U.S. patent application number 16/708793 was filed with the patent office on 2020-06-11 for method for improving oxidation and deposit resistance of lubricating oils.
The applicant listed for this patent is ExxonMobil Research and Engineering Company. Invention is credited to Douglas E. Deckman, Mark P. Hagemeister, Andrew D. Satterfield, Andrew E. Taggi.
Application Number | 20200181525 16/708793 |
Document ID | / |
Family ID | 69160279 |
Filed Date | 2020-06-11 |
United States Patent
Application |
20200181525 |
Kind Code |
A1 |
Deckman; Douglas E. ; et
al. |
June 11, 2020 |
METHOD FOR IMPROVING OXIDATION AND DEPOSIT RESISTANCE OF
LUBRICATING OILS
Abstract
Provided is a method for improving oxidation resistance and
deposit resistance of a lubricating oil for use in lubricating a
mechanical component. The method includes the step of providing the
lubricating oil to the mechanical component and measuring the
improved oxidation and deposit resistance. The lubricating oil
includes a lubricating oil base stock at from 0 to 80 wt %, at
least one branched isoparaffin having a mole % of epsilon carbon as
measured by C.sub.13 NMR of less than or equal to 10% at from 20 to
80 wt %, at least one viscosity modifier at from 5 to 20 wt %, and
one or more other lubricating oil additives. The oxidation
resistance in the CEC L-109 oxidation resistance test is improved
to greater than 310 hours to achieve a 100% viscosity increase and
the deposit resistance in the TEOST 33C is improve to total
deposits of less than 45 mg as compared to oxidation resistance and
deposit resistance achieved using a lubricating oil not containing
the at least one branched isoparaffin.
Inventors: |
Deckman; Douglas E.;
(Easton, PA) ; Taggi; Andrew E.; (New Hope,
PA) ; Hagemeister; Mark P.; (Morris Plains, NJ)
; Satterfield; Andrew D.; (Furlong, PA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
ExxonMobil Research and Engineering Company |
Annandale |
NJ |
US |
|
|
Family ID: |
69160279 |
Appl. No.: |
16/708793 |
Filed: |
December 10, 2019 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62777451 |
Dec 10, 2018 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C10M 169/02 20130101;
C10N 2030/10 20130101; C10M 2205/022 20130101; C10N 2030/74
20200501; C10M 2205/173 20130101; C10N 2040/135 20200501; C10N
2030/02 20130101; C10M 171/00 20130101; C10M 2205/046 20130101;
C10M 2205/024 20130101; C10N 2030/04 20130101; C10M 101/00
20130101; C10N 2020/073 20200501; C10M 2205/04 20130101; C10M
2205/066 20130101; C10M 2207/2825 20130101; C10M 2207/2835
20130101; C10N 2020/071 20200501; C10N 2040/02 20130101; C10N
2040/08 20130101; C10N 2020/02 20130101; C10N 2040/04 20130101;
C10N 2040/30 20130101; C10M 107/10 20130101; C10N 2040/25 20130101;
C10M 2205/223 20130101; C10N 2020/015 20200501; C10M 2205/026
20130101; C10M 2205/0285 20130101; C10N 2020/065 20200501; C10M
2209/0866 20130101; C10M 2209/1023 20130101; C10M 2209/084
20130101; C10M 105/04 20130101; C10M 105/32 20130101; C10M
2203/0206 20130101; C10M 119/12 20130101; C10M 2203/1025 20130101;
C10M 2203/1025 20130101; C10N 2020/02 20130101; C10M 2205/022
20130101; C10M 2205/024 20130101; C10M 2205/024 20130101; C10M
2205/04 20130101; C10N 2060/04 20130101; C10M 2205/026 20130101;
C10M 2205/04 20130101; C10N 2060/04 20130101 |
International
Class: |
C10M 169/02 20060101
C10M169/02; C10M 101/00 20060101 C10M101/00; C10M 105/04 20060101
C10M105/04; C10M 105/32 20060101 C10M105/32; C10M 107/10 20060101
C10M107/10; C10M 119/12 20060101 C10M119/12 |
Claims
1. A lubricating oil comprising: a lubricating oil base stock at
from 0 to 80 wt % of the lubricating oil, at least one branched
isoparaffin having a mole % of epsilon carbon as measured by
.sup.13C NMR of less than or equal to 10% at from 20 to 80 wt % of
the lubricating oil, at least one viscosity modifier at from 5 to
20 wt % of the lubricating oil, and wherein the remainder of the
lubricating oil includes one or more other lubricating oil
additives; and wherein oxidation resistance is improved (CEC L-109
oxidation resistance to a 100% viscosity increase greater than 310
hours) and deposit resistance is improved (TEOST 33C total deposits
less than 45 mg) for the lubricating oil as compared to oxidation
resistance and deposit resistance achieved using a lubricating oil
not containing the at least one branched isoparaffin having a mole
% of epsilon carbon as measured by .sup.13C NMR of less than or
equal to 10%.
2. The oil of claim 1, wherein the lubricating oil base stock is
selected from the from the group consisting of a Group I base
stock, a Group II base stock, a Group III base stock, a Group IV
base stock, a Group V base stock and combinations thereof. The oil
of claim 2, wherein the Group III base stock is a gas to liquids
(GTL) base stock and the Group IV base stock is a polyalphaolefin
(PAO) base stock.
3. The oil of claim 2, wherein the Group V base stock is an ester
based Group V base stock selected from the group consisting of a
C11/C13/C15/C17 Estolide, a C8/C10 TMP ester, a C7/C9/C11/C13/C15
TMP ester, a C6/C7/C9 TMP ester, a C15/C17 diester, a C6/C7/C9 TMP
ester, a C4/C5/C6/C7/C8/C9 TMP ester, C16 mixed mono and di
alkylated naphthalene, and combinations thereof.
4. The oil of claim 3, wherein the ester based Group V base stock
comprises a monoester, a di-ester, a polyol ester, a complex ester
or mixtures thereof derived from a renewable biological
material.
5. The oil of claim 4, wherein the renewable biological material is
derived from coconut oil, palm oil, rapeseed oil, soy oil,
vegetable oil, or sunflower oil.
6. The oil of claim 2, wherein the lubricating oil base stock is a
blend of Group III, Group IV and Group V base stocks.
7. The oil of claim 1, wherein the at least one branched
isoparaffin is selected from the group consisting of squalane,
isosqualane, pristine, tetracosane, isoparaffins represented by the
formulas ##STR00005## and combinations thereof.
8. The oil of claim 7, wherein the at least one branched
isoparaffin is squalane having a kinematic viscosity at 100 deg. C.
ranging from 3.9 to 4.3 cSt.
9. The oil of claim 1, wherein the at least one viscosity modifier
comprises linear or star-shaped polymers and copolymers of
methacrylate, butadiene, olefins, alkylated styrenes or
combinations thereof.
10. The oil of claim 1, wherein the at least one viscosity modifier
is selected from the group consisting of polyisobutylene,
polymethacrylate, polyisoprene, copolymers of ethylene and
propylene, hydrogenated block copolymers of styrene and isoprene,
styrene-butadiene based polymers, star polyisoprene polymers, star
polyisoprene-styrene copolymers and combinations thereof.
11. The oil of claim 1, wherein the one or more other lubricating
oil additives are selected from the group consisting of an
anti-wear additive, viscosity index improver, antioxidant,
detergent, dispersant, pour point depressant, corrosion inhibitor,
metal deactivator, seal compatibility additive, anti-foam agent,
inhibitor, anti-rust additive, and friction modifier.
12. The oil of claim 1, wherein the lubricating oil has a kinematic
viscosity at 100 deg. C. ranging from 4.5 to 12.5 cSt.
13. The oil of claim 1, wherein lubricating oil is an SAE viscosity
grade selected from the group consisting of 0W-30, 5W-30, 0W-20,
5W-20, 0W-16, 5W-16, 0W-12, 5W-12, 0W-8, and 5W-8.
14. The oil of claim 1, wherein the lubricating oil is a passenger
vehicle engine oil (PVEO) or a commercial vehicle engine oil
(CVEO).
15. The oil of claim 1, wherein the oxidation resistance or deposit
resistance is measured at an oxygen partial pressure of less than
90 psig.
16. The oil of claim 1, wherein the at least one branched
isoparaffin has a mole % of alpha carbon as measured by .sup.13C
NMR of less than 3.8%.
17. The oil of claim 1, wherein the at least one branched
isoparaffin has a mole % of T/P methyl as measured by .sup.13C NMR
of greater than 2%.
18. The oil of claim 1, wherein the at least one branched
isoparaffin has a mole % of P-methyl as measured by .sup.13C NMR of
greater than 5%.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional
Application No. 62/777,451, filed on Dec. 10, 2019, the entire
contents of which are incorporated herein by reference.
FIELD
[0002] This disclosure relates to a method for improving oxidation
resistance and deposit control of lubricating oils. The lubricating
oils include a branched isoparaffin and at least one viscosity
modifier and are useful as passenger vehicle engine oil (PVEO)
products or commercial vehicle engine oil (CVEO) products.
BACKGROUND
[0003] Lubricant oxidative stability is one of the key parameters
controlling oil life, which translates in oil drain interval in
practical terms. Additionally, deposit formation is an issue
associated with the decomposition of the base stock molecules
mostly propagated by oxidative chain reactions. There are several
conventional approaches to improve the resistance to oxidation of a
finished lubricant product, but most products are formulated using
small molecules such as diphenylamine (DPA) or a phenolic
antioxidant.
[0004] Improved oxidation stability is necessary to increase oil
life and oil drain intervals, thus reducing the amount of used oil
generated as a consequence of more frequent oil changes. Longer oil
life and oil drain intervals are key benefits that are desirable to
end customers. Traditional antioxidant packages provide standard
protection leaving the main differentiation hinging on the quality
of the base stock in the formulation.
[0005] What is needed is newly designed lubricating oils capable of
controlling oxidation and oil thickening for longer periods of time
as compared to conventional lubricants. Further, what is needed is
newly designed lubricants that enable extended oil life in
combination with desired deposit control and cleanliness
performance.
SUMMARY
[0006] This disclosure relates to a method for improving oxidation
resistance and deposit resistance of lubricating oils by including
in the oil a combination of base stocks and viscosity modifiers
that lead to advantageous performance.
[0007] More particularly, this disclosure relates to a method for
improving oxidation resistance and deposit resistance of a
lubricating oil for use in lubricating a mechanical component
comprising: providing a lubricating oil to a mechanical component,
wherein the lubricating oil comprises a lubricating oil base stock
at from 0 to 80 wt % of the lubricating oil, at least one branched
isoparaffin having a mole % of epsilon carbon as measured by
.sup.13C NMR of less than or equal to 10% at from 20 to 80 wt % of
the lubricating oil, at least one viscosity modifier at from 5 to
20 wt % of the lubricating oil, and wherein the remainder of the
lubricating oil includes one or more other lubricating oil
additives. The method provides an oxidation resistance improvement
(CEC L-109 oxidation resistance to a 100% viscosity increase
greater than 310 hours) and deposit resistance improvement (TEOST
33C total deposits less than 45 mg) as compared to oxidation
resistance and deposit resistance achieved using a lubricating oil
not containing the at least one branched isoparaffin having a mole
% of epsilon carbon as measured by .sup.13C NMR of less than or
equal to 10%.
[0008] This disclosure also relates to a lubricating oil
composition including a lubricating oil base stock at from 0 to 80
wt % of the lubricating oil, at least one branched isoparaffin
having a mole % of epsilon carbon as measured by .sup.13C NMR of
less than or equal to 10% at from 20 to 80 wt % of the lubricating
oil, at least one viscosity modifier at from 5 to 20 wt % of the
lubricating oil, and wherein the remainder of the lubricating oil
includes one or more other lubricating oil additives. The
lubricating oil composition provides an oxidation resistance
improvement (CEC L-109 oxidation resistance to a 100% viscosity
increase greater than 310 hours) and deposit resistance improvement
(TEOST 33C total deposits less than 45 mg) as compared to oxidation
resistance and deposit resistance achieved using a lubricating oil
not containing the at least one branched isoparaffin having a mole
% of epsilon carbon as measured by .sup.13C NMR of less than or
equal to 10%.
[0009] Other objects and advantages of the present disclosure will
become apparent from the detailed description that follows.
DETAILED DESCRIPTION
Definitions
[0010] "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.
[0011] "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.
[0012] "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.
[0013] "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).
[0014] "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.
[0015] "Hydrocarbon" refers to a compound consisting of carbon
atoms and hydrogen atoms.
[0016] "Alkane" refers to a hydrocarbon that is completely
saturated. An alkane can be linear, branched, cyclic, or
substituted cyclic.
[0017] "Olefin" refers to a non-aromatic hydrocarbon comprising one
or more carbon-carbon double bond in the molecular structure
thereof.
[0018] "Mono-olefin" refers to an olefin comprising a single
carbon-carbon double bond.
[0019] "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.
[0020] "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."
[0021] "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.
[0022] "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.
[0023] "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.
[0024] "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.
[0025] "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.
[0026] "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.
[0027] "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.
[0028] "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.
[0029] 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.
[0030] All viscosity index ("VI") values in this disclosure are as
determined pursuant to ASTM D2270.
[0031] 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.
[0032] All pour point values in this disclosure are as determined
pursuant to ASTM D5950 or D97.
[0033] 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.
[0034] All percentages in describing chemical compositions herein
are by weight unless specified otherwise. "Wt. %" means percent by
weight.
Methods and Lubricating Oil Compositions of this Disclosure
[0035] It has been surprisingly found that, in accordance with this
disclosure, oxidative stability is improved, and deposit control is
maintained or improved, as compared to oxidative stability and
deposit control achieved using a lubricating oil other than the
formulated oil of this disclosure.
[0036] In particular, it has been surprisingly found that, for
lubricating oils of this disclosure containing at least one
branched isoparaffin having a mole % of epsilon carbon as measured
by .sup.13C NMR of less than or equal to 10% at from 20 to 80 wt %
of the lubricating oil and at least one viscosity modifier at from
5 to 20 wt % of the lubricating oil provide for an improved
oxidative stability (CEC L-109 oxidation resistance to a 100%
viscosity increase greater than 310 hours) and improved deposit
resistance (TEOST 33C total deposits less than 45 mg) as compared
to oxidative stability and deposit resistance achieved using a
lubricating oil not containing the at least one branched
isoparaffin. The improvement in the oxidation resistance or deposit
resistance of this disclosure was measured at an oxygen partial
pressure of less than 90 psig, or less than 70 psig, or less than
50 psig, or less than 30 psig, or less than 15 psig.
[0037] The present disclosure provides significant improvements in
lubricant life as determined by the time to a 100% viscosity
increase for engine oils exposed to biodiesel fuel and oxidized at
150.degree. C. using the operating conditions of the CEC L-109-16
bench test. This disclosure facilitates the development of engine
oils with extended drain capabilities.
[0038] The current state of the art is to meet the industry ACEA
2016 requirements in the CEC L-109-16 Bio-Diesel Oxidation Bench
test. The present disclosure identifies approaches to significantly
surpass industry requirements in the CEC L-109-16 Bio-Diesel
Oxidation Bench test. The industry standard CEC L-109-16 Bio-Diesel
Oxidation Bench test runs for 168 or 216 hours. The CEC L-109-16
oxidation bench test is conducted at 150.degree. C. An organo-iron
catalyst is added to the test oil to deliver 100 ppm Fe. Also 7%
B100 biodiesel fuel is added prior to initiating the oxidation test
to accelerate the oxidative degradation. The present disclosure
facilitates running the CEC L-109-16 Bio-Diesel Oxidation Bench
test for extended durations (.gtoreq.310 hours) to document the
benefits of this disclosure.
[0039] More, in particular, it has been surprisingly found that, in
deposit measurements of the lubricating oil of this disclosure by
thermo-oxidation engine oil simulation (TEOST 33C) measured by ASTM
D6335, the amount of total deposits is reduced or maintained as
compared to the amount of total deposits in a lubricating oil not
containing the at least one branched isoparaffin.
[0040] This disclosure relates to lubricating oils for combustion
engines that contain at least one least one branched isoparaffin in
an amount greater than or equal to 20, 25, 30, 40, 50, 60, 70, 75,
and 80 weight percent. Lubricating oils formulated with this level
of the at least one branched isoparaffin base stock provides
unexpectedly good oxidative stability as measured by the CEC
L-109-16 Bio-Diesel Oxidation Bench test and unexpectedly good
deposit resistance as measured by the TEOST 33C test.
[0041] In particular, for lubricating oils of this disclosure
containing at least one branched isoparaffin having a mole % of
epsilon carbon as measured by .sup.13C NMR of less than or equal to
10%, in a CEC L-109-16 Bio-Diesel Oxidation Bench test, the
relative kinematic viscosity at 100.degree. C. (KV100) increase
from 300 to 400 hours of the lubricating oil, is less than about
100 percent increase as compared to the relative kinematic
viscosity at 100.degree. C. (KV100) increase from 300 to 400 hours
of a lubricating oil not having the at least one branched
isoparaffin.
[0042] In an embodiment, the lubricating oils of this disclosure
containing at least one branched isoparaffin having a mole % of
epsilon carbon as measured by .sup.13C NMR of less than or equal to
10%, in a CEC L-109-16 Bio-Diesel Oxidation Bench test, the time
for a relative kinematic viscosity at 100.degree. C. (KV100)
increase of 100% of the lubricating oil, is greater than at least
about 5%, or 10%, or 15%, or 20%, or 25%, or 30%, or 35%, or 40%,
or 45%, or 50%, or greater, of the time for a relative kinematic
viscosity at 100.degree. C. (KV100) increase of 100% of a
lubricating oil not having the at least one branched
isoparaffin.
[0043] In accordance with this disclosure, a method is provided to
improve oxidative stability through the lifetime of a lubricant and
the deposit resistance in combustion through selection of a at
least one branched isoparaffin having a mole % of epsilon carbon as
measured by .sup.13C NMR of less than or equal to 10% and at least
one viscosity modifier in the lubricating oil. Specifically, when
from 20-80 weight percent of a branched isoparaffin having a mole %
of epsilon carbon as measured by .sup.13C NMR of less than or equal
to 10% is used in the formulation, the lubricant oxidation
performance and deposit resistance is significantly improved as
compared to formulations not containing the at least one branched
isoparaffin having a mole % of epsilon carbon as measured by
.sup.13C NMR of less than or equal to 10%.
[0044] Further, in accordance with this disclosure, finished
lubricants can be designed that are capable of controlling
oxidation and oil thickening for long durations in engines as
compared to lubricants not having the at least one branched
isoparaffin. This disclosure also enables extended oil life in
combination with superior deposit resistance in the combustion
engine and viscosity control.
[0045] The at least one branched isoparaffin may have a mole % of
epsilon carbon as measured by .sup.13C NMR of less than or equal to
10%, or less than or equal to 9%, or less than or equal to 8%, or
less than or equal to 7%, or less than or equal to 6%, or less than
or equal to 5%. The at least one branched isoparaffin may have a
mole % of alpha carbon as measured by .sup.13C NMR of less than
3.8%, or less than 3.5%, or less than 3.0%, or less than 2.0%, or
less than 1.5%, or less than 1.0%. The at least one branched
isoparaffin may also have a mole % of T/P methyl as measured by
.sup.13C NMR of greater than 2%, or greater than 5%, or greater
than 7%, or greater than 10%, or greater than 12%. The at least one
branched isoparaffin may also have a mole % of P-methyl as measured
by .sup.13C NMR of greater than 5%, or greater than 7%, or greater
than 10%, or greater than 12%.
[0046] The at least one branched isoparaffin having a mole % of
epsilon carbon as measured by .sup.13C NMR of less than or equal to
10% is selected from the group consisting of squalane, isosqualane,
pristine, tetracosane, isoparaffins represented by the following
two structures below,
##STR00001##
and combinations thereof. A particularly preferred at least one
branched isoparaffin having a mole % of epsilon carbon as measured
by .sup.13C NMR of less than or equal to 10% is squalane.
[0047] The at least one branched isoparaffin having a mole % of
epsilon carbon as measured by .sup.13C NMR of less than or equal to
10% is incorporated into the inventive lubricating oils of this
disclosure at from 20 to 80 wt %, or 25 to 75 wt %, or 30 to 70 wt
%, or 35 to 65 wt %, or 40 to 60 wt %, or 45 to 55 wt % based on
the total weight of the lubricating oil.
[0048] The other lubricating oil base stock of inventive
lubrication oils is incorporated at from 0 to 80 wt %, or 10 to 70
wt %, or 20 to 60 wt %, or 30 to 50 wt %, or 34 to 45 wt % of the
lubricating oil. Non-limiting exemplary other lubricating oil base
stocks are disclosed in the next section of the disclosure.
[0049] The inventive lubricating oils of this disclosure provide an
improvement in oxidation resistance compared to comparable
lubricating oils not including the at least one branched
isoparaffin having a mole % of epsilon carbon as measured by
.sup.13C NMR of less than or equal to 10% as measured by the CEC
L-109 oxidation resistance to a 100% viscosity test. In particular,
the inventive lubricating oils provide a CEC L-109 oxidation
resistance to a 100% viscosity increase that is greater than 310
hours, or greater than 330 hours, or greater than 350 hours, or
greater than 370 hours, or greater than 400 hours, or greater than
420 hours.
[0050] The inventive lubricating oils of this disclosure provide an
improvement in deposit resistance compared to comparable
lubricating oils not including the at least one branched
isoparaffin having a mole % of epsilon carbon as measured by
.sup.13C NMR of less than or equal to 10% as measured by TEOST 33C
total deposits test. In particular, the inventive lubricating oils
provide a deposit resistance that is less than 45 mg, or less than
43 mg, or less than 41 mg, or less than 39 mg, or less than 37 mg,
or less than 35 mg.
[0051] Viscosity modifiers (also known as viscosity index improvers
(VI improvers), and viscosity improvers) are in included in the
lubricant compositions of this disclosure. The at least one
viscosity modifier of the inventive lubricating oils is
incorporated at from 0.1 to 20 wt %, or 0.3 to 20 wt %, or 0.5 to
20 wt %, or 1 to 18 wt %, or 5 to 16 wt %, or 10 to 15 w % of the
lubricating oil. Viscosity modifiers provide lubricants with high
and low temperature operability. These additives impart shear
stability at elevated temperatures and acceptable viscosity at low
temperatures.
[0052] Non-limiting exemplary viscosity modifiers for the at least
one viscosity modifier of the inventive lubricating oils are as
follows: high molecular weight hydrocarbons, polyesters and
viscosity modifier dispersants that function as both a viscosity
modifier and a dispersant. Typical molecular weights of these
polymers are between about 10,000 to 1,500,000, more typically
about 20,000 to 1,200,000, and even more typically between about
50,000 and 1,000,000.
[0053] Other examples of suitable viscosity modifiers are linear or
star-shaped polymers and copolymers of methacrylate, butadiene,
olefins, or alkylated styrenes. Polyisobutylene is a commonly used
viscosity modifier. Another suitable viscosity modifier is
polymethacrylate (copolymers of various chain length alkyl
methacrylates, for example), some formulations of which also serve
as pour point depressants. Other suitable viscosity modifiers
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.
[0054] Olefin copolymers are commercially available from Chevron
Oronite Company LLC under the trade designation "PARATONE.RTM."
(such as "PARATONE.RTM. 8921" and "PARATONE.RTM. 8941"); from Afton
Chemical Corporation under the trade designation "HiTEC.RTM." (such
as "HiTEC.RTM. 5850B"; and from The Lubrizol Corporation under the
trade designation "Lubrizol.RTM. 7067C". Hydrogenated polyisoprene
star polymers are commercially available from Infineum
International Limited, e.g., under the trade designation "SV200"
and "SV600". Hydrogenated diene-styrene block copolymers are
commercially available from Infineum International Limited, e.g.,
under the trade designation "SV140", "SV150", and "SV160".
[0055] The polymethacrylate or polyacrylate polymers can be linear
polymers which are available from Evonik Industries under the trade
designation "Viscoplex.RTM." (e.g., Viscoplex 6-954) or star
polymers which are available from Lubrizol Corporation under the
trade designation Asteric.TM. (e.g., Lubrizol 87708 and Lubrizol
87725).
[0056] Illustrative vinyl aromatic-containing polymers as viscosity
modifiers useful in this disclosure may be derived predominantly
from vinyl aromatic hydrocarbon monomer. Illustrative vinyl
aromatic-containing copolymers useful in this disclosure may be
represented by the following general formula:
A-B
wherein A is a polymeric block derived predominantly from vinyl
aromatic hydrocarbon monomer, and B is a polymeric block derived
predominantly from conjugated diene monomer.
[0057] In another embodiment of this disclosure, the at least one
viscosity modifier may be used in an amount of less than about 20
weight percent, or less than about 15 weight percent, or less than
about 10 weight percent, or less than about 7 weight percent, or
less than about 5 weight percent, and in certain instances, may be
used at less than 2 weight percent, or less than about 1 weight
percent, or less than about 0.5 weight percent, or less than 0.3 wt
%, or less than 0.1 wt % based on the total weight of the
formulated oil or lubricating engine oil. The preferred range for
the at least one viscosity modifier is from 5 to 20 wt % of the
formulated oil.
[0058] Viscosity modifiers are typically added as concentrates, in
large amounts of diluent oil. As used herein, the viscosity
modifier concentrations are given on an "as delivered" basis.
Typically, the active polymer is delivered with a diluent oil. The
"as delivered" viscosity modifier typically contains from 20 weight
percent to 75 weight percent of an active polymer for
polymethacrylate or polyacrylate polymers, or from 6 weight percent
to 20 weight percent of an active polymer for olefin copolymers,
hydrogenated polyisoprene star polymers, or hydrogenated
diene-styrene block copolymers, in the "as delivered" polymer
concentrate.
Other Lubricating Oil Base Stocks
[0059] A wide range of other lubricating oil base stocks known in
the art can be used in conjunction with the at least one branched
isoparaffin having a mole % of epsilon carbon as measured by
.sup.13C NMR of less than or equal to 10% in the lubricating oil
compositions of the instant disclosure as primary base stock or
co-base stock. Such other base stocks can be either derived from
natural resources or synthetic, including un-refined, refined, or
re-refined oils. Un-refined oil base stocks include shale oil
obtained directly from retorting operations, petroleum oil obtained
directly from primary distillation, and ester oil obtained directly
from a natural source (such as plant matters and animal tissues) or
directly from a chemical esterification process. Refined oil base
stocks are those un-refined base stocks further subjected to one or
more purification steps such as solvent extraction, secondary
distillation, acid extraction, base extraction, filtration, and
percolation to improve the at least one lubricating oil property.
Re-refined oil base stocks are obtained by processes analogous to
refined oils but using an oil that has been previously used as a
feed stock.
[0060] Groups I, II, III, IV, and V are broad base oil stock
categories 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 have a viscosity index
of between about 80 to 120 and contain greater than about 0.03%
sulfur and/or less than about 90% saturates. Group II base stocks
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 stocks have a viscosity index
greater than about 120 and contain less than or equal to about
0.03% sulfur and greater than about 90% saturates. Group IV
includes polyalphaolefins (PAO). Group V base stock includes 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 .sup. <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
polyalphaolefins (PAO) Group V All other base oil stocks not
included in Groups I, II, III or IV
[0061] 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. 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.
[0062] Group II and/or Group III hydroprocessed or hydrocracked
base stocks, including synthetic oils such as alkyl aromatics and
synthetic esters are also well known base stock oils.
[0063] Synthetic oils include hydrocarbon oil. Hydrocarbon oils
include oils 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 are 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.
[0064] The number average molecular weights of the PAOs, which are
known materials and generally available on a major commercial scale
from suppliers such as ExxonMobil Chemical Company, Chevron
Phillips Chemical Company, BP, and others, typically vary from
about 250 to about 3,000, although PAO's may be made in viscosities
up to about 150 cSt (100.degree. C.). The PAOs are typically
comprised of relatively low molecular weight hydrogenated polymers
or oligomers of alphaolefins which include, but are not limited to,
C.sub.2 to about C.sub.32 alphaolefins with the C.sub.8 to about
C.sub.16 alphaolefins, such as 1-octene, 1-decene, 1-dodecene and
the like, being preferred. The preferred polyalphaolefins are
poly-1-octene, poly-1-decene and poly-1-dodecene and mixtures
thereof and mixed olefin-derived polyolefins. However, the dimers
of higher olefins in the range of C.sub.14 to C.sub.18 may be used
to provide low viscosity base stocks of acceptably low volatility.
Depending on the viscosity grade and the starting oligomer, the
PAOs may be predominantly trimers and tetramers of the starting
olefins, with minor amounts of the higher oligomers, having a
viscosity range of 1.5 to 12 cSt. PAO fluids of particular use may
include 3.0 cSt, 3.4 cSt, and/or 3.6 cSt and combinations thereof.
Mixtures of PAO fluids having a viscosity range of 1.5 to
approximately 150 cSt or more may be used if desired.
[0065] The PAO fluids may be conveniently made by the
polymerization of an alphaolefin in the presence of a
polymerization catalyst such as the Friedel-Crafts catalysts
including, for example, aluminum trichloride, boron trifluoride or
complexes of boron trifluoride with water, alcohols such as
ethanol, propanol or butanol, carboxylic acids or esters such as
ethyl acetate or ethyl propionate. For example the methods
disclosed by U.S. Pat. No. 4,149,178 or 3,382,291 may be
conveniently used herein. Other descriptions of PAO synthesis are
found in the following U.S. Pat. Nos. 3,742,082; 3,769,363;
3,876,720; 4,239,930; 4,367,352; 4,413,156; 4,434,408; 4,910,355;
4,956,122; and 5,068,487. The dimers of the C.sub.14 to C.sub.18
olefins are described in U.S. Pat. No. 4,218,330.
[0066] Other useful lubricant oil base stocks include wax isomerate
base stocks and base oils, comprising hydroisomerized waxy stocks
(e.g. waxy stocks such as gas oils, slack waxes, fuels hydrocracker
bottoms, etc.), hydroisomerized Fischer-Tropsch waxes,
Gas-to-Liquids (GTL) base stocks and base oils, and other wax
isomerate hydroisomerized base stocks and base oils, or mixtures
thereof. Fischer-Tropsch waxes, the high boiling point residues of
Fischer-Tropsch synthesis, are highly paraffinic hydrocarbons with
very low sulfur content. The hydroprocessing used for the
production of such base stocks may use an amorphous
hydrocracking/hydroisomerization catalyst, such as one of the
specialized lube hydrocracking (LHDC) catalysts or a crystalline
hydrocracking/hydroisomerization catalyst, preferably a zeolitic
catalyst. For example, one useful catalyst is ZSM-48 as described
in U.S. Pat. No. 5,075,269, the disclosure of which is incorporated
herein by reference in its entirety. Processes for making
hydrocracked/hydroisomerized distillates and
hydrocracked/hydroisomerized waxes are described, for example, in
U.S. Pat. Nos. 2,817,693; 4,975,177; 4,921,594 and 4,897,178 as
well as in British Patent Nos. 1,429,494; 1,350,257; 1,440,230 and
1,390,359. Each of the aforementioned patents is incorporated
herein in their entirety. Particularly favorable processes are
described in European Patent Application Nos. 464546 and 464547,
also incorporated herein by reference. Processes using
Fischer-Tropsch wax feeds are described in U.S. Pat. Nos. 4,594,172
and 4,943,672, the disclosures of which are incorporated herein by
reference in their entirety.
[0067] Gas-to-Liquids (GTL) base oils, Fischer-Tropsch wax derived
base oils, and other wax-derived hydroisomerized (wax isomerate)
base oils be advantageously used in the instant disclosure, and may
have useful kinematic viscosities at 100.degree. C. of about 3 cSt
to about 50 cSt, preferably about 3 cSt to about 30 cSt, more
preferably about 3.5 cSt to about 25 cSt, as exemplified by GTL 4
with kinematic viscosity of about 4.0 cSt at 100.degree. C. and a
viscosity index of about 141. These Gas-to-Liquids (GTL) base oils,
Fischer-Tropsch wax derived base oils, and other wax-derived
hydroisomerized base oils may have useful pour points of about
-20.degree. C. or lower, and under some conditions may have
advantageous pour points of about -25.degree. C. or lower, with
useful pour points of about -30.degree. C. to about -40.degree. C.
or lower. Useful compositions of Gas-to-Liquids (GTL) base oils,
Fischer-Tropsch wax derived base oils, and wax-derived
hydroisomerized base oils are recited in U.S. Pat. Nos. 6,080,301;
6,090,989, and 6,165,949 for example, and are incorporated herein
in their entirety by reference.
[0068] The hydrocarbyl aromatics can be used as a base oil or base
oil component and can be any hydrocarbyl molecule that contains at
least about 5% of its weight derived from an aromatic moiety such
as a benzenoid moiety or naphthenoid moiety, or their derivatives.
These hydrocarbyl aromatics include alkyl benzenes, alkyl
naphthalenes, alkyl diphenyl oxides, alkyl naphthols, alkyl
diphenyl sulfides, alkylated bis-phenol A, alkylated thiodiphenol,
and the like. The aromatic can be mono-alkylated, dialkylated,
polyalkylated, and the like. The aromatic can be mono- or
poly-functionalized. The hydrocarbyl groups can also be comprised
of mixtures of alkyl groups, alkenyl groups, alkynyl, cycloalkyl
groups, cycloalkenyl groups and other related hydrocarbyl groups.
The hydrocarbyl groups can range from about C.sub.6 up to about
C.sub.60 with a range of about C.sub.8 to about C.sub.20 often
being preferred. A mixture of hydrocarbyl groups is often
preferred, and up to about three such substituents may be present.
The hydrocarbyl group can optionally contain sulfur, oxygen, and/or
nitrogen containing substituents. The aromatic group can also be
derived from natural (petroleum) sources, provided at least about
5% of the molecule is comprised of an above-type aromatic moiety.
Viscosities at 100.degree. C. of approximately 3 cSt to about 50
cSt are preferred, with viscosities of approximately 3.4 cSt to
about 20 cSt often being more preferred for the hydrocarbyl
aromatic component. In one embodiment, an alkyl naphthalene where
the alkyl group is primarily comprised of 1-hexadecene is used.
Other alkylates of aromatics can be advantageously used.
Naphthalene or methyl naphthalene, for example, can be alkylated
with olefins such as octene, decene, dodecene, tetradecene or
higher, mixtures of similar olefins, and the like. Useful
concentrations of hydrocarbyl aromatic in a lubricant oil
composition can be about 2% to about 25%, preferably about 4% to
about 20%, and more preferably about 4% to about 15%, depending on
the application.
[0069] Alkylated aromatics such as the hydrocarbyl aromatics of the
present disclosure may be produced by well-known Friedel-Crafts
alkylation of aromatic compounds. See Friedel-Crafts and Related
Reactions, Olah, G. A. (ed.), Inter-science Publishers, New York,
1963. For example, an aromatic compound, such as benzene or
naphthalene, is alkylated by an olefin, alkyl halide or alcohol in
the presence of a Friedel-Crafts catalyst. See Friedel-Crafts and
Related Reactions, Vol. 2, part 1, chapters 14, 17, and 18, See
Olah, G. A. (ed.), Inter-science Publishers, New York, 1964. Many
homogeneous or heterogeneous, solid catalysts are known to one
skilled in the art. The choice of catalyst depends on the
reactivity of the starting materials and product quality
requirements. For example, strong acids such as AlCl.sub.3,
BF.sub.3, or HF may be used. In some cases, milder catalysts such
as FeCl.sub.3 or SnCl.sub.4 are preferred. Newer alkylation
technology uses zeolites or solid super acids.
[0070] Esters comprise a useful base stock. 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, alkyl succinic acid, alkenyl succinic
acid, maleic acid, azelaic acid, suberic 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.
[0071] 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 acid, 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.
[0072] Suitable synthetic ester components include the esters of
trimethylol propane, trimethylol butane, trimethylol ethane,
pentaerythritol and/or dipentaerythritol with one or more
monocarboxylic acids containing from about 5 to about 10 carbon
atoms. These esters are widely available commercially, for example,
the Mobil P-41 and P-51 esters of ExxonMobil Chemical Company.
[0073] Also useful are esters derived from renewable material such
as coconut, palm, rapeseed, soy, sunflower and the like. These
esters may be monoesters, di-esters, polyol esters, complex esters,
or mixtures thereof. These esters are widely available
commercially, for example, the Esterex NP 343 ester of ExxonMobil
Chemical Company.
[0074] More particularly, branched polyol esters comprise a useful
base stock of this disclosure. The branched polyol esters 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 single or mixed
branched mono-carboxylic acids containing at least about 4 carbon
atoms, preferably C.sub.5 to C.sub.30 branched mono-carboxylic
acids including 2,2-dimethyl propionic acid (neopentanoic acid),
neoheptanoic acid, neooctanoic acid, neononanoic acid, iso-hexanoic
acid, neodecanoic acid, 2-ethyl hexanoic acid (2EH),
3,5,5-trimethyl hexanoic acid (TMH), isoheptanoic acid, isooctanoic
acid, isononanoic acid, isodecanoic acid, or mixtures of any of
these materials. These branched polyol esters include fully
converted and partially converted polyol esters.
[0075] Particularly useful polyols include, for example, neopentyl
glycol, 2,2-dimethylol butane, trimethylol ethane, trimethylol
propane, trimethylol butane, mono-pentaerythritol, technical grade
pentaerythritol, di-pentaerythritol, tri-pentaerythritol, ethylene
glycol, propylene glycol and polyalkylene glycols (e.g.,
polyethylene glycols, polypropylene glycols, 1,4-butanediol,
sorbitol and the like, 2-methylpropanediol, polybutylene glycols,
etc., and blends thereof such as a polymerized mixture of ethylene
glycol and propylene glycol). The most preferred alcohols are
technical grade (e.g., approximately 88% mono-, 10% di- and 1-2%
tri-pentaerythritol) pentaerythritol, mono-pentaerythritol,
di-pentaerythritol, neopentyl glycol and trimethylol propane.
[0076] Particularly useful branched mono-carboxylic acids include,
for example, 2,2-dimethyl propionic acid (neopentanoic acid),
neoheptanoic acid, neooctanoic acid, neononanoic acid, iso-hexanoic
acid, neodecanoic acid, 2-ethyl hexanoic acid (2EH),
3,5,5-trimethyl hexanoic acid (TMH), isoheptanoic acid, isooctanoic
acid, isononanoic acid, isodecanoic acid, or mixtures of any of
these materials. One especially preferred branched acid is
3,5,5-trimethyl hexanoic acid. The term "neo" as used herein refers
to a trialkyl acetic acid, i.e., an acid which is triply
substituted at the alpha carbon with alkyl groups.
[0077] Preferably, the branched polyol ester is derived from a
polyhydric alcohol and a branched mono-carboxylic acid. In
particular, the branched polyol ester is obtained by reacting one
or more polyhydric alcohols with one or more branched
mono-carboxylic acids containing at least about 4 carbon atoms.
[0078] Preferred branched polyol esters useful in this disclosure
include, for example, mono-pentaerythritol ester of branched
mono-carboxylic acids, di-pentaerythritol ester of branched
mono-carboxylic acids, trimethylolpropane ester of C8-C10 acids,
and the like.
[0079] Other synthetic esters that can be useful in this disclosure
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 mono carboxylic acids
containing at least about 4 carbon atoms, preferably branched
C.sub.5 to C.sub.30 acids including caprylic acid, capric acid,
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.
[0080] Other ester base oils useful in this disclosure include
adipate esters. The dialkyl adipate ester is derived from adipic
acid and a branched alkyl alcohol.
[0081] Mixtures of branched polyol ester base stocks with other
lubricating oil base stocks (e.g., Groups I, II, III, IV and V base
stocks) may be useful in the lubricating oil formulations of this
disclosure.
[0082] The branched polyol ester can be present in an amount of
from about 1 to about 50 weight percent, or from about 5 to about
45 weight percent, or from about 10 to about 40 weight percent, or
from about 15 to about 35 weight percent, or from about 20 to about
30 weight percent, based on the total weight of the formulated
oil.
[0083] Engine oil formulations containing renewable esters are
included in this disclosure. For such formulations, the renewable
content of the ester is typically greater than about 70 weight
percent, preferably more than about 80 weight percent and most
preferably more than about 90 weight percent.
[0084] Other useful fluids of lubricating viscosity include
non-conventional or unconventional base stocks that have been
processed, preferably catalytically, or synthesized to provide high
performance lubrication characteristics.
[0085] Non-conventional or unconventional base stocks/base oils
include one or more of a mixture of base stock(s) derived from one
or more Gas-to-Liquids (GTL) materials, as well as
isomerate/isodewaxate base stock(s) derived from natural wax or
waxy feeds, mineral and or non-mineral oil waxy feed stocks such as
slack waxes, natural waxes, and waxy stocks such as gas oils, waxy
fuels hydrocracker bottoms, waxy raffinate, hydrocrackate, thermal
crackates, or other mineral, mineral oil, or even non-petroleum oil
derived waxy materials such as waxy materials received from coal
liquefaction or shale oil, and mixtures of such base stocks.
[0086] 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.
[0087] 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).
[0088] 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 phosphorus and aromatics make this
materially especially suitable for the formulation of low SAP
products.
[0089] 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.
[0090] 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).
[0091] 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, and
Group V oils and mixtures thereof, preferably API Group II, Group
III, Group IV, and Group V oils and mixtures thereof, more
preferably the Group III to Group V 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.
Groups II and III base stocks can be included in the lubricating
oil formulations of this disclosure, but preferably only those with
high quality, e.g., those having a VI from 100 to 120. Group IV and
V base stocks, preferably those of high quality, are desirably
included into the lubricating oil formulations of this
disclosure.
[0092] The base oil constitutes the major component of the
lubricating oil compositions of the present disclosure and
typically is present in an amount ranging from about 5 to about 99
weight percent, or about 7 to about 95 weight percent, or about 10
to about 90 weight percent, or about 20 to about 80 weight percent,
preferably 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. The base oil may be selected from
any of the synthetic or natural oils typically used as crankcase
lubricating oils for spark-ignited and compression-ignited engines.
The base oil conveniently has a kinematic viscosity, according to
ASTM standards, of about 2.5 cSt to about 12 cSt (or mm.sup.2/s) at
100.degree. C. and preferably of about 2.5 cSt to about 9 cSt (or
mm.sup.2/s) at 100.degree. C. Mixtures of synthetic and natural
base oils may be used if desired. Bi-modal mixtures of Group I, II,
III, IV, and/or V base stocks may be used if desired. A second base
stock or co-base stock may be also optionally incorporated into the
lubricating oil compositions of this disclosure in an amount
ranging from about 5 to about 80 weight percent, or about 10 to
about 60 weight percent, or about 15 to about 50 weight percent, or
about 20 to about 40 weight percent, or from about 25 to about 35
weight percent.
Other Lubricating Oil Additives of the Lubricating Oil Compositions
of this Disclosure
[0093] The lubricating oil compositions (preferably lubricating oil
formulations) of this disclosure may additionally contain one or
more of the commonly used other lubricating oil performance
additives including but not limited to dispersants, detergents,
viscosity modifiers, antiwear additives, corrosion inhibitors, rust
inhibitors, metal deactivators, extreme pressure additives,
anti-seizure agents, wax modifiers, fluid-loss additives, seal
compatibility agents, lubricity agents, anti-staining agents,
chromophoric agents, defoamants, demulsifiers, densifiers, wetting
agents, gelling agents, tackiness agents, colorants, and others.
For a review of many commonly used additives and the quantities
used, see: (i) Klamann in Lubricants and Related Products, Verlag
Chemie, Deerfield Beach, Fla.; ISBN 0-89573-177-0; (ii) "Lubricant
Additives," M. W. Ranney, published by Noyes Data Corporation of
Parkridge, N J (1973); (iii) "Synthetics, Mineral Oils, and
Bio-Based Lubricants," Edited by L. R. Rudnick, CRC Taylor and
Francis, 2006, ISBN 1-57444-723-8; (iv) "Lubrication Fundamentals",
J. G. Wills, Marcel Dekker Inc., (New York, 1980); (v) Synthetic
Lubricants and High-Performance Functional Fluids, 2nd Ed., Rudnick
and Shubkin, Marcel Dekker Inc., (New York, 1999); and (vi)
"Polyalphaolefins," L. R. Rudnick, Chemical Industries (Boca Raton,
Fla., United States) (2006), 111 (Synthetics, Mineral Oils, and
Bio-Based Lubricants), 3-36. Reference is also made to: (a) U.S.
Pat. No. 7,704,930 B2; (b) U.S. Pat. No. 9,458,403 B2, Column 18,
line 46 to Colum 39, line 68; (c) U.S. Pat. No. 9,422,497 B2,
Column 34, line 4 to Column 40, line 55; and (d) U.S. Pat. No.
8,048,833 B2, Column 17, line 48 to Colum 27, line 12, the
disclosures of which are incorporated herein in its entirety. These
additives are commonly delivered with varying amounts of diluent
oil that may range from 5 wt % to 50 wt % based on the total weight
of the additive package before incorporation into the formulated
oil.
[0094] Further details of the other lubricating oil additives
useful in the lubricating oil compositions of this disclosure are
as follows:
Friction Modifiers
[0095] 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.
[0096] Illustrative friction modifiers may include, for example,
inorganic compounds or materials, or mixtures thereof. Illustrative
inorganic 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.
[0097] 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.
[0098] 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.
[0099] 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.
[0100] 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.
[0101] 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.
[0102] Illustrative fatty alcohol ethers include, for example,
stearyl ether, myristyl ether, and the like. Alcohols, including
those that have carbon numbers from C.sub.3 to C.sub.50, can be
ethoxylated, propoxylated, or butoxylated to form the corresponding
fatty alkyl ethers. The underlying alcohol portion can preferably
be stearyl, myristyl, C.sub.11-C.sub.13 hydrocarbon, oleyl,
isosteryl, and the like.
[0103] 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 700 ppm
or more, and often with a preferred range of 50-200 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.
Antiwear Additives
[0104] A metal alkylthiophosphate and more particularly a metal
dialkyl dithio phosphate in which the metal constituent is zinc, or
zinc dialkyl dithio phosphate (ZDDP) can be a useful component of
the lubricating oils of this disclosure. ZDDP can be derived from
primary alcohols, secondary alcohols or mixtures thereof. ZDDP
compounds generally are of the formula
Zn[SP(S)(OR.sup.1)(OR.sup.2)].sub.2
where R.sup.1 and R.sup.2 are C.sub.1-C.sub.18 alkyl groups,
preferably C.sub.2-C.sub.12 alkyl groups. These alkyl groups may be
straight chain or branched. Alcohols used in the ZDDP can be
2-propanol, butanol, secondary butanol, pentanols, hexanols such as
4-methyl-2-pentanol, n-hexanol, n-octanol, 2-ethyl hexanol,
alkylated phenols, and the like. Mixtures of secondary alcohols or
of primary and secondary alcohol can be preferred. Alkyl aryl
groups may also be used.
[0105] Preferable zinc dithiophosphates which are commercially
available include secondary zinc dithiophosphates such as those
available from for example, The Lubrizol Corporation under the
trade designations "LZ 677A", "LZ 1095" and "LZ 1371", from for
example Chevron Oronite under the trade designation "OLOA 262" and
from for example Afton Chemical under the trade designation "HITEC
7169".
[0106] The ZDDP is typically used in amounts of from about 0.4
weight percent to about 1.2 weight percent, preferably from about
0.5 weight percent to about 1.0 weight percent, and more preferably
from about 0.6 weight percent to about 0.8 weight percent, based on
the total weight of the lubricating oil, although more or less can
often be used advantageously. Preferably, the ZDDP is a secondary
ZDDP and present in an amount of from about 0.6 to 1.0 weight
percent of the total weight of the lubricating oil.
[0107] Low phosphorus engine oil formulations are included in this
disclosure. For such formulations, the phosphorus content is
typically less than about 0.12 weight percent preferably less than
about 0.10 weight percent and most preferably less than about 0.085
weight percent.
Dispersants
[0108] During engine operation, oil-insoluble oxidation byproducts
are produced. Dispersants help keep these byproducts in solution,
thus diminishing their deposition on metal surfaces. Dispersants
used in the formulation of the lubricating oil 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 herein form ash upon combustion.
[0109] 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.
[0110] A particularly useful class of dispersants are the
(poly)alkenylsuccinic derivatives, typically produced by the
reaction of a long chain hydrocarbyl substituted succinic compound,
usually a hydrocarbyl substituted succinic anhydride, with a
polyhydroxy or polyamino compound. The long chain hydrocarbyl 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 U.S. patents describing such
dispersants are U.S. Pat. Nos. 3,172,892; 3,215,707; 3,219,666;
3,316,177; 3,341,542; 3,444,170; 3,454,607; 3,541,012; 3,630,904;
3,632,511; 3,787,374 and 4,234,435. Other types of dispersant are
described in U.S. Pat. Nos. 3,036,003; 3,200,107; 3,254,025;
3,275,554; 3,438,757; 3,454,555; 3,565,804; 3,413,347; 3,697,574;
3,725,277; 3,725,480; 3,726,882; 4,454,059; 3,329,658; 3,449,250;
3,519,565; 3,666,730; 3,687,849; 3,702,300; 4,100,082; 5,705,458. A
further description of dispersants may be found, for example, in
European Patent Application No. 471 071, to which reference is made
for this purpose.
[0111] Hydrocarbyl-substituted succinic acid and
hydrocarbyl-substituted succinic anhydride derivatives are useful
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.
[0112] Succinimides are formed by the condensation reaction between
hydrocarbyl substituted succinic anhydrides and amines. Molar
ratios can vary depending on the polyamine. For example, the molar
ratio of hydrocarbyl substituted succinic anhydride to TEPA can
vary from about 1:1 to about 5:1. Representative examples are shown
in U.S. Pat. Nos. 3,087,936; 3,172,892; 3,219,666; 3,272,746;
3,322,670; and 3,652,616, 3,948,800; and Canada Patent No.
1,094,044.
[0113] Succinate esters are formed by the condensation reaction
between hydrocarbyl substituted succinic anhydrides and alcohols or
polyols. Molar ratios can vary depending on the alcohol or polyol
used. For example, the condensation product of a hydrocarbyl
substituted succinic anhydride and pentaerythritol is a useful
dispersant.
[0114] Succinate ester amides are formed by condensation reaction
between hydrocarbyl substituted 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. Representative examples are
shown in U.S. Pat. No. 4,426,305.
[0115] The molecular weight of the hydrocarbyl substituted succinic
anhydrides used in the preceding paragraphs will typically range
between 800 and 2,500 or more. The above products can be
post-reacted with various reagents such as sulfur, oxygen,
formaldehyde, carboxylic acids such as oleic acid. The above
products can also be post reacted with boron compounds such as
boric acid, borate esters or highly borated dispersants, to form
borated dispersants generally having from about 0.1 to about 5
moles of boron per mole of dispersant reaction product.
[0116] Mannich base dispersants are made from the reaction of
alkylphenols, formaldehyde, and amines. See U.S. Pat. No.
4,767,551, which is incorporated herein by reference. 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. Representative examples are shown in U.S.
Pat. Nos. 3,697,574; 3,703,536; 3,704,308; 3,751,365; 3,756,953;
3,798,165; and 3,803,039.
[0117] Typical high molecular weight aliphatic acid modified
Mannich condensation products useful in this disclosure can be
prepared from high molecular weight alkyl-substituted
hydroxyaromatics or HNR.sub.2 group-containing reactants.
[0118] Hydrocarbyl substituted amine ashless dispersant additives
are well known to one skilled in the art; see, for example, U.S.
Pat. Nos. 3,275,554; 3,438,757; 3,565,804; 3,755,433, 3,822,209,
and 5,084,197.
[0119] 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 from about 1000 to about 3000, or about
1000 to about 2000, or a mixture of such hydrocarbylene groups,
often with high terminal vinylic groups. Other preferred
dispersants include succinic acid-esters and amides,
alkylphenol-polyamine-coupled Mannich adducts, their capped
derivatives, and other related components.
[0120] Polymethacrylate or polyacrylate derivatives are another
class of dispersants. These dispersants are typically prepared by
reacting a nitrogen containing monomer and a methacrylic or acrylic
acid esters containing 5-25 carbon atoms in the ester group.
Representative examples are shown in U.S. Pat. Nos. 2,100,993, and
6,323,164. Polymethacrylate and polyacrylate dispersants are
normally used as multifunctional viscosity modifiers. The lower
molecular weight versions can be used as lubricant dispersants or
fuel detergents.
[0121] Illustrative preferred dispersants useful in this disclosure
include those derived from polyalkenyl-substituted mono- or
dicarboxylic acid, anhydride or ester, which dispersant has a
polyalkenyl moiety with a number average molecular weight of at
least 900 and from greater than 1.3 to 1.7, preferably from greater
than 1.3 to 1.6, most preferably from greater than 1.3 to 1.5,
functional groups (mono- or dicarboxylic acid producing moieties)
per polyalkenyl moiety (a medium functionality dispersant).
Functionality (F) can be determined according to the following
formula:
F=(SAP.times.M.sub.n)/((112,200.times.A.I.)-(SAP.times.98))
wherein SAP is the saponification number (i.e., the number of
milligrams of KOH consumed in the complete neutralization of the
acid groups in one gram of the succinic-containing reaction
product, as determined according to ASTM D94); M.sub.n is the
number average molecular weight of the starting olefin polymer; and
A.I. is the percent active ingredient of the succinic-containing
reaction product (the remainder being unreacted olefin polymer,
succinic anhydride and diluent).
[0122] The polyalkenyl moiety of the dispersant may have a number
average molecular weight of at least 900, suitably at least 1500,
preferably between 1800 and 3000, such as between 2000 and 2800,
more preferably from about 2100 to 2500, and most preferably from
about 2200 to about 2400. The molecular weight of a dispersant is
generally expressed in terms of the molecular weight of the
polyalkenyl moiety. This is because the precise molecular weight
range of the dispersant depends on numerous parameters including
the type of polymer used to derive the dispersant, the number of
functional groups, and the type of nucleophilic group employed.
[0123] Polymer molecular weight, specifically M.sub.n, can be
determined by various known techniques. One convenient method is
gel permeation chromatography (GPC), which additionally provides
molecular weight distribution information (see W. W. Yau, J. J.
Kirkland and D. D. Bly, "Modern Size Exclusion Liquid
Chromatography", John Wiley and Sons, New York, 1979). Another
useful method for determining molecular weight, particularly for
lower molecular weight polymers, is vapor pressure osmometry (e.g.,
ASTM D3592).
[0124] The polyalkenyl moiety in a dispersant preferably has a
narrow molecular weight distribution (MWD), also referred to as
polydispersity, as determined by the ratio of weight average
molecular weight (M.sub.w) to number average molecular weight
(M.sub.n). Polymers having a M.sub.w/M.sub.n of less than 2.2,
preferably less than 2.0, are most desirable. Suitable polymers
have a polydispersity of from about 1.5 to 2.1, preferably from
about 1.6 to about 1.8.
[0125] Suitable polyalkenes employed in the formation of the
dispersants include homopolymers, interpolymers or lower molecular
weight hydrocarbons. One family of such polymers comprise polymers
of ethylene and/or at least one C.sub.3 to C.sub.2 alpha-olefin
having the formula H.sub.2C=CHR.sup.1 wherein R.sup.1 is a straight
or branched chain alkyl radical comprising 1 to 26 carbon atoms and
wherein the polymer contains carbon-to-carbon unsaturation, and a
high degree of terminal ethenylidene unsaturation. Preferably, such
polymers comprise interpolymers of ethylene and at least one
alpha-olefin of the above formula, wherein R.sup.1 is alkyl of from
1 to 18 carbon atoms, and more preferably is alkyl of from 1 to 8
carbon atoms, and more preferably still of from 1 to 2 carbon
atoms.
[0126] Another useful class of polymers is polymers prepared by
cationic polymerization of monomers such as isobutene and styrene.
Common polymers from this class include polyisobutenes obtained by
polymerization of a C.sub.4 refinery stream having a butene content
of 35 to 75% by wt., and an isobutene content of 30 to 60% by wt. A
preferred source of monomer for making poly-n-butenes is petroleum
feedstreams such as Raffinate II. These feedstocks are disclosed in
the art such as in U.S. Pat. No. 4,952,739. A preferred embodiment
utilizes polyisobutylene prepared from a pure isobutylene stream or
a Raffinate I stream to prepare reactive isobutylene polymers with
terminal vinylidene olefins. Polyisobutene polymers that may be
employed are generally based on a polymer chain of from 1500 to
3000.
[0127] The dispersant(s) are preferably non-polymeric (e.g., mono-
or bis-succinimides). Such dispersants can be prepared by
conventional processes such as disclosed in U.S. Patent Application
Publication No. 2008/0020950, the disclosure of which is
incorporated herein by reference.
[0128] The dispersant(s) can be borated by conventional means, as
generally disclosed in U.S. Pat. Nos. 3,087,936, 3,254,025 and
5,430,105.
[0129] Such dispersants may be used in an amount of about 0.01 to
20 weight percent or 0.01 to 10 weight percent, preferably about
0.5 to 8 weight percent, or more preferably 0.5 to 4 weight
percent. Or such dispersants may be used in an amount of about 2 to
12 weight percent, preferably about 4 to 10 weight percent, or more
preferably 6 to 9 weight percent. On an active ingredient basis,
such additives may be used in an amount of about 0.06 to 14 weight
percent, preferably about 0.3 to 6 weight percent. The hydrocarbon
portion of the dispersant atoms can range from C.sub.60 to
C.sub.1000, or from C.sub.70 to C.sub.300, or from C.sub.70 to
C.sub.200. These dispersants may contain both neutral and basic
nitrogen, and mixtures of both. Dispersants can be end-capped by
borates and/or cyclic carbonates. Nitrogen content in the finished
oil can vary from about 200 ppm by weight to about 2000 ppm by
weight, preferably from about 200 ppm by weight to about 1200 ppm
by weight. Basic nitrogen can vary from about 100 ppm by weight to
about 1000 ppm by weight, preferably from about 100 ppm by weight
to about 600 ppm by weight.
[0130] As used herein, the dispersant concentrations are given on
an "as delivered" basis. Typically, the active dispersant is
delivered with a process oil. The "as delivered" dispersant
typically contains from about 20 weight percent to about 80 weight
percent, or from about 40 weight percent to about 60 weight
percent, of active dispersant in the "as delivered" dispersant
product.
Detergents
[0131] Illustrative detergents useful in this disclosure include,
for example, alkali metal detergents, alkaline earth metal
detergents, or mixtures of one or more alkali metal detergents and
one or more alkaline earth metal detergents. A typical detergent is
an anionic material that contains a long chain hydrophobic portion
of the molecule and a smaller anionic or oleophobic hydrophilic
portion of the molecule. The anionic portion of the detergent is
typically derived from an organic acid such as a sulfur-containing
acid, carboxylic acid (e.g., salicylic acid), phosphorus-containing
acid, phenol, or mixtures thereof. The counterion is typically an
alkaline earth or alkali metal. The detergent can be overbased as
described herein.
[0132] The detergent is preferably a metal salt of an organic or
inorganic acid, a metal salt of a phenol, or mixtures thereof. The
metal is preferably selected from an alkali metal, an alkaline
earth metal, and mixtures thereof. The organic or inorganic acid is
selected from an aliphatic organic or inorganic acid, a
cycloaliphatic organic or inorganic acid, an aromatic organic or
inorganic acid, and mixtures thereof.
[0133] The metal is preferably selected from an alkali metal, an
alkaline earth metal, and mixtures thereof. More preferably, the
metal is selected from calcium (Ca), magnesium (Mg), and mixtures
thereof.
[0134] The organic acid or inorganic acid is preferably selected
from a sulfur-containing acid, a carboxylic acid, a
phosphorus-containing acid, and mixtures thereof.
[0135] Preferably, the metal salt of an organic or inorganic acid
or the metal salt of a phenol comprises calcium phenate, calcium
sulfonate, calcium salicylate, magnesium phenate, magnesium
sulfonate, magnesium salicylate, an overbased detergent, and
mixtures thereof.
[0136] Salts that contain a substantially stochiometric amount of
the metal are described as neutral salts and have a total base
number (TBN, as measured by ASTM D2896) of from 0 to 80. Many
compositions are overbased, containing large amounts of a metal
base that is achieved by reacting an excess of a metal compound (a
metal hydroxide or oxide, for example) with an acidic gas (such as
carbon dioxide). Useful detergents can be neutral, mildly
overbased, or highly overbased. These detergents can be used in
mixtures of neutral, overbased, highly overbased calcium
salicylate, sulfonates, phenates and/or magnesium salicylate,
sulfonates, phenates. The TBN ranges can vary from low, medium to
high TBN products, including as low as 0 to as high as 600.
Preferably the TBN delivered by the detergent is between 1 and 20.
More preferably between 1 and 12. Mixtures of low, medium, high TBN
can be used, along with mixtures of calcium and magnesium metal
based detergents, and including sulfonates, phenates, salicylates,
and carboxylates. A detergent mixture with a metal ratio of 1, in
conjunction of a detergent with a metal ratio of 2, and as high as
a detergent with a metal ratio of 5, can be used. Borated
detergents can also be used.
[0137] Alkaline earth phenates are another useful class of
detergent. These detergents can be made by reacting alkaline earth
metal hydroxide or oxide (CaO, Ca(OH).sub.2, BaO, Ba(OH).sub.2,
MgO, Mg(OH).sub.2, for example) with an alkyl phenol or sulfurized
alkylphenol. Useful alkyl groups include straight chain or branched
C.sub.1-C.sub.30 alkyl groups, preferably, C.sub.4-C.sub.20 or
mixtures thereof. Examples of suitable phenols include
isobutylphenol, 2-ethylhexylphenol, nonylphenol, dodecyl phenol,
and the like. It should be noted that starting alkylphenols may
contain more than one alkyl substituent that are each independently
straight chain or branched and can be used from 0.5 to 6 weight
percent. When a non-sulfurized alkylphenol is used, the sulfurized
product may be obtained by methods well known in the art. These
methods include heating a mixture of alkylphenol and sulfurizing
agent (including elemental sulfur, sulfur halides such as sulfur
dichloride, and the like) and then reacting the sulfurized phenol
with an alkaline earth metal base.
[0138] In accordance with this disclosure, metal salts of
carboxylic acids are preferred detergents. These carboxylic acid
detergents may be prepared by reacting a basic metal compound with
at least one carboxylic acid and removing free water from the
reaction product. These compounds may be overbased to produce the
desired TBN level. Detergents made from salicylic acid are one
preferred class of detergents derived from carboxylic acids. Useful
salicylates include long chain alkyl salicylates. One useful family
of compositions is of the formula
##STR00002##
where R is an alkyl group having 1 to about 30 carbon atoms, n is
an integer from 1 to 4, and M is an alkaline earth metal. Preferred
R groups are alkyl chains of at least C.sub.11, preferably C.sub.13
or greater. R may be optionally substituted with substituents that
do not interfere with the detergent's function. M is preferably,
calcium, magnesium, barium, or mixtures thereof. More preferably, M
is calcium.
[0139] Hydrocarbyl-substituted salicylic acids may be prepared from
phenols by the Kolbe reaction (see U.S. Pat. No. 3,595,791). The
metal salts of the hydrocarbyl-substituted salicylic acids may be
prepared by double decomposition of a metal salt in a polar solvent
such as water or alcohol.
[0140] Alkaline earth metal phosphates are also used as detergents
and are known in the art.
[0141] Detergents may be simple detergents or what is known as
hybrid or complex detergents. The latter detergents can provide the
properties of two detergents without the need to blend separate
materials. See U.S. Pat. No. 6,034,039.
[0142] Preferred detergents include calcium sulfonates, magnesium
sulfonates, calcium salicylates, magnesium salicylates, calcium
phenates, magnesium phenates, and other related components
(including borated detergents), and mixtures thereof. Preferred
mixtures of detergents include magnesium sulfonate and calcium
salicylate, magnesium sulfonate and calcium sulfonate, magnesium
sulfonate and calcium phenate, calcium phenate and calcium
salicylate, calcium phenate and calcium sulfonate, calcium phenate
and magnesium salicylate, calcium phenate and magnesium phenate.
Overbased detergents are also preferred.
[0143] The detergent concentration in the lubricating oils of this
disclosure can range from about 0.5 to about 6.0 weight percent,
preferably about 0.6 to 5.0 weight percent, and more preferably
from about 0.8 weight percent to about 4.0 weight percent, based on
the total weight of the lubricating oil.
[0144] As used herein, the detergent concentrations are given on an
"as delivered" basis. Typically, the active detergent is delivered
with a process oil. The "as delivered" detergent typically contains
from about 20 weight percent to about 100 weight percent, or from
about 40 weight percent to about 60 weight percent, of active
detergent in the "as delivered" detergent product.
Antioxidants
[0145] Antioxidants retard the oxidative degradation of base oils
during service. Such degradation may result in deposits on metal
surfaces, the presence of sludge, or a viscosity increase in the
lubricant. One skilled in the art knows a wide variety of oxidation
inhibitors that are useful in lubricating oil compositions. See,
Klamann in Lubricants and Related Products, op cite, and U.S. Pat.
Nos. 4,798,684 and 5,084,197, for example.
[0146] Useful antioxidants include hindered phenols. These phenolic
antioxidants may be ashless (metal-free) phenolic compounds or
neutral or basic metal salts of certain phenolic compounds. Typical
phenolic antioxidant compounds are the hindered phenolics which are
the ones 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 antioxidants include the hindered phenols
substituted with C.sub.6+ 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; and 2-methyl-6-t-butyl-4-dodecyl phenol. Other useful
hindered mono-phenolic antioxidants may include for example
hindered 2,6-di-alkyl-phenolic proprionic ester derivatives.
Bis-phenolic antioxidants may also be advantageously used in
combination with the instant disclosure. Examples of ortho-coupled
phenols include: 2,2'-bis(4-heptyl-6-t-butyl-phenol);
2,2'-bis(4-octyl-6-t-butyl-phenol); and
2,2'-bis(4-dodecyl-6-t-butyl-phenol). Para-coupled bisphenols
include for example 4,4'-bis(2,6-di-t-butyl phenol) and
4,4'-methylene-bis(2,6-di-t-butyl phenol).
[0147] Effective amounts of one or more catalytic antioxidants may
also be used. The catalytic antioxidants comprise an effective
amount of a) one or more oil soluble polymetal organic compounds;
and, effective amounts of b) one or more substituted
N,N'-diaryl-o-phenylenediamine compounds or c) one or more hindered
phenol compounds; or a combination of both b) and c). Catalytic
antioxidants are more fully described in U.S. Pat. No. 8,048,833,
herein incorporated by reference in its entirety.
[0148] Non-phenolic oxidation inhibitors which may be used include
aromatic amine antioxidants and these may be used either as such or
in combination with phenolics. Typical examples of non-phenolic
antioxidants include: 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)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.
[0149] Typical aromatic amines antioxidants 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 amine antioxidants useful in the
present compositions include diphenylamines, phenyl naphthylamines,
phenothiazines, imidodibenzyls and diphenyl phenylene diamines.
Mixtures of two or more aromatic amines are also useful. Polymeric
amine antioxidants can also be used. Particular examples of
aromatic amine antioxidants useful in the present disclosure
include: p,p'-dioctyldiphenylamine;
t-octylphenyl-alpha-naphthylamine; phenyl-alphanaphthylamine; and
p-octylphenyl-alpha-naphthylamine.
[0150] Sulfurized alkyl phenols and alkali or alkaline earth metal
salts thereof also are useful antioxidants.
[0151] Preferred antioxidants include hindered phenols, arylamines.
These antioxidants may be used individually by type or in
combination with one another. Such additives may be used in an
amount of about 0.01 to 5 weight percent, preferably about 0.01 to
1.5 weight percent, more preferably zero to less than 1.5 weight
percent, more preferably zero to less than 1 weight percent.
Pour Point Depressants (PPDs)
[0152] Conventional pour point depressants (also known as lube oil
flow improvers) may be added to the compositions of the present
disclosure if desired. These pour point depressant may be added to
lubricating compositions of the present disclosure to lower the
minimum temperature at which the fluid will flow or can be poured.
Examples of suitable pour point depressants include
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. U.S. Pat. Nos.
1,815,022; 2,015,748; 2,191,498; 2,387,501; 2,655, 479; 2,666,746;
2,721,877; 2,721,878; and 3,250,715 describe useful pour point
depressants and/or the preparation thereof. Such additives may be
used in an amount of about 0.01 to 5 weight percent, preferably
about 0.01 to 1.5 weight percent.
Seal Compatibility Agents
[0153] 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. Such additives may be used in an amount of
about 0.01 to 3 weight percent, preferably about 0.01 to 2 weight
percent.
Antifoam Agents
[0154] 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 weight
percent and often less than 0.1 weight percent.
Inhibitors and Antirust Additives
[0155] Antirust additives (or corrosion inhibitors) are additives
that protect lubricated metal surfaces against chemical attack by
water or other contaminants. A wide variety of these are
commercially available.
[0156] One type of antirust additive is a polar compound that wets
the metal surface preferentially, protecting it with a film of oil.
Another type of antirust additive absorbs water by incorporating it
in a water-in-oil emulsion so that only the oil touches the metal
surface. Yet another type of antirust 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 weight percent, preferably
about 0.01 to 1.5 weight percent.
[0157] 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.
[0158] When lubricating oil compositions contain one or more of the
additives discussed above, the additive(s) are blended into the
composition in an amount sufficient for it to perform its intended
function. Typical amounts of such additives useful in the present
disclosure are shown in Table 1 below.
[0159] It is noted that many of the additives are shipped from the
additive manufacturer as a concentrate, containing one or more
additives together, with a certain amount of base oil diluents.
Accordingly, the weight amounts in the table below, as well as
other amounts mentioned herein, are directed to the amount of
active ingredient (that is the non-diluent portion of the
ingredient). The weight percent (wt %) indicated below is based on
the total weight of the lubricating oil composition.
[0160] When lubricating oil compositions contain one or more of the
additives discussed above, the additive(s) are blended into the
composition in an amount sufficient for it to perform its intended
function. Typical amounts of such additives useful in the present
disclosure are shown in Table 1 below.
[0161] It is noted that many of the additives are shipped from the
additive manufacturer as a concentrate, containing one or more
additives together, with a certain amount of base oil diluents.
Accordingly, the weight amounts in the table below, as well as
other amounts mentioned herein, are directed to the amount of
active ingredient (that is the non-diluent portion of the
ingredient). The weight percent (wt %) indicated below is based on
the total weight of the lubricating oil composition.
TABLE-US-00002 TABLE 1 Typical Amounts of Other Lubricating Oil
Components Approximate Approximate Compound wt % (Useful) wt %
(Preferred) Antiwear 0.1-2 0.5-1 Dispersant 0.1-20 0.1-8 Detergent
0.1-20 0.1-8 Antioxidant 0.1-10 0.1-5 Friction Modifier 0.01-5
0.01-1.5 Pour Point Depressant 0.0-5 0.01-1.5 (PPD) Anti-foam Agent
0.001-3 0.001-0.15 Viscosity Index Improver 0.0-8 0.1-6 (pure
polymer basis) Inhibitor and Antirust 0.01-5 0.01-1.5
[0162] The foregoing additives are all commercially available
materials. These additives may be added independently but are
usually precombined in packages which can be obtained from
suppliers of lubricant oil additives. Additive packages with a
variety of ingredients, proportions and characteristics are
available and selection of the appropriate package will take the
requisite use of the ultimate composition into account.
[0163] The following non-limiting examples are provided to
illustrate the disclosure.
EXAMPLES
Test Methods
[0164] In all Examples herein, unless specified otherwise, the
following properties are determined pursuant to the following ASTM
standards:
TABLE-US-00003 Properties Noack KV100 KV40 VI Volatility Pour Point
ASTM Standard D445 D445 D2270 D5800 D5950
[0165] Additional bench testing was conducted for the lubricating
oil compositions or formulations of this disclosure. The additional
bench testing included the following: thermo-oxidation engine oil
simulation testing (TEOST 33C-SAE 932837 and SAE 962039), Rotary
Pressurized Vessel Oxidation Test (D2272), and Pressurized
Differential Scanning Calorimetry. TEOST 33C is conducted at 1
atmosphere of air pressure.
[0166] Oil life was assessed using the CEC L-109 oxidation test and
determining time to a 100% viscosity increase.
[0167] The CEC L-109-16 oxidation bench test is conducted at
150.degree. C. to a 100% viscosity increase. The CEC L-109-16
oxidation bench test is conducted at 1 atmosphere of air pressure.
An organo-iron catalyst is added to the test oil to deliver 100 ppm
Fe. Also 7% B100 biodiesel fuel is added prior to initiating the
oxidation test to accelerate the oxidative degradation. The present
disclosure facilitates running the CEC L-109-16 Bio-Diesel
Oxidation Bench test for extended durations (.gtoreq.310 hours) to
document the benefits of this disclosure.
[0168] Deposit resistance formation of the lubricating oils was
compared using the thermo-oxidation engine oil simulation test
(TEOST 33C), ASTM D6335. A good result in the TEOST test is defined
as less than 60 mg, or less than 50 mg, or less than 45 mg, or less
than 40 mg.
Inventive and Comparative Lubricating Oil Compositions
[0169] Table 2 below compares physical properties of squalane to
other Group II, Group III, and Group IV base stocks. Squalane has a
115 VI and as a result is an API Group II base stock. Compared to
EHC 45 which also has a 115 VI (also an API Group II base stock),
squalane has a lower D445 KV 100, and a lower Noack volatility.
Compared to Yubase 4 Group III base stock, squalane has a lower
D445 KV 100, and a lower Noack volatility. In addition, squalane
has improved simulated distillation volatility characteristics
compared to EHC 45 or Yubase 4. 13C NMR was also used to
characterize the Group II, III, and IV basestocks. The 13C NMR
designations are as follows:
[0170] Alpha carbon--methyl end with no branch on the first 4
carbons
[0171] Epsilon carbon--4 carbons from the end and 3 carbons from a
branch
[0172] T/P methyl--methyl end and a methyl in the 2 position
[0173] P-methyl--is a methyl branch anywhere on the chain, except
in the 2 position.
TABLE-US-00004 TABLE 2 Base Stock Properties Squalane EHC 45 Yubase
4 GTL 4 PAO 4 PAO 3.6 PAO 3.4 KV40, cSt 19.04 23.18 19.35 18.41
18.33 15.35 13.49 KV100, cSt 4.09 4.61 4.22 4.09 4.11 3.60 3.40 VI
115 115 124 127 124 118 129 Noack, % loss 12.4 13.2 13.4 11.7 11.6
13.9 11.7 SimDis distilled at 790 F., % 12 47 44 35 12 14.5 13C NMR
alpha, mol % 0.0 3.8 4.1 4.7 9.7 nm 9.5 13C NMR epsilon, mol % 0.0
13.9 15.8 11.0 18.6 nm 16.4 13C NMR T/P methyl, mol % 12.9 1.4 1.3
1.6 0.5 nm nm 13C NMR P-methyl, mol % 12.2 4.2 4.1 4.9 0.3 nm
0.3
[0174] Table 3 below shows deposit and oxidation results for an
engine oil formulated with squalane compared to other Group II,
Group III, and Group IV base stocks. For Table 3, all of the
examples contained 5.5 wt. % of a styrene-isoprene star polymer
viscosity modifier (VM) wherein the Mw of the VM is 990,000 by
light scattering and the polydispersity is 1.78. In the TEOST 33C
deposit test, which is designed to simulate turbocharger deposits,
the engine oil formulated with squalane produced 36 mg of deposits.
The results obtained for the same engine oil formulated with PAO
3.4, PAO 3.6, GTL 4, Yubase 4, and EHC 45 were 159 to 39% poorer.
This is a very significant benefit in deposit control for squalane.
The CEC L-109 oxidation test was used to measure the oxidation
stability of squalane versus PAO 4, PAO 3.4, GTL 4, Yubase 4, and
EHC 45. The comparative basestocks are Group IV, III, and II
hydrocarbon basestocks. Squalane lasted 67 to 39% longer until a
viscosity increase of 100% occurred. This is a very significant
benefit in oxidation control for squalane. The CEC L-109 viscosity
control stability benefit for squalane also produced a benefit in
superior IR oxidation control. The engine oil formulated with
squalane lasted 44 to 156% longer until the IR oxidation reached 80
A/cm. A distinguishing feature of the TEOST 33C deposit test and
the CEC L109 oxidation test is both operate in a 1 atmosphere air
environment. Table 3 also shows Pressurized Differential Scanning
Calorimetry (PDSC) Onset Temperature measurements conducted on the
same formulated oils. In the PDSC experiments, 500 psig air (oxygen
partial pressure=105 psig) is used with a heating rate of
10.degree. C./minute. In the high pressure PDSC oxidation test,
there was no performance benefit for squalane compared to other
hydrocarbon basestocks. Likewise in the D2272 RPVOT oxidation test
where the test oil is pressurized with 90 psig of oxygen, there was
no performance benefit for squalane compared to other hydrocarbon
basestocks. For both PDSC oxidation and RPVOT oxidation tests, a
higher value indicates better oxidative stability of the
lubricating oil composition.
TABLE-US-00005 TABLE 3 Formulated Engine Oil Deposit and Oxidation
Performance Comp Comp Comp Inv Comp Comp Comp Exp 1 Exp 2 Exp 3 Exp
1 Exp 4 Exp 5 Exp 6 Additives plus VM, % 21.1 21.1 21.1 21.1 21.1
21.1 21.1 Yubase 4, % 78.9 EHC 45, % 78.9 Squalane, % 78.9 GTL 4, %
78.9 PAO 4 78.9 PAO 3.4 78.9 PAO 3.6 78.9 TEOST 33C Deposit, mg
53.9 51.2 50.1 36.1 30.7 57.4 93.6 CEC L-109 Oxidation hrs to 100%
visc Inc 259 274 282 390 247 233 Nm hrs to 80 A/cm 223 254 189 367
143 168 nm DSC Onset Temp, .degree. C. 268.1 268.9 269.6 262.0
262.9 267.5 263.9 D2272 Time, min Nm Nm Nm 73.2 69.8 91.5 74.8
[0175] Table 4 below shows additional D2272 data using lower levels
of additive compared to the formulations presented in Table 3.
Similar to the D2272 data presented in Table 3, there was no
performance benefit for squalane compared to other hydrocarbon
basestocks with low levels of additive in the high pressure D2272
oxidation test.
TABLE-US-00006 TABLE 4 High Pressure Oxidation Performance Results
Comp Comp Comp Comp Exp 7 Exp 8 Exp 9 Exp 10 Squalane, % 99.5 0 0 0
Yubase 4, % 0 99.5 0 0 PAO 3.6, % 0 0 99.5 0 PAO 4, % 0 0 0 99.5
Alkylated Diphenyl 0.5 0.5 0.5 0.5 Amine Antioxidant, % D2272, min
621 1334 2017 1973
[0176] Another example of the superior deposit control performance
of squalane is shown below in Table 5. In this case, squalane is
used in an engine oil at 25%. Sequence IIIH (ASTM D8111) testing
was conducted on the squalane containing formulation and on a
formulation that contained no squalane. Of note is the significant
improvement in Land 3 deposit merits for the squalane containing
formulation compared to the formulation without squalane (7.5
merits vs. 3.7 merits). Land 3 precision for ASTM reference oils is
1 standard deviation unit=1.2. The Sequence IIIH engine test
operates at ambient pressure.
TABLE-US-00007 TABLE 5 Formulated Engine Oil Sequence IIIH Deposit
Performance Inv Exp 2 Comp Exp 11 0W-20 0W-20 Additives + VM 17.3
18.1 SHELL QHVI 4 GTL 30.0 73.4 PAO 4 PAO 22.2 3.5 MCP 166 TMP
ester ester 5.4 5.0 NEOSSENCE SQUALANE Squalane 25.0 0.0 Sequence
IIIH Piston Ratings Groove 1 merits 0.7 0.9 Groove 2 merits 1.1 0.8
Groove 3 merits 9.7 9.9 Land 2 merits 0.8 1.3 Land 3 merits 7.5 3.7
Undercrown merits 4.3 5.0 Varnish merits 9.8 9.9
[0177] For the inventive example 2 of Table 5, the viscosity
modifier (VM) used was a combination of a styrene isoprene star
polymer (Mw=990,000 by light scattering, polydispersity=1.78,
styrene content=26%) at a loading of 3 wt. % and a styrene isoprene
block co-polymer (Mw=106,000 by light scattering,
polydispersity=1.02, styrene content=35%) at a loading of 6 wt. %.
For the comparative example 11 of Table 5, the viscosity modifier
(VM) used was a combination of a styrene isoprene star polymer
(Mw=990,000 by light scattering, polydispersity=1.78, styrene
content=26%) at a loading of 3.25 wt. % and a styrene isoprene
block co-polymer (Mw=106,000 by light scattering,
polydispersity=1.02, styrene content=35%) at a loading of 6.5 wt.
%.
[0178] In summary, it has been discovered that by employing
squalane in lubricating oil formulations in combination with at
least one viscosity modifier, oxidation resistance and deposit
resistance are improved significantly in comparison to comparable
lubricating oils not including squalane.
PCT and EP Clauses:
[0179] 1. A method for improving oxidation resistance and deposit
resistance of a lubricating oil for use in lubricating a mechanical
component comprising: providing a lubricating oil to a mechanical
component, wherein the lubricating oil comprises a lubricating oil
base stock at from 0 to 80 wt % of the lubricating oil, at least
one branched isoparaffin having a mole % of epsilon carbon as
measured by .sup.13C NMR of less than or equal to 10% at from 20 to
80 wt % of the lubricating oil, at least one viscosity modifier at
from 5 to 20 wt % of the lubricating oil, and wherein the remainder
of the lubricating oil includes one or more other lubricating oil
additives; and wherein oxidation resistance is improved (CEC L-109
oxidation resistance to a 100% viscosity increase greater than 310
hours) and deposit resistance is improved (TEOST 33C total deposits
less than 45 mg) as compared to oxidation resistance and deposit
resistance achieved using a lubricating oil not containing the at
least one branched isoparaffin having a mole % of epsilon carbon as
measured by .sup.13C NMR of less than or equal to 10%.
[0180] 2. The method of clause 1, wherein the lubricating oil base
stock is selected from the from the group consisting of a Group I
base stock, a Group II base stock, a Group III base stock, a Group
IV base stock, a Group V base stock and combinations thereof.
[0181] 3. The method of clause 2, wherein the Group III base stock
is a gas to liquids (GTL) base stock and the Group IV base stock is
a polyalphaolefin (PAO) base stock.
[0182] 4. The method of clause 2, wherein the Group V base stock is
an ester based Group V base stock selected from the group
consisting of a C11/C13/C15/C17 Estolide, a C8/C10 TMP ester, a
C7/C9/C11/C13/C15 TMP ester, a C6/C7/C9 TMP ester, a C15/C17
diester, a C6/C7/C9 TMP ester, a C4/C5/C6/C7/C8/C9 TMP ester, C16
mixed mono and di alkylated naphthalene, and combinations
thereof.
[0183] 5. The method of clause 4, wherein the ester based Group V
base stock comprises a monoester, a di-ester, a polyol ester, a
complex ester or mixtures thereof derived from a renewable
biological material.
[0184] 6. The method of clause 5, wherein the renewable biological
material is derived from coconut oil, palm oil, rapeseed oil, soy
oil, vegetable oil, or sunflower oil.
[0185] 7. The method of clauses 1-6, wherein the at least one
branched isoparaffin is selected from the group consisting of
squalane, isosqualane, pristine, tetracosane, isoparaffins
represented by the formulas
##STR00003##
and combinations thereof.
[0186] 8. The method of clause 7, wherein the at least one branched
isoparaffin is squalane having a kinematic viscosity at 100 deg. C.
ranging from 3.9 to 4.3 cSt.
[0187] 9. The method of clauses 1-8, wherein the at least one
viscosity modifier comprises linear or star-shaped polymers and
copolymers of methacrylate, butadiene, olefins, alkylated styrenes
or combinations thereof.
[0188] 10. The method of clauses 1-8, wherein the at least one
viscosity modifier is selected from the group consisting of
polyisobutylene, polymethacrylate, polyisoprene, copolymers of
ethylene and propylene, hydrogenated block copolymers of styrene
and isoprene, styrene-butadiene based polymers, star polyisoprene
polymers, star polyisoprene-styrene copolymers and combinations
thereof.
[0189] 11. The method of clauses 1-10, wherein the one or more
other lubricating oil additives are selected from the group
consisting of an anti-wear additive, viscosity index improver,
antioxidant, detergent, dispersant, pour point depressant,
corrosion inhibitor, metal deactivator, seal compatibility
additive, anti-foam agent, inhibitor, anti-rust additive, and
friction modifier.
[0190] 12. The method of clauses 1-11, wherein the mechanical
component is selected from the group consisting of internal
combustion engines, power trains, drivelines, transmissions, gears,
gear trains, gear sets, compressors, pumps, hydraulic systems,
bearings, bushings, turbines, pistons, piston rings, cylinder
liners, cylinders, cams, tappets, lifters, bearings (journal,
roller, tapered, needle, ball), gears and valves.
[0191] 13. The method of clause 12, wherein the lubricating oil
provides the engine with a Sequence III H piston land 3 merit
rating of greater than or equal to 4.0.
[0192] 14. The method of clause 1-13, wherein the oxidation
resistance or deposit resistance is measured at an oxygen partial
pressure of less than 90 psig.
[0193] 15. The method of clause 1-14, wherein the at least one
branched isoparaffin has a mole % of alpha carbon as measured by
.sup.13C NMR of less than 3.8%.
[0194] 16. The method of clause 1-14, wherein the at least one
branched isoparaffin has a mole % of T/P methyl as measured by
.sup.13C NMR of greater than 2%.
[0195] 17. The method of clauses 1-14, wherein the at least one
branched isoparaffin has a mole % of P-methyl as measured by
.sup.13C NMR of greater than 5%.
[0196] 18. A lubricating oil comprising: a lubricating oil base
stock at from 0 to 80 wt % of the lubricating oil, at least one
branched isoparaffin having a mole % of epsilon carbon as measured
by .sup.13C NMR of less than or equal to 10% at from 20 to 80 wt %
of the lubricating oil, at least one viscosity modifier at from 5
to 20 wt % of the lubricating oil, and wherein the remainder of the
lubricating oil includes one or more other lubricating oil
additives; and wherein oxidation resistance is improved (CEC L-109
oxidation resistance to a 100% viscosity increase greater than 310
hours) and deposit resistance is improved (TEOST 33C total deposits
less than 45 mg) for the lubricating oil as compared to oxidation
resistance and deposit resistance achieved using a lubricating oil
not containing the at least one branched isoparaffin having a mole
% of epsilon carbon as measured by .sup.13C NMR of less than or
equal to 10%.
[0197] 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.
[0198] 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.
[0199] Non-limiting embodiments:
Embodiment 1
[0200] A method for improving oxidation resistance and deposit
resistance of a lubricating oil for use in lubricating a mechanical
component comprising:
[0201] providing a lubricating oil to a mechanical component,
wherein the lubricating oil comprises a lubricating oil base stock
at from 0 to 80 wt % of the lubricating oil, at least one branched
isoparaffin having a mole % of epsilon carbon as measured by
.sup.13C NMR of less than or equal to 10% at from 20 to 80 wt % of
the lubricating oil, at least one viscosity modifier at from 5 to
20 wt % of the lubricating oil, and wherein the remainder of the
lubricating oil includes one or more other lubricating oil
additives; and
[0202] wherein oxidation resistance is improved (CEC L-109
oxidation resistance to a 100% viscosity increase greater than 310
hours) and deposit resistance is improved (TEOST 33C total deposits
less than 45 mg) as compared to oxidation resistance and deposit
resistance achieved using a lubricating oil not containing the at
least one branched isoparaffin having a mole % of epsilon carbon as
measured by .sup.13C NMR of less than or equal to 10%.
Embodiment 2
[0203] The method of embodiment 1, wherein the lubricating oil base
stock is selected from the from the group consisting of a Group I
base stock, a Group II base stock, a Group III base stock, a Group
IV base stock, a Group V base stock and combinations thereof.
Embodiment 3
[0204] The method of embodiment 2, wherein the Group III base stock
is a gas to liquids (GTL) base stock and the Group IV base stock is
a polyalphaolefin (PAO) base stock.
Embodiment 4
[0205] The method of embodiment 2, wherein the Group V base stock
is an ester based Group V base stock selected from the group
consisting of a C11/C13/C15/C17 Estolide, a C8/C10 TMP ester, a
C7/C9/C11/C13/C15 TMP ester, a C6/C7/C9 TMP ester, a C15/C17
diester, a C6/C7/C9 TMP ester, a C4/C5/C6/C7/C8/C9 TMP ester, C16
mixed mono and di alkylated naphthalene, and combinations
thereof.
Embodiment 5
[0206] The method of embodiment 4, wherein the ester based Group V
base stock comprises a monoester, a di-ester, a polyol ester, a
complex ester or mixtures thereof derived from a renewable
biological material.
Embodiment 6
[0207] The method of embodiment 5, wherein the renewable biological
material is derived from coconut oil, palm oil, rapeseed oil, soy
oil, vegetable oil, or sunflower oil.
Embodiment 7
[0208] The method of embodiment 2, wherein the lubricating oil base
stock is a blend of Group III, Group IV and Group V base
stocks.
Embodiment 8
[0209] The method of embodiment 1, wherein the at least one
branched isoparaffin is selected from the group consisting of
squalane, isosqualane, pristine, tetracosane, isoparaffins
represented by the formulas
##STR00004##
[0210] and combinations thereof.
Embodiment 9
[0211] The method of embodiment 8, wherein the at least one
branched isoparaffin is squalane having a kinematic viscosity at
100 deg. C. ranging from 3.9 to 4.3 cSt.
Embodiment 10
[0212] The method of embodiment 1, wherein the at least one
viscosity modifier comprises linear or star-shaped polymers and
copolymers of methacrylate, butadiene, olefins, alkylated styrenes
or combinations thereof.
Embodiment 11
[0213] The method of embodiment 1, wherein the at least one
viscosity modifier is selected from the group consisting of
polyisobutylene, polymethacrylate, polyisoprene, copolymers of
ethylene and propylene, hydrogenated block copolymers of styrene
and isoprene, styrene-butadiene based polymers, star polyisoprene
polymers, star polyisoprene-styrene copolymers and combinations
thereof.
Embodiment 12
[0214] The method of embodiment 1, wherein the one or more other
lubricating oil additives are selected from the group consisting of
an anti-wear additive, viscosity index improver, antioxidant,
detergent, dispersant, pour point depressant, corrosion inhibitor,
metal deactivator, seal compatibility additive, anti-foam agent,
inhibitor, anti-rust additive, and friction modifier.
Embodiment 13
[0215] The method of embodiment 1, wherein the lubricating oil has
a kinematic viscosity at 100 deg. C. ranging from 4.5 to 12.5
cSt.
Embodiment 14
[0216] The method of embodiment 1, wherein the mechanical component
is selected from the group consisting of internal combustion
engines, power trains, drivelines, transmissions, gears, gear
trains, gear sets, compressors, pumps, hydraulic systems, bearings,
bushings, turbines, pistons, piston rings, cylinder liners,
cylinders, cams, tappets, lifters, bearings (journal, roller,
tapered, needle, ball), gears and valves.
Embodiment 15
[0217] The method of embodiment 14, wherein the mechanical
component is an internal combustion engine.
Embodiment 16
[0218] The method of embodiment 15, wherein the lubricating oil
provides the engine with a Sequence III H piston land 3 merit
rating of greater than or equal to 4.0.
Embodiment 17
[0219] The method of embodiment 15, wherein lubricating oil is an
SAE viscosity grade selected from the group consisting of 0W-30,
5W-30, 0W-20, 5W-20, 0W-16, 5W-16, 0W-12, 5W-12, 0W-8, and
5W-8.
Embodiment 18
[0220] The method of embodiment 17, wherein the lubricating oil is
a passenger vehicle engine oil (PVEO) or a commercial vehicle
engine oil (CVEO).
Embodiment 19
[0221] The method of embodiment 1, wherein the oxidation resistance
or deposit resistance is measured at an oxygen partial pressure of
less than 90 psig.
Embodiment 20
[0222] The method of embodiment 1, wherein the at least one
branched isoparaffin has a mole % of alpha carbon as measured by
.sup.13C NMR of less than 3.8%.
Embodiment 21
[0223] The method of embodiment 1, wherein the at least one
branched isoparaffin has a mole % of T/P methyl as measured by
.sup.13C NMR of greater than 2%.
Embodiment 22
[0224] The method of embodiment 1, wherein the at least one
branched isoparaffin has a mole % of P-methyl as measured by
.sup.13C NMR of greater than 5%.
[0225] 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