, calcium phenates, calcium
salicylates, calcium stearates and mixtures thereof. Overbased
detergents may be low overbased (e.g., Total Base Number (TBN)
below about 50). Suitable overbased detergents may alternatively be
high overbased (e.g., TBN above about 150) or medium overbased
(e.g., TBN between 50 and 150). The lubricating oil compositions
may comprise more than one overbased detergents, which may be all
low-TBN detergents, all high-TBN detergents, or a mix of those two
types. Other suitable detergents for the lubricating oil
compositions include "hybrid" detergents such as, for example,
phenate/salicylates, sulfonate/phenates, sulfonate/salicylates,
sulfonates/phenates/salicylates, and the like. In other
embodiments, the composition comprises detergents made from alkyl
benzene and fuming sulfonic acid, phenates (high overbased, medium
overbased, or low overbased), high overbased phenate stearates,
phenolates, salicylates, phosphonates, thiophosphonates,
sulfonates, carboxylates, ionic surfactants and sulfonates and the
like.
[0064] Oxidation Inhibitors/Antioxidants: Oxidation inhibitors or
antioxidants reduce the tendency of mineral oils to deteriorate in
service, which deterioration is evidenced by the products of
oxidation such as sludge, lacquer, and varnish-like deposits on
metal surfaces. In one embodiment, the engine oil composition
contains from about 50 ppm to about 5.00 wt. % of at least an
antioxidant selected from the group of phenolic antioxidants,
aminic antioxidants, or a combination thereof. In other
embodiments, the amount of antioxidants is between 0.10 to 3.00 wt.
%. In yet other embodiments, ranging from about 0.20 to 0.80 wt. %.
An example of an antioxidant used is di-C.sub.8-diphenylamine, in
an amount of about 0.05 to 2.00 wt. % of the total weight of the
oil composition. Other examples of antioxidants include MoS and Mo
oxide compounds.
[0065] Other examples of antioxidants include hindered phenols,
alkaline earth metal salts of alkylphenolthioesters having C.sub.5
to C.sub.12 alkyl side chains; calcium nonylphenol sulphide; oil
soluble phenates and sulfurized phenates; phosphosulfurized or
sulfurized hydrocarbons or esters; phosphorous esters; metal
thiocarbamates; oil soluble copper compounds known in the art;
phenyl naphthyl amines such as phenylene diamine phenothiazine
diphenyl amine, diarylamine; phenyl-alphanaphthylamine,
2,2'-diethyl-4,4'-dioctyl diphenylamine,
2,2'diethyl-4-t-octyldiphenylamine; alkaline earth metal salts of
alkylphenol thioesters, having C.sub.5 to C.sub.12 alkyl side
chains, e.g., calcium nonylphenol sulfide, barium t-octylphenol
sulfide, zinc dialkylditbiophosphates, dioctylphenylamine,
phenylalphanaphthylamine and mixtures thereof. Some of these
antioxidants further function as corrosion inhibitors. Other
suitable antioxidants which also function as antiwear agents
include bis alkyl dithiothiadiazoles such as 2,5-bis-octyl
dithiothiadiazole.
[0066] Anti-foamants: In one embodiment, the engine oil further
comprises an anti-foamant (foam inhibitor) in amounts ranging from
about 5 to about 50 ppm. Examples include alkyl methacrylate
polymers, dimethyl silicone polymers, and foam inhibitors of the
polysiloxane type, e.g., silicone oil and polydimethyl siloxane for
foam control. In another embodiment, the anti-foamant is a mixture
of polydimethyl siloxane and fluorosilicone. In yet another
embodiment, the engine oil further comprises an acrylate polymer
anti-foamant with a weight ratio of the fluorosilicone antifoamant
to the acrylate anti-foamant ranging from about 3:1 to about 1:4.
In a fourth embodiment, the engine oil comprises an
anti-foam-effective amount of a silicon-containing anti-foamant
such that the total amount of silicon in the engine oil is at least
30 ppm. In yet another embodiment, the silicon-containing antifoam
agent is selected from the group consisting of fluorosilicones,
polydimethylsiloxane, phenyl-methyl polysiloxane, linear siloxanes,
cyclic siloxanes, branched siloxanes, silicone polymers and
copolymers, organo-silicone copolymers, and mixtures thereof.
[0067] Anti-wear agents: Anti-wear agents can also be added to the
engine oil composition. Representative of suitable antiwear agents
are zinc dialkyldithiophosphate, zinc diaryldilhiophosphate, Zn or
Me dithiocarbamates, phosphites, amine phosphates, borated
succinimide, magnesium sulfonate, and mixtures thereof. In one
embodiment, the composition further comprises at least a
dihydrocarbyl dithiophosphate metal as antiwear and antioxidant
agent in amounts of about 0.1 to about 10 wt. %. The metal may be
an alkali or alkaline earth metal, or aluminum, lead, tin,
molybdenum, manganese, nickel or copper.
[0068] Some of the above-mentioned additives call provide a
multiplicity of effects; thus for example, a single additive may
act as a dispersant as well as an oxidation inhibitor. These
multifunctional additives are well know. In one embodiment, when
the engine oil composition contains one or more of the
above-mentioned additives, each additive is typically blended into
the base oil in an amount that enables the additive to provide its
desired function. It may be desirable, although not essential, to
prepare one or more additive concentrates comprising additives
(concentrates sometimes being referred to as "additive packages")
whereby several additives can be added simultaneously to the oil to
form the end oil composition. The final composition may employ from
about 0.5 to about 30 wt. % of the concentrate, the remainder being
the oil of lubricating viscosity. The components can be blended in
any order and can be blended as combinations of components.
[0069] Method for Making: The Pour Point Reducing Blend Component
and other additives can be blended into the base oil matrix
individually or in various sub-combinations. In one embodiment, all
of the components are blended concurrently as an additive
concentrate, or additives plus a diluent, such as a hydrocarbon
solvent. The use of an additive concentrate takes advantage of the
mutual compatibility afforded by the combination of ingredients
when in the form of an additive concentrate. In another embodiment,
the engine oil composition is prepared by mixing the base oil and
the pour point depressant with the separate additives or additive
package(s) at an appropriate temperature, e.g., 60.degree. C.,
until homogeneous.
[0070] Applications: Among other things, the engine oil composition
resists viscosity shear and is formulated with a lower level of
viscosity modifiers for excellent protection of gears, bearings,
cam lobes, cam followers, and other high-pressure components in
engines and transmissions.
[0071] The composition delivers lubrication in all types of
automotive and commercial vehicles gasoline and diesel engines,
gasoline fueled four-stroke outboard, inboard, inboard/outboard
(I/O) and personal watercraft motors, including but not limited to
large and small gasoline or diesel engines in cars, motorcycles
trucks, motor homes, maintenance equipment, heavy equipment, street
rods, military, and marine applications.
[0072] Properties: The engine oil composition is characterized as
meeting SAE specifications, API specifications (API 1509) as well
as the ACEA Specifications for service fill oils for gasoline and
diesel engines. In another embodiment, the engine oil composition
meets the specifications for SAE J300 viscosity grade 0W-XX, 5W-XX,
10W-XX, 15W-XX, 20W-XX, or 25W-XX engine oil, wherein XX represents
the integer 20, 30, 40, 50 or 60. In yet anther embodiment the
multi-grade engine oil meets the SAE specifications, API
specifications (API 1509) as well as the ACEA Specifications.
[0073] In one embodiment, the engine oil composition is
characterized as meeting the requirements of SAE J300 over a wide
temperature range while still having a low level of viscosity
modifiers. Depending on the diluted factor of the viscosity
modifiers used, this amount may range from 0.3 to 25 wt. %. In one
embodiment, the reduced amount of viscosity modifiers is less than
10 wt. %. In a second embodiment, the engine oil composition
meeting SAE J300 requirements contains less than 7.5 wt. %
viscosity modifiers. In a third embodiment, the engine oil
composition meeting SAE J300 requirements contains less than 5 wt.
% viscosity modifiers.
[0074] The engine oil composition is further characterized as
having a reduced deposit-formation tendency (as shown, for example,
using the Panel Coker Test and compared with compositions without
the Pour Point Reducing Blend Component) with a reduced level of
viscosity index modifiers. The amount of viscosity index modifier
is reduced at least 10% in one embodiment (compared to a
composition without the sufficient amount of a Pour Point Reducing
Blend Component). In one embodiment, the amount of reduced level of
viscosity index modifier is less than 2 wt. %, less than 1.5 wt. %
in a second embodiment, and less than 1.25 wt. % in a third
embodiment.
[0075] As the engine oil composition contains less viscosity index
improvers, it also has a reduced tendency to form engine deposits.
In one embodiment, the composition forms at least 10% less deposit
(as tested under the Panel Coker Test) as compared to a comparable
composition without the sufficient amount of Pour Point Reducing
Blend Component. In yet another embodiment, the composition forms
at least 25% less deposit than a comparable composition without the
Pour Point Reducing Blend Component. In a third embodiment, the
reduction in the deposit is at least 50% less.
[0076] Viscometrics is an important lubricant parameter that
governs the successful operation of engine oils. In one embodiment,
the engine oil composition comprising the Pour Point Reducing Blend
Component has an apparent viscosity of 60,000 cP or less in MRV
test (ASTM D4684-07@30.degree. C.) and a yield stress of less than
35 Pa (as measured per ASTM D4684-89@-30.degree. C.).
[0077] In yet another embodiment, the engine oil composition has a
kinematic viscosity at 100.degree. C. as specified according to SAE
J300 for the applicable grade. In one embodiment, the engine oil
composition has a cold crank simulator viscosity at -20.degree. C.
of less than 9000 cP, and less than 7500 cP in a second embodiment.
In one embodiment, the engine oil composition has a mini rotary
viscosity at -30.degree. C. of less than 60000 cP and a yield
stress of less than 35 Pa (as measured per ASTM
D4684-07@-30.degree. C.)
[0078] In one embodiment, the composition has a kinematic viscosity
at 100.degree. C. between 3.5 and 25 mm.sup.2/s. In a second
embodiment a kinematic viscosity at 100.degree. C. between 13.50
and 20 mm.sup.2/s.
EXAMPLES
[0079] The following examples are given as non-limitative
illustration of aspects of the invention. Unless specified
otherwise, the components in the examples are as follows (and
expressed as wt. % in the Tables):
[0080] Pour Point Reducing Blend Component (PPRBC-FTBO) is from
Chevron Corporation of San Ramon, Calif. The properties are as
listed in Table 4.
[0081] XOM 150N and 600N are Group I base stocks from ExxonMobil
Corporation.
[0082] NESTE.TM. 3050, 3080 and 3043XV are Group III base oil
stocks from Neste Oil Corporation, NESTE.TM. 3043, 3050 and 3080
have properties as follows: TABLE-US-00001 TABLE 1 Typical value
Typical value Typical value NESTE .TM. NESTE .TM. NESTE .TM.
Property 3043 3050 3080 Viscosity @ 40.degree. C., 20-21 26 50 cSt
(mm.sup.2/s) Viscosity @ 100.degree. C., 4.2-4.4 5.1 8.0 cSt
(mm.sup.2/s) Viscosity index >121 126 128 Pour point, .degree.
C. -18 -15 -15 Flash point, .degree. C. 224 240 260 Color (ASTM D-
<0.5 <0.5 <0.5 1500-04a) Noack volatility, w % 14.4
<=8.4 <=3.5 Density at 15.degree. C. 831 835 843
[0083] XOA3161F, OLOA.TM. 4594HA, and OLOA.TM. 59912 are additive
packages from Chevron Oronite of San Ramon, Calif.
[0084] OLOA.TM. 2509Z and 19803 are pour point depressants from
Chevron Oronite.
[0085] PARATONE.TM. 8071 and PARATONE.TM. 8900 are viscosity index
improvers from Chevron Oronite.
EXAMPLES 1-4
[0086] The components in Table 2 were blended together and their
properties were measured. The results are also show in Table 2.
[0087] The results establish that the addition of the Pour Point
Reducing Blend Component allows up to 20% reduction in the
viscosity modifier (VM) content, with low temperature performance
remaining essentially similar to samples with a high VM content.
Low VM content is key in European engine deposit tests.
TABLE-US-00002 TABLE 2 Example Example Example Example All examples
are 10W40 blends 1 2 3 4 Base stock NEXBASE 3050, wt. % 48.87 52.61
58.27 61.34 Base stock NEXBASE 3080, wt. % 26.9 19.46 11.10 5.33
PPRBC - FTBO, wt. % 0 4.00 7.00 10.00 XOA3161F Additive, wt. % 19.4
19.4 19.4 19.4 PARATONE 8071, wt. % 4.90 4.60 4.30 4.00 =100%
=93.9% =87.9% =81.6% Kinematic Viscosity @ 40.degree. C.,
mm.sup.2/s -- -- -- -- Kinematic Viscosity @ 100.degree. C.,
mm.sup.2/s 14.01 14.03 13.82 13.76 CCS at -25.degree. C. 6767 6852
6795 6868 Mini Rotary Viscosimeter Viscosity cP (max 60,000) ASTM
27400.sup. 35000 23900 24900 D4684 @ -30.degree. C. Yield Stress,
Pa (max <= 35 Pa) <=35 <=35 <=35 <=35 ASTM D4684@
-30.degree. C. Pour Point, .degree. C. -30.sup. -30 -30 -30 Bosch
injector test 90 cycles, % loss 5.92 6.13 5.72 5.60 CEC-L-14-A-79
Sheared oil at 100.degree. C., mm.sup.2/s ASTM D445 13.18 13.17
13.03 12.99
EXAMPLES 5-8
[0088] The components in Table 3 were blended together and their
properties were measured. The results are shown in Table 3.
[0089] As shown, the addition of the Pour Point Reducing Blend
Component allows a reduction in the viscosity modifier. There is
also significantly less deposit build-up with the reduced amount of
viscosity modifier used. TABLE-US-00003 TABLE 3 Example 5 Example 6
Example 7 Example 8 Components in wt. % 10W40 10W40 15W50 15W50
NEXBASE 3043XV 40 30 -- -- XOM 150N 28.96 41.55 69.72 63.06 XOM
600N 14.92 2.65 19.09 16.26 PPRBC - FTBO, wt. % -- 10 -- 10 OLOA
4594HA 14.7 14.7 OLOA 59912 -- -- 9.50 9.50 OLOA 2509Z -- -- 0.40
-- OLOA 19803 0.30 -- -- -- Paratone 8900, wt. % 1.12 = 100% 1.10 =
98.2% 1.29 = 100% 1.18 = 91.4% Kinematic Viscosity @ 102.9 102 --
-- 40.degree. C., mm.sup.2/s Kinematic Viscosity @ 15.51 15.49
18.24 18.32 100.degree. C., mm.sup.2/s CCS at -20.degree. C. -- --
7140 7200 CCS at -25.degree. C. 7150 7090 -- -- HTHS viscosity, cP
4.48 4.51 4.80 4.92 ASTM D5481 Panel Coker Deposit - mg., 519.9
371.0 271.6 138.6 average from 4 panels
[0090] TABLE-US-00004 TABLE 4 Properties PPRBC - FTBO Kinematic
Viscosity @ 40.degree. C., cSt (mm.sup.2/s) 106.4 Kinematic
Viscosity @ 100.degree. C., cSt (mm.sup.2/s) 16.01 Viscosity Index
161 Cold Crank Viscosity @ -30.degree. C., cP 46,991 Cold Crank
Viscosity @ -25.degree. C., cP 18,905 Pour Point, .degree. C. -10
n-d-m (ASTM D3238-95 Reapproved 2005) with normalization to 100%
total wt % carbon) Molecular Weight, gm/mol (VPO) 743 Density,
gm/ml 0.8330 Refractive Index 1.4641 Paraffinic Carbon, % 92.98
Naphthenic Carbon, % 7.02 Aromatic Carbon, % 0.00 Oxidator BN, hrs
45.32, 43.95 Noack, wt. % 0.95 Total Aromatics, wt % by HPLC UV
0.03062 SIMDIST TBP (WT %), F (ASTM D-6352-04) TBP @0.5 915 TBP @5
963 TBP @10 988 TBP @20 1011 TBP @30 1040 TBP @40 1057 TBP @50 1074
TBP @60 1092 TBP @70 1113 TBP @80 1141 TBP @90 1181 TBP @95 1213
TBP @99.5 1290 FIMS by Probe sample introduction tof556 Saturates
65.4 1-Unsaturation 33.1 2-Unsaturation 1.2 3-Unsaturation 0.3
4-Unsaturation 0 5-Unsaturation 0 6-Unsaturation 0 NMR Analysis:
Branching Index 20.83 Branching Proximity 27.05 Alkyl Branches per
Molecule 4.02 FCI 14.36 Alkyl Branches per 100 Carbons 7.58
[0091] For the purpose of this specification and appended claims,
unless otherwise indicated, all numbers expressing quantities,
percentages or proportions, and other numerical values used in the
specification and claims, are to be understood as being modified in
all instances by the term "about." Accordingly, unless indicated to
the contrary, the numerical parameters set forth in the following
specification and attached claims are approximations that may vary
depending upon the desired properties sought to be obtained and/or
the precision of an instrument for measuring the value, thus
including the standard deviation of error for the device or method
being employed to determine the value. The use of the tem "or" in
the claims is used to mean "and/or" unless explicitly indicated to
refer to alternatives only or the alternative are mutually
exclusive, although the disclosure supports a definition that
refers to only alternatives and "and/or." The use of the word "a"
or "an" when used in conjunction with the term "comprising" in the
claims and/or the specification may mean "one," but it is also
consistent with the meanings of "one or more," "at least one," and
"one or more than one." Furthermore, all ranges disclosed herein
are inclusive of the endpoints and are independently combinable. In
general, unless otherwise indicated, singular elements may be in
the plural and vice versa with no loss of generality. As used
herein, the term "include" and its grammatical variants are
intended to be non-limiting, such that recitation of items in a
list is not to the exclusion of other like items that can be
substituted or added to the listed items.
[0092] It is contemplated that any aspect of the invention
discussed in the context of one embodiment of the invention may be
implemented or applied with respect to any other embodiment of the
invention. Likewise, any composition of the invention may be the
result or may lie used in any method or process of the invention.
This written description uses examples to disclose the invention,
including the best mode, and also to enable any person skilled in
the art to make and use the invention. The patentable scope is
defined by the claims, and may include other examples that occur to
those skilled in the art. Such other examples are intended to be
within the scope of the claims if they have structural elements
that do not differ from the literal language of the claims, or if
they include equivalent structural elements with insubstantial
differences from the literal languages of the claims. All citations
referred herein are expressly incorporated herein by reference.
* * * * *