U.S. patent application number 14/408572 was filed with the patent office on 2015-10-01 for lubricating composition.
This patent application is currently assigned to Shell Oil Company. The applicant listed for this patent is SHELL OIL COMPANY. Invention is credited to Richard Thomas Dixon, Malcom J. Willars.
Application Number | 20150275130 14/408572 |
Document ID | / |
Family ID | 48628726 |
Filed Date | 2015-10-01 |
United States Patent
Application |
20150275130 |
Kind Code |
A1 |
Willars; Malcom J. ; et
al. |
October 1, 2015 |
LUBRICATING COMPOSITION
Abstract
A lubricating composition for use in the crankcase of an engine
comprising a base oil and one or more additives, wherein the base
oil comprises a Fischer-Tropsch derived base oil and wherein the
lubricating composition comprises one or more comb polymers. The
lubricating composition of the present invention has been found to
improve sustained fuel economy properties whilst obtaining improved
piston cleanliness properties and improved dispersancy
properties.
Inventors: |
Willars; Malcom J.; (Ince,
GB) ; Dixon; Richard Thomas; (Ince, GB) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SHELL OIL COMPANY |
Houston |
TX |
US |
|
|
Assignee: |
Shell Oil Company
Houston
TX
|
Family ID: |
48628726 |
Appl. No.: |
14/408572 |
Filed: |
June 18, 2013 |
PCT Filed: |
June 18, 2013 |
PCT NO: |
PCT/EP2013/062666 |
371 Date: |
December 17, 2014 |
Current U.S.
Class: |
508/161 |
Current CPC
Class: |
C10M 169/047 20130101;
C10M 2209/086 20130101; C10N 2030/54 20200501; C10N 2010/04
20130101; C10N 2020/071 20200501; C10M 2209/04 20130101; C10N
2030/68 20200501; C10M 2203/1025 20130101; C10N 2030/43 20200501;
C10M 169/041 20130101; C10M 2205/08 20130101; C10N 2020/04
20130101; C10N 2030/45 20200501; C10N 2030/04 20130101; C10M
2209/062 20130101; C10N 2030/74 20200501; C10M 2205/173 20130101;
C10M 2209/084 20130101; C10M 2205/02 20130101; C10N 2020/01
20200501; C10N 2030/02 20130101; C10M 2205/024 20130101; C10N
2040/25 20130101; C10N 2020/011 20200501; C10M 2205/04 20130101;
C10M 2205/06 20130101; C10M 2203/1025 20130101; C10N 2020/02
20130101; C10M 2205/024 20130101; C10M 2205/04 20130101; C10M
2205/024 20130101; C10N 2060/02 20130101; C10M 2203/1025 20130101;
C10N 2020/02 20130101; C10M 2205/024 20130101; C10N 2060/02
20130101 |
International
Class: |
C10M 169/04 20060101
C10M169/04 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 21, 2012 |
EP |
12172943.8 |
Claims
1. A lubricating composition for use in the crankcase of an engine
comprising a base oil and one or more additives, wherein the base
oil comprises a Fischer-Tropsch derived base oil and wherein the
lubricating composition comprises one or more comb polymers.
2. A lubricating composition according to claim 1, wherein the comb
polymer comprises, in the main chain, at least one repeat unit
which is obtained from at least one polyolefin-based macromonomer,
and at least one repeat unit which is obtained from at least one
low molecular weight monomer selected from the group consisting of
styrene monomers having 8 to 17 carbon atoms, alkyl(meth)acrylates
having 1 to 10 carbon atoms in the alcohol group, vinyl esters
having from 1 to 11 carbon atoms in the acyl group, vinyl ethers
having 1 to 10 carbon atoms in the alcohol group, (di)alkyl
fumurates having 1 to 10 carbon atoms in the alcohol group,
(di)alkyl maleates having 1 to 10 carbon atoms in the alcohol group
and mixtures thereof, where the molar degree of branching is in the
range of 0.1 to 10 mol % and the comb polymer comprises a total of
at least 80% by weight, based on the total weight of repeat units
of the comb polymer, of the at least one repeat unit which is
obtained from the at least one polyolefin-based macromonomer and
the at least one repeat unit which is obtained from the at least
one low molecular weight monomer.
3. A lubricating composition according to claim 2, wherein the comb
polymer has a molar degree of branching in the range of 0.3 to 3.6
mol %.
4. A lubricating composition according to claim 2, wherein the comb
polymer has 8 to 30% by weight of the at least one repeat unit
which is derived from the at least one polyolefin-based
macromonomer, and the molar degree of branching of the comb polymer
is in the range of 0.3% to 1.1%.
5. A lubricating composition according to claim 2 wherein the comb
polymer has 11 to 26% by weight of the at least one repeat unit
which is obtained from the at least one polyolefin-based
macromonomer.
6. A lubricating composition according to claim 2, wherein the at
least one repeat unit which is obtained from the at least one
polyolefin-based macromonomer has a number-average molecular weight
in the range of 700 to 10000 g/mol.
7. A lubricating composition according to claim 2 wherein the comb
polymer comprises at least 90% by weight of repeat units which are
obtained from at least one polyolefin-based macromonomer and from
at least one low molecular weight monomer selected from the group
consisting of styrene monomers having 8 to 17 carbon atoms,
alkyl(meth)acrylates having 1 to 10 carbon atoms in the alcohol
group, vinyl esters having from 1 to 11 carbon atoms in the acyl
group, vinyl ethers having 1 to 10 carbon atoms in the alcohol
group, (di)alkyl fumurates having 1 to 10 carbon atoms in the
alcohol group, (di)alkyl maleates having 1 to 10 carbon atoms in
the alcohol group and mixtures thereof.
8. A lubricating composition according to claim 2 wherein the
polydispersity index Mw/Mn is in the range of from 1 to 5.
9. A lubricating composition according to claim 2 wherein the molar
degree of branching of the comb polymer is in the range of from
0.4% to 1.0%.
10. A lubricating composition according to claim 2 wherein the at
least one repeat unit obtained from the at least one
polyolefin-based macromonomer comprises a group which is obtained
from monomers selected from the group consisting of
C.sub.2-C.sub.10 alkenes and C.sub.4-C.sub.10 alkadienes.
11. A lubricating composition according to claim 2 wherein the at
least one repeat unit obtained from the at least one
polyolefin-based macromonomer comprises at least 80% by weight of
groups which are derived from monomers selected from the group
consisting of C.sub.2-C.sub.10 alkenes and C.sub.4-C.sub.10
alkadienes, based on the weight of the at least one repeat unit
derived from the at least one polyolefin-based macromonomer.
12. A lubricating composition according to claim 2 wherein the
melting point of the at least one repeat unit obtained from the at
least one polyolefin-based macromonomers is less than or equal to
10.degree. C.
13. A lubricating composition according to claim 2 wherein no
melting point of the at least one repeat unit obtained from the at
least one polyolefin-based macromonomer is measured.
14. A lubricating composition according to claim 2 wherein the comb
polymer has repeat units, preferably in a proportion of at least
50% by weight, which are obtained from at least one of n butyl
methacrylate and n butyl acrylate.
15. A lubricating composition according to claim 2 wherein the comb
polymer has repeat units which are obtained from styrene,
preferably in a proportion in the range of from 5 to 25% by
weight.
16. A lubricating composition according to claim 2 wherein the comb
polymer has a weight-average molecular weight in the range of
100,000 to 500,000 g/mol.
17. A lubricating composition according to claim 2 wherein the comb
polymer has repeat units which are obtained from
alkyl(meth)acrylates having 11-30 carbon atoms in the alkyl
radical, preferably in a proportion in the range of from 1 to 10%
by weight.
18. A lubricating composition according to claim 1 wherein the
Fischer-Tropsch derived base oil has a kinematic viscosity at
100.degree. C. in the range of 2 mm.sup.2/s to 10 mm.sup.2/s.
19. (canceled)
20. (canceled)
21. A method comprising: applying a lubricating oil composition to
a surface in relative movement to another surface in the crankcase
of an engine, wherein the lubricating oil composition comprises a
base oil and one or more additives, wherein the base oil comprises
a Fischer-Tropsch derived base oil and wherein the lubricating
composition comprises one or more comb polymers.
22. The method according to claim 21, wherein the comb polymer
comprises, in the main chain, at least one repeat unit which is
obtained from at least one polyolefin-based macromonomer, and at
least one repeat unit which is obtained from at least one low
molecular weight monomer selected from the group consisting of
styrene monomers having 8 to 17 carbon atoms, alkyl(meth)acrylates
having 1 to 10 carbon atoms in the alcohol group, vinyl esters
having from 1 to 11 carbon atoms in the acyl group, vinyl ethers
having 1 to 10 carbon atoms in the alcohol group, (di)alkyl
fumurates having 1 to 10 carbon atoms in the alcohol group,
(di)alkyl maleates having 1 to 10 carbon atoms in the alcohol group
and mixtures thereof, where the molar degree of branching is in the
range of 0.1 to 10 mol % and the comb polymer comprises a total of
at least 80% by weight, based on the total weight of repeat units
of the comb polymer, of the at least one repeat unit which is
obtained from the at least one polyolefin-based macromonomer and
the at least one repeat unit which is obtained from the at least
one low molecular weight monomer.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a lubricating composition
comprising a base oil and one or more additives for particular use
in the crankcase of an engine. In particular, the present invention
relates to a lubricating composition comprising a base oil and one
or more additives for use in the crankcase of an engine for
providing improved sustained fuel economy in a diesel engine, as
well as improved dispersancy and piston cleanliness.
BACKGROUND OF THE INVENTION
[0002] Government regulations and market demands continue to
emphasize conservation of fossil fuels in the transportation
industry. There is increasing demand for more fuel-efficient
vehicles in order to meet CO.sub.2 emissions reductions targets.
Therefore, any incremental improvement in fuel economy (FE) is of
great importance in the automotive sector. Lubricants can play an
important role in reducing a vehicle's fuel consumption and there
is a continuing need for improvements in fuel economy performance,
in particular long term or sustained fuel economy performance, of
lubricant compositions contained within an internal combustion
engine.
[0003] Various attempts have been made to improve the fuel economy
performance of lubricating engine oils. US2010/0190671 relates to
the use of comb polymers for reducing fuel consumption. In
particular, the comb polymer disclosed therein comprises, in the
main chain, at least one repeat unit which is obtained from at
least one polyolefin-based macromonomer, and at least one repeat
unit which is obtained from at least one low molecular weight
monomer selected from the group consisting of styrene monomers
having 8 to 17 carbon atoms, alkyl(meth)acrylates having 1 to 10
carbon atoms in the alcohol group, vinyl esters having from 1 to 11
carbon atoms in the acyl group, vinyl ethers having 1 to 10 carbon
atoms in the alcohol group, (di)alkyl fumurates having 1 to 10
carbon atoms in the alcohol group, (di)alkyl maleates having 1 to
10 carbon atoms in the alcohol group and mixtures thereof, where
the molar degree of branching is in the range of 0.1 to 10 mol %
and the comb polymer comprises a total of at least 80% by weight,
based on the total weight of repeat units of the comb polymer, of
the at least one repeat unit which is obtained from the at least
one polyolefin-based macromonomer and the at least one repeat unit
which is obtained from the at least one low molecular weight
monomer. There is no disclosure in US2010/0190671, however, of the
use of such comb polymers for providing improved long-term or
sustained fuel economy.
[0004] There is also a need to provide lubricating compositions for
use in the crankcase of an engine, wherein the compositions provide
improved dispersancy and piston cleanliness benefits as well as
long term or sustained fuel economy benefits.
SUMMARY OF THE INVENTION
[0005] According to the present invention there is provided a
lubricating composition for use in the crankcase of an engine
comprising a base oil and one or more additives, wherein the base
oil comprises a Fischer-Tropsch derived base oil and wherein the
lubricating composition comprises one or more comb polymers. The
lubricating composition of the present invention provides improved
dispersancy and improved piston cleanliness in addition to improved
long term or sustained fuel economy.
[0006] According to another aspect of the present invention there
is provided the use of a lubricating composition as described
herein, in the crankcase of an engine, in order to improve
sustained fuel economy properties whilst obtaining improved piston
cleanliness properties.
[0007] According to a further aspect of the present invention there
is provided the use of a lubricating composition in the crankcase
of an engine, in order to improve sustained fuel economy properties
whilst obtaining improved dispersancy properties.
DETAILED DESCRIPTION OF THE INVENTION
[0008] As used herein, the term "sustained fuel economy" means good
fuel economy throughout the oil drain interval. A lubricant
exhibiting sustained fuel economy has comparable good fuel economy
performance throughout the oil drain interval as at the start.
[0009] While not wishing to be limited by theory it is believed
that the improved soot dispersancy exhibited by the lubricating
compositions of the present invention leads to a lower viscosity
increase in the lubricating oil compositions over the oil drain
interval and hence an improvement in sustained fuel economy
properties.
[0010] There are no particular limitations regarding the base oil
used in lubricating composition according to the present invention
(provided that the base oil comprises at least a Fischer-Tropsch
derived base oil), and various conventional mineral oils, synthetic
oils as well as naturally derived esters such as vegetable oils may
be conveniently used.
[0011] The base oil used in the present invention may--in addition
to the Fischer-Tropsch derived base oil--conveniently comprise
mixtures of one or more mineral oils and/or one or more synthetic
oils; thus, according to the present invention, the term "base oil"
may refer to a mixture containing more than one base oil, including
at least one Fischer-Tropsch derived base oil. Mineral oils include
liquid petroleum oils and solvent-treated or acid-treated mineral
lubricating oil of the paraffinic, naphthenic, or mixed
paraffinic/naphthenic type which may be further refined by
hydrofinishing processes and/or dewaxing.
[0012] Suitable base oils for use in the lubricating oil
composition of the present invention are Group I-III mineral base
oils (preferably Group III), Group IV poly-alpha olefins (PAOs),
Group II-III Fischer-Tropsch derived base oils (preferably Group
III), Group V ester base oils, and mixtures thereof.
[0013] By "Group I", "Group II" "Group III" and "Group IV" and
"Group V" base oils in the present invention are meant lubricating
oil base oils according to the definitions of American Petroleum
Institute (API) for categories I, II, III, IV and V. These API
categories are defined in API Publication 1509, 15th Edition,
Appendix E, April 2002.
[0014] Fischer-Tropsch derived base oils are known in the art. By
the term "Fischer-Tropsch derived" is meant that a base oil 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. Suitable 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 0 776 959, EP 0 668 342, WO 97/21788, WO
00/15736, WO 00/14188, WO 00/14187, WO 00/14183, WO 00/14179, WO
00/08115, WO 99/41332, EP 1 029 029, WO 01/18156 and WO
01/57166.
[0015] Typically, the aromatics content of a Fischer-Tropsch
derived base oil, suitably determined by ASTM D 4629, will
typically be below 1 wt. %, preferably below 0.5 wt. % and more
preferably below 0.1 wt. %. Suitably, the base oil has a total
paraffin content of at least 80 wt. %, preferably at least 85, more
preferably at least 90, yet more preferably at least 95 and most
preferably at least 99 wt. %. It suitably has a saturates content
(as measured by IP-368) of greater than 98 wt. %. Preferably the
saturates content of the base oil is greater than 99 wt. %, more
preferably greater than 99.5 wt. %. It further preferably has a
maximum n-paraffin content of 0.5 wt. %. The base oil preferably
also has a content of naphthenic compounds of from 0 to less than
20 wt. %, more preferably of from 0.5 to 10 wt. %.
[0016] Typically, the Fischer-Tropsch derived base oil or base oil
blend has a kinematic viscosity at 100.degree. C. (as measured by
ASTM D 7042) in the range of from 1 to 30 mm.sup.2/s (cSt),
preferably from 1 to 25 mm.sup.2/s (cSt), and more preferably from
2 mm.sup.2/s to 12 mm.sup.2/s. Preferably, the Fischer-Tropsch
derived base oil has a kinematic viscosity at 100.degree. C. (as
measured by ASTM D 7042) of at least 2.5 mm.sup.2/s, more
preferably at least 3.0 mm.sup.2/s. In one embodiment of the
present invention, the Fischer-Tropsch derived base oil has a
kinematic viscosity at 100.degree. C. of at most 5.0 mm.sup.2/s,
preferably at most 4.5 mm.sup.2/s, more preferably at most 4.2
mm.sup.2/s (e.g. "GTL 4"). In another embodiment of the present
invention, the Fischer-Tropsch derived base oil has a kinematic
viscosity at 100.degree. C. of at most 8.5 mm.sup.2/s, preferably
at most 8 mm.sup.2/s (e.g. "GTL 8").
[0017] 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), preferably from 15 to 50
mm.sup.2/s.
[0018] Also, the Fischer-Tropsch derived base oil preferably has a
pour point (as measured according to ASTM D 5950) of below
-30.degree. C., more preferably below -40.degree. C., and most
preferably below -45.degree. C.
[0019] The flash point (as measured by ASTM D92) of the
Fischer-Tropsch derived base oil is preferably greater than
120.degree. C., more preferably even greater than 140.degree.
C.
[0020] The Fischer-Tropsch derived base oil preferably has a
viscosity index (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 130. Also it is
preferred that the viscosity index is below 180, preferably below
150.
[0021] 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.
[0022] The lubricating oil composition preferably comprises 80 wt %
or greater of Fischer-Tropsch derived base oil.
[0023] Synthetic oils 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 be conveniently used.
[0024] Poly-alpha olefin base oils (PAOs) and their manufacture are
well known in the art. Preferred poly-alpha olefin base oils that
may be used in the lubricating compositions of the present
invention may be derived from linear C.sub.2 to C.sub.32,
preferably C.sub.6 to C.sub.16, alpha olefins. Particularly
preferred feedstocks for said poly-alpha olefins are 1-octene,
1-decene, 1-dodecene and 1-tetradecene.
[0025] There is a strong preference for using a Fischer-Tropsch
derived base oil over a PAO base oil, in view of the high cost of
manufacture of the PAOs. Thus, preferably, the base oil contains
more than 50 wt. %, preferably more than 60 wt. %, more preferably
more than 70 wt. %, even more preferably more than 80 wt. %. most
preferably more than 90 wt. % Fischer-Tropsch derived base oil. In
an especially preferred embodiment not more than 5 wt. %,
preferably not more than 2 wt. %, of the base oil is not a
Fischer-Tropsch derived base oil. It is even more preferred that
100 wt % of the base oil is based on one or more Fischer-Tropsch
derived base oils.
[0026] The total amount of base oil incorporated in the lubricating
composition of the present invention is preferably in the range of
from 60 to 99 wt. %, more preferably in the range of from 65 to 90
wt. % and most preferably in the range of from 70 to 85 wt. %, with
respect to the total weight of the lubricating composition.
[0027] Typically the base oil (or base oil blend) as used according
to the present invention has a kinematic viscosity at 100.degree.
C. (according to ASTM D445) of above 2.5 cSt and below 5.6 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.
[0028] Typically the lubricating compositions of the present
invention would be utilised in, but not necessarily limited to, SAE
J300 viscosity grades 0 W-20, 0 W-30, 0 W-40, 5 W-20, 5 W-30 and 5
W-40 as these are the grades which target fuel economy. As new SAE
J300 viscosity grades are published, with lower viscosities than
the current 0 W-20, the present invention would also be very much
applicable to these new viscosity lower grades. It is conceivable
that the present invention could also be used with higher viscosity
grades.
[0029] The lubricating composition according to the present
invention preferably has a Noack volatility (according to ASTM D
5800) of below 15 wt. %. Typically, the Noack volatility (according
to ASTM D 5800) of the composition is between 1 and 15 wt. %,
preferably below 14.6 wt. % and more preferably below 14.0 wt.
%.
[0030] The lubricating composition according to the present
invention comprises one or more comb polymers, preferably in a
solid polymer amount of from 0.1 wt % to 10 wt %, more preferably
from 0.25 wt % to 7 wt %, and even more preferably from 0.5 wt % to
4 wt %, by weight of the total lubricating composition.
[0031] Preferably for use herein the comb polymer comprises, in the
main chain, at least one repeat unit which is obtained from at
least one polyolefin-based macromonomer, and at least one repeat
unit which is obtained from at least one low molecular weight
monomer selected from the group consisting of styrene monomers
having 8 to 17 carbon atoms, alkyl(meth)acrylates having 1 to 10
carbon atoms in the alcohol group, vinyl esters having from 1 to 11
carbon atoms in the acyl group, vinyl ethers having 1 to 10 carbon
atoms in the alcohol group, (di)alkyl fumurates having 1 to 10
carbon atoms in the alcohol group, (di)alkyl maleates having 1 to
10 carbon atoms in the alcohol group and mixtures thereof, where
the molar degree of branching is in the range of 0.1 to 10 mol %
and the comb polymer comprises a total of at least 80% by weight,
based on the total weight of repeat units of the comb polymer, (or
in another aspect based on the total weight of the comb polymer),
of the at least one repeat unit which is obtained from the at least
one polyolefin-based macromonomer and the at least one repeat unit
which is obtained from the at least one low molecular weight
monomer.
[0032] Preferably, the comb polymer used herein has 8% to 30% by
weight of repeat units which are derived from polyolefin-based
macromonomers, and the molar degree of branching of the comb
polymer is in the range of 0.3% to 1.1%.
[0033] The term "comb polymer" as used herein means that relatively
long side chains are bonded to a polymeric main chain, frequently
also known as the backbone. The comb polymers used in the present
invention have at least one repeat unit which is derived from
polyolefin-based macromonomers. The exact proportion is evident via
the molar degree of branching. The term "main chain" as used herein
does not necessarily mean that the chain length of the main chain
is greater than that of the side chains. Instead, this term relates
to the composition of this chain. While the side chain has very
high proportions of olefinic repeat units, especially units which
are derived from alkenes or alkadienes, for example ethylene,
propylene, n-butene, isobutene, butadiene, isoprene, the main chain
comprises relatively large proportions of polar unsaturated
monomers which have been detailed above.
[0034] The term "repeat unit" is known to those skilled in the art.
The present comb polymers can be obtained by a process which
involves the free-radical polymerisation of macromonomers and low
molecular weight monomers, wherein double bonds are opened up to
form covalent bonds. Accordingly, the repeat unit arises from the
monomers used. However, the comb polymers can also be prepared by
polymer-analagous reactions and graft copolymerisation. In this
case, the converted repeat unit of the main chain is counted as a
repeat unit which is derived from a polyolefin-based macromonomer.
The same applies in the case of preparation of the comb polymers by
graft polymerization.
[0035] Further details of preparation methods of the comb polymers
use herein can be found in US2010/0190671 and US2008/0194443, which
are incorporated herein by reference.
[0036] The comb polymers used in the present invention comprise
repeat units which are derived from polyolefin-based macromonomers.
These repeat units comprise at least one group which is derived
from polyolefins. Examples of suitable polyolefins include
C.sub.2-C.sub.10 alkenes, such as ethylene, propylene, n-butene,
isobutene, norbornene, and/or C.sub.4-C.sub.10 alkadienes such as
butadiene, isoprene, norbornadiene, and the like.
[0037] The repeat units derived from polyolefin-based macromonomers
preferably comprise at least 70% by weight and more preferably at
least 80% by weight and most preferably at least 90% by weight of
groups which are derived from alkene and/or alkadienes, based on
the weight of the repeat units derived from polyolefin-based
macromonomers.
[0038] The polyolefinic groups may also be present in hydrogenated
form. In addition to the groups which are derived from alkenes
and/or alkadienes, the repeat units derived from polyolefin-based
macromonomers may comprise further groups. These include small
proportions of copolymerizable monomers, including among others,
alkyl (meth)acrylates, styrene monomers, fumurates, maleates, vinyl
esters and/or vinyl ethers. The proportion of these groups based on
copolymerizable monomers is preferably at most 30% by weight, more
preferably at most 15% by weight, based on the weight of the repeat
units derived from polyolefin-based macromonomers. The repeat units
derived from polyolefin-based macromonomers may comprise start
groups and/or end groups which serve from functionalization or are
caused by the preparation of the repeat units derived from
polyolefin-based macromonomers. The proportion of these start
groups and/or end groups is preferably at most 30% by weight, more
preferably at most 15% by weight, based on the weight of the repeat
units derived from polyolefin-based macromonomers.
[0039] The number-average molecular weight of the repeat units
which are derived from polyolefin-based macromonomers is preferably
in the range from 500 to 50000 g/mol, more preferably from 700 to
10000 g/mol, even more preferably from 1500 to 4900 g/mol and most
preferably from 2000 to 3000 g/mol.
[0040] The melting point of the repeat units derived from the
polyolefin-based macromonomers is preferably less than or equal to
-10.degree. C., more preferably less than or equal to -20.degree.
C., even more preferably less than or equal to -40.degree. C., as
measured by DSC. Most preferably, no DSC melting point can be
measured for the repeat units derived from the polyolefin-based
macromonomers.
[0041] In addition to the repeat units which are derived from the
polyolefin-based macromonomers, the comb polymers used in the
present invention comprise repeat units which are derived from low
molecular weight monomers selected from the group consisting of
styrene monomers having 8 to 17 carbon atoms, alkyl(meth)acrylates
having 1 to 10 carbon atoms in the alcohol group, vinyl esters
having 1 to 11 carbon atoms in the acyl group, vinyl ethers having
1 to 10 carbon atoms in the alcohol group, di(alkyl) fumurates
having 1 to 10 carbon atoms in the alcohol group, (di)alkyl
maleates having 1 to 10 carbon atoms in the alcohol group, and
mixtures of these monomers.
[0042] The molecular weight of the low molecular weight repeat
units or of the low molecular weight monomers is preferably at most
400 g/mol, more preferably at most 200 g/mol and most preferably at
most 150 g/mol.
[0043] Examples of styrene monomers having 8 to 17 carbon atoms are
styrene, substituted styrenes having an alkyl substituent in the
side chain, for example, alpha-methylstyrene and
alpha-ethyl-styrene, substituted styrenes having an alkyl
substituent on the ring, such as vinyltoluene p-methylstyrene,
halogenated styrenes, for example monochlorostyrenes,
dichlorostyrenes, tribromostyrenes, and tetrabromostyrenes.
[0044] The term "(meth)acrylates" encompasses acrylates and
methacrylates, and also mixtures of acrylates and methacrylates.
The alkyl (meth)acrylates having 1 to 10 carbon atoms in the
alcohol group include (meth)acrylates which are derived from
saturated alcohols, such as methyl(meth)acrylate,
ethyl(meth)acrylate, n-propyl(meth)acrylate,
isopropyl(meth)acrylate, n-butyl(meth)acrylate,
tert-butyl(meth)acrylate, pentyl(meth)acrylate,
hexyl(meth)acrylate, 2-ethyl-hexyl(meth)acrylate,
heptyl(meth)acrylate, 2-tert-butylheptyl(meth)acrylate,
octyl(meth)acrylate, 3-isopropylheptyl(meth)acrylate,
nonyl(meth)acrylate, decyl(meth)acrylate; (meth)acrylates which
derive from unsaturated alcohols, for example 2-propynyl
(meth)acrylate, allyl(meth)acrylate, vinyl(meth)acrylate,
oleyl(meth)acrylate; cycloalkyl(meth)acrylates such as
cyclpentyl(meth)acrylate, and 3-vinylcyclohexyl(meth)acrylate.
[0045] Preferred alkyl(meth)acrylates include 1 to 8, more
preferably 1 to 4 carbon atoms in the alcohol group. The alcohol
group here may be linear or branched.
[0046] Examples of vinyl esters having 1 to 11 carbon atoms in the
acyl group include vinyl formate, vinyl acetate, vinyl propionate,
vinyl butyrate. Preferred vinyl esters include 2 to 9, more
preferably 2 to 5 carbon atoms in the acyl group. The acyl group
may be linear or branched.
[0047] Examples of vinyl ethers having 1 to 10 carbon atoms in the
alcohol group include vinyl methyl ether, vinyl ethyl ether, vinyl
propyl ether, vinyl butyl ether. Preferred vinyl ethers include 1
to 8, more preferably 1 to 4 carbon atoms in the alcohol group. The
alcohol group may be linear or branched.
[0048] The term "(di)ester" as used herein means that monoesters,
diesters and mixtures of esters, especially of fumaric acid and/or
of maleic acid may be used. The (di) alkyl fumurates having 1 to 10
carbon atoms in the alcohol group include monomethyl fumurate,
dimethyl fumurate, monoethyl fumurate, diethyl fumurate, methyl
ethyl fumurate, monobutyl fumurate, dibutyl fumurate, dipentyl
fumurate and dihexyl fumurate. Preferred (di)alkyl fumurates
comprise 1 to 8, more preferably 1 to 4, carbon atoms in the
alcohol group. The alcohol group may be linear or branched.
[0049] The di(alkyl) maleates having 1 to 10 carbon atoms in the
alcohol group include monomethyl maleate, dimethyl maleate,
monoethyl maleate, diethyl maleate, methyl ethyl maleate, monobutyl
maleate, dibutyl maleate. Preferred (di)alkyl maleates comprise 1
to 8, more preferably 1 to 4 carbon atoms in the alcohol group. The
alcohol group herein may be linear or branched.
[0050] In addition to the repeat units detailed above, the comb
polymers used herein may comprise further repeat units which are
derived from further comonomers, their proportion being at most 20%
by weight, preferably at most 10% by weight and more preferably at
most 5% by weight, based on the weight of the repeat units.
[0051] These also include repeat units which are derived from
alkyl(meth)acrylates having 11 to 30 carbon atoms in the alcohol
group, especially undecyl(meth)acrylate,
5-methylundecyl(meth)acrylate, dodecyl(meth)acrylate,
2-methyldodecyl(meth)acrylate, tridecyl(meth)acrylate,
5-methyltridecyl(meth)acrylate, tetradecyl(meth)acrylate,
pentadecyl(meth)acrylate, hexadecyl(meth)acrylate,
2-methylhexadecyl(meth)acrylate, heptadecyl(meth)acrylate,
5-isopropylheptadecyl(meth)acrylate,
4-tert-butyloctadecyl(meth)acrylate,
5-ethyloctadecyl(meth)acrylate, 3-isopropyloctadecyl(meth)acrylate,
octadecyl(meth)acrylate, nonadecyl(meth)acrylate,
eicosyl(meth)acrylate, cetyleicosyl(meth)acrylate,
stearyleicosyl(meth)acrylate, docosyl(meth)acrylate and/or
eicosyltetratriacontyl(meth)acrylate.
[0052] These also include repeat units which are derived from
dispersing oxygen- and nitrogen-functionalized monomers such as
those listed in paragraphs [0036]-[0059] of US2010/0190671,
incorporated herein by reference.
[0053] The comb polymers used herein preferably have a molar degree
of branching in the range of from 0.1 to 10 mol %, more preferably
from 0.3 to 6 mol %, even more preferably from 0.3 to 1.1 mol %,
especially from 0.4 to 1.0 mol % and most preferably from 0.4 to
0.6 mol %.
[0054] The molar degree of branching of the comb polymers
f.sub.branch is calculated by the formula:
f branch = a = 1 A n a a = 1 A n a + b = 1 B n b ##EQU00001##
where:
[0055] A is the number of types of repeat units which are derived
from polyolefin-based macromonomers,
[0056] B is the number of types of repeat units which are derived
from low molecular weight monomers selected from the group
consisting of styrene monomers having 8 to 17 carbon atoms,
alkyl(meth)acrylates having 1 to 10 carbon atoms in the alcohol
group, vinyl esters having 1 to 11 carbon atoms in the acyl group,
vinyl ethers having 1 to 10 carbon atoms in the alcohol group,
(di)alkyl fumurates having 1 to 10 carbon atoms in the alcohol
group, (di)alkyl maleates having 1 to 10 carbon atoms in the
alcohol group, and mixtures of these monomers,
[0057] n.sub.a is the number of repeat units which are derived from
polyolefin-based macromonomers of the type a in the comb polymer
molecule,
[0058] n.sub.b is the number of repeat units which are derived from
low molecular weight monomers selected from the group consisting of
styrene monomers having 8 to 17 carbon atoms, alkyl(meth)acrylates
having 1 to 10 carbon atoms in the alcohol group, vinyl esters
having 1 to 11 carbon atoms in the acyl group, vinyl ethers having
1 to 10 carbon atoms in the alcohol group, (di)alkyl fumurates
having 1 to 10 carbon atoms in the alcohol group, (di)alkyl
maleates having 1 to 10 carbon atoms in the alcohol group, and
mixtures of these monomers, of type b in the comb polymer
molecule.
[0059] The molar degree of branching arises generally from the
ratio of the monomers used if the comb polymer has been prepared by
copolymerization of low molecular weight and macromolecular
monomers. For the calculation, it is possible here to use the
number-average molecular weight of the macromonomer.
[0060] If the comb polymer has been obtained by polymer-analogous
reaction or by grant copolymerization, the molar degree of
branching is found by known methods of determining the
conversion.
[0061] The proportion of at least 80% by weight, preferably at
least 90% by weight, of low molecular weight repeat units which are
derived from monomers selected from the group consisting of styrene
monomers having 8 to 17 carbon atoms, alkyl (meth)acrylates having
1 to 10 carbon atoms in the alcohol group, vinyl esters having 1 to
11 carbon atoms in the acyl group, vinyl ethers having 1 to 10
carbon atoms in the alcohol group, (di)alkyl fumurates having 1 to
10 carbon atoms in the alcohol group, (di)alkyl maleates having 1
to 10 carbon atoms in the alcohol group, and mixtures of these
monomers, and of repeat units which are derived from
polyolefin-based macromonomers, is based on the weight of the
repeat units. In addition to the repeat units, polymers generally
also comprise start groups and end groups which can form through
initiation reactions and termination reactions. In one aspect of
the present invention, the statement of at least 80% by weight,
preferably at least 90% by weight, of low molecular weight repeat
units which are derived from monomers selected from the group
consisting of styrene monomers having 8 to 17 carbon atoms, alkyl
(meth)acrylates having 1 to 10 carbon atoms in the alcohol group,
vinyl esters having 1 to 11 carbon atoms in the acyl group, vinyl
ethers having 1 to 10 carbon atoms in the alcohol group, (di)alkyl
fumurates having 1 to 10 carbon atoms in the alcohol group,
(di)alkyl maleates having 1 to 10 carbon atoms in the alcohol
group, and mixtures of these monomers, and of repeat units which
are derived from polyolefin-based macromonomers, is based on the
weight of the comb polymers.
[0062] The comb polymer used herein preferably has 8 to 30% by
weight, more preferably 10 to 26% by weight, of repeat units which
are derived from polyolefin-based macromonomers, based on the total
weight of the repeat units.
[0063] Preferred comb polymers for use herein include those which
have a weight average molecular weight Mw in the range of 500,000
to 1,000,000 g/mol, more preferably 100,000 to 500,000 g/mol and
most preferably 150,000 to 450,000 g/mol.
[0064] The number-average molecular weight Mn, may preferably be in
the range of 20,000 to 800,000 g/mol, more preferably 40,000 to
200,000 g/mol and most preferably 50,000 to 150,000 g/mol.
[0065] Preferably the comb polymers used herein have a
polydipersity index Mw/Mn in the range of 1 to 5, more preferably
in the range of from 2.5 to 4.5. The number average and the weight
average molecular weight can be determined by known processes such
as Gas Permeation Chromatography (GPC).
[0066] In a particular aspect of the present invention, the comb
polymer has a low proportion of olefinic double bonds. The iodine
number is preferably less than or equal to 0.2 g per g of comb
polymer, more preferably less than or equal to 0.1 g per g of comb
polymer. This proportion can be determined according to DIN 53241
after drawing off carrier oil and low molecular weight residual
monomers at 180.degree. C. under reduced pressure for 24 hours.
[0067] In a preferred embodiment herein the comb polymer has repeat
units which are derived from n-butyl methacrylate and/or from
n-butyl acrylate. Preferably, the proportion of repeat units which
are derived from n-butyl methacrylate and/or from n-butyl acrylate
is at least 50% by weight, more preferably at least 60% by weight,
based on the total weight of repeat units.
[0068] In a preferred embodiment herein the comb polymer has repeat
units which are derived from styrene. The proportion of repeat
units which are derived from styrene are preferably in the range of
0.1 to 30% by weight, more preferably 5 to 25% by weight.
[0069] In a preferred embodiment herein, the comb polymers have
repeat units which are derived from alkyl(meth)acrylate having
11-30 carbon atoms in the alkyl radical, preferably in an amount in
the range of 0.1% to 15% by weight, more preferably in the range of
1 to 10% by weight.
[0070] In a preferred embodiment herein the comb polymer has repeat
units which are derived from styrene and repeat units which are
derived from n-butyl methacrylate. The weight ratio of styrene
repeat units and n-butylmethacrylate repeat units is preferably in
the range of 1:1 to 1:9, more preferably 1:2 to 1:8.
[0071] In another preferred embodiment, the comb polymer has repeat
units which are derived from methyl methacrylate and repeat units
which are derived from n-butyl methacrylate, preferably in a weight
ratio of 1:1 to 0:100, more preferably 3:7 to 0:100.
[0072] A commercially available comb polymer suitable for use
herein is available from Evonik under the tradename Viscoplex
3-201.
[0073] The lubricating composition according to the present
invention further comprises 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.
[0074] 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.
[0075] Anti-oxidants that may be conveniently used include
phenyl-naphthylamines (such as "IRGANOX L-06" 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 1 058 720 B1, phenolic anti-oxidants, etc. The
teaching of WO 2007/045629 and EP 1 058 720 B1 is hereby
incorporated by reference.
[0076] Anti-wear additives that may be conveniently used 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 or unsubstituted thiophosphoric acids, and salts
thereof.
[0077] Examples of such molybdenum-containing compounds may
conveniently include molybdenum dithiocarbamates, trinuclear
molybdenum compounds, for example as described in WO 98/26030,
sulphides of molybdenum and molybdenum dithiophosphate.
[0078] Boron-containing compounds that may be conveniently 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.
[0079] The dispersant used is preferably an ashless dispersant.
Suitable examples of ashless dispersants are polybutylene
succinimide polyamines and Mannich base type dispersants.
[0080] The detergent used is preferably an overbased detergent or
detergent mixture containing e.g. salicylate, sulphonate and/or
phenate-type detergents.
[0081] Examples of viscosity index improvers which may conveniently
be used in the lubricating composition of the present invention
include the 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 may be used in the lubricating composition of the
present invention. However, preferably the composition according to
the present invention contains less than 1.0 wt. %, preferably less
than 0.5 wt. %, of a Viscosity Index improver concentrate (i.e. VI
improver plus "carrier oil" or "diluent"), based on the total
weight of the composition. Most preferably, the composition is free
of Viscosity Index improver concentrate. The term "Viscosity
Modifier" as used hereafter (such as in Table 2) is meant to be the
same as the above-mentioned term "Viscosity Index improver
concentrate".
[0082] Preferably, the composition contains at least 0.1 wt. % of a
pour point depressant. As an example, alkylated naphthalene and
phenolic polymers, polymethacrylates, maleate/fumarate copolymer
esters may be conveniently used as effective pour point
depressants. Preferably not more than 0.3 wt. % of the pour point
depressant is used.
[0083] Furthermore, compounds such as alkenyl succinic acid or
ester moieties thereof, benzotriazole-based compounds and
thiodiazole-based compounds may be conveniently used in the
lubricating composition of the present invention as corrosion
inhibitors.
[0084] Compounds such as polysiloxanes, dimethyl polycyclohexane
and polyacrylates may be conveniently used in the lubricating
composition of the present invention as defoaming agents.
[0085] Compounds which may be conveniently used in the lubricating
composition of the present invention as seal fix or seal
compatibility agents include, for example, commercially available
aromatic esters.
[0086] The lubricating compositions of the present invention may be
conveniently prepared by admixing the comb polymer with the base
oil(s), and one or more additives.
[0087] The above-mentioned additives are typically 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. %, more preferably from 1.0 to
20.0 wt. %, based on the total weight of the lubricating
composition.
[0088] 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.
[0089] 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.
[0090] For Passenger Car Motor Oil (PCMO) engine oils the above
ranges mean:
[0091] a sulphated ash content (according to ASTM D 874) of up to
0.5 wt. %, up to 0.8 wt. % and up to 1.5 wt. %, respectively;
[0092] a phosphorus content (according to ASTM D 5185) of up to
0.05 wt. %, up to 0.08 wt. % and typically up to 0.1 wt. %,
respectively; and
[0093] a sulphur content (according to ASTM D 5185) of up to 0.2
wt. %, up to 0.3 wt. % and typically up to 0.5 wt. %,
respectively.
[0094] For Heavy Duty Diesel Engine Oils the above ranges mean:
[0095] a sulphated ash content (according to ASTM D 874) of up to 1
wt. %, up to 1 wt. % and up to 2 wt. %, respectively;
[0096] a phosphorus content (according to ASTM D 5185) of up to
0.08 wt. % (low SAPS) and up to 0.12 wt. % (mid SAPS),
respectively; and
[0097] a sulphur content (according to ASTM D 5185) of up to 0.3
wt. % (low SAPS) and up to 0.4 wt. % (mid SAPS), respectively.
[0098] In another aspect, the present invention provides the use of
a lubricating composition according to the present invention as an
engine oil in the crankcase of an engine, in order to improve
sustained fuel economy properties whilst also improving dispersancy
and piston cleanliness properties. The engine oil may include a
heavy duty diesel engine oil, a passenger car motor engine oil, as
well as other types of engine oils.
[0099] The present invention is described below with reference to
the following Examples, which are not intended to limit the scope
of the present invention in any way.
Examples
Lubricating Oil Compositions
[0100] Various engine oils for use in a crankcase engine were
formulated.
[0101] Table 1 indicates the properties for the base oils used.
Table 2 indicates the composition and properties of the fully
formulated engine oil formulations that were tested; the amounts of
the components are given in wt. %, based on the total weight of the
fully formulated formulations.
[0102] "Base oil 1" was a commercially available Group III base
oils having a kinematic viscosity at 100.degree. C. (ASTM D445) of
4.2 cSt (average value). Base oil 1 is commercially available from
e.g. SK Energy (Ulsan, South Korea) (under the trade designation
"Yubase 4").
[0103] "Base oil 2" was a commercially available Group III base
oils having a kinematic viscosity at 100.degree. C. (ASTM D445) of
6.5 cSt (average value). Base oil 2 is commercially available from
e.g. SK Energy (Ulsan, South Korea) (under the trade designation
"Yubase 6").
[0104] "Base oil 3" was a Fischer-Tropsch derived base oil ("GTL
4") having a kinematic viscosity at 100.degree. C. (ASTM D445) of
approx. 4 cSt (mm.sup.2 s.sup.-1). This GTL 4 base oil may be
conveniently manufactured by the process described in e.g. WO
02/070631, the teaching of which is hereby incorporated by
reference.
[0105] "Base oil 4" was a Fischer-Tropsch derived base oil ("GTL
8") having a kinematic viscosity at 100.degree. C. (ASTM D445) of
approx. 8 cSt (mm.sup.2 s.sup.-1). This GTL 8 base oil may be
conveniently manufactured by the process described in e.g. WO
02/070631, the teaching of which is hereby incorporated by
reference.
[0106] All tested engine oil formulations contained a combination
of a base oil, a comb polymer (or other Viscosity Modifier in the
case of Comparative Example 1), an additive package, optionally a
pour point depressant, and optionally a friction modifier which
additive package was the same in all tested compositions.
[0107] The additive package was a so-called "mid SAPS" (medium
sulphated ash, phosphorus and sulphur) formulation.
[0108] The additive package contained a combination of additives
including anti-oxidants, a zinc-based anti-wear additive, an
ashless dispersant, an overbased detergent mixture and about 10 ppm
of an anti-foaming agent.
[0109] The comb polymer was a commercially available comb polymer
available from Evonik under the tradename "Viscoplex 3-201".
[0110] The pour point depressant in Comparative Example 1 was
Viscoplex 6-054 which is a dispersant PMA commercially available
from Evonik.
[0111] The viscosity modifier in Comparative Example 1 was a
conventional styrene-hydrogenated isoprene co-polymer viscosity
modifier concentrate, commercially available from Infineum under
the trade designation "SV 201".
[0112] The friction modifier was a conventional friction modifier,
commercially available from Lubrizol under the tradename
LZ8621.
[0113] The compositions of the Examples and the Comparative
Examples were obtained by mixing the base oils with the other
components, using conventional lubricant blending procedures.
[0114] In order to demonstrate the fuel economy properties of the
compositions of the present invention, fuel economy measurements
were performed on the examples and comparative examples according
to the industry standard M111 Fuel Economy Test Method (according
to CEC-L-054-96). The results of these tests are shown in Table
2.
[0115] In order to demonstrate the piston cleanliness properties of
the compositions of the present invention, piston cleanliness
measurements were performed on the examples and comparative
examples according to the industry standard VW TDI Test Method
(according to CEC-L-078-99). A "pass" for this method is deemed to
be a value of greater than or equal to the reference oil (which in
this case is 65 merits). The results of these tests are shown in
Table 2.
[0116] In order to demonstrate the diesel soot dispersancy
properties of the compositions of the present invention,
measurements were performed on the examples and comparative
examples according to the industry standard DV4 test (according to
CEC-L-093-04). The results of these tests are shown in Table 2.
[0117] In order to demonstrate the propensity of the lubricating
compositions of the present invention to form deposits when
subjected to high temperatures (thermal stability) the examples and
comparative examples were subjected to Microcoking Test (MCT)
Method. In the MCT Method 0.6 cm.sup.3 of the lubricating
composition was put in the trough of an aluminium-alloy plate
heated at one end (hot spot) and regulated at the other end (cold
spot). The measurement of the temperature between these two spots
allows to establish a thermal gradient, estimated to be linear,
between the two ends of the trough. The standard duration of the
test is 90 minutes. At the end of the test, the initiating
temperature of deposit formation is determined and rated according
to the CEC M-02-A-78 Code of Practice. The results of these tests
are shown in Table 2.
TABLE-US-00001 TABLE 1 Base oil 1 Base oil 2 Base oil 3 Base oil 4
(Yubase 4) (Yubase 6) (GTL 4) (GTL 8) Kinematic viscosity 4.2 6.5
4.0 8 at 100.degree. C..sup.1 [cSt] VI Index.sup.2 120 125 120 120
Pour point.sup.3 [.degree. C.] -15 -12 -30 -30 Noack
volatility.sup.4 15.3 8 14.0 5 [wt. %] .sup.1According to ASTM D
445. Average figures quoted .sup.2According to ASTM D 2270. Minimum
values quoted. .sup.3According to ASTM D 5950. Maximum values
quoted. .sup.4According to CEC L-40-A-93/ASTM D 5800. Maximum
values quoted
TABLE-US-00002 TABLE 2 Comp. Comp. Comp. Component [wt. %] Example
1 Example 2 Example 1 Example. 3 Example 2 Base oil 1(Yubase 4)
49.5 76 -- 78.1 -- Base oil 2(Yubase 6) 33.0 -- -- -- -- Base oil 3
(GTL 4) -- -- 55 -- 53 Base oil 4 (GTL 8) -- -- 21 -- 26 Viscoplex
3-201 -- 11.5 11.5 9.4 8.5 Viscosity Modifier 5 -- -- -- --
Additive package 12 12 12 12 12 Pour point depressant 0.5 -- -- --
-- Friction Modifier -- 0.5 0.5 0.5 0.5 TOTAL 100 100 100 100 100
Properties of the total composition Kinematic viscosity at 11.83
11.31 10.88 9.853 9.707 100.degree. C..sup.1 [cSt] Kinematic
viscosity at 71.2 41.6 44.21 38.62 43.75 40.degree. C..sup.1 [cSt]
VI 165 281 247 255 216 HTHS 150.sup.2 [cP] 3.53 3.45 3.49 3.15 3.24
M111 2.17 2.97 Not measured 3.45/3.32 3.07 (two measure- ments were
taken) VW TDI 65 Not measured 65 60 (average 65 measurement) (fail)
MCT 6.3 4.1 6.6 5.2 7.5 DV4 9.5% 2.14% 2.22% 1.08% Not measured
.sup.1According to ASTM D 445 .sup.2According to ASTM D 4683
DISCUSSION
[0118] The results in Table 2 demonstrate that the lubricating
compositions of the present invention surprisingly exhibit improved
fuel economy, improved piston cleanliness, reduced high temperature
deposit formation and improved soot dispersancy. Only when there is
a combination of both GTL and comb polymer do we see fuel economy
benefits together with piston cleanliness and reduced high
temperature deposit formation.
* * * * *