U.S. patent application number 14/332890 was filed with the patent office on 2015-01-22 for low viscosity lubricant compositions.
The applicant listed for this patent is SHELL OIL COMPANY. Invention is credited to Mark Clift SOUTHBY.
Application Number | 20150024979 14/332890 |
Document ID | / |
Family ID | 52344044 |
Filed Date | 2015-01-22 |
United States Patent
Application |
20150024979 |
Kind Code |
A1 |
SOUTHBY; Mark Clift |
January 22, 2015 |
LOW VISCOSITY LUBRICANT COMPOSITIONS
Abstract
Lubricant formulations are provided having a base oil blend, the
base oil blend having a first Fischer-Tropsch derived base oil
having a kinematic viscosity at 100.degree. C. of between 2.5 and
3.5 cSt and a second Fischer-Tropsch derived base oil having a
kinematic viscosity at 100.degree. C. of between 3.5 and 4.5 cSt,
wherein the resulting base oil blend has a Noack volatility of less
than 15%. The first Fischer-Tropsch derived base oil can be present
in an amount up to 12 wt. % and the second Fischer-Tropsch derived
base oil can be present in an amount up to 88 wt. %.
Inventors: |
SOUTHBY; Mark Clift;
(Chester, GB) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SHELL OIL COMPANY |
Houston |
TX |
US |
|
|
Family ID: |
52344044 |
Appl. No.: |
14/332890 |
Filed: |
July 16, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61847692 |
Jul 18, 2013 |
|
|
|
Current U.S.
Class: |
508/110 |
Current CPC
Class: |
C10N 2030/02 20130101;
C10N 2030/74 20200501; C10N 2040/25 20130101; C10M 2205/173
20130101; C10N 2020/02 20130101; C10M 107/02 20130101 |
Class at
Publication: |
508/110 |
International
Class: |
C10M 107/02 20060101
C10M107/02 |
Claims
1. A lubricating composition for use in the crankcase of an engine
comprising a base oil blend and one or more additives, wherein the
base oil blend comprises a Fischer-Tropsch derived base oil and
wherein the lubricating composition has a first Fischer-Tropsch
derived base oil, said first Fischer-Tropsch derived base oil
having a kinematic viscosity at 100.degree. C. of between 2.5 and
3.5 cSt and a second Fischer-Tropsch derived base oil, said second
Fischer-Tropsch derived base oil having a kinematic viscosity at
100.degree. C. of between 3.5 and 4.5 cSt, wherein the resulting
base oil blend has a Noack volatility of less than 15 wt. %.
2. The lubricating composition of claim 1, wherein the composition
comprises up to 12 wt. % of the first Fischer-Tropsch derived base
oil and at least 88 wt. % of the second Fischer-Tropsch derived
base oil.
3. The lubricating composition of claim 1, wherein the composition
comprises between 1 and 12 wt. % of the first Fischer-Tropsch
derived base oil and between 88 and 99 wt. % of the second
Fischer-Tropsch derived base oil.
4. The lubricating composition of claim 1, wherein the composition
comprises between 8 and 12 wt. % of the first Fischer-Tropsch
derived base oil and between 88 and 92 wt. % of the second
Fischer-Tropsch derived base oil.
5. The lubricating composition of claim 1, wherein the composition
comprises between 4 and 8 wt. % of the first Fischer-Tropsch
derived base oil and between 92 and 96 wt. % of the second
Fischer-Tropsch derived base oil.
6. The lubricating composition of claim 1, wherein the composition
comprises between 0.5 and 4 wt. % of the first Fischer-Tropsch
derived base oil and between 96 and 99.5 wt. % of the second
Fischer-Tropsch derived base oil.
7. The lubricating composition of claim 1, wherein the first
Fischer-Tropsch derived base oil has a kinematic viscosity at
100.degree. C. of between 2.6 and 2.9 cSt.
8. The lubricating composition of claim 1, wherein the second
Fischer-Tropsch derived base oil has a kinematic viscosity at
100.degree. C. of between 3.7 and 4.
9. The lubricating composition of claim 1, wherein the NOACK
volatility of the lubricating composition is less than 15%.
10. The lubricating composition of claim 1, wherein the NOACK
volatility of the lubricating composition is less than 14%.
11. The lubricating composition of claim 1, wherein the NOACK
volatility of the lubricating composition is less than 13%.
12. The lubricating composition of claim 1, wherein the NOACK
volatility of the lubricating composition is less than 12%.
13. The lubricating composition of claim 1, wherein the NOACK
volatility of the lubricating composition is less than 11%.
14. The lubricating composition of claim 1 wherein the NOACK
volatility of the lubricating composition is less than 10%.
15. The lubricating composition of claim 1, the composition further
comprising a lubricant additive package, said lubricant additive
package comprising one or more of the additives selected from the
group consisting of anti-oxidants, anti-wear additives, viscosity
modifiers, detergents, dispersants and anti-foaming agents.
16. A method of lubricating an engine, the method comprising the
step of supplying a lubricating composition of claim 1 to an
engine.
Description
[0001] This non-provisional application claims priority from U.S.
Provisional Application Ser. No. 61/847692 filed Jul. 18, 2013,
which is hereby incorporated by reference in its entirety.
FIELD OF THE INVENTION
[0002] The present invention relates to a lubricating composition,
in particular a crank case lubricating composition having a low
viscosity relative to Group III base oils.
BACKGROUND OF THE INVENTION
[0003] Lubricating oils find use in internal combustion engines,
gearboxes and other mechanical devices to promote smoother
functioning, to reduce wear at metal-to-metal contact between
moving parts, and to remove heat. Lubricating oils used in internal
combustion engine (engine oils), in particular, must exhibit a high
level of performance under the high-performance, high-output and
harsh operating conditions of internal combustion engines. The fuel
efficiency performance required of lubricating oils has continued
to increase in recent years, and this has led to application of
various high viscosity-index base oils or friction modifiers.
Various additives such as anti-wear agents, overbased detergents,
ashless dispersants, viscosity modifiers, and antioxidants can be
added to conventional engine oils to meet such performance
demands.
[0004] In many applications, the lubricant compositions require the
presence of polymeric viscosity modifier additives to obtain the
desired viscometric properties over a broad range of shear and/or
temperatures. These additives are usually highly viscous liquids or
solids at room temperature. In order to be able to achieve
homogenous distribution, avoid handling of solids, and to be able
to administer the amounts of additives added into lubricant
compositions and thus ensure consistent product quality, these
additives are usually added as an additive concentrate.
[0005] Fischer-Tropsch derived base oils (hereinafter,
gas-to-liquid or "GTL" base oils) have found increased use in
lubricating compositions, such as engine oils, transmission fluids,
and industrial lubricants. These compositions benefit from various
performance benefits over traditional mineral based oils, including
improved oxidation properties, improved engine cleanliness,
improved wear protection, improved emissions, and improved
after-treatment device compatibility.
[0006] Mineral based oils have typically been used in the
preparation of lubricating compositions. It is problematic,
however, to formulate engine oils (including passenger car motor
oils and heavy-duty diesel engine oils) with mineral base oils that
meet the thinner grades of the SAE J300 Specifications (as revised
in April 2013), such as SAE 0W-X. Additionally, mineral based
engine oils may suffer from one or more of poor fuel economy, poor
wear performance, and low Noack volatility when used in relatively
thin engine oils.
[0007] As the demand for ever improving lubricating performance
increases, there is a need for developing lower viscosity
lubricating compositions demonstrating improved properties.
SUMMARY OF THE INVENTION
[0008] One or more of the above or other objects can be obtained by
a lubricating oil composition comprising a blend of base oils, said
blend comprising: (a) a GTL 3 base oil; and (b) a GTL 4 base oil.
In certain embodiments, the base oil blend can include up to about
12% by weight of the GTL 3 base oil. Alternatively, the base oil
blend can include between 1 and 12% by weight of the GTL 3 base
oil. In other embodiments, the base oil blend can include at least
88% by weight of the GTL 4 base oil. In other embodiments, the base
oil blend can include between 88 and 99% by weight of the GTL 4
base oil.
[0009] In certain embodiments, one or more of the objects can be
achieved with a lubricating composition having Fischer-Tropsch
derived base oils, wherein a first Fischer-Tropsch derived base oil
has a kinematic viscosity at 100.degree. C. of between 2.5 and 3.0
cSt and a Noack volatility of greater than 30 wt. % and a second
Fischer-Tropsch derived base oil has kinematic viscosity at
100.degree. C. of between 3.7 and 4.3 cSt and a Noack volatility of
less than 15 wt. %.
[0010] In certain embodiments, one or more of the above or other
objects can be obtained by a lubricating composition comprising a
blend of base oils, wherein the blend comprises: up to about 12 wt.
% of a first Fischer-Tropsch derived base oil having a kinematic
viscosity at 100.degree. C. of between 2.5 and 3.5 cSt and at least
88 wt. % of a second Fischer-Tropsch derived base oil having a
kinematic viscosity at 100.degree. C. of between 3.5 and 4.5 cSt,
base oil, wherein the lubricating composition has a NOACK
volatility of less than 15 wt. %.
DETAILED DESCRIPTION
[0011] One or more of the objects of the present invention can be
achieved by a lubricating composition that includes a blend of
Fischer-Tropsch derived base oils. More specifically, a blend of
Fischer-Tropsch derived base oils that includes a GTL3 base oil and
a GTL4 base oil. It has been unexpectedly found that by combining
the GTL3 and GTL4 base oils, a low viscosity lubricating
composition for use in high fuel efficiency engines has been
provided. In certain embodiments, the lubricating composition can
include a GTL8 base oil that may be added for volatility
purposes.
[0012] The term "Fischer-Tropsch derived" refers to a base oil that
is, or is derived from, a synthesis product of a Fischer-Tropsch
process. A Fischer-Tropsch derived base oil may also be referred to
as a GTL (Gas-To-Liquids) base oil. Fischer-Tropsch derived base
oils that may be conveniently used as the base oil in the
lubricating composition of the present invention are those as for
example disclosed in EP 0776959; EP 0668342; WO 1997/21788; WO
2000/15736; WO 2000/14188; WO 2000/14187; WO 2000/14183; WO
2000/14179; WO 2000/08115; WO 1999/41332; EP 1029029; WO
2001/18156; and WO 2001/57166.
[0013] Suitable base oils for use in the lubricating oil
composition of the present invention include Group I-III mineral
base oils (preferably Group III), Group IV poly-alpha olefins
(PAOs), and mixtures thereof.
[0014] As used herein, "Group I" , "Group II" "Group III" and
"Group IV" base oils in the present invention refers to one or more
of the above or other objects can be obtained by a lubricating oil
composition comprising: lubricating oil base oils according to the
definitions of American Petroleum Institute (API) for categories I,
II, III and IV. (These API categories are defined in API
Publication 1509, 15th Edition, Appendix E, April 2002).
Fischer-Tropsch derived base oils are known in the art.
[0015] Synthetic oils that can be included in the formulations of
the present invention can include hydrocarbon oils such as olefin
oligomers (including polyalphaolefin base oils; PAOs), dibasic acid
esters, polyol esters, polyalkylene glycols (PAGs), alkyl
naphthalenes, and dewaxed waxy isomerates. Synthetic hydrocarbon
base oils sold by the Shell Group under the designation "Shell
XHVI" (trade mark) may also be conveniently used in the present
invention.
[0016] Fischer-Tropsch derived base oils are highly paraffinic API
group III base oils (API Base Oil Interchangeability Guidelines)
exhibiting very good cold flow properties, high oxidative
stability, and high viscosity indices.
[0017] The base oil used in the present invention may, in addition
to the Fischer-Tropsch derived base oils specified herein,
conveniently include mixtures of one or more mineral oils and/or
one or more synthetic oils. As used herein, the term "base oil" may
refer to a mixture that includes more than one base oil, including
the at least one Fischer-Tropsch derived base oils of the present
invention. Mineral oils can include liquid petroleum oils and
solvent-treated or acid-treated mineral lubricating oil of the
paraffinic, naphthenic, or mixed paraffinic/naphthenic type, and
which may be further refined by hydrofinishing processes and/or
dewaxing.
[0018] Fischer-Tropsch derived base oils are highly paraffinic API
group III base oils (as defined by API Base Oil Interchangeability
Guidelines) exhibiting very good cold flow properties, high
oxidative stability, and high viscosity indices. However, due to
the high paraffin content, the solvency of the base oils is
generally low, often resulting in incompatibility with other
lubricant components and additives.
[0019] Fischer-Tropsch derived base oils are known in the art. In
the present context, the term "Fischer-Tropsch derived" means that
a material is, or derives from, a synthesis product of a
Fischer-Tropsch condensation process. The term "non-Fischer-Tropsch
derived" may be interpreted accordingly. A Fischer-Tropsch derived
base oil will therefore be a hydrocarbon stream of which a
substantial portion, except for added hydrogen, is derived directly
or indirectly from a Fischer-Tropsch condensation process. A
Fischer-Tropsch derived base oil may also be referred to as a GTL,
(Gas-To-Liquids) base oil, and includes base oils marketed under
the Shell XHVI trademark. Further information on the
Fischer-Tropsch derived base oils and the preparation thereof,
reference is made to WO 2009/074572, the teaching of which is
hereby incorporated by specific reference.
[0020] Typically, the aromatics content of a Fischer-Tropsch
derived base oil (as generally determined by ASTM D 4629), will be
less than 1 wt. %, preferably less than 0.5 wt. %, and more
preferably less than 0.1 wt. %. The base oil typically has a total
paraffin content of at least 80 wt. %, preferably at least 85 wt.
%, more preferably at least 90 wt. %, yet more preferably at least
95 wt. %, and most preferably at least 99 wt. %. Additionally, the
Fischer-Tropsch derived base oil typically has a saturates content
(as measured by IP-368, ASTM D2007, ASTM D7419, or any other
chromatographic method that will yield similar results) of greater
than 98 wt. %, preferably greater than 99 wt. %, and more
preferably greater than 99.5 wt. %. The Fischer-Tropsch derived
base oil can have a maximum n-paraffin content of 0.5 wt. %. The
Fischer-Tropsch derived base oil can have a content of naphthenic
compounds of up to about 20 wt. %, alternatively between 0.1 and 20
wt. %, and alternatively between 0.5 to 10 wt. %, alternatively
between 5 and 15 wt. %, and alternatively between 5 and 10 wt.
%.
[0021] Typically, the Fischer-Tropsch derived base oil has a
kinematic viscosity at 100.degree. C. (as measured by ASTM D 7042)
of from 2 to 8 mm.sup.2/s (cSt), preferably greater than 2.5, and
more preferably greater than 3.0 mm.sup.2/s. Preferably, the
Fischer-Tropsch derived base oil has a kinematic viscosity at
100.degree. C., of less than 5.0 mm.sup.2/s, preferably less than
4.5 mm.sup.2/s, and more preferably less than 4.2 mm.sup.2/s. In
certain embodiments, the Fischer-Tropsch derived base oil has
kinematic viscosity at 100.degree. C. between 2.5 to 5 mm.sup.2/s
(cSt), alternatively between 3 to 4.5 mm.sup.2/s (cSt),
alternatively between 4.0 to 4.2 mm.sup.2/S (cSt).
[0022] Further, the Fischer-Tropsch derived base oil typically has
a kinematic viscosity at 40.degree. C. (as measured by ASTM D 7042)
of from 10 to 100 mm.sup.2/s (cSt), alternatively from 15 to 50
mm.sup.2/s (cSt).
[0023] Also, the Fischer-Tropsch derived base oil preferably has a
pour point (as measured according to ASTM D 5950) of less than
-30.degree. C., more preferably less than -40.degree. C., and most
preferably less than -45.degree. C. In certain embodiments, the
pour point is between -30.degree. C. and -40.degree. C.,
alternatively between -40.degree. C. and -45.degree. C.
[0024] The flash point (as measured by ASTM D92) of the
Fischer-Tropsch derived base oil is greater than 120.degree. C.,
preferably greater than 130.degree. C., more preferably even
greater than 140.degree. C. Alternatively the flash point can be
between 120.degree. C. and 130.degree. C., alternatively between
130.degree. C. and 140.degree. C.
[0025] The Fischer-Tropsch derived base oil preferably has a
viscosity index (a measured according to ASTM D 2270) in the range
of from 100 to 200. Preferably, the Fischer-Tropsch derived base
oil has a viscosity index of at least 125, preferably at least 130.
Also, it is preferred that the viscosity index is less than 180,
preferably less than 150. in certain embodiments, the viscosity
index is between 125 and 180, alternatively between 130 and
150.
[0026] In the event the Fischer-Tropsch derived base oil contains a
blend of two or more Fischer-Tropsch derived base oils, the above
values apply to the blend of the two or more Fischer-Tropsch
derived base oils.
[0027] As used herein, a GTL 3 base oil refers to a Fischer-Tropsch
derived base oil having a kinematic viscosity at 100.degree. C. of
between about 2 and 4 cSt, alternatively between 2.2 and 3.2 cSt,
alternatively between 2.6 and 2.9 cSt, a saturates content of at
least about 98.5 wt. %, an aromatics content of not greater than
about 0.7 wt. %, and a Noack volatility of about 42 wt. %.
[0028] As used herein, a GTL 4 base oil refers to a Fischer-Tropsch
derived base oil having a kinematic viscosity at 100.degree. C. of
between about 3.5 and 5 cSt, alternatively between 4 and 4.2 cSt, a
saturates content of at least about 99 wt. %, an aromatics content
of not greater than about 0.7 wt. %, and a Noack volatility of
about 13.5 wt. %.
[0029] In addition to the Fischer-Tropsch derived base oil, the
additive concentrate may include one or more non-Fischer-Tropsch
derived base oils, such as mineral derived base oils and so-called
synthetic base oils (such as PAOs) including Group I-V base oils
according to the definitions of American Petroleum Institute (API).
These API categories are defined in API Publication 1509, 15th
Edition, Appendix E, July 2009.
[0030] In certain embodiments, the lubricant composition of the
present invention includes a blend of two Fischer-Tropsch derived
base oils, the blend including: a first Fischer-Tropsch derived
base oil having a kinematic viscosity at 100.degree. C. of between
2.5 and 3.5 cSt and a second Fischer-Tropsch derived base oil
having a kinematic viscosity at 100.degree. C. of between 3.5 and
4.5 cSt. In certain embodiments, blend of two Fischer-Tropsch
derived base oils will include up to 12 wt. % of the first
Fischer-Tropsch derived base oil and at least 88 wt. % of the
second Fischer-Tropsch derived base oil, alternatively between 0.5
and 3 wt. % of the first Fischer-Tropsch derived base oil and
between 97 and 99.5 wt. % of the second Fischer-Tropsch derived
base oil, alternatively between 3 and 6 wt. % of the first
Fischer-Tropsch derived base oil and between 94 and 97 wt. % of the
second Fischer-Tropsch derived base oil, alternatively between 6
and 9 wt. % of the first Fischer-Tropsch derived base oil and
between 91 and 94 wt. % of the second Fischer-Tropsch derived base
oil, or alternatively between 9 and 12 wt. % of the first
Fischer-Tropsch derived base oil and between 88 and 91 wt. % of the
second Fischer-Tropsch derived base oil. In certain embodiments
blend of two Fischer-Tropsch derived base oils will include between
1 and 12 wt. % of the first Fischer-Tropsch derived base oil and
between 88 and 99 wt. % of the second Fischer-Tropsch derived base
oil, alternatively between 0.5 and 4 wt. % of the first
Fischer-Tropsch derived base oil and between 96 and 99.5 wt. % of
the second Fischer-Tropsch derived base oil, alternatively between
4 and 8 wt. % of the first Fischer-Tropsch derived base oil and
between 92 and 96 wt. % of the second Fischer-Tropsch derived base
oil, alternatively between 8 and 12 wt. % of the first
Fischer-Tropsch derived base oil and between 88 and 92 wt. % of the
second Fischer-Tropsch derived base oil.
[0031] The resulting lubricant composition will have a NOACK
volatility (as tested according to ASTM D-5800) of less than 15 wt.
%, alternatively less than 14 wt. %, alternatively less than 13 wt.
%, alternatively less than 12 wt. %.
[0032] The resulting lubricant composition will have a kinematic
viscosity at 100.degree. C. (as tested according to ASTM D445) of
between 3 and 10 cSt, alternatively between 3 and 5 cSt,
alternatively between 4 and 6 cSt, alternatively between 5 and 8
cSt, and alternatively between 6 and 9 cSt. In certain other
embodiments, the kinematic viscosity at 100.degree. C. does not
exceed 8 cSt, alternatively it does not exceed 5 cSt.
[0033] The resulting lubricant composition will have a cold
cranking viscosity at -30.degree. C. (as tested according to ASTM
D5893) of between 900 cP and 6600 cP, alternatively between 900 cP
and 3000 cP, alternatively between 900 cP and 2000 cP. In certain
embodiments, the cold cranking viscosity at -30.degree. C. will be
less than 6600 cP, alternatively less than 2000 cP, alternatively
less than 1400 cP, alternatively less than 1200 cP. In certain
embodiments, the cold cranking viscosity at -30.degree. C. no
greater than 2000 cP, alternatively no greater than 1500 cP.
[0034] The resulting lubricant composition will have a cold
cranking viscosity at -35.degree. C. (as tested according to ASTM
D5893) of between about 1400 cP and 6200 cP, alternatively between
1400 cP and 2500 cP, alternatively between 1500 cP and 2000 cP. In
certain embodiments, the cold cranking viscosity at -35.degree. C.
will be not greater than 2500 cP, alternatively not greater than
2000 cP. In certain embodiments, the cold cranking viscosity at
-35.degree. C. will be less than 6200 cP, alternatively less than
2500 cP, alternatively less than 2000 cP.
[0035] The resulting lubricant composition will have a high
temperature high shear (HTHS) viscosity at 150.degree. C. of
between 1.4 and 3.0 cP, alternatively between 1.7 and 2.2 cP,
alternatively between 1.7 and 1.9 cP. In certain embodiments, the
HTHS viscosity at 150.degree. C. is not greater than 2.2 cP,
alternatively not greater than 1.9 cP.
[0036] Typically the base oil (or blend of base oils) as used
according to the present invention has a kinematic viscosity at
100.degree. C.: {according to ASTM D445) of between 2.5 and 8 cSt,
alternatively between about 3 and 5 cSt. According to a preferred
embodiment of the present invention the base oil has a kinematic
viscosity at 100.degree. C. {according to ASTM D445) of between 3.5
and 4.5 cSt. In the event the base oil contains a blend of two or
more base oils, it is preferred that the blend has a kinematic
viscosity at 100.degree. C. of between 3.5 and 4.5 cSt.
[0037] Preferably, the dynamic viscosity at -35.degree. C.
(according to ASTM D5293) of the lubricant composition according to
the present invention is less than 6200 cP (wherein 1 cP equals 1
mPas), preferably less 5500 cP, more preferably less than 5000 cP,
even more preferably less than 4500 cP, or in certain embodiments
less than 4000 cP, or less than 3500 cP. Typically, the dynamic
viscosity at -.about.35.degree. C. is greater than 2000 cP. In
certain embodiments, the dynamic viscosity is between about 2000
and 4000 cP, alternatively between about 4000 and 6000 cP, or
alternatively between about 5000 and 6200 cP.
[0038] Preferably, the high temperature, high shear viscosity
("HTHS"; according to ASTM D4683) of the composition according to
the present invention is less than 2.6 cP, preferably less than 2.0
cP, more preferably less than 1.9 cP. Typically, the HTHS is
greater than 1.5 cP. In certain embodiments, the HTHS is between
1.5 and 2.6 cP, alternatively between about 1.5 and 2 cP, or
alternatively between about 1.5 and 1.9 cP.
[0039] The lubricant composition according to the present invention
has a Noack volatility (according to ASTM D5800) of less than 15
wt. %. Typically, the Noack volatility (according to ASTM D 5800)
of the lubricant composition is between 1 and 15 wt. %,
alternatively between 10 and 14 wt. %, alternatively between 11 and
13.5 wt. %. In certain embodiments, the Noack volatility is less
than 14.6 wt. %, alternatively less than 14 wt. %, alternatively
less than 13.5 wt. %, or alternatively less than 13 wt. %. In
certain embodiments, the Noack volatility of the lubricant
composition is less than 12.5 wt. %, alternatively less than 12 wt.
%, and alternatively less than 11.5 wt. %, alternatively less than
11 wt. %, and alternatively less than 10 wt. %.
[0040] The lubricating composition according to the present
invention can further include one or more additives, such as
anti-oxidants, anti-wear additives, dispersants, detergents,
overbased detergents, extreme pressure additives, friction
modifiers, viscosity index improvers, pour point depressants, metal
passivators, corrosion inhibitors, demulsifiers, anti-foam, agents,
seal compatibility agents, and additive diluent base oils, etc. As
the person skilled in the art is familiar with the above and other
additives, these are not further discussed here in detail. Specific
examples of such additives are described in for example Kirk-Othmer
Encyclopedia of Chemical Technology, third edition, volume 14,
pages 477-526. Anti-oxidants that may be conveniently used include
phenyl-naphthylamines (such as "IRGANOX L-O6" available from Ciba
Specialty Chemicals) and diphenylamines (such as "IRGANOX L-57"
available from Ciba Specialty Chemicals), as e.g. disclosed in WO
2007/045629 and EP 1058720, phenolic anti-oxidants, etc. The
teachings of WO 2007/045629 and EP 1058720 are hereby incorporated
by reference.
[0041] Anti-wear additives that can be added include
zinc-containing compounds, such as zinc dithiophosphate compounds
selected from zinc dialkyl-, diaryl- and/or
alkylaryl-dithiophosphates, molybdenum containing compounds, boron
containing compounds, and ashless anti-wear additives such as
substituted and unsubstituted thiophosphoric acids, and salts
thereof. Examples of molybdenum containing compounds can include
molybdenum dithiocarbamates, trinuclear molybdenum compounds (as
described in WO 1998/26030), molybdenum sulphides, and molybdenum
dithiophosphate. Boron containing compounds that can be used
include borate esters, borated fatty amines, borated epoxides,
alkali metal (or mixed alkali metal or alkaline earth metal)
borates, and borated overbased metal salts. The dispersant used is
preferably an ashless dispersant. Suitable ashless dispersants can
include polybutylene succinimide polyamines, and Mannich base type
dispersants
[0042] Examples of viscosity index improvers that can be used in
the lubricating compositions of the present invention include
styrene-butadiene stellate copolymers, styrene-isoprene stellate
copolymers, and the polymethacrylate copolymer and
ethylene-propylene copolymers (also known as olefin copolymers) of
the crystalline and non-crystalline type. Dispersant-viscosity
index improvers can also be used in the lubricating composition of
the present invention. Preferably the compositions according to the
present invention include less than 1.0 wt. %, of a Viscosity Index
improver concentrate (i.e., VI improver plus "carrier oil" or
"diluent"), based on the total weight of the composition,
preferably less than 0.5 wt. %. Most preferably, the composition is
free of Viscosity Index improver concentrate.
[0043] In certain embodiments, the composition according to the
present invention includes at least 0.1 wt. % of a pour point
depressant. For example, alkylated naphthalene and phenolic
polymers, polymethacrylates, and maleate/fumarate copolymer esters
can be used as pour point depressants. Preferably, not more than
0.3 wt. % of the pour point depressant is used. In certain
embodiments, compounds such as alkenyl succinic acid or ester
moieties thereof, benzotriazole-based compounds, and
thiodiazole-based compounds can be used as corrosion inhibitors in
the lubricating composition of the present invention.
[0044] Compounds such as polysiloxanes, dimethyl polycyclohexane,
and polyacrylates can be used in the lubricating composition of the
present invention as defoaming agents.
[0045] In certain embodiments, a pour point depressant can be
added, such as a conventional polytnethacrylate pour point
depressant, commercially available from Infineum Additives
(Abingdon, United Kingdom) under the trade designation "Infineum
351".
[0046] Compounds that can used in the lubricating composition of
the present invention as seal fix or seal compatibility agents
include, for example, commercially available aromatic esters. The
lubricating compositions of the present invention can be prepared
by admixing the one or more additives with the base oil(s).
[0047] In general, additives present in the compositions of the
present invention are present in an amount in the range of from
0.01 to 35.0 wt. %, based on the total weight of the lubricating
composition, preferably in an amount in the range of from 0.05 to
25.0 wt. %, and more preferably from 1.0 to 20.0 wt. %. Preferably,
the composition contains at least 9.0 wt. %, preferably at least
10.0 wt. %, more preferably at least 11.0 wt. % of an additive
package comprising an anti-wear additive, a metal detergent, an
ashless dispersant and an anti-oxidant. Alternatively, the
compositions of the present invention include between 10 and 35 wt.
% of additives, alternatively between 10 and 25 wt. %,
alternatively between 10 and 20 wt. %. In certain embodiments, the
lubricating compositions according to the present invention may be
so-called "low SAPS" (SAPS=sulphated ash, phosphorus and sulphur),
"mid SAPS" or "regular SAPS" formulations.
[0048] In one embodiment, the lubricant composition of the present
invention includes a base oil blend, wherein the base oil blend
includes a first Fischer-Tropsch derived base oil, said first
Fischer-Tropsch derived base oil having a kinematic viscosity at
100.degree. C. of between 2.5 and 3.5 cSt and a second
Fischer-Tropsch derived base oil, said second Fischer-Tropsch
derived base oil having a kinematic viscosity at 100.degree. C. of
between 3.5 and 4.5 cSt, wherein the base oil blend has a Noack
volatility of below 15 wt. %. Optionally, the lubricant composition
according to the present invention can include an additive package.
The optional additive package can include a combination of
additives, such as anti-oxidants, a zinc-based anti-wear additives,
an ashless dispersant, an overbased detergent mixture, and an
anti-foaming agent.
EXAMPLES
[0049] The properties of 3 base oils are provided in Table 1.
[0050] Base oil 1 is a commercially available Group III mineral
based base oil having a kinematic viscosity at 100.degree. C. (ASTM
D445) of approximately 4.3 cSt. Base oil 1 is commercially
available from e.g. SK Energy (Ulsan, South Korea) under the trade
designation Yubase 4.
[0051] Base oil 2 was a Fischer-Tropsch derived base oil having a
kinematic viscosity at 100.degree. C. (ASTM D445) of approximately
3.89 cSt. Base oil 2 may be conveniently manufactured by the
process described in e.g. WO2002/070631, the teaching of which is
hereby incorporated by reference.
[0052] Base oil 3 is a Fischer-Tropsch derived base oil having
having a kinematic viscosity at 100.degree. C. (ASTM D445) of
approximately 2.70 cSt. Base oil 3 may be conveniently manufactured
by the process described in e.g. WO2002/070631, the teaching of
which is hereby incorporated by reference.
TABLE-US-00001 TABLE 1 Base oil 1 Base oil 2 Base oil 3 (GTL 4)
(Yubase 4) (GTL 3) Kinematic viscosity at 16.91 19.49 9.930
40.degree. C..sup.1 [cSt] Kinematic viscosity at 3.89 4.3 2.707
100.degree. C..sup.1 [cSt] VI Index.sup.2 127 126 112 Pour
point.sup.3 -39 -18 -39 [.degree. C.] Noack volatility.sup.4 [wt.
%] 11.2 14.2 46.8 Saturates.sup.5 99.2 99.3 99.9 [wt. %] Tertiary
Carbon, %.sup.6 18.1 n.d. n.d. Secondary Carbon, %.sup.6 66.7 n.d.
n.d. Primary Carbon, %.sup.6 14.3 n.d. n.d. Epsilon carbon content,
%.sup.6 12.1 n.d. n.d. n- and iso- paraffins.sup.7 92.35 n.d. n.d.
Mono-naphthenics.sup.7 6.85 n.d. n.d. di- and poly-
naphthenics.sup.7 0.87 n.d. n.d. Aromatics.sup.5 0.5 n.d. n.d.
Dynamic viscosity at -20.degree. C..sup.8 n.d. 713 n.d. [cP]
Dynamic viscosity at -25.degree. C..sup.8 n.d. 931 n.d. [cP]
Dynamic viscosity at -30.degree. C..sup.8 948 n.d. n.d. [cP]
Dynamic viscosity at-35.degree. C..sup.8 1580 n.d. n.d. [cP]
.sup.1According to ASTM D445 .sup.2According to ASTM D2270
.sup.3According to ASTM D5950 .sup.4According to CEC L-40-A-93/ASTM
D5800 .sup.5According to IP 368 (modified) .sup.6According to 13C
NMR .sup.7According to FIMS .sup.8According to ASTM D5293 n.d. =
not determined
[0053] Table 2 provides properties for several compositions which
include a base oil and an additive package. As shown in the table,
GTL4 provides improved viscosity and volatility as compared with
mineral based Yubase 4.
TABLE-US-00002 TABLE 2 Blend 1. Base Oil 1 Blend 2. Base Oil 2
(Yubase 4; 90.77 wt. %) (GTL 4; 90.77 wt. %) and Additive Package
and Additive Package (9.23 wt. %) (9.23 wt. %) Kinematic Viscosity
5.38 5.33 at 100.degree. C. [cSt] CCS (-30.degree. C.) 1539 1257
CCS (-35.degree. C.) 2647 2087 HTHS (150.degree. C.).sup.9 1.86
1.83 TNOACK.sup.10 12.7 12.4 .sup.9According to ASTM D4683
.sup.10TGA simulation of NOACK volatility according to ASTM
D6375.
[0054] As used herein, the words "include" and "comprise" and
variants thereof may be used interchangeably.
[0055] The singular forms "a", "an" and "the" include plural
referents, unless the context clearly dictates otherwise. Optional
or optionally means that the subsequently described event or
circumstances may or may not occur. The description includes
instances where the event or circumstance occurs and instances
where it does not occur.
[0056] Ranges may be expressed herein as from about one particular
value, and/or to about another particular value. When such a range
is expressed, it is to be understood that another embodiment is
from the one particular value and/or to the other particular value,
along with all combinations within said range.
[0057] Throughout this application, where patents or publications
are referenced, the disclosures of these references in their
entireties are intended to be incorporated by reference into this
application, in order to more fully describe the state of the art
to which the invention pertains, except when these reference
contradict the statements made herein.
[0058] Although the present invention has been described in detail,
it should be understood that various changes, substitutions, and
alterations can be made hereupon without departing from the
principle and scope of the invention. Accordingly, the scope of the
present invention should be determined by the following claims and
their appropriate legal equivalents.
* * * * *