U.S. patent application number 16/002109 was filed with the patent office on 2018-12-27 for low viscosity lubricants based on methyl paraffin containing hydrocarbon fluids.
The applicant listed for this patent is ExxonMobil Research and Engineering Company. Invention is credited to Mark P. HAGEMEISTER, Halou OUMAR-MAHAMAT.
Application Number | 20180371348 16/002109 |
Document ID | / |
Family ID | 62751583 |
Filed Date | 2018-12-27 |
View All Diagrams
United States Patent
Application |
20180371348 |
Kind Code |
A1 |
OUMAR-MAHAMAT; Halou ; et
al. |
December 27, 2018 |
LOW VISCOSITY LUBRICANTS BASED ON METHYL PARAFFIN CONTAINING
HYDROCARBON FLUIDS
Abstract
A lubricating oil base stock including a lubricating oil base
stock including from 5 to 50 wt % of 9-methylnonadecane and from 95
to 50 wt % of 9-methyl-11-octylheneicosane. The lubricating oil
base stock has a relationship between Noack volatility at
250.degree. C. as measured by ASTM D5800 (y) and kinematic
viscosity at 40.degree. C. as measured by ASTM D445 (x) that is
less than y=2.15-0.765*ln(x). Also provided is a lubricating oil
containing the lubricating oil base stock and one or more
lubricating oil additives. A method for improving one or more of
thermal and oxidative stability, deposit control and traction
control in a lubricating oil by using as the lubricating oil a
formulated oil containing the lubricating oil base stock and one or
more lubricating oil additives is also provided.
Inventors: |
OUMAR-MAHAMAT; Halou;
(Mullica Hill, NJ) ; HAGEMEISTER; Mark P.;
(Mullica Hill, NJ) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
ExxonMobil Research and Engineering Company |
Annandale |
NJ |
US |
|
|
Family ID: |
62751583 |
Appl. No.: |
16/002109 |
Filed: |
June 7, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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62523398 |
Jun 22, 2017 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C10M 105/04 20130101;
C10M 107/10 20130101; C10N 2040/25 20130101; C10N 2020/017
20200501; C10N 2030/02 20130101; C10N 2030/08 20130101; C10N
2030/54 20200501; C10N 2030/06 20130101; C10N 2030/74 20200501;
C10N 2020/071 20200501; C10M 2209/084 20130101; C10N 2020/083
20200501; C10N 2030/10 20130101; C10M 2203/0206 20130101; C10M
2203/022 20130101; C10M 2205/0285 20130101; C10N 2020/02 20130101;
C10N 2020/065 20200501 |
International
Class: |
C10M 105/04 20060101
C10M105/04 |
Claims
1. A lubricating oil base stock comprising from 5 to 50 wt % of
9-methylnonadecane and from 95 to 50 wt % of
9-methyl-11-octylheneicosane, wherein the base stock has a
relationship between Noack volatility at 250.degree. C. as measured
by ASTM D5800 (y) and kinematic viscosity at 40.degree. C. as
measured by ASTM D445 (x) that is less than y=2.15-0.765*ln(x).
2. The lubricating oil base stock of claim 1, wherein the base
stock has a kinematic viscosity at 100.degree. C. as measured by
ASTM D445 of from 1.5 to 3.5 cSt.
3. The lubricating oil base stock of claim 1, wherein the base
stock has a kinematic viscosity at 40.degree. C. as measured by
ASTM D445 of from 4.0 to 14.0 cSt.
4. The lubricating oil base stock of claim 1 comprising about 30 wt
% of 9-methylnonadecane and about 70 wt % of
9-methyl-11-octylheneicosane.
5. The lubricating oil base stock of claim 1 comprising about 10 wt
% of 9-methylnonadecane and about 90 wt % of
9-methyl-11-octylheneicosane.
6. The lubricating oil base stock of claim 1, wherein the base
stock has a Noack volatility at 250.degree. C. as measured by ASTM
D5800 of 10 to 90%.
7. The lubricating oil base stock of claim 1, wherein the base
stock has a Viscosity Index from about 100 to 170 as determined by
ASTM D2270.
8. The lubricating oil base stock of claim 1, wherein the base
stock has a pour point of from about -10 to -80.degree. C. as
determined by ASTM D5950.
9. The lubricating oil base stock of claim 1, wherein the base
stock has a MTM average traction coefficient (at 100 deg. C, 1 GPa,
2 m/s and 0-100% SRR) of from about 0.0060 to 0.0090.
10. The lubricating oil base stock of claim 1, wherein the base
stock has a MTM average traction coefficient (at 100 deg. C, 1 GPa,
2 m/s and 0-100% SRR) that is about 20 to 180% lower than a Group
II or Group III base stock of comparable KV100.degree. C.
viscosity.
11. The lubricating oil base stock of claim 1, wherein the base
stock has a high temperature high shear (HTHS) viscosity of less
than about 1.6 cP as determined by ASTM D4683, and a Noack
volatility from about 16 to about 30 percent as determined by ASTM
D5800.
12. A lubricating oil comprising a major amount of a lubricating
oil base stock and a minor amount of one or more additives, said
lubricating oil base stock comprising from 5 to 50 wt % of
9-methylnonadecane and from 95 to 50 wt % of
9-methyl-11-octylheneicosane, wherein the base stock has a
relationship between Noack volatility at 250.degree. C. as measured
by ASTM D5800 (y) and kinematic viscosity at 40.degree. C. as
measured by ASTM D445 (x) that is less than y=2.15-0.765*ln(x).
13. The lubricating oil of claim 12 wherein the one or more
additives are selected from the group consisting of a viscosity
improver or modifier, antioxidant, detergent, dispersant, pour
point depressant, corrosion inhibitor, metal deactivator, seal
compatibility additive, anti-foam agent, inhibitor, anti-rust
additive and combinations thereof.
14. The lubricating oil of claim 12, wherein the major amount of
the lubricating oil base stock is from about 55 to 99 wt % of the
lubricating oil and the minor amount of the one or more additives
is from about 45 to 1 wt % of the lubricating oil.
15. The lubricating oil of claim 12, wherein the oil has a
kinematic viscosity at 100.degree. C. as measured by ASTM D445 of
from 2.0 to 6.0 cSt.
16. The lubricating oil of claim 12, wherein the oil has a
kinematic viscosity at 40.degree. C. as measured by ASTM D445 of
from 5.0 to 25.0 cSt.
17. The lubricating oil of claim 12 wherein the lubricating oil
base stock comprises about 30 wt % of 9-methylnonadecane and about
70 wt % of 9-methyl-11-octylheneicosane.
18. The lubricating oil of claim 12 wherein the lubricating oil
base stock comprises about 10 wt % of 9-methylnonadecane and about
90 wt % of 9-methyl-11-octylheneicosane.
19. The lubricating oil of claim 12, wherein the oil has a Noack
volatility at 250.degree. C. as measured by ASTM D5800 of 10 to
90%.
20. The lubricating oil of claim 12, wherein the oil has a
Viscosity Index from about 100 to 200 as determined by ASTM
D2270.
21. The lubricating oil of claim 12, wherein the oil has a pour
point of from about -10 to -60.degree. C. as determined by ASTM
D5950.
22. The lubricating oil base stock of claim 12, wherein the oil has
a MTM average traction coefficient (at 100 deg. C, 1 GPa, 2 m/s and
0-100% SRR) of from about 0.0050 to 0.0090.
23. The lubricating oil of claim 12, wherein the oil has a MTM
average traction coefficient (at 100 deg. C, 1 GPa, 2 m/s and
0-100% SRR) that is about 20 to 180% lower than a comparable
lubricating oil including a Group II or a Group III base stock of
comparable KV100.degree. C. viscosity.
24. The lubricating oil of claim 12, wherein the oil has a high
temperature high shear (HTHS) viscosity of less than about 2.3 cP
as determined by ASTM D4683.
25. The lubricating oil of claim 12, wherein the oil has an
oxidation stability (210 hour test with time to 200% KV40 increase)
of from about 60 to 150 hours.
26. The lubricating oil of claim 12, wherein the oil has resistance
to deposit formation as measured by TEOST 33C test for 2 hours at
200 to 480 deg. C per ASTM D6335 of from 10 to 30 mg.
27. The lubricating oil of claim 12, wherein the oil has a Cold
Crank Simulator (CC S) viscosity at -35 deg. C per ASTM D5293 of
from 700 to 1000 mPas.
28. The lubricating oil of claim 13 wherein the one or more
additives include a viscosity modifier selected from a
polymethacrylate, a hydrocarbon hydrogenated polyisoprene star
polymer and combinations thereof.
29. The lubricating oil of claim 28 wherein the oil has a high
temperature high shear (HTHS) viscosity of less than about 2.3 cP
as determined by ASTM D4683.
30. The lubricating oil of claim 28 wherein the oil has a Viscosity
Index from about 220 to 340 as determined by ASTM D2270.
31. The lubricating oil of claim 12 further including a cobase
stock at from 5 to 40 wt %, wherein the cobase stock is selected
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.
32. The lubricating oil of claim 12, wherein the oil has a high
temperature high shear (HTHS) viscosity of less than about 2.3 cP
as determined by ASTM D4683, and a Noack volatility from about 15
to about 90 percent as determined by ASTM D5800.
33. A method for improving one or more of thermal and oxidative
stability, deposit control and traction control in a lubricating
oil comprising: providing a lubricating oil including a major
amount of a lubricating oil base stock and a minor amount of one or
more additives, said lubricating oil base stock comprising from 5
to 50 wt % of 9-methylnonadecane and from 95 to 50 wt % of
9-methyl-11-octylheneicosane, wherein the base stock has a
relationship between Noack volatility at 250.degree. C. as measured
by ASTM D5800 (y) and kinematic viscosity at 40.degree. C. as
measured by ASTM D445 (x) that is less than y=2.15-0.765*ln(x), and
using the lubricating oil in a formulated oil to improve one or
more of thermal and oxidative stability, deposit control and
traction control.
34. The method of claim 33 wherein the one or more additives are
selected from the group consisting of a viscosity improver or
modifier, antioxidant, detergent, dispersant, pour point
depressant, corrosion inhibitor, metal deactivator, seal
compatibility additive, anti-foam agent, inhibitor, anti-rust
additive and combinations thereof.
35. The method of claim 33, wherein the major amount of the
lubricating oil base stock is from about 55 to 99 wt % of the
lubricating oil and the minor amount of the one or more additives
is from about 45 to 1 wt % of the lubricating oil.
36. The method of claim 33, wherein the oil has a kinematic
viscosity at 100.degree. C. as measured by ASTM D445 of from 2.0 to
6.0 cSt.
37. The method of claim 33, wherein the oil has a kinematic
viscosity at 40.degree. C. as measured by ASTM D445 of from 5.0 to
25.0 cSt.
38. The method of claim 33, wherein the lubricating oil base stock
comprises about 30 wt % of 9-methylnonadecane and about 70 wt % of
9-methyl-11-octylheneicosane.
39. The method of claim 33, wherein the lubricating oil base stock
comprises about 10 wt % of 9-methylnonadecane and about 90 wt % of
9-methyl-11-octylheneicosane.
40. The method of claim 33, wherein the oil has a Noack volatility
at 250.degree. C. as measured by ASTM D5800 of 10 to 90%.
41. The method of claim 33, wherein the oil has a Viscosity Index
from about 100 to 200 as determined by ASTM D2270.
42. The method of claim 33, wherein the oil has a pour point of
from about -10 to -60.degree. C. as determined by ASTM D5950.
43. The method of claim 33, wherein the oil has a MTM average
traction coefficient (at 100 deg. C, 1 GPa, 2 m/s and 0-100% SRR)
of from about 0.0050 to 0.0090.
44. The method of claim 33, wherein the oil has a MTM average
traction coefficient (at 100 deg. C, 1 GPa, 2 m/s and 0-100% SRR)
that is about 20 to 180% lower than a comparable lubricating oil
including a Group II or a Group III base stock of comparable
KV100.degree. C. viscosity.
45. The method of claim 33, wherein the oil has a high temperature
high shear (HTHS) viscosity of less than about 2.3 cP as determined
by ASTM D4683.
46. The method of claim 33, wherein the oil has an oxidation
stability (210 hour test with time to 200% KV40 increase) of from
about 60 to 150 hours.
47. The method of claim 33, wherein the oil has resistance to
deposit formation as measured by TEOST 33C test for 2 hours at 200
to 480 deg. C per ASTM D6335 of from 10 to 30 mg.
48. The method of claim 33, wherein the oil has a Cold Crank
Simulator (CCS) viscosity at -35 deg. C per ASTM D5293 of from 700
to 1000 mPas.
49. The method of claim 34, wherein the one or more additives
include a viscosity modifier selected from a polymethacrylate, a
hydrocarbon hydrogenated polyisoprene star polymer and combinations
thereof.
50. The method of claim 49 wherein the oil has a high temperature
high shear (HTHS) viscosity of less than about 2.3 cP as determined
by ASTM D4683.
51. The method of claim 49 wherein the oil has a Viscosity Index
from about 220 to 340 as determined by ASTM D2270.
52. The method of claim 33 wherein the oil further includes a
cobase stock at from 5 to 40 wt % of the formulated oil, wherein
the cobase stock is selected 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.
53. The method of claim 33, wherein the oil has a high temperature
high shear (HTHS) viscosity of less than about 2.3 cP as determined
by ASTM D4683, and a Noack volatility from about 15 to about 90
percent as determined by ASTM D5800.
54. A method of making a low viscosity low volatility lubricating
oil comprising: providing a lubricating oil base stock and one or
more additives, wherein the lubricating oil base stock comprises
from 5 to 50 wt % of 9-methylnonadecane and from 95 to 50 wt % of
9-methyl-11-octylheneicosane, and blending a major amount of the
lubricating oil base stock and a minor amount of the one or more
additives to form the lubricating oil, wherein the lubricating oil
base has a relationship between Noack volatility at 250.degree. C.
as measured by ASTM D5800 (y) and kinematic viscosity at 40.degree.
C. as measured by ASTM D445 (x) that is less than y=2.15-0.765
ln(x).
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional
Application No. 62/523,398, filed on Jun. 22, 2017, the entire
contents of which are incorporated herein by reference.
FIELD
[0002] This disclosure relates to low viscosity, low volatility
lubricating oil base stocks, and lubricating oils containing the
lubricating oil base stocks. This disclosure also relates to a
method for improving one or more of thermal and oxidative
stability, volatility, viscosity index, deposit control and
traction control in a lubricating oil by using as the lubricating
oil a formulated oil containing the lubricating oil base stock.
BACKGROUND
[0003] Lubricants in commercial use today are prepared from a
variety of natural and synthetic base stocks admixed with various
additive packages and solvents depending upon their intended
application. The base stocks typically include mineral oils,
polyalphaolefins (PAO), gas-to-liquid base oils (GTL), silicone
oils, phosphate esters, monoesters, diesters, polyol esters, and
the like.
[0004] A major trend for passenger car engine oils (PCEOs) is an
overall improvement in quality as higher quality base stocks become
more readily available. Typically the highest quality PCEO products
are formulated with base stocks such as PAOs or GTL stocks admixed
with various additive packages.
[0005] For improving fuel economy, base oil viscosity is very
important. Substantial improved fuel economy (>2%) requires
breakthrough in: (1) base oil volatility (2) durability and (3)
friction. Friction losses occur between the moving components
within the engine. Models developed to date indicate that fuel
economy is heavily influenced by the lubricant properties at high
shear. The base stock contributes a greater proportion of the total
viscosity under high shear conditions than under low shear.
Lowering base stock viscosity is likely to have the largest impact
on future fuel economy gains.
[0006] Current commercial PAO fluids (e.g., SpectraSyn.TM. 2) based
on hydrocarbon and commercial esters (e.g., 2-ethylhexyl adipate,
di-2-ethylhexyl azelate, Esterex.TM. A32, Esterex.TM. A34) do not
adequately allow formulation of ultra-low viscosity lubricant while
still meeting API specification (e.g., Noack volatility of 15% or
less) and/or other OEM (original equipment manufacturers) set
specifications or requirements. In order to formulate ultra-low
viscosity lubricant for fuel economy benefit, it is desirable to
have low viscosity and low volatility properties co-exist in the
same base stock, for meeting volatility requirement. In addition,
the base stock should also possess adequate thermal and oxidative
stability at high temperature to prevent or minimize deposit
formation. Good compatibility with additives commonly used in
lubricant formulations (PVL, Passenger Vehicle Lubricants, CVL,
Commercial Vehicle Lubricants, and industrial lubricants), good low
temperature properties, and acceptable viscosity indices are also
necessary for the base stocks.
[0007] Poly-.alpha.-olefins (PAOs) are important lube base stocks
with many excellent lubricant properties, including high viscosity
index (VI), low volatility and are available in various viscosity
range (Kv.sub.100 2-300 cSt). However, PAOs are paraffinic
hydrocarbons with low polarity. This low polarity leads to low
solubility and dispersancy for polar additives or sludge generated
during service. To compensate for this low polarity, lube
formulators usually add one or multiple polar cobase stocks. Ester
or alkylated naphthalene (AN) is usually present at 1 wt. % to 50
wt. % levels in many finished lubricant formulations to increase
the fluid polarity which improves the solubility of polar additives
and sludge.
[0008] Future automotive and industrial trend suggest that there
will be a need for advanced additive technology and synthetic base
stocks with substantially better thermal and oxidative stability.
This is primarily because of smaller sump sizes that will have more
thermal and oxidative stresses on the lubricants. Performance
requirements have become more stringent in the past 10 to 20 years
and the demand for longer drain intervals has grown steadily. Also,
the use of Group II, III and IV base oils is becoming more
widespread. Such base oils have very little sulfur content since
natural sulfur-containing antioxidants are either absent or removed
during the severe refining process.
[0009] It is known that lubricant oils used in internal combustion
engines and transmission of automobile engines or trucks are
subjected to demanding environments during use. These environments
result in the lubricant suffering oxidation catalyzed by the
presence of impurities in the oil, such as iron (wear) compounds
and elevated temperatures. The oxidation manifests itself by
increase in acid or viscosity and deposit formation or any
combination of these symptoms. These are controlled to some extent
by the use of antioxidants which can extend the useful life of the
lubricating oil, particularly by reducing or preventing
unacceptable viscosity increases. Besides oxidation inhibition,
other parameters such as rust and wear control are also
important.
[0010] A major challenge in engine oil formulation is
simultaneously achieving improved fuel economy while also achieving
appropriate low temperature properties, and oxidative
stability.
[0011] Therefore, there is need for better additive and base stock
technology for lubricant compositions that will meet ever more
stringent requirements of lubricant users. In particular, there is
a need for additive technology and synthetic base stocks with
improved fuel economy, viscosity indices, and oxidative
stability.
[0012] The present disclosure also provides many additional
advantages, which shall become apparent as described below.
SUMMARY
[0013] This disclosure provides lubricating oil base stocks that
include one or more methyl substituted hydrocarbon fluids that have
desirable low viscosity/low volatility properties while exhibiting
good high-temperature thermal-oxidative stability. Thus, the
lubricating oil base stocks of this disclosure provide a solution
to achieve enhanced fuel economy and energy efficiency. In
addition, thermal, oxidative, and inherent hydrolytic stability,
deposit control and traction control are other advantages of these
base stocks.
[0014] This disclosure relates in part to a lubricating oil base
stock comprising from 5 to 50 wt % of 9-methylnonadecane and from
95 to 50 wt % of 9-methyl-11-octylheneicosane, wherein the base
stock has a relationship between Noack volatility at 250.degree. C.
as measured by ASTM D5800 (y) and kinematic viscosity at 40.degree.
C. as measured by ASTM D445 (x) that is less than
y=2.15-0.765*ln(x). The chemical structures of the
9-methylnonadecane and 9-methyl-11-octylheneicosane base stocks for
blending are as follows:
##STR00001##
[0015] This disclosure also relates in part to a lubricating oil
comprising a major amount of a lubricating oil base stock and a
minor amount of one or more additives. The lubricating oil base
stock comprising from 5 to 50 wt % of 9-methylnonadecane and from
95 to 50 wt % of 9-methyl-11-octylheneicosane, wherein the base
stock has a relationship between Noack volatility at 250.degree. C.
as measured by ASTM D5800 (y) and kinematic viscosity at 40.degree.
C. as measured by ASTM D445 (x) that is less than
y=2.15-0.7651n(x).
[0016] This disclosure also relates in part to a method for
improving one or more of thermal and oxidative stability, deposit
control and traction control in a lubricating oil comprising:
providing a lubricating oil including a major amount of a
lubricating oil base stock and a minor amount of one or more
additives, said lubricating oil base stock comprising from 5 to 50
wt % of 9-methylnonadecane and from 95 to 50 wt % of
9-methyl-11-octylheneicosane, wherein the base stock has a
relationship between Noack volatility at 250.degree. C. as measured
by ASTM D5800 (y) and kinematic viscosity at 40.degree. C. as
measured by ASTM D445 (x) that is less than y=2.15-0.765*ln(x), and
using the lubricating oil in a formulated oil to improve one or
more of thermal and oxidative stability, deposit control and
traction control.
[0017] This disclosure also relates in part to a method for making
a low viscosity low volatility lubricating oil comprising:
providing a lubricating oil base stock and one or more additives,
wherein the lubricating oil base stock comprises from 5 to 50 wt %
of 9-methylnonadecane and from 95 to 50 wt % of
9-methyl-11-octylheneicosane, and blending a major amount of the
lubricating oil base stock and a minor amount of the one or more
additives to form the lubricating oil, wherein the lubricating oil
base has a relationship between Noack volatility at 250.degree. C.
as measured by ASTM D5800 (y) and kinematic viscosity at 40.degree.
C. as measured by ASTM D445 (x) that is less than
y=2.15-0.765*ln(x).
[0018] It has been surprisingly found that outstanding low
viscosity low volatility properties, good high-temperature thermal
and oxidative stability, deposit control, and traction benefits,
can be attained in an engine lubricated with a lubricating oil by
using as the lubricating oil a formulated oil in accordance with
this disclosure. In particular, a lubricating oil base stock
comprising low viscosity methyl paraffins exhibits low viscosity,
low volatility, superior oxidative stability, desired deposit
control and traction benefits, which helps to prolong the useful
life of lubricants and significantly improve the durability and
resistance of lubricants when exposed to high temperatures. The
lubricating oils of this disclosure are particularly advantageous
as passenger vehicle (PVL) or commercial vehicle (CVL) engine oils
and/or driveline oil products.
[0019] The lubricating oils of this disclosure are particularly
advantageous as passenger vehicle engine oil (PVEO) products, more
specifically SAE 0WX, SAE SWX, or SAE 10WX, (where X=4, 8, 12, 16,
20, 30, 40, or 50), and similar oil formulations, especially oil
formulations exhibiting lowered volatility when blended with the
components of this invention.
[0020] Further objects, features and advantages of the present
disclosure will be understood by reference to the following
drawings and detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] FIG. 1 shows the physical characteristics of inventive low
viscosity methyl paraffin based base stocks and comparative low
viscosity base stocks.
[0022] FIG. 2 shows the physical characteristics and performance
test results of engine oils formulations including the inventive
methyl paraffin based and comparative low viscosity base
stocks.
[0023] FIG. 3 shows kinematic viscosity and viscosity index of
engine oils formulations including the inventive methyl paraffin
based and comparative low viscosity base stocks which also include
viscosity modifier.
[0024] FIG. 4 is a graph of the relationship between Noack
volatility and kinematic viscosity at 40 deg. C and shows that the
inventive methyl paraffin based low viscosity base stock blends
have a relationship between Noack volatility (y) and KV40 (x) that
is less than y=2.15-0.765*ln(x).
[0025] FIG. 5 shows the base stock blend ratios for the inventive
mixtures of C10 dimer and C10 trimer of the inventive methyl
paraffin based low viscosity base stock blends and the comparative
mixtures of 2 cSt and 3.6 cSt conventional PAOs of the comparative
PAO low viscosity base stock blends of FIG. 4.
DETAILED DESCRIPTION
[0026] 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.
Lubricating Oil Base Stocks
[0027] The inventive base stocks of this disclosure are blends of
C10 dimer and C10 trimer. In particular, the inventive base stocks
of this disclosure are blends of 9-methylnonadecane (also referred
to herein as "C10 dimer") and 9-methyl-11-octylheneicosane (also
referred to herein as "C10 trimer"). The chemical structures of the
9-methylnonadecane and 9-methyl-11-octylheneicosane base stocks for
blending are as follows:
##STR00002##
[0028] Also shown below is the chemical structure of a comparative
11-methyltricosane basestock (also referred to herein as "C12
dimer").
##STR00003##
[0029] These base stocks exhibit (1) outstanding low viscosity low
volatility properties, (2) good high-temperature thermal and
oxidative stability, (3) good low temperature properties and in
particular high viscosity indices, (4) good deposit control, and
(4) traction benefits, which make them attractive as Group IV
synthetic base stocks in high performance, fuel economy lubricant
applications.
[0030] Low viscosity base stocks (e.g., kinematic viscosity at
100.degree. C., 2-3 cSt) currently available in the marketplace are
too volatile to be used for formulating next-generation ultra-low
viscosity engine oils (i.e., xxW-4.fwdarw.xxW-16). These base
stocks (e.g., SpectraSyn.TM. 2, QHVI.TM. 3, bis-(2-ethylhexyl)
adipate, di-2-ethylhexyl azelate, Esterex.TM. A32) are unable to
provide formulated engine oils that also meet current volatility
API specification or other OEM volatility requirements. The present
disclosure provides blends of methyl paraffins that have desirable
low viscosity and low volatility properties while exhibiting
traction benefits, good deposit control behavior and good
high-temperature thermal-oxidative stability, and hence provide a
solution to achieve enhanced fuel economy and energy
efficiency.
[0031] As indicated above, the methyl paraffin base stock
components useful in this disclosure include, a blend of a C10
dimer compound and a C10 trimer compound represented by the formula
below.
##STR00004##
[0032] The methyl paraffin lubricating oil base stock may include
from 10 to 60 wt % of the C10 dimer and from 40 to 90 wt % of the
C10 trimer or may include from 5 to 50 wt % of the C10 dimer and
from 50 to 95 wt % of the C10 trimer. More particularly, the C10
dimer in the inventive methyl paraffin base stock blend may be 5 wt
%, 10 wt %, or 15 wt %, or 20 wt %, or 25 wt %, or 30 wt %, or 35
wt %, or 40 wt %, or 45 wt %, or 50 wt %, or 55 wt %, or 60 wt % of
the total base stock blend. The C10 trimer in the inventive methyl
paraffin base stock blend may be 95 wt %, 90 wt %, or 85 wt %, or
80 wt %, or 75 wt %, or 70 wt %, or 65 wt %, or 60 wt %, or 55 wt
%, or 50 wt %, or 45 wt %, or 40 wt % of the total base stock
blend. In one preferred form of the inventive methyl paraffin base
stock blend, the C10 dimer constitutes 30 wt % of the total base
stock blend and the C10 trimer constitutes 70 wt % of the total
base stock blend. In another preferred form of the inventive methyl
paraffin base stock blend, the C10 dimer constitutes 10 wt % of the
total base stock blend and the C10 trimer constitutes 90 wt % of
the total base stock blend.
[0033] The methyl paraffin lubricating oil base stocks of the
instant disclosure have a viscosity (Kv.sub.100) from 1.5 cSt to
3.5 cSt, or 1.7 to 3.3 cSt, or 1.9 to 3.1 cSt, or 2.1 to 2.9 cSt,
or 2.3 to 2.7 cSt at 100.degree. C., as determined by ASTM D445 or
ASTM D7042. The methyl paraffin lubricating oil base stocks of the
instant disclosure have a viscosity (Kv.sub.40) from 4.0 cSt to
14.0 cSt, or 4.5 to 13.5 cSt, or 5.0 to 13.0 cSt, or 5.5 to 12.5
cSt, or 6.0 to 12.0 cSt, 6.5 cSt to 11.5 cSt, or 7.0 to 11.0 cSt,
or 7.5 to 10.5 cSt, or 8.0 to 10.0 cSt, or 8.5 to 9.5 cSt, or 8.7
to 9.3 cSt, as determined by ASTM D445 or ASTM D7042.
[0034] The methyl paraffin lubricating oil base stocks of the
instant disclosure may have a Noack volatility at 250.degree. C.
from about 10 to about 90 percent as determined by ASTM D5800.
Alternatively, the methyl paraffin lubricating oil base stocks
blends may have a Noack volatility at 250.degree. C. of from 12 to
85%, or 16 to 80%, or 20 to 75%, or 24 to 70%, or 28 to 65%, or 32
to 60%, or 36 to 55% as determined by ASTM D5800.
[0035] The methyl paraffin lubricating oil base stocks of the
instant disclosure may have a Viscosity Index from about 100 to
about 170 as determined by ASTM D2270. Alternatively, the methyl
paraffin lubricating oil base stocks blends may have a Viscosity
Index of from 105 to 165, or 110 to 160, or 115 to 155, or 120 to
150, or 125 to 145, or 130 to 140 as determined by ASTM D2270.
[0036] The methyl paraffin lubricating oil base stocks of the
instant disclosure may have a pour point of from about -10 to
-80.degree. C. as determined by ASTM D5950. Alternatively, the
methyl paraffin lubricating oil base stocks blends may have a pour
point of from -15 to -70.degree. C., or -17 to -65.degree. C., or
-19 to -60.degree. C., or -21 to -55.degree. C., or -23 to
-50.degree. C., or -25 to -40.degree. C. as determined by ASTM
D5950.
[0037] The methyl paraffin lubricating oil base stocks of the
instant disclosure may have a MTM average traction coefficient (at
100 deg. C, 1 GPa, 2 m/s and 0-100% SRR) ranging from 0.0060 to
0.0090. Alternatively, the methyl paraffin lubricating oil base
stocks blends may have a MTM average traction coefficient ranging
from 0.0055 to 0.0090, or 0.0060 to 0.0085, or 0.0065 to 0.0080.
The MTM average traction coefficient may correlate with fuel
efficiency with lower values providing improved fuel economy. The
methyl paraffin lubricating oil base stocks blends of the instant
disclosure have MTM average traction coefficient values that are
from 20 to 180% lower, or from 40 to 160% lower, or from 60 to 140%
lower, or from 80 to 120% lower, or from 90 to 110% lower than
conventional Group II, Group III and Group III (GTL) base stocks of
comparable KV100.degree. C. viscosity.
Method of Making Lubricating Oil Base Stocks
[0038] The methyl paraffin lubricating oil base stock components of
the present disclosure can be prepared by a process that involves
the oligomerization of linear alpha olefins using a metallocene
catalyst followed by hydrogenation. More specifically,
9-methylnonadecane (C10 Dimer) and 9-methyl-11-octylheneicosane
(C10 trimer), may be manufactured by oligomerization of 1-decene,
[1-dodecene for 11-methyltricosane (C12 Dimer)], using a
metallocene catalyst followed by hydrogenation. Pure compounds may
then be obtained for the C10 dimer, C10 trimer, and C12 dimer by
fractionation.
[0039] The methyl paraffin lubricating oil base stock components of
the present disclosure can be prepared by the same process used to
produce low viscosity polyalphaolefin ("PAO") base stocks. In
particular, the low viscosity polyalphaolefin ("PAO") base stocks
and the methyl paraffin lubricating oil base stock may be made by
the metallocene catalyzed process or the two-step process described
herein.
[0040] In a preferred embodiment, the first step involves
oligomerizing low molecular weight linear alpha olefins in the
presence of a single site catalyst and the second step involves
oligomerization of at least a portion of the product from the first
step in the presence of an oligomerization catalyst.
[0041] This invention is also directed to the PAO composition
formed in the first oligomerization, wherein at least portions of
the PAO have properties that make them highly desirable for
subsequent oligomerization. A preferred process for the first
oligomerization uses a single site catalyst at high temperatures
without adding hydrogen to produce a low viscosity PAO with
excellent Noack volatility at high conversion rates. This PAO
comprises a dimer product with at least 25 wt % tri-substituted
vinylene olefins wherein said dimer product is highly desirable as
a feedstock for a subsequent oligomerization. This PAO also
comprises trimer and optionally tetramer and higher oligomer
products with outstanding properties that make these products
useful as lubricant basestocks following hydrogenation. The
hydrogenated trimer portion can be used as a methyl paraffin
lubricating oil base stock component in the inventive lubricating
oil base stock and engine oil compositions.
[0042] This invention also is directed to improved methyl paraffin
lubricating oil base stock components characterized by very low
viscosity and excellent Noack volatility that are obtained
following the two-step process.
[0043] The methyl paraffin lubricating oil base stock components
formed in the invention, both intermediate and final methyl
paraffins, are liquids. For the purposes of this invention, a term
"liquid" is defined to be a fluid that has no distinct melting
point above 0.degree. C., preferably no distinct melting point
above -10.degree. C., and has a kinematic viscosity at 100.degree.
C. of 3000 cSt or less--though all of the liquid PAOs of the
present invention have a kinematic viscosity at 100.degree. C. of
20 cSt or less as further disclosed.
[0044] When used in the present invention, in accordance with
conventional terminology in the art, the following terms are
defined for the sake of clarity. The term "vinyl" is used to
designate groups of formula RCH.dbd.CH2. The term "vinylidene" is
used to designate groups of formula RR'.dbd.CH2. The term
"disubstituted vinylene" is used to designate groups of formula
RCH.dbd.CHR'. The term "trisubstituted vinylene" is used to
designate groups of formula RR' C.dbd.CHR''. The term
"tetrasubstituted vinylene" is used to designate groups of formula
RR'C.dbd.CR''R'''. For all of these formulas, R, R', R'', and R'''
are alkyl groups which may be identical or different from each
other.
[0045] The monomer feed used in both the first oligomerization and
optionally contacted with the recycled intermediate PAO dimer and
light olefin fractions in the subsequent oligomerization is at
least one linear alpha olefin (LAO) typically comprised of monomers
of 6 to 24 carbon atoms, usually 6 to 20, and preferably 6 to 14
carbon atoms, such as 1-hexene, 1-octene, 1-nonene, 1-decene,
1-dodecene, and 1-tetradecene. Olefins with even carbon numbers are
preferred LAOS. Additionally, these olefins are preferably treated
to remove catalyst poisons, such as peroxides, oxygen, sulfur,
nitrogen-containing organic compounds, and/or acetylenic compounds
as described in WO 2007/011973.
Catalyst
[0046] Useful catalysts in the first oligomerization include single
site catalysts. In a preferred embodiment, the first
oligomerization uses a metallocene catalyst. In this disclosure,
the terms "metallocene catalyst" and "transition metal compound"
are used interchangeably. Preferred classes of catalysts give high
catalyst productivity and result in low product viscosity and low
molecular weight. Useful metallocene catalysts may be bridged or
un-bridged and substituted or un-substituted. They may have leaving
groups including dihalides or dialkyls. When the leaving groups are
dihalides, tri-alkylaluminum may be used to promote the reaction.
In general, useful transition metal compounds may be represented by
the following formula:
X.sub.1X.sub.2M.sub.1(CpCp*)M.sub.2X.sub.3X.sub.4
wherein: [0047] M.sub.1 is an optional bridging element, preferably
selected from silicon or carbon; [0048] M.sub.2 is a Group 4 metal;
[0049] Cp and Cp* are the same or different substituted or
unsubstituted cyclopentadienyl ligand systems wherein, if
substituted, the substitutions may be independent or linked to form
multicyclic structures; [0050] X.sub.1 and X.sub.2 are
independently hydrogen, hydride radicals, hydrocarbyl radicals,
substituted hydrocarbyl radicals, silylcarbyl radicals, substituted
silylcarbyl radicals, germylcarbyl radicals, or substituted
germylcarbyl radicals or are preferably independently selected from
hydrogen, branched or unbranched C.sub.1 to C.sub.20 hydrocarbyl
radicals, or branched or unbranched substituted C.sub.1 to C.sub.20
hydrocarbyl radicals; and [0051] X.sub.3 and X.sub.4 are
independently hydrogen, halogen, hydride radicals, hydrocarbyl
radicals, substituted hydrocarbyl radicals, halocarbyl radicals,
substituted halocarbyl radicals, silylcarbyl radicals, substituted
silylcarbyl radicals, germylcarbyl radicals, or substituted
germylcarbyl radicals; or both X.sub.3 and X.sub.4 are joined and
bound to the metal atom to form a metallacycle ring containing from
about 3 to about 20 carbon atoms, or are preferably independently
selected from hydrogen, branched or unbranched C.sub.1 to C.sub.20
hydrocarbyl radicals, or branched or unbranched substituted C.sub.1
to C.sub.20 hydrocarbyl radicals.
[0052] For this disclosure, a hydrocarbyl radical is C1-C100
radical and may be linear, branched, or cyclic. A substituted
hydrocarbyl radical includes halocarbyl radicals, substituted
halocarbyl radicals, silylcarbyl radicals, and germylcarbyl
radicals as these terms are defined below.
[0053] Substituted hydrocarbyl radicals are radicals in which at
least one hydrogen atom has been substituted with at least one
functional group such as NR*2, OR*, SeR*, TeR*, PR*2, AsR*2, SbR*2,
SR*, BR*2, SiR*3, GeR*3, SnR*3, PbR*3 and the like or where at
least one non-hydrocarbon atom or group has been inserted within
the hydrocarbyl radical, such as --O--, --S--, --Se--, --Te--,
--N(R*)--, .dbd.N--, --P(R*)--, .dbd.P--, --As(R*)--, .dbd.As--,
--Sb(R*)--, .dbd.Sb--, --B(R*)--, .dbd.B--, --Si(R*)2-, --Ge(R*)2-,
--Sn(R*)2-, --Pb(R*)2- and the like, where R* is independently a
hydrocarbyl or halocarbyl radical, and two or more R* may join
together to form a substituted or unsubstituted saturated,
partially unsaturated or aromatic cyclic or polycyclic ring
structure.
[0054] Halocarbyl radicals are radicals in which one or more
hydrocarbyl hydrogen atoms have been substituted with at least one
halogen (e.g., F, C1, Br, I) or halogen-containing group (e.g.,
CF3).
[0055] Substituted halocarbyl radicals are radicals in which at
least one halocarbyl hydrogen or halogen atom has been substituted
with at least one functional group such as NR*2, OR*, SeR*, TeR*,
PR*2, AsR*2, SbR*2, SR*, BR*2, SiR*3, GeR*3, SnR*3, PbR*3 and the
like or where at least one non-carbon atom or group has been
inserted within the halocarbyl radical such as --O--, --S--,
--Se--, --Te--, --N(R*)--, .dbd.N--, --P(R*)--, .dbd.P--,
--As(R*)--, .dbd.As--, --Sb(R*)--, .dbd.Sb--, --B(R*)--, .dbd.B--,
--Si(R*)2-, --Ge(R*)2-, --Sn(R*)2-, --Pb(R*)2- and the like, where
R* is independently a hydrocarbyl or halocarbyl radical provided
that at least one halogen atom remains on the original halocarbyl
radical. Additionally, two or more R* may join together to form a
substituted or unsubstituted saturated, partially unsaturated or
aromatic cyclic or polycyclic ring structure.
[0056] Silylcarbyl radicals (also called silylcarbyls) are groups
in which the silyl functionality is bonded directly to the
indicated atom or atoms. Examples include SiH3, SiH2R*, SiHR*2,
SiR*3, SiH2(OR*), SiH(OR*)2, Si(OR*)3, SiH2(NR*2), SiH(NR*2)2,
Si(NR*2)3, and the like where R* is independently a hydrocarbyl or
halocarbyl radical and two or more R* may join together to form a
substituted or unsubstituted saturated, partially unsaturated or
aromatic cyclic or polycyclic ring structure.
[0057] Germylcarbyl radicals (also called germylcarbyls) are groups
in which the germyl functionality is bonded directly to the
indicated atom or atoms. Examples include GeH3, GeH2R*, GeHR*2,
GeR53, GeH2(OR*), GeH(OR*)2, Ge(OR*)3, GeH2(NR*2), GeH(NR*2)2,
Ge(NR*2)3, and the like where R* is independently a hydrocarbyl or
halocarbyl radical and two or more R* may join together to form a
substituted or unsubstituted saturated, partially unsaturated or
aromatic cyclic or polycyclic ring structure.
[0058] In an embodiment, the transition metal compound may be
represented by the following formula:
X.sub.1X.sub.2M.sub.1(CpCp*)M.sub.2X.sub.3X.sub.4
wherein: [0059] M.sub.1 is a bridging element, and preferably
silicon; [0060] M.sub.2 is a Group 4 metal, and preferably
titanium, zirconium or hafnium; [0061] Cp and Cp* are the same or
different substituted or unsubstituted indenyl or tetrahydroindenyl
rings that are each bonded to both M.sub.1 and M.sub.2; [0062]
X.sub.1 and X.sub.2 are independently hydrogen, hydride radicals,
hydrocarbyl radicals, substituted hydrocarbyl radicals, silylcarbyl
radicals, substituted silylcarbyl radicals, germylcarbyl radicals,
or substituted germylcarbyl radicals; and [0063] X.sub.3 and
X.sub.4 are independently hydrogen, halogen, hydride radicals,
hydrocarbyl radicals, substituted hydrocarbyl radicals, halocarbyl
radicals, substituted halocarbyl radicals, silylcarbyl radicals,
substituted silylcarbyl radicals, germylcarbyl radicals, or
substituted germylcarbyl radicals; or both X.sub.3 and X.sub.4 are
joined and bound to the metal atom to form a metallacycle ring
containing from about 3 to about 20 carbon atoms.
[0064] In using the terms "substituted or unsubstituted
tetrahydroindenyl," "substituted or unsubstituted tetrahydroindenyl
ligand," and the like, the substitution to the aforementioned
ligand may be hydrocarbyl, substituted hydrocarbyl, halocarbyl,
substituted halocarbyl, silylcarbyl, or germylcarbyl. The
substitution may also be within the ring giving heteroindenyl
ligands or heterotetrahydroindenyl ligands, either of which can
additionally be substituted or unsubstituted.
[0065] In another embodiment, useful transition metal compounds may
be represented by the following formula:
L.sup.AL.sup.BL.sup.C.sub.iMDE
wherein: [0066] L.sup.A is a substituted cyclopentadienyl or
heterocyclopentadienyl ancillary ligand .pi.-bonded to M; [0067]
L.sup.B is a member of the class of ancillary ligands defined for
L.sup.A, or is J, a heteroatom ancillary ligand .sigma.-bonded to
M; the L.sup.A and L.sup.B ligands may be covalently bridged
together through a Group 14 element linking group; [0068]
L.sup.C.sub.i is an optional neutral, non-oxidizing ligand having a
dative bond to M (i equals 0 to 3); [0069] M is a Group 4 or 5
transition metal; and [0070] D and E are independently monoanionic
labile ligands, each having a .pi.-bond to M, optionally bridged to
each other or L.sup.A or L.sup.B. The mono-anionic ligands are
displaceable by a suitable activator to permit insertion of a
polymerizable monomer or a macromonomer can insert for coordination
polymerization on the vacant coordination site of the transition
metal compound.
[0071] One embodiment of this invention uses a highly active
metallocene catalyst. In this embodiment, the catalyst productivity
is greater than 15,000,
g PAO g catalyst , ##EQU00001##
preferably greater man 20,000
g PAO g catalyst , ##EQU00002##
preferably greater than 25,000
g PAO g catalyst , ##EQU00003##
and more preferably greater than 30,000
g PAO g catalyst , ##EQU00004##
wherein
g PAO g catalyst ##EQU00005##
represents grams of PAO formed per grams of catalyst used in the
oligomerization reaction.
[0072] High productivity rates are also achieved. In an embodiment,
the productivity rate in the first oligomerization is greater than
4,000
g PAO g catalyst * hour , ##EQU00006##
preferably greater than 6,000
g PAO g catalyst * hour , ##EQU00007##
preferably greater than 8,000
g PAO g catalyst * hour , ##EQU00008##
preferably greater than 10,000
g PAO g catalyst * hour , ##EQU00009##
wherein
g PAO g catalyst ##EQU00010##
represents grams of PAO formed per grams of catalyst used in the
oligomerization reaction.
Activator
[0073] The catalyst may be activated by a commonly known activator
such as non-coordinating anion (NCA) activator. An NCA is an anion
which either does not coordinate to the catalyst metal cation or
that coordinates only weakly to the metal cation. An NCA
coordinates weakly enough that a neutral Lewis base, such as an
olefinically or acetylenically unsaturated monomer, can displace it
from the catalyst center. Any metal or metalloid that can form a
compatible, weakly coordinating complex with the catalyst metal
cation may be used or contained in the NCA. Suitable metals
include, but are not limited to, aluminum, gold, and platinum.
Suitable metalloids include, but are not limited to, boron,
aluminum, phosphorus, and silicon.
[0074] Lewis acid and ionic activators may also be used. Useful but
non-limiting examples of Lewis acid activators include
triphenylboron, tris-perfluorophenylboron,
tris-perfluorophenylaluminum, and the like. Useful but non-limiting
examples of ionic activators include dimethylanilinium
tetrakisperfluorophenylborate, triphenyl carb onium
tetrakisperfluorophenylborate, dimethylanilinium
tetrakisperfluorophenylaluminate, and the like.
[0075] An additional subclass of useful NCAs comprises
stoichiometric activators, which can be either neutral or ionic.
Examples of neutral stoichiometric activators include
tri-substituted boron, tellurium, aluminum, gallium and indium or
mixtures thereof. The three substituent groups are each
independently selected from alkyls, alkenyls, halogen, substituted
alkyls, aryls, arylhalides, alkoxy and halides. Preferably, the
three groups are independently selected from halogen, mono or
multicyclic (including halosubstituted) aryls, alkyls, and alkenyl
compounds and mixtures thereof, preferred are alkenyl groups having
1 to 20 carbon atoms, alkyl groups having 1 to 20 carbon atoms,
alkoxy groups having 1 to 20 carbon atoms and aryl groups having 3
to 20 carbon atoms (including substituted aryls). More preferably,
the three groups are alkyls having 1 to 4 carbon groups, phenyl,
naphthyl or mixtures thereof. Even more preferably, the three
groups are halogenated, preferably fluorinated, aryl groups. Ionic
stoichiometric activator compounds may contain an active proton, or
some other cation associated with, but not coordinated to, or only
loosely coordinated to, the remaining ion of the ionizing
compound.
[0076] Ionic catalysts can be prepared by reacting a transition
metal compound with an activator, such as B(C6F6)3, which upon
reaction with the hydrolyzable ligand (X') of the transition metal
compound forms an anion, such as ([B(C6F5)3(X')]--), which
stabilizes the cationic transition metal species generated by the
reaction. The catalysts can be, and preferably are, prepared with
activator components which are ionic compounds or compositions.
However preparation of activators utilizing neutral compounds is
also contemplated by this invention.
[0077] Compounds useful as an activator component in the
preparation of the ionic catalyst systems used in the process of
this invention comprise a cation, which is preferably a Bronsted
acid capable of donating a proton, and a compatible NCA which anion
is relatively large (bulky), capable of stabilizing the active
catalyst species which is formed when the two compounds are
combined and said anion will be sufficiently labile to be displaced
by olefinic diolefinic and acetylenically unsaturated substrates or
other neutral Lewis bases such as ethers, nitriles and the
like.
[0078] In an embodiment, the ionic stoichiometric activators
include a cation and an anion component, and may be represented by
the following formula:
(L**-H).sub.d.sup.+(A.sup.d-)
wherein: L** is an neutral Lewis base; H is hydrogen; (L**-H).sup.+
is a Bronsted acid or a reducible Lewis Acid; and A.sup.d- is an
NCA having the charge d-, and d is an integer from 1 to 3.
[0079] The cation component, (L**-H).sub.d.sup.+ may include
Bronsted acids such as protons or protonated Lewis bases or
reducible Lewis acids capable of protonating or abstracting a
moiety, such as an alkyl or aryl, from the catalyst after
alkylation.
[0080] The activating cation (L**-H)d+ may be a Bronsted acid,
capable of donating a proton to the alkylated transition metal
catalytic precursor resulting in a transition metal cation,
including ammoniums, oxoniums, phosphoniums, silyliums, and
mixtures thereof, preferably ammoniums of methylamine, aniline,
dimethylamine, diethylamine, N-methylaniline, diphenylamine,
trimethylamine, triethylamine, N,N-dimethylaniline,
methyldiphenylamine, pyridine, p-bromo N,N-dimethylaniline,
p-nitro-N,N-dimethylaniline, phosphoniums from triethylphosphine,
triphenylphosphine, and diphenylphosphine, oxomiuns from ethers
such as dimethyl ether, diethyl ether, tetrahydrofuran and dioxane,
sulfoniums from thioethers, such as diethyl thioethers and
tetrahydrothiophene, and mixtures thereof. The activating cation
(L**-H)d+ may also be a moiety such as silver, tropylium,
carbeniums, ferroceniums and mixtures, preferably carboniums and
ferroceniums; most preferably triphenyl carbonium. The anion
component Ad--include those having the formula [Mk+Qn]d- wherein k
is an integer from 1 to 3; n is an integer from 2-6; n-k=d; M is an
element selected from Group 13 of the Periodic Table of the
Elements, preferably boron or aluminum, and Q is independently a
hydride, bridged or unbridged dialkylamido, halide, alkoxide,
aryloxide, hydrocarbyl, substituted hydrocarbyl, halocarbyl,
substituted halocarbyl, and halosubstituted-hydrocarbyl radicals,
said Q having up to 20 carbon atoms with the proviso that in not
more than one occurrence is Q a halide. Preferably, each Q is a
fluorinated hydrocarbyl group having 1 to 20 carbon atoms, more
preferably each Q is a fluorinated aryl group, and most preferably
each Q is a pentafluoryl aryl group. Examples of suitable A.sup.d-
also include diboron compounds as disclosed in U.S. Pat. No.
5,447,895, which is incorporated herein by reference.
[0081] Illustrative but non-limiting examples of boron compounds
which may be used as an NCA activator in combination with a
co-activator are tri-substituted ammonium salts such as:
trimethylammonium tetraphenylborate, triethyl ammonium
tetraphenylborate, tripropylammonium tetraphenylborate,
tri(n-butyl)ammonium tetraphenylborate, tri(tert-butyl)ammonium
tetraphenylborate, N,N-dimethylanilinium tetraphenylborate,
N,N-diethylanilinium tetraphenylborate,
N,N-dimethyl-(2,4,6-trimethylanilinium) tetraphenylborate,
trimethylammonium tetrakis(pentafluorophenyl)borate,
triethylammonium tetrakis(pentafluorophenyl)borate,
tripropylammonium tetrakis(pentafluorophenyl)borate,
tri(n-butyl)ammonium tetrakis(pentafluorophenyl)borate,
tri(sec-butyl)ammonium tetrakis(pentafluorophenyl)borate,
N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate,
N,N-diethylanilinium tetrakis(pentafluorophenyl)borate,
N,N-dimethyl-(2,4,6-trimethylanilinium)
tetrakis(pentafluorophenyl)borate, trimethylammonium
tetrakis-(2,3,4,6-tetrafluorophenyl) borate, triethylammonium
tetrakis-(2,3,4,6-tetrafluorophenyl)borate, tripropylammonium
tetrakis-(2,3,4,6-tetrafluorophenyl)borate, tri(n-butyl)ammonium
tetrakis-(2,3,4,6-tetrafluorophenyl)borate,
dimethyl(tert-butyl)ammonium
tetrakis-(2,3,4,6-tetrafluorophenyl)borate, N,N-dimethylanilinium
tetrakis-(2,3,4,6-tetrafluorophenyl)borate, N,N-diethylanilinium
tetrakis-(2,3,4,6-tetrafluorophenyl)borate,
N,N-dimethyl-(2,4,6-trimethylanilinium)
tetrakis-(2,3,4,6-tetrafluorophenyl)borate, trimethylammonium
tetrakis(perfluoronaphthyl)borate, triethylammonium
tetrakis(perfluoronaphthyl)borate, tripropylammonium
tetrakis(perfluoronaphthyl)borate, tri(n-butyl)ammonium
tetrakis(perfluoronaphthyl)borate, tri(tert-butyl)ammonium
tetrakis(perfluoronaphthyl)borate, N,N-dimethylanilinium
tetrakis(perfluoronaphthyl)borate, N,N-diethylanilinium
tetrakis(perfluoronaphthyl)borate,
N,N-dimethyl-(2,4,6-trimethylanilinium)
tetrakis(perfluoronaphthyl)borate, trimethylammonium
tetrakis(perfluorobiphenyl)borate, triethylammonium
tetrakis(perfluorobiphenyl)borate, tripropylammonium
tetrakis(perfluorobiphenyl)borate, tri(n-butyl)ammonium
tetrakis(perfluorobiphenyl)borate, tri(tert-butyl)ammonium
tetrakis(perfluorobiphenyl)borate, N,N-dimethylanilinium
tetrakis(perfluorobiphenyl)borate, N,N-diethylanilinium
tetrakis(perfluorobiphenyl)borate,
N,N-dimethyl-(2,4,6-trimethylanilinium)
tetrakis(perfluorobiphenyl)borate, trimethylammonium
tetrakis(3,5-bis(trifluoromethyl)phenyl)borate, triethylammonium
tetrakis(3,5-bis(trifluoromethyl)phenyl)borate, tripropylammonium
tetrakis(3,5-bis(trifluoromethyl)phenyl)borate,
tri(n-butyl)ammonium
tetrakis(3,5-bis(trifluoromethyl)phenyl)borate,
tri(tert-butyl)ammonium
tetrakis(3,5-bis(trifluoromethyl)phenyl)borate,
N,N-dimethylanilinium
tetrakis(3,5-bis(trifluoromethyl)phenyl)borate,
N,N-diethylanilinium
tetrakis(3,5-bis(trifluoromethyl)phenyl)borate,
N,N-dimethyl-(2,4,6-trimethylanilinium)
tetrakis(3,5-bis(trifluoromethyl)phenyl)borate, and dialkyl
ammonium salts such as: di-(iso-propyl)ammonium
tetrakis(pentafluorophenyl)borate, and dicyclohexylammonium
tetrakis(pentafluorophenyl)borate; and other salts such as
tri(o-tolyl)phosphonium tetrakis(pentafluorophenyl)borate,
tri(2,6-dimethylphenyl)phosphonium
tetrakis(pentafluorophenyl)borate, tropillium tetraphenylborate,
triphenylcarbenium tetraphenylborate, triphenylphosphonium
tetraphenylborate, triethylsilylium tetraphenylborate,
benzene(diazonium)tetraphenylborate, tropillium
tetrakis(pentafluorophenyl)borate, triphenylcarbenium
tetrakis(pentafluorophenyl)borate, triphenylphosphonium
tetrakis(pentafluorophenyl)borate, triethyl silylium
tetrakis(pentafluorophenyl)borate, benzene(diazonium)
tetrakis(pentafluorophenyl)borate, tropillium
tetrakis-(2,3,4,6-tetrafluorophenyl)borate, triphenylcarbenium
tetrakis-(2,3,4,6-tetrafluorophenyl)borate, triphenylphosphonium
tetrakis-(2,3,4,6-tetrafluorophenyl)borate, triethyl silylium
tetrakis-(2,3,4,6-tetrafluorophenyl)borate, benzene(diazonium)
tetrakis-(2,3,4,6-tetrafluorophenyl)borate, tropillium
tetrakis(perfluoronaphthyl)borate, triphenylcarbenium
tetrakis(perfluoronaphthyl)borate, triphenylphosphonium
tetrakis(perfluoronaphthyl)borate, triethyl silylium
tetrakis(perfluoronaphthyl)borate, benzene(diazonium)
tetrakis(perfluoronaphthyl)borate, tropillium
tetrakis(perfluorobiphenyl)borate, triphenylcarbenium tetrakis
(perfluorobiphenyl)borate, triphenylphosphonium
tetrakis(perfluorobiphenyl)borate, triethyl silylium
tetrakis(perfluorobiphenyl)borate, benzene(diazonium)
tetrakis(perfluorobiphenyl)borate, tropillium
tetrakis(3,5-bis(trifluoromethyl)phenyl)borate, triphenylcarbenium
tetrakis(3,5-bis(trifluoromethyl)phenyl)borate,
triphenylphosphonium
tetrakis(3,5-bis(trifluoromethyl)phenyl)borate, triethyl silylium
tetrakis(3,5-bis (trifluoromethyl)phenyl)borate, and
benzene(diazonium)
tetrakis(3,5-bis(trifluoromethyl)phenyl)borate.
[0082] In an embodiment, the NCA activator, (L**-H)d.sup.+
(A.sup.d-), is N,N-dimethylanilinium
tetrakis(perfluorophenyl)borate, N,N-dimethylanilinium
tetrakis(perfluoronaphthyl)borate, N,N-dimethyl anilinium
tetrakis(perfluorobiphenyl)borate, N,N-dimethylanilinium
tetrakis(3,5-bis(trifluoromethyl)phenyl)borate, triphenylcarbenium
tetrakis (perfluoronaphthyl)borate, triphenylcarbenium tetrakis
(perfluorobiphenyl)borate, triphenylcarbenium
tetrakis(3,5-bis(trifluoromethyl)phenyl)borate, or
triphenylcarbenium tetra(perfluorophenyl)borate.
[0083] Pehlert et al., U.S. Pat. No. 7,511,104 provides additional
details on NCA activators that may be useful in this invention, and
these details are hereby fully incorporated by reference.
[0084] Additional activators that may be used include alumoxanes or
alumoxanes in combination with an NCA. In one embodiment, alumoxane
activators are utilized as an activator. Alumoxanes are generally
oligomeric compounds containing --Al(R1)-O-- sub-units, where R1 is
an alkyl group. Examples of alumoxanes include methylalumoxane
(MAO), modified methylalumoxane (MMAO), ethylalumoxane and
isobutylalumoxane. Alkylalumoxanes and modified alkylalumoxanes are
suitable as catalyst activators, particularly when the abstractable
ligand is an alkyl, halide, alkoxide or amide. Mixtures of
different alumoxanes and modified alumoxanes may also be used.
[0085] A catalyst co-activator is a compound capable of alkylating
the catalyst, such that when used in combination with an activator,
an active catalyst is formed. Co-activators may include alumoxanes
such as methylalumoxane, modified alumoxanes such as modified
methylalumoxane, and aluminum alkyls such trimethylaluminum,
tri-isobutylaluminum, triethylaluminum, and tri-isopropylaluminum,
tri-n-hexylaluminum, tri-n-octylaluminum, tri-n-decylaluminum or
tri-n-dodecylaluminum. Co-activators are typically used in
combination with Lewis acid activators and ionic activators when
the catalyst is not a dihydrocarbyl or dihydride complex. Preferred
activators are non-oxygen containing compounds such as the aluminum
alkyls, and are preferably tri-alkylaluminums.
[0086] The co-activator may also be used as a scavenger to
deactivate impurities in feed or reactors. A scavenger is a
compound that is sufficiently Lewis acidic to coordinate with polar
contaminates and impurities adventitiously occurring in the
polymerization feedstocks or reaction medium. Such impurities can
be inadvertently introduced with any of the reaction components,
and adversely affect catalyst activity and stability. Useful
scavenging compounds may be organometallic compounds such as
triethyl aluminum, triethyl borane, tri-isobutyl aluminum,
methylalumoxane, isobutyl aluminumoxane, tri-n-hexyl aluminum,
tri-n-octyl aluminum, and those having bulky substituents
covalently bound to the metal or metalloid center being preferred
to minimize adverse interaction with the active catalyst. Other
useful scavenger compounds may include those mentioned in U.S. Pat.
No. 5,241,025, EP-A 0426638, and WO 97/22635, which are hereby
incorporated by reference for such details.
[0087] The reaction time or reactor residence time is usually
dependent on the type of catalyst used, the amount of catalyst
used, and the desired conversion level. Different transition metal
compounds (also referred to as metallocene) have different
activities. High amount of catalyst loading tends to gives high
conversion at short reaction time. However, high amount of catalyst
usage make the production process uneconomical and difficult to
manage the reaction heat or to control the reaction temperature.
Therefore, it is useful to choose a catalyst with maximum catalyst
productivity to minimize the amount of metallocene and the amount
of activators needed. For the preferred catalyst system of
metallocene plus a Lewis Acid or an ionic promoter with NCA
component, the transition metal compound use is typically in the
range of 0.01 microgram to 500 micrograms of metallocene
component/gram of alpha-olefin feed. Usually the preferred range is
from 0.1 microgram to 100 microgram of metallocene component per
gram of alpha-olefin feed. Furthermore, the molar ratio of the NCA
activator to metallocene is in the range from 0.1 to 10, preferably
0.5 to 5, preferably 0.5 to 3. For the co-activators of
alkylaluminums, the molar ratio of the co-activator to metallocene
is in the range from 1 to 1000, preferably 2 to 500, preferably 4
to 400.
[0088] In selecting oligomerization conditions, to obtain the
desired first reactor effluent, the system uses the transition
metal compound (also referred to as the catalyst), activator, and
co-activator.
[0089] US 2007/0043248 and US 2010/029242 provides additional
details of metallocene catalysts, activators, co-activators, and
appropriate ratios of such compounds in the feedstock that may be
useful in this invention, and these additional details are hereby
incorporated by reference.
Oligomerization Process
[0090] Many oligomerization processes and reactor types used for
single site- or metallocene-catalyzed oligomerizations such as
solution, slurry, and bulk oligomerization processes may be used in
this invention. In some embodiments, if a solid catalyst is used, a
slurry or continuous fixed bed or plug flow process is suitable. In
a preferred embodiment, the monomers are contacted with the
metallocene compound and the activator in the solution phase, bulk
phase, or slurry phase, preferably in a continuous stirred tank
reactor or a continuous tubular reactor. In a preferred embodiment,
the temperature in any reactor used herein is from -10.degree. C.
to 250.degree. C., preferably from 30.degree. C. to 220.degree. C.,
preferably from 50.degree. C. to 180.degree. C., preferably from
80.degree. C. to 150.degree. C. In a preferred embodiment, the
pressure in any reactor used herein is from 10.13 to 10132.5 kPa
(0.1 to 100 atm/1.5 to 1500 psi), preferably from 50.66 to 7600 kPa
(0.5 to 75 atm/8 to 1125 psi), and most preferably from 101.3 to
5066.25 kPa (1 to 50 atm/15 to 750 psi). In another embodiment, the
pressure in any reactor used herein is from 101.3 to 5,066,250 kPa
(1 to 50,000 atm), preferably 101.3 to 2,533,125 kPa (1 to 25,000
atm). In another embodiment, the residence time in any reactor is 1
second to 100 hours, preferably 30 seconds to 50 hours, preferably
2 minutes to 6 hours, preferably 1 to 6 hours. In another
embodiment, solvent or diluent is present in the reactor. These
solvents or diluents are usually pre-treated in same manners as the
feed olefins.
[0091] The oligomerization can be run in batch mode, where all the
components are added into a reactor and allowed to react to a
degree of conversion, either partial or full conversion.
Subsequently, the catalyst is deactivated by any possible means,
such as exposure to air or water, or by addition of alcohols or
solvents containing deactivating agents. The oligomerization can
also be carried out in a semi-continuous operation, where feeds and
catalyst system components are continuously and simultaneously
added to the reactor so as to maintain a constant ratio of catalyst
system components to feed olefin(s). When all feeds and catalyst
components are added, the reaction is allowed to proceed to a
pre-determined stage. The reaction is then discontinued by catalyst
deactivation in the same manner as described for batch operation.
The oligomerization can also be carried out in a continuous
operation, where feeds and catalyst system components are
continuously and simultaneously added to the reactor so to maintain
a constant ratio of catalyst system and feeds. The reaction product
is continuously withdrawn from the reactor, as in a typical
continuous stirred tank reactor (CSTR) operation. The residence
times of the reactants are controlled by a pre-determined degree of
conversion. The withdrawn product is then typically quenched in the
separate reactor in a similar manner as other operation. In a
preferred embodiment, any of the processes to prepare PAOs
described herein are continuous processes.
[0092] A production facility may have one single reactor or several
reactors arranged in series or in parallel, or both, to maximize
productivity, product properties, and general process efficiency.
The catalyst, activator, and co-activator may be delivered as a
solution or slurry in a solvent or in the LAO feed stream, either
separately to the reactor, activated in-line just prior to the
reactor, or pre-activated and pumped as an activated solution or
slurry to the reactor. Oligomerizations are carried out in either
single reactor operation, in which the monomer, or several
monomers, catalyst/activator/co-activator, optional scavenger, and
optional modifiers are added continuously to a single reactor or in
series reactor operation, in which the above components are added
to each of two or more reactors connected in series. The catalyst
components can be added to the first reactor in the series. The
catalyst component may also be added to both reactors, with one
component being added to first reaction and another component to
other reactors.
[0093] The reactors and associated equipment are usually
pre-treated to ensure proper reaction rates and catalyst
performance. The reaction is usually conducted under inert
atmosphere, where the catalyst system and feed components will not
be in contact with any catalyst deactivator or poison which is
usually polar oxygen, nitrogen, sulfur or acetylenic compounds.
Additionally, in one embodiment of any of the process described
herein, the feed olefins and or solvents are treated to remove
catalyst poisons, such as peroxides, oxygen or nitrogen-containing
organic compounds or acetylenic compounds. Such treatment will
increase catalyst productivity 2- to 10-fold or more.
[0094] The reaction time or reactor residence time is usually
dependent on the type of catalyst used, the amount of catalyst
used, and the desired conversion level. When the catalyst is a
metallocene, different metallocenes have different activities.
Usually, a higher degree of alkyl substitution on the
cyclopentadienyl ring, or bridging improves catalyst productivity.
High catalyst loading tends to gives high conversion in short
reaction time. However, high catalyst usage makes the process
uneconomical and difficult to manage the reaction heat or to
control the reaction temperature. Therefore, it is useful to choose
a catalyst with maximum catalyst productivity to minimize the
amount of metallocene and the amount of activators needed.
[0095] US 2007/0043248 and US 2010/0292424 provide significant
additional details on acceptable oligomerization processes using
metallocene catalysts, and the details of these processes, process
conditions, catalysts, activators, co-activators, etc. are hereby
incorporated by reference to the extent that they are not
inconsistent with anything described in this disclosure.
[0096] Due to the low activity of some metallocene catalysts at
high temperatures, low viscosity PAOs are typically oligomerized in
the presence of added hydrogen at lower temperatures. The advantage
is that hydrogen acts as a chain terminator, effectively decreasing
molecular weight and viscosity of the PAO. Hydrogen can also
hydrogenate the olefin, however, saturating the LAO feedstock and
PAO. This would prevent LAO or the PAO dimer from being usefully
recycled or used as feedstock into a further oligomerization
process. Thus it is an improvement over prior art to be able to
make an intermediate PAO without having to add hydrogen for chain
termination because the unreacted LAO feedstock and intermediate
PAO dimer maintain their unsaturation, and thus their reactivity,
for a subsequent recycle step or use as a feedstock in a further
oligomerization process.
[0097] The intermediate PAO produced is a mixture of dimers,
trimers, and optionally tetramer and higher oligomers of the
respective alpha olefin feedstocks. This intermediate PAO and
portions thereof is referred to interchangeably as the "first
reactor effluent" from which unreacted monomers have optionally
been removed. In an embodiment, the dimer portion of the
intermediate PAO may be a reactor effluent that has not been
subject to a distillation process. In another embodiment, the dimer
portion of the intermediate PAO may be subjected to a distillation
process to separate it from the trimer and optional higher oligomer
portion prior to feeding the at least dimer portion of the first
reactor to a second reactor. In another embodiment, the dimer
portion of the intermediate PAO may be a distillate effluent. In
another embodiment, the at least dimer portion of the intermediate
PAO is fed directly into the second reactor. In a further
embodiment, the trimer portion of the intermediate PAO and the
tetramer and higher oligomer portion of the intermediate PAO can be
isolated from the first effluent by distillation. In another
embodiment, the intermediate PAO is not subjected to a separate
isomerization process following oligomerization.
[0098] In the invention, the intermediate PAO product has a
kinematic viscosity at 100.degree. C. (KV100) of less than 20 cSt,
preferably less than 15 cSt, preferably less than 12 cSt, more
preferably less than 10 cSt. In the invention, the intermediate PAO
trimer portion after a hydrogenation step has a KV100 of less than
4 cSt, preferably less than 3.6 cSt. In an embodiment, the
tetramers and higher oligomer portion of the intermediate PAO after
a hydrogenation step has a KV100 of less than 30 cSt. In an
embodiment, the intermediate PAO oligomer portion remaining after
the intermediate PAO dimer portion is removed has a KV100 of less
than 25 cSt.
[0099] The intermediate PAO trimer portion has a VI of greater than
125, preferably greater than 130. In an embodiment, the trimer and
higher oligomer portion of the intermediate PAO has a VI of greater
than 130, preferably greater than 135. In an embodiment, the
tetramer and higher oligomer portion of the intermediate PAO has a
VI of greater than 150, preferably greater than 155.
[0100] The intermediate PAO trimer portion has a Noack volatility
that is less than 15 wt %, preferably less than 14 wt %, preferably
less than 13 wt %, preferably less than 12 wt %. In an embodiment,
the intermediate PAO tetramers and higher oligomer portion has a
Noack volatility that is less than 8 wt %, preferably less than 7
wt %, preferably less than 6 wt %.
[0101] The intermediate PAO dimer portion has a number average
molecular weight in the range of 120 to 600.
[0102] The intermediate PAO dimer portion possesses at least one
carbon-carbon unsaturated double bond. A portion of this
intermediate PAO dimer comprises tri-substituted vinylene. This
tri-substituted vinylene has two possible isomer structures that
may coexist and differ regarding where the unsaturated double bond
is located, as represented by the following structure:
##STR00005##
wherein the dashed line represents the two possible locations where
the unsaturated double bond may be located and Rx and Ry are
independently selected from a C.sub.3 to C.sub.21 alkyl group,
preferably from linear C.sub.3 to C.sub.21 alkyl group.
[0103] In any embodiment, the intermediate PAO dimer contains
greater than 20 wt %, preferably greater than 25 wt %, preferably
greater than 30 wt %, preferably greater than 40 wt %, preferably
greater than 50 wt %, preferably greater than 60 wt %, preferably
greater than 70 wt %, preferably greater than 80 wt % of
tri-substituted vinylene olefins represented by the general
structure above.
[0104] In a preferred embodiment, Rx and Ry are independently C3 to
C11 alkyl groups. In a preferred embodiment, Rx and Ry are both C7.
In a preferred embodiment, the intermediate PAO dimer comprises a
portion of tri-substituted vinylene dimer that is represented by
the following structure:
##STR00006##
wherein the dashed line represents the two possible locations where
the unsaturated double bond may be located.
[0105] In any embodiment, the intermediate PAO contains less than
70 wt %, preferably less than 60 wt %, preferably less than 50 wt
%, preferably less than 40 wt %, preferably less than 30 wt %,
preferably less than 20 wt % of di-substituted vinylidene
represented by the formula:
RqRzC.dbd.CH2
wherein Rq and Rz are independently selected from alkyl groups,
preferably linear alkyl groups, or preferably C3 to C21 linear
alkyl groups.
[0106] One embodiment of the first oligomerization is illustrated
and explained below as a non-limiting example. First, the following
reactions show alkylation of a metallocene catalyst with tri
n-octyl aluminum followed by activation of the catalyst with
N,N-Dimethylanilinium tetrakis (penta-fluorophenyl) borate
(1-):
[0107] Catalyst Alkylation
##STR00007##
[0108] Catalyst Activation
##STR00008##
[0109] Following catalyst activation, a 1,2 insertion process may
take place as shown below:
##STR00009##
[0110] Both vinyl and vinylidene chain ends may be formed as a
result of elimination from 1,2 terminated chains, as shown below.
This chain termination mechanism shown below competes with
propagation during this reaction phase.
##STR00010##
[0111] Alternatively following catalyst activation, a 2,1 insertion
process may take place as shown below:
##STR00011##
[0112] Elimination is favored over propagation after 2,1 insertions
due to the proximity of the alpha alkyl branch to the active center
(see the area identified with the letter "A" in the reaction
above). In other words, the more crowded active site hinders
propagation and enhances elimination. 2,1 insertions are detected
by nuclear magnetic resonance (NMR) using signals from the unique
methylene-methylene unit (see the area identified with the letter
"B" in the reaction above).
[0113] Certain metallocene catalysts result in a higher occurrence
of 2,1 insertions, and elimination from 2,1 terminated chains
preferentially forms vinylene chain ends, as shown below.
##STR00012##
Subsequent Oligomerization
[0114] The intermediate PAO dimer from the first oligomerization
may be used as the sole olefin feedstock to the subsequent
oligomerization or it may be used together with an alpha olefin
feedstock of the type used as the olefin starting material for the
first oligomerization. Other portions of the effluent from the
first oligomerization may also be used as a feedstock to the
subsequent oligomerization, including unreacted LAO. The
intermediate PAO dimer may suitably be separated from the overall
intermediate PAO product by distillation, with the cut point set at
a value dependent upon the fraction to be used as lube base stock
or the fraction to be used as feed for the subsequent
oligomerization. Alpha olefins with the same attributes as those
preferred for the first oligomerization are preferred for the
subsequent oligomerization. Typically ratios for the intermediate
PAO dimer fraction to the alpha olefins fraction in the feedstock
are from 90:10 to 10:90 and more usually 80:20 to 20:80 by weight.
But preferably the intermediate PAO dimer will make up around 50
mole % of the olefinic feed material since the properties and
distribution of the final product, dependent in part upon the
starting material, are favorably affected by feeding the
intermediate PAO dimer at an equimolar ratio with the alpha
olefins. Temperatures for the subsequent oligomerization in the
second reactor range from 15 to 60.degree. C.
[0115] Any oligomerization process and catalyst may be used for the
subsequent oligomerization. A preferred catalyst for the subsequent
oligomerization is a non-transition metal catalyst, and preferably
a Lewis acid catalyst. Patent applications US 2009/0156874 and US
2009/0240012 describe a preferred process for the subsequent
oligomerization, to which reference is made for details of
feedstocks, compositions, catalysts and co-catalysts, and process
conditions. The Lewis acid catalysts of US 2009/0156874 and US
2009/0240012 include the metal and metalloid halides conventionally
used as Friedel-Crafts catalysts, examples include AlCl.sub.3,
BF.sub.3, AlBr.sub.3, TiCl.sub.3, and TiCl.sub.4 either alone or
with a protic promoter/activator. Boron trifluoride is commonly
used but not particularly suitable unless it is used with a protic
promoter. Useful co-catalysts are well known and described in
detail in US 2009/0156874 and US 2009/0240012. Solid Lewis acid
catalysts, such as synthetic or natural zeolites, acid clays,
polymeric acidic resins, amorphous solid catalysts such as
silica-alumina, and heteropoly acids such as the tungsten
zirconates, tungsten molybdates, tungsten vanadates,
phosphotungstates and molybdotungstovanadogermanates (e.g.,
WOx/ZrO.sub.2, WOx/MoO.sub.3) may also be used although these are
not generally as favored economically. Additional process
conditions and other details are described in detail in US
2009/0156874 and US 2009/0240012, and incorporated herein by
reference.
[0116] In a preferred embodiment, the subsequent oligomerization
occurs in the presence of BF.sub.3 and at least two different
activators selected from alcohols and alkyl acetates. The alcohols
are C.sub.1 to C.sub.10 alcohols and the alkyl acetates are C.sub.1
to C.sub.10 alkyl acetates. Preferably, both co-activators are
C.sub.1 to C.sub.6 based compounds. Two most preferred combination
of co-activators are i) ethanol and ethyl acetate and ii) n-butanol
and n-butyl acetate. The ratio of alcohol to alkyl acetate range
from 0.2 to 15, or preferably 0.5 to 7.
[0117] The structure of the invented intermediate PAO is such that,
when reacted in a subsequent oligomerization, the intermediate PAO
reacts preferentially with the optional LAO to form a co-dimer of
the dimer and LAO at high yields. This allows for high conversion
and yield rates of the desired PAO products. In an embodiment, the
PAO product from the subsequent oligomerization comprises primarily
a co-dimer of the dimer and the respective LAO feedstock. In an
embodiment, where the LAO feedstock for both oligomerization steps
is 1-decene, the incorporation of intermediate C.sub.20 PAO dimer
into higher oligomers is greater than 80%, the conversion of the
LAO is greater than 95%, and the yield % of C30 product in the
overall product mix is greater than 75%. In another embodiment,
where the LAO feedstock is 1-octene, the incorporation of the
intermediate PAO dimer into higher oligomers is greater than 85%,
the conversion of the LAO is greater than 90%, and the yield % of
C28 product in the overall product mix is greater than 70%. In
another embodiment, where the feedstock is 1-dodecene, the
incorporation of the intermediate PAO dimer into higher oligomers
is greater than 90%, the conversion of the LAO is greater than 75%,
and the yield % of C32 product in the overall product mix is
greater than 70%.
[0118] In an embodiment, the monomer is optional as a feedstock in
the second reactor. In another embodiment, the first reactor
effluent comprises unreacted monomer, and the unreacted monomer is
fed to the second reactor. In another embodiment, monomer is fed
into the second reactor, and the monomer is an LAO selected from
the group including 1-hexene, 1-octene, 1-nonene, 1-decene,
1-dodecene, and 1-tetradecene. In another embodiment, the PAO
produced in the subsequent oligomerization is derived from the
intermediate PAO dimer plus only one monomer. In another
embodiment, the PAO produced in the subsequent oligomerization is
derived from the intermediate PAO dimer plus two or more monomers,
or three or more monomers, or four or more monomers, or even five
or more monomers. For example, the intermediate PAO dimer plus a
C.sub.8, C.sub.10, C.sub.12-LAO mixture, or a C.sub.6, C.sub.7,
C.sub.8, C.sub.9, C.sub.10, C.sub.11, C.sub.12, C.sub.13,
C.sub.14-LAO mixture, or a C.sub.4, C.sub.6, C.sub.8, C.sub.10,
C.sub.12, C.sub.14, C.sub.16, C.sub.18-LAO mixture can be used as a
feed. In another embodiment, the PAO produced in the subsequent
oligomerization comprises less than 30 mole % of C2, C3 and C4
monomers, preferably less than 20 mole %, preferably less than 10
mole %, preferably less than 5 mole %, preferably less than 3 mole
%, and preferably 0 mole %. Specifically, in another embodiment,
the PAO produced in the subsequent oligomerization comprises less
than 30 mole % of ethylene, propylene and butene, preferably less
than 20 mole %, preferably less than 10 mole %, preferably less
than 5 mole %, preferably less than 3 mole %, preferably 0 mole
%.
[0119] The PAOs produced in the subsequent oligomerization may be a
mixture of dimers, trimers, and optionally tetramer and higher
oligomers. This PAO is referred to interchangeably as the "second
reactor effluent" from which unreacted monomer may be optionally
removed and recycled back to the second reactor. The desirable
properties of the intermediate PAO dimer enable a high yield of a
co-dimer of intermediate PAO dimer and LAO in the second reactor
effluent. The PAOs in the second reactor effluent are especially
notable because very low viscosity PAOs are achieved at very high
yields and these PAOs have excellent rheological properties,
including low pour point, outstanding Noack volatility, and very
high viscosity indexes.
[0120] In an embodiment, this PAO may contain trace amounts of
transition metal compound if the catalyst in the intermediate or
subsequent oligomerization is a metallocene catalyst. A trace
amount of transition metal compound is defined for purposes of this
disclosure as any amount of transition metal compound or Group 4
metal present in the PAO. Presence of Group 4 metal may be detected
at the ppm or ppb level by ASTM 5185 or other methods known in the
art.
[0121] Preferably, the second reactor effluent PAO has a portion
having a carbon count of C28-C32, wherein the C28-C32 portion is at
least 65 wt %, preferably at least 70 wt %, preferably at least 75
wt %, more preferably at least 80 wt % of the second reactor
effluent.
[0122] The kinematic viscosity at 100.degree. C. of the PAO is less
than 10 cSt, preferably less than 6 cSt, preferably less than 4.5
cSt, preferably less than 3.2 cSt, or preferably in the range of
2.8 to 4.5 cSt. The kinematic viscosity at 100.degree. C. of the
C28 portion of the PAO is less than 3.2 cSt. In an embodiment, the
kinematic viscosity at 100.degree. C. of the C28 to C32 portion of
the PAO is less than 10 cSt, preferably less than 6 cSt, preferably
less than 4.5 cSt, and preferably in the range of 2.8 to 4.5
cSt.
[0123] In an embodiment, the pour point of the PAO is below
-40.degree. C., preferably below -50.degree. C., preferably below
-60.degree. C., preferably below -70.degree. C., or preferably
below -80.degree. C. The pour point of the C28 to C32 portion of
the PAO is below -30.degree. C., preferably below -40.degree. C.,
preferably below -50.degree. C., preferably below -60.degree. C.,
preferably below -70.degree. C., or preferably below -80.degree.
C.
[0124] The Noack volatility of the PAO is not more than 9.0 wt %,
preferably not more than 8.5 wt %, preferably not more than 8.0 wt
%, or preferably not more than 7.5 wt %. The Noack volatility of
the C28 to C32 portion of the PAO is less than 19 wt %, preferably
less than 14 wt %, preferably less than 12 wt %, preferably less
than 10 wt %, or more preferably less than 9 wt %.
[0125] The viscosity index of the PAO is more than 121, preferably
more than 125, preferably more than 130, or preferably more than
136. The viscosity index of the trimer or C28 to C32 portion of the
PAO is above 120, preferably above 125, preferably above 130, or
more preferably at least 135.
[0126] The cold crank simulator value (CCS) at -25.degree. C. of
the PAO or a portion of the PAO is not more than 500 cP, preferably
not more than 450 cP, preferably not more than 350 cP, preferably
not more than 250 cP, preferably in the range of 200 to 450 cP, or
preferably in the range of 100 to 250 cP.
[0127] In an embodiment, the PAO has a kinematic viscosity at
100.degree. C. of not more than 3.2 cSt and a Noack volatility of
not more than 19 wt %. In another embodiment, the PAO has a
kinematic viscosity at 100.degree. C. of not more than 4.1 cSt and
a Noack volatility of not more than 9 wt %.
[0128] The ability to achieve such low viscosity PAOs with such low
Noack volatility at such high yields is especially remarkable, and
highly attributable to the intermediate PAO tri-substituted
vinylene dimer having properties that make it especially desirable
in the subsequent oligomerization process.
[0129] The overall reaction scheme enabled by the present invention
may be represented as shown below, starting from the original LAO
feed and passing through the intermediate PAO dimer used as the
feed for the subsequent oligomerization.
##STR00013##
[0130] The lube range oligomer product from the subsequent
oligomerization is desirably hydrogenated prior to use as a
lubricant basestock to remove any residual unsaturation and
stabilize the product. Optional hydrogenation may be carried out in
the manner conventional to the hydrotreating of conventional PAOs.
Prior to any hydrogenation, the PAO is comprised of at least 10 wt
% of tetra-substituted olefins; as determined via carbon NMR
(described later herein); in other embodiments, the amount of
tetra-substitution is at least 15 wt %, or at least 20 wt % as
determined by carbon NMR. The tetra-substituted olefin has the
following structure:
##STR00014##
Additionally, prior to any hydrogenation, the PAO is comprised of
at least 60 wt % tri-substituted olefins, preferably at least 70 wt
% tri-substituted olefins.
[0131] The intermediate PAOs and second reactor PAOs produced,
particularly those of ultra-low viscosity, are especially suitable
for high performance automotive engine oil formulations either by
themselves or by blending with other fluids, such as Group II,
Group II+, Group III, Group III+ or lube basestocks derived from
hydroisomerization of wax fractions from Fisher-Tropsch hydrocarbon
synthesis from CO/H2 syn gas, or other Group IV or Group V
basestocks. They are also preferred grades for high performance
industrial oil formulations that call for ultra-low and low
viscosity oils. Additionally, they are also suitable for use in
personal care applications, such as soaps, detergents, creams,
lotions, sticks, shampoos, detergents, etc.
Lubricating Oils
[0132] The methyl paraffin lubricating oil base stock blends of the
instant disclosure described above may be formulated into
lubricating oils by the addition of a minor amount of one or more
lubricating oil additives to a major amount of the methyl paraffin
lubricating oil base stock blend. The methyl paraffin lubricating
oil base stock can be present as the major base stock in the
lubricating oils of this disclosure. Accordingly, the methyl
paraffin lubricating oil base stock can be present in an amount
from 55 to 99 wt %, or 60 to 97 wt %, or 65 to 95 wt %, or 70 to 90
wt %, or 75 to 85 wt %, or 77 to 83 wt % of the fully formulated
lubricating oil. The one or more lubricating oil additives are
present as a minor amount of the lubricating oils of this
disclosure. Accordingly, the lubricating oil additives can be
present in an amount from 1 to 45 wt %, or 3 to 40 wt %, or 5 to 35
wt %, or 10 to 30 wt %, or 15 to 25 wt %, or 17 to 23 wt % of the
fully formulated lubricating oil. The lubricating oils include a
major amount of the methyl paraffin lubricating oil base stock
blend
[0133] The methyl paraffin lubricating oils of the present
disclosure have a viscosity (Kv.sub.100) from 2.0 to 6.0 cSt, or
2.5 to 5.5 cSt, or 3.0 to 5.0 cSt, or 3.5 to 4.5 cSt, or 3.7 to 4.3
cSt at 100.degree. C., as determined by ASTM D445 or ASTM D7042.
The methyl paraffin lubricating oils of the instant disclosure have
a viscosity (K.sub.40) from 5.0 cSt to 25.0 cSt, or 7.0 to 23.0
cSt, or 9.0 to 21.0 cSt, or 10.0 to 20.0 cSt, or 11.0 to 19.0 cSt,
or 12.0 to 18.0 cSt, or 13.0 to 17.0 cSt, or 14.0 to 16.0 cSt, as
determined by ASTM D445 or ASTM D7042.
[0134] The methyl paraffin lubricating oils of the present
disclosure have a high temperature high shear (HTHS) viscosity at
150 deg. C of less than about 2.3 cP, or less than about 2.2 cP, or
less than about 2.1 cP, or less than about 2.0 cP, or less than
about 1.9 cP, or less than about 1.8 cP, or less than about 1.7 cP,
or less than 1.6 cP, or less than 1.5 cP, or less than 1.4 cP, or
less than 1.3 cP, or less than 1.2 cP, or less than 1.1 cP, or less
than 1.0 cP, as determined by ASTM D4683.
[0135] The methyl paraffin lubricating oils of the present
disclosure may have a Noack volatility at 250.degree. C. from about
10 to about 90 percent as determined by ASTM D5800. Alternatively,
the methyl paraffin lubricating oils may have a Noack volatility at
250.degree. C. of from 15 to 85%, or 20 to 80%, or 25 to 75%, or 30
to 70%, or 35 to 65%, or 40 to 60%, or 45 to 55% as determined by
ASTM D5800.
[0136] The viscosity-temperature relationship of a lubricating oil
is one of the critical criteria which must be considered when
selecting a lubricant for a particular application. Viscosity Index
(VI) is an empirical, unitless number which indicates the rate of
change in the viscosity of an oil within a given temperature range.
Fluids exhibiting a relatively large change in viscosity with
temperature are said to have a low viscosity index. A low VI oil,
for example, will thin out at elevated temperatures faster than a
high VI oil. Usually, the high VI oil is more desirable because it
has higher viscosity at higher temperature, which translates into
better or thicker lubrication film and better protection of the
contacting machine elements.
[0137] The methyl paraffin lubricating oils of the present
disclosure may have a Viscosity Index from about 100 to about 200
as determined by ASTM D2270. Alternatively, the methyl paraffin
lubricating oils may have a Viscosity Index of from 100 to 190, or
120 to 180, or 130 to 170, or 140 to 160, or 145 to 155, as
determined by ASTM D2270.
[0138] Surprisingly, as shown in the Examples herein, it has been
discovered that formulated engine oils employing these methyl
paraffin base stock blends as a major component possess
unexpectedly high thermal and oxidative stability along with good
deposit control benefit, as confirmed by their consistently low
deposit formation from the Thermo-Oxidation Engine Oil Simulation
Test (TEOST 33C ASTM D6335) conducted at high temperature.
[0139] The methyl paraffin lubricating oils of the present
disclosure in particular yield a synergistic improvement in
oxidative stability relative to the oxidative stabilities of the
C10 dimer and C10 trimer that are incorporated into the methyl
paraffin base stock blend. In particular, the methyl paraffin
lubricating oils of the present disclosure have an oxidation
stability (210 hour test with time to 200% KV40 increase) of from
60 to 150 hours, or 70 to 140 hours, or 80 to 130 hours, or 90 to
120 hours, or 100 to 110 hours.
[0140] The methyl paraffin lubricating oils of the present
disclosure also provide for outstanding resistance to deposit
formation as measured by the TEOST 33C test for 2 hours at 200 to
480 deg. C per ASTM D6335. In particular, the methyl paraffin
lubricating oils of the present disclosure yield a synergistic
improvement in deposit formation relative to the deposit formation
of the C10 dimer and C10 trimer that are incorporated into the
methyl paraffin base stock blend. The methyl paraffin lubricating
oils of the present disclosure provide total deposits ranging from
10 to 30 mg, or 12 to 28 mg, or 14 to 26 mg, or 16 to 24 mg, or 18
to 22 mg, or 19 to 21 mg.
[0141] The methyl paraffin lubricating oils of the instant
disclosure may have a MTM average traction coefficient (at 100 deg.
C, 1 GPa, 2 m/s and 0-100% SRR) ranging from 0.0050 to 0.0090.
Alternatively, the methyl paraffin lubricating oils may have a MTM
average traction coefficient ranging from 0.0055 to 0.0085, or
0.0060 to 0.0080, or 0.0065 to 0.0075. The MTM average traction
coefficient correlates with fuel efficiency with lower values
providing improved fuel economy. The methyl paraffin lubricating
oils of the instant disclosure have MTM average traction
coefficient values that are from 20 to 180% lower, or from 40 to
120% lower, or from 60 to 100% lower, or from 70 to 90% lower, or
from 75 to 85% lower than conventional lubricating oils utilizing
Group II, Group III or Group III (GTL) base stocks as the major
component of the lubricating oil.
[0142] The methyl paraffin lubricating oils of the instant
disclosure may have a pour point of from about -10 to -60.degree.
C. as determined by ASTM D5950. Alternatively, the methyl paraffin
lubricating oils may have a pour point of from -15 to -55.degree.
C., or -20 to -50.degree. C., or -25 to -45.degree. C., or -30 to
-40.degree. C., or -32 to -47.degree. C., as determined by ASTM
D5950.
[0143] The methyl paraffin lubricating oils of the instant
disclosure may also have a Cold Crank Simulator (CCS) viscosity
(-35 deg. C) that ranges from 700 to 1000 mPas, or 750 to 950 mPas,
or 800 to 900 mPas, or 830 to 880 mPas, as determined by ASTM
D5293.
[0144] One particularly preferred lubricating oil additive to be
incorporated into the methyl paraffin lubricating oils of the
present disclosure is a viscosity modifier. A polymethacrylate
(PMA) viscosity modifier (e.g. Viscoplex 3-200 by Evnoik
Industries) and a hydrocarbon (HC) hydrogenated polyisoprene star
polymer type viscosity modifier (SV600 by Infineum) are two
particularly preferred viscosity modifiers. The methyl paraffin
lubricating oils of the instant disclosure with a viscosity
modifier may have a Viscosity Index from about 200 to about 350 as
determined by ASTM D2270. Alternatively, the methyl paraffin
lubricating oils of the instant disclosure with a viscosity
modifier may have a Viscosity Index of from 220 to 340, or 240 to
330, or 260 to 320, or 270 to 310, or 280 to 300, as determined by
ASTM D2270.
[0145] The methyl paraffin lubricating oils of the present
disclosure may also include a cobase stock as a minor component.
The cobase stock may be included in the lubricating oil at from 5
to 40 wt %, or 10 to 35 wt %, or 15 to 30 wt %, or 20 to 25 wt
%.
[0146] The methyl paraffin lubricating oils of the present
disclosure have a high temperature high shear (HTHS) viscosity of
less than about 2.3 cP as determined by ASTM D4683, and a Noack
volatility from about 15 to about 90 percent as determined by ASTM
D5800.
[0147] Illustrative methyl paraffin lubricating oils of the instant
disclosure have a viscosity (Kv.sub.100) from about 1 cSt to about
8 cSt, more preferably from about 2 cSt to about 6 cSt, even more
preferably from about 1 cSt to about 4 cSt, still even more
preferably from about 2 cSt to about 3 cSt, at 100.degree. C. as
determined by ASTM D445 or ASTM D7042, a viscosity index (VI) from
about -100 to about 300, more preferably from about 0 to about 200,
even more preferably from about 25 to about 150, still even more
preferably from about 100 to about 170, as determined by ASTM
D2270, a Noack volatility of no greater than 90 percent, more
preferably no greater than 75 percent, still more preferably no
greater than 50 percent, even still more preferably no greater than
40 percent, yet more even more preferably no greater than 30
percent, as determined by ASTM D5800, and a high temperature high
shear (HTHS) viscosity of less than about 2.5 cP, more preferably
less than about 2.25 cP, even more preferably less than about 2.0
cP, as determined by ASTM D4683.
[0148] Preferred methyl paraffin base stocks of the instant
disclosure have a high temperature high shear (HTHS) viscosity of
less than about 1.7 cP as determined by ASTM D4683, and a Noack
volatility from about 15 to about 90 percent as determined by ASTM
D5800.
[0149] The methyl paraffin base stocks of the instant disclosure
have more desirable viscosity-volatility characteristics when
compared to commercially available low viscosity Group IV PAO
synthetic base stocks (e.g., SpectraSyn.TM. 2, SpectraSyn.TM. 4) or
Group V ester base stocks (e.g., 2-ethylhexyl oleate, 2-ethylhexyl
adipate, isodecyl adipate, 2-ethylhexyl phthalate, nC8/nC10
neopentyl glycol esters, nC7 trimethyolpropane ester, and the
like). The methyl paraffin base stocks of the instant disclosure
have lower viscosities than commercially available esters at
similar volatility. Additionally, the methyl paraffin base stocks
of the instant disclosure have lower volatility than commercially
available esters at comparable viscosities.
[0150] Surprisingly, as shown in the Examples herein, it has been
discovered that formulated engine oils employing these methyl
paraffin base stocks of the instant disclosure as a major component
possess unexpectedly high thermal and oxidative stability along
with good deposit control benefit, as confirmed by their
consistently low deposit formation from the Thermo-Oxidation Engine
Oil Simulation Test (TEOST 33C ASTM D6335) conducted at high
temperature. In comparison, the same formulation based on
commercially available ester base stocks (e.g., diisooctyl adipate)
show high deposit formation in the same test.
[0151] As shown in the Examples herein, the methyl paraffin base
stocks of the instant disclosure have more desirable
viscosity-volatility characteristics when compared to commercially
available low viscosity Group IV PAO synthetic base stocks (e.g.,
SpectraSyn.TM. 2, SpectraSyn.TM. 4) or commercially available low
viscosity Group II and Group III base stocks.
[0152] Surprisingly, as shown in the Examples herein, it has been
discovered that formulated engine oils employing these methyl
paraffin base stocks of the instant disclosure as a major component
possess unexpectedly high thermal and oxidative stability along
with good deposit control benefit, as confirmed by their
consistently low deposit formation from the Thermo-Oxidation Engine
Oil Simulation Test (TEOST 33C ASTM D6335) conducted at high
temperature. In comparison, the same formulation based on
commercially available ester base stocks (e.g., diisooctyl adipate)
show high deposit formation in the same test.
[0153] The methyl paraffin base stocks of the instant disclosure
have more desirable viscosity-volatility characteristics when
compared to commercially available low viscosity Group IV PAO
synthetic base stocks (e.g., SpectraSyn.TM. 2, SpectraSyn.TM. 4))
or Group V ester base stocks (e.g., 2-ethylhexyl oleate,
2-ethylhexyl adipate, isodecyl adipate, 2-ethylhexyl phthalate,
nC8/nC10 neopentyl glycol esters, nC7 trimethyolpropane ester, and
the like) or commercially available low viscosity Group II and
Group III base stocks.
[0154] Surprisingly, as shown in the Examples herein, it has been
discovered that formulated engine oils employing these methyl
paraffin base stocks of the instant disclosure as a major component
possess unexpectedly good traction properties.
[0155] As shown in the Examples herein, the methyl paraffin base
stocks of the instant disclosure have more desirable
viscosity-volatility characteristics when compared to commercially
available low viscosity Group IV PAO synthetic base stocks (e.g.,
SpectraSyn.TM. 2, SpectraSyn.TM. 4) or Group II base stocks or
Group III base stocks
[0156] Examples of techniques that can be employed to characterize
the compositions formed by the process described above include, but
are not limited to, analytical gas chromatography, nuclear magnetic
resonance, thermogravimetric analysis (TGA), inductively coupled
plasma mass spectrometry, differential scanning calorimetry (DSC),
volatility and viscosity measurements.
[0157] This disclosure provides lubricating oils useful as engine
oils, driveline oils, and in other applications characterized by
excellent oxidative stability. The lubricating oils are based on
methyl paraffin base stocks of the instant disclosure. In the
present specification and claims, the terms base oil(s) and base
stock(s) are used interchangeably.
[0158] In another aspect, as the oil operating temperature
decreases, the viscosity of a high VI oil will not increase as much
as the viscosity of a low VI oil. This is advantageous because the
excessive high viscosity of the low VI oil will decrease the
efficiency of the operating machine. Thus high VI (HVI) oil has
performance advantages in both high and low temperature operation.
VI is determined according to ASTM D2270. VI is related to
kinematic viscosities measured at 40.degree. C. and 100.degree. C.
using ASTM D445.
Lubricating Oil Co-Base Stocks
[0159] The methyl paraffin lubricating oils of the instant
disclosure may also include co-base stock as a minor component. The
co-base stock component of the present lubricating oils will
typically be from 1 to 50 percent, or more preferably from 5 to 45
percent, or more preferably from 10 to 40 percent, or more
preferably from 20 to 30 percent.
[0160] A wide range of lubricating oils is known in the art that
can function as a co-base stock component of the instant
application. Lubricating oils that are useful as a co-base stock
component in the present disclosure are both natural oils and
synthetic oils. Natural and synthetic oils (or mixtures thereof)
can be used unrefined, refined, or re-refined (the latter is also
known as reclaimed or reprocessed oil). Unrefined oils are those
obtained directly from a natural or synthetic source and used
without added purification. These include shale oil obtained
directly from retorting operations, petroleum oil obtained directly
from primary distillation, and ester oil obtained directly from an
esterification process. Refined oils are similar to the oils
discussed for unrefined oils except refined oils are subjected to
one or more purification steps to improve the at least one
lubricating oil property. One skilled in the art is familiar with
many purification processes. These processes include solvent
extraction, secondary distillation, acid extraction, base
extraction, filtration, and percolation. Re-refined oils are
obtained by processes analogous to refined oils but using an oil
that has been previously used as a feed stock.
[0161] Groups I, II, III, IV and V are broad categories of base oil
stocks developed and defined by the American Petroleum Institute
(API Publication 1509; www.API.org) to create guidelines for
lubricant base oils. Group I base stocks generally have a viscosity
index of between about 80 to 120 and contain greater than about
0.03% sulfur and less than about 90% saturates. Group II base
stocks generally have a viscosity index of between about 80 to 120,
and contain less than or equal to about 0.03% sulfur and greater
than or equal to about 90% saturates. Group III stock generally has
a viscosity index greater than about 120 and contains less than or
equal to about 0.03% sulfur and greater than about 90% saturates.
Group IV includes polyalphaolefins (PAO). Group V base stocks
include base stocks not included in Groups I-IV. The table below
summarizes properties of each of these five groups.
TABLE-US-00001 Base Oil Properties Saturates Sulfur Viscosity Index
Group I <90 and/or >0.03% and .gtoreq.80 and <120 Group II
.gtoreq.90 and .ltoreq.0.03% and .gtoreq.80 and <120 Group III
.gtoreq.90 and .ltoreq.0.03% and .gtoreq.120 Group IV Includes
polyalphaolefins (PAO) products Group V All other base oil stocks
not included in Groups I, II, III or IV
[0162] 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.
[0163] Oils derived from coal or shale are also useful in the
present disclosure. Natural oils vary also as to the method used
for their production and purification, for example, their
distillation range and whether they are straight run or cracked,
hydrorefined, or solvent extracted.
[0164] Group II and/or Group III hydroprocessed or hydrocracked
base stocks, as well as synthetic oils such as polyalphaolefins,
alkyl aromatics and synthetic esters, i.e. Group IV and Group V
oils are also well known base stock oils.
[0165] Synthetic oils include hydrocarbon oil such as polymerized
and interpolymerized olefins (polybutylenes, polypropylenes,
propylene isobutylene copolymers, ethylene-olefin copolymers, and
ethylene-alphaolefin copolymers, for example). Polyalphaolefin
(PAO) oil base stocks, the Group IV API base stocks, are a commonly
used synthetic hydrocarbon oil. By way of example, PAOs derived
from C.sub.8, C.sub.10, C.sub.12, C.sub.14 olefins or mixtures
thereof may be utilized. See U.S. Pat. Nos. 4,956,122; 4,827,064;
and 4,827,073, which are incorporated herein by reference in their
entirety. Group IV oils, that is, the PAO base stocks have
viscosity indices preferably greater than 130, more preferably
greater than 135, still more preferably greater than 140.
[0166] Esters may be useful in the lubricating oils of this
disclosure. Additive solvency and seal compatibility
characteristics may be secured by the use of esters such as the
esters of dibasic acids with monoalkanols and the polyol esters of
monocarboxylic acids. Esters of the former type include, for
example, the esters of dicarboxylic acids such as phthalic acid,
succinic acid, sebacic acid, fumaric acid, adipic acid, linoleic
acid dimer, malonic acid, alkyl malonic acid, alkenyl malonic acid,
etc., with a variety of alcohols such as butyl alcohol, hexyl
alcohol, dodecyl alcohol, 2-ethylhexyl alcohol, etc. Specific
examples of these types of esters include dibutyl adipate,
di-(2-ethylhexyl) sebacate, di-n-hexyl fumarate, dioctyl sebacate,
diisooctyl azelate, diisodecyl azelate, dioctyl phthalate, didecyl
phthalate, dieicosyl sebacate, etc.
[0167] 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.8 to C.sub.30 acids such as saturated straight chain fatty
acids including caprylic acid, capric acids, lauric acid, myristic
acid, palmitic acid, stearic acid, arachic acid, and behenic acid,
or the corresponding branched chain fatty acids or unsaturated
fatty acids such as oleic acid, or mixtures of any of these
materials.
[0168] Esters should be used in an amount such that the improved
wear and corrosion resistance provided by the lubricating oils of
this disclosure are not adversely affected.
[0169] Non-conventional or unconventional base stocks and/or base
oils include one or a mixture of base stock(s) and/or base oil(s)
derived from: (1) one or more Gas-to-Liquids (GTL) materials, as
well as (2) hydrodewaxed, or hydroisomerized/cat (and/or solvent)
dewaxed base stock(s) and/or base oils derived from synthetic wax,
natural wax or waxy feeds, mineral and/or non-mineral oil waxy feed
stocks such as gas oils, slack waxes (derived from the solvent
dewaxing of natural oils, mineral oils or synthetic oils; e.g.,
Fischer-Tropsch feed stocks), natural waxes, and waxy stocks such
as gas oils, waxy fuels hydrocracker bottoms, waxy raffinate,
hydrocrackate, thermal crackates, foots oil or other mineral,
mineral oil, or even non-petroleum oil derived waxy materials such
as waxy materials recovered from coal liquefaction or shale oil,
linear or branched hydrocarbyl compounds with carbon number of
about 20 or greater, preferably about 30 or greater and mixtures of
such base stocks and/or base oils.
[0170] 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.
[0171] 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).
[0172] In addition, the GTL base stock(s) and/or base oil(s) are
typically highly paraffinic (>90% saturates), and may contain
mixtures of monocycloparaffins and multicycloparaffins in
combination with non-cyclic isoparaffins. The ratio of the
naphthenic (i.e., cycloparaffin) content in such combinations
varies with the catalyst and temperature used. Further, GTL base
stock(s) and/or base oil(s) typically have very low sulfur and
nitrogen content, generally containing less than about 10 ppm, and
more typically less than about 5 ppm of each of these elements. The
sulfur and nitrogen content of GTL base stock(s) and/or base oil(s)
obtained from F-T material, especially F-T wax, is essentially nil.
In addition, the absence of phosphorous and aromatics make this
materially especially suitable for the formulation of low SAP
products.
[0173] 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.
[0174] 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).
[0175] Base oils for use in the formulated lubricating oils useful
in the present disclosure are any of the variety of oils
corresponding to API Group I, Group II, Group III, Group IV, Group
V and Group VI oils and mixtures thereof, preferably API Group II,
Group III, Group IV, Group V and Group VI oils and mixtures
thereof, more preferably the Group III to Group VI base oils due to
their exceptional volatility, stability, viscometric and
cleanliness features. Minor quantities of Group I stock, such as
the amount used to dilute additives for blending into formulated
lube oil products, can be tolerated but should be kept to a
minimum, i.e. amounts only associated with their use as
diluent/carrier oil for additives used on an "as received" basis.
Even in regard to the Group II stocks, it is preferred that the
Group II stock be in the higher quality range associated with that
stock, i.e. a Group II stock having a viscosity index in the range
100<VI<120.
[0176] In addition, the GTL base stock(s) and/or base oil(s) are
typically highly paraffinic (>90% saturates), and may contain
mixtures of monocycloparaffins and multicycloparaffins in
combination with non-cyclic isoparaffins. The ratio of the
naphthenic (i.e., cycloparaffin) content in such combinations
varies with the catalyst and temperature used. Further, GTL base
stock(s) and/or base oil(s) and hydrodewaxed, or
hydroisomerized/cat (and/or solvent) dewaxed base stock(s) and/or
base oil(s) typically have very low sulfur and nitrogen content,
generally containing less than about 10 ppm, and more typically
less than about 5 ppm of each of these elements. The sulfur and
nitrogen content of GTL base stock(s) and/or base oil(s) obtained
from F-T material, especially F-T wax, is essentially nil. In
addition, the absence of phosphorous and aromatics make this
material especially suitable for the formulation of low sulfur,
sulfated ash, and phosphorus (low SAP) products.
Other Additives
[0177] The formulated methyl paraffin lubricating oil useful in the
present disclosure may additionally contain one or more of the
other commonly used lubricating oil performance additives including
but not limited to dispersants, other detergents, corrosion
inhibitors, rust inhibitors, metal deactivators, other anti-wear
agents and/or extreme pressure additives, anti-seizure agents, wax
modifiers, viscosity index improvers, viscosity modifiers,
fluid-loss additives, seal compatibility agents, other friction
modifiers, lubricity agents, anti-staining agents, chromophoric
agents, defoamants, demulsifiers, emulsifiers, densifiers, wetting
agents, gelling agents, tackiness agents, colorants, and others.
For a review of many commonly used additives, see Klamann in
Lubricants and Related Products, Verlag Chemie, Deerfield Beach,
Fla.; ISBN 0-89573-177-0. Reference is also made to "Lubricant
Additives Chemistry and Applications" edited by Leslie R. Rudnick,
Marcel Dekker, Inc. New York, 2003 ISBN: 0-8247-0857-1.
[0178] All of the lubricating oil additives described below can be
used alone or in combination. The total treat rates for the
additives can range from 1 to 30 weight percent, or more preferably
from 2 to 25 weight percent, or more preferably from 3 to 20 weight
percent, or more preferably from 4 to 15 weight percent, or more
preferably from 5 to 10 weight percent. Particularly preferred
compositions have additive levels between 15 and 20 weight
percent.
[0179] When used in lubricating oils, the inventive methyl paraffin
base stocks disclosed herein may be included in the lubricating oil
at from 70 to 99 weight percent, or more preferably from 75 to 98
weight percent, or more preferably from 80 to 97 weight percent, or
more preferably from 85 to 96 weight percent, or more preferably
from 90 to 95 weight percent of the total lubricating oil
composition. Particularly preferred oil compositions have base
stock loadings between 80 and 85 weight percent.
[0180] The types and quantities of performance additives used in
combination with the instant disclosure in lubricant compositions
are not limited by the examples shown herein as illustrations.
Viscosity Modifiers
[0181] Viscosity modifiers (also known as viscosity index improvers
(VI improvers), and viscosity improvers) can be included in the
lubricant compositions of this disclosure.
[0182] Viscosity modifiers provide lubricants with high and low
temperature operability. These additives impart shear stability at
elevated temperatures and acceptable viscosity at low
temperatures.
[0183] Suitable viscosity modifiers include 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.
[0184] 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.
[0185] 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 "SV 50".
[0186] 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, Viscoplex
3-200) or star polymers which are available from Lubrizol
Corporation under the trade designation Asteric.TM. (e.g., Lubrizol
87708 and Lubrizol 87725).
[0187] Illustrative vinyl aromatic-containing polymers 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.
[0188] The vinyl aromatic-containing polymers or copolymers useful
in this disclosure have a weight average molecular weight greater
than about 80,000, and a number average molecular weight greater
than about 40,000; preferably a weight average molecular weight
greater than about 90,000, and a number average molecular weight
greater than about 75,000; and more preferably a weight average
molecular weight greater than about 100,000 and less than
1,000,000, and a number average molecular weight greater than about
100,000 and less than 1,000,000. The vinyl aromatic-containing
polymers or copolymers have an amount of vinyl aromatic content
greater than about 10% by weight, or greater than about 20% by
weight, or greater than about 30% by weight, of the vinyl
aromatic-containing polymer or copolymer. The vinyl
aromatic-containing polymers or copolymers have an amount of vinyl
aromatic content preferably between about 10% and about 50% by
weight, more preferably between about 15% and about 40% by weight,
and even more preferably between about 20% and about 35% by weight,
of the vinyl aromatic-containing polymer or copolymer.
[0189] In an embodiment of this disclosure, the viscosity modifiers
may be used in an amount of less than about 2.0 weight percent,
preferably less than about 1.0 weight percent, and more preferably
less than about 0.5 weight percent, based on the total weight of
the formulated oil or lubricating engine oil. Viscosity modifiers
are typically added as concentrates, in large amounts of diluent
oil.
[0190] In another embodiment of this disclosure, the viscosity
modifiers may be used in an amount of from 0.05 to about 2.0 weight
percent, preferably 0.15 to about 1.0 weight percent, and more
preferably 0.25 to about 0.5 weight percent, based on the total
weight of the formulated oil or lubricating engine oil. Or the
viscosity modifiers may be used in an amount (total solid polymer
content) of from 0.5 to about 2.0 weight percent, preferably 0.8 to
about 1.5 weight percent, and more preferably 1.0 to about 1.3
weight percent, based on the total weight of the formulated oil or
lubricating engine oil.
[0191] 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 8 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.
Antioxidants
[0192] Typical anti-oxidant include phenolic anti-oxidants, aminic
anti-oxidants and oil-soluble copper complexes.
[0193] The phenolic antioxidants include sulfurized and
non-sulfurized phenolic antioxidants. The terms "phenolic type" or
"phenolic antioxidant" used herein includes compounds having one or
more than one hydroxyl group bound to an aromatic ring which may
itself be mononuclear, e.g., benzyl, or poly-nuclear, e.g.,
naphthyl and spiro aromatic compounds. Thus "phenol type" includes
phenol per se, catechol, resorcinol, hydroquinone, naphthol, etc.,
as well as alkyl or alkenyl and sulfurized alkyl or alkenyl
derivatives thereof, and bisphenol type compounds including such
bi-phenol compounds linked by alkylene bridges sulfuric bridges or
oxygen bridges. Alkyl phenols include mono- and poly-alkyl or
alkenyl phenols, the alkyl or alkenyl group containing from about
3-100 carbons, preferably 4 to 50 carbons and sulfurized
derivatives thereof, the number of alkyl or alkenyl groups present
in the aromatic ring ranging from 1 to up to the available
unsatisfied valences of the aromatic ring remaining after counting
the number of hydroxyl groups bound to the aromatic ring.
[0194] Generally, therefore, the phenolic anti-oxidant may be
represented by the general formula:
(R).sub.x--Ar.sub.x(OH).sub.y
where Ar is selected from the group consisting of:
##STR00015##
wherein R is a C.sub.3-C.sub.100 alkyl or alkenyl group, a sulfur
substituted alkyl or alkenyl group, preferably a C.sub.4-C.sub.50
alkyl or alkenyl group or sulfur substituted alkyl or alkenyl
group, more preferably C.sub.3-C.sub.100 alkyl or sulfur
substituted alkyl group, most preferably a C.sub.4-C.sub.50 alkyl
group, R.sup.G is a C.sub.1-C.sub.100 alkylene or sulfur
substituted alkylene group, preferably a C.sub.2-C.sub.50 alkylene
or sulfur substituted alkylene group, more preferably a
C.sub.2-C.sub.2 alkylene or sulfur substituted alkylene group, y is
at least 1 to up to the available valences of Ar, x ranges from 0
to up to the available valances of Ar-y, z ranges from 1 to 10, n
ranges from 0 to 20, and m is 0 to 4 and p is 0 or 1, preferably y
ranges from 1 to 3, x ranges from 0 to 3, z ranges from 1 to 4 and
n ranges from 0 to 5, and p is 0.
[0195] Preferred phenolic anti-oxidant compounds are the hindered
phenolics and phenolic esters which contain a sterically hindered
hydroxyl group, and these include those derivatives of dihydroxy
aryl compounds in which the hydroxyl groups are in the o- or
p-position to each other. Typical phenolic anti-oxidants include
the hindered phenols substituted with C.sub.1+ alkyl groups and the
alkylene coupled derivatives of these hindered phenols. Examples of
phenolic materials of this type 2-t-butyl-4-heptyl phenol;
2-t-butyl-4-octyl phenol; 2-t-butyl-4-dodecyl phenol;
2,6-di-t-butyl-4-heptyl phenol; 2,6-di-t-butyl-4-dodecyl phenol;
2-methyl-6-t-butyl-4-heptyl phenol; 2-methyl-6-t-butyl-4-dodecyl
phenol; 2,6-di-t-butyl-4 methyl phenol; 2,6-di-t-butyl-4-ethyl
phenol; and 2,6-di-t-butyl 4 alkoxy phenol; and
##STR00016##
[0196] Phenolic type anti-oxidants are well known in the
lubricating industry and commercial examples such as Ethanox.RTM.
4710, Irganox.RTM. 1076, Irganox.RTM. L1035, Irganox.RTM. 1010,
Irganox.RTM. L109, Irganox.RTM. L118, Irganox.RTM. L135 and the
like are familiar to those skilled in the art. The above is
presented only by way of exemplification, not limitation on the
type of phenolic anti-oxidants which can be used.
[0197] The phenolic anti-oxidant can be employed in an amount in
the range of about 0.1 to 3 wt %, preferably about 1 to 3 wt %,
more preferably 1.5 to 3 wt % on an active ingredient basis.
[0198] Aromatic amine anti-oxidants include phenyl-.alpha.-naphthyl
amine which is described by the following molecular structure:
##STR00017##
wherein R.sup.z is hydrogen or a C.sub.1 to C.sub.14 linear or
C.sub.3 to C.sub.14 branched alkyl group, preferably C.sub.1 to
C.sub.10 linear or C.sub.3 to C.sub.10 branched alkyl group, more
preferably linear or branched C.sub.6 to C.sub.8 and n is an
integer ranging from 1 to 5 preferably 1. A particular example is
Irganox L06.
[0199] Other aromatic amine anti-oxidants include other alkylated
and non-alkylated aromatic amines such as aromatic monoamines of
the formula R.sup.8R.sup.9R.sup.10N where R.sup.8 is an aliphatic,
aromatic or substituted aromatic group, R.sup.9 is an aromatic or a
substituted aromatic group, and R.sup.10 is H, alkyl, aryl or
R.sup.11S(O).sub.xR.sup.12 where R.sup.11 is an alkylene,
alkenylene, or aralkylene group, R.sup.12 is a higher alkyl group,
or an alkenyl, aryl, or alkaryl group, and x is 0, 1 or 2. The
aliphatic group R.sup.8 may contain from 1 to about 20 carbon
atoms, and preferably contains from about 6 to 12 carbon atoms. The
aliphatic group is a saturated aliphatic group. Preferably, both
R.sup.8 and R.sup.9 are aromatic or substituted aromatic groups,
and the aromatic group may be a fused ring aromatic group such as
naphthyl. Aromatic groups R.sup.8 and R.sup.9 may be joined
together with other groups such as S.
[0200] Typical aromatic amines anti-oxidants have alkyl substituent
groups of at least about 6 carbon atoms. Examples of aliphatic
groups include hexyl, heptyl, octyl, nonyl, and decyl. Generally,
the aliphatic groups will not contain more than about 14 carbon
atoms. The general types of such other additional amine
anti-oxidants which may be present include diphenylamines,
phenothiazines, imidodibenzyls and diphenyl phenylene diamines.
Mixtures of two or more of such other additional aromatic amines
may also be present. Polymeric amine antioxidants can also be
used.
[0201] Aromatic amines anti-oxidants can be employed in an amount
in the range of about 0.1 to 5 wt %, preferably about 0.5 to 3 wt
%, more preferably 1 to 3 wt % on an active ingredient basis.
[0202] Another class of anti-oxidant used in lubricating oil
compositions and which may also be present are oil-soluble copper
compounds. Any oil-soluble suitable copper compound may be blended
into the lubricating oil. Examples of suitable copper antioxidants
include copper dihydrocarbyl thio- or dithio-phosphates and copper
salts of carboxylic acid (naturally occurring or synthetic). Other
suitable copper salts include copper dithiacarbamates, sulphonates,
phenates, and acetylacetonates. Basic, neutral, or acidic copper
Cu(I) and or Cu(II) salts derived from alkenyl succinic acids or
anhydrides are known to be particularly useful.
[0203] Such antioxidants may be used individually or as mixtures of
one or more types of antioxidants, the total amount employed being
an amount of about 0.50 to 5 wt %, preferably about 0.75 to 3 wt %
(on an as-received basis).
Detergents
[0204] 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. Oils formulated with
low concentrations of detergents and/or low ash detergents can be
preferred as low ash, low metals, low phosphorus oils. 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 acid, carboxylic acid, phosphorous acid, phenol, or
mixtures thereof. The counterion is typically an alkaline earth or
alkali metal.
[0205] 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.
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.
[0206] 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)2, BaO, Ba(OH)2, MgO, Mg(OH)2,
for example) with an alkyl phenol or sulfurized alkylphenol. Useful
alkyl groups include straight chain or branched C1-C30 alkyl
groups, preferably, C4-C20 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.
[0207] Metal salts of carboxylic acids are also useful as
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
##STR00018##
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 C11, preferably C13 or
greater. R may be optionally substituted with substituents that do
not interfere with the detergent's function. M is preferably,
calcium, magnesium, or barium. More preferably, M is calcium or
magnesium.
[0208] 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.
[0209] Alkaline earth metal phosphates are also used as detergents
and are known in the art.
[0210] 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.
[0211] Preferred detergents include calcium phenates, calcium
sulfonates, calcium salicylates, magnesium phenates, magnesium
sulfonates, magnesium salicylates 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.
[0212] The lubricating oils of this disclosure exhibit desired
properties, e.g., wear control, deposit control and fuel
efficiency, in the presence or absence of a detergent, in
particular, the presence or absence of a salicylate detergent or a
sulfonate detergent.
[0213] The detergent concentration in the lubricating oils of this
disclosure can range from about 0.5 to about 20 weight percent or
more, 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.
[0214] As used herein, the detergent concentrations are given on an
"as delivered" basis.
[0215] 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.
Dispersants
[0216] During engine operation, oil-insoluble oxidation byproducts
are produced. Dispersants help keep these byproducts in solution,
thus diminishing their deposition on metal surfaces. Dispersants
may be ashless or ash-forming in nature. Preferably, the dispersant
is ashless. So called ashless dispersants are organic materials
that form substantially no ash upon combustion. For example,
non-metal-containing or borated metal-free dispersants are
considered ashless. In contrast, metal-containing detergents
discussed above form ash upon combustion.
[0217] 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.
[0218] A particularly useful class of dispersants are the
alkenylsuccinic derivatives, typically produced by the reaction of
a long chain substituted alkenyl succinic compound, usually a
substituted succinic anhydride, with a polyhydroxy or polyamino
compound. The long chain group constituting the oleophilic portion
of the molecule which confers solubility in the oil, is normally a
polyisobutylene group. Many examples of this type of dispersant are
well known commercially and in the literature. Exemplary patents
describing such dispersants are U.S. Pat. Nos. 3,172,892;
3,219,666; 3,316,177 and 4,234,435. Other types of dispersants are
described in U.S. Pat. Nos. 3,036,003; and 5,705,458.
[0219] Hydrocarbyl-substituted succinic acid compounds are popular
dispersants. In particular, succinimide, succinate esters, or
succinate ester amides prepared by the reaction of a
hydrocarbon-substituted succinic acid compound preferably having at
least 50 carbon atoms in the hydrocarbon substituent, with at least
one equivalent of an alkylene amine are particularly useful.
[0220] Succinimides are formed by the condensation reaction between
alkenyl succinic anhydrides and amines. Molar ratios can vary
depending on the amine or polyamine. For example, the molar ratio
of alkenyl succinic anhydride to TEPA can vary from about 1:1 to
about 5:1.
[0221] Succinate esters are formed by the condensation reaction
between alkenyl succinic anhydrides and alcohols or polyols. Molar
ratios can vary depending on the alcohol or polyol used. For
example, the condensation product of an alkenyl succinic anhydride
and pentaerythritol is a useful dispersant.
[0222] Succinate ester amides are formed by condensation reaction
between alkenyl succinic anhydrides and alkanol amines. For
example, suitable alkanol amines include ethoxylated
polyalkylpolyamines, propoxylated polyalkylpolyamines and
polyalkenylpolyamines such as polyethylene polyamines. One example
is propoxylated hexamethylenediamine.
[0223] The molecular weight of the alkenyl succinic anhydrides will
typically range between 800 and 2,500. The above products can be
post-reacted with various reagents such as sulfur, oxygen,
formaldehyde, carboxylic acids such as oleic acid, and boron
compounds such as borate esters or highly borated dispersants. The
dispersants can be borated with from about 0.1 to about 5 moles of
boron per mole of dispersant reaction product.
[0224] Mannich base dispersants are made from the reaction of
alkylphenols, formaldehyde, and amines. Process aids and catalysts,
such as oleic acid and sulfonic acids, can also be part of the
reaction mixture. Molecular weights of the alkylphenols range from
800 to 2,500. Mannich base dispersants can also be borated and
mixtures of Mannich base dispersant can be used.
[0225] Typical high molecular weight aliphatic acid modified
Mannich condensation products can be prepared from high molecular
weight alkyl-substituted hydroxyaromatics or HN(R)2
group-containing reactants.
[0226] Examples of high molecular weight alkyl-substituted
hydroxyaromatic compounds are polypropylphenol, polybutylphenol,
and other polyalkylphenols. These polyalkylphenols can be obtained
by the alkylation, in the presence of an alkylating catalyst, such
as BF.sub.3, of phenol with high molecular weight polypropylene,
polybutylene, and other polyalkylene compounds to give alkyl
substituents on the benzene ring of phenol having an average
600-100,000 molecular weight.
[0227] Examples of HN(R).sub.2 group-containing reactants are
alkylene polyamines, principally polyethylene polyamines. Other
representative organic compounds containing at least one
HN(R).sub.2 group suitable for use in the preparation of Mannich
condensation products are well known and include the mono- and
di-amino alkanes and their substituted analogs, e.g., ethylamine
and diethanol amine; aromatic diamines, e.g., phenylene diamine,
diamino naphthalenes; heterocyclic amines, e.g., morpholine,
pyrrole, pyrrolidine, imidazole, imidazolidine, and piperidine;
melamine and their substituted analogs.
[0228] Examples of alkylene polyamine reactants include
ethylenediamine, diethylene triamine, triethylene tetraamine,
tetraethylene pentaamine, pentaethylene hexamine, hexaethylene
heptaamine, heptaethylene octaamine, octaethylene nonaamine,
nonaethylene decamine, and decaethylene undecamine and mixture of
such amines having nitrogen contents corresponding to the alkylene
polyamines, in the formula H.sub.2N--(Z--NH--).sub.nH, mentioned
before, Z is a divalent ethylene and n is 1 to 10 of the foregoing
formula. Corresponding propylene polyamines such as propylene
diamine and di-, tri-, tetra-, pentapropylene tri-, tetra-, penta-
and hexaamines are also suitable reactants. The alkylene polyamines
are usually obtained by the reaction of ammonia and dihalo alkanes,
such as dichloro alkanes. Thus the alkylene polyamines obtained
from the reaction of 2 to 11 moles of ammonia with 1 to 10 moles of
dichloroalkanes having 2 to 6 carbon atoms and the chlorines on
different carbons are suitable alkylene polyamine reactants.
[0229] Aldehyde reactants useful in the preparation of the high
molecular products useful in this disclosure include the aliphatic
aldehydes such as formaldehyde (also as paraformaldehyde and
formalin), acetaldehyde and aldol (.beta.-hydroxybutyraldehyde).
Formaldehyde or a formaldehyde-yielding reactant is preferred.
[0230] Preferred dispersants include borated and non-borated
succinimides, including those derivatives from mono-succinimides,
bis-succinimides, and/or mixtures of mono- and bis-succinimides,
wherein the hydrocarbyl succinimide is derived from a
hydrocarbylene group such as polyisobutylene having a Mn of from
about 500 to about 5000 or a mixture of such hydrocarbylene groups.
Other preferred dispersants include succinic acid-esters and
amides, alkylphenol-polyamine-coupled Mannich adducts, their capped
derivatives, and other related components. Such additives may be
used in an amount of about 0.1 to 20 wt %, preferably about 0.1 to
8 wt %, more preferably about 1 to 6 wt % (on an as-received basis
or 0-10 wt % on an active ingredient basis) based on the weight of
the total lubricant.
Pour Point Depressants
[0231] Conventional pour point depressants (also known as lube oil
flow improvers) may also be present. Pour point depressant may be
added to lower the minimum temperature at which the fluid will flow
or can be poured. Examples of suitable pour point depressants
include alkylated naphthalenes polymethacrylates, polyacrylates,
polyarylamides, condensation products of haloparaffin waxes and
aromatic compounds, vinyl carboxylate polymers, and terpolymers of
dialkylfumarates, vinyl esters of fatty acids and allyl vinyl
ethers. Such additives may be used in amount of about 0.0 to 0.5 wt
%, preferably about 0 to 0.3 wt %, more preferably about 0.001 to
0.1 wt % on an as-received basis.
Corrosion Inhibitors/Metal Deactivators
[0232] Corrosion inhibitors are used to reduce the degradation of
metallic parts that are in contact with the lubricating oil
composition. Suitable corrosion inhibitors include aryl thiazines,
alkyl substituted dimercapto thiodiazoles thiadiazoles and mixtures
thereof. Such additives may be used in an amount of about 0.01 to 5
wt %, preferably about 0.01 to 1.5 wt %, more preferably about 0.01
to 0.2 wt %, still more preferably about 0.01 to 0.1 wt % (on an
as-received basis) based on the total weight of the lubricating oil
composition.
Seal Compatibility Additives
[0233] Seal compatibility agents help to swell elastomeric seals by
causing a chemical reaction in the fluid or physical change in the
elastomer. Suitable seal compatibility agents for lubricating oils
include organic phosphates, aromatic esters, aromatic hydrocarbons,
esters (butylbenzyl phthalate, for example), and polybutenyl
succinic anhydride and sulfolane-type seal swell agents such as
Lubrizol 730-type seal swell additives. Such additives may be used
in an amount of about 0.01 to 3 wt %, preferably about 0.01 to 2 wt
% on an as-received basis.
Anti-Foam Agents
[0234] Anti-foam agents may advantageously be added to lubricant
compositions. These agents retard the formation of stable foams.
Silicones and organic polymers are typical anti-foam agents. For
example, polysiloxanes, such as silicon oil or polydimethyl
siloxane, provide antifoam properties. Anti-foam agents are
commercially available and may be used in conventional minor
amounts along with other additives such as demulsifiers; usually
the amount of these additives combined is less than 1 percent,
preferably 0.001 to about 0.5 wt %, more preferably about 0.001 to
about 0.2 wt %, still more preferably about 0.0001 to 0.15 wt % (on
an as-received basis) based on the total weight of the lubricating
oil composition.
Inhibitors and Antirust Additives
[0235] Anti-rust additives (or corrosion inhibitors) are additives
that protect lubricated metal surfaces against chemical attack by
water or other contaminants. One type of anti-rust additive is a
polar compound that wets the metal surface preferentially,
protecting it with a film of oil. Another type of anti-rust
additive absorbs water by incorporating it in a water-in-oil
emulsion so that only the oil touches the surface. Yet another type
of anti-rust additive chemically adheres to the metal to produce a
non-reactive surface. Examples of suitable additives include zinc
dithiophosphates, metal phenolates, basic metal sulfonates, fatty
acids and amines. Such additives may be used in an amount of about
0.01 to 5 wt %, preferably about 0.01 to 1.5 wt % on an as-received
basis.
[0236] ZDDP anti-wear additives are essential components of the
present disclosure. ZDDP derived from C8 to C18 primary or
secondary alcohols and preferably derived from C4, C5, and/or C7
primary or secondary alcohols and mixtures thereof are often
preferred. In some applications, low phosphorus ZDDP additives with
<0.10% by weight phosphorus, leading to about from 0.02% to
0.08% phosphorus in finished oils can be preferred. In addition to
ZDDP, other anti-wear additives can be present, including zinc
dithiocarbamates, molybdenum dialkyldithiophosphates, molybdenum
dithiocarbamates, other organo molybdenum-nitrogen complexes,
sulfurized olefins, etc.
[0237] The term "organo molybdenum-nitrogen complexes" embraces the
organo molybdenum-nitrogen complexes described in U.S. Pat. No.
4,889,647. The complexes are reaction products of a fatty oil,
dithanolamine and a molybdenum source. Specific chemical structures
have not been assigned to the complexes. U.S. Pat. No. 4,889,647
reports an infrared spectrum for a typical reaction product of that
disclosure; the spectrum identifies an ester carbonyl band at 1740
cm.sup.-1 and an amide carbonyl band at 1620 cm.sup.-1. The fatty
oils are glyceryl esters of higher fatty acids containing at least
12 carbon atoms up to 22 carbon atoms or more. The molybdenum
source is an oxygen-containing compound such as ammonium
molybdates, molybdenum oxides and mixtures.
[0238] Other organo molybdenum complexes which can be used in the
present disclosure are tri-nuclear molybdenum-sulfur compounds
described in EP 1 040 115 and WO 99/31113 and the molybdenum
complexes described in U.S. Pat. No. 4,978,464.
Performance and Uses
[0239] The methyl paraffin lubricant compositions of this
disclosure give advantaged performance in the lubrication of
internal combustion engines, power trains, drivelines,
transmissions, gears, gear trains, gear sets, compressors, pumps,
hydraulic systems, bearings, bushings, turbines, and the like,
[0240] Also, the methyl paraffin lubricant compositions of this
disclosure also give advantaged friction, wear, and other lubricant
performances in the lubrication of mechanical components, which
comprise, for example, pistons, piston rings, cylinder liners,
cylinders, cams, tappets, lifters, bearings (journal, roller,
tapered, needle, ball, and the like), gears, valves, and the
like.
[0241] Further, the methyl paraffin lubricant compositions of this
disclosure give advantaged friction, wear, and other lubricant
performances under a range of lubrication contact pressures, from 1
MPas to greater than 10 GPas, preferably greater than 10 MPas, more
preferably greater than 100 MPas, even more preferable greater than
300 MPas. Under certain circumstances, the methyl paraffin
lubricant compositions of this disclosure give advantaged wear and
friction performance at greater than 0.5 GPas, often at greater
than 1 GPas, sometimes greater than 2 GPas, under selected
circumstances greater than 5 GPas.
[0242] Yet further, the methyl paraffin lubricant compositions of
this disclosure give advantaged friction, wear, and other lubricant
performances when used in combination with lubricated surfaces
comprising: metals, metal alloys, non-metals, non-metal alloys,
mixed carbon-metal composites and alloys, mixed carbon-nonmetal
composites and alloys, ferrous metals, ferrous composites and
alloys, non-ferrous metals, non-ferrous composites and alloys,
titanium, titanium composites and alloys, aluminum, aluminum
composites and alloys, magnesium, magnesium composites and alloys,
ion-implanted metals and alloys, plasma modified surfaces; surface
modified materials; coatings; mono-layer, multi-layer, and gradient
layered coatings; honed surfaces; polished surfaces; etched
surfaces; textured surfaces; micro and nano structures on textured
surfaces; super-finished surfaces; diamond-like carbon (DLC), DLC
with high-hydrogen content, DLC with moderate hydrogen content, DLC
with low-hydrogen content, DLC with zero hydrogen content, DLC
composites, DLC-metal compositions and composites, DLC-nonmetal
compositions and composites; glasses, metallic glasses; ceramics,
cermets, ceramic oxides, ceramic nitrides, FeN, CrN, ceramic
carbides, mixed ceramic compositions, and the like; polymers,
plastics, thermoplastic polymers, engineered polymers, polymer
blends, polymer alloys, polymer composites; elastomers; materials
compositions and composites containing dry lubricants, comprising
for example graphite, carbon, molybdenum, molybdenum disulfide,
polytetrafluoroethylene, polyperfluoropropylene,
polyperfluoroalkylethers, and the like.
[0243] The viscometric properties of the methyl paraffin lubricants
of this disclosure can be measured according to standard practices.
A low viscosity can be advantageous for lubricants in modern
equipment. A low high temperature high shear (HTHS) viscosity, in
accordance with ASTM D4683, can indicate performance of a lubricant
in a modern engine. In particular, the methyl paraffin lubricants
of this disclosure can have an HTHS of less than 2.0 cP, or more
preferably less than 1.9 cP, or more preferably less than 1.8 cP,
or more preferably less than 1.7 cP.
[0244] The methyl paraffin lubricants of this disclosure can have
lower volatility, as determined by the Noack volatility test ASTM
D5800, or as predicted by a TGA test that simulates the Noack
volatility. In particular, the lubricants of this disclosure can
have a Noack between 1% and 50%, or more preferably between 10% and
50%, or more preferably between 15% and 45%, or more preferably
between 20% and 35%. Particularly preferred compositions have a
Noack between 15% and 30%.
[0245] The methyl paraffin lubricants of this disclosure can have
lower deposition tendancy, as determined by the TEOST 33C
deposition test ASTM D6335. In particular, the lubricants of this
disclosure can have a TEOST 33C of less than 30 mg, or more
preferably less than 20 mg, or more preferably less than 15 mg.
[0246] The methyl paraffin lubricants of this disclosure can have
reduced traction as determined by the MTM (Mini Traction Machine)
traction test. Traction is most easily assessed by comparison to a
reference fluid, in this case a suitable reference fluid is an
engine oil formulated with commercial GTL QHVI-3. Accordingly, the
lubricants of this disclosure can have an MTM traction reduction of
5% versus a reference, or more preferably a reduction of 10% versus
a reference, or more preferably a reduction of 20% versus a
reference, or more preferably a reduction of 30% versus a
reference, or more preferably a reduction of 40% versus a
reference.
[0247] In the above detailed description, the specific embodiments
of this disclosure have been described in connection with its
preferred embodiments. However, to the extent that the above
description is specific to a particular embodiment or a particular
use of this disclosure, this is intended to be illustrative only
and merely provides a concise description of the exemplary
embodiments. Accordingly, the disclosure is not limited to the
specific embodiments described above, but rather, the disclosure
includes all alternatives, modifications, and equivalents falling
within the true scope of the appended claims. Various modifications
and variations of this disclosure will be obvious to a worker
skilled in the art and it is to be understood that such
modifications and variations are to be included within the purview
of this application and the spirit and scope of the claims.
EXAMPLES
Example 1
Physical Characteristics of Inventive and Comparative Base
Stocks
[0248] Low viscosity inventive C10 dimer, C10 trimer, blends of C10
dimer and trimer and comparative base stocks (C12 dimer, Group II,
GTL and Group III) were prepared using the processes described in
the detailed description and characterized for viscometric
properties, volatility, density, pour point and MTM average
traction coefficient. The inventive base stocks of this disclosure
are blends of 9-methylnonadecane (also referred to herein as "C10
dimer") and 9-methyl-11-octylheneicosane (also referred to herein
as "C10 trimer"). The chemical structures of the 9-methylnonadecane
and 9-methyl-11-octylheneicosane base stocks for blending were as
follows:
##STR00019##
[0249] Also shown below is the chemical structure of the
comparative 11-methyltricosane basestock (also referred to herein
as "C12 dimer").
##STR00020##
[0250] FIG. 1 shows the physical characteristics of inventive
methyl paraffin based low viscosity base stocks and the comparative
low viscosity base stocks. From FIG. 1, it can be seen that the
30/70 blend of C10 dimer and C10 trimer has a higher VI than GTL,
Group III and Group II basestocks and lower Noack volatility than
GTL and Group II of the same kinematic viscosity at 100.degree. C.
The 30/70 blend of C10 dimer and C10 trimer has also improved low
temperature properties than the neat C10 dimer and C12 dimer as
illustrated by the lower pour point. In addition, the 30/70 blend
of C10 dimer and C10 trimer provided a 26% to 158% improvement
relative to low viscosity Group II, Group III and GTL comparative
base stocks in terms of MTM traction coefficient, which may
correlate directly with fuel and energy efficiency. This
improvement in MTM traction coefficient for the 30/70 blend of C10
dimer and C10 trimer low viscosity base stock blend was surprising
and unexpected relative to the low viscosity Group II, Group III
and GTL comparative base stocks.
Example 2
Physical Characteristics and Performance Results of Inventive and
Comparative Engine Oils
[0251] FIG. 2 shows the physical characteristics and performance
test results of engine oils formulations including the inventive
methyl paraffin low viscosity based base stocks and comparative low
viscosity base stocks. From FIG. 2, it can be seen that engine oil
formulations including the 30/70 blend of C10 dimer and C10 trimer
as the low viscosity base stock provided a 45 to 105% improvement
relative to engine oils formulations including low viscosity Group
II, Group III and GTL comparative base stocks in terms of MTM
traction coefficient, which correlates directly with fuel
efficiency. This improvement in MTM traction coefficient for the
engine oil with the 30/70 blend of C10 dimer and C10 trimer low
viscosity base stock was surprising and unexpected relative to the
low viscosity engine oils including comparative Group II, Group III
and GTL base stocks. From FIG. 2, it can also be seen that the
engine oil formulations including the 30/70 blend of C10 dimer and
C10 trimer as the low viscosity base stock also provided lower
Noack volatility, lower TEOST 33C deposits, higher 210 hour
oxidation stability, higher Viscosity Index, lower HTHS and lower
CCS viscosity relative to the low viscosity engine oils including
comparative Group II, Group III and GTL base stocks. In fact, the
TEOST 33C deposits of the engine oil formulations including the
30/70 blend of C10 dimer and C10 trimer as the low viscosity base
stock was significantly lower than the TEOST 33C deposits of low
viscosity engine oils including either C10 dimer or C10 trimer as
the low viscosity base stock. Thus there are synergies in engine
oil physical characteristics and performance upon blending of the
C10 dimer and C10 trimer. The same synergistic improvement in
blending also applies for the CCS viscosity as the engine oil
formulations including the 30/70 blend of C10 dimer and C10 trimer
was lower in CCS viscosity than engine oils including either C10
dimer or C10 trimer as the low viscosity base stock. Hence the
blend of the C10 dimer and C10 trimer as the low viscosity base
stock in engine oil formulations also provides unexpected
improvements in engine oil physical and performance
characteristics. It should be noted that for all the inventive and
comparative engine oil formulations in FIG. 2, there was no
viscosity modifier included in the formulations.
Example 3
[0252] Viscometric Characteristics of Inventive and Comparative
Engine Oils with Viscosity Modifier
[0253] FIG. 3 shows kinematic viscosity and viscosity index of
engine oils formulations including the inventive methyl paraffin
based low viscosity base stock (30/70 blend of C10 dimer and C10
trimer) and comparative low viscosity base stocks (GTL and Yubase
3) which also include viscosity modifier. The two viscosity
modifiers tested were a PMA (Viscoplex 3-200 VM) and HC (Infineum
SV600 hydrocarbonVM). The treat rate of each of the viscosity
modifiers in the engine oil formulations was adjusted to achieve a
measured HTHS (high Temperature and High Shear) viscosity of 1.9 cP
for the PMA and 2.2 cP for the HC, using test method ASTM D4663.
Comparing FIG. 3 to FIG. 2, it can be seen that the viscosity
modifier dramatically increases the Viscosity Index of all engine
oil formulations, however, higher viscosity index was observed for
the C10 dimer and C10 trimer mixture of the invention, resulting in
lower KV40, indicating a potential fuel economy advantage.
Example 4
Noack Volatility Versus KV40 of Inventive and Comparative Base
Stocks
[0254] FIG. 4 is a graph of the relationship between Noack
volatility and kinematic viscosity at 40 deg. C for various
mixtures of the C10 dimer and the C10 trimer (low viscosity
inventive methyl paraffin base stocks) and also various mixtures of
2 cSt and 3.6 cSt comparative conventional PAOs. Also indicated on
the graph are the relationship between Noack volatility and
kinematic viscosity at 40 deg. C for the neat C10 dimer, C10
trimer, conventional 2 cSt PAO, conventional 3.6 cSt PAO, GTL
(Shell QHVI 3), Group II (ExxonMobil EHC 20), and Group III (SK Oil
Yubase 3). FIG. 5 shows the base stock blend ratios for the
inventive mixtures of C10 dimer and C10 trimer of the inventive
methyl paraffin based low viscosity base stock blends and the
comparative mixtures of 2 cSt and 3.6 cSt conventional PAOs of the
comparative PAO low viscosity base stock blends of FIG. 4.
[0255] FIG. 4 shows that the inventive methyl paraffin based low
viscosity base stock blends of C10 dimer and C10 trimer have a
relationship between Noack volatility (y) and KV40 (x) that is less
than y=2.15-0.765*ln(x). In contrast, the comparative blends of 2
cSt and 3.6 cSt conventional PAOs have a relationship between Noack
volatility (y) and KV40 (x) that is greater than
y=2.15-0.765*ln(x). Therefore, for a given KV40, a base stock blend
of C10 dimer and C10 trimer has a lower Noack Volatility than a
conventional blend of a conventional 2 cSt PAO and a conventional
3.6 cSt PAO. This improvement and relationship between Noack
volatility and kinematic viscosity at 40 deg. C for inventive base
stock blends of C10 dimer and C10 trimer is surprising and
unexpected.
PCT and EP Clauses:
[0256] 1. A lubricating oil base stock comprising from 5 to 50 wt %
of 9-methylnonadecane and from 95 to 50 wt % of
9-methyl-11-octylheneicosane, wherein the base stock has a
relationship between Noack volatility at 250.degree. C. as measured
by ASTM D5800 (y) and kinematic viscosity at 40.degree. C. as
measured by ASTM D445 (x) that is less than y=2.15-0.765*ln(x).
[0257] 2. The lubricating oil base stock of clause 1, wherein the
base stock has a kinematic viscosity at 100.degree. C. as measured
by ASTM D445 of from 1.5 to 3.5 cSt.
[0258] 3. The lubricating oil base stock of clauses 1-2, wherein
the base stock has a kinematic viscosity at 40.degree. C. as
measured by ASTM D445 of from 4.0 to 14.0 cSt.
[0259] 4. The lubricating oil base stock of clauses 1-3, wherein
the base stock has a Noack volatility at 250.degree. C. as measured
by ASTM D5800 of 10 to 90%.
[0260] 5. The lubricating oil base stock of clauses 1-4, wherein
the base stock has a Viscosity Index from about 100 to 170 as
determined by ASTM D2270.
[0261] 6. The lubricating oil base stock of clauses 1-5, wherein
the base stock has a pour point of from about -10 to -80.degree. C.
as determined by ASTM D5950.
[0262] 7. The lubricating oil base stock of clauses 1-6, wherein
the base stock has a MTM average traction coefficient (at 100 deg.
C, 1 GPa, 2 m/s and 0-100% SRR) of from about 0.0060 to 0.0090.
[0263] 8. The lubricating oil base stock of clauses 1-7, wherein
the base stock has a MTM average traction coefficient (at 100 deg.
C, 1 GPa, 2 m/s and 0-100% SRR) that is about 20 to 180% lower than
a Group II or Group III base stock of comparable KV100.degree. C.
viscosity.
[0264] 9. The lubricating oil base stock of clauses 1-8, wherein
the base stock has a high temperature high shear (HTHS) viscosity
of less than about 1.6 cP as determined by ASTM D4683, and a Noack
volatility from about 16 to about 30 percent as determined by ASTM
D5800.
[0265] 10. The lubricating oil base stock of clauses 1-9 further
including a minor amount of one or more additives to form a
lubricating oil.
[0266] 11. The lubricating oil base stock of clause 10, wherein the
one or more additives are selected from the group consisting of a
viscosity improver or modifier, antioxidant, detergent, dispersant,
pour point depressant, corrosion inhibitor, metal deactivator, seal
compatibility additive, anti-foam agent, inhibitor, anti-rust
additive and combinations thereof.
[0267] 12. The lubricating oil base stock of clauses 10-11 wherein
the lubricating oil has an oxidation stability (210 hour test with
time to 200% KV40 increase) of from about 60 to 150 hours.
[0268] 13. The lubricating oil base stock of clauses 10-12 wherein
the lubricating oil has resistance to deposit formation as measured
by TEOST 33C test for 2 hours at 200 to 480 deg. C per ASTM D6335
of from 10 to 30 mg.
[0269] 14. The lubricating oil base stock of clauses 10-13 wherein
the lubricating oil has a Cold Crank Simulator (CCS) viscosity at
-35 deg. C per ASTM D5293 of from 700 to 1000 mPas.
[0270] 15. The lubricating oil base stock of clauses 10-14 wherein
the one or more additives include a viscosity modifier selected
from a polymethacrylate, a hydrocarbon hydrogenated polyisoprene
star polymer and combinations thereof.
[0271] 16. The lubricating oil base stock of clause 15 wherein the
lubricating oil has a high temperature high shear (HTHS) viscosity
of less than about 2.3 cP as determined by ASTM D4683.
[0272] 17. The lubricating oil base stock of clauses 15-16 wherein
the lubricating oil has a Viscosity Index from about 220 to 340 as
determined by ASTM D2270.
[0273] 18. The lubricating oil base stock of clauses 10-17 wherein
the lubricating oil further includes a cobase stock at from 5 to 40
wt %, wherein the cobase stock is selected 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.
[0274] 19. A method for improving one or more of thermal and
oxidative stability, deposit control and traction control in a
lubricating oil comprising: providing a lubricating oil including a
major amount of a lubricating oil base stock and a minor amount of
one or more additives, said lubricating oil base stock comprising
from 5 to 50 wt % of 9-methylnonadecane and from 95 to 50 wt % of
9-methyl-11-octylheneicosane, wherein the base stock has a
relationship between Noack volatility at 250.degree. C. as measured
by ASTM D5800 (y) and kinematic viscosity at 40.degree. C. as
measured by ASTM D445 (x) that is less than y=2.15-0.765*ln(x), and
using the lubricating oil in a formulated oil to improve one or
more of thermal and oxidative stability, deposit control and
traction control.
[0275] 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.
[0276] 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.
[0277] 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